xref: /dragonfly/contrib/gcc-8.0/gcc/lto/lto.c (revision ed183f8c)
1 /* Top-level LTO routines.
2    Copyright (C) 2009-2018 Free Software Foundation, Inc.
3    Contributed by CodeSourcery, Inc.
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11 
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15 for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3.  If not see
19 <http://www.gnu.org/licenses/>.  */
20 
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "tm.h"
25 #include "function.h"
26 #include "bitmap.h"
27 #include "basic-block.h"
28 #include "tree.h"
29 #include "gimple.h"
30 #include "cfghooks.h"
31 #include "alloc-pool.h"
32 #include "tree-pass.h"
33 #include "tree-streamer.h"
34 #include "cgraph.h"
35 #include "opts.h"
36 #include "toplev.h"
37 #include "stor-layout.h"
38 #include "symbol-summary.h"
39 #include "tree-vrp.h"
40 #include "ipa-prop.h"
41 #include "common.h"
42 #include "debug.h"
43 #include "lto.h"
44 #include "lto-section-names.h"
45 #include "splay-tree.h"
46 #include "lto-partition.h"
47 #include "context.h"
48 #include "pass_manager.h"
49 #include "ipa-fnsummary.h"
50 #include "params.h"
51 #include "ipa-utils.h"
52 #include "gomp-constants.h"
53 #include "lto-symtab.h"
54 #include "stringpool.h"
55 #include "fold-const.h"
56 #include "attribs.h"
57 #include "builtins.h"
58 
59 
60 /* Number of parallel tasks to run, -1 if we want to use GNU Make jobserver.  */
61 static int lto_parallelism;
62 
63 static GTY(()) tree first_personality_decl;
64 
65 static GTY(()) const unsigned char *lto_mode_identity_table;
66 
67 /* Returns a hash code for P.  */
68 
69 static hashval_t
70 hash_name (const void *p)
71 {
72   const struct lto_section_slot *ds = (const struct lto_section_slot *) p;
73   return (hashval_t) htab_hash_string (ds->name);
74 }
75 
76 
77 /* Returns nonzero if P1 and P2 are equal.  */
78 
79 static int
80 eq_name (const void *p1, const void *p2)
81 {
82   const struct lto_section_slot *s1 =
83     (const struct lto_section_slot *) p1;
84   const struct lto_section_slot *s2 =
85     (const struct lto_section_slot *) p2;
86 
87   return strcmp (s1->name, s2->name) == 0;
88 }
89 
90 /* Free lto_section_slot */
91 
92 static void
93 free_with_string (void *arg)
94 {
95   struct lto_section_slot *s = (struct lto_section_slot *)arg;
96 
97   free (CONST_CAST (char *, s->name));
98   free (arg);
99 }
100 
101 /* Create section hash table */
102 
103 htab_t
104 lto_obj_create_section_hash_table (void)
105 {
106   return htab_create (37, hash_name, eq_name, free_with_string);
107 }
108 
109 /* Delete an allocated integer KEY in the splay tree.  */
110 
111 static void
112 lto_splay_tree_delete_id (splay_tree_key key)
113 {
114   free ((void *) key);
115 }
116 
117 /* Compare splay tree node ids A and B.  */
118 
119 static int
120 lto_splay_tree_compare_ids (splay_tree_key a, splay_tree_key b)
121 {
122   unsigned HOST_WIDE_INT ai;
123   unsigned HOST_WIDE_INT bi;
124 
125   ai = *(unsigned HOST_WIDE_INT *) a;
126   bi = *(unsigned HOST_WIDE_INT *) b;
127 
128   if (ai < bi)
129     return -1;
130   else if (ai > bi)
131     return 1;
132   return 0;
133 }
134 
135 /* Look up splay tree node by ID in splay tree T.  */
136 
137 static splay_tree_node
138 lto_splay_tree_lookup (splay_tree t, unsigned HOST_WIDE_INT id)
139 {
140   return splay_tree_lookup (t, (splay_tree_key) &id);
141 }
142 
143 /* Check if KEY has ID.  */
144 
145 static bool
146 lto_splay_tree_id_equal_p (splay_tree_key key, unsigned HOST_WIDE_INT id)
147 {
148   return *(unsigned HOST_WIDE_INT *) key == id;
149 }
150 
151 /* Insert a splay tree node into tree T with ID as key and FILE_DATA as value.
152    The ID is allocated separately because we need HOST_WIDE_INTs which may
153    be wider than a splay_tree_key. */
154 
155 static void
156 lto_splay_tree_insert (splay_tree t, unsigned HOST_WIDE_INT id,
157 		       struct lto_file_decl_data *file_data)
158 {
159   unsigned HOST_WIDE_INT *idp = XCNEW (unsigned HOST_WIDE_INT);
160   *idp = id;
161   splay_tree_insert (t, (splay_tree_key) idp, (splay_tree_value) file_data);
162 }
163 
164 /* Create a splay tree.  */
165 
166 static splay_tree
167 lto_splay_tree_new (void)
168 {
169   return splay_tree_new (lto_splay_tree_compare_ids,
170 	 	         lto_splay_tree_delete_id,
171 			 NULL);
172 }
173 
174 /* Return true when NODE has a clone that is analyzed (i.e. we need
175    to load its body even if the node itself is not needed).  */
176 
177 static bool
178 has_analyzed_clone_p (struct cgraph_node *node)
179 {
180   struct cgraph_node *orig = node;
181   node = node->clones;
182   if (node)
183     while (node != orig)
184       {
185 	if (node->analyzed)
186 	  return true;
187 	if (node->clones)
188 	  node = node->clones;
189 	else if (node->next_sibling_clone)
190 	  node = node->next_sibling_clone;
191 	else
192 	  {
193 	    while (node != orig && !node->next_sibling_clone)
194 	      node = node->clone_of;
195 	    if (node != orig)
196 	      node = node->next_sibling_clone;
197 	  }
198       }
199   return false;
200 }
201 
202 /* Read the function body for the function associated with NODE.  */
203 
204 static void
205 lto_materialize_function (struct cgraph_node *node)
206 {
207   tree decl;
208 
209   decl = node->decl;
210   /* Read in functions with body (analyzed nodes)
211      and also functions that are needed to produce virtual clones.  */
212   if ((node->has_gimple_body_p () && node->analyzed)
213       || node->used_as_abstract_origin
214       || has_analyzed_clone_p (node))
215     {
216       /* Clones don't need to be read.  */
217       if (node->clone_of)
218 	return;
219       if (DECL_FUNCTION_PERSONALITY (decl) && !first_personality_decl)
220 	first_personality_decl = DECL_FUNCTION_PERSONALITY (decl);
221     }
222 
223   /* Let the middle end know about the function.  */
224   rest_of_decl_compilation (decl, 1, 0);
225 }
226 
227 
228 /* Decode the content of memory pointed to by DATA in the in decl
229    state object STATE. DATA_IN points to a data_in structure for
230    decoding. Return the address after the decoded object in the
231    input.  */
232 
233 static const uint32_t *
234 lto_read_in_decl_state (struct data_in *data_in, const uint32_t *data,
235 			struct lto_in_decl_state *state)
236 {
237   uint32_t ix;
238   tree decl;
239   uint32_t i, j;
240 
241   ix = *data++;
242   state->compressed = ix & 1;
243   ix /= 2;
244   decl = streamer_tree_cache_get_tree (data_in->reader_cache, ix);
245   if (!VAR_OR_FUNCTION_DECL_P (decl))
246     {
247       gcc_assert (decl == void_type_node);
248       decl = NULL_TREE;
249     }
250   state->fn_decl = decl;
251 
252   for (i = 0; i < LTO_N_DECL_STREAMS; i++)
253     {
254       uint32_t size = *data++;
255       vec<tree, va_gc> *decls = NULL;
256       vec_alloc (decls, size);
257 
258       for (j = 0; j < size; j++)
259 	vec_safe_push (decls,
260 		       streamer_tree_cache_get_tree (data_in->reader_cache,
261 						     data[j]));
262 
263       state->streams[i] = decls;
264       data += size;
265     }
266 
267   return data;
268 }
269 
270 
271 /* Global canonical type table.  */
272 static htab_t gimple_canonical_types;
273 static hash_map<const_tree, hashval_t> *canonical_type_hash_cache;
274 static unsigned long num_canonical_type_hash_entries;
275 static unsigned long num_canonical_type_hash_queries;
276 
277 static void iterative_hash_canonical_type (tree type, inchash::hash &hstate);
278 static hashval_t gimple_canonical_type_hash (const void *p);
279 static void gimple_register_canonical_type_1 (tree t, hashval_t hash);
280 
281 /* Returning a hash value for gimple type TYPE.
282 
283    The hash value returned is equal for types considered compatible
284    by gimple_canonical_types_compatible_p.  */
285 
286 static hashval_t
287 hash_canonical_type (tree type)
288 {
289   inchash::hash hstate;
290   enum tree_code code;
291 
292   /* We compute alias sets only for types that needs them.
293      Be sure we do not recurse to something else as we can not hash incomplete
294      types in a way they would have same hash value as compatible complete
295      types.  */
296   gcc_checking_assert (type_with_alias_set_p (type));
297 
298   /* Combine a few common features of types so that types are grouped into
299      smaller sets; when searching for existing matching types to merge,
300      only existing types having the same features as the new type will be
301      checked.  */
302   code = tree_code_for_canonical_type_merging (TREE_CODE (type));
303   hstate.add_int (code);
304   hstate.add_int (TYPE_MODE (type));
305 
306   /* Incorporate common features of numerical types.  */
307   if (INTEGRAL_TYPE_P (type)
308       || SCALAR_FLOAT_TYPE_P (type)
309       || FIXED_POINT_TYPE_P (type)
310       || TREE_CODE (type) == OFFSET_TYPE
311       || POINTER_TYPE_P (type))
312     {
313       hstate.add_int (TYPE_PRECISION (type));
314       if (!type_with_interoperable_signedness (type))
315         hstate.add_int (TYPE_UNSIGNED (type));
316     }
317 
318   if (VECTOR_TYPE_P (type))
319     {
320       hstate.add_poly_int (TYPE_VECTOR_SUBPARTS (type));
321       hstate.add_int (TYPE_UNSIGNED (type));
322     }
323 
324   if (TREE_CODE (type) == COMPLEX_TYPE)
325     hstate.add_int (TYPE_UNSIGNED (type));
326 
327   /* Fortran's C_SIGNED_CHAR is !TYPE_STRING_FLAG but needs to be
328      interoperable with "signed char".  Unless all frontends are revisited to
329      agree on these types, we must ignore the flag completely.  */
330 
331   /* Fortran standard define C_PTR type that is compatible with every
332      C pointer.  For this reason we need to glob all pointers into one.
333      Still pointers in different address spaces are not compatible.  */
334   if (POINTER_TYPE_P (type))
335     hstate.add_int (TYPE_ADDR_SPACE (TREE_TYPE (type)));
336 
337   /* For array types hash the domain bounds and the string flag.  */
338   if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
339     {
340       hstate.add_int (TYPE_STRING_FLAG (type));
341       /* OMP lowering can introduce error_mark_node in place of
342 	 random local decls in types.  */
343       if (TYPE_MIN_VALUE (TYPE_DOMAIN (type)) != error_mark_node)
344 	inchash::add_expr (TYPE_MIN_VALUE (TYPE_DOMAIN (type)), hstate);
345       if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) != error_mark_node)
346 	inchash::add_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)), hstate);
347     }
348 
349   /* Recurse for aggregates with a single element type.  */
350   if (TREE_CODE (type) == ARRAY_TYPE
351       || TREE_CODE (type) == COMPLEX_TYPE
352       || TREE_CODE (type) == VECTOR_TYPE)
353     iterative_hash_canonical_type (TREE_TYPE (type), hstate);
354 
355   /* Incorporate function return and argument types.  */
356   if (TREE_CODE (type) == FUNCTION_TYPE || TREE_CODE (type) == METHOD_TYPE)
357     {
358       unsigned na;
359       tree p;
360 
361       iterative_hash_canonical_type (TREE_TYPE (type), hstate);
362 
363       for (p = TYPE_ARG_TYPES (type), na = 0; p; p = TREE_CHAIN (p))
364 	{
365 	  iterative_hash_canonical_type (TREE_VALUE (p), hstate);
366 	  na++;
367 	}
368 
369       hstate.add_int (na);
370     }
371 
372   if (RECORD_OR_UNION_TYPE_P (type))
373     {
374       unsigned nf;
375       tree f;
376 
377       for (f = TYPE_FIELDS (type), nf = 0; f; f = TREE_CHAIN (f))
378 	if (TREE_CODE (f) == FIELD_DECL
379 	    && (! DECL_SIZE (f)
380 		|| ! integer_zerop (DECL_SIZE (f))))
381 	  {
382 	    iterative_hash_canonical_type (TREE_TYPE (f), hstate);
383 	    nf++;
384 	  }
385 
386       hstate.add_int (nf);
387     }
388 
389   return hstate.end();
390 }
391 
392 /* Returning a hash value for gimple type TYPE combined with VAL.  */
393 
394 static void
395 iterative_hash_canonical_type (tree type, inchash::hash &hstate)
396 {
397   hashval_t v;
398 
399   /* All type variants have same TYPE_CANONICAL.  */
400   type = TYPE_MAIN_VARIANT (type);
401 
402   if (!canonical_type_used_p (type))
403     v = hash_canonical_type (type);
404   /* An already processed type.  */
405   else if (TYPE_CANONICAL (type))
406     {
407       type = TYPE_CANONICAL (type);
408       v = gimple_canonical_type_hash (type);
409     }
410   else
411     {
412       /* Canonical types should not be able to form SCCs by design, this
413 	 recursion is just because we do not register canonical types in
414 	 optimal order.  To avoid quadratic behavior also register the
415 	 type here.  */
416       v = hash_canonical_type (type);
417       gimple_register_canonical_type_1 (type, v);
418     }
419   hstate.add_int (v);
420 }
421 
422 /* Returns the hash for a canonical type P.  */
423 
424 static hashval_t
425 gimple_canonical_type_hash (const void *p)
426 {
427   num_canonical_type_hash_queries++;
428   hashval_t *slot = canonical_type_hash_cache->get ((const_tree) p);
429   gcc_assert (slot != NULL);
430   return *slot;
431 }
432 
433 
434 
435 /* Returns nonzero if P1 and P2 are equal.  */
436 
437 static int
438 gimple_canonical_type_eq (const void *p1, const void *p2)
439 {
440   const_tree t1 = (const_tree) p1;
441   const_tree t2 = (const_tree) p2;
442   return gimple_canonical_types_compatible_p (CONST_CAST_TREE (t1),
443 					      CONST_CAST_TREE (t2));
444 }
445 
446 /* Main worker for gimple_register_canonical_type.  */
447 
448 static void
449 gimple_register_canonical_type_1 (tree t, hashval_t hash)
450 {
451   void **slot;
452 
453   gcc_checking_assert (TYPE_P (t) && !TYPE_CANONICAL (t)
454 		       && type_with_alias_set_p (t)
455 		       && canonical_type_used_p (t));
456 
457   slot = htab_find_slot_with_hash (gimple_canonical_types, t, hash, INSERT);
458   if (*slot)
459     {
460       tree new_type = (tree)(*slot);
461       gcc_checking_assert (new_type != t);
462       TYPE_CANONICAL (t) = new_type;
463     }
464   else
465     {
466       TYPE_CANONICAL (t) = t;
467       *slot = (void *) t;
468       /* Cache the just computed hash value.  */
469       num_canonical_type_hash_entries++;
470       bool existed_p = canonical_type_hash_cache->put (t, hash);
471       gcc_assert (!existed_p);
472     }
473 }
474 
475 /* Register type T in the global type table gimple_types and set
476    TYPE_CANONICAL of T accordingly.
477    This is used by LTO to merge structurally equivalent types for
478    type-based aliasing purposes across different TUs and languages.
479 
480    ???  This merging does not exactly match how the tree.c middle-end
481    functions will assign TYPE_CANONICAL when new types are created
482    during optimization (which at least happens for pointer and array
483    types).  */
484 
485 static void
486 gimple_register_canonical_type (tree t)
487 {
488   if (TYPE_CANONICAL (t) || !type_with_alias_set_p (t)
489       || !canonical_type_used_p (t))
490     return;
491 
492   /* Canonical types are same among all complete variants.  */
493   if (TYPE_CANONICAL (TYPE_MAIN_VARIANT (t)))
494     TYPE_CANONICAL (t) = TYPE_CANONICAL (TYPE_MAIN_VARIANT (t));
495   else
496     {
497       gimple_register_canonical_type_1 (TYPE_MAIN_VARIANT (t),
498 					hash_canonical_type (TYPE_MAIN_VARIANT (t)));
499       TYPE_CANONICAL (t) = TYPE_CANONICAL (TYPE_MAIN_VARIANT (t));
500     }
501 }
502 
503 /* Re-compute TYPE_CANONICAL for NODE and related types.  */
504 
505 static void
506 lto_register_canonical_types (tree node, bool first_p)
507 {
508   if (!node
509       || !TYPE_P (node))
510     return;
511 
512   if (first_p)
513     TYPE_CANONICAL (node) = NULL_TREE;
514 
515   if (POINTER_TYPE_P (node)
516       || TREE_CODE (node) == COMPLEX_TYPE
517       || TREE_CODE (node) == ARRAY_TYPE)
518     lto_register_canonical_types (TREE_TYPE (node), first_p);
519 
520  if (!first_p)
521     gimple_register_canonical_type (node);
522 }
523 
524 
525 /* Remember trees that contains references to declarations.  */
526 static GTY(()) vec <tree, va_gc> *tree_with_vars;
527 
528 #define CHECK_VAR(tt) \
529   do \
530     { \
531       if ((tt) && VAR_OR_FUNCTION_DECL_P (tt) \
532 	  && (TREE_PUBLIC (tt) || DECL_EXTERNAL (tt))) \
533 	return true; \
534     } while (0)
535 
536 #define CHECK_NO_VAR(tt) \
537   gcc_checking_assert (!(tt) || !VAR_OR_FUNCTION_DECL_P (tt))
538 
539 /* Check presence of pointers to decls in fields of a tree_typed T.  */
540 
541 static inline bool
542 mentions_vars_p_typed (tree t)
543 {
544   CHECK_NO_VAR (TREE_TYPE (t));
545   return false;
546 }
547 
548 /* Check presence of pointers to decls in fields of a tree_common T.  */
549 
550 static inline bool
551 mentions_vars_p_common (tree t)
552 {
553   if (mentions_vars_p_typed (t))
554     return true;
555   CHECK_NO_VAR (TREE_CHAIN (t));
556   return false;
557 }
558 
559 /* Check presence of pointers to decls in fields of a decl_minimal T.  */
560 
561 static inline bool
562 mentions_vars_p_decl_minimal (tree t)
563 {
564   if (mentions_vars_p_common (t))
565     return true;
566   CHECK_NO_VAR (DECL_NAME (t));
567   CHECK_VAR (DECL_CONTEXT (t));
568   return false;
569 }
570 
571 /* Check presence of pointers to decls in fields of a decl_common T.  */
572 
573 static inline bool
574 mentions_vars_p_decl_common (tree t)
575 {
576   if (mentions_vars_p_decl_minimal (t))
577     return true;
578   CHECK_VAR (DECL_SIZE (t));
579   CHECK_VAR (DECL_SIZE_UNIT (t));
580   CHECK_VAR (DECL_INITIAL (t));
581   CHECK_NO_VAR (DECL_ATTRIBUTES (t));
582   CHECK_VAR (DECL_ABSTRACT_ORIGIN (t));
583   return false;
584 }
585 
586 /* Check presence of pointers to decls in fields of a decl_with_vis T.  */
587 
588 static inline bool
589 mentions_vars_p_decl_with_vis (tree t)
590 {
591   if (mentions_vars_p_decl_common (t))
592     return true;
593 
594   /* Accessor macro has side-effects, use field-name here. */
595   CHECK_NO_VAR (DECL_ASSEMBLER_NAME_RAW (t));
596   return false;
597 }
598 
599 /* Check presence of pointers to decls in fields of a decl_non_common T.  */
600 
601 static inline bool
602 mentions_vars_p_decl_non_common (tree t)
603 {
604   if (mentions_vars_p_decl_with_vis (t))
605     return true;
606   CHECK_NO_VAR (DECL_RESULT_FLD (t));
607   return false;
608 }
609 
610 /* Check presence of pointers to decls in fields of a decl_non_common T.  */
611 
612 static bool
613 mentions_vars_p_function (tree t)
614 {
615   if (mentions_vars_p_decl_non_common (t))
616     return true;
617   CHECK_NO_VAR (DECL_ARGUMENTS (t));
618   CHECK_NO_VAR (DECL_VINDEX (t));
619   CHECK_VAR (DECL_FUNCTION_PERSONALITY (t));
620   return false;
621 }
622 
623 /* Check presence of pointers to decls in fields of a field_decl T.  */
624 
625 static bool
626 mentions_vars_p_field_decl (tree t)
627 {
628   if (mentions_vars_p_decl_common (t))
629     return true;
630   CHECK_VAR (DECL_FIELD_OFFSET (t));
631   CHECK_NO_VAR (DECL_BIT_FIELD_TYPE (t));
632   CHECK_NO_VAR (DECL_QUALIFIER (t));
633   CHECK_NO_VAR (DECL_FIELD_BIT_OFFSET (t));
634   CHECK_NO_VAR (DECL_FCONTEXT (t));
635   return false;
636 }
637 
638 /* Check presence of pointers to decls in fields of a type T.  */
639 
640 static bool
641 mentions_vars_p_type (tree t)
642 {
643   if (mentions_vars_p_common (t))
644     return true;
645   CHECK_NO_VAR (TYPE_CACHED_VALUES (t));
646   CHECK_VAR (TYPE_SIZE (t));
647   CHECK_VAR (TYPE_SIZE_UNIT (t));
648   CHECK_NO_VAR (TYPE_ATTRIBUTES (t));
649   CHECK_NO_VAR (TYPE_NAME (t));
650 
651   CHECK_VAR (TYPE_MIN_VALUE_RAW (t));
652   CHECK_VAR (TYPE_MAX_VALUE_RAW (t));
653 
654   /* Accessor is for derived node types only. */
655   CHECK_NO_VAR (TYPE_LANG_SLOT_1 (t));
656 
657   CHECK_VAR (TYPE_CONTEXT (t));
658   CHECK_NO_VAR (TYPE_CANONICAL (t));
659   CHECK_NO_VAR (TYPE_MAIN_VARIANT (t));
660   CHECK_NO_VAR (TYPE_NEXT_VARIANT (t));
661   return false;
662 }
663 
664 /* Check presence of pointers to decls in fields of a BINFO T.  */
665 
666 static bool
667 mentions_vars_p_binfo (tree t)
668 {
669   unsigned HOST_WIDE_INT i, n;
670 
671   if (mentions_vars_p_common (t))
672     return true;
673   CHECK_VAR (BINFO_VTABLE (t));
674   CHECK_NO_VAR (BINFO_OFFSET (t));
675   CHECK_NO_VAR (BINFO_VIRTUALS (t));
676   CHECK_NO_VAR (BINFO_VPTR_FIELD (t));
677   n = vec_safe_length (BINFO_BASE_ACCESSES (t));
678   for (i = 0; i < n; i++)
679     CHECK_NO_VAR (BINFO_BASE_ACCESS (t, i));
680   /* Do not walk BINFO_INHERITANCE_CHAIN, BINFO_SUBVTT_INDEX
681      and BINFO_VPTR_INDEX; these are used by C++ FE only.  */
682   n = BINFO_N_BASE_BINFOS (t);
683   for (i = 0; i < n; i++)
684     CHECK_NO_VAR (BINFO_BASE_BINFO (t, i));
685   return false;
686 }
687 
688 /* Check presence of pointers to decls in fields of a CONSTRUCTOR T.  */
689 
690 static bool
691 mentions_vars_p_constructor (tree t)
692 {
693   unsigned HOST_WIDE_INT idx;
694   constructor_elt *ce;
695 
696   if (mentions_vars_p_typed (t))
697     return true;
698 
699   for (idx = 0; vec_safe_iterate (CONSTRUCTOR_ELTS (t), idx, &ce); idx++)
700     {
701       CHECK_NO_VAR (ce->index);
702       CHECK_VAR (ce->value);
703     }
704   return false;
705 }
706 
707 /* Check presence of pointers to decls in fields of an expression tree T.  */
708 
709 static bool
710 mentions_vars_p_expr (tree t)
711 {
712   int i;
713   if (mentions_vars_p_typed (t))
714     return true;
715   for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
716     CHECK_VAR (TREE_OPERAND (t, i));
717   return false;
718 }
719 
720 /* Check presence of pointers to decls in fields of an OMP_CLAUSE T.  */
721 
722 static bool
723 mentions_vars_p_omp_clause (tree t)
724 {
725   int i;
726   if (mentions_vars_p_common (t))
727     return true;
728   for (i = omp_clause_num_ops[OMP_CLAUSE_CODE (t)] - 1; i >= 0; --i)
729     CHECK_VAR (OMP_CLAUSE_OPERAND (t, i));
730   return false;
731 }
732 
733 /* Check presence of pointers to decls that needs later fixup in T.  */
734 
735 static bool
736 mentions_vars_p (tree t)
737 {
738   switch (TREE_CODE (t))
739     {
740     case IDENTIFIER_NODE:
741       break;
742 
743     case TREE_LIST:
744       CHECK_VAR (TREE_VALUE (t));
745       CHECK_VAR (TREE_PURPOSE (t));
746       CHECK_NO_VAR (TREE_CHAIN (t));
747       break;
748 
749     case FIELD_DECL:
750       return mentions_vars_p_field_decl (t);
751 
752     case LABEL_DECL:
753     case CONST_DECL:
754     case PARM_DECL:
755     case RESULT_DECL:
756     case IMPORTED_DECL:
757     case NAMESPACE_DECL:
758     case NAMELIST_DECL:
759       return mentions_vars_p_decl_common (t);
760 
761     case VAR_DECL:
762       return mentions_vars_p_decl_with_vis (t);
763 
764     case TYPE_DECL:
765       return mentions_vars_p_decl_non_common (t);
766 
767     case FUNCTION_DECL:
768       return mentions_vars_p_function (t);
769 
770     case TREE_BINFO:
771       return mentions_vars_p_binfo (t);
772 
773     case PLACEHOLDER_EXPR:
774       return mentions_vars_p_common (t);
775 
776     case BLOCK:
777     case TRANSLATION_UNIT_DECL:
778     case OPTIMIZATION_NODE:
779     case TARGET_OPTION_NODE:
780       break;
781 
782     case CONSTRUCTOR:
783       return mentions_vars_p_constructor (t);
784 
785     case OMP_CLAUSE:
786       return mentions_vars_p_omp_clause (t);
787 
788     default:
789       if (TYPE_P (t))
790 	{
791 	  if (mentions_vars_p_type (t))
792 	    return true;
793 	}
794       else if (EXPR_P (t))
795 	{
796 	  if (mentions_vars_p_expr (t))
797 	    return true;
798 	}
799       else if (CONSTANT_CLASS_P (t))
800 	CHECK_NO_VAR (TREE_TYPE (t));
801       else
802 	gcc_unreachable ();
803     }
804   return false;
805 }
806 
807 
808 /* Return the resolution for the decl with index INDEX from DATA_IN. */
809 
810 static enum ld_plugin_symbol_resolution
811 get_resolution (struct data_in *data_in, unsigned index)
812 {
813   if (data_in->globals_resolution.exists ())
814     {
815       ld_plugin_symbol_resolution_t ret;
816       /* We can have references to not emitted functions in
817 	 DECL_FUNCTION_PERSONALITY at least.  So we can and have
818 	 to indeed return LDPR_UNKNOWN in some cases.   */
819       if (data_in->globals_resolution.length () <= index)
820 	return LDPR_UNKNOWN;
821       ret = data_in->globals_resolution[index];
822       return ret;
823     }
824   else
825     /* Delay resolution finding until decl merging.  */
826     return LDPR_UNKNOWN;
827 }
828 
829 /* We need to record resolutions until symbol table is read.  */
830 static void
831 register_resolution (struct lto_file_decl_data *file_data, tree decl,
832 		     enum ld_plugin_symbol_resolution resolution)
833 {
834   bool existed;
835   if (resolution == LDPR_UNKNOWN)
836     return;
837   if (!file_data->resolution_map)
838     file_data->resolution_map
839       = new hash_map<tree, ld_plugin_symbol_resolution>;
840   ld_plugin_symbol_resolution_t &res
841      = file_data->resolution_map->get_or_insert (decl, &existed);
842   if (!existed
843       || resolution == LDPR_PREVAILING_DEF_IRONLY
844       || resolution == LDPR_PREVAILING_DEF
845       || resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
846     res = resolution;
847 }
848 
849 /* Register DECL with the global symbol table and change its
850    name if necessary to avoid name clashes for static globals across
851    different files.  */
852 
853 static void
854 lto_register_var_decl_in_symtab (struct data_in *data_in, tree decl,
855 				 unsigned ix)
856 {
857   tree context;
858 
859   /* Variable has file scope, not local.  */
860   if (!TREE_PUBLIC (decl)
861       && !((context = decl_function_context (decl))
862 	   && auto_var_in_fn_p (decl, context)))
863     rest_of_decl_compilation (decl, 1, 0);
864 
865   /* If this variable has already been declared, queue the
866      declaration for merging.  */
867   if (TREE_PUBLIC (decl))
868     register_resolution (data_in->file_data,
869 			 decl, get_resolution (data_in, ix));
870 }
871 
872 
873 /* Register DECL with the global symbol table and change its
874    name if necessary to avoid name clashes for static globals across
875    different files.  DATA_IN contains descriptors and tables for the
876    file being read.  */
877 
878 static void
879 lto_register_function_decl_in_symtab (struct data_in *data_in, tree decl,
880 				      unsigned ix)
881 {
882   /* If this variable has already been declared, queue the
883      declaration for merging.  */
884   if (TREE_PUBLIC (decl) && !DECL_ABSTRACT_P (decl))
885     register_resolution (data_in->file_data,
886 			 decl, get_resolution (data_in, ix));
887 }
888 
889 /* Check if T is a decl and needs register its resolution info.  */
890 
891 static void
892 lto_maybe_register_decl (struct data_in *data_in, tree t, unsigned ix)
893 {
894   if (TREE_CODE (t) == VAR_DECL)
895     lto_register_var_decl_in_symtab (data_in, t, ix);
896   else if (TREE_CODE (t) == FUNCTION_DECL
897 	   && !DECL_BUILT_IN (t))
898     lto_register_function_decl_in_symtab (data_in, t, ix);
899 }
900 
901 
902 /* For the type T re-materialize it in the type variant list and
903    the pointer/reference-to chains.  */
904 
905 static void
906 lto_fixup_prevailing_type (tree t)
907 {
908   /* The following re-creates proper variant lists while fixing up
909      the variant leaders.  We do not stream TYPE_NEXT_VARIANT so the
910      variant list state before fixup is broken.  */
911 
912   /* If we are not our own variant leader link us into our new leaders
913      variant list.  */
914   if (TYPE_MAIN_VARIANT (t) != t)
915     {
916       tree mv = TYPE_MAIN_VARIANT (t);
917       TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (mv);
918       TYPE_NEXT_VARIANT (mv) = t;
919     }
920 
921   /* The following reconstructs the pointer chains
922      of the new pointed-to type if we are a main variant.  We do
923      not stream those so they are broken before fixup.  */
924   if (TREE_CODE (t) == POINTER_TYPE
925       && TYPE_MAIN_VARIANT (t) == t)
926     {
927       TYPE_NEXT_PTR_TO (t) = TYPE_POINTER_TO (TREE_TYPE (t));
928       TYPE_POINTER_TO (TREE_TYPE (t)) = t;
929     }
930   else if (TREE_CODE (t) == REFERENCE_TYPE
931 	   && TYPE_MAIN_VARIANT (t) == t)
932     {
933       TYPE_NEXT_REF_TO (t) = TYPE_REFERENCE_TO (TREE_TYPE (t));
934       TYPE_REFERENCE_TO (TREE_TYPE (t)) = t;
935     }
936 }
937 
938 
939 /* We keep prevailing tree SCCs in a hashtable with manual collision
940    handling (in case all hashes compare the same) and keep the colliding
941    entries in the tree_scc->next chain.  */
942 
943 struct tree_scc
944 {
945   tree_scc *next;
946   /* Hash of the whole SCC.  */
947   hashval_t hash;
948   /* Number of trees in the SCC.  */
949   unsigned len;
950   /* Number of possible entries into the SCC (tree nodes [0..entry_len-1]
951      which share the same individual tree hash).  */
952   unsigned entry_len;
953   /* The members of the SCC.
954      We only need to remember the first entry node candidate for prevailing
955      SCCs (but of course have access to all entries for SCCs we are
956      processing).
957      ???  For prevailing SCCs we really only need hash and the first
958      entry candidate, but that's too awkward to implement.  */
959   tree entries[1];
960 };
961 
962 struct tree_scc_hasher : nofree_ptr_hash <tree_scc>
963 {
964   static inline hashval_t hash (const tree_scc *);
965   static inline bool equal (const tree_scc *, const tree_scc *);
966 };
967 
968 hashval_t
969 tree_scc_hasher::hash (const tree_scc *scc)
970 {
971   return scc->hash;
972 }
973 
974 bool
975 tree_scc_hasher::equal (const tree_scc *scc1, const tree_scc *scc2)
976 {
977   if (scc1->hash != scc2->hash
978       || scc1->len != scc2->len
979       || scc1->entry_len != scc2->entry_len)
980     return false;
981   return true;
982 }
983 
984 static hash_table<tree_scc_hasher> *tree_scc_hash;
985 static struct obstack tree_scc_hash_obstack;
986 
987 static unsigned long num_merged_types;
988 static unsigned long num_prevailing_types;
989 static unsigned long num_type_scc_trees;
990 static unsigned long total_scc_size;
991 static unsigned long num_sccs_read;
992 static unsigned long total_scc_size_merged;
993 static unsigned long num_sccs_merged;
994 static unsigned long num_scc_compares;
995 static unsigned long num_scc_compare_collisions;
996 
997 
998 /* Compare the two entries T1 and T2 of two SCCs that are possibly equal,
999    recursing through in-SCC tree edges.  Returns true if the SCCs entered
1000    through T1 and T2 are equal and fills in *MAP with the pairs of
1001    SCC entries we visited, starting with (*MAP)[0] = T1 and (*MAP)[1] = T2.  */
1002 
1003 static bool
1004 compare_tree_sccs_1 (tree t1, tree t2, tree **map)
1005 {
1006   enum tree_code code;
1007 
1008   /* Mark already visited nodes.  */
1009   TREE_ASM_WRITTEN (t2) = 1;
1010 
1011   /* Push the pair onto map.  */
1012   (*map)[0] = t1;
1013   (*map)[1] = t2;
1014   *map = *map + 2;
1015 
1016   /* Compare value-fields.  */
1017 #define compare_values(X) \
1018   do { \
1019     if (X(t1) != X(t2)) \
1020       return false; \
1021   } while (0)
1022 
1023   compare_values (TREE_CODE);
1024   code = TREE_CODE (t1);
1025 
1026   if (!TYPE_P (t1))
1027     {
1028       compare_values (TREE_SIDE_EFFECTS);
1029       compare_values (TREE_CONSTANT);
1030       compare_values (TREE_READONLY);
1031       compare_values (TREE_PUBLIC);
1032     }
1033   compare_values (TREE_ADDRESSABLE);
1034   compare_values (TREE_THIS_VOLATILE);
1035   if (DECL_P (t1))
1036     compare_values (DECL_UNSIGNED);
1037   else if (TYPE_P (t1))
1038     compare_values (TYPE_UNSIGNED);
1039   if (TYPE_P (t1))
1040     compare_values (TYPE_ARTIFICIAL);
1041   else
1042     compare_values (TREE_NO_WARNING);
1043   compare_values (TREE_NOTHROW);
1044   compare_values (TREE_STATIC);
1045   if (code != TREE_BINFO)
1046     compare_values (TREE_PRIVATE);
1047   compare_values (TREE_PROTECTED);
1048   compare_values (TREE_DEPRECATED);
1049   if (TYPE_P (t1))
1050     {
1051       if (AGGREGATE_TYPE_P (t1))
1052 	compare_values (TYPE_REVERSE_STORAGE_ORDER);
1053       else
1054 	compare_values (TYPE_SATURATING);
1055       compare_values (TYPE_ADDR_SPACE);
1056     }
1057   else if (code == SSA_NAME)
1058     compare_values (SSA_NAME_IS_DEFAULT_DEF);
1059 
1060   if (CODE_CONTAINS_STRUCT (code, TS_INT_CST))
1061     {
1062       if (wi::to_wide (t1) != wi::to_wide (t2))
1063 	return false;
1064     }
1065 
1066   if (CODE_CONTAINS_STRUCT (code, TS_REAL_CST))
1067     {
1068       /* ???  No suitable compare routine available.  */
1069       REAL_VALUE_TYPE r1 = TREE_REAL_CST (t1);
1070       REAL_VALUE_TYPE r2 = TREE_REAL_CST (t2);
1071       if (r1.cl != r2.cl
1072 	  || r1.decimal != r2.decimal
1073 	  || r1.sign != r2.sign
1074 	  || r1.signalling != r2.signalling
1075 	  || r1.canonical != r2.canonical
1076 	  || r1.uexp != r2.uexp)
1077 	return false;
1078       for (unsigned i = 0; i < SIGSZ; ++i)
1079 	if (r1.sig[i] != r2.sig[i])
1080 	  return false;
1081     }
1082 
1083   if (CODE_CONTAINS_STRUCT (code, TS_FIXED_CST))
1084     if (!fixed_compare (EQ_EXPR,
1085 			TREE_FIXED_CST_PTR (t1), TREE_FIXED_CST_PTR (t2)))
1086       return false;
1087 
1088   if (CODE_CONTAINS_STRUCT (code, TS_VECTOR))
1089     {
1090       compare_values (VECTOR_CST_LOG2_NPATTERNS);
1091       compare_values (VECTOR_CST_NELTS_PER_PATTERN);
1092     }
1093 
1094   if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
1095     {
1096       compare_values (DECL_MODE);
1097       compare_values (DECL_NONLOCAL);
1098       compare_values (DECL_VIRTUAL_P);
1099       compare_values (DECL_IGNORED_P);
1100       compare_values (DECL_ABSTRACT_P);
1101       compare_values (DECL_ARTIFICIAL);
1102       compare_values (DECL_USER_ALIGN);
1103       compare_values (DECL_PRESERVE_P);
1104       compare_values (DECL_EXTERNAL);
1105       compare_values (DECL_GIMPLE_REG_P);
1106       compare_values (DECL_ALIGN);
1107       if (code == LABEL_DECL)
1108 	{
1109 	  compare_values (EH_LANDING_PAD_NR);
1110 	  compare_values (LABEL_DECL_UID);
1111 	}
1112       else if (code == FIELD_DECL)
1113 	{
1114 	  compare_values (DECL_PACKED);
1115 	  compare_values (DECL_NONADDRESSABLE_P);
1116 	  compare_values (DECL_PADDING_P);
1117 	  compare_values (DECL_OFFSET_ALIGN);
1118 	}
1119       else if (code == VAR_DECL)
1120 	{
1121 	  compare_values (DECL_HAS_DEBUG_EXPR_P);
1122 	  compare_values (DECL_NONLOCAL_FRAME);
1123 	}
1124       if (code == RESULT_DECL
1125 	  || code == PARM_DECL
1126 	  || code == VAR_DECL)
1127 	{
1128 	  compare_values (DECL_BY_REFERENCE);
1129 	  if (code == VAR_DECL
1130 	      || code == PARM_DECL)
1131 	    compare_values (DECL_HAS_VALUE_EXPR_P);
1132 	}
1133     }
1134 
1135   if (CODE_CONTAINS_STRUCT (code, TS_DECL_WRTL))
1136     compare_values (DECL_REGISTER);
1137 
1138   if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
1139     {
1140       compare_values (DECL_COMMON);
1141       compare_values (DECL_DLLIMPORT_P);
1142       compare_values (DECL_WEAK);
1143       compare_values (DECL_SEEN_IN_BIND_EXPR_P);
1144       compare_values (DECL_COMDAT);
1145       compare_values (DECL_VISIBILITY);
1146       compare_values (DECL_VISIBILITY_SPECIFIED);
1147       if (code == VAR_DECL)
1148 	{
1149 	  compare_values (DECL_HARD_REGISTER);
1150           /* DECL_IN_TEXT_SECTION is set during final asm output only.  */
1151 	  compare_values (DECL_IN_CONSTANT_POOL);
1152 	}
1153     }
1154 
1155   if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL))
1156     {
1157       compare_values (DECL_BUILT_IN_CLASS);
1158       compare_values (DECL_STATIC_CONSTRUCTOR);
1159       compare_values (DECL_STATIC_DESTRUCTOR);
1160       compare_values (DECL_UNINLINABLE);
1161       compare_values (DECL_POSSIBLY_INLINED);
1162       compare_values (DECL_IS_NOVOPS);
1163       compare_values (DECL_IS_RETURNS_TWICE);
1164       compare_values (DECL_IS_MALLOC);
1165       compare_values (DECL_IS_OPERATOR_NEW);
1166       compare_values (DECL_DECLARED_INLINE_P);
1167       compare_values (DECL_STATIC_CHAIN);
1168       compare_values (DECL_NO_INLINE_WARNING_P);
1169       compare_values (DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT);
1170       compare_values (DECL_NO_LIMIT_STACK);
1171       compare_values (DECL_DISREGARD_INLINE_LIMITS);
1172       compare_values (DECL_PURE_P);
1173       compare_values (DECL_LOOPING_CONST_OR_PURE_P);
1174       compare_values (DECL_FINAL_P);
1175       compare_values (DECL_CXX_CONSTRUCTOR_P);
1176       compare_values (DECL_CXX_DESTRUCTOR_P);
1177       if (DECL_BUILT_IN_CLASS (t1) != NOT_BUILT_IN)
1178 	compare_values (DECL_FUNCTION_CODE);
1179     }
1180 
1181   if (CODE_CONTAINS_STRUCT (code, TS_TYPE_COMMON))
1182     {
1183       compare_values (TYPE_MODE);
1184       compare_values (TYPE_STRING_FLAG);
1185       compare_values (TYPE_NEEDS_CONSTRUCTING);
1186       if (RECORD_OR_UNION_TYPE_P (t1))
1187 	{
1188 	  compare_values (TYPE_TRANSPARENT_AGGR);
1189 	  compare_values (TYPE_FINAL_P);
1190 	}
1191       else if (code == ARRAY_TYPE)
1192 	compare_values (TYPE_NONALIASED_COMPONENT);
1193       if (AGGREGATE_TYPE_P (t1))
1194 	compare_values (TYPE_TYPELESS_STORAGE);
1195       compare_values (TYPE_EMPTY_P);
1196       compare_values (TYPE_PACKED);
1197       compare_values (TYPE_RESTRICT);
1198       compare_values (TYPE_USER_ALIGN);
1199       compare_values (TYPE_READONLY);
1200       compare_values (TYPE_PRECISION);
1201       compare_values (TYPE_ALIGN);
1202       /* Do not compare TYPE_ALIAS_SET.  Doing so introduce ordering issues
1203          with calls to get_alias_set which may initialize it for streamed
1204  	 in types.  */
1205     }
1206 
1207   /* We don't want to compare locations, so there is nothing do compare
1208      for TS_EXP.  */
1209 
1210   /* BLOCKs are function local and we don't merge anything there, so
1211      simply refuse to merge.  */
1212   if (CODE_CONTAINS_STRUCT (code, TS_BLOCK))
1213     return false;
1214 
1215   if (CODE_CONTAINS_STRUCT (code, TS_TRANSLATION_UNIT_DECL))
1216     if (strcmp (TRANSLATION_UNIT_LANGUAGE (t1),
1217 		TRANSLATION_UNIT_LANGUAGE (t2)) != 0)
1218       return false;
1219 
1220   if (CODE_CONTAINS_STRUCT (code, TS_TARGET_OPTION))
1221     if (!cl_target_option_eq (TREE_TARGET_OPTION (t1), TREE_TARGET_OPTION (t2)))
1222       return false;
1223 
1224   if (CODE_CONTAINS_STRUCT (code, TS_OPTIMIZATION))
1225     if (memcmp (TREE_OPTIMIZATION (t1), TREE_OPTIMIZATION (t2),
1226 		sizeof (struct cl_optimization)) != 0)
1227       return false;
1228 
1229   if (CODE_CONTAINS_STRUCT (code, TS_BINFO))
1230     if (vec_safe_length (BINFO_BASE_ACCESSES (t1))
1231 	!= vec_safe_length (BINFO_BASE_ACCESSES (t2)))
1232       return false;
1233 
1234   if (CODE_CONTAINS_STRUCT (code, TS_CONSTRUCTOR))
1235     compare_values (CONSTRUCTOR_NELTS);
1236 
1237   if (CODE_CONTAINS_STRUCT (code, TS_IDENTIFIER))
1238     if (IDENTIFIER_LENGTH (t1) != IDENTIFIER_LENGTH (t2)
1239 	|| memcmp (IDENTIFIER_POINTER (t1), IDENTIFIER_POINTER (t2),
1240 		   IDENTIFIER_LENGTH (t1)) != 0)
1241       return false;
1242 
1243   if (CODE_CONTAINS_STRUCT (code, TS_STRING))
1244     if (TREE_STRING_LENGTH (t1) != TREE_STRING_LENGTH (t2)
1245 	|| memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
1246 		   TREE_STRING_LENGTH (t1)) != 0)
1247       return false;
1248 
1249   if (code == OMP_CLAUSE)
1250     {
1251       compare_values (OMP_CLAUSE_CODE);
1252       switch (OMP_CLAUSE_CODE (t1))
1253 	{
1254 	case OMP_CLAUSE_DEFAULT:
1255 	  compare_values (OMP_CLAUSE_DEFAULT_KIND);
1256 	  break;
1257 	case OMP_CLAUSE_SCHEDULE:
1258 	  compare_values (OMP_CLAUSE_SCHEDULE_KIND);
1259 	  break;
1260 	case OMP_CLAUSE_DEPEND:
1261 	  compare_values (OMP_CLAUSE_DEPEND_KIND);
1262 	  break;
1263 	case OMP_CLAUSE_MAP:
1264 	  compare_values (OMP_CLAUSE_MAP_KIND);
1265 	  break;
1266 	case OMP_CLAUSE_PROC_BIND:
1267 	  compare_values (OMP_CLAUSE_PROC_BIND_KIND);
1268 	  break;
1269 	case OMP_CLAUSE_REDUCTION:
1270 	  compare_values (OMP_CLAUSE_REDUCTION_CODE);
1271 	  compare_values (OMP_CLAUSE_REDUCTION_GIMPLE_INIT);
1272 	  compare_values (OMP_CLAUSE_REDUCTION_GIMPLE_MERGE);
1273 	  break;
1274 	default:
1275 	  break;
1276 	}
1277     }
1278 
1279 #undef compare_values
1280 
1281 
1282   /* Compare pointer fields.  */
1283 
1284   /* Recurse.  Search & Replaced from DFS_write_tree_body.
1285      Folding the early checks into the compare_tree_edges recursion
1286      macro makes debugging way quicker as you are able to break on
1287      compare_tree_sccs_1 and simply finish until a call returns false
1288      to spot the SCC members with the difference.  */
1289 #define compare_tree_edges(E1, E2) \
1290   do { \
1291     tree t1_ = (E1), t2_ = (E2); \
1292     if (t1_ != t2_ \
1293 	&& (!t1_ || !t2_ \
1294 	    || !TREE_VISITED (t2_) \
1295 	    || (!TREE_ASM_WRITTEN (t2_) \
1296 		&& !compare_tree_sccs_1 (t1_, t2_, map)))) \
1297       return false; \
1298     /* Only non-NULL trees outside of the SCC may compare equal.  */ \
1299     gcc_checking_assert (t1_ != t2_ || (!t2_ || !TREE_VISITED (t2_))); \
1300   } while (0)
1301 
1302   if (CODE_CONTAINS_STRUCT (code, TS_TYPED))
1303     {
1304       if (code != IDENTIFIER_NODE)
1305 	compare_tree_edges (TREE_TYPE (t1), TREE_TYPE (t2));
1306     }
1307 
1308   if (CODE_CONTAINS_STRUCT (code, TS_VECTOR))
1309     {
1310       /* Note that the number of elements for EXPR has already been emitted
1311 	 in EXPR's header (see streamer_write_tree_header).  */
1312       unsigned int count = vector_cst_encoded_nelts (t1);
1313       for (unsigned int i = 0; i < count; ++i)
1314 	compare_tree_edges (VECTOR_CST_ENCODED_ELT (t1, i),
1315 			    VECTOR_CST_ENCODED_ELT (t2, i));
1316     }
1317 
1318   if (CODE_CONTAINS_STRUCT (code, TS_COMPLEX))
1319     {
1320       compare_tree_edges (TREE_REALPART (t1), TREE_REALPART (t2));
1321       compare_tree_edges (TREE_IMAGPART (t1), TREE_IMAGPART (t2));
1322     }
1323 
1324   if (CODE_CONTAINS_STRUCT (code, TS_DECL_MINIMAL))
1325     {
1326       compare_tree_edges (DECL_NAME (t1), DECL_NAME (t2));
1327       /* ???  Global decls from different TUs have non-matching
1328 	 TRANSLATION_UNIT_DECLs.  Only consider a small set of
1329 	 decls equivalent, we should not end up merging others.  */
1330       if ((code == TYPE_DECL
1331 	   || code == NAMESPACE_DECL
1332 	   || code == IMPORTED_DECL
1333 	   || code == CONST_DECL
1334 	   || (VAR_OR_FUNCTION_DECL_P (t1)
1335 	       && (TREE_PUBLIC (t1) || DECL_EXTERNAL (t1))))
1336 	  && DECL_FILE_SCOPE_P (t1) && DECL_FILE_SCOPE_P (t2))
1337 	;
1338       else
1339 	compare_tree_edges (DECL_CONTEXT (t1), DECL_CONTEXT (t2));
1340     }
1341 
1342   if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
1343     {
1344       compare_tree_edges (DECL_SIZE (t1), DECL_SIZE (t2));
1345       compare_tree_edges (DECL_SIZE_UNIT (t1), DECL_SIZE_UNIT (t2));
1346       compare_tree_edges (DECL_ATTRIBUTES (t1), DECL_ATTRIBUTES (t2));
1347       compare_tree_edges (DECL_ABSTRACT_ORIGIN (t1), DECL_ABSTRACT_ORIGIN (t2));
1348       if ((code == VAR_DECL
1349 	   || code == PARM_DECL)
1350 	  && DECL_HAS_VALUE_EXPR_P (t1))
1351 	compare_tree_edges (DECL_VALUE_EXPR (t1), DECL_VALUE_EXPR (t2));
1352       if (code == VAR_DECL
1353 	  && DECL_HAS_DEBUG_EXPR_P (t1))
1354 	compare_tree_edges (DECL_DEBUG_EXPR (t1), DECL_DEBUG_EXPR (t2));
1355       /* LTO specific edges.  */
1356       if (code != FUNCTION_DECL
1357 	  && code != TRANSLATION_UNIT_DECL)
1358 	compare_tree_edges (DECL_INITIAL (t1), DECL_INITIAL (t2));
1359     }
1360 
1361   if (CODE_CONTAINS_STRUCT (code, TS_DECL_NON_COMMON))
1362     {
1363       if (code == FUNCTION_DECL)
1364 	{
1365 	  tree a1, a2;
1366 	  for (a1 = DECL_ARGUMENTS (t1), a2 = DECL_ARGUMENTS (t2);
1367 	       a1 || a2;
1368 	       a1 = TREE_CHAIN (a1), a2 = TREE_CHAIN (a2))
1369 	    compare_tree_edges (a1, a2);
1370 	  compare_tree_edges (DECL_RESULT (t1), DECL_RESULT (t2));
1371 	}
1372       else if (code == TYPE_DECL)
1373 	compare_tree_edges (DECL_ORIGINAL_TYPE (t1), DECL_ORIGINAL_TYPE (t2));
1374     }
1375 
1376   if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
1377     {
1378       /* Make sure we don't inadvertently set the assembler name.  */
1379       if (DECL_ASSEMBLER_NAME_SET_P (t1))
1380 	compare_tree_edges (DECL_ASSEMBLER_NAME (t1),
1381 			    DECL_ASSEMBLER_NAME (t2));
1382     }
1383 
1384   if (CODE_CONTAINS_STRUCT (code, TS_FIELD_DECL))
1385     {
1386       compare_tree_edges (DECL_FIELD_OFFSET (t1), DECL_FIELD_OFFSET (t2));
1387       compare_tree_edges (DECL_BIT_FIELD_TYPE (t1), DECL_BIT_FIELD_TYPE (t2));
1388       compare_tree_edges (DECL_BIT_FIELD_REPRESENTATIVE (t1),
1389 			  DECL_BIT_FIELD_REPRESENTATIVE (t2));
1390       compare_tree_edges (DECL_FIELD_BIT_OFFSET (t1),
1391 			  DECL_FIELD_BIT_OFFSET (t2));
1392       compare_tree_edges (DECL_FCONTEXT (t1), DECL_FCONTEXT (t2));
1393     }
1394 
1395   if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL))
1396     {
1397       compare_tree_edges (DECL_FUNCTION_PERSONALITY (t1),
1398 			  DECL_FUNCTION_PERSONALITY (t2));
1399       compare_tree_edges (DECL_VINDEX (t1), DECL_VINDEX (t2));
1400       compare_tree_edges (DECL_FUNCTION_SPECIFIC_TARGET (t1),
1401 			  DECL_FUNCTION_SPECIFIC_TARGET (t2));
1402       compare_tree_edges (DECL_FUNCTION_SPECIFIC_OPTIMIZATION (t1),
1403 			  DECL_FUNCTION_SPECIFIC_OPTIMIZATION (t2));
1404     }
1405 
1406   if (CODE_CONTAINS_STRUCT (code, TS_TYPE_COMMON))
1407     {
1408       compare_tree_edges (TYPE_SIZE (t1), TYPE_SIZE (t2));
1409       compare_tree_edges (TYPE_SIZE_UNIT (t1), TYPE_SIZE_UNIT (t2));
1410       compare_tree_edges (TYPE_ATTRIBUTES (t1), TYPE_ATTRIBUTES (t2));
1411       compare_tree_edges (TYPE_NAME (t1), TYPE_NAME (t2));
1412       /* Do not compare TYPE_POINTER_TO or TYPE_REFERENCE_TO.  They will be
1413 	 reconstructed during fixup.  */
1414       /* Do not compare TYPE_NEXT_VARIANT, we reconstruct the variant lists
1415 	 during fixup.  */
1416       compare_tree_edges (TYPE_MAIN_VARIANT (t1), TYPE_MAIN_VARIANT (t2));
1417       /* ???  Global types from different TUs have non-matching
1418 	 TRANSLATION_UNIT_DECLs.  Still merge them if they are otherwise
1419 	 equal.  */
1420       if (TYPE_FILE_SCOPE_P (t1) && TYPE_FILE_SCOPE_P (t2))
1421 	;
1422       else
1423 	compare_tree_edges (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1424       /* TYPE_CANONICAL is re-computed during type merging, so do not
1425 	 compare it here.  */
1426       compare_tree_edges (TYPE_STUB_DECL (t1), TYPE_STUB_DECL (t2));
1427     }
1428 
1429   if (CODE_CONTAINS_STRUCT (code, TS_TYPE_NON_COMMON))
1430     {
1431       if (code == ENUMERAL_TYPE)
1432 	compare_tree_edges (TYPE_VALUES (t1), TYPE_VALUES (t2));
1433       else if (code == ARRAY_TYPE)
1434 	compare_tree_edges (TYPE_DOMAIN (t1), TYPE_DOMAIN (t2));
1435       else if (RECORD_OR_UNION_TYPE_P (t1))
1436 	{
1437 	  tree f1, f2;
1438 	  for (f1 = TYPE_FIELDS (t1), f2 = TYPE_FIELDS (t2);
1439 	       f1 || f2;
1440 	       f1 = TREE_CHAIN (f1), f2 = TREE_CHAIN (f2))
1441 	    compare_tree_edges (f1, f2);
1442 	}
1443       else if (code == FUNCTION_TYPE
1444 	       || code == METHOD_TYPE)
1445 	compare_tree_edges (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
1446 
1447       if (!POINTER_TYPE_P (t1))
1448 	compare_tree_edges (TYPE_MIN_VALUE_RAW (t1), TYPE_MIN_VALUE_RAW (t2));
1449       compare_tree_edges (TYPE_MAX_VALUE_RAW (t1), TYPE_MAX_VALUE_RAW (t2));
1450     }
1451 
1452   if (CODE_CONTAINS_STRUCT (code, TS_LIST))
1453     {
1454       compare_tree_edges (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
1455       compare_tree_edges (TREE_VALUE (t1), TREE_VALUE (t2));
1456       compare_tree_edges (TREE_CHAIN (t1), TREE_CHAIN (t2));
1457     }
1458 
1459   if (CODE_CONTAINS_STRUCT (code, TS_VEC))
1460     for (int i = 0; i < TREE_VEC_LENGTH (t1); i++)
1461       compare_tree_edges (TREE_VEC_ELT (t1, i), TREE_VEC_ELT (t2, i));
1462 
1463   if (CODE_CONTAINS_STRUCT (code, TS_EXP))
1464     {
1465       for (int i = 0; i < TREE_OPERAND_LENGTH (t1); i++)
1466 	compare_tree_edges (TREE_OPERAND (t1, i),
1467 			    TREE_OPERAND (t2, i));
1468 
1469       /* BLOCKs are function local and we don't merge anything there.  */
1470       if (TREE_BLOCK (t1) || TREE_BLOCK (t2))
1471 	return false;
1472     }
1473 
1474   if (CODE_CONTAINS_STRUCT (code, TS_BINFO))
1475     {
1476       unsigned i;
1477       tree t;
1478       /* Lengths have already been compared above.  */
1479       FOR_EACH_VEC_ELT (*BINFO_BASE_BINFOS (t1), i, t)
1480 	compare_tree_edges (t, BINFO_BASE_BINFO (t2, i));
1481       FOR_EACH_VEC_SAFE_ELT (BINFO_BASE_ACCESSES (t1), i, t)
1482 	compare_tree_edges (t, BINFO_BASE_ACCESS (t2, i));
1483       compare_tree_edges (BINFO_OFFSET (t1), BINFO_OFFSET (t2));
1484       compare_tree_edges (BINFO_VTABLE (t1), BINFO_VTABLE (t2));
1485       compare_tree_edges (BINFO_VPTR_FIELD (t1), BINFO_VPTR_FIELD (t2));
1486       /* Do not walk BINFO_INHERITANCE_CHAIN, BINFO_SUBVTT_INDEX
1487 	 and BINFO_VPTR_INDEX; these are used by C++ FE only.  */
1488     }
1489 
1490   if (CODE_CONTAINS_STRUCT (code, TS_CONSTRUCTOR))
1491     {
1492       unsigned i;
1493       tree index, value;
1494       /* Lengths have already been compared above.  */
1495       FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t1), i, index, value)
1496 	{
1497 	  compare_tree_edges (index, CONSTRUCTOR_ELT (t2, i)->index);
1498 	  compare_tree_edges (value, CONSTRUCTOR_ELT (t2, i)->value);
1499 	}
1500     }
1501 
1502   if (code == OMP_CLAUSE)
1503     {
1504       int i;
1505 
1506       for (i = 0; i < omp_clause_num_ops[OMP_CLAUSE_CODE (t1)]; i++)
1507 	compare_tree_edges (OMP_CLAUSE_OPERAND (t1, i),
1508 			    OMP_CLAUSE_OPERAND (t2, i));
1509       compare_tree_edges (OMP_CLAUSE_CHAIN (t1), OMP_CLAUSE_CHAIN (t2));
1510     }
1511 
1512 #undef compare_tree_edges
1513 
1514   return true;
1515 }
1516 
1517 /* Compare the tree scc SCC to the prevailing candidate PSCC, filling
1518    out MAP if they are equal.  */
1519 
1520 static bool
1521 compare_tree_sccs (tree_scc *pscc, tree_scc *scc,
1522 		   tree *map)
1523 {
1524   /* Assume SCC entry hashes are sorted after their cardinality.  Which
1525      means we can simply take the first n-tuple of equal hashes
1526      (which is recorded as entry_len) and do n SCC entry candidate
1527      comparisons.  */
1528   for (unsigned i = 0; i < pscc->entry_len; ++i)
1529     {
1530       tree *mapp = map;
1531       num_scc_compare_collisions++;
1532       if (compare_tree_sccs_1 (pscc->entries[0], scc->entries[i], &mapp))
1533 	{
1534 	  /* Equal - no need to reset TREE_VISITED or TREE_ASM_WRITTEN
1535 	     on the scc as all trees will be freed.  */
1536 	  return true;
1537 	}
1538       /* Reset TREE_ASM_WRITTEN on scc for the next compare or in case
1539          the SCC prevails.  */
1540       for (unsigned j = 0; j < scc->len; ++j)
1541 	TREE_ASM_WRITTEN (scc->entries[j]) = 0;
1542     }
1543 
1544   return false;
1545 }
1546 
1547 /* QSort sort function to sort a map of two pointers after the 2nd
1548    pointer.  */
1549 
1550 static int
1551 cmp_tree (const void *p1_, const void *p2_)
1552 {
1553   tree *p1 = (tree *)(const_cast<void *>(p1_));
1554   tree *p2 = (tree *)(const_cast<void *>(p2_));
1555   if (p1[1] == p2[1])
1556     return 0;
1557   return ((uintptr_t)p1[1] < (uintptr_t)p2[1]) ? -1 : 1;
1558 }
1559 
1560 /* Try to unify the SCC with nodes FROM to FROM + LEN in CACHE and
1561    hash value SCC_HASH with an already recorded SCC.  Return true if
1562    that was successful, otherwise return false.  */
1563 
1564 static bool
1565 unify_scc (struct data_in *data_in, unsigned from,
1566 	   unsigned len, unsigned scc_entry_len, hashval_t scc_hash)
1567 {
1568   bool unified_p = false;
1569   struct streamer_tree_cache_d *cache = data_in->reader_cache;
1570   tree_scc *scc
1571     = (tree_scc *) alloca (sizeof (tree_scc) + (len - 1) * sizeof (tree));
1572   scc->next = NULL;
1573   scc->hash = scc_hash;
1574   scc->len = len;
1575   scc->entry_len = scc_entry_len;
1576   for (unsigned i = 0; i < len; ++i)
1577     {
1578       tree t = streamer_tree_cache_get_tree (cache, from + i);
1579       scc->entries[i] = t;
1580       /* Do not merge SCCs with local entities inside them.  Also do
1581 	 not merge TRANSLATION_UNIT_DECLs.  */
1582       if (TREE_CODE (t) == TRANSLATION_UNIT_DECL
1583 	  || (VAR_OR_FUNCTION_DECL_P (t)
1584 	      && !(TREE_PUBLIC (t) || DECL_EXTERNAL (t)))
1585 	  || TREE_CODE (t) == LABEL_DECL)
1586 	{
1587 	  /* Avoid doing any work for these cases and do not worry to
1588 	     record the SCCs for further merging.  */
1589 	  return false;
1590 	}
1591     }
1592 
1593   /* Look for the list of candidate SCCs to compare against.  */
1594   tree_scc **slot;
1595   slot = tree_scc_hash->find_slot_with_hash (scc, scc_hash, INSERT);
1596   if (*slot)
1597     {
1598       /* Try unifying against each candidate.  */
1599       num_scc_compares++;
1600 
1601       /* Set TREE_VISITED on the scc so we can easily identify tree nodes
1602 	 outside of the scc when following tree edges.  Make sure
1603 	 that TREE_ASM_WRITTEN is unset so we can use it as 2nd bit
1604 	 to track whether we visited the SCC member during the compare.
1605 	 We cannot use TREE_VISITED on the pscc members as the extended
1606 	 scc and pscc can overlap.  */
1607       for (unsigned i = 0; i < scc->len; ++i)
1608 	{
1609 	  TREE_VISITED (scc->entries[i]) = 1;
1610 	  gcc_checking_assert (!TREE_ASM_WRITTEN (scc->entries[i]));
1611 	}
1612 
1613       tree *map = XALLOCAVEC (tree, 2 * len);
1614       for (tree_scc *pscc = *slot; pscc; pscc = pscc->next)
1615 	{
1616 	  if (!compare_tree_sccs (pscc, scc, map))
1617 	    continue;
1618 
1619 	  /* Found an equal SCC.  */
1620 	  unified_p = true;
1621 	  num_scc_compare_collisions--;
1622 	  num_sccs_merged++;
1623 	  total_scc_size_merged += len;
1624 
1625 	  if (flag_checking)
1626 	    for (unsigned i = 0; i < len; ++i)
1627 	      {
1628 		tree t = map[2*i+1];
1629 		enum tree_code code = TREE_CODE (t);
1630 		/* IDENTIFIER_NODEs should be singletons and are merged by the
1631 		   streamer.  The others should be singletons, too, and we
1632 		   should not merge them in any way.  */
1633 		gcc_assert (code != TRANSLATION_UNIT_DECL
1634 			    && code != IDENTIFIER_NODE);
1635 	      }
1636 
1637 	  /* Fixup the streamer cache with the prevailing nodes according
1638 	     to the tree node mapping computed by compare_tree_sccs.  */
1639 	  if (len == 1)
1640 	    {
1641 	      lto_maybe_register_decl (data_in, pscc->entries[0], from);
1642 	      streamer_tree_cache_replace_tree (cache, pscc->entries[0], from);
1643 	    }
1644 	  else
1645 	    {
1646 	      tree *map2 = XALLOCAVEC (tree, 2 * len);
1647 	      for (unsigned i = 0; i < len; ++i)
1648 		{
1649 		  map2[i*2] = (tree)(uintptr_t)(from + i);
1650 		  map2[i*2+1] = scc->entries[i];
1651 		}
1652 	      qsort (map2, len, 2 * sizeof (tree), cmp_tree);
1653 	      qsort (map, len, 2 * sizeof (tree), cmp_tree);
1654 	      for (unsigned i = 0; i < len; ++i)
1655 		{
1656 		  lto_maybe_register_decl (data_in, map[2*i],
1657 					   (uintptr_t)map2[2*i]);
1658 		  streamer_tree_cache_replace_tree (cache, map[2*i],
1659 						    (uintptr_t)map2[2*i]);
1660 		}
1661 	    }
1662 
1663 	  /* Free the tree nodes from the read SCC.  */
1664 	  data_in->location_cache.revert_location_cache ();
1665 	  for (unsigned i = 0; i < len; ++i)
1666 	    {
1667 	      if (TYPE_P (scc->entries[i]))
1668 		num_merged_types++;
1669 	      free_node (scc->entries[i]);
1670 	    }
1671 
1672 	  /* Drop DIE references.  */
1673 	  dref_queue.truncate (0);
1674 
1675 	  break;
1676 	}
1677 
1678       /* Reset TREE_VISITED if we didn't unify the SCC with another.  */
1679       if (!unified_p)
1680 	for (unsigned i = 0; i < scc->len; ++i)
1681 	  TREE_VISITED (scc->entries[i]) = 0;
1682     }
1683 
1684   /* If we didn't unify it to any candidate duplicate the relevant
1685      pieces to permanent storage and link it into the chain.  */
1686   if (!unified_p)
1687     {
1688       tree_scc *pscc
1689 	= XOBNEWVAR (&tree_scc_hash_obstack, tree_scc, sizeof (tree_scc));
1690       memcpy (pscc, scc, sizeof (tree_scc));
1691       pscc->next = (*slot);
1692       *slot = pscc;
1693     }
1694   return unified_p;
1695 }
1696 
1697 
1698 /* Compare types based on source file location.  */
1699 
1700 static int
1701 cmp_type_location (const void *p1_, const void *p2_)
1702 {
1703   tree *p1 = (tree*)(const_cast<void *>(p1_));
1704   tree *p2 = (tree*)(const_cast<void *>(p2_));
1705   if (*p1 == *p2)
1706     return 0;
1707 
1708   tree tname1 = TYPE_NAME (*p1);
1709   tree tname2 = TYPE_NAME (*p2);
1710 
1711   const char *f1 = DECL_SOURCE_FILE (tname1);
1712   const char *f2 = DECL_SOURCE_FILE (tname2);
1713 
1714   int r = strcmp (f1, f2);
1715   if (r == 0)
1716     {
1717       int l1 = DECL_SOURCE_LINE (tname1);
1718       int l2 = DECL_SOURCE_LINE (tname2);
1719       if (l1 == l2)
1720        {
1721 	 int l1 = DECL_SOURCE_COLUMN (tname1);
1722 	 int l2 = DECL_SOURCE_COLUMN (tname2);
1723 	 return l1 - l2;
1724        }
1725       else
1726        return l1 - l2;
1727     }
1728   else
1729     return r;
1730 }
1731 
1732 /* Read all the symbols from buffer DATA, using descriptors in DECL_DATA.
1733    RESOLUTIONS is the set of symbols picked by the linker (read from the
1734    resolution file when the linker plugin is being used).  */
1735 
1736 static void
1737 lto_read_decls (struct lto_file_decl_data *decl_data, const void *data,
1738 		vec<ld_plugin_symbol_resolution_t> resolutions)
1739 {
1740   const struct lto_decl_header *header = (const struct lto_decl_header *) data;
1741   const int decl_offset = sizeof (struct lto_decl_header);
1742   const int main_offset = decl_offset + header->decl_state_size;
1743   const int string_offset = main_offset + header->main_size;
1744   struct data_in *data_in;
1745   unsigned int i;
1746   const uint32_t *data_ptr, *data_end;
1747   uint32_t num_decl_states;
1748   auto_vec<tree> odr_types;
1749 
1750   lto_input_block ib_main ((const char *) data + main_offset,
1751 			   header->main_size, decl_data->mode_table);
1752 
1753   data_in = lto_data_in_create (decl_data, (const char *) data + string_offset,
1754 				header->string_size, resolutions);
1755 
1756   /* We do not uniquify the pre-loaded cache entries, those are middle-end
1757      internal types that should not be merged.  */
1758 
1759   /* Read the global declarations and types.  */
1760   while (ib_main.p < ib_main.len)
1761     {
1762       tree t;
1763       unsigned from = data_in->reader_cache->nodes.length ();
1764       /* Read and uniquify SCCs as in the input stream.  */
1765       enum LTO_tags tag = streamer_read_record_start (&ib_main);
1766       if (tag == LTO_tree_scc)
1767 	{
1768 	  unsigned len_;
1769 	  unsigned scc_entry_len;
1770 	  hashval_t scc_hash = lto_input_scc (&ib_main, data_in, &len_,
1771 					      &scc_entry_len);
1772 	  unsigned len = data_in->reader_cache->nodes.length () - from;
1773 	  gcc_assert (len == len_);
1774 
1775 	  total_scc_size += len;
1776 	  num_sccs_read++;
1777 
1778 	  /* We have the special case of size-1 SCCs that are pre-merged
1779 	     by means of identifier and string sharing for example.
1780 	     ???  Maybe we should avoid streaming those as SCCs.  */
1781 	  tree first = streamer_tree_cache_get_tree (data_in->reader_cache,
1782 						     from);
1783 	  if (len == 1
1784 	      && (TREE_CODE (first) == IDENTIFIER_NODE
1785 		  || TREE_CODE (first) == INTEGER_CST))
1786 	    continue;
1787 
1788 	  /* Try to unify the SCC with already existing ones.  */
1789 	  if (!flag_ltrans
1790 	      && unify_scc (data_in, from,
1791 			    len, scc_entry_len, scc_hash))
1792 	    continue;
1793 
1794 	  /* Tree merging failed, mark entries in location cache as
1795 	     permanent.  */
1796 	  data_in->location_cache.accept_location_cache ();
1797 
1798 	  bool seen_type = false;
1799 	  for (unsigned i = 0; i < len; ++i)
1800 	    {
1801 	      tree t = streamer_tree_cache_get_tree (data_in->reader_cache,
1802 						     from + i);
1803 	      /* Reconstruct the type variant and pointer-to/reference-to
1804 		 chains.  */
1805 	      if (TYPE_P (t))
1806 		{
1807 		  seen_type = true;
1808 		  num_prevailing_types++;
1809 		  lto_fixup_prevailing_type (t);
1810 
1811 		  /* Compute the canonical type of all types.
1812 		     Because SCC components are streamed in random (hash) order
1813 		     we may have encountered the type before while registering
1814 		     type canonical of a derived type in the same SCC.  */
1815 		  if (!TYPE_CANONICAL (t))
1816 		    gimple_register_canonical_type (t);
1817 		  if (odr_type_p (t))
1818 		    odr_types.safe_push (t);
1819 		}
1820 	      /* Link shared INTEGER_CSTs into TYPE_CACHED_VALUEs of its
1821 		 type which is also member of this SCC.  */
1822 	      if (TREE_CODE (t) == INTEGER_CST
1823 		  && !TREE_OVERFLOW (t))
1824 		cache_integer_cst (t);
1825 	      if (!flag_ltrans)
1826 		{
1827 		  lto_maybe_register_decl (data_in, t, from + i);
1828 		  /* Scan the tree for references to global functions or
1829 		     variables and record those for later fixup.  */
1830 		  if (mentions_vars_p (t))
1831 		    vec_safe_push (tree_with_vars, t);
1832 		}
1833 	    }
1834 
1835 	  /* Register DECLs with the debuginfo machinery.  */
1836 	  while (!dref_queue.is_empty ())
1837 	    {
1838 	      dref_entry e = dref_queue.pop ();
1839 	      debug_hooks->register_external_die (e.decl, e.sym, e.off);
1840 	    }
1841 
1842 	  if (seen_type)
1843 	    num_type_scc_trees += len;
1844 	}
1845       else
1846 	{
1847 	  /* Pickle stray references.  */
1848 	  t = lto_input_tree_1 (&ib_main, data_in, tag, 0);
1849 	  gcc_assert (t && data_in->reader_cache->nodes.length () == from);
1850 	}
1851     }
1852   data_in->location_cache.apply_location_cache ();
1853 
1854   /* Read in lto_in_decl_state objects.  */
1855   data_ptr = (const uint32_t *) ((const char*) data + decl_offset);
1856   data_end =
1857      (const uint32_t *) ((const char*) data_ptr + header->decl_state_size);
1858   num_decl_states = *data_ptr++;
1859 
1860   gcc_assert (num_decl_states > 0);
1861   decl_data->global_decl_state = lto_new_in_decl_state ();
1862   data_ptr = lto_read_in_decl_state (data_in, data_ptr,
1863 				     decl_data->global_decl_state);
1864 
1865   /* Read in per-function decl states and enter them in hash table.  */
1866   decl_data->function_decl_states =
1867     hash_table<decl_state_hasher>::create_ggc (37);
1868 
1869   for (i = 1; i < num_decl_states; i++)
1870     {
1871       struct lto_in_decl_state *state = lto_new_in_decl_state ();
1872 
1873       data_ptr = lto_read_in_decl_state (data_in, data_ptr, state);
1874       lto_in_decl_state **slot
1875 	= decl_data->function_decl_states->find_slot (state, INSERT);
1876       gcc_assert (*slot == NULL);
1877       *slot = state;
1878     }
1879 
1880   /* Sort types for the file before registering in ODR machinery.  */
1881   if (lto_location_cache::current_cache)
1882     lto_location_cache::current_cache->apply_location_cache ();
1883   odr_types.qsort (cmp_type_location);
1884 
1885   /* Register ODR types.  */
1886   for (unsigned i = 0; i < odr_types.length (); i++)
1887     register_odr_type (odr_types[i]);
1888 
1889   if (data_ptr != data_end)
1890     internal_error ("bytecode stream: garbage at the end of symbols section");
1891 
1892   /* Set the current decl state to be the global state. */
1893   decl_data->current_decl_state = decl_data->global_decl_state;
1894 
1895   lto_data_in_delete (data_in);
1896 }
1897 
1898 /* Custom version of strtoll, which is not portable.  */
1899 
1900 static int64_t
1901 lto_parse_hex (const char *p)
1902 {
1903   int64_t ret = 0;
1904 
1905   for (; *p != '\0'; ++p)
1906     {
1907       char c = *p;
1908       unsigned char part;
1909       ret <<= 4;
1910       if (c >= '0' && c <= '9')
1911         part = c - '0';
1912       else if (c >= 'a' && c <= 'f')
1913         part = c - 'a' + 10;
1914       else if (c >= 'A' && c <= 'F')
1915         part = c - 'A' + 10;
1916       else
1917         internal_error ("could not parse hex number");
1918       ret |= part;
1919     }
1920 
1921   return ret;
1922 }
1923 
1924 /* Read resolution for file named FILE_NAME. The resolution is read from
1925    RESOLUTION. */
1926 
1927 static void
1928 lto_resolution_read (splay_tree file_ids, FILE *resolution, lto_file *file)
1929 {
1930   /* We require that objects in the resolution file are in the same
1931      order as the lto1 command line. */
1932   unsigned int name_len;
1933   char *obj_name;
1934   unsigned int num_symbols;
1935   unsigned int i;
1936   struct lto_file_decl_data *file_data;
1937   splay_tree_node nd = NULL;
1938 
1939   if (!resolution)
1940     return;
1941 
1942   name_len = strlen (file->filename);
1943   obj_name = XNEWVEC (char, name_len + 1);
1944   fscanf (resolution, " ");   /* Read white space. */
1945 
1946   fread (obj_name, sizeof (char), name_len, resolution);
1947   obj_name[name_len] = '\0';
1948   if (filename_cmp (obj_name, file->filename) != 0)
1949     internal_error ("unexpected file name %s in linker resolution file. "
1950 		    "Expected %s", obj_name, file->filename);
1951   if (file->offset != 0)
1952     {
1953       int t;
1954       char offset_p[17];
1955       int64_t offset;
1956       t = fscanf (resolution, "@0x%16s", offset_p);
1957       if (t != 1)
1958         internal_error ("could not parse file offset");
1959       offset = lto_parse_hex (offset_p);
1960       if (offset != file->offset)
1961         internal_error ("unexpected offset");
1962     }
1963 
1964   free (obj_name);
1965 
1966   fscanf (resolution, "%u", &num_symbols);
1967 
1968   for (i = 0; i < num_symbols; i++)
1969     {
1970       int t;
1971       unsigned index;
1972       unsigned HOST_WIDE_INT id;
1973       char r_str[27];
1974       enum ld_plugin_symbol_resolution r = (enum ld_plugin_symbol_resolution) 0;
1975       unsigned int j;
1976       unsigned int lto_resolution_str_len =
1977 	sizeof (lto_resolution_str) / sizeof (char *);
1978       res_pair rp;
1979 
1980       t = fscanf (resolution, "%u " HOST_WIDE_INT_PRINT_HEX_PURE " %26s %*[^\n]\n",
1981 		  &index, &id, r_str);
1982       if (t != 3)
1983         internal_error ("invalid line in the resolution file");
1984 
1985       for (j = 0; j < lto_resolution_str_len; j++)
1986 	{
1987 	  if (strcmp (lto_resolution_str[j], r_str) == 0)
1988 	    {
1989 	      r = (enum ld_plugin_symbol_resolution) j;
1990 	      break;
1991 	    }
1992 	}
1993       if (j == lto_resolution_str_len)
1994 	internal_error ("invalid resolution in the resolution file");
1995 
1996       if (!(nd && lto_splay_tree_id_equal_p (nd->key, id)))
1997 	{
1998 	  nd = lto_splay_tree_lookup (file_ids, id);
1999 	  if (nd == NULL)
2000 	    internal_error ("resolution sub id %wx not in object file", id);
2001 	}
2002 
2003       file_data = (struct lto_file_decl_data *)nd->value;
2004       /* The indexes are very sparse. To save memory save them in a compact
2005          format that is only unpacked later when the subfile is processed. */
2006       rp.res = r;
2007       rp.index = index;
2008       file_data->respairs.safe_push (rp);
2009       if (file_data->max_index < index)
2010         file_data->max_index = index;
2011     }
2012 }
2013 
2014 /* List of file_decl_datas */
2015 struct file_data_list
2016   {
2017     struct lto_file_decl_data *first, *last;
2018   };
2019 
2020 /* Is the name for a id'ed LTO section? */
2021 
2022 static int
2023 lto_section_with_id (const char *name, unsigned HOST_WIDE_INT *id)
2024 {
2025   const char *s;
2026 
2027   if (strncmp (name, section_name_prefix, strlen (section_name_prefix)))
2028     return 0;
2029   s = strrchr (name, '.');
2030   if (!s)
2031     return 0;
2032   /* If the section is not suffixed with an ID return.  */
2033   if ((size_t)(s - name) == strlen (section_name_prefix))
2034     return 0;
2035   return sscanf (s, "." HOST_WIDE_INT_PRINT_HEX_PURE, id) == 1;
2036 }
2037 
2038 /* Create file_data of each sub file id */
2039 
2040 static int
2041 create_subid_section_table (struct lto_section_slot *ls, splay_tree file_ids,
2042                             struct file_data_list *list)
2043 {
2044   struct lto_section_slot s_slot, *new_slot;
2045   unsigned HOST_WIDE_INT id;
2046   splay_tree_node nd;
2047   void **hash_slot;
2048   char *new_name;
2049   struct lto_file_decl_data *file_data;
2050 
2051   if (!lto_section_with_id (ls->name, &id))
2052     return 1;
2053 
2054   /* Find hash table of sub module id */
2055   nd = lto_splay_tree_lookup (file_ids, id);
2056   if (nd != NULL)
2057     {
2058       file_data = (struct lto_file_decl_data *)nd->value;
2059     }
2060   else
2061     {
2062       file_data = ggc_alloc<lto_file_decl_data> ();
2063       memset(file_data, 0, sizeof (struct lto_file_decl_data));
2064       file_data->id = id;
2065       file_data->section_hash_table = lto_obj_create_section_hash_table ();
2066       lto_splay_tree_insert (file_ids, id, file_data);
2067 
2068       /* Maintain list in linker order */
2069       if (!list->first)
2070         list->first = file_data;
2071       if (list->last)
2072         list->last->next = file_data;
2073       list->last = file_data;
2074     }
2075 
2076   /* Copy section into sub module hash table */
2077   new_name = XDUPVEC (char, ls->name, strlen (ls->name) + 1);
2078   s_slot.name = new_name;
2079   hash_slot = htab_find_slot (file_data->section_hash_table, &s_slot, INSERT);
2080   gcc_assert (*hash_slot == NULL);
2081 
2082   new_slot = XDUP (struct lto_section_slot, ls);
2083   new_slot->name = new_name;
2084   *hash_slot = new_slot;
2085   return 1;
2086 }
2087 
2088 /* Read declarations and other initializations for a FILE_DATA. */
2089 
2090 static void
2091 lto_file_finalize (struct lto_file_decl_data *file_data, lto_file *file)
2092 {
2093   const char *data;
2094   size_t len;
2095   vec<ld_plugin_symbol_resolution_t>
2096 	resolutions = vNULL;
2097   int i;
2098   res_pair *rp;
2099 
2100   /* Create vector for fast access of resolution. We do this lazily
2101      to save memory. */
2102   resolutions.safe_grow_cleared (file_data->max_index + 1);
2103   for (i = 0; file_data->respairs.iterate (i, &rp); i++)
2104     resolutions[rp->index] = rp->res;
2105   file_data->respairs.release ();
2106 
2107   file_data->renaming_hash_table = lto_create_renaming_table ();
2108   file_data->file_name = file->filename;
2109 #ifdef ACCEL_COMPILER
2110   lto_input_mode_table (file_data);
2111 #else
2112   file_data->mode_table = lto_mode_identity_table;
2113 #endif
2114   data = lto_get_section_data (file_data, LTO_section_decls, NULL, &len);
2115   if (data == NULL)
2116     {
2117       internal_error ("cannot read LTO decls from %s", file_data->file_name);
2118       return;
2119     }
2120   /* Frees resolutions */
2121   lto_read_decls (file_data, data, resolutions);
2122   lto_free_section_data (file_data, LTO_section_decls, NULL, data, len);
2123 }
2124 
2125 /* Finalize FILE_DATA in FILE and increase COUNT. */
2126 
2127 static int
2128 lto_create_files_from_ids (lto_file *file, struct lto_file_decl_data *file_data,
2129 			   int *count)
2130 {
2131   lto_file_finalize (file_data, file);
2132   if (symtab->dump_file)
2133     fprintf (symtab->dump_file,
2134 	     "Creating file %s with sub id " HOST_WIDE_INT_PRINT_HEX "\n",
2135 	     file_data->file_name, file_data->id);
2136   (*count)++;
2137   return 0;
2138 }
2139 
2140 /* Generate a TREE representation for all types and external decls
2141    entities in FILE.
2142 
2143    Read all of the globals out of the file.  Then read the cgraph
2144    and process the .o index into the cgraph nodes so that it can open
2145    the .o file to load the functions and ipa information.   */
2146 
2147 static struct lto_file_decl_data *
2148 lto_file_read (lto_file *file, FILE *resolution_file, int *count)
2149 {
2150   struct lto_file_decl_data *file_data = NULL;
2151   splay_tree file_ids;
2152   htab_t section_hash_table;
2153   struct lto_section_slot *section;
2154   struct file_data_list file_list;
2155   struct lto_section_list section_list;
2156 
2157   memset (&section_list, 0, sizeof (struct lto_section_list));
2158   section_hash_table = lto_obj_build_section_table (file, &section_list);
2159 
2160   /* Find all sub modules in the object and put their sections into new hash
2161      tables in a splay tree. */
2162   file_ids = lto_splay_tree_new ();
2163   memset (&file_list, 0, sizeof (struct file_data_list));
2164   for (section = section_list.first; section != NULL; section = section->next)
2165     create_subid_section_table (section, file_ids, &file_list);
2166 
2167   /* Add resolutions to file ids */
2168   lto_resolution_read (file_ids, resolution_file, file);
2169 
2170   /* Finalize each lto file for each submodule in the merged object */
2171   for (file_data = file_list.first; file_data != NULL; file_data = file_data->next)
2172     lto_create_files_from_ids (file, file_data, count);
2173 
2174   splay_tree_delete (file_ids);
2175   htab_delete (section_hash_table);
2176 
2177   return file_list.first;
2178 }
2179 
2180 #if HAVE_MMAP_FILE && HAVE_SYSCONF && defined _SC_PAGE_SIZE
2181 #define LTO_MMAP_IO 1
2182 #endif
2183 
2184 #if LTO_MMAP_IO
2185 /* Page size of machine is used for mmap and munmap calls.  */
2186 static size_t page_mask;
2187 #endif
2188 
2189 /* Get the section data of length LEN from FILENAME starting at
2190    OFFSET.  The data segment must be freed by the caller when the
2191    caller is finished.  Returns NULL if all was not well.  */
2192 
2193 static char *
2194 lto_read_section_data (struct lto_file_decl_data *file_data,
2195 		       intptr_t offset, size_t len)
2196 {
2197   char *result;
2198   static int fd = -1;
2199   static char *fd_name;
2200 #if LTO_MMAP_IO
2201   intptr_t computed_len;
2202   intptr_t computed_offset;
2203   intptr_t diff;
2204 #endif
2205 
2206   /* Keep a single-entry file-descriptor cache.  The last file we
2207      touched will get closed at exit.
2208      ???  Eventually we want to add a more sophisticated larger cache
2209      or rather fix function body streaming to not stream them in
2210      practically random order.  */
2211   if (fd != -1
2212       && filename_cmp (fd_name, file_data->file_name) != 0)
2213     {
2214       free (fd_name);
2215       close (fd);
2216       fd = -1;
2217     }
2218   if (fd == -1)
2219     {
2220       fd = open (file_data->file_name, O_RDONLY|O_BINARY);
2221       if (fd == -1)
2222         {
2223 	  fatal_error (input_location, "Cannot open %s", file_data->file_name);
2224 	  return NULL;
2225         }
2226       fd_name = xstrdup (file_data->file_name);
2227     }
2228 
2229 #if LTO_MMAP_IO
2230   if (!page_mask)
2231     {
2232       size_t page_size = sysconf (_SC_PAGE_SIZE);
2233       page_mask = ~(page_size - 1);
2234     }
2235 
2236   computed_offset = offset & page_mask;
2237   diff = offset - computed_offset;
2238   computed_len = len + diff;
2239 
2240   result = (char *) mmap (NULL, computed_len, PROT_READ, MAP_PRIVATE,
2241 			  fd, computed_offset);
2242   if (result == MAP_FAILED)
2243     {
2244       fatal_error (input_location, "Cannot map %s", file_data->file_name);
2245       return NULL;
2246     }
2247 
2248   return result + diff;
2249 #else
2250   result = (char *) xmalloc (len);
2251   if (lseek (fd, offset, SEEK_SET) != offset
2252       || read (fd, result, len) != (ssize_t) len)
2253     {
2254       free (result);
2255       fatal_error (input_location, "Cannot read %s", file_data->file_name);
2256       result = NULL;
2257     }
2258 #ifdef __MINGW32__
2259   /* Native windows doesn't supports delayed unlink on opened file. So
2260      we close file here again. This produces higher I/O load, but at least
2261      it prevents to have dangling file handles preventing unlink.  */
2262   free (fd_name);
2263   fd_name = NULL;
2264   close (fd);
2265   fd = -1;
2266 #endif
2267   return result;
2268 #endif
2269 }
2270 
2271 
2272 /* Get the section data from FILE_DATA of SECTION_TYPE with NAME.
2273    NAME will be NULL unless the section type is for a function
2274    body.  */
2275 
2276 static const char *
2277 get_section_data (struct lto_file_decl_data *file_data,
2278 		      enum lto_section_type section_type,
2279 		      const char *name,
2280 		      size_t *len)
2281 {
2282   htab_t section_hash_table = file_data->section_hash_table;
2283   struct lto_section_slot *f_slot;
2284   struct lto_section_slot s_slot;
2285   const char *section_name = lto_get_section_name (section_type, name, file_data);
2286   char *data = NULL;
2287 
2288   *len = 0;
2289   s_slot.name = section_name;
2290   f_slot = (struct lto_section_slot *) htab_find (section_hash_table, &s_slot);
2291   if (f_slot)
2292     {
2293       data = lto_read_section_data (file_data, f_slot->start, f_slot->len);
2294       *len = f_slot->len;
2295     }
2296 
2297   free (CONST_CAST (char *, section_name));
2298   return data;
2299 }
2300 
2301 
2302 /* Free the section data from FILE_DATA of SECTION_TYPE with NAME that
2303    starts at OFFSET and has LEN bytes.  */
2304 
2305 static void
2306 free_section_data (struct lto_file_decl_data *file_data ATTRIBUTE_UNUSED,
2307 		   enum lto_section_type section_type ATTRIBUTE_UNUSED,
2308 		   const char *name ATTRIBUTE_UNUSED,
2309 		   const char *offset, size_t len ATTRIBUTE_UNUSED)
2310 {
2311 #if LTO_MMAP_IO
2312   intptr_t computed_len;
2313   intptr_t computed_offset;
2314   intptr_t diff;
2315 #endif
2316 
2317 #if LTO_MMAP_IO
2318   computed_offset = ((intptr_t) offset) & page_mask;
2319   diff = (intptr_t) offset - computed_offset;
2320   computed_len = len + diff;
2321 
2322   munmap ((caddr_t) computed_offset, computed_len);
2323 #else
2324   free (CONST_CAST(char *, offset));
2325 #endif
2326 }
2327 
2328 static lto_file *current_lto_file;
2329 
2330 /* Actually stream out ENCODER into TEMP_FILENAME.  */
2331 
2332 static void
2333 do_stream_out (char *temp_filename, lto_symtab_encoder_t encoder)
2334 {
2335   lto_file *file = lto_obj_file_open (temp_filename, true);
2336   if (!file)
2337     fatal_error (input_location, "lto_obj_file_open() failed");
2338   lto_set_current_out_file (file);
2339 
2340   ipa_write_optimization_summaries (encoder);
2341 
2342   free (CONST_CAST (char *, file->filename));
2343 
2344   lto_set_current_out_file (NULL);
2345   lto_obj_file_close (file);
2346   free (file);
2347 }
2348 
2349 /* Wait for forked process and signal errors.  */
2350 #ifdef HAVE_WORKING_FORK
2351 static void
2352 wait_for_child ()
2353 {
2354   int status;
2355   do
2356     {
2357 #ifndef WCONTINUED
2358 #define WCONTINUED 0
2359 #endif
2360       int w = waitpid (0, &status, WUNTRACED | WCONTINUED);
2361       if (w == -1)
2362 	fatal_error (input_location, "waitpid failed");
2363 
2364       if (WIFEXITED (status) && WEXITSTATUS (status))
2365 	fatal_error (input_location, "streaming subprocess failed");
2366       else if (WIFSIGNALED (status))
2367 	fatal_error (input_location,
2368 		     "streaming subprocess was killed by signal");
2369     }
2370   while (!WIFEXITED (status) && !WIFSIGNALED (status));
2371 }
2372 #endif
2373 
2374 /* Stream out ENCODER into TEMP_FILENAME
2375    Fork if that seems to help.  */
2376 
2377 static void
2378 stream_out (char *temp_filename, lto_symtab_encoder_t encoder,
2379 	    bool ARG_UNUSED (last))
2380 {
2381 #ifdef HAVE_WORKING_FORK
2382   static int nruns;
2383 
2384   if (lto_parallelism <= 1)
2385     {
2386       do_stream_out (temp_filename, encoder);
2387       return;
2388     }
2389 
2390   /* Do not run more than LTO_PARALLELISM streamings
2391      FIXME: we ignore limits on jobserver.  */
2392   if (lto_parallelism > 0 && nruns >= lto_parallelism)
2393     {
2394       wait_for_child ();
2395       nruns --;
2396     }
2397   /* If this is not the last parallel partition, execute new
2398      streaming process.  */
2399   if (!last)
2400     {
2401       pid_t cpid = fork ();
2402 
2403       if (!cpid)
2404 	{
2405 	  setproctitle ("lto1-wpa-streaming");
2406 	  do_stream_out (temp_filename, encoder);
2407 	  exit (0);
2408 	}
2409       /* Fork failed; lets do the job ourseleves.  */
2410       else if (cpid == -1)
2411         do_stream_out (temp_filename, encoder);
2412       else
2413 	nruns++;
2414     }
2415   /* Last partition; stream it and wait for all children to die.  */
2416   else
2417     {
2418       int i;
2419       do_stream_out (temp_filename, encoder);
2420       for (i = 0; i < nruns; i++)
2421 	wait_for_child ();
2422     }
2423   asm_nodes_output = true;
2424 #else
2425   do_stream_out (temp_filename, encoder);
2426 #endif
2427 }
2428 
2429 /* Write all output files in WPA mode and the file with the list of
2430    LTRANS units.  */
2431 
2432 static void
2433 lto_wpa_write_files (void)
2434 {
2435   unsigned i, n_sets;
2436   ltrans_partition part;
2437   FILE *ltrans_output_list_stream;
2438   char *temp_filename;
2439   auto_vec <char *>temp_filenames;
2440   auto_vec <int>temp_priority;
2441   size_t blen;
2442 
2443   /* Open the LTRANS output list.  */
2444   if (!ltrans_output_list)
2445     fatal_error (input_location, "no LTRANS output list filename provided");
2446 
2447   timevar_push (TV_WHOPR_WPA);
2448 
2449   FOR_EACH_VEC_ELT (ltrans_partitions, i, part)
2450     lto_stats.num_output_symtab_nodes += lto_symtab_encoder_size (part->encoder);
2451 
2452   timevar_pop (TV_WHOPR_WPA);
2453 
2454   timevar_push (TV_WHOPR_WPA_IO);
2455 
2456   /* Generate a prefix for the LTRANS unit files.  */
2457   blen = strlen (ltrans_output_list);
2458   temp_filename = (char *) xmalloc (blen + sizeof ("2147483648.o"));
2459   strcpy (temp_filename, ltrans_output_list);
2460   if (blen > sizeof (".out")
2461       && strcmp (temp_filename + blen - sizeof (".out") + 1,
2462 		 ".out") == 0)
2463     temp_filename[blen - sizeof (".out") + 1] = '\0';
2464   blen = strlen (temp_filename);
2465 
2466   n_sets = ltrans_partitions.length ();
2467 
2468   for (i = 0; i < n_sets; i++)
2469     {
2470       ltrans_partition part = ltrans_partitions[i];
2471 
2472       /* Write all the nodes in SET.  */
2473       sprintf (temp_filename + blen, "%u.o", i);
2474 
2475       if (!quiet_flag)
2476 	fprintf (stderr, " %s (%s %i insns)", temp_filename, part->name, part->insns);
2477       if (symtab->dump_file)
2478 	{
2479           lto_symtab_encoder_iterator lsei;
2480 
2481 	  fprintf (symtab->dump_file, "Writing partition %s to file %s, %i insns\n",
2482 		   part->name, temp_filename, part->insns);
2483 	  fprintf (symtab->dump_file, "  Symbols in partition: ");
2484 	  for (lsei = lsei_start_in_partition (part->encoder); !lsei_end_p (lsei);
2485 	       lsei_next_in_partition (&lsei))
2486 	    {
2487 	      symtab_node *node = lsei_node (lsei);
2488 	      fprintf (symtab->dump_file, "%s ", node->asm_name ());
2489 	    }
2490 	  fprintf (symtab->dump_file, "\n  Symbols in boundary: ");
2491 	  for (lsei = lsei_start (part->encoder); !lsei_end_p (lsei);
2492 	       lsei_next (&lsei))
2493 	    {
2494 	      symtab_node *node = lsei_node (lsei);
2495 	      if (!lto_symtab_encoder_in_partition_p (part->encoder, node))
2496 		{
2497 		  fprintf (symtab->dump_file, "%s ", node->asm_name ());
2498 		  cgraph_node *cnode = dyn_cast <cgraph_node *> (node);
2499 		  if (cnode
2500 		      && lto_symtab_encoder_encode_body_p (part->encoder, cnode))
2501 		    fprintf (symtab->dump_file, "(body included)");
2502 		  else
2503 		    {
2504 		      varpool_node *vnode = dyn_cast <varpool_node *> (node);
2505 		      if (vnode
2506 			  && lto_symtab_encoder_encode_initializer_p (part->encoder, vnode))
2507 			fprintf (symtab->dump_file, "(initializer included)");
2508 		    }
2509 		}
2510 	    }
2511 	  fprintf (symtab->dump_file, "\n");
2512 	}
2513       gcc_checking_assert (lto_symtab_encoder_size (part->encoder) || !i);
2514 
2515       stream_out (temp_filename, part->encoder, i == n_sets - 1);
2516 
2517       part->encoder = NULL;
2518 
2519       temp_priority.safe_push (part->insns);
2520       temp_filenames.safe_push (xstrdup (temp_filename));
2521     }
2522   ltrans_output_list_stream = fopen (ltrans_output_list, "w");
2523   if (ltrans_output_list_stream == NULL)
2524     fatal_error (input_location,
2525 		 "opening LTRANS output list %s: %m", ltrans_output_list);
2526   for (i = 0; i < n_sets; i++)
2527     {
2528       unsigned int len = strlen (temp_filenames[i]);
2529       if (fprintf (ltrans_output_list_stream, "%i\n", temp_priority[i]) < 0
2530 	  || fwrite (temp_filenames[i], 1, len, ltrans_output_list_stream) < len
2531 	  || fwrite ("\n", 1, 1, ltrans_output_list_stream) < 1)
2532 	fatal_error (input_location, "writing to LTRANS output list %s: %m",
2533 		     ltrans_output_list);
2534      free (temp_filenames[i]);
2535     }
2536 
2537   lto_stats.num_output_files += n_sets;
2538 
2539   /* Close the LTRANS output list.  */
2540   if (fclose (ltrans_output_list_stream))
2541     fatal_error (input_location,
2542 		 "closing LTRANS output list %s: %m", ltrans_output_list);
2543 
2544   free_ltrans_partitions();
2545   free (temp_filename);
2546 
2547   timevar_pop (TV_WHOPR_WPA_IO);
2548 }
2549 
2550 
2551 /* If TT is a variable or function decl replace it with its
2552    prevailing variant.  */
2553 #define LTO_SET_PREVAIL(tt) \
2554   do {\
2555     if ((tt) && VAR_OR_FUNCTION_DECL_P (tt) \
2556 	&& (TREE_PUBLIC (tt) || DECL_EXTERNAL (tt))) \
2557       { \
2558         tt = lto_symtab_prevailing_decl (tt); \
2559 	fixed = true; \
2560       } \
2561   } while (0)
2562 
2563 /* Ensure that TT isn't a replacable var of function decl.  */
2564 #define LTO_NO_PREVAIL(tt) \
2565   gcc_checking_assert (!(tt) || !VAR_OR_FUNCTION_DECL_P (tt))
2566 
2567 /* Given a tree T replace all fields referring to variables or functions
2568    with their prevailing variant.  */
2569 static void
2570 lto_fixup_prevailing_decls (tree t)
2571 {
2572   enum tree_code code = TREE_CODE (t);
2573   bool fixed = false;
2574 
2575   gcc_checking_assert (code != TREE_BINFO);
2576   LTO_NO_PREVAIL (TREE_TYPE (t));
2577   if (CODE_CONTAINS_STRUCT (code, TS_COMMON)
2578       /* lto_symtab_prevail_decl use TREE_CHAIN to link to the prevailing decl.
2579 	 in the case T is a prevailed declaration we would ICE here. */
2580       && !VAR_OR_FUNCTION_DECL_P (t))
2581     LTO_NO_PREVAIL (TREE_CHAIN (t));
2582   if (DECL_P (t))
2583     {
2584       LTO_NO_PREVAIL (DECL_NAME (t));
2585       LTO_SET_PREVAIL (DECL_CONTEXT (t));
2586       if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
2587 	{
2588 	  LTO_SET_PREVAIL (DECL_SIZE (t));
2589 	  LTO_SET_PREVAIL (DECL_SIZE_UNIT (t));
2590 	  LTO_SET_PREVAIL (DECL_INITIAL (t));
2591 	  LTO_NO_PREVAIL (DECL_ATTRIBUTES (t));
2592 	  LTO_SET_PREVAIL (DECL_ABSTRACT_ORIGIN (t));
2593 	}
2594       if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
2595 	{
2596 	  LTO_NO_PREVAIL (DECL_ASSEMBLER_NAME_RAW (t));
2597 	}
2598       if (CODE_CONTAINS_STRUCT (code, TS_DECL_NON_COMMON))
2599 	{
2600 	  LTO_NO_PREVAIL (DECL_RESULT_FLD (t));
2601 	}
2602       if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL))
2603 	{
2604 	  LTO_NO_PREVAIL (DECL_ARGUMENTS (t));
2605 	  LTO_SET_PREVAIL (DECL_FUNCTION_PERSONALITY (t));
2606 	  LTO_NO_PREVAIL (DECL_VINDEX (t));
2607 	}
2608       if (CODE_CONTAINS_STRUCT (code, TS_FIELD_DECL))
2609 	{
2610 	  LTO_SET_PREVAIL (DECL_FIELD_OFFSET (t));
2611 	  LTO_NO_PREVAIL (DECL_BIT_FIELD_TYPE (t));
2612 	  LTO_NO_PREVAIL (DECL_QUALIFIER (t));
2613 	  LTO_NO_PREVAIL (DECL_FIELD_BIT_OFFSET (t));
2614 	  LTO_NO_PREVAIL (DECL_FCONTEXT (t));
2615 	}
2616     }
2617   else if (TYPE_P (t))
2618     {
2619       LTO_NO_PREVAIL (TYPE_CACHED_VALUES (t));
2620       LTO_SET_PREVAIL (TYPE_SIZE (t));
2621       LTO_SET_PREVAIL (TYPE_SIZE_UNIT (t));
2622       LTO_NO_PREVAIL (TYPE_ATTRIBUTES (t));
2623       LTO_NO_PREVAIL (TYPE_NAME (t));
2624 
2625       LTO_SET_PREVAIL (TYPE_MIN_VALUE_RAW (t));
2626       LTO_SET_PREVAIL (TYPE_MAX_VALUE_RAW (t));
2627       LTO_NO_PREVAIL (TYPE_LANG_SLOT_1 (t));
2628 
2629       LTO_SET_PREVAIL (TYPE_CONTEXT (t));
2630 
2631       LTO_NO_PREVAIL (TYPE_CANONICAL (t));
2632       LTO_NO_PREVAIL (TYPE_MAIN_VARIANT (t));
2633       LTO_NO_PREVAIL (TYPE_NEXT_VARIANT (t));
2634     }
2635   else if (EXPR_P (t))
2636     {
2637       int i;
2638       for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
2639 	LTO_SET_PREVAIL (TREE_OPERAND (t, i));
2640     }
2641   else if (TREE_CODE (t) == CONSTRUCTOR)
2642     {
2643       unsigned i;
2644       tree val;
2645       FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), i, val)
2646 	LTO_SET_PREVAIL (val);
2647     }
2648   else
2649     {
2650       switch (code)
2651 	{
2652 	case TREE_LIST:
2653 	  LTO_SET_PREVAIL (TREE_VALUE (t));
2654 	  LTO_SET_PREVAIL (TREE_PURPOSE (t));
2655 	  LTO_NO_PREVAIL (TREE_PURPOSE (t));
2656 	  break;
2657 	default:
2658 	  gcc_unreachable ();
2659 	}
2660     }
2661   /* If we fixed nothing, then we missed something seen by
2662      mentions_vars_p.  */
2663   gcc_checking_assert (fixed);
2664 }
2665 #undef LTO_SET_PREVAIL
2666 #undef LTO_NO_PREVAIL
2667 
2668 /* Helper function of lto_fixup_decls. Walks the var and fn streams in STATE,
2669    replaces var and function decls with the corresponding prevailing def.  */
2670 
2671 static void
2672 lto_fixup_state (struct lto_in_decl_state *state)
2673 {
2674   unsigned i, si;
2675 
2676   /* Although we only want to replace FUNCTION_DECLs and VAR_DECLs,
2677      we still need to walk from all DECLs to find the reachable
2678      FUNCTION_DECLs and VAR_DECLs.  */
2679   for (si = 0; si < LTO_N_DECL_STREAMS; si++)
2680     {
2681       vec<tree, va_gc> *trees = state->streams[si];
2682       for (i = 0; i < vec_safe_length (trees); i++)
2683 	{
2684 	  tree t = (*trees)[i];
2685 	  if (flag_checking && TYPE_P (t))
2686 	    verify_type (t);
2687 	  if (VAR_OR_FUNCTION_DECL_P (t)
2688 	      && (TREE_PUBLIC (t) || DECL_EXTERNAL (t)))
2689 	    (*trees)[i] = lto_symtab_prevailing_decl (t);
2690 	}
2691     }
2692 }
2693 
2694 /* Fix the decls from all FILES. Replaces each decl with the corresponding
2695    prevailing one.  */
2696 
2697 static void
2698 lto_fixup_decls (struct lto_file_decl_data **files)
2699 {
2700   unsigned int i;
2701   tree t;
2702 
2703   if (tree_with_vars)
2704     FOR_EACH_VEC_ELT ((*tree_with_vars), i, t)
2705       lto_fixup_prevailing_decls (t);
2706 
2707   for (i = 0; files[i]; i++)
2708     {
2709       struct lto_file_decl_data *file = files[i];
2710       struct lto_in_decl_state *state = file->global_decl_state;
2711       lto_fixup_state (state);
2712 
2713       hash_table<decl_state_hasher>::iterator iter;
2714       lto_in_decl_state *elt;
2715       FOR_EACH_HASH_TABLE_ELEMENT (*file->function_decl_states, elt,
2716 				   lto_in_decl_state *, iter)
2717 	lto_fixup_state (elt);
2718     }
2719 }
2720 
2721 static GTY((length ("lto_stats.num_input_files + 1"))) struct lto_file_decl_data **all_file_decl_data;
2722 
2723 /* Turn file datas for sub files into a single array, so that they look
2724    like separate files for further passes. */
2725 
2726 static void
2727 lto_flatten_files (struct lto_file_decl_data **orig, int count, int last_file_ix)
2728 {
2729   struct lto_file_decl_data *n, *next;
2730   int i, k;
2731 
2732   lto_stats.num_input_files = count;
2733   all_file_decl_data
2734     = ggc_cleared_vec_alloc<lto_file_decl_data_ptr> (count + 1);
2735   /* Set the hooks so that all of the ipa passes can read in their data.  */
2736   lto_set_in_hooks (all_file_decl_data, get_section_data, free_section_data);
2737   for (i = 0, k = 0; i < last_file_ix; i++)
2738     {
2739       for (n = orig[i]; n != NULL; n = next)
2740 	{
2741 	  all_file_decl_data[k++] = n;
2742 	  next = n->next;
2743 	  n->next = NULL;
2744 	}
2745     }
2746   all_file_decl_data[k] = NULL;
2747   gcc_assert (k == count);
2748 }
2749 
2750 /* Input file data before flattening (i.e. splitting them to subfiles to support
2751    incremental linking.  */
2752 static int real_file_count;
2753 static GTY((length ("real_file_count + 1"))) struct lto_file_decl_data **real_file_decl_data;
2754 
2755 static void print_lto_report_1 (void);
2756 
2757 /* Read all the symbols from the input files FNAMES.  NFILES is the
2758    number of files requested in the command line.  Instantiate a
2759    global call graph by aggregating all the sub-graphs found in each
2760    file.  */
2761 
2762 static void
2763 read_cgraph_and_symbols (unsigned nfiles, const char **fnames)
2764 {
2765   unsigned int i, last_file_ix;
2766   FILE *resolution;
2767   int count = 0;
2768   struct lto_file_decl_data **decl_data;
2769   symtab_node *snode;
2770 
2771   symtab->initialize ();
2772 
2773   timevar_push (TV_IPA_LTO_DECL_IN);
2774 
2775 #ifdef ACCEL_COMPILER
2776   section_name_prefix = OFFLOAD_SECTION_NAME_PREFIX;
2777   lto_stream_offload_p = true;
2778 #endif
2779 
2780   real_file_decl_data
2781     = decl_data = ggc_cleared_vec_alloc<lto_file_decl_data_ptr> (nfiles + 1);
2782   real_file_count = nfiles;
2783 
2784   /* Read the resolution file.  */
2785   resolution = NULL;
2786   if (resolution_file_name)
2787     {
2788       int t;
2789       unsigned num_objects;
2790 
2791       resolution = fopen (resolution_file_name, "r");
2792       if (resolution == NULL)
2793 	fatal_error (input_location,
2794 		     "could not open symbol resolution file: %m");
2795 
2796       t = fscanf (resolution, "%u", &num_objects);
2797       gcc_assert (t == 1);
2798 
2799       /* True, since the plugin splits the archives.  */
2800       gcc_assert (num_objects == nfiles);
2801     }
2802   symtab->state = LTO_STREAMING;
2803 
2804   canonical_type_hash_cache = new hash_map<const_tree, hashval_t> (251);
2805   gimple_canonical_types = htab_create (16381, gimple_canonical_type_hash,
2806 					gimple_canonical_type_eq, NULL);
2807   gcc_obstack_init (&tree_scc_hash_obstack);
2808   tree_scc_hash = new hash_table<tree_scc_hasher> (4096);
2809 
2810   /* Register the common node types with the canonical type machinery so
2811      we properly share alias-sets across languages and TUs.  Do not
2812      expose the common nodes as type merge target - those that should be
2813      are already exposed so by pre-loading the LTO streamer caches.
2814      Do two passes - first clear TYPE_CANONICAL and then re-compute it.  */
2815   for (i = 0; i < itk_none; ++i)
2816     lto_register_canonical_types (integer_types[i], true);
2817   for (i = 0; i < stk_type_kind_last; ++i)
2818     lto_register_canonical_types (sizetype_tab[i], true);
2819   for (i = 0; i < TI_MAX; ++i)
2820     lto_register_canonical_types (global_trees[i], true);
2821   for (i = 0; i < itk_none; ++i)
2822     lto_register_canonical_types (integer_types[i], false);
2823   for (i = 0; i < stk_type_kind_last; ++i)
2824     lto_register_canonical_types (sizetype_tab[i], false);
2825   for (i = 0; i < TI_MAX; ++i)
2826     lto_register_canonical_types (global_trees[i], false);
2827 
2828   if (!quiet_flag)
2829     fprintf (stderr, "Reading object files:");
2830 
2831   /* Read all of the object files specified on the command line.  */
2832   for (i = 0, last_file_ix = 0; i < nfiles; ++i)
2833     {
2834       struct lto_file_decl_data *file_data = NULL;
2835       if (!quiet_flag)
2836 	{
2837 	  fprintf (stderr, " %s", fnames[i]);
2838 	  fflush (stderr);
2839 	}
2840 
2841       current_lto_file = lto_obj_file_open (fnames[i], false);
2842       if (!current_lto_file)
2843 	break;
2844 
2845       file_data = lto_file_read (current_lto_file, resolution, &count);
2846       if (!file_data)
2847 	{
2848 	  lto_obj_file_close (current_lto_file);
2849 	  free (current_lto_file);
2850 	  current_lto_file = NULL;
2851 	  break;
2852 	}
2853 
2854       decl_data[last_file_ix++] = file_data;
2855 
2856       lto_obj_file_close (current_lto_file);
2857       free (current_lto_file);
2858       current_lto_file = NULL;
2859     }
2860 
2861   lto_flatten_files (decl_data, count, last_file_ix);
2862   lto_stats.num_input_files = count;
2863   ggc_free(decl_data);
2864   real_file_decl_data = NULL;
2865 
2866   if (resolution_file_name)
2867     fclose (resolution);
2868 
2869   /* Show the LTO report before launching LTRANS.  */
2870   if (flag_lto_report || (flag_wpa && flag_lto_report_wpa))
2871     print_lto_report_1 ();
2872 
2873   /* Free gimple type merging datastructures.  */
2874   delete tree_scc_hash;
2875   tree_scc_hash = NULL;
2876   obstack_free (&tree_scc_hash_obstack, NULL);
2877   htab_delete (gimple_canonical_types);
2878   gimple_canonical_types = NULL;
2879   delete canonical_type_hash_cache;
2880   canonical_type_hash_cache = NULL;
2881 
2882   /* At this stage we know that majority of GGC memory is reachable.
2883      Growing the limits prevents unnecesary invocation of GGC.  */
2884   ggc_grow ();
2885   ggc_collect ();
2886 
2887   /* Set the hooks so that all of the ipa passes can read in their data.  */
2888   lto_set_in_hooks (all_file_decl_data, get_section_data, free_section_data);
2889 
2890   timevar_pop (TV_IPA_LTO_DECL_IN);
2891 
2892   if (!quiet_flag)
2893     fprintf (stderr, "\nReading the callgraph\n");
2894 
2895   timevar_push (TV_IPA_LTO_CGRAPH_IO);
2896   /* Read the symtab.  */
2897   input_symtab ();
2898 
2899   input_offload_tables (!flag_ltrans);
2900 
2901   /* Store resolutions into the symbol table.  */
2902 
2903   FOR_EACH_SYMBOL (snode)
2904     if (snode->externally_visible && snode->real_symbol_p ()
2905 	&& snode->lto_file_data && snode->lto_file_data->resolution_map
2906 	&& !is_builtin_fn (snode->decl)
2907 	&& !(VAR_P (snode->decl) && DECL_HARD_REGISTER (snode->decl)))
2908       {
2909 	ld_plugin_symbol_resolution_t *res;
2910 
2911 	res = snode->lto_file_data->resolution_map->get (snode->decl);
2912 	if (!res || *res == LDPR_UNKNOWN)
2913 	  {
2914 	    if (snode->output_to_lto_symbol_table_p ())
2915 	      fatal_error (input_location, "missing resolution data for %s",
2916 		           IDENTIFIER_POINTER
2917 			     (DECL_ASSEMBLER_NAME (snode->decl)));
2918 	  }
2919 	else
2920           snode->resolution = *res;
2921       }
2922   for (i = 0; all_file_decl_data[i]; i++)
2923     if (all_file_decl_data[i]->resolution_map)
2924       {
2925         delete all_file_decl_data[i]->resolution_map;
2926         all_file_decl_data[i]->resolution_map = NULL;
2927       }
2928 
2929   timevar_pop (TV_IPA_LTO_CGRAPH_IO);
2930 
2931   if (!quiet_flag)
2932     fprintf (stderr, "Merging declarations\n");
2933 
2934   timevar_push (TV_IPA_LTO_DECL_MERGE);
2935   /* Merge global decls.  In ltrans mode we read merged cgraph, we do not
2936      need to care about resolving symbols again, we only need to replace
2937      duplicated declarations read from the callgraph and from function
2938      sections.  */
2939   if (!flag_ltrans)
2940     {
2941       lto_symtab_merge_decls ();
2942 
2943       /* If there were errors during symbol merging bail out, we have no
2944 	 good way to recover here.  */
2945       if (seen_error ())
2946 	fatal_error (input_location,
2947 		     "errors during merging of translation units");
2948 
2949       /* Fixup all decls.  */
2950       lto_fixup_decls (all_file_decl_data);
2951     }
2952   if (tree_with_vars)
2953     ggc_free (tree_with_vars);
2954   tree_with_vars = NULL;
2955   ggc_collect ();
2956 
2957   timevar_pop (TV_IPA_LTO_DECL_MERGE);
2958   /* Each pass will set the appropriate timer.  */
2959 
2960   if (!quiet_flag)
2961     fprintf (stderr, "Reading summaries\n");
2962 
2963   /* Read the IPA summary data.  */
2964   if (flag_ltrans)
2965     ipa_read_optimization_summaries ();
2966   else
2967     ipa_read_summaries ();
2968 
2969   for (i = 0; all_file_decl_data[i]; i++)
2970     {
2971       gcc_assert (all_file_decl_data[i]->symtab_node_encoder);
2972       lto_symtab_encoder_delete (all_file_decl_data[i]->symtab_node_encoder);
2973       all_file_decl_data[i]->symtab_node_encoder = NULL;
2974       lto_free_function_in_decl_state (all_file_decl_data[i]->global_decl_state);
2975       all_file_decl_data[i]->global_decl_state = NULL;
2976       all_file_decl_data[i]->current_decl_state = NULL;
2977     }
2978 
2979   /* Finally merge the cgraph according to the decl merging decisions.  */
2980   timevar_push (TV_IPA_LTO_CGRAPH_MERGE);
2981   if (symtab->dump_file)
2982     {
2983       fprintf (symtab->dump_file, "Before merging:\n");
2984       symtab->dump (symtab->dump_file);
2985     }
2986   if (!flag_ltrans)
2987     {
2988       lto_symtab_merge_symbols ();
2989       /* Removal of unreachable symbols is needed to make verify_symtab to pass;
2990 	 we are still having duplicated comdat groups containing local statics.
2991 	 We could also just remove them while merging.  */
2992       symtab->remove_unreachable_nodes (dump_file);
2993     }
2994   ggc_collect ();
2995   symtab->state = IPA_SSA;
2996   /* FIXME: Technically all node removals happening here are useless, because
2997      WPA should not stream them.  */
2998   if (flag_ltrans)
2999     symtab->remove_unreachable_nodes (dump_file);
3000 
3001   timevar_pop (TV_IPA_LTO_CGRAPH_MERGE);
3002 
3003   /* Indicate that the cgraph is built and ready.  */
3004   symtab->function_flags_ready = true;
3005 
3006   ggc_free (all_file_decl_data);
3007   all_file_decl_data = NULL;
3008 }
3009 
3010 
3011 /* Materialize all the bodies for all the nodes in the callgraph.  */
3012 
3013 static void
3014 materialize_cgraph (void)
3015 {
3016   struct cgraph_node *node;
3017   timevar_id_t lto_timer;
3018 
3019   if (!quiet_flag)
3020     fprintf (stderr,
3021 	     flag_wpa ? "Materializing decls:" : "Reading function bodies:");
3022 
3023 
3024   FOR_EACH_FUNCTION (node)
3025     {
3026       if (node->lto_file_data)
3027 	{
3028 	  lto_materialize_function (node);
3029 	  lto_stats.num_input_cgraph_nodes++;
3030 	}
3031     }
3032 
3033 
3034   /* Start the appropriate timer depending on the mode that we are
3035      operating in.  */
3036   lto_timer = (flag_wpa) ? TV_WHOPR_WPA
3037 	      : (flag_ltrans) ? TV_WHOPR_LTRANS
3038 	      : TV_LTO;
3039   timevar_push (lto_timer);
3040 
3041   current_function_decl = NULL;
3042   set_cfun (NULL);
3043 
3044   if (!quiet_flag)
3045     fprintf (stderr, "\n");
3046 
3047   timevar_pop (lto_timer);
3048 }
3049 
3050 
3051 /* Show various memory usage statistics related to LTO.  */
3052 static void
3053 print_lto_report_1 (void)
3054 {
3055   const char *pfx = (flag_lto) ? "LTO" : (flag_wpa) ? "WPA" : "LTRANS";
3056   fprintf (stderr, "%s statistics\n", pfx);
3057 
3058   fprintf (stderr, "[%s] read %lu SCCs of average size %f\n",
3059 	   pfx, num_sccs_read, total_scc_size / (double)num_sccs_read);
3060   fprintf (stderr, "[%s] %lu tree bodies read in total\n", pfx, total_scc_size);
3061   if (flag_wpa && tree_scc_hash)
3062     {
3063       fprintf (stderr, "[%s] tree SCC table: size %ld, %ld elements, "
3064 	       "collision ratio: %f\n", pfx,
3065 	       (long) tree_scc_hash->size (),
3066 	       (long) tree_scc_hash->elements (),
3067 	       tree_scc_hash->collisions ());
3068       hash_table<tree_scc_hasher>::iterator hiter;
3069       tree_scc *scc, *max_scc = NULL;
3070       unsigned max_length = 0;
3071       FOR_EACH_HASH_TABLE_ELEMENT (*tree_scc_hash, scc, x, hiter)
3072 	{
3073 	  unsigned length = 0;
3074 	  tree_scc *s = scc;
3075 	  for (; s; s = s->next)
3076 	    length++;
3077 	  if (length > max_length)
3078 	    {
3079 	      max_length = length;
3080 	      max_scc = scc;
3081 	    }
3082 	}
3083       fprintf (stderr, "[%s] tree SCC max chain length %u (size %u)\n",
3084 	       pfx, max_length, max_scc->len);
3085       fprintf (stderr, "[%s] Compared %lu SCCs, %lu collisions (%f)\n", pfx,
3086 	       num_scc_compares, num_scc_compare_collisions,
3087 	       num_scc_compare_collisions / (double) num_scc_compares);
3088       fprintf (stderr, "[%s] Merged %lu SCCs\n", pfx, num_sccs_merged);
3089       fprintf (stderr, "[%s] Merged %lu tree bodies\n", pfx,
3090 	       total_scc_size_merged);
3091       fprintf (stderr, "[%s] Merged %lu types\n", pfx, num_merged_types);
3092       fprintf (stderr, "[%s] %lu types prevailed (%lu associated trees)\n",
3093 	       pfx, num_prevailing_types, num_type_scc_trees);
3094       fprintf (stderr, "[%s] GIMPLE canonical type table: size %ld, "
3095 	       "%ld elements, %ld searches, %ld collisions (ratio: %f)\n", pfx,
3096 	       (long) htab_size (gimple_canonical_types),
3097 	       (long) htab_elements (gimple_canonical_types),
3098 	       (long) gimple_canonical_types->searches,
3099 	       (long) gimple_canonical_types->collisions,
3100 	       htab_collisions (gimple_canonical_types));
3101       fprintf (stderr, "[%s] GIMPLE canonical type pointer-map: "
3102 	       "%lu elements, %ld searches\n", pfx,
3103 	       num_canonical_type_hash_entries,
3104 	       num_canonical_type_hash_queries);
3105     }
3106 
3107   print_lto_report (pfx);
3108 }
3109 
3110 /* Perform whole program analysis (WPA) on the callgraph and write out the
3111    optimization plan.  */
3112 
3113 static void
3114 do_whole_program_analysis (void)
3115 {
3116   symtab_node *node;
3117 
3118   lto_parallelism = 1;
3119 
3120   /* TODO: jobserver communicatoin is not supported, yet.  */
3121   if (!strcmp (flag_wpa, "jobserver"))
3122     lto_parallelism = -1;
3123   else
3124     {
3125       lto_parallelism = atoi (flag_wpa);
3126       if (lto_parallelism <= 0)
3127 	lto_parallelism = 0;
3128     }
3129 
3130   timevar_start (TV_PHASE_OPT_GEN);
3131 
3132   /* Note that since we are in WPA mode, materialize_cgraph will not
3133      actually read in all the function bodies.  It only materializes
3134      the decls and cgraph nodes so that analysis can be performed.  */
3135   materialize_cgraph ();
3136 
3137   /* Reading in the cgraph uses different timers, start timing WPA now.  */
3138   timevar_push (TV_WHOPR_WPA);
3139 
3140   if (pre_ipa_mem_report)
3141     {
3142       fprintf (stderr, "Memory consumption before IPA\n");
3143       dump_memory_report (false);
3144     }
3145 
3146   symtab->function_flags_ready = true;
3147 
3148   if (symtab->dump_file)
3149     symtab->dump (symtab->dump_file);
3150   bitmap_obstack_initialize (NULL);
3151   symtab->state = IPA_SSA;
3152 
3153   execute_ipa_pass_list (g->get_passes ()->all_regular_ipa_passes);
3154 
3155   /* When WPA analysis raises errors, do not bother to output anything.  */
3156   if (seen_error ())
3157     return;
3158 
3159   if (symtab->dump_file)
3160     {
3161       fprintf (symtab->dump_file, "Optimized ");
3162       symtab->dump (symtab->dump_file);
3163     }
3164 
3165   symtab_node::checking_verify_symtab_nodes ();
3166   bitmap_obstack_release (NULL);
3167 
3168   /* We are about to launch the final LTRANS phase, stop the WPA timer.  */
3169   timevar_pop (TV_WHOPR_WPA);
3170 
3171   timevar_push (TV_WHOPR_PARTITIONING);
3172   if (flag_lto_partition == LTO_PARTITION_1TO1)
3173     lto_1_to_1_map ();
3174   else if (flag_lto_partition == LTO_PARTITION_MAX)
3175     lto_max_map ();
3176   else if (flag_lto_partition == LTO_PARTITION_ONE)
3177     lto_balanced_map (1, INT_MAX);
3178   else if (flag_lto_partition == LTO_PARTITION_BALANCED)
3179     lto_balanced_map (PARAM_VALUE (PARAM_LTO_PARTITIONS),
3180 		      PARAM_VALUE (MAX_PARTITION_SIZE));
3181   else
3182     gcc_unreachable ();
3183 
3184   /* Inline summaries are needed for balanced partitioning.  Free them now so
3185      the memory can be used for streamer caches.  */
3186   ipa_free_fn_summary ();
3187 
3188   /* AUX pointers are used by partitioning code to bookkeep number of
3189      partitions symbol is in.  This is no longer needed.  */
3190   FOR_EACH_SYMBOL (node)
3191     node->aux = NULL;
3192 
3193   lto_stats.num_cgraph_partitions += ltrans_partitions.length ();
3194 
3195   /* Find out statics that need to be promoted
3196      to globals with hidden visibility because they are accessed from multiple
3197      partitions.  */
3198   lto_promote_cross_file_statics ();
3199   timevar_pop (TV_WHOPR_PARTITIONING);
3200 
3201   timevar_stop (TV_PHASE_OPT_GEN);
3202 
3203   /* Collect a last time - in lto_wpa_write_files we may end up forking
3204      with the idea that this doesn't increase memory usage.  So we
3205      absoultely do not want to collect after that.  */
3206   ggc_collect ();
3207 
3208   timevar_start (TV_PHASE_STREAM_OUT);
3209   if (!quiet_flag)
3210     {
3211       fprintf (stderr, "\nStreaming out");
3212       fflush (stderr);
3213     }
3214   lto_wpa_write_files ();
3215   if (!quiet_flag)
3216     fprintf (stderr, "\n");
3217   timevar_stop (TV_PHASE_STREAM_OUT);
3218 
3219   if (post_ipa_mem_report)
3220     {
3221       fprintf (stderr, "Memory consumption after IPA\n");
3222       dump_memory_report (false);
3223     }
3224 
3225   /* Show the LTO report before launching LTRANS.  */
3226   if (flag_lto_report || (flag_wpa && flag_lto_report_wpa))
3227     print_lto_report_1 ();
3228   if (mem_report_wpa)
3229     dump_memory_report (true);
3230 }
3231 
3232 
3233 static GTY(()) tree lto_eh_personality_decl;
3234 
3235 /* Return the LTO personality function decl.  */
3236 
3237 tree
3238 lto_eh_personality (void)
3239 {
3240   if (!lto_eh_personality_decl)
3241     {
3242       /* Use the first personality DECL for our personality if we don't
3243 	 support multiple ones.  This ensures that we don't artificially
3244 	 create the need for them in a single-language program.  */
3245       if (first_personality_decl && !dwarf2out_do_cfi_asm ())
3246 	lto_eh_personality_decl = first_personality_decl;
3247       else
3248 	lto_eh_personality_decl = lhd_gcc_personality ();
3249     }
3250 
3251   return lto_eh_personality_decl;
3252 }
3253 
3254 /* Set the process name based on the LTO mode. */
3255 
3256 static void
3257 lto_process_name (void)
3258 {
3259   if (flag_lto)
3260     setproctitle ("lto1-lto");
3261   if (flag_wpa)
3262     setproctitle ("lto1-wpa");
3263   if (flag_ltrans)
3264     setproctitle ("lto1-ltrans");
3265 }
3266 
3267 
3268 /* Initialize the LTO front end.  */
3269 
3270 static void
3271 lto_init (void)
3272 {
3273   lto_process_name ();
3274   lto_streamer_hooks_init ();
3275   lto_reader_init ();
3276   lto_set_in_hooks (NULL, get_section_data, free_section_data);
3277   memset (&lto_stats, 0, sizeof (lto_stats));
3278   bitmap_obstack_initialize (NULL);
3279   gimple_register_cfg_hooks ();
3280 #ifndef ACCEL_COMPILER
3281   unsigned char *table
3282     = ggc_vec_alloc<unsigned char> (MAX_MACHINE_MODE);
3283   for (int m = 0; m < MAX_MACHINE_MODE; m++)
3284     table[m] = m;
3285   lto_mode_identity_table = table;
3286 #endif
3287 }
3288 
3289 /* Create artificial pointers for "omp declare target link" vars.  */
3290 
3291 static void
3292 offload_handle_link_vars (void)
3293 {
3294 #ifdef ACCEL_COMPILER
3295   varpool_node *var;
3296   FOR_EACH_VARIABLE (var)
3297     if (lookup_attribute ("omp declare target link",
3298 			  DECL_ATTRIBUTES (var->decl)))
3299       {
3300 	tree type = build_pointer_type (TREE_TYPE (var->decl));
3301 	tree link_ptr_var = make_node (VAR_DECL);
3302 	TREE_TYPE (link_ptr_var) = type;
3303 	TREE_USED (link_ptr_var) = 1;
3304 	TREE_STATIC (link_ptr_var) = 1;
3305 	SET_DECL_MODE (link_ptr_var, TYPE_MODE (type));
3306 	DECL_SIZE (link_ptr_var) = TYPE_SIZE (type);
3307 	DECL_SIZE_UNIT (link_ptr_var) = TYPE_SIZE_UNIT (type);
3308 	DECL_ARTIFICIAL (link_ptr_var) = 1;
3309 	tree var_name = DECL_ASSEMBLER_NAME (var->decl);
3310 	char *new_name
3311 	  = ACONCAT ((IDENTIFIER_POINTER (var_name), "_linkptr", NULL));
3312 	DECL_NAME (link_ptr_var) = get_identifier (new_name);
3313 	SET_DECL_ASSEMBLER_NAME (link_ptr_var, DECL_NAME (link_ptr_var));
3314 	SET_DECL_VALUE_EXPR (var->decl, build_simple_mem_ref (link_ptr_var));
3315 	DECL_HAS_VALUE_EXPR_P (var->decl) = 1;
3316       }
3317 #endif
3318 }
3319 
3320 
3321 /* Main entry point for the GIMPLE front end.  This front end has
3322    three main personalities:
3323 
3324    - LTO (-flto).  All the object files on the command line are
3325      loaded in memory and processed as a single translation unit.
3326      This is the traditional link-time optimization behavior.
3327 
3328    - WPA (-fwpa).  Only the callgraph and summary information for
3329      files in the command file are loaded.  A single callgraph
3330      (without function bodies) is instantiated for the whole set of
3331      files.  IPA passes are only allowed to analyze the call graph
3332      and make transformation decisions.  The callgraph is
3333      partitioned, each partition is written to a new object file
3334      together with the transformation decisions.
3335 
3336    - LTRANS (-fltrans).  Similar to -flto but it prevents the IPA
3337      summary files from running again.  Since WPA computed summary
3338      information and decided what transformations to apply, LTRANS
3339      simply applies them.  */
3340 
3341 void
3342 lto_main (void)
3343 {
3344   /* LTO is called as a front end, even though it is not a front end.
3345      Because it is called as a front end, TV_PHASE_PARSING and
3346      TV_PARSE_GLOBAL are active, and we need to turn them off while
3347      doing LTO.  Later we turn them back on so they are active up in
3348      toplev.c.  */
3349   timevar_pop (TV_PARSE_GLOBAL);
3350   timevar_stop (TV_PHASE_PARSING);
3351 
3352   timevar_start (TV_PHASE_SETUP);
3353 
3354   /* Initialize the LTO front end.  */
3355   lto_init ();
3356 
3357   timevar_stop (TV_PHASE_SETUP);
3358   timevar_start (TV_PHASE_STREAM_IN);
3359 
3360   /* Read all the symbols and call graph from all the files in the
3361      command line.  */
3362   read_cgraph_and_symbols (num_in_fnames, in_fnames);
3363 
3364   timevar_stop (TV_PHASE_STREAM_IN);
3365 
3366   if (!seen_error ())
3367     {
3368       offload_handle_link_vars ();
3369 
3370       /* If WPA is enabled analyze the whole call graph and create an
3371 	 optimization plan.  Otherwise, read in all the function
3372 	 bodies and continue with optimization.  */
3373       if (flag_wpa)
3374 	do_whole_program_analysis ();
3375       else
3376 	{
3377 	  timevar_start (TV_PHASE_OPT_GEN);
3378 
3379 	  materialize_cgraph ();
3380 	  if (!flag_ltrans)
3381 	    lto_promote_statics_nonwpa ();
3382 
3383 	  /* Annotate the CU DIE and mark the early debug phase as finished.  */
3384 	  debug_hooks->early_finish ("<artificial>");
3385 
3386 	  /* Let the middle end know that we have read and merged all of
3387 	     the input files.  */
3388 	  symtab->compile ();
3389 
3390 	  timevar_stop (TV_PHASE_OPT_GEN);
3391 
3392 	  /* FIXME lto, if the processes spawned by WPA fail, we miss
3393 	     the chance to print WPA's report, so WPA will call
3394 	     print_lto_report before launching LTRANS.  If LTRANS was
3395 	     launched directly by the driver we would not need to do
3396 	     this.  */
3397 	  if (flag_lto_report || (flag_wpa && flag_lto_report_wpa))
3398 	    print_lto_report_1 ();
3399 	}
3400     }
3401 
3402   /* Here we make LTO pretend to be a parser.  */
3403   timevar_start (TV_PHASE_PARSING);
3404   timevar_push (TV_PARSE_GLOBAL);
3405 }
3406 
3407 #include "gt-lto-lto.h"
3408