xref: /dragonfly/contrib/gcc-4.7/gcc/gimplify.c (revision 9f7604d7)
1 /* Tree lowering pass.  This pass converts the GENERIC functions-as-trees
2    tree representation into the GIMPLE form.
3    Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011,
4    2012 Free Software Foundation, Inc.
5    Major work done by Sebastian Pop <s.pop@laposte.net>,
6    Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.
7 
8 This file is part of GCC.
9 
10 GCC is free software; you can redistribute it and/or modify it under
11 the terms of the GNU General Public License as published by the Free
12 Software Foundation; either version 3, or (at your option) any later
13 version.
14 
15 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
16 WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18 for more details.
19 
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3.  If not see
22 <http://www.gnu.org/licenses/>.  */
23 
24 #include "config.h"
25 #include "system.h"
26 #include "coretypes.h"
27 #include "tm.h"
28 #include "tree.h"
29 #include "gimple.h"
30 #include "tree-iterator.h"
31 #include "tree-inline.h"
32 #include "tree-pretty-print.h"
33 #include "langhooks.h"
34 #include "tree-flow.h"
35 #include "cgraph.h"
36 #include "timevar.h"
37 #include "hashtab.h"
38 #include "flags.h"
39 #include "function.h"
40 #include "output.h"
41 #include "ggc.h"
42 #include "diagnostic-core.h"
43 #include "target.h"
44 #include "pointer-set.h"
45 #include "splay-tree.h"
46 #include "vec.h"
47 #include "gimple.h"
48 #include "tree-pass.h"
49 
50 #include "langhooks-def.h"	/* FIXME: for lhd_set_decl_assembler_name.  */
51 #include "expr.h"		/* FIXME: for can_move_by_pieces
52 				   and STACK_CHECK_MAX_VAR_SIZE.  */
53 
54 enum gimplify_omp_var_data
55 {
56   GOVD_SEEN = 1,
57   GOVD_EXPLICIT = 2,
58   GOVD_SHARED = 4,
59   GOVD_PRIVATE = 8,
60   GOVD_FIRSTPRIVATE = 16,
61   GOVD_LASTPRIVATE = 32,
62   GOVD_REDUCTION = 64,
63   GOVD_LOCAL = 128,
64   GOVD_DEBUG_PRIVATE = 256,
65   GOVD_PRIVATE_OUTER_REF = 512,
66   GOVD_DATA_SHARE_CLASS = (GOVD_SHARED | GOVD_PRIVATE | GOVD_FIRSTPRIVATE
67 			   | GOVD_LASTPRIVATE | GOVD_REDUCTION | GOVD_LOCAL)
68 };
69 
70 
71 enum omp_region_type
72 {
73   ORT_WORKSHARE = 0,
74   ORT_PARALLEL = 2,
75   ORT_COMBINED_PARALLEL = 3,
76   ORT_TASK = 4,
77   ORT_UNTIED_TASK = 5
78 };
79 
80 struct gimplify_omp_ctx
81 {
82   struct gimplify_omp_ctx *outer_context;
83   splay_tree variables;
84   struct pointer_set_t *privatized_types;
85   location_t location;
86   enum omp_clause_default_kind default_kind;
87   enum omp_region_type region_type;
88 };
89 
90 static struct gimplify_ctx *gimplify_ctxp;
91 static struct gimplify_omp_ctx *gimplify_omp_ctxp;
92 
93 
94 /* Formal (expression) temporary table handling: multiple occurrences of
95    the same scalar expression are evaluated into the same temporary.  */
96 
97 typedef struct gimple_temp_hash_elt
98 {
99   tree val;   /* Key */
100   tree temp;  /* Value */
101 } elt_t;
102 
103 /* Forward declaration.  */
104 static enum gimplify_status gimplify_compound_expr (tree *, gimple_seq *, bool);
105 
106 /* Mark X addressable.  Unlike the langhook we expect X to be in gimple
107    form and we don't do any syntax checking.  */
108 
109 void
110 mark_addressable (tree x)
111 {
112   while (handled_component_p (x))
113     x = TREE_OPERAND (x, 0);
114   if (TREE_CODE (x) == MEM_REF
115       && TREE_CODE (TREE_OPERAND (x, 0)) == ADDR_EXPR)
116     x = TREE_OPERAND (TREE_OPERAND (x, 0), 0);
117   if (TREE_CODE (x) != VAR_DECL
118       && TREE_CODE (x) != PARM_DECL
119       && TREE_CODE (x) != RESULT_DECL)
120     return;
121   TREE_ADDRESSABLE (x) = 1;
122 
123   /* Also mark the artificial SSA_NAME that points to the partition of X.  */
124   if (TREE_CODE (x) == VAR_DECL
125       && !DECL_EXTERNAL (x)
126       && !TREE_STATIC (x)
127       && cfun->gimple_df != NULL
128       && cfun->gimple_df->decls_to_pointers != NULL)
129     {
130       void *namep
131 	= pointer_map_contains (cfun->gimple_df->decls_to_pointers, x);
132       if (namep)
133 	TREE_ADDRESSABLE (*(tree *)namep) = 1;
134     }
135 }
136 
137 /* Return a hash value for a formal temporary table entry.  */
138 
139 static hashval_t
140 gimple_tree_hash (const void *p)
141 {
142   tree t = ((const elt_t *) p)->val;
143   return iterative_hash_expr (t, 0);
144 }
145 
146 /* Compare two formal temporary table entries.  */
147 
148 static int
149 gimple_tree_eq (const void *p1, const void *p2)
150 {
151   tree t1 = ((const elt_t *) p1)->val;
152   tree t2 = ((const elt_t *) p2)->val;
153   enum tree_code code = TREE_CODE (t1);
154 
155   if (TREE_CODE (t2) != code
156       || TREE_TYPE (t1) != TREE_TYPE (t2))
157     return 0;
158 
159   if (!operand_equal_p (t1, t2, 0))
160     return 0;
161 
162 #ifdef ENABLE_CHECKING
163   /* Only allow them to compare equal if they also hash equal; otherwise
164      results are nondeterminate, and we fail bootstrap comparison.  */
165   gcc_assert (gimple_tree_hash (p1) == gimple_tree_hash (p2));
166 #endif
167 
168   return 1;
169 }
170 
171 /* Link gimple statement GS to the end of the sequence *SEQ_P.  If
172    *SEQ_P is NULL, a new sequence is allocated.  This function is
173    similar to gimple_seq_add_stmt, but does not scan the operands.
174    During gimplification, we need to manipulate statement sequences
175    before the def/use vectors have been constructed.  */
176 
177 void
178 gimple_seq_add_stmt_without_update (gimple_seq *seq_p, gimple gs)
179 {
180   gimple_stmt_iterator si;
181 
182   if (gs == NULL)
183     return;
184 
185   if (*seq_p == NULL)
186     *seq_p = gimple_seq_alloc ();
187 
188   si = gsi_last (*seq_p);
189 
190   gsi_insert_after_without_update (&si, gs, GSI_NEW_STMT);
191 }
192 
193 /* Shorter alias name for the above function for use in gimplify.c
194    only.  */
195 
196 static inline void
197 gimplify_seq_add_stmt (gimple_seq *seq_p, gimple gs)
198 {
199   gimple_seq_add_stmt_without_update (seq_p, gs);
200 }
201 
202 /* Append sequence SRC to the end of sequence *DST_P.  If *DST_P is
203    NULL, a new sequence is allocated.   This function is
204    similar to gimple_seq_add_seq, but does not scan the operands.
205    During gimplification, we need to manipulate statement sequences
206    before the def/use vectors have been constructed.  */
207 
208 static void
209 gimplify_seq_add_seq (gimple_seq *dst_p, gimple_seq src)
210 {
211   gimple_stmt_iterator si;
212 
213   if (src == NULL)
214     return;
215 
216   if (*dst_p == NULL)
217     *dst_p = gimple_seq_alloc ();
218 
219   si = gsi_last (*dst_p);
220   gsi_insert_seq_after_without_update (&si, src, GSI_NEW_STMT);
221 }
222 
223 /* Set up a context for the gimplifier.  */
224 
225 void
226 push_gimplify_context (struct gimplify_ctx *c)
227 {
228   memset (c, '\0', sizeof (*c));
229   c->prev_context = gimplify_ctxp;
230   gimplify_ctxp = c;
231 }
232 
233 /* Tear down a context for the gimplifier.  If BODY is non-null, then
234    put the temporaries into the outer BIND_EXPR.  Otherwise, put them
235    in the local_decls.
236 
237    BODY is not a sequence, but the first tuple in a sequence.  */
238 
239 void
240 pop_gimplify_context (gimple body)
241 {
242   struct gimplify_ctx *c = gimplify_ctxp;
243 
244   gcc_assert (c && (c->bind_expr_stack == NULL
245 		    || VEC_empty (gimple, c->bind_expr_stack)));
246   VEC_free (gimple, heap, c->bind_expr_stack);
247   gimplify_ctxp = c->prev_context;
248 
249   if (body)
250     declare_vars (c->temps, body, false);
251   else
252     record_vars (c->temps);
253 
254   if (c->temp_htab)
255     htab_delete (c->temp_htab);
256 }
257 
258 /* Push a GIMPLE_BIND tuple onto the stack of bindings.  */
259 
260 static void
261 gimple_push_bind_expr (gimple gimple_bind)
262 {
263   if (gimplify_ctxp->bind_expr_stack == NULL)
264     gimplify_ctxp->bind_expr_stack = VEC_alloc (gimple, heap, 8);
265   VEC_safe_push (gimple, heap, gimplify_ctxp->bind_expr_stack, gimple_bind);
266 }
267 
268 /* Pop the first element off the stack of bindings.  */
269 
270 static void
271 gimple_pop_bind_expr (void)
272 {
273   VEC_pop (gimple, gimplify_ctxp->bind_expr_stack);
274 }
275 
276 /* Return the first element of the stack of bindings.  */
277 
278 gimple
279 gimple_current_bind_expr (void)
280 {
281   return VEC_last (gimple, gimplify_ctxp->bind_expr_stack);
282 }
283 
284 /* Return the stack of bindings created during gimplification.  */
285 
286 VEC(gimple, heap) *
287 gimple_bind_expr_stack (void)
288 {
289   return gimplify_ctxp->bind_expr_stack;
290 }
291 
292 /* Return true iff there is a COND_EXPR between us and the innermost
293    CLEANUP_POINT_EXPR.  This info is used by gimple_push_cleanup.  */
294 
295 static bool
296 gimple_conditional_context (void)
297 {
298   return gimplify_ctxp->conditions > 0;
299 }
300 
301 /* Note that we've entered a COND_EXPR.  */
302 
303 static void
304 gimple_push_condition (void)
305 {
306 #ifdef ENABLE_GIMPLE_CHECKING
307   if (gimplify_ctxp->conditions == 0)
308     gcc_assert (gimple_seq_empty_p (gimplify_ctxp->conditional_cleanups));
309 #endif
310   ++(gimplify_ctxp->conditions);
311 }
312 
313 /* Note that we've left a COND_EXPR.  If we're back at unconditional scope
314    now, add any conditional cleanups we've seen to the prequeue.  */
315 
316 static void
317 gimple_pop_condition (gimple_seq *pre_p)
318 {
319   int conds = --(gimplify_ctxp->conditions);
320 
321   gcc_assert (conds >= 0);
322   if (conds == 0)
323     {
324       gimplify_seq_add_seq (pre_p, gimplify_ctxp->conditional_cleanups);
325       gimplify_ctxp->conditional_cleanups = NULL;
326     }
327 }
328 
329 /* A stable comparison routine for use with splay trees and DECLs.  */
330 
331 static int
332 splay_tree_compare_decl_uid (splay_tree_key xa, splay_tree_key xb)
333 {
334   tree a = (tree) xa;
335   tree b = (tree) xb;
336 
337   return DECL_UID (a) - DECL_UID (b);
338 }
339 
340 /* Create a new omp construct that deals with variable remapping.  */
341 
342 static struct gimplify_omp_ctx *
343 new_omp_context (enum omp_region_type region_type)
344 {
345   struct gimplify_omp_ctx *c;
346 
347   c = XCNEW (struct gimplify_omp_ctx);
348   c->outer_context = gimplify_omp_ctxp;
349   c->variables = splay_tree_new (splay_tree_compare_decl_uid, 0, 0);
350   c->privatized_types = pointer_set_create ();
351   c->location = input_location;
352   c->region_type = region_type;
353   if ((region_type & ORT_TASK) == 0)
354     c->default_kind = OMP_CLAUSE_DEFAULT_SHARED;
355   else
356     c->default_kind = OMP_CLAUSE_DEFAULT_UNSPECIFIED;
357 
358   return c;
359 }
360 
361 /* Destroy an omp construct that deals with variable remapping.  */
362 
363 static void
364 delete_omp_context (struct gimplify_omp_ctx *c)
365 {
366   splay_tree_delete (c->variables);
367   pointer_set_destroy (c->privatized_types);
368   XDELETE (c);
369 }
370 
371 static void omp_add_variable (struct gimplify_omp_ctx *, tree, unsigned int);
372 static bool omp_notice_variable (struct gimplify_omp_ctx *, tree, bool);
373 
374 /* Both gimplify the statement T and append it to *SEQ_P.  This function
375    behaves exactly as gimplify_stmt, but you don't have to pass T as a
376    reference.  */
377 
378 void
379 gimplify_and_add (tree t, gimple_seq *seq_p)
380 {
381   gimplify_stmt (&t, seq_p);
382 }
383 
384 /* Gimplify statement T into sequence *SEQ_P, and return the first
385    tuple in the sequence of generated tuples for this statement.
386    Return NULL if gimplifying T produced no tuples.  */
387 
388 static gimple
389 gimplify_and_return_first (tree t, gimple_seq *seq_p)
390 {
391   gimple_stmt_iterator last = gsi_last (*seq_p);
392 
393   gimplify_and_add (t, seq_p);
394 
395   if (!gsi_end_p (last))
396     {
397       gsi_next (&last);
398       return gsi_stmt (last);
399     }
400   else
401     return gimple_seq_first_stmt (*seq_p);
402 }
403 
404 /* Strip off a legitimate source ending from the input string NAME of
405    length LEN.  Rather than having to know the names used by all of
406    our front ends, we strip off an ending of a period followed by
407    up to five characters.  (Java uses ".class".)  */
408 
409 static inline void
410 remove_suffix (char *name, int len)
411 {
412   int i;
413 
414   for (i = 2;  i < 8 && len > i;  i++)
415     {
416       if (name[len - i] == '.')
417 	{
418 	  name[len - i] = '\0';
419 	  break;
420 	}
421     }
422 }
423 
424 /* Create a new temporary name with PREFIX.  Return an identifier.  */
425 
426 static GTY(()) unsigned int tmp_var_id_num;
427 
428 tree
429 create_tmp_var_name (const char *prefix)
430 {
431   char *tmp_name;
432 
433   if (prefix)
434     {
435       char *preftmp = ASTRDUP (prefix);
436 
437       remove_suffix (preftmp, strlen (preftmp));
438       clean_symbol_name (preftmp);
439 
440       prefix = preftmp;
441     }
442 
443   ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
444   return get_identifier (tmp_name);
445 }
446 
447 /* Create a new temporary variable declaration of type TYPE.
448    Do NOT push it into the current binding.  */
449 
450 tree
451 create_tmp_var_raw (tree type, const char *prefix)
452 {
453   tree tmp_var;
454 
455   tmp_var = build_decl (input_location,
456 			VAR_DECL, prefix ? create_tmp_var_name (prefix) : NULL,
457 			type);
458 
459   /* The variable was declared by the compiler.  */
460   DECL_ARTIFICIAL (tmp_var) = 1;
461   /* And we don't want debug info for it.  */
462   DECL_IGNORED_P (tmp_var) = 1;
463 
464   /* Make the variable writable.  */
465   TREE_READONLY (tmp_var) = 0;
466 
467   DECL_EXTERNAL (tmp_var) = 0;
468   TREE_STATIC (tmp_var) = 0;
469   TREE_USED (tmp_var) = 1;
470 
471   return tmp_var;
472 }
473 
474 /* Create a new temporary variable declaration of type TYPE.  DO push the
475    variable into the current binding.  Further, assume that this is called
476    only from gimplification or optimization, at which point the creation of
477    certain types are bugs.  */
478 
479 tree
480 create_tmp_var (tree type, const char *prefix)
481 {
482   tree tmp_var;
483 
484   /* We don't allow types that are addressable (meaning we can't make copies),
485      or incomplete.  We also used to reject every variable size objects here,
486      but now support those for which a constant upper bound can be obtained.
487      The processing for variable sizes is performed in gimple_add_tmp_var,
488      point at which it really matters and possibly reached via paths not going
489      through this function, e.g. after direct calls to create_tmp_var_raw.  */
490   gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
491 
492   tmp_var = create_tmp_var_raw (type, prefix);
493   gimple_add_tmp_var (tmp_var);
494   return tmp_var;
495 }
496 
497 /* Create a new temporary variable declaration of type TYPE by calling
498    create_tmp_var and if TYPE is a vector or a complex number, mark the new
499    temporary as gimple register.  */
500 
501 tree
502 create_tmp_reg (tree type, const char *prefix)
503 {
504   tree tmp;
505 
506   tmp = create_tmp_var (type, prefix);
507   if (TREE_CODE (type) == COMPLEX_TYPE
508       || TREE_CODE (type) == VECTOR_TYPE)
509     DECL_GIMPLE_REG_P (tmp) = 1;
510 
511   return tmp;
512 }
513 
514 /* Create a temporary with a name derived from VAL.  Subroutine of
515    lookup_tmp_var; nobody else should call this function.  */
516 
517 static inline tree
518 create_tmp_from_val (tree val)
519 {
520   /* Drop all qualifiers and address-space information from the value type.  */
521   return create_tmp_var (TYPE_MAIN_VARIANT (TREE_TYPE (val)), get_name (val));
522 }
523 
524 /* Create a temporary to hold the value of VAL.  If IS_FORMAL, try to reuse
525    an existing expression temporary.  */
526 
527 static tree
528 lookup_tmp_var (tree val, bool is_formal)
529 {
530   tree ret;
531 
532   /* If not optimizing, never really reuse a temporary.  local-alloc
533      won't allocate any variable that is used in more than one basic
534      block, which means it will go into memory, causing much extra
535      work in reload and final and poorer code generation, outweighing
536      the extra memory allocation here.  */
537   if (!optimize || !is_formal || TREE_SIDE_EFFECTS (val))
538     ret = create_tmp_from_val (val);
539   else
540     {
541       elt_t elt, *elt_p;
542       void **slot;
543 
544       elt.val = val;
545       if (gimplify_ctxp->temp_htab == NULL)
546         gimplify_ctxp->temp_htab
547 	  = htab_create (1000, gimple_tree_hash, gimple_tree_eq, free);
548       slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
549       if (*slot == NULL)
550 	{
551 	  elt_p = XNEW (elt_t);
552 	  elt_p->val = val;
553 	  elt_p->temp = ret = create_tmp_from_val (val);
554 	  *slot = (void *) elt_p;
555 	}
556       else
557 	{
558 	  elt_p = (elt_t *) *slot;
559           ret = elt_p->temp;
560 	}
561     }
562 
563   return ret;
564 }
565 
566 /* Return true if T is a CALL_EXPR or an expression that can be
567    assigned to a temporary.  Note that this predicate should only be
568    used during gimplification.  See the rationale for this in
569    gimplify_modify_expr.  */
570 
571 static bool
572 is_gimple_reg_rhs_or_call (tree t)
573 {
574   return (get_gimple_rhs_class (TREE_CODE (t)) != GIMPLE_INVALID_RHS
575 	  || TREE_CODE (t) == CALL_EXPR);
576 }
577 
578 /* Return true if T is a valid memory RHS or a CALL_EXPR.  Note that
579    this predicate should only be used during gimplification.  See the
580    rationale for this in gimplify_modify_expr.  */
581 
582 static bool
583 is_gimple_mem_rhs_or_call (tree t)
584 {
585   /* If we're dealing with a renamable type, either source or dest must be
586      a renamed variable.  */
587   if (is_gimple_reg_type (TREE_TYPE (t)))
588     return is_gimple_val (t);
589   else
590     return (is_gimple_val (t) || is_gimple_lvalue (t)
591 	    || TREE_CODE (t) == CALL_EXPR);
592 }
593 
594 /* Helper for get_formal_tmp_var and get_initialized_tmp_var.  */
595 
596 static tree
597 internal_get_tmp_var (tree val, gimple_seq *pre_p, gimple_seq *post_p,
598                       bool is_formal)
599 {
600   tree t, mod;
601 
602   /* Notice that we explicitly allow VAL to be a CALL_EXPR so that we
603      can create an INIT_EXPR and convert it into a GIMPLE_CALL below.  */
604   gimplify_expr (&val, pre_p, post_p, is_gimple_reg_rhs_or_call,
605 		 fb_rvalue);
606 
607   t = lookup_tmp_var (val, is_formal);
608 
609   if (is_formal
610       && (TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE
611 	  || TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE))
612     DECL_GIMPLE_REG_P (t) = 1;
613 
614   mod = build2 (INIT_EXPR, TREE_TYPE (t), t, unshare_expr (val));
615 
616   SET_EXPR_LOCATION (mod, EXPR_LOC_OR_HERE (val));
617 
618   /* gimplify_modify_expr might want to reduce this further.  */
619   gimplify_and_add (mod, pre_p);
620   ggc_free (mod);
621 
622   /* If we're gimplifying into ssa, gimplify_modify_expr will have
623      given our temporary an SSA name.  Find and return it.  */
624   if (gimplify_ctxp->into_ssa)
625     {
626       gimple last = gimple_seq_last_stmt (*pre_p);
627       t = gimple_get_lhs (last);
628     }
629 
630   return t;
631 }
632 
633 /* Return a formal temporary variable initialized with VAL.  PRE_P is as
634    in gimplify_expr.  Only use this function if:
635 
636    1) The value of the unfactored expression represented by VAL will not
637       change between the initialization and use of the temporary, and
638    2) The temporary will not be otherwise modified.
639 
640    For instance, #1 means that this is inappropriate for SAVE_EXPR temps,
641    and #2 means it is inappropriate for && temps.
642 
643    For other cases, use get_initialized_tmp_var instead.  */
644 
645 tree
646 get_formal_tmp_var (tree val, gimple_seq *pre_p)
647 {
648   return internal_get_tmp_var (val, pre_p, NULL, true);
649 }
650 
651 /* Return a temporary variable initialized with VAL.  PRE_P and POST_P
652    are as in gimplify_expr.  */
653 
654 tree
655 get_initialized_tmp_var (tree val, gimple_seq *pre_p, gimple_seq *post_p)
656 {
657   return internal_get_tmp_var (val, pre_p, post_p, false);
658 }
659 
660 /* Declare all the variables in VARS in SCOPE.  If DEBUG_INFO is true,
661    generate debug info for them; otherwise don't.  */
662 
663 void
664 declare_vars (tree vars, gimple scope, bool debug_info)
665 {
666   tree last = vars;
667   if (last)
668     {
669       tree temps, block;
670 
671       gcc_assert (gimple_code (scope) == GIMPLE_BIND);
672 
673       temps = nreverse (last);
674 
675       block = gimple_bind_block (scope);
676       gcc_assert (!block || TREE_CODE (block) == BLOCK);
677       if (!block || !debug_info)
678 	{
679 	  DECL_CHAIN (last) = gimple_bind_vars (scope);
680 	  gimple_bind_set_vars (scope, temps);
681 	}
682       else
683 	{
684 	  /* We need to attach the nodes both to the BIND_EXPR and to its
685 	     associated BLOCK for debugging purposes.  The key point here
686 	     is that the BLOCK_VARS of the BIND_EXPR_BLOCK of a BIND_EXPR
687 	     is a subchain of the BIND_EXPR_VARS of the BIND_EXPR.  */
688 	  if (BLOCK_VARS (block))
689 	    BLOCK_VARS (block) = chainon (BLOCK_VARS (block), temps);
690 	  else
691 	    {
692 	      gimple_bind_set_vars (scope,
693 	      			    chainon (gimple_bind_vars (scope), temps));
694 	      BLOCK_VARS (block) = temps;
695 	    }
696 	}
697     }
698 }
699 
700 /* For VAR a VAR_DECL of variable size, try to find a constant upper bound
701    for the size and adjust DECL_SIZE/DECL_SIZE_UNIT accordingly.  Abort if
702    no such upper bound can be obtained.  */
703 
704 static void
705 force_constant_size (tree var)
706 {
707   /* The only attempt we make is by querying the maximum size of objects
708      of the variable's type.  */
709 
710   HOST_WIDE_INT max_size;
711 
712   gcc_assert (TREE_CODE (var) == VAR_DECL);
713 
714   max_size = max_int_size_in_bytes (TREE_TYPE (var));
715 
716   gcc_assert (max_size >= 0);
717 
718   DECL_SIZE_UNIT (var)
719     = build_int_cst (TREE_TYPE (DECL_SIZE_UNIT (var)), max_size);
720   DECL_SIZE (var)
721     = build_int_cst (TREE_TYPE (DECL_SIZE (var)), max_size * BITS_PER_UNIT);
722 }
723 
724 /* Push the temporary variable TMP into the current binding.  */
725 
726 void
727 gimple_add_tmp_var (tree tmp)
728 {
729   gcc_assert (!DECL_CHAIN (tmp) && !DECL_SEEN_IN_BIND_EXPR_P (tmp));
730 
731   /* Later processing assumes that the object size is constant, which might
732      not be true at this point.  Force the use of a constant upper bound in
733      this case.  */
734   if (!host_integerp (DECL_SIZE_UNIT (tmp), 1))
735     force_constant_size (tmp);
736 
737   DECL_CONTEXT (tmp) = current_function_decl;
738   DECL_SEEN_IN_BIND_EXPR_P (tmp) = 1;
739 
740   if (gimplify_ctxp)
741     {
742       DECL_CHAIN (tmp) = gimplify_ctxp->temps;
743       gimplify_ctxp->temps = tmp;
744 
745       /* Mark temporaries local within the nearest enclosing parallel.  */
746       if (gimplify_omp_ctxp)
747 	{
748 	  struct gimplify_omp_ctx *ctx = gimplify_omp_ctxp;
749 	  while (ctx && ctx->region_type == ORT_WORKSHARE)
750 	    ctx = ctx->outer_context;
751 	  if (ctx)
752 	    omp_add_variable (ctx, tmp, GOVD_LOCAL | GOVD_SEEN);
753 	}
754     }
755   else if (cfun)
756     record_vars (tmp);
757   else
758     {
759       gimple_seq body_seq;
760 
761       /* This case is for nested functions.  We need to expose the locals
762 	 they create.  */
763       body_seq = gimple_body (current_function_decl);
764       declare_vars (tmp, gimple_seq_first_stmt (body_seq), false);
765     }
766 }
767 
768 /* Determine whether to assign a location to the statement GS.  */
769 
770 static bool
771 should_carry_location_p (gimple gs)
772 {
773   /* Don't emit a line note for a label.  We particularly don't want to
774      emit one for the break label, since it doesn't actually correspond
775      to the beginning of the loop/switch.  */
776   if (gimple_code (gs) == GIMPLE_LABEL)
777     return false;
778 
779   return true;
780 }
781 
782 /* Return true if a location should not be emitted for this statement
783    by annotate_one_with_location.  */
784 
785 static inline bool
786 gimple_do_not_emit_location_p (gimple g)
787 {
788   return gimple_plf (g, GF_PLF_1);
789 }
790 
791 /* Mark statement G so a location will not be emitted by
792    annotate_one_with_location.  */
793 
794 static inline void
795 gimple_set_do_not_emit_location (gimple g)
796 {
797   /* The PLF flags are initialized to 0 when a new tuple is created,
798      so no need to initialize it anywhere.  */
799   gimple_set_plf (g, GF_PLF_1, true);
800 }
801 
802 /* Set the location for gimple statement GS to LOCATION.  */
803 
804 static void
805 annotate_one_with_location (gimple gs, location_t location)
806 {
807   if (!gimple_has_location (gs)
808       && !gimple_do_not_emit_location_p (gs)
809       && should_carry_location_p (gs))
810     gimple_set_location (gs, location);
811 }
812 
813 /* Set LOCATION for all the statements after iterator GSI in sequence
814    SEQ.  If GSI is pointing to the end of the sequence, start with the
815    first statement in SEQ.  */
816 
817 static void
818 annotate_all_with_location_after (gimple_seq seq, gimple_stmt_iterator gsi,
819 				  location_t location)
820 {
821   if (gsi_end_p (gsi))
822     gsi = gsi_start (seq);
823   else
824     gsi_next (&gsi);
825 
826   for (; !gsi_end_p (gsi); gsi_next (&gsi))
827     annotate_one_with_location (gsi_stmt (gsi), location);
828 }
829 
830 /* Set the location for all the statements in a sequence STMT_P to LOCATION.  */
831 
832 void
833 annotate_all_with_location (gimple_seq stmt_p, location_t location)
834 {
835   gimple_stmt_iterator i;
836 
837   if (gimple_seq_empty_p (stmt_p))
838     return;
839 
840   for (i = gsi_start (stmt_p); !gsi_end_p (i); gsi_next (&i))
841     {
842       gimple gs = gsi_stmt (i);
843       annotate_one_with_location (gs, location);
844     }
845 }
846 
847 /* This page contains routines to unshare tree nodes, i.e. to duplicate tree
848    nodes that are referenced more than once in GENERIC functions.  This is
849    necessary because gimplification (translation into GIMPLE) is performed
850    by modifying tree nodes in-place, so gimplication of a shared node in a
851    first context could generate an invalid GIMPLE form in a second context.
852 
853    This is achieved with a simple mark/copy/unmark algorithm that walks the
854    GENERIC representation top-down, marks nodes with TREE_VISITED the first
855    time it encounters them, duplicates them if they already have TREE_VISITED
856    set, and finally removes the TREE_VISITED marks it has set.
857 
858    The algorithm works only at the function level, i.e. it generates a GENERIC
859    representation of a function with no nodes shared within the function when
860    passed a GENERIC function (except for nodes that are allowed to be shared).
861 
862    At the global level, it is also necessary to unshare tree nodes that are
863    referenced in more than one function, for the same aforementioned reason.
864    This requires some cooperation from the front-end.  There are 2 strategies:
865 
866      1. Manual unsharing.  The front-end needs to call unshare_expr on every
867         expression that might end up being shared across functions.
868 
869      2. Deep unsharing.  This is an extension of regular unsharing.  Instead
870         of calling unshare_expr on expressions that might be shared across
871         functions, the front-end pre-marks them with TREE_VISITED.  This will
872         ensure that they are unshared on the first reference within functions
873         when the regular unsharing algorithm runs.  The counterpart is that
874         this algorithm must look deeper than for manual unsharing, which is
875         specified by LANG_HOOKS_DEEP_UNSHARING.
876 
877   If there are only few specific cases of node sharing across functions, it is
878   probably easier for a front-end to unshare the expressions manually.  On the
879   contrary, if the expressions generated at the global level are as widespread
880   as expressions generated within functions, deep unsharing is very likely the
881   way to go.  */
882 
883 /* Similar to copy_tree_r but do not copy SAVE_EXPR or TARGET_EXPR nodes.
884    These nodes model computations that must be done once.  If we were to
885    unshare something like SAVE_EXPR(i++), the gimplification process would
886    create wrong code.  However, if DATA is non-null, it must hold a pointer
887    set that is used to unshare the subtrees of these nodes.  */
888 
889 static tree
890 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
891 {
892   tree t = *tp;
893   enum tree_code code = TREE_CODE (t);
894 
895   /* Do not copy SAVE_EXPR, TARGET_EXPR or BIND_EXPR nodes themselves, but
896      copy their subtrees if we can make sure to do it only once.  */
897   if (code == SAVE_EXPR || code == TARGET_EXPR || code == BIND_EXPR)
898     {
899       if (data && !pointer_set_insert ((struct pointer_set_t *)data, t))
900 	;
901       else
902 	*walk_subtrees = 0;
903     }
904 
905   /* Stop at types, decls, constants like copy_tree_r.  */
906   else if (TREE_CODE_CLASS (code) == tcc_type
907 	   || TREE_CODE_CLASS (code) == tcc_declaration
908 	   || TREE_CODE_CLASS (code) == tcc_constant
909 	   /* We can't do anything sensible with a BLOCK used as an
910 	      expression, but we also can't just die when we see it
911 	      because of non-expression uses.  So we avert our eyes
912 	      and cross our fingers.  Silly Java.  */
913 	   || code == BLOCK)
914     *walk_subtrees = 0;
915 
916   /* Cope with the statement expression extension.  */
917   else if (code == STATEMENT_LIST)
918     ;
919 
920   /* Leave the bulk of the work to copy_tree_r itself.  */
921   else
922     copy_tree_r (tp, walk_subtrees, NULL);
923 
924   return NULL_TREE;
925 }
926 
927 /* Callback for walk_tree to unshare most of the shared trees rooted at *TP.
928    If *TP has been visited already, then *TP is deeply copied by calling
929    mostly_copy_tree_r.  DATA is passed to mostly_copy_tree_r unmodified.  */
930 
931 static tree
932 copy_if_shared_r (tree *tp, int *walk_subtrees, void *data)
933 {
934   tree t = *tp;
935   enum tree_code code = TREE_CODE (t);
936 
937   /* Skip types, decls, and constants.  But we do want to look at their
938      types and the bounds of types.  Mark them as visited so we properly
939      unmark their subtrees on the unmark pass.  If we've already seen them,
940      don't look down further.  */
941   if (TREE_CODE_CLASS (code) == tcc_type
942       || TREE_CODE_CLASS (code) == tcc_declaration
943       || TREE_CODE_CLASS (code) == tcc_constant)
944     {
945       if (TREE_VISITED (t))
946 	*walk_subtrees = 0;
947       else
948 	TREE_VISITED (t) = 1;
949     }
950 
951   /* If this node has been visited already, unshare it and don't look
952      any deeper.  */
953   else if (TREE_VISITED (t))
954     {
955       walk_tree (tp, mostly_copy_tree_r, data, NULL);
956       *walk_subtrees = 0;
957     }
958 
959   /* Otherwise, mark the node as visited and keep looking.  */
960   else
961     TREE_VISITED (t) = 1;
962 
963   return NULL_TREE;
964 }
965 
966 /* Unshare most of the shared trees rooted at *TP.  DATA is passed to the
967    copy_if_shared_r callback unmodified.  */
968 
969 static inline void
970 copy_if_shared (tree *tp, void *data)
971 {
972   walk_tree (tp, copy_if_shared_r, data, NULL);
973 }
974 
975 /* Unshare all the trees in the body of FNDECL, as well as in the bodies of
976    any nested functions.  */
977 
978 static void
979 unshare_body (tree fndecl)
980 {
981   struct cgraph_node *cgn = cgraph_get_node (fndecl);
982   /* If the language requires deep unsharing, we need a pointer set to make
983      sure we don't repeatedly unshare subtrees of unshareable nodes.  */
984   struct pointer_set_t *visited
985     = lang_hooks.deep_unsharing ? pointer_set_create () : NULL;
986 
987   copy_if_shared (&DECL_SAVED_TREE (fndecl), visited);
988   copy_if_shared (&DECL_SIZE (DECL_RESULT (fndecl)), visited);
989   copy_if_shared (&DECL_SIZE_UNIT (DECL_RESULT (fndecl)), visited);
990 
991   if (visited)
992     pointer_set_destroy (visited);
993 
994   if (cgn)
995     for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
996       unshare_body (cgn->decl);
997 }
998 
999 /* Callback for walk_tree to unmark the visited trees rooted at *TP.
1000    Subtrees are walked until the first unvisited node is encountered.  */
1001 
1002 static tree
1003 unmark_visited_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1004 {
1005   tree t = *tp;
1006 
1007   /* If this node has been visited, unmark it and keep looking.  */
1008   if (TREE_VISITED (t))
1009     TREE_VISITED (t) = 0;
1010 
1011   /* Otherwise, don't look any deeper.  */
1012   else
1013     *walk_subtrees = 0;
1014 
1015   return NULL_TREE;
1016 }
1017 
1018 /* Unmark the visited trees rooted at *TP.  */
1019 
1020 static inline void
1021 unmark_visited (tree *tp)
1022 {
1023   walk_tree (tp, unmark_visited_r, NULL, NULL);
1024 }
1025 
1026 /* Likewise, but mark all trees as not visited.  */
1027 
1028 static void
1029 unvisit_body (tree fndecl)
1030 {
1031   struct cgraph_node *cgn = cgraph_get_node (fndecl);
1032 
1033   unmark_visited (&DECL_SAVED_TREE (fndecl));
1034   unmark_visited (&DECL_SIZE (DECL_RESULT (fndecl)));
1035   unmark_visited (&DECL_SIZE_UNIT (DECL_RESULT (fndecl)));
1036 
1037   if (cgn)
1038     for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
1039       unvisit_body (cgn->decl);
1040 }
1041 
1042 /* Unconditionally make an unshared copy of EXPR.  This is used when using
1043    stored expressions which span multiple functions, such as BINFO_VTABLE,
1044    as the normal unsharing process can't tell that they're shared.  */
1045 
1046 tree
1047 unshare_expr (tree expr)
1048 {
1049   walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
1050   return expr;
1051 }
1052 
1053 /* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
1054    contain statements and have a value.  Assign its value to a temporary
1055    and give it void_type_node.  Return the temporary, or NULL_TREE if
1056    WRAPPER was already void.  */
1057 
1058 tree
1059 voidify_wrapper_expr (tree wrapper, tree temp)
1060 {
1061   tree type = TREE_TYPE (wrapper);
1062   if (type && !VOID_TYPE_P (type))
1063     {
1064       tree *p;
1065 
1066       /* Set p to point to the body of the wrapper.  Loop until we find
1067 	 something that isn't a wrapper.  */
1068       for (p = &wrapper; p && *p; )
1069 	{
1070 	  switch (TREE_CODE (*p))
1071 	    {
1072 	    case BIND_EXPR:
1073 	      TREE_SIDE_EFFECTS (*p) = 1;
1074 	      TREE_TYPE (*p) = void_type_node;
1075 	      /* For a BIND_EXPR, the body is operand 1.  */
1076 	      p = &BIND_EXPR_BODY (*p);
1077 	      break;
1078 
1079 	    case CLEANUP_POINT_EXPR:
1080 	    case TRY_FINALLY_EXPR:
1081 	    case TRY_CATCH_EXPR:
1082 	      TREE_SIDE_EFFECTS (*p) = 1;
1083 	      TREE_TYPE (*p) = void_type_node;
1084 	      p = &TREE_OPERAND (*p, 0);
1085 	      break;
1086 
1087 	    case STATEMENT_LIST:
1088 	      {
1089 		tree_stmt_iterator i = tsi_last (*p);
1090 		TREE_SIDE_EFFECTS (*p) = 1;
1091 		TREE_TYPE (*p) = void_type_node;
1092 		p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
1093 	      }
1094 	      break;
1095 
1096 	    case COMPOUND_EXPR:
1097 	      /* Advance to the last statement.  Set all container types to
1098 		 void.  */
1099 	      for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
1100 		{
1101 		  TREE_SIDE_EFFECTS (*p) = 1;
1102 		  TREE_TYPE (*p) = void_type_node;
1103 		}
1104 	      break;
1105 
1106 	    case TRANSACTION_EXPR:
1107 	      TREE_SIDE_EFFECTS (*p) = 1;
1108 	      TREE_TYPE (*p) = void_type_node;
1109 	      p = &TRANSACTION_EXPR_BODY (*p);
1110 	      break;
1111 
1112 	    default:
1113 	      /* Assume that any tree upon which voidify_wrapper_expr is
1114 		 directly called is a wrapper, and that its body is op0.  */
1115 	      if (p == &wrapper)
1116 		{
1117 		  TREE_SIDE_EFFECTS (*p) = 1;
1118 		  TREE_TYPE (*p) = void_type_node;
1119 		  p = &TREE_OPERAND (*p, 0);
1120 		  break;
1121 		}
1122 	      goto out;
1123 	    }
1124 	}
1125 
1126     out:
1127       if (p == NULL || IS_EMPTY_STMT (*p))
1128 	temp = NULL_TREE;
1129       else if (temp)
1130 	{
1131 	  /* The wrapper is on the RHS of an assignment that we're pushing
1132 	     down.  */
1133 	  gcc_assert (TREE_CODE (temp) == INIT_EXPR
1134 		      || TREE_CODE (temp) == MODIFY_EXPR);
1135 	  TREE_OPERAND (temp, 1) = *p;
1136 	  *p = temp;
1137 	}
1138       else
1139 	{
1140 	  temp = create_tmp_var (type, "retval");
1141 	  *p = build2 (INIT_EXPR, type, temp, *p);
1142 	}
1143 
1144       return temp;
1145     }
1146 
1147   return NULL_TREE;
1148 }
1149 
1150 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
1151    a temporary through which they communicate.  */
1152 
1153 static void
1154 build_stack_save_restore (gimple *save, gimple *restore)
1155 {
1156   tree tmp_var;
1157 
1158   *save = gimple_build_call (builtin_decl_implicit (BUILT_IN_STACK_SAVE), 0);
1159   tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
1160   gimple_call_set_lhs (*save, tmp_var);
1161 
1162   *restore
1163     = gimple_build_call (builtin_decl_implicit (BUILT_IN_STACK_RESTORE),
1164 			 1, tmp_var);
1165 }
1166 
1167 /* Gimplify a BIND_EXPR.  Just voidify and recurse.  */
1168 
1169 static enum gimplify_status
1170 gimplify_bind_expr (tree *expr_p, gimple_seq *pre_p)
1171 {
1172   tree bind_expr = *expr_p;
1173   bool old_save_stack = gimplify_ctxp->save_stack;
1174   tree t;
1175   gimple gimple_bind;
1176   gimple_seq body, cleanup;
1177   gimple stack_save;
1178 
1179   tree temp = voidify_wrapper_expr (bind_expr, NULL);
1180 
1181   /* Mark variables seen in this bind expr.  */
1182   for (t = BIND_EXPR_VARS (bind_expr); t ; t = DECL_CHAIN (t))
1183     {
1184       if (TREE_CODE (t) == VAR_DECL)
1185 	{
1186 	  struct gimplify_omp_ctx *ctx = gimplify_omp_ctxp;
1187 
1188 	  /* Mark variable as local.  */
1189 	  if (ctx && !DECL_EXTERNAL (t)
1190 	      && (! DECL_SEEN_IN_BIND_EXPR_P (t)
1191 		  || splay_tree_lookup (ctx->variables,
1192 					(splay_tree_key) t) == NULL))
1193 	    omp_add_variable (gimplify_omp_ctxp, t, GOVD_LOCAL | GOVD_SEEN);
1194 
1195 	  DECL_SEEN_IN_BIND_EXPR_P (t) = 1;
1196 
1197 	  if (DECL_HARD_REGISTER (t) && !is_global_var (t) && cfun)
1198 	    cfun->has_local_explicit_reg_vars = true;
1199 	}
1200 
1201       /* Preliminarily mark non-addressed complex variables as eligible
1202 	 for promotion to gimple registers.  We'll transform their uses
1203 	 as we find them.  */
1204       if ((TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE
1205 	   || TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
1206 	  && !TREE_THIS_VOLATILE (t)
1207 	  && (TREE_CODE (t) == VAR_DECL && !DECL_HARD_REGISTER (t))
1208 	  && !needs_to_live_in_memory (t))
1209 	DECL_GIMPLE_REG_P (t) = 1;
1210     }
1211 
1212   gimple_bind = gimple_build_bind (BIND_EXPR_VARS (bind_expr), NULL,
1213                                    BIND_EXPR_BLOCK (bind_expr));
1214   gimple_push_bind_expr (gimple_bind);
1215 
1216   gimplify_ctxp->save_stack = false;
1217 
1218   /* Gimplify the body into the GIMPLE_BIND tuple's body.  */
1219   body = NULL;
1220   gimplify_stmt (&BIND_EXPR_BODY (bind_expr), &body);
1221   gimple_bind_set_body (gimple_bind, body);
1222 
1223   cleanup = NULL;
1224   stack_save = NULL;
1225   if (gimplify_ctxp->save_stack)
1226     {
1227       gimple stack_restore;
1228 
1229       /* Save stack on entry and restore it on exit.  Add a try_finally
1230 	 block to achieve this.  Note that mudflap depends on the
1231 	 format of the emitted code: see mx_register_decls().  */
1232       build_stack_save_restore (&stack_save, &stack_restore);
1233 
1234       gimplify_seq_add_stmt (&cleanup, stack_restore);
1235     }
1236 
1237   /* Add clobbers for all variables that go out of scope.  */
1238   for (t = BIND_EXPR_VARS (bind_expr); t ; t = DECL_CHAIN (t))
1239     {
1240       if (TREE_CODE (t) == VAR_DECL
1241 	  && !is_global_var (t)
1242 	  && DECL_CONTEXT (t) == current_function_decl
1243 	  && !DECL_HARD_REGISTER (t)
1244 	  && !TREE_THIS_VOLATILE (t)
1245 	  && !DECL_HAS_VALUE_EXPR_P (t)
1246 	  /* Only care for variables that have to be in memory.  Others
1247 	     will be rewritten into SSA names, hence moved to the top-level.  */
1248 	  && !is_gimple_reg (t))
1249 	{
1250 	  tree clobber = build_constructor (TREE_TYPE (t), NULL);
1251 	  TREE_THIS_VOLATILE (clobber) = 1;
1252 	  gimplify_seq_add_stmt (&cleanup, gimple_build_assign (t, clobber));
1253 	}
1254     }
1255 
1256   if (cleanup)
1257     {
1258       gimple gs;
1259       gimple_seq new_body;
1260 
1261       new_body = NULL;
1262       gs = gimple_build_try (gimple_bind_body (gimple_bind), cleanup,
1263 	  		     GIMPLE_TRY_FINALLY);
1264 
1265       if (stack_save)
1266 	gimplify_seq_add_stmt (&new_body, stack_save);
1267       gimplify_seq_add_stmt (&new_body, gs);
1268       gimple_bind_set_body (gimple_bind, new_body);
1269     }
1270 
1271   gimplify_ctxp->save_stack = old_save_stack;
1272   gimple_pop_bind_expr ();
1273 
1274   gimplify_seq_add_stmt (pre_p, gimple_bind);
1275 
1276   if (temp)
1277     {
1278       *expr_p = temp;
1279       return GS_OK;
1280     }
1281 
1282   *expr_p = NULL_TREE;
1283   return GS_ALL_DONE;
1284 }
1285 
1286 /* Gimplify a RETURN_EXPR.  If the expression to be returned is not a
1287    GIMPLE value, it is assigned to a new temporary and the statement is
1288    re-written to return the temporary.
1289 
1290    PRE_P points to the sequence where side effects that must happen before
1291    STMT should be stored.  */
1292 
1293 static enum gimplify_status
1294 gimplify_return_expr (tree stmt, gimple_seq *pre_p)
1295 {
1296   gimple ret;
1297   tree ret_expr = TREE_OPERAND (stmt, 0);
1298   tree result_decl, result;
1299 
1300   if (ret_expr == error_mark_node)
1301     return GS_ERROR;
1302 
1303   if (!ret_expr
1304       || TREE_CODE (ret_expr) == RESULT_DECL
1305       || ret_expr == error_mark_node)
1306     {
1307       gimple ret = gimple_build_return (ret_expr);
1308       gimple_set_no_warning (ret, TREE_NO_WARNING (stmt));
1309       gimplify_seq_add_stmt (pre_p, ret);
1310       return GS_ALL_DONE;
1311     }
1312 
1313   if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
1314     result_decl = NULL_TREE;
1315   else
1316     {
1317       result_decl = TREE_OPERAND (ret_expr, 0);
1318 
1319       /* See through a return by reference.  */
1320       if (TREE_CODE (result_decl) == INDIRECT_REF)
1321 	result_decl = TREE_OPERAND (result_decl, 0);
1322 
1323       gcc_assert ((TREE_CODE (ret_expr) == MODIFY_EXPR
1324 		   || TREE_CODE (ret_expr) == INIT_EXPR)
1325 		  && TREE_CODE (result_decl) == RESULT_DECL);
1326     }
1327 
1328   /* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
1329      Recall that aggregate_value_p is FALSE for any aggregate type that is
1330      returned in registers.  If we're returning values in registers, then
1331      we don't want to extend the lifetime of the RESULT_DECL, particularly
1332      across another call.  In addition, for those aggregates for which
1333      hard_function_value generates a PARALLEL, we'll die during normal
1334      expansion of structure assignments; there's special code in expand_return
1335      to handle this case that does not exist in expand_expr.  */
1336   if (!result_decl)
1337     result = NULL_TREE;
1338   else if (aggregate_value_p (result_decl, TREE_TYPE (current_function_decl)))
1339     {
1340       if (TREE_CODE (DECL_SIZE (result_decl)) != INTEGER_CST)
1341 	{
1342 	  if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (result_decl)))
1343 	    gimplify_type_sizes (TREE_TYPE (result_decl), pre_p);
1344 	  /* Note that we don't use gimplify_vla_decl because the RESULT_DECL
1345 	     should be effectively allocated by the caller, i.e. all calls to
1346 	     this function must be subject to the Return Slot Optimization.  */
1347 	  gimplify_one_sizepos (&DECL_SIZE (result_decl), pre_p);
1348 	  gimplify_one_sizepos (&DECL_SIZE_UNIT (result_decl), pre_p);
1349 	}
1350       result = result_decl;
1351     }
1352   else if (gimplify_ctxp->return_temp)
1353     result = gimplify_ctxp->return_temp;
1354   else
1355     {
1356       result = create_tmp_reg (TREE_TYPE (result_decl), NULL);
1357 
1358       /* ??? With complex control flow (usually involving abnormal edges),
1359 	 we can wind up warning about an uninitialized value for this.  Due
1360 	 to how this variable is constructed and initialized, this is never
1361 	 true.  Give up and never warn.  */
1362       TREE_NO_WARNING (result) = 1;
1363 
1364       gimplify_ctxp->return_temp = result;
1365     }
1366 
1367   /* Smash the lhs of the MODIFY_EXPR to the temporary we plan to use.
1368      Then gimplify the whole thing.  */
1369   if (result != result_decl)
1370     TREE_OPERAND (ret_expr, 0) = result;
1371 
1372   gimplify_and_add (TREE_OPERAND (stmt, 0), pre_p);
1373 
1374   ret = gimple_build_return (result);
1375   gimple_set_no_warning (ret, TREE_NO_WARNING (stmt));
1376   gimplify_seq_add_stmt (pre_p, ret);
1377 
1378   return GS_ALL_DONE;
1379 }
1380 
1381 /* Gimplify a variable-length array DECL.  */
1382 
1383 static void
1384 gimplify_vla_decl (tree decl, gimple_seq *seq_p)
1385 {
1386   /* This is a variable-sized decl.  Simplify its size and mark it
1387      for deferred expansion.  Note that mudflap depends on the format
1388      of the emitted code: see mx_register_decls().  */
1389   tree t, addr, ptr_type;
1390 
1391   gimplify_one_sizepos (&DECL_SIZE (decl), seq_p);
1392   gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), seq_p);
1393 
1394   /* All occurrences of this decl in final gimplified code will be
1395      replaced by indirection.  Setting DECL_VALUE_EXPR does two
1396      things: First, it lets the rest of the gimplifier know what
1397      replacement to use.  Second, it lets the debug info know
1398      where to find the value.  */
1399   ptr_type = build_pointer_type (TREE_TYPE (decl));
1400   addr = create_tmp_var (ptr_type, get_name (decl));
1401   DECL_IGNORED_P (addr) = 0;
1402   t = build_fold_indirect_ref (addr);
1403   TREE_THIS_NOTRAP (t) = 1;
1404   SET_DECL_VALUE_EXPR (decl, t);
1405   DECL_HAS_VALUE_EXPR_P (decl) = 1;
1406 
1407   t = builtin_decl_explicit (BUILT_IN_ALLOCA_WITH_ALIGN);
1408   t = build_call_expr (t, 2, DECL_SIZE_UNIT (decl),
1409 		       size_int (DECL_ALIGN (decl)));
1410   /* The call has been built for a variable-sized object.  */
1411   CALL_ALLOCA_FOR_VAR_P (t) = 1;
1412   t = fold_convert (ptr_type, t);
1413   t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
1414 
1415   gimplify_and_add (t, seq_p);
1416 
1417   /* Indicate that we need to restore the stack level when the
1418      enclosing BIND_EXPR is exited.  */
1419   gimplify_ctxp->save_stack = true;
1420 }
1421 
1422 /* Gimplify a DECL_EXPR node *STMT_P by making any necessary allocation
1423    and initialization explicit.  */
1424 
1425 static enum gimplify_status
1426 gimplify_decl_expr (tree *stmt_p, gimple_seq *seq_p)
1427 {
1428   tree stmt = *stmt_p;
1429   tree decl = DECL_EXPR_DECL (stmt);
1430 
1431   *stmt_p = NULL_TREE;
1432 
1433   if (TREE_TYPE (decl) == error_mark_node)
1434     return GS_ERROR;
1435 
1436   if ((TREE_CODE (decl) == TYPE_DECL
1437        || TREE_CODE (decl) == VAR_DECL)
1438       && !TYPE_SIZES_GIMPLIFIED (TREE_TYPE (decl)))
1439     gimplify_type_sizes (TREE_TYPE (decl), seq_p);
1440 
1441   /* ??? DECL_ORIGINAL_TYPE is streamed for LTO so it needs to be gimplified
1442      in case its size expressions contain problematic nodes like CALL_EXPR.  */
1443   if (TREE_CODE (decl) == TYPE_DECL
1444       && DECL_ORIGINAL_TYPE (decl)
1445       && !TYPE_SIZES_GIMPLIFIED (DECL_ORIGINAL_TYPE (decl)))
1446     gimplify_type_sizes (DECL_ORIGINAL_TYPE (decl), seq_p);
1447 
1448   if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
1449     {
1450       tree init = DECL_INITIAL (decl);
1451 
1452       if (TREE_CODE (DECL_SIZE_UNIT (decl)) != INTEGER_CST
1453 	  || (!TREE_STATIC (decl)
1454 	      && flag_stack_check == GENERIC_STACK_CHECK
1455 	      && compare_tree_int (DECL_SIZE_UNIT (decl),
1456 				   STACK_CHECK_MAX_VAR_SIZE) > 0))
1457 	gimplify_vla_decl (decl, seq_p);
1458 
1459       /* Some front ends do not explicitly declare all anonymous
1460 	 artificial variables.  We compensate here by declaring the
1461 	 variables, though it would be better if the front ends would
1462 	 explicitly declare them.  */
1463       if (!DECL_SEEN_IN_BIND_EXPR_P (decl)
1464 	  && DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1465 	gimple_add_tmp_var (decl);
1466 
1467       if (init && init != error_mark_node)
1468 	{
1469 	  if (!TREE_STATIC (decl))
1470 	    {
1471 	      DECL_INITIAL (decl) = NULL_TREE;
1472 	      init = build2 (INIT_EXPR, void_type_node, decl, init);
1473 	      gimplify_and_add (init, seq_p);
1474 	      ggc_free (init);
1475 	    }
1476 	  else
1477 	    /* We must still examine initializers for static variables
1478 	       as they may contain a label address.  */
1479 	    walk_tree (&init, force_labels_r, NULL, NULL);
1480 	}
1481     }
1482 
1483   return GS_ALL_DONE;
1484 }
1485 
1486 /* Gimplify a LOOP_EXPR.  Normally this just involves gimplifying the body
1487    and replacing the LOOP_EXPR with goto, but if the loop contains an
1488    EXIT_EXPR, we need to append a label for it to jump to.  */
1489 
1490 static enum gimplify_status
1491 gimplify_loop_expr (tree *expr_p, gimple_seq *pre_p)
1492 {
1493   tree saved_label = gimplify_ctxp->exit_label;
1494   tree start_label = create_artificial_label (UNKNOWN_LOCATION);
1495 
1496   gimplify_seq_add_stmt (pre_p, gimple_build_label (start_label));
1497 
1498   gimplify_ctxp->exit_label = NULL_TREE;
1499 
1500   gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1501 
1502   gimplify_seq_add_stmt (pre_p, gimple_build_goto (start_label));
1503 
1504   if (gimplify_ctxp->exit_label)
1505     gimplify_seq_add_stmt (pre_p,
1506 			   gimple_build_label (gimplify_ctxp->exit_label));
1507 
1508   gimplify_ctxp->exit_label = saved_label;
1509 
1510   *expr_p = NULL;
1511   return GS_ALL_DONE;
1512 }
1513 
1514 /* Gimplify a statement list onto a sequence.  These may be created either
1515    by an enlightened front-end, or by shortcut_cond_expr.  */
1516 
1517 static enum gimplify_status
1518 gimplify_statement_list (tree *expr_p, gimple_seq *pre_p)
1519 {
1520   tree temp = voidify_wrapper_expr (*expr_p, NULL);
1521 
1522   tree_stmt_iterator i = tsi_start (*expr_p);
1523 
1524   while (!tsi_end_p (i))
1525     {
1526       gimplify_stmt (tsi_stmt_ptr (i), pre_p);
1527       tsi_delink (&i);
1528     }
1529 
1530   if (temp)
1531     {
1532       *expr_p = temp;
1533       return GS_OK;
1534     }
1535 
1536   return GS_ALL_DONE;
1537 }
1538 
1539 /* Compare two case labels.  Because the front end should already have
1540    made sure that case ranges do not overlap, it is enough to only compare
1541    the CASE_LOW values of each case label.  */
1542 
1543 static int
1544 compare_case_labels (const void *p1, const void *p2)
1545 {
1546   const_tree const case1 = *(const_tree const*)p1;
1547   const_tree const case2 = *(const_tree const*)p2;
1548 
1549   /* The 'default' case label always goes first.  */
1550   if (!CASE_LOW (case1))
1551     return -1;
1552   else if (!CASE_LOW (case2))
1553     return 1;
1554   else
1555     return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1556 }
1557 
1558 /* Sort the case labels in LABEL_VEC in place in ascending order.  */
1559 
1560 void
1561 sort_case_labels (VEC(tree,heap)* label_vec)
1562 {
1563   VEC_qsort (tree, label_vec, compare_case_labels);
1564 }
1565 
1566 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1567    branch to.  */
1568 
1569 static enum gimplify_status
1570 gimplify_switch_expr (tree *expr_p, gimple_seq *pre_p)
1571 {
1572   tree switch_expr = *expr_p;
1573   gimple_seq switch_body_seq = NULL;
1574   enum gimplify_status ret;
1575 
1576   ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL, is_gimple_val,
1577                        fb_rvalue);
1578   if (ret == GS_ERROR || ret == GS_UNHANDLED)
1579     return ret;
1580 
1581   if (SWITCH_BODY (switch_expr))
1582     {
1583       VEC (tree,heap) *labels;
1584       VEC (tree,heap) *saved_labels;
1585       tree default_case = NULL_TREE;
1586       size_t i, len;
1587       gimple gimple_switch;
1588 
1589       /* If someone can be bothered to fill in the labels, they can
1590 	 be bothered to null out the body too.  */
1591       gcc_assert (!SWITCH_LABELS (switch_expr));
1592 
1593       /* save old labels, get new ones from body, then restore the old
1594          labels.  Save all the things from the switch body to append after.  */
1595       saved_labels = gimplify_ctxp->case_labels;
1596       gimplify_ctxp->case_labels = VEC_alloc (tree, heap, 8);
1597 
1598       gimplify_stmt (&SWITCH_BODY (switch_expr), &switch_body_seq);
1599       labels = gimplify_ctxp->case_labels;
1600       gimplify_ctxp->case_labels = saved_labels;
1601 
1602       i = 0;
1603       while (i < VEC_length (tree, labels))
1604 	{
1605 	  tree elt = VEC_index (tree, labels, i);
1606 	  tree low = CASE_LOW (elt);
1607 	  bool remove_element = FALSE;
1608 
1609 	  if (low)
1610 	    {
1611 	      /* Discard empty ranges.  */
1612 	      tree high = CASE_HIGH (elt);
1613 	      if (high && tree_int_cst_lt (high, low))
1614 	        remove_element = TRUE;
1615 	    }
1616 	  else
1617 	    {
1618 	      /* The default case must be the last label in the list.  */
1619 	      gcc_assert (!default_case);
1620 	      default_case = elt;
1621 	      remove_element = TRUE;
1622 	    }
1623 
1624 	  if (remove_element)
1625 	    VEC_ordered_remove (tree, labels, i);
1626 	  else
1627 	    i++;
1628 	}
1629       len = i;
1630 
1631       if (!VEC_empty (tree, labels))
1632 	sort_case_labels (labels);
1633 
1634       if (!default_case)
1635 	{
1636 	  tree type = TREE_TYPE (switch_expr);
1637 
1638 	  /* If the switch has no default label, add one, so that we jump
1639 	     around the switch body.  If the labels already cover the whole
1640 	     range of type, add the default label pointing to one of the
1641 	     existing labels.  */
1642 	  if (type == void_type_node)
1643 	    type = TREE_TYPE (SWITCH_COND (switch_expr));
1644 	  if (len
1645 	      && INTEGRAL_TYPE_P (type)
1646 	      && TYPE_MIN_VALUE (type)
1647 	      && TYPE_MAX_VALUE (type)
1648 	      && tree_int_cst_equal (CASE_LOW (VEC_index (tree, labels, 0)),
1649 				     TYPE_MIN_VALUE (type)))
1650 	    {
1651 	      tree low, high = CASE_HIGH (VEC_index (tree, labels, len - 1));
1652 	      if (!high)
1653 		high = CASE_LOW (VEC_index (tree, labels, len - 1));
1654 	      if (tree_int_cst_equal (high, TYPE_MAX_VALUE (type)))
1655 		{
1656 		  for (i = 1; i < len; i++)
1657 		    {
1658 		      high = CASE_LOW (VEC_index (tree, labels, i));
1659 		      low = CASE_HIGH (VEC_index (tree, labels, i - 1));
1660 		      if (!low)
1661 			low = CASE_LOW (VEC_index (tree, labels, i - 1));
1662 		      if ((TREE_INT_CST_LOW (low) + 1
1663 			   != TREE_INT_CST_LOW (high))
1664 			  || (TREE_INT_CST_HIGH (low)
1665 			      + (TREE_INT_CST_LOW (high) == 0)
1666 			      != TREE_INT_CST_HIGH (high)))
1667 			break;
1668 		    }
1669 		  if (i == len)
1670 		    {
1671 		      tree label = CASE_LABEL (VEC_index (tree, labels, 0));
1672 		      default_case = build_case_label (NULL_TREE, NULL_TREE,
1673 						       label);
1674 		    }
1675 		}
1676 	    }
1677 
1678 	  if (!default_case)
1679 	    {
1680 	      gimple new_default;
1681 
1682 	      default_case
1683 		= build_case_label (NULL_TREE, NULL_TREE,
1684 				    create_artificial_label (UNKNOWN_LOCATION));
1685 	      new_default = gimple_build_label (CASE_LABEL (default_case));
1686 	      gimplify_seq_add_stmt (&switch_body_seq, new_default);
1687 	    }
1688 	}
1689 
1690       gimple_switch = gimple_build_switch_vec (SWITCH_COND (switch_expr),
1691                                                default_case, labels);
1692       gimplify_seq_add_stmt (pre_p, gimple_switch);
1693       gimplify_seq_add_seq (pre_p, switch_body_seq);
1694       VEC_free(tree, heap, labels);
1695     }
1696   else
1697     gcc_assert (SWITCH_LABELS (switch_expr));
1698 
1699   return GS_ALL_DONE;
1700 }
1701 
1702 /* Gimplify the CASE_LABEL_EXPR pointed to by EXPR_P.  */
1703 
1704 static enum gimplify_status
1705 gimplify_case_label_expr (tree *expr_p, gimple_seq *pre_p)
1706 {
1707   struct gimplify_ctx *ctxp;
1708   gimple gimple_label;
1709 
1710   /* Invalid OpenMP programs can play Duff's Device type games with
1711      #pragma omp parallel.  At least in the C front end, we don't
1712      detect such invalid branches until after gimplification.  */
1713   for (ctxp = gimplify_ctxp; ; ctxp = ctxp->prev_context)
1714     if (ctxp->case_labels)
1715       break;
1716 
1717   gimple_label = gimple_build_label (CASE_LABEL (*expr_p));
1718   VEC_safe_push (tree, heap, ctxp->case_labels, *expr_p);
1719   gimplify_seq_add_stmt (pre_p, gimple_label);
1720 
1721   return GS_ALL_DONE;
1722 }
1723 
1724 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1725    if necessary.  */
1726 
1727 tree
1728 build_and_jump (tree *label_p)
1729 {
1730   if (label_p == NULL)
1731     /* If there's nowhere to jump, just fall through.  */
1732     return NULL_TREE;
1733 
1734   if (*label_p == NULL_TREE)
1735     {
1736       tree label = create_artificial_label (UNKNOWN_LOCATION);
1737       *label_p = label;
1738     }
1739 
1740   return build1 (GOTO_EXPR, void_type_node, *label_p);
1741 }
1742 
1743 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1744    This also involves building a label to jump to and communicating it to
1745    gimplify_loop_expr through gimplify_ctxp->exit_label.  */
1746 
1747 static enum gimplify_status
1748 gimplify_exit_expr (tree *expr_p)
1749 {
1750   tree cond = TREE_OPERAND (*expr_p, 0);
1751   tree expr;
1752 
1753   expr = build_and_jump (&gimplify_ctxp->exit_label);
1754   expr = build3 (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1755   *expr_p = expr;
1756 
1757   return GS_OK;
1758 }
1759 
1760 /* A helper function to be called via walk_tree.  Mark all labels under *TP
1761    as being forced.  To be called for DECL_INITIAL of static variables.  */
1762 
1763 tree
1764 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1765 {
1766   if (TYPE_P (*tp))
1767     *walk_subtrees = 0;
1768   if (TREE_CODE (*tp) == LABEL_DECL)
1769     FORCED_LABEL (*tp) = 1;
1770 
1771   return NULL_TREE;
1772 }
1773 
1774 /* *EXPR_P is a COMPONENT_REF being used as an rvalue.  If its type is
1775    different from its canonical type, wrap the whole thing inside a
1776    NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1777    type.
1778 
1779    The canonical type of a COMPONENT_REF is the type of the field being
1780    referenced--unless the field is a bit-field which can be read directly
1781    in a smaller mode, in which case the canonical type is the
1782    sign-appropriate type corresponding to that mode.  */
1783 
1784 static void
1785 canonicalize_component_ref (tree *expr_p)
1786 {
1787   tree expr = *expr_p;
1788   tree type;
1789 
1790   gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1791 
1792   if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1793     type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1794   else
1795     type = TREE_TYPE (TREE_OPERAND (expr, 1));
1796 
1797   /* One could argue that all the stuff below is not necessary for
1798      the non-bitfield case and declare it a FE error if type
1799      adjustment would be needed.  */
1800   if (TREE_TYPE (expr) != type)
1801     {
1802 #ifdef ENABLE_TYPES_CHECKING
1803       tree old_type = TREE_TYPE (expr);
1804 #endif
1805       int type_quals;
1806 
1807       /* We need to preserve qualifiers and propagate them from
1808 	 operand 0.  */
1809       type_quals = TYPE_QUALS (type)
1810 	| TYPE_QUALS (TREE_TYPE (TREE_OPERAND (expr, 0)));
1811       if (TYPE_QUALS (type) != type_quals)
1812 	type = build_qualified_type (TYPE_MAIN_VARIANT (type), type_quals);
1813 
1814       /* Set the type of the COMPONENT_REF to the underlying type.  */
1815       TREE_TYPE (expr) = type;
1816 
1817 #ifdef ENABLE_TYPES_CHECKING
1818       /* It is now a FE error, if the conversion from the canonical
1819 	 type to the original expression type is not useless.  */
1820       gcc_assert (useless_type_conversion_p (old_type, type));
1821 #endif
1822     }
1823 }
1824 
1825 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1826    to foo, embed that change in the ADDR_EXPR by converting
1827       T array[U];
1828       (T *)&array
1829    ==>
1830       &array[L]
1831    where L is the lower bound.  For simplicity, only do this for constant
1832    lower bound.
1833    The constraint is that the type of &array[L] is trivially convertible
1834    to T *.  */
1835 
1836 static void
1837 canonicalize_addr_expr (tree *expr_p)
1838 {
1839   tree expr = *expr_p;
1840   tree addr_expr = TREE_OPERAND (expr, 0);
1841   tree datype, ddatype, pddatype;
1842 
1843   /* We simplify only conversions from an ADDR_EXPR to a pointer type.  */
1844   if (!POINTER_TYPE_P (TREE_TYPE (expr))
1845       || TREE_CODE (addr_expr) != ADDR_EXPR)
1846     return;
1847 
1848   /* The addr_expr type should be a pointer to an array.  */
1849   datype = TREE_TYPE (TREE_TYPE (addr_expr));
1850   if (TREE_CODE (datype) != ARRAY_TYPE)
1851     return;
1852 
1853   /* The pointer to element type shall be trivially convertible to
1854      the expression pointer type.  */
1855   ddatype = TREE_TYPE (datype);
1856   pddatype = build_pointer_type (ddatype);
1857   if (!useless_type_conversion_p (TYPE_MAIN_VARIANT (TREE_TYPE (expr)),
1858 				  pddatype))
1859     return;
1860 
1861   /* The lower bound and element sizes must be constant.  */
1862   if (!TYPE_SIZE_UNIT (ddatype)
1863       || TREE_CODE (TYPE_SIZE_UNIT (ddatype)) != INTEGER_CST
1864       || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1865       || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1866     return;
1867 
1868   /* All checks succeeded.  Build a new node to merge the cast.  */
1869   *expr_p = build4 (ARRAY_REF, ddatype, TREE_OPERAND (addr_expr, 0),
1870 		    TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1871 		    NULL_TREE, NULL_TREE);
1872   *expr_p = build1 (ADDR_EXPR, pddatype, *expr_p);
1873 
1874   /* We can have stripped a required restrict qualifier above.  */
1875   if (!useless_type_conversion_p (TREE_TYPE (expr), TREE_TYPE (*expr_p)))
1876     *expr_p = fold_convert (TREE_TYPE (expr), *expr_p);
1877 }
1878 
1879 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR.  Remove it and/or other conversions
1880    underneath as appropriate.  */
1881 
1882 static enum gimplify_status
1883 gimplify_conversion (tree *expr_p)
1884 {
1885   location_t loc = EXPR_LOCATION (*expr_p);
1886   gcc_assert (CONVERT_EXPR_P (*expr_p));
1887 
1888   /* Then strip away all but the outermost conversion.  */
1889   STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1890 
1891   /* And remove the outermost conversion if it's useless.  */
1892   if (tree_ssa_useless_type_conversion (*expr_p))
1893     *expr_p = TREE_OPERAND (*expr_p, 0);
1894 
1895   /* If we still have a conversion at the toplevel,
1896      then canonicalize some constructs.  */
1897   if (CONVERT_EXPR_P (*expr_p))
1898     {
1899       tree sub = TREE_OPERAND (*expr_p, 0);
1900 
1901       /* If a NOP conversion is changing the type of a COMPONENT_REF
1902 	 expression, then canonicalize its type now in order to expose more
1903 	 redundant conversions.  */
1904       if (TREE_CODE (sub) == COMPONENT_REF)
1905 	canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1906 
1907       /* If a NOP conversion is changing a pointer to array of foo
1908 	 to a pointer to foo, embed that change in the ADDR_EXPR.  */
1909       else if (TREE_CODE (sub) == ADDR_EXPR)
1910 	canonicalize_addr_expr (expr_p);
1911     }
1912 
1913   /* If we have a conversion to a non-register type force the
1914      use of a VIEW_CONVERT_EXPR instead.  */
1915   if (CONVERT_EXPR_P (*expr_p) && !is_gimple_reg_type (TREE_TYPE (*expr_p)))
1916     *expr_p = fold_build1_loc (loc, VIEW_CONVERT_EXPR, TREE_TYPE (*expr_p),
1917 			       TREE_OPERAND (*expr_p, 0));
1918 
1919   return GS_OK;
1920 }
1921 
1922 /* Nonlocal VLAs seen in the current function.  */
1923 static struct pointer_set_t *nonlocal_vlas;
1924 
1925 /* Gimplify a VAR_DECL or PARM_DECL.  Return GS_OK if we expanded a
1926    DECL_VALUE_EXPR, and it's worth re-examining things.  */
1927 
1928 static enum gimplify_status
1929 gimplify_var_or_parm_decl (tree *expr_p)
1930 {
1931   tree decl = *expr_p;
1932 
1933   /* ??? If this is a local variable, and it has not been seen in any
1934      outer BIND_EXPR, then it's probably the result of a duplicate
1935      declaration, for which we've already issued an error.  It would
1936      be really nice if the front end wouldn't leak these at all.
1937      Currently the only known culprit is C++ destructors, as seen
1938      in g++.old-deja/g++.jason/binding.C.  */
1939   if (TREE_CODE (decl) == VAR_DECL
1940       && !DECL_SEEN_IN_BIND_EXPR_P (decl)
1941       && !TREE_STATIC (decl) && !DECL_EXTERNAL (decl)
1942       && decl_function_context (decl) == current_function_decl)
1943     {
1944       gcc_assert (seen_error ());
1945       return GS_ERROR;
1946     }
1947 
1948   /* When within an OpenMP context, notice uses of variables.  */
1949   if (gimplify_omp_ctxp && omp_notice_variable (gimplify_omp_ctxp, decl, true))
1950     return GS_ALL_DONE;
1951 
1952   /* If the decl is an alias for another expression, substitute it now.  */
1953   if (DECL_HAS_VALUE_EXPR_P (decl))
1954     {
1955       tree value_expr = DECL_VALUE_EXPR (decl);
1956 
1957       /* For referenced nonlocal VLAs add a decl for debugging purposes
1958 	 to the current function.  */
1959       if (TREE_CODE (decl) == VAR_DECL
1960 	  && TREE_CODE (DECL_SIZE_UNIT (decl)) != INTEGER_CST
1961 	  && nonlocal_vlas != NULL
1962 	  && TREE_CODE (value_expr) == INDIRECT_REF
1963 	  && TREE_CODE (TREE_OPERAND (value_expr, 0)) == VAR_DECL
1964 	  && decl_function_context (decl) != current_function_decl)
1965 	{
1966 	  struct gimplify_omp_ctx *ctx = gimplify_omp_ctxp;
1967 	  while (ctx && ctx->region_type == ORT_WORKSHARE)
1968 	    ctx = ctx->outer_context;
1969 	  if (!ctx && !pointer_set_insert (nonlocal_vlas, decl))
1970 	    {
1971 	      tree copy = copy_node (decl), block;
1972 
1973 	      lang_hooks.dup_lang_specific_decl (copy);
1974 	      SET_DECL_RTL (copy, 0);
1975 	      TREE_USED (copy) = 1;
1976 	      block = DECL_INITIAL (current_function_decl);
1977 	      DECL_CHAIN (copy) = BLOCK_VARS (block);
1978 	      BLOCK_VARS (block) = copy;
1979 	      SET_DECL_VALUE_EXPR (copy, unshare_expr (value_expr));
1980 	      DECL_HAS_VALUE_EXPR_P (copy) = 1;
1981 	    }
1982 	}
1983 
1984       *expr_p = unshare_expr (value_expr);
1985       return GS_OK;
1986     }
1987 
1988   return GS_ALL_DONE;
1989 }
1990 
1991 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1992    node *EXPR_P.
1993 
1994       compound_lval
1995 	      : min_lval '[' val ']'
1996 	      | min_lval '.' ID
1997 	      | compound_lval '[' val ']'
1998 	      | compound_lval '.' ID
1999 
2000    This is not part of the original SIMPLE definition, which separates
2001    array and member references, but it seems reasonable to handle them
2002    together.  Also, this way we don't run into problems with union
2003    aliasing; gcc requires that for accesses through a union to alias, the
2004    union reference must be explicit, which was not always the case when we
2005    were splitting up array and member refs.
2006 
2007    PRE_P points to the sequence where side effects that must happen before
2008      *EXPR_P should be stored.
2009 
2010    POST_P points to the sequence where side effects that must happen after
2011      *EXPR_P should be stored.  */
2012 
2013 static enum gimplify_status
2014 gimplify_compound_lval (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
2015 			fallback_t fallback)
2016 {
2017   tree *p;
2018   VEC(tree,heap) *stack;
2019   enum gimplify_status ret = GS_ALL_DONE, tret;
2020   int i;
2021   location_t loc = EXPR_LOCATION (*expr_p);
2022   tree expr = *expr_p;
2023 
2024   /* Create a stack of the subexpressions so later we can walk them in
2025      order from inner to outer.  */
2026   stack = VEC_alloc (tree, heap, 10);
2027 
2028   /* We can handle anything that get_inner_reference can deal with.  */
2029   for (p = expr_p; ; p = &TREE_OPERAND (*p, 0))
2030     {
2031     restart:
2032       /* Fold INDIRECT_REFs now to turn them into ARRAY_REFs.  */
2033       if (TREE_CODE (*p) == INDIRECT_REF)
2034 	*p = fold_indirect_ref_loc (loc, *p);
2035 
2036       if (handled_component_p (*p))
2037 	;
2038       /* Expand DECL_VALUE_EXPR now.  In some cases that may expose
2039 	 additional COMPONENT_REFs.  */
2040       else if ((TREE_CODE (*p) == VAR_DECL || TREE_CODE (*p) == PARM_DECL)
2041 	       && gimplify_var_or_parm_decl (p) == GS_OK)
2042 	goto restart;
2043       else
2044 	break;
2045 
2046       VEC_safe_push (tree, heap, stack, *p);
2047     }
2048 
2049   gcc_assert (VEC_length (tree, stack));
2050 
2051   /* Now STACK is a stack of pointers to all the refs we've walked through
2052      and P points to the innermost expression.
2053 
2054      Java requires that we elaborated nodes in source order.  That
2055      means we must gimplify the inner expression followed by each of
2056      the indices, in order.  But we can't gimplify the inner
2057      expression until we deal with any variable bounds, sizes, or
2058      positions in order to deal with PLACEHOLDER_EXPRs.
2059 
2060      So we do this in three steps.  First we deal with the annotations
2061      for any variables in the components, then we gimplify the base,
2062      then we gimplify any indices, from left to right.  */
2063   for (i = VEC_length (tree, stack) - 1; i >= 0; i--)
2064     {
2065       tree t = VEC_index (tree, stack, i);
2066 
2067       if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
2068 	{
2069 	  /* Gimplify the low bound and element type size and put them into
2070 	     the ARRAY_REF.  If these values are set, they have already been
2071 	     gimplified.  */
2072 	  if (TREE_OPERAND (t, 2) == NULL_TREE)
2073 	    {
2074 	      tree low = unshare_expr (array_ref_low_bound (t));
2075 	      if (!is_gimple_min_invariant (low))
2076 		{
2077 		  TREE_OPERAND (t, 2) = low;
2078 		  tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p,
2079 					post_p, is_gimple_reg,
2080 					fb_rvalue);
2081 		  ret = MIN (ret, tret);
2082 		}
2083 	    }
2084 	  else
2085 	    {
2086 	      tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
2087 				    is_gimple_reg, fb_rvalue);
2088 	      ret = MIN (ret, tret);
2089 	    }
2090 
2091 	  if (TREE_OPERAND (t, 3) == NULL_TREE)
2092 	    {
2093 	      tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
2094 	      tree elmt_size = unshare_expr (array_ref_element_size (t));
2095 	      tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
2096 
2097 	      /* Divide the element size by the alignment of the element
2098 		 type (above).  */
2099 	      elmt_size
2100 		= size_binop_loc (loc, EXACT_DIV_EXPR, elmt_size, factor);
2101 
2102 	      if (!is_gimple_min_invariant (elmt_size))
2103 		{
2104 		  TREE_OPERAND (t, 3) = elmt_size;
2105 		  tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p,
2106 					post_p, is_gimple_reg,
2107 					fb_rvalue);
2108 		  ret = MIN (ret, tret);
2109 		}
2110 	    }
2111 	  else
2112 	    {
2113 	      tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
2114 				    is_gimple_reg, fb_rvalue);
2115 	      ret = MIN (ret, tret);
2116 	    }
2117 	}
2118       else if (TREE_CODE (t) == COMPONENT_REF)
2119 	{
2120 	  /* Set the field offset into T and gimplify it.  */
2121 	  if (TREE_OPERAND (t, 2) == NULL_TREE)
2122 	    {
2123 	      tree offset = unshare_expr (component_ref_field_offset (t));
2124 	      tree field = TREE_OPERAND (t, 1);
2125 	      tree factor
2126 		= size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
2127 
2128 	      /* Divide the offset by its alignment.  */
2129 	      offset = size_binop_loc (loc, EXACT_DIV_EXPR, offset, factor);
2130 
2131 	      if (!is_gimple_min_invariant (offset))
2132 		{
2133 		  TREE_OPERAND (t, 2) = offset;
2134 		  tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p,
2135 					post_p, is_gimple_reg,
2136 					fb_rvalue);
2137 		  ret = MIN (ret, tret);
2138 		}
2139 	    }
2140 	  else
2141 	    {
2142 	      tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
2143 				    is_gimple_reg, fb_rvalue);
2144 	      ret = MIN (ret, tret);
2145 	    }
2146 	}
2147     }
2148 
2149   /* Step 2 is to gimplify the base expression.  Make sure lvalue is set
2150      so as to match the min_lval predicate.  Failure to do so may result
2151      in the creation of large aggregate temporaries.  */
2152   tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval,
2153 			fallback | fb_lvalue);
2154   ret = MIN (ret, tret);
2155 
2156   /* And finally, the indices and operands to BIT_FIELD_REF.  During this
2157      loop we also remove any useless conversions.  */
2158   for (; VEC_length (tree, stack) > 0; )
2159     {
2160       tree t = VEC_pop (tree, stack);
2161 
2162       if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
2163 	{
2164 	  /* Gimplify the dimension.  */
2165 	  if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
2166 	    {
2167 	      tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
2168 				    is_gimple_val, fb_rvalue);
2169 	      ret = MIN (ret, tret);
2170 	    }
2171 	}
2172       else if (TREE_CODE (t) == BIT_FIELD_REF)
2173 	{
2174 	  tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
2175 				is_gimple_val, fb_rvalue);
2176 	  ret = MIN (ret, tret);
2177 	  tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
2178 				is_gimple_val, fb_rvalue);
2179 	  ret = MIN (ret, tret);
2180 	}
2181 
2182       STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
2183 
2184       /* The innermost expression P may have originally had
2185 	 TREE_SIDE_EFFECTS set which would have caused all the outer
2186 	 expressions in *EXPR_P leading to P to also have had
2187 	 TREE_SIDE_EFFECTS set.  */
2188       recalculate_side_effects (t);
2189     }
2190 
2191   /* If the outermost expression is a COMPONENT_REF, canonicalize its type.  */
2192   if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
2193     {
2194       canonicalize_component_ref (expr_p);
2195     }
2196 
2197   VEC_free (tree, heap, stack);
2198 
2199   gcc_assert (*expr_p == expr || ret != GS_ALL_DONE);
2200 
2201   return ret;
2202 }
2203 
2204 /*  Gimplify the self modifying expression pointed to by EXPR_P
2205     (++, --, +=, -=).
2206 
2207     PRE_P points to the list where side effects that must happen before
2208 	*EXPR_P should be stored.
2209 
2210     POST_P points to the list where side effects that must happen after
2211 	*EXPR_P should be stored.
2212 
2213     WANT_VALUE is nonzero iff we want to use the value of this expression
2214 	in another expression.  */
2215 
2216 static enum gimplify_status
2217 gimplify_self_mod_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
2218 			bool want_value)
2219 {
2220   enum tree_code code;
2221   tree lhs, lvalue, rhs, t1;
2222   gimple_seq post = NULL, *orig_post_p = post_p;
2223   bool postfix;
2224   enum tree_code arith_code;
2225   enum gimplify_status ret;
2226   location_t loc = EXPR_LOCATION (*expr_p);
2227 
2228   code = TREE_CODE (*expr_p);
2229 
2230   gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
2231 	      || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
2232 
2233   /* Prefix or postfix?  */
2234   if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
2235     /* Faster to treat as prefix if result is not used.  */
2236     postfix = want_value;
2237   else
2238     postfix = false;
2239 
2240   /* For postfix, make sure the inner expression's post side effects
2241      are executed after side effects from this expression.  */
2242   if (postfix)
2243     post_p = &post;
2244 
2245   /* Add or subtract?  */
2246   if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2247     arith_code = PLUS_EXPR;
2248   else
2249     arith_code = MINUS_EXPR;
2250 
2251   /* Gimplify the LHS into a GIMPLE lvalue.  */
2252   lvalue = TREE_OPERAND (*expr_p, 0);
2253   ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2254   if (ret == GS_ERROR)
2255     return ret;
2256 
2257   /* Extract the operands to the arithmetic operation.  */
2258   lhs = lvalue;
2259   rhs = TREE_OPERAND (*expr_p, 1);
2260 
2261   /* For postfix operator, we evaluate the LHS to an rvalue and then use
2262      that as the result value and in the postqueue operation.  We also
2263      make sure to make lvalue a minimal lval, see
2264      gcc.c-torture/execute/20040313-1.c for an example where this matters.  */
2265   if (postfix)
2266     {
2267       if (!is_gimple_min_lval (lvalue))
2268 	{
2269 	  mark_addressable (lvalue);
2270 	  lvalue = build_fold_addr_expr_loc (input_location, lvalue);
2271 	  gimplify_expr (&lvalue, pre_p, post_p, is_gimple_val, fb_rvalue);
2272 	  lvalue = build_fold_indirect_ref_loc (input_location, lvalue);
2273 	}
2274       ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
2275       if (ret == GS_ERROR)
2276 	return ret;
2277     }
2278 
2279   /* For POINTERs increment, use POINTER_PLUS_EXPR.  */
2280   if (POINTER_TYPE_P (TREE_TYPE (lhs)))
2281     {
2282       rhs = convert_to_ptrofftype_loc (loc, rhs);
2283       if (arith_code == MINUS_EXPR)
2284 	rhs = fold_build1_loc (loc, NEGATE_EXPR, TREE_TYPE (rhs), rhs);
2285       arith_code = POINTER_PLUS_EXPR;
2286     }
2287 
2288   t1 = build2 (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
2289 
2290   if (postfix)
2291     {
2292       gimplify_assign (lvalue, t1, orig_post_p);
2293       gimplify_seq_add_seq (orig_post_p, post);
2294       *expr_p = lhs;
2295       return GS_ALL_DONE;
2296     }
2297   else
2298     {
2299       *expr_p = build2 (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
2300       return GS_OK;
2301     }
2302 }
2303 
2304 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR.  */
2305 
2306 static void
2307 maybe_with_size_expr (tree *expr_p)
2308 {
2309   tree expr = *expr_p;
2310   tree type = TREE_TYPE (expr);
2311   tree size;
2312 
2313   /* If we've already wrapped this or the type is error_mark_node, we can't do
2314      anything.  */
2315   if (TREE_CODE (expr) == WITH_SIZE_EXPR
2316       || type == error_mark_node)
2317     return;
2318 
2319   /* If the size isn't known or is a constant, we have nothing to do.  */
2320   size = TYPE_SIZE_UNIT (type);
2321   if (!size || TREE_CODE (size) == INTEGER_CST)
2322     return;
2323 
2324   /* Otherwise, make a WITH_SIZE_EXPR.  */
2325   size = unshare_expr (size);
2326   size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
2327   *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
2328 }
2329 
2330 /* Helper for gimplify_call_expr.  Gimplify a single argument *ARG_P
2331    Store any side-effects in PRE_P.  CALL_LOCATION is the location of
2332    the CALL_EXPR.  */
2333 
2334 static enum gimplify_status
2335 gimplify_arg (tree *arg_p, gimple_seq *pre_p, location_t call_location)
2336 {
2337   bool (*test) (tree);
2338   fallback_t fb;
2339 
2340   /* In general, we allow lvalues for function arguments to avoid
2341      extra overhead of copying large aggregates out of even larger
2342      aggregates into temporaries only to copy the temporaries to
2343      the argument list.  Make optimizers happy by pulling out to
2344      temporaries those types that fit in registers.  */
2345   if (is_gimple_reg_type (TREE_TYPE (*arg_p)))
2346     test = is_gimple_val, fb = fb_rvalue;
2347   else
2348     {
2349       test = is_gimple_lvalue, fb = fb_either;
2350       /* Also strip a TARGET_EXPR that would force an extra copy.  */
2351       if (TREE_CODE (*arg_p) == TARGET_EXPR)
2352 	{
2353 	  tree init = TARGET_EXPR_INITIAL (*arg_p);
2354 	  if (init
2355 	      && !VOID_TYPE_P (TREE_TYPE (init)))
2356 	    *arg_p = init;
2357 	}
2358     }
2359 
2360   /* If this is a variable sized type, we must remember the size.  */
2361   maybe_with_size_expr (arg_p);
2362 
2363   /* FIXME diagnostics: This will mess up gcc.dg/Warray-bounds.c.  */
2364   /* Make sure arguments have the same location as the function call
2365      itself.  */
2366   protected_set_expr_location (*arg_p, call_location);
2367 
2368   /* There is a sequence point before a function call.  Side effects in
2369      the argument list must occur before the actual call. So, when
2370      gimplifying arguments, force gimplify_expr to use an internal
2371      post queue which is then appended to the end of PRE_P.  */
2372   return gimplify_expr (arg_p, pre_p, NULL, test, fb);
2373 }
2374 
2375 /* Gimplify the CALL_EXPR node *EXPR_P into the GIMPLE sequence PRE_P.
2376    WANT_VALUE is true if the result of the call is desired.  */
2377 
2378 static enum gimplify_status
2379 gimplify_call_expr (tree *expr_p, gimple_seq *pre_p, bool want_value)
2380 {
2381   tree fndecl, parms, p, fnptrtype;
2382   enum gimplify_status ret;
2383   int i, nargs;
2384   gimple call;
2385   bool builtin_va_start_p = FALSE;
2386   location_t loc = EXPR_LOCATION (*expr_p);
2387 
2388   gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
2389 
2390   /* For reliable diagnostics during inlining, it is necessary that
2391      every call_expr be annotated with file and line.  */
2392   if (! EXPR_HAS_LOCATION (*expr_p))
2393     SET_EXPR_LOCATION (*expr_p, input_location);
2394 
2395   /* This may be a call to a builtin function.
2396 
2397      Builtin function calls may be transformed into different
2398      (and more efficient) builtin function calls under certain
2399      circumstances.  Unfortunately, gimplification can muck things
2400      up enough that the builtin expanders are not aware that certain
2401      transformations are still valid.
2402 
2403      So we attempt transformation/gimplification of the call before
2404      we gimplify the CALL_EXPR.  At this time we do not manage to
2405      transform all calls in the same manner as the expanders do, but
2406      we do transform most of them.  */
2407   fndecl = get_callee_fndecl (*expr_p);
2408   if (fndecl && DECL_BUILT_IN (fndecl))
2409     {
2410       tree new_tree = fold_call_expr (input_location, *expr_p, !want_value);
2411 
2412       if (new_tree && new_tree != *expr_p)
2413 	{
2414 	  /* There was a transformation of this call which computes the
2415 	     same value, but in a more efficient way.  Return and try
2416 	     again.  */
2417 	  *expr_p = new_tree;
2418 	  return GS_OK;
2419 	}
2420 
2421       if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
2422 	  && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_VA_START)
2423         {
2424 	  builtin_va_start_p = TRUE;
2425 	  if (call_expr_nargs (*expr_p) < 2)
2426 	    {
2427 	      error ("too few arguments to function %<va_start%>");
2428 	      *expr_p = build_empty_stmt (EXPR_LOCATION (*expr_p));
2429 	      return GS_OK;
2430 	    }
2431 
2432 	  if (fold_builtin_next_arg (*expr_p, true))
2433 	    {
2434 	      *expr_p = build_empty_stmt (EXPR_LOCATION (*expr_p));
2435 	      return GS_OK;
2436 	    }
2437 	}
2438     }
2439 
2440   /* Remember the original function pointer type.  */
2441   fnptrtype = TREE_TYPE (CALL_EXPR_FN (*expr_p));
2442 
2443   /* There is a sequence point before the call, so any side effects in
2444      the calling expression must occur before the actual call.  Force
2445      gimplify_expr to use an internal post queue.  */
2446   ret = gimplify_expr (&CALL_EXPR_FN (*expr_p), pre_p, NULL,
2447 		       is_gimple_call_addr, fb_rvalue);
2448 
2449   nargs = call_expr_nargs (*expr_p);
2450 
2451   /* Get argument types for verification.  */
2452   fndecl = get_callee_fndecl (*expr_p);
2453   parms = NULL_TREE;
2454   if (fndecl)
2455     parms = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
2456   else if (POINTER_TYPE_P (TREE_TYPE (CALL_EXPR_FN (*expr_p))))
2457     parms = TYPE_ARG_TYPES (TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (*expr_p))));
2458 
2459   if (fndecl && DECL_ARGUMENTS (fndecl))
2460     p = DECL_ARGUMENTS (fndecl);
2461   else if (parms)
2462     p = parms;
2463   else
2464     p = NULL_TREE;
2465   for (i = 0; i < nargs && p; i++, p = TREE_CHAIN (p))
2466     ;
2467 
2468   /* If the last argument is __builtin_va_arg_pack () and it is not
2469      passed as a named argument, decrease the number of CALL_EXPR
2470      arguments and set instead the CALL_EXPR_VA_ARG_PACK flag.  */
2471   if (!p
2472       && i < nargs
2473       && TREE_CODE (CALL_EXPR_ARG (*expr_p, nargs - 1)) == CALL_EXPR)
2474     {
2475       tree last_arg = CALL_EXPR_ARG (*expr_p, nargs - 1);
2476       tree last_arg_fndecl = get_callee_fndecl (last_arg);
2477 
2478       if (last_arg_fndecl
2479 	  && TREE_CODE (last_arg_fndecl) == FUNCTION_DECL
2480 	  && DECL_BUILT_IN_CLASS (last_arg_fndecl) == BUILT_IN_NORMAL
2481 	  && DECL_FUNCTION_CODE (last_arg_fndecl) == BUILT_IN_VA_ARG_PACK)
2482 	{
2483 	  tree call = *expr_p;
2484 
2485 	  --nargs;
2486 	  *expr_p = build_call_array_loc (loc, TREE_TYPE (call),
2487 					  CALL_EXPR_FN (call),
2488 					  nargs, CALL_EXPR_ARGP (call));
2489 
2490 	  /* Copy all CALL_EXPR flags, location and block, except
2491 	     CALL_EXPR_VA_ARG_PACK flag.  */
2492 	  CALL_EXPR_STATIC_CHAIN (*expr_p) = CALL_EXPR_STATIC_CHAIN (call);
2493 	  CALL_EXPR_TAILCALL (*expr_p) = CALL_EXPR_TAILCALL (call);
2494 	  CALL_EXPR_RETURN_SLOT_OPT (*expr_p)
2495 	    = CALL_EXPR_RETURN_SLOT_OPT (call);
2496 	  CALL_FROM_THUNK_P (*expr_p) = CALL_FROM_THUNK_P (call);
2497 	  SET_EXPR_LOCATION (*expr_p, EXPR_LOCATION (call));
2498 	  TREE_BLOCK (*expr_p) = TREE_BLOCK (call);
2499 
2500 	  /* Set CALL_EXPR_VA_ARG_PACK.  */
2501 	  CALL_EXPR_VA_ARG_PACK (*expr_p) = 1;
2502 	}
2503     }
2504 
2505   /* Finally, gimplify the function arguments.  */
2506   if (nargs > 0)
2507     {
2508       for (i = (PUSH_ARGS_REVERSED ? nargs - 1 : 0);
2509            PUSH_ARGS_REVERSED ? i >= 0 : i < nargs;
2510            PUSH_ARGS_REVERSED ? i-- : i++)
2511         {
2512           enum gimplify_status t;
2513 
2514           /* Avoid gimplifying the second argument to va_start, which needs to
2515              be the plain PARM_DECL.  */
2516           if ((i != 1) || !builtin_va_start_p)
2517             {
2518               t = gimplify_arg (&CALL_EXPR_ARG (*expr_p, i), pre_p,
2519 				EXPR_LOCATION (*expr_p));
2520 
2521               if (t == GS_ERROR)
2522                 ret = GS_ERROR;
2523             }
2524         }
2525     }
2526 
2527   /* Verify the function result.  */
2528   if (want_value && fndecl
2529       && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fnptrtype))))
2530     {
2531       error_at (loc, "using result of function returning %<void%>");
2532       ret = GS_ERROR;
2533     }
2534 
2535   /* Try this again in case gimplification exposed something.  */
2536   if (ret != GS_ERROR)
2537     {
2538       tree new_tree = fold_call_expr (input_location, *expr_p, !want_value);
2539 
2540       if (new_tree && new_tree != *expr_p)
2541 	{
2542 	  /* There was a transformation of this call which computes the
2543 	     same value, but in a more efficient way.  Return and try
2544 	     again.  */
2545 	  *expr_p = new_tree;
2546 	  return GS_OK;
2547 	}
2548     }
2549   else
2550     {
2551       *expr_p = error_mark_node;
2552       return GS_ERROR;
2553     }
2554 
2555   /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
2556      decl.  This allows us to eliminate redundant or useless
2557      calls to "const" functions.  */
2558   if (TREE_CODE (*expr_p) == CALL_EXPR)
2559     {
2560       int flags = call_expr_flags (*expr_p);
2561       if (flags & (ECF_CONST | ECF_PURE)
2562 	  /* An infinite loop is considered a side effect.  */
2563 	  && !(flags & (ECF_LOOPING_CONST_OR_PURE)))
2564 	TREE_SIDE_EFFECTS (*expr_p) = 0;
2565     }
2566 
2567   /* If the value is not needed by the caller, emit a new GIMPLE_CALL
2568      and clear *EXPR_P.  Otherwise, leave *EXPR_P in its gimplified
2569      form and delegate the creation of a GIMPLE_CALL to
2570      gimplify_modify_expr.  This is always possible because when
2571      WANT_VALUE is true, the caller wants the result of this call into
2572      a temporary, which means that we will emit an INIT_EXPR in
2573      internal_get_tmp_var which will then be handled by
2574      gimplify_modify_expr.  */
2575   if (!want_value)
2576     {
2577       /* The CALL_EXPR in *EXPR_P is already in GIMPLE form, so all we
2578 	 have to do is replicate it as a GIMPLE_CALL tuple.  */
2579       gimple_stmt_iterator gsi;
2580       call = gimple_build_call_from_tree (*expr_p);
2581       gimple_call_set_fntype (call, TREE_TYPE (fnptrtype));
2582       gimplify_seq_add_stmt (pre_p, call);
2583       gsi = gsi_last (*pre_p);
2584       fold_stmt (&gsi);
2585       *expr_p = NULL_TREE;
2586     }
2587   else
2588     /* Remember the original function type.  */
2589     CALL_EXPR_FN (*expr_p) = build1 (NOP_EXPR, fnptrtype,
2590 				     CALL_EXPR_FN (*expr_p));
2591 
2592   return ret;
2593 }
2594 
2595 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
2596    rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
2597 
2598    TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
2599    condition is true or false, respectively.  If null, we should generate
2600    our own to skip over the evaluation of this specific expression.
2601 
2602    LOCUS is the source location of the COND_EXPR.
2603 
2604    This function is the tree equivalent of do_jump.
2605 
2606    shortcut_cond_r should only be called by shortcut_cond_expr.  */
2607 
2608 static tree
2609 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p,
2610 		 location_t locus)
2611 {
2612   tree local_label = NULL_TREE;
2613   tree t, expr = NULL;
2614 
2615   /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
2616      retain the shortcut semantics.  Just insert the gotos here;
2617      shortcut_cond_expr will append the real blocks later.  */
2618   if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
2619     {
2620       location_t new_locus;
2621 
2622       /* Turn if (a && b) into
2623 
2624 	 if (a); else goto no;
2625 	 if (b) goto yes; else goto no;
2626 	 (no:) */
2627 
2628       if (false_label_p == NULL)
2629 	false_label_p = &local_label;
2630 
2631       /* Keep the original source location on the first 'if'.  */
2632       t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p, locus);
2633       append_to_statement_list (t, &expr);
2634 
2635       /* Set the source location of the && on the second 'if'.  */
2636       new_locus = EXPR_HAS_LOCATION (pred) ? EXPR_LOCATION (pred) : locus;
2637       t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p, false_label_p,
2638 			   new_locus);
2639       append_to_statement_list (t, &expr);
2640     }
2641   else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
2642     {
2643       location_t new_locus;
2644 
2645       /* Turn if (a || b) into
2646 
2647 	 if (a) goto yes;
2648 	 if (b) goto yes; else goto no;
2649 	 (yes:) */
2650 
2651       if (true_label_p == NULL)
2652 	true_label_p = &local_label;
2653 
2654       /* Keep the original source location on the first 'if'.  */
2655       t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL, locus);
2656       append_to_statement_list (t, &expr);
2657 
2658       /* Set the source location of the || on the second 'if'.  */
2659       new_locus = EXPR_HAS_LOCATION (pred) ? EXPR_LOCATION (pred) : locus;
2660       t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p, false_label_p,
2661 			   new_locus);
2662       append_to_statement_list (t, &expr);
2663     }
2664   else if (TREE_CODE (pred) == COND_EXPR
2665 	   && !VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (pred, 1)))
2666 	   && !VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (pred, 2))))
2667     {
2668       location_t new_locus;
2669 
2670       /* As long as we're messing with gotos, turn if (a ? b : c) into
2671 	 if (a)
2672 	   if (b) goto yes; else goto no;
2673 	 else
2674 	   if (c) goto yes; else goto no;
2675 
2676 	 Don't do this if one of the arms has void type, which can happen
2677 	 in C++ when the arm is throw.  */
2678 
2679       /* Keep the original source location on the first 'if'.  Set the source
2680 	 location of the ? on the second 'if'.  */
2681       new_locus = EXPR_HAS_LOCATION (pred) ? EXPR_LOCATION (pred) : locus;
2682       expr = build3 (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
2683 		     shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
2684 				      false_label_p, locus),
2685 		     shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
2686 				      false_label_p, new_locus));
2687     }
2688   else
2689     {
2690       expr = build3 (COND_EXPR, void_type_node, pred,
2691 		     build_and_jump (true_label_p),
2692 		     build_and_jump (false_label_p));
2693       SET_EXPR_LOCATION (expr, locus);
2694     }
2695 
2696   if (local_label)
2697     {
2698       t = build1 (LABEL_EXPR, void_type_node, local_label);
2699       append_to_statement_list (t, &expr);
2700     }
2701 
2702   return expr;
2703 }
2704 
2705 /* Given a conditional expression EXPR with short-circuit boolean
2706    predicates using TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR, break the
2707    predicate appart into the equivalent sequence of conditionals.  */
2708 
2709 static tree
2710 shortcut_cond_expr (tree expr)
2711 {
2712   tree pred = TREE_OPERAND (expr, 0);
2713   tree then_ = TREE_OPERAND (expr, 1);
2714   tree else_ = TREE_OPERAND (expr, 2);
2715   tree true_label, false_label, end_label, t;
2716   tree *true_label_p;
2717   tree *false_label_p;
2718   bool emit_end, emit_false, jump_over_else;
2719   bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
2720   bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
2721 
2722   /* First do simple transformations.  */
2723   if (!else_se)
2724     {
2725       /* If there is no 'else', turn
2726 	   if (a && b) then c
2727 	 into
2728 	   if (a) if (b) then c.  */
2729       while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
2730 	{
2731 	  /* Keep the original source location on the first 'if'.  */
2732 	  location_t locus = EXPR_LOC_OR_HERE (expr);
2733 	  TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
2734 	  /* Set the source location of the && on the second 'if'.  */
2735 	  if (EXPR_HAS_LOCATION (pred))
2736 	    SET_EXPR_LOCATION (expr, EXPR_LOCATION (pred));
2737 	  then_ = shortcut_cond_expr (expr);
2738 	  then_se = then_ && TREE_SIDE_EFFECTS (then_);
2739 	  pred = TREE_OPERAND (pred, 0);
2740 	  expr = build3 (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
2741 	  SET_EXPR_LOCATION (expr, locus);
2742 	}
2743     }
2744 
2745   if (!then_se)
2746     {
2747       /* If there is no 'then', turn
2748 	   if (a || b); else d
2749 	 into
2750 	   if (a); else if (b); else d.  */
2751       while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
2752 	{
2753 	  /* Keep the original source location on the first 'if'.  */
2754 	  location_t locus = EXPR_LOC_OR_HERE (expr);
2755 	  TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
2756 	  /* Set the source location of the || on the second 'if'.  */
2757 	  if (EXPR_HAS_LOCATION (pred))
2758 	    SET_EXPR_LOCATION (expr, EXPR_LOCATION (pred));
2759 	  else_ = shortcut_cond_expr (expr);
2760 	  else_se = else_ && TREE_SIDE_EFFECTS (else_);
2761 	  pred = TREE_OPERAND (pred, 0);
2762 	  expr = build3 (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
2763 	  SET_EXPR_LOCATION (expr, locus);
2764 	}
2765     }
2766 
2767   /* If we're done, great.  */
2768   if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
2769       && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
2770     return expr;
2771 
2772   /* Otherwise we need to mess with gotos.  Change
2773        if (a) c; else d;
2774      to
2775        if (a); else goto no;
2776        c; goto end;
2777        no: d; end:
2778      and recursively gimplify the condition.  */
2779 
2780   true_label = false_label = end_label = NULL_TREE;
2781 
2782   /* If our arms just jump somewhere, hijack those labels so we don't
2783      generate jumps to jumps.  */
2784 
2785   if (then_
2786       && TREE_CODE (then_) == GOTO_EXPR
2787       && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
2788     {
2789       true_label = GOTO_DESTINATION (then_);
2790       then_ = NULL;
2791       then_se = false;
2792     }
2793 
2794   if (else_
2795       && TREE_CODE (else_) == GOTO_EXPR
2796       && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
2797     {
2798       false_label = GOTO_DESTINATION (else_);
2799       else_ = NULL;
2800       else_se = false;
2801     }
2802 
2803   /* If we aren't hijacking a label for the 'then' branch, it falls through.  */
2804   if (true_label)
2805     true_label_p = &true_label;
2806   else
2807     true_label_p = NULL;
2808 
2809   /* The 'else' branch also needs a label if it contains interesting code.  */
2810   if (false_label || else_se)
2811     false_label_p = &false_label;
2812   else
2813     false_label_p = NULL;
2814 
2815   /* If there was nothing else in our arms, just forward the label(s).  */
2816   if (!then_se && !else_se)
2817     return shortcut_cond_r (pred, true_label_p, false_label_p,
2818 			    EXPR_LOC_OR_HERE (expr));
2819 
2820   /* If our last subexpression already has a terminal label, reuse it.  */
2821   if (else_se)
2822     t = expr_last (else_);
2823   else if (then_se)
2824     t = expr_last (then_);
2825   else
2826     t = NULL;
2827   if (t && TREE_CODE (t) == LABEL_EXPR)
2828     end_label = LABEL_EXPR_LABEL (t);
2829 
2830   /* If we don't care about jumping to the 'else' branch, jump to the end
2831      if the condition is false.  */
2832   if (!false_label_p)
2833     false_label_p = &end_label;
2834 
2835   /* We only want to emit these labels if we aren't hijacking them.  */
2836   emit_end = (end_label == NULL_TREE);
2837   emit_false = (false_label == NULL_TREE);
2838 
2839   /* We only emit the jump over the else clause if we have to--if the
2840      then clause may fall through.  Otherwise we can wind up with a
2841      useless jump and a useless label at the end of gimplified code,
2842      which will cause us to think that this conditional as a whole
2843      falls through even if it doesn't.  If we then inline a function
2844      which ends with such a condition, that can cause us to issue an
2845      inappropriate warning about control reaching the end of a
2846      non-void function.  */
2847   jump_over_else = block_may_fallthru (then_);
2848 
2849   pred = shortcut_cond_r (pred, true_label_p, false_label_p,
2850 			  EXPR_LOC_OR_HERE (expr));
2851 
2852   expr = NULL;
2853   append_to_statement_list (pred, &expr);
2854 
2855   append_to_statement_list (then_, &expr);
2856   if (else_se)
2857     {
2858       if (jump_over_else)
2859 	{
2860 	  tree last = expr_last (expr);
2861 	  t = build_and_jump (&end_label);
2862 	  if (EXPR_HAS_LOCATION (last))
2863 	    SET_EXPR_LOCATION (t, EXPR_LOCATION (last));
2864 	  append_to_statement_list (t, &expr);
2865 	}
2866       if (emit_false)
2867 	{
2868 	  t = build1 (LABEL_EXPR, void_type_node, false_label);
2869 	  append_to_statement_list (t, &expr);
2870 	}
2871       append_to_statement_list (else_, &expr);
2872     }
2873   if (emit_end && end_label)
2874     {
2875       t = build1 (LABEL_EXPR, void_type_node, end_label);
2876       append_to_statement_list (t, &expr);
2877     }
2878 
2879   return expr;
2880 }
2881 
2882 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE.  */
2883 
2884 tree
2885 gimple_boolify (tree expr)
2886 {
2887   tree type = TREE_TYPE (expr);
2888   location_t loc = EXPR_LOCATION (expr);
2889 
2890   if (TREE_CODE (expr) == NE_EXPR
2891       && TREE_CODE (TREE_OPERAND (expr, 0)) == CALL_EXPR
2892       && integer_zerop (TREE_OPERAND (expr, 1)))
2893     {
2894       tree call = TREE_OPERAND (expr, 0);
2895       tree fn = get_callee_fndecl (call);
2896 
2897       /* For __builtin_expect ((long) (x), y) recurse into x as well
2898 	 if x is truth_value_p.  */
2899       if (fn
2900 	  && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL
2901 	  && DECL_FUNCTION_CODE (fn) == BUILT_IN_EXPECT
2902 	  && call_expr_nargs (call) == 2)
2903 	{
2904 	  tree arg = CALL_EXPR_ARG (call, 0);
2905 	  if (arg)
2906 	    {
2907 	      if (TREE_CODE (arg) == NOP_EXPR
2908 		  && TREE_TYPE (arg) == TREE_TYPE (call))
2909 		arg = TREE_OPERAND (arg, 0);
2910 	      if (truth_value_p (TREE_CODE (arg)))
2911 		{
2912 		  arg = gimple_boolify (arg);
2913 		  CALL_EXPR_ARG (call, 0)
2914 		    = fold_convert_loc (loc, TREE_TYPE (call), arg);
2915 		}
2916 	    }
2917 	}
2918     }
2919 
2920   switch (TREE_CODE (expr))
2921     {
2922     case TRUTH_AND_EXPR:
2923     case TRUTH_OR_EXPR:
2924     case TRUTH_XOR_EXPR:
2925     case TRUTH_ANDIF_EXPR:
2926     case TRUTH_ORIF_EXPR:
2927       /* Also boolify the arguments of truth exprs.  */
2928       TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2929       /* FALLTHRU */
2930 
2931     case TRUTH_NOT_EXPR:
2932       TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2933 
2934       /* These expressions always produce boolean results.  */
2935       if (TREE_CODE (type) != BOOLEAN_TYPE)
2936 	TREE_TYPE (expr) = boolean_type_node;
2937       return expr;
2938 
2939     default:
2940       if (COMPARISON_CLASS_P (expr))
2941 	{
2942 	  /* There expressions always prduce boolean results.  */
2943 	  if (TREE_CODE (type) != BOOLEAN_TYPE)
2944 	    TREE_TYPE (expr) = boolean_type_node;
2945 	  return expr;
2946 	}
2947       /* Other expressions that get here must have boolean values, but
2948 	 might need to be converted to the appropriate mode.  */
2949       if (TREE_CODE (type) == BOOLEAN_TYPE)
2950 	return expr;
2951       return fold_convert_loc (loc, boolean_type_node, expr);
2952     }
2953 }
2954 
2955 /* Given a conditional expression *EXPR_P without side effects, gimplify
2956    its operands.  New statements are inserted to PRE_P.  */
2957 
2958 static enum gimplify_status
2959 gimplify_pure_cond_expr (tree *expr_p, gimple_seq *pre_p)
2960 {
2961   tree expr = *expr_p, cond;
2962   enum gimplify_status ret, tret;
2963   enum tree_code code;
2964 
2965   cond = gimple_boolify (COND_EXPR_COND (expr));
2966 
2967   /* We need to handle && and || specially, as their gimplification
2968      creates pure cond_expr, thus leading to an infinite cycle otherwise.  */
2969   code = TREE_CODE (cond);
2970   if (code == TRUTH_ANDIF_EXPR)
2971     TREE_SET_CODE (cond, TRUTH_AND_EXPR);
2972   else if (code == TRUTH_ORIF_EXPR)
2973     TREE_SET_CODE (cond, TRUTH_OR_EXPR);
2974   ret = gimplify_expr (&cond, pre_p, NULL, is_gimple_condexpr, fb_rvalue);
2975   COND_EXPR_COND (*expr_p) = cond;
2976 
2977   tret = gimplify_expr (&COND_EXPR_THEN (expr), pre_p, NULL,
2978 				   is_gimple_val, fb_rvalue);
2979   ret = MIN (ret, tret);
2980   tret = gimplify_expr (&COND_EXPR_ELSE (expr), pre_p, NULL,
2981 				   is_gimple_val, fb_rvalue);
2982 
2983   return MIN (ret, tret);
2984 }
2985 
2986 /* Return true if evaluating EXPR could trap.
2987    EXPR is GENERIC, while tree_could_trap_p can be called
2988    only on GIMPLE.  */
2989 
2990 static bool
2991 generic_expr_could_trap_p (tree expr)
2992 {
2993   unsigned i, n;
2994 
2995   if (!expr || is_gimple_val (expr))
2996     return false;
2997 
2998   if (!EXPR_P (expr) || tree_could_trap_p (expr))
2999     return true;
3000 
3001   n = TREE_OPERAND_LENGTH (expr);
3002   for (i = 0; i < n; i++)
3003     if (generic_expr_could_trap_p (TREE_OPERAND (expr, i)))
3004       return true;
3005 
3006   return false;
3007 }
3008 
3009 /*  Convert the conditional expression pointed to by EXPR_P '(p) ? a : b;'
3010     into
3011 
3012     if (p)			if (p)
3013       t1 = a;			  a;
3014     else		or	else
3015       t1 = b;			  b;
3016     t1;
3017 
3018     The second form is used when *EXPR_P is of type void.
3019 
3020     PRE_P points to the list where side effects that must happen before
3021       *EXPR_P should be stored.  */
3022 
3023 static enum gimplify_status
3024 gimplify_cond_expr (tree *expr_p, gimple_seq *pre_p, fallback_t fallback)
3025 {
3026   tree expr = *expr_p;
3027   tree type = TREE_TYPE (expr);
3028   location_t loc = EXPR_LOCATION (expr);
3029   tree tmp, arm1, arm2;
3030   enum gimplify_status ret;
3031   tree label_true, label_false, label_cont;
3032   bool have_then_clause_p, have_else_clause_p;
3033   gimple gimple_cond;
3034   enum tree_code pred_code;
3035   gimple_seq seq = NULL;
3036 
3037   /* If this COND_EXPR has a value, copy the values into a temporary within
3038      the arms.  */
3039   if (!VOID_TYPE_P (type))
3040     {
3041       tree then_ = TREE_OPERAND (expr, 1), else_ = TREE_OPERAND (expr, 2);
3042       tree result;
3043 
3044       /* If either an rvalue is ok or we do not require an lvalue, create the
3045 	 temporary.  But we cannot do that if the type is addressable.  */
3046       if (((fallback & fb_rvalue) || !(fallback & fb_lvalue))
3047 	  && !TREE_ADDRESSABLE (type))
3048 	{
3049 	  if (gimplify_ctxp->allow_rhs_cond_expr
3050 	      /* If either branch has side effects or could trap, it can't be
3051 		 evaluated unconditionally.  */
3052 	      && !TREE_SIDE_EFFECTS (then_)
3053 	      && !generic_expr_could_trap_p (then_)
3054 	      && !TREE_SIDE_EFFECTS (else_)
3055 	      && !generic_expr_could_trap_p (else_))
3056 	    return gimplify_pure_cond_expr (expr_p, pre_p);
3057 
3058 	  tmp = create_tmp_var (type, "iftmp");
3059 	  result = tmp;
3060 	}
3061 
3062       /* Otherwise, only create and copy references to the values.  */
3063       else
3064 	{
3065 	  type = build_pointer_type (type);
3066 
3067 	  if (!VOID_TYPE_P (TREE_TYPE (then_)))
3068 	    then_ = build_fold_addr_expr_loc (loc, then_);
3069 
3070 	  if (!VOID_TYPE_P (TREE_TYPE (else_)))
3071 	    else_ = build_fold_addr_expr_loc (loc, else_);
3072 
3073 	  expr
3074 	    = build3 (COND_EXPR, type, TREE_OPERAND (expr, 0), then_, else_);
3075 
3076 	  tmp = create_tmp_var (type, "iftmp");
3077 	  result = build_simple_mem_ref_loc (loc, tmp);
3078 	}
3079 
3080       /* Build the new then clause, `tmp = then_;'.  But don't build the
3081 	 assignment if the value is void; in C++ it can be if it's a throw.  */
3082       if (!VOID_TYPE_P (TREE_TYPE (then_)))
3083 	TREE_OPERAND (expr, 1) = build2 (MODIFY_EXPR, type, tmp, then_);
3084 
3085       /* Similarly, build the new else clause, `tmp = else_;'.  */
3086       if (!VOID_TYPE_P (TREE_TYPE (else_)))
3087 	TREE_OPERAND (expr, 2) = build2 (MODIFY_EXPR, type, tmp, else_);
3088 
3089       TREE_TYPE (expr) = void_type_node;
3090       recalculate_side_effects (expr);
3091 
3092       /* Move the COND_EXPR to the prequeue.  */
3093       gimplify_stmt (&expr, pre_p);
3094 
3095       *expr_p = result;
3096       return GS_ALL_DONE;
3097     }
3098 
3099   /* Remove any COMPOUND_EXPR so the following cases will be caught.  */
3100   STRIP_TYPE_NOPS (TREE_OPERAND (expr, 0));
3101   if (TREE_CODE (TREE_OPERAND (expr, 0)) == COMPOUND_EXPR)
3102     gimplify_compound_expr (&TREE_OPERAND (expr, 0), pre_p, true);
3103 
3104   /* Make sure the condition has BOOLEAN_TYPE.  */
3105   TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
3106 
3107   /* Break apart && and || conditions.  */
3108   if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
3109       || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
3110     {
3111       expr = shortcut_cond_expr (expr);
3112 
3113       if (expr != *expr_p)
3114 	{
3115 	  *expr_p = expr;
3116 
3117 	  /* We can't rely on gimplify_expr to re-gimplify the expanded
3118 	     form properly, as cleanups might cause the target labels to be
3119 	     wrapped in a TRY_FINALLY_EXPR.  To prevent that, we need to
3120 	     set up a conditional context.  */
3121 	  gimple_push_condition ();
3122 	  gimplify_stmt (expr_p, &seq);
3123 	  gimple_pop_condition (pre_p);
3124 	  gimple_seq_add_seq (pre_p, seq);
3125 
3126 	  return GS_ALL_DONE;
3127 	}
3128     }
3129 
3130   /* Now do the normal gimplification.  */
3131 
3132   /* Gimplify condition.  */
3133   ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL, is_gimple_condexpr,
3134 		       fb_rvalue);
3135   if (ret == GS_ERROR)
3136     return GS_ERROR;
3137   gcc_assert (TREE_OPERAND (expr, 0) != NULL_TREE);
3138 
3139   gimple_push_condition ();
3140 
3141   have_then_clause_p = have_else_clause_p = false;
3142   if (TREE_OPERAND (expr, 1) != NULL
3143       && TREE_CODE (TREE_OPERAND (expr, 1)) == GOTO_EXPR
3144       && TREE_CODE (GOTO_DESTINATION (TREE_OPERAND (expr, 1))) == LABEL_DECL
3145       && (DECL_CONTEXT (GOTO_DESTINATION (TREE_OPERAND (expr, 1)))
3146 	  == current_function_decl)
3147       /* For -O0 avoid this optimization if the COND_EXPR and GOTO_EXPR
3148 	 have different locations, otherwise we end up with incorrect
3149 	 location information on the branches.  */
3150       && (optimize
3151 	  || !EXPR_HAS_LOCATION (expr)
3152 	  || !EXPR_HAS_LOCATION (TREE_OPERAND (expr, 1))
3153 	  || EXPR_LOCATION (expr) == EXPR_LOCATION (TREE_OPERAND (expr, 1))))
3154     {
3155       label_true = GOTO_DESTINATION (TREE_OPERAND (expr, 1));
3156       have_then_clause_p = true;
3157     }
3158   else
3159     label_true = create_artificial_label (UNKNOWN_LOCATION);
3160   if (TREE_OPERAND (expr, 2) != NULL
3161       && TREE_CODE (TREE_OPERAND (expr, 2)) == GOTO_EXPR
3162       && TREE_CODE (GOTO_DESTINATION (TREE_OPERAND (expr, 2))) == LABEL_DECL
3163       && (DECL_CONTEXT (GOTO_DESTINATION (TREE_OPERAND (expr, 2)))
3164 	  == current_function_decl)
3165       /* For -O0 avoid this optimization if the COND_EXPR and GOTO_EXPR
3166 	 have different locations, otherwise we end up with incorrect
3167 	 location information on the branches.  */
3168       && (optimize
3169 	  || !EXPR_HAS_LOCATION (expr)
3170 	  || !EXPR_HAS_LOCATION (TREE_OPERAND (expr, 2))
3171 	  || EXPR_LOCATION (expr) == EXPR_LOCATION (TREE_OPERAND (expr, 2))))
3172     {
3173       label_false = GOTO_DESTINATION (TREE_OPERAND (expr, 2));
3174       have_else_clause_p = true;
3175     }
3176   else
3177     label_false = create_artificial_label (UNKNOWN_LOCATION);
3178 
3179   gimple_cond_get_ops_from_tree (COND_EXPR_COND (expr), &pred_code, &arm1,
3180 				 &arm2);
3181 
3182   gimple_cond = gimple_build_cond (pred_code, arm1, arm2, label_true,
3183                                    label_false);
3184 
3185   gimplify_seq_add_stmt (&seq, gimple_cond);
3186   label_cont = NULL_TREE;
3187   if (!have_then_clause_p)
3188     {
3189       /* For if (...) {} else { code; } put label_true after
3190 	 the else block.  */
3191       if (TREE_OPERAND (expr, 1) == NULL_TREE
3192 	  && !have_else_clause_p
3193 	  && TREE_OPERAND (expr, 2) != NULL_TREE)
3194 	label_cont = label_true;
3195       else
3196 	{
3197 	  gimplify_seq_add_stmt (&seq, gimple_build_label (label_true));
3198 	  have_then_clause_p = gimplify_stmt (&TREE_OPERAND (expr, 1), &seq);
3199 	  /* For if (...) { code; } else {} or
3200 	     if (...) { code; } else goto label; or
3201 	     if (...) { code; return; } else { ... }
3202 	     label_cont isn't needed.  */
3203 	  if (!have_else_clause_p
3204 	      && TREE_OPERAND (expr, 2) != NULL_TREE
3205 	      && gimple_seq_may_fallthru (seq))
3206 	    {
3207 	      gimple g;
3208 	      label_cont = create_artificial_label (UNKNOWN_LOCATION);
3209 
3210 	      g = gimple_build_goto (label_cont);
3211 
3212 	      /* GIMPLE_COND's are very low level; they have embedded
3213 		 gotos.  This particular embedded goto should not be marked
3214 		 with the location of the original COND_EXPR, as it would
3215 		 correspond to the COND_EXPR's condition, not the ELSE or the
3216 		 THEN arms.  To avoid marking it with the wrong location, flag
3217 		 it as "no location".  */
3218 	      gimple_set_do_not_emit_location (g);
3219 
3220 	      gimplify_seq_add_stmt (&seq, g);
3221 	    }
3222 	}
3223     }
3224   if (!have_else_clause_p)
3225     {
3226       gimplify_seq_add_stmt (&seq, gimple_build_label (label_false));
3227       have_else_clause_p = gimplify_stmt (&TREE_OPERAND (expr, 2), &seq);
3228     }
3229   if (label_cont)
3230     gimplify_seq_add_stmt (&seq, gimple_build_label (label_cont));
3231 
3232   gimple_pop_condition (pre_p);
3233   gimple_seq_add_seq (pre_p, seq);
3234 
3235   if (ret == GS_ERROR)
3236     ; /* Do nothing.  */
3237   else if (have_then_clause_p || have_else_clause_p)
3238     ret = GS_ALL_DONE;
3239   else
3240     {
3241       /* Both arms are empty; replace the COND_EXPR with its predicate.  */
3242       expr = TREE_OPERAND (expr, 0);
3243       gimplify_stmt (&expr, pre_p);
3244     }
3245 
3246   *expr_p = NULL;
3247   return ret;
3248 }
3249 
3250 /* Prepare the node pointed to by EXPR_P, an is_gimple_addressable expression,
3251    to be marked addressable.
3252 
3253    We cannot rely on such an expression being directly markable if a temporary
3254    has been created by the gimplification.  In this case, we create another
3255    temporary and initialize it with a copy, which will become a store after we
3256    mark it addressable.  This can happen if the front-end passed us something
3257    that it could not mark addressable yet, like a Fortran pass-by-reference
3258    parameter (int) floatvar.  */
3259 
3260 static void
3261 prepare_gimple_addressable (tree *expr_p, gimple_seq *seq_p)
3262 {
3263   while (handled_component_p (*expr_p))
3264     expr_p = &TREE_OPERAND (*expr_p, 0);
3265   if (is_gimple_reg (*expr_p))
3266     *expr_p = get_initialized_tmp_var (*expr_p, seq_p, NULL);
3267 }
3268 
3269 /* A subroutine of gimplify_modify_expr.  Replace a MODIFY_EXPR with
3270    a call to __builtin_memcpy.  */
3271 
3272 static enum gimplify_status
3273 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value,
3274     				gimple_seq *seq_p)
3275 {
3276   tree t, to, to_ptr, from, from_ptr;
3277   gimple gs;
3278   location_t loc = EXPR_LOCATION (*expr_p);
3279 
3280   to = TREE_OPERAND (*expr_p, 0);
3281   from = TREE_OPERAND (*expr_p, 1);
3282 
3283   /* Mark the RHS addressable.  Beware that it may not be possible to do so
3284      directly if a temporary has been created by the gimplification.  */
3285   prepare_gimple_addressable (&from, seq_p);
3286 
3287   mark_addressable (from);
3288   from_ptr = build_fold_addr_expr_loc (loc, from);
3289   gimplify_arg (&from_ptr, seq_p, loc);
3290 
3291   mark_addressable (to);
3292   to_ptr = build_fold_addr_expr_loc (loc, to);
3293   gimplify_arg (&to_ptr, seq_p, loc);
3294 
3295   t = builtin_decl_implicit (BUILT_IN_MEMCPY);
3296 
3297   gs = gimple_build_call (t, 3, to_ptr, from_ptr, size);
3298 
3299   if (want_value)
3300     {
3301       /* tmp = memcpy() */
3302       t = create_tmp_var (TREE_TYPE (to_ptr), NULL);
3303       gimple_call_set_lhs (gs, t);
3304       gimplify_seq_add_stmt (seq_p, gs);
3305 
3306       *expr_p = build_simple_mem_ref (t);
3307       return GS_ALL_DONE;
3308     }
3309 
3310   gimplify_seq_add_stmt (seq_p, gs);
3311   *expr_p = NULL;
3312   return GS_ALL_DONE;
3313 }
3314 
3315 /* A subroutine of gimplify_modify_expr.  Replace a MODIFY_EXPR with
3316    a call to __builtin_memset.  In this case we know that the RHS is
3317    a CONSTRUCTOR with an empty element list.  */
3318 
3319 static enum gimplify_status
3320 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value,
3321     				gimple_seq *seq_p)
3322 {
3323   tree t, from, to, to_ptr;
3324   gimple gs;
3325   location_t loc = EXPR_LOCATION (*expr_p);
3326 
3327   /* Assert our assumptions, to abort instead of producing wrong code
3328      silently if they are not met.  Beware that the RHS CONSTRUCTOR might
3329      not be immediately exposed.  */
3330   from = TREE_OPERAND (*expr_p, 1);
3331   if (TREE_CODE (from) == WITH_SIZE_EXPR)
3332     from = TREE_OPERAND (from, 0);
3333 
3334   gcc_assert (TREE_CODE (from) == CONSTRUCTOR
3335 	      && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (from)));
3336 
3337   /* Now proceed.  */
3338   to = TREE_OPERAND (*expr_p, 0);
3339 
3340   to_ptr = build_fold_addr_expr_loc (loc, to);
3341   gimplify_arg (&to_ptr, seq_p, loc);
3342   t = builtin_decl_implicit (BUILT_IN_MEMSET);
3343 
3344   gs = gimple_build_call (t, 3, to_ptr, integer_zero_node, size);
3345 
3346   if (want_value)
3347     {
3348       /* tmp = memset() */
3349       t = create_tmp_var (TREE_TYPE (to_ptr), NULL);
3350       gimple_call_set_lhs (gs, t);
3351       gimplify_seq_add_stmt (seq_p, gs);
3352 
3353       *expr_p = build1 (INDIRECT_REF, TREE_TYPE (to), t);
3354       return GS_ALL_DONE;
3355     }
3356 
3357   gimplify_seq_add_stmt (seq_p, gs);
3358   *expr_p = NULL;
3359   return GS_ALL_DONE;
3360 }
3361 
3362 /* A subroutine of gimplify_init_ctor_preeval.  Called via walk_tree,
3363    determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
3364    assignment.  Return non-null if we detect a potential overlap.  */
3365 
3366 struct gimplify_init_ctor_preeval_data
3367 {
3368   /* The base decl of the lhs object.  May be NULL, in which case we
3369      have to assume the lhs is indirect.  */
3370   tree lhs_base_decl;
3371 
3372   /* The alias set of the lhs object.  */
3373   alias_set_type lhs_alias_set;
3374 };
3375 
3376 static tree
3377 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
3378 {
3379   struct gimplify_init_ctor_preeval_data *data
3380     = (struct gimplify_init_ctor_preeval_data *) xdata;
3381   tree t = *tp;
3382 
3383   /* If we find the base object, obviously we have overlap.  */
3384   if (data->lhs_base_decl == t)
3385     return t;
3386 
3387   /* If the constructor component is indirect, determine if we have a
3388      potential overlap with the lhs.  The only bits of information we
3389      have to go on at this point are addressability and alias sets.  */
3390   if ((INDIRECT_REF_P (t)
3391        || TREE_CODE (t) == MEM_REF)
3392       && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
3393       && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
3394     return t;
3395 
3396   /* If the constructor component is a call, determine if it can hide a
3397      potential overlap with the lhs through an INDIRECT_REF like above.
3398      ??? Ugh - this is completely broken.  In fact this whole analysis
3399      doesn't look conservative.  */
3400   if (TREE_CODE (t) == CALL_EXPR)
3401     {
3402       tree type, fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (t)));
3403 
3404       for (type = TYPE_ARG_TYPES (fntype); type; type = TREE_CHAIN (type))
3405 	if (POINTER_TYPE_P (TREE_VALUE (type))
3406 	    && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
3407 	    && alias_sets_conflict_p (data->lhs_alias_set,
3408 				      get_alias_set
3409 				        (TREE_TYPE (TREE_VALUE (type)))))
3410 	  return t;
3411     }
3412 
3413   if (IS_TYPE_OR_DECL_P (t))
3414     *walk_subtrees = 0;
3415   return NULL;
3416 }
3417 
3418 /* A subroutine of gimplify_init_constructor.  Pre-evaluate EXPR,
3419    force values that overlap with the lhs (as described by *DATA)
3420    into temporaries.  */
3421 
3422 static void
3423 gimplify_init_ctor_preeval (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
3424 			    struct gimplify_init_ctor_preeval_data *data)
3425 {
3426   enum gimplify_status one;
3427 
3428   /* If the value is constant, then there's nothing to pre-evaluate.  */
3429   if (TREE_CONSTANT (*expr_p))
3430     {
3431       /* Ensure it does not have side effects, it might contain a reference to
3432 	 the object we're initializing.  */
3433       gcc_assert (!TREE_SIDE_EFFECTS (*expr_p));
3434       return;
3435     }
3436 
3437   /* If the type has non-trivial constructors, we can't pre-evaluate.  */
3438   if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
3439     return;
3440 
3441   /* Recurse for nested constructors.  */
3442   if (TREE_CODE (*expr_p) == CONSTRUCTOR)
3443     {
3444       unsigned HOST_WIDE_INT ix;
3445       constructor_elt *ce;
3446       VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (*expr_p);
3447 
3448       FOR_EACH_VEC_ELT (constructor_elt, v, ix, ce)
3449 	gimplify_init_ctor_preeval (&ce->value, pre_p, post_p, data);
3450 
3451       return;
3452     }
3453 
3454   /* If this is a variable sized type, we must remember the size.  */
3455   maybe_with_size_expr (expr_p);
3456 
3457   /* Gimplify the constructor element to something appropriate for the rhs
3458      of a MODIFY_EXPR.  Given that we know the LHS is an aggregate, we know
3459      the gimplifier will consider this a store to memory.  Doing this
3460      gimplification now means that we won't have to deal with complicated
3461      language-specific trees, nor trees like SAVE_EXPR that can induce
3462      exponential search behavior.  */
3463   one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
3464   if (one == GS_ERROR)
3465     {
3466       *expr_p = NULL;
3467       return;
3468     }
3469 
3470   /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
3471      with the lhs, since "a = { .x=a }" doesn't make sense.  This will
3472      always be true for all scalars, since is_gimple_mem_rhs insists on a
3473      temporary variable for them.  */
3474   if (DECL_P (*expr_p))
3475     return;
3476 
3477   /* If this is of variable size, we have no choice but to assume it doesn't
3478      overlap since we can't make a temporary for it.  */
3479   if (TREE_CODE (TYPE_SIZE (TREE_TYPE (*expr_p))) != INTEGER_CST)
3480     return;
3481 
3482   /* Otherwise, we must search for overlap ...  */
3483   if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
3484     return;
3485 
3486   /* ... and if found, force the value into a temporary.  */
3487   *expr_p = get_formal_tmp_var (*expr_p, pre_p);
3488 }
3489 
3490 /* A subroutine of gimplify_init_ctor_eval.  Create a loop for
3491    a RANGE_EXPR in a CONSTRUCTOR for an array.
3492 
3493       var = lower;
3494     loop_entry:
3495       object[var] = value;
3496       if (var == upper)
3497 	goto loop_exit;
3498       var = var + 1;
3499       goto loop_entry;
3500     loop_exit:
3501 
3502    We increment var _after_ the loop exit check because we might otherwise
3503    fail if upper == TYPE_MAX_VALUE (type for upper).
3504 
3505    Note that we never have to deal with SAVE_EXPRs here, because this has
3506    already been taken care of for us, in gimplify_init_ctor_preeval().  */
3507 
3508 static void gimplify_init_ctor_eval (tree, VEC(constructor_elt,gc) *,
3509 				     gimple_seq *, bool);
3510 
3511 static void
3512 gimplify_init_ctor_eval_range (tree object, tree lower, tree upper,
3513 			       tree value, tree array_elt_type,
3514 			       gimple_seq *pre_p, bool cleared)
3515 {
3516   tree loop_entry_label, loop_exit_label, fall_thru_label;
3517   tree var, var_type, cref, tmp;
3518 
3519   loop_entry_label = create_artificial_label (UNKNOWN_LOCATION);
3520   loop_exit_label = create_artificial_label (UNKNOWN_LOCATION);
3521   fall_thru_label = create_artificial_label (UNKNOWN_LOCATION);
3522 
3523   /* Create and initialize the index variable.  */
3524   var_type = TREE_TYPE (upper);
3525   var = create_tmp_var (var_type, NULL);
3526   gimplify_seq_add_stmt (pre_p, gimple_build_assign (var, lower));
3527 
3528   /* Add the loop entry label.  */
3529   gimplify_seq_add_stmt (pre_p, gimple_build_label (loop_entry_label));
3530 
3531   /* Build the reference.  */
3532   cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
3533 		 var, NULL_TREE, NULL_TREE);
3534 
3535   /* If we are a constructor, just call gimplify_init_ctor_eval to do
3536      the store.  Otherwise just assign value to the reference.  */
3537 
3538   if (TREE_CODE (value) == CONSTRUCTOR)
3539     /* NB we might have to call ourself recursively through
3540        gimplify_init_ctor_eval if the value is a constructor.  */
3541     gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
3542 			     pre_p, cleared);
3543   else
3544     gimplify_seq_add_stmt (pre_p, gimple_build_assign (cref, value));
3545 
3546   /* We exit the loop when the index var is equal to the upper bound.  */
3547   gimplify_seq_add_stmt (pre_p,
3548 			 gimple_build_cond (EQ_EXPR, var, upper,
3549 					    loop_exit_label, fall_thru_label));
3550 
3551   gimplify_seq_add_stmt (pre_p, gimple_build_label (fall_thru_label));
3552 
3553   /* Otherwise, increment the index var...  */
3554   tmp = build2 (PLUS_EXPR, var_type, var,
3555 		fold_convert (var_type, integer_one_node));
3556   gimplify_seq_add_stmt (pre_p, gimple_build_assign (var, tmp));
3557 
3558   /* ...and jump back to the loop entry.  */
3559   gimplify_seq_add_stmt (pre_p, gimple_build_goto (loop_entry_label));
3560 
3561   /* Add the loop exit label.  */
3562   gimplify_seq_add_stmt (pre_p, gimple_build_label (loop_exit_label));
3563 }
3564 
3565 /* Return true if FDECL is accessing a field that is zero sized.  */
3566 
3567 static bool
3568 zero_sized_field_decl (const_tree fdecl)
3569 {
3570   if (TREE_CODE (fdecl) == FIELD_DECL && DECL_SIZE (fdecl)
3571       && integer_zerop (DECL_SIZE (fdecl)))
3572     return true;
3573   return false;
3574 }
3575 
3576 /* Return true if TYPE is zero sized.  */
3577 
3578 static bool
3579 zero_sized_type (const_tree type)
3580 {
3581   if (AGGREGATE_TYPE_P (type) && TYPE_SIZE (type)
3582       && integer_zerop (TYPE_SIZE (type)))
3583     return true;
3584   return false;
3585 }
3586 
3587 /* A subroutine of gimplify_init_constructor.  Generate individual
3588    MODIFY_EXPRs for a CONSTRUCTOR.  OBJECT is the LHS against which the
3589    assignments should happen.  ELTS is the CONSTRUCTOR_ELTS of the
3590    CONSTRUCTOR.  CLEARED is true if the entire LHS object has been
3591    zeroed first.  */
3592 
3593 static void
3594 gimplify_init_ctor_eval (tree object, VEC(constructor_elt,gc) *elts,
3595 			 gimple_seq *pre_p, bool cleared)
3596 {
3597   tree array_elt_type = NULL;
3598   unsigned HOST_WIDE_INT ix;
3599   tree purpose, value;
3600 
3601   if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
3602     array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
3603 
3604   FOR_EACH_CONSTRUCTOR_ELT (elts, ix, purpose, value)
3605     {
3606       tree cref;
3607 
3608       /* NULL values are created above for gimplification errors.  */
3609       if (value == NULL)
3610 	continue;
3611 
3612       if (cleared && initializer_zerop (value))
3613 	continue;
3614 
3615       /* ??? Here's to hoping the front end fills in all of the indices,
3616 	 so we don't have to figure out what's missing ourselves.  */
3617       gcc_assert (purpose);
3618 
3619       /* Skip zero-sized fields, unless value has side-effects.  This can
3620 	 happen with calls to functions returning a zero-sized type, which
3621 	 we shouldn't discard.  As a number of downstream passes don't
3622 	 expect sets of zero-sized fields, we rely on the gimplification of
3623 	 the MODIFY_EXPR we make below to drop the assignment statement.  */
3624       if (! TREE_SIDE_EFFECTS (value) && zero_sized_field_decl (purpose))
3625 	continue;
3626 
3627       /* If we have a RANGE_EXPR, we have to build a loop to assign the
3628 	 whole range.  */
3629       if (TREE_CODE (purpose) == RANGE_EXPR)
3630 	{
3631 	  tree lower = TREE_OPERAND (purpose, 0);
3632 	  tree upper = TREE_OPERAND (purpose, 1);
3633 
3634 	  /* If the lower bound is equal to upper, just treat it as if
3635 	     upper was the index.  */
3636 	  if (simple_cst_equal (lower, upper))
3637 	    purpose = upper;
3638 	  else
3639 	    {
3640 	      gimplify_init_ctor_eval_range (object, lower, upper, value,
3641 					     array_elt_type, pre_p, cleared);
3642 	      continue;
3643 	    }
3644 	}
3645 
3646       if (array_elt_type)
3647 	{
3648 	  /* Do not use bitsizetype for ARRAY_REF indices.  */
3649 	  if (TYPE_DOMAIN (TREE_TYPE (object)))
3650 	    purpose
3651 	      = fold_convert (TREE_TYPE (TYPE_DOMAIN (TREE_TYPE (object))),
3652 			      purpose);
3653 	  cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
3654 			 purpose, NULL_TREE, NULL_TREE);
3655 	}
3656       else
3657 	{
3658 	  gcc_assert (TREE_CODE (purpose) == FIELD_DECL);
3659 	  cref = build3 (COMPONENT_REF, TREE_TYPE (purpose),
3660 			 unshare_expr (object), purpose, NULL_TREE);
3661 	}
3662 
3663       if (TREE_CODE (value) == CONSTRUCTOR
3664 	  && TREE_CODE (TREE_TYPE (value)) != VECTOR_TYPE)
3665 	gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
3666 				 pre_p, cleared);
3667       else
3668 	{
3669 	  tree init = build2 (INIT_EXPR, TREE_TYPE (cref), cref, value);
3670 	  gimplify_and_add (init, pre_p);
3671 	  ggc_free (init);
3672 	}
3673     }
3674 }
3675 
3676 /* Return the appropriate RHS predicate for this LHS.  */
3677 
3678 gimple_predicate
3679 rhs_predicate_for (tree lhs)
3680 {
3681   if (is_gimple_reg (lhs))
3682     return is_gimple_reg_rhs_or_call;
3683   else
3684     return is_gimple_mem_rhs_or_call;
3685 }
3686 
3687 /* Gimplify a C99 compound literal expression.  This just means adding
3688    the DECL_EXPR before the current statement and using its anonymous
3689    decl instead.  */
3690 
3691 static enum gimplify_status
3692 gimplify_compound_literal_expr (tree *expr_p, gimple_seq *pre_p)
3693 {
3694   tree decl_s = COMPOUND_LITERAL_EXPR_DECL_EXPR (*expr_p);
3695   tree decl = DECL_EXPR_DECL (decl_s);
3696   /* Mark the decl as addressable if the compound literal
3697      expression is addressable now, otherwise it is marked too late
3698      after we gimplify the initialization expression.  */
3699   if (TREE_ADDRESSABLE (*expr_p))
3700     TREE_ADDRESSABLE (decl) = 1;
3701 
3702   /* Preliminarily mark non-addressed complex variables as eligible
3703      for promotion to gimple registers.  We'll transform their uses
3704      as we find them.  */
3705   if ((TREE_CODE (TREE_TYPE (decl)) == COMPLEX_TYPE
3706        || TREE_CODE (TREE_TYPE (decl)) == VECTOR_TYPE)
3707       && !TREE_THIS_VOLATILE (decl)
3708       && !needs_to_live_in_memory (decl))
3709     DECL_GIMPLE_REG_P (decl) = 1;
3710 
3711   /* This decl isn't mentioned in the enclosing block, so add it to the
3712      list of temps.  FIXME it seems a bit of a kludge to say that
3713      anonymous artificial vars aren't pushed, but everything else is.  */
3714   if (DECL_NAME (decl) == NULL_TREE && !DECL_SEEN_IN_BIND_EXPR_P (decl))
3715     gimple_add_tmp_var (decl);
3716 
3717   gimplify_and_add (decl_s, pre_p);
3718   *expr_p = decl;
3719   return GS_OK;
3720 }
3721 
3722 /* Optimize embedded COMPOUND_LITERAL_EXPRs within a CONSTRUCTOR,
3723    return a new CONSTRUCTOR if something changed.  */
3724 
3725 static tree
3726 optimize_compound_literals_in_ctor (tree orig_ctor)
3727 {
3728   tree ctor = orig_ctor;
3729   VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (ctor);
3730   unsigned int idx, num = VEC_length (constructor_elt, elts);
3731 
3732   for (idx = 0; idx < num; idx++)
3733     {
3734       tree value = VEC_index (constructor_elt, elts, idx)->value;
3735       tree newval = value;
3736       if (TREE_CODE (value) == CONSTRUCTOR)
3737 	newval = optimize_compound_literals_in_ctor (value);
3738       else if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
3739 	{
3740 	  tree decl_s = COMPOUND_LITERAL_EXPR_DECL_EXPR (value);
3741 	  tree decl = DECL_EXPR_DECL (decl_s);
3742 	  tree init = DECL_INITIAL (decl);
3743 
3744 	  if (!TREE_ADDRESSABLE (value)
3745 	      && !TREE_ADDRESSABLE (decl)
3746 	      && init
3747 	      && TREE_CODE (init) == CONSTRUCTOR)
3748 	    newval = optimize_compound_literals_in_ctor (init);
3749 	}
3750       if (newval == value)
3751 	continue;
3752 
3753       if (ctor == orig_ctor)
3754 	{
3755 	  ctor = copy_node (orig_ctor);
3756 	  CONSTRUCTOR_ELTS (ctor) = VEC_copy (constructor_elt, gc, elts);
3757 	  elts = CONSTRUCTOR_ELTS (ctor);
3758 	}
3759       VEC_index (constructor_elt, elts, idx)->value = newval;
3760     }
3761   return ctor;
3762 }
3763 
3764 /* A subroutine of gimplify_modify_expr.  Break out elements of a
3765    CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
3766 
3767    Note that we still need to clear any elements that don't have explicit
3768    initializers, so if not all elements are initialized we keep the
3769    original MODIFY_EXPR, we just remove all of the constructor elements.
3770 
3771    If NOTIFY_TEMP_CREATION is true, do not gimplify, just return
3772    GS_ERROR if we would have to create a temporary when gimplifying
3773    this constructor.  Otherwise, return GS_OK.
3774 
3775    If NOTIFY_TEMP_CREATION is false, just do the gimplification.  */
3776 
3777 static enum gimplify_status
3778 gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
3779 			   bool want_value, bool notify_temp_creation)
3780 {
3781   tree object, ctor, type;
3782   enum gimplify_status ret;
3783   VEC(constructor_elt,gc) *elts;
3784 
3785   gcc_assert (TREE_CODE (TREE_OPERAND (*expr_p, 1)) == CONSTRUCTOR);
3786 
3787   if (!notify_temp_creation)
3788     {
3789       ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3790 			   is_gimple_lvalue, fb_lvalue);
3791       if (ret == GS_ERROR)
3792 	return ret;
3793     }
3794 
3795   object = TREE_OPERAND (*expr_p, 0);
3796   ctor = TREE_OPERAND (*expr_p, 1) =
3797     optimize_compound_literals_in_ctor (TREE_OPERAND (*expr_p, 1));
3798   type = TREE_TYPE (ctor);
3799   elts = CONSTRUCTOR_ELTS (ctor);
3800   ret = GS_ALL_DONE;
3801 
3802   switch (TREE_CODE (type))
3803     {
3804     case RECORD_TYPE:
3805     case UNION_TYPE:
3806     case QUAL_UNION_TYPE:
3807     case ARRAY_TYPE:
3808       {
3809 	struct gimplify_init_ctor_preeval_data preeval_data;
3810 	HOST_WIDE_INT num_ctor_elements, num_nonzero_elements;
3811 	bool cleared, complete_p, valid_const_initializer;
3812 
3813 	/* Aggregate types must lower constructors to initialization of
3814 	   individual elements.  The exception is that a CONSTRUCTOR node
3815 	   with no elements indicates zero-initialization of the whole.  */
3816 	if (VEC_empty (constructor_elt, elts))
3817 	  {
3818 	    if (notify_temp_creation)
3819 	      return GS_OK;
3820 	    break;
3821 	  }
3822 
3823 	/* Fetch information about the constructor to direct later processing.
3824 	   We might want to make static versions of it in various cases, and
3825 	   can only do so if it known to be a valid constant initializer.  */
3826 	valid_const_initializer
3827 	  = categorize_ctor_elements (ctor, &num_nonzero_elements,
3828 				      &num_ctor_elements, &complete_p);
3829 
3830 	/* If a const aggregate variable is being initialized, then it
3831 	   should never be a lose to promote the variable to be static.  */
3832 	if (valid_const_initializer
3833 	    && num_nonzero_elements > 1
3834 	    && TREE_READONLY (object)
3835 	    && TREE_CODE (object) == VAR_DECL
3836 	    && (flag_merge_constants >= 2 || !TREE_ADDRESSABLE (object)))
3837 	  {
3838 	    if (notify_temp_creation)
3839 	      return GS_ERROR;
3840 	    DECL_INITIAL (object) = ctor;
3841 	    TREE_STATIC (object) = 1;
3842 	    if (!DECL_NAME (object))
3843 	      DECL_NAME (object) = create_tmp_var_name ("C");
3844 	    walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
3845 
3846 	    /* ??? C++ doesn't automatically append a .<number> to the
3847 	       assembler name, and even when it does, it looks a FE private
3848 	       data structures to figure out what that number should be,
3849 	       which are not set for this variable.  I suppose this is
3850 	       important for local statics for inline functions, which aren't
3851 	       "local" in the object file sense.  So in order to get a unique
3852 	       TU-local symbol, we must invoke the lhd version now.  */
3853 	    lhd_set_decl_assembler_name (object);
3854 
3855 	    *expr_p = NULL_TREE;
3856 	    break;
3857 	  }
3858 
3859 	/* If there are "lots" of initialized elements, even discounting
3860 	   those that are not address constants (and thus *must* be
3861 	   computed at runtime), then partition the constructor into
3862 	   constant and non-constant parts.  Block copy the constant
3863 	   parts in, then generate code for the non-constant parts.  */
3864 	/* TODO.  There's code in cp/typeck.c to do this.  */
3865 
3866 	if (int_size_in_bytes (TREE_TYPE (ctor)) < 0)
3867 	  /* store_constructor will ignore the clearing of variable-sized
3868 	     objects.  Initializers for such objects must explicitly set
3869 	     every field that needs to be set.  */
3870 	  cleared = false;
3871 	else if (!complete_p)
3872 	  /* If the constructor isn't complete, clear the whole object
3873 	     beforehand.
3874 
3875 	     ??? This ought not to be needed.  For any element not present
3876 	     in the initializer, we should simply set them to zero.  Except
3877 	     we'd need to *find* the elements that are not present, and that
3878 	     requires trickery to avoid quadratic compile-time behavior in
3879 	     large cases or excessive memory use in small cases.  */
3880 	  cleared = true;
3881 	else if (num_ctor_elements - num_nonzero_elements
3882 		 > CLEAR_RATIO (optimize_function_for_speed_p (cfun))
3883 		 && num_nonzero_elements < num_ctor_elements / 4)
3884 	  /* If there are "lots" of zeros, it's more efficient to clear
3885 	     the memory and then set the nonzero elements.  */
3886 	  cleared = true;
3887 	else
3888 	  cleared = false;
3889 
3890 	/* If there are "lots" of initialized elements, and all of them
3891 	   are valid address constants, then the entire initializer can
3892 	   be dropped to memory, and then memcpy'd out.  Don't do this
3893 	   for sparse arrays, though, as it's more efficient to follow
3894 	   the standard CONSTRUCTOR behavior of memset followed by
3895 	   individual element initialization.  Also don't do this for small
3896 	   all-zero initializers (which aren't big enough to merit
3897 	   clearing), and don't try to make bitwise copies of
3898 	   TREE_ADDRESSABLE types.  */
3899 	if (valid_const_initializer
3900 	    && !(cleared || num_nonzero_elements == 0)
3901 	    && !TREE_ADDRESSABLE (type))
3902 	  {
3903 	    HOST_WIDE_INT size = int_size_in_bytes (type);
3904 	    unsigned int align;
3905 
3906 	    /* ??? We can still get unbounded array types, at least
3907 	       from the C++ front end.  This seems wrong, but attempt
3908 	       to work around it for now.  */
3909 	    if (size < 0)
3910 	      {
3911 		size = int_size_in_bytes (TREE_TYPE (object));
3912 		if (size >= 0)
3913 		  TREE_TYPE (ctor) = type = TREE_TYPE (object);
3914 	      }
3915 
3916 	    /* Find the maximum alignment we can assume for the object.  */
3917 	    /* ??? Make use of DECL_OFFSET_ALIGN.  */
3918 	    if (DECL_P (object))
3919 	      align = DECL_ALIGN (object);
3920 	    else
3921 	      align = TYPE_ALIGN (type);
3922 
3923 	    if (size > 0
3924 		&& num_nonzero_elements > 1
3925 		&& !can_move_by_pieces (size, align))
3926 	      {
3927 		if (notify_temp_creation)
3928 		  return GS_ERROR;
3929 
3930 		walk_tree (&ctor, force_labels_r, NULL, NULL);
3931 		ctor = tree_output_constant_def (ctor);
3932 		if (!useless_type_conversion_p (type, TREE_TYPE (ctor)))
3933 		  ctor = build1 (VIEW_CONVERT_EXPR, type, ctor);
3934 		TREE_OPERAND (*expr_p, 1) = ctor;
3935 
3936 		/* This is no longer an assignment of a CONSTRUCTOR, but
3937 		   we still may have processing to do on the LHS.  So
3938 		   pretend we didn't do anything here to let that happen.  */
3939 		return GS_UNHANDLED;
3940 	      }
3941 	  }
3942 
3943 	/* If the target is volatile, we have non-zero elements and more than
3944 	   one field to assign, initialize the target from a temporary.  */
3945 	if (TREE_THIS_VOLATILE (object)
3946 	    && !TREE_ADDRESSABLE (type)
3947 	    && num_nonzero_elements > 0
3948 	    && VEC_length (constructor_elt, elts) > 1)
3949 	  {
3950 	    tree temp = create_tmp_var (TYPE_MAIN_VARIANT (type), NULL);
3951 	    TREE_OPERAND (*expr_p, 0) = temp;
3952 	    *expr_p = build2 (COMPOUND_EXPR, TREE_TYPE (*expr_p),
3953 			      *expr_p,
3954 			      build2 (MODIFY_EXPR, void_type_node,
3955 				      object, temp));
3956 	    return GS_OK;
3957 	  }
3958 
3959 	if (notify_temp_creation)
3960 	  return GS_OK;
3961 
3962 	/* If there are nonzero elements and if needed, pre-evaluate to capture
3963 	   elements overlapping with the lhs into temporaries.  We must do this
3964 	   before clearing to fetch the values before they are zeroed-out.  */
3965 	if (num_nonzero_elements > 0 && TREE_CODE (*expr_p) != INIT_EXPR)
3966 	  {
3967 	    preeval_data.lhs_base_decl = get_base_address (object);
3968 	    if (!DECL_P (preeval_data.lhs_base_decl))
3969 	      preeval_data.lhs_base_decl = NULL;
3970 	    preeval_data.lhs_alias_set = get_alias_set (object);
3971 
3972 	    gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
3973 					pre_p, post_p, &preeval_data);
3974 	  }
3975 
3976 	if (cleared)
3977 	  {
3978 	    /* Zap the CONSTRUCTOR element list, which simplifies this case.
3979 	       Note that we still have to gimplify, in order to handle the
3980 	       case of variable sized types.  Avoid shared tree structures.  */
3981 	    CONSTRUCTOR_ELTS (ctor) = NULL;
3982 	    TREE_SIDE_EFFECTS (ctor) = 0;
3983 	    object = unshare_expr (object);
3984 	    gimplify_stmt (expr_p, pre_p);
3985 	  }
3986 
3987 	/* If we have not block cleared the object, or if there are nonzero
3988 	   elements in the constructor, add assignments to the individual
3989 	   scalar fields of the object.  */
3990 	if (!cleared || num_nonzero_elements > 0)
3991 	  gimplify_init_ctor_eval (object, elts, pre_p, cleared);
3992 
3993 	*expr_p = NULL_TREE;
3994       }
3995       break;
3996 
3997     case COMPLEX_TYPE:
3998       {
3999 	tree r, i;
4000 
4001 	if (notify_temp_creation)
4002 	  return GS_OK;
4003 
4004 	/* Extract the real and imaginary parts out of the ctor.  */
4005 	gcc_assert (VEC_length (constructor_elt, elts) == 2);
4006 	r = VEC_index (constructor_elt, elts, 0)->value;
4007 	i = VEC_index (constructor_elt, elts, 1)->value;
4008 	if (r == NULL || i == NULL)
4009 	  {
4010 	    tree zero = build_zero_cst (TREE_TYPE (type));
4011 	    if (r == NULL)
4012 	      r = zero;
4013 	    if (i == NULL)
4014 	      i = zero;
4015 	  }
4016 
4017 	/* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
4018 	   represent creation of a complex value.  */
4019 	if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
4020 	  {
4021 	    ctor = build_complex (type, r, i);
4022 	    TREE_OPERAND (*expr_p, 1) = ctor;
4023 	  }
4024 	else
4025 	  {
4026 	    ctor = build2 (COMPLEX_EXPR, type, r, i);
4027 	    TREE_OPERAND (*expr_p, 1) = ctor;
4028 	    ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1),
4029 				 pre_p,
4030 				 post_p,
4031 				 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
4032 				 fb_rvalue);
4033 	  }
4034       }
4035       break;
4036 
4037     case VECTOR_TYPE:
4038       {
4039 	unsigned HOST_WIDE_INT ix;
4040 	constructor_elt *ce;
4041 
4042 	if (notify_temp_creation)
4043 	  return GS_OK;
4044 
4045 	/* Go ahead and simplify constant constructors to VECTOR_CST.  */
4046 	if (TREE_CONSTANT (ctor))
4047 	  {
4048 	    bool constant_p = true;
4049 	    tree value;
4050 
4051 	    /* Even when ctor is constant, it might contain non-*_CST
4052 	       elements, such as addresses or trapping values like
4053 	       1.0/0.0 - 1.0/0.0.  Such expressions don't belong
4054 	       in VECTOR_CST nodes.  */
4055 	    FOR_EACH_CONSTRUCTOR_VALUE (elts, ix, value)
4056 	      if (!CONSTANT_CLASS_P (value))
4057 		{
4058 		  constant_p = false;
4059 		  break;
4060 		}
4061 
4062 	    if (constant_p)
4063 	      {
4064 		TREE_OPERAND (*expr_p, 1) = build_vector_from_ctor (type, elts);
4065 		break;
4066 	      }
4067 
4068 	    /* Don't reduce an initializer constant even if we can't
4069 	       make a VECTOR_CST.  It won't do anything for us, and it'll
4070 	       prevent us from representing it as a single constant.  */
4071 	    if (initializer_constant_valid_p (ctor, type))
4072 	      break;
4073 
4074 	    TREE_CONSTANT (ctor) = 0;
4075 	  }
4076 
4077 	/* Vector types use CONSTRUCTOR all the way through gimple
4078 	  compilation as a general initializer.  */
4079 	FOR_EACH_VEC_ELT (constructor_elt, elts, ix, ce)
4080 	  {
4081 	    enum gimplify_status tret;
4082 	    tret = gimplify_expr (&ce->value, pre_p, post_p, is_gimple_val,
4083 				  fb_rvalue);
4084 	    if (tret == GS_ERROR)
4085 	      ret = GS_ERROR;
4086 	  }
4087 	if (!is_gimple_reg (TREE_OPERAND (*expr_p, 0)))
4088 	  TREE_OPERAND (*expr_p, 1) = get_formal_tmp_var (ctor, pre_p);
4089       }
4090       break;
4091 
4092     default:
4093       /* So how did we get a CONSTRUCTOR for a scalar type?  */
4094       gcc_unreachable ();
4095     }
4096 
4097   if (ret == GS_ERROR)
4098     return GS_ERROR;
4099   else if (want_value)
4100     {
4101       *expr_p = object;
4102       return GS_OK;
4103     }
4104   else
4105     {
4106       /* If we have gimplified both sides of the initializer but have
4107 	 not emitted an assignment, do so now.  */
4108       if (*expr_p)
4109 	{
4110 	  tree lhs = TREE_OPERAND (*expr_p, 0);
4111 	  tree rhs = TREE_OPERAND (*expr_p, 1);
4112 	  gimple init = gimple_build_assign (lhs, rhs);
4113 	  gimplify_seq_add_stmt (pre_p, init);
4114 	  *expr_p = NULL;
4115 	}
4116 
4117       return GS_ALL_DONE;
4118     }
4119 }
4120 
4121 /* Given a pointer value OP0, return a simplified version of an
4122    indirection through OP0, or NULL_TREE if no simplification is
4123    possible.  Note that the resulting type may be different from
4124    the type pointed to in the sense that it is still compatible
4125    from the langhooks point of view. */
4126 
4127 tree
4128 gimple_fold_indirect_ref (tree t)
4129 {
4130   tree ptype = TREE_TYPE (t), type = TREE_TYPE (ptype);
4131   tree sub = t;
4132   tree subtype;
4133 
4134   STRIP_NOPS (sub);
4135   subtype = TREE_TYPE (sub);
4136   if (!POINTER_TYPE_P (subtype))
4137     return NULL_TREE;
4138 
4139   if (TREE_CODE (sub) == ADDR_EXPR)
4140     {
4141       tree op = TREE_OPERAND (sub, 0);
4142       tree optype = TREE_TYPE (op);
4143       /* *&p => p */
4144       if (useless_type_conversion_p (type, optype))
4145         return op;
4146 
4147       /* *(foo *)&fooarray => fooarray[0] */
4148       if (TREE_CODE (optype) == ARRAY_TYPE
4149 	  && TREE_CODE (TYPE_SIZE (TREE_TYPE (optype))) == INTEGER_CST
4150 	  && useless_type_conversion_p (type, TREE_TYPE (optype)))
4151        {
4152          tree type_domain = TYPE_DOMAIN (optype);
4153          tree min_val = size_zero_node;
4154          if (type_domain && TYPE_MIN_VALUE (type_domain))
4155            min_val = TYPE_MIN_VALUE (type_domain);
4156 	 if (TREE_CODE (min_val) == INTEGER_CST)
4157 	   return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
4158        }
4159       /* *(foo *)&complexfoo => __real__ complexfoo */
4160       else if (TREE_CODE (optype) == COMPLEX_TYPE
4161                && useless_type_conversion_p (type, TREE_TYPE (optype)))
4162         return fold_build1 (REALPART_EXPR, type, op);
4163       /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
4164       else if (TREE_CODE (optype) == VECTOR_TYPE
4165                && useless_type_conversion_p (type, TREE_TYPE (optype)))
4166         {
4167           tree part_width = TYPE_SIZE (type);
4168           tree index = bitsize_int (0);
4169           return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
4170         }
4171     }
4172 
4173   /* *(p + CST) -> ...  */
4174   if (TREE_CODE (sub) == POINTER_PLUS_EXPR
4175       && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
4176     {
4177       tree addr = TREE_OPERAND (sub, 0);
4178       tree off = TREE_OPERAND (sub, 1);
4179       tree addrtype;
4180 
4181       STRIP_NOPS (addr);
4182       addrtype = TREE_TYPE (addr);
4183 
4184       /* ((foo*)&vectorfoo)[1] -> BIT_FIELD_REF<vectorfoo,...> */
4185       if (TREE_CODE (addr) == ADDR_EXPR
4186 	  && TREE_CODE (TREE_TYPE (addrtype)) == VECTOR_TYPE
4187 	  && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (addrtype)))
4188 	  && host_integerp (off, 1))
4189 	{
4190           unsigned HOST_WIDE_INT offset = tree_low_cst (off, 1);
4191           tree part_width = TYPE_SIZE (type);
4192           unsigned HOST_WIDE_INT part_widthi
4193             = tree_low_cst (part_width, 0) / BITS_PER_UNIT;
4194           unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
4195           tree index = bitsize_int (indexi);
4196           if (offset / part_widthi
4197               <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (addrtype)))
4198             return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (addr, 0),
4199                                 part_width, index);
4200 	}
4201 
4202       /* ((foo*)&complexfoo)[1] -> __imag__ complexfoo */
4203       if (TREE_CODE (addr) == ADDR_EXPR
4204 	  && TREE_CODE (TREE_TYPE (addrtype)) == COMPLEX_TYPE
4205 	  && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (addrtype))))
4206         {
4207           tree size = TYPE_SIZE_UNIT (type);
4208           if (tree_int_cst_equal (size, off))
4209             return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (addr, 0));
4210         }
4211 
4212       /* *(p + CST) -> MEM_REF <p, CST>.  */
4213       if (TREE_CODE (addr) != ADDR_EXPR
4214 	  || DECL_P (TREE_OPERAND (addr, 0)))
4215 	return fold_build2 (MEM_REF, type,
4216 			    addr,
4217 			    build_int_cst_wide (ptype,
4218 						TREE_INT_CST_LOW (off),
4219 						TREE_INT_CST_HIGH (off)));
4220     }
4221 
4222   /* *(foo *)fooarrptr => (*fooarrptr)[0] */
4223   if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
4224       && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (subtype)))) == INTEGER_CST
4225       && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (subtype))))
4226     {
4227       tree type_domain;
4228       tree min_val = size_zero_node;
4229       tree osub = sub;
4230       sub = gimple_fold_indirect_ref (sub);
4231       if (! sub)
4232 	sub = build1 (INDIRECT_REF, TREE_TYPE (subtype), osub);
4233       type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
4234       if (type_domain && TYPE_MIN_VALUE (type_domain))
4235         min_val = TYPE_MIN_VALUE (type_domain);
4236       if (TREE_CODE (min_val) == INTEGER_CST)
4237 	return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
4238     }
4239 
4240   return NULL_TREE;
4241 }
4242 
4243 /* Given a pointer value OP0, return a simplified version of an
4244    indirection through OP0, or NULL_TREE if no simplification is
4245    possible.  This may only be applied to a rhs of an expression.
4246    Note that the resulting type may be different from the type pointed
4247    to in the sense that it is still compatible from the langhooks
4248    point of view. */
4249 
4250 static tree
4251 gimple_fold_indirect_ref_rhs (tree t)
4252 {
4253   return gimple_fold_indirect_ref (t);
4254 }
4255 
4256 /* Subroutine of gimplify_modify_expr to do simplifications of
4257    MODIFY_EXPRs based on the code of the RHS.  We loop for as long as
4258    something changes.  */
4259 
4260 static enum gimplify_status
4261 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p,
4262 			  gimple_seq *pre_p, gimple_seq *post_p,
4263 			  bool want_value)
4264 {
4265   enum gimplify_status ret = GS_UNHANDLED;
4266   bool changed;
4267 
4268   do
4269     {
4270       changed = false;
4271       switch (TREE_CODE (*from_p))
4272 	{
4273 	case VAR_DECL:
4274 	  /* If we're assigning from a read-only variable initialized with
4275 	     a constructor, do the direct assignment from the constructor,
4276 	     but only if neither source nor target are volatile since this
4277 	     latter assignment might end up being done on a per-field basis.  */
4278 	  if (DECL_INITIAL (*from_p)
4279 	      && TREE_READONLY (*from_p)
4280 	      && !TREE_THIS_VOLATILE (*from_p)
4281 	      && !TREE_THIS_VOLATILE (*to_p)
4282 	      && TREE_CODE (DECL_INITIAL (*from_p)) == CONSTRUCTOR)
4283 	    {
4284 	      tree old_from = *from_p;
4285 	      enum gimplify_status subret;
4286 
4287 	      /* Move the constructor into the RHS.  */
4288 	      *from_p = unshare_expr (DECL_INITIAL (*from_p));
4289 
4290 	      /* Let's see if gimplify_init_constructor will need to put
4291 		 it in memory.  */
4292 	      subret = gimplify_init_constructor (expr_p, NULL, NULL,
4293 						  false, true);
4294 	      if (subret == GS_ERROR)
4295 		{
4296 		  /* If so, revert the change.  */
4297 		  *from_p = old_from;
4298 		}
4299 	      else
4300 		{
4301 		  ret = GS_OK;
4302 		  changed = true;
4303 		}
4304 	    }
4305 	  break;
4306 	case INDIRECT_REF:
4307 	  {
4308 	    /* If we have code like
4309 
4310 	     *(const A*)(A*)&x
4311 
4312 	     where the type of "x" is a (possibly cv-qualified variant
4313 	     of "A"), treat the entire expression as identical to "x".
4314 	     This kind of code arises in C++ when an object is bound
4315 	     to a const reference, and if "x" is a TARGET_EXPR we want
4316 	     to take advantage of the optimization below.  */
4317 	    bool volatile_p = TREE_THIS_VOLATILE (*from_p);
4318 	    tree t = gimple_fold_indirect_ref_rhs (TREE_OPERAND (*from_p, 0));
4319 	    if (t)
4320 	      {
4321 		if (TREE_THIS_VOLATILE (t) != volatile_p)
4322 		  {
4323 		    if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration)
4324 		      t = build_simple_mem_ref_loc (EXPR_LOCATION (*from_p),
4325 						    build_fold_addr_expr (t));
4326 		    if (REFERENCE_CLASS_P (t))
4327 		      TREE_THIS_VOLATILE (t) = volatile_p;
4328 		  }
4329 		*from_p = t;
4330 		ret = GS_OK;
4331 		changed = true;
4332 	      }
4333 	    break;
4334 	  }
4335 
4336 	case TARGET_EXPR:
4337 	  {
4338 	    /* If we are initializing something from a TARGET_EXPR, strip the
4339 	       TARGET_EXPR and initialize it directly, if possible.  This can't
4340 	       be done if the initializer is void, since that implies that the
4341 	       temporary is set in some non-trivial way.
4342 
4343 	       ??? What about code that pulls out the temp and uses it
4344 	       elsewhere? I think that such code never uses the TARGET_EXPR as
4345 	       an initializer.  If I'm wrong, we'll die because the temp won't
4346 	       have any RTL.  In that case, I guess we'll need to replace
4347 	       references somehow.  */
4348 	    tree init = TARGET_EXPR_INITIAL (*from_p);
4349 
4350 	    if (init
4351 		&& !VOID_TYPE_P (TREE_TYPE (init)))
4352 	      {
4353 		*from_p = init;
4354 		ret = GS_OK;
4355 		changed = true;
4356 	      }
4357 	  }
4358 	  break;
4359 
4360 	case COMPOUND_EXPR:
4361 	  /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
4362 	     caught.  */
4363 	  gimplify_compound_expr (from_p, pre_p, true);
4364 	  ret = GS_OK;
4365 	  changed = true;
4366 	  break;
4367 
4368 	case CONSTRUCTOR:
4369 	  /* If we already made some changes, let the front end have a
4370 	     crack at this before we break it down.  */
4371 	  if (ret != GS_UNHANDLED)
4372 	    break;
4373 	  /* If we're initializing from a CONSTRUCTOR, break this into
4374 	     individual MODIFY_EXPRs.  */
4375 	  return gimplify_init_constructor (expr_p, pre_p, post_p, want_value,
4376 					    false);
4377 
4378 	case COND_EXPR:
4379 	  /* If we're assigning to a non-register type, push the assignment
4380 	     down into the branches.  This is mandatory for ADDRESSABLE types,
4381 	     since we cannot generate temporaries for such, but it saves a
4382 	     copy in other cases as well.  */
4383 	  if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
4384 	    {
4385 	      /* This code should mirror the code in gimplify_cond_expr. */
4386 	      enum tree_code code = TREE_CODE (*expr_p);
4387 	      tree cond = *from_p;
4388 	      tree result = *to_p;
4389 
4390 	      ret = gimplify_expr (&result, pre_p, post_p,
4391 				   is_gimple_lvalue, fb_lvalue);
4392 	      if (ret != GS_ERROR)
4393 		ret = GS_OK;
4394 
4395 	      if (TREE_TYPE (TREE_OPERAND (cond, 1)) != void_type_node)
4396 		TREE_OPERAND (cond, 1)
4397 		  = build2 (code, void_type_node, result,
4398 			    TREE_OPERAND (cond, 1));
4399 	      if (TREE_TYPE (TREE_OPERAND (cond, 2)) != void_type_node)
4400 		TREE_OPERAND (cond, 2)
4401 		  = build2 (code, void_type_node, unshare_expr (result),
4402 			    TREE_OPERAND (cond, 2));
4403 
4404 	      TREE_TYPE (cond) = void_type_node;
4405 	      recalculate_side_effects (cond);
4406 
4407 	      if (want_value)
4408 		{
4409 		  gimplify_and_add (cond, pre_p);
4410 		  *expr_p = unshare_expr (result);
4411 		}
4412 	      else
4413 		*expr_p = cond;
4414 	      return ret;
4415 	    }
4416 	  break;
4417 
4418 	case CALL_EXPR:
4419 	  /* For calls that return in memory, give *to_p as the CALL_EXPR's
4420 	     return slot so that we don't generate a temporary.  */
4421 	  if (!CALL_EXPR_RETURN_SLOT_OPT (*from_p)
4422 	      && aggregate_value_p (*from_p, *from_p))
4423 	    {
4424 	      bool use_target;
4425 
4426 	      if (!(rhs_predicate_for (*to_p))(*from_p))
4427 		/* If we need a temporary, *to_p isn't accurate.  */
4428 		use_target = false;
4429 	      /* It's OK to use the return slot directly unless it's an NRV. */
4430 	      else if (TREE_CODE (*to_p) == RESULT_DECL
4431 		       && DECL_NAME (*to_p) == NULL_TREE
4432 		       && needs_to_live_in_memory (*to_p))
4433 		use_target = true;
4434 	      else if (is_gimple_reg_type (TREE_TYPE (*to_p))
4435 		       || (DECL_P (*to_p) && DECL_REGISTER (*to_p)))
4436 		/* Don't force regs into memory.  */
4437 		use_target = false;
4438 	      else if (TREE_CODE (*expr_p) == INIT_EXPR)
4439 		/* It's OK to use the target directly if it's being
4440 		   initialized. */
4441 		use_target = true;
4442 	      else if (variably_modified_type_p (TREE_TYPE (*to_p), NULL_TREE))
4443 		/* Always use the target and thus RSO for variable-sized types.
4444 		   GIMPLE cannot deal with a variable-sized assignment
4445 		   embedded in a call statement.  */
4446 		use_target = true;
4447 	      else if (TREE_CODE (*to_p) != SSA_NAME
4448 		      && (!is_gimple_variable (*to_p)
4449 			  || needs_to_live_in_memory (*to_p)))
4450 		/* Don't use the original target if it's already addressable;
4451 		   if its address escapes, and the called function uses the
4452 		   NRV optimization, a conforming program could see *to_p
4453 		   change before the called function returns; see c++/19317.
4454 		   When optimizing, the return_slot pass marks more functions
4455 		   as safe after we have escape info.  */
4456 		use_target = false;
4457 	      else
4458 		use_target = true;
4459 
4460 	      if (use_target)
4461 		{
4462 		  CALL_EXPR_RETURN_SLOT_OPT (*from_p) = 1;
4463 		  mark_addressable (*to_p);
4464 		}
4465 	    }
4466 	  break;
4467 
4468 	case WITH_SIZE_EXPR:
4469 	  /* Likewise for calls that return an aggregate of non-constant size,
4470 	     since we would not be able to generate a temporary at all.  */
4471 	  if (TREE_CODE (TREE_OPERAND (*from_p, 0)) == CALL_EXPR)
4472 	    {
4473 	      *from_p = TREE_OPERAND (*from_p, 0);
4474 	      /* We don't change ret in this case because the
4475 		 WITH_SIZE_EXPR might have been added in
4476 		 gimplify_modify_expr, so returning GS_OK would lead to an
4477 		 infinite loop.  */
4478 	      changed = true;
4479 	    }
4480 	  break;
4481 
4482 	  /* If we're initializing from a container, push the initialization
4483 	     inside it.  */
4484 	case CLEANUP_POINT_EXPR:
4485 	case BIND_EXPR:
4486 	case STATEMENT_LIST:
4487 	  {
4488 	    tree wrap = *from_p;
4489 	    tree t;
4490 
4491 	    ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_min_lval,
4492 				 fb_lvalue);
4493 	    if (ret != GS_ERROR)
4494 	      ret = GS_OK;
4495 
4496 	    t = voidify_wrapper_expr (wrap, *expr_p);
4497 	    gcc_assert (t == *expr_p);
4498 
4499 	    if (want_value)
4500 	      {
4501 		gimplify_and_add (wrap, pre_p);
4502 		*expr_p = unshare_expr (*to_p);
4503 	      }
4504 	    else
4505 	      *expr_p = wrap;
4506 	    return GS_OK;
4507 	  }
4508 
4509 	case COMPOUND_LITERAL_EXPR:
4510 	  {
4511 	    tree complit = TREE_OPERAND (*expr_p, 1);
4512 	    tree decl_s = COMPOUND_LITERAL_EXPR_DECL_EXPR (complit);
4513 	    tree decl = DECL_EXPR_DECL (decl_s);
4514 	    tree init = DECL_INITIAL (decl);
4515 
4516 	    /* struct T x = (struct T) { 0, 1, 2 } can be optimized
4517 	       into struct T x = { 0, 1, 2 } if the address of the
4518 	       compound literal has never been taken.  */
4519 	    if (!TREE_ADDRESSABLE (complit)
4520 		&& !TREE_ADDRESSABLE (decl)
4521 		&& init)
4522 	      {
4523 		*expr_p = copy_node (*expr_p);
4524 		TREE_OPERAND (*expr_p, 1) = init;
4525 		return GS_OK;
4526 	      }
4527 	  }
4528 
4529 	default:
4530 	  break;
4531 	}
4532     }
4533   while (changed);
4534 
4535   return ret;
4536 }
4537 
4538 /* Promote partial stores to COMPLEX variables to total stores.  *EXPR_P is
4539    a MODIFY_EXPR with a lhs of a REAL/IMAGPART_EXPR of a variable with
4540    DECL_GIMPLE_REG_P set.
4541 
4542    IMPORTANT NOTE: This promotion is performed by introducing a load of the
4543    other, unmodified part of the complex object just before the total store.
4544    As a consequence, if the object is still uninitialized, an undefined value
4545    will be loaded into a register, which may result in a spurious exception
4546    if the register is floating-point and the value happens to be a signaling
4547    NaN for example.  Then the fully-fledged complex operations lowering pass
4548    followed by a DCE pass are necessary in order to fix things up.  */
4549 
4550 static enum gimplify_status
4551 gimplify_modify_expr_complex_part (tree *expr_p, gimple_seq *pre_p,
4552                                    bool want_value)
4553 {
4554   enum tree_code code, ocode;
4555   tree lhs, rhs, new_rhs, other, realpart, imagpart;
4556 
4557   lhs = TREE_OPERAND (*expr_p, 0);
4558   rhs = TREE_OPERAND (*expr_p, 1);
4559   code = TREE_CODE (lhs);
4560   lhs = TREE_OPERAND (lhs, 0);
4561 
4562   ocode = code == REALPART_EXPR ? IMAGPART_EXPR : REALPART_EXPR;
4563   other = build1 (ocode, TREE_TYPE (rhs), lhs);
4564   TREE_NO_WARNING (other) = 1;
4565   other = get_formal_tmp_var (other, pre_p);
4566 
4567   realpart = code == REALPART_EXPR ? rhs : other;
4568   imagpart = code == REALPART_EXPR ? other : rhs;
4569 
4570   if (TREE_CONSTANT (realpart) && TREE_CONSTANT (imagpart))
4571     new_rhs = build_complex (TREE_TYPE (lhs), realpart, imagpart);
4572   else
4573     new_rhs = build2 (COMPLEX_EXPR, TREE_TYPE (lhs), realpart, imagpart);
4574 
4575   gimplify_seq_add_stmt (pre_p, gimple_build_assign (lhs, new_rhs));
4576   *expr_p = (want_value) ? rhs : NULL_TREE;
4577 
4578   return GS_ALL_DONE;
4579 }
4580 
4581 /* Gimplify the MODIFY_EXPR node pointed to by EXPR_P.
4582 
4583       modify_expr
4584 	      : varname '=' rhs
4585 	      | '*' ID '=' rhs
4586 
4587     PRE_P points to the list where side effects that must happen before
4588 	*EXPR_P should be stored.
4589 
4590     POST_P points to the list where side effects that must happen after
4591 	*EXPR_P should be stored.
4592 
4593     WANT_VALUE is nonzero iff we want to use the value of this expression
4594 	in another expression.  */
4595 
4596 static enum gimplify_status
4597 gimplify_modify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
4598 		      bool want_value)
4599 {
4600   tree *from_p = &TREE_OPERAND (*expr_p, 1);
4601   tree *to_p = &TREE_OPERAND (*expr_p, 0);
4602   enum gimplify_status ret = GS_UNHANDLED;
4603   gimple assign;
4604   location_t loc = EXPR_LOCATION (*expr_p);
4605 
4606   gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
4607 	      || TREE_CODE (*expr_p) == INIT_EXPR);
4608 
4609   /* Trying to simplify a clobber using normal logic doesn't work,
4610      so handle it here.  */
4611   if (TREE_CLOBBER_P (*from_p))
4612     {
4613       gcc_assert (!want_value && TREE_CODE (*to_p) == VAR_DECL);
4614       gimplify_seq_add_stmt (pre_p, gimple_build_assign (*to_p, *from_p));
4615       *expr_p = NULL;
4616       return GS_ALL_DONE;
4617     }
4618 
4619   /* Insert pointer conversions required by the middle-end that are not
4620      required by the frontend.  This fixes middle-end type checking for
4621      for example gcc.dg/redecl-6.c.  */
4622   if (POINTER_TYPE_P (TREE_TYPE (*to_p)))
4623     {
4624       STRIP_USELESS_TYPE_CONVERSION (*from_p);
4625       if (!useless_type_conversion_p (TREE_TYPE (*to_p), TREE_TYPE (*from_p)))
4626 	*from_p = fold_convert_loc (loc, TREE_TYPE (*to_p), *from_p);
4627     }
4628 
4629   /* See if any simplifications can be done based on what the RHS is.  */
4630   ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
4631 				  want_value);
4632   if (ret != GS_UNHANDLED)
4633     return ret;
4634 
4635   /* For zero sized types only gimplify the left hand side and right hand
4636      side as statements and throw away the assignment.  Do this after
4637      gimplify_modify_expr_rhs so we handle TARGET_EXPRs of addressable
4638      types properly.  */
4639   if (zero_sized_type (TREE_TYPE (*from_p)) && !want_value)
4640     {
4641       gimplify_stmt (from_p, pre_p);
4642       gimplify_stmt (to_p, pre_p);
4643       *expr_p = NULL_TREE;
4644       return GS_ALL_DONE;
4645     }
4646 
4647   /* If the value being copied is of variable width, compute the length
4648      of the copy into a WITH_SIZE_EXPR.   Note that we need to do this
4649      before gimplifying any of the operands so that we can resolve any
4650      PLACEHOLDER_EXPRs in the size.  Also note that the RTL expander uses
4651      the size of the expression to be copied, not of the destination, so
4652      that is what we must do here.  */
4653   maybe_with_size_expr (from_p);
4654 
4655   ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
4656   if (ret == GS_ERROR)
4657     return ret;
4658 
4659   /* As a special case, we have to temporarily allow for assignments
4660      with a CALL_EXPR on the RHS.  Since in GIMPLE a function call is
4661      a toplevel statement, when gimplifying the GENERIC expression
4662      MODIFY_EXPR <a, CALL_EXPR <foo>>, we cannot create the tuple
4663      GIMPLE_ASSIGN <a, GIMPLE_CALL <foo>>.
4664 
4665      Instead, we need to create the tuple GIMPLE_CALL <a, foo>.  To
4666      prevent gimplify_expr from trying to create a new temporary for
4667      foo's LHS, we tell it that it should only gimplify until it
4668      reaches the CALL_EXPR.  On return from gimplify_expr, the newly
4669      created GIMPLE_CALL <foo> will be the last statement in *PRE_P
4670      and all we need to do here is set 'a' to be its LHS.  */
4671   ret = gimplify_expr (from_p, pre_p, post_p, rhs_predicate_for (*to_p),
4672 		       fb_rvalue);
4673   if (ret == GS_ERROR)
4674     return ret;
4675 
4676   /* Now see if the above changed *from_p to something we handle specially.  */
4677   ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
4678 				  want_value);
4679   if (ret != GS_UNHANDLED)
4680     return ret;
4681 
4682   /* If we've got a variable sized assignment between two lvalues (i.e. does
4683      not involve a call), then we can make things a bit more straightforward
4684      by converting the assignment to memcpy or memset.  */
4685   if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
4686     {
4687       tree from = TREE_OPERAND (*from_p, 0);
4688       tree size = TREE_OPERAND (*from_p, 1);
4689 
4690       if (TREE_CODE (from) == CONSTRUCTOR)
4691 	return gimplify_modify_expr_to_memset (expr_p, size, want_value, pre_p);
4692 
4693       if (is_gimple_addressable (from))
4694 	{
4695 	  *from_p = from;
4696 	  return gimplify_modify_expr_to_memcpy (expr_p, size, want_value,
4697 	      					 pre_p);
4698 	}
4699     }
4700 
4701   /* Transform partial stores to non-addressable complex variables into
4702      total stores.  This allows us to use real instead of virtual operands
4703      for these variables, which improves optimization.  */
4704   if ((TREE_CODE (*to_p) == REALPART_EXPR
4705        || TREE_CODE (*to_p) == IMAGPART_EXPR)
4706       && is_gimple_reg (TREE_OPERAND (*to_p, 0)))
4707     return gimplify_modify_expr_complex_part (expr_p, pre_p, want_value);
4708 
4709   /* Try to alleviate the effects of the gimplification creating artificial
4710      temporaries (see for example is_gimple_reg_rhs) on the debug info.  */
4711   if (!gimplify_ctxp->into_ssa
4712       && TREE_CODE (*from_p) == VAR_DECL
4713       && DECL_IGNORED_P (*from_p)
4714       && DECL_P (*to_p)
4715       && !DECL_IGNORED_P (*to_p))
4716     {
4717       if (!DECL_NAME (*from_p) && DECL_NAME (*to_p))
4718 	DECL_NAME (*from_p)
4719 	  = create_tmp_var_name (IDENTIFIER_POINTER (DECL_NAME (*to_p)));
4720       DECL_DEBUG_EXPR_IS_FROM (*from_p) = 1;
4721       SET_DECL_DEBUG_EXPR (*from_p, *to_p);
4722    }
4723 
4724   if (want_value && TREE_THIS_VOLATILE (*to_p))
4725     *from_p = get_initialized_tmp_var (*from_p, pre_p, post_p);
4726 
4727   if (TREE_CODE (*from_p) == CALL_EXPR)
4728     {
4729       /* Since the RHS is a CALL_EXPR, we need to create a GIMPLE_CALL
4730 	 instead of a GIMPLE_ASSIGN.  */
4731       tree fnptrtype = TREE_TYPE (CALL_EXPR_FN (*from_p));
4732       CALL_EXPR_FN (*from_p) = TREE_OPERAND (CALL_EXPR_FN (*from_p), 0);
4733       STRIP_USELESS_TYPE_CONVERSION (CALL_EXPR_FN (*from_p));
4734       assign = gimple_build_call_from_tree (*from_p);
4735       gimple_call_set_fntype (assign, TREE_TYPE (fnptrtype));
4736       if (!gimple_call_noreturn_p (assign))
4737 	gimple_call_set_lhs (assign, *to_p);
4738     }
4739   else
4740     {
4741       assign = gimple_build_assign (*to_p, *from_p);
4742       gimple_set_location (assign, EXPR_LOCATION (*expr_p));
4743     }
4744 
4745   gimplify_seq_add_stmt (pre_p, assign);
4746 
4747   if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
4748     {
4749       /* If we've somehow already got an SSA_NAME on the LHS, then
4750 	 we've probably modified it twice.  Not good.  */
4751       gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
4752       *to_p = make_ssa_name (*to_p, assign);
4753       gimple_set_lhs (assign, *to_p);
4754     }
4755 
4756   if (want_value)
4757     {
4758       *expr_p = TREE_THIS_VOLATILE (*to_p) ? *from_p : unshare_expr (*to_p);
4759       return GS_OK;
4760     }
4761   else
4762     *expr_p = NULL;
4763 
4764   return GS_ALL_DONE;
4765 }
4766 
4767 /* Gimplify a comparison between two variable-sized objects.  Do this
4768    with a call to BUILT_IN_MEMCMP.  */
4769 
4770 static enum gimplify_status
4771 gimplify_variable_sized_compare (tree *expr_p)
4772 {
4773   location_t loc = EXPR_LOCATION (*expr_p);
4774   tree op0 = TREE_OPERAND (*expr_p, 0);
4775   tree op1 = TREE_OPERAND (*expr_p, 1);
4776   tree t, arg, dest, src, expr;
4777 
4778   arg = TYPE_SIZE_UNIT (TREE_TYPE (op0));
4779   arg = unshare_expr (arg);
4780   arg = SUBSTITUTE_PLACEHOLDER_IN_EXPR (arg, op0);
4781   src = build_fold_addr_expr_loc (loc, op1);
4782   dest = build_fold_addr_expr_loc (loc, op0);
4783   t = builtin_decl_implicit (BUILT_IN_MEMCMP);
4784   t = build_call_expr_loc (loc, t, 3, dest, src, arg);
4785 
4786   expr
4787     = build2 (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
4788   SET_EXPR_LOCATION (expr, loc);
4789   *expr_p = expr;
4790 
4791   return GS_OK;
4792 }
4793 
4794 /* Gimplify a comparison between two aggregate objects of integral scalar
4795    mode as a comparison between the bitwise equivalent scalar values.  */
4796 
4797 static enum gimplify_status
4798 gimplify_scalar_mode_aggregate_compare (tree *expr_p)
4799 {
4800   location_t loc = EXPR_LOCATION (*expr_p);
4801   tree op0 = TREE_OPERAND (*expr_p, 0);
4802   tree op1 = TREE_OPERAND (*expr_p, 1);
4803 
4804   tree type = TREE_TYPE (op0);
4805   tree scalar_type = lang_hooks.types.type_for_mode (TYPE_MODE (type), 1);
4806 
4807   op0 = fold_build1_loc (loc, VIEW_CONVERT_EXPR, scalar_type, op0);
4808   op1 = fold_build1_loc (loc, VIEW_CONVERT_EXPR, scalar_type, op1);
4809 
4810   *expr_p
4811     = fold_build2_loc (loc, TREE_CODE (*expr_p), TREE_TYPE (*expr_p), op0, op1);
4812 
4813   return GS_OK;
4814 }
4815 
4816 /* Gimplify an expression sequence.  This function gimplifies each
4817    expression and rewrites the original expression with the last
4818    expression of the sequence in GIMPLE form.
4819 
4820    PRE_P points to the list where the side effects for all the
4821        expressions in the sequence will be emitted.
4822 
4823    WANT_VALUE is true when the result of the last COMPOUND_EXPR is used.  */
4824 
4825 static enum gimplify_status
4826 gimplify_compound_expr (tree *expr_p, gimple_seq *pre_p, bool want_value)
4827 {
4828   tree t = *expr_p;
4829 
4830   do
4831     {
4832       tree *sub_p = &TREE_OPERAND (t, 0);
4833 
4834       if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
4835 	gimplify_compound_expr (sub_p, pre_p, false);
4836       else
4837 	gimplify_stmt (sub_p, pre_p);
4838 
4839       t = TREE_OPERAND (t, 1);
4840     }
4841   while (TREE_CODE (t) == COMPOUND_EXPR);
4842 
4843   *expr_p = t;
4844   if (want_value)
4845     return GS_OK;
4846   else
4847     {
4848       gimplify_stmt (expr_p, pre_p);
4849       return GS_ALL_DONE;
4850     }
4851 }
4852 
4853 /* Gimplify a SAVE_EXPR node.  EXPR_P points to the expression to
4854    gimplify.  After gimplification, EXPR_P will point to a new temporary
4855    that holds the original value of the SAVE_EXPR node.
4856 
4857    PRE_P points to the list where side effects that must happen before
4858    *EXPR_P should be stored.  */
4859 
4860 static enum gimplify_status
4861 gimplify_save_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
4862 {
4863   enum gimplify_status ret = GS_ALL_DONE;
4864   tree val;
4865 
4866   gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
4867   val = TREE_OPERAND (*expr_p, 0);
4868 
4869   /* If the SAVE_EXPR has not been resolved, then evaluate it once.  */
4870   if (!SAVE_EXPR_RESOLVED_P (*expr_p))
4871     {
4872       /* The operand may be a void-valued expression such as SAVE_EXPRs
4873 	 generated by the Java frontend for class initialization.  It is
4874 	 being executed only for its side-effects.  */
4875       if (TREE_TYPE (val) == void_type_node)
4876 	{
4877 	  ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4878 			       is_gimple_stmt, fb_none);
4879 	  val = NULL;
4880 	}
4881       else
4882 	val = get_initialized_tmp_var (val, pre_p, post_p);
4883 
4884       TREE_OPERAND (*expr_p, 0) = val;
4885       SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
4886     }
4887 
4888   *expr_p = val;
4889 
4890   return ret;
4891 }
4892 
4893 /* Rewrite the ADDR_EXPR node pointed to by EXPR_P
4894 
4895       unary_expr
4896 	      : ...
4897 	      | '&' varname
4898 	      ...
4899 
4900     PRE_P points to the list where side effects that must happen before
4901 	*EXPR_P should be stored.
4902 
4903     POST_P points to the list where side effects that must happen after
4904 	*EXPR_P should be stored.  */
4905 
4906 static enum gimplify_status
4907 gimplify_addr_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
4908 {
4909   tree expr = *expr_p;
4910   tree op0 = TREE_OPERAND (expr, 0);
4911   enum gimplify_status ret;
4912   location_t loc = EXPR_LOCATION (*expr_p);
4913 
4914   switch (TREE_CODE (op0))
4915     {
4916     case INDIRECT_REF:
4917     do_indirect_ref:
4918       /* Check if we are dealing with an expression of the form '&*ptr'.
4919 	 While the front end folds away '&*ptr' into 'ptr', these
4920 	 expressions may be generated internally by the compiler (e.g.,
4921 	 builtins like __builtin_va_end).  */
4922       /* Caution: the silent array decomposition semantics we allow for
4923 	 ADDR_EXPR means we can't always discard the pair.  */
4924       /* Gimplification of the ADDR_EXPR operand may drop
4925 	 cv-qualification conversions, so make sure we add them if
4926 	 needed.  */
4927       {
4928 	tree op00 = TREE_OPERAND (op0, 0);
4929 	tree t_expr = TREE_TYPE (expr);
4930 	tree t_op00 = TREE_TYPE (op00);
4931 
4932         if (!useless_type_conversion_p (t_expr, t_op00))
4933 	  op00 = fold_convert_loc (loc, TREE_TYPE (expr), op00);
4934         *expr_p = op00;
4935         ret = GS_OK;
4936       }
4937       break;
4938 
4939     case VIEW_CONVERT_EXPR:
4940       /* Take the address of our operand and then convert it to the type of
4941 	 this ADDR_EXPR.
4942 
4943 	 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
4944 	 all clear.  The impact of this transformation is even less clear.  */
4945 
4946       /* If the operand is a useless conversion, look through it.  Doing so
4947 	 guarantees that the ADDR_EXPR and its operand will remain of the
4948 	 same type.  */
4949       if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
4950 	op0 = TREE_OPERAND (op0, 0);
4951 
4952       *expr_p = fold_convert_loc (loc, TREE_TYPE (expr),
4953 				  build_fold_addr_expr_loc (loc,
4954 							TREE_OPERAND (op0, 0)));
4955       ret = GS_OK;
4956       break;
4957 
4958     default:
4959       /* We use fb_either here because the C frontend sometimes takes
4960 	 the address of a call that returns a struct; see
4961 	 gcc.dg/c99-array-lval-1.c.  The gimplifier will correctly make
4962 	 the implied temporary explicit.  */
4963 
4964       /* Make the operand addressable.  */
4965       ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
4966 			   is_gimple_addressable, fb_either);
4967       if (ret == GS_ERROR)
4968 	break;
4969 
4970       /* Then mark it.  Beware that it may not be possible to do so directly
4971 	 if a temporary has been created by the gimplification.  */
4972       prepare_gimple_addressable (&TREE_OPERAND (expr, 0), pre_p);
4973 
4974       op0 = TREE_OPERAND (expr, 0);
4975 
4976       /* For various reasons, the gimplification of the expression
4977 	 may have made a new INDIRECT_REF.  */
4978       if (TREE_CODE (op0) == INDIRECT_REF)
4979 	goto do_indirect_ref;
4980 
4981       mark_addressable (TREE_OPERAND (expr, 0));
4982 
4983       /* The FEs may end up building ADDR_EXPRs early on a decl with
4984 	 an incomplete type.  Re-build ADDR_EXPRs in canonical form
4985 	 here.  */
4986       if (!types_compatible_p (TREE_TYPE (op0), TREE_TYPE (TREE_TYPE (expr))))
4987 	*expr_p = build_fold_addr_expr (op0);
4988 
4989       /* Make sure TREE_CONSTANT and TREE_SIDE_EFFECTS are set properly.  */
4990       recompute_tree_invariant_for_addr_expr (*expr_p);
4991 
4992       /* If we re-built the ADDR_EXPR add a conversion to the original type
4993          if required.  */
4994       if (!useless_type_conversion_p (TREE_TYPE (expr), TREE_TYPE (*expr_p)))
4995 	*expr_p = fold_convert (TREE_TYPE (expr), *expr_p);
4996 
4997       break;
4998     }
4999 
5000   return ret;
5001 }
5002 
5003 /* Gimplify the operands of an ASM_EXPR.  Input operands should be a gimple
5004    value; output operands should be a gimple lvalue.  */
5005 
5006 static enum gimplify_status
5007 gimplify_asm_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
5008 {
5009   tree expr;
5010   int noutputs;
5011   const char **oconstraints;
5012   int i;
5013   tree link;
5014   const char *constraint;
5015   bool allows_mem, allows_reg, is_inout;
5016   enum gimplify_status ret, tret;
5017   gimple stmt;
5018   VEC(tree, gc) *inputs;
5019   VEC(tree, gc) *outputs;
5020   VEC(tree, gc) *clobbers;
5021   VEC(tree, gc) *labels;
5022   tree link_next;
5023 
5024   expr = *expr_p;
5025   noutputs = list_length (ASM_OUTPUTS (expr));
5026   oconstraints = (const char **) alloca ((noutputs) * sizeof (const char *));
5027 
5028   inputs = outputs = clobbers = labels = NULL;
5029 
5030   ret = GS_ALL_DONE;
5031   link_next = NULL_TREE;
5032   for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = link_next)
5033     {
5034       bool ok;
5035       size_t constraint_len;
5036 
5037       link_next = TREE_CHAIN (link);
5038 
5039       oconstraints[i]
5040 	= constraint
5041 	= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
5042       constraint_len = strlen (constraint);
5043       if (constraint_len == 0)
5044         continue;
5045 
5046       ok = parse_output_constraint (&constraint, i, 0, 0,
5047 				    &allows_mem, &allows_reg, &is_inout);
5048       if (!ok)
5049 	{
5050 	  ret = GS_ERROR;
5051 	  is_inout = false;
5052 	}
5053 
5054       if (!allows_reg && allows_mem)
5055 	mark_addressable (TREE_VALUE (link));
5056 
5057       tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
5058 			    is_inout ? is_gimple_min_lval : is_gimple_lvalue,
5059 			    fb_lvalue | fb_mayfail);
5060       if (tret == GS_ERROR)
5061 	{
5062 	  error ("invalid lvalue in asm output %d", i);
5063 	  ret = tret;
5064 	}
5065 
5066       VEC_safe_push (tree, gc, outputs, link);
5067       TREE_CHAIN (link) = NULL_TREE;
5068 
5069       if (is_inout)
5070 	{
5071 	  /* An input/output operand.  To give the optimizers more
5072 	     flexibility, split it into separate input and output
5073  	     operands.  */
5074 	  tree input;
5075 	  char buf[10];
5076 
5077 	  /* Turn the in/out constraint into an output constraint.  */
5078 	  char *p = xstrdup (constraint);
5079 	  p[0] = '=';
5080 	  TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
5081 
5082 	  /* And add a matching input constraint.  */
5083 	  if (allows_reg)
5084 	    {
5085 	      sprintf (buf, "%d", i);
5086 
5087 	      /* If there are multiple alternatives in the constraint,
5088 		 handle each of them individually.  Those that allow register
5089 		 will be replaced with operand number, the others will stay
5090 		 unchanged.  */
5091 	      if (strchr (p, ',') != NULL)
5092 		{
5093 		  size_t len = 0, buflen = strlen (buf);
5094 		  char *beg, *end, *str, *dst;
5095 
5096 		  for (beg = p + 1;;)
5097 		    {
5098 		      end = strchr (beg, ',');
5099 		      if (end == NULL)
5100 			end = strchr (beg, '\0');
5101 		      if ((size_t) (end - beg) < buflen)
5102 			len += buflen + 1;
5103 		      else
5104 			len += end - beg + 1;
5105 		      if (*end)
5106 			beg = end + 1;
5107 		      else
5108 			break;
5109 		    }
5110 
5111 		  str = (char *) alloca (len);
5112 		  for (beg = p + 1, dst = str;;)
5113 		    {
5114 		      const char *tem;
5115 		      bool mem_p, reg_p, inout_p;
5116 
5117 		      end = strchr (beg, ',');
5118 		      if (end)
5119 			*end = '\0';
5120 		      beg[-1] = '=';
5121 		      tem = beg - 1;
5122 		      parse_output_constraint (&tem, i, 0, 0,
5123 					       &mem_p, &reg_p, &inout_p);
5124 		      if (dst != str)
5125 			*dst++ = ',';
5126 		      if (reg_p)
5127 			{
5128 			  memcpy (dst, buf, buflen);
5129 			  dst += buflen;
5130 			}
5131 		      else
5132 			{
5133 			  if (end)
5134 			    len = end - beg;
5135 			  else
5136 			    len = strlen (beg);
5137 			  memcpy (dst, beg, len);
5138 			  dst += len;
5139 			}
5140 		      if (end)
5141 			beg = end + 1;
5142 		      else
5143 			break;
5144 		    }
5145 		  *dst = '\0';
5146 		  input = build_string (dst - str, str);
5147 		}
5148 	      else
5149 		input = build_string (strlen (buf), buf);
5150 	    }
5151 	  else
5152 	    input = build_string (constraint_len - 1, constraint + 1);
5153 
5154 	  free (p);
5155 
5156 	  input = build_tree_list (build_tree_list (NULL_TREE, input),
5157 				   unshare_expr (TREE_VALUE (link)));
5158 	  ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
5159 	}
5160     }
5161 
5162   link_next = NULL_TREE;
5163   for (link = ASM_INPUTS (expr); link; ++i, link = link_next)
5164     {
5165       link_next = TREE_CHAIN (link);
5166       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
5167       parse_input_constraint (&constraint, 0, 0, noutputs, 0,
5168 			      oconstraints, &allows_mem, &allows_reg);
5169 
5170       /* If we can't make copies, we can only accept memory.  */
5171       if (TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (link))))
5172 	{
5173 	  if (allows_mem)
5174 	    allows_reg = 0;
5175 	  else
5176 	    {
5177 	      error ("impossible constraint in %<asm%>");
5178 	      error ("non-memory input %d must stay in memory", i);
5179 	      return GS_ERROR;
5180 	    }
5181 	}
5182 
5183       /* If the operand is a memory input, it should be an lvalue.  */
5184       if (!allows_reg && allows_mem)
5185 	{
5186 	  tree inputv = TREE_VALUE (link);
5187 	  STRIP_NOPS (inputv);
5188 	  if (TREE_CODE (inputv) == PREDECREMENT_EXPR
5189 	      || TREE_CODE (inputv) == PREINCREMENT_EXPR
5190 	      || TREE_CODE (inputv) == POSTDECREMENT_EXPR
5191 	      || TREE_CODE (inputv) == POSTINCREMENT_EXPR)
5192 	    TREE_VALUE (link) = error_mark_node;
5193 	  tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
5194 				is_gimple_lvalue, fb_lvalue | fb_mayfail);
5195 	  mark_addressable (TREE_VALUE (link));
5196 	  if (tret == GS_ERROR)
5197 	    {
5198 	      if (EXPR_HAS_LOCATION (TREE_VALUE (link)))
5199 	        input_location = EXPR_LOCATION (TREE_VALUE (link));
5200 	      error ("memory input %d is not directly addressable", i);
5201 	      ret = tret;
5202 	    }
5203 	}
5204       else
5205 	{
5206 	  tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
5207 				is_gimple_asm_val, fb_rvalue);
5208 	  if (tret == GS_ERROR)
5209 	    ret = tret;
5210 	}
5211 
5212       TREE_CHAIN (link) = NULL_TREE;
5213       VEC_safe_push (tree, gc, inputs, link);
5214     }
5215 
5216   for (link = ASM_CLOBBERS (expr); link; ++i, link = TREE_CHAIN (link))
5217     VEC_safe_push (tree, gc, clobbers, link);
5218 
5219   for (link = ASM_LABELS (expr); link; ++i, link = TREE_CHAIN (link))
5220     VEC_safe_push (tree, gc, labels, link);
5221 
5222   /* Do not add ASMs with errors to the gimple IL stream.  */
5223   if (ret != GS_ERROR)
5224     {
5225       stmt = gimple_build_asm_vec (TREE_STRING_POINTER (ASM_STRING (expr)),
5226 				   inputs, outputs, clobbers, labels);
5227 
5228       gimple_asm_set_volatile (stmt, ASM_VOLATILE_P (expr));
5229       gimple_asm_set_input (stmt, ASM_INPUT_P (expr));
5230 
5231       gimplify_seq_add_stmt (pre_p, stmt);
5232     }
5233 
5234   return ret;
5235 }
5236 
5237 /* Gimplify a CLEANUP_POINT_EXPR.  Currently this works by adding
5238    GIMPLE_WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
5239    gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
5240    return to this function.
5241 
5242    FIXME should we complexify the prequeue handling instead?  Or use flags
5243    for all the cleanups and let the optimizer tighten them up?  The current
5244    code seems pretty fragile; it will break on a cleanup within any
5245    non-conditional nesting.  But any such nesting would be broken, anyway;
5246    we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
5247    and continues out of it.  We can do that at the RTL level, though, so
5248    having an optimizer to tighten up try/finally regions would be a Good
5249    Thing.  */
5250 
5251 static enum gimplify_status
5252 gimplify_cleanup_point_expr (tree *expr_p, gimple_seq *pre_p)
5253 {
5254   gimple_stmt_iterator iter;
5255   gimple_seq body_sequence = NULL;
5256 
5257   tree temp = voidify_wrapper_expr (*expr_p, NULL);
5258 
5259   /* We only care about the number of conditions between the innermost
5260      CLEANUP_POINT_EXPR and the cleanup.  So save and reset the count and
5261      any cleanups collected outside the CLEANUP_POINT_EXPR.  */
5262   int old_conds = gimplify_ctxp->conditions;
5263   gimple_seq old_cleanups = gimplify_ctxp->conditional_cleanups;
5264   bool old_in_cleanup_point_expr = gimplify_ctxp->in_cleanup_point_expr;
5265   gimplify_ctxp->conditions = 0;
5266   gimplify_ctxp->conditional_cleanups = NULL;
5267   gimplify_ctxp->in_cleanup_point_expr = true;
5268 
5269   gimplify_stmt (&TREE_OPERAND (*expr_p, 0), &body_sequence);
5270 
5271   gimplify_ctxp->conditions = old_conds;
5272   gimplify_ctxp->conditional_cleanups = old_cleanups;
5273   gimplify_ctxp->in_cleanup_point_expr = old_in_cleanup_point_expr;
5274 
5275   for (iter = gsi_start (body_sequence); !gsi_end_p (iter); )
5276     {
5277       gimple wce = gsi_stmt (iter);
5278 
5279       if (gimple_code (wce) == GIMPLE_WITH_CLEANUP_EXPR)
5280 	{
5281 	  if (gsi_one_before_end_p (iter))
5282 	    {
5283               /* Note that gsi_insert_seq_before and gsi_remove do not
5284                  scan operands, unlike some other sequence mutators.  */
5285 	      if (!gimple_wce_cleanup_eh_only (wce))
5286 		gsi_insert_seq_before_without_update (&iter,
5287 						      gimple_wce_cleanup (wce),
5288 						      GSI_SAME_STMT);
5289 	      gsi_remove (&iter, true);
5290 	      break;
5291 	    }
5292 	  else
5293 	    {
5294 	      gimple gtry;
5295 	      gimple_seq seq;
5296 	      enum gimple_try_flags kind;
5297 
5298 	      if (gimple_wce_cleanup_eh_only (wce))
5299 		kind = GIMPLE_TRY_CATCH;
5300 	      else
5301 		kind = GIMPLE_TRY_FINALLY;
5302 	      seq = gsi_split_seq_after (iter);
5303 
5304 	      gtry = gimple_build_try (seq, gimple_wce_cleanup (wce), kind);
5305               /* Do not use gsi_replace here, as it may scan operands.
5306                  We want to do a simple structural modification only.  */
5307               *gsi_stmt_ptr (&iter) = gtry;
5308 	      iter = gsi_start (seq);
5309 	    }
5310 	}
5311       else
5312 	gsi_next (&iter);
5313     }
5314 
5315   gimplify_seq_add_seq (pre_p, body_sequence);
5316   if (temp)
5317     {
5318       *expr_p = temp;
5319       return GS_OK;
5320     }
5321   else
5322     {
5323       *expr_p = NULL;
5324       return GS_ALL_DONE;
5325     }
5326 }
5327 
5328 /* Insert a cleanup marker for gimplify_cleanup_point_expr.  CLEANUP
5329    is the cleanup action required.  EH_ONLY is true if the cleanup should
5330    only be executed if an exception is thrown, not on normal exit.  */
5331 
5332 static void
5333 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, gimple_seq *pre_p)
5334 {
5335   gimple wce;
5336   gimple_seq cleanup_stmts = NULL;
5337 
5338   /* Errors can result in improperly nested cleanups.  Which results in
5339      confusion when trying to resolve the GIMPLE_WITH_CLEANUP_EXPR.  */
5340   if (seen_error ())
5341     return;
5342 
5343   if (gimple_conditional_context ())
5344     {
5345       /* If we're in a conditional context, this is more complex.  We only
5346 	 want to run the cleanup if we actually ran the initialization that
5347 	 necessitates it, but we want to run it after the end of the
5348 	 conditional context.  So we wrap the try/finally around the
5349 	 condition and use a flag to determine whether or not to actually
5350 	 run the destructor.  Thus
5351 
5352 	   test ? f(A()) : 0
5353 
5354 	 becomes (approximately)
5355 
5356 	   flag = 0;
5357 	   try {
5358 	     if (test) { A::A(temp); flag = 1; val = f(temp); }
5359 	     else { val = 0; }
5360 	   } finally {
5361 	     if (flag) A::~A(temp);
5362 	   }
5363 	   val
5364       */
5365       tree flag = create_tmp_var (boolean_type_node, "cleanup");
5366       gimple ffalse = gimple_build_assign (flag, boolean_false_node);
5367       gimple ftrue = gimple_build_assign (flag, boolean_true_node);
5368 
5369       cleanup = build3 (COND_EXPR, void_type_node, flag, cleanup, NULL);
5370       gimplify_stmt (&cleanup, &cleanup_stmts);
5371       wce = gimple_build_wce (cleanup_stmts);
5372 
5373       gimplify_seq_add_stmt (&gimplify_ctxp->conditional_cleanups, ffalse);
5374       gimplify_seq_add_stmt (&gimplify_ctxp->conditional_cleanups, wce);
5375       gimplify_seq_add_stmt (pre_p, ftrue);
5376 
5377       /* Because of this manipulation, and the EH edges that jump
5378 	 threading cannot redirect, the temporary (VAR) will appear
5379 	 to be used uninitialized.  Don't warn.  */
5380       TREE_NO_WARNING (var) = 1;
5381     }
5382   else
5383     {
5384       gimplify_stmt (&cleanup, &cleanup_stmts);
5385       wce = gimple_build_wce (cleanup_stmts);
5386       gimple_wce_set_cleanup_eh_only (wce, eh_only);
5387       gimplify_seq_add_stmt (pre_p, wce);
5388     }
5389 }
5390 
5391 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR.  */
5392 
5393 static enum gimplify_status
5394 gimplify_target_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
5395 {
5396   tree targ = *expr_p;
5397   tree temp = TARGET_EXPR_SLOT (targ);
5398   tree init = TARGET_EXPR_INITIAL (targ);
5399   enum gimplify_status ret;
5400 
5401   if (init)
5402     {
5403       tree cleanup = NULL_TREE;
5404 
5405       /* TARGET_EXPR temps aren't part of the enclosing block, so add it
5406 	 to the temps list.  Handle also variable length TARGET_EXPRs.  */
5407       if (TREE_CODE (DECL_SIZE (temp)) != INTEGER_CST)
5408 	{
5409 	  if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (temp)))
5410 	    gimplify_type_sizes (TREE_TYPE (temp), pre_p);
5411 	  gimplify_vla_decl (temp, pre_p);
5412 	}
5413       else
5414 	gimple_add_tmp_var (temp);
5415 
5416       /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
5417 	 expression is supposed to initialize the slot.  */
5418       if (VOID_TYPE_P (TREE_TYPE (init)))
5419 	ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
5420       else
5421 	{
5422 	  tree init_expr = build2 (INIT_EXPR, void_type_node, temp, init);
5423 	  init = init_expr;
5424 	  ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
5425 	  init = NULL;
5426 	  ggc_free (init_expr);
5427 	}
5428       if (ret == GS_ERROR)
5429 	{
5430 	  /* PR c++/28266 Make sure this is expanded only once. */
5431 	  TARGET_EXPR_INITIAL (targ) = NULL_TREE;
5432 	  return GS_ERROR;
5433 	}
5434       if (init)
5435 	gimplify_and_add (init, pre_p);
5436 
5437       /* If needed, push the cleanup for the temp.  */
5438       if (TARGET_EXPR_CLEANUP (targ))
5439 	{
5440 	  if (CLEANUP_EH_ONLY (targ))
5441 	    gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
5442 				 CLEANUP_EH_ONLY (targ), pre_p);
5443 	  else
5444 	    cleanup = TARGET_EXPR_CLEANUP (targ);
5445 	}
5446 
5447       /* Add a clobber for the temporary going out of scope, like
5448 	 gimplify_bind_expr.  */
5449       if (gimplify_ctxp->in_cleanup_point_expr
5450 	  && needs_to_live_in_memory (temp))
5451 	{
5452 	  tree clobber = build_constructor (TREE_TYPE (temp), NULL);
5453 	  TREE_THIS_VOLATILE (clobber) = true;
5454 	  clobber = build2 (MODIFY_EXPR, TREE_TYPE (temp), temp, clobber);
5455 	  if (cleanup)
5456 	    cleanup = build2 (COMPOUND_EXPR, void_type_node, cleanup,
5457 			      clobber);
5458 	  else
5459 	    cleanup = clobber;
5460 	}
5461 
5462       if (cleanup)
5463 	gimple_push_cleanup (temp, cleanup, false, pre_p);
5464 
5465       /* Only expand this once.  */
5466       TREE_OPERAND (targ, 3) = init;
5467       TARGET_EXPR_INITIAL (targ) = NULL_TREE;
5468     }
5469   else
5470     /* We should have expanded this before.  */
5471     gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
5472 
5473   *expr_p = temp;
5474   return GS_OK;
5475 }
5476 
5477 /* Gimplification of expression trees.  */
5478 
5479 /* Gimplify an expression which appears at statement context.  The
5480    corresponding GIMPLE statements are added to *SEQ_P.  If *SEQ_P is
5481    NULL, a new sequence is allocated.
5482 
5483    Return true if we actually added a statement to the queue.  */
5484 
5485 bool
5486 gimplify_stmt (tree *stmt_p, gimple_seq *seq_p)
5487 {
5488   gimple_seq_node last;
5489 
5490   if (!*seq_p)
5491     *seq_p = gimple_seq_alloc ();
5492 
5493   last = gimple_seq_last (*seq_p);
5494   gimplify_expr (stmt_p, seq_p, NULL, is_gimple_stmt, fb_none);
5495   return last != gimple_seq_last (*seq_p);
5496 }
5497 
5498 /* Add FIRSTPRIVATE entries for DECL in the OpenMP the surrounding parallels
5499    to CTX.  If entries already exist, force them to be some flavor of private.
5500    If there is no enclosing parallel, do nothing.  */
5501 
5502 void
5503 omp_firstprivatize_variable (struct gimplify_omp_ctx *ctx, tree decl)
5504 {
5505   splay_tree_node n;
5506 
5507   if (decl == NULL || !DECL_P (decl))
5508     return;
5509 
5510   do
5511     {
5512       n = splay_tree_lookup (ctx->variables, (splay_tree_key)decl);
5513       if (n != NULL)
5514 	{
5515 	  if (n->value & GOVD_SHARED)
5516 	    n->value = GOVD_FIRSTPRIVATE | (n->value & GOVD_SEEN);
5517 	  else
5518 	    return;
5519 	}
5520       else if (ctx->region_type != ORT_WORKSHARE)
5521 	omp_add_variable (ctx, decl, GOVD_FIRSTPRIVATE);
5522 
5523       ctx = ctx->outer_context;
5524     }
5525   while (ctx);
5526 }
5527 
5528 /* Similarly for each of the type sizes of TYPE.  */
5529 
5530 static void
5531 omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *ctx, tree type)
5532 {
5533   if (type == NULL || type == error_mark_node)
5534     return;
5535   type = TYPE_MAIN_VARIANT (type);
5536 
5537   if (pointer_set_insert (ctx->privatized_types, type))
5538     return;
5539 
5540   switch (TREE_CODE (type))
5541     {
5542     case INTEGER_TYPE:
5543     case ENUMERAL_TYPE:
5544     case BOOLEAN_TYPE:
5545     case REAL_TYPE:
5546     case FIXED_POINT_TYPE:
5547       omp_firstprivatize_variable (ctx, TYPE_MIN_VALUE (type));
5548       omp_firstprivatize_variable (ctx, TYPE_MAX_VALUE (type));
5549       break;
5550 
5551     case ARRAY_TYPE:
5552       omp_firstprivatize_type_sizes (ctx, TREE_TYPE (type));
5553       omp_firstprivatize_type_sizes (ctx, TYPE_DOMAIN (type));
5554       break;
5555 
5556     case RECORD_TYPE:
5557     case UNION_TYPE:
5558     case QUAL_UNION_TYPE:
5559       {
5560 	tree field;
5561 	for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
5562 	  if (TREE_CODE (field) == FIELD_DECL)
5563 	    {
5564 	      omp_firstprivatize_variable (ctx, DECL_FIELD_OFFSET (field));
5565 	      omp_firstprivatize_type_sizes (ctx, TREE_TYPE (field));
5566 	    }
5567       }
5568       break;
5569 
5570     case POINTER_TYPE:
5571     case REFERENCE_TYPE:
5572       omp_firstprivatize_type_sizes (ctx, TREE_TYPE (type));
5573       break;
5574 
5575     default:
5576       break;
5577     }
5578 
5579   omp_firstprivatize_variable (ctx, TYPE_SIZE (type));
5580   omp_firstprivatize_variable (ctx, TYPE_SIZE_UNIT (type));
5581   lang_hooks.types.omp_firstprivatize_type_sizes (ctx, type);
5582 }
5583 
5584 /* Add an entry for DECL in the OpenMP context CTX with FLAGS.  */
5585 
5586 static void
5587 omp_add_variable (struct gimplify_omp_ctx *ctx, tree decl, unsigned int flags)
5588 {
5589   splay_tree_node n;
5590   unsigned int nflags;
5591   tree t;
5592 
5593   if (error_operand_p (decl))
5594     return;
5595 
5596   /* Never elide decls whose type has TREE_ADDRESSABLE set.  This means
5597      there are constructors involved somewhere.  */
5598   if (TREE_ADDRESSABLE (TREE_TYPE (decl))
5599       || TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (decl)))
5600     flags |= GOVD_SEEN;
5601 
5602   n = splay_tree_lookup (ctx->variables, (splay_tree_key)decl);
5603   if (n != NULL)
5604     {
5605       /* We shouldn't be re-adding the decl with the same data
5606 	 sharing class.  */
5607       gcc_assert ((n->value & GOVD_DATA_SHARE_CLASS & flags) == 0);
5608       /* The only combination of data sharing classes we should see is
5609 	 FIRSTPRIVATE and LASTPRIVATE.  */
5610       nflags = n->value | flags;
5611       gcc_assert ((nflags & GOVD_DATA_SHARE_CLASS)
5612 		  == (GOVD_FIRSTPRIVATE | GOVD_LASTPRIVATE));
5613       n->value = nflags;
5614       return;
5615     }
5616 
5617   /* When adding a variable-sized variable, we have to handle all sorts
5618      of additional bits of data: the pointer replacement variable, and
5619      the parameters of the type.  */
5620   if (DECL_SIZE (decl) && TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
5621     {
5622       /* Add the pointer replacement variable as PRIVATE if the variable
5623 	 replacement is private, else FIRSTPRIVATE since we'll need the
5624 	 address of the original variable either for SHARED, or for the
5625 	 copy into or out of the context.  */
5626       if (!(flags & GOVD_LOCAL))
5627 	{
5628 	  nflags = flags & GOVD_PRIVATE ? GOVD_PRIVATE : GOVD_FIRSTPRIVATE;
5629 	  nflags |= flags & GOVD_SEEN;
5630 	  t = DECL_VALUE_EXPR (decl);
5631 	  gcc_assert (TREE_CODE (t) == INDIRECT_REF);
5632 	  t = TREE_OPERAND (t, 0);
5633 	  gcc_assert (DECL_P (t));
5634 	  omp_add_variable (ctx, t, nflags);
5635 	}
5636 
5637       /* Add all of the variable and type parameters (which should have
5638 	 been gimplified to a formal temporary) as FIRSTPRIVATE.  */
5639       omp_firstprivatize_variable (ctx, DECL_SIZE_UNIT (decl));
5640       omp_firstprivatize_variable (ctx, DECL_SIZE (decl));
5641       omp_firstprivatize_type_sizes (ctx, TREE_TYPE (decl));
5642 
5643       /* The variable-sized variable itself is never SHARED, only some form
5644 	 of PRIVATE.  The sharing would take place via the pointer variable
5645 	 which we remapped above.  */
5646       if (flags & GOVD_SHARED)
5647 	flags = GOVD_PRIVATE | GOVD_DEBUG_PRIVATE
5648 		| (flags & (GOVD_SEEN | GOVD_EXPLICIT));
5649 
5650       /* We're going to make use of the TYPE_SIZE_UNIT at least in the
5651 	 alloca statement we generate for the variable, so make sure it
5652 	 is available.  This isn't automatically needed for the SHARED
5653 	 case, since we won't be allocating local storage then.
5654 	 For local variables TYPE_SIZE_UNIT might not be gimplified yet,
5655 	 in this case omp_notice_variable will be called later
5656 	 on when it is gimplified.  */
5657       else if (! (flags & GOVD_LOCAL)
5658 	       && DECL_P (TYPE_SIZE_UNIT (TREE_TYPE (decl))))
5659 	omp_notice_variable (ctx, TYPE_SIZE_UNIT (TREE_TYPE (decl)), true);
5660     }
5661   else if (lang_hooks.decls.omp_privatize_by_reference (decl))
5662     {
5663       gcc_assert ((flags & GOVD_LOCAL) == 0);
5664       omp_firstprivatize_type_sizes (ctx, TREE_TYPE (decl));
5665 
5666       /* Similar to the direct variable sized case above, we'll need the
5667 	 size of references being privatized.  */
5668       if ((flags & GOVD_SHARED) == 0)
5669 	{
5670 	  t = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (decl)));
5671 	  if (TREE_CODE (t) != INTEGER_CST)
5672 	    omp_notice_variable (ctx, t, true);
5673 	}
5674     }
5675 
5676   splay_tree_insert (ctx->variables, (splay_tree_key)decl, flags);
5677 }
5678 
5679 /* Notice a threadprivate variable DECL used in OpenMP context CTX.
5680    This just prints out diagnostics about threadprivate variable uses
5681    in untied tasks.  If DECL2 is non-NULL, prevent this warning
5682    on that variable.  */
5683 
5684 static bool
5685 omp_notice_threadprivate_variable (struct gimplify_omp_ctx *ctx, tree decl,
5686 				   tree decl2)
5687 {
5688   splay_tree_node n;
5689 
5690   if (ctx->region_type != ORT_UNTIED_TASK)
5691     return false;
5692   n = splay_tree_lookup (ctx->variables, (splay_tree_key)decl);
5693   if (n == NULL)
5694     {
5695       error ("threadprivate variable %qE used in untied task",
5696 	     DECL_NAME (decl));
5697       error_at (ctx->location, "enclosing task");
5698       splay_tree_insert (ctx->variables, (splay_tree_key)decl, 0);
5699     }
5700   if (decl2)
5701     splay_tree_insert (ctx->variables, (splay_tree_key)decl2, 0);
5702   return false;
5703 }
5704 
5705 /* Record the fact that DECL was used within the OpenMP context CTX.
5706    IN_CODE is true when real code uses DECL, and false when we should
5707    merely emit default(none) errors.  Return true if DECL is going to
5708    be remapped and thus DECL shouldn't be gimplified into its
5709    DECL_VALUE_EXPR (if any).  */
5710 
5711 static bool
5712 omp_notice_variable (struct gimplify_omp_ctx *ctx, tree decl, bool in_code)
5713 {
5714   splay_tree_node n;
5715   unsigned flags = in_code ? GOVD_SEEN : 0;
5716   bool ret = false, shared;
5717 
5718   if (error_operand_p (decl))
5719     return false;
5720 
5721   /* Threadprivate variables are predetermined.  */
5722   if (is_global_var (decl))
5723     {
5724       if (DECL_THREAD_LOCAL_P (decl))
5725 	return omp_notice_threadprivate_variable (ctx, decl, NULL_TREE);
5726 
5727       if (DECL_HAS_VALUE_EXPR_P (decl))
5728 	{
5729 	  tree value = get_base_address (DECL_VALUE_EXPR (decl));
5730 
5731 	  if (value && DECL_P (value) && DECL_THREAD_LOCAL_P (value))
5732 	    return omp_notice_threadprivate_variable (ctx, decl, value);
5733 	}
5734     }
5735 
5736   n = splay_tree_lookup (ctx->variables, (splay_tree_key)decl);
5737   if (n == NULL)
5738     {
5739       enum omp_clause_default_kind default_kind, kind;
5740       struct gimplify_omp_ctx *octx;
5741 
5742       if (ctx->region_type == ORT_WORKSHARE)
5743 	goto do_outer;
5744 
5745       /* ??? Some compiler-generated variables (like SAVE_EXPRs) could be
5746 	 remapped firstprivate instead of shared.  To some extent this is
5747 	 addressed in omp_firstprivatize_type_sizes, but not effectively.  */
5748       default_kind = ctx->default_kind;
5749       kind = lang_hooks.decls.omp_predetermined_sharing (decl);
5750       if (kind != OMP_CLAUSE_DEFAULT_UNSPECIFIED)
5751 	default_kind = kind;
5752 
5753       switch (default_kind)
5754 	{
5755 	case OMP_CLAUSE_DEFAULT_NONE:
5756 	  error ("%qE not specified in enclosing parallel",
5757 		 DECL_NAME (lang_hooks.decls.omp_report_decl (decl)));
5758 	  if ((ctx->region_type & ORT_TASK) != 0)
5759 	    error_at (ctx->location, "enclosing task");
5760 	  else
5761 	    error_at (ctx->location, "enclosing parallel");
5762 	  /* FALLTHRU */
5763 	case OMP_CLAUSE_DEFAULT_SHARED:
5764 	  flags |= GOVD_SHARED;
5765 	  break;
5766 	case OMP_CLAUSE_DEFAULT_PRIVATE:
5767 	  flags |= GOVD_PRIVATE;
5768 	  break;
5769 	case OMP_CLAUSE_DEFAULT_FIRSTPRIVATE:
5770 	  flags |= GOVD_FIRSTPRIVATE;
5771 	  break;
5772 	case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
5773 	  /* decl will be either GOVD_FIRSTPRIVATE or GOVD_SHARED.  */
5774 	  gcc_assert ((ctx->region_type & ORT_TASK) != 0);
5775 	  if (ctx->outer_context)
5776 	    omp_notice_variable (ctx->outer_context, decl, in_code);
5777 	  for (octx = ctx->outer_context; octx; octx = octx->outer_context)
5778 	    {
5779 	      splay_tree_node n2;
5780 
5781 	      n2 = splay_tree_lookup (octx->variables, (splay_tree_key) decl);
5782 	      if (n2 && (n2->value & GOVD_DATA_SHARE_CLASS) != GOVD_SHARED)
5783 		{
5784 		  flags |= GOVD_FIRSTPRIVATE;
5785 		  break;
5786 		}
5787 	      if ((octx->region_type & ORT_PARALLEL) != 0)
5788 		break;
5789 	    }
5790 	  if (flags & GOVD_FIRSTPRIVATE)
5791 	    break;
5792 	  if (octx == NULL
5793 	      && (TREE_CODE (decl) == PARM_DECL
5794 		  || (!is_global_var (decl)
5795 		      && DECL_CONTEXT (decl) == current_function_decl)))
5796 	    {
5797 	      flags |= GOVD_FIRSTPRIVATE;
5798 	      break;
5799 	    }
5800 	  flags |= GOVD_SHARED;
5801 	  break;
5802 	default:
5803 	  gcc_unreachable ();
5804 	}
5805 
5806       if ((flags & GOVD_PRIVATE)
5807 	  && lang_hooks.decls.omp_private_outer_ref (decl))
5808 	flags |= GOVD_PRIVATE_OUTER_REF;
5809 
5810       omp_add_variable (ctx, decl, flags);
5811 
5812       shared = (flags & GOVD_SHARED) != 0;
5813       ret = lang_hooks.decls.omp_disregard_value_expr (decl, shared);
5814       goto do_outer;
5815     }
5816 
5817   if ((n->value & (GOVD_SEEN | GOVD_LOCAL)) == 0
5818       && (flags & (GOVD_SEEN | GOVD_LOCAL)) == GOVD_SEEN
5819       && DECL_SIZE (decl)
5820       && TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
5821     {
5822       splay_tree_node n2;
5823       tree t = DECL_VALUE_EXPR (decl);
5824       gcc_assert (TREE_CODE (t) == INDIRECT_REF);
5825       t = TREE_OPERAND (t, 0);
5826       gcc_assert (DECL_P (t));
5827       n2 = splay_tree_lookup (ctx->variables, (splay_tree_key) t);
5828       n2->value |= GOVD_SEEN;
5829     }
5830 
5831   shared = ((flags | n->value) & GOVD_SHARED) != 0;
5832   ret = lang_hooks.decls.omp_disregard_value_expr (decl, shared);
5833 
5834   /* If nothing changed, there's nothing left to do.  */
5835   if ((n->value & flags) == flags)
5836     return ret;
5837   flags |= n->value;
5838   n->value = flags;
5839 
5840  do_outer:
5841   /* If the variable is private in the current context, then we don't
5842      need to propagate anything to an outer context.  */
5843   if ((flags & GOVD_PRIVATE) && !(flags & GOVD_PRIVATE_OUTER_REF))
5844     return ret;
5845   if (ctx->outer_context
5846       && omp_notice_variable (ctx->outer_context, decl, in_code))
5847     return true;
5848   return ret;
5849 }
5850 
5851 /* Verify that DECL is private within CTX.  If there's specific information
5852    to the contrary in the innermost scope, generate an error.  */
5853 
5854 static bool
5855 omp_is_private (struct gimplify_omp_ctx *ctx, tree decl)
5856 {
5857   splay_tree_node n;
5858 
5859   n = splay_tree_lookup (ctx->variables, (splay_tree_key)decl);
5860   if (n != NULL)
5861     {
5862       if (n->value & GOVD_SHARED)
5863 	{
5864 	  if (ctx == gimplify_omp_ctxp)
5865 	    {
5866 	      error ("iteration variable %qE should be private",
5867 		     DECL_NAME (decl));
5868 	      n->value = GOVD_PRIVATE;
5869 	      return true;
5870 	    }
5871 	  else
5872 	    return false;
5873 	}
5874       else if ((n->value & GOVD_EXPLICIT) != 0
5875 	       && (ctx == gimplify_omp_ctxp
5876 		   || (ctx->region_type == ORT_COMBINED_PARALLEL
5877 		       && gimplify_omp_ctxp->outer_context == ctx)))
5878 	{
5879 	  if ((n->value & GOVD_FIRSTPRIVATE) != 0)
5880 	    error ("iteration variable %qE should not be firstprivate",
5881 		   DECL_NAME (decl));
5882 	  else if ((n->value & GOVD_REDUCTION) != 0)
5883 	    error ("iteration variable %qE should not be reduction",
5884 		   DECL_NAME (decl));
5885 	}
5886       return (ctx == gimplify_omp_ctxp
5887 	      || (ctx->region_type == ORT_COMBINED_PARALLEL
5888 		  && gimplify_omp_ctxp->outer_context == ctx));
5889     }
5890 
5891   if (ctx->region_type != ORT_WORKSHARE)
5892     return false;
5893   else if (ctx->outer_context)
5894     return omp_is_private (ctx->outer_context, decl);
5895   return false;
5896 }
5897 
5898 /* Return true if DECL is private within a parallel region
5899    that binds to the current construct's context or in parallel
5900    region's REDUCTION clause.  */
5901 
5902 static bool
5903 omp_check_private (struct gimplify_omp_ctx *ctx, tree decl)
5904 {
5905   splay_tree_node n;
5906 
5907   do
5908     {
5909       ctx = ctx->outer_context;
5910       if (ctx == NULL)
5911 	return !(is_global_var (decl)
5912 		 /* References might be private, but might be shared too.  */
5913 		 || lang_hooks.decls.omp_privatize_by_reference (decl));
5914 
5915       n = splay_tree_lookup (ctx->variables, (splay_tree_key) decl);
5916       if (n != NULL)
5917 	return (n->value & GOVD_SHARED) == 0;
5918     }
5919   while (ctx->region_type == ORT_WORKSHARE);
5920   return false;
5921 }
5922 
5923 /* Scan the OpenMP clauses in *LIST_P, installing mappings into a new
5924    and previous omp contexts.  */
5925 
5926 static void
5927 gimplify_scan_omp_clauses (tree *list_p, gimple_seq *pre_p,
5928 			   enum omp_region_type region_type)
5929 {
5930   struct gimplify_omp_ctx *ctx, *outer_ctx;
5931   struct gimplify_ctx gctx;
5932   tree c;
5933 
5934   ctx = new_omp_context (region_type);
5935   outer_ctx = ctx->outer_context;
5936 
5937   while ((c = *list_p) != NULL)
5938     {
5939       bool remove = false;
5940       bool notice_outer = true;
5941       const char *check_non_private = NULL;
5942       unsigned int flags;
5943       tree decl;
5944 
5945       switch (OMP_CLAUSE_CODE (c))
5946 	{
5947 	case OMP_CLAUSE_PRIVATE:
5948 	  flags = GOVD_PRIVATE | GOVD_EXPLICIT;
5949 	  if (lang_hooks.decls.omp_private_outer_ref (OMP_CLAUSE_DECL (c)))
5950 	    {
5951 	      flags |= GOVD_PRIVATE_OUTER_REF;
5952 	      OMP_CLAUSE_PRIVATE_OUTER_REF (c) = 1;
5953 	    }
5954 	  else
5955 	    notice_outer = false;
5956 	  goto do_add;
5957 	case OMP_CLAUSE_SHARED:
5958 	  flags = GOVD_SHARED | GOVD_EXPLICIT;
5959 	  goto do_add;
5960 	case OMP_CLAUSE_FIRSTPRIVATE:
5961 	  flags = GOVD_FIRSTPRIVATE | GOVD_EXPLICIT;
5962 	  check_non_private = "firstprivate";
5963 	  goto do_add;
5964 	case OMP_CLAUSE_LASTPRIVATE:
5965 	  flags = GOVD_LASTPRIVATE | GOVD_SEEN | GOVD_EXPLICIT;
5966 	  check_non_private = "lastprivate";
5967 	  goto do_add;
5968 	case OMP_CLAUSE_REDUCTION:
5969 	  flags = GOVD_REDUCTION | GOVD_SEEN | GOVD_EXPLICIT;
5970 	  check_non_private = "reduction";
5971 	  goto do_add;
5972 
5973 	do_add:
5974 	  decl = OMP_CLAUSE_DECL (c);
5975 	  if (error_operand_p (decl))
5976 	    {
5977 	      remove = true;
5978 	      break;
5979 	    }
5980 	  omp_add_variable (ctx, decl, flags);
5981 	  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
5982 	      && OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
5983 	    {
5984 	      omp_add_variable (ctx, OMP_CLAUSE_REDUCTION_PLACEHOLDER (c),
5985 				GOVD_LOCAL | GOVD_SEEN);
5986 	      gimplify_omp_ctxp = ctx;
5987 	      push_gimplify_context (&gctx);
5988 
5989 	      OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c) = gimple_seq_alloc ();
5990 	      OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c) = gimple_seq_alloc ();
5991 
5992 	      gimplify_and_add (OMP_CLAUSE_REDUCTION_INIT (c),
5993 		  		&OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c));
5994 	      pop_gimplify_context
5995 		(gimple_seq_first_stmt (OMP_CLAUSE_REDUCTION_GIMPLE_INIT (c)));
5996 	      push_gimplify_context (&gctx);
5997 	      gimplify_and_add (OMP_CLAUSE_REDUCTION_MERGE (c),
5998 		  		&OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c));
5999 	      pop_gimplify_context
6000 		(gimple_seq_first_stmt (OMP_CLAUSE_REDUCTION_GIMPLE_MERGE (c)));
6001 	      OMP_CLAUSE_REDUCTION_INIT (c) = NULL_TREE;
6002 	      OMP_CLAUSE_REDUCTION_MERGE (c) = NULL_TREE;
6003 
6004 	      gimplify_omp_ctxp = outer_ctx;
6005 	    }
6006 	  else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE
6007 		   && OMP_CLAUSE_LASTPRIVATE_STMT (c))
6008 	    {
6009 	      gimplify_omp_ctxp = ctx;
6010 	      push_gimplify_context (&gctx);
6011 	      if (TREE_CODE (OMP_CLAUSE_LASTPRIVATE_STMT (c)) != BIND_EXPR)
6012 		{
6013 		  tree bind = build3 (BIND_EXPR, void_type_node, NULL,
6014 				      NULL, NULL);
6015 		  TREE_SIDE_EFFECTS (bind) = 1;
6016 		  BIND_EXPR_BODY (bind) = OMP_CLAUSE_LASTPRIVATE_STMT (c);
6017 		  OMP_CLAUSE_LASTPRIVATE_STMT (c) = bind;
6018 		}
6019 	      gimplify_and_add (OMP_CLAUSE_LASTPRIVATE_STMT (c),
6020 				&OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c));
6021 	      pop_gimplify_context
6022 		(gimple_seq_first_stmt (OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c)));
6023 	      OMP_CLAUSE_LASTPRIVATE_STMT (c) = NULL_TREE;
6024 
6025 	      gimplify_omp_ctxp = outer_ctx;
6026 	    }
6027 	  if (notice_outer)
6028 	    goto do_notice;
6029 	  break;
6030 
6031 	case OMP_CLAUSE_COPYIN:
6032 	case OMP_CLAUSE_COPYPRIVATE:
6033 	  decl = OMP_CLAUSE_DECL (c);
6034 	  if (error_operand_p (decl))
6035 	    {
6036 	      remove = true;
6037 	      break;
6038 	    }
6039 	do_notice:
6040 	  if (outer_ctx)
6041 	    omp_notice_variable (outer_ctx, decl, true);
6042 	  if (check_non_private
6043 	      && region_type == ORT_WORKSHARE
6044 	      && omp_check_private (ctx, decl))
6045 	    {
6046 	      error ("%s variable %qE is private in outer context",
6047 		     check_non_private, DECL_NAME (decl));
6048 	      remove = true;
6049 	    }
6050 	  break;
6051 
6052 	case OMP_CLAUSE_FINAL:
6053 	case OMP_CLAUSE_IF:
6054 	  OMP_CLAUSE_OPERAND (c, 0)
6055 	    = gimple_boolify (OMP_CLAUSE_OPERAND (c, 0));
6056 	  /* Fall through.  */
6057 
6058 	case OMP_CLAUSE_SCHEDULE:
6059 	case OMP_CLAUSE_NUM_THREADS:
6060 	  if (gimplify_expr (&OMP_CLAUSE_OPERAND (c, 0), pre_p, NULL,
6061 			     is_gimple_val, fb_rvalue) == GS_ERROR)
6062 	      remove = true;
6063 	  break;
6064 
6065 	case OMP_CLAUSE_NOWAIT:
6066 	case OMP_CLAUSE_ORDERED:
6067 	case OMP_CLAUSE_UNTIED:
6068 	case OMP_CLAUSE_COLLAPSE:
6069 	case OMP_CLAUSE_MERGEABLE:
6070 	  break;
6071 
6072 	case OMP_CLAUSE_DEFAULT:
6073 	  ctx->default_kind = OMP_CLAUSE_DEFAULT_KIND (c);
6074 	  break;
6075 
6076 	default:
6077 	  gcc_unreachable ();
6078 	}
6079 
6080       if (remove)
6081 	*list_p = OMP_CLAUSE_CHAIN (c);
6082       else
6083 	list_p = &OMP_CLAUSE_CHAIN (c);
6084     }
6085 
6086   gimplify_omp_ctxp = ctx;
6087 }
6088 
6089 /* For all variables that were not actually used within the context,
6090    remove PRIVATE, SHARED, and FIRSTPRIVATE clauses.  */
6091 
6092 static int
6093 gimplify_adjust_omp_clauses_1 (splay_tree_node n, void *data)
6094 {
6095   tree *list_p = (tree *) data;
6096   tree decl = (tree) n->key;
6097   unsigned flags = n->value;
6098   enum omp_clause_code code;
6099   tree clause;
6100   bool private_debug;
6101 
6102   if (flags & (GOVD_EXPLICIT | GOVD_LOCAL))
6103     return 0;
6104   if ((flags & GOVD_SEEN) == 0)
6105     return 0;
6106   if (flags & GOVD_DEBUG_PRIVATE)
6107     {
6108       gcc_assert ((flags & GOVD_DATA_SHARE_CLASS) == GOVD_PRIVATE);
6109       private_debug = true;
6110     }
6111   else
6112     private_debug
6113       = lang_hooks.decls.omp_private_debug_clause (decl,
6114 						   !!(flags & GOVD_SHARED));
6115   if (private_debug)
6116     code = OMP_CLAUSE_PRIVATE;
6117   else if (flags & GOVD_SHARED)
6118     {
6119       if (is_global_var (decl))
6120 	{
6121 	  struct gimplify_omp_ctx *ctx = gimplify_omp_ctxp->outer_context;
6122 	  while (ctx != NULL)
6123 	    {
6124 	      splay_tree_node on
6125 		= splay_tree_lookup (ctx->variables, (splay_tree_key) decl);
6126 	      if (on && (on->value & (GOVD_FIRSTPRIVATE | GOVD_LASTPRIVATE
6127 				      | GOVD_PRIVATE | GOVD_REDUCTION)) != 0)
6128 		break;
6129 	      ctx = ctx->outer_context;
6130 	    }
6131 	  if (ctx == NULL)
6132 	    return 0;
6133 	}
6134       code = OMP_CLAUSE_SHARED;
6135     }
6136   else if (flags & GOVD_PRIVATE)
6137     code = OMP_CLAUSE_PRIVATE;
6138   else if (flags & GOVD_FIRSTPRIVATE)
6139     code = OMP_CLAUSE_FIRSTPRIVATE;
6140   else
6141     gcc_unreachable ();
6142 
6143   clause = build_omp_clause (input_location, code);
6144   OMP_CLAUSE_DECL (clause) = decl;
6145   OMP_CLAUSE_CHAIN (clause) = *list_p;
6146   if (private_debug)
6147     OMP_CLAUSE_PRIVATE_DEBUG (clause) = 1;
6148   else if (code == OMP_CLAUSE_PRIVATE && (flags & GOVD_PRIVATE_OUTER_REF))
6149     OMP_CLAUSE_PRIVATE_OUTER_REF (clause) = 1;
6150   *list_p = clause;
6151   lang_hooks.decls.omp_finish_clause (clause);
6152 
6153   return 0;
6154 }
6155 
6156 static void
6157 gimplify_adjust_omp_clauses (tree *list_p)
6158 {
6159   struct gimplify_omp_ctx *ctx = gimplify_omp_ctxp;
6160   tree c, decl;
6161 
6162   while ((c = *list_p) != NULL)
6163     {
6164       splay_tree_node n;
6165       bool remove = false;
6166 
6167       switch (OMP_CLAUSE_CODE (c))
6168 	{
6169 	case OMP_CLAUSE_PRIVATE:
6170 	case OMP_CLAUSE_SHARED:
6171 	case OMP_CLAUSE_FIRSTPRIVATE:
6172 	  decl = OMP_CLAUSE_DECL (c);
6173 	  n = splay_tree_lookup (ctx->variables, (splay_tree_key) decl);
6174 	  remove = !(n->value & GOVD_SEEN);
6175 	  if (! remove)
6176 	    {
6177 	      bool shared = OMP_CLAUSE_CODE (c) == OMP_CLAUSE_SHARED;
6178 	      if ((n->value & GOVD_DEBUG_PRIVATE)
6179 		  || lang_hooks.decls.omp_private_debug_clause (decl, shared))
6180 		{
6181 		  gcc_assert ((n->value & GOVD_DEBUG_PRIVATE) == 0
6182 			      || ((n->value & GOVD_DATA_SHARE_CLASS)
6183 				  == GOVD_PRIVATE));
6184 		  OMP_CLAUSE_SET_CODE (c, OMP_CLAUSE_PRIVATE);
6185 		  OMP_CLAUSE_PRIVATE_DEBUG (c) = 1;
6186 		}
6187 	    }
6188 	  break;
6189 
6190 	case OMP_CLAUSE_LASTPRIVATE:
6191 	  /* Make sure OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE is set to
6192 	     accurately reflect the presence of a FIRSTPRIVATE clause.  */
6193 	  decl = OMP_CLAUSE_DECL (c);
6194 	  n = splay_tree_lookup (ctx->variables, (splay_tree_key) decl);
6195 	  OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c)
6196 	    = (n->value & GOVD_FIRSTPRIVATE) != 0;
6197 	  break;
6198 
6199 	case OMP_CLAUSE_REDUCTION:
6200 	case OMP_CLAUSE_COPYIN:
6201 	case OMP_CLAUSE_COPYPRIVATE:
6202 	case OMP_CLAUSE_IF:
6203 	case OMP_CLAUSE_NUM_THREADS:
6204 	case OMP_CLAUSE_SCHEDULE:
6205 	case OMP_CLAUSE_NOWAIT:
6206 	case OMP_CLAUSE_ORDERED:
6207 	case OMP_CLAUSE_DEFAULT:
6208 	case OMP_CLAUSE_UNTIED:
6209 	case OMP_CLAUSE_COLLAPSE:
6210 	case OMP_CLAUSE_FINAL:
6211 	case OMP_CLAUSE_MERGEABLE:
6212 	  break;
6213 
6214 	default:
6215 	  gcc_unreachable ();
6216 	}
6217 
6218       if (remove)
6219 	*list_p = OMP_CLAUSE_CHAIN (c);
6220       else
6221 	list_p = &OMP_CLAUSE_CHAIN (c);
6222     }
6223 
6224   /* Add in any implicit data sharing.  */
6225   splay_tree_foreach (ctx->variables, gimplify_adjust_omp_clauses_1, list_p);
6226 
6227   gimplify_omp_ctxp = ctx->outer_context;
6228   delete_omp_context (ctx);
6229 }
6230 
6231 /* Gimplify the contents of an OMP_PARALLEL statement.  This involves
6232    gimplification of the body, as well as scanning the body for used
6233    variables.  We need to do this scan now, because variable-sized
6234    decls will be decomposed during gimplification.  */
6235 
6236 static void
6237 gimplify_omp_parallel (tree *expr_p, gimple_seq *pre_p)
6238 {
6239   tree expr = *expr_p;
6240   gimple g;
6241   gimple_seq body = NULL;
6242   struct gimplify_ctx gctx;
6243 
6244   gimplify_scan_omp_clauses (&OMP_PARALLEL_CLAUSES (expr), pre_p,
6245 			     OMP_PARALLEL_COMBINED (expr)
6246 			     ? ORT_COMBINED_PARALLEL
6247 			     : ORT_PARALLEL);
6248 
6249   push_gimplify_context (&gctx);
6250 
6251   g = gimplify_and_return_first (OMP_PARALLEL_BODY (expr), &body);
6252   if (gimple_code (g) == GIMPLE_BIND)
6253     pop_gimplify_context (g);
6254   else
6255     pop_gimplify_context (NULL);
6256 
6257   gimplify_adjust_omp_clauses (&OMP_PARALLEL_CLAUSES (expr));
6258 
6259   g = gimple_build_omp_parallel (body,
6260 				 OMP_PARALLEL_CLAUSES (expr),
6261 				 NULL_TREE, NULL_TREE);
6262   if (OMP_PARALLEL_COMBINED (expr))
6263     gimple_omp_set_subcode (g, GF_OMP_PARALLEL_COMBINED);
6264   gimplify_seq_add_stmt (pre_p, g);
6265   *expr_p = NULL_TREE;
6266 }
6267 
6268 /* Gimplify the contents of an OMP_TASK statement.  This involves
6269    gimplification of the body, as well as scanning the body for used
6270    variables.  We need to do this scan now, because variable-sized
6271    decls will be decomposed during gimplification.  */
6272 
6273 static void
6274 gimplify_omp_task (tree *expr_p, gimple_seq *pre_p)
6275 {
6276   tree expr = *expr_p;
6277   gimple g;
6278   gimple_seq body = NULL;
6279   struct gimplify_ctx gctx;
6280 
6281   gimplify_scan_omp_clauses (&OMP_TASK_CLAUSES (expr), pre_p,
6282 			     find_omp_clause (OMP_TASK_CLAUSES (expr),
6283 					      OMP_CLAUSE_UNTIED)
6284 			     ? ORT_UNTIED_TASK : ORT_TASK);
6285 
6286   push_gimplify_context (&gctx);
6287 
6288   g = gimplify_and_return_first (OMP_TASK_BODY (expr), &body);
6289   if (gimple_code (g) == GIMPLE_BIND)
6290     pop_gimplify_context (g);
6291   else
6292     pop_gimplify_context (NULL);
6293 
6294   gimplify_adjust_omp_clauses (&OMP_TASK_CLAUSES (expr));
6295 
6296   g = gimple_build_omp_task (body,
6297 			     OMP_TASK_CLAUSES (expr),
6298 			     NULL_TREE, NULL_TREE,
6299 			     NULL_TREE, NULL_TREE, NULL_TREE);
6300   gimplify_seq_add_stmt (pre_p, g);
6301   *expr_p = NULL_TREE;
6302 }
6303 
6304 /* Gimplify the gross structure of an OMP_FOR statement.  */
6305 
6306 static enum gimplify_status
6307 gimplify_omp_for (tree *expr_p, gimple_seq *pre_p)
6308 {
6309   tree for_stmt, decl, var, t;
6310   enum gimplify_status ret = GS_ALL_DONE;
6311   enum gimplify_status tret;
6312   gimple gfor;
6313   gimple_seq for_body, for_pre_body;
6314   int i;
6315 
6316   for_stmt = *expr_p;
6317 
6318   gimplify_scan_omp_clauses (&OMP_FOR_CLAUSES (for_stmt), pre_p,
6319 			     ORT_WORKSHARE);
6320 
6321   /* Handle OMP_FOR_INIT.  */
6322   for_pre_body = NULL;
6323   gimplify_and_add (OMP_FOR_PRE_BODY (for_stmt), &for_pre_body);
6324   OMP_FOR_PRE_BODY (for_stmt) = NULL_TREE;
6325 
6326   for_body = gimple_seq_alloc ();
6327   gcc_assert (TREE_VEC_LENGTH (OMP_FOR_INIT (for_stmt))
6328 	      == TREE_VEC_LENGTH (OMP_FOR_COND (for_stmt)));
6329   gcc_assert (TREE_VEC_LENGTH (OMP_FOR_INIT (for_stmt))
6330 	      == TREE_VEC_LENGTH (OMP_FOR_INCR (for_stmt)));
6331   for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (for_stmt)); i++)
6332     {
6333       t = TREE_VEC_ELT (OMP_FOR_INIT (for_stmt), i);
6334       gcc_assert (TREE_CODE (t) == MODIFY_EXPR);
6335       decl = TREE_OPERAND (t, 0);
6336       gcc_assert (DECL_P (decl));
6337       gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (decl))
6338 		  || POINTER_TYPE_P (TREE_TYPE (decl)));
6339 
6340       /* Make sure the iteration variable is private.  */
6341       if (omp_is_private (gimplify_omp_ctxp, decl))
6342 	omp_notice_variable (gimplify_omp_ctxp, decl, true);
6343       else
6344 	omp_add_variable (gimplify_omp_ctxp, decl, GOVD_PRIVATE | GOVD_SEEN);
6345 
6346       /* If DECL is not a gimple register, create a temporary variable to act
6347 	 as an iteration counter.  This is valid, since DECL cannot be
6348 	 modified in the body of the loop.  */
6349       if (!is_gimple_reg (decl))
6350 	{
6351 	  var = create_tmp_var (TREE_TYPE (decl), get_name (decl));
6352 	  TREE_OPERAND (t, 0) = var;
6353 
6354 	  gimplify_seq_add_stmt (&for_body, gimple_build_assign (decl, var));
6355 
6356 	  omp_add_variable (gimplify_omp_ctxp, var, GOVD_PRIVATE | GOVD_SEEN);
6357 	}
6358       else
6359 	var = decl;
6360 
6361       tret = gimplify_expr (&TREE_OPERAND (t, 1), &for_pre_body, NULL,
6362 			    is_gimple_val, fb_rvalue);
6363       ret = MIN (ret, tret);
6364       if (ret == GS_ERROR)
6365 	return ret;
6366 
6367       /* Handle OMP_FOR_COND.  */
6368       t = TREE_VEC_ELT (OMP_FOR_COND (for_stmt), i);
6369       gcc_assert (COMPARISON_CLASS_P (t));
6370       gcc_assert (TREE_OPERAND (t, 0) == decl);
6371 
6372       tret = gimplify_expr (&TREE_OPERAND (t, 1), &for_pre_body, NULL,
6373 			    is_gimple_val, fb_rvalue);
6374       ret = MIN (ret, tret);
6375 
6376       /* Handle OMP_FOR_INCR.  */
6377       t = TREE_VEC_ELT (OMP_FOR_INCR (for_stmt), i);
6378       switch (TREE_CODE (t))
6379 	{
6380 	case PREINCREMENT_EXPR:
6381 	case POSTINCREMENT_EXPR:
6382 	  t = build_int_cst (TREE_TYPE (decl), 1);
6383 	  t = build2 (PLUS_EXPR, TREE_TYPE (decl), var, t);
6384 	  t = build2 (MODIFY_EXPR, TREE_TYPE (var), var, t);
6385 	  TREE_VEC_ELT (OMP_FOR_INCR (for_stmt), i) = t;
6386 	  break;
6387 
6388 	case PREDECREMENT_EXPR:
6389 	case POSTDECREMENT_EXPR:
6390 	  t = build_int_cst (TREE_TYPE (decl), -1);
6391 	  t = build2 (PLUS_EXPR, TREE_TYPE (decl), var, t);
6392 	  t = build2 (MODIFY_EXPR, TREE_TYPE (var), var, t);
6393 	  TREE_VEC_ELT (OMP_FOR_INCR (for_stmt), i) = t;
6394 	  break;
6395 
6396 	case MODIFY_EXPR:
6397 	  gcc_assert (TREE_OPERAND (t, 0) == decl);
6398 	  TREE_OPERAND (t, 0) = var;
6399 
6400 	  t = TREE_OPERAND (t, 1);
6401 	  switch (TREE_CODE (t))
6402 	    {
6403 	    case PLUS_EXPR:
6404 	      if (TREE_OPERAND (t, 1) == decl)
6405 		{
6406 		  TREE_OPERAND (t, 1) = TREE_OPERAND (t, 0);
6407 		  TREE_OPERAND (t, 0) = var;
6408 		  break;
6409 		}
6410 
6411 	      /* Fallthru.  */
6412 	    case MINUS_EXPR:
6413 	    case POINTER_PLUS_EXPR:
6414 	      gcc_assert (TREE_OPERAND (t, 0) == decl);
6415 	      TREE_OPERAND (t, 0) = var;
6416 	      break;
6417 	    default:
6418 	      gcc_unreachable ();
6419 	    }
6420 
6421 	  tret = gimplify_expr (&TREE_OPERAND (t, 1), &for_pre_body, NULL,
6422 				is_gimple_val, fb_rvalue);
6423 	  ret = MIN (ret, tret);
6424 	  break;
6425 
6426 	default:
6427 	  gcc_unreachable ();
6428 	}
6429 
6430       if (var != decl || TREE_VEC_LENGTH (OMP_FOR_INIT (for_stmt)) > 1)
6431 	{
6432 	  tree c;
6433 	  for (c = OMP_FOR_CLAUSES (for_stmt); c ; c = OMP_CLAUSE_CHAIN (c))
6434 	    if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE
6435 		&& OMP_CLAUSE_DECL (c) == decl
6436 		&& OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c) == NULL)
6437 	      {
6438 		t = TREE_VEC_ELT (OMP_FOR_INCR (for_stmt), i);
6439 		gcc_assert (TREE_CODE (t) == MODIFY_EXPR);
6440 		gcc_assert (TREE_OPERAND (t, 0) == var);
6441 		t = TREE_OPERAND (t, 1);
6442 		gcc_assert (TREE_CODE (t) == PLUS_EXPR
6443 			    || TREE_CODE (t) == MINUS_EXPR
6444 			    || TREE_CODE (t) == POINTER_PLUS_EXPR);
6445 		gcc_assert (TREE_OPERAND (t, 0) == var);
6446 		t = build2 (TREE_CODE (t), TREE_TYPE (decl), decl,
6447 			    TREE_OPERAND (t, 1));
6448 		gimplify_assign (decl, t,
6449 				 &OMP_CLAUSE_LASTPRIVATE_GIMPLE_SEQ (c));
6450 	    }
6451 	}
6452     }
6453 
6454   gimplify_and_add (OMP_FOR_BODY (for_stmt), &for_body);
6455 
6456   gimplify_adjust_omp_clauses (&OMP_FOR_CLAUSES (for_stmt));
6457 
6458   gfor = gimple_build_omp_for (for_body, OMP_FOR_CLAUSES (for_stmt),
6459 			       TREE_VEC_LENGTH (OMP_FOR_INIT (for_stmt)),
6460 			       for_pre_body);
6461 
6462   for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (for_stmt)); i++)
6463     {
6464       t = TREE_VEC_ELT (OMP_FOR_INIT (for_stmt), i);
6465       gimple_omp_for_set_index (gfor, i, TREE_OPERAND (t, 0));
6466       gimple_omp_for_set_initial (gfor, i, TREE_OPERAND (t, 1));
6467       t = TREE_VEC_ELT (OMP_FOR_COND (for_stmt), i);
6468       gimple_omp_for_set_cond (gfor, i, TREE_CODE (t));
6469       gimple_omp_for_set_final (gfor, i, TREE_OPERAND (t, 1));
6470       t = TREE_VEC_ELT (OMP_FOR_INCR (for_stmt), i);
6471       gimple_omp_for_set_incr (gfor, i, TREE_OPERAND (t, 1));
6472     }
6473 
6474   gimplify_seq_add_stmt (pre_p, gfor);
6475   return ret == GS_ALL_DONE ? GS_ALL_DONE : GS_ERROR;
6476 }
6477 
6478 /* Gimplify the gross structure of other OpenMP worksharing constructs.
6479    In particular, OMP_SECTIONS and OMP_SINGLE.  */
6480 
6481 static void
6482 gimplify_omp_workshare (tree *expr_p, gimple_seq *pre_p)
6483 {
6484   tree expr = *expr_p;
6485   gimple stmt;
6486   gimple_seq body = NULL;
6487 
6488   gimplify_scan_omp_clauses (&OMP_CLAUSES (expr), pre_p, ORT_WORKSHARE);
6489   gimplify_and_add (OMP_BODY (expr), &body);
6490   gimplify_adjust_omp_clauses (&OMP_CLAUSES (expr));
6491 
6492   if (TREE_CODE (expr) == OMP_SECTIONS)
6493     stmt = gimple_build_omp_sections (body, OMP_CLAUSES (expr));
6494   else if (TREE_CODE (expr) == OMP_SINGLE)
6495     stmt = gimple_build_omp_single (body, OMP_CLAUSES (expr));
6496   else
6497     gcc_unreachable ();
6498 
6499   gimplify_seq_add_stmt (pre_p, stmt);
6500 }
6501 
6502 /* A subroutine of gimplify_omp_atomic.  The front end is supposed to have
6503    stabilized the lhs of the atomic operation as *ADDR.  Return true if
6504    EXPR is this stabilized form.  */
6505 
6506 static bool
6507 goa_lhs_expr_p (tree expr, tree addr)
6508 {
6509   /* Also include casts to other type variants.  The C front end is fond
6510      of adding these for e.g. volatile variables.  This is like
6511      STRIP_TYPE_NOPS but includes the main variant lookup.  */
6512   STRIP_USELESS_TYPE_CONVERSION (expr);
6513 
6514   if (TREE_CODE (expr) == INDIRECT_REF)
6515     {
6516       expr = TREE_OPERAND (expr, 0);
6517       while (expr != addr
6518 	     && (CONVERT_EXPR_P (expr)
6519 		 || TREE_CODE (expr) == NON_LVALUE_EXPR)
6520 	     && TREE_CODE (expr) == TREE_CODE (addr)
6521 	     && types_compatible_p (TREE_TYPE (expr), TREE_TYPE (addr)))
6522 	{
6523 	  expr = TREE_OPERAND (expr, 0);
6524 	  addr = TREE_OPERAND (addr, 0);
6525 	}
6526       if (expr == addr)
6527 	return true;
6528       return (TREE_CODE (addr) == ADDR_EXPR
6529 	      && TREE_CODE (expr) == ADDR_EXPR
6530 	      && TREE_OPERAND (addr, 0) == TREE_OPERAND (expr, 0));
6531     }
6532   if (TREE_CODE (addr) == ADDR_EXPR && expr == TREE_OPERAND (addr, 0))
6533     return true;
6534   return false;
6535 }
6536 
6537 /* Walk *EXPR_P and replace appearances of *LHS_ADDR with LHS_VAR.  If an
6538    expression does not involve the lhs, evaluate it into a temporary.
6539    Return 1 if the lhs appeared as a subexpression, 0 if it did not,
6540    or -1 if an error was encountered.  */
6541 
6542 static int
6543 goa_stabilize_expr (tree *expr_p, gimple_seq *pre_p, tree lhs_addr,
6544 		    tree lhs_var)
6545 {
6546   tree expr = *expr_p;
6547   int saw_lhs;
6548 
6549   if (goa_lhs_expr_p (expr, lhs_addr))
6550     {
6551       *expr_p = lhs_var;
6552       return 1;
6553     }
6554   if (is_gimple_val (expr))
6555     return 0;
6556 
6557   saw_lhs = 0;
6558   switch (TREE_CODE_CLASS (TREE_CODE (expr)))
6559     {
6560     case tcc_binary:
6561     case tcc_comparison:
6562       saw_lhs |= goa_stabilize_expr (&TREE_OPERAND (expr, 1), pre_p, lhs_addr,
6563 				     lhs_var);
6564     case tcc_unary:
6565       saw_lhs |= goa_stabilize_expr (&TREE_OPERAND (expr, 0), pre_p, lhs_addr,
6566 				     lhs_var);
6567       break;
6568     case tcc_expression:
6569       switch (TREE_CODE (expr))
6570 	{
6571 	case TRUTH_ANDIF_EXPR:
6572 	case TRUTH_ORIF_EXPR:
6573 	case TRUTH_AND_EXPR:
6574 	case TRUTH_OR_EXPR:
6575 	case TRUTH_XOR_EXPR:
6576 	  saw_lhs |= goa_stabilize_expr (&TREE_OPERAND (expr, 1), pre_p,
6577 					 lhs_addr, lhs_var);
6578 	case TRUTH_NOT_EXPR:
6579 	  saw_lhs |= goa_stabilize_expr (&TREE_OPERAND (expr, 0), pre_p,
6580 					 lhs_addr, lhs_var);
6581 	  break;
6582 	case COMPOUND_EXPR:
6583 	  /* Break out any preevaluations from cp_build_modify_expr.  */
6584 	  for (; TREE_CODE (expr) == COMPOUND_EXPR;
6585 	       expr = TREE_OPERAND (expr, 1))
6586 	    gimplify_stmt (&TREE_OPERAND (expr, 0), pre_p);
6587 	  *expr_p = expr;
6588 	  return goa_stabilize_expr (expr_p, pre_p, lhs_addr, lhs_var);
6589 	default:
6590 	  break;
6591 	}
6592       break;
6593     default:
6594       break;
6595     }
6596 
6597   if (saw_lhs == 0)
6598     {
6599       enum gimplify_status gs;
6600       gs = gimplify_expr (expr_p, pre_p, NULL, is_gimple_val, fb_rvalue);
6601       if (gs != GS_ALL_DONE)
6602 	saw_lhs = -1;
6603     }
6604 
6605   return saw_lhs;
6606 }
6607 
6608 /* Gimplify an OMP_ATOMIC statement.  */
6609 
6610 static enum gimplify_status
6611 gimplify_omp_atomic (tree *expr_p, gimple_seq *pre_p)
6612 {
6613   tree addr = TREE_OPERAND (*expr_p, 0);
6614   tree rhs = TREE_CODE (*expr_p) == OMP_ATOMIC_READ
6615 	     ? NULL : TREE_OPERAND (*expr_p, 1);
6616   tree type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (addr)));
6617   tree tmp_load;
6618   gimple loadstmt, storestmt;
6619 
6620   tmp_load = create_tmp_reg (type, NULL);
6621   if (rhs && goa_stabilize_expr (&rhs, pre_p, addr, tmp_load) < 0)
6622     return GS_ERROR;
6623 
6624   if (gimplify_expr (&addr, pre_p, NULL, is_gimple_val, fb_rvalue)
6625       != GS_ALL_DONE)
6626     return GS_ERROR;
6627 
6628   loadstmt = gimple_build_omp_atomic_load (tmp_load, addr);
6629   gimplify_seq_add_stmt (pre_p, loadstmt);
6630   if (rhs && gimplify_expr (&rhs, pre_p, NULL, is_gimple_val, fb_rvalue)
6631       != GS_ALL_DONE)
6632     return GS_ERROR;
6633 
6634   if (TREE_CODE (*expr_p) == OMP_ATOMIC_READ)
6635     rhs = tmp_load;
6636   storestmt = gimple_build_omp_atomic_store (rhs);
6637   gimplify_seq_add_stmt (pre_p, storestmt);
6638   switch (TREE_CODE (*expr_p))
6639     {
6640     case OMP_ATOMIC_READ:
6641     case OMP_ATOMIC_CAPTURE_OLD:
6642       *expr_p = tmp_load;
6643       gimple_omp_atomic_set_need_value (loadstmt);
6644       break;
6645     case OMP_ATOMIC_CAPTURE_NEW:
6646       *expr_p = rhs;
6647       gimple_omp_atomic_set_need_value (storestmt);
6648       break;
6649     default:
6650       *expr_p = NULL;
6651       break;
6652     }
6653 
6654    return GS_ALL_DONE;
6655 }
6656 
6657 /* Gimplify a TRANSACTION_EXPR.  This involves gimplification of the
6658    body, and adding some EH bits.  */
6659 
6660 static enum gimplify_status
6661 gimplify_transaction (tree *expr_p, gimple_seq *pre_p)
6662 {
6663   tree expr = *expr_p, temp, tbody = TRANSACTION_EXPR_BODY (expr);
6664   gimple g;
6665   gimple_seq body = NULL;
6666   struct gimplify_ctx gctx;
6667   int subcode = 0;
6668 
6669   /* Wrap the transaction body in a BIND_EXPR so we have a context
6670      where to put decls for OpenMP.  */
6671   if (TREE_CODE (tbody) != BIND_EXPR)
6672     {
6673       tree bind = build3 (BIND_EXPR, void_type_node, NULL, tbody, NULL);
6674       TREE_SIDE_EFFECTS (bind) = 1;
6675       SET_EXPR_LOCATION (bind, EXPR_LOCATION (tbody));
6676       TRANSACTION_EXPR_BODY (expr) = bind;
6677     }
6678 
6679   push_gimplify_context (&gctx);
6680   temp = voidify_wrapper_expr (*expr_p, NULL);
6681 
6682   g = gimplify_and_return_first (TRANSACTION_EXPR_BODY (expr), &body);
6683   pop_gimplify_context (g);
6684 
6685   g = gimple_build_transaction (body, NULL);
6686   if (TRANSACTION_EXPR_OUTER (expr))
6687     subcode = GTMA_IS_OUTER;
6688   else if (TRANSACTION_EXPR_RELAXED (expr))
6689     subcode = GTMA_IS_RELAXED;
6690   gimple_transaction_set_subcode (g, subcode);
6691 
6692   gimplify_seq_add_stmt (pre_p, g);
6693 
6694   if (temp)
6695     {
6696       *expr_p = temp;
6697       return GS_OK;
6698     }
6699 
6700   *expr_p = NULL_TREE;
6701   return GS_ALL_DONE;
6702 }
6703 
6704 /* Convert the GENERIC expression tree *EXPR_P to GIMPLE.  If the
6705    expression produces a value to be used as an operand inside a GIMPLE
6706    statement, the value will be stored back in *EXPR_P.  This value will
6707    be a tree of class tcc_declaration, tcc_constant, tcc_reference or
6708    an SSA_NAME.  The corresponding sequence of GIMPLE statements is
6709    emitted in PRE_P and POST_P.
6710 
6711    Additionally, this process may overwrite parts of the input
6712    expression during gimplification.  Ideally, it should be
6713    possible to do non-destructive gimplification.
6714 
6715    EXPR_P points to the GENERIC expression to convert to GIMPLE.  If
6716       the expression needs to evaluate to a value to be used as
6717       an operand in a GIMPLE statement, this value will be stored in
6718       *EXPR_P on exit.  This happens when the caller specifies one
6719       of fb_lvalue or fb_rvalue fallback flags.
6720 
6721    PRE_P will contain the sequence of GIMPLE statements corresponding
6722        to the evaluation of EXPR and all the side-effects that must
6723        be executed before the main expression.  On exit, the last
6724        statement of PRE_P is the core statement being gimplified.  For
6725        instance, when gimplifying 'if (++a)' the last statement in
6726        PRE_P will be 'if (t.1)' where t.1 is the result of
6727        pre-incrementing 'a'.
6728 
6729    POST_P will contain the sequence of GIMPLE statements corresponding
6730        to the evaluation of all the side-effects that must be executed
6731        after the main expression.  If this is NULL, the post
6732        side-effects are stored at the end of PRE_P.
6733 
6734        The reason why the output is split in two is to handle post
6735        side-effects explicitly.  In some cases, an expression may have
6736        inner and outer post side-effects which need to be emitted in
6737        an order different from the one given by the recursive
6738        traversal.  For instance, for the expression (*p--)++ the post
6739        side-effects of '--' must actually occur *after* the post
6740        side-effects of '++'.  However, gimplification will first visit
6741        the inner expression, so if a separate POST sequence was not
6742        used, the resulting sequence would be:
6743 
6744        	    1	t.1 = *p
6745        	    2	p = p - 1
6746        	    3	t.2 = t.1 + 1
6747        	    4	*p = t.2
6748 
6749        However, the post-decrement operation in line #2 must not be
6750        evaluated until after the store to *p at line #4, so the
6751        correct sequence should be:
6752 
6753        	    1	t.1 = *p
6754        	    2	t.2 = t.1 + 1
6755        	    3	*p = t.2
6756        	    4	p = p - 1
6757 
6758        So, by specifying a separate post queue, it is possible
6759        to emit the post side-effects in the correct order.
6760        If POST_P is NULL, an internal queue will be used.  Before
6761        returning to the caller, the sequence POST_P is appended to
6762        the main output sequence PRE_P.
6763 
6764    GIMPLE_TEST_F points to a function that takes a tree T and
6765        returns nonzero if T is in the GIMPLE form requested by the
6766        caller.  The GIMPLE predicates are in gimple.c.
6767 
6768    FALLBACK tells the function what sort of a temporary we want if
6769        gimplification cannot produce an expression that complies with
6770        GIMPLE_TEST_F.
6771 
6772        fb_none means that no temporary should be generated
6773        fb_rvalue means that an rvalue is OK to generate
6774        fb_lvalue means that an lvalue is OK to generate
6775        fb_either means that either is OK, but an lvalue is preferable.
6776        fb_mayfail means that gimplification may fail (in which case
6777        GS_ERROR will be returned)
6778 
6779    The return value is either GS_ERROR or GS_ALL_DONE, since this
6780    function iterates until EXPR is completely gimplified or an error
6781    occurs.  */
6782 
6783 enum gimplify_status
6784 gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
6785 	       bool (*gimple_test_f) (tree), fallback_t fallback)
6786 {
6787   tree tmp;
6788   gimple_seq internal_pre = NULL;
6789   gimple_seq internal_post = NULL;
6790   tree save_expr;
6791   bool is_statement;
6792   location_t saved_location;
6793   enum gimplify_status ret;
6794   gimple_stmt_iterator pre_last_gsi, post_last_gsi;
6795 
6796   save_expr = *expr_p;
6797   if (save_expr == NULL_TREE)
6798     return GS_ALL_DONE;
6799 
6800   /* If we are gimplifying a top-level statement, PRE_P must be valid.  */
6801   is_statement = gimple_test_f == is_gimple_stmt;
6802   if (is_statement)
6803     gcc_assert (pre_p);
6804 
6805   /* Consistency checks.  */
6806   if (gimple_test_f == is_gimple_reg)
6807     gcc_assert (fallback & (fb_rvalue | fb_lvalue));
6808   else if (gimple_test_f == is_gimple_val
6809            || gimple_test_f == is_gimple_call_addr
6810            || gimple_test_f == is_gimple_condexpr
6811            || gimple_test_f == is_gimple_mem_rhs
6812            || gimple_test_f == is_gimple_mem_rhs_or_call
6813            || gimple_test_f == is_gimple_reg_rhs
6814            || gimple_test_f == is_gimple_reg_rhs_or_call
6815            || gimple_test_f == is_gimple_asm_val
6816 	   || gimple_test_f == is_gimple_mem_ref_addr)
6817     gcc_assert (fallback & fb_rvalue);
6818   else if (gimple_test_f == is_gimple_min_lval
6819 	   || gimple_test_f == is_gimple_lvalue)
6820     gcc_assert (fallback & fb_lvalue);
6821   else if (gimple_test_f == is_gimple_addressable)
6822     gcc_assert (fallback & fb_either);
6823   else if (gimple_test_f == is_gimple_stmt)
6824     gcc_assert (fallback == fb_none);
6825   else
6826     {
6827       /* We should have recognized the GIMPLE_TEST_F predicate to
6828 	 know what kind of fallback to use in case a temporary is
6829 	 needed to hold the value or address of *EXPR_P.  */
6830       gcc_unreachable ();
6831     }
6832 
6833   /* We used to check the predicate here and return immediately if it
6834      succeeds.  This is wrong; the design is for gimplification to be
6835      idempotent, and for the predicates to only test for valid forms, not
6836      whether they are fully simplified.  */
6837   if (pre_p == NULL)
6838     pre_p = &internal_pre;
6839 
6840   if (post_p == NULL)
6841     post_p = &internal_post;
6842 
6843   /* Remember the last statements added to PRE_P and POST_P.  Every
6844      new statement added by the gimplification helpers needs to be
6845      annotated with location information.  To centralize the
6846      responsibility, we remember the last statement that had been
6847      added to both queues before gimplifying *EXPR_P.  If
6848      gimplification produces new statements in PRE_P and POST_P, those
6849      statements will be annotated with the same location information
6850      as *EXPR_P.  */
6851   pre_last_gsi = gsi_last (*pre_p);
6852   post_last_gsi = gsi_last (*post_p);
6853 
6854   saved_location = input_location;
6855   if (save_expr != error_mark_node
6856       && EXPR_HAS_LOCATION (*expr_p))
6857     input_location = EXPR_LOCATION (*expr_p);
6858 
6859   /* Loop over the specific gimplifiers until the toplevel node
6860      remains the same.  */
6861   do
6862     {
6863       /* Strip away as many useless type conversions as possible
6864 	 at the toplevel.  */
6865       STRIP_USELESS_TYPE_CONVERSION (*expr_p);
6866 
6867       /* Remember the expr.  */
6868       save_expr = *expr_p;
6869 
6870       /* Die, die, die, my darling.  */
6871       if (save_expr == error_mark_node
6872 	  || (TREE_TYPE (save_expr)
6873 	      && TREE_TYPE (save_expr) == error_mark_node))
6874 	{
6875 	  ret = GS_ERROR;
6876 	  break;
6877 	}
6878 
6879       /* Do any language-specific gimplification.  */
6880       ret = ((enum gimplify_status)
6881 	     lang_hooks.gimplify_expr (expr_p, pre_p, post_p));
6882       if (ret == GS_OK)
6883 	{
6884 	  if (*expr_p == NULL_TREE)
6885 	    break;
6886 	  if (*expr_p != save_expr)
6887 	    continue;
6888 	}
6889       else if (ret != GS_UNHANDLED)
6890 	break;
6891 
6892       /* Make sure that all the cases set 'ret' appropriately.  */
6893       ret = GS_UNHANDLED;
6894       switch (TREE_CODE (*expr_p))
6895 	{
6896 	  /* First deal with the special cases.  */
6897 
6898 	case POSTINCREMENT_EXPR:
6899 	case POSTDECREMENT_EXPR:
6900 	case PREINCREMENT_EXPR:
6901 	case PREDECREMENT_EXPR:
6902 	  ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
6903 					fallback != fb_none);
6904 	  break;
6905 
6906 	case ARRAY_REF:
6907 	case ARRAY_RANGE_REF:
6908 	case REALPART_EXPR:
6909 	case IMAGPART_EXPR:
6910 	case COMPONENT_REF:
6911 	case VIEW_CONVERT_EXPR:
6912 	  ret = gimplify_compound_lval (expr_p, pre_p, post_p,
6913 					fallback ? fallback : fb_rvalue);
6914 	  break;
6915 
6916 	case COND_EXPR:
6917 	  ret = gimplify_cond_expr (expr_p, pre_p, fallback);
6918 
6919 	  /* C99 code may assign to an array in a structure value of a
6920 	     conditional expression, and this has undefined behavior
6921 	     only on execution, so create a temporary if an lvalue is
6922 	     required.  */
6923 	  if (fallback == fb_lvalue)
6924 	    {
6925 	      *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
6926 	      mark_addressable (*expr_p);
6927 	      ret = GS_OK;
6928 	    }
6929 	  break;
6930 
6931 	case CALL_EXPR:
6932 	  ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
6933 
6934 	  /* C99 code may assign to an array in a structure returned
6935 	     from a function, and this has undefined behavior only on
6936 	     execution, so create a temporary if an lvalue is
6937 	     required.  */
6938 	  if (fallback == fb_lvalue)
6939 	    {
6940 	      *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
6941 	      mark_addressable (*expr_p);
6942 	      ret = GS_OK;
6943 	    }
6944 	  break;
6945 
6946 	case TREE_LIST:
6947 	  gcc_unreachable ();
6948 
6949 	case COMPOUND_EXPR:
6950 	  ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
6951 	  break;
6952 
6953 	case COMPOUND_LITERAL_EXPR:
6954 	  ret = gimplify_compound_literal_expr (expr_p, pre_p);
6955 	  break;
6956 
6957 	case MODIFY_EXPR:
6958 	case INIT_EXPR:
6959 	  ret = gimplify_modify_expr (expr_p, pre_p, post_p,
6960 				      fallback != fb_none);
6961 	  break;
6962 
6963 	case TRUTH_ANDIF_EXPR:
6964 	case TRUTH_ORIF_EXPR:
6965 	  {
6966 	    /* Preserve the original type of the expression and the
6967 	       source location of the outer expression.  */
6968 	    tree org_type = TREE_TYPE (*expr_p);
6969 	    *expr_p = gimple_boolify (*expr_p);
6970 	    *expr_p = build3_loc (input_location, COND_EXPR,
6971 				  org_type, *expr_p,
6972 				  fold_convert_loc
6973 				    (input_location,
6974 				     org_type, boolean_true_node),
6975 				  fold_convert_loc
6976 				    (input_location,
6977 				     org_type, boolean_false_node));
6978 	    ret = GS_OK;
6979 	    break;
6980 	  }
6981 
6982 	case TRUTH_NOT_EXPR:
6983 	  {
6984 	    tree type = TREE_TYPE (*expr_p);
6985 	    /* The parsers are careful to generate TRUTH_NOT_EXPR
6986 	       only with operands that are always zero or one.
6987 	       We do not fold here but handle the only interesting case
6988 	       manually, as fold may re-introduce the TRUTH_NOT_EXPR.  */
6989 	    *expr_p = gimple_boolify (*expr_p);
6990 	    if (TYPE_PRECISION (TREE_TYPE (*expr_p)) == 1)
6991 	      *expr_p = build1_loc (input_location, BIT_NOT_EXPR,
6992 				    TREE_TYPE (*expr_p),
6993 				    TREE_OPERAND (*expr_p, 0));
6994 	    else
6995 	      *expr_p = build2_loc (input_location, BIT_XOR_EXPR,
6996 				    TREE_TYPE (*expr_p),
6997 				    TREE_OPERAND (*expr_p, 0),
6998 				    build_int_cst (TREE_TYPE (*expr_p), 1));
6999 	    if (!useless_type_conversion_p (type, TREE_TYPE (*expr_p)))
7000 	      *expr_p = fold_convert_loc (input_location, type, *expr_p);
7001 	    ret = GS_OK;
7002 	    break;
7003 	  }
7004 
7005 	case ADDR_EXPR:
7006 	  ret = gimplify_addr_expr (expr_p, pre_p, post_p);
7007 	  break;
7008 
7009 	case VA_ARG_EXPR:
7010 	  ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
7011 	  break;
7012 
7013 	CASE_CONVERT:
7014 	  if (IS_EMPTY_STMT (*expr_p))
7015 	    {
7016 	      ret = GS_ALL_DONE;
7017 	      break;
7018 	    }
7019 
7020 	  if (VOID_TYPE_P (TREE_TYPE (*expr_p))
7021 	      || fallback == fb_none)
7022 	    {
7023 	      /* Just strip a conversion to void (or in void context) and
7024 		 try again.  */
7025 	      *expr_p = TREE_OPERAND (*expr_p, 0);
7026 	      ret = GS_OK;
7027 	      break;
7028 	    }
7029 
7030 	  ret = gimplify_conversion (expr_p);
7031 	  if (ret == GS_ERROR)
7032 	    break;
7033 	  if (*expr_p != save_expr)
7034 	    break;
7035 	  /* FALLTHRU */
7036 
7037 	case FIX_TRUNC_EXPR:
7038 	  /* unary_expr: ... | '(' cast ')' val | ...  */
7039 	  ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
7040 			       is_gimple_val, fb_rvalue);
7041 	  recalculate_side_effects (*expr_p);
7042 	  break;
7043 
7044 	case INDIRECT_REF:
7045 	  {
7046 	    bool volatilep = TREE_THIS_VOLATILE (*expr_p);
7047 	    bool notrap = TREE_THIS_NOTRAP (*expr_p);
7048 	    tree saved_ptr_type = TREE_TYPE (TREE_OPERAND (*expr_p, 0));
7049 
7050 	    *expr_p = fold_indirect_ref_loc (input_location, *expr_p);
7051 	    if (*expr_p != save_expr)
7052 	      {
7053 		ret = GS_OK;
7054 		break;
7055 	      }
7056 
7057 	    ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
7058 				 is_gimple_reg, fb_rvalue);
7059 	    if (ret == GS_ERROR)
7060 	      break;
7061 
7062 	    recalculate_side_effects (*expr_p);
7063 	    *expr_p = fold_build2_loc (input_location, MEM_REF,
7064 				       TREE_TYPE (*expr_p),
7065 				       TREE_OPERAND (*expr_p, 0),
7066 				       build_int_cst (saved_ptr_type, 0));
7067 	    TREE_THIS_VOLATILE (*expr_p) = volatilep;
7068 	    TREE_THIS_NOTRAP (*expr_p) = notrap;
7069 	    ret = GS_OK;
7070 	    break;
7071 	  }
7072 
7073 	/* We arrive here through the various re-gimplifcation paths.  */
7074 	case MEM_REF:
7075 	  /* First try re-folding the whole thing.  */
7076 	  tmp = fold_binary (MEM_REF, TREE_TYPE (*expr_p),
7077 			     TREE_OPERAND (*expr_p, 0),
7078 			     TREE_OPERAND (*expr_p, 1));
7079 	  if (tmp)
7080 	    {
7081 	      *expr_p = tmp;
7082 	      recalculate_side_effects (*expr_p);
7083 	      ret = GS_OK;
7084 	      break;
7085 	    }
7086 	  /* Avoid re-gimplifying the address operand if it is already
7087 	     in suitable form.  Re-gimplifying would mark the address
7088 	     operand addressable.  Always gimplify when not in SSA form
7089 	     as we still may have to gimplify decls with value-exprs.  */
7090 	  if (!gimplify_ctxp || !gimplify_ctxp->into_ssa
7091 	      || !is_gimple_mem_ref_addr (TREE_OPERAND (*expr_p, 0)))
7092 	    {
7093 	      ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
7094 				   is_gimple_mem_ref_addr, fb_rvalue);
7095 	      if (ret == GS_ERROR)
7096 		break;
7097 	    }
7098 	  recalculate_side_effects (*expr_p);
7099 	  ret = GS_ALL_DONE;
7100 	  break;
7101 
7102 	/* Constants need not be gimplified.  */
7103 	case INTEGER_CST:
7104 	case REAL_CST:
7105 	case FIXED_CST:
7106 	case STRING_CST:
7107 	case COMPLEX_CST:
7108 	case VECTOR_CST:
7109 	  ret = GS_ALL_DONE;
7110 	  break;
7111 
7112 	case CONST_DECL:
7113 	  /* If we require an lvalue, such as for ADDR_EXPR, retain the
7114 	     CONST_DECL node.  Otherwise the decl is replaceable by its
7115 	     value.  */
7116 	  /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either.  */
7117 	  if (fallback & fb_lvalue)
7118 	    ret = GS_ALL_DONE;
7119 	  else
7120 	    {
7121 	      *expr_p = DECL_INITIAL (*expr_p);
7122 	      ret = GS_OK;
7123 	    }
7124 	  break;
7125 
7126 	case DECL_EXPR:
7127 	  ret = gimplify_decl_expr (expr_p, pre_p);
7128 	  break;
7129 
7130 	case BIND_EXPR:
7131 	  ret = gimplify_bind_expr (expr_p, pre_p);
7132 	  break;
7133 
7134 	case LOOP_EXPR:
7135 	  ret = gimplify_loop_expr (expr_p, pre_p);
7136 	  break;
7137 
7138 	case SWITCH_EXPR:
7139 	  ret = gimplify_switch_expr (expr_p, pre_p);
7140 	  break;
7141 
7142 	case EXIT_EXPR:
7143 	  ret = gimplify_exit_expr (expr_p);
7144 	  break;
7145 
7146 	case GOTO_EXPR:
7147 	  /* If the target is not LABEL, then it is a computed jump
7148 	     and the target needs to be gimplified.  */
7149 	  if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
7150 	    {
7151 	      ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
7152 				   NULL, is_gimple_val, fb_rvalue);
7153 	      if (ret == GS_ERROR)
7154 		break;
7155 	    }
7156 	  gimplify_seq_add_stmt (pre_p,
7157 			  gimple_build_goto (GOTO_DESTINATION (*expr_p)));
7158 	  ret = GS_ALL_DONE;
7159 	  break;
7160 
7161 	case PREDICT_EXPR:
7162 	  gimplify_seq_add_stmt (pre_p,
7163 			gimple_build_predict (PREDICT_EXPR_PREDICTOR (*expr_p),
7164 					      PREDICT_EXPR_OUTCOME (*expr_p)));
7165 	  ret = GS_ALL_DONE;
7166 	  break;
7167 
7168 	case LABEL_EXPR:
7169 	  ret = GS_ALL_DONE;
7170 	  gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
7171 		      == current_function_decl);
7172 	  gimplify_seq_add_stmt (pre_p,
7173 			  gimple_build_label (LABEL_EXPR_LABEL (*expr_p)));
7174 	  break;
7175 
7176 	case CASE_LABEL_EXPR:
7177 	  ret = gimplify_case_label_expr (expr_p, pre_p);
7178 	  break;
7179 
7180 	case RETURN_EXPR:
7181 	  ret = gimplify_return_expr (*expr_p, pre_p);
7182 	  break;
7183 
7184 	case CONSTRUCTOR:
7185 	  /* Don't reduce this in place; let gimplify_init_constructor work its
7186 	     magic.  Buf if we're just elaborating this for side effects, just
7187 	     gimplify any element that has side-effects.  */
7188 	  if (fallback == fb_none)
7189 	    {
7190 	      unsigned HOST_WIDE_INT ix;
7191 	      tree val;
7192 	      tree temp = NULL_TREE;
7193 	      FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (*expr_p), ix, val)
7194 		if (TREE_SIDE_EFFECTS (val))
7195 		  append_to_statement_list (val, &temp);
7196 
7197 	      *expr_p = temp;
7198 	      ret = temp ? GS_OK : GS_ALL_DONE;
7199 	    }
7200 	  /* C99 code may assign to an array in a constructed
7201 	     structure or union, and this has undefined behavior only
7202 	     on execution, so create a temporary if an lvalue is
7203 	     required.  */
7204 	  else if (fallback == fb_lvalue)
7205 	    {
7206 	      *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
7207 	      mark_addressable (*expr_p);
7208 	      ret = GS_OK;
7209 	    }
7210 	  else
7211 	    ret = GS_ALL_DONE;
7212 	  break;
7213 
7214 	  /* The following are special cases that are not handled by the
7215 	     original GIMPLE grammar.  */
7216 
7217 	  /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
7218 	     eliminated.  */
7219 	case SAVE_EXPR:
7220 	  ret = gimplify_save_expr (expr_p, pre_p, post_p);
7221 	  break;
7222 
7223 	case BIT_FIELD_REF:
7224 	  {
7225 	    enum gimplify_status r0, r1, r2;
7226 
7227 	    r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
7228 				post_p, is_gimple_lvalue, fb_either);
7229 	    r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
7230 				post_p, is_gimple_val, fb_rvalue);
7231 	    r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p,
7232 				post_p, is_gimple_val, fb_rvalue);
7233 	    recalculate_side_effects (*expr_p);
7234 
7235 	    ret = MIN (r0, MIN (r1, r2));
7236 	  }
7237 	  break;
7238 
7239 	case TARGET_MEM_REF:
7240 	  {
7241 	    enum gimplify_status r0 = GS_ALL_DONE, r1 = GS_ALL_DONE;
7242 
7243 	    if (TMR_BASE (*expr_p))
7244 	      r0 = gimplify_expr (&TMR_BASE (*expr_p), pre_p,
7245 				  post_p, is_gimple_mem_ref_addr, fb_either);
7246 	    if (TMR_INDEX (*expr_p))
7247 	      r1 = gimplify_expr (&TMR_INDEX (*expr_p), pre_p,
7248 				  post_p, is_gimple_val, fb_rvalue);
7249 	    if (TMR_INDEX2 (*expr_p))
7250 	      r1 = gimplify_expr (&TMR_INDEX2 (*expr_p), pre_p,
7251 				  post_p, is_gimple_val, fb_rvalue);
7252 	    /* TMR_STEP and TMR_OFFSET are always integer constants.  */
7253 	    ret = MIN (r0, r1);
7254 	  }
7255 	  break;
7256 
7257 	case NON_LVALUE_EXPR:
7258 	  /* This should have been stripped above.  */
7259 	  gcc_unreachable ();
7260 
7261 	case ASM_EXPR:
7262 	  ret = gimplify_asm_expr (expr_p, pre_p, post_p);
7263 	  break;
7264 
7265 	case TRY_FINALLY_EXPR:
7266 	case TRY_CATCH_EXPR:
7267 	  {
7268 	    gimple_seq eval, cleanup;
7269 	    gimple try_;
7270 
7271 	    eval = cleanup = NULL;
7272 	    gimplify_and_add (TREE_OPERAND (*expr_p, 0), &eval);
7273 	    gimplify_and_add (TREE_OPERAND (*expr_p, 1), &cleanup);
7274 	    /* Don't create bogus GIMPLE_TRY with empty cleanup.  */
7275 	    if (gimple_seq_empty_p (cleanup))
7276 	      {
7277 		gimple_seq_add_seq (pre_p, eval);
7278 		ret = GS_ALL_DONE;
7279 		break;
7280 	      }
7281 	    try_ = gimple_build_try (eval, cleanup,
7282 				     TREE_CODE (*expr_p) == TRY_FINALLY_EXPR
7283 				     ? GIMPLE_TRY_FINALLY
7284 				     : GIMPLE_TRY_CATCH);
7285 	    if (TREE_CODE (*expr_p) == TRY_CATCH_EXPR)
7286 	      gimple_try_set_catch_is_cleanup (try_,
7287 					       TRY_CATCH_IS_CLEANUP (*expr_p));
7288 	    gimplify_seq_add_stmt (pre_p, try_);
7289 	    ret = GS_ALL_DONE;
7290 	    break;
7291 	  }
7292 
7293 	case CLEANUP_POINT_EXPR:
7294 	  ret = gimplify_cleanup_point_expr (expr_p, pre_p);
7295 	  break;
7296 
7297 	case TARGET_EXPR:
7298 	  ret = gimplify_target_expr (expr_p, pre_p, post_p);
7299 	  break;
7300 
7301 	case CATCH_EXPR:
7302 	  {
7303 	    gimple c;
7304 	    gimple_seq handler = NULL;
7305 	    gimplify_and_add (CATCH_BODY (*expr_p), &handler);
7306 	    c = gimple_build_catch (CATCH_TYPES (*expr_p), handler);
7307 	    gimplify_seq_add_stmt (pre_p, c);
7308 	    ret = GS_ALL_DONE;
7309 	    break;
7310 	  }
7311 
7312 	case EH_FILTER_EXPR:
7313 	  {
7314 	    gimple ehf;
7315 	    gimple_seq failure = NULL;
7316 
7317 	    gimplify_and_add (EH_FILTER_FAILURE (*expr_p), &failure);
7318 	    ehf = gimple_build_eh_filter (EH_FILTER_TYPES (*expr_p), failure);
7319 	    gimple_set_no_warning (ehf, TREE_NO_WARNING (*expr_p));
7320 	    gimplify_seq_add_stmt (pre_p, ehf);
7321 	    ret = GS_ALL_DONE;
7322 	    break;
7323 	  }
7324 
7325 	case OBJ_TYPE_REF:
7326 	  {
7327 	    enum gimplify_status r0, r1;
7328 	    r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p,
7329 				post_p, is_gimple_val, fb_rvalue);
7330 	    r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p,
7331 				post_p, is_gimple_val, fb_rvalue);
7332 	    TREE_SIDE_EFFECTS (*expr_p) = 0;
7333 	    ret = MIN (r0, r1);
7334 	  }
7335 	  break;
7336 
7337 	case LABEL_DECL:
7338 	  /* We get here when taking the address of a label.  We mark
7339 	     the label as "forced"; meaning it can never be removed and
7340 	     it is a potential target for any computed goto.  */
7341 	  FORCED_LABEL (*expr_p) = 1;
7342 	  ret = GS_ALL_DONE;
7343 	  break;
7344 
7345 	case STATEMENT_LIST:
7346 	  ret = gimplify_statement_list (expr_p, pre_p);
7347 	  break;
7348 
7349 	case WITH_SIZE_EXPR:
7350 	  {
7351 	    gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
7352 			   post_p == &internal_post ? NULL : post_p,
7353 			   gimple_test_f, fallback);
7354 	    gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
7355 			   is_gimple_val, fb_rvalue);
7356 	    ret = GS_ALL_DONE;
7357 	  }
7358 	  break;
7359 
7360 	case VAR_DECL:
7361 	case PARM_DECL:
7362 	  ret = gimplify_var_or_parm_decl (expr_p);
7363 	  break;
7364 
7365 	case RESULT_DECL:
7366 	  /* When within an OpenMP context, notice uses of variables.  */
7367 	  if (gimplify_omp_ctxp)
7368 	    omp_notice_variable (gimplify_omp_ctxp, *expr_p, true);
7369 	  ret = GS_ALL_DONE;
7370 	  break;
7371 
7372 	case SSA_NAME:
7373 	  /* Allow callbacks into the gimplifier during optimization.  */
7374 	  ret = GS_ALL_DONE;
7375 	  break;
7376 
7377 	case OMP_PARALLEL:
7378 	  gimplify_omp_parallel (expr_p, pre_p);
7379 	  ret = GS_ALL_DONE;
7380 	  break;
7381 
7382 	case OMP_TASK:
7383 	  gimplify_omp_task (expr_p, pre_p);
7384 	  ret = GS_ALL_DONE;
7385 	  break;
7386 
7387 	case OMP_FOR:
7388 	  ret = gimplify_omp_for (expr_p, pre_p);
7389 	  break;
7390 
7391 	case OMP_SECTIONS:
7392 	case OMP_SINGLE:
7393 	  gimplify_omp_workshare (expr_p, pre_p);
7394 	  ret = GS_ALL_DONE;
7395 	  break;
7396 
7397 	case OMP_SECTION:
7398 	case OMP_MASTER:
7399 	case OMP_ORDERED:
7400 	case OMP_CRITICAL:
7401 	  {
7402 	    gimple_seq body = NULL;
7403 	    gimple g;
7404 
7405 	    gimplify_and_add (OMP_BODY (*expr_p), &body);
7406 	    switch (TREE_CODE (*expr_p))
7407 	      {
7408 	      case OMP_SECTION:
7409 	        g = gimple_build_omp_section (body);
7410 	        break;
7411 	      case OMP_MASTER:
7412 	        g = gimple_build_omp_master (body);
7413 		break;
7414 	      case OMP_ORDERED:
7415 		g = gimple_build_omp_ordered (body);
7416 		break;
7417 	      case OMP_CRITICAL:
7418 		g = gimple_build_omp_critical (body,
7419 		    			       OMP_CRITICAL_NAME (*expr_p));
7420 		break;
7421 	      default:
7422 		gcc_unreachable ();
7423 	      }
7424 	    gimplify_seq_add_stmt (pre_p, g);
7425 	    ret = GS_ALL_DONE;
7426 	    break;
7427 	  }
7428 
7429 	case OMP_ATOMIC:
7430 	case OMP_ATOMIC_READ:
7431 	case OMP_ATOMIC_CAPTURE_OLD:
7432 	case OMP_ATOMIC_CAPTURE_NEW:
7433 	  ret = gimplify_omp_atomic (expr_p, pre_p);
7434 	  break;
7435 
7436 	case TRANSACTION_EXPR:
7437 	  ret = gimplify_transaction (expr_p, pre_p);
7438 	  break;
7439 
7440 	case TRUTH_AND_EXPR:
7441 	case TRUTH_OR_EXPR:
7442 	case TRUTH_XOR_EXPR:
7443 	  {
7444 	    tree orig_type = TREE_TYPE (*expr_p);
7445 	    tree new_type, xop0, xop1;
7446 	    *expr_p = gimple_boolify (*expr_p);
7447 	    new_type = TREE_TYPE (*expr_p);
7448 	    if (!useless_type_conversion_p (orig_type, new_type))
7449 	      {
7450 		*expr_p = fold_convert_loc (input_location, orig_type, *expr_p);
7451 		ret = GS_OK;
7452 		break;
7453 	      }
7454 
7455 	  /* Boolified binary truth expressions are semantically equivalent
7456 	     to bitwise binary expressions.  Canonicalize them to the
7457 	     bitwise variant.  */
7458 	    switch (TREE_CODE (*expr_p))
7459 	      {
7460 	      case TRUTH_AND_EXPR:
7461 		TREE_SET_CODE (*expr_p, BIT_AND_EXPR);
7462 		break;
7463 	      case TRUTH_OR_EXPR:
7464 		TREE_SET_CODE (*expr_p, BIT_IOR_EXPR);
7465 		break;
7466 	      case TRUTH_XOR_EXPR:
7467 		TREE_SET_CODE (*expr_p, BIT_XOR_EXPR);
7468 		break;
7469 	      default:
7470 		break;
7471 	      }
7472 	    /* Now make sure that operands have compatible type to
7473 	       expression's new_type.  */
7474 	    xop0 = TREE_OPERAND (*expr_p, 0);
7475 	    xop1 = TREE_OPERAND (*expr_p, 1);
7476 	    if (!useless_type_conversion_p (new_type, TREE_TYPE (xop0)))
7477 	      TREE_OPERAND (*expr_p, 0) = fold_convert_loc (input_location,
7478 							    new_type,
7479 	      						    xop0);
7480 	    if (!useless_type_conversion_p (new_type, TREE_TYPE (xop1)))
7481 	      TREE_OPERAND (*expr_p, 1) = fold_convert_loc (input_location,
7482 							    new_type,
7483 	      						    xop1);
7484 	    /* Continue classified as tcc_binary.  */
7485 	    goto expr_2;
7486 	  }
7487 
7488 	case FMA_EXPR:
7489 	case VEC_PERM_EXPR:
7490 	  /* Classified as tcc_expression.  */
7491 	  goto expr_3;
7492 
7493 	case POINTER_PLUS_EXPR:
7494 	  {
7495 	    enum gimplify_status r0, r1;
7496 	    r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
7497 				post_p, is_gimple_val, fb_rvalue);
7498 	    r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
7499 				post_p, is_gimple_val, fb_rvalue);
7500 	    recalculate_side_effects (*expr_p);
7501 	    ret = MIN (r0, r1);
7502 	    /* Convert &X + CST to invariant &MEM[&X, CST].  Do this
7503 	       after gimplifying operands - this is similar to how
7504 	       it would be folding all gimplified stmts on creation
7505 	       to have them canonicalized, which is what we eventually
7506 	       should do anyway.  */
7507 	    if (TREE_CODE (TREE_OPERAND (*expr_p, 1)) == INTEGER_CST
7508 		&& is_gimple_min_invariant (TREE_OPERAND (*expr_p, 0)))
7509 	      {
7510 		*expr_p = build_fold_addr_expr_with_type_loc
7511 		   (input_location,
7512 		    fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (*expr_p)),
7513 				 TREE_OPERAND (*expr_p, 0),
7514 				 fold_convert (ptr_type_node,
7515 					       TREE_OPERAND (*expr_p, 1))),
7516 		    TREE_TYPE (*expr_p));
7517 		ret = MIN (ret, GS_OK);
7518 	      }
7519 	    break;
7520 	  }
7521 
7522 	default:
7523 	  switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
7524 	    {
7525 	    case tcc_comparison:
7526 	      /* Handle comparison of objects of non scalar mode aggregates
7527 	     	 with a call to memcmp.  It would be nice to only have to do
7528 	     	 this for variable-sized objects, but then we'd have to allow
7529 	     	 the same nest of reference nodes we allow for MODIFY_EXPR and
7530 	     	 that's too complex.
7531 
7532 		 Compare scalar mode aggregates as scalar mode values.  Using
7533 		 memcmp for them would be very inefficient at best, and is
7534 		 plain wrong if bitfields are involved.  */
7535 		{
7536 		  tree type = TREE_TYPE (TREE_OPERAND (*expr_p, 1));
7537 
7538 		  /* Vector comparisons need no boolification.  */
7539 		  if (TREE_CODE (type) == VECTOR_TYPE)
7540 		    goto expr_2;
7541 		  else if (!AGGREGATE_TYPE_P (type))
7542 		    {
7543 		      tree org_type = TREE_TYPE (*expr_p);
7544 		      *expr_p = gimple_boolify (*expr_p);
7545 		      if (!useless_type_conversion_p (org_type,
7546 						      TREE_TYPE (*expr_p)))
7547 			{
7548 			  *expr_p = fold_convert_loc (input_location,
7549 						      org_type, *expr_p);
7550 			  ret = GS_OK;
7551 			}
7552 		      else
7553 			goto expr_2;
7554 		    }
7555 		  else if (TYPE_MODE (type) != BLKmode)
7556 		    ret = gimplify_scalar_mode_aggregate_compare (expr_p);
7557 		  else
7558 		    ret = gimplify_variable_sized_compare (expr_p);
7559 
7560 		  break;
7561 		}
7562 
7563 	    /* If *EXPR_P does not need to be special-cased, handle it
7564 	       according to its class.  */
7565 	    case tcc_unary:
7566 	      ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
7567 				   post_p, is_gimple_val, fb_rvalue);
7568 	      break;
7569 
7570 	    case tcc_binary:
7571 	    expr_2:
7572 	      {
7573 		enum gimplify_status r0, r1;
7574 
7575 		r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
7576 		                    post_p, is_gimple_val, fb_rvalue);
7577 		r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
7578 				    post_p, is_gimple_val, fb_rvalue);
7579 
7580 		ret = MIN (r0, r1);
7581 		break;
7582 	      }
7583 
7584 	    expr_3:
7585 	      {
7586 		enum gimplify_status r0, r1, r2;
7587 
7588 		r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
7589 		                    post_p, is_gimple_val, fb_rvalue);
7590 		r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
7591 				    post_p, is_gimple_val, fb_rvalue);
7592 		r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p,
7593 				    post_p, is_gimple_val, fb_rvalue);
7594 
7595 		ret = MIN (MIN (r0, r1), r2);
7596 		break;
7597 	      }
7598 
7599 	    case tcc_declaration:
7600 	    case tcc_constant:
7601 	      ret = GS_ALL_DONE;
7602 	      goto dont_recalculate;
7603 
7604 	    default:
7605 	      gcc_unreachable ();
7606 	    }
7607 
7608 	  recalculate_side_effects (*expr_p);
7609 
7610 	dont_recalculate:
7611 	  break;
7612 	}
7613 
7614       gcc_assert (*expr_p || ret != GS_OK);
7615     }
7616   while (ret == GS_OK);
7617 
7618   /* If we encountered an error_mark somewhere nested inside, either
7619      stub out the statement or propagate the error back out.  */
7620   if (ret == GS_ERROR)
7621     {
7622       if (is_statement)
7623 	*expr_p = NULL;
7624       goto out;
7625     }
7626 
7627   /* This was only valid as a return value from the langhook, which
7628      we handled.  Make sure it doesn't escape from any other context.  */
7629   gcc_assert (ret != GS_UNHANDLED);
7630 
7631   if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
7632     {
7633       /* We aren't looking for a value, and we don't have a valid
7634 	 statement.  If it doesn't have side-effects, throw it away.  */
7635       if (!TREE_SIDE_EFFECTS (*expr_p))
7636 	*expr_p = NULL;
7637       else if (!TREE_THIS_VOLATILE (*expr_p))
7638 	{
7639 	  /* This is probably a _REF that contains something nested that
7640 	     has side effects.  Recurse through the operands to find it.  */
7641 	  enum tree_code code = TREE_CODE (*expr_p);
7642 
7643 	  switch (code)
7644 	    {
7645 	    case COMPONENT_REF:
7646 	    case REALPART_EXPR:
7647 	    case IMAGPART_EXPR:
7648 	    case VIEW_CONVERT_EXPR:
7649 	      gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
7650 			     gimple_test_f, fallback);
7651 	      break;
7652 
7653 	    case ARRAY_REF:
7654 	    case ARRAY_RANGE_REF:
7655 	      gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
7656 			     gimple_test_f, fallback);
7657 	      gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
7658 			     gimple_test_f, fallback);
7659 	      break;
7660 
7661 	    default:
7662 	       /* Anything else with side-effects must be converted to
7663 		  a valid statement before we get here.  */
7664 	      gcc_unreachable ();
7665 	    }
7666 
7667 	  *expr_p = NULL;
7668 	}
7669       else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p))
7670 	       && TYPE_MODE (TREE_TYPE (*expr_p)) != BLKmode)
7671 	{
7672 	  /* Historically, the compiler has treated a bare reference
7673 	     to a non-BLKmode volatile lvalue as forcing a load.  */
7674 	  tree type = TYPE_MAIN_VARIANT (TREE_TYPE (*expr_p));
7675 
7676 	  /* Normally, we do not want to create a temporary for a
7677 	     TREE_ADDRESSABLE type because such a type should not be
7678 	     copied by bitwise-assignment.  However, we make an
7679 	     exception here, as all we are doing here is ensuring that
7680 	     we read the bytes that make up the type.  We use
7681 	     create_tmp_var_raw because create_tmp_var will abort when
7682 	     given a TREE_ADDRESSABLE type.  */
7683 	  tree tmp = create_tmp_var_raw (type, "vol");
7684 	  gimple_add_tmp_var (tmp);
7685 	  gimplify_assign (tmp, *expr_p, pre_p);
7686 	  *expr_p = NULL;
7687 	}
7688       else
7689 	/* We can't do anything useful with a volatile reference to
7690 	   an incomplete type, so just throw it away.  Likewise for
7691 	   a BLKmode type, since any implicit inner load should
7692 	   already have been turned into an explicit one by the
7693 	   gimplification process.  */
7694 	*expr_p = NULL;
7695     }
7696 
7697   /* If we are gimplifying at the statement level, we're done.  Tack
7698      everything together and return.  */
7699   if (fallback == fb_none || is_statement)
7700     {
7701       /* Since *EXPR_P has been converted into a GIMPLE tuple, clear
7702          it out for GC to reclaim it.  */
7703       *expr_p = NULL_TREE;
7704 
7705       if (!gimple_seq_empty_p (internal_pre)
7706 	  || !gimple_seq_empty_p (internal_post))
7707 	{
7708 	  gimplify_seq_add_seq (&internal_pre, internal_post);
7709 	  gimplify_seq_add_seq (pre_p, internal_pre);
7710 	}
7711 
7712       /* The result of gimplifying *EXPR_P is going to be the last few
7713 	 statements in *PRE_P and *POST_P.  Add location information
7714 	 to all the statements that were added by the gimplification
7715 	 helpers.  */
7716       if (!gimple_seq_empty_p (*pre_p))
7717 	annotate_all_with_location_after (*pre_p, pre_last_gsi, input_location);
7718 
7719       if (!gimple_seq_empty_p (*post_p))
7720 	annotate_all_with_location_after (*post_p, post_last_gsi,
7721 					  input_location);
7722 
7723       goto out;
7724     }
7725 
7726 #ifdef ENABLE_GIMPLE_CHECKING
7727   if (*expr_p)
7728     {
7729       enum tree_code code = TREE_CODE (*expr_p);
7730       /* These expressions should already be in gimple IR form.  */
7731       gcc_assert (code != MODIFY_EXPR
7732 		  && code != ASM_EXPR
7733 		  && code != BIND_EXPR
7734 		  && code != CATCH_EXPR
7735 		  && (code != COND_EXPR || gimplify_ctxp->allow_rhs_cond_expr)
7736 		  && code != EH_FILTER_EXPR
7737 		  && code != GOTO_EXPR
7738 		  && code != LABEL_EXPR
7739 		  && code != LOOP_EXPR
7740 		  && code != SWITCH_EXPR
7741 		  && code != TRY_FINALLY_EXPR
7742 		  && code != OMP_CRITICAL
7743 		  && code != OMP_FOR
7744 		  && code != OMP_MASTER
7745 		  && code != OMP_ORDERED
7746 		  && code != OMP_PARALLEL
7747 		  && code != OMP_SECTIONS
7748 		  && code != OMP_SECTION
7749 		  && code != OMP_SINGLE);
7750     }
7751 #endif
7752 
7753   /* Otherwise we're gimplifying a subexpression, so the resulting
7754      value is interesting.  If it's a valid operand that matches
7755      GIMPLE_TEST_F, we're done. Unless we are handling some
7756      post-effects internally; if that's the case, we need to copy into
7757      a temporary before adding the post-effects to POST_P.  */
7758   if (gimple_seq_empty_p (internal_post) && (*gimple_test_f) (*expr_p))
7759     goto out;
7760 
7761   /* Otherwise, we need to create a new temporary for the gimplified
7762      expression.  */
7763 
7764   /* We can't return an lvalue if we have an internal postqueue.  The
7765      object the lvalue refers to would (probably) be modified by the
7766      postqueue; we need to copy the value out first, which means an
7767      rvalue.  */
7768   if ((fallback & fb_lvalue)
7769       && gimple_seq_empty_p (internal_post)
7770       && is_gimple_addressable (*expr_p))
7771     {
7772       /* An lvalue will do.  Take the address of the expression, store it
7773 	 in a temporary, and replace the expression with an INDIRECT_REF of
7774 	 that temporary.  */
7775       tmp = build_fold_addr_expr_loc (input_location, *expr_p);
7776       gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
7777       *expr_p = build_simple_mem_ref (tmp);
7778     }
7779   else if ((fallback & fb_rvalue) && is_gimple_reg_rhs_or_call (*expr_p))
7780     {
7781       /* An rvalue will do.  Assign the gimplified expression into a
7782 	 new temporary TMP and replace the original expression with
7783 	 TMP.  First, make sure that the expression has a type so that
7784 	 it can be assigned into a temporary.  */
7785       gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
7786 
7787       if (!gimple_seq_empty_p (internal_post) || (fallback & fb_lvalue))
7788 	/* The postqueue might change the value of the expression between
7789 	   the initialization and use of the temporary, so we can't use a
7790 	   formal temp.  FIXME do we care?  */
7791 	{
7792 	  *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
7793 	  if (TREE_CODE (TREE_TYPE (*expr_p)) == COMPLEX_TYPE
7794 	      || TREE_CODE (TREE_TYPE (*expr_p)) == VECTOR_TYPE)
7795 	    DECL_GIMPLE_REG_P (*expr_p) = 1;
7796 	}
7797       else
7798 	*expr_p = get_formal_tmp_var (*expr_p, pre_p);
7799     }
7800   else
7801     {
7802 #ifdef ENABLE_GIMPLE_CHECKING
7803       if (!(fallback & fb_mayfail))
7804 	{
7805 	  fprintf (stderr, "gimplification failed:\n");
7806 	  print_generic_expr (stderr, *expr_p, 0);
7807 	  debug_tree (*expr_p);
7808 	  internal_error ("gimplification failed");
7809 	}
7810 #endif
7811       gcc_assert (fallback & fb_mayfail);
7812 
7813       /* If this is an asm statement, and the user asked for the
7814 	 impossible, don't die.  Fail and let gimplify_asm_expr
7815 	 issue an error.  */
7816       ret = GS_ERROR;
7817       goto out;
7818     }
7819 
7820   /* Make sure the temporary matches our predicate.  */
7821   gcc_assert ((*gimple_test_f) (*expr_p));
7822 
7823   if (!gimple_seq_empty_p (internal_post))
7824     {
7825       annotate_all_with_location (internal_post, input_location);
7826       gimplify_seq_add_seq (pre_p, internal_post);
7827     }
7828 
7829  out:
7830   input_location = saved_location;
7831   return ret;
7832 }
7833 
7834 /* Look through TYPE for variable-sized objects and gimplify each such
7835    size that we find.  Add to LIST_P any statements generated.  */
7836 
7837 void
7838 gimplify_type_sizes (tree type, gimple_seq *list_p)
7839 {
7840   tree field, t;
7841 
7842   if (type == NULL || type == error_mark_node)
7843     return;
7844 
7845   /* We first do the main variant, then copy into any other variants.  */
7846   type = TYPE_MAIN_VARIANT (type);
7847 
7848   /* Avoid infinite recursion.  */
7849   if (TYPE_SIZES_GIMPLIFIED (type))
7850     return;
7851 
7852   TYPE_SIZES_GIMPLIFIED (type) = 1;
7853 
7854   switch (TREE_CODE (type))
7855     {
7856     case INTEGER_TYPE:
7857     case ENUMERAL_TYPE:
7858     case BOOLEAN_TYPE:
7859     case REAL_TYPE:
7860     case FIXED_POINT_TYPE:
7861       gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
7862       gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
7863 
7864       for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
7865 	{
7866 	  TYPE_MIN_VALUE (t) = TYPE_MIN_VALUE (type);
7867 	  TYPE_MAX_VALUE (t) = TYPE_MAX_VALUE (type);
7868 	}
7869       break;
7870 
7871     case ARRAY_TYPE:
7872       /* These types may not have declarations, so handle them here.  */
7873       gimplify_type_sizes (TREE_TYPE (type), list_p);
7874       gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
7875       /* Ensure VLA bounds aren't removed, for -O0 they should be variables
7876 	 with assigned stack slots, for -O1+ -g they should be tracked
7877 	 by VTA.  */
7878       if (!(TYPE_NAME (type)
7879 	    && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
7880 	    && DECL_IGNORED_P (TYPE_NAME (type)))
7881 	  && TYPE_DOMAIN (type)
7882 	  && INTEGRAL_TYPE_P (TYPE_DOMAIN (type)))
7883 	{
7884 	  t = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
7885 	  if (t && TREE_CODE (t) == VAR_DECL && DECL_ARTIFICIAL (t))
7886 	    DECL_IGNORED_P (t) = 0;
7887 	  t = TYPE_MAX_VALUE (TYPE_DOMAIN (type));
7888 	  if (t && TREE_CODE (t) == VAR_DECL && DECL_ARTIFICIAL (t))
7889 	    DECL_IGNORED_P (t) = 0;
7890 	}
7891       break;
7892 
7893     case RECORD_TYPE:
7894     case UNION_TYPE:
7895     case QUAL_UNION_TYPE:
7896       for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
7897 	if (TREE_CODE (field) == FIELD_DECL)
7898 	  {
7899 	    gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
7900 	    gimplify_one_sizepos (&DECL_SIZE (field), list_p);
7901 	    gimplify_one_sizepos (&DECL_SIZE_UNIT (field), list_p);
7902 	    gimplify_type_sizes (TREE_TYPE (field), list_p);
7903 	  }
7904       break;
7905 
7906     case POINTER_TYPE:
7907     case REFERENCE_TYPE:
7908 	/* We used to recurse on the pointed-to type here, which turned out to
7909 	   be incorrect because its definition might refer to variables not
7910 	   yet initialized at this point if a forward declaration is involved.
7911 
7912 	   It was actually useful for anonymous pointed-to types to ensure
7913 	   that the sizes evaluation dominates every possible later use of the
7914 	   values.  Restricting to such types here would be safe since there
7915 	   is no possible forward declaration around, but would introduce an
7916 	   undesirable middle-end semantic to anonymity.  We then defer to
7917 	   front-ends the responsibility of ensuring that the sizes are
7918 	   evaluated both early and late enough, e.g. by attaching artificial
7919 	   type declarations to the tree.  */
7920       break;
7921 
7922     default:
7923       break;
7924     }
7925 
7926   gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
7927   gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
7928 
7929   for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
7930     {
7931       TYPE_SIZE (t) = TYPE_SIZE (type);
7932       TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (type);
7933       TYPE_SIZES_GIMPLIFIED (t) = 1;
7934     }
7935 }
7936 
7937 /* A subroutine of gimplify_type_sizes to make sure that *EXPR_P,
7938    a size or position, has had all of its SAVE_EXPRs evaluated.
7939    We add any required statements to *STMT_P.  */
7940 
7941 void
7942 gimplify_one_sizepos (tree *expr_p, gimple_seq *stmt_p)
7943 {
7944   tree type, expr = *expr_p;
7945 
7946   /* We don't do anything if the value isn't there, is constant, or contains
7947      A PLACEHOLDER_EXPR.  We also don't want to do anything if it's already
7948      a VAR_DECL.  If it's a VAR_DECL from another function, the gimplifier
7949      will want to replace it with a new variable, but that will cause problems
7950      if this type is from outside the function.  It's OK to have that here.  */
7951   if (is_gimple_sizepos (expr))
7952     return;
7953 
7954   type = TREE_TYPE (expr);
7955   *expr_p = unshare_expr (expr);
7956 
7957   gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
7958   expr = *expr_p;
7959 
7960   /* Verify that we've an exact type match with the original expression.
7961      In particular, we do not wish to drop a "sizetype" in favour of a
7962      type of similar dimensions.  We don't want to pollute the generic
7963      type-stripping code with this knowledge because it doesn't matter
7964      for the bulk of GENERIC/GIMPLE.  It only matters that TYPE_SIZE_UNIT
7965      and friends retain their "sizetype-ness".  */
7966   if (TREE_TYPE (expr) != type
7967       && TREE_CODE (type) == INTEGER_TYPE
7968       && TYPE_IS_SIZETYPE (type))
7969     {
7970       tree tmp;
7971       gimple stmt;
7972 
7973       *expr_p = create_tmp_var (type, NULL);
7974       tmp = build1 (NOP_EXPR, type, expr);
7975       stmt = gimplify_assign (*expr_p, tmp, stmt_p);
7976       gimple_set_location (stmt, EXPR_LOC_OR_HERE (expr));
7977     }
7978 }
7979 
7980 /* Gimplify the body of statements of FNDECL and return a GIMPLE_BIND node
7981    containing the sequence of corresponding GIMPLE statements.  If DO_PARMS
7982    is true, also gimplify the parameters.  */
7983 
7984 gimple
7985 gimplify_body (tree fndecl, bool do_parms)
7986 {
7987   location_t saved_location = input_location;
7988   gimple_seq parm_stmts, seq;
7989   gimple outer_bind;
7990   struct gimplify_ctx gctx;
7991   struct cgraph_node *cgn;
7992 
7993   timevar_push (TV_TREE_GIMPLIFY);
7994 
7995   /* Initialize for optimize_insn_for_s{ize,peed}_p possibly called during
7996      gimplification.  */
7997   default_rtl_profile ();
7998 
7999   gcc_assert (gimplify_ctxp == NULL);
8000   push_gimplify_context (&gctx);
8001 
8002   /* Unshare most shared trees in the body and in that of any nested functions.
8003      It would seem we don't have to do this for nested functions because
8004      they are supposed to be output and then the outer function gimplified
8005      first, but the g++ front end doesn't always do it that way.  */
8006   unshare_body (fndecl);
8007   unvisit_body (fndecl);
8008 
8009   cgn = cgraph_get_node (fndecl);
8010   if (cgn && cgn->origin)
8011     nonlocal_vlas = pointer_set_create ();
8012 
8013   /* Make sure input_location isn't set to something weird.  */
8014   input_location = DECL_SOURCE_LOCATION (fndecl);
8015 
8016   /* Resolve callee-copies.  This has to be done before processing
8017      the body so that DECL_VALUE_EXPR gets processed correctly.  */
8018   parm_stmts = do_parms ? gimplify_parameters () : NULL;
8019 
8020   /* Gimplify the function's body.  */
8021   seq = NULL;
8022   gimplify_stmt (&DECL_SAVED_TREE (fndecl), &seq);
8023   outer_bind = gimple_seq_first_stmt (seq);
8024   if (!outer_bind)
8025     {
8026       outer_bind = gimple_build_nop ();
8027       gimplify_seq_add_stmt (&seq, outer_bind);
8028     }
8029 
8030   /* The body must contain exactly one statement, a GIMPLE_BIND.  If this is
8031      not the case, wrap everything in a GIMPLE_BIND to make it so.  */
8032   if (gimple_code (outer_bind) == GIMPLE_BIND
8033       && gimple_seq_first (seq) == gimple_seq_last (seq))
8034     ;
8035   else
8036     outer_bind = gimple_build_bind (NULL_TREE, seq, NULL);
8037 
8038   DECL_SAVED_TREE (fndecl) = NULL_TREE;
8039 
8040   /* If we had callee-copies statements, insert them at the beginning
8041      of the function and clear DECL_VALUE_EXPR_P on the parameters.  */
8042   if (!gimple_seq_empty_p (parm_stmts))
8043     {
8044       tree parm;
8045 
8046       gimplify_seq_add_seq (&parm_stmts, gimple_bind_body (outer_bind));
8047       gimple_bind_set_body (outer_bind, parm_stmts);
8048 
8049       for (parm = DECL_ARGUMENTS (current_function_decl);
8050 	   parm; parm = DECL_CHAIN (parm))
8051 	if (DECL_HAS_VALUE_EXPR_P (parm))
8052 	  {
8053 	    DECL_HAS_VALUE_EXPR_P (parm) = 0;
8054 	    DECL_IGNORED_P (parm) = 0;
8055 	  }
8056     }
8057 
8058   if (nonlocal_vlas)
8059     {
8060       pointer_set_destroy (nonlocal_vlas);
8061       nonlocal_vlas = NULL;
8062     }
8063 
8064   pop_gimplify_context (outer_bind);
8065   gcc_assert (gimplify_ctxp == NULL);
8066 
8067   if (!seen_error ())
8068     verify_gimple_in_seq (gimple_bind_body (outer_bind));
8069 
8070   timevar_pop (TV_TREE_GIMPLIFY);
8071   input_location = saved_location;
8072 
8073   return outer_bind;
8074 }
8075 
8076 typedef char *char_p; /* For DEF_VEC_P.  */
8077 DEF_VEC_P(char_p);
8078 DEF_VEC_ALLOC_P(char_p,heap);
8079 
8080 /* Return whether we should exclude FNDECL from instrumentation.  */
8081 
8082 static bool
8083 flag_instrument_functions_exclude_p (tree fndecl)
8084 {
8085   VEC(char_p,heap) *vec;
8086 
8087   vec = (VEC(char_p,heap) *) flag_instrument_functions_exclude_functions;
8088   if (VEC_length (char_p, vec) > 0)
8089     {
8090       const char *name;
8091       int i;
8092       char *s;
8093 
8094       name = lang_hooks.decl_printable_name (fndecl, 0);
8095       FOR_EACH_VEC_ELT (char_p, vec, i, s)
8096 	if (strstr (name, s) != NULL)
8097 	  return true;
8098     }
8099 
8100   vec = (VEC(char_p,heap) *) flag_instrument_functions_exclude_files;
8101   if (VEC_length (char_p, vec) > 0)
8102     {
8103       const char *name;
8104       int i;
8105       char *s;
8106 
8107       name = DECL_SOURCE_FILE (fndecl);
8108       FOR_EACH_VEC_ELT (char_p, vec, i, s)
8109 	if (strstr (name, s) != NULL)
8110 	  return true;
8111     }
8112 
8113   return false;
8114 }
8115 
8116 /* Entry point to the gimplification pass.  FNDECL is the FUNCTION_DECL
8117    node for the function we want to gimplify.
8118 
8119    Return the sequence of GIMPLE statements corresponding to the body
8120    of FNDECL.  */
8121 
8122 void
8123 gimplify_function_tree (tree fndecl)
8124 {
8125   tree oldfn, parm, ret;
8126   gimple_seq seq;
8127   gimple bind;
8128 
8129   gcc_assert (!gimple_body (fndecl));
8130 
8131   oldfn = current_function_decl;
8132   current_function_decl = fndecl;
8133   if (DECL_STRUCT_FUNCTION (fndecl))
8134     push_cfun (DECL_STRUCT_FUNCTION (fndecl));
8135   else
8136     push_struct_function (fndecl);
8137 
8138   for (parm = DECL_ARGUMENTS (fndecl); parm ; parm = DECL_CHAIN (parm))
8139     {
8140       /* Preliminarily mark non-addressed complex variables as eligible
8141          for promotion to gimple registers.  We'll transform their uses
8142          as we find them.  */
8143       if ((TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
8144 	   || TREE_CODE (TREE_TYPE (parm)) == VECTOR_TYPE)
8145           && !TREE_THIS_VOLATILE (parm)
8146           && !needs_to_live_in_memory (parm))
8147         DECL_GIMPLE_REG_P (parm) = 1;
8148     }
8149 
8150   ret = DECL_RESULT (fndecl);
8151   if ((TREE_CODE (TREE_TYPE (ret)) == COMPLEX_TYPE
8152        || TREE_CODE (TREE_TYPE (ret)) == VECTOR_TYPE)
8153       && !needs_to_live_in_memory (ret))
8154     DECL_GIMPLE_REG_P (ret) = 1;
8155 
8156   bind = gimplify_body (fndecl, true);
8157 
8158   /* The tree body of the function is no longer needed, replace it
8159      with the new GIMPLE body.  */
8160   seq = gimple_seq_alloc ();
8161   gimple_seq_add_stmt (&seq, bind);
8162   gimple_set_body (fndecl, seq);
8163 
8164   /* If we're instrumenting function entry/exit, then prepend the call to
8165      the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
8166      catch the exit hook.  */
8167   /* ??? Add some way to ignore exceptions for this TFE.  */
8168   if (flag_instrument_function_entry_exit
8169       && !DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl)
8170       && !flag_instrument_functions_exclude_p (fndecl))
8171     {
8172       tree x;
8173       gimple new_bind;
8174       gimple tf;
8175       gimple_seq cleanup = NULL, body = NULL;
8176       tree tmp_var;
8177       gimple call;
8178 
8179       x = builtin_decl_implicit (BUILT_IN_RETURN_ADDRESS);
8180       call = gimple_build_call (x, 1, integer_zero_node);
8181       tmp_var = create_tmp_var (ptr_type_node, "return_addr");
8182       gimple_call_set_lhs (call, tmp_var);
8183       gimplify_seq_add_stmt (&cleanup, call);
8184       x = builtin_decl_implicit (BUILT_IN_PROFILE_FUNC_EXIT);
8185       call = gimple_build_call (x, 2,
8186 				build_fold_addr_expr (current_function_decl),
8187 				tmp_var);
8188       gimplify_seq_add_stmt (&cleanup, call);
8189       tf = gimple_build_try (seq, cleanup, GIMPLE_TRY_FINALLY);
8190 
8191       x = builtin_decl_implicit (BUILT_IN_RETURN_ADDRESS);
8192       call = gimple_build_call (x, 1, integer_zero_node);
8193       tmp_var = create_tmp_var (ptr_type_node, "return_addr");
8194       gimple_call_set_lhs (call, tmp_var);
8195       gimplify_seq_add_stmt (&body, call);
8196       x = builtin_decl_implicit (BUILT_IN_PROFILE_FUNC_ENTER);
8197       call = gimple_build_call (x, 2,
8198 				build_fold_addr_expr (current_function_decl),
8199 				tmp_var);
8200       gimplify_seq_add_stmt (&body, call);
8201       gimplify_seq_add_stmt (&body, tf);
8202       new_bind = gimple_build_bind (NULL, body, gimple_bind_block (bind));
8203       /* Clear the block for BIND, since it is no longer directly inside
8204          the function, but within a try block.  */
8205       gimple_bind_set_block (bind, NULL);
8206 
8207       /* Replace the current function body with the body
8208          wrapped in the try/finally TF.  */
8209       seq = gimple_seq_alloc ();
8210       gimple_seq_add_stmt (&seq, new_bind);
8211       gimple_set_body (fndecl, seq);
8212     }
8213 
8214   DECL_SAVED_TREE (fndecl) = NULL_TREE;
8215   cfun->curr_properties = PROP_gimple_any;
8216 
8217   current_function_decl = oldfn;
8218   pop_cfun ();
8219 }
8220 
8221 /* Some transformations like inlining may invalidate the GIMPLE form
8222    for operands.  This function traverses all the operands in STMT and
8223    gimplifies anything that is not a valid gimple operand.  Any new
8224    GIMPLE statements are inserted before *GSI_P.  */
8225 
8226 void
8227 gimple_regimplify_operands (gimple stmt, gimple_stmt_iterator *gsi_p)
8228 {
8229   size_t i, num_ops;
8230   tree orig_lhs = NULL_TREE, lhs, t;
8231   gimple_seq pre = NULL;
8232   gimple post_stmt = NULL;
8233   struct gimplify_ctx gctx;
8234 
8235   push_gimplify_context (&gctx);
8236   gimplify_ctxp->into_ssa = gimple_in_ssa_p (cfun);
8237 
8238   switch (gimple_code (stmt))
8239     {
8240     case GIMPLE_COND:
8241       gimplify_expr (gimple_cond_lhs_ptr (stmt), &pre, NULL,
8242 		     is_gimple_val, fb_rvalue);
8243       gimplify_expr (gimple_cond_rhs_ptr (stmt), &pre, NULL,
8244 		     is_gimple_val, fb_rvalue);
8245       break;
8246     case GIMPLE_SWITCH:
8247       gimplify_expr (gimple_switch_index_ptr (stmt), &pre, NULL,
8248 		     is_gimple_val, fb_rvalue);
8249       break;
8250     case GIMPLE_OMP_ATOMIC_LOAD:
8251       gimplify_expr (gimple_omp_atomic_load_rhs_ptr (stmt), &pre, NULL,
8252 		     is_gimple_val, fb_rvalue);
8253       break;
8254     case GIMPLE_ASM:
8255       {
8256 	size_t i, noutputs = gimple_asm_noutputs (stmt);
8257 	const char *constraint, **oconstraints;
8258 	bool allows_mem, allows_reg, is_inout;
8259 
8260 	oconstraints
8261 	  = (const char **) alloca ((noutputs) * sizeof (const char *));
8262 	for (i = 0; i < noutputs; i++)
8263 	  {
8264 	    tree op = gimple_asm_output_op (stmt, i);
8265 	    constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
8266 	    oconstraints[i] = constraint;
8267 	    parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
8268 				     &allows_reg, &is_inout);
8269 	    gimplify_expr (&TREE_VALUE (op), &pre, NULL,
8270 			   is_inout ? is_gimple_min_lval : is_gimple_lvalue,
8271 			   fb_lvalue | fb_mayfail);
8272 	  }
8273 	for (i = 0; i < gimple_asm_ninputs (stmt); i++)
8274 	  {
8275 	    tree op = gimple_asm_input_op (stmt, i);
8276 	    constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
8277 	    parse_input_constraint (&constraint, 0, 0, noutputs, 0,
8278 				    oconstraints, &allows_mem, &allows_reg);
8279 	    if (TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (op))) && allows_mem)
8280 	      allows_reg = 0;
8281 	    if (!allows_reg && allows_mem)
8282 	      gimplify_expr (&TREE_VALUE (op), &pre, NULL,
8283 			     is_gimple_lvalue, fb_lvalue | fb_mayfail);
8284 	    else
8285 	      gimplify_expr (&TREE_VALUE (op), &pre, NULL,
8286 			     is_gimple_asm_val, fb_rvalue);
8287 	  }
8288       }
8289       break;
8290     default:
8291       /* NOTE: We start gimplifying operands from last to first to
8292 	 make sure that side-effects on the RHS of calls, assignments
8293 	 and ASMs are executed before the LHS.  The ordering is not
8294 	 important for other statements.  */
8295       num_ops = gimple_num_ops (stmt);
8296       orig_lhs = gimple_get_lhs (stmt);
8297       for (i = num_ops; i > 0; i--)
8298 	{
8299 	  tree op = gimple_op (stmt, i - 1);
8300 	  if (op == NULL_TREE)
8301 	    continue;
8302 	  if (i == 1 && (is_gimple_call (stmt) || is_gimple_assign (stmt)))
8303 	    gimplify_expr (&op, &pre, NULL, is_gimple_lvalue, fb_lvalue);
8304 	  else if (i == 2
8305 		   && is_gimple_assign (stmt)
8306 		   && num_ops == 2
8307 		   && get_gimple_rhs_class (gimple_expr_code (stmt))
8308 		      == GIMPLE_SINGLE_RHS)
8309 	    gimplify_expr (&op, &pre, NULL,
8310 			   rhs_predicate_for (gimple_assign_lhs (stmt)),
8311 			   fb_rvalue);
8312 	  else if (i == 2 && is_gimple_call (stmt))
8313 	    {
8314 	      if (TREE_CODE (op) == FUNCTION_DECL)
8315 		continue;
8316 	      gimplify_expr (&op, &pre, NULL, is_gimple_call_addr, fb_rvalue);
8317 	    }
8318 	  else
8319 	    gimplify_expr (&op, &pre, NULL, is_gimple_val, fb_rvalue);
8320 	  gimple_set_op (stmt, i - 1, op);
8321 	}
8322 
8323       lhs = gimple_get_lhs (stmt);
8324       /* If the LHS changed it in a way that requires a simple RHS,
8325 	 create temporary.  */
8326       if (lhs && !is_gimple_reg (lhs))
8327 	{
8328 	  bool need_temp = false;
8329 
8330 	  if (is_gimple_assign (stmt)
8331 	      && num_ops == 2
8332 	      && get_gimple_rhs_class (gimple_expr_code (stmt))
8333 		 == GIMPLE_SINGLE_RHS)
8334 	    gimplify_expr (gimple_assign_rhs1_ptr (stmt), &pre, NULL,
8335 			   rhs_predicate_for (gimple_assign_lhs (stmt)),
8336 			   fb_rvalue);
8337 	  else if (is_gimple_reg (lhs))
8338 	    {
8339 	      if (is_gimple_reg_type (TREE_TYPE (lhs)))
8340 		{
8341 		  if (is_gimple_call (stmt))
8342 		    {
8343 		      i = gimple_call_flags (stmt);
8344 		      if ((i & ECF_LOOPING_CONST_OR_PURE)
8345 			  || !(i & (ECF_CONST | ECF_PURE)))
8346 			need_temp = true;
8347 		    }
8348 		  if (stmt_can_throw_internal (stmt))
8349 		    need_temp = true;
8350 		}
8351 	    }
8352 	  else
8353 	    {
8354 	      if (is_gimple_reg_type (TREE_TYPE (lhs)))
8355 		need_temp = true;
8356 	      else if (TYPE_MODE (TREE_TYPE (lhs)) != BLKmode)
8357 		{
8358 		  if (is_gimple_call (stmt))
8359 		    {
8360 		      tree fndecl = gimple_call_fndecl (stmt);
8361 
8362 		      if (!aggregate_value_p (TREE_TYPE (lhs), fndecl)
8363 			  && !(fndecl && DECL_RESULT (fndecl)
8364 			       && DECL_BY_REFERENCE (DECL_RESULT (fndecl))))
8365 			need_temp = true;
8366 		    }
8367 		  else
8368 		    need_temp = true;
8369 		}
8370 	    }
8371 	  if (need_temp)
8372 	    {
8373 	      tree temp = create_tmp_reg (TREE_TYPE (lhs), NULL);
8374 
8375 	      if (TREE_CODE (orig_lhs) == SSA_NAME)
8376 		orig_lhs = SSA_NAME_VAR (orig_lhs);
8377 
8378 	      if (gimple_in_ssa_p (cfun))
8379 		temp = make_ssa_name (temp, NULL);
8380 	      gimple_set_lhs (stmt, temp);
8381 	      post_stmt = gimple_build_assign (lhs, temp);
8382 	      if (TREE_CODE (lhs) == SSA_NAME)
8383 		SSA_NAME_DEF_STMT (lhs) = post_stmt;
8384 	    }
8385 	}
8386       break;
8387     }
8388 
8389   if (gimple_referenced_vars (cfun))
8390     for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
8391       add_referenced_var (t);
8392 
8393   if (!gimple_seq_empty_p (pre))
8394     {
8395       if (gimple_in_ssa_p (cfun))
8396 	{
8397 	  gimple_stmt_iterator i;
8398 
8399 	  for (i = gsi_start (pre); !gsi_end_p (i); gsi_next (&i))
8400 	    mark_symbols_for_renaming (gsi_stmt (i));
8401 	}
8402       gsi_insert_seq_before (gsi_p, pre, GSI_SAME_STMT);
8403     }
8404   if (post_stmt)
8405     gsi_insert_after (gsi_p, post_stmt, GSI_NEW_STMT);
8406 
8407   pop_gimplify_context (NULL);
8408 }
8409 
8410 /* Expand EXPR to list of gimple statements STMTS.  GIMPLE_TEST_F specifies
8411    the predicate that will hold for the result.  If VAR is not NULL, make the
8412    base variable of the final destination be VAR if suitable.  */
8413 
8414 tree
8415 force_gimple_operand_1 (tree expr, gimple_seq *stmts,
8416 			gimple_predicate gimple_test_f, tree var)
8417 {
8418   tree t;
8419   enum gimplify_status ret;
8420   struct gimplify_ctx gctx;
8421 
8422   *stmts = NULL;
8423 
8424   /* gimple_test_f might be more strict than is_gimple_val, make
8425      sure we pass both.  Just checking gimple_test_f doesn't work
8426      because most gimple predicates do not work recursively.  */
8427   if (is_gimple_val (expr)
8428       && (*gimple_test_f) (expr))
8429     return expr;
8430 
8431   push_gimplify_context (&gctx);
8432   gimplify_ctxp->into_ssa = gimple_in_ssa_p (cfun);
8433   gimplify_ctxp->allow_rhs_cond_expr = true;
8434 
8435   if (var)
8436     expr = build2 (MODIFY_EXPR, TREE_TYPE (var), var, expr);
8437 
8438   if (TREE_CODE (expr) != MODIFY_EXPR
8439       && TREE_TYPE (expr) == void_type_node)
8440     {
8441       gimplify_and_add (expr, stmts);
8442       expr = NULL_TREE;
8443     }
8444   else
8445     {
8446       ret = gimplify_expr (&expr, stmts, NULL, gimple_test_f, fb_rvalue);
8447       gcc_assert (ret != GS_ERROR);
8448     }
8449 
8450   if (gimple_referenced_vars (cfun))
8451     for (t = gimplify_ctxp->temps; t ; t = DECL_CHAIN (t))
8452       add_referenced_var (t);
8453 
8454   pop_gimplify_context (NULL);
8455 
8456   return expr;
8457 }
8458 
8459 /* Expand EXPR to list of gimple statements STMTS.  If SIMPLE is true,
8460    force the result to be either ssa_name or an invariant, otherwise
8461    just force it to be a rhs expression.  If VAR is not NULL, make the
8462    base variable of the final destination be VAR if suitable.  */
8463 
8464 tree
8465 force_gimple_operand (tree expr, gimple_seq *stmts, bool simple, tree var)
8466 {
8467   return force_gimple_operand_1 (expr, stmts,
8468 				 simple ? is_gimple_val : is_gimple_reg_rhs,
8469 				 var);
8470 }
8471 
8472 /* Invoke force_gimple_operand_1 for EXPR with parameters GIMPLE_TEST_F
8473    and VAR.  If some statements are produced, emits them at GSI.
8474    If BEFORE is true.  the statements are appended before GSI, otherwise
8475    they are appended after it.  M specifies the way GSI moves after
8476    insertion (GSI_SAME_STMT or GSI_CONTINUE_LINKING are the usual values).  */
8477 
8478 tree
8479 force_gimple_operand_gsi_1 (gimple_stmt_iterator *gsi, tree expr,
8480 			    gimple_predicate gimple_test_f,
8481 			    tree var, bool before,
8482 			    enum gsi_iterator_update m)
8483 {
8484   gimple_seq stmts;
8485 
8486   expr = force_gimple_operand_1 (expr, &stmts, gimple_test_f, var);
8487 
8488   if (!gimple_seq_empty_p (stmts))
8489     {
8490       if (gimple_in_ssa_p (cfun))
8491 	{
8492 	  gimple_stmt_iterator i;
8493 
8494 	  for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i))
8495 	    mark_symbols_for_renaming (gsi_stmt (i));
8496 	}
8497 
8498       if (before)
8499 	gsi_insert_seq_before (gsi, stmts, m);
8500       else
8501 	gsi_insert_seq_after (gsi, stmts, m);
8502     }
8503 
8504   return expr;
8505 }
8506 
8507 /* Invoke force_gimple_operand_1 for EXPR with parameter VAR.
8508    If SIMPLE is true, force the result to be either ssa_name or an invariant,
8509    otherwise just force it to be a rhs expression.  If some statements are
8510    produced, emits them at GSI.  If BEFORE is true, the statements are
8511    appended before GSI, otherwise they are appended after it.  M specifies
8512    the way GSI moves after insertion (GSI_SAME_STMT or GSI_CONTINUE_LINKING
8513    are the usual values).  */
8514 
8515 tree
8516 force_gimple_operand_gsi (gimple_stmt_iterator *gsi, tree expr,
8517 			  bool simple_p, tree var, bool before,
8518 			  enum gsi_iterator_update m)
8519 {
8520   return force_gimple_operand_gsi_1 (gsi, expr,
8521 				     simple_p
8522 				     ? is_gimple_val : is_gimple_reg_rhs,
8523 				     var, before, m);
8524 }
8525 
8526 
8527 #include "gt-gimplify.h"
8528