xref: /dragonfly/contrib/gcc-4.7/gcc/tree.c (revision 91dc43dd)
1 /* Language-independent node constructors for parse phase of GNU compiler.
2    Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3    1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
4    2011, 2012 Free Software Foundation, Inc.
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12 
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16 for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3.  If not see
20 <http://www.gnu.org/licenses/>.  */
21 
22 /* This file contains the low level primitives for operating on tree nodes,
23    including allocation, list operations, interning of identifiers,
24    construction of data type nodes and statement nodes,
25    and construction of type conversion nodes.  It also contains
26    tables index by tree code that describe how to take apart
27    nodes of that code.
28 
29    It is intended to be language-independent, but occasionally
30    calls language-dependent routines defined (for C) in typecheck.c.  */
31 
32 #include "config.h"
33 #include "system.h"
34 #include "coretypes.h"
35 #include "tm.h"
36 #include "flags.h"
37 #include "tree.h"
38 #include "tm_p.h"
39 #include "function.h"
40 #include "obstack.h"
41 #include "toplev.h"
42 #include "ggc.h"
43 #include "hashtab.h"
44 #include "filenames.h"
45 #include "output.h"
46 #include "target.h"
47 #include "common/common-target.h"
48 #include "langhooks.h"
49 #include "tree-inline.h"
50 #include "tree-iterator.h"
51 #include "basic-block.h"
52 #include "tree-flow.h"
53 #include "params.h"
54 #include "pointer-set.h"
55 #include "tree-pass.h"
56 #include "langhooks-def.h"
57 #include "diagnostic.h"
58 #include "tree-diagnostic.h"
59 #include "tree-pretty-print.h"
60 #include "cgraph.h"
61 #include "timevar.h"
62 #include "except.h"
63 #include "debug.h"
64 #include "intl.h"
65 
66 /* Tree code classes.  */
67 
68 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
69 #define END_OF_BASE_TREE_CODES tcc_exceptional,
70 
71 const enum tree_code_class tree_code_type[] = {
72 #include "all-tree.def"
73 };
74 
75 #undef DEFTREECODE
76 #undef END_OF_BASE_TREE_CODES
77 
78 /* Table indexed by tree code giving number of expression
79    operands beyond the fixed part of the node structure.
80    Not used for types or decls.  */
81 
82 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
83 #define END_OF_BASE_TREE_CODES 0,
84 
85 const unsigned char tree_code_length[] = {
86 #include "all-tree.def"
87 };
88 
89 #undef DEFTREECODE
90 #undef END_OF_BASE_TREE_CODES
91 
92 /* Names of tree components.
93    Used for printing out the tree and error messages.  */
94 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
95 #define END_OF_BASE_TREE_CODES "@dummy",
96 
97 const char *const tree_code_name[] = {
98 #include "all-tree.def"
99 };
100 
101 #undef DEFTREECODE
102 #undef END_OF_BASE_TREE_CODES
103 
104 /* Each tree code class has an associated string representation.
105    These must correspond to the tree_code_class entries.  */
106 
107 const char *const tree_code_class_strings[] =
108 {
109   "exceptional",
110   "constant",
111   "type",
112   "declaration",
113   "reference",
114   "comparison",
115   "unary",
116   "binary",
117   "statement",
118   "vl_exp",
119   "expression"
120 };
121 
122 /* obstack.[ch] explicitly declined to prototype this.  */
123 extern int _obstack_allocated_p (struct obstack *h, void *obj);
124 
125 #ifdef GATHER_STATISTICS
126 /* Statistics-gathering stuff.  */
127 
128 static int tree_code_counts[MAX_TREE_CODES];
129 int tree_node_counts[(int) all_kinds];
130 int tree_node_sizes[(int) all_kinds];
131 
132 /* Keep in sync with tree.h:enum tree_node_kind.  */
133 static const char * const tree_node_kind_names[] = {
134   "decls",
135   "types",
136   "blocks",
137   "stmts",
138   "refs",
139   "exprs",
140   "constants",
141   "identifiers",
142   "vecs",
143   "binfos",
144   "ssa names",
145   "constructors",
146   "random kinds",
147   "lang_decl kinds",
148   "lang_type kinds",
149   "omp clauses",
150 };
151 #endif /* GATHER_STATISTICS */
152 
153 /* Unique id for next decl created.  */
154 static GTY(()) int next_decl_uid;
155 /* Unique id for next type created.  */
156 static GTY(()) int next_type_uid = 1;
157 /* Unique id for next debug decl created.  Use negative numbers,
158    to catch erroneous uses.  */
159 static GTY(()) int next_debug_decl_uid;
160 
161 /* Since we cannot rehash a type after it is in the table, we have to
162    keep the hash code.  */
163 
164 struct GTY(()) type_hash {
165   unsigned long hash;
166   tree type;
167 };
168 
169 /* Initial size of the hash table (rounded to next prime).  */
170 #define TYPE_HASH_INITIAL_SIZE 1000
171 
172 /* Now here is the hash table.  When recording a type, it is added to
173    the slot whose index is the hash code.  Note that the hash table is
174    used for several kinds of types (function types, array types and
175    array index range types, for now).  While all these live in the
176    same table, they are completely independent, and the hash code is
177    computed differently for each of these.  */
178 
179 static GTY ((if_marked ("type_hash_marked_p"), param_is (struct type_hash)))
180      htab_t type_hash_table;
181 
182 /* Hash table and temporary node for larger integer const values.  */
183 static GTY (()) tree int_cst_node;
184 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
185      htab_t int_cst_hash_table;
186 
187 /* Hash table for optimization flags and target option flags.  Use the same
188    hash table for both sets of options.  Nodes for building the current
189    optimization and target option nodes.  The assumption is most of the time
190    the options created will already be in the hash table, so we avoid
191    allocating and freeing up a node repeatably.  */
192 static GTY (()) tree cl_optimization_node;
193 static GTY (()) tree cl_target_option_node;
194 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
195      htab_t cl_option_hash_table;
196 
197 /* General tree->tree mapping  structure for use in hash tables.  */
198 
199 
200 static GTY ((if_marked ("tree_decl_map_marked_p"), param_is (struct tree_decl_map)))
201      htab_t debug_expr_for_decl;
202 
203 static GTY ((if_marked ("tree_decl_map_marked_p"), param_is (struct tree_decl_map)))
204      htab_t value_expr_for_decl;
205 
206 static GTY ((if_marked ("tree_vec_map_marked_p"), param_is (struct tree_vec_map)))
207      htab_t debug_args_for_decl;
208 
209 static GTY ((if_marked ("tree_priority_map_marked_p"),
210 	     param_is (struct tree_priority_map)))
211   htab_t init_priority_for_decl;
212 
213 static void set_type_quals (tree, int);
214 static int type_hash_eq (const void *, const void *);
215 static hashval_t type_hash_hash (const void *);
216 static hashval_t int_cst_hash_hash (const void *);
217 static int int_cst_hash_eq (const void *, const void *);
218 static hashval_t cl_option_hash_hash (const void *);
219 static int cl_option_hash_eq (const void *, const void *);
220 static void print_type_hash_statistics (void);
221 static void print_debug_expr_statistics (void);
222 static void print_value_expr_statistics (void);
223 static int type_hash_marked_p (const void *);
224 static unsigned int type_hash_list (const_tree, hashval_t);
225 static unsigned int attribute_hash_list (const_tree, hashval_t);
226 
227 tree global_trees[TI_MAX];
228 tree integer_types[itk_none];
229 
230 unsigned char tree_contains_struct[MAX_TREE_CODES][64];
231 
232 /* Number of operands for each OpenMP clause.  */
233 unsigned const char omp_clause_num_ops[] =
234 {
235   0, /* OMP_CLAUSE_ERROR  */
236   1, /* OMP_CLAUSE_PRIVATE  */
237   1, /* OMP_CLAUSE_SHARED  */
238   1, /* OMP_CLAUSE_FIRSTPRIVATE  */
239   2, /* OMP_CLAUSE_LASTPRIVATE  */
240   4, /* OMP_CLAUSE_REDUCTION  */
241   1, /* OMP_CLAUSE_COPYIN  */
242   1, /* OMP_CLAUSE_COPYPRIVATE  */
243   1, /* OMP_CLAUSE_IF  */
244   1, /* OMP_CLAUSE_NUM_THREADS  */
245   1, /* OMP_CLAUSE_SCHEDULE  */
246   0, /* OMP_CLAUSE_NOWAIT  */
247   0, /* OMP_CLAUSE_ORDERED  */
248   0, /* OMP_CLAUSE_DEFAULT  */
249   3, /* OMP_CLAUSE_COLLAPSE  */
250   0, /* OMP_CLAUSE_UNTIED   */
251   1, /* OMP_CLAUSE_FINAL  */
252   0  /* OMP_CLAUSE_MERGEABLE  */
253 };
254 
255 const char * const omp_clause_code_name[] =
256 {
257   "error_clause",
258   "private",
259   "shared",
260   "firstprivate",
261   "lastprivate",
262   "reduction",
263   "copyin",
264   "copyprivate",
265   "if",
266   "num_threads",
267   "schedule",
268   "nowait",
269   "ordered",
270   "default",
271   "collapse",
272   "untied",
273   "final",
274   "mergeable"
275 };
276 
277 
278 /* Return the tree node structure used by tree code CODE.  */
279 
280 static inline enum tree_node_structure_enum
281 tree_node_structure_for_code (enum tree_code code)
282 {
283   switch (TREE_CODE_CLASS (code))
284     {
285     case tcc_declaration:
286       {
287 	switch (code)
288 	  {
289 	  case FIELD_DECL:
290 	    return TS_FIELD_DECL;
291 	  case PARM_DECL:
292 	    return TS_PARM_DECL;
293 	  case VAR_DECL:
294 	    return TS_VAR_DECL;
295 	  case LABEL_DECL:
296 	    return TS_LABEL_DECL;
297 	  case RESULT_DECL:
298 	    return TS_RESULT_DECL;
299 	  case DEBUG_EXPR_DECL:
300 	    return TS_DECL_WRTL;
301 	  case CONST_DECL:
302 	    return TS_CONST_DECL;
303 	  case TYPE_DECL:
304 	    return TS_TYPE_DECL;
305 	  case FUNCTION_DECL:
306 	    return TS_FUNCTION_DECL;
307 	  case TRANSLATION_UNIT_DECL:
308 	    return TS_TRANSLATION_UNIT_DECL;
309 	  default:
310 	    return TS_DECL_NON_COMMON;
311 	  }
312       }
313     case tcc_type:
314       return TS_TYPE_NON_COMMON;
315     case tcc_reference:
316     case tcc_comparison:
317     case tcc_unary:
318     case tcc_binary:
319     case tcc_expression:
320     case tcc_statement:
321     case tcc_vl_exp:
322       return TS_EXP;
323     default:  /* tcc_constant and tcc_exceptional */
324       break;
325     }
326   switch (code)
327     {
328       /* tcc_constant cases.  */
329     case INTEGER_CST:		return TS_INT_CST;
330     case REAL_CST:		return TS_REAL_CST;
331     case FIXED_CST:		return TS_FIXED_CST;
332     case COMPLEX_CST:		return TS_COMPLEX;
333     case VECTOR_CST:		return TS_VECTOR;
334     case STRING_CST:		return TS_STRING;
335       /* tcc_exceptional cases.  */
336     case ERROR_MARK:		return TS_COMMON;
337     case IDENTIFIER_NODE:	return TS_IDENTIFIER;
338     case TREE_LIST:		return TS_LIST;
339     case TREE_VEC:		return TS_VEC;
340     case SSA_NAME:		return TS_SSA_NAME;
341     case PLACEHOLDER_EXPR:	return TS_COMMON;
342     case STATEMENT_LIST:	return TS_STATEMENT_LIST;
343     case BLOCK:			return TS_BLOCK;
344     case CONSTRUCTOR:		return TS_CONSTRUCTOR;
345     case TREE_BINFO:		return TS_BINFO;
346     case OMP_CLAUSE:		return TS_OMP_CLAUSE;
347     case OPTIMIZATION_NODE:	return TS_OPTIMIZATION;
348     case TARGET_OPTION_NODE:	return TS_TARGET_OPTION;
349 
350     default:
351       gcc_unreachable ();
352     }
353 }
354 
355 
356 /* Initialize tree_contains_struct to describe the hierarchy of tree
357    nodes.  */
358 
359 static void
360 initialize_tree_contains_struct (void)
361 {
362   unsigned i;
363 
364   for (i = ERROR_MARK; i < LAST_AND_UNUSED_TREE_CODE; i++)
365     {
366       enum tree_code code;
367       enum tree_node_structure_enum ts_code;
368 
369       code = (enum tree_code) i;
370       ts_code = tree_node_structure_for_code (code);
371 
372       /* Mark the TS structure itself.  */
373       tree_contains_struct[code][ts_code] = 1;
374 
375       /* Mark all the structures that TS is derived from.  */
376       switch (ts_code)
377 	{
378 	case TS_TYPED:
379 	case TS_BLOCK:
380 	  MARK_TS_BASE (code);
381 	  break;
382 
383 	case TS_COMMON:
384 	case TS_INT_CST:
385 	case TS_REAL_CST:
386 	case TS_FIXED_CST:
387 	case TS_VECTOR:
388 	case TS_STRING:
389 	case TS_COMPLEX:
390 	case TS_SSA_NAME:
391 	case TS_CONSTRUCTOR:
392 	case TS_EXP:
393 	case TS_STATEMENT_LIST:
394 	  MARK_TS_TYPED (code);
395 	  break;
396 
397 	case TS_IDENTIFIER:
398 	case TS_DECL_MINIMAL:
399 	case TS_TYPE_COMMON:
400 	case TS_LIST:
401 	case TS_VEC:
402 	case TS_BINFO:
403 	case TS_OMP_CLAUSE:
404 	case TS_OPTIMIZATION:
405 	case TS_TARGET_OPTION:
406 	  MARK_TS_COMMON (code);
407 	  break;
408 
409 	case TS_TYPE_WITH_LANG_SPECIFIC:
410 	  MARK_TS_TYPE_COMMON (code);
411 	  break;
412 
413 	case TS_TYPE_NON_COMMON:
414 	  MARK_TS_TYPE_WITH_LANG_SPECIFIC (code);
415 	  break;
416 
417 	case TS_DECL_COMMON:
418 	  MARK_TS_DECL_MINIMAL (code);
419 	  break;
420 
421 	case TS_DECL_WRTL:
422 	case TS_CONST_DECL:
423 	  MARK_TS_DECL_COMMON (code);
424 	  break;
425 
426 	case TS_DECL_NON_COMMON:
427 	  MARK_TS_DECL_WITH_VIS (code);
428 	  break;
429 
430 	case TS_DECL_WITH_VIS:
431 	case TS_PARM_DECL:
432 	case TS_LABEL_DECL:
433 	case TS_RESULT_DECL:
434 	  MARK_TS_DECL_WRTL (code);
435 	  break;
436 
437 	case TS_FIELD_DECL:
438 	  MARK_TS_DECL_COMMON (code);
439 	  break;
440 
441 	case TS_VAR_DECL:
442 	  MARK_TS_DECL_WITH_VIS (code);
443 	  break;
444 
445 	case TS_TYPE_DECL:
446 	case TS_FUNCTION_DECL:
447 	  MARK_TS_DECL_NON_COMMON (code);
448 	  break;
449 
450 	case TS_TRANSLATION_UNIT_DECL:
451 	  MARK_TS_DECL_COMMON (code);
452 	  break;
453 
454 	default:
455 	  gcc_unreachable ();
456 	}
457     }
458 
459   /* Basic consistency checks for attributes used in fold.  */
460   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_NON_COMMON]);
461   gcc_assert (tree_contains_struct[TYPE_DECL][TS_DECL_NON_COMMON]);
462   gcc_assert (tree_contains_struct[CONST_DECL][TS_DECL_COMMON]);
463   gcc_assert (tree_contains_struct[VAR_DECL][TS_DECL_COMMON]);
464   gcc_assert (tree_contains_struct[PARM_DECL][TS_DECL_COMMON]);
465   gcc_assert (tree_contains_struct[RESULT_DECL][TS_DECL_COMMON]);
466   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_COMMON]);
467   gcc_assert (tree_contains_struct[TYPE_DECL][TS_DECL_COMMON]);
468   gcc_assert (tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_COMMON]);
469   gcc_assert (tree_contains_struct[LABEL_DECL][TS_DECL_COMMON]);
470   gcc_assert (tree_contains_struct[FIELD_DECL][TS_DECL_COMMON]);
471   gcc_assert (tree_contains_struct[VAR_DECL][TS_DECL_WRTL]);
472   gcc_assert (tree_contains_struct[PARM_DECL][TS_DECL_WRTL]);
473   gcc_assert (tree_contains_struct[RESULT_DECL][TS_DECL_WRTL]);
474   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_WRTL]);
475   gcc_assert (tree_contains_struct[LABEL_DECL][TS_DECL_WRTL]);
476   gcc_assert (tree_contains_struct[CONST_DECL][TS_DECL_MINIMAL]);
477   gcc_assert (tree_contains_struct[VAR_DECL][TS_DECL_MINIMAL]);
478   gcc_assert (tree_contains_struct[PARM_DECL][TS_DECL_MINIMAL]);
479   gcc_assert (tree_contains_struct[RESULT_DECL][TS_DECL_MINIMAL]);
480   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_MINIMAL]);
481   gcc_assert (tree_contains_struct[TYPE_DECL][TS_DECL_MINIMAL]);
482   gcc_assert (tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_MINIMAL]);
483   gcc_assert (tree_contains_struct[LABEL_DECL][TS_DECL_MINIMAL]);
484   gcc_assert (tree_contains_struct[FIELD_DECL][TS_DECL_MINIMAL]);
485   gcc_assert (tree_contains_struct[VAR_DECL][TS_DECL_WITH_VIS]);
486   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_WITH_VIS]);
487   gcc_assert (tree_contains_struct[TYPE_DECL][TS_DECL_WITH_VIS]);
488   gcc_assert (tree_contains_struct[VAR_DECL][TS_VAR_DECL]);
489   gcc_assert (tree_contains_struct[FIELD_DECL][TS_FIELD_DECL]);
490   gcc_assert (tree_contains_struct[PARM_DECL][TS_PARM_DECL]);
491   gcc_assert (tree_contains_struct[LABEL_DECL][TS_LABEL_DECL]);
492   gcc_assert (tree_contains_struct[RESULT_DECL][TS_RESULT_DECL]);
493   gcc_assert (tree_contains_struct[CONST_DECL][TS_CONST_DECL]);
494   gcc_assert (tree_contains_struct[TYPE_DECL][TS_TYPE_DECL]);
495   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_FUNCTION_DECL]);
496   gcc_assert (tree_contains_struct[IMPORTED_DECL][TS_DECL_MINIMAL]);
497   gcc_assert (tree_contains_struct[IMPORTED_DECL][TS_DECL_COMMON]);
498 }
499 
500 
501 /* Init tree.c.  */
502 
503 void
504 init_ttree (void)
505 {
506   /* Initialize the hash table of types.  */
507   type_hash_table = htab_create_ggc (TYPE_HASH_INITIAL_SIZE, type_hash_hash,
508 				     type_hash_eq, 0);
509 
510   debug_expr_for_decl = htab_create_ggc (512, tree_decl_map_hash,
511 					 tree_decl_map_eq, 0);
512 
513   value_expr_for_decl = htab_create_ggc (512, tree_decl_map_hash,
514 					 tree_decl_map_eq, 0);
515   init_priority_for_decl = htab_create_ggc (512, tree_priority_map_hash,
516 					    tree_priority_map_eq, 0);
517 
518   int_cst_hash_table = htab_create_ggc (1024, int_cst_hash_hash,
519 					int_cst_hash_eq, NULL);
520 
521   int_cst_node = make_node (INTEGER_CST);
522 
523   cl_option_hash_table = htab_create_ggc (64, cl_option_hash_hash,
524 					  cl_option_hash_eq, NULL);
525 
526   cl_optimization_node = make_node (OPTIMIZATION_NODE);
527   cl_target_option_node = make_node (TARGET_OPTION_NODE);
528 
529   /* Initialize the tree_contains_struct array.  */
530   initialize_tree_contains_struct ();
531   lang_hooks.init_ts ();
532 }
533 
534 
535 /* The name of the object as the assembler will see it (but before any
536    translations made by ASM_OUTPUT_LABELREF).  Often this is the same
537    as DECL_NAME.  It is an IDENTIFIER_NODE.  */
538 tree
539 decl_assembler_name (tree decl)
540 {
541   if (!DECL_ASSEMBLER_NAME_SET_P (decl))
542     lang_hooks.set_decl_assembler_name (decl);
543   return DECL_WITH_VIS_CHECK (decl)->decl_with_vis.assembler_name;
544 }
545 
546 /* Compare ASMNAME with the DECL_ASSEMBLER_NAME of DECL.  */
547 
548 bool
549 decl_assembler_name_equal (tree decl, const_tree asmname)
550 {
551   tree decl_asmname = DECL_ASSEMBLER_NAME (decl);
552   const char *decl_str;
553   const char *asmname_str;
554   bool test = false;
555 
556   if (decl_asmname == asmname)
557     return true;
558 
559   decl_str = IDENTIFIER_POINTER (decl_asmname);
560   asmname_str = IDENTIFIER_POINTER (asmname);
561 
562 
563   /* If the target assembler name was set by the user, things are trickier.
564      We have a leading '*' to begin with.  After that, it's arguable what
565      is the correct thing to do with -fleading-underscore.  Arguably, we've
566      historically been doing the wrong thing in assemble_alias by always
567      printing the leading underscore.  Since we're not changing that, make
568      sure user_label_prefix follows the '*' before matching.  */
569   if (decl_str[0] == '*')
570     {
571       size_t ulp_len = strlen (user_label_prefix);
572 
573       decl_str ++;
574 
575       if (ulp_len == 0)
576 	test = true;
577       else if (strncmp (decl_str, user_label_prefix, ulp_len) == 0)
578 	decl_str += ulp_len, test=true;
579       else
580 	decl_str --;
581     }
582   if (asmname_str[0] == '*')
583     {
584       size_t ulp_len = strlen (user_label_prefix);
585 
586       asmname_str ++;
587 
588       if (ulp_len == 0)
589 	test = true;
590       else if (strncmp (asmname_str, user_label_prefix, ulp_len) == 0)
591 	asmname_str += ulp_len, test=true;
592       else
593 	asmname_str --;
594     }
595 
596   if (!test)
597     return false;
598   return strcmp (decl_str, asmname_str) == 0;
599 }
600 
601 /* Hash asmnames ignoring the user specified marks.  */
602 
603 hashval_t
604 decl_assembler_name_hash (const_tree asmname)
605 {
606   if (IDENTIFIER_POINTER (asmname)[0] == '*')
607     {
608       const char *decl_str = IDENTIFIER_POINTER (asmname) + 1;
609       size_t ulp_len = strlen (user_label_prefix);
610 
611       if (ulp_len == 0)
612 	;
613       else if (strncmp (decl_str, user_label_prefix, ulp_len) == 0)
614 	decl_str += ulp_len;
615 
616       return htab_hash_string (decl_str);
617     }
618 
619   return htab_hash_string (IDENTIFIER_POINTER (asmname));
620 }
621 
622 /* Compute the number of bytes occupied by a tree with code CODE.
623    This function cannot be used for nodes that have variable sizes,
624    including TREE_VEC, STRING_CST, and CALL_EXPR.  */
625 size_t
626 tree_code_size (enum tree_code code)
627 {
628   switch (TREE_CODE_CLASS (code))
629     {
630     case tcc_declaration:  /* A decl node */
631       {
632 	switch (code)
633 	  {
634 	  case FIELD_DECL:
635 	    return sizeof (struct tree_field_decl);
636 	  case PARM_DECL:
637 	    return sizeof (struct tree_parm_decl);
638 	  case VAR_DECL:
639 	    return sizeof (struct tree_var_decl);
640 	  case LABEL_DECL:
641 	    return sizeof (struct tree_label_decl);
642 	  case RESULT_DECL:
643 	    return sizeof (struct tree_result_decl);
644 	  case CONST_DECL:
645 	    return sizeof (struct tree_const_decl);
646 	  case TYPE_DECL:
647 	    return sizeof (struct tree_type_decl);
648 	  case FUNCTION_DECL:
649 	    return sizeof (struct tree_function_decl);
650 	  case DEBUG_EXPR_DECL:
651 	    return sizeof (struct tree_decl_with_rtl);
652 	  default:
653 	    return sizeof (struct tree_decl_non_common);
654 	  }
655       }
656 
657     case tcc_type:  /* a type node */
658       return sizeof (struct tree_type_non_common);
659 
660     case tcc_reference:   /* a reference */
661     case tcc_expression:  /* an expression */
662     case tcc_statement:   /* an expression with side effects */
663     case tcc_comparison:  /* a comparison expression */
664     case tcc_unary:       /* a unary arithmetic expression */
665     case tcc_binary:      /* a binary arithmetic expression */
666       return (sizeof (struct tree_exp)
667 	      + (TREE_CODE_LENGTH (code) - 1) * sizeof (tree));
668 
669     case tcc_constant:  /* a constant */
670       switch (code)
671 	{
672 	case INTEGER_CST:	return sizeof (struct tree_int_cst);
673 	case REAL_CST:		return sizeof (struct tree_real_cst);
674 	case FIXED_CST:		return sizeof (struct tree_fixed_cst);
675 	case COMPLEX_CST:	return sizeof (struct tree_complex);
676 	case VECTOR_CST:	return sizeof (struct tree_vector);
677 	case STRING_CST:	gcc_unreachable ();
678 	default:
679 	  return lang_hooks.tree_size (code);
680 	}
681 
682     case tcc_exceptional:  /* something random, like an identifier.  */
683       switch (code)
684 	{
685 	case IDENTIFIER_NODE:	return lang_hooks.identifier_size;
686 	case TREE_LIST:		return sizeof (struct tree_list);
687 
688 	case ERROR_MARK:
689 	case PLACEHOLDER_EXPR:	return sizeof (struct tree_common);
690 
691 	case TREE_VEC:
692 	case OMP_CLAUSE:	gcc_unreachable ();
693 
694 	case SSA_NAME:		return sizeof (struct tree_ssa_name);
695 
696 	case STATEMENT_LIST:	return sizeof (struct tree_statement_list);
697 	case BLOCK:		return sizeof (struct tree_block);
698 	case CONSTRUCTOR:	return sizeof (struct tree_constructor);
699 	case OPTIMIZATION_NODE: return sizeof (struct tree_optimization_option);
700 	case TARGET_OPTION_NODE: return sizeof (struct tree_target_option);
701 
702 	default:
703 	  return lang_hooks.tree_size (code);
704 	}
705 
706     default:
707       gcc_unreachable ();
708     }
709 }
710 
711 /* Compute the number of bytes occupied by NODE.  This routine only
712    looks at TREE_CODE, except for those nodes that have variable sizes.  */
713 size_t
714 tree_size (const_tree node)
715 {
716   const enum tree_code code = TREE_CODE (node);
717   switch (code)
718     {
719     case TREE_BINFO:
720       return (offsetof (struct tree_binfo, base_binfos)
721 	      + VEC_embedded_size (tree, BINFO_N_BASE_BINFOS (node)));
722 
723     case TREE_VEC:
724       return (sizeof (struct tree_vec)
725 	      + (TREE_VEC_LENGTH (node) - 1) * sizeof (tree));
726 
727     case STRING_CST:
728       return TREE_STRING_LENGTH (node) + offsetof (struct tree_string, str) + 1;
729 
730     case OMP_CLAUSE:
731       return (sizeof (struct tree_omp_clause)
732 	      + (omp_clause_num_ops[OMP_CLAUSE_CODE (node)] - 1)
733 	        * sizeof (tree));
734 
735     default:
736       if (TREE_CODE_CLASS (code) == tcc_vl_exp)
737 	return (sizeof (struct tree_exp)
738 		+ (VL_EXP_OPERAND_LENGTH (node) - 1) * sizeof (tree));
739       else
740 	return tree_code_size (code);
741     }
742 }
743 
744 /* Record interesting allocation statistics for a tree node with CODE
745    and LENGTH.  */
746 
747 static void
748 record_node_allocation_statistics (enum tree_code code ATTRIBUTE_UNUSED,
749 				   size_t length ATTRIBUTE_UNUSED)
750 {
751 #ifdef GATHER_STATISTICS
752   enum tree_code_class type = TREE_CODE_CLASS (code);
753   tree_node_kind kind;
754 
755   switch (type)
756     {
757     case tcc_declaration:  /* A decl node */
758       kind = d_kind;
759       break;
760 
761     case tcc_type:  /* a type node */
762       kind = t_kind;
763       break;
764 
765     case tcc_statement:  /* an expression with side effects */
766       kind = s_kind;
767       break;
768 
769     case tcc_reference:  /* a reference */
770       kind = r_kind;
771       break;
772 
773     case tcc_expression:  /* an expression */
774     case tcc_comparison:  /* a comparison expression */
775     case tcc_unary:  /* a unary arithmetic expression */
776     case tcc_binary:  /* a binary arithmetic expression */
777       kind = e_kind;
778       break;
779 
780     case tcc_constant:  /* a constant */
781       kind = c_kind;
782       break;
783 
784     case tcc_exceptional:  /* something random, like an identifier.  */
785       switch (code)
786 	{
787 	case IDENTIFIER_NODE:
788 	  kind = id_kind;
789 	  break;
790 
791 	case TREE_VEC:
792 	  kind = vec_kind;
793 	  break;
794 
795 	case TREE_BINFO:
796 	  kind = binfo_kind;
797 	  break;
798 
799 	case SSA_NAME:
800 	  kind = ssa_name_kind;
801 	  break;
802 
803 	case BLOCK:
804 	  kind = b_kind;
805 	  break;
806 
807 	case CONSTRUCTOR:
808 	  kind = constr_kind;
809 	  break;
810 
811 	case OMP_CLAUSE:
812 	  kind = omp_clause_kind;
813 	  break;
814 
815 	default:
816 	  kind = x_kind;
817 	  break;
818 	}
819       break;
820 
821     case tcc_vl_exp:
822       kind = e_kind;
823       break;
824 
825     default:
826       gcc_unreachable ();
827     }
828 
829   tree_code_counts[(int) code]++;
830   tree_node_counts[(int) kind]++;
831   tree_node_sizes[(int) kind] += length;
832 #endif
833 }
834 
835 /* Allocate and return a new UID from the DECL_UID namespace.  */
836 
837 int
838 allocate_decl_uid (void)
839 {
840   return next_decl_uid++;
841 }
842 
843 /* Return a newly allocated node of code CODE.  For decl and type
844    nodes, some other fields are initialized.  The rest of the node is
845    initialized to zero.  This function cannot be used for TREE_VEC or
846    OMP_CLAUSE nodes, which is enforced by asserts in tree_code_size.
847 
848    Achoo!  I got a code in the node.  */
849 
850 tree
851 make_node_stat (enum tree_code code MEM_STAT_DECL)
852 {
853   tree t;
854   enum tree_code_class type = TREE_CODE_CLASS (code);
855   size_t length = tree_code_size (code);
856 
857   record_node_allocation_statistics (code, length);
858 
859   t = ggc_alloc_zone_cleared_tree_node_stat (
860                (code == IDENTIFIER_NODE) ? &tree_id_zone : &tree_zone,
861                length PASS_MEM_STAT);
862   TREE_SET_CODE (t, code);
863 
864   switch (type)
865     {
866     case tcc_statement:
867       TREE_SIDE_EFFECTS (t) = 1;
868       break;
869 
870     case tcc_declaration:
871       if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
872 	{
873 	  if (code == FUNCTION_DECL)
874 	    {
875 	      DECL_ALIGN (t) = FUNCTION_BOUNDARY;
876 	      DECL_MODE (t) = FUNCTION_MODE;
877 	    }
878 	  else
879 	    DECL_ALIGN (t) = 1;
880 	}
881       DECL_SOURCE_LOCATION (t) = input_location;
882       if (TREE_CODE (t) == DEBUG_EXPR_DECL)
883 	DECL_UID (t) = --next_debug_decl_uid;
884       else
885 	{
886 	  DECL_UID (t) = allocate_decl_uid ();
887 	  SET_DECL_PT_UID (t, -1);
888 	}
889       if (TREE_CODE (t) == LABEL_DECL)
890 	LABEL_DECL_UID (t) = -1;
891 
892       break;
893 
894     case tcc_type:
895       TYPE_UID (t) = next_type_uid++;
896       TYPE_ALIGN (t) = BITS_PER_UNIT;
897       TYPE_USER_ALIGN (t) = 0;
898       TYPE_MAIN_VARIANT (t) = t;
899       TYPE_CANONICAL (t) = t;
900 
901       /* Default to no attributes for type, but let target change that.  */
902       TYPE_ATTRIBUTES (t) = NULL_TREE;
903       targetm.set_default_type_attributes (t);
904 
905       /* We have not yet computed the alias set for this type.  */
906       TYPE_ALIAS_SET (t) = -1;
907       break;
908 
909     case tcc_constant:
910       TREE_CONSTANT (t) = 1;
911       break;
912 
913     case tcc_expression:
914       switch (code)
915 	{
916 	case INIT_EXPR:
917 	case MODIFY_EXPR:
918 	case VA_ARG_EXPR:
919 	case PREDECREMENT_EXPR:
920 	case PREINCREMENT_EXPR:
921 	case POSTDECREMENT_EXPR:
922 	case POSTINCREMENT_EXPR:
923 	  /* All of these have side-effects, no matter what their
924 	     operands are.  */
925 	  TREE_SIDE_EFFECTS (t) = 1;
926 	  break;
927 
928 	default:
929 	  break;
930 	}
931       break;
932 
933     default:
934       /* Other classes need no special treatment.  */
935       break;
936     }
937 
938   return t;
939 }
940 
941 /* Return a new node with the same contents as NODE except that its
942    TREE_CHAIN, if it has one, is zero and it has a fresh uid.  */
943 
944 tree
945 copy_node_stat (tree node MEM_STAT_DECL)
946 {
947   tree t;
948   enum tree_code code = TREE_CODE (node);
949   size_t length;
950 
951   gcc_assert (code != STATEMENT_LIST);
952 
953   length = tree_size (node);
954   record_node_allocation_statistics (code, length);
955   t = ggc_alloc_zone_tree_node_stat (&tree_zone, length PASS_MEM_STAT);
956   memcpy (t, node, length);
957 
958   if (CODE_CONTAINS_STRUCT (code, TS_COMMON))
959     TREE_CHAIN (t) = 0;
960   TREE_ASM_WRITTEN (t) = 0;
961   TREE_VISITED (t) = 0;
962   if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
963     *DECL_VAR_ANN_PTR (t) = 0;
964 
965   if (TREE_CODE_CLASS (code) == tcc_declaration)
966     {
967       if (code == DEBUG_EXPR_DECL)
968 	DECL_UID (t) = --next_debug_decl_uid;
969       else
970 	{
971 	  DECL_UID (t) = allocate_decl_uid ();
972 	  if (DECL_PT_UID_SET_P (node))
973 	    SET_DECL_PT_UID (t, DECL_PT_UID (node));
974 	}
975       if ((TREE_CODE (node) == PARM_DECL || TREE_CODE (node) == VAR_DECL)
976 	  && DECL_HAS_VALUE_EXPR_P (node))
977 	{
978 	  SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (node));
979 	  DECL_HAS_VALUE_EXPR_P (t) = 1;
980 	}
981       if (TREE_CODE (node) == VAR_DECL && DECL_HAS_INIT_PRIORITY_P (node))
982 	{
983 	  SET_DECL_INIT_PRIORITY (t, DECL_INIT_PRIORITY (node));
984 	  DECL_HAS_INIT_PRIORITY_P (t) = 1;
985 	}
986     }
987   else if (TREE_CODE_CLASS (code) == tcc_type)
988     {
989       TYPE_UID (t) = next_type_uid++;
990       /* The following is so that the debug code for
991 	 the copy is different from the original type.
992 	 The two statements usually duplicate each other
993 	 (because they clear fields of the same union),
994 	 but the optimizer should catch that.  */
995       TYPE_SYMTAB_POINTER (t) = 0;
996       TYPE_SYMTAB_ADDRESS (t) = 0;
997 
998       /* Do not copy the values cache.  */
999       if (TYPE_CACHED_VALUES_P(t))
1000 	{
1001 	  TYPE_CACHED_VALUES_P (t) = 0;
1002 	  TYPE_CACHED_VALUES (t) = NULL_TREE;
1003 	}
1004     }
1005 
1006   return t;
1007 }
1008 
1009 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1010    For example, this can copy a list made of TREE_LIST nodes.  */
1011 
1012 tree
1013 copy_list (tree list)
1014 {
1015   tree head;
1016   tree prev, next;
1017 
1018   if (list == 0)
1019     return 0;
1020 
1021   head = prev = copy_node (list);
1022   next = TREE_CHAIN (list);
1023   while (next)
1024     {
1025       TREE_CHAIN (prev) = copy_node (next);
1026       prev = TREE_CHAIN (prev);
1027       next = TREE_CHAIN (next);
1028     }
1029   return head;
1030 }
1031 
1032 
1033 /* Create an INT_CST node with a LOW value sign extended to TYPE.  */
1034 
1035 tree
1036 build_int_cst (tree type, HOST_WIDE_INT low)
1037 {
1038   /* Support legacy code.  */
1039   if (!type)
1040     type = integer_type_node;
1041 
1042   return double_int_to_tree (type, shwi_to_double_int (low));
1043 }
1044 
1045 /* Create an INT_CST node with a LOW value sign extended to TYPE.  */
1046 
1047 tree
1048 build_int_cst_type (tree type, HOST_WIDE_INT low)
1049 {
1050   gcc_assert (type);
1051 
1052   return double_int_to_tree (type, shwi_to_double_int (low));
1053 }
1054 
1055 /* Constructs tree in type TYPE from with value given by CST.  Signedness
1056    of CST is assumed to be the same as the signedness of TYPE.  */
1057 
1058 tree
1059 double_int_to_tree (tree type, double_int cst)
1060 {
1061   /* Size types *are* sign extended.  */
1062   bool sign_extended_type = (!TYPE_UNSIGNED (type)
1063 			     || (TREE_CODE (type) == INTEGER_TYPE
1064 				 && TYPE_IS_SIZETYPE (type)));
1065 
1066   cst = double_int_ext (cst, TYPE_PRECISION (type), !sign_extended_type);
1067 
1068   return build_int_cst_wide (type, cst.low, cst.high);
1069 }
1070 
1071 /* Returns true if CST fits into range of TYPE.  Signedness of CST is assumed
1072    to be the same as the signedness of TYPE.  */
1073 
1074 bool
1075 double_int_fits_to_tree_p (const_tree type, double_int cst)
1076 {
1077   /* Size types *are* sign extended.  */
1078   bool sign_extended_type = (!TYPE_UNSIGNED (type)
1079 			     || (TREE_CODE (type) == INTEGER_TYPE
1080 				 && TYPE_IS_SIZETYPE (type)));
1081 
1082   double_int ext
1083     = double_int_ext (cst, TYPE_PRECISION (type), !sign_extended_type);
1084 
1085   return double_int_equal_p (cst, ext);
1086 }
1087 
1088 /* We force the double_int CST to the range of the type TYPE by sign or
1089    zero extending it.  OVERFLOWABLE indicates if we are interested in
1090    overflow of the value, when >0 we are only interested in signed
1091    overflow, for <0 we are interested in any overflow.  OVERFLOWED
1092    indicates whether overflow has already occurred.  CONST_OVERFLOWED
1093    indicates whether constant overflow has already occurred.  We force
1094    T's value to be within range of T's type (by setting to 0 or 1 all
1095    the bits outside the type's range).  We set TREE_OVERFLOWED if,
1096         OVERFLOWED is nonzero,
1097         or OVERFLOWABLE is >0 and signed overflow occurs
1098         or OVERFLOWABLE is <0 and any overflow occurs
1099    We return a new tree node for the extended double_int.  The node
1100    is shared if no overflow flags are set.  */
1101 
1102 
1103 tree
1104 force_fit_type_double (tree type, double_int cst, int overflowable,
1105 		       bool overflowed)
1106 {
1107   bool sign_extended_type;
1108 
1109   /* Size types *are* sign extended.  */
1110   sign_extended_type = (!TYPE_UNSIGNED (type)
1111                         || (TREE_CODE (type) == INTEGER_TYPE
1112                             && TYPE_IS_SIZETYPE (type)));
1113 
1114   /* If we need to set overflow flags, return a new unshared node.  */
1115   if (overflowed || !double_int_fits_to_tree_p(type, cst))
1116     {
1117       if (overflowed
1118 	  || overflowable < 0
1119 	  || (overflowable > 0 && sign_extended_type))
1120 	{
1121 	  tree t = make_node (INTEGER_CST);
1122 	  TREE_INT_CST (t) = double_int_ext (cst, TYPE_PRECISION (type),
1123 					     !sign_extended_type);
1124 	  TREE_TYPE (t) = type;
1125 	  TREE_OVERFLOW (t) = 1;
1126 	  return t;
1127 	}
1128     }
1129 
1130   /* Else build a shared node.  */
1131   return double_int_to_tree (type, cst);
1132 }
1133 
1134 /* These are the hash table functions for the hash table of INTEGER_CST
1135    nodes of a sizetype.  */
1136 
1137 /* Return the hash code code X, an INTEGER_CST.  */
1138 
1139 static hashval_t
1140 int_cst_hash_hash (const void *x)
1141 {
1142   const_tree const t = (const_tree) x;
1143 
1144   return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1145 	  ^ htab_hash_pointer (TREE_TYPE (t)));
1146 }
1147 
1148 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1149    is the same as that given by *Y, which is the same.  */
1150 
1151 static int
1152 int_cst_hash_eq (const void *x, const void *y)
1153 {
1154   const_tree const xt = (const_tree) x;
1155   const_tree const yt = (const_tree) y;
1156 
1157   return (TREE_TYPE (xt) == TREE_TYPE (yt)
1158 	  && TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1159 	  && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt));
1160 }
1161 
1162 /* Create an INT_CST node of TYPE and value HI:LOW.
1163    The returned node is always shared.  For small integers we use a
1164    per-type vector cache, for larger ones we use a single hash table.  */
1165 
1166 tree
1167 build_int_cst_wide (tree type, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
1168 {
1169   tree t;
1170   int ix = -1;
1171   int limit = 0;
1172 
1173   gcc_assert (type);
1174 
1175   switch (TREE_CODE (type))
1176     {
1177     case NULLPTR_TYPE:
1178       gcc_assert (hi == 0 && low == 0);
1179       /* Fallthru.  */
1180 
1181     case POINTER_TYPE:
1182     case REFERENCE_TYPE:
1183       /* Cache NULL pointer.  */
1184       if (!hi && !low)
1185 	{
1186 	  limit = 1;
1187 	  ix = 0;
1188 	}
1189       break;
1190 
1191     case BOOLEAN_TYPE:
1192       /* Cache false or true.  */
1193       limit = 2;
1194       if (!hi && low < 2)
1195 	ix = low;
1196       break;
1197 
1198     case INTEGER_TYPE:
1199     case OFFSET_TYPE:
1200       if (TYPE_UNSIGNED (type))
1201 	{
1202 	  /* Cache 0..N */
1203 	  limit = INTEGER_SHARE_LIMIT;
1204 	  if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
1205 	    ix = low;
1206 	}
1207       else
1208 	{
1209 	  /* Cache -1..N */
1210 	  limit = INTEGER_SHARE_LIMIT + 1;
1211 	  if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
1212 	    ix = low + 1;
1213 	  else if (hi == -1 && low == -(unsigned HOST_WIDE_INT)1)
1214 	    ix = 0;
1215 	}
1216       break;
1217 
1218     case ENUMERAL_TYPE:
1219       break;
1220 
1221     default:
1222       gcc_unreachable ();
1223     }
1224 
1225   if (ix >= 0)
1226     {
1227       /* Look for it in the type's vector of small shared ints.  */
1228       if (!TYPE_CACHED_VALUES_P (type))
1229 	{
1230 	  TYPE_CACHED_VALUES_P (type) = 1;
1231 	  TYPE_CACHED_VALUES (type) = make_tree_vec (limit);
1232 	}
1233 
1234       t = TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix);
1235       if (t)
1236 	{
1237 	  /* Make sure no one is clobbering the shared constant.  */
1238 	  gcc_assert (TREE_TYPE (t) == type);
1239 	  gcc_assert (TREE_INT_CST_LOW (t) == low);
1240 	  gcc_assert (TREE_INT_CST_HIGH (t) == hi);
1241 	}
1242       else
1243 	{
1244 	  /* Create a new shared int.  */
1245 	  t = make_node (INTEGER_CST);
1246 
1247 	  TREE_INT_CST_LOW (t) = low;
1248 	  TREE_INT_CST_HIGH (t) = hi;
1249 	  TREE_TYPE (t) = type;
1250 
1251 	  TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix) = t;
1252 	}
1253     }
1254   else
1255     {
1256       /* Use the cache of larger shared ints.  */
1257       void **slot;
1258 
1259       TREE_INT_CST_LOW (int_cst_node) = low;
1260       TREE_INT_CST_HIGH (int_cst_node) = hi;
1261       TREE_TYPE (int_cst_node) = type;
1262 
1263       slot = htab_find_slot (int_cst_hash_table, int_cst_node, INSERT);
1264       t = (tree) *slot;
1265       if (!t)
1266 	{
1267 	  /* Insert this one into the hash table.  */
1268 	  t = int_cst_node;
1269 	  *slot = t;
1270 	  /* Make a new node for next time round.  */
1271 	  int_cst_node = make_node (INTEGER_CST);
1272 	}
1273     }
1274 
1275   return t;
1276 }
1277 
1278 /* Builds an integer constant in TYPE such that lowest BITS bits are ones
1279    and the rest are zeros.  */
1280 
1281 tree
1282 build_low_bits_mask (tree type, unsigned bits)
1283 {
1284   double_int mask;
1285 
1286   gcc_assert (bits <= TYPE_PRECISION (type));
1287 
1288   if (bits == TYPE_PRECISION (type)
1289       && !TYPE_UNSIGNED (type))
1290     /* Sign extended all-ones mask.  */
1291     mask = double_int_minus_one;
1292   else
1293     mask = double_int_mask (bits);
1294 
1295   return build_int_cst_wide (type, mask.low, mask.high);
1296 }
1297 
1298 /* Checks that X is integer constant that can be expressed in (unsigned)
1299    HOST_WIDE_INT without loss of precision.  */
1300 
1301 bool
1302 cst_and_fits_in_hwi (const_tree x)
1303 {
1304   if (TREE_CODE (x) != INTEGER_CST)
1305     return false;
1306 
1307   if (TYPE_PRECISION (TREE_TYPE (x)) > HOST_BITS_PER_WIDE_INT)
1308     return false;
1309 
1310   return (TREE_INT_CST_HIGH (x) == 0
1311 	  || TREE_INT_CST_HIGH (x) == -1);
1312 }
1313 
1314 /* Return a new VECTOR_CST node whose type is TYPE and whose values
1315    are in a list pointed to by VALS.  */
1316 
1317 tree
1318 build_vector (tree type, tree vals)
1319 {
1320   tree v = make_node (VECTOR_CST);
1321   int over = 0;
1322   tree link;
1323   unsigned cnt = 0;
1324 
1325   TREE_VECTOR_CST_ELTS (v) = vals;
1326   TREE_TYPE (v) = type;
1327 
1328   /* Iterate through elements and check for overflow.  */
1329   for (link = vals; link; link = TREE_CHAIN (link))
1330     {
1331       tree value = TREE_VALUE (link);
1332       cnt++;
1333 
1334       /* Don't crash if we get an address constant.  */
1335       if (!CONSTANT_CLASS_P (value))
1336 	continue;
1337 
1338       over |= TREE_OVERFLOW (value);
1339     }
1340 
1341   gcc_assert (cnt == TYPE_VECTOR_SUBPARTS (type));
1342 
1343   TREE_OVERFLOW (v) = over;
1344   return v;
1345 }
1346 
1347 /* Return a new VECTOR_CST node whose type is TYPE and whose values
1348    are extracted from V, a vector of CONSTRUCTOR_ELT.  */
1349 
1350 tree
1351 build_vector_from_ctor (tree type, VEC(constructor_elt,gc) *v)
1352 {
1353   tree list = NULL_TREE;
1354   unsigned HOST_WIDE_INT idx;
1355   tree value;
1356 
1357   FOR_EACH_CONSTRUCTOR_VALUE (v, idx, value)
1358     list = tree_cons (NULL_TREE, value, list);
1359   for (; idx < TYPE_VECTOR_SUBPARTS (type); ++idx)
1360     list = tree_cons (NULL_TREE,
1361 		      build_zero_cst (TREE_TYPE (type)), list);
1362   return build_vector (type, nreverse (list));
1363 }
1364 
1365 /* Build a vector of type VECTYPE where all the elements are SCs.  */
1366 tree
1367 build_vector_from_val (tree vectype, tree sc)
1368 {
1369   int i, nunits = TYPE_VECTOR_SUBPARTS (vectype);
1370   VEC(constructor_elt, gc) *v = NULL;
1371 
1372   if (sc == error_mark_node)
1373     return sc;
1374 
1375   /* Verify that the vector type is suitable for SC.  Note that there
1376      is some inconsistency in the type-system with respect to restrict
1377      qualifications of pointers.  Vector types always have a main-variant
1378      element type and the qualification is applied to the vector-type.
1379      So TREE_TYPE (vector-type) does not return a properly qualified
1380      vector element-type.  */
1381   gcc_checking_assert (types_compatible_p (TYPE_MAIN_VARIANT (TREE_TYPE (sc)),
1382 					   TREE_TYPE (vectype)));
1383 
1384   v = VEC_alloc (constructor_elt, gc, nunits);
1385   for (i = 0; i < nunits; ++i)
1386     CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, sc);
1387 
1388   if (CONSTANT_CLASS_P (sc))
1389     return build_vector_from_ctor (vectype, v);
1390   else
1391     return build_constructor (vectype, v);
1392 }
1393 
1394 /* Return a new CONSTRUCTOR node whose type is TYPE and whose values
1395    are in the VEC pointed to by VALS.  */
1396 tree
1397 build_constructor (tree type, VEC(constructor_elt,gc) *vals)
1398 {
1399   tree c = make_node (CONSTRUCTOR);
1400   unsigned int i;
1401   constructor_elt *elt;
1402   bool constant_p = true;
1403 
1404   TREE_TYPE (c) = type;
1405   CONSTRUCTOR_ELTS (c) = vals;
1406 
1407   FOR_EACH_VEC_ELT (constructor_elt, vals, i, elt)
1408     if (!TREE_CONSTANT (elt->value))
1409       {
1410 	constant_p = false;
1411 	break;
1412       }
1413 
1414   TREE_CONSTANT (c) = constant_p;
1415 
1416   return c;
1417 }
1418 
1419 /* Build a CONSTRUCTOR node made of a single initializer, with the specified
1420    INDEX and VALUE.  */
1421 tree
1422 build_constructor_single (tree type, tree index, tree value)
1423 {
1424   VEC(constructor_elt,gc) *v;
1425   constructor_elt *elt;
1426 
1427   v = VEC_alloc (constructor_elt, gc, 1);
1428   elt = VEC_quick_push (constructor_elt, v, NULL);
1429   elt->index = index;
1430   elt->value = value;
1431 
1432   return build_constructor (type, v);
1433 }
1434 
1435 
1436 /* Return a new CONSTRUCTOR node whose type is TYPE and whose values
1437    are in a list pointed to by VALS.  */
1438 tree
1439 build_constructor_from_list (tree type, tree vals)
1440 {
1441   tree t;
1442   VEC(constructor_elt,gc) *v = NULL;
1443 
1444   if (vals)
1445     {
1446       v = VEC_alloc (constructor_elt, gc, list_length (vals));
1447       for (t = vals; t; t = TREE_CHAIN (t))
1448 	CONSTRUCTOR_APPEND_ELT (v, TREE_PURPOSE (t), TREE_VALUE (t));
1449     }
1450 
1451   return build_constructor (type, v);
1452 }
1453 
1454 /* Return a new FIXED_CST node whose type is TYPE and value is F.  */
1455 
1456 tree
1457 build_fixed (tree type, FIXED_VALUE_TYPE f)
1458 {
1459   tree v;
1460   FIXED_VALUE_TYPE *fp;
1461 
1462   v = make_node (FIXED_CST);
1463   fp = ggc_alloc_fixed_value ();
1464   memcpy (fp, &f, sizeof (FIXED_VALUE_TYPE));
1465 
1466   TREE_TYPE (v) = type;
1467   TREE_FIXED_CST_PTR (v) = fp;
1468   return v;
1469 }
1470 
1471 /* Return a new REAL_CST node whose type is TYPE and value is D.  */
1472 
1473 tree
1474 build_real (tree type, REAL_VALUE_TYPE d)
1475 {
1476   tree v;
1477   REAL_VALUE_TYPE *dp;
1478   int overflow = 0;
1479 
1480   /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
1481      Consider doing it via real_convert now.  */
1482 
1483   v = make_node (REAL_CST);
1484   dp = ggc_alloc_real_value ();
1485   memcpy (dp, &d, sizeof (REAL_VALUE_TYPE));
1486 
1487   TREE_TYPE (v) = type;
1488   TREE_REAL_CST_PTR (v) = dp;
1489   TREE_OVERFLOW (v) = overflow;
1490   return v;
1491 }
1492 
1493 /* Return a new REAL_CST node whose type is TYPE
1494    and whose value is the integer value of the INTEGER_CST node I.  */
1495 
1496 REAL_VALUE_TYPE
1497 real_value_from_int_cst (const_tree type, const_tree i)
1498 {
1499   REAL_VALUE_TYPE d;
1500 
1501   /* Clear all bits of the real value type so that we can later do
1502      bitwise comparisons to see if two values are the same.  */
1503   memset (&d, 0, sizeof d);
1504 
1505   real_from_integer (&d, type ? TYPE_MODE (type) : VOIDmode,
1506 		     TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1507 		     TYPE_UNSIGNED (TREE_TYPE (i)));
1508   return d;
1509 }
1510 
1511 /* Given a tree representing an integer constant I, return a tree
1512    representing the same value as a floating-point constant of type TYPE.  */
1513 
1514 tree
1515 build_real_from_int_cst (tree type, const_tree i)
1516 {
1517   tree v;
1518   int overflow = TREE_OVERFLOW (i);
1519 
1520   v = build_real (type, real_value_from_int_cst (type, i));
1521 
1522   TREE_OVERFLOW (v) |= overflow;
1523   return v;
1524 }
1525 
1526 /* Return a newly constructed STRING_CST node whose value is
1527    the LEN characters at STR.
1528    Note that for a C string literal, LEN should include the trailing NUL.
1529    The TREE_TYPE is not initialized.  */
1530 
1531 tree
1532 build_string (int len, const char *str)
1533 {
1534   tree s;
1535   size_t length;
1536 
1537   /* Do not waste bytes provided by padding of struct tree_string.  */
1538   length = len + offsetof (struct tree_string, str) + 1;
1539 
1540   record_node_allocation_statistics (STRING_CST, length);
1541 
1542   s = ggc_alloc_tree_node (length);
1543 
1544   memset (s, 0, sizeof (struct tree_typed));
1545   TREE_SET_CODE (s, STRING_CST);
1546   TREE_CONSTANT (s) = 1;
1547   TREE_STRING_LENGTH (s) = len;
1548   memcpy (s->string.str, str, len);
1549   s->string.str[len] = '\0';
1550 
1551   return s;
1552 }
1553 
1554 /* Return a newly constructed COMPLEX_CST node whose value is
1555    specified by the real and imaginary parts REAL and IMAG.
1556    Both REAL and IMAG should be constant nodes.  TYPE, if specified,
1557    will be the type of the COMPLEX_CST; otherwise a new type will be made.  */
1558 
1559 tree
1560 build_complex (tree type, tree real, tree imag)
1561 {
1562   tree t = make_node (COMPLEX_CST);
1563 
1564   TREE_REALPART (t) = real;
1565   TREE_IMAGPART (t) = imag;
1566   TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1567   TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1568   return t;
1569 }
1570 
1571 /* Return a constant of arithmetic type TYPE which is the
1572    multiplicative identity of the set TYPE.  */
1573 
1574 tree
1575 build_one_cst (tree type)
1576 {
1577   switch (TREE_CODE (type))
1578     {
1579     case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1580     case POINTER_TYPE: case REFERENCE_TYPE:
1581     case OFFSET_TYPE:
1582       return build_int_cst (type, 1);
1583 
1584     case REAL_TYPE:
1585       return build_real (type, dconst1);
1586 
1587     case FIXED_POINT_TYPE:
1588       /* We can only generate 1 for accum types.  */
1589       gcc_assert (ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type)));
1590       return build_fixed (type, FCONST1(TYPE_MODE (type)));
1591 
1592     case VECTOR_TYPE:
1593       {
1594 	tree scalar = build_one_cst (TREE_TYPE (type));
1595 
1596 	return build_vector_from_val (type, scalar);
1597       }
1598 
1599     case COMPLEX_TYPE:
1600       return build_complex (type,
1601 			    build_one_cst (TREE_TYPE (type)),
1602 			    build_zero_cst (TREE_TYPE (type)));
1603 
1604     default:
1605       gcc_unreachable ();
1606     }
1607 }
1608 
1609 /* Build 0 constant of type TYPE.  This is used by constructor folding
1610    and thus the constant should be represented in memory by
1611    zero(es).  */
1612 
1613 tree
1614 build_zero_cst (tree type)
1615 {
1616   switch (TREE_CODE (type))
1617     {
1618     case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1619     case POINTER_TYPE: case REFERENCE_TYPE:
1620     case OFFSET_TYPE: case NULLPTR_TYPE:
1621       return build_int_cst (type, 0);
1622 
1623     case REAL_TYPE:
1624       return build_real (type, dconst0);
1625 
1626     case FIXED_POINT_TYPE:
1627       return build_fixed (type, FCONST0 (TYPE_MODE (type)));
1628 
1629     case VECTOR_TYPE:
1630       {
1631 	tree scalar = build_zero_cst (TREE_TYPE (type));
1632 
1633 	return build_vector_from_val (type, scalar);
1634       }
1635 
1636     case COMPLEX_TYPE:
1637       {
1638 	tree zero = build_zero_cst (TREE_TYPE (type));
1639 
1640 	return build_complex (type, zero, zero);
1641       }
1642 
1643     default:
1644       if (!AGGREGATE_TYPE_P (type))
1645 	return fold_convert (type, integer_zero_node);
1646       return build_constructor (type, NULL);
1647     }
1648 }
1649 
1650 
1651 /* Build a BINFO with LEN language slots.  */
1652 
1653 tree
1654 make_tree_binfo_stat (unsigned base_binfos MEM_STAT_DECL)
1655 {
1656   tree t;
1657   size_t length = (offsetof (struct tree_binfo, base_binfos)
1658 		   + VEC_embedded_size (tree, base_binfos));
1659 
1660   record_node_allocation_statistics (TREE_BINFO, length);
1661 
1662   t = ggc_alloc_zone_tree_node_stat (&tree_zone, length PASS_MEM_STAT);
1663 
1664   memset (t, 0, offsetof (struct tree_binfo, base_binfos));
1665 
1666   TREE_SET_CODE (t, TREE_BINFO);
1667 
1668   VEC_embedded_init (tree, BINFO_BASE_BINFOS (t), base_binfos);
1669 
1670   return t;
1671 }
1672 
1673 /* Create a CASE_LABEL_EXPR tree node and return it.  */
1674 
1675 tree
1676 build_case_label (tree low_value, tree high_value, tree label_decl)
1677 {
1678   tree t = make_node (CASE_LABEL_EXPR);
1679 
1680   TREE_TYPE (t) = void_type_node;
1681   SET_EXPR_LOCATION (t, DECL_SOURCE_LOCATION (label_decl));
1682 
1683   CASE_LOW (t) = low_value;
1684   CASE_HIGH (t) = high_value;
1685   CASE_LABEL (t) = label_decl;
1686   CASE_CHAIN (t) = NULL_TREE;
1687 
1688   return t;
1689 }
1690 
1691 /* Build a newly constructed TREE_VEC node of length LEN.  */
1692 
1693 tree
1694 make_tree_vec_stat (int len MEM_STAT_DECL)
1695 {
1696   tree t;
1697   int length = (len - 1) * sizeof (tree) + sizeof (struct tree_vec);
1698 
1699   record_node_allocation_statistics (TREE_VEC, length);
1700 
1701   t = ggc_alloc_zone_cleared_tree_node_stat (&tree_zone, length PASS_MEM_STAT);
1702 
1703   TREE_SET_CODE (t, TREE_VEC);
1704   TREE_VEC_LENGTH (t) = len;
1705 
1706   return t;
1707 }
1708 
1709 /* Return 1 if EXPR is the integer constant zero or a complex constant
1710    of zero.  */
1711 
1712 int
1713 integer_zerop (const_tree expr)
1714 {
1715   STRIP_NOPS (expr);
1716 
1717   return ((TREE_CODE (expr) == INTEGER_CST
1718 	   && TREE_INT_CST_LOW (expr) == 0
1719 	   && TREE_INT_CST_HIGH (expr) == 0)
1720 	  || (TREE_CODE (expr) == COMPLEX_CST
1721 	      && integer_zerop (TREE_REALPART (expr))
1722 	      && integer_zerop (TREE_IMAGPART (expr))));
1723 }
1724 
1725 /* Return 1 if EXPR is the integer constant one or the corresponding
1726    complex constant.  */
1727 
1728 int
1729 integer_onep (const_tree expr)
1730 {
1731   STRIP_NOPS (expr);
1732 
1733   return ((TREE_CODE (expr) == INTEGER_CST
1734 	   && TREE_INT_CST_LOW (expr) == 1
1735 	   && TREE_INT_CST_HIGH (expr) == 0)
1736 	  || (TREE_CODE (expr) == COMPLEX_CST
1737 	      && integer_onep (TREE_REALPART (expr))
1738 	      && integer_zerop (TREE_IMAGPART (expr))));
1739 }
1740 
1741 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1742    it contains.  Likewise for the corresponding complex constant.  */
1743 
1744 int
1745 integer_all_onesp (const_tree expr)
1746 {
1747   int prec;
1748   int uns;
1749 
1750   STRIP_NOPS (expr);
1751 
1752   if (TREE_CODE (expr) == COMPLEX_CST
1753       && integer_all_onesp (TREE_REALPART (expr))
1754       && integer_zerop (TREE_IMAGPART (expr)))
1755     return 1;
1756 
1757   else if (TREE_CODE (expr) != INTEGER_CST)
1758     return 0;
1759 
1760   uns = TYPE_UNSIGNED (TREE_TYPE (expr));
1761   if (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
1762       && TREE_INT_CST_HIGH (expr) == -1)
1763     return 1;
1764   if (!uns)
1765     return 0;
1766 
1767   prec = TYPE_PRECISION (TREE_TYPE (expr));
1768   if (prec >= HOST_BITS_PER_WIDE_INT)
1769     {
1770       HOST_WIDE_INT high_value;
1771       int shift_amount;
1772 
1773       shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1774 
1775       /* Can not handle precisions greater than twice the host int size.  */
1776       gcc_assert (shift_amount <= HOST_BITS_PER_WIDE_INT);
1777       if (shift_amount == HOST_BITS_PER_WIDE_INT)
1778 	/* Shifting by the host word size is undefined according to the ANSI
1779 	   standard, so we must handle this as a special case.  */
1780 	high_value = -1;
1781       else
1782 	high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1783 
1784       return (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
1785 	      && TREE_INT_CST_HIGH (expr) == high_value);
1786     }
1787   else
1788     return TREE_INT_CST_LOW (expr) == ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1789 }
1790 
1791 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1792    one bit on).  */
1793 
1794 int
1795 integer_pow2p (const_tree expr)
1796 {
1797   int prec;
1798   HOST_WIDE_INT high, low;
1799 
1800   STRIP_NOPS (expr);
1801 
1802   if (TREE_CODE (expr) == COMPLEX_CST
1803       && integer_pow2p (TREE_REALPART (expr))
1804       && integer_zerop (TREE_IMAGPART (expr)))
1805     return 1;
1806 
1807   if (TREE_CODE (expr) != INTEGER_CST)
1808     return 0;
1809 
1810   prec = TYPE_PRECISION (TREE_TYPE (expr));
1811   high = TREE_INT_CST_HIGH (expr);
1812   low = TREE_INT_CST_LOW (expr);
1813 
1814   /* First clear all bits that are beyond the type's precision in case
1815      we've been sign extended.  */
1816 
1817   if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1818     ;
1819   else if (prec > HOST_BITS_PER_WIDE_INT)
1820     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1821   else
1822     {
1823       high = 0;
1824       if (prec < HOST_BITS_PER_WIDE_INT)
1825 	low &= ~((HOST_WIDE_INT) (-1) << prec);
1826     }
1827 
1828   if (high == 0 && low == 0)
1829     return 0;
1830 
1831   return ((high == 0 && (low & (low - 1)) == 0)
1832 	  || (low == 0 && (high & (high - 1)) == 0));
1833 }
1834 
1835 /* Return 1 if EXPR is an integer constant other than zero or a
1836    complex constant other than zero.  */
1837 
1838 int
1839 integer_nonzerop (const_tree expr)
1840 {
1841   STRIP_NOPS (expr);
1842 
1843   return ((TREE_CODE (expr) == INTEGER_CST
1844 	   && (TREE_INT_CST_LOW (expr) != 0
1845 	       || TREE_INT_CST_HIGH (expr) != 0))
1846 	  || (TREE_CODE (expr) == COMPLEX_CST
1847 	      && (integer_nonzerop (TREE_REALPART (expr))
1848 		  || integer_nonzerop (TREE_IMAGPART (expr)))));
1849 }
1850 
1851 /* Return 1 if EXPR is the fixed-point constant zero.  */
1852 
1853 int
1854 fixed_zerop (const_tree expr)
1855 {
1856   return (TREE_CODE (expr) == FIXED_CST
1857 	  && double_int_zero_p (TREE_FIXED_CST (expr).data));
1858 }
1859 
1860 /* Return the power of two represented by a tree node known to be a
1861    power of two.  */
1862 
1863 int
1864 tree_log2 (const_tree expr)
1865 {
1866   int prec;
1867   HOST_WIDE_INT high, low;
1868 
1869   STRIP_NOPS (expr);
1870 
1871   if (TREE_CODE (expr) == COMPLEX_CST)
1872     return tree_log2 (TREE_REALPART (expr));
1873 
1874   prec = TYPE_PRECISION (TREE_TYPE (expr));
1875   high = TREE_INT_CST_HIGH (expr);
1876   low = TREE_INT_CST_LOW (expr);
1877 
1878   /* First clear all bits that are beyond the type's precision in case
1879      we've been sign extended.  */
1880 
1881   if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1882     ;
1883   else if (prec > HOST_BITS_PER_WIDE_INT)
1884     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1885   else
1886     {
1887       high = 0;
1888       if (prec < HOST_BITS_PER_WIDE_INT)
1889 	low &= ~((HOST_WIDE_INT) (-1) << prec);
1890     }
1891 
1892   return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1893 	  : exact_log2 (low));
1894 }
1895 
1896 /* Similar, but return the largest integer Y such that 2 ** Y is less
1897    than or equal to EXPR.  */
1898 
1899 int
1900 tree_floor_log2 (const_tree expr)
1901 {
1902   int prec;
1903   HOST_WIDE_INT high, low;
1904 
1905   STRIP_NOPS (expr);
1906 
1907   if (TREE_CODE (expr) == COMPLEX_CST)
1908     return tree_log2 (TREE_REALPART (expr));
1909 
1910   prec = TYPE_PRECISION (TREE_TYPE (expr));
1911   high = TREE_INT_CST_HIGH (expr);
1912   low = TREE_INT_CST_LOW (expr);
1913 
1914   /* First clear all bits that are beyond the type's precision in case
1915      we've been sign extended.  Ignore if type's precision hasn't been set
1916      since what we are doing is setting it.  */
1917 
1918   if (prec == 2 * HOST_BITS_PER_WIDE_INT || prec == 0)
1919     ;
1920   else if (prec > HOST_BITS_PER_WIDE_INT)
1921     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1922   else
1923     {
1924       high = 0;
1925       if (prec < HOST_BITS_PER_WIDE_INT)
1926 	low &= ~((HOST_WIDE_INT) (-1) << prec);
1927     }
1928 
1929   return (high != 0 ? HOST_BITS_PER_WIDE_INT + floor_log2 (high)
1930 	  : floor_log2 (low));
1931 }
1932 
1933 /* Return 1 if EXPR is the real constant zero.  Trailing zeroes matter for
1934    decimal float constants, so don't return 1 for them.  */
1935 
1936 int
1937 real_zerop (const_tree expr)
1938 {
1939   STRIP_NOPS (expr);
1940 
1941   return ((TREE_CODE (expr) == REAL_CST
1942 	   && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0)
1943 	   && !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
1944 	  || (TREE_CODE (expr) == COMPLEX_CST
1945 	      && real_zerop (TREE_REALPART (expr))
1946 	      && real_zerop (TREE_IMAGPART (expr))));
1947 }
1948 
1949 /* Return 1 if EXPR is the real constant one in real or complex form.
1950    Trailing zeroes matter for decimal float constants, so don't return
1951    1 for them.  */
1952 
1953 int
1954 real_onep (const_tree expr)
1955 {
1956   STRIP_NOPS (expr);
1957 
1958   return ((TREE_CODE (expr) == REAL_CST
1959 	   && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1)
1960 	   && !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
1961 	  || (TREE_CODE (expr) == COMPLEX_CST
1962 	      && real_onep (TREE_REALPART (expr))
1963 	      && real_zerop (TREE_IMAGPART (expr))));
1964 }
1965 
1966 /* Return 1 if EXPR is the real constant two.  Trailing zeroes matter
1967    for decimal float constants, so don't return 1 for them.  */
1968 
1969 int
1970 real_twop (const_tree expr)
1971 {
1972   STRIP_NOPS (expr);
1973 
1974   return ((TREE_CODE (expr) == REAL_CST
1975 	   && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2)
1976 	   && !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
1977 	  || (TREE_CODE (expr) == COMPLEX_CST
1978 	      && real_twop (TREE_REALPART (expr))
1979 	      && real_zerop (TREE_IMAGPART (expr))));
1980 }
1981 
1982 /* Return 1 if EXPR is the real constant minus one.  Trailing zeroes
1983    matter for decimal float constants, so don't return 1 for them.  */
1984 
1985 int
1986 real_minus_onep (const_tree expr)
1987 {
1988   STRIP_NOPS (expr);
1989 
1990   return ((TREE_CODE (expr) == REAL_CST
1991 	   && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconstm1)
1992 	   && !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
1993 	  || (TREE_CODE (expr) == COMPLEX_CST
1994 	      && real_minus_onep (TREE_REALPART (expr))
1995 	      && real_zerop (TREE_IMAGPART (expr))));
1996 }
1997 
1998 /* Nonzero if EXP is a constant or a cast of a constant.  */
1999 
2000 int
2001 really_constant_p (const_tree exp)
2002 {
2003   /* This is not quite the same as STRIP_NOPS.  It does more.  */
2004   while (CONVERT_EXPR_P (exp)
2005 	 || TREE_CODE (exp) == NON_LVALUE_EXPR)
2006     exp = TREE_OPERAND (exp, 0);
2007   return TREE_CONSTANT (exp);
2008 }
2009 
2010 /* Return first list element whose TREE_VALUE is ELEM.
2011    Return 0 if ELEM is not in LIST.  */
2012 
2013 tree
2014 value_member (tree elem, tree list)
2015 {
2016   while (list)
2017     {
2018       if (elem == TREE_VALUE (list))
2019 	return list;
2020       list = TREE_CHAIN (list);
2021     }
2022   return NULL_TREE;
2023 }
2024 
2025 /* Return first list element whose TREE_PURPOSE is ELEM.
2026    Return 0 if ELEM is not in LIST.  */
2027 
2028 tree
2029 purpose_member (const_tree elem, tree list)
2030 {
2031   while (list)
2032     {
2033       if (elem == TREE_PURPOSE (list))
2034 	return list;
2035       list = TREE_CHAIN (list);
2036     }
2037   return NULL_TREE;
2038 }
2039 
2040 /* Return true if ELEM is in V.  */
2041 
2042 bool
2043 vec_member (const_tree elem, VEC(tree,gc) *v)
2044 {
2045   unsigned ix;
2046   tree t;
2047   FOR_EACH_VEC_ELT (tree, v, ix, t)
2048     if (elem == t)
2049       return true;
2050   return false;
2051 }
2052 
2053 /* Returns element number IDX (zero-origin) of chain CHAIN, or
2054    NULL_TREE.  */
2055 
2056 tree
2057 chain_index (int idx, tree chain)
2058 {
2059   for (; chain && idx > 0; --idx)
2060     chain = TREE_CHAIN (chain);
2061   return chain;
2062 }
2063 
2064 /* Return nonzero if ELEM is part of the chain CHAIN.  */
2065 
2066 int
2067 chain_member (const_tree elem, const_tree chain)
2068 {
2069   while (chain)
2070     {
2071       if (elem == chain)
2072 	return 1;
2073       chain = DECL_CHAIN (chain);
2074     }
2075 
2076   return 0;
2077 }
2078 
2079 /* Return the length of a chain of nodes chained through TREE_CHAIN.
2080    We expect a null pointer to mark the end of the chain.
2081    This is the Lisp primitive `length'.  */
2082 
2083 int
2084 list_length (const_tree t)
2085 {
2086   const_tree p = t;
2087 #ifdef ENABLE_TREE_CHECKING
2088   const_tree q = t;
2089 #endif
2090   int len = 0;
2091 
2092   while (p)
2093     {
2094       p = TREE_CHAIN (p);
2095 #ifdef ENABLE_TREE_CHECKING
2096       if (len % 2)
2097 	q = TREE_CHAIN (q);
2098       gcc_assert (p != q);
2099 #endif
2100       len++;
2101     }
2102 
2103   return len;
2104 }
2105 
2106 /* Returns the number of FIELD_DECLs in TYPE.  */
2107 
2108 int
2109 fields_length (const_tree type)
2110 {
2111   tree t = TYPE_FIELDS (type);
2112   int count = 0;
2113 
2114   for (; t; t = DECL_CHAIN (t))
2115     if (TREE_CODE (t) == FIELD_DECL)
2116       ++count;
2117 
2118   return count;
2119 }
2120 
2121 /* Returns the first FIELD_DECL in the TYPE_FIELDS of the RECORD_TYPE or
2122    UNION_TYPE TYPE, or NULL_TREE if none.  */
2123 
2124 tree
2125 first_field (const_tree type)
2126 {
2127   tree t = TYPE_FIELDS (type);
2128   while (t && TREE_CODE (t) != FIELD_DECL)
2129     t = TREE_CHAIN (t);
2130   return t;
2131 }
2132 
2133 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
2134    by modifying the last node in chain 1 to point to chain 2.
2135    This is the Lisp primitive `nconc'.  */
2136 
2137 tree
2138 chainon (tree op1, tree op2)
2139 {
2140   tree t1;
2141 
2142   if (!op1)
2143     return op2;
2144   if (!op2)
2145     return op1;
2146 
2147   for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
2148     continue;
2149   TREE_CHAIN (t1) = op2;
2150 
2151 #ifdef ENABLE_TREE_CHECKING
2152   {
2153     tree t2;
2154     for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
2155       gcc_assert (t2 != t1);
2156   }
2157 #endif
2158 
2159   return op1;
2160 }
2161 
2162 /* Return the last node in a chain of nodes (chained through TREE_CHAIN).  */
2163 
2164 tree
2165 tree_last (tree chain)
2166 {
2167   tree next;
2168   if (chain)
2169     while ((next = TREE_CHAIN (chain)))
2170       chain = next;
2171   return chain;
2172 }
2173 
2174 /* Reverse the order of elements in the chain T,
2175    and return the new head of the chain (old last element).  */
2176 
2177 tree
2178 nreverse (tree t)
2179 {
2180   tree prev = 0, decl, next;
2181   for (decl = t; decl; decl = next)
2182     {
2183       /* We shouldn't be using this function to reverse BLOCK chains; we
2184 	 have blocks_nreverse for that.  */
2185       gcc_checking_assert (TREE_CODE (decl) != BLOCK);
2186       next = TREE_CHAIN (decl);
2187       TREE_CHAIN (decl) = prev;
2188       prev = decl;
2189     }
2190   return prev;
2191 }
2192 
2193 /* Return a newly created TREE_LIST node whose
2194    purpose and value fields are PARM and VALUE.  */
2195 
2196 tree
2197 build_tree_list_stat (tree parm, tree value MEM_STAT_DECL)
2198 {
2199   tree t = make_node_stat (TREE_LIST PASS_MEM_STAT);
2200   TREE_PURPOSE (t) = parm;
2201   TREE_VALUE (t) = value;
2202   return t;
2203 }
2204 
2205 /* Build a chain of TREE_LIST nodes from a vector.  */
2206 
2207 tree
2208 build_tree_list_vec_stat (const VEC(tree,gc) *vec MEM_STAT_DECL)
2209 {
2210   tree ret = NULL_TREE;
2211   tree *pp = &ret;
2212   unsigned int i;
2213   tree t;
2214   FOR_EACH_VEC_ELT (tree, vec, i, t)
2215     {
2216       *pp = build_tree_list_stat (NULL, t PASS_MEM_STAT);
2217       pp = &TREE_CHAIN (*pp);
2218     }
2219   return ret;
2220 }
2221 
2222 /* Return a newly created TREE_LIST node whose
2223    purpose and value fields are PURPOSE and VALUE
2224    and whose TREE_CHAIN is CHAIN.  */
2225 
2226 tree
2227 tree_cons_stat (tree purpose, tree value, tree chain MEM_STAT_DECL)
2228 {
2229   tree node;
2230 
2231   node = ggc_alloc_zone_tree_node_stat (&tree_zone, sizeof (struct tree_list)
2232                                         PASS_MEM_STAT);
2233   memset (node, 0, sizeof (struct tree_common));
2234 
2235   record_node_allocation_statistics (TREE_LIST, sizeof (struct tree_list));
2236 
2237   TREE_SET_CODE (node, TREE_LIST);
2238   TREE_CHAIN (node) = chain;
2239   TREE_PURPOSE (node) = purpose;
2240   TREE_VALUE (node) = value;
2241   return node;
2242 }
2243 
2244 /* Return the values of the elements of a CONSTRUCTOR as a vector of
2245    trees.  */
2246 
2247 VEC(tree,gc) *
2248 ctor_to_vec (tree ctor)
2249 {
2250   VEC(tree, gc) *vec = VEC_alloc (tree, gc, CONSTRUCTOR_NELTS (ctor));
2251   unsigned int ix;
2252   tree val;
2253 
2254   FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), ix, val)
2255     VEC_quick_push (tree, vec, val);
2256 
2257   return vec;
2258 }
2259 
2260 /* Return the size nominally occupied by an object of type TYPE
2261    when it resides in memory.  The value is measured in units of bytes,
2262    and its data type is that normally used for type sizes
2263    (which is the first type created by make_signed_type or
2264    make_unsigned_type).  */
2265 
2266 tree
2267 size_in_bytes (const_tree type)
2268 {
2269   tree t;
2270 
2271   if (type == error_mark_node)
2272     return integer_zero_node;
2273 
2274   type = TYPE_MAIN_VARIANT (type);
2275   t = TYPE_SIZE_UNIT (type);
2276 
2277   if (t == 0)
2278     {
2279       lang_hooks.types.incomplete_type_error (NULL_TREE, type);
2280       return size_zero_node;
2281     }
2282 
2283   return t;
2284 }
2285 
2286 /* Return the size of TYPE (in bytes) as a wide integer
2287    or return -1 if the size can vary or is larger than an integer.  */
2288 
2289 HOST_WIDE_INT
2290 int_size_in_bytes (const_tree type)
2291 {
2292   tree t;
2293 
2294   if (type == error_mark_node)
2295     return 0;
2296 
2297   type = TYPE_MAIN_VARIANT (type);
2298   t = TYPE_SIZE_UNIT (type);
2299   if (t == 0
2300       || TREE_CODE (t) != INTEGER_CST
2301       || TREE_INT_CST_HIGH (t) != 0
2302       /* If the result would appear negative, it's too big to represent.  */
2303       || (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0)
2304     return -1;
2305 
2306   return TREE_INT_CST_LOW (t);
2307 }
2308 
2309 /* Return the maximum size of TYPE (in bytes) as a wide integer
2310    or return -1 if the size can vary or is larger than an integer.  */
2311 
2312 HOST_WIDE_INT
2313 max_int_size_in_bytes (const_tree type)
2314 {
2315   HOST_WIDE_INT size = -1;
2316   tree size_tree;
2317 
2318   /* If this is an array type, check for a possible MAX_SIZE attached.  */
2319 
2320   if (TREE_CODE (type) == ARRAY_TYPE)
2321     {
2322       size_tree = TYPE_ARRAY_MAX_SIZE (type);
2323 
2324       if (size_tree && host_integerp (size_tree, 1))
2325 	size = tree_low_cst (size_tree, 1);
2326     }
2327 
2328   /* If we still haven't been able to get a size, see if the language
2329      can compute a maximum size.  */
2330 
2331   if (size == -1)
2332     {
2333       size_tree = lang_hooks.types.max_size (type);
2334 
2335       if (size_tree && host_integerp (size_tree, 1))
2336 	size = tree_low_cst (size_tree, 1);
2337     }
2338 
2339   return size;
2340 }
2341 
2342 /* Returns a tree for the size of EXP in bytes.  */
2343 
2344 tree
2345 tree_expr_size (const_tree exp)
2346 {
2347   if (DECL_P (exp)
2348       && DECL_SIZE_UNIT (exp) != 0)
2349     return DECL_SIZE_UNIT (exp);
2350   else
2351     return size_in_bytes (TREE_TYPE (exp));
2352 }
2353 
2354 /* Return the bit position of FIELD, in bits from the start of the record.
2355    This is a tree of type bitsizetype.  */
2356 
2357 tree
2358 bit_position (const_tree field)
2359 {
2360   return bit_from_pos (DECL_FIELD_OFFSET (field),
2361 		       DECL_FIELD_BIT_OFFSET (field));
2362 }
2363 
2364 /* Likewise, but return as an integer.  It must be representable in
2365    that way (since it could be a signed value, we don't have the
2366    option of returning -1 like int_size_in_byte can.  */
2367 
2368 HOST_WIDE_INT
2369 int_bit_position (const_tree field)
2370 {
2371   return tree_low_cst (bit_position (field), 0);
2372 }
2373 
2374 /* Return the byte position of FIELD, in bytes from the start of the record.
2375    This is a tree of type sizetype.  */
2376 
2377 tree
2378 byte_position (const_tree field)
2379 {
2380   return byte_from_pos (DECL_FIELD_OFFSET (field),
2381 			DECL_FIELD_BIT_OFFSET (field));
2382 }
2383 
2384 /* Likewise, but return as an integer.  It must be representable in
2385    that way (since it could be a signed value, we don't have the
2386    option of returning -1 like int_size_in_byte can.  */
2387 
2388 HOST_WIDE_INT
2389 int_byte_position (const_tree field)
2390 {
2391   return tree_low_cst (byte_position (field), 0);
2392 }
2393 
2394 /* Return the strictest alignment, in bits, that T is known to have.  */
2395 
2396 unsigned int
2397 expr_align (const_tree t)
2398 {
2399   unsigned int align0, align1;
2400 
2401   switch (TREE_CODE (t))
2402     {
2403     CASE_CONVERT:  case NON_LVALUE_EXPR:
2404       /* If we have conversions, we know that the alignment of the
2405 	 object must meet each of the alignments of the types.  */
2406       align0 = expr_align (TREE_OPERAND (t, 0));
2407       align1 = TYPE_ALIGN (TREE_TYPE (t));
2408       return MAX (align0, align1);
2409 
2410     case SAVE_EXPR:         case COMPOUND_EXPR:       case MODIFY_EXPR:
2411     case INIT_EXPR:         case TARGET_EXPR:         case WITH_CLEANUP_EXPR:
2412     case CLEANUP_POINT_EXPR:
2413       /* These don't change the alignment of an object.  */
2414       return expr_align (TREE_OPERAND (t, 0));
2415 
2416     case COND_EXPR:
2417       /* The best we can do is say that the alignment is the least aligned
2418 	 of the two arms.  */
2419       align0 = expr_align (TREE_OPERAND (t, 1));
2420       align1 = expr_align (TREE_OPERAND (t, 2));
2421       return MIN (align0, align1);
2422 
2423       /* FIXME: LABEL_DECL and CONST_DECL never have DECL_ALIGN set
2424 	 meaningfully, it's always 1.  */
2425     case LABEL_DECL:     case CONST_DECL:
2426     case VAR_DECL:       case PARM_DECL:   case RESULT_DECL:
2427     case FUNCTION_DECL:
2428       gcc_assert (DECL_ALIGN (t) != 0);
2429       return DECL_ALIGN (t);
2430 
2431     default:
2432       break;
2433     }
2434 
2435   /* Otherwise take the alignment from that of the type.  */
2436   return TYPE_ALIGN (TREE_TYPE (t));
2437 }
2438 
2439 /* Return, as a tree node, the number of elements for TYPE (which is an
2440    ARRAY_TYPE) minus one. This counts only elements of the top array.  */
2441 
2442 tree
2443 array_type_nelts (const_tree type)
2444 {
2445   tree index_type, min, max;
2446 
2447   /* If they did it with unspecified bounds, then we should have already
2448      given an error about it before we got here.  */
2449   if (! TYPE_DOMAIN (type))
2450     return error_mark_node;
2451 
2452   index_type = TYPE_DOMAIN (type);
2453   min = TYPE_MIN_VALUE (index_type);
2454   max = TYPE_MAX_VALUE (index_type);
2455 
2456   /* TYPE_MAX_VALUE may not be set if the array has unknown length.  */
2457   if (!max)
2458     return error_mark_node;
2459 
2460   return (integer_zerop (min)
2461 	  ? max
2462 	  : fold_build2 (MINUS_EXPR, TREE_TYPE (max), max, min));
2463 }
2464 
2465 /* If arg is static -- a reference to an object in static storage -- then
2466    return the object.  This is not the same as the C meaning of `static'.
2467    If arg isn't static, return NULL.  */
2468 
2469 tree
2470 staticp (tree arg)
2471 {
2472   switch (TREE_CODE (arg))
2473     {
2474     case FUNCTION_DECL:
2475       /* Nested functions are static, even though taking their address will
2476 	 involve a trampoline as we unnest the nested function and create
2477 	 the trampoline on the tree level.  */
2478       return arg;
2479 
2480     case VAR_DECL:
2481       return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2482 	      && ! DECL_THREAD_LOCAL_P (arg)
2483 	      && ! DECL_DLLIMPORT_P (arg)
2484 	      ? arg : NULL);
2485 
2486     case CONST_DECL:
2487       return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2488 	      ? arg : NULL);
2489 
2490     case CONSTRUCTOR:
2491       return TREE_STATIC (arg) ? arg : NULL;
2492 
2493     case LABEL_DECL:
2494     case STRING_CST:
2495       return arg;
2496 
2497     case COMPONENT_REF:
2498       /* If the thing being referenced is not a field, then it is
2499 	 something language specific.  */
2500       gcc_assert (TREE_CODE (TREE_OPERAND (arg, 1)) == FIELD_DECL);
2501 
2502       /* If we are referencing a bitfield, we can't evaluate an
2503 	 ADDR_EXPR at compile time and so it isn't a constant.  */
2504       if (DECL_BIT_FIELD (TREE_OPERAND (arg, 1)))
2505 	return NULL;
2506 
2507       return staticp (TREE_OPERAND (arg, 0));
2508 
2509     case BIT_FIELD_REF:
2510       return NULL;
2511 
2512     case INDIRECT_REF:
2513       return TREE_CONSTANT (TREE_OPERAND (arg, 0)) ? arg : NULL;
2514 
2515     case ARRAY_REF:
2516     case ARRAY_RANGE_REF:
2517       if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2518 	  && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2519 	return staticp (TREE_OPERAND (arg, 0));
2520       else
2521 	return NULL;
2522 
2523     case COMPOUND_LITERAL_EXPR:
2524       return TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (arg)) ? arg : NULL;
2525 
2526     default:
2527       return NULL;
2528     }
2529 }
2530 
2531 
2532 
2533 
2534 /* Return whether OP is a DECL whose address is function-invariant.  */
2535 
2536 bool
2537 decl_address_invariant_p (const_tree op)
2538 {
2539   /* The conditions below are slightly less strict than the one in
2540      staticp.  */
2541 
2542   switch (TREE_CODE (op))
2543     {
2544     case PARM_DECL:
2545     case RESULT_DECL:
2546     case LABEL_DECL:
2547     case FUNCTION_DECL:
2548       return true;
2549 
2550     case VAR_DECL:
2551       if ((TREE_STATIC (op) || DECL_EXTERNAL (op))
2552           || DECL_THREAD_LOCAL_P (op)
2553           || DECL_CONTEXT (op) == current_function_decl
2554           || decl_function_context (op) == current_function_decl)
2555         return true;
2556       break;
2557 
2558     case CONST_DECL:
2559       if ((TREE_STATIC (op) || DECL_EXTERNAL (op))
2560           || decl_function_context (op) == current_function_decl)
2561         return true;
2562       break;
2563 
2564     default:
2565       break;
2566     }
2567 
2568   return false;
2569 }
2570 
2571 /* Return whether OP is a DECL whose address is interprocedural-invariant.  */
2572 
2573 bool
2574 decl_address_ip_invariant_p (const_tree op)
2575 {
2576   /* The conditions below are slightly less strict than the one in
2577      staticp.  */
2578 
2579   switch (TREE_CODE (op))
2580     {
2581     case LABEL_DECL:
2582     case FUNCTION_DECL:
2583     case STRING_CST:
2584       return true;
2585 
2586     case VAR_DECL:
2587       if (((TREE_STATIC (op) || DECL_EXTERNAL (op))
2588            && !DECL_DLLIMPORT_P (op))
2589           || DECL_THREAD_LOCAL_P (op))
2590         return true;
2591       break;
2592 
2593     case CONST_DECL:
2594       if ((TREE_STATIC (op) || DECL_EXTERNAL (op)))
2595         return true;
2596       break;
2597 
2598     default:
2599       break;
2600     }
2601 
2602   return false;
2603 }
2604 
2605 
2606 /* Return true if T is function-invariant (internal function, does
2607    not handle arithmetic; that's handled in skip_simple_arithmetic and
2608    tree_invariant_p).  */
2609 
2610 static bool tree_invariant_p (tree t);
2611 
2612 static bool
2613 tree_invariant_p_1 (tree t)
2614 {
2615   tree op;
2616 
2617   if (TREE_CONSTANT (t)
2618       || (TREE_READONLY (t) && !TREE_SIDE_EFFECTS (t)))
2619     return true;
2620 
2621   switch (TREE_CODE (t))
2622     {
2623     case SAVE_EXPR:
2624       return true;
2625 
2626     case ADDR_EXPR:
2627       op = TREE_OPERAND (t, 0);
2628       while (handled_component_p (op))
2629 	{
2630 	  switch (TREE_CODE (op))
2631 	    {
2632 	    case ARRAY_REF:
2633 	    case ARRAY_RANGE_REF:
2634 	      if (!tree_invariant_p (TREE_OPERAND (op, 1))
2635 		  || TREE_OPERAND (op, 2) != NULL_TREE
2636 		  || TREE_OPERAND (op, 3) != NULL_TREE)
2637 		return false;
2638 	      break;
2639 
2640 	    case COMPONENT_REF:
2641 	      if (TREE_OPERAND (op, 2) != NULL_TREE)
2642 		return false;
2643 	      break;
2644 
2645 	    default:;
2646 	    }
2647 	  op = TREE_OPERAND (op, 0);
2648 	}
2649 
2650       return CONSTANT_CLASS_P (op) || decl_address_invariant_p (op);
2651 
2652     default:
2653       break;
2654     }
2655 
2656   return false;
2657 }
2658 
2659 /* Return true if T is function-invariant.  */
2660 
2661 static bool
2662 tree_invariant_p (tree t)
2663 {
2664   tree inner = skip_simple_arithmetic (t);
2665   return tree_invariant_p_1 (inner);
2666 }
2667 
2668 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2669    Do this to any expression which may be used in more than one place,
2670    but must be evaluated only once.
2671 
2672    Normally, expand_expr would reevaluate the expression each time.
2673    Calling save_expr produces something that is evaluated and recorded
2674    the first time expand_expr is called on it.  Subsequent calls to
2675    expand_expr just reuse the recorded value.
2676 
2677    The call to expand_expr that generates code that actually computes
2678    the value is the first call *at compile time*.  Subsequent calls
2679    *at compile time* generate code to use the saved value.
2680    This produces correct result provided that *at run time* control
2681    always flows through the insns made by the first expand_expr
2682    before reaching the other places where the save_expr was evaluated.
2683    You, the caller of save_expr, must make sure this is so.
2684 
2685    Constants, and certain read-only nodes, are returned with no
2686    SAVE_EXPR because that is safe.  Expressions containing placeholders
2687    are not touched; see tree.def for an explanation of what these
2688    are used for.  */
2689 
2690 tree
2691 save_expr (tree expr)
2692 {
2693   tree t = fold (expr);
2694   tree inner;
2695 
2696   /* If the tree evaluates to a constant, then we don't want to hide that
2697      fact (i.e. this allows further folding, and direct checks for constants).
2698      However, a read-only object that has side effects cannot be bypassed.
2699      Since it is no problem to reevaluate literals, we just return the
2700      literal node.  */
2701   inner = skip_simple_arithmetic (t);
2702   if (TREE_CODE (inner) == ERROR_MARK)
2703     return inner;
2704 
2705   if (tree_invariant_p_1 (inner))
2706     return t;
2707 
2708   /* If INNER contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2709      it means that the size or offset of some field of an object depends on
2710      the value within another field.
2711 
2712      Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2713      and some variable since it would then need to be both evaluated once and
2714      evaluated more than once.  Front-ends must assure this case cannot
2715      happen by surrounding any such subexpressions in their own SAVE_EXPR
2716      and forcing evaluation at the proper time.  */
2717   if (contains_placeholder_p (inner))
2718     return t;
2719 
2720   t = build1 (SAVE_EXPR, TREE_TYPE (expr), t);
2721   SET_EXPR_LOCATION (t, EXPR_LOCATION (expr));
2722 
2723   /* This expression might be placed ahead of a jump to ensure that the
2724      value was computed on both sides of the jump.  So make sure it isn't
2725      eliminated as dead.  */
2726   TREE_SIDE_EFFECTS (t) = 1;
2727   return t;
2728 }
2729 
2730 /* Look inside EXPR and into any simple arithmetic operations.  Return
2731    the innermost non-arithmetic node.  */
2732 
2733 tree
2734 skip_simple_arithmetic (tree expr)
2735 {
2736   tree inner;
2737 
2738   /* We don't care about whether this can be used as an lvalue in this
2739      context.  */
2740   while (TREE_CODE (expr) == NON_LVALUE_EXPR)
2741     expr = TREE_OPERAND (expr, 0);
2742 
2743   /* If we have simple operations applied to a SAVE_EXPR or to a SAVE_EXPR and
2744      a constant, it will be more efficient to not make another SAVE_EXPR since
2745      it will allow better simplification and GCSE will be able to merge the
2746      computations if they actually occur.  */
2747   inner = expr;
2748   while (1)
2749     {
2750       if (UNARY_CLASS_P (inner))
2751 	inner = TREE_OPERAND (inner, 0);
2752       else if (BINARY_CLASS_P (inner))
2753 	{
2754 	  if (tree_invariant_p (TREE_OPERAND (inner, 1)))
2755 	    inner = TREE_OPERAND (inner, 0);
2756 	  else if (tree_invariant_p (TREE_OPERAND (inner, 0)))
2757 	    inner = TREE_OPERAND (inner, 1);
2758 	  else
2759 	    break;
2760 	}
2761       else
2762 	break;
2763     }
2764 
2765   return inner;
2766 }
2767 
2768 
2769 /* Return which tree structure is used by T.  */
2770 
2771 enum tree_node_structure_enum
2772 tree_node_structure (const_tree t)
2773 {
2774   const enum tree_code code = TREE_CODE (t);
2775   return tree_node_structure_for_code (code);
2776 }
2777 
2778 /* Set various status flags when building a CALL_EXPR object T.  */
2779 
2780 static void
2781 process_call_operands (tree t)
2782 {
2783   bool side_effects = TREE_SIDE_EFFECTS (t);
2784   bool read_only = false;
2785   int i = call_expr_flags (t);
2786 
2787   /* Calls have side-effects, except those to const or pure functions.  */
2788   if ((i & ECF_LOOPING_CONST_OR_PURE) || !(i & (ECF_CONST | ECF_PURE)))
2789     side_effects = true;
2790   /* Propagate TREE_READONLY of arguments for const functions.  */
2791   if (i & ECF_CONST)
2792     read_only = true;
2793 
2794   if (!side_effects || read_only)
2795     for (i = 1; i < TREE_OPERAND_LENGTH (t); i++)
2796       {
2797 	tree op = TREE_OPERAND (t, i);
2798 	if (op && TREE_SIDE_EFFECTS (op))
2799 	  side_effects = true;
2800 	if (op && !TREE_READONLY (op) && !CONSTANT_CLASS_P (op))
2801 	  read_only = false;
2802       }
2803 
2804   TREE_SIDE_EFFECTS (t) = side_effects;
2805   TREE_READONLY (t) = read_only;
2806 }
2807 
2808 /* Return true if EXP contains a PLACEHOLDER_EXPR, i.e. if it represents a
2809    size or offset that depends on a field within a record.  */
2810 
2811 bool
2812 contains_placeholder_p (const_tree exp)
2813 {
2814   enum tree_code code;
2815 
2816   if (!exp)
2817     return 0;
2818 
2819   code = TREE_CODE (exp);
2820   if (code == PLACEHOLDER_EXPR)
2821     return 1;
2822 
2823   switch (TREE_CODE_CLASS (code))
2824     {
2825     case tcc_reference:
2826       /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2827 	 position computations since they will be converted into a
2828 	 WITH_RECORD_EXPR involving the reference, which will assume
2829 	 here will be valid.  */
2830       return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
2831 
2832     case tcc_exceptional:
2833       if (code == TREE_LIST)
2834 	return (CONTAINS_PLACEHOLDER_P (TREE_VALUE (exp))
2835 		|| CONTAINS_PLACEHOLDER_P (TREE_CHAIN (exp)));
2836       break;
2837 
2838     case tcc_unary:
2839     case tcc_binary:
2840     case tcc_comparison:
2841     case tcc_expression:
2842       switch (code)
2843 	{
2844 	case COMPOUND_EXPR:
2845 	  /* Ignoring the first operand isn't quite right, but works best.  */
2846 	  return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1));
2847 
2848 	case COND_EXPR:
2849 	  return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
2850 		  || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1))
2851 		  || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 2)));
2852 
2853 	case SAVE_EXPR:
2854 	  /* The save_expr function never wraps anything containing
2855 	     a PLACEHOLDER_EXPR. */
2856 	  return 0;
2857 
2858 	default:
2859 	  break;
2860 	}
2861 
2862       switch (TREE_CODE_LENGTH (code))
2863 	{
2864 	case 1:
2865 	  return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
2866 	case 2:
2867 	  return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
2868 		  || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1)));
2869 	default:
2870 	  return 0;
2871 	}
2872 
2873     case tcc_vl_exp:
2874       switch (code)
2875 	{
2876 	case CALL_EXPR:
2877 	  {
2878 	    const_tree arg;
2879 	    const_call_expr_arg_iterator iter;
2880 	    FOR_EACH_CONST_CALL_EXPR_ARG (arg, iter, exp)
2881 	      if (CONTAINS_PLACEHOLDER_P (arg))
2882 		return 1;
2883 	    return 0;
2884 	  }
2885 	default:
2886 	  return 0;
2887 	}
2888 
2889     default:
2890       return 0;
2891     }
2892   return 0;
2893 }
2894 
2895 /* Return true if any part of the structure of TYPE involves a PLACEHOLDER_EXPR
2896    directly.  This includes size, bounds, qualifiers (for QUAL_UNION_TYPE) and
2897    field positions.  */
2898 
2899 static bool
2900 type_contains_placeholder_1 (const_tree type)
2901 {
2902   /* If the size contains a placeholder or the parent type (component type in
2903      the case of arrays) type involves a placeholder, this type does.  */
2904   if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
2905       || CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (type))
2906       || (!POINTER_TYPE_P (type)
2907 	  && TREE_TYPE (type)
2908 	  && type_contains_placeholder_p (TREE_TYPE (type))))
2909     return true;
2910 
2911   /* Now do type-specific checks.  Note that the last part of the check above
2912      greatly limits what we have to do below.  */
2913   switch (TREE_CODE (type))
2914     {
2915     case VOID_TYPE:
2916     case COMPLEX_TYPE:
2917     case ENUMERAL_TYPE:
2918     case BOOLEAN_TYPE:
2919     case POINTER_TYPE:
2920     case OFFSET_TYPE:
2921     case REFERENCE_TYPE:
2922     case METHOD_TYPE:
2923     case FUNCTION_TYPE:
2924     case VECTOR_TYPE:
2925     case NULLPTR_TYPE:
2926       return false;
2927 
2928     case INTEGER_TYPE:
2929     case REAL_TYPE:
2930     case FIXED_POINT_TYPE:
2931       /* Here we just check the bounds.  */
2932       return (CONTAINS_PLACEHOLDER_P (TYPE_MIN_VALUE (type))
2933 	      || CONTAINS_PLACEHOLDER_P (TYPE_MAX_VALUE (type)));
2934 
2935     case ARRAY_TYPE:
2936       /* We have already checked the component type above, so just check the
2937 	 domain type.  */
2938       return type_contains_placeholder_p (TYPE_DOMAIN (type));
2939 
2940     case RECORD_TYPE:
2941     case UNION_TYPE:
2942     case QUAL_UNION_TYPE:
2943       {
2944 	tree field;
2945 
2946 	for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
2947 	  if (TREE_CODE (field) == FIELD_DECL
2948 	      && (CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (field))
2949 		  || (TREE_CODE (type) == QUAL_UNION_TYPE
2950 		      && CONTAINS_PLACEHOLDER_P (DECL_QUALIFIER (field)))
2951 		  || type_contains_placeholder_p (TREE_TYPE (field))))
2952 	    return true;
2953 
2954 	return false;
2955       }
2956 
2957     default:
2958       gcc_unreachable ();
2959     }
2960 }
2961 
2962 /* Wrapper around above function used to cache its result.  */
2963 
2964 bool
2965 type_contains_placeholder_p (tree type)
2966 {
2967   bool result;
2968 
2969   /* If the contains_placeholder_bits field has been initialized,
2970      then we know the answer.  */
2971   if (TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) > 0)
2972     return TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) - 1;
2973 
2974   /* Indicate that we've seen this type node, and the answer is false.
2975      This is what we want to return if we run into recursion via fields.  */
2976   TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = 1;
2977 
2978   /* Compute the real value.  */
2979   result = type_contains_placeholder_1 (type);
2980 
2981   /* Store the real value.  */
2982   TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = result + 1;
2983 
2984   return result;
2985 }
2986 
2987 /* Push tree EXP onto vector QUEUE if it is not already present.  */
2988 
2989 static void
2990 push_without_duplicates (tree exp, VEC (tree, heap) **queue)
2991 {
2992   unsigned int i;
2993   tree iter;
2994 
2995   FOR_EACH_VEC_ELT (tree, *queue, i, iter)
2996     if (simple_cst_equal (iter, exp) == 1)
2997       break;
2998 
2999   if (!iter)
3000     VEC_safe_push (tree, heap, *queue, exp);
3001 }
3002 
3003 /* Given a tree EXP, find all occurences of references to fields
3004    in a PLACEHOLDER_EXPR and place them in vector REFS without
3005    duplicates.  Also record VAR_DECLs and CONST_DECLs.  Note that
3006    we assume here that EXP contains only arithmetic expressions
3007    or CALL_EXPRs with PLACEHOLDER_EXPRs occurring only in their
3008    argument list.  */
3009 
3010 void
3011 find_placeholder_in_expr (tree exp, VEC (tree, heap) **refs)
3012 {
3013   enum tree_code code = TREE_CODE (exp);
3014   tree inner;
3015   int i;
3016 
3017   /* We handle TREE_LIST and COMPONENT_REF separately.  */
3018   if (code == TREE_LIST)
3019     {
3020       FIND_PLACEHOLDER_IN_EXPR (TREE_CHAIN (exp), refs);
3021       FIND_PLACEHOLDER_IN_EXPR (TREE_VALUE (exp), refs);
3022     }
3023   else if (code == COMPONENT_REF)
3024     {
3025       for (inner = TREE_OPERAND (exp, 0);
3026 	   REFERENCE_CLASS_P (inner);
3027 	   inner = TREE_OPERAND (inner, 0))
3028 	;
3029 
3030       if (TREE_CODE (inner) == PLACEHOLDER_EXPR)
3031 	push_without_duplicates (exp, refs);
3032       else
3033 	FIND_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), refs);
3034    }
3035   else
3036     switch (TREE_CODE_CLASS (code))
3037       {
3038       case tcc_constant:
3039 	break;
3040 
3041       case tcc_declaration:
3042 	/* Variables allocated to static storage can stay.  */
3043         if (!TREE_STATIC (exp))
3044 	  push_without_duplicates (exp, refs);
3045 	break;
3046 
3047       case tcc_expression:
3048 	/* This is the pattern built in ada/make_aligning_type.  */
3049 	if (code == ADDR_EXPR
3050 	    && TREE_CODE (TREE_OPERAND (exp, 0)) == PLACEHOLDER_EXPR)
3051 	  {
3052 	    push_without_duplicates (exp, refs);
3053 	    break;
3054 	  }
3055 
3056         /* Fall through...  */
3057 
3058       case tcc_exceptional:
3059       case tcc_unary:
3060       case tcc_binary:
3061       case tcc_comparison:
3062       case tcc_reference:
3063 	for (i = 0; i < TREE_CODE_LENGTH (code); i++)
3064 	  FIND_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, i), refs);
3065 	break;
3066 
3067       case tcc_vl_exp:
3068 	for (i = 1; i < TREE_OPERAND_LENGTH (exp); i++)
3069 	  FIND_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, i), refs);
3070 	break;
3071 
3072       default:
3073 	gcc_unreachable ();
3074       }
3075 }
3076 
3077 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
3078    return a tree with all occurrences of references to F in a
3079    PLACEHOLDER_EXPR replaced by R.  Also handle VAR_DECLs and
3080    CONST_DECLs.  Note that we assume here that EXP contains only
3081    arithmetic expressions or CALL_EXPRs with PLACEHOLDER_EXPRs
3082    occurring only in their argument list.  */
3083 
3084 tree
3085 substitute_in_expr (tree exp, tree f, tree r)
3086 {
3087   enum tree_code code = TREE_CODE (exp);
3088   tree op0, op1, op2, op3;
3089   tree new_tree;
3090 
3091   /* We handle TREE_LIST and COMPONENT_REF separately.  */
3092   if (code == TREE_LIST)
3093     {
3094       op0 = SUBSTITUTE_IN_EXPR (TREE_CHAIN (exp), f, r);
3095       op1 = SUBSTITUTE_IN_EXPR (TREE_VALUE (exp), f, r);
3096       if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
3097 	return exp;
3098 
3099       return tree_cons (TREE_PURPOSE (exp), op1, op0);
3100     }
3101   else if (code == COMPONENT_REF)
3102     {
3103       tree inner;
3104 
3105       /* If this expression is getting a value from a PLACEHOLDER_EXPR
3106 	 and it is the right field, replace it with R.  */
3107       for (inner = TREE_OPERAND (exp, 0);
3108 	   REFERENCE_CLASS_P (inner);
3109 	   inner = TREE_OPERAND (inner, 0))
3110 	;
3111 
3112       /* The field.  */
3113       op1 = TREE_OPERAND (exp, 1);
3114 
3115       if (TREE_CODE (inner) == PLACEHOLDER_EXPR && op1 == f)
3116 	return r;
3117 
3118       /* If this expression hasn't been completed let, leave it alone.  */
3119       if (TREE_CODE (inner) == PLACEHOLDER_EXPR && !TREE_TYPE (inner))
3120 	return exp;
3121 
3122       op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3123       if (op0 == TREE_OPERAND (exp, 0))
3124 	return exp;
3125 
3126       new_tree
3127 	= fold_build3 (COMPONENT_REF, TREE_TYPE (exp), op0, op1, NULL_TREE);
3128    }
3129   else
3130     switch (TREE_CODE_CLASS (code))
3131       {
3132       case tcc_constant:
3133 	return exp;
3134 
3135       case tcc_declaration:
3136 	if (exp == f)
3137 	  return r;
3138 	else
3139 	  return exp;
3140 
3141       case tcc_expression:
3142 	if (exp == f)
3143 	  return r;
3144 
3145         /* Fall through...  */
3146 
3147       case tcc_exceptional:
3148       case tcc_unary:
3149       case tcc_binary:
3150       case tcc_comparison:
3151       case tcc_reference:
3152 	switch (TREE_CODE_LENGTH (code))
3153 	  {
3154 	  case 0:
3155 	    return exp;
3156 
3157 	  case 1:
3158 	    op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3159 	    if (op0 == TREE_OPERAND (exp, 0))
3160 	      return exp;
3161 
3162 	    new_tree = fold_build1 (code, TREE_TYPE (exp), op0);
3163 	    break;
3164 
3165 	  case 2:
3166 	    op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3167 	    op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
3168 
3169 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
3170 	      return exp;
3171 
3172 	    new_tree = fold_build2 (code, TREE_TYPE (exp), op0, op1);
3173 	    break;
3174 
3175 	  case 3:
3176 	    op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3177 	    op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
3178 	    op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
3179 
3180 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3181 		&& op2 == TREE_OPERAND (exp, 2))
3182 	      return exp;
3183 
3184 	    new_tree = fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
3185 	    break;
3186 
3187 	  case 4:
3188 	    op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3189 	    op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
3190 	    op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
3191 	    op3 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 3), f, r);
3192 
3193 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3194 		&& op2 == TREE_OPERAND (exp, 2)
3195 		&& op3 == TREE_OPERAND (exp, 3))
3196 	      return exp;
3197 
3198 	    new_tree
3199 	      = fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
3200 	    break;
3201 
3202 	  default:
3203 	    gcc_unreachable ();
3204 	  }
3205 	break;
3206 
3207       case tcc_vl_exp:
3208 	{
3209 	  int i;
3210 
3211 	  new_tree = NULL_TREE;
3212 
3213 	  /* If we are trying to replace F with a constant, inline back
3214 	     functions which do nothing else than computing a value from
3215 	     the arguments they are passed.  This makes it possible to
3216 	     fold partially or entirely the replacement expression.  */
3217 	  if (CONSTANT_CLASS_P (r) && code == CALL_EXPR)
3218 	    {
3219 	      tree t = maybe_inline_call_in_expr (exp);
3220 	      if (t)
3221 		return SUBSTITUTE_IN_EXPR (t, f, r);
3222 	    }
3223 
3224 	  for (i = 1; i < TREE_OPERAND_LENGTH (exp); i++)
3225 	    {
3226 	      tree op = TREE_OPERAND (exp, i);
3227 	      tree new_op = SUBSTITUTE_IN_EXPR (op, f, r);
3228 	      if (new_op != op)
3229 		{
3230 		  if (!new_tree)
3231 		    new_tree = copy_node (exp);
3232 		  TREE_OPERAND (new_tree, i) = new_op;
3233 		}
3234 	    }
3235 
3236 	  if (new_tree)
3237 	    {
3238 	      new_tree = fold (new_tree);
3239 	      if (TREE_CODE (new_tree) == CALL_EXPR)
3240 		process_call_operands (new_tree);
3241 	    }
3242 	  else
3243 	    return exp;
3244 	}
3245 	break;
3246 
3247       default:
3248 	gcc_unreachable ();
3249       }
3250 
3251   TREE_READONLY (new_tree) |= TREE_READONLY (exp);
3252 
3253   if (code == INDIRECT_REF || code == ARRAY_REF || code == ARRAY_RANGE_REF)
3254     TREE_THIS_NOTRAP (new_tree) |= TREE_THIS_NOTRAP (exp);
3255 
3256   return new_tree;
3257 }
3258 
3259 /* Similar, but look for a PLACEHOLDER_EXPR in EXP and find a replacement
3260    for it within OBJ, a tree that is an object or a chain of references.  */
3261 
3262 tree
3263 substitute_placeholder_in_expr (tree exp, tree obj)
3264 {
3265   enum tree_code code = TREE_CODE (exp);
3266   tree op0, op1, op2, op3;
3267   tree new_tree;
3268 
3269   /* If this is a PLACEHOLDER_EXPR, see if we find a corresponding type
3270      in the chain of OBJ.  */
3271   if (code == PLACEHOLDER_EXPR)
3272     {
3273       tree need_type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
3274       tree elt;
3275 
3276       for (elt = obj; elt != 0;
3277 	   elt = ((TREE_CODE (elt) == COMPOUND_EXPR
3278 		   || TREE_CODE (elt) == COND_EXPR)
3279 		  ? TREE_OPERAND (elt, 1)
3280 		  : (REFERENCE_CLASS_P (elt)
3281 		     || UNARY_CLASS_P (elt)
3282 		     || BINARY_CLASS_P (elt)
3283 		     || VL_EXP_CLASS_P (elt)
3284 		     || EXPRESSION_CLASS_P (elt))
3285 		  ? TREE_OPERAND (elt, 0) : 0))
3286 	if (TYPE_MAIN_VARIANT (TREE_TYPE (elt)) == need_type)
3287 	  return elt;
3288 
3289       for (elt = obj; elt != 0;
3290 	   elt = ((TREE_CODE (elt) == COMPOUND_EXPR
3291 		   || TREE_CODE (elt) == COND_EXPR)
3292 		  ? TREE_OPERAND (elt, 1)
3293 		  : (REFERENCE_CLASS_P (elt)
3294 		     || UNARY_CLASS_P (elt)
3295 		     || BINARY_CLASS_P (elt)
3296 		     || VL_EXP_CLASS_P (elt)
3297 		     || EXPRESSION_CLASS_P (elt))
3298 		  ? TREE_OPERAND (elt, 0) : 0))
3299 	if (POINTER_TYPE_P (TREE_TYPE (elt))
3300 	    && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (elt)))
3301 		== need_type))
3302 	  return fold_build1 (INDIRECT_REF, need_type, elt);
3303 
3304       /* If we didn't find it, return the original PLACEHOLDER_EXPR.  If it
3305 	 survives until RTL generation, there will be an error.  */
3306       return exp;
3307     }
3308 
3309   /* TREE_LIST is special because we need to look at TREE_VALUE
3310      and TREE_CHAIN, not TREE_OPERANDS.  */
3311   else if (code == TREE_LIST)
3312     {
3313       op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_CHAIN (exp), obj);
3314       op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_VALUE (exp), obj);
3315       if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
3316 	return exp;
3317 
3318       return tree_cons (TREE_PURPOSE (exp), op1, op0);
3319     }
3320   else
3321     switch (TREE_CODE_CLASS (code))
3322       {
3323       case tcc_constant:
3324       case tcc_declaration:
3325 	return exp;
3326 
3327       case tcc_exceptional:
3328       case tcc_unary:
3329       case tcc_binary:
3330       case tcc_comparison:
3331       case tcc_expression:
3332       case tcc_reference:
3333       case tcc_statement:
3334 	switch (TREE_CODE_LENGTH (code))
3335 	  {
3336 	  case 0:
3337 	    return exp;
3338 
3339 	  case 1:
3340 	    op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
3341 	    if (op0 == TREE_OPERAND (exp, 0))
3342 	      return exp;
3343 
3344 	    new_tree = fold_build1 (code, TREE_TYPE (exp), op0);
3345 	    break;
3346 
3347 	  case 2:
3348 	    op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
3349 	    op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
3350 
3351 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
3352 	      return exp;
3353 
3354 	    new_tree = fold_build2 (code, TREE_TYPE (exp), op0, op1);
3355 	    break;
3356 
3357 	  case 3:
3358 	    op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
3359 	    op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
3360 	    op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
3361 
3362 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3363 		&& op2 == TREE_OPERAND (exp, 2))
3364 	      return exp;
3365 
3366 	    new_tree = fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
3367 	    break;
3368 
3369 	  case 4:
3370 	    op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
3371 	    op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
3372 	    op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
3373 	    op3 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 3), obj);
3374 
3375 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3376 		&& op2 == TREE_OPERAND (exp, 2)
3377 		&& op3 == TREE_OPERAND (exp, 3))
3378 	      return exp;
3379 
3380 	    new_tree
3381 	      = fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
3382 	    break;
3383 
3384 	  default:
3385 	    gcc_unreachable ();
3386 	  }
3387 	break;
3388 
3389       case tcc_vl_exp:
3390 	{
3391 	  int i;
3392 
3393 	  new_tree = NULL_TREE;
3394 
3395 	  for (i = 1; i < TREE_OPERAND_LENGTH (exp); i++)
3396 	    {
3397 	      tree op = TREE_OPERAND (exp, i);
3398 	      tree new_op = SUBSTITUTE_PLACEHOLDER_IN_EXPR (op, obj);
3399 	      if (new_op != op)
3400 		{
3401 		  if (!new_tree)
3402 		    new_tree = copy_node (exp);
3403 		  TREE_OPERAND (new_tree, i) = new_op;
3404 		}
3405 	    }
3406 
3407 	  if (new_tree)
3408 	    {
3409 	      new_tree = fold (new_tree);
3410 	      if (TREE_CODE (new_tree) == CALL_EXPR)
3411 		process_call_operands (new_tree);
3412 	    }
3413 	  else
3414 	    return exp;
3415 	}
3416 	break;
3417 
3418       default:
3419 	gcc_unreachable ();
3420       }
3421 
3422   TREE_READONLY (new_tree) |= TREE_READONLY (exp);
3423 
3424   if (code == INDIRECT_REF || code == ARRAY_REF || code == ARRAY_RANGE_REF)
3425     TREE_THIS_NOTRAP (new_tree) |= TREE_THIS_NOTRAP (exp);
3426 
3427   return new_tree;
3428 }
3429 
3430 /* Stabilize a reference so that we can use it any number of times
3431    without causing its operands to be evaluated more than once.
3432    Returns the stabilized reference.  This works by means of save_expr,
3433    so see the caveats in the comments about save_expr.
3434 
3435    Also allows conversion expressions whose operands are references.
3436    Any other kind of expression is returned unchanged.  */
3437 
3438 tree
3439 stabilize_reference (tree ref)
3440 {
3441   tree result;
3442   enum tree_code code = TREE_CODE (ref);
3443 
3444   switch (code)
3445     {
3446     case VAR_DECL:
3447     case PARM_DECL:
3448     case RESULT_DECL:
3449       /* No action is needed in this case.  */
3450       return ref;
3451 
3452     CASE_CONVERT:
3453     case FLOAT_EXPR:
3454     case FIX_TRUNC_EXPR:
3455       result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
3456       break;
3457 
3458     case INDIRECT_REF:
3459       result = build_nt (INDIRECT_REF,
3460 			 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
3461       break;
3462 
3463     case COMPONENT_REF:
3464       result = build_nt (COMPONENT_REF,
3465 			 stabilize_reference (TREE_OPERAND (ref, 0)),
3466 			 TREE_OPERAND (ref, 1), NULL_TREE);
3467       break;
3468 
3469     case BIT_FIELD_REF:
3470       result = build_nt (BIT_FIELD_REF,
3471 			 stabilize_reference (TREE_OPERAND (ref, 0)),
3472 			 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
3473 			 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
3474       break;
3475 
3476     case ARRAY_REF:
3477       result = build_nt (ARRAY_REF,
3478 			 stabilize_reference (TREE_OPERAND (ref, 0)),
3479 			 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
3480 			 TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
3481       break;
3482 
3483     case ARRAY_RANGE_REF:
3484       result = build_nt (ARRAY_RANGE_REF,
3485 			 stabilize_reference (TREE_OPERAND (ref, 0)),
3486 			 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
3487 			 TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
3488       break;
3489 
3490     case COMPOUND_EXPR:
3491       /* We cannot wrap the first expression in a SAVE_EXPR, as then
3492 	 it wouldn't be ignored.  This matters when dealing with
3493 	 volatiles.  */
3494       return stabilize_reference_1 (ref);
3495 
3496       /* If arg isn't a kind of lvalue we recognize, make no change.
3497 	 Caller should recognize the error for an invalid lvalue.  */
3498     default:
3499       return ref;
3500 
3501     case ERROR_MARK:
3502       return error_mark_node;
3503     }
3504 
3505   TREE_TYPE (result) = TREE_TYPE (ref);
3506   TREE_READONLY (result) = TREE_READONLY (ref);
3507   TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
3508   TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
3509 
3510   return result;
3511 }
3512 
3513 /* Subroutine of stabilize_reference; this is called for subtrees of
3514    references.  Any expression with side-effects must be put in a SAVE_EXPR
3515    to ensure that it is only evaluated once.
3516 
3517    We don't put SAVE_EXPR nodes around everything, because assigning very
3518    simple expressions to temporaries causes us to miss good opportunities
3519    for optimizations.  Among other things, the opportunity to fold in the
3520    addition of a constant into an addressing mode often gets lost, e.g.
3521    "y[i+1] += x;".  In general, we take the approach that we should not make
3522    an assignment unless we are forced into it - i.e., that any non-side effect
3523    operator should be allowed, and that cse should take care of coalescing
3524    multiple utterances of the same expression should that prove fruitful.  */
3525 
3526 tree
3527 stabilize_reference_1 (tree e)
3528 {
3529   tree result;
3530   enum tree_code code = TREE_CODE (e);
3531 
3532   /* We cannot ignore const expressions because it might be a reference
3533      to a const array but whose index contains side-effects.  But we can
3534      ignore things that are actual constant or that already have been
3535      handled by this function.  */
3536 
3537   if (tree_invariant_p (e))
3538     return e;
3539 
3540   switch (TREE_CODE_CLASS (code))
3541     {
3542     case tcc_exceptional:
3543     case tcc_type:
3544     case tcc_declaration:
3545     case tcc_comparison:
3546     case tcc_statement:
3547     case tcc_expression:
3548     case tcc_reference:
3549     case tcc_vl_exp:
3550       /* If the expression has side-effects, then encase it in a SAVE_EXPR
3551 	 so that it will only be evaluated once.  */
3552       /* The reference (r) and comparison (<) classes could be handled as
3553 	 below, but it is generally faster to only evaluate them once.  */
3554       if (TREE_SIDE_EFFECTS (e))
3555 	return save_expr (e);
3556       return e;
3557 
3558     case tcc_constant:
3559       /* Constants need no processing.  In fact, we should never reach
3560 	 here.  */
3561       return e;
3562 
3563     case tcc_binary:
3564       /* Division is slow and tends to be compiled with jumps,
3565 	 especially the division by powers of 2 that is often
3566 	 found inside of an array reference.  So do it just once.  */
3567       if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
3568 	  || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
3569 	  || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
3570 	  || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
3571 	return save_expr (e);
3572       /* Recursively stabilize each operand.  */
3573       result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
3574 			 stabilize_reference_1 (TREE_OPERAND (e, 1)));
3575       break;
3576 
3577     case tcc_unary:
3578       /* Recursively stabilize each operand.  */
3579       result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
3580       break;
3581 
3582     default:
3583       gcc_unreachable ();
3584     }
3585 
3586   TREE_TYPE (result) = TREE_TYPE (e);
3587   TREE_READONLY (result) = TREE_READONLY (e);
3588   TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
3589   TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
3590 
3591   return result;
3592 }
3593 
3594 /* Low-level constructors for expressions.  */
3595 
3596 /* A helper function for build1 and constant folders.  Set TREE_CONSTANT,
3597    and TREE_SIDE_EFFECTS for an ADDR_EXPR.  */
3598 
3599 void
3600 recompute_tree_invariant_for_addr_expr (tree t)
3601 {
3602   tree node;
3603   bool tc = true, se = false;
3604 
3605   /* We started out assuming this address is both invariant and constant, but
3606      does not have side effects.  Now go down any handled components and see if
3607      any of them involve offsets that are either non-constant or non-invariant.
3608      Also check for side-effects.
3609 
3610      ??? Note that this code makes no attempt to deal with the case where
3611      taking the address of something causes a copy due to misalignment.  */
3612 
3613 #define UPDATE_FLAGS(NODE)  \
3614 do { tree _node = (NODE); \
3615      if (_node && !TREE_CONSTANT (_node)) tc = false; \
3616      if (_node && TREE_SIDE_EFFECTS (_node)) se = true; } while (0)
3617 
3618   for (node = TREE_OPERAND (t, 0); handled_component_p (node);
3619        node = TREE_OPERAND (node, 0))
3620     {
3621       /* If the first operand doesn't have an ARRAY_TYPE, this is a bogus
3622 	 array reference (probably made temporarily by the G++ front end),
3623 	 so ignore all the operands.  */
3624       if ((TREE_CODE (node) == ARRAY_REF
3625 	   || TREE_CODE (node) == ARRAY_RANGE_REF)
3626 	  && TREE_CODE (TREE_TYPE (TREE_OPERAND (node, 0))) == ARRAY_TYPE)
3627 	{
3628 	  UPDATE_FLAGS (TREE_OPERAND (node, 1));
3629 	  if (TREE_OPERAND (node, 2))
3630 	    UPDATE_FLAGS (TREE_OPERAND (node, 2));
3631 	  if (TREE_OPERAND (node, 3))
3632 	    UPDATE_FLAGS (TREE_OPERAND (node, 3));
3633 	}
3634       /* Likewise, just because this is a COMPONENT_REF doesn't mean we have a
3635 	 FIELD_DECL, apparently.  The G++ front end can put something else
3636 	 there, at least temporarily.  */
3637       else if (TREE_CODE (node) == COMPONENT_REF
3638 	       && TREE_CODE (TREE_OPERAND (node, 1)) == FIELD_DECL)
3639 	{
3640 	  if (TREE_OPERAND (node, 2))
3641 	    UPDATE_FLAGS (TREE_OPERAND (node, 2));
3642 	}
3643       else if (TREE_CODE (node) == BIT_FIELD_REF)
3644 	UPDATE_FLAGS (TREE_OPERAND (node, 2));
3645     }
3646 
3647   node = lang_hooks.expr_to_decl (node, &tc, &se);
3648 
3649   /* Now see what's inside.  If it's an INDIRECT_REF, copy our properties from
3650      the address, since &(*a)->b is a form of addition.  If it's a constant, the
3651      address is constant too.  If it's a decl, its address is constant if the
3652      decl is static.  Everything else is not constant and, furthermore,
3653      taking the address of a volatile variable is not volatile.  */
3654   if (TREE_CODE (node) == INDIRECT_REF
3655       || TREE_CODE (node) == MEM_REF)
3656     UPDATE_FLAGS (TREE_OPERAND (node, 0));
3657   else if (CONSTANT_CLASS_P (node))
3658     ;
3659   else if (DECL_P (node))
3660     tc &= (staticp (node) != NULL_TREE);
3661   else
3662     {
3663       tc = false;
3664       se |= TREE_SIDE_EFFECTS (node);
3665     }
3666 
3667 
3668   TREE_CONSTANT (t) = tc;
3669   TREE_SIDE_EFFECTS (t) = se;
3670 #undef UPDATE_FLAGS
3671 }
3672 
3673 /* Build an expression of code CODE, data type TYPE, and operands as
3674    specified.  Expressions and reference nodes can be created this way.
3675    Constants, decls, types and misc nodes cannot be.
3676 
3677    We define 5 non-variadic functions, from 0 to 4 arguments.  This is
3678    enough for all extant tree codes.  */
3679 
3680 tree
3681 build0_stat (enum tree_code code, tree tt MEM_STAT_DECL)
3682 {
3683   tree t;
3684 
3685   gcc_assert (TREE_CODE_LENGTH (code) == 0);
3686 
3687   t = make_node_stat (code PASS_MEM_STAT);
3688   TREE_TYPE (t) = tt;
3689 
3690   return t;
3691 }
3692 
3693 tree
3694 build1_stat (enum tree_code code, tree type, tree node MEM_STAT_DECL)
3695 {
3696   int length = sizeof (struct tree_exp);
3697   tree t;
3698 
3699   record_node_allocation_statistics (code, length);
3700 
3701   gcc_assert (TREE_CODE_LENGTH (code) == 1);
3702 
3703   t = ggc_alloc_zone_tree_node_stat (&tree_zone, length PASS_MEM_STAT);
3704 
3705   memset (t, 0, sizeof (struct tree_common));
3706 
3707   TREE_SET_CODE (t, code);
3708 
3709   TREE_TYPE (t) = type;
3710   SET_EXPR_LOCATION (t, UNKNOWN_LOCATION);
3711   TREE_OPERAND (t, 0) = node;
3712   TREE_BLOCK (t) = NULL_TREE;
3713   if (node && !TYPE_P (node))
3714     {
3715       TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (node);
3716       TREE_READONLY (t) = TREE_READONLY (node);
3717     }
3718 
3719   if (TREE_CODE_CLASS (code) == tcc_statement)
3720     TREE_SIDE_EFFECTS (t) = 1;
3721   else switch (code)
3722     {
3723     case VA_ARG_EXPR:
3724       /* All of these have side-effects, no matter what their
3725 	 operands are.  */
3726       TREE_SIDE_EFFECTS (t) = 1;
3727       TREE_READONLY (t) = 0;
3728       break;
3729 
3730     case INDIRECT_REF:
3731       /* Whether a dereference is readonly has nothing to do with whether
3732 	 its operand is readonly.  */
3733       TREE_READONLY (t) = 0;
3734       break;
3735 
3736     case ADDR_EXPR:
3737       if (node)
3738 	recompute_tree_invariant_for_addr_expr (t);
3739       break;
3740 
3741     default:
3742       if ((TREE_CODE_CLASS (code) == tcc_unary || code == VIEW_CONVERT_EXPR)
3743 	  && node && !TYPE_P (node)
3744 	  && TREE_CONSTANT (node))
3745 	TREE_CONSTANT (t) = 1;
3746       if (TREE_CODE_CLASS (code) == tcc_reference
3747 	  && node && TREE_THIS_VOLATILE (node))
3748 	TREE_THIS_VOLATILE (t) = 1;
3749       break;
3750     }
3751 
3752   return t;
3753 }
3754 
3755 #define PROCESS_ARG(N)				\
3756   do {						\
3757     TREE_OPERAND (t, N) = arg##N;		\
3758     if (arg##N &&!TYPE_P (arg##N))		\
3759       {						\
3760         if (TREE_SIDE_EFFECTS (arg##N))		\
3761 	  side_effects = 1;			\
3762         if (!TREE_READONLY (arg##N)		\
3763 	    && !CONSTANT_CLASS_P (arg##N))	\
3764 	  (void) (read_only = 0);		\
3765         if (!TREE_CONSTANT (arg##N))		\
3766 	  (void) (constant = 0);		\
3767       }						\
3768   } while (0)
3769 
3770 tree
3771 build2_stat (enum tree_code code, tree tt, tree arg0, tree arg1 MEM_STAT_DECL)
3772 {
3773   bool constant, read_only, side_effects;
3774   tree t;
3775 
3776   gcc_assert (TREE_CODE_LENGTH (code) == 2);
3777 
3778   if ((code == MINUS_EXPR || code == PLUS_EXPR || code == MULT_EXPR)
3779       && arg0 && arg1 && tt && POINTER_TYPE_P (tt)
3780       /* When sizetype precision doesn't match that of pointers
3781          we need to be able to build explicit extensions or truncations
3782 	 of the offset argument.  */
3783       && TYPE_PRECISION (sizetype) == TYPE_PRECISION (tt))
3784     gcc_assert (TREE_CODE (arg0) == INTEGER_CST
3785 		&& TREE_CODE (arg1) == INTEGER_CST);
3786 
3787   if (code == POINTER_PLUS_EXPR && arg0 && arg1 && tt)
3788     gcc_assert (POINTER_TYPE_P (tt) && POINTER_TYPE_P (TREE_TYPE (arg0))
3789 		&& ptrofftype_p (TREE_TYPE (arg1)));
3790 
3791   t = make_node_stat (code PASS_MEM_STAT);
3792   TREE_TYPE (t) = tt;
3793 
3794   /* Below, we automatically set TREE_SIDE_EFFECTS and TREE_READONLY for the
3795      result based on those same flags for the arguments.  But if the
3796      arguments aren't really even `tree' expressions, we shouldn't be trying
3797      to do this.  */
3798 
3799   /* Expressions without side effects may be constant if their
3800      arguments are as well.  */
3801   constant = (TREE_CODE_CLASS (code) == tcc_comparison
3802 	      || TREE_CODE_CLASS (code) == tcc_binary);
3803   read_only = 1;
3804   side_effects = TREE_SIDE_EFFECTS (t);
3805 
3806   PROCESS_ARG(0);
3807   PROCESS_ARG(1);
3808 
3809   TREE_READONLY (t) = read_only;
3810   TREE_CONSTANT (t) = constant;
3811   TREE_SIDE_EFFECTS (t) = side_effects;
3812   TREE_THIS_VOLATILE (t)
3813     = (TREE_CODE_CLASS (code) == tcc_reference
3814        && arg0 && TREE_THIS_VOLATILE (arg0));
3815 
3816   return t;
3817 }
3818 
3819 
3820 tree
3821 build3_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3822 	     tree arg2 MEM_STAT_DECL)
3823 {
3824   bool constant, read_only, side_effects;
3825   tree t;
3826 
3827   gcc_assert (TREE_CODE_LENGTH (code) == 3);
3828   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
3829 
3830   t = make_node_stat (code PASS_MEM_STAT);
3831   TREE_TYPE (t) = tt;
3832 
3833   read_only = 1;
3834 
3835   /* As a special exception, if COND_EXPR has NULL branches, we
3836      assume that it is a gimple statement and always consider
3837      it to have side effects.  */
3838   if (code == COND_EXPR
3839       && tt == void_type_node
3840       && arg1 == NULL_TREE
3841       && arg2 == NULL_TREE)
3842     side_effects = true;
3843   else
3844     side_effects = TREE_SIDE_EFFECTS (t);
3845 
3846   PROCESS_ARG(0);
3847   PROCESS_ARG(1);
3848   PROCESS_ARG(2);
3849 
3850   if (code == COND_EXPR)
3851     TREE_READONLY (t) = read_only;
3852 
3853   TREE_SIDE_EFFECTS (t) = side_effects;
3854   TREE_THIS_VOLATILE (t)
3855     = (TREE_CODE_CLASS (code) == tcc_reference
3856        && arg0 && TREE_THIS_VOLATILE (arg0));
3857 
3858   return t;
3859 }
3860 
3861 tree
3862 build4_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3863 	     tree arg2, tree arg3 MEM_STAT_DECL)
3864 {
3865   bool constant, read_only, side_effects;
3866   tree t;
3867 
3868   gcc_assert (TREE_CODE_LENGTH (code) == 4);
3869 
3870   t = make_node_stat (code PASS_MEM_STAT);
3871   TREE_TYPE (t) = tt;
3872 
3873   side_effects = TREE_SIDE_EFFECTS (t);
3874 
3875   PROCESS_ARG(0);
3876   PROCESS_ARG(1);
3877   PROCESS_ARG(2);
3878   PROCESS_ARG(3);
3879 
3880   TREE_SIDE_EFFECTS (t) = side_effects;
3881   TREE_THIS_VOLATILE (t)
3882     = (TREE_CODE_CLASS (code) == tcc_reference
3883        && arg0 && TREE_THIS_VOLATILE (arg0));
3884 
3885   return t;
3886 }
3887 
3888 tree
3889 build5_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3890 	     tree arg2, tree arg3, tree arg4 MEM_STAT_DECL)
3891 {
3892   bool constant, read_only, side_effects;
3893   tree t;
3894 
3895   gcc_assert (TREE_CODE_LENGTH (code) == 5);
3896 
3897   t = make_node_stat (code PASS_MEM_STAT);
3898   TREE_TYPE (t) = tt;
3899 
3900   side_effects = TREE_SIDE_EFFECTS (t);
3901 
3902   PROCESS_ARG(0);
3903   PROCESS_ARG(1);
3904   PROCESS_ARG(2);
3905   PROCESS_ARG(3);
3906   PROCESS_ARG(4);
3907 
3908   TREE_SIDE_EFFECTS (t) = side_effects;
3909   TREE_THIS_VOLATILE (t)
3910     = (TREE_CODE_CLASS (code) == tcc_reference
3911        && arg0 && TREE_THIS_VOLATILE (arg0));
3912 
3913   return t;
3914 }
3915 
3916 tree
3917 build6_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3918 	     tree arg2, tree arg3, tree arg4, tree arg5 MEM_STAT_DECL)
3919 {
3920   bool constant, read_only, side_effects;
3921   tree t;
3922 
3923   gcc_assert (code == TARGET_MEM_REF);
3924 
3925   t = make_node_stat (code PASS_MEM_STAT);
3926   TREE_TYPE (t) = tt;
3927 
3928   side_effects = TREE_SIDE_EFFECTS (t);
3929 
3930   PROCESS_ARG(0);
3931   PROCESS_ARG(1);
3932   PROCESS_ARG(2);
3933   PROCESS_ARG(3);
3934   PROCESS_ARG(4);
3935   if (code == TARGET_MEM_REF)
3936     side_effects = 0;
3937   PROCESS_ARG(5);
3938 
3939   TREE_SIDE_EFFECTS (t) = side_effects;
3940   TREE_THIS_VOLATILE (t)
3941     = (code == TARGET_MEM_REF
3942        && arg5 && TREE_THIS_VOLATILE (arg5));
3943 
3944   return t;
3945 }
3946 
3947 /* Build a simple MEM_REF tree with the sematics of a plain INDIRECT_REF
3948    on the pointer PTR.  */
3949 
3950 tree
3951 build_simple_mem_ref_loc (location_t loc, tree ptr)
3952 {
3953   HOST_WIDE_INT offset = 0;
3954   tree ptype = TREE_TYPE (ptr);
3955   tree tem;
3956   /* For convenience allow addresses that collapse to a simple base
3957      and offset.  */
3958   if (TREE_CODE (ptr) == ADDR_EXPR
3959       && (handled_component_p (TREE_OPERAND (ptr, 0))
3960 	  || TREE_CODE (TREE_OPERAND (ptr, 0)) == MEM_REF))
3961     {
3962       ptr = get_addr_base_and_unit_offset (TREE_OPERAND (ptr, 0), &offset);
3963       gcc_assert (ptr);
3964       ptr = build_fold_addr_expr (ptr);
3965       gcc_assert (is_gimple_reg (ptr) || is_gimple_min_invariant (ptr));
3966     }
3967   tem = build2 (MEM_REF, TREE_TYPE (ptype),
3968 		ptr, build_int_cst (ptype, offset));
3969   SET_EXPR_LOCATION (tem, loc);
3970   return tem;
3971 }
3972 
3973 /* Return the constant offset of a MEM_REF or TARGET_MEM_REF tree T.  */
3974 
3975 double_int
3976 mem_ref_offset (const_tree t)
3977 {
3978   tree toff = TREE_OPERAND (t, 1);
3979   return double_int_sext (tree_to_double_int (toff),
3980 			  TYPE_PRECISION (TREE_TYPE (toff)));
3981 }
3982 
3983 /* Return the pointer-type relevant for TBAA purposes from the
3984    gimple memory reference tree T.  This is the type to be used for
3985    the offset operand of MEM_REF or TARGET_MEM_REF replacements of T.  */
3986 
3987 tree
3988 reference_alias_ptr_type (const_tree t)
3989 {
3990   const_tree base = t;
3991   while (handled_component_p (base))
3992     base = TREE_OPERAND (base, 0);
3993   if (TREE_CODE (base) == MEM_REF)
3994     return TREE_TYPE (TREE_OPERAND (base, 1));
3995   else if (TREE_CODE (base) == TARGET_MEM_REF)
3996     return TREE_TYPE (TMR_OFFSET (base));
3997   else
3998     return build_pointer_type (TYPE_MAIN_VARIANT (TREE_TYPE (base)));
3999 }
4000 
4001 /* Return an invariant ADDR_EXPR of type TYPE taking the address of BASE
4002    offsetted by OFFSET units.  */
4003 
4004 tree
4005 build_invariant_address (tree type, tree base, HOST_WIDE_INT offset)
4006 {
4007   tree ref = fold_build2 (MEM_REF, TREE_TYPE (type),
4008 			  build_fold_addr_expr (base),
4009 			  build_int_cst (ptr_type_node, offset));
4010   tree addr = build1 (ADDR_EXPR, type, ref);
4011   recompute_tree_invariant_for_addr_expr (addr);
4012   return addr;
4013 }
4014 
4015 /* Similar except don't specify the TREE_TYPE
4016    and leave the TREE_SIDE_EFFECTS as 0.
4017    It is permissible for arguments to be null,
4018    or even garbage if their values do not matter.  */
4019 
4020 tree
4021 build_nt (enum tree_code code, ...)
4022 {
4023   tree t;
4024   int length;
4025   int i;
4026   va_list p;
4027 
4028   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
4029 
4030   va_start (p, code);
4031 
4032   t = make_node (code);
4033   length = TREE_CODE_LENGTH (code);
4034 
4035   for (i = 0; i < length; i++)
4036     TREE_OPERAND (t, i) = va_arg (p, tree);
4037 
4038   va_end (p);
4039   return t;
4040 }
4041 
4042 /* Similar to build_nt, but for creating a CALL_EXPR object with a
4043    tree VEC.  */
4044 
4045 tree
4046 build_nt_call_vec (tree fn, VEC(tree,gc) *args)
4047 {
4048   tree ret, t;
4049   unsigned int ix;
4050 
4051   ret = build_vl_exp (CALL_EXPR, VEC_length (tree, args) + 3);
4052   CALL_EXPR_FN (ret) = fn;
4053   CALL_EXPR_STATIC_CHAIN (ret) = NULL_TREE;
4054   FOR_EACH_VEC_ELT (tree, args, ix, t)
4055     CALL_EXPR_ARG (ret, ix) = t;
4056   return ret;
4057 }
4058 
4059 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
4060    We do NOT enter this node in any sort of symbol table.
4061 
4062    LOC is the location of the decl.
4063 
4064    layout_decl is used to set up the decl's storage layout.
4065    Other slots are initialized to 0 or null pointers.  */
4066 
4067 tree
4068 build_decl_stat (location_t loc, enum tree_code code, tree name,
4069     		 tree type MEM_STAT_DECL)
4070 {
4071   tree t;
4072 
4073   t = make_node_stat (code PASS_MEM_STAT);
4074   DECL_SOURCE_LOCATION (t) = loc;
4075 
4076 /*  if (type == error_mark_node)
4077     type = integer_type_node; */
4078 /* That is not done, deliberately, so that having error_mark_node
4079    as the type can suppress useless errors in the use of this variable.  */
4080 
4081   DECL_NAME (t) = name;
4082   TREE_TYPE (t) = type;
4083 
4084   if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
4085     layout_decl (t, 0);
4086 
4087   return t;
4088 }
4089 
4090 /* Builds and returns function declaration with NAME and TYPE.  */
4091 
4092 tree
4093 build_fn_decl (const char *name, tree type)
4094 {
4095   tree id = get_identifier (name);
4096   tree decl = build_decl (input_location, FUNCTION_DECL, id, type);
4097 
4098   DECL_EXTERNAL (decl) = 1;
4099   TREE_PUBLIC (decl) = 1;
4100   DECL_ARTIFICIAL (decl) = 1;
4101   TREE_NOTHROW (decl) = 1;
4102 
4103   return decl;
4104 }
4105 
4106 VEC(tree,gc) *all_translation_units;
4107 
4108 /* Builds a new translation-unit decl with name NAME, queues it in the
4109    global list of translation-unit decls and returns it.   */
4110 
4111 tree
4112 build_translation_unit_decl (tree name)
4113 {
4114   tree tu = build_decl (UNKNOWN_LOCATION, TRANSLATION_UNIT_DECL,
4115 			name, NULL_TREE);
4116   TRANSLATION_UNIT_LANGUAGE (tu) = lang_hooks.name;
4117   VEC_safe_push (tree, gc, all_translation_units, tu);
4118   return tu;
4119 }
4120 
4121 
4122 /* BLOCK nodes are used to represent the structure of binding contours
4123    and declarations, once those contours have been exited and their contents
4124    compiled.  This information is used for outputting debugging info.  */
4125 
4126 tree
4127 build_block (tree vars, tree subblocks, tree supercontext, tree chain)
4128 {
4129   tree block = make_node (BLOCK);
4130 
4131   BLOCK_VARS (block) = vars;
4132   BLOCK_SUBBLOCKS (block) = subblocks;
4133   BLOCK_SUPERCONTEXT (block) = supercontext;
4134   BLOCK_CHAIN (block) = chain;
4135   return block;
4136 }
4137 
4138 
4139 /* Like SET_EXPR_LOCATION, but make sure the tree can have a location.
4140 
4141    LOC is the location to use in tree T.  */
4142 
4143 void
4144 protected_set_expr_location (tree t, location_t loc)
4145 {
4146   if (t && CAN_HAVE_LOCATION_P (t))
4147     SET_EXPR_LOCATION (t, loc);
4148 }
4149 
4150 /* Return a declaration like DDECL except that its DECL_ATTRIBUTES
4151    is ATTRIBUTE.  */
4152 
4153 tree
4154 build_decl_attribute_variant (tree ddecl, tree attribute)
4155 {
4156   DECL_ATTRIBUTES (ddecl) = attribute;
4157   return ddecl;
4158 }
4159 
4160 /* Borrowed from hashtab.c iterative_hash implementation.  */
4161 #define mix(a,b,c) \
4162 { \
4163   a -= b; a -= c; a ^= (c>>13); \
4164   b -= c; b -= a; b ^= (a<< 8); \
4165   c -= a; c -= b; c ^= ((b&0xffffffff)>>13); \
4166   a -= b; a -= c; a ^= ((c&0xffffffff)>>12); \
4167   b -= c; b -= a; b = (b ^ (a<<16)) & 0xffffffff; \
4168   c -= a; c -= b; c = (c ^ (b>> 5)) & 0xffffffff; \
4169   a -= b; a -= c; a = (a ^ (c>> 3)) & 0xffffffff; \
4170   b -= c; b -= a; b = (b ^ (a<<10)) & 0xffffffff; \
4171   c -= a; c -= b; c = (c ^ (b>>15)) & 0xffffffff; \
4172 }
4173 
4174 
4175 /* Produce good hash value combining VAL and VAL2.  */
4176 hashval_t
4177 iterative_hash_hashval_t (hashval_t val, hashval_t val2)
4178 {
4179   /* the golden ratio; an arbitrary value.  */
4180   hashval_t a = 0x9e3779b9;
4181 
4182   mix (a, val, val2);
4183   return val2;
4184 }
4185 
4186 /* Produce good hash value combining VAL and VAL2.  */
4187 hashval_t
4188 iterative_hash_host_wide_int (HOST_WIDE_INT val, hashval_t val2)
4189 {
4190   if (sizeof (HOST_WIDE_INT) == sizeof (hashval_t))
4191     return iterative_hash_hashval_t (val, val2);
4192   else
4193     {
4194       hashval_t a = (hashval_t) val;
4195       /* Avoid warnings about shifting of more than the width of the type on
4196          hosts that won't execute this path.  */
4197       int zero = 0;
4198       hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 8 + zero));
4199       mix (a, b, val2);
4200       if (sizeof (HOST_WIDE_INT) > 2 * sizeof (hashval_t))
4201 	{
4202 	  hashval_t a = (hashval_t) (val >> (sizeof (hashval_t) * 16 + zero));
4203 	  hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 24 + zero));
4204 	  mix (a, b, val2);
4205 	}
4206       return val2;
4207     }
4208 }
4209 
4210 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
4211    is ATTRIBUTE and its qualifiers are QUALS.
4212 
4213    Record such modified types already made so we don't make duplicates.  */
4214 
4215 tree
4216 build_type_attribute_qual_variant (tree ttype, tree attribute, int quals)
4217 {
4218   if (! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
4219     {
4220       hashval_t hashcode = 0;
4221       tree ntype;
4222       enum tree_code code = TREE_CODE (ttype);
4223 
4224       /* Building a distinct copy of a tagged type is inappropriate; it
4225 	 causes breakage in code that expects there to be a one-to-one
4226 	 relationship between a struct and its fields.
4227 	 build_duplicate_type is another solution (as used in
4228 	 handle_transparent_union_attribute), but that doesn't play well
4229 	 with the stronger C++ type identity model.  */
4230       if (TREE_CODE (ttype) == RECORD_TYPE
4231 	  || TREE_CODE (ttype) == UNION_TYPE
4232 	  || TREE_CODE (ttype) == QUAL_UNION_TYPE
4233 	  || TREE_CODE (ttype) == ENUMERAL_TYPE)
4234 	{
4235 	  warning (OPT_Wattributes,
4236 		   "ignoring attributes applied to %qT after definition",
4237 		   TYPE_MAIN_VARIANT (ttype));
4238 	  return build_qualified_type (ttype, quals);
4239 	}
4240 
4241       ttype = build_qualified_type (ttype, TYPE_UNQUALIFIED);
4242       ntype = build_distinct_type_copy (ttype);
4243 
4244       TYPE_ATTRIBUTES (ntype) = attribute;
4245 
4246       hashcode = iterative_hash_object (code, hashcode);
4247       if (TREE_TYPE (ntype))
4248 	hashcode = iterative_hash_object (TYPE_HASH (TREE_TYPE (ntype)),
4249 					  hashcode);
4250       hashcode = attribute_hash_list (attribute, hashcode);
4251 
4252       switch (TREE_CODE (ntype))
4253 	{
4254 	case FUNCTION_TYPE:
4255 	  hashcode = type_hash_list (TYPE_ARG_TYPES (ntype), hashcode);
4256 	  break;
4257 	case ARRAY_TYPE:
4258 	  if (TYPE_DOMAIN (ntype))
4259 	    hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (ntype)),
4260 					      hashcode);
4261 	  break;
4262 	case INTEGER_TYPE:
4263 	  hashcode = iterative_hash_object
4264 	    (TREE_INT_CST_LOW (TYPE_MAX_VALUE (ntype)), hashcode);
4265 	  hashcode = iterative_hash_object
4266 	    (TREE_INT_CST_HIGH (TYPE_MAX_VALUE (ntype)), hashcode);
4267 	  break;
4268 	case REAL_TYPE:
4269 	case FIXED_POINT_TYPE:
4270 	  {
4271 	    unsigned int precision = TYPE_PRECISION (ntype);
4272 	    hashcode = iterative_hash_object (precision, hashcode);
4273 	  }
4274 	  break;
4275 	default:
4276 	  break;
4277 	}
4278 
4279       ntype = type_hash_canon (hashcode, ntype);
4280 
4281       /* If the target-dependent attributes make NTYPE different from
4282 	 its canonical type, we will need to use structural equality
4283 	 checks for this type. */
4284       if (TYPE_STRUCTURAL_EQUALITY_P (ttype)
4285           || !comp_type_attributes (ntype, ttype))
4286 	SET_TYPE_STRUCTURAL_EQUALITY (ntype);
4287       else if (TYPE_CANONICAL (ntype) == ntype)
4288 	TYPE_CANONICAL (ntype) = TYPE_CANONICAL (ttype);
4289 
4290       ttype = build_qualified_type (ntype, quals);
4291     }
4292   else if (TYPE_QUALS (ttype) != quals)
4293     ttype = build_qualified_type (ttype, quals);
4294 
4295   return ttype;
4296 }
4297 
4298 /* Compare two attributes for their value identity.  Return true if the
4299    attribute values are known to be equal; otherwise return false.
4300 */
4301 
4302 static bool
4303 attribute_value_equal (const_tree attr1, const_tree attr2)
4304 {
4305   if (TREE_VALUE (attr1) == TREE_VALUE (attr2))
4306     return true;
4307 
4308   if (TREE_VALUE (attr1) != NULL_TREE
4309       && TREE_CODE (TREE_VALUE (attr1)) == TREE_LIST
4310       && TREE_VALUE (attr2) != NULL
4311       && TREE_CODE (TREE_VALUE (attr2)) == TREE_LIST)
4312     return (simple_cst_list_equal (TREE_VALUE (attr1),
4313 				   TREE_VALUE (attr2)) == 1);
4314 
4315   return (simple_cst_equal (TREE_VALUE (attr1), TREE_VALUE (attr2)) == 1);
4316 }
4317 
4318 /* Return 0 if the attributes for two types are incompatible, 1 if they
4319    are compatible, and 2 if they are nearly compatible (which causes a
4320    warning to be generated).  */
4321 int
4322 comp_type_attributes (const_tree type1, const_tree type2)
4323 {
4324   const_tree a1 = TYPE_ATTRIBUTES (type1);
4325   const_tree a2 = TYPE_ATTRIBUTES (type2);
4326   const_tree a;
4327 
4328   if (a1 == a2)
4329     return 1;
4330   for (a = a1; a != NULL_TREE; a = TREE_CHAIN (a))
4331     {
4332       const struct attribute_spec *as;
4333       const_tree attr;
4334 
4335       as = lookup_attribute_spec (TREE_PURPOSE (a));
4336       if (!as || as->affects_type_identity == false)
4337         continue;
4338 
4339       attr = lookup_attribute (as->name, CONST_CAST_TREE (a2));
4340       if (!attr || !attribute_value_equal (a, attr))
4341         break;
4342     }
4343   if (!a)
4344     {
4345       for (a = a2; a != NULL_TREE; a = TREE_CHAIN (a))
4346 	{
4347 	  const struct attribute_spec *as;
4348 
4349 	  as = lookup_attribute_spec (TREE_PURPOSE (a));
4350 	  if (!as || as->affects_type_identity == false)
4351 	    continue;
4352 
4353 	  if (!lookup_attribute (as->name, CONST_CAST_TREE (a1)))
4354 	    break;
4355 	  /* We don't need to compare trees again, as we did this
4356 	     already in first loop.  */
4357 	}
4358       /* All types - affecting identity - are equal, so
4359          there is no need to call target hook for comparison.  */
4360       if (!a)
4361         return 1;
4362     }
4363   /* As some type combinations - like default calling-convention - might
4364      be compatible, we have to call the target hook to get the final result.  */
4365   return targetm.comp_type_attributes (type1, type2);
4366 }
4367 
4368 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
4369    is ATTRIBUTE.
4370 
4371    Record such modified types already made so we don't make duplicates.  */
4372 
4373 tree
4374 build_type_attribute_variant (tree ttype, tree attribute)
4375 {
4376   return build_type_attribute_qual_variant (ttype, attribute,
4377 					    TYPE_QUALS (ttype));
4378 }
4379 
4380 
4381 /* Reset the expression *EXPR_P, a size or position.
4382 
4383    ??? We could reset all non-constant sizes or positions.  But it's cheap
4384    enough to not do so and refrain from adding workarounds to dwarf2out.c.
4385 
4386    We need to reset self-referential sizes or positions because they cannot
4387    be gimplified and thus can contain a CALL_EXPR after the gimplification
4388    is finished, which will run afoul of LTO streaming.  And they need to be
4389    reset to something essentially dummy but not constant, so as to preserve
4390    the properties of the object they are attached to.  */
4391 
4392 static inline void
4393 free_lang_data_in_one_sizepos (tree *expr_p)
4394 {
4395   tree expr = *expr_p;
4396   if (CONTAINS_PLACEHOLDER_P (expr))
4397     *expr_p = build0 (PLACEHOLDER_EXPR, TREE_TYPE (expr));
4398 }
4399 
4400 
4401 /* Reset all the fields in a binfo node BINFO.  We only keep
4402    BINFO_VTABLE, which is used by gimple_fold_obj_type_ref.  */
4403 
4404 static void
4405 free_lang_data_in_binfo (tree binfo)
4406 {
4407   unsigned i;
4408   tree t;
4409 
4410   gcc_assert (TREE_CODE (binfo) == TREE_BINFO);
4411 
4412   BINFO_VIRTUALS (binfo) = NULL_TREE;
4413   BINFO_BASE_ACCESSES (binfo) = NULL;
4414   BINFO_INHERITANCE_CHAIN (binfo) = NULL_TREE;
4415   BINFO_SUBVTT_INDEX (binfo) = NULL_TREE;
4416 
4417   FOR_EACH_VEC_ELT (tree, BINFO_BASE_BINFOS (binfo), i, t)
4418     free_lang_data_in_binfo (t);
4419 }
4420 
4421 
4422 /* Reset all language specific information still present in TYPE.  */
4423 
4424 static void
4425 free_lang_data_in_type (tree type)
4426 {
4427   gcc_assert (TYPE_P (type));
4428 
4429   /* Give the FE a chance to remove its own data first.  */
4430   lang_hooks.free_lang_data (type);
4431 
4432   TREE_LANG_FLAG_0 (type) = 0;
4433   TREE_LANG_FLAG_1 (type) = 0;
4434   TREE_LANG_FLAG_2 (type) = 0;
4435   TREE_LANG_FLAG_3 (type) = 0;
4436   TREE_LANG_FLAG_4 (type) = 0;
4437   TREE_LANG_FLAG_5 (type) = 0;
4438   TREE_LANG_FLAG_6 (type) = 0;
4439 
4440   if (TREE_CODE (type) == FUNCTION_TYPE)
4441     {
4442       /* Remove the const and volatile qualifiers from arguments.  The
4443 	 C++ front end removes them, but the C front end does not,
4444 	 leading to false ODR violation errors when merging two
4445 	 instances of the same function signature compiled by
4446 	 different front ends.  */
4447       tree p;
4448 
4449       for (p = TYPE_ARG_TYPES (type); p; p = TREE_CHAIN (p))
4450 	{
4451 	  tree arg_type = TREE_VALUE (p);
4452 
4453 	  if (TYPE_READONLY (arg_type) || TYPE_VOLATILE (arg_type))
4454 	    {
4455 	      int quals = TYPE_QUALS (arg_type)
4456 			  & ~TYPE_QUAL_CONST
4457 			  & ~TYPE_QUAL_VOLATILE;
4458 	      TREE_VALUE (p) = build_qualified_type (arg_type, quals);
4459 	      free_lang_data_in_type (TREE_VALUE (p));
4460 	    }
4461 	}
4462     }
4463 
4464   /* Remove members that are not actually FIELD_DECLs from the field
4465      list of an aggregate.  These occur in C++.  */
4466   if (RECORD_OR_UNION_TYPE_P (type))
4467     {
4468       tree prev, member;
4469 
4470       /* Note that TYPE_FIELDS can be shared across distinct
4471 	 TREE_TYPEs.  Therefore, if the first field of TYPE_FIELDS is
4472 	 to be removed, we cannot set its TREE_CHAIN to NULL.
4473 	 Otherwise, we would not be able to find all the other fields
4474 	 in the other instances of this TREE_TYPE.
4475 
4476 	 This was causing an ICE in testsuite/g++.dg/lto/20080915.C.  */
4477       prev = NULL_TREE;
4478       member = TYPE_FIELDS (type);
4479       while (member)
4480 	{
4481 	  if (TREE_CODE (member) == FIELD_DECL
4482 	      || TREE_CODE (member) == TYPE_DECL)
4483 	    {
4484 	      if (prev)
4485 		TREE_CHAIN (prev) = member;
4486 	      else
4487 		TYPE_FIELDS (type) = member;
4488 	      prev = member;
4489 	    }
4490 
4491 	  member = TREE_CHAIN (member);
4492 	}
4493 
4494       if (prev)
4495 	TREE_CHAIN (prev) = NULL_TREE;
4496       else
4497 	TYPE_FIELDS (type) = NULL_TREE;
4498 
4499       TYPE_METHODS (type) = NULL_TREE;
4500       if (TYPE_BINFO (type))
4501 	free_lang_data_in_binfo (TYPE_BINFO (type));
4502     }
4503   else
4504     {
4505       /* For non-aggregate types, clear out the language slot (which
4506 	 overloads TYPE_BINFO).  */
4507       TYPE_LANG_SLOT_1 (type) = NULL_TREE;
4508 
4509       if (INTEGRAL_TYPE_P (type)
4510 	  || SCALAR_FLOAT_TYPE_P (type)
4511 	  || FIXED_POINT_TYPE_P (type))
4512 	{
4513 	  free_lang_data_in_one_sizepos (&TYPE_MIN_VALUE (type));
4514 	  free_lang_data_in_one_sizepos (&TYPE_MAX_VALUE (type));
4515 	}
4516     }
4517 
4518   free_lang_data_in_one_sizepos (&TYPE_SIZE (type));
4519   free_lang_data_in_one_sizepos (&TYPE_SIZE_UNIT (type));
4520 
4521   if (TYPE_CONTEXT (type)
4522       && TREE_CODE (TYPE_CONTEXT (type)) == BLOCK)
4523     {
4524       tree ctx = TYPE_CONTEXT (type);
4525       do
4526 	{
4527 	  ctx = BLOCK_SUPERCONTEXT (ctx);
4528 	}
4529       while (ctx && TREE_CODE (ctx) == BLOCK);
4530       TYPE_CONTEXT (type) = ctx;
4531     }
4532 }
4533 
4534 
4535 /* Return true if DECL may need an assembler name to be set.  */
4536 
4537 static inline bool
4538 need_assembler_name_p (tree decl)
4539 {
4540   /* Only FUNCTION_DECLs and VAR_DECLs are considered.  */
4541   if (TREE_CODE (decl) != FUNCTION_DECL
4542       && TREE_CODE (decl) != VAR_DECL)
4543     return false;
4544 
4545   /* If DECL already has its assembler name set, it does not need a
4546      new one.  */
4547   if (!HAS_DECL_ASSEMBLER_NAME_P (decl)
4548       || DECL_ASSEMBLER_NAME_SET_P (decl))
4549     return false;
4550 
4551   /* Abstract decls do not need an assembler name.  */
4552   if (DECL_ABSTRACT (decl))
4553     return false;
4554 
4555   /* For VAR_DECLs, only static, public and external symbols need an
4556      assembler name.  */
4557   if (TREE_CODE (decl) == VAR_DECL
4558       && !TREE_STATIC (decl)
4559       && !TREE_PUBLIC (decl)
4560       && !DECL_EXTERNAL (decl))
4561     return false;
4562 
4563   if (TREE_CODE (decl) == FUNCTION_DECL)
4564     {
4565       /* Do not set assembler name on builtins.  Allow RTL expansion to
4566 	 decide whether to expand inline or via a regular call.  */
4567       if (DECL_BUILT_IN (decl)
4568 	  && DECL_BUILT_IN_CLASS (decl) != BUILT_IN_FRONTEND)
4569 	return false;
4570 
4571       /* Functions represented in the callgraph need an assembler name.  */
4572       if (cgraph_get_node (decl) != NULL)
4573 	return true;
4574 
4575       /* Unused and not public functions don't need an assembler name.  */
4576       if (!TREE_USED (decl) && !TREE_PUBLIC (decl))
4577 	return false;
4578     }
4579 
4580   return true;
4581 }
4582 
4583 
4584 /* Reset all language specific information still present in symbol
4585    DECL.  */
4586 
4587 static void
4588 free_lang_data_in_decl (tree decl)
4589 {
4590   gcc_assert (DECL_P (decl));
4591 
4592   /* Give the FE a chance to remove its own data first.  */
4593   lang_hooks.free_lang_data (decl);
4594 
4595   TREE_LANG_FLAG_0 (decl) = 0;
4596   TREE_LANG_FLAG_1 (decl) = 0;
4597   TREE_LANG_FLAG_2 (decl) = 0;
4598   TREE_LANG_FLAG_3 (decl) = 0;
4599   TREE_LANG_FLAG_4 (decl) = 0;
4600   TREE_LANG_FLAG_5 (decl) = 0;
4601   TREE_LANG_FLAG_6 (decl) = 0;
4602 
4603   free_lang_data_in_one_sizepos (&DECL_SIZE (decl));
4604   free_lang_data_in_one_sizepos (&DECL_SIZE_UNIT (decl));
4605   if (TREE_CODE (decl) == FIELD_DECL)
4606     {
4607       free_lang_data_in_one_sizepos (&DECL_FIELD_OFFSET (decl));
4608       if (TREE_CODE (DECL_CONTEXT (decl)) == QUAL_UNION_TYPE)
4609 	DECL_QUALIFIER (decl) = NULL_TREE;
4610     }
4611 
4612  if (TREE_CODE (decl) == FUNCTION_DECL)
4613     {
4614       if (gimple_has_body_p (decl))
4615 	{
4616 	  tree t;
4617 
4618 	  /* If DECL has a gimple body, then the context for its
4619 	     arguments must be DECL.  Otherwise, it doesn't really
4620 	     matter, as we will not be emitting any code for DECL.  In
4621 	     general, there may be other instances of DECL created by
4622 	     the front end and since PARM_DECLs are generally shared,
4623 	     their DECL_CONTEXT changes as the replicas of DECL are
4624 	     created.  The only time where DECL_CONTEXT is important
4625 	     is for the FUNCTION_DECLs that have a gimple body (since
4626 	     the PARM_DECL will be used in the function's body).  */
4627 	  for (t = DECL_ARGUMENTS (decl); t; t = TREE_CHAIN (t))
4628 	    DECL_CONTEXT (t) = decl;
4629 	}
4630 
4631       /* DECL_SAVED_TREE holds the GENERIC representation for DECL.
4632 	 At this point, it is not needed anymore.  */
4633       DECL_SAVED_TREE (decl) = NULL_TREE;
4634 
4635       /* Clear the abstract origin if it refers to a method.  Otherwise
4636          dwarf2out.c will ICE as we clear TYPE_METHODS and thus the
4637 	 origin will not be output correctly.  */
4638       if (DECL_ABSTRACT_ORIGIN (decl)
4639 	  && DECL_CONTEXT (DECL_ABSTRACT_ORIGIN (decl))
4640 	  && RECORD_OR_UNION_TYPE_P
4641 	       (DECL_CONTEXT (DECL_ABSTRACT_ORIGIN (decl))))
4642 	DECL_ABSTRACT_ORIGIN (decl) = NULL_TREE;
4643 
4644       /* Sometimes the C++ frontend doesn't manage to transform a temporary
4645          DECL_VINDEX referring to itself into a vtable slot number as it
4646 	 should.  Happens with functions that are copied and then forgotten
4647 	 about.  Just clear it, it won't matter anymore.  */
4648       if (DECL_VINDEX (decl) && !host_integerp (DECL_VINDEX (decl), 0))
4649 	DECL_VINDEX (decl) = NULL_TREE;
4650     }
4651   else if (TREE_CODE (decl) == VAR_DECL)
4652     {
4653       if ((DECL_EXTERNAL (decl)
4654 	   && (!TREE_STATIC (decl) || !TREE_READONLY (decl)))
4655 	  || (decl_function_context (decl) && !TREE_STATIC (decl)))
4656 	DECL_INITIAL (decl) = NULL_TREE;
4657     }
4658   else if (TREE_CODE (decl) == TYPE_DECL
4659 	   || TREE_CODE (decl) == FIELD_DECL)
4660     DECL_INITIAL (decl) = NULL_TREE;
4661   else if (TREE_CODE (decl) == TRANSLATION_UNIT_DECL
4662            && DECL_INITIAL (decl)
4663            && TREE_CODE (DECL_INITIAL (decl)) == BLOCK)
4664     {
4665       /* Strip builtins from the translation-unit BLOCK.  We still have targets
4666 	 without builtin_decl_explicit support and also builtins are shared
4667 	 nodes and thus we can't use TREE_CHAIN in multiple lists.  */
4668       tree *nextp = &BLOCK_VARS (DECL_INITIAL (decl));
4669       while (*nextp)
4670         {
4671           tree var = *nextp;
4672           if (TREE_CODE (var) == FUNCTION_DECL
4673               && DECL_BUILT_IN (var))
4674 	    *nextp = TREE_CHAIN (var);
4675 	  else
4676 	    nextp = &TREE_CHAIN (var);
4677         }
4678     }
4679 }
4680 
4681 
4682 /* Data used when collecting DECLs and TYPEs for language data removal.  */
4683 
4684 struct free_lang_data_d
4685 {
4686   /* Worklist to avoid excessive recursion.  */
4687   VEC(tree,heap) *worklist;
4688 
4689   /* Set of traversed objects.  Used to avoid duplicate visits.  */
4690   struct pointer_set_t *pset;
4691 
4692   /* Array of symbols to process with free_lang_data_in_decl.  */
4693   VEC(tree,heap) *decls;
4694 
4695   /* Array of types to process with free_lang_data_in_type.  */
4696   VEC(tree,heap) *types;
4697 };
4698 
4699 
4700 /* Save all language fields needed to generate proper debug information
4701    for DECL.  This saves most fields cleared out by free_lang_data_in_decl.  */
4702 
4703 static void
4704 save_debug_info_for_decl (tree t)
4705 {
4706   /*struct saved_debug_info_d *sdi;*/
4707 
4708   gcc_assert (debug_info_level > DINFO_LEVEL_TERSE && t && DECL_P (t));
4709 
4710   /* FIXME.  Partial implementation for saving debug info removed.  */
4711 }
4712 
4713 
4714 /* Save all language fields needed to generate proper debug information
4715    for TYPE.  This saves most fields cleared out by free_lang_data_in_type.  */
4716 
4717 static void
4718 save_debug_info_for_type (tree t)
4719 {
4720   /*struct saved_debug_info_d *sdi;*/
4721 
4722   gcc_assert (debug_info_level > DINFO_LEVEL_TERSE && t && TYPE_P (t));
4723 
4724   /* FIXME.  Partial implementation for saving debug info removed.  */
4725 }
4726 
4727 
4728 /* Add type or decl T to one of the list of tree nodes that need their
4729    language data removed.  The lists are held inside FLD.  */
4730 
4731 static void
4732 add_tree_to_fld_list (tree t, struct free_lang_data_d *fld)
4733 {
4734   if (DECL_P (t))
4735     {
4736       VEC_safe_push (tree, heap, fld->decls, t);
4737       if (debug_info_level > DINFO_LEVEL_TERSE)
4738 	save_debug_info_for_decl (t);
4739     }
4740   else if (TYPE_P (t))
4741     {
4742       VEC_safe_push (tree, heap, fld->types, t);
4743       if (debug_info_level > DINFO_LEVEL_TERSE)
4744 	save_debug_info_for_type (t);
4745     }
4746   else
4747     gcc_unreachable ();
4748 }
4749 
4750 /* Push tree node T into FLD->WORKLIST.  */
4751 
4752 static inline void
4753 fld_worklist_push (tree t, struct free_lang_data_d *fld)
4754 {
4755   if (t && !is_lang_specific (t) && !pointer_set_contains (fld->pset, t))
4756     VEC_safe_push (tree, heap, fld->worklist, (t));
4757 }
4758 
4759 
4760 /* Operand callback helper for free_lang_data_in_node.  *TP is the
4761    subtree operand being considered.  */
4762 
4763 static tree
4764 find_decls_types_r (tree *tp, int *ws, void *data)
4765 {
4766   tree t = *tp;
4767   struct free_lang_data_d *fld = (struct free_lang_data_d *) data;
4768 
4769   if (TREE_CODE (t) == TREE_LIST)
4770     return NULL_TREE;
4771 
4772   /* Language specific nodes will be removed, so there is no need
4773      to gather anything under them.  */
4774   if (is_lang_specific (t))
4775     {
4776       *ws = 0;
4777       return NULL_TREE;
4778     }
4779 
4780   if (DECL_P (t))
4781     {
4782       /* Note that walk_tree does not traverse every possible field in
4783 	 decls, so we have to do our own traversals here.  */
4784       add_tree_to_fld_list (t, fld);
4785 
4786       fld_worklist_push (DECL_NAME (t), fld);
4787       fld_worklist_push (DECL_CONTEXT (t), fld);
4788       fld_worklist_push (DECL_SIZE (t), fld);
4789       fld_worklist_push (DECL_SIZE_UNIT (t), fld);
4790 
4791       /* We are going to remove everything under DECL_INITIAL for
4792 	 TYPE_DECLs.  No point walking them.  */
4793       if (TREE_CODE (t) != TYPE_DECL)
4794 	fld_worklist_push (DECL_INITIAL (t), fld);
4795 
4796       fld_worklist_push (DECL_ATTRIBUTES (t), fld);
4797       fld_worklist_push (DECL_ABSTRACT_ORIGIN (t), fld);
4798 
4799       if (TREE_CODE (t) == FUNCTION_DECL)
4800 	{
4801 	  fld_worklist_push (DECL_ARGUMENTS (t), fld);
4802 	  fld_worklist_push (DECL_RESULT (t), fld);
4803 	}
4804       else if (TREE_CODE (t) == TYPE_DECL)
4805 	{
4806 	  fld_worklist_push (DECL_ARGUMENT_FLD (t), fld);
4807 	  fld_worklist_push (DECL_VINDEX (t), fld);
4808 	  fld_worklist_push (DECL_ORIGINAL_TYPE (t), fld);
4809 	}
4810       else if (TREE_CODE (t) == FIELD_DECL)
4811 	{
4812 	  fld_worklist_push (DECL_FIELD_OFFSET (t), fld);
4813 	  fld_worklist_push (DECL_BIT_FIELD_TYPE (t), fld);
4814 	  fld_worklist_push (DECL_FIELD_BIT_OFFSET (t), fld);
4815 	  fld_worklist_push (DECL_FCONTEXT (t), fld);
4816 	}
4817       else if (TREE_CODE (t) == VAR_DECL)
4818 	{
4819 	  fld_worklist_push (DECL_SECTION_NAME (t), fld);
4820 	  fld_worklist_push (DECL_COMDAT_GROUP (t), fld);
4821 	}
4822 
4823       if ((TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == PARM_DECL)
4824 	  && DECL_HAS_VALUE_EXPR_P (t))
4825 	fld_worklist_push (DECL_VALUE_EXPR (t), fld);
4826 
4827       if (TREE_CODE (t) != FIELD_DECL
4828 	  && TREE_CODE (t) != TYPE_DECL)
4829 	fld_worklist_push (TREE_CHAIN (t), fld);
4830       *ws = 0;
4831     }
4832   else if (TYPE_P (t))
4833     {
4834       /* Note that walk_tree does not traverse every possible field in
4835 	 types, so we have to do our own traversals here.  */
4836       add_tree_to_fld_list (t, fld);
4837 
4838       if (!RECORD_OR_UNION_TYPE_P (t))
4839 	fld_worklist_push (TYPE_CACHED_VALUES (t), fld);
4840       fld_worklist_push (TYPE_SIZE (t), fld);
4841       fld_worklist_push (TYPE_SIZE_UNIT (t), fld);
4842       fld_worklist_push (TYPE_ATTRIBUTES (t), fld);
4843       fld_worklist_push (TYPE_POINTER_TO (t), fld);
4844       fld_worklist_push (TYPE_REFERENCE_TO (t), fld);
4845       fld_worklist_push (TYPE_NAME (t), fld);
4846       /* Do not walk TYPE_NEXT_PTR_TO or TYPE_NEXT_REF_TO.  We do not stream
4847 	 them and thus do not and want not to reach unused pointer types
4848 	 this way.  */
4849       if (!POINTER_TYPE_P (t))
4850 	fld_worklist_push (TYPE_MINVAL (t), fld);
4851       if (!RECORD_OR_UNION_TYPE_P (t))
4852 	fld_worklist_push (TYPE_MAXVAL (t), fld);
4853       fld_worklist_push (TYPE_MAIN_VARIANT (t), fld);
4854       /* Do not walk TYPE_NEXT_VARIANT.  We do not stream it and thus
4855          do not and want not to reach unused variants this way.  */
4856       if (TYPE_CONTEXT (t))
4857 	{
4858 	  tree ctx = TYPE_CONTEXT (t);
4859 	  /* We adjust BLOCK TYPE_CONTEXTs to the innermost non-BLOCK one.
4860 	     So push that instead.  */
4861 	  while (ctx && TREE_CODE (ctx) == BLOCK)
4862 	    ctx = BLOCK_SUPERCONTEXT (ctx);
4863 	  fld_worklist_push (ctx, fld);
4864 	}
4865       /* Do not walk TYPE_CANONICAL.  We do not stream it and thus do not
4866 	 and want not to reach unused types this way.  */
4867 
4868       if (RECORD_OR_UNION_TYPE_P (t) && TYPE_BINFO (t))
4869 	{
4870 	  unsigned i;
4871 	  tree tem;
4872 	  for (i = 0; VEC_iterate (tree, BINFO_BASE_BINFOS (TYPE_BINFO (t)),
4873 				   i, tem); ++i)
4874 	    fld_worklist_push (TREE_TYPE (tem), fld);
4875 	  tem = BINFO_VIRTUALS (TYPE_BINFO (t));
4876 	  if (tem
4877 	      /* The Java FE overloads BINFO_VIRTUALS for its own purpose.  */
4878 	      && TREE_CODE (tem) == TREE_LIST)
4879 	    do
4880 	      {
4881 		fld_worklist_push (TREE_VALUE (tem), fld);
4882 		tem = TREE_CHAIN (tem);
4883 	      }
4884 	    while (tem);
4885 	}
4886       if (RECORD_OR_UNION_TYPE_P (t))
4887 	{
4888 	  tree tem;
4889 	  /* Push all TYPE_FIELDS - there can be interleaving interesting
4890 	     and non-interesting things.  */
4891 	  tem = TYPE_FIELDS (t);
4892 	  while (tem)
4893 	    {
4894 	      if (TREE_CODE (tem) == FIELD_DECL
4895 		  || TREE_CODE (tem) == TYPE_DECL)
4896 		fld_worklist_push (tem, fld);
4897 	      tem = TREE_CHAIN (tem);
4898 	    }
4899 	}
4900 
4901       fld_worklist_push (TYPE_STUB_DECL (t), fld);
4902       *ws = 0;
4903     }
4904   else if (TREE_CODE (t) == BLOCK)
4905     {
4906       tree tem;
4907       for (tem = BLOCK_VARS (t); tem; tem = TREE_CHAIN (tem))
4908 	fld_worklist_push (tem, fld);
4909       for (tem = BLOCK_SUBBLOCKS (t); tem; tem = BLOCK_CHAIN (tem))
4910 	fld_worklist_push (tem, fld);
4911       fld_worklist_push (BLOCK_ABSTRACT_ORIGIN (t), fld);
4912     }
4913 
4914   if (TREE_CODE (t) != IDENTIFIER_NODE
4915       && CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED))
4916     fld_worklist_push (TREE_TYPE (t), fld);
4917 
4918   return NULL_TREE;
4919 }
4920 
4921 
4922 /* Find decls and types in T.  */
4923 
4924 static void
4925 find_decls_types (tree t, struct free_lang_data_d *fld)
4926 {
4927   while (1)
4928     {
4929       if (!pointer_set_contains (fld->pset, t))
4930 	walk_tree (&t, find_decls_types_r, fld, fld->pset);
4931       if (VEC_empty (tree, fld->worklist))
4932 	break;
4933       t = VEC_pop (tree, fld->worklist);
4934     }
4935 }
4936 
4937 /* Translate all the types in LIST with the corresponding runtime
4938    types.  */
4939 
4940 static tree
4941 get_eh_types_for_runtime (tree list)
4942 {
4943   tree head, prev;
4944 
4945   if (list == NULL_TREE)
4946     return NULL_TREE;
4947 
4948   head = build_tree_list (0, lookup_type_for_runtime (TREE_VALUE (list)));
4949   prev = head;
4950   list = TREE_CHAIN (list);
4951   while (list)
4952     {
4953       tree n = build_tree_list (0, lookup_type_for_runtime (TREE_VALUE (list)));
4954       TREE_CHAIN (prev) = n;
4955       prev = TREE_CHAIN (prev);
4956       list = TREE_CHAIN (list);
4957     }
4958 
4959   return head;
4960 }
4961 
4962 
4963 /* Find decls and types referenced in EH region R and store them in
4964    FLD->DECLS and FLD->TYPES.  */
4965 
4966 static void
4967 find_decls_types_in_eh_region (eh_region r, struct free_lang_data_d *fld)
4968 {
4969   switch (r->type)
4970     {
4971     case ERT_CLEANUP:
4972       break;
4973 
4974     case ERT_TRY:
4975       {
4976 	eh_catch c;
4977 
4978 	/* The types referenced in each catch must first be changed to the
4979 	   EH types used at runtime.  This removes references to FE types
4980 	   in the region.  */
4981 	for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
4982 	  {
4983 	    c->type_list = get_eh_types_for_runtime (c->type_list);
4984 	    walk_tree (&c->type_list, find_decls_types_r, fld, fld->pset);
4985 	  }
4986       }
4987       break;
4988 
4989     case ERT_ALLOWED_EXCEPTIONS:
4990       r->u.allowed.type_list
4991 	= get_eh_types_for_runtime (r->u.allowed.type_list);
4992       walk_tree (&r->u.allowed.type_list, find_decls_types_r, fld, fld->pset);
4993       break;
4994 
4995     case ERT_MUST_NOT_THROW:
4996       walk_tree (&r->u.must_not_throw.failure_decl,
4997 		 find_decls_types_r, fld, fld->pset);
4998       break;
4999     }
5000 }
5001 
5002 
5003 /* Find decls and types referenced in cgraph node N and store them in
5004    FLD->DECLS and FLD->TYPES.  Unlike pass_referenced_vars, this will
5005    look for *every* kind of DECL and TYPE node reachable from N,
5006    including those embedded inside types and decls (i.e,, TYPE_DECLs,
5007    NAMESPACE_DECLs, etc).  */
5008 
5009 static void
5010 find_decls_types_in_node (struct cgraph_node *n, struct free_lang_data_d *fld)
5011 {
5012   basic_block bb;
5013   struct function *fn;
5014   unsigned ix;
5015   tree t;
5016 
5017   find_decls_types (n->decl, fld);
5018 
5019   if (!gimple_has_body_p (n->decl))
5020     return;
5021 
5022   gcc_assert (current_function_decl == NULL_TREE && cfun == NULL);
5023 
5024   fn = DECL_STRUCT_FUNCTION (n->decl);
5025 
5026   /* Traverse locals. */
5027   FOR_EACH_LOCAL_DECL (fn, ix, t)
5028     find_decls_types (t, fld);
5029 
5030   /* Traverse EH regions in FN.  */
5031   {
5032     eh_region r;
5033     FOR_ALL_EH_REGION_FN (r, fn)
5034       find_decls_types_in_eh_region (r, fld);
5035   }
5036 
5037   /* Traverse every statement in FN.  */
5038   FOR_EACH_BB_FN (bb, fn)
5039     {
5040       gimple_stmt_iterator si;
5041       unsigned i;
5042 
5043       for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
5044 	{
5045 	  gimple phi = gsi_stmt (si);
5046 
5047 	  for (i = 0; i < gimple_phi_num_args (phi); i++)
5048 	    {
5049 	      tree *arg_p = gimple_phi_arg_def_ptr (phi, i);
5050 	      find_decls_types (*arg_p, fld);
5051 	    }
5052 	}
5053 
5054       for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5055 	{
5056 	  gimple stmt = gsi_stmt (si);
5057 
5058 	  if (is_gimple_call (stmt))
5059 	    find_decls_types (gimple_call_fntype (stmt), fld);
5060 
5061 	  for (i = 0; i < gimple_num_ops (stmt); i++)
5062 	    {
5063 	      tree arg = gimple_op (stmt, i);
5064 	      find_decls_types (arg, fld);
5065 	    }
5066 	}
5067     }
5068 }
5069 
5070 
5071 /* Find decls and types referenced in varpool node N and store them in
5072    FLD->DECLS and FLD->TYPES.  Unlike pass_referenced_vars, this will
5073    look for *every* kind of DECL and TYPE node reachable from N,
5074    including those embedded inside types and decls (i.e,, TYPE_DECLs,
5075    NAMESPACE_DECLs, etc).  */
5076 
5077 static void
5078 find_decls_types_in_var (struct varpool_node *v, struct free_lang_data_d *fld)
5079 {
5080   find_decls_types (v->decl, fld);
5081 }
5082 
5083 /* If T needs an assembler name, have one created for it.  */
5084 
5085 void
5086 assign_assembler_name_if_neeeded (tree t)
5087 {
5088   if (need_assembler_name_p (t))
5089     {
5090       /* When setting DECL_ASSEMBLER_NAME, the C++ mangler may emit
5091 	 diagnostics that use input_location to show locus
5092 	 information.  The problem here is that, at this point,
5093 	 input_location is generally anchored to the end of the file
5094 	 (since the parser is long gone), so we don't have a good
5095 	 position to pin it to.
5096 
5097 	 To alleviate this problem, this uses the location of T's
5098 	 declaration.  Examples of this are
5099 	 testsuite/g++.dg/template/cond2.C and
5100 	 testsuite/g++.dg/template/pr35240.C.  */
5101       location_t saved_location = input_location;
5102       input_location = DECL_SOURCE_LOCATION (t);
5103 
5104       decl_assembler_name (t);
5105 
5106       input_location = saved_location;
5107     }
5108 }
5109 
5110 
5111 /* Free language specific information for every operand and expression
5112    in every node of the call graph.  This process operates in three stages:
5113 
5114    1- Every callgraph node and varpool node is traversed looking for
5115       decls and types embedded in them.  This is a more exhaustive
5116       search than that done by find_referenced_vars, because it will
5117       also collect individual fields, decls embedded in types, etc.
5118 
5119    2- All the decls found are sent to free_lang_data_in_decl.
5120 
5121    3- All the types found are sent to free_lang_data_in_type.
5122 
5123    The ordering between decls and types is important because
5124    free_lang_data_in_decl sets assembler names, which includes
5125    mangling.  So types cannot be freed up until assembler names have
5126    been set up.  */
5127 
5128 static void
5129 free_lang_data_in_cgraph (void)
5130 {
5131   struct cgraph_node *n;
5132   struct varpool_node *v;
5133   struct free_lang_data_d fld;
5134   tree t;
5135   unsigned i;
5136   alias_pair *p;
5137 
5138   /* Initialize sets and arrays to store referenced decls and types.  */
5139   fld.pset = pointer_set_create ();
5140   fld.worklist = NULL;
5141   fld.decls = VEC_alloc (tree, heap, 100);
5142   fld.types = VEC_alloc (tree, heap, 100);
5143 
5144   /* Find decls and types in the body of every function in the callgraph.  */
5145   for (n = cgraph_nodes; n; n = n->next)
5146     find_decls_types_in_node (n, &fld);
5147 
5148   FOR_EACH_VEC_ELT (alias_pair, alias_pairs, i, p)
5149     find_decls_types (p->decl, &fld);
5150 
5151   /* Find decls and types in every varpool symbol.  */
5152   for (v = varpool_nodes; v; v = v->next)
5153     find_decls_types_in_var (v, &fld);
5154 
5155   /* Set the assembler name on every decl found.  We need to do this
5156      now because free_lang_data_in_decl will invalidate data needed
5157      for mangling.  This breaks mangling on interdependent decls.  */
5158   FOR_EACH_VEC_ELT (tree, fld.decls, i, t)
5159     assign_assembler_name_if_neeeded (t);
5160 
5161   /* Traverse every decl found freeing its language data.  */
5162   FOR_EACH_VEC_ELT (tree, fld.decls, i, t)
5163     free_lang_data_in_decl (t);
5164 
5165   /* Traverse every type found freeing its language data.  */
5166   FOR_EACH_VEC_ELT (tree, fld.types, i, t)
5167     free_lang_data_in_type (t);
5168 
5169   pointer_set_destroy (fld.pset);
5170   VEC_free (tree, heap, fld.worklist);
5171   VEC_free (tree, heap, fld.decls);
5172   VEC_free (tree, heap, fld.types);
5173 }
5174 
5175 
5176 /* Free resources that are used by FE but are not needed once they are done. */
5177 
5178 static unsigned
5179 free_lang_data (void)
5180 {
5181   unsigned i;
5182 
5183   /* If we are the LTO frontend we have freed lang-specific data already.  */
5184   if (in_lto_p
5185       || !flag_generate_lto)
5186     return 0;
5187 
5188   /* Allocate and assign alias sets to the standard integer types
5189      while the slots are still in the way the frontends generated them.  */
5190   for (i = 0; i < itk_none; ++i)
5191     if (integer_types[i])
5192       TYPE_ALIAS_SET (integer_types[i]) = get_alias_set (integer_types[i]);
5193 
5194   /* Traverse the IL resetting language specific information for
5195      operands, expressions, etc.  */
5196   free_lang_data_in_cgraph ();
5197 
5198   /* Create gimple variants for common types.  */
5199   ptrdiff_type_node = integer_type_node;
5200   fileptr_type_node = ptr_type_node;
5201 
5202   /* Reset some langhooks.  Do not reset types_compatible_p, it may
5203      still be used indirectly via the get_alias_set langhook.  */
5204   lang_hooks.callgraph.analyze_expr = NULL;
5205   lang_hooks.dwarf_name = lhd_dwarf_name;
5206   lang_hooks.decl_printable_name = gimple_decl_printable_name;
5207   /* We do not want the default decl_assembler_name implementation,
5208      rather if we have fixed everything we want a wrapper around it
5209      asserting that all non-local symbols already got their assembler
5210      name and only produce assembler names for local symbols.  Or rather
5211      make sure we never call decl_assembler_name on local symbols and
5212      devise a separate, middle-end private scheme for it.  */
5213 
5214   /* Reset diagnostic machinery.  */
5215   diagnostic_starter (global_dc) = default_tree_diagnostic_starter;
5216   diagnostic_finalizer (global_dc) = default_diagnostic_finalizer;
5217   diagnostic_format_decoder (global_dc) = default_tree_printer;
5218 
5219   return 0;
5220 }
5221 
5222 
5223 struct simple_ipa_opt_pass pass_ipa_free_lang_data =
5224 {
5225  {
5226   SIMPLE_IPA_PASS,
5227   "*free_lang_data",			/* name */
5228   NULL,					/* gate */
5229   free_lang_data,			/* execute */
5230   NULL,					/* sub */
5231   NULL,					/* next */
5232   0,					/* static_pass_number */
5233   TV_IPA_FREE_LANG_DATA,		/* tv_id */
5234   0,	                                /* properties_required */
5235   0,					/* properties_provided */
5236   0,					/* properties_destroyed */
5237   0,					/* todo_flags_start */
5238   TODO_ggc_collect			/* todo_flags_finish */
5239  }
5240 };
5241 
5242 /* The backbone of is_attribute_p().  ATTR_LEN is the string length of
5243    ATTR_NAME.  Also used internally by remove_attribute().  */
5244 bool
5245 private_is_attribute_p (const char *attr_name, size_t attr_len, const_tree ident)
5246 {
5247   size_t ident_len = IDENTIFIER_LENGTH (ident);
5248 
5249   if (ident_len == attr_len)
5250     {
5251       if (strcmp (attr_name, IDENTIFIER_POINTER (ident)) == 0)
5252 	return true;
5253     }
5254   else if (ident_len == attr_len + 4)
5255     {
5256       /* There is the possibility that ATTR is 'text' and IDENT is
5257 	 '__text__'.  */
5258       const char *p = IDENTIFIER_POINTER (ident);
5259       if (p[0] == '_' && p[1] == '_'
5260 	  && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
5261 	  && strncmp (attr_name, p + 2, attr_len) == 0)
5262 	return true;
5263     }
5264 
5265   return false;
5266 }
5267 
5268 /* The backbone of lookup_attribute().  ATTR_LEN is the string length
5269    of ATTR_NAME, and LIST is not NULL_TREE.  */
5270 tree
5271 private_lookup_attribute (const char *attr_name, size_t attr_len, tree list)
5272 {
5273   while (list)
5274     {
5275       size_t ident_len = IDENTIFIER_LENGTH (TREE_PURPOSE (list));
5276 
5277       if (ident_len == attr_len)
5278 	{
5279 	  if (strcmp (attr_name, IDENTIFIER_POINTER (TREE_PURPOSE (list))) == 0)
5280 	    break;
5281 	}
5282       /* TODO: If we made sure that attributes were stored in the
5283 	 canonical form without '__...__' (ie, as in 'text' as opposed
5284 	 to '__text__') then we could avoid the following case.  */
5285       else if (ident_len == attr_len + 4)
5286 	{
5287 	  const char *p = IDENTIFIER_POINTER (TREE_PURPOSE (list));
5288 	  if (p[0] == '_' && p[1] == '_'
5289 	      && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
5290 	      && strncmp (attr_name, p + 2, attr_len) == 0)
5291 	    break;
5292 	}
5293       list = TREE_CHAIN (list);
5294     }
5295 
5296   return list;
5297 }
5298 
5299 /* A variant of lookup_attribute() that can be used with an identifier
5300    as the first argument, and where the identifier can be either
5301    'text' or '__text__'.
5302 
5303    Given an attribute ATTR_IDENTIFIER, and a list of attributes LIST,
5304    return a pointer to the attribute's list element if the attribute
5305    is part of the list, or NULL_TREE if not found.  If the attribute
5306    appears more than once, this only returns the first occurrence; the
5307    TREE_CHAIN of the return value should be passed back in if further
5308    occurrences are wanted.  ATTR_IDENTIFIER must be an identifier but
5309    can be in the form 'text' or '__text__'.  */
5310 static tree
5311 lookup_ident_attribute (tree attr_identifier, tree list)
5312 {
5313   gcc_checking_assert (TREE_CODE (attr_identifier) == IDENTIFIER_NODE);
5314 
5315   while (list)
5316     {
5317       gcc_checking_assert (TREE_CODE (TREE_PURPOSE (list)) == IDENTIFIER_NODE);
5318 
5319       /* Identifiers can be compared directly for equality.  */
5320       if (attr_identifier == TREE_PURPOSE (list))
5321 	break;
5322 
5323       /* If they are not equal, they may still be one in the form
5324 	 'text' while the other one is in the form '__text__'.  TODO:
5325 	 If we were storing attributes in normalized 'text' form, then
5326 	 this could all go away and we could take full advantage of
5327 	 the fact that we're comparing identifiers. :-)  */
5328       {
5329 	size_t attr_len = IDENTIFIER_LENGTH (attr_identifier);
5330 	size_t ident_len = IDENTIFIER_LENGTH (TREE_PURPOSE (list));
5331 
5332 	if (ident_len == attr_len + 4)
5333 	  {
5334 	    const char *p = IDENTIFIER_POINTER (TREE_PURPOSE (list));
5335 	    const char *q = IDENTIFIER_POINTER (attr_identifier);
5336 	    if (p[0] == '_' && p[1] == '_'
5337 		&& p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
5338 		&& strncmp (q, p + 2, attr_len) == 0)
5339 	      break;
5340 	  }
5341 	else if (ident_len + 4 == attr_len)
5342 	  {
5343 	    const char *p = IDENTIFIER_POINTER (TREE_PURPOSE (list));
5344 	    const char *q = IDENTIFIER_POINTER (attr_identifier);
5345 	    if (q[0] == '_' && q[1] == '_'
5346 		&& q[attr_len - 2] == '_' && q[attr_len - 1] == '_'
5347 		&& strncmp (q + 2, p, ident_len) == 0)
5348 	      break;
5349 	  }
5350       }
5351       list = TREE_CHAIN (list);
5352     }
5353 
5354   return list;
5355 }
5356 
5357 /* Remove any instances of attribute ATTR_NAME in LIST and return the
5358    modified list.  */
5359 
5360 tree
5361 remove_attribute (const char *attr_name, tree list)
5362 {
5363   tree *p;
5364   size_t attr_len = strlen (attr_name);
5365 
5366   gcc_checking_assert (attr_name[0] != '_');
5367 
5368   for (p = &list; *p; )
5369     {
5370       tree l = *p;
5371       /* TODO: If we were storing attributes in normalized form, here
5372 	 we could use a simple strcmp().  */
5373       if (private_is_attribute_p (attr_name, attr_len, TREE_PURPOSE (l)))
5374 	*p = TREE_CHAIN (l);
5375       else
5376 	p = &TREE_CHAIN (l);
5377     }
5378 
5379   return list;
5380 }
5381 
5382 /* Return an attribute list that is the union of a1 and a2.  */
5383 
5384 tree
5385 merge_attributes (tree a1, tree a2)
5386 {
5387   tree attributes;
5388 
5389   /* Either one unset?  Take the set one.  */
5390 
5391   if ((attributes = a1) == 0)
5392     attributes = a2;
5393 
5394   /* One that completely contains the other?  Take it.  */
5395 
5396   else if (a2 != 0 && ! attribute_list_contained (a1, a2))
5397     {
5398       if (attribute_list_contained (a2, a1))
5399 	attributes = a2;
5400       else
5401 	{
5402 	  /* Pick the longest list, and hang on the other list.  */
5403 
5404 	  if (list_length (a1) < list_length (a2))
5405 	    attributes = a2, a2 = a1;
5406 
5407 	  for (; a2 != 0; a2 = TREE_CHAIN (a2))
5408 	    {
5409 	      tree a;
5410 	      for (a = lookup_ident_attribute (TREE_PURPOSE (a2), attributes);
5411 		   a != NULL_TREE && !attribute_value_equal (a, a2);
5412 		   a = lookup_ident_attribute (TREE_PURPOSE (a2), TREE_CHAIN (a)))
5413 		;
5414 	      if (a == NULL_TREE)
5415 		{
5416 		  a1 = copy_node (a2);
5417 		  TREE_CHAIN (a1) = attributes;
5418 		  attributes = a1;
5419 		}
5420 	    }
5421 	}
5422     }
5423   return attributes;
5424 }
5425 
5426 /* Given types T1 and T2, merge their attributes and return
5427   the result.  */
5428 
5429 tree
5430 merge_type_attributes (tree t1, tree t2)
5431 {
5432   return merge_attributes (TYPE_ATTRIBUTES (t1),
5433 			   TYPE_ATTRIBUTES (t2));
5434 }
5435 
5436 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
5437    the result.  */
5438 
5439 tree
5440 merge_decl_attributes (tree olddecl, tree newdecl)
5441 {
5442   return merge_attributes (DECL_ATTRIBUTES (olddecl),
5443 			   DECL_ATTRIBUTES (newdecl));
5444 }
5445 
5446 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
5447 
5448 /* Specialization of merge_decl_attributes for various Windows targets.
5449 
5450    This handles the following situation:
5451 
5452      __declspec (dllimport) int foo;
5453      int foo;
5454 
5455    The second instance of `foo' nullifies the dllimport.  */
5456 
5457 tree
5458 merge_dllimport_decl_attributes (tree old, tree new_tree)
5459 {
5460   tree a;
5461   int delete_dllimport_p = 1;
5462 
5463   /* What we need to do here is remove from `old' dllimport if it doesn't
5464      appear in `new'.  dllimport behaves like extern: if a declaration is
5465      marked dllimport and a definition appears later, then the object
5466      is not dllimport'd.  We also remove a `new' dllimport if the old list
5467      contains dllexport:  dllexport always overrides dllimport, regardless
5468      of the order of declaration.  */
5469   if (!VAR_OR_FUNCTION_DECL_P (new_tree))
5470     delete_dllimport_p = 0;
5471   else if (DECL_DLLIMPORT_P (new_tree)
5472      	   && lookup_attribute ("dllexport", DECL_ATTRIBUTES (old)))
5473     {
5474       DECL_DLLIMPORT_P (new_tree) = 0;
5475       warning (OPT_Wattributes, "%q+D already declared with dllexport attribute: "
5476 	      "dllimport ignored", new_tree);
5477     }
5478   else if (DECL_DLLIMPORT_P (old) && !DECL_DLLIMPORT_P (new_tree))
5479     {
5480       /* Warn about overriding a symbol that has already been used, e.g.:
5481            extern int __attribute__ ((dllimport)) foo;
5482 	   int* bar () {return &foo;}
5483 	   int foo;
5484       */
5485       if (TREE_USED (old))
5486 	{
5487 	  warning (0, "%q+D redeclared without dllimport attribute "
5488 		   "after being referenced with dll linkage", new_tree);
5489 	  /* If we have used a variable's address with dllimport linkage,
5490 	      keep the old DECL_DLLIMPORT_P flag: the ADDR_EXPR using the
5491 	      decl may already have had TREE_CONSTANT computed.
5492 	      We still remove the attribute so that assembler code refers
5493 	      to '&foo rather than '_imp__foo'.  */
5494 	  if (TREE_CODE (old) == VAR_DECL && TREE_ADDRESSABLE (old))
5495 	    DECL_DLLIMPORT_P (new_tree) = 1;
5496 	}
5497 
5498       /* Let an inline definition silently override the external reference,
5499 	 but otherwise warn about attribute inconsistency.  */
5500       else if (TREE_CODE (new_tree) == VAR_DECL
5501 	       || !DECL_DECLARED_INLINE_P (new_tree))
5502 	warning (OPT_Wattributes, "%q+D redeclared without dllimport attribute: "
5503 		  "previous dllimport ignored", new_tree);
5504     }
5505   else
5506     delete_dllimport_p = 0;
5507 
5508   a = merge_attributes (DECL_ATTRIBUTES (old), DECL_ATTRIBUTES (new_tree));
5509 
5510   if (delete_dllimport_p)
5511     a = remove_attribute ("dllimport", a);
5512 
5513   return a;
5514 }
5515 
5516 /* Handle a "dllimport" or "dllexport" attribute; arguments as in
5517    struct attribute_spec.handler.  */
5518 
5519 tree
5520 handle_dll_attribute (tree * pnode, tree name, tree args, int flags,
5521 		      bool *no_add_attrs)
5522 {
5523   tree node = *pnode;
5524   bool is_dllimport;
5525 
5526   /* These attributes may apply to structure and union types being created,
5527      but otherwise should pass to the declaration involved.  */
5528   if (!DECL_P (node))
5529     {
5530       if (flags & ((int) ATTR_FLAG_DECL_NEXT | (int) ATTR_FLAG_FUNCTION_NEXT
5531 		   | (int) ATTR_FLAG_ARRAY_NEXT))
5532 	{
5533 	  *no_add_attrs = true;
5534 	  return tree_cons (name, args, NULL_TREE);
5535 	}
5536       if (TREE_CODE (node) == RECORD_TYPE
5537 	  || TREE_CODE (node) == UNION_TYPE)
5538 	{
5539 	  node = TYPE_NAME (node);
5540 	  if (!node)
5541 	    return NULL_TREE;
5542 	}
5543       else
5544 	{
5545 	  warning (OPT_Wattributes, "%qE attribute ignored",
5546 		   name);
5547 	  *no_add_attrs = true;
5548 	  return NULL_TREE;
5549 	}
5550     }
5551 
5552   if (TREE_CODE (node) != FUNCTION_DECL
5553       && TREE_CODE (node) != VAR_DECL
5554       && TREE_CODE (node) != TYPE_DECL)
5555     {
5556       *no_add_attrs = true;
5557       warning (OPT_Wattributes, "%qE attribute ignored",
5558 	       name);
5559       return NULL_TREE;
5560     }
5561 
5562   if (TREE_CODE (node) == TYPE_DECL
5563       && TREE_CODE (TREE_TYPE (node)) != RECORD_TYPE
5564       && TREE_CODE (TREE_TYPE (node)) != UNION_TYPE)
5565     {
5566       *no_add_attrs = true;
5567       warning (OPT_Wattributes, "%qE attribute ignored",
5568 	       name);
5569       return NULL_TREE;
5570     }
5571 
5572   is_dllimport = is_attribute_p ("dllimport", name);
5573 
5574   /* Report error on dllimport ambiguities seen now before they cause
5575      any damage.  */
5576   if (is_dllimport)
5577     {
5578       /* Honor any target-specific overrides. */
5579       if (!targetm.valid_dllimport_attribute_p (node))
5580 	*no_add_attrs = true;
5581 
5582      else if (TREE_CODE (node) == FUNCTION_DECL
5583 	        && DECL_DECLARED_INLINE_P (node))
5584 	{
5585 	  warning (OPT_Wattributes, "inline function %q+D declared as "
5586 		  " dllimport: attribute ignored", node);
5587 	  *no_add_attrs = true;
5588 	}
5589       /* Like MS, treat definition of dllimported variables and
5590 	 non-inlined functions on declaration as syntax errors. */
5591      else if (TREE_CODE (node) == FUNCTION_DECL && DECL_INITIAL (node))
5592 	{
5593 	  error ("function %q+D definition is marked dllimport", node);
5594 	  *no_add_attrs = true;
5595 	}
5596 
5597      else if (TREE_CODE (node) == VAR_DECL)
5598 	{
5599 	  if (DECL_INITIAL (node))
5600 	    {
5601 	      error ("variable %q+D definition is marked dllimport",
5602 		     node);
5603 	      *no_add_attrs = true;
5604 	    }
5605 
5606 	  /* `extern' needn't be specified with dllimport.
5607 	     Specify `extern' now and hope for the best.  Sigh.  */
5608 	  DECL_EXTERNAL (node) = 1;
5609 	  /* Also, implicitly give dllimport'd variables declared within
5610 	     a function global scope, unless declared static.  */
5611 	  if (current_function_decl != NULL_TREE && !TREE_STATIC (node))
5612 	    TREE_PUBLIC (node) = 1;
5613 	}
5614 
5615       if (*no_add_attrs == false)
5616         DECL_DLLIMPORT_P (node) = 1;
5617     }
5618   else if (TREE_CODE (node) == FUNCTION_DECL
5619 	   && DECL_DECLARED_INLINE_P (node)
5620 	   && flag_keep_inline_dllexport)
5621     /* An exported function, even if inline, must be emitted.  */
5622     DECL_EXTERNAL (node) = 0;
5623 
5624   /*  Report error if symbol is not accessible at global scope.  */
5625   if (!TREE_PUBLIC (node)
5626       && (TREE_CODE (node) == VAR_DECL
5627 	  || TREE_CODE (node) == FUNCTION_DECL))
5628     {
5629       error ("external linkage required for symbol %q+D because of "
5630 	     "%qE attribute", node, name);
5631       *no_add_attrs = true;
5632     }
5633 
5634   /* A dllexport'd entity must have default visibility so that other
5635      program units (shared libraries or the main executable) can see
5636      it.  A dllimport'd entity must have default visibility so that
5637      the linker knows that undefined references within this program
5638      unit can be resolved by the dynamic linker.  */
5639   if (!*no_add_attrs)
5640     {
5641       if (DECL_VISIBILITY_SPECIFIED (node)
5642 	  && DECL_VISIBILITY (node) != VISIBILITY_DEFAULT)
5643 	error ("%qE implies default visibility, but %qD has already "
5644 	       "been declared with a different visibility",
5645 	       name, node);
5646       DECL_VISIBILITY (node) = VISIBILITY_DEFAULT;
5647       DECL_VISIBILITY_SPECIFIED (node) = 1;
5648     }
5649 
5650   return NULL_TREE;
5651 }
5652 
5653 #endif /* TARGET_DLLIMPORT_DECL_ATTRIBUTES  */
5654 
5655 /* Set the type qualifiers for TYPE to TYPE_QUALS, which is a bitmask
5656    of the various TYPE_QUAL values.  */
5657 
5658 static void
5659 set_type_quals (tree type, int type_quals)
5660 {
5661   TYPE_READONLY (type) = (type_quals & TYPE_QUAL_CONST) != 0;
5662   TYPE_VOLATILE (type) = (type_quals & TYPE_QUAL_VOLATILE) != 0;
5663   TYPE_RESTRICT (type) = (type_quals & TYPE_QUAL_RESTRICT) != 0;
5664   TYPE_ADDR_SPACE (type) = DECODE_QUAL_ADDR_SPACE (type_quals);
5665 }
5666 
5667 /* Returns true iff CAND is equivalent to BASE with TYPE_QUALS.  */
5668 
5669 bool
5670 check_qualified_type (const_tree cand, const_tree base, int type_quals)
5671 {
5672   return (TYPE_QUALS (cand) == type_quals
5673 	  && TYPE_NAME (cand) == TYPE_NAME (base)
5674 	  /* Apparently this is needed for Objective-C.  */
5675 	  && TYPE_CONTEXT (cand) == TYPE_CONTEXT (base)
5676 	  /* Check alignment.  */
5677 	  && TYPE_ALIGN (cand) == TYPE_ALIGN (base)
5678 	  && attribute_list_equal (TYPE_ATTRIBUTES (cand),
5679 				   TYPE_ATTRIBUTES (base)));
5680 }
5681 
5682 /* Returns true iff CAND is equivalent to BASE with ALIGN.  */
5683 
5684 static bool
5685 check_aligned_type (const_tree cand, const_tree base, unsigned int align)
5686 {
5687   return (TYPE_QUALS (cand) == TYPE_QUALS (base)
5688 	  && TYPE_NAME (cand) == TYPE_NAME (base)
5689 	  /* Apparently this is needed for Objective-C.  */
5690 	  && TYPE_CONTEXT (cand) == TYPE_CONTEXT (base)
5691 	  /* Check alignment.  */
5692 	  && TYPE_ALIGN (cand) == align
5693 	  && attribute_list_equal (TYPE_ATTRIBUTES (cand),
5694 				   TYPE_ATTRIBUTES (base)));
5695 }
5696 
5697 /* Return a version of the TYPE, qualified as indicated by the
5698    TYPE_QUALS, if one exists.  If no qualified version exists yet,
5699    return NULL_TREE.  */
5700 
5701 tree
5702 get_qualified_type (tree type, int type_quals)
5703 {
5704   tree t;
5705 
5706   if (TYPE_QUALS (type) == type_quals)
5707     return type;
5708 
5709   /* Search the chain of variants to see if there is already one there just
5710      like the one we need to have.  If so, use that existing one.  We must
5711      preserve the TYPE_NAME, since there is code that depends on this.  */
5712   for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
5713     if (check_qualified_type (t, type, type_quals))
5714       return t;
5715 
5716   return NULL_TREE;
5717 }
5718 
5719 /* Like get_qualified_type, but creates the type if it does not
5720    exist.  This function never returns NULL_TREE.  */
5721 
5722 tree
5723 build_qualified_type (tree type, int type_quals)
5724 {
5725   tree t;
5726 
5727   /* See if we already have the appropriate qualified variant.  */
5728   t = get_qualified_type (type, type_quals);
5729 
5730   /* If not, build it.  */
5731   if (!t)
5732     {
5733       t = build_variant_type_copy (type);
5734       set_type_quals (t, type_quals);
5735 
5736       if (TYPE_STRUCTURAL_EQUALITY_P (type))
5737 	/* Propagate structural equality. */
5738 	SET_TYPE_STRUCTURAL_EQUALITY (t);
5739       else if (TYPE_CANONICAL (type) != type)
5740 	/* Build the underlying canonical type, since it is different
5741 	   from TYPE. */
5742 	TYPE_CANONICAL (t) = build_qualified_type (TYPE_CANONICAL (type),
5743 						   type_quals);
5744       else
5745 	/* T is its own canonical type. */
5746 	TYPE_CANONICAL (t) = t;
5747 
5748     }
5749 
5750   return t;
5751 }
5752 
5753 /* Create a variant of type T with alignment ALIGN.  */
5754 
5755 tree
5756 build_aligned_type (tree type, unsigned int align)
5757 {
5758   tree t;
5759 
5760   if (TYPE_PACKED (type)
5761       || TYPE_ALIGN (type) == align)
5762     return type;
5763 
5764   for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
5765     if (check_aligned_type (t, type, align))
5766       return t;
5767 
5768   t = build_variant_type_copy (type);
5769   TYPE_ALIGN (t) = align;
5770 
5771   return t;
5772 }
5773 
5774 /* Create a new distinct copy of TYPE.  The new type is made its own
5775    MAIN_VARIANT. If TYPE requires structural equality checks, the
5776    resulting type requires structural equality checks; otherwise, its
5777    TYPE_CANONICAL points to itself. */
5778 
5779 tree
5780 build_distinct_type_copy (tree type)
5781 {
5782   tree t = copy_node (type);
5783 
5784   TYPE_POINTER_TO (t) = 0;
5785   TYPE_REFERENCE_TO (t) = 0;
5786 
5787   /* Set the canonical type either to a new equivalence class, or
5788      propagate the need for structural equality checks. */
5789   if (TYPE_STRUCTURAL_EQUALITY_P (type))
5790     SET_TYPE_STRUCTURAL_EQUALITY (t);
5791   else
5792     TYPE_CANONICAL (t) = t;
5793 
5794   /* Make it its own variant.  */
5795   TYPE_MAIN_VARIANT (t) = t;
5796   TYPE_NEXT_VARIANT (t) = 0;
5797 
5798   /* Note that it is now possible for TYPE_MIN_VALUE to be a value
5799      whose TREE_TYPE is not t.  This can also happen in the Ada
5800      frontend when using subtypes.  */
5801 
5802   return t;
5803 }
5804 
5805 /* Create a new variant of TYPE, equivalent but distinct.  This is so
5806    the caller can modify it. TYPE_CANONICAL for the return type will
5807    be equivalent to TYPE_CANONICAL of TYPE, indicating that the types
5808    are considered equal by the language itself (or that both types
5809    require structural equality checks). */
5810 
5811 tree
5812 build_variant_type_copy (tree type)
5813 {
5814   tree t, m = TYPE_MAIN_VARIANT (type);
5815 
5816   t = build_distinct_type_copy (type);
5817 
5818   /* Since we're building a variant, assume that it is a non-semantic
5819      variant. This also propagates TYPE_STRUCTURAL_EQUALITY_P. */
5820   TYPE_CANONICAL (t) = TYPE_CANONICAL (type);
5821 
5822   /* Add the new type to the chain of variants of TYPE.  */
5823   TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
5824   TYPE_NEXT_VARIANT (m) = t;
5825   TYPE_MAIN_VARIANT (t) = m;
5826 
5827   return t;
5828 }
5829 
5830 /* Return true if the from tree in both tree maps are equal.  */
5831 
5832 int
5833 tree_map_base_eq (const void *va, const void *vb)
5834 {
5835   const struct tree_map_base  *const a = (const struct tree_map_base *) va,
5836     *const b = (const struct tree_map_base *) vb;
5837   return (a->from == b->from);
5838 }
5839 
5840 /* Hash a from tree in a tree_base_map.  */
5841 
5842 unsigned int
5843 tree_map_base_hash (const void *item)
5844 {
5845   return htab_hash_pointer (((const struct tree_map_base *)item)->from);
5846 }
5847 
5848 /* Return true if this tree map structure is marked for garbage collection
5849    purposes.  We simply return true if the from tree is marked, so that this
5850    structure goes away when the from tree goes away.  */
5851 
5852 int
5853 tree_map_base_marked_p (const void *p)
5854 {
5855   return ggc_marked_p (((const struct tree_map_base *) p)->from);
5856 }
5857 
5858 /* Hash a from tree in a tree_map.  */
5859 
5860 unsigned int
5861 tree_map_hash (const void *item)
5862 {
5863   return (((const struct tree_map *) item)->hash);
5864 }
5865 
5866 /* Hash a from tree in a tree_decl_map.  */
5867 
5868 unsigned int
5869 tree_decl_map_hash (const void *item)
5870 {
5871   return DECL_UID (((const struct tree_decl_map *) item)->base.from);
5872 }
5873 
5874 /* Return the initialization priority for DECL.  */
5875 
5876 priority_type
5877 decl_init_priority_lookup (tree decl)
5878 {
5879   struct tree_priority_map *h;
5880   struct tree_map_base in;
5881 
5882   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
5883   in.from = decl;
5884   h = (struct tree_priority_map *) htab_find (init_priority_for_decl, &in);
5885   return h ? h->init : DEFAULT_INIT_PRIORITY;
5886 }
5887 
5888 /* Return the finalization priority for DECL.  */
5889 
5890 priority_type
5891 decl_fini_priority_lookup (tree decl)
5892 {
5893   struct tree_priority_map *h;
5894   struct tree_map_base in;
5895 
5896   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
5897   in.from = decl;
5898   h = (struct tree_priority_map *) htab_find (init_priority_for_decl, &in);
5899   return h ? h->fini : DEFAULT_INIT_PRIORITY;
5900 }
5901 
5902 /* Return the initialization and finalization priority information for
5903    DECL.  If there is no previous priority information, a freshly
5904    allocated structure is returned.  */
5905 
5906 static struct tree_priority_map *
5907 decl_priority_info (tree decl)
5908 {
5909   struct tree_priority_map in;
5910   struct tree_priority_map *h;
5911   void **loc;
5912 
5913   in.base.from = decl;
5914   loc = htab_find_slot (init_priority_for_decl, &in, INSERT);
5915   h = (struct tree_priority_map *) *loc;
5916   if (!h)
5917     {
5918       h = ggc_alloc_cleared_tree_priority_map ();
5919       *loc = h;
5920       h->base.from = decl;
5921       h->init = DEFAULT_INIT_PRIORITY;
5922       h->fini = DEFAULT_INIT_PRIORITY;
5923     }
5924 
5925   return h;
5926 }
5927 
5928 /* Set the initialization priority for DECL to PRIORITY.  */
5929 
5930 void
5931 decl_init_priority_insert (tree decl, priority_type priority)
5932 {
5933   struct tree_priority_map *h;
5934 
5935   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
5936   if (priority == DEFAULT_INIT_PRIORITY)
5937     return;
5938   h = decl_priority_info (decl);
5939   h->init = priority;
5940 }
5941 
5942 /* Set the finalization priority for DECL to PRIORITY.  */
5943 
5944 void
5945 decl_fini_priority_insert (tree decl, priority_type priority)
5946 {
5947   struct tree_priority_map *h;
5948 
5949   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
5950   if (priority == DEFAULT_INIT_PRIORITY)
5951     return;
5952   h = decl_priority_info (decl);
5953   h->fini = priority;
5954 }
5955 
5956 /* Print out the statistics for the DECL_DEBUG_EXPR hash table.  */
5957 
5958 static void
5959 print_debug_expr_statistics (void)
5960 {
5961   fprintf (stderr, "DECL_DEBUG_EXPR  hash: size %ld, %ld elements, %f collisions\n",
5962 	   (long) htab_size (debug_expr_for_decl),
5963 	   (long) htab_elements (debug_expr_for_decl),
5964 	   htab_collisions (debug_expr_for_decl));
5965 }
5966 
5967 /* Print out the statistics for the DECL_VALUE_EXPR hash table.  */
5968 
5969 static void
5970 print_value_expr_statistics (void)
5971 {
5972   fprintf (stderr, "DECL_VALUE_EXPR  hash: size %ld, %ld elements, %f collisions\n",
5973 	   (long) htab_size (value_expr_for_decl),
5974 	   (long) htab_elements (value_expr_for_decl),
5975 	   htab_collisions (value_expr_for_decl));
5976 }
5977 
5978 /* Lookup a debug expression for FROM, and return it if we find one.  */
5979 
5980 tree
5981 decl_debug_expr_lookup (tree from)
5982 {
5983   struct tree_decl_map *h, in;
5984   in.base.from = from;
5985 
5986   h = (struct tree_decl_map *)
5987       htab_find_with_hash (debug_expr_for_decl, &in, DECL_UID (from));
5988   if (h)
5989     return h->to;
5990   return NULL_TREE;
5991 }
5992 
5993 /* Insert a mapping FROM->TO in the debug expression hashtable.  */
5994 
5995 void
5996 decl_debug_expr_insert (tree from, tree to)
5997 {
5998   struct tree_decl_map *h;
5999   void **loc;
6000 
6001   h = ggc_alloc_tree_decl_map ();
6002   h->base.from = from;
6003   h->to = to;
6004   loc = htab_find_slot_with_hash (debug_expr_for_decl, h, DECL_UID (from),
6005 				  INSERT);
6006   *(struct tree_decl_map **) loc = h;
6007 }
6008 
6009 /* Lookup a value expression for FROM, and return it if we find one.  */
6010 
6011 tree
6012 decl_value_expr_lookup (tree from)
6013 {
6014   struct tree_decl_map *h, in;
6015   in.base.from = from;
6016 
6017   h = (struct tree_decl_map *)
6018       htab_find_with_hash (value_expr_for_decl, &in, DECL_UID (from));
6019   if (h)
6020     return h->to;
6021   return NULL_TREE;
6022 }
6023 
6024 /* Insert a mapping FROM->TO in the value expression hashtable.  */
6025 
6026 void
6027 decl_value_expr_insert (tree from, tree to)
6028 {
6029   struct tree_decl_map *h;
6030   void **loc;
6031 
6032   h = ggc_alloc_tree_decl_map ();
6033   h->base.from = from;
6034   h->to = to;
6035   loc = htab_find_slot_with_hash (value_expr_for_decl, h, DECL_UID (from),
6036 				  INSERT);
6037   *(struct tree_decl_map **) loc = h;
6038 }
6039 
6040 /* Lookup a vector of debug arguments for FROM, and return it if we
6041    find one.  */
6042 
6043 VEC(tree, gc) **
6044 decl_debug_args_lookup (tree from)
6045 {
6046   struct tree_vec_map *h, in;
6047 
6048   if (!DECL_HAS_DEBUG_ARGS_P (from))
6049     return NULL;
6050   gcc_checking_assert (debug_args_for_decl != NULL);
6051   in.base.from = from;
6052   h = (struct tree_vec_map *)
6053       htab_find_with_hash (debug_args_for_decl, &in, DECL_UID (from));
6054   if (h)
6055     return &h->to;
6056   return NULL;
6057 }
6058 
6059 /* Insert a mapping FROM->empty vector of debug arguments in the value
6060    expression hashtable.  */
6061 
6062 VEC(tree, gc) **
6063 decl_debug_args_insert (tree from)
6064 {
6065   struct tree_vec_map *h;
6066   void **loc;
6067 
6068   if (DECL_HAS_DEBUG_ARGS_P (from))
6069     return decl_debug_args_lookup (from);
6070   if (debug_args_for_decl == NULL)
6071     debug_args_for_decl = htab_create_ggc (64, tree_vec_map_hash,
6072 					   tree_vec_map_eq, 0);
6073   h = ggc_alloc_tree_vec_map ();
6074   h->base.from = from;
6075   h->to = NULL;
6076   loc = htab_find_slot_with_hash (debug_args_for_decl, h, DECL_UID (from),
6077 				  INSERT);
6078   *(struct tree_vec_map **) loc = h;
6079   DECL_HAS_DEBUG_ARGS_P (from) = 1;
6080   return &h->to;
6081 }
6082 
6083 /* Hashing of types so that we don't make duplicates.
6084    The entry point is `type_hash_canon'.  */
6085 
6086 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
6087    with types in the TREE_VALUE slots), by adding the hash codes
6088    of the individual types.  */
6089 
6090 static unsigned int
6091 type_hash_list (const_tree list, hashval_t hashcode)
6092 {
6093   const_tree tail;
6094 
6095   for (tail = list; tail; tail = TREE_CHAIN (tail))
6096     if (TREE_VALUE (tail) != error_mark_node)
6097       hashcode = iterative_hash_object (TYPE_HASH (TREE_VALUE (tail)),
6098 					hashcode);
6099 
6100   return hashcode;
6101 }
6102 
6103 /* These are the Hashtable callback functions.  */
6104 
6105 /* Returns true iff the types are equivalent.  */
6106 
6107 static int
6108 type_hash_eq (const void *va, const void *vb)
6109 {
6110   const struct type_hash *const a = (const struct type_hash *) va,
6111     *const b = (const struct type_hash *) vb;
6112 
6113   /* First test the things that are the same for all types.  */
6114   if (a->hash != b->hash
6115       || TREE_CODE (a->type) != TREE_CODE (b->type)
6116       || TREE_TYPE (a->type) != TREE_TYPE (b->type)
6117       || !attribute_list_equal (TYPE_ATTRIBUTES (a->type),
6118 				 TYPE_ATTRIBUTES (b->type))
6119       || (TREE_CODE (a->type) != COMPLEX_TYPE
6120           && TYPE_NAME (a->type) != TYPE_NAME (b->type)))
6121     return 0;
6122 
6123   /* Be careful about comparing arrays before and after the element type
6124      has been completed; don't compare TYPE_ALIGN unless both types are
6125      complete.  */
6126   if (COMPLETE_TYPE_P (a->type) && COMPLETE_TYPE_P (b->type)
6127       && (TYPE_ALIGN (a->type) != TYPE_ALIGN (b->type)
6128 	  || TYPE_MODE (a->type) != TYPE_MODE (b->type)))
6129     return 0;
6130 
6131   switch (TREE_CODE (a->type))
6132     {
6133     case VOID_TYPE:
6134     case COMPLEX_TYPE:
6135     case POINTER_TYPE:
6136     case REFERENCE_TYPE:
6137     case NULLPTR_TYPE:
6138       return 1;
6139 
6140     case VECTOR_TYPE:
6141       return TYPE_VECTOR_SUBPARTS (a->type) == TYPE_VECTOR_SUBPARTS (b->type);
6142 
6143     case ENUMERAL_TYPE:
6144       if (TYPE_VALUES (a->type) != TYPE_VALUES (b->type)
6145 	  && !(TYPE_VALUES (a->type)
6146 	       && TREE_CODE (TYPE_VALUES (a->type)) == TREE_LIST
6147 	       && TYPE_VALUES (b->type)
6148 	       && TREE_CODE (TYPE_VALUES (b->type)) == TREE_LIST
6149 	       && type_list_equal (TYPE_VALUES (a->type),
6150 				   TYPE_VALUES (b->type))))
6151 	return 0;
6152 
6153       /* ... fall through ... */
6154 
6155     case INTEGER_TYPE:
6156     case REAL_TYPE:
6157     case BOOLEAN_TYPE:
6158       return ((TYPE_MAX_VALUE (a->type) == TYPE_MAX_VALUE (b->type)
6159 	       || tree_int_cst_equal (TYPE_MAX_VALUE (a->type),
6160 				      TYPE_MAX_VALUE (b->type)))
6161 	      && (TYPE_MIN_VALUE (a->type) == TYPE_MIN_VALUE (b->type)
6162 		  || tree_int_cst_equal (TYPE_MIN_VALUE (a->type),
6163 					 TYPE_MIN_VALUE (b->type))));
6164 
6165     case FIXED_POINT_TYPE:
6166       return TYPE_SATURATING (a->type) == TYPE_SATURATING (b->type);
6167 
6168     case OFFSET_TYPE:
6169       return TYPE_OFFSET_BASETYPE (a->type) == TYPE_OFFSET_BASETYPE (b->type);
6170 
6171     case METHOD_TYPE:
6172       if (TYPE_METHOD_BASETYPE (a->type) == TYPE_METHOD_BASETYPE (b->type)
6173 	  && (TYPE_ARG_TYPES (a->type) == TYPE_ARG_TYPES (b->type)
6174 	      || (TYPE_ARG_TYPES (a->type)
6175 		  && TREE_CODE (TYPE_ARG_TYPES (a->type)) == TREE_LIST
6176 		  && TYPE_ARG_TYPES (b->type)
6177 		  && TREE_CODE (TYPE_ARG_TYPES (b->type)) == TREE_LIST
6178 		  && type_list_equal (TYPE_ARG_TYPES (a->type),
6179 				      TYPE_ARG_TYPES (b->type)))))
6180         break;
6181       return 0;
6182     case ARRAY_TYPE:
6183       return TYPE_DOMAIN (a->type) == TYPE_DOMAIN (b->type);
6184 
6185     case RECORD_TYPE:
6186     case UNION_TYPE:
6187     case QUAL_UNION_TYPE:
6188       return (TYPE_FIELDS (a->type) == TYPE_FIELDS (b->type)
6189 	      || (TYPE_FIELDS (a->type)
6190 		  && TREE_CODE (TYPE_FIELDS (a->type)) == TREE_LIST
6191 		  && TYPE_FIELDS (b->type)
6192 		  && TREE_CODE (TYPE_FIELDS (b->type)) == TREE_LIST
6193 		  && type_list_equal (TYPE_FIELDS (a->type),
6194 				      TYPE_FIELDS (b->type))));
6195 
6196     case FUNCTION_TYPE:
6197       if (TYPE_ARG_TYPES (a->type) == TYPE_ARG_TYPES (b->type)
6198 	  || (TYPE_ARG_TYPES (a->type)
6199 	      && TREE_CODE (TYPE_ARG_TYPES (a->type)) == TREE_LIST
6200 	      && TYPE_ARG_TYPES (b->type)
6201 	      && TREE_CODE (TYPE_ARG_TYPES (b->type)) == TREE_LIST
6202 	      && type_list_equal (TYPE_ARG_TYPES (a->type),
6203 				  TYPE_ARG_TYPES (b->type))))
6204 	break;
6205       return 0;
6206 
6207     default:
6208       return 0;
6209     }
6210 
6211   if (lang_hooks.types.type_hash_eq != NULL)
6212     return lang_hooks.types.type_hash_eq (a->type, b->type);
6213 
6214   return 1;
6215 }
6216 
6217 /* Return the cached hash value.  */
6218 
6219 static hashval_t
6220 type_hash_hash (const void *item)
6221 {
6222   return ((const struct type_hash *) item)->hash;
6223 }
6224 
6225 /* Look in the type hash table for a type isomorphic to TYPE.
6226    If one is found, return it.  Otherwise return 0.  */
6227 
6228 tree
6229 type_hash_lookup (hashval_t hashcode, tree type)
6230 {
6231   struct type_hash *h, in;
6232 
6233   /* The TYPE_ALIGN field of a type is set by layout_type(), so we
6234      must call that routine before comparing TYPE_ALIGNs.  */
6235   layout_type (type);
6236 
6237   in.hash = hashcode;
6238   in.type = type;
6239 
6240   h = (struct type_hash *) htab_find_with_hash (type_hash_table, &in,
6241 						hashcode);
6242   if (h)
6243     return h->type;
6244   return NULL_TREE;
6245 }
6246 
6247 /* Add an entry to the type-hash-table
6248    for a type TYPE whose hash code is HASHCODE.  */
6249 
6250 void
6251 type_hash_add (hashval_t hashcode, tree type)
6252 {
6253   struct type_hash *h;
6254   void **loc;
6255 
6256   h = ggc_alloc_type_hash ();
6257   h->hash = hashcode;
6258   h->type = type;
6259   loc = htab_find_slot_with_hash (type_hash_table, h, hashcode, INSERT);
6260   *loc = (void *)h;
6261 }
6262 
6263 /* Given TYPE, and HASHCODE its hash code, return the canonical
6264    object for an identical type if one already exists.
6265    Otherwise, return TYPE, and record it as the canonical object.
6266 
6267    To use this function, first create a type of the sort you want.
6268    Then compute its hash code from the fields of the type that
6269    make it different from other similar types.
6270    Then call this function and use the value.  */
6271 
6272 tree
6273 type_hash_canon (unsigned int hashcode, tree type)
6274 {
6275   tree t1;
6276 
6277   /* The hash table only contains main variants, so ensure that's what we're
6278      being passed.  */
6279   gcc_assert (TYPE_MAIN_VARIANT (type) == type);
6280 
6281   /* See if the type is in the hash table already.  If so, return it.
6282      Otherwise, add the type.  */
6283   t1 = type_hash_lookup (hashcode, type);
6284   if (t1 != 0)
6285     {
6286 #ifdef GATHER_STATISTICS
6287       tree_code_counts[(int) TREE_CODE (type)]--;
6288       tree_node_counts[(int) t_kind]--;
6289       tree_node_sizes[(int) t_kind] -= sizeof (struct tree_type_non_common);
6290 #endif
6291       return t1;
6292     }
6293   else
6294     {
6295       type_hash_add (hashcode, type);
6296       return type;
6297     }
6298 }
6299 
6300 /* See if the data pointed to by the type hash table is marked.  We consider
6301    it marked if the type is marked or if a debug type number or symbol
6302    table entry has been made for the type.  */
6303 
6304 static int
6305 type_hash_marked_p (const void *p)
6306 {
6307   const_tree const type = ((const struct type_hash *) p)->type;
6308 
6309   return ggc_marked_p (type);
6310 }
6311 
6312 static void
6313 print_type_hash_statistics (void)
6314 {
6315   fprintf (stderr, "Type hash: size %ld, %ld elements, %f collisions\n",
6316 	   (long) htab_size (type_hash_table),
6317 	   (long) htab_elements (type_hash_table),
6318 	   htab_collisions (type_hash_table));
6319 }
6320 
6321 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
6322    with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
6323    by adding the hash codes of the individual attributes.  */
6324 
6325 static unsigned int
6326 attribute_hash_list (const_tree list, hashval_t hashcode)
6327 {
6328   const_tree tail;
6329 
6330   for (tail = list; tail; tail = TREE_CHAIN (tail))
6331     /* ??? Do we want to add in TREE_VALUE too? */
6332     hashcode = iterative_hash_object
6333       (IDENTIFIER_HASH_VALUE (TREE_PURPOSE (tail)), hashcode);
6334   return hashcode;
6335 }
6336 
6337 /* Given two lists of attributes, return true if list l2 is
6338    equivalent to l1.  */
6339 
6340 int
6341 attribute_list_equal (const_tree l1, const_tree l2)
6342 {
6343   if (l1 == l2)
6344     return 1;
6345 
6346   return attribute_list_contained (l1, l2)
6347 	 && attribute_list_contained (l2, l1);
6348 }
6349 
6350 /* Given two lists of attributes, return true if list L2 is
6351    completely contained within L1.  */
6352 /* ??? This would be faster if attribute names were stored in a canonicalized
6353    form.  Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
6354    must be used to show these elements are equivalent (which they are).  */
6355 /* ??? It's not clear that attributes with arguments will always be handled
6356    correctly.  */
6357 
6358 int
6359 attribute_list_contained (const_tree l1, const_tree l2)
6360 {
6361   const_tree t1, t2;
6362 
6363   /* First check the obvious, maybe the lists are identical.  */
6364   if (l1 == l2)
6365     return 1;
6366 
6367   /* Maybe the lists are similar.  */
6368   for (t1 = l1, t2 = l2;
6369        t1 != 0 && t2 != 0
6370         && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
6371         && TREE_VALUE (t1) == TREE_VALUE (t2);
6372        t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
6373     ;
6374 
6375   /* Maybe the lists are equal.  */
6376   if (t1 == 0 && t2 == 0)
6377     return 1;
6378 
6379   for (; t2 != 0; t2 = TREE_CHAIN (t2))
6380     {
6381       const_tree attr;
6382       /* This CONST_CAST is okay because lookup_attribute does not
6383 	 modify its argument and the return value is assigned to a
6384 	 const_tree.  */
6385       for (attr = lookup_ident_attribute (TREE_PURPOSE (t2), CONST_CAST_TREE(l1));
6386 	   attr != NULL_TREE && !attribute_value_equal (t2, attr);
6387 	   attr = lookup_ident_attribute (TREE_PURPOSE (t2), TREE_CHAIN (attr)))
6388 	;
6389 
6390       if (attr == NULL_TREE)
6391 	return 0;
6392     }
6393 
6394   return 1;
6395 }
6396 
6397 /* Given two lists of types
6398    (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
6399    return 1 if the lists contain the same types in the same order.
6400    Also, the TREE_PURPOSEs must match.  */
6401 
6402 int
6403 type_list_equal (const_tree l1, const_tree l2)
6404 {
6405   const_tree t1, t2;
6406 
6407   for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
6408     if (TREE_VALUE (t1) != TREE_VALUE (t2)
6409 	|| (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
6410 	    && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
6411 		  && (TREE_TYPE (TREE_PURPOSE (t1))
6412 		      == TREE_TYPE (TREE_PURPOSE (t2))))))
6413       return 0;
6414 
6415   return t1 == t2;
6416 }
6417 
6418 /* Returns the number of arguments to the FUNCTION_TYPE or METHOD_TYPE
6419    given by TYPE.  If the argument list accepts variable arguments,
6420    then this function counts only the ordinary arguments.  */
6421 
6422 int
6423 type_num_arguments (const_tree type)
6424 {
6425   int i = 0;
6426   tree t;
6427 
6428   for (t = TYPE_ARG_TYPES (type); t; t = TREE_CHAIN (t))
6429     /* If the function does not take a variable number of arguments,
6430        the last element in the list will have type `void'.  */
6431     if (VOID_TYPE_P (TREE_VALUE (t)))
6432       break;
6433     else
6434       ++i;
6435 
6436   return i;
6437 }
6438 
6439 /* Nonzero if integer constants T1 and T2
6440    represent the same constant value.  */
6441 
6442 int
6443 tree_int_cst_equal (const_tree t1, const_tree t2)
6444 {
6445   if (t1 == t2)
6446     return 1;
6447 
6448   if (t1 == 0 || t2 == 0)
6449     return 0;
6450 
6451   if (TREE_CODE (t1) == INTEGER_CST
6452       && TREE_CODE (t2) == INTEGER_CST
6453       && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
6454       && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
6455     return 1;
6456 
6457   return 0;
6458 }
6459 
6460 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
6461    The precise way of comparison depends on their data type.  */
6462 
6463 int
6464 tree_int_cst_lt (const_tree t1, const_tree t2)
6465 {
6466   if (t1 == t2)
6467     return 0;
6468 
6469   if (TYPE_UNSIGNED (TREE_TYPE (t1)) != TYPE_UNSIGNED (TREE_TYPE (t2)))
6470     {
6471       int t1_sgn = tree_int_cst_sgn (t1);
6472       int t2_sgn = tree_int_cst_sgn (t2);
6473 
6474       if (t1_sgn < t2_sgn)
6475 	return 1;
6476       else if (t1_sgn > t2_sgn)
6477 	return 0;
6478       /* Otherwise, both are non-negative, so we compare them as
6479 	 unsigned just in case one of them would overflow a signed
6480 	 type.  */
6481     }
6482   else if (!TYPE_UNSIGNED (TREE_TYPE (t1)))
6483     return INT_CST_LT (t1, t2);
6484 
6485   return INT_CST_LT_UNSIGNED (t1, t2);
6486 }
6487 
6488 /* Returns -1 if T1 < T2, 0 if T1 == T2, and 1 if T1 > T2.  */
6489 
6490 int
6491 tree_int_cst_compare (const_tree t1, const_tree t2)
6492 {
6493   if (tree_int_cst_lt (t1, t2))
6494     return -1;
6495   else if (tree_int_cst_lt (t2, t1))
6496     return 1;
6497   else
6498     return 0;
6499 }
6500 
6501 /* Return 1 if T is an INTEGER_CST that can be manipulated efficiently on
6502    the host.  If POS is zero, the value can be represented in a single
6503    HOST_WIDE_INT.  If POS is nonzero, the value must be non-negative and can
6504    be represented in a single unsigned HOST_WIDE_INT.  */
6505 
6506 int
6507 host_integerp (const_tree t, int pos)
6508 {
6509   if (t == NULL_TREE)
6510     return 0;
6511 
6512   return (TREE_CODE (t) == INTEGER_CST
6513 	  && ((TREE_INT_CST_HIGH (t) == 0
6514 	       && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) >= 0)
6515 	      || (! pos && TREE_INT_CST_HIGH (t) == -1
6516 		  && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0
6517 		  && (!TYPE_UNSIGNED (TREE_TYPE (t))
6518 		      || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
6519 			  && TYPE_IS_SIZETYPE (TREE_TYPE (t)))))
6520 	      || (pos && TREE_INT_CST_HIGH (t) == 0)));
6521 }
6522 
6523 /* Return the HOST_WIDE_INT least significant bits of T if it is an
6524    INTEGER_CST and there is no overflow.  POS is nonzero if the result must
6525    be non-negative.  We must be able to satisfy the above conditions.  */
6526 
6527 HOST_WIDE_INT
6528 tree_low_cst (const_tree t, int pos)
6529 {
6530   gcc_assert (host_integerp (t, pos));
6531   return TREE_INT_CST_LOW (t);
6532 }
6533 
6534 /* Return the HOST_WIDE_INT least significant bits of T, a sizetype
6535    kind INTEGER_CST.  This makes sure to properly sign-extend the
6536    constant.  */
6537 
6538 HOST_WIDE_INT
6539 size_low_cst (const_tree t)
6540 {
6541   double_int d = tree_to_double_int (t);
6542   return double_int_sext (d, TYPE_PRECISION (TREE_TYPE (t))).low;
6543 }
6544 
6545 /* Return the most significant (sign) bit of T.  */
6546 
6547 int
6548 tree_int_cst_sign_bit (const_tree t)
6549 {
6550   unsigned bitno = TYPE_PRECISION (TREE_TYPE (t)) - 1;
6551   unsigned HOST_WIDE_INT w;
6552 
6553   if (bitno < HOST_BITS_PER_WIDE_INT)
6554     w = TREE_INT_CST_LOW (t);
6555   else
6556     {
6557       w = TREE_INT_CST_HIGH (t);
6558       bitno -= HOST_BITS_PER_WIDE_INT;
6559     }
6560 
6561   return (w >> bitno) & 1;
6562 }
6563 
6564 /* Return an indication of the sign of the integer constant T.
6565    The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
6566    Note that -1 will never be returned if T's type is unsigned.  */
6567 
6568 int
6569 tree_int_cst_sgn (const_tree t)
6570 {
6571   if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
6572     return 0;
6573   else if (TYPE_UNSIGNED (TREE_TYPE (t)))
6574     return 1;
6575   else if (TREE_INT_CST_HIGH (t) < 0)
6576     return -1;
6577   else
6578     return 1;
6579 }
6580 
6581 /* Return the minimum number of bits needed to represent VALUE in a
6582    signed or unsigned type, UNSIGNEDP says which.  */
6583 
6584 unsigned int
6585 tree_int_cst_min_precision (tree value, bool unsignedp)
6586 {
6587   int log;
6588 
6589   /* If the value is negative, compute its negative minus 1.  The latter
6590      adjustment is because the absolute value of the largest negative value
6591      is one larger than the largest positive value.  This is equivalent to
6592      a bit-wise negation, so use that operation instead.  */
6593 
6594   if (tree_int_cst_sgn (value) < 0)
6595     value = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (value), value);
6596 
6597   /* Return the number of bits needed, taking into account the fact
6598      that we need one more bit for a signed than unsigned type.  */
6599 
6600   if (integer_zerop (value))
6601     log = 0;
6602   else
6603     log = tree_floor_log2 (value);
6604 
6605   return log + 1 + !unsignedp;
6606 }
6607 
6608 /* Compare two constructor-element-type constants.  Return 1 if the lists
6609    are known to be equal; otherwise return 0.  */
6610 
6611 int
6612 simple_cst_list_equal (const_tree l1, const_tree l2)
6613 {
6614   while (l1 != NULL_TREE && l2 != NULL_TREE)
6615     {
6616       if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
6617 	return 0;
6618 
6619       l1 = TREE_CHAIN (l1);
6620       l2 = TREE_CHAIN (l2);
6621     }
6622 
6623   return l1 == l2;
6624 }
6625 
6626 /* Return truthvalue of whether T1 is the same tree structure as T2.
6627    Return 1 if they are the same.
6628    Return 0 if they are understandably different.
6629    Return -1 if either contains tree structure not understood by
6630    this function.  */
6631 
6632 int
6633 simple_cst_equal (const_tree t1, const_tree t2)
6634 {
6635   enum tree_code code1, code2;
6636   int cmp;
6637   int i;
6638 
6639   if (t1 == t2)
6640     return 1;
6641   if (t1 == 0 || t2 == 0)
6642     return 0;
6643 
6644   code1 = TREE_CODE (t1);
6645   code2 = TREE_CODE (t2);
6646 
6647   if (CONVERT_EXPR_CODE_P (code1) || code1 == NON_LVALUE_EXPR)
6648     {
6649       if (CONVERT_EXPR_CODE_P (code2)
6650 	  || code2 == NON_LVALUE_EXPR)
6651 	return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6652       else
6653 	return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
6654     }
6655 
6656   else if (CONVERT_EXPR_CODE_P (code2)
6657 	   || code2 == NON_LVALUE_EXPR)
6658     return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
6659 
6660   if (code1 != code2)
6661     return 0;
6662 
6663   switch (code1)
6664     {
6665     case INTEGER_CST:
6666       return (TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
6667 	      && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2));
6668 
6669     case REAL_CST:
6670       return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
6671 
6672     case FIXED_CST:
6673       return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
6674 
6675     case STRING_CST:
6676       return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
6677 	      && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
6678 			 TREE_STRING_LENGTH (t1)));
6679 
6680     case CONSTRUCTOR:
6681       {
6682 	unsigned HOST_WIDE_INT idx;
6683 	VEC(constructor_elt, gc) *v1 = CONSTRUCTOR_ELTS (t1);
6684 	VEC(constructor_elt, gc) *v2 = CONSTRUCTOR_ELTS (t2);
6685 
6686 	if (VEC_length (constructor_elt, v1) != VEC_length (constructor_elt, v2))
6687 	  return false;
6688 
6689         for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
6690 	  /* ??? Should we handle also fields here? */
6691 	  if (!simple_cst_equal (VEC_index (constructor_elt, v1, idx)->value,
6692 				 VEC_index (constructor_elt, v2, idx)->value))
6693 	    return false;
6694 	return true;
6695       }
6696 
6697     case SAVE_EXPR:
6698       return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6699 
6700     case CALL_EXPR:
6701       cmp = simple_cst_equal (CALL_EXPR_FN (t1), CALL_EXPR_FN (t2));
6702       if (cmp <= 0)
6703 	return cmp;
6704       if (call_expr_nargs (t1) != call_expr_nargs (t2))
6705 	return 0;
6706       {
6707 	const_tree arg1, arg2;
6708 	const_call_expr_arg_iterator iter1, iter2;
6709 	for (arg1 = first_const_call_expr_arg (t1, &iter1),
6710 	       arg2 = first_const_call_expr_arg (t2, &iter2);
6711 	     arg1 && arg2;
6712 	     arg1 = next_const_call_expr_arg (&iter1),
6713 	       arg2 = next_const_call_expr_arg (&iter2))
6714 	  {
6715 	    cmp = simple_cst_equal (arg1, arg2);
6716 	    if (cmp <= 0)
6717 	      return cmp;
6718 	  }
6719 	return arg1 == arg2;
6720       }
6721 
6722     case TARGET_EXPR:
6723       /* Special case: if either target is an unallocated VAR_DECL,
6724 	 it means that it's going to be unified with whatever the
6725 	 TARGET_EXPR is really supposed to initialize, so treat it
6726 	 as being equivalent to anything.  */
6727       if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
6728 	   && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
6729 	   && !DECL_RTL_SET_P (TREE_OPERAND (t1, 0)))
6730 	  || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
6731 	      && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
6732 	      && !DECL_RTL_SET_P (TREE_OPERAND (t2, 0))))
6733 	cmp = 1;
6734       else
6735 	cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6736 
6737       if (cmp <= 0)
6738 	return cmp;
6739 
6740       return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
6741 
6742     case WITH_CLEANUP_EXPR:
6743       cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6744       if (cmp <= 0)
6745 	return cmp;
6746 
6747       return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t1, 1));
6748 
6749     case COMPONENT_REF:
6750       if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
6751 	return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6752 
6753       return 0;
6754 
6755     case VAR_DECL:
6756     case PARM_DECL:
6757     case CONST_DECL:
6758     case FUNCTION_DECL:
6759       return 0;
6760 
6761     default:
6762       break;
6763     }
6764 
6765   /* This general rule works for most tree codes.  All exceptions should be
6766      handled above.  If this is a language-specific tree code, we can't
6767      trust what might be in the operand, so say we don't know
6768      the situation.  */
6769   if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
6770     return -1;
6771 
6772   switch (TREE_CODE_CLASS (code1))
6773     {
6774     case tcc_unary:
6775     case tcc_binary:
6776     case tcc_comparison:
6777     case tcc_expression:
6778     case tcc_reference:
6779     case tcc_statement:
6780       cmp = 1;
6781       for (i = 0; i < TREE_CODE_LENGTH (code1); i++)
6782 	{
6783 	  cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
6784 	  if (cmp <= 0)
6785 	    return cmp;
6786 	}
6787 
6788       return cmp;
6789 
6790     default:
6791       return -1;
6792     }
6793 }
6794 
6795 /* Compare the value of T, an INTEGER_CST, with U, an unsigned integer value.
6796    Return -1, 0, or 1 if the value of T is less than, equal to, or greater
6797    than U, respectively.  */
6798 
6799 int
6800 compare_tree_int (const_tree t, unsigned HOST_WIDE_INT u)
6801 {
6802   if (tree_int_cst_sgn (t) < 0)
6803     return -1;
6804   else if (TREE_INT_CST_HIGH (t) != 0)
6805     return 1;
6806   else if (TREE_INT_CST_LOW (t) == u)
6807     return 0;
6808   else if (TREE_INT_CST_LOW (t) < u)
6809     return -1;
6810   else
6811     return 1;
6812 }
6813 
6814 /* Return true if CODE represents an associative tree code.  Otherwise
6815    return false.  */
6816 bool
6817 associative_tree_code (enum tree_code code)
6818 {
6819   switch (code)
6820     {
6821     case BIT_IOR_EXPR:
6822     case BIT_AND_EXPR:
6823     case BIT_XOR_EXPR:
6824     case PLUS_EXPR:
6825     case MULT_EXPR:
6826     case MIN_EXPR:
6827     case MAX_EXPR:
6828       return true;
6829 
6830     default:
6831       break;
6832     }
6833   return false;
6834 }
6835 
6836 /* Return true if CODE represents a commutative tree code.  Otherwise
6837    return false.  */
6838 bool
6839 commutative_tree_code (enum tree_code code)
6840 {
6841   switch (code)
6842     {
6843     case PLUS_EXPR:
6844     case MULT_EXPR:
6845     case MIN_EXPR:
6846     case MAX_EXPR:
6847     case BIT_IOR_EXPR:
6848     case BIT_XOR_EXPR:
6849     case BIT_AND_EXPR:
6850     case NE_EXPR:
6851     case EQ_EXPR:
6852     case UNORDERED_EXPR:
6853     case ORDERED_EXPR:
6854     case UNEQ_EXPR:
6855     case LTGT_EXPR:
6856     case TRUTH_AND_EXPR:
6857     case TRUTH_XOR_EXPR:
6858     case TRUTH_OR_EXPR:
6859       return true;
6860 
6861     default:
6862       break;
6863     }
6864   return false;
6865 }
6866 
6867 /* Return true if CODE represents a ternary tree code for which the
6868    first two operands are commutative.  Otherwise return false.  */
6869 bool
6870 commutative_ternary_tree_code (enum tree_code code)
6871 {
6872   switch (code)
6873     {
6874     case WIDEN_MULT_PLUS_EXPR:
6875     case WIDEN_MULT_MINUS_EXPR:
6876       return true;
6877 
6878     default:
6879       break;
6880     }
6881   return false;
6882 }
6883 
6884 /* Generate a hash value for an expression.  This can be used iteratively
6885    by passing a previous result as the VAL argument.
6886 
6887    This function is intended to produce the same hash for expressions which
6888    would compare equal using operand_equal_p.  */
6889 
6890 hashval_t
6891 iterative_hash_expr (const_tree t, hashval_t val)
6892 {
6893   int i;
6894   enum tree_code code;
6895   char tclass;
6896 
6897   if (t == NULL_TREE)
6898     return iterative_hash_hashval_t (0, val);
6899 
6900   code = TREE_CODE (t);
6901 
6902   switch (code)
6903     {
6904     /* Alas, constants aren't shared, so we can't rely on pointer
6905        identity.  */
6906     case INTEGER_CST:
6907       val = iterative_hash_host_wide_int (TREE_INT_CST_LOW (t), val);
6908       return iterative_hash_host_wide_int (TREE_INT_CST_HIGH (t), val);
6909     case REAL_CST:
6910       {
6911 	unsigned int val2 = real_hash (TREE_REAL_CST_PTR (t));
6912 
6913 	return iterative_hash_hashval_t (val2, val);
6914       }
6915     case FIXED_CST:
6916       {
6917 	unsigned int val2 = fixed_hash (TREE_FIXED_CST_PTR (t));
6918 
6919 	return iterative_hash_hashval_t (val2, val);
6920       }
6921     case STRING_CST:
6922       return iterative_hash (TREE_STRING_POINTER (t),
6923 			     TREE_STRING_LENGTH (t), val);
6924     case COMPLEX_CST:
6925       val = iterative_hash_expr (TREE_REALPART (t), val);
6926       return iterative_hash_expr (TREE_IMAGPART (t), val);
6927     case VECTOR_CST:
6928       return iterative_hash_expr (TREE_VECTOR_CST_ELTS (t), val);
6929     case SSA_NAME:
6930       /* We can just compare by pointer.  */
6931       return iterative_hash_host_wide_int (SSA_NAME_VERSION (t), val);
6932     case PLACEHOLDER_EXPR:
6933       /* The node itself doesn't matter.  */
6934       return val;
6935     case TREE_LIST:
6936       /* A list of expressions, for a CALL_EXPR or as the elements of a
6937 	 VECTOR_CST.  */
6938       for (; t; t = TREE_CHAIN (t))
6939 	val = iterative_hash_expr (TREE_VALUE (t), val);
6940       return val;
6941     case CONSTRUCTOR:
6942       {
6943 	unsigned HOST_WIDE_INT idx;
6944 	tree field, value;
6945 	FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), idx, field, value)
6946 	  {
6947 	    val = iterative_hash_expr (field, val);
6948 	    val = iterative_hash_expr (value, val);
6949 	  }
6950 	return val;
6951       }
6952     case MEM_REF:
6953       {
6954 	/* The type of the second operand is relevant, except for
6955 	   its top-level qualifiers.  */
6956 	tree type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (t, 1)));
6957 
6958 	val = iterative_hash_object (TYPE_HASH (type), val);
6959 
6960 	/* We could use the standard hash computation from this point
6961 	   on.  */
6962 	val = iterative_hash_object (code, val);
6963 	val = iterative_hash_expr (TREE_OPERAND (t, 1), val);
6964 	val = iterative_hash_expr (TREE_OPERAND (t, 0), val);
6965 	return val;
6966       }
6967     case FUNCTION_DECL:
6968       /* When referring to a built-in FUNCTION_DECL, use the __builtin__ form.
6969 	 Otherwise nodes that compare equal according to operand_equal_p might
6970 	 get different hash codes.  However, don't do this for machine specific
6971 	 or front end builtins, since the function code is overloaded in those
6972 	 cases.  */
6973       if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL
6974 	  && builtin_decl_explicit_p (DECL_FUNCTION_CODE (t)))
6975 	{
6976 	  t = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
6977 	  code = TREE_CODE (t);
6978 	}
6979       /* FALL THROUGH */
6980     default:
6981       tclass = TREE_CODE_CLASS (code);
6982 
6983       if (tclass == tcc_declaration)
6984 	{
6985 	  /* DECL's have a unique ID */
6986 	  val = iterative_hash_host_wide_int (DECL_UID (t), val);
6987 	}
6988       else
6989 	{
6990 	  gcc_assert (IS_EXPR_CODE_CLASS (tclass));
6991 
6992 	  val = iterative_hash_object (code, val);
6993 
6994 	  /* Don't hash the type, that can lead to having nodes which
6995 	     compare equal according to operand_equal_p, but which
6996 	     have different hash codes.  */
6997 	  if (CONVERT_EXPR_CODE_P (code)
6998 	      || code == NON_LVALUE_EXPR)
6999 	    {
7000 	      /* Make sure to include signness in the hash computation.  */
7001 	      val += TYPE_UNSIGNED (TREE_TYPE (t));
7002 	      val = iterative_hash_expr (TREE_OPERAND (t, 0), val);
7003 	    }
7004 
7005 	  else if (commutative_tree_code (code))
7006 	    {
7007 	      /* It's a commutative expression.  We want to hash it the same
7008 		 however it appears.  We do this by first hashing both operands
7009 		 and then rehashing based on the order of their independent
7010 		 hashes.  */
7011 	      hashval_t one = iterative_hash_expr (TREE_OPERAND (t, 0), 0);
7012 	      hashval_t two = iterative_hash_expr (TREE_OPERAND (t, 1), 0);
7013 	      hashval_t t;
7014 
7015 	      if (one > two)
7016 		t = one, one = two, two = t;
7017 
7018 	      val = iterative_hash_hashval_t (one, val);
7019 	      val = iterative_hash_hashval_t (two, val);
7020 	    }
7021 	  else
7022 	    for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
7023 	      val = iterative_hash_expr (TREE_OPERAND (t, i), val);
7024 	}
7025       return val;
7026     }
7027 }
7028 
7029 /* Generate a hash value for a pair of expressions.  This can be used
7030    iteratively by passing a previous result as the VAL argument.
7031 
7032    The same hash value is always returned for a given pair of expressions,
7033    regardless of the order in which they are presented.  This is useful in
7034    hashing the operands of commutative functions.  */
7035 
7036 hashval_t
7037 iterative_hash_exprs_commutative (const_tree t1,
7038                                   const_tree t2, hashval_t val)
7039 {
7040   hashval_t one = iterative_hash_expr (t1, 0);
7041   hashval_t two = iterative_hash_expr (t2, 0);
7042   hashval_t t;
7043 
7044   if (one > two)
7045     t = one, one = two, two = t;
7046   val = iterative_hash_hashval_t (one, val);
7047   val = iterative_hash_hashval_t (two, val);
7048 
7049   return val;
7050 }
7051 
7052 /* Constructors for pointer, array and function types.
7053    (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
7054    constructed by language-dependent code, not here.)  */
7055 
7056 /* Construct, lay out and return the type of pointers to TO_TYPE with
7057    mode MODE.  If CAN_ALIAS_ALL is TRUE, indicate this type can
7058    reference all of memory. If such a type has already been
7059    constructed, reuse it.  */
7060 
7061 tree
7062 build_pointer_type_for_mode (tree to_type, enum machine_mode mode,
7063 			     bool can_alias_all)
7064 {
7065   tree t;
7066 
7067   if (to_type == error_mark_node)
7068     return error_mark_node;
7069 
7070   /* If the pointed-to type has the may_alias attribute set, force
7071      a TYPE_REF_CAN_ALIAS_ALL pointer to be generated.  */
7072   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (to_type)))
7073     can_alias_all = true;
7074 
7075   /* In some cases, languages will have things that aren't a POINTER_TYPE
7076      (such as a RECORD_TYPE for fat pointers in Ada) as TYPE_POINTER_TO.
7077      In that case, return that type without regard to the rest of our
7078      operands.
7079 
7080      ??? This is a kludge, but consistent with the way this function has
7081      always operated and there doesn't seem to be a good way to avoid this
7082      at the moment.  */
7083   if (TYPE_POINTER_TO (to_type) != 0
7084       && TREE_CODE (TYPE_POINTER_TO (to_type)) != POINTER_TYPE)
7085     return TYPE_POINTER_TO (to_type);
7086 
7087   /* First, if we already have a type for pointers to TO_TYPE and it's
7088      the proper mode, use it.  */
7089   for (t = TYPE_POINTER_TO (to_type); t; t = TYPE_NEXT_PTR_TO (t))
7090     if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
7091       return t;
7092 
7093   t = make_node (POINTER_TYPE);
7094 
7095   TREE_TYPE (t) = to_type;
7096   SET_TYPE_MODE (t, mode);
7097   TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
7098   TYPE_NEXT_PTR_TO (t) = TYPE_POINTER_TO (to_type);
7099   TYPE_POINTER_TO (to_type) = t;
7100 
7101   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
7102     SET_TYPE_STRUCTURAL_EQUALITY (t);
7103   else if (TYPE_CANONICAL (to_type) != to_type)
7104     TYPE_CANONICAL (t)
7105       = build_pointer_type_for_mode (TYPE_CANONICAL (to_type),
7106 				     mode, can_alias_all);
7107 
7108   /* Lay out the type.  This function has many callers that are concerned
7109      with expression-construction, and this simplifies them all.  */
7110   layout_type (t);
7111 
7112   return t;
7113 }
7114 
7115 /* By default build pointers in ptr_mode.  */
7116 
7117 tree
7118 build_pointer_type (tree to_type)
7119 {
7120   addr_space_t as = to_type == error_mark_node? ADDR_SPACE_GENERIC
7121 					      : TYPE_ADDR_SPACE (to_type);
7122   enum machine_mode pointer_mode = targetm.addr_space.pointer_mode (as);
7123   return build_pointer_type_for_mode (to_type, pointer_mode, false);
7124 }
7125 
7126 /* Same as build_pointer_type_for_mode, but for REFERENCE_TYPE.  */
7127 
7128 tree
7129 build_reference_type_for_mode (tree to_type, enum machine_mode mode,
7130 			       bool can_alias_all)
7131 {
7132   tree t;
7133 
7134   if (to_type == error_mark_node)
7135     return error_mark_node;
7136 
7137   /* If the pointed-to type has the may_alias attribute set, force
7138      a TYPE_REF_CAN_ALIAS_ALL pointer to be generated.  */
7139   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (to_type)))
7140     can_alias_all = true;
7141 
7142   /* In some cases, languages will have things that aren't a REFERENCE_TYPE
7143      (such as a RECORD_TYPE for fat pointers in Ada) as TYPE_REFERENCE_TO.
7144      In that case, return that type without regard to the rest of our
7145      operands.
7146 
7147      ??? This is a kludge, but consistent with the way this function has
7148      always operated and there doesn't seem to be a good way to avoid this
7149      at the moment.  */
7150   if (TYPE_REFERENCE_TO (to_type) != 0
7151       && TREE_CODE (TYPE_REFERENCE_TO (to_type)) != REFERENCE_TYPE)
7152     return TYPE_REFERENCE_TO (to_type);
7153 
7154   /* First, if we already have a type for pointers to TO_TYPE and it's
7155      the proper mode, use it.  */
7156   for (t = TYPE_REFERENCE_TO (to_type); t; t = TYPE_NEXT_REF_TO (t))
7157     if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
7158       return t;
7159 
7160   t = make_node (REFERENCE_TYPE);
7161 
7162   TREE_TYPE (t) = to_type;
7163   SET_TYPE_MODE (t, mode);
7164   TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
7165   TYPE_NEXT_REF_TO (t) = TYPE_REFERENCE_TO (to_type);
7166   TYPE_REFERENCE_TO (to_type) = t;
7167 
7168   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
7169     SET_TYPE_STRUCTURAL_EQUALITY (t);
7170   else if (TYPE_CANONICAL (to_type) != to_type)
7171     TYPE_CANONICAL (t)
7172       = build_reference_type_for_mode (TYPE_CANONICAL (to_type),
7173 				       mode, can_alias_all);
7174 
7175   layout_type (t);
7176 
7177   return t;
7178 }
7179 
7180 
7181 /* Build the node for the type of references-to-TO_TYPE by default
7182    in ptr_mode.  */
7183 
7184 tree
7185 build_reference_type (tree to_type)
7186 {
7187   addr_space_t as = to_type == error_mark_node? ADDR_SPACE_GENERIC
7188 					      : TYPE_ADDR_SPACE (to_type);
7189   enum machine_mode pointer_mode = targetm.addr_space.pointer_mode (as);
7190   return build_reference_type_for_mode (to_type, pointer_mode, false);
7191 }
7192 
7193 /* Build a type that is compatible with t but has no cv quals anywhere
7194    in its type, thus
7195 
7196    const char *const *const *  ->  char ***.  */
7197 
7198 tree
7199 build_type_no_quals (tree t)
7200 {
7201   switch (TREE_CODE (t))
7202     {
7203     case POINTER_TYPE:
7204       return build_pointer_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
7205 					  TYPE_MODE (t),
7206 					  TYPE_REF_CAN_ALIAS_ALL (t));
7207     case REFERENCE_TYPE:
7208       return
7209 	build_reference_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
7210 				       TYPE_MODE (t),
7211 				       TYPE_REF_CAN_ALIAS_ALL (t));
7212     default:
7213       return TYPE_MAIN_VARIANT (t);
7214     }
7215 }
7216 
7217 #define MAX_INT_CACHED_PREC \
7218   (HOST_BITS_PER_WIDE_INT > 64 ? HOST_BITS_PER_WIDE_INT : 64)
7219 static GTY(()) tree nonstandard_integer_type_cache[2 * MAX_INT_CACHED_PREC + 2];
7220 
7221 /* Builds a signed or unsigned integer type of precision PRECISION.
7222    Used for C bitfields whose precision does not match that of
7223    built-in target types.  */
7224 tree
7225 build_nonstandard_integer_type (unsigned HOST_WIDE_INT precision,
7226 				int unsignedp)
7227 {
7228   tree itype, ret;
7229 
7230   if (unsignedp)
7231     unsignedp = MAX_INT_CACHED_PREC + 1;
7232 
7233   if (precision <= MAX_INT_CACHED_PREC)
7234     {
7235       itype = nonstandard_integer_type_cache[precision + unsignedp];
7236       if (itype)
7237 	return itype;
7238     }
7239 
7240   itype = make_node (INTEGER_TYPE);
7241   TYPE_PRECISION (itype) = precision;
7242 
7243   if (unsignedp)
7244     fixup_unsigned_type (itype);
7245   else
7246     fixup_signed_type (itype);
7247 
7248   ret = itype;
7249   if (host_integerp (TYPE_MAX_VALUE (itype), 1))
7250     ret = type_hash_canon (tree_low_cst (TYPE_MAX_VALUE (itype), 1), itype);
7251   if (precision <= MAX_INT_CACHED_PREC)
7252     nonstandard_integer_type_cache[precision + unsignedp] = ret;
7253 
7254   return ret;
7255 }
7256 
7257 /* Create a range of some discrete type TYPE (an INTEGER_TYPE, ENUMERAL_TYPE
7258    or BOOLEAN_TYPE) with low bound LOWVAL and high bound HIGHVAL.  If SHARED
7259    is true, reuse such a type that has already been constructed.  */
7260 
7261 static tree
7262 build_range_type_1 (tree type, tree lowval, tree highval, bool shared)
7263 {
7264   tree itype = make_node (INTEGER_TYPE);
7265   hashval_t hashcode = 0;
7266 
7267   TREE_TYPE (itype) = type;
7268 
7269   TYPE_MIN_VALUE (itype) = fold_convert (type, lowval);
7270   TYPE_MAX_VALUE (itype) = highval ? fold_convert (type, highval) : NULL;
7271 
7272   TYPE_PRECISION (itype) = TYPE_PRECISION (type);
7273   SET_TYPE_MODE (itype, TYPE_MODE (type));
7274   TYPE_SIZE (itype) = TYPE_SIZE (type);
7275   TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (type);
7276   TYPE_ALIGN (itype) = TYPE_ALIGN (type);
7277   TYPE_USER_ALIGN (itype) = TYPE_USER_ALIGN (type);
7278 
7279   if (!shared)
7280     return itype;
7281 
7282   if ((TYPE_MIN_VALUE (itype)
7283        && TREE_CODE (TYPE_MIN_VALUE (itype)) != INTEGER_CST)
7284       || (TYPE_MAX_VALUE (itype)
7285 	  && TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST))
7286     {
7287       /* Since we cannot reliably merge this type, we need to compare it using
7288 	 structural equality checks.  */
7289       SET_TYPE_STRUCTURAL_EQUALITY (itype);
7290       return itype;
7291     }
7292 
7293   hashcode = iterative_hash_expr (TYPE_MIN_VALUE (itype), hashcode);
7294   hashcode = iterative_hash_expr (TYPE_MAX_VALUE (itype), hashcode);
7295   hashcode = iterative_hash_hashval_t (TYPE_HASH (type), hashcode);
7296   itype = type_hash_canon (hashcode, itype);
7297 
7298   return itype;
7299 }
7300 
7301 /* Wrapper around build_range_type_1 with SHARED set to true.  */
7302 
7303 tree
7304 build_range_type (tree type, tree lowval, tree highval)
7305 {
7306   return build_range_type_1 (type, lowval, highval, true);
7307 }
7308 
7309 /* Wrapper around build_range_type_1 with SHARED set to false.  */
7310 
7311 tree
7312 build_nonshared_range_type (tree type, tree lowval, tree highval)
7313 {
7314   return build_range_type_1 (type, lowval, highval, false);
7315 }
7316 
7317 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
7318    MAXVAL should be the maximum value in the domain
7319    (one less than the length of the array).
7320 
7321    The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
7322    We don't enforce this limit, that is up to caller (e.g. language front end).
7323    The limit exists because the result is a signed type and we don't handle
7324    sizes that use more than one HOST_WIDE_INT.  */
7325 
7326 tree
7327 build_index_type (tree maxval)
7328 {
7329   return build_range_type (sizetype, size_zero_node, maxval);
7330 }
7331 
7332 /* Return true if the debug information for TYPE, a subtype, should be emitted
7333    as a subrange type.  If so, set LOWVAL to the low bound and HIGHVAL to the
7334    high bound, respectively.  Sometimes doing so unnecessarily obfuscates the
7335    debug info and doesn't reflect the source code.  */
7336 
7337 bool
7338 subrange_type_for_debug_p (const_tree type, tree *lowval, tree *highval)
7339 {
7340   tree base_type = TREE_TYPE (type), low, high;
7341 
7342   /* Subrange types have a base type which is an integral type.  */
7343   if (!INTEGRAL_TYPE_P (base_type))
7344     return false;
7345 
7346   /* Get the real bounds of the subtype.  */
7347   if (lang_hooks.types.get_subrange_bounds)
7348     lang_hooks.types.get_subrange_bounds (type, &low, &high);
7349   else
7350     {
7351       low = TYPE_MIN_VALUE (type);
7352       high = TYPE_MAX_VALUE (type);
7353     }
7354 
7355   /* If the type and its base type have the same representation and the same
7356      name, then the type is not a subrange but a copy of the base type.  */
7357   if ((TREE_CODE (base_type) == INTEGER_TYPE
7358        || TREE_CODE (base_type) == BOOLEAN_TYPE)
7359       && int_size_in_bytes (type) == int_size_in_bytes (base_type)
7360       && tree_int_cst_equal (low, TYPE_MIN_VALUE (base_type))
7361       && tree_int_cst_equal (high, TYPE_MAX_VALUE (base_type)))
7362     {
7363       tree type_name = TYPE_NAME (type);
7364       tree base_type_name = TYPE_NAME (base_type);
7365 
7366       if (type_name && TREE_CODE (type_name) == TYPE_DECL)
7367 	type_name = DECL_NAME (type_name);
7368 
7369       if (base_type_name && TREE_CODE (base_type_name) == TYPE_DECL)
7370 	base_type_name = DECL_NAME (base_type_name);
7371 
7372       if (type_name == base_type_name)
7373 	return false;
7374     }
7375 
7376   if (lowval)
7377     *lowval = low;
7378   if (highval)
7379     *highval = high;
7380   return true;
7381 }
7382 
7383 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
7384    and number of elements specified by the range of values of INDEX_TYPE.
7385    If SHARED is true, reuse such a type that has already been constructed.  */
7386 
7387 static tree
7388 build_array_type_1 (tree elt_type, tree index_type, bool shared)
7389 {
7390   tree t;
7391 
7392   if (TREE_CODE (elt_type) == FUNCTION_TYPE)
7393     {
7394       error ("arrays of functions are not meaningful");
7395       elt_type = integer_type_node;
7396     }
7397 
7398   t = make_node (ARRAY_TYPE);
7399   TREE_TYPE (t) = elt_type;
7400   TYPE_DOMAIN (t) = index_type;
7401   TYPE_ADDR_SPACE (t) = TYPE_ADDR_SPACE (elt_type);
7402   layout_type (t);
7403 
7404   /* If the element type is incomplete at this point we get marked for
7405      structural equality.  Do not record these types in the canonical
7406      type hashtable.  */
7407   if (TYPE_STRUCTURAL_EQUALITY_P (t))
7408     return t;
7409 
7410   if (shared)
7411     {
7412       hashval_t hashcode = iterative_hash_object (TYPE_HASH (elt_type), 0);
7413       if (index_type)
7414 	hashcode = iterative_hash_object (TYPE_HASH (index_type), hashcode);
7415       t = type_hash_canon (hashcode, t);
7416     }
7417 
7418   if (TYPE_CANONICAL (t) == t)
7419     {
7420       if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
7421 	  || (index_type && TYPE_STRUCTURAL_EQUALITY_P (index_type)))
7422 	SET_TYPE_STRUCTURAL_EQUALITY (t);
7423       else if (TYPE_CANONICAL (elt_type) != elt_type
7424 	       || (index_type && TYPE_CANONICAL (index_type) != index_type))
7425 	TYPE_CANONICAL (t)
7426 	  = build_array_type_1 (TYPE_CANONICAL (elt_type),
7427 				index_type
7428 				? TYPE_CANONICAL (index_type) : NULL_TREE,
7429 				shared);
7430     }
7431 
7432   return t;
7433 }
7434 
7435 /* Wrapper around build_array_type_1 with SHARED set to true.  */
7436 
7437 tree
7438 build_array_type (tree elt_type, tree index_type)
7439 {
7440   return build_array_type_1 (elt_type, index_type, true);
7441 }
7442 
7443 /* Wrapper around build_array_type_1 with SHARED set to false.  */
7444 
7445 tree
7446 build_nonshared_array_type (tree elt_type, tree index_type)
7447 {
7448   return build_array_type_1 (elt_type, index_type, false);
7449 }
7450 
7451 /* Return a representation of ELT_TYPE[NELTS], using indices of type
7452    sizetype.  */
7453 
7454 tree
7455 build_array_type_nelts (tree elt_type, unsigned HOST_WIDE_INT nelts)
7456 {
7457   return build_array_type (elt_type, build_index_type (size_int (nelts - 1)));
7458 }
7459 
7460 /* Recursively examines the array elements of TYPE, until a non-array
7461    element type is found.  */
7462 
7463 tree
7464 strip_array_types (tree type)
7465 {
7466   while (TREE_CODE (type) == ARRAY_TYPE)
7467     type = TREE_TYPE (type);
7468 
7469   return type;
7470 }
7471 
7472 /* Computes the canonical argument types from the argument type list
7473    ARGTYPES.
7474 
7475    Upon return, *ANY_STRUCTURAL_P will be true iff either it was true
7476    on entry to this function, or if any of the ARGTYPES are
7477    structural.
7478 
7479    Upon return, *ANY_NONCANONICAL_P will be true iff either it was
7480    true on entry to this function, or if any of the ARGTYPES are
7481    non-canonical.
7482 
7483    Returns a canonical argument list, which may be ARGTYPES when the
7484    canonical argument list is unneeded (i.e., *ANY_STRUCTURAL_P is
7485    true) or would not differ from ARGTYPES.  */
7486 
7487 static tree
7488 maybe_canonicalize_argtypes(tree argtypes,
7489 			    bool *any_structural_p,
7490 			    bool *any_noncanonical_p)
7491 {
7492   tree arg;
7493   bool any_noncanonical_argtypes_p = false;
7494 
7495   for (arg = argtypes; arg && !(*any_structural_p); arg = TREE_CHAIN (arg))
7496     {
7497       if (!TREE_VALUE (arg) || TREE_VALUE (arg) == error_mark_node)
7498 	/* Fail gracefully by stating that the type is structural.  */
7499 	*any_structural_p = true;
7500       else if (TYPE_STRUCTURAL_EQUALITY_P (TREE_VALUE (arg)))
7501 	*any_structural_p = true;
7502       else if (TYPE_CANONICAL (TREE_VALUE (arg)) != TREE_VALUE (arg)
7503 	       || TREE_PURPOSE (arg))
7504 	/* If the argument has a default argument, we consider it
7505 	   non-canonical even though the type itself is canonical.
7506 	   That way, different variants of function and method types
7507 	   with default arguments will all point to the variant with
7508 	   no defaults as their canonical type.  */
7509         any_noncanonical_argtypes_p = true;
7510     }
7511 
7512   if (*any_structural_p)
7513     return argtypes;
7514 
7515   if (any_noncanonical_argtypes_p)
7516     {
7517       /* Build the canonical list of argument types.  */
7518       tree canon_argtypes = NULL_TREE;
7519       bool is_void = false;
7520 
7521       for (arg = argtypes; arg; arg = TREE_CHAIN (arg))
7522         {
7523           if (arg == void_list_node)
7524             is_void = true;
7525           else
7526             canon_argtypes = tree_cons (NULL_TREE,
7527                                         TYPE_CANONICAL (TREE_VALUE (arg)),
7528                                         canon_argtypes);
7529         }
7530 
7531       canon_argtypes = nreverse (canon_argtypes);
7532       if (is_void)
7533         canon_argtypes = chainon (canon_argtypes, void_list_node);
7534 
7535       /* There is a non-canonical type.  */
7536       *any_noncanonical_p = true;
7537       return canon_argtypes;
7538     }
7539 
7540   /* The canonical argument types are the same as ARGTYPES.  */
7541   return argtypes;
7542 }
7543 
7544 /* Construct, lay out and return
7545    the type of functions returning type VALUE_TYPE
7546    given arguments of types ARG_TYPES.
7547    ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
7548    are data type nodes for the arguments of the function.
7549    If such a type has already been constructed, reuse it.  */
7550 
7551 tree
7552 build_function_type (tree value_type, tree arg_types)
7553 {
7554   tree t;
7555   hashval_t hashcode = 0;
7556   bool any_structural_p, any_noncanonical_p;
7557   tree canon_argtypes;
7558 
7559   if (TREE_CODE (value_type) == FUNCTION_TYPE)
7560     {
7561       error ("function return type cannot be function");
7562       value_type = integer_type_node;
7563     }
7564 
7565   /* Make a node of the sort we want.  */
7566   t = make_node (FUNCTION_TYPE);
7567   TREE_TYPE (t) = value_type;
7568   TYPE_ARG_TYPES (t) = arg_types;
7569 
7570   /* If we already have such a type, use the old one.  */
7571   hashcode = iterative_hash_object (TYPE_HASH (value_type), hashcode);
7572   hashcode = type_hash_list (arg_types, hashcode);
7573   t = type_hash_canon (hashcode, t);
7574 
7575   /* Set up the canonical type. */
7576   any_structural_p   = TYPE_STRUCTURAL_EQUALITY_P (value_type);
7577   any_noncanonical_p = TYPE_CANONICAL (value_type) != value_type;
7578   canon_argtypes = maybe_canonicalize_argtypes (arg_types,
7579 						&any_structural_p,
7580 						&any_noncanonical_p);
7581   if (any_structural_p)
7582     SET_TYPE_STRUCTURAL_EQUALITY (t);
7583   else if (any_noncanonical_p)
7584     TYPE_CANONICAL (t) = build_function_type (TYPE_CANONICAL (value_type),
7585 					      canon_argtypes);
7586 
7587   if (!COMPLETE_TYPE_P (t))
7588     layout_type (t);
7589   return t;
7590 }
7591 
7592 /* Build variant of function type ORIG_TYPE skipping ARGS_TO_SKIP and the
7593    return value if SKIP_RETURN is true.  */
7594 
7595 static tree
7596 build_function_type_skip_args (tree orig_type, bitmap args_to_skip,
7597 			       bool skip_return)
7598 {
7599   tree new_type = NULL;
7600   tree args, new_args = NULL, t;
7601   tree new_reversed;
7602   int i = 0;
7603 
7604   for (args = TYPE_ARG_TYPES (orig_type); args && args != void_list_node;
7605        args = TREE_CHAIN (args), i++)
7606     if (!args_to_skip || !bitmap_bit_p (args_to_skip, i))
7607       new_args = tree_cons (NULL_TREE, TREE_VALUE (args), new_args);
7608 
7609   new_reversed = nreverse (new_args);
7610   if (args)
7611     {
7612       if (new_reversed)
7613         TREE_CHAIN (new_args) = void_list_node;
7614       else
7615 	new_reversed = void_list_node;
7616     }
7617 
7618   /* Use copy_node to preserve as much as possible from original type
7619      (debug info, attribute lists etc.)
7620      Exception is METHOD_TYPEs must have THIS argument.
7621      When we are asked to remove it, we need to build new FUNCTION_TYPE
7622      instead.  */
7623   if (TREE_CODE (orig_type) != METHOD_TYPE
7624       || !args_to_skip
7625       || !bitmap_bit_p (args_to_skip, 0))
7626     {
7627       new_type = build_distinct_type_copy (orig_type);
7628       TYPE_ARG_TYPES (new_type) = new_reversed;
7629     }
7630   else
7631     {
7632       new_type
7633         = build_distinct_type_copy (build_function_type (TREE_TYPE (orig_type),
7634 							 new_reversed));
7635       TYPE_CONTEXT (new_type) = TYPE_CONTEXT (orig_type);
7636     }
7637 
7638   if (skip_return)
7639     TREE_TYPE (new_type) = void_type_node;
7640 
7641   /* This is a new type, not a copy of an old type.  Need to reassociate
7642      variants.  We can handle everything except the main variant lazily.  */
7643   t = TYPE_MAIN_VARIANT (orig_type);
7644   if (t != orig_type)
7645     {
7646       t = build_function_type_skip_args (t, args_to_skip, skip_return);
7647       TYPE_MAIN_VARIANT (new_type) = t;
7648       TYPE_NEXT_VARIANT (new_type) = TYPE_NEXT_VARIANT (t);
7649       TYPE_NEXT_VARIANT (t) = new_type;
7650     }
7651   else
7652     {
7653       TYPE_MAIN_VARIANT (new_type) = new_type;
7654       TYPE_NEXT_VARIANT (new_type) = NULL;
7655     }
7656 
7657   return new_type;
7658 }
7659 
7660 /* Build variant of function decl ORIG_DECL skipping ARGS_TO_SKIP and the
7661    return value if SKIP_RETURN is true.
7662 
7663    Arguments from DECL_ARGUMENTS list can't be removed now, since they are
7664    linked by TREE_CHAIN directly.  The caller is responsible for eliminating
7665    them when they are being duplicated (i.e. copy_arguments_for_versioning).  */
7666 
7667 tree
7668 build_function_decl_skip_args (tree orig_decl, bitmap args_to_skip,
7669 			       bool skip_return)
7670 {
7671   tree new_decl = copy_node (orig_decl);
7672   tree new_type;
7673 
7674   new_type = TREE_TYPE (orig_decl);
7675   if (prototype_p (new_type)
7676       || (skip_return && !VOID_TYPE_P (TREE_TYPE (new_type))))
7677     new_type
7678       = build_function_type_skip_args (new_type, args_to_skip, skip_return);
7679   TREE_TYPE (new_decl) = new_type;
7680 
7681   /* For declarations setting DECL_VINDEX (i.e. methods)
7682      we expect first argument to be THIS pointer.   */
7683   if (args_to_skip && bitmap_bit_p (args_to_skip, 0))
7684     DECL_VINDEX (new_decl) = NULL_TREE;
7685 
7686   /* When signature changes, we need to clear builtin info.  */
7687   if (DECL_BUILT_IN (new_decl)
7688       && args_to_skip
7689       && !bitmap_empty_p (args_to_skip))
7690     {
7691       DECL_BUILT_IN_CLASS (new_decl) = NOT_BUILT_IN;
7692       DECL_FUNCTION_CODE (new_decl) = (enum built_in_function) 0;
7693     }
7694   return new_decl;
7695 }
7696 
7697 /* Build a function type.  The RETURN_TYPE is the type returned by the
7698    function.  If VAARGS is set, no void_type_node is appended to the
7699    the list.  ARGP must be always be terminated be a NULL_TREE.  */
7700 
7701 static tree
7702 build_function_type_list_1 (bool vaargs, tree return_type, va_list argp)
7703 {
7704   tree t, args, last;
7705 
7706   t = va_arg (argp, tree);
7707   for (args = NULL_TREE; t != NULL_TREE; t = va_arg (argp, tree))
7708     args = tree_cons (NULL_TREE, t, args);
7709 
7710   if (vaargs)
7711     {
7712       last = args;
7713       if (args != NULL_TREE)
7714 	args = nreverse (args);
7715       gcc_assert (last != void_list_node);
7716     }
7717   else if (args == NULL_TREE)
7718     args = void_list_node;
7719   else
7720     {
7721       last = args;
7722       args = nreverse (args);
7723       TREE_CHAIN (last) = void_list_node;
7724     }
7725   args = build_function_type (return_type, args);
7726 
7727   return args;
7728 }
7729 
7730 /* Build a function type.  The RETURN_TYPE is the type returned by the
7731    function.  If additional arguments are provided, they are
7732    additional argument types.  The list of argument types must always
7733    be terminated by NULL_TREE.  */
7734 
7735 tree
7736 build_function_type_list (tree return_type, ...)
7737 {
7738   tree args;
7739   va_list p;
7740 
7741   va_start (p, return_type);
7742   args = build_function_type_list_1 (false, return_type, p);
7743   va_end (p);
7744   return args;
7745 }
7746 
7747 /* Build a variable argument function type.  The RETURN_TYPE is the
7748    type returned by the function.  If additional arguments are provided,
7749    they are additional argument types.  The list of argument types must
7750    always be terminated by NULL_TREE.  */
7751 
7752 tree
7753 build_varargs_function_type_list (tree return_type, ...)
7754 {
7755   tree args;
7756   va_list p;
7757 
7758   va_start (p, return_type);
7759   args = build_function_type_list_1 (true, return_type, p);
7760   va_end (p);
7761 
7762   return args;
7763 }
7764 
7765 /* Build a function type.  RETURN_TYPE is the type returned by the
7766    function; VAARGS indicates whether the function takes varargs.  The
7767    function takes N named arguments, the types of which are provided in
7768    ARG_TYPES.  */
7769 
7770 static tree
7771 build_function_type_array_1 (bool vaargs, tree return_type, int n,
7772 			     tree *arg_types)
7773 {
7774   int i;
7775   tree t = vaargs ? NULL_TREE : void_list_node;
7776 
7777   for (i = n - 1; i >= 0; i--)
7778     t = tree_cons (NULL_TREE, arg_types[i], t);
7779 
7780   return build_function_type (return_type, t);
7781 }
7782 
7783 /* Build a function type.  RETURN_TYPE is the type returned by the
7784    function.  The function takes N named arguments, the types of which
7785    are provided in ARG_TYPES.  */
7786 
7787 tree
7788 build_function_type_array (tree return_type, int n, tree *arg_types)
7789 {
7790   return build_function_type_array_1 (false, return_type, n, arg_types);
7791 }
7792 
7793 /* Build a variable argument function type.  RETURN_TYPE is the type
7794    returned by the function.  The function takes N named arguments, the
7795    types of which are provided in ARG_TYPES.  */
7796 
7797 tree
7798 build_varargs_function_type_array (tree return_type, int n, tree *arg_types)
7799 {
7800   return build_function_type_array_1 (true, return_type, n, arg_types);
7801 }
7802 
7803 /* Build a METHOD_TYPE for a member of BASETYPE.  The RETTYPE (a TYPE)
7804    and ARGTYPES (a TREE_LIST) are the return type and arguments types
7805    for the method.  An implicit additional parameter (of type
7806    pointer-to-BASETYPE) is added to the ARGTYPES.  */
7807 
7808 tree
7809 build_method_type_directly (tree basetype,
7810 			    tree rettype,
7811 			    tree argtypes)
7812 {
7813   tree t;
7814   tree ptype;
7815   int hashcode = 0;
7816   bool any_structural_p, any_noncanonical_p;
7817   tree canon_argtypes;
7818 
7819   /* Make a node of the sort we want.  */
7820   t = make_node (METHOD_TYPE);
7821 
7822   TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
7823   TREE_TYPE (t) = rettype;
7824   ptype = build_pointer_type (basetype);
7825 
7826   /* The actual arglist for this function includes a "hidden" argument
7827      which is "this".  Put it into the list of argument types.  */
7828   argtypes = tree_cons (NULL_TREE, ptype, argtypes);
7829   TYPE_ARG_TYPES (t) = argtypes;
7830 
7831   /* If we already have such a type, use the old one.  */
7832   hashcode = iterative_hash_object (TYPE_HASH (basetype), hashcode);
7833   hashcode = iterative_hash_object (TYPE_HASH (rettype), hashcode);
7834   hashcode = type_hash_list (argtypes, hashcode);
7835   t = type_hash_canon (hashcode, t);
7836 
7837   /* Set up the canonical type. */
7838   any_structural_p
7839     = (TYPE_STRUCTURAL_EQUALITY_P (basetype)
7840        || TYPE_STRUCTURAL_EQUALITY_P (rettype));
7841   any_noncanonical_p
7842     = (TYPE_CANONICAL (basetype) != basetype
7843        || TYPE_CANONICAL (rettype) != rettype);
7844   canon_argtypes = maybe_canonicalize_argtypes (TREE_CHAIN (argtypes),
7845 						&any_structural_p,
7846 						&any_noncanonical_p);
7847   if (any_structural_p)
7848     SET_TYPE_STRUCTURAL_EQUALITY (t);
7849   else if (any_noncanonical_p)
7850     TYPE_CANONICAL (t)
7851       = build_method_type_directly (TYPE_CANONICAL (basetype),
7852 				    TYPE_CANONICAL (rettype),
7853 				    canon_argtypes);
7854   if (!COMPLETE_TYPE_P (t))
7855     layout_type (t);
7856 
7857   return t;
7858 }
7859 
7860 /* Construct, lay out and return the type of methods belonging to class
7861    BASETYPE and whose arguments and values are described by TYPE.
7862    If that type exists already, reuse it.
7863    TYPE must be a FUNCTION_TYPE node.  */
7864 
7865 tree
7866 build_method_type (tree basetype, tree type)
7867 {
7868   gcc_assert (TREE_CODE (type) == FUNCTION_TYPE);
7869 
7870   return build_method_type_directly (basetype,
7871 				     TREE_TYPE (type),
7872 				     TYPE_ARG_TYPES (type));
7873 }
7874 
7875 /* Construct, lay out and return the type of offsets to a value
7876    of type TYPE, within an object of type BASETYPE.
7877    If a suitable offset type exists already, reuse it.  */
7878 
7879 tree
7880 build_offset_type (tree basetype, tree type)
7881 {
7882   tree t;
7883   hashval_t hashcode = 0;
7884 
7885   /* Make a node of the sort we want.  */
7886   t = make_node (OFFSET_TYPE);
7887 
7888   TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
7889   TREE_TYPE (t) = type;
7890 
7891   /* If we already have such a type, use the old one.  */
7892   hashcode = iterative_hash_object (TYPE_HASH (basetype), hashcode);
7893   hashcode = iterative_hash_object (TYPE_HASH (type), hashcode);
7894   t = type_hash_canon (hashcode, t);
7895 
7896   if (!COMPLETE_TYPE_P (t))
7897     layout_type (t);
7898 
7899   if (TYPE_CANONICAL (t) == t)
7900     {
7901       if (TYPE_STRUCTURAL_EQUALITY_P (basetype)
7902 	  || TYPE_STRUCTURAL_EQUALITY_P (type))
7903 	SET_TYPE_STRUCTURAL_EQUALITY (t);
7904       else if (TYPE_CANONICAL (TYPE_MAIN_VARIANT (basetype)) != basetype
7905 	       || TYPE_CANONICAL (type) != type)
7906 	TYPE_CANONICAL (t)
7907 	  = build_offset_type (TYPE_CANONICAL (TYPE_MAIN_VARIANT (basetype)),
7908 			       TYPE_CANONICAL (type));
7909     }
7910 
7911   return t;
7912 }
7913 
7914 /* Create a complex type whose components are COMPONENT_TYPE.  */
7915 
7916 tree
7917 build_complex_type (tree component_type)
7918 {
7919   tree t;
7920   hashval_t hashcode;
7921 
7922   gcc_assert (INTEGRAL_TYPE_P (component_type)
7923 	      || SCALAR_FLOAT_TYPE_P (component_type)
7924 	      || FIXED_POINT_TYPE_P (component_type));
7925 
7926   /* Make a node of the sort we want.  */
7927   t = make_node (COMPLEX_TYPE);
7928 
7929   TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
7930 
7931   /* If we already have such a type, use the old one.  */
7932   hashcode = iterative_hash_object (TYPE_HASH (component_type), 0);
7933   t = type_hash_canon (hashcode, t);
7934 
7935   if (!COMPLETE_TYPE_P (t))
7936     layout_type (t);
7937 
7938   if (TYPE_CANONICAL (t) == t)
7939     {
7940       if (TYPE_STRUCTURAL_EQUALITY_P (component_type))
7941 	SET_TYPE_STRUCTURAL_EQUALITY (t);
7942       else if (TYPE_CANONICAL (component_type) != component_type)
7943 	TYPE_CANONICAL (t)
7944 	  = build_complex_type (TYPE_CANONICAL (component_type));
7945     }
7946 
7947   /* We need to create a name, since complex is a fundamental type.  */
7948   if (! TYPE_NAME (t))
7949     {
7950       const char *name;
7951       if (component_type == char_type_node)
7952 	name = "complex char";
7953       else if (component_type == signed_char_type_node)
7954 	name = "complex signed char";
7955       else if (component_type == unsigned_char_type_node)
7956 	name = "complex unsigned char";
7957       else if (component_type == short_integer_type_node)
7958 	name = "complex short int";
7959       else if (component_type == short_unsigned_type_node)
7960 	name = "complex short unsigned int";
7961       else if (component_type == integer_type_node)
7962 	name = "complex int";
7963       else if (component_type == unsigned_type_node)
7964 	name = "complex unsigned int";
7965       else if (component_type == long_integer_type_node)
7966 	name = "complex long int";
7967       else if (component_type == long_unsigned_type_node)
7968 	name = "complex long unsigned int";
7969       else if (component_type == long_long_integer_type_node)
7970 	name = "complex long long int";
7971       else if (component_type == long_long_unsigned_type_node)
7972 	name = "complex long long unsigned int";
7973       else
7974 	name = 0;
7975 
7976       if (name != 0)
7977 	TYPE_NAME (t) = build_decl (UNKNOWN_LOCATION, TYPE_DECL,
7978 	    			    get_identifier (name), t);
7979     }
7980 
7981   return build_qualified_type (t, TYPE_QUALS (component_type));
7982 }
7983 
7984 /* If TYPE is a real or complex floating-point type and the target
7985    does not directly support arithmetic on TYPE then return the wider
7986    type to be used for arithmetic on TYPE.  Otherwise, return
7987    NULL_TREE.  */
7988 
7989 tree
7990 excess_precision_type (tree type)
7991 {
7992   if (flag_excess_precision != EXCESS_PRECISION_FAST)
7993     {
7994       int flt_eval_method = TARGET_FLT_EVAL_METHOD;
7995       switch (TREE_CODE (type))
7996 	{
7997 	case REAL_TYPE:
7998 	  switch (flt_eval_method)
7999 	    {
8000 	    case 1:
8001 	      if (TYPE_MODE (type) == TYPE_MODE (float_type_node))
8002 		return double_type_node;
8003 	      break;
8004 	    case 2:
8005 	      if (TYPE_MODE (type) == TYPE_MODE (float_type_node)
8006 		  || TYPE_MODE (type) == TYPE_MODE (double_type_node))
8007 		return long_double_type_node;
8008 	      break;
8009 	    default:
8010 	      gcc_unreachable ();
8011 	    }
8012 	  break;
8013 	case COMPLEX_TYPE:
8014 	  if (TREE_CODE (TREE_TYPE (type)) != REAL_TYPE)
8015 	    return NULL_TREE;
8016 	  switch (flt_eval_method)
8017 	    {
8018 	    case 1:
8019 	      if (TYPE_MODE (TREE_TYPE (type)) == TYPE_MODE (float_type_node))
8020 		return complex_double_type_node;
8021 	      break;
8022 	    case 2:
8023 	      if (TYPE_MODE (TREE_TYPE (type)) == TYPE_MODE (float_type_node)
8024 		  || (TYPE_MODE (TREE_TYPE (type))
8025 		      == TYPE_MODE (double_type_node)))
8026 		return complex_long_double_type_node;
8027 	      break;
8028 	    default:
8029 	      gcc_unreachable ();
8030 	    }
8031 	  break;
8032 	default:
8033 	  break;
8034 	}
8035     }
8036   return NULL_TREE;
8037 }
8038 
8039 /* Return OP, stripped of any conversions to wider types as much as is safe.
8040    Converting the value back to OP's type makes a value equivalent to OP.
8041 
8042    If FOR_TYPE is nonzero, we return a value which, if converted to
8043    type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
8044 
8045    OP must have integer, real or enumeral type.  Pointers are not allowed!
8046 
8047    There are some cases where the obvious value we could return
8048    would regenerate to OP if converted to OP's type,
8049    but would not extend like OP to wider types.
8050    If FOR_TYPE indicates such extension is contemplated, we eschew such values.
8051    For example, if OP is (unsigned short)(signed char)-1,
8052    we avoid returning (signed char)-1 if FOR_TYPE is int,
8053    even though extending that to an unsigned short would regenerate OP,
8054    since the result of extending (signed char)-1 to (int)
8055    is different from (int) OP.  */
8056 
8057 tree
8058 get_unwidened (tree op, tree for_type)
8059 {
8060   /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension.  */
8061   tree type = TREE_TYPE (op);
8062   unsigned final_prec
8063     = TYPE_PRECISION (for_type != 0 ? for_type : type);
8064   int uns
8065     = (for_type != 0 && for_type != type
8066        && final_prec > TYPE_PRECISION (type)
8067        && TYPE_UNSIGNED (type));
8068   tree win = op;
8069 
8070   while (CONVERT_EXPR_P (op))
8071     {
8072       int bitschange;
8073 
8074       /* TYPE_PRECISION on vector types has different meaning
8075 	 (TYPE_VECTOR_SUBPARTS) and casts from vectors are view conversions,
8076 	 so avoid them here.  */
8077       if (TREE_CODE (TREE_TYPE (TREE_OPERAND (op, 0))) == VECTOR_TYPE)
8078 	break;
8079 
8080       bitschange = TYPE_PRECISION (TREE_TYPE (op))
8081 		   - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
8082 
8083       /* Truncations are many-one so cannot be removed.
8084 	 Unless we are later going to truncate down even farther.  */
8085       if (bitschange < 0
8086 	  && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
8087 	break;
8088 
8089       /* See what's inside this conversion.  If we decide to strip it,
8090 	 we will set WIN.  */
8091       op = TREE_OPERAND (op, 0);
8092 
8093       /* If we have not stripped any zero-extensions (uns is 0),
8094 	 we can strip any kind of extension.
8095 	 If we have previously stripped a zero-extension,
8096 	 only zero-extensions can safely be stripped.
8097 	 Any extension can be stripped if the bits it would produce
8098 	 are all going to be discarded later by truncating to FOR_TYPE.  */
8099 
8100       if (bitschange > 0)
8101 	{
8102 	  if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
8103 	    win = op;
8104 	  /* TYPE_UNSIGNED says whether this is a zero-extension.
8105 	     Let's avoid computing it if it does not affect WIN
8106 	     and if UNS will not be needed again.  */
8107 	  if ((uns
8108 	       || CONVERT_EXPR_P (op))
8109 	      && TYPE_UNSIGNED (TREE_TYPE (op)))
8110 	    {
8111 	      uns = 1;
8112 	      win = op;
8113 	    }
8114 	}
8115     }
8116 
8117   /* If we finally reach a constant see if it fits in for_type and
8118      in that case convert it.  */
8119   if (for_type
8120       && TREE_CODE (win) == INTEGER_CST
8121       && TREE_TYPE (win) != for_type
8122       && int_fits_type_p (win, for_type))
8123     win = fold_convert (for_type, win);
8124 
8125   return win;
8126 }
8127 
8128 /* Return OP or a simpler expression for a narrower value
8129    which can be sign-extended or zero-extended to give back OP.
8130    Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
8131    or 0 if the value should be sign-extended.  */
8132 
8133 tree
8134 get_narrower (tree op, int *unsignedp_ptr)
8135 {
8136   int uns = 0;
8137   int first = 1;
8138   tree win = op;
8139   bool integral_p = INTEGRAL_TYPE_P (TREE_TYPE (op));
8140 
8141   while (TREE_CODE (op) == NOP_EXPR)
8142     {
8143       int bitschange
8144 	= (TYPE_PRECISION (TREE_TYPE (op))
8145 	   - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0))));
8146 
8147       /* Truncations are many-one so cannot be removed.  */
8148       if (bitschange < 0)
8149 	break;
8150 
8151       /* See what's inside this conversion.  If we decide to strip it,
8152 	 we will set WIN.  */
8153 
8154       if (bitschange > 0)
8155 	{
8156 	  op = TREE_OPERAND (op, 0);
8157 	  /* An extension: the outermost one can be stripped,
8158 	     but remember whether it is zero or sign extension.  */
8159 	  if (first)
8160 	    uns = TYPE_UNSIGNED (TREE_TYPE (op));
8161 	  /* Otherwise, if a sign extension has been stripped,
8162 	     only sign extensions can now be stripped;
8163 	     if a zero extension has been stripped, only zero-extensions.  */
8164 	  else if (uns != TYPE_UNSIGNED (TREE_TYPE (op)))
8165 	    break;
8166 	  first = 0;
8167 	}
8168       else /* bitschange == 0 */
8169 	{
8170 	  /* A change in nominal type can always be stripped, but we must
8171 	     preserve the unsignedness.  */
8172 	  if (first)
8173 	    uns = TYPE_UNSIGNED (TREE_TYPE (op));
8174 	  first = 0;
8175 	  op = TREE_OPERAND (op, 0);
8176 	  /* Keep trying to narrow, but don't assign op to win if it
8177 	     would turn an integral type into something else.  */
8178 	  if (INTEGRAL_TYPE_P (TREE_TYPE (op)) != integral_p)
8179 	    continue;
8180 	}
8181 
8182       win = op;
8183     }
8184 
8185   if (TREE_CODE (op) == COMPONENT_REF
8186       /* Since type_for_size always gives an integer type.  */
8187       && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE
8188       && TREE_CODE (TREE_TYPE (op)) != FIXED_POINT_TYPE
8189       /* Ensure field is laid out already.  */
8190       && DECL_SIZE (TREE_OPERAND (op, 1)) != 0
8191       && host_integerp (DECL_SIZE (TREE_OPERAND (op, 1)), 1))
8192     {
8193       unsigned HOST_WIDE_INT innerprec
8194 	= tree_low_cst (DECL_SIZE (TREE_OPERAND (op, 1)), 1);
8195       int unsignedp = (DECL_UNSIGNED (TREE_OPERAND (op, 1))
8196 		       || TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op, 1))));
8197       tree type = lang_hooks.types.type_for_size (innerprec, unsignedp);
8198 
8199       /* We can get this structure field in a narrower type that fits it,
8200 	 but the resulting extension to its nominal type (a fullword type)
8201 	 must satisfy the same conditions as for other extensions.
8202 
8203 	 Do this only for fields that are aligned (not bit-fields),
8204 	 because when bit-field insns will be used there is no
8205 	 advantage in doing this.  */
8206 
8207       if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
8208 	  && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
8209 	  && (first || uns == DECL_UNSIGNED (TREE_OPERAND (op, 1)))
8210 	  && type != 0)
8211 	{
8212 	  if (first)
8213 	    uns = DECL_UNSIGNED (TREE_OPERAND (op, 1));
8214 	  win = fold_convert (type, op);
8215 	}
8216     }
8217 
8218   *unsignedp_ptr = uns;
8219   return win;
8220 }
8221 
8222 /* Returns true if integer constant C has a value that is permissible
8223    for type TYPE (an INTEGER_TYPE).  */
8224 
8225 bool
8226 int_fits_type_p (const_tree c, const_tree type)
8227 {
8228   tree type_low_bound, type_high_bound;
8229   bool ok_for_low_bound, ok_for_high_bound, unsc;
8230   double_int dc, dd;
8231 
8232   dc = tree_to_double_int (c);
8233   unsc = TYPE_UNSIGNED (TREE_TYPE (c));
8234 
8235   if (TREE_CODE (TREE_TYPE (c)) == INTEGER_TYPE
8236       && TYPE_IS_SIZETYPE (TREE_TYPE (c))
8237       && unsc)
8238     /* So c is an unsigned integer whose type is sizetype and type is not.
8239        sizetype'd integers are sign extended even though they are
8240        unsigned. If the integer value fits in the lower end word of c,
8241        and if the higher end word has all its bits set to 1, that
8242        means the higher end bits are set to 1 only for sign extension.
8243        So let's convert c into an equivalent zero extended unsigned
8244        integer.  */
8245     dc = double_int_zext (dc, TYPE_PRECISION (TREE_TYPE (c)));
8246 
8247 retry:
8248   type_low_bound = TYPE_MIN_VALUE (type);
8249   type_high_bound = TYPE_MAX_VALUE (type);
8250 
8251   /* If at least one bound of the type is a constant integer, we can check
8252      ourselves and maybe make a decision. If no such decision is possible, but
8253      this type is a subtype, try checking against that.  Otherwise, use
8254      double_int_fits_to_tree_p, which checks against the precision.
8255 
8256      Compute the status for each possibly constant bound, and return if we see
8257      one does not match. Use ok_for_xxx_bound for this purpose, assigning -1
8258      for "unknown if constant fits", 0 for "constant known *not* to fit" and 1
8259      for "constant known to fit".  */
8260 
8261   /* Check if c >= type_low_bound.  */
8262   if (type_low_bound && TREE_CODE (type_low_bound) == INTEGER_CST)
8263     {
8264       dd = tree_to_double_int (type_low_bound);
8265       if (TREE_CODE (type) == INTEGER_TYPE
8266 	  && TYPE_IS_SIZETYPE (type)
8267 	  && TYPE_UNSIGNED (type))
8268 	dd = double_int_zext (dd, TYPE_PRECISION (type));
8269       if (unsc != TYPE_UNSIGNED (TREE_TYPE (type_low_bound)))
8270 	{
8271 	  int c_neg = (!unsc && double_int_negative_p (dc));
8272 	  int t_neg = (unsc && double_int_negative_p (dd));
8273 
8274 	  if (c_neg && !t_neg)
8275 	    return false;
8276 	  if ((c_neg || !t_neg) && double_int_ucmp (dc, dd) < 0)
8277 	    return false;
8278 	}
8279       else if (double_int_cmp (dc, dd, unsc) < 0)
8280 	return false;
8281       ok_for_low_bound = true;
8282     }
8283   else
8284     ok_for_low_bound = false;
8285 
8286   /* Check if c <= type_high_bound.  */
8287   if (type_high_bound && TREE_CODE (type_high_bound) == INTEGER_CST)
8288     {
8289       dd = tree_to_double_int (type_high_bound);
8290       if (TREE_CODE (type) == INTEGER_TYPE
8291 	  && TYPE_IS_SIZETYPE (type)
8292 	  && TYPE_UNSIGNED (type))
8293 	dd = double_int_zext (dd, TYPE_PRECISION (type));
8294       if (unsc != TYPE_UNSIGNED (TREE_TYPE (type_high_bound)))
8295 	{
8296 	  int c_neg = (!unsc && double_int_negative_p (dc));
8297 	  int t_neg = (unsc && double_int_negative_p (dd));
8298 
8299 	  if (t_neg && !c_neg)
8300 	    return false;
8301 	  if ((t_neg || !c_neg) && double_int_ucmp (dc, dd) > 0)
8302 	    return false;
8303 	}
8304       else if (double_int_cmp (dc, dd, unsc) > 0)
8305 	return false;
8306       ok_for_high_bound = true;
8307     }
8308   else
8309     ok_for_high_bound = false;
8310 
8311   /* If the constant fits both bounds, the result is known.  */
8312   if (ok_for_low_bound && ok_for_high_bound)
8313     return true;
8314 
8315   /* Perform some generic filtering which may allow making a decision
8316      even if the bounds are not constant.  First, negative integers
8317      never fit in unsigned types, */
8318   if (TYPE_UNSIGNED (type) && !unsc && double_int_negative_p (dc))
8319     return false;
8320 
8321   /* Second, narrower types always fit in wider ones.  */
8322   if (TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (c)))
8323     return true;
8324 
8325   /* Third, unsigned integers with top bit set never fit signed types.  */
8326   if (! TYPE_UNSIGNED (type) && unsc)
8327     {
8328       int prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (c))) - 1;
8329       if (prec < HOST_BITS_PER_WIDE_INT)
8330 	{
8331 	  if (((((unsigned HOST_WIDE_INT) 1) << prec) & dc.low) != 0)
8332 	    return false;
8333         }
8334       else if (((((unsigned HOST_WIDE_INT) 1)
8335 		 << (prec - HOST_BITS_PER_WIDE_INT)) & dc.high) != 0)
8336 	return false;
8337     }
8338 
8339   /* If we haven't been able to decide at this point, there nothing more we
8340      can check ourselves here.  Look at the base type if we have one and it
8341      has the same precision.  */
8342   if (TREE_CODE (type) == INTEGER_TYPE
8343       && TREE_TYPE (type) != 0
8344       && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (type)))
8345     {
8346       type = TREE_TYPE (type);
8347       goto retry;
8348     }
8349 
8350   /* Or to double_int_fits_to_tree_p, if nothing else.  */
8351   return double_int_fits_to_tree_p (type, dc);
8352 }
8353 
8354 /* Stores bounds of an integer TYPE in MIN and MAX.  If TYPE has non-constant
8355    bounds or is a POINTER_TYPE, the maximum and/or minimum values that can be
8356    represented (assuming two's-complement arithmetic) within the bit
8357    precision of the type are returned instead.  */
8358 
8359 void
8360 get_type_static_bounds (const_tree type, mpz_t min, mpz_t max)
8361 {
8362   if (!POINTER_TYPE_P (type) && TYPE_MIN_VALUE (type)
8363       && TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST)
8364     mpz_set_double_int (min, tree_to_double_int (TYPE_MIN_VALUE (type)),
8365 			TYPE_UNSIGNED (type));
8366   else
8367     {
8368       if (TYPE_UNSIGNED (type))
8369 	mpz_set_ui (min, 0);
8370       else
8371 	{
8372 	  double_int mn;
8373 	  mn = double_int_mask (TYPE_PRECISION (type) - 1);
8374 	  mn = double_int_sext (double_int_add (mn, double_int_one),
8375 				TYPE_PRECISION (type));
8376 	  mpz_set_double_int (min, mn, false);
8377 	}
8378     }
8379 
8380   if (!POINTER_TYPE_P (type) && TYPE_MAX_VALUE (type)
8381       && TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST)
8382     mpz_set_double_int (max, tree_to_double_int (TYPE_MAX_VALUE (type)),
8383 			TYPE_UNSIGNED (type));
8384   else
8385     {
8386       if (TYPE_UNSIGNED (type))
8387 	mpz_set_double_int (max, double_int_mask (TYPE_PRECISION (type)),
8388 			    true);
8389       else
8390 	mpz_set_double_int (max, double_int_mask (TYPE_PRECISION (type) - 1),
8391 			    true);
8392     }
8393 }
8394 
8395 /* Return true if VAR is an automatic variable defined in function FN.  */
8396 
8397 bool
8398 auto_var_in_fn_p (const_tree var, const_tree fn)
8399 {
8400   return (DECL_P (var) && DECL_CONTEXT (var) == fn
8401 	  && ((((TREE_CODE (var) == VAR_DECL && ! DECL_EXTERNAL (var))
8402 		|| TREE_CODE (var) == PARM_DECL)
8403 	       && ! TREE_STATIC (var))
8404 	      || TREE_CODE (var) == LABEL_DECL
8405 	      || TREE_CODE (var) == RESULT_DECL));
8406 }
8407 
8408 /* Subprogram of following function.  Called by walk_tree.
8409 
8410    Return *TP if it is an automatic variable or parameter of the
8411    function passed in as DATA.  */
8412 
8413 static tree
8414 find_var_from_fn (tree *tp, int *walk_subtrees, void *data)
8415 {
8416   tree fn = (tree) data;
8417 
8418   if (TYPE_P (*tp))
8419     *walk_subtrees = 0;
8420 
8421   else if (DECL_P (*tp)
8422 	   && auto_var_in_fn_p (*tp, fn))
8423     return *tp;
8424 
8425   return NULL_TREE;
8426 }
8427 
8428 /* Returns true if T is, contains, or refers to a type with variable
8429    size.  For METHOD_TYPEs and FUNCTION_TYPEs we exclude the
8430    arguments, but not the return type.  If FN is nonzero, only return
8431    true if a modifier of the type or position of FN is a variable or
8432    parameter inside FN.
8433 
8434    This concept is more general than that of C99 'variably modified types':
8435    in C99, a struct type is never variably modified because a VLA may not
8436    appear as a structure member.  However, in GNU C code like:
8437 
8438      struct S { int i[f()]; };
8439 
8440    is valid, and other languages may define similar constructs.  */
8441 
8442 bool
8443 variably_modified_type_p (tree type, tree fn)
8444 {
8445   tree t;
8446 
8447 /* Test if T is either variable (if FN is zero) or an expression containing
8448    a variable in FN.  If TYPE isn't gimplified, return true also if
8449    gimplify_one_sizepos would gimplify the expression into a local
8450    variable.  */
8451 #define RETURN_TRUE_IF_VAR(T)						\
8452   do { tree _t = (T);							\
8453     if (_t != NULL_TREE							\
8454 	&& _t != error_mark_node					\
8455 	&& TREE_CODE (_t) != INTEGER_CST				\
8456 	&& TREE_CODE (_t) != PLACEHOLDER_EXPR				\
8457 	&& (!fn								\
8458 	    || (!TYPE_SIZES_GIMPLIFIED (type)				\
8459 		&& !is_gimple_sizepos (_t))				\
8460 	    || walk_tree (&_t, find_var_from_fn, fn, NULL)))		\
8461       return true;  } while (0)
8462 
8463   if (type == error_mark_node)
8464     return false;
8465 
8466   /* If TYPE itself has variable size, it is variably modified.  */
8467   RETURN_TRUE_IF_VAR (TYPE_SIZE (type));
8468   RETURN_TRUE_IF_VAR (TYPE_SIZE_UNIT (type));
8469 
8470   switch (TREE_CODE (type))
8471     {
8472     case POINTER_TYPE:
8473     case REFERENCE_TYPE:
8474     case VECTOR_TYPE:
8475       if (variably_modified_type_p (TREE_TYPE (type), fn))
8476 	return true;
8477       break;
8478 
8479     case FUNCTION_TYPE:
8480     case METHOD_TYPE:
8481       /* If TYPE is a function type, it is variably modified if the
8482 	 return type is variably modified.  */
8483       if (variably_modified_type_p (TREE_TYPE (type), fn))
8484 	  return true;
8485       break;
8486 
8487     case INTEGER_TYPE:
8488     case REAL_TYPE:
8489     case FIXED_POINT_TYPE:
8490     case ENUMERAL_TYPE:
8491     case BOOLEAN_TYPE:
8492       /* Scalar types are variably modified if their end points
8493 	 aren't constant.  */
8494       RETURN_TRUE_IF_VAR (TYPE_MIN_VALUE (type));
8495       RETURN_TRUE_IF_VAR (TYPE_MAX_VALUE (type));
8496       break;
8497 
8498     case RECORD_TYPE:
8499     case UNION_TYPE:
8500     case QUAL_UNION_TYPE:
8501       /* We can't see if any of the fields are variably-modified by the
8502 	 definition we normally use, since that would produce infinite
8503 	 recursion via pointers.  */
8504       /* This is variably modified if some field's type is.  */
8505       for (t = TYPE_FIELDS (type); t; t = DECL_CHAIN (t))
8506 	if (TREE_CODE (t) == FIELD_DECL)
8507 	  {
8508 	    RETURN_TRUE_IF_VAR (DECL_FIELD_OFFSET (t));
8509 	    RETURN_TRUE_IF_VAR (DECL_SIZE (t));
8510 	    RETURN_TRUE_IF_VAR (DECL_SIZE_UNIT (t));
8511 
8512 	    if (TREE_CODE (type) == QUAL_UNION_TYPE)
8513 	      RETURN_TRUE_IF_VAR (DECL_QUALIFIER (t));
8514 	  }
8515 	break;
8516 
8517     case ARRAY_TYPE:
8518       /* Do not call ourselves to avoid infinite recursion.  This is
8519 	 variably modified if the element type is.  */
8520       RETURN_TRUE_IF_VAR (TYPE_SIZE (TREE_TYPE (type)));
8521       RETURN_TRUE_IF_VAR (TYPE_SIZE_UNIT (TREE_TYPE (type)));
8522       break;
8523 
8524     default:
8525       break;
8526     }
8527 
8528   /* The current language may have other cases to check, but in general,
8529      all other types are not variably modified.  */
8530   return lang_hooks.tree_inlining.var_mod_type_p (type, fn);
8531 
8532 #undef RETURN_TRUE_IF_VAR
8533 }
8534 
8535 /* Given a DECL or TYPE, return the scope in which it was declared, or
8536    NULL_TREE if there is no containing scope.  */
8537 
8538 tree
8539 get_containing_scope (const_tree t)
8540 {
8541   return (TYPE_P (t) ? TYPE_CONTEXT (t) : DECL_CONTEXT (t));
8542 }
8543 
8544 /* Return the innermost context enclosing DECL that is
8545    a FUNCTION_DECL, or zero if none.  */
8546 
8547 tree
8548 decl_function_context (const_tree decl)
8549 {
8550   tree context;
8551 
8552   if (TREE_CODE (decl) == ERROR_MARK)
8553     return 0;
8554 
8555   /* C++ virtual functions use DECL_CONTEXT for the class of the vtable
8556      where we look up the function at runtime.  Such functions always take
8557      a first argument of type 'pointer to real context'.
8558 
8559      C++ should really be fixed to use DECL_CONTEXT for the real context,
8560      and use something else for the "virtual context".  */
8561   else if (TREE_CODE (decl) == FUNCTION_DECL && DECL_VINDEX (decl))
8562     context
8563       = TYPE_MAIN_VARIANT
8564 	(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (decl)))));
8565   else
8566     context = DECL_CONTEXT (decl);
8567 
8568   while (context && TREE_CODE (context) != FUNCTION_DECL)
8569     {
8570       if (TREE_CODE (context) == BLOCK)
8571 	context = BLOCK_SUPERCONTEXT (context);
8572       else
8573 	context = get_containing_scope (context);
8574     }
8575 
8576   return context;
8577 }
8578 
8579 /* Return the innermost context enclosing DECL that is
8580    a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
8581    TYPE_DECLs and FUNCTION_DECLs are transparent to this function.  */
8582 
8583 tree
8584 decl_type_context (const_tree decl)
8585 {
8586   tree context = DECL_CONTEXT (decl);
8587 
8588   while (context)
8589     switch (TREE_CODE (context))
8590       {
8591       case NAMESPACE_DECL:
8592       case TRANSLATION_UNIT_DECL:
8593 	return NULL_TREE;
8594 
8595       case RECORD_TYPE:
8596       case UNION_TYPE:
8597       case QUAL_UNION_TYPE:
8598 	return context;
8599 
8600       case TYPE_DECL:
8601       case FUNCTION_DECL:
8602 	context = DECL_CONTEXT (context);
8603 	break;
8604 
8605       case BLOCK:
8606 	context = BLOCK_SUPERCONTEXT (context);
8607 	break;
8608 
8609       default:
8610 	gcc_unreachable ();
8611       }
8612 
8613   return NULL_TREE;
8614 }
8615 
8616 /* CALL is a CALL_EXPR.  Return the declaration for the function
8617    called, or NULL_TREE if the called function cannot be
8618    determined.  */
8619 
8620 tree
8621 get_callee_fndecl (const_tree call)
8622 {
8623   tree addr;
8624 
8625   if (call == error_mark_node)
8626     return error_mark_node;
8627 
8628   /* It's invalid to call this function with anything but a
8629      CALL_EXPR.  */
8630   gcc_assert (TREE_CODE (call) == CALL_EXPR);
8631 
8632   /* The first operand to the CALL is the address of the function
8633      called.  */
8634   addr = CALL_EXPR_FN (call);
8635 
8636   STRIP_NOPS (addr);
8637 
8638   /* If this is a readonly function pointer, extract its initial value.  */
8639   if (DECL_P (addr) && TREE_CODE (addr) != FUNCTION_DECL
8640       && TREE_READONLY (addr) && ! TREE_THIS_VOLATILE (addr)
8641       && DECL_INITIAL (addr))
8642     addr = DECL_INITIAL (addr);
8643 
8644   /* If the address is just `&f' for some function `f', then we know
8645      that `f' is being called.  */
8646   if (TREE_CODE (addr) == ADDR_EXPR
8647       && TREE_CODE (TREE_OPERAND (addr, 0)) == FUNCTION_DECL)
8648     return TREE_OPERAND (addr, 0);
8649 
8650   /* We couldn't figure out what was being called.  */
8651   return NULL_TREE;
8652 }
8653 
8654 /* Print debugging information about tree nodes generated during the compile,
8655    and any language-specific information.  */
8656 
8657 void
8658 dump_tree_statistics (void)
8659 {
8660 #ifdef GATHER_STATISTICS
8661   int i;
8662   int total_nodes, total_bytes;
8663 #endif
8664 
8665   fprintf (stderr, "\n??? tree nodes created\n\n");
8666 #ifdef GATHER_STATISTICS
8667   fprintf (stderr, "Kind                   Nodes      Bytes\n");
8668   fprintf (stderr, "---------------------------------------\n");
8669   total_nodes = total_bytes = 0;
8670   for (i = 0; i < (int) all_kinds; i++)
8671     {
8672       fprintf (stderr, "%-20s %7d %10d\n", tree_node_kind_names[i],
8673 	       tree_node_counts[i], tree_node_sizes[i]);
8674       total_nodes += tree_node_counts[i];
8675       total_bytes += tree_node_sizes[i];
8676     }
8677   fprintf (stderr, "---------------------------------------\n");
8678   fprintf (stderr, "%-20s %7d %10d\n", "Total", total_nodes, total_bytes);
8679   fprintf (stderr, "---------------------------------------\n");
8680   fprintf (stderr, "Code                   Nodes\n");
8681   fprintf (stderr, "----------------------------\n");
8682   for (i = 0; i < (int) MAX_TREE_CODES; i++)
8683     fprintf (stderr, "%-20s %7d\n", tree_code_name[i], tree_code_counts[i]);
8684   fprintf (stderr, "----------------------------\n");
8685   ssanames_print_statistics ();
8686   phinodes_print_statistics ();
8687 #else
8688   fprintf (stderr, "(No per-node statistics)\n");
8689 #endif
8690   print_type_hash_statistics ();
8691   print_debug_expr_statistics ();
8692   print_value_expr_statistics ();
8693   lang_hooks.print_statistics ();
8694 }
8695 
8696 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
8697 
8698 /* Generate a crc32 of a byte.  */
8699 
8700 unsigned
8701 crc32_byte (unsigned chksum, char byte)
8702 {
8703   unsigned value = (unsigned) byte << 24;
8704       unsigned ix;
8705 
8706       for (ix = 8; ix--; value <<= 1)
8707   	{
8708   	  unsigned feedback;
8709 
8710   	  feedback = (value ^ chksum) & 0x80000000 ? 0x04c11db7 : 0;
8711  	  chksum <<= 1;
8712  	  chksum ^= feedback;
8713   	}
8714   return chksum;
8715 }
8716 
8717 
8718 /* Generate a crc32 of a string.  */
8719 
8720 unsigned
8721 crc32_string (unsigned chksum, const char *string)
8722 {
8723   do
8724     {
8725       chksum = crc32_byte (chksum, *string);
8726     }
8727   while (*string++);
8728   return chksum;
8729 }
8730 
8731 /* P is a string that will be used in a symbol.  Mask out any characters
8732    that are not valid in that context.  */
8733 
8734 void
8735 clean_symbol_name (char *p)
8736 {
8737   for (; *p; p++)
8738     if (! (ISALNUM (*p)
8739 #ifndef NO_DOLLAR_IN_LABEL	/* this for `$'; unlikely, but... -- kr */
8740 	    || *p == '$'
8741 #endif
8742 #ifndef NO_DOT_IN_LABEL		/* this for `.'; unlikely, but...  */
8743 	    || *p == '.'
8744 #endif
8745 	   ))
8746       *p = '_';
8747 }
8748 
8749 /* Generate a name for a special-purpose function.
8750    The generated name may need to be unique across the whole link.
8751    Changes to this function may also require corresponding changes to
8752    xstrdup_mask_random.
8753    TYPE is some string to identify the purpose of this function to the
8754    linker or collect2; it must start with an uppercase letter,
8755    one of:
8756    I - for constructors
8757    D - for destructors
8758    N - for C++ anonymous namespaces
8759    F - for DWARF unwind frame information.  */
8760 
8761 tree
8762 get_file_function_name (const char *type)
8763 {
8764   char *buf;
8765   const char *p;
8766   char *q;
8767 
8768   /* If we already have a name we know to be unique, just use that.  */
8769   if (first_global_object_name)
8770     p = q = ASTRDUP (first_global_object_name);
8771   /* If the target is handling the constructors/destructors, they
8772      will be local to this file and the name is only necessary for
8773      debugging purposes.
8774      We also assign sub_I and sub_D sufixes to constructors called from
8775      the global static constructors.  These are always local.  */
8776   else if (((type[0] == 'I' || type[0] == 'D') && targetm.have_ctors_dtors)
8777 	   || (strncmp (type, "sub_", 4) == 0
8778 	       && (type[4] == 'I' || type[4] == 'D')))
8779     {
8780       const char *file = main_input_filename;
8781       if (! file)
8782 	file = input_filename;
8783       /* Just use the file's basename, because the full pathname
8784 	 might be quite long.  */
8785       p = q = ASTRDUP (lbasename (file));
8786     }
8787   else
8788     {
8789       /* Otherwise, the name must be unique across the entire link.
8790 	 We don't have anything that we know to be unique to this translation
8791 	 unit, so use what we do have and throw in some randomness.  */
8792       unsigned len;
8793       const char *name = weak_global_object_name;
8794       const char *file = main_input_filename;
8795 
8796       if (! name)
8797 	name = "";
8798       if (! file)
8799 	file = input_filename;
8800 
8801       len = strlen (file);
8802       q = (char *) alloca (9 + 17 + len + 1);
8803       memcpy (q, file, len + 1);
8804 
8805       snprintf (q + len, 9 + 17 + 1, "_%08X_" HOST_WIDE_INT_PRINT_HEX,
8806 		crc32_string (0, name), get_random_seed (false));
8807 
8808       p = q;
8809     }
8810 
8811   clean_symbol_name (q);
8812   buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p)
8813 			 + strlen (type));
8814 
8815   /* Set up the name of the file-level functions we may need.
8816      Use a global object (which is already required to be unique over
8817      the program) rather than the file name (which imposes extra
8818      constraints).  */
8819   sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
8820 
8821   return get_identifier (buf);
8822 }
8823 
8824 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
8825 
8826 /* Complain that the tree code of NODE does not match the expected 0
8827    terminated list of trailing codes. The trailing code list can be
8828    empty, for a more vague error message.  FILE, LINE, and FUNCTION
8829    are of the caller.  */
8830 
8831 void
8832 tree_check_failed (const_tree node, const char *file,
8833 		   int line, const char *function, ...)
8834 {
8835   va_list args;
8836   const char *buffer;
8837   unsigned length = 0;
8838   int code;
8839 
8840   va_start (args, function);
8841   while ((code = va_arg (args, int)))
8842     length += 4 + strlen (tree_code_name[code]);
8843   va_end (args);
8844   if (length)
8845     {
8846       char *tmp;
8847       va_start (args, function);
8848       length += strlen ("expected ");
8849       buffer = tmp = (char *) alloca (length);
8850       length = 0;
8851       while ((code = va_arg (args, int)))
8852 	{
8853 	  const char *prefix = length ? " or " : "expected ";
8854 
8855 	  strcpy (tmp + length, prefix);
8856 	  length += strlen (prefix);
8857 	  strcpy (tmp + length, tree_code_name[code]);
8858 	  length += strlen (tree_code_name[code]);
8859 	}
8860       va_end (args);
8861     }
8862   else
8863     buffer = "unexpected node";
8864 
8865   internal_error ("tree check: %s, have %s in %s, at %s:%d",
8866 		  buffer, tree_code_name[TREE_CODE (node)],
8867 		  function, trim_filename (file), line);
8868 }
8869 
8870 /* Complain that the tree code of NODE does match the expected 0
8871    terminated list of trailing codes. FILE, LINE, and FUNCTION are of
8872    the caller.  */
8873 
8874 void
8875 tree_not_check_failed (const_tree node, const char *file,
8876 		       int line, const char *function, ...)
8877 {
8878   va_list args;
8879   char *buffer;
8880   unsigned length = 0;
8881   int code;
8882 
8883   va_start (args, function);
8884   while ((code = va_arg (args, int)))
8885     length += 4 + strlen (tree_code_name[code]);
8886   va_end (args);
8887   va_start (args, function);
8888   buffer = (char *) alloca (length);
8889   length = 0;
8890   while ((code = va_arg (args, int)))
8891     {
8892       if (length)
8893 	{
8894 	  strcpy (buffer + length, " or ");
8895 	  length += 4;
8896 	}
8897       strcpy (buffer + length, tree_code_name[code]);
8898       length += strlen (tree_code_name[code]);
8899     }
8900   va_end (args);
8901 
8902   internal_error ("tree check: expected none of %s, have %s in %s, at %s:%d",
8903 		  buffer, tree_code_name[TREE_CODE (node)],
8904 		  function, trim_filename (file), line);
8905 }
8906 
8907 /* Similar to tree_check_failed, except that we check for a class of tree
8908    code, given in CL.  */
8909 
8910 void
8911 tree_class_check_failed (const_tree node, const enum tree_code_class cl,
8912 			 const char *file, int line, const char *function)
8913 {
8914   internal_error
8915     ("tree check: expected class %qs, have %qs (%s) in %s, at %s:%d",
8916      TREE_CODE_CLASS_STRING (cl),
8917      TREE_CODE_CLASS_STRING (TREE_CODE_CLASS (TREE_CODE (node))),
8918      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
8919 }
8920 
8921 /* Similar to tree_check_failed, except that instead of specifying a
8922    dozen codes, use the knowledge that they're all sequential.  */
8923 
8924 void
8925 tree_range_check_failed (const_tree node, const char *file, int line,
8926 			 const char *function, enum tree_code c1,
8927 			 enum tree_code c2)
8928 {
8929   char *buffer;
8930   unsigned length = 0;
8931   unsigned int c;
8932 
8933   for (c = c1; c <= c2; ++c)
8934     length += 4 + strlen (tree_code_name[c]);
8935 
8936   length += strlen ("expected ");
8937   buffer = (char *) alloca (length);
8938   length = 0;
8939 
8940   for (c = c1; c <= c2; ++c)
8941     {
8942       const char *prefix = length ? " or " : "expected ";
8943 
8944       strcpy (buffer + length, prefix);
8945       length += strlen (prefix);
8946       strcpy (buffer + length, tree_code_name[c]);
8947       length += strlen (tree_code_name[c]);
8948     }
8949 
8950   internal_error ("tree check: %s, have %s in %s, at %s:%d",
8951 		  buffer, tree_code_name[TREE_CODE (node)],
8952 		  function, trim_filename (file), line);
8953 }
8954 
8955 
8956 /* Similar to tree_check_failed, except that we check that a tree does
8957    not have the specified code, given in CL.  */
8958 
8959 void
8960 tree_not_class_check_failed (const_tree node, const enum tree_code_class cl,
8961 			     const char *file, int line, const char *function)
8962 {
8963   internal_error
8964     ("tree check: did not expect class %qs, have %qs (%s) in %s, at %s:%d",
8965      TREE_CODE_CLASS_STRING (cl),
8966      TREE_CODE_CLASS_STRING (TREE_CODE_CLASS (TREE_CODE (node))),
8967      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
8968 }
8969 
8970 
8971 /* Similar to tree_check_failed but applied to OMP_CLAUSE codes.  */
8972 
8973 void
8974 omp_clause_check_failed (const_tree node, const char *file, int line,
8975                          const char *function, enum omp_clause_code code)
8976 {
8977   internal_error ("tree check: expected omp_clause %s, have %s in %s, at %s:%d",
8978 		  omp_clause_code_name[code], tree_code_name[TREE_CODE (node)],
8979 		  function, trim_filename (file), line);
8980 }
8981 
8982 
8983 /* Similar to tree_range_check_failed but applied to OMP_CLAUSE codes.  */
8984 
8985 void
8986 omp_clause_range_check_failed (const_tree node, const char *file, int line,
8987 			       const char *function, enum omp_clause_code c1,
8988 			       enum omp_clause_code c2)
8989 {
8990   char *buffer;
8991   unsigned length = 0;
8992   unsigned int c;
8993 
8994   for (c = c1; c <= c2; ++c)
8995     length += 4 + strlen (omp_clause_code_name[c]);
8996 
8997   length += strlen ("expected ");
8998   buffer = (char *) alloca (length);
8999   length = 0;
9000 
9001   for (c = c1; c <= c2; ++c)
9002     {
9003       const char *prefix = length ? " or " : "expected ";
9004 
9005       strcpy (buffer + length, prefix);
9006       length += strlen (prefix);
9007       strcpy (buffer + length, omp_clause_code_name[c]);
9008       length += strlen (omp_clause_code_name[c]);
9009     }
9010 
9011   internal_error ("tree check: %s, have %s in %s, at %s:%d",
9012 		  buffer, omp_clause_code_name[TREE_CODE (node)],
9013 		  function, trim_filename (file), line);
9014 }
9015 
9016 
9017 #undef DEFTREESTRUCT
9018 #define DEFTREESTRUCT(VAL, NAME) NAME,
9019 
9020 static const char *ts_enum_names[] = {
9021 #include "treestruct.def"
9022 };
9023 #undef DEFTREESTRUCT
9024 
9025 #define TS_ENUM_NAME(EN) (ts_enum_names[(EN)])
9026 
9027 /* Similar to tree_class_check_failed, except that we check for
9028    whether CODE contains the tree structure identified by EN.  */
9029 
9030 void
9031 tree_contains_struct_check_failed (const_tree node,
9032 				   const enum tree_node_structure_enum en,
9033 				   const char *file, int line,
9034 				   const char *function)
9035 {
9036   internal_error
9037     ("tree check: expected tree that contains %qs structure, have %qs in %s, at %s:%d",
9038      TS_ENUM_NAME(en),
9039      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
9040 }
9041 
9042 
9043 /* Similar to above, except that the check is for the bounds of a TREE_VEC's
9044    (dynamically sized) vector.  */
9045 
9046 void
9047 tree_vec_elt_check_failed (int idx, int len, const char *file, int line,
9048 			   const char *function)
9049 {
9050   internal_error
9051     ("tree check: accessed elt %d of tree_vec with %d elts in %s, at %s:%d",
9052      idx + 1, len, function, trim_filename (file), line);
9053 }
9054 
9055 /* Similar to above, except that the check is for the bounds of the operand
9056    vector of an expression node EXP.  */
9057 
9058 void
9059 tree_operand_check_failed (int idx, const_tree exp, const char *file,
9060 			   int line, const char *function)
9061 {
9062   int code = TREE_CODE (exp);
9063   internal_error
9064     ("tree check: accessed operand %d of %s with %d operands in %s, at %s:%d",
9065      idx + 1, tree_code_name[code], TREE_OPERAND_LENGTH (exp),
9066      function, trim_filename (file), line);
9067 }
9068 
9069 /* Similar to above, except that the check is for the number of
9070    operands of an OMP_CLAUSE node.  */
9071 
9072 void
9073 omp_clause_operand_check_failed (int idx, const_tree t, const char *file,
9074 			         int line, const char *function)
9075 {
9076   internal_error
9077     ("tree check: accessed operand %d of omp_clause %s with %d operands "
9078      "in %s, at %s:%d", idx + 1, omp_clause_code_name[OMP_CLAUSE_CODE (t)],
9079      omp_clause_num_ops [OMP_CLAUSE_CODE (t)], function,
9080      trim_filename (file), line);
9081 }
9082 #endif /* ENABLE_TREE_CHECKING */
9083 
9084 /* Create a new vector type node holding SUBPARTS units of type INNERTYPE,
9085    and mapped to the machine mode MODE.  Initialize its fields and build
9086    the information necessary for debugging output.  */
9087 
9088 static tree
9089 make_vector_type (tree innertype, int nunits, enum machine_mode mode)
9090 {
9091   tree t;
9092   hashval_t hashcode = 0;
9093 
9094   t = make_node (VECTOR_TYPE);
9095   TREE_TYPE (t) = TYPE_MAIN_VARIANT (innertype);
9096   SET_TYPE_VECTOR_SUBPARTS (t, nunits);
9097   SET_TYPE_MODE (t, mode);
9098 
9099   if (TYPE_STRUCTURAL_EQUALITY_P (innertype))
9100     SET_TYPE_STRUCTURAL_EQUALITY (t);
9101   else if (TYPE_CANONICAL (innertype) != innertype
9102 	   || mode != VOIDmode)
9103     TYPE_CANONICAL (t)
9104       = make_vector_type (TYPE_CANONICAL (innertype), nunits, VOIDmode);
9105 
9106   layout_type (t);
9107 
9108   hashcode = iterative_hash_host_wide_int (VECTOR_TYPE, hashcode);
9109   hashcode = iterative_hash_host_wide_int (nunits, hashcode);
9110   hashcode = iterative_hash_host_wide_int (mode, hashcode);
9111   hashcode = iterative_hash_object (TYPE_HASH (TREE_TYPE (t)), hashcode);
9112   t = type_hash_canon (hashcode, t);
9113 
9114   /* We have built a main variant, based on the main variant of the
9115      inner type. Use it to build the variant we return.  */
9116   if ((TYPE_ATTRIBUTES (innertype) || TYPE_QUALS (innertype))
9117       && TREE_TYPE (t) != innertype)
9118     return build_type_attribute_qual_variant (t,
9119 					      TYPE_ATTRIBUTES (innertype),
9120 					      TYPE_QUALS (innertype));
9121 
9122   return t;
9123 }
9124 
9125 static tree
9126 make_or_reuse_type (unsigned size, int unsignedp)
9127 {
9128   if (size == INT_TYPE_SIZE)
9129     return unsignedp ? unsigned_type_node : integer_type_node;
9130   if (size == CHAR_TYPE_SIZE)
9131     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
9132   if (size == SHORT_TYPE_SIZE)
9133     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
9134   if (size == LONG_TYPE_SIZE)
9135     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
9136   if (size == LONG_LONG_TYPE_SIZE)
9137     return (unsignedp ? long_long_unsigned_type_node
9138             : long_long_integer_type_node);
9139   if (size == 128 && int128_integer_type_node)
9140     return (unsignedp ? int128_unsigned_type_node
9141             : int128_integer_type_node);
9142 
9143   if (unsignedp)
9144     return make_unsigned_type (size);
9145   else
9146     return make_signed_type (size);
9147 }
9148 
9149 /* Create or reuse a fract type by SIZE, UNSIGNEDP, and SATP.  */
9150 
9151 static tree
9152 make_or_reuse_fract_type (unsigned size, int unsignedp, int satp)
9153 {
9154   if (satp)
9155     {
9156       if (size == SHORT_FRACT_TYPE_SIZE)
9157 	return unsignedp ? sat_unsigned_short_fract_type_node
9158 			 : sat_short_fract_type_node;
9159       if (size == FRACT_TYPE_SIZE)
9160 	return unsignedp ? sat_unsigned_fract_type_node : sat_fract_type_node;
9161       if (size == LONG_FRACT_TYPE_SIZE)
9162 	return unsignedp ? sat_unsigned_long_fract_type_node
9163 			 : sat_long_fract_type_node;
9164       if (size == LONG_LONG_FRACT_TYPE_SIZE)
9165 	return unsignedp ? sat_unsigned_long_long_fract_type_node
9166 			 : sat_long_long_fract_type_node;
9167     }
9168   else
9169     {
9170       if (size == SHORT_FRACT_TYPE_SIZE)
9171 	return unsignedp ? unsigned_short_fract_type_node
9172 			 : short_fract_type_node;
9173       if (size == FRACT_TYPE_SIZE)
9174 	return unsignedp ? unsigned_fract_type_node : fract_type_node;
9175       if (size == LONG_FRACT_TYPE_SIZE)
9176 	return unsignedp ? unsigned_long_fract_type_node
9177 			 : long_fract_type_node;
9178       if (size == LONG_LONG_FRACT_TYPE_SIZE)
9179 	return unsignedp ? unsigned_long_long_fract_type_node
9180 			 : long_long_fract_type_node;
9181     }
9182 
9183   return make_fract_type (size, unsignedp, satp);
9184 }
9185 
9186 /* Create or reuse an accum type by SIZE, UNSIGNEDP, and SATP.  */
9187 
9188 static tree
9189 make_or_reuse_accum_type (unsigned size, int unsignedp, int satp)
9190 {
9191   if (satp)
9192     {
9193       if (size == SHORT_ACCUM_TYPE_SIZE)
9194 	return unsignedp ? sat_unsigned_short_accum_type_node
9195 			 : sat_short_accum_type_node;
9196       if (size == ACCUM_TYPE_SIZE)
9197 	return unsignedp ? sat_unsigned_accum_type_node : sat_accum_type_node;
9198       if (size == LONG_ACCUM_TYPE_SIZE)
9199 	return unsignedp ? sat_unsigned_long_accum_type_node
9200 			 : sat_long_accum_type_node;
9201       if (size == LONG_LONG_ACCUM_TYPE_SIZE)
9202 	return unsignedp ? sat_unsigned_long_long_accum_type_node
9203 			 : sat_long_long_accum_type_node;
9204     }
9205   else
9206     {
9207       if (size == SHORT_ACCUM_TYPE_SIZE)
9208 	return unsignedp ? unsigned_short_accum_type_node
9209 			 : short_accum_type_node;
9210       if (size == ACCUM_TYPE_SIZE)
9211 	return unsignedp ? unsigned_accum_type_node : accum_type_node;
9212       if (size == LONG_ACCUM_TYPE_SIZE)
9213 	return unsignedp ? unsigned_long_accum_type_node
9214 			 : long_accum_type_node;
9215       if (size == LONG_LONG_ACCUM_TYPE_SIZE)
9216 	return unsignedp ? unsigned_long_long_accum_type_node
9217 			 : long_long_accum_type_node;
9218     }
9219 
9220   return make_accum_type (size, unsignedp, satp);
9221 }
9222 
9223 /* Create nodes for all integer types (and error_mark_node) using the sizes
9224    of C datatypes.  SIGNED_CHAR specifies whether char is signed,
9225    SHORT_DOUBLE specifies whether double should be of the same precision
9226    as float.  */
9227 
9228 void
9229 build_common_tree_nodes (bool signed_char, bool short_double)
9230 {
9231   error_mark_node = make_node (ERROR_MARK);
9232   TREE_TYPE (error_mark_node) = error_mark_node;
9233 
9234   initialize_sizetypes ();
9235 
9236   /* Define both `signed char' and `unsigned char'.  */
9237   signed_char_type_node = make_signed_type (CHAR_TYPE_SIZE);
9238   TYPE_STRING_FLAG (signed_char_type_node) = 1;
9239   unsigned_char_type_node = make_unsigned_type (CHAR_TYPE_SIZE);
9240   TYPE_STRING_FLAG (unsigned_char_type_node) = 1;
9241 
9242   /* Define `char', which is like either `signed char' or `unsigned char'
9243      but not the same as either.  */
9244   char_type_node
9245     = (signed_char
9246        ? make_signed_type (CHAR_TYPE_SIZE)
9247        : make_unsigned_type (CHAR_TYPE_SIZE));
9248   TYPE_STRING_FLAG (char_type_node) = 1;
9249 
9250   short_integer_type_node = make_signed_type (SHORT_TYPE_SIZE);
9251   short_unsigned_type_node = make_unsigned_type (SHORT_TYPE_SIZE);
9252   integer_type_node = make_signed_type (INT_TYPE_SIZE);
9253   unsigned_type_node = make_unsigned_type (INT_TYPE_SIZE);
9254   long_integer_type_node = make_signed_type (LONG_TYPE_SIZE);
9255   long_unsigned_type_node = make_unsigned_type (LONG_TYPE_SIZE);
9256   long_long_integer_type_node = make_signed_type (LONG_LONG_TYPE_SIZE);
9257   long_long_unsigned_type_node = make_unsigned_type (LONG_LONG_TYPE_SIZE);
9258 #if HOST_BITS_PER_WIDE_INT >= 64
9259     /* TODO: This isn't correct, but as logic depends at the moment on
9260        host's instead of target's wide-integer.
9261        If there is a target not supporting TImode, but has an 128-bit
9262        integer-scalar register, this target check needs to be adjusted. */
9263     if (targetm.scalar_mode_supported_p (TImode))
9264       {
9265         int128_integer_type_node = make_signed_type (128);
9266         int128_unsigned_type_node = make_unsigned_type (128);
9267       }
9268 #endif
9269 
9270   /* Define a boolean type.  This type only represents boolean values but
9271      may be larger than char depending on the value of BOOL_TYPE_SIZE.
9272      Front ends which want to override this size (i.e. Java) can redefine
9273      boolean_type_node before calling build_common_tree_nodes_2.  */
9274   boolean_type_node = make_unsigned_type (BOOL_TYPE_SIZE);
9275   TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
9276   TYPE_MAX_VALUE (boolean_type_node) = build_int_cst (boolean_type_node, 1);
9277   TYPE_PRECISION (boolean_type_node) = 1;
9278 
9279   /* Define what type to use for size_t.  */
9280   if (strcmp (SIZE_TYPE, "unsigned int") == 0)
9281     size_type_node = unsigned_type_node;
9282   else if (strcmp (SIZE_TYPE, "long unsigned int") == 0)
9283     size_type_node = long_unsigned_type_node;
9284   else if (strcmp (SIZE_TYPE, "long long unsigned int") == 0)
9285     size_type_node = long_long_unsigned_type_node;
9286   else if (strcmp (SIZE_TYPE, "short unsigned int") == 0)
9287     size_type_node = short_unsigned_type_node;
9288   else
9289     gcc_unreachable ();
9290 
9291   /* Fill in the rest of the sized types.  Reuse existing type nodes
9292      when possible.  */
9293   intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 0);
9294   intHI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (HImode), 0);
9295   intSI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (SImode), 0);
9296   intDI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (DImode), 0);
9297   intTI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (TImode), 0);
9298 
9299   unsigned_intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 1);
9300   unsigned_intHI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (HImode), 1);
9301   unsigned_intSI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (SImode), 1);
9302   unsigned_intDI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (DImode), 1);
9303   unsigned_intTI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (TImode), 1);
9304 
9305   access_public_node = get_identifier ("public");
9306   access_protected_node = get_identifier ("protected");
9307   access_private_node = get_identifier ("private");
9308 
9309   /* Define these next since types below may used them.  */
9310   integer_zero_node = build_int_cst (integer_type_node, 0);
9311   integer_one_node = build_int_cst (integer_type_node, 1);
9312   integer_three_node = build_int_cst (integer_type_node, 3);
9313   integer_minus_one_node = build_int_cst (integer_type_node, -1);
9314 
9315   size_zero_node = size_int (0);
9316   size_one_node = size_int (1);
9317   bitsize_zero_node = bitsize_int (0);
9318   bitsize_one_node = bitsize_int (1);
9319   bitsize_unit_node = bitsize_int (BITS_PER_UNIT);
9320 
9321   boolean_false_node = TYPE_MIN_VALUE (boolean_type_node);
9322   boolean_true_node = TYPE_MAX_VALUE (boolean_type_node);
9323 
9324   void_type_node = make_node (VOID_TYPE);
9325   layout_type (void_type_node);
9326 
9327   /* We are not going to have real types in C with less than byte alignment,
9328      so we might as well not have any types that claim to have it.  */
9329   TYPE_ALIGN (void_type_node) = BITS_PER_UNIT;
9330   TYPE_USER_ALIGN (void_type_node) = 0;
9331 
9332   null_pointer_node = build_int_cst (build_pointer_type (void_type_node), 0);
9333   layout_type (TREE_TYPE (null_pointer_node));
9334 
9335   ptr_type_node = build_pointer_type (void_type_node);
9336   const_ptr_type_node
9337     = build_pointer_type (build_type_variant (void_type_node, 1, 0));
9338   fileptr_type_node = ptr_type_node;
9339 
9340   float_type_node = make_node (REAL_TYPE);
9341   TYPE_PRECISION (float_type_node) = FLOAT_TYPE_SIZE;
9342   layout_type (float_type_node);
9343 
9344   double_type_node = make_node (REAL_TYPE);
9345   if (short_double)
9346     TYPE_PRECISION (double_type_node) = FLOAT_TYPE_SIZE;
9347   else
9348     TYPE_PRECISION (double_type_node) = DOUBLE_TYPE_SIZE;
9349   layout_type (double_type_node);
9350 
9351   long_double_type_node = make_node (REAL_TYPE);
9352   TYPE_PRECISION (long_double_type_node) = LONG_DOUBLE_TYPE_SIZE;
9353   layout_type (long_double_type_node);
9354 
9355   float_ptr_type_node = build_pointer_type (float_type_node);
9356   double_ptr_type_node = build_pointer_type (double_type_node);
9357   long_double_ptr_type_node = build_pointer_type (long_double_type_node);
9358   integer_ptr_type_node = build_pointer_type (integer_type_node);
9359 
9360   /* Fixed size integer types.  */
9361   uint32_type_node = build_nonstandard_integer_type (32, true);
9362   uint64_type_node = build_nonstandard_integer_type (64, true);
9363 
9364   /* Decimal float types. */
9365   dfloat32_type_node = make_node (REAL_TYPE);
9366   TYPE_PRECISION (dfloat32_type_node) = DECIMAL32_TYPE_SIZE;
9367   layout_type (dfloat32_type_node);
9368   SET_TYPE_MODE (dfloat32_type_node, SDmode);
9369   dfloat32_ptr_type_node = build_pointer_type (dfloat32_type_node);
9370 
9371   dfloat64_type_node = make_node (REAL_TYPE);
9372   TYPE_PRECISION (dfloat64_type_node) = DECIMAL64_TYPE_SIZE;
9373   layout_type (dfloat64_type_node);
9374   SET_TYPE_MODE (dfloat64_type_node, DDmode);
9375   dfloat64_ptr_type_node = build_pointer_type (dfloat64_type_node);
9376 
9377   dfloat128_type_node = make_node (REAL_TYPE);
9378   TYPE_PRECISION (dfloat128_type_node) = DECIMAL128_TYPE_SIZE;
9379   layout_type (dfloat128_type_node);
9380   SET_TYPE_MODE (dfloat128_type_node, TDmode);
9381   dfloat128_ptr_type_node = build_pointer_type (dfloat128_type_node);
9382 
9383   complex_integer_type_node = build_complex_type (integer_type_node);
9384   complex_float_type_node = build_complex_type (float_type_node);
9385   complex_double_type_node = build_complex_type (double_type_node);
9386   complex_long_double_type_node = build_complex_type (long_double_type_node);
9387 
9388 /* Make fixed-point nodes based on sat/non-sat and signed/unsigned.  */
9389 #define MAKE_FIXED_TYPE_NODE(KIND,SIZE) \
9390   sat_ ## KIND ## _type_node = \
9391     make_sat_signed_ ## KIND ## _type (SIZE); \
9392   sat_unsigned_ ## KIND ## _type_node = \
9393     make_sat_unsigned_ ## KIND ## _type (SIZE); \
9394   KIND ## _type_node = make_signed_ ## KIND ## _type (SIZE); \
9395   unsigned_ ## KIND ## _type_node = \
9396     make_unsigned_ ## KIND ## _type (SIZE);
9397 
9398 #define MAKE_FIXED_TYPE_NODE_WIDTH(KIND,WIDTH,SIZE) \
9399   sat_ ## WIDTH ## KIND ## _type_node = \
9400     make_sat_signed_ ## KIND ## _type (SIZE); \
9401   sat_unsigned_ ## WIDTH ## KIND ## _type_node = \
9402     make_sat_unsigned_ ## KIND ## _type (SIZE); \
9403   WIDTH ## KIND ## _type_node = make_signed_ ## KIND ## _type (SIZE); \
9404   unsigned_ ## WIDTH ## KIND ## _type_node = \
9405     make_unsigned_ ## KIND ## _type (SIZE);
9406 
9407 /* Make fixed-point type nodes based on four different widths.  */
9408 #define MAKE_FIXED_TYPE_NODE_FAMILY(N1,N2) \
9409   MAKE_FIXED_TYPE_NODE_WIDTH (N1, short_, SHORT_ ## N2 ## _TYPE_SIZE) \
9410   MAKE_FIXED_TYPE_NODE (N1, N2 ## _TYPE_SIZE) \
9411   MAKE_FIXED_TYPE_NODE_WIDTH (N1, long_, LONG_ ## N2 ## _TYPE_SIZE) \
9412   MAKE_FIXED_TYPE_NODE_WIDTH (N1, long_long_, LONG_LONG_ ## N2 ## _TYPE_SIZE)
9413 
9414 /* Make fixed-point mode nodes based on sat/non-sat and signed/unsigned.  */
9415 #define MAKE_FIXED_MODE_NODE(KIND,NAME,MODE) \
9416   NAME ## _type_node = \
9417     make_or_reuse_signed_ ## KIND ## _type (GET_MODE_BITSIZE (MODE ## mode)); \
9418   u ## NAME ## _type_node = \
9419     make_or_reuse_unsigned_ ## KIND ## _type \
9420       (GET_MODE_BITSIZE (U ## MODE ## mode)); \
9421   sat_ ## NAME ## _type_node = \
9422     make_or_reuse_sat_signed_ ## KIND ## _type \
9423       (GET_MODE_BITSIZE (MODE ## mode)); \
9424   sat_u ## NAME ## _type_node = \
9425     make_or_reuse_sat_unsigned_ ## KIND ## _type \
9426       (GET_MODE_BITSIZE (U ## MODE ## mode));
9427 
9428   /* Fixed-point type and mode nodes.  */
9429   MAKE_FIXED_TYPE_NODE_FAMILY (fract, FRACT)
9430   MAKE_FIXED_TYPE_NODE_FAMILY (accum, ACCUM)
9431   MAKE_FIXED_MODE_NODE (fract, qq, QQ)
9432   MAKE_FIXED_MODE_NODE (fract, hq, HQ)
9433   MAKE_FIXED_MODE_NODE (fract, sq, SQ)
9434   MAKE_FIXED_MODE_NODE (fract, dq, DQ)
9435   MAKE_FIXED_MODE_NODE (fract, tq, TQ)
9436   MAKE_FIXED_MODE_NODE (accum, ha, HA)
9437   MAKE_FIXED_MODE_NODE (accum, sa, SA)
9438   MAKE_FIXED_MODE_NODE (accum, da, DA)
9439   MAKE_FIXED_MODE_NODE (accum, ta, TA)
9440 
9441   {
9442     tree t = targetm.build_builtin_va_list ();
9443 
9444     /* Many back-ends define record types without setting TYPE_NAME.
9445        If we copied the record type here, we'd keep the original
9446        record type without a name.  This breaks name mangling.  So,
9447        don't copy record types and let c_common_nodes_and_builtins()
9448        declare the type to be __builtin_va_list.  */
9449     if (TREE_CODE (t) != RECORD_TYPE)
9450       t = build_variant_type_copy (t);
9451 
9452     va_list_type_node = t;
9453   }
9454 }
9455 
9456 /* A subroutine of build_common_builtin_nodes.  Define a builtin function.  */
9457 
9458 static void
9459 local_define_builtin (const char *name, tree type, enum built_in_function code,
9460                       const char *library_name, int ecf_flags)
9461 {
9462   tree decl;
9463 
9464   decl = add_builtin_function (name, type, code, BUILT_IN_NORMAL,
9465 			       library_name, NULL_TREE);
9466   if (ecf_flags & ECF_CONST)
9467     TREE_READONLY (decl) = 1;
9468   if (ecf_flags & ECF_PURE)
9469     DECL_PURE_P (decl) = 1;
9470   if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
9471     DECL_LOOPING_CONST_OR_PURE_P (decl) = 1;
9472   if (ecf_flags & ECF_NORETURN)
9473     TREE_THIS_VOLATILE (decl) = 1;
9474   if (ecf_flags & ECF_NOTHROW)
9475     TREE_NOTHROW (decl) = 1;
9476   if (ecf_flags & ECF_MALLOC)
9477     DECL_IS_MALLOC (decl) = 1;
9478   if (ecf_flags & ECF_LEAF)
9479     DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("leaf"),
9480 					NULL, DECL_ATTRIBUTES (decl));
9481   if ((ecf_flags & ECF_TM_PURE) && flag_tm)
9482     apply_tm_attr (decl, get_identifier ("transaction_pure"));
9483 
9484   set_builtin_decl (code, decl, true);
9485 }
9486 
9487 /* Call this function after instantiating all builtins that the language
9488    front end cares about.  This will build the rest of the builtins that
9489    are relied upon by the tree optimizers and the middle-end.  */
9490 
9491 void
9492 build_common_builtin_nodes (void)
9493 {
9494   tree tmp, ftype;
9495   int ecf_flags;
9496 
9497   if (!builtin_decl_explicit_p (BUILT_IN_MEMCPY)
9498       || !builtin_decl_explicit_p (BUILT_IN_MEMMOVE))
9499     {
9500       ftype = build_function_type_list (ptr_type_node,
9501 					ptr_type_node, const_ptr_type_node,
9502 					size_type_node, NULL_TREE);
9503 
9504       if (!builtin_decl_explicit_p (BUILT_IN_MEMCPY))
9505 	local_define_builtin ("__builtin_memcpy", ftype, BUILT_IN_MEMCPY,
9506 			      "memcpy", ECF_NOTHROW | ECF_LEAF);
9507       if (!builtin_decl_explicit_p (BUILT_IN_MEMMOVE))
9508 	local_define_builtin ("__builtin_memmove", ftype, BUILT_IN_MEMMOVE,
9509 			      "memmove", ECF_NOTHROW | ECF_LEAF);
9510     }
9511 
9512   if (!builtin_decl_explicit_p (BUILT_IN_MEMCMP))
9513     {
9514       ftype = build_function_type_list (integer_type_node, const_ptr_type_node,
9515 					const_ptr_type_node, size_type_node,
9516 					NULL_TREE);
9517       local_define_builtin ("__builtin_memcmp", ftype, BUILT_IN_MEMCMP,
9518 			    "memcmp", ECF_PURE | ECF_NOTHROW | ECF_LEAF);
9519     }
9520 
9521   if (!builtin_decl_explicit_p (BUILT_IN_MEMSET))
9522     {
9523       ftype = build_function_type_list (ptr_type_node,
9524 					ptr_type_node, integer_type_node,
9525 					size_type_node, NULL_TREE);
9526       local_define_builtin ("__builtin_memset", ftype, BUILT_IN_MEMSET,
9527 			    "memset", ECF_NOTHROW | ECF_LEAF);
9528     }
9529 
9530   if (!builtin_decl_explicit_p (BUILT_IN_ALLOCA))
9531     {
9532       ftype = build_function_type_list (ptr_type_node,
9533 					size_type_node, NULL_TREE);
9534       local_define_builtin ("__builtin_alloca", ftype, BUILT_IN_ALLOCA,
9535 			    "alloca", ECF_MALLOC | ECF_NOTHROW | ECF_LEAF);
9536     }
9537 
9538   ftype = build_function_type_list (ptr_type_node, size_type_node,
9539 				    size_type_node, NULL_TREE);
9540   local_define_builtin ("__builtin_alloca_with_align", ftype,
9541 			BUILT_IN_ALLOCA_WITH_ALIGN, "alloca",
9542 			ECF_MALLOC | ECF_NOTHROW | ECF_LEAF);
9543 
9544   /* If we're checking the stack, `alloca' can throw.  */
9545   if (flag_stack_check)
9546     {
9547       TREE_NOTHROW (builtin_decl_explicit (BUILT_IN_ALLOCA)) = 0;
9548       TREE_NOTHROW (builtin_decl_explicit (BUILT_IN_ALLOCA_WITH_ALIGN)) = 0;
9549     }
9550 
9551   ftype = build_function_type_list (void_type_node,
9552 				    ptr_type_node, ptr_type_node,
9553 				    ptr_type_node, NULL_TREE);
9554   local_define_builtin ("__builtin_init_trampoline", ftype,
9555 			BUILT_IN_INIT_TRAMPOLINE,
9556 			"__builtin_init_trampoline", ECF_NOTHROW | ECF_LEAF);
9557   local_define_builtin ("__builtin_init_heap_trampoline", ftype,
9558 			BUILT_IN_INIT_HEAP_TRAMPOLINE,
9559 			"__builtin_init_heap_trampoline",
9560 			ECF_NOTHROW | ECF_LEAF);
9561 
9562   ftype = build_function_type_list (ptr_type_node, ptr_type_node, NULL_TREE);
9563   local_define_builtin ("__builtin_adjust_trampoline", ftype,
9564 			BUILT_IN_ADJUST_TRAMPOLINE,
9565 			"__builtin_adjust_trampoline",
9566 			ECF_CONST | ECF_NOTHROW);
9567 
9568   ftype = build_function_type_list (void_type_node,
9569 				    ptr_type_node, ptr_type_node, NULL_TREE);
9570   local_define_builtin ("__builtin_nonlocal_goto", ftype,
9571 			BUILT_IN_NONLOCAL_GOTO,
9572 			"__builtin_nonlocal_goto",
9573 			ECF_NORETURN | ECF_NOTHROW);
9574 
9575   ftype = build_function_type_list (void_type_node,
9576 				    ptr_type_node, ptr_type_node, NULL_TREE);
9577   local_define_builtin ("__builtin_setjmp_setup", ftype,
9578 			BUILT_IN_SETJMP_SETUP,
9579 			"__builtin_setjmp_setup", ECF_NOTHROW);
9580 
9581   ftype = build_function_type_list (ptr_type_node, ptr_type_node, NULL_TREE);
9582   local_define_builtin ("__builtin_setjmp_dispatcher", ftype,
9583 			BUILT_IN_SETJMP_DISPATCHER,
9584 			"__builtin_setjmp_dispatcher",
9585 			ECF_PURE | ECF_NOTHROW);
9586 
9587   ftype = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);
9588   local_define_builtin ("__builtin_setjmp_receiver", ftype,
9589 			BUILT_IN_SETJMP_RECEIVER,
9590 			"__builtin_setjmp_receiver", ECF_NOTHROW);
9591 
9592   ftype = build_function_type_list (ptr_type_node, NULL_TREE);
9593   local_define_builtin ("__builtin_stack_save", ftype, BUILT_IN_STACK_SAVE,
9594 			"__builtin_stack_save", ECF_NOTHROW | ECF_LEAF);
9595 
9596   ftype = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);
9597   local_define_builtin ("__builtin_stack_restore", ftype,
9598 			BUILT_IN_STACK_RESTORE,
9599 			"__builtin_stack_restore", ECF_NOTHROW | ECF_LEAF);
9600 
9601   /* If there's a possibility that we might use the ARM EABI, build the
9602     alternate __cxa_end_cleanup node used to resume from C++ and Java.  */
9603   if (targetm.arm_eabi_unwinder)
9604     {
9605       ftype = build_function_type_list (void_type_node, NULL_TREE);
9606       local_define_builtin ("__builtin_cxa_end_cleanup", ftype,
9607 			    BUILT_IN_CXA_END_CLEANUP,
9608 			    "__cxa_end_cleanup", ECF_NORETURN | ECF_LEAF);
9609     }
9610 
9611   ftype = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);
9612   local_define_builtin ("__builtin_unwind_resume", ftype,
9613 			BUILT_IN_UNWIND_RESUME,
9614 			((targetm_common.except_unwind_info (&global_options)
9615 			  == UI_SJLJ)
9616 			 ? "_Unwind_SjLj_Resume" : "_Unwind_Resume"),
9617 			ECF_NORETURN);
9618 
9619   if (builtin_decl_explicit (BUILT_IN_RETURN_ADDRESS) == NULL_TREE)
9620     {
9621       ftype = build_function_type_list (ptr_type_node, integer_type_node,
9622 					NULL_TREE);
9623       local_define_builtin ("__builtin_return_address", ftype,
9624 			    BUILT_IN_RETURN_ADDRESS,
9625 			    "__builtin_return_address",
9626 			    ECF_NOTHROW);
9627     }
9628 
9629   if (!builtin_decl_explicit_p (BUILT_IN_PROFILE_FUNC_ENTER)
9630       || !builtin_decl_explicit_p (BUILT_IN_PROFILE_FUNC_EXIT))
9631     {
9632       ftype = build_function_type_list (void_type_node, ptr_type_node,
9633 					ptr_type_node, NULL_TREE);
9634       if (!builtin_decl_explicit_p (BUILT_IN_PROFILE_FUNC_ENTER))
9635 	local_define_builtin ("__cyg_profile_func_enter", ftype,
9636 			      BUILT_IN_PROFILE_FUNC_ENTER,
9637 			      "__cyg_profile_func_enter", 0);
9638       if (!builtin_decl_explicit_p (BUILT_IN_PROFILE_FUNC_EXIT))
9639 	local_define_builtin ("__cyg_profile_func_exit", ftype,
9640 			      BUILT_IN_PROFILE_FUNC_EXIT,
9641 			      "__cyg_profile_func_exit", 0);
9642     }
9643 
9644   /* The exception object and filter values from the runtime.  The argument
9645      must be zero before exception lowering, i.e. from the front end.  After
9646      exception lowering, it will be the region number for the exception
9647      landing pad.  These functions are PURE instead of CONST to prevent
9648      them from being hoisted past the exception edge that will initialize
9649      its value in the landing pad.  */
9650   ftype = build_function_type_list (ptr_type_node,
9651 				    integer_type_node, NULL_TREE);
9652   ecf_flags = ECF_PURE | ECF_NOTHROW | ECF_LEAF;
9653   /* Only use TM_PURE if we we have TM language support.  */
9654   if (builtin_decl_explicit_p (BUILT_IN_TM_LOAD_1))
9655     ecf_flags |= ECF_TM_PURE;
9656   local_define_builtin ("__builtin_eh_pointer", ftype, BUILT_IN_EH_POINTER,
9657 			"__builtin_eh_pointer", ecf_flags);
9658 
9659   tmp = lang_hooks.types.type_for_mode (targetm.eh_return_filter_mode (), 0);
9660   ftype = build_function_type_list (tmp, integer_type_node, NULL_TREE);
9661   local_define_builtin ("__builtin_eh_filter", ftype, BUILT_IN_EH_FILTER,
9662 			"__builtin_eh_filter", ECF_PURE | ECF_NOTHROW | ECF_LEAF);
9663 
9664   ftype = build_function_type_list (void_type_node,
9665 				    integer_type_node, integer_type_node,
9666 				    NULL_TREE);
9667   local_define_builtin ("__builtin_eh_copy_values", ftype,
9668 			BUILT_IN_EH_COPY_VALUES,
9669 			"__builtin_eh_copy_values", ECF_NOTHROW);
9670 
9671   /* Complex multiplication and division.  These are handled as builtins
9672      rather than optabs because emit_library_call_value doesn't support
9673      complex.  Further, we can do slightly better with folding these
9674      beasties if the real and complex parts of the arguments are separate.  */
9675   {
9676     int mode;
9677 
9678     for (mode = MIN_MODE_COMPLEX_FLOAT; mode <= MAX_MODE_COMPLEX_FLOAT; ++mode)
9679       {
9680 	char mode_name_buf[4], *q;
9681 	const char *p;
9682 	enum built_in_function mcode, dcode;
9683 	tree type, inner_type;
9684 	const char *prefix = "__";
9685 
9686 	if (targetm.libfunc_gnu_prefix)
9687 	  prefix = "__gnu_";
9688 
9689 	type = lang_hooks.types.type_for_mode ((enum machine_mode) mode, 0);
9690 	if (type == NULL)
9691 	  continue;
9692 	inner_type = TREE_TYPE (type);
9693 
9694 	ftype = build_function_type_list (type, inner_type, inner_type,
9695 					  inner_type, inner_type, NULL_TREE);
9696 
9697         mcode = ((enum built_in_function)
9698 		 (BUILT_IN_COMPLEX_MUL_MIN + mode - MIN_MODE_COMPLEX_FLOAT));
9699         dcode = ((enum built_in_function)
9700 		 (BUILT_IN_COMPLEX_DIV_MIN + mode - MIN_MODE_COMPLEX_FLOAT));
9701 
9702         for (p = GET_MODE_NAME (mode), q = mode_name_buf; *p; p++, q++)
9703 	  *q = TOLOWER (*p);
9704 	*q = '\0';
9705 
9706 	built_in_names[mcode] = concat (prefix, "mul", mode_name_buf, "3",
9707 					NULL);
9708         local_define_builtin (built_in_names[mcode], ftype, mcode,
9709 			      built_in_names[mcode],
9710 			      ECF_CONST | ECF_NOTHROW | ECF_LEAF);
9711 
9712 	built_in_names[dcode] = concat (prefix, "div", mode_name_buf, "3",
9713 					NULL);
9714         local_define_builtin (built_in_names[dcode], ftype, dcode,
9715 			      built_in_names[dcode],
9716 			      ECF_CONST | ECF_NOTHROW | ECF_LEAF);
9717       }
9718   }
9719 }
9720 
9721 /* HACK.  GROSS.  This is absolutely disgusting.  I wish there was a
9722    better way.
9723 
9724    If we requested a pointer to a vector, build up the pointers that
9725    we stripped off while looking for the inner type.  Similarly for
9726    return values from functions.
9727 
9728    The argument TYPE is the top of the chain, and BOTTOM is the
9729    new type which we will point to.  */
9730 
9731 tree
9732 reconstruct_complex_type (tree type, tree bottom)
9733 {
9734   tree inner, outer;
9735 
9736   if (TREE_CODE (type) == POINTER_TYPE)
9737     {
9738       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9739       outer = build_pointer_type_for_mode (inner, TYPE_MODE (type),
9740 					   TYPE_REF_CAN_ALIAS_ALL (type));
9741     }
9742   else if (TREE_CODE (type) == REFERENCE_TYPE)
9743     {
9744       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9745       outer = build_reference_type_for_mode (inner, TYPE_MODE (type),
9746 					     TYPE_REF_CAN_ALIAS_ALL (type));
9747     }
9748   else if (TREE_CODE (type) == ARRAY_TYPE)
9749     {
9750       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9751       outer = build_array_type (inner, TYPE_DOMAIN (type));
9752     }
9753   else if (TREE_CODE (type) == FUNCTION_TYPE)
9754     {
9755       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9756       outer = build_function_type (inner, TYPE_ARG_TYPES (type));
9757     }
9758   else if (TREE_CODE (type) == METHOD_TYPE)
9759     {
9760       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9761       /* The build_method_type_directly() routine prepends 'this' to argument list,
9762          so we must compensate by getting rid of it.  */
9763       outer
9764 	= build_method_type_directly
9765 	    (TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (type))),
9766 	     inner,
9767 	     TREE_CHAIN (TYPE_ARG_TYPES (type)));
9768     }
9769   else if (TREE_CODE (type) == OFFSET_TYPE)
9770     {
9771       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9772       outer = build_offset_type (TYPE_OFFSET_BASETYPE (type), inner);
9773     }
9774   else
9775     return bottom;
9776 
9777   return build_type_attribute_qual_variant (outer, TYPE_ATTRIBUTES (type),
9778 					    TYPE_QUALS (type));
9779 }
9780 
9781 /* Returns a vector tree node given a mode (integer, vector, or BLKmode) and
9782    the inner type.  */
9783 tree
9784 build_vector_type_for_mode (tree innertype, enum machine_mode mode)
9785 {
9786   int nunits;
9787 
9788   switch (GET_MODE_CLASS (mode))
9789     {
9790     case MODE_VECTOR_INT:
9791     case MODE_VECTOR_FLOAT:
9792     case MODE_VECTOR_FRACT:
9793     case MODE_VECTOR_UFRACT:
9794     case MODE_VECTOR_ACCUM:
9795     case MODE_VECTOR_UACCUM:
9796       nunits = GET_MODE_NUNITS (mode);
9797       break;
9798 
9799     case MODE_INT:
9800       /* Check that there are no leftover bits.  */
9801       gcc_assert (GET_MODE_BITSIZE (mode)
9802 		  % TREE_INT_CST_LOW (TYPE_SIZE (innertype)) == 0);
9803 
9804       nunits = GET_MODE_BITSIZE (mode)
9805 	       / TREE_INT_CST_LOW (TYPE_SIZE (innertype));
9806       break;
9807 
9808     default:
9809       gcc_unreachable ();
9810     }
9811 
9812   return make_vector_type (innertype, nunits, mode);
9813 }
9814 
9815 /* Similarly, but takes the inner type and number of units, which must be
9816    a power of two.  */
9817 
9818 tree
9819 build_vector_type (tree innertype, int nunits)
9820 {
9821   return make_vector_type (innertype, nunits, VOIDmode);
9822 }
9823 
9824 /* Similarly, but builds a variant type with TYPE_VECTOR_OPAQUE set.  */
9825 
9826 tree
9827 build_opaque_vector_type (tree innertype, int nunits)
9828 {
9829   tree t = make_vector_type (innertype, nunits, VOIDmode);
9830   tree cand;
9831   /* We always build the non-opaque variant before the opaque one,
9832      so if it already exists, it is TYPE_NEXT_VARIANT of this one.  */
9833   cand = TYPE_NEXT_VARIANT (t);
9834   if (cand
9835       && TYPE_VECTOR_OPAQUE (cand)
9836       && check_qualified_type (cand, t, TYPE_QUALS (t)))
9837     return cand;
9838   /* Othewise build a variant type and make sure to queue it after
9839      the non-opaque type.  */
9840   cand = build_distinct_type_copy (t);
9841   TYPE_VECTOR_OPAQUE (cand) = true;
9842   TYPE_CANONICAL (cand) = TYPE_CANONICAL (t);
9843   TYPE_NEXT_VARIANT (cand) = TYPE_NEXT_VARIANT (t);
9844   TYPE_NEXT_VARIANT (t) = cand;
9845   TYPE_MAIN_VARIANT (cand) = TYPE_MAIN_VARIANT (t);
9846   return cand;
9847 }
9848 
9849 
9850 /* Given an initializer INIT, return TRUE if INIT is zero or some
9851    aggregate of zeros.  Otherwise return FALSE.  */
9852 bool
9853 initializer_zerop (const_tree init)
9854 {
9855   tree elt;
9856 
9857   STRIP_NOPS (init);
9858 
9859   switch (TREE_CODE (init))
9860     {
9861     case INTEGER_CST:
9862       return integer_zerop (init);
9863 
9864     case REAL_CST:
9865       /* ??? Note that this is not correct for C4X float formats.  There,
9866 	 a bit pattern of all zeros is 1.0; 0.0 is encoded with the most
9867 	 negative exponent.  */
9868       return real_zerop (init)
9869 	&& ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (init));
9870 
9871     case FIXED_CST:
9872       return fixed_zerop (init);
9873 
9874     case COMPLEX_CST:
9875       return integer_zerop (init)
9876 	|| (real_zerop (init)
9877 	    && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (TREE_REALPART (init)))
9878 	    && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (TREE_IMAGPART (init))));
9879 
9880     case VECTOR_CST:
9881       for (elt = TREE_VECTOR_CST_ELTS (init); elt; elt = TREE_CHAIN (elt))
9882 	if (!initializer_zerop (TREE_VALUE (elt)))
9883 	  return false;
9884       return true;
9885 
9886     case CONSTRUCTOR:
9887       {
9888 	unsigned HOST_WIDE_INT idx;
9889 
9890 	FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (init), idx, elt)
9891 	  if (!initializer_zerop (elt))
9892 	    return false;
9893 	return true;
9894       }
9895 
9896     case STRING_CST:
9897       {
9898 	int i;
9899 
9900 	/* We need to loop through all elements to handle cases like
9901 	   "\0" and "\0foobar".  */
9902 	for (i = 0; i < TREE_STRING_LENGTH (init); ++i)
9903 	  if (TREE_STRING_POINTER (init)[i] != '\0')
9904 	    return false;
9905 
9906 	return true;
9907       }
9908 
9909     default:
9910       return false;
9911     }
9912 }
9913 
9914 /* Build an empty statement at location LOC.  */
9915 
9916 tree
9917 build_empty_stmt (location_t loc)
9918 {
9919   tree t = build1 (NOP_EXPR, void_type_node, size_zero_node);
9920   SET_EXPR_LOCATION (t, loc);
9921   return t;
9922 }
9923 
9924 
9925 /* Build an OpenMP clause with code CODE.  LOC is the location of the
9926    clause.  */
9927 
9928 tree
9929 build_omp_clause (location_t loc, enum omp_clause_code code)
9930 {
9931   tree t;
9932   int size, length;
9933 
9934   length = omp_clause_num_ops[code];
9935   size = (sizeof (struct tree_omp_clause) + (length - 1) * sizeof (tree));
9936 
9937   record_node_allocation_statistics (OMP_CLAUSE, size);
9938 
9939   t = ggc_alloc_tree_node (size);
9940   memset (t, 0, size);
9941   TREE_SET_CODE (t, OMP_CLAUSE);
9942   OMP_CLAUSE_SET_CODE (t, code);
9943   OMP_CLAUSE_LOCATION (t) = loc;
9944 
9945   return t;
9946 }
9947 
9948 /* Build a tcc_vl_exp object with code CODE and room for LEN operands.  LEN
9949    includes the implicit operand count in TREE_OPERAND 0, and so must be >= 1.
9950    Except for the CODE and operand count field, other storage for the
9951    object is initialized to zeros.  */
9952 
9953 tree
9954 build_vl_exp_stat (enum tree_code code, int len MEM_STAT_DECL)
9955 {
9956   tree t;
9957   int length = (len - 1) * sizeof (tree) + sizeof (struct tree_exp);
9958 
9959   gcc_assert (TREE_CODE_CLASS (code) == tcc_vl_exp);
9960   gcc_assert (len >= 1);
9961 
9962   record_node_allocation_statistics (code, length);
9963 
9964   t = ggc_alloc_zone_cleared_tree_node_stat (&tree_zone, length PASS_MEM_STAT);
9965 
9966   TREE_SET_CODE (t, code);
9967 
9968   /* Can't use TREE_OPERAND to store the length because if checking is
9969      enabled, it will try to check the length before we store it.  :-P  */
9970   t->exp.operands[0] = build_int_cst (sizetype, len);
9971 
9972   return t;
9973 }
9974 
9975 /* Helper function for build_call_* functions; build a CALL_EXPR with
9976    indicated RETURN_TYPE, FN, and NARGS, but do not initialize any of
9977    the argument slots.  */
9978 
9979 static tree
9980 build_call_1 (tree return_type, tree fn, int nargs)
9981 {
9982   tree t;
9983 
9984   t = build_vl_exp (CALL_EXPR, nargs + 3);
9985   TREE_TYPE (t) = return_type;
9986   CALL_EXPR_FN (t) = fn;
9987   CALL_EXPR_STATIC_CHAIN (t) = NULL;
9988 
9989   return t;
9990 }
9991 
9992 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
9993    FN and a null static chain slot.  NARGS is the number of call arguments
9994    which are specified as "..." arguments.  */
9995 
9996 tree
9997 build_call_nary (tree return_type, tree fn, int nargs, ...)
9998 {
9999   tree ret;
10000   va_list args;
10001   va_start (args, nargs);
10002   ret = build_call_valist (return_type, fn, nargs, args);
10003   va_end (args);
10004   return ret;
10005 }
10006 
10007 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
10008    FN and a null static chain slot.  NARGS is the number of call arguments
10009    which are specified as a va_list ARGS.  */
10010 
10011 tree
10012 build_call_valist (tree return_type, tree fn, int nargs, va_list args)
10013 {
10014   tree t;
10015   int i;
10016 
10017   t = build_call_1 (return_type, fn, nargs);
10018   for (i = 0; i < nargs; i++)
10019     CALL_EXPR_ARG (t, i) = va_arg (args, tree);
10020   process_call_operands (t);
10021   return t;
10022 }
10023 
10024 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
10025    FN and a null static chain slot.  NARGS is the number of call arguments
10026    which are specified as a tree array ARGS.  */
10027 
10028 tree
10029 build_call_array_loc (location_t loc, tree return_type, tree fn,
10030 		      int nargs, const tree *args)
10031 {
10032   tree t;
10033   int i;
10034 
10035   t = build_call_1 (return_type, fn, nargs);
10036   for (i = 0; i < nargs; i++)
10037     CALL_EXPR_ARG (t, i) = args[i];
10038   process_call_operands (t);
10039   SET_EXPR_LOCATION (t, loc);
10040   return t;
10041 }
10042 
10043 /* Like build_call_array, but takes a VEC.  */
10044 
10045 tree
10046 build_call_vec (tree return_type, tree fn, VEC(tree,gc) *args)
10047 {
10048   tree ret, t;
10049   unsigned int ix;
10050 
10051   ret = build_call_1 (return_type, fn, VEC_length (tree, args));
10052   FOR_EACH_VEC_ELT (tree, args, ix, t)
10053     CALL_EXPR_ARG (ret, ix) = t;
10054   process_call_operands (ret);
10055   return ret;
10056 }
10057 
10058 
10059 /* Returns true if it is possible to prove that the index of
10060    an array access REF (an ARRAY_REF expression) falls into the
10061    array bounds.  */
10062 
10063 bool
10064 in_array_bounds_p (tree ref)
10065 {
10066   tree idx = TREE_OPERAND (ref, 1);
10067   tree min, max;
10068 
10069   if (TREE_CODE (idx) != INTEGER_CST)
10070     return false;
10071 
10072   min = array_ref_low_bound (ref);
10073   max = array_ref_up_bound (ref);
10074   if (!min
10075       || !max
10076       || TREE_CODE (min) != INTEGER_CST
10077       || TREE_CODE (max) != INTEGER_CST)
10078     return false;
10079 
10080   if (tree_int_cst_lt (idx, min)
10081       || tree_int_cst_lt (max, idx))
10082     return false;
10083 
10084   return true;
10085 }
10086 
10087 /* Returns true if it is possible to prove that the range of
10088    an array access REF (an ARRAY_RANGE_REF expression) falls
10089    into the array bounds.  */
10090 
10091 bool
10092 range_in_array_bounds_p (tree ref)
10093 {
10094   tree domain_type = TYPE_DOMAIN (TREE_TYPE (ref));
10095   tree range_min, range_max, min, max;
10096 
10097   range_min = TYPE_MIN_VALUE (domain_type);
10098   range_max = TYPE_MAX_VALUE (domain_type);
10099   if (!range_min
10100       || !range_max
10101       || TREE_CODE (range_min) != INTEGER_CST
10102       || TREE_CODE (range_max) != INTEGER_CST)
10103     return false;
10104 
10105   min = array_ref_low_bound (ref);
10106   max = array_ref_up_bound (ref);
10107   if (!min
10108       || !max
10109       || TREE_CODE (min) != INTEGER_CST
10110       || TREE_CODE (max) != INTEGER_CST)
10111     return false;
10112 
10113   if (tree_int_cst_lt (range_min, min)
10114       || tree_int_cst_lt (max, range_max))
10115     return false;
10116 
10117   return true;
10118 }
10119 
10120 /* Return true if T (assumed to be a DECL) must be assigned a memory
10121    location.  */
10122 
10123 bool
10124 needs_to_live_in_memory (const_tree t)
10125 {
10126   if (TREE_CODE (t) == SSA_NAME)
10127     t = SSA_NAME_VAR (t);
10128 
10129   return (TREE_ADDRESSABLE (t)
10130 	  || is_global_var (t)
10131 	  || (TREE_CODE (t) == RESULT_DECL
10132 	      && !DECL_BY_REFERENCE (t)
10133 	      && aggregate_value_p (t, current_function_decl)));
10134 }
10135 
10136 /* Return value of a constant X and sign-extend it.  */
10137 
10138 HOST_WIDE_INT
10139 int_cst_value (const_tree x)
10140 {
10141   unsigned bits = TYPE_PRECISION (TREE_TYPE (x));
10142   unsigned HOST_WIDE_INT val = TREE_INT_CST_LOW (x);
10143 
10144   /* Make sure the sign-extended value will fit in a HOST_WIDE_INT.  */
10145   gcc_assert (TREE_INT_CST_HIGH (x) == 0
10146 	      || TREE_INT_CST_HIGH (x) == -1);
10147 
10148   if (bits < HOST_BITS_PER_WIDE_INT)
10149     {
10150       bool negative = ((val >> (bits - 1)) & 1) != 0;
10151       if (negative)
10152 	val |= (~(unsigned HOST_WIDE_INT) 0) << (bits - 1) << 1;
10153       else
10154 	val &= ~((~(unsigned HOST_WIDE_INT) 0) << (bits - 1) << 1);
10155     }
10156 
10157   return val;
10158 }
10159 
10160 /* Return value of a constant X and sign-extend it.  */
10161 
10162 HOST_WIDEST_INT
10163 widest_int_cst_value (const_tree x)
10164 {
10165   unsigned bits = TYPE_PRECISION (TREE_TYPE (x));
10166   unsigned HOST_WIDEST_INT val = TREE_INT_CST_LOW (x);
10167 
10168 #if HOST_BITS_PER_WIDEST_INT > HOST_BITS_PER_WIDE_INT
10169   gcc_assert (HOST_BITS_PER_WIDEST_INT >= 2 * HOST_BITS_PER_WIDE_INT);
10170   val |= (((unsigned HOST_WIDEST_INT) TREE_INT_CST_HIGH (x))
10171 	  << HOST_BITS_PER_WIDE_INT);
10172 #else
10173   /* Make sure the sign-extended value will fit in a HOST_WIDE_INT.  */
10174   gcc_assert (TREE_INT_CST_HIGH (x) == 0
10175 	      || TREE_INT_CST_HIGH (x) == -1);
10176 #endif
10177 
10178   if (bits < HOST_BITS_PER_WIDEST_INT)
10179     {
10180       bool negative = ((val >> (bits - 1)) & 1) != 0;
10181       if (negative)
10182 	val |= (~(unsigned HOST_WIDEST_INT) 0) << (bits - 1) << 1;
10183       else
10184 	val &= ~((~(unsigned HOST_WIDEST_INT) 0) << (bits - 1) << 1);
10185     }
10186 
10187   return val;
10188 }
10189 
10190 /* If TYPE is an integral type, return an equivalent type which is
10191     unsigned iff UNSIGNEDP is true.  If TYPE is not an integral type,
10192     return TYPE itself.  */
10193 
10194 tree
10195 signed_or_unsigned_type_for (int unsignedp, tree type)
10196 {
10197   tree t = type;
10198   if (POINTER_TYPE_P (type))
10199     {
10200       /* If the pointer points to the normal address space, use the
10201 	 size_type_node.  Otherwise use an appropriate size for the pointer
10202 	 based on the named address space it points to.  */
10203       if (!TYPE_ADDR_SPACE (TREE_TYPE (t)))
10204 	t = size_type_node;
10205       else
10206 	return lang_hooks.types.type_for_size (TYPE_PRECISION (t), unsignedp);
10207     }
10208 
10209   if (!INTEGRAL_TYPE_P (t) || TYPE_UNSIGNED (t) == unsignedp)
10210     return t;
10211 
10212   return lang_hooks.types.type_for_size (TYPE_PRECISION (t), unsignedp);
10213 }
10214 
10215 /* Returns unsigned variant of TYPE.  */
10216 
10217 tree
10218 unsigned_type_for (tree type)
10219 {
10220   return signed_or_unsigned_type_for (1, type);
10221 }
10222 
10223 /* Returns signed variant of TYPE.  */
10224 
10225 tree
10226 signed_type_for (tree type)
10227 {
10228   return signed_or_unsigned_type_for (0, type);
10229 }
10230 
10231 /* Returns the largest value obtainable by casting something in INNER type to
10232    OUTER type.  */
10233 
10234 tree
10235 upper_bound_in_type (tree outer, tree inner)
10236 {
10237   double_int high;
10238   unsigned int det = 0;
10239   unsigned oprec = TYPE_PRECISION (outer);
10240   unsigned iprec = TYPE_PRECISION (inner);
10241   unsigned prec;
10242 
10243   /* Compute a unique number for every combination.  */
10244   det |= (oprec > iprec) ? 4 : 0;
10245   det |= TYPE_UNSIGNED (outer) ? 2 : 0;
10246   det |= TYPE_UNSIGNED (inner) ? 1 : 0;
10247 
10248   /* Determine the exponent to use.  */
10249   switch (det)
10250     {
10251     case 0:
10252     case 1:
10253       /* oprec <= iprec, outer: signed, inner: don't care.  */
10254       prec = oprec - 1;
10255       break;
10256     case 2:
10257     case 3:
10258       /* oprec <= iprec, outer: unsigned, inner: don't care.  */
10259       prec = oprec;
10260       break;
10261     case 4:
10262       /* oprec > iprec, outer: signed, inner: signed.  */
10263       prec = iprec - 1;
10264       break;
10265     case 5:
10266       /* oprec > iprec, outer: signed, inner: unsigned.  */
10267       prec = iprec;
10268       break;
10269     case 6:
10270       /* oprec > iprec, outer: unsigned, inner: signed.  */
10271       prec = oprec;
10272       break;
10273     case 7:
10274       /* oprec > iprec, outer: unsigned, inner: unsigned.  */
10275       prec = iprec;
10276       break;
10277     default:
10278       gcc_unreachable ();
10279     }
10280 
10281   /* Compute 2^^prec - 1.  */
10282   if (prec <= HOST_BITS_PER_WIDE_INT)
10283     {
10284       high.high = 0;
10285       high.low = ((~(unsigned HOST_WIDE_INT) 0)
10286 	    >> (HOST_BITS_PER_WIDE_INT - prec));
10287     }
10288   else
10289     {
10290       high.high = ((~(unsigned HOST_WIDE_INT) 0)
10291 	    >> (2 * HOST_BITS_PER_WIDE_INT - prec));
10292       high.low = ~(unsigned HOST_WIDE_INT) 0;
10293     }
10294 
10295   return double_int_to_tree (outer, high);
10296 }
10297 
10298 /* Returns the smallest value obtainable by casting something in INNER type to
10299    OUTER type.  */
10300 
10301 tree
10302 lower_bound_in_type (tree outer, tree inner)
10303 {
10304   double_int low;
10305   unsigned oprec = TYPE_PRECISION (outer);
10306   unsigned iprec = TYPE_PRECISION (inner);
10307 
10308   /* If OUTER type is unsigned, we can definitely cast 0 to OUTER type
10309      and obtain 0.  */
10310   if (TYPE_UNSIGNED (outer)
10311       /* If we are widening something of an unsigned type, OUTER type
10312 	 contains all values of INNER type.  In particular, both INNER
10313 	 and OUTER types have zero in common.  */
10314       || (oprec > iprec && TYPE_UNSIGNED (inner)))
10315     low.low = low.high = 0;
10316   else
10317     {
10318       /* If we are widening a signed type to another signed type, we
10319 	 want to obtain -2^^(iprec-1).  If we are keeping the
10320 	 precision or narrowing to a signed type, we want to obtain
10321 	 -2^(oprec-1).  */
10322       unsigned prec = oprec > iprec ? iprec : oprec;
10323 
10324       if (prec <= HOST_BITS_PER_WIDE_INT)
10325 	{
10326 	  low.high = ~(unsigned HOST_WIDE_INT) 0;
10327 	  low.low = (~(unsigned HOST_WIDE_INT) 0) << (prec - 1);
10328 	}
10329       else
10330 	{
10331 	  low.high = ((~(unsigned HOST_WIDE_INT) 0)
10332 		<< (prec - HOST_BITS_PER_WIDE_INT - 1));
10333 	  low.low = 0;
10334 	}
10335     }
10336 
10337   return double_int_to_tree (outer, low);
10338 }
10339 
10340 /* Return nonzero if two operands that are suitable for PHI nodes are
10341    necessarily equal.  Specifically, both ARG0 and ARG1 must be either
10342    SSA_NAME or invariant.  Note that this is strictly an optimization.
10343    That is, callers of this function can directly call operand_equal_p
10344    and get the same result, only slower.  */
10345 
10346 int
10347 operand_equal_for_phi_arg_p (const_tree arg0, const_tree arg1)
10348 {
10349   if (arg0 == arg1)
10350     return 1;
10351   if (TREE_CODE (arg0) == SSA_NAME || TREE_CODE (arg1) == SSA_NAME)
10352     return 0;
10353   return operand_equal_p (arg0, arg1, 0);
10354 }
10355 
10356 /* Returns number of zeros at the end of binary representation of X.
10357 
10358    ??? Use ffs if available?  */
10359 
10360 tree
10361 num_ending_zeros (const_tree x)
10362 {
10363   unsigned HOST_WIDE_INT fr, nfr;
10364   unsigned num, abits;
10365   tree type = TREE_TYPE (x);
10366 
10367   if (TREE_INT_CST_LOW (x) == 0)
10368     {
10369       num = HOST_BITS_PER_WIDE_INT;
10370       fr = TREE_INT_CST_HIGH (x);
10371     }
10372   else
10373     {
10374       num = 0;
10375       fr = TREE_INT_CST_LOW (x);
10376     }
10377 
10378   for (abits = HOST_BITS_PER_WIDE_INT / 2; abits; abits /= 2)
10379     {
10380       nfr = fr >> abits;
10381       if (nfr << abits == fr)
10382 	{
10383 	  num += abits;
10384 	  fr = nfr;
10385 	}
10386     }
10387 
10388   if (num > TYPE_PRECISION (type))
10389     num = TYPE_PRECISION (type);
10390 
10391   return build_int_cst_type (type, num);
10392 }
10393 
10394 
10395 #define WALK_SUBTREE(NODE)				\
10396   do							\
10397     {							\
10398       result = walk_tree_1 (&(NODE), func, data, pset, lh);	\
10399       if (result)					\
10400 	return result;					\
10401     }							\
10402   while (0)
10403 
10404 /* This is a subroutine of walk_tree that walks field of TYPE that are to
10405    be walked whenever a type is seen in the tree.  Rest of operands and return
10406    value are as for walk_tree.  */
10407 
10408 static tree
10409 walk_type_fields (tree type, walk_tree_fn func, void *data,
10410 		  struct pointer_set_t *pset, walk_tree_lh lh)
10411 {
10412   tree result = NULL_TREE;
10413 
10414   switch (TREE_CODE (type))
10415     {
10416     case POINTER_TYPE:
10417     case REFERENCE_TYPE:
10418       /* We have to worry about mutually recursive pointers.  These can't
10419 	 be written in C.  They can in Ada.  It's pathological, but
10420 	 there's an ACATS test (c38102a) that checks it.  Deal with this
10421 	 by checking if we're pointing to another pointer, that one
10422 	 points to another pointer, that one does too, and we have no htab.
10423 	 If so, get a hash table.  We check three levels deep to avoid
10424 	 the cost of the hash table if we don't need one.  */
10425       if (POINTER_TYPE_P (TREE_TYPE (type))
10426 	  && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (type)))
10427 	  && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (TREE_TYPE (type))))
10428 	  && !pset)
10429 	{
10430 	  result = walk_tree_without_duplicates (&TREE_TYPE (type),
10431 						 func, data);
10432 	  if (result)
10433 	    return result;
10434 
10435 	  break;
10436 	}
10437 
10438       /* ... fall through ... */
10439 
10440     case COMPLEX_TYPE:
10441       WALK_SUBTREE (TREE_TYPE (type));
10442       break;
10443 
10444     case METHOD_TYPE:
10445       WALK_SUBTREE (TYPE_METHOD_BASETYPE (type));
10446 
10447       /* Fall through.  */
10448 
10449     case FUNCTION_TYPE:
10450       WALK_SUBTREE (TREE_TYPE (type));
10451       {
10452 	tree arg;
10453 
10454 	/* We never want to walk into default arguments.  */
10455 	for (arg = TYPE_ARG_TYPES (type); arg; arg = TREE_CHAIN (arg))
10456 	  WALK_SUBTREE (TREE_VALUE (arg));
10457       }
10458       break;
10459 
10460     case ARRAY_TYPE:
10461       /* Don't follow this nodes's type if a pointer for fear that
10462 	 we'll have infinite recursion.  If we have a PSET, then we
10463 	 need not fear.  */
10464       if (pset
10465 	  || (!POINTER_TYPE_P (TREE_TYPE (type))
10466 	      && TREE_CODE (TREE_TYPE (type)) != OFFSET_TYPE))
10467 	WALK_SUBTREE (TREE_TYPE (type));
10468       WALK_SUBTREE (TYPE_DOMAIN (type));
10469       break;
10470 
10471     case OFFSET_TYPE:
10472       WALK_SUBTREE (TREE_TYPE (type));
10473       WALK_SUBTREE (TYPE_OFFSET_BASETYPE (type));
10474       break;
10475 
10476     default:
10477       break;
10478     }
10479 
10480   return NULL_TREE;
10481 }
10482 
10483 /* Apply FUNC to all the sub-trees of TP in a pre-order traversal.  FUNC is
10484    called with the DATA and the address of each sub-tree.  If FUNC returns a
10485    non-NULL value, the traversal is stopped, and the value returned by FUNC
10486    is returned.  If PSET is non-NULL it is used to record the nodes visited,
10487    and to avoid visiting a node more than once.  */
10488 
10489 tree
10490 walk_tree_1 (tree *tp, walk_tree_fn func, void *data,
10491 	     struct pointer_set_t *pset, walk_tree_lh lh)
10492 {
10493   enum tree_code code;
10494   int walk_subtrees;
10495   tree result;
10496 
10497 #define WALK_SUBTREE_TAIL(NODE)				\
10498   do							\
10499     {							\
10500        tp = & (NODE);					\
10501        goto tail_recurse;				\
10502     }							\
10503   while (0)
10504 
10505  tail_recurse:
10506   /* Skip empty subtrees.  */
10507   if (!*tp)
10508     return NULL_TREE;
10509 
10510   /* Don't walk the same tree twice, if the user has requested
10511      that we avoid doing so.  */
10512   if (pset && pointer_set_insert (pset, *tp))
10513     return NULL_TREE;
10514 
10515   /* Call the function.  */
10516   walk_subtrees = 1;
10517   result = (*func) (tp, &walk_subtrees, data);
10518 
10519   /* If we found something, return it.  */
10520   if (result)
10521     return result;
10522 
10523   code = TREE_CODE (*tp);
10524 
10525   /* Even if we didn't, FUNC may have decided that there was nothing
10526      interesting below this point in the tree.  */
10527   if (!walk_subtrees)
10528     {
10529       /* But we still need to check our siblings.  */
10530       if (code == TREE_LIST)
10531 	WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
10532       else if (code == OMP_CLAUSE)
10533 	WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10534       else
10535 	return NULL_TREE;
10536     }
10537 
10538   if (lh)
10539     {
10540       result = (*lh) (tp, &walk_subtrees, func, data, pset);
10541       if (result || !walk_subtrees)
10542         return result;
10543     }
10544 
10545   switch (code)
10546     {
10547     case ERROR_MARK:
10548     case IDENTIFIER_NODE:
10549     case INTEGER_CST:
10550     case REAL_CST:
10551     case FIXED_CST:
10552     case VECTOR_CST:
10553     case STRING_CST:
10554     case BLOCK:
10555     case PLACEHOLDER_EXPR:
10556     case SSA_NAME:
10557     case FIELD_DECL:
10558     case RESULT_DECL:
10559       /* None of these have subtrees other than those already walked
10560 	 above.  */
10561       break;
10562 
10563     case TREE_LIST:
10564       WALK_SUBTREE (TREE_VALUE (*tp));
10565       WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
10566       break;
10567 
10568     case TREE_VEC:
10569       {
10570 	int len = TREE_VEC_LENGTH (*tp);
10571 
10572 	if (len == 0)
10573 	  break;
10574 
10575 	/* Walk all elements but the first.  */
10576 	while (--len)
10577 	  WALK_SUBTREE (TREE_VEC_ELT (*tp, len));
10578 
10579 	/* Now walk the first one as a tail call.  */
10580 	WALK_SUBTREE_TAIL (TREE_VEC_ELT (*tp, 0));
10581       }
10582 
10583     case COMPLEX_CST:
10584       WALK_SUBTREE (TREE_REALPART (*tp));
10585       WALK_SUBTREE_TAIL (TREE_IMAGPART (*tp));
10586 
10587     case CONSTRUCTOR:
10588       {
10589 	unsigned HOST_WIDE_INT idx;
10590 	constructor_elt *ce;
10591 
10592 	for (idx = 0;
10593 	     VEC_iterate(constructor_elt, CONSTRUCTOR_ELTS (*tp), idx, ce);
10594 	     idx++)
10595 	  WALK_SUBTREE (ce->value);
10596       }
10597       break;
10598 
10599     case SAVE_EXPR:
10600       WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, 0));
10601 
10602     case BIND_EXPR:
10603       {
10604 	tree decl;
10605 	for (decl = BIND_EXPR_VARS (*tp); decl; decl = DECL_CHAIN (decl))
10606 	  {
10607 	    /* Walk the DECL_INITIAL and DECL_SIZE.  We don't want to walk
10608 	       into declarations that are just mentioned, rather than
10609 	       declared; they don't really belong to this part of the tree.
10610 	       And, we can see cycles: the initializer for a declaration
10611 	       can refer to the declaration itself.  */
10612 	    WALK_SUBTREE (DECL_INITIAL (decl));
10613 	    WALK_SUBTREE (DECL_SIZE (decl));
10614 	    WALK_SUBTREE (DECL_SIZE_UNIT (decl));
10615 	  }
10616 	WALK_SUBTREE_TAIL (BIND_EXPR_BODY (*tp));
10617       }
10618 
10619     case STATEMENT_LIST:
10620       {
10621 	tree_stmt_iterator i;
10622 	for (i = tsi_start (*tp); !tsi_end_p (i); tsi_next (&i))
10623 	  WALK_SUBTREE (*tsi_stmt_ptr (i));
10624       }
10625       break;
10626 
10627     case OMP_CLAUSE:
10628       switch (OMP_CLAUSE_CODE (*tp))
10629 	{
10630 	case OMP_CLAUSE_PRIVATE:
10631 	case OMP_CLAUSE_SHARED:
10632 	case OMP_CLAUSE_FIRSTPRIVATE:
10633 	case OMP_CLAUSE_COPYIN:
10634 	case OMP_CLAUSE_COPYPRIVATE:
10635 	case OMP_CLAUSE_FINAL:
10636 	case OMP_CLAUSE_IF:
10637 	case OMP_CLAUSE_NUM_THREADS:
10638 	case OMP_CLAUSE_SCHEDULE:
10639 	  WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, 0));
10640 	  /* FALLTHRU */
10641 
10642 	case OMP_CLAUSE_NOWAIT:
10643 	case OMP_CLAUSE_ORDERED:
10644 	case OMP_CLAUSE_DEFAULT:
10645 	case OMP_CLAUSE_UNTIED:
10646 	case OMP_CLAUSE_MERGEABLE:
10647 	  WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10648 
10649 	case OMP_CLAUSE_LASTPRIVATE:
10650 	  WALK_SUBTREE (OMP_CLAUSE_DECL (*tp));
10651 	  WALK_SUBTREE (OMP_CLAUSE_LASTPRIVATE_STMT (*tp));
10652 	  WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10653 
10654 	case OMP_CLAUSE_COLLAPSE:
10655 	  {
10656 	    int i;
10657 	    for (i = 0; i < 3; i++)
10658 	      WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, i));
10659 	    WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10660 	  }
10661 
10662 	case OMP_CLAUSE_REDUCTION:
10663 	  {
10664 	    int i;
10665 	    for (i = 0; i < 4; i++)
10666 	      WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, i));
10667 	    WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10668 	  }
10669 
10670 	default:
10671 	  gcc_unreachable ();
10672 	}
10673       break;
10674 
10675     case TARGET_EXPR:
10676       {
10677 	int i, len;
10678 
10679 	/* TARGET_EXPRs are peculiar: operands 1 and 3 can be the same.
10680 	   But, we only want to walk once.  */
10681 	len = (TREE_OPERAND (*tp, 3) == TREE_OPERAND (*tp, 1)) ? 2 : 3;
10682 	for (i = 0; i < len; ++i)
10683 	  WALK_SUBTREE (TREE_OPERAND (*tp, i));
10684 	WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, len));
10685       }
10686 
10687     case DECL_EXPR:
10688       /* If this is a TYPE_DECL, walk into the fields of the type that it's
10689 	 defining.  We only want to walk into these fields of a type in this
10690 	 case and not in the general case of a mere reference to the type.
10691 
10692 	 The criterion is as follows: if the field can be an expression, it
10693 	 must be walked only here.  This should be in keeping with the fields
10694 	 that are directly gimplified in gimplify_type_sizes in order for the
10695 	 mark/copy-if-shared/unmark machinery of the gimplifier to work with
10696 	 variable-sized types.
10697 
10698 	 Note that DECLs get walked as part of processing the BIND_EXPR.  */
10699       if (TREE_CODE (DECL_EXPR_DECL (*tp)) == TYPE_DECL)
10700 	{
10701 	  tree *type_p = &TREE_TYPE (DECL_EXPR_DECL (*tp));
10702 	  if (TREE_CODE (*type_p) == ERROR_MARK)
10703 	    return NULL_TREE;
10704 
10705 	  /* Call the function for the type.  See if it returns anything or
10706 	     doesn't want us to continue.  If we are to continue, walk both
10707 	     the normal fields and those for the declaration case.  */
10708 	  result = (*func) (type_p, &walk_subtrees, data);
10709 	  if (result || !walk_subtrees)
10710 	    return result;
10711 
10712 	  /* But do not walk a pointed-to type since it may itself need to
10713 	     be walked in the declaration case if it isn't anonymous.  */
10714 	  if (!POINTER_TYPE_P (*type_p))
10715 	    {
10716 	      result = walk_type_fields (*type_p, func, data, pset, lh);
10717 	      if (result)
10718 		return result;
10719 	    }
10720 
10721 	  /* If this is a record type, also walk the fields.  */
10722 	  if (RECORD_OR_UNION_TYPE_P (*type_p))
10723 	    {
10724 	      tree field;
10725 
10726 	      for (field = TYPE_FIELDS (*type_p); field;
10727 		   field = DECL_CHAIN (field))
10728 		{
10729 		  /* We'd like to look at the type of the field, but we can
10730 		     easily get infinite recursion.  So assume it's pointed
10731 		     to elsewhere in the tree.  Also, ignore things that
10732 		     aren't fields.  */
10733 		  if (TREE_CODE (field) != FIELD_DECL)
10734 		    continue;
10735 
10736 		  WALK_SUBTREE (DECL_FIELD_OFFSET (field));
10737 		  WALK_SUBTREE (DECL_SIZE (field));
10738 		  WALK_SUBTREE (DECL_SIZE_UNIT (field));
10739 		  if (TREE_CODE (*type_p) == QUAL_UNION_TYPE)
10740 		    WALK_SUBTREE (DECL_QUALIFIER (field));
10741 		}
10742 	    }
10743 
10744 	  /* Same for scalar types.  */
10745 	  else if (TREE_CODE (*type_p) == BOOLEAN_TYPE
10746 		   || TREE_CODE (*type_p) == ENUMERAL_TYPE
10747 		   || TREE_CODE (*type_p) == INTEGER_TYPE
10748 		   || TREE_CODE (*type_p) == FIXED_POINT_TYPE
10749 		   || TREE_CODE (*type_p) == REAL_TYPE)
10750 	    {
10751 	      WALK_SUBTREE (TYPE_MIN_VALUE (*type_p));
10752 	      WALK_SUBTREE (TYPE_MAX_VALUE (*type_p));
10753 	    }
10754 
10755 	  WALK_SUBTREE (TYPE_SIZE (*type_p));
10756 	  WALK_SUBTREE_TAIL (TYPE_SIZE_UNIT (*type_p));
10757 	}
10758       /* FALLTHRU */
10759 
10760     default:
10761       if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
10762 	{
10763 	  int i, len;
10764 
10765 	  /* Walk over all the sub-trees of this operand.  */
10766 	  len = TREE_OPERAND_LENGTH (*tp);
10767 
10768 	  /* Go through the subtrees.  We need to do this in forward order so
10769 	     that the scope of a FOR_EXPR is handled properly.  */
10770 	  if (len)
10771 	    {
10772 	      for (i = 0; i < len - 1; ++i)
10773 		WALK_SUBTREE (TREE_OPERAND (*tp, i));
10774 	      WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, len - 1));
10775 	    }
10776 	}
10777       /* If this is a type, walk the needed fields in the type.  */
10778       else if (TYPE_P (*tp))
10779 	return walk_type_fields (*tp, func, data, pset, lh);
10780       break;
10781     }
10782 
10783   /* We didn't find what we were looking for.  */
10784   return NULL_TREE;
10785 
10786 #undef WALK_SUBTREE_TAIL
10787 }
10788 #undef WALK_SUBTREE
10789 
10790 /* Like walk_tree, but does not walk duplicate nodes more than once.  */
10791 
10792 tree
10793 walk_tree_without_duplicates_1 (tree *tp, walk_tree_fn func, void *data,
10794 				walk_tree_lh lh)
10795 {
10796   tree result;
10797   struct pointer_set_t *pset;
10798 
10799   pset = pointer_set_create ();
10800   result = walk_tree_1 (tp, func, data, pset, lh);
10801   pointer_set_destroy (pset);
10802   return result;
10803 }
10804 
10805 
10806 tree *
10807 tree_block (tree t)
10808 {
10809   char const c = TREE_CODE_CLASS (TREE_CODE (t));
10810 
10811   if (IS_EXPR_CODE_CLASS (c))
10812     return &t->exp.block;
10813   gcc_unreachable ();
10814   return NULL;
10815 }
10816 
10817 /* Create a nameless artificial label and put it in the current
10818    function context.  The label has a location of LOC.  Returns the
10819    newly created label.  */
10820 
10821 tree
10822 create_artificial_label (location_t loc)
10823 {
10824   tree lab = build_decl (loc,
10825       			 LABEL_DECL, NULL_TREE, void_type_node);
10826 
10827   DECL_ARTIFICIAL (lab) = 1;
10828   DECL_IGNORED_P (lab) = 1;
10829   DECL_CONTEXT (lab) = current_function_decl;
10830   return lab;
10831 }
10832 
10833 /*  Given a tree, try to return a useful variable name that we can use
10834     to prefix a temporary that is being assigned the value of the tree.
10835     I.E. given  <temp> = &A, return A.  */
10836 
10837 const char *
10838 get_name (tree t)
10839 {
10840   tree stripped_decl;
10841 
10842   stripped_decl = t;
10843   STRIP_NOPS (stripped_decl);
10844   if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
10845     return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
10846   else
10847     {
10848       switch (TREE_CODE (stripped_decl))
10849 	{
10850 	case ADDR_EXPR:
10851 	  return get_name (TREE_OPERAND (stripped_decl, 0));
10852 	default:
10853 	  return NULL;
10854 	}
10855     }
10856 }
10857 
10858 /* Return true if TYPE has a variable argument list.  */
10859 
10860 bool
10861 stdarg_p (const_tree fntype)
10862 {
10863   function_args_iterator args_iter;
10864   tree n = NULL_TREE, t;
10865 
10866   if (!fntype)
10867     return false;
10868 
10869   FOREACH_FUNCTION_ARGS(fntype, t, args_iter)
10870     {
10871       n = t;
10872     }
10873 
10874   return n != NULL_TREE && n != void_type_node;
10875 }
10876 
10877 /* Return true if TYPE has a prototype.  */
10878 
10879 bool
10880 prototype_p (tree fntype)
10881 {
10882   tree t;
10883 
10884   gcc_assert (fntype != NULL_TREE);
10885 
10886   t = TYPE_ARG_TYPES (fntype);
10887   return (t != NULL_TREE);
10888 }
10889 
10890 /* If BLOCK is inlined from an __attribute__((__artificial__))
10891    routine, return pointer to location from where it has been
10892    called.  */
10893 location_t *
10894 block_nonartificial_location (tree block)
10895 {
10896   location_t *ret = NULL;
10897 
10898   while (block && TREE_CODE (block) == BLOCK
10899 	 && BLOCK_ABSTRACT_ORIGIN (block))
10900     {
10901       tree ao = BLOCK_ABSTRACT_ORIGIN (block);
10902 
10903       while (TREE_CODE (ao) == BLOCK
10904 	     && BLOCK_ABSTRACT_ORIGIN (ao)
10905 	     && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
10906 	ao = BLOCK_ABSTRACT_ORIGIN (ao);
10907 
10908       if (TREE_CODE (ao) == FUNCTION_DECL)
10909 	{
10910 	  /* If AO is an artificial inline, point RET to the
10911 	     call site locus at which it has been inlined and continue
10912 	     the loop, in case AO's caller is also an artificial
10913 	     inline.  */
10914 	  if (DECL_DECLARED_INLINE_P (ao)
10915 	      && lookup_attribute ("artificial", DECL_ATTRIBUTES (ao)))
10916 	    ret = &BLOCK_SOURCE_LOCATION (block);
10917 	  else
10918 	    break;
10919 	}
10920       else if (TREE_CODE (ao) != BLOCK)
10921 	break;
10922 
10923       block = BLOCK_SUPERCONTEXT (block);
10924     }
10925   return ret;
10926 }
10927 
10928 
10929 /* If EXP is inlined from an __attribute__((__artificial__))
10930    function, return the location of the original call expression.  */
10931 
10932 location_t
10933 tree_nonartificial_location (tree exp)
10934 {
10935   location_t *loc = block_nonartificial_location (TREE_BLOCK (exp));
10936 
10937   if (loc)
10938     return *loc;
10939   else
10940     return EXPR_LOCATION (exp);
10941 }
10942 
10943 
10944 /* These are the hash table functions for the hash table of OPTIMIZATION_NODEq
10945    nodes.  */
10946 
10947 /* Return the hash code code X, an OPTIMIZATION_NODE or TARGET_OPTION code.  */
10948 
10949 static hashval_t
10950 cl_option_hash_hash (const void *x)
10951 {
10952   const_tree const t = (const_tree) x;
10953   const char *p;
10954   size_t i;
10955   size_t len = 0;
10956   hashval_t hash = 0;
10957 
10958   if (TREE_CODE (t) == OPTIMIZATION_NODE)
10959     {
10960       p = (const char *)TREE_OPTIMIZATION (t);
10961       len = sizeof (struct cl_optimization);
10962     }
10963 
10964   else if (TREE_CODE (t) == TARGET_OPTION_NODE)
10965     {
10966       p = (const char *)TREE_TARGET_OPTION (t);
10967       len = sizeof (struct cl_target_option);
10968     }
10969 
10970   else
10971     gcc_unreachable ();
10972 
10973   /* assume most opt flags are just 0/1, some are 2-3, and a few might be
10974      something else.  */
10975   for (i = 0; i < len; i++)
10976     if (p[i])
10977       hash = (hash << 4) ^ ((i << 2) | p[i]);
10978 
10979   return hash;
10980 }
10981 
10982 /* Return nonzero if the value represented by *X (an OPTIMIZATION or
10983    TARGET_OPTION tree node) is the same as that given by *Y, which is the
10984    same.  */
10985 
10986 static int
10987 cl_option_hash_eq (const void *x, const void *y)
10988 {
10989   const_tree const xt = (const_tree) x;
10990   const_tree const yt = (const_tree) y;
10991   const char *xp;
10992   const char *yp;
10993   size_t len;
10994 
10995   if (TREE_CODE (xt) != TREE_CODE (yt))
10996     return 0;
10997 
10998   if (TREE_CODE (xt) == OPTIMIZATION_NODE)
10999     {
11000       xp = (const char *)TREE_OPTIMIZATION (xt);
11001       yp = (const char *)TREE_OPTIMIZATION (yt);
11002       len = sizeof (struct cl_optimization);
11003     }
11004 
11005   else if (TREE_CODE (xt) == TARGET_OPTION_NODE)
11006     {
11007       xp = (const char *)TREE_TARGET_OPTION (xt);
11008       yp = (const char *)TREE_TARGET_OPTION (yt);
11009       len = sizeof (struct cl_target_option);
11010     }
11011 
11012   else
11013     gcc_unreachable ();
11014 
11015   return (memcmp (xp, yp, len) == 0);
11016 }
11017 
11018 /* Build an OPTIMIZATION_NODE based on the current options.  */
11019 
11020 tree
11021 build_optimization_node (void)
11022 {
11023   tree t;
11024   void **slot;
11025 
11026   /* Use the cache of optimization nodes.  */
11027 
11028   cl_optimization_save (TREE_OPTIMIZATION (cl_optimization_node),
11029 			&global_options);
11030 
11031   slot = htab_find_slot (cl_option_hash_table, cl_optimization_node, INSERT);
11032   t = (tree) *slot;
11033   if (!t)
11034     {
11035       /* Insert this one into the hash table.  */
11036       t = cl_optimization_node;
11037       *slot = t;
11038 
11039       /* Make a new node for next time round.  */
11040       cl_optimization_node = make_node (OPTIMIZATION_NODE);
11041     }
11042 
11043   return t;
11044 }
11045 
11046 /* Build a TARGET_OPTION_NODE based on the current options.  */
11047 
11048 tree
11049 build_target_option_node (void)
11050 {
11051   tree t;
11052   void **slot;
11053 
11054   /* Use the cache of optimization nodes.  */
11055 
11056   cl_target_option_save (TREE_TARGET_OPTION (cl_target_option_node),
11057 			 &global_options);
11058 
11059   slot = htab_find_slot (cl_option_hash_table, cl_target_option_node, INSERT);
11060   t = (tree) *slot;
11061   if (!t)
11062     {
11063       /* Insert this one into the hash table.  */
11064       t = cl_target_option_node;
11065       *slot = t;
11066 
11067       /* Make a new node for next time round.  */
11068       cl_target_option_node = make_node (TARGET_OPTION_NODE);
11069     }
11070 
11071   return t;
11072 }
11073 
11074 /* Determine the "ultimate origin" of a block.  The block may be an inlined
11075    instance of an inlined instance of a block which is local to an inline
11076    function, so we have to trace all of the way back through the origin chain
11077    to find out what sort of node actually served as the original seed for the
11078    given block.  */
11079 
11080 tree
11081 block_ultimate_origin (const_tree block)
11082 {
11083   tree immediate_origin = BLOCK_ABSTRACT_ORIGIN (block);
11084 
11085   /* output_inline_function sets BLOCK_ABSTRACT_ORIGIN for all the
11086      nodes in the function to point to themselves; ignore that if
11087      we're trying to output the abstract instance of this function.  */
11088   if (BLOCK_ABSTRACT (block) && immediate_origin == block)
11089     return NULL_TREE;
11090 
11091   if (immediate_origin == NULL_TREE)
11092     return NULL_TREE;
11093   else
11094     {
11095       tree ret_val;
11096       tree lookahead = immediate_origin;
11097 
11098       do
11099 	{
11100 	  ret_val = lookahead;
11101 	  lookahead = (TREE_CODE (ret_val) == BLOCK
11102 		       ? BLOCK_ABSTRACT_ORIGIN (ret_val) : NULL);
11103 	}
11104       while (lookahead != NULL && lookahead != ret_val);
11105 
11106       /* The block's abstract origin chain may not be the *ultimate* origin of
11107 	 the block. It could lead to a DECL that has an abstract origin set.
11108 	 If so, we want that DECL's abstract origin (which is what DECL_ORIGIN
11109 	 will give us if it has one).  Note that DECL's abstract origins are
11110 	 supposed to be the most distant ancestor (or so decl_ultimate_origin
11111 	 claims), so we don't need to loop following the DECL origins.  */
11112       if (DECL_P (ret_val))
11113 	return DECL_ORIGIN (ret_val);
11114 
11115       return ret_val;
11116     }
11117 }
11118 
11119 /* Return true if T1 and T2 are equivalent lists.  */
11120 
11121 bool
11122 list_equal_p (const_tree t1, const_tree t2)
11123 {
11124   for (; t1 && t2; t1 = TREE_CHAIN (t1) , t2 = TREE_CHAIN (t2))
11125     if (TREE_VALUE (t1) != TREE_VALUE (t2))
11126       return false;
11127   return !t1 && !t2;
11128 }
11129 
11130 /* Return true iff conversion in EXP generates no instruction.  Mark
11131    it inline so that we fully inline into the stripping functions even
11132    though we have two uses of this function.  */
11133 
11134 static inline bool
11135 tree_nop_conversion (const_tree exp)
11136 {
11137   tree outer_type, inner_type;
11138 
11139   if (!CONVERT_EXPR_P (exp)
11140       && TREE_CODE (exp) != NON_LVALUE_EXPR)
11141     return false;
11142   if (TREE_OPERAND (exp, 0) == error_mark_node)
11143     return false;
11144 
11145   outer_type = TREE_TYPE (exp);
11146   inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));
11147 
11148   if (!inner_type)
11149     return false;
11150 
11151   /* Use precision rather then machine mode when we can, which gives
11152      the correct answer even for submode (bit-field) types.  */
11153   if ((INTEGRAL_TYPE_P (outer_type)
11154        || POINTER_TYPE_P (outer_type)
11155        || TREE_CODE (outer_type) == OFFSET_TYPE)
11156       && (INTEGRAL_TYPE_P (inner_type)
11157 	  || POINTER_TYPE_P (inner_type)
11158 	  || TREE_CODE (inner_type) == OFFSET_TYPE))
11159     return TYPE_PRECISION (outer_type) == TYPE_PRECISION (inner_type);
11160 
11161   /* Otherwise fall back on comparing machine modes (e.g. for
11162      aggregate types, floats).  */
11163   return TYPE_MODE (outer_type) == TYPE_MODE (inner_type);
11164 }
11165 
11166 /* Return true iff conversion in EXP generates no instruction.  Don't
11167    consider conversions changing the signedness.  */
11168 
11169 static bool
11170 tree_sign_nop_conversion (const_tree exp)
11171 {
11172   tree outer_type, inner_type;
11173 
11174   if (!tree_nop_conversion (exp))
11175     return false;
11176 
11177   outer_type = TREE_TYPE (exp);
11178   inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));
11179 
11180   return (TYPE_UNSIGNED (outer_type) == TYPE_UNSIGNED (inner_type)
11181 	  && POINTER_TYPE_P (outer_type) == POINTER_TYPE_P (inner_type));
11182 }
11183 
11184 /* Strip conversions from EXP according to tree_nop_conversion and
11185    return the resulting expression.  */
11186 
11187 tree
11188 tree_strip_nop_conversions (tree exp)
11189 {
11190   while (tree_nop_conversion (exp))
11191     exp = TREE_OPERAND (exp, 0);
11192   return exp;
11193 }
11194 
11195 /* Strip conversions from EXP according to tree_sign_nop_conversion
11196    and return the resulting expression.  */
11197 
11198 tree
11199 tree_strip_sign_nop_conversions (tree exp)
11200 {
11201   while (tree_sign_nop_conversion (exp))
11202     exp = TREE_OPERAND (exp, 0);
11203   return exp;
11204 }
11205 
11206 /* Strip out all handled components that produce invariant
11207    offsets.  */
11208 
11209 const_tree
11210 strip_invariant_refs (const_tree op)
11211 {
11212   while (handled_component_p (op))
11213     {
11214       switch (TREE_CODE (op))
11215 	{
11216 	case ARRAY_REF:
11217 	case ARRAY_RANGE_REF:
11218 	  if (!is_gimple_constant (TREE_OPERAND (op, 1))
11219 	      || TREE_OPERAND (op, 2) != NULL_TREE
11220 	      || TREE_OPERAND (op, 3) != NULL_TREE)
11221 	    return NULL;
11222 	  break;
11223 
11224 	case COMPONENT_REF:
11225 	  if (TREE_OPERAND (op, 2) != NULL_TREE)
11226 	    return NULL;
11227 	  break;
11228 
11229 	default:;
11230 	}
11231       op = TREE_OPERAND (op, 0);
11232     }
11233 
11234   return op;
11235 }
11236 
11237 static GTY(()) tree gcc_eh_personality_decl;
11238 
11239 /* Return the GCC personality function decl.  */
11240 
11241 tree
11242 lhd_gcc_personality (void)
11243 {
11244   if (!gcc_eh_personality_decl)
11245     gcc_eh_personality_decl = build_personality_function ("gcc");
11246   return gcc_eh_personality_decl;
11247 }
11248 
11249 /* Try to find a base info of BINFO that would have its field decl at offset
11250    OFFSET within the BINFO type and which is of EXPECTED_TYPE.  If it can be
11251    found, return, otherwise return NULL_TREE.  */
11252 
11253 tree
11254 get_binfo_at_offset (tree binfo, HOST_WIDE_INT offset, tree expected_type)
11255 {
11256   tree type = BINFO_TYPE (binfo);
11257 
11258   while (true)
11259     {
11260       HOST_WIDE_INT pos, size;
11261       tree fld;
11262       int i;
11263 
11264       if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (expected_type))
11265 	  return binfo;
11266       if (offset < 0)
11267 	return NULL_TREE;
11268 
11269       for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
11270 	{
11271 	  if (TREE_CODE (fld) != FIELD_DECL)
11272 	    continue;
11273 
11274 	  pos = int_bit_position (fld);
11275 	  size = tree_low_cst (DECL_SIZE (fld), 1);
11276 	  if (pos <= offset && (pos + size) > offset)
11277 	    break;
11278 	}
11279       if (!fld || TREE_CODE (TREE_TYPE (fld)) != RECORD_TYPE)
11280 	return NULL_TREE;
11281 
11282       if (!DECL_ARTIFICIAL (fld))
11283 	{
11284 	  binfo = TYPE_BINFO (TREE_TYPE (fld));
11285 	  if (!binfo)
11286 	    return NULL_TREE;
11287 	}
11288       /* Offset 0 indicates the primary base, whose vtable contents are
11289 	 represented in the binfo for the derived class.  */
11290       else if (offset != 0)
11291 	{
11292 	  tree base_binfo, found_binfo = NULL_TREE;
11293 	  for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
11294 	    if (TREE_TYPE (base_binfo) == TREE_TYPE (fld))
11295 	      {
11296 		found_binfo = base_binfo;
11297 		break;
11298 	      }
11299 	  if (!found_binfo)
11300 	    return NULL_TREE;
11301 	  binfo = found_binfo;
11302 	}
11303 
11304       type = TREE_TYPE (fld);
11305       offset -= pos;
11306     }
11307 }
11308 
11309 /* Returns true if X is a typedef decl.  */
11310 
11311 bool
11312 is_typedef_decl (tree x)
11313 {
11314   return (x && TREE_CODE (x) == TYPE_DECL
11315           && DECL_ORIGINAL_TYPE (x) != NULL_TREE);
11316 }
11317 
11318 /* Returns true iff TYPE is a type variant created for a typedef. */
11319 
11320 bool
11321 typedef_variant_p (tree type)
11322 {
11323   return is_typedef_decl (TYPE_NAME (type));
11324 }
11325 
11326 /* Warn about a use of an identifier which was marked deprecated.  */
11327 void
11328 warn_deprecated_use (tree node, tree attr)
11329 {
11330   const char *msg;
11331 
11332   if (node == 0 || !warn_deprecated_decl)
11333     return;
11334 
11335   if (!attr)
11336     {
11337       if (DECL_P (node))
11338 	attr = DECL_ATTRIBUTES (node);
11339       else if (TYPE_P (node))
11340 	{
11341 	  tree decl = TYPE_STUB_DECL (node);
11342 	  if (decl)
11343 	    attr = lookup_attribute ("deprecated",
11344 				     TYPE_ATTRIBUTES (TREE_TYPE (decl)));
11345 	}
11346     }
11347 
11348   if (attr)
11349     attr = lookup_attribute ("deprecated", attr);
11350 
11351   if (attr)
11352     msg = TREE_STRING_POINTER (TREE_VALUE (TREE_VALUE (attr)));
11353   else
11354     msg = NULL;
11355 
11356   if (DECL_P (node))
11357     {
11358       expanded_location xloc = expand_location (DECL_SOURCE_LOCATION (node));
11359       if (msg)
11360 	warning (OPT_Wdeprecated_declarations,
11361 		 "%qD is deprecated (declared at %s:%d): %s",
11362 		 node, xloc.file, xloc.line, msg);
11363       else
11364 	warning (OPT_Wdeprecated_declarations,
11365 		 "%qD is deprecated (declared at %s:%d)",
11366 		 node, xloc.file, xloc.line);
11367     }
11368   else if (TYPE_P (node))
11369     {
11370       tree what = NULL_TREE;
11371       tree decl = TYPE_STUB_DECL (node);
11372 
11373       if (TYPE_NAME (node))
11374 	{
11375 	  if (TREE_CODE (TYPE_NAME (node)) == IDENTIFIER_NODE)
11376 	    what = TYPE_NAME (node);
11377 	  else if (TREE_CODE (TYPE_NAME (node)) == TYPE_DECL
11378 		   && DECL_NAME (TYPE_NAME (node)))
11379 	    what = DECL_NAME (TYPE_NAME (node));
11380 	}
11381 
11382       if (decl)
11383 	{
11384 	  expanded_location xloc
11385 	    = expand_location (DECL_SOURCE_LOCATION (decl));
11386 	  if (what)
11387 	    {
11388 	      if (msg)
11389 		warning (OPT_Wdeprecated_declarations,
11390 			 "%qE is deprecated (declared at %s:%d): %s",
11391 			 what, xloc.file, xloc.line, msg);
11392 	      else
11393 		warning (OPT_Wdeprecated_declarations,
11394 			 "%qE is deprecated (declared at %s:%d)", what,
11395 			 xloc.file, xloc.line);
11396 	    }
11397 	  else
11398 	    {
11399 	      if (msg)
11400 		warning (OPT_Wdeprecated_declarations,
11401 			 "type is deprecated (declared at %s:%d): %s",
11402 			 xloc.file, xloc.line, msg);
11403 	      else
11404 		warning (OPT_Wdeprecated_declarations,
11405 			 "type is deprecated (declared at %s:%d)",
11406 			 xloc.file, xloc.line);
11407 	    }
11408 	}
11409       else
11410 	{
11411 	  if (what)
11412 	    {
11413 	      if (msg)
11414 		warning (OPT_Wdeprecated_declarations, "%qE is deprecated: %s",
11415 			 what, msg);
11416 	      else
11417 		warning (OPT_Wdeprecated_declarations, "%qE is deprecated", what);
11418 	    }
11419 	  else
11420 	    {
11421 	      if (msg)
11422 		warning (OPT_Wdeprecated_declarations, "type is deprecated: %s",
11423 			 msg);
11424 	      else
11425 		warning (OPT_Wdeprecated_declarations, "type is deprecated");
11426 	    }
11427 	}
11428     }
11429 }
11430 
11431 #include "gt-tree.h"
11432