xref: /dragonfly/contrib/gcc-4.7/gcc/cgraph.c (revision 0085a56d)
1 /* Callgraph handling code.
2    Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
3    Free Software Foundation, Inc.
4    Contributed by Jan Hubicka
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12 
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16 for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3.  If not see
20 <http://www.gnu.org/licenses/>.  */
21 
22 /*  This file contains basic routines manipulating call graph
23 
24 The callgraph:
25 
26     The call-graph is data structure designed for intra-procedural optimization
27     but it is also used in non-unit-at-a-time compilation to allow easier code
28     sharing.
29 
30     The call-graph consist of nodes and edges represented via linked lists.
31     Each function (external or not) corresponds to the unique node.
32 
33     The mapping from declarations to call-graph nodes is done using hash table
34     based on DECL_UID.  The call-graph nodes are created lazily using
35     cgraph_node function when called for unknown declaration.
36 
37     The callgraph at the moment does not represent all indirect calls or calls
38     from other compilation units.  Flag NEEDED is set for each node that may be
39     accessed in such an invisible way and it shall be considered an entry point
40     to the callgraph.
41 
42     On the other hand, the callgraph currently does contain some edges for
43     indirect calls with unknown callees which can be accessed through
44     indirect_calls field of a node.  It should be noted however that at the
45     moment only calls which are potential candidates for indirect inlining are
46     added there.
47 
48     Interprocedural information:
49 
50       Callgraph is place to store data needed for interprocedural optimization.
51       All data structures are divided into three components: local_info that
52       is produced while analyzing the function, global_info that is result
53       of global walking of the callgraph on the end of compilation and
54       rtl_info used by RTL backend to propagate data from already compiled
55       functions to their callers.
56 
57       Moreover, each node has a uid which can be used to keep information in
58       on-the-side arrays.  UIDs are reused and therefore reasonably dense.
59 
60     Inlining plans:
61 
62       The function inlining information is decided in advance and maintained
63       in the callgraph as so called inline plan.
64       For each inlined call, the callee's node is cloned to represent the
65       new function copy produced by inliner.
66       Each inlined call gets a unique corresponding clone node of the callee
67       and the data structure is updated while inlining is performed, so
68       the clones are eliminated and their callee edges redirected to the
69       caller.
70 
71       Each edge has "inline_failed" field.  When the field is set to NULL,
72       the call will be inlined.  When it is non-NULL it contains a reason
73       why inlining wasn't performed.  */
74 
75 #include "config.h"
76 #include "system.h"
77 #include "coretypes.h"
78 #include "tm.h"
79 #include "tree.h"
80 #include "tree-inline.h"
81 #include "langhooks.h"
82 #include "hashtab.h"
83 #include "toplev.h"
84 #include "flags.h"
85 #include "ggc.h"
86 #include "debug.h"
87 #include "target.h"
88 #include "basic-block.h"
89 #include "cgraph.h"
90 #include "output.h"
91 #include "intl.h"
92 #include "gimple.h"
93 #include "tree-dump.h"
94 #include "tree-flow.h"
95 #include "value-prof.h"
96 #include "except.h"
97 #include "diagnostic-core.h"
98 #include "rtl.h"
99 #include "ipa-utils.h"
100 #include "lto-streamer.h"
101 #include "ipa-inline.h"
102 
103 const char * const ld_plugin_symbol_resolution_names[]=
104 {
105   "",
106   "undef",
107   "prevailing_def",
108   "prevailing_def_ironly",
109   "preempted_reg",
110   "preempted_ir",
111   "resolved_ir",
112   "resolved_exec",
113   "resolved_dyn",
114   "prevailing_def_ironly_exp"
115 };
116 
117 static void cgraph_node_remove_callers (struct cgraph_node *node);
118 static inline void cgraph_edge_remove_caller (struct cgraph_edge *e);
119 static inline void cgraph_edge_remove_callee (struct cgraph_edge *e);
120 
121 /* Hash table used to convert declarations into nodes.  */
122 static GTY((param_is (struct cgraph_node))) htab_t cgraph_hash;
123 /* Hash table used to convert assembler names into nodes.  */
124 static GTY((param_is (struct cgraph_node))) htab_t assembler_name_hash;
125 
126 /* The linked list of cgraph nodes.  */
127 struct cgraph_node *cgraph_nodes;
128 
129 /* Queue of cgraph nodes scheduled to be lowered.  */
130 struct cgraph_node *cgraph_nodes_queue;
131 
132 /* Queue of cgraph nodes scheduled to be added into cgraph.  This is a
133    secondary queue used during optimization to accommodate passes that
134    may generate new functions that need to be optimized and expanded.  */
135 struct cgraph_node *cgraph_new_nodes;
136 
137 /* Number of nodes in existence.  */
138 int cgraph_n_nodes;
139 
140 /* Maximal uid used in cgraph nodes.  */
141 int cgraph_max_uid;
142 
143 /* Maximal uid used in cgraph edges.  */
144 int cgraph_edge_max_uid;
145 
146 /* Set when whole unit has been analyzed so we can access global info.  */
147 bool cgraph_global_info_ready = false;
148 
149 /* What state callgraph is in right now.  */
150 enum cgraph_state cgraph_state = CGRAPH_STATE_CONSTRUCTION;
151 
152 /* Set when the cgraph is fully build and the basic flags are computed.  */
153 bool cgraph_function_flags_ready = false;
154 
155 /* Linked list of cgraph asm nodes.  */
156 struct cgraph_asm_node *cgraph_asm_nodes;
157 
158 /* Last node in cgraph_asm_nodes.  */
159 static GTY(()) struct cgraph_asm_node *cgraph_asm_last_node;
160 
161 /* The order index of the next cgraph node to be created.  This is
162    used so that we can sort the cgraph nodes in order by when we saw
163    them, to support -fno-toplevel-reorder.  */
164 int cgraph_order;
165 
166 /* List of hooks triggered on cgraph_edge events.  */
167 struct cgraph_edge_hook_list {
168   cgraph_edge_hook hook;
169   void *data;
170   struct cgraph_edge_hook_list *next;
171 };
172 
173 /* List of hooks triggered on cgraph_node events.  */
174 struct cgraph_node_hook_list {
175   cgraph_node_hook hook;
176   void *data;
177   struct cgraph_node_hook_list *next;
178 };
179 
180 /* List of hooks triggered on events involving two cgraph_edges.  */
181 struct cgraph_2edge_hook_list {
182   cgraph_2edge_hook hook;
183   void *data;
184   struct cgraph_2edge_hook_list *next;
185 };
186 
187 /* List of hooks triggered on events involving two cgraph_nodes.  */
188 struct cgraph_2node_hook_list {
189   cgraph_2node_hook hook;
190   void *data;
191   struct cgraph_2node_hook_list *next;
192 };
193 
194 /* List of hooks triggered when an edge is removed.  */
195 struct cgraph_edge_hook_list *first_cgraph_edge_removal_hook;
196 /* List of hooks triggered when a node is removed.  */
197 struct cgraph_node_hook_list *first_cgraph_node_removal_hook;
198 /* List of hooks triggered when an edge is duplicated.  */
199 struct cgraph_2edge_hook_list *first_cgraph_edge_duplicated_hook;
200 /* List of hooks triggered when a node is duplicated.  */
201 struct cgraph_2node_hook_list *first_cgraph_node_duplicated_hook;
202 /* List of hooks triggered when an function is inserted.  */
203 struct cgraph_node_hook_list *first_cgraph_function_insertion_hook;
204 
205 /* Head of a linked list of unused (freed) call graph nodes.
206    Do not GTY((delete)) this list so UIDs gets reliably recycled.  */
207 static GTY(()) struct cgraph_node *free_nodes;
208 /* Head of a linked list of unused (freed) call graph edges.
209    Do not GTY((delete)) this list so UIDs gets reliably recycled.  */
210 static GTY(()) struct cgraph_edge *free_edges;
211 
212 /* Did procss_same_body_aliases run?  */
213 bool same_body_aliases_done;
214 
215 /* Macros to access the next item in the list of free cgraph nodes and
216    edges. */
217 #define NEXT_FREE_NODE(NODE) (NODE)->next
218 #define NEXT_FREE_EDGE(EDGE) (EDGE)->prev_caller
219 
220 /* Register HOOK to be called with DATA on each removed edge.  */
221 struct cgraph_edge_hook_list *
222 cgraph_add_edge_removal_hook (cgraph_edge_hook hook, void *data)
223 {
224   struct cgraph_edge_hook_list *entry;
225   struct cgraph_edge_hook_list **ptr = &first_cgraph_edge_removal_hook;
226 
227   entry = (struct cgraph_edge_hook_list *) xmalloc (sizeof (*entry));
228   entry->hook = hook;
229   entry->data = data;
230   entry->next = NULL;
231   while (*ptr)
232     ptr = &(*ptr)->next;
233   *ptr = entry;
234   return entry;
235 }
236 
237 /* Remove ENTRY from the list of hooks called on removing edges.  */
238 void
239 cgraph_remove_edge_removal_hook (struct cgraph_edge_hook_list *entry)
240 {
241   struct cgraph_edge_hook_list **ptr = &first_cgraph_edge_removal_hook;
242 
243   while (*ptr != entry)
244     ptr = &(*ptr)->next;
245   *ptr = entry->next;
246   free (entry);
247 }
248 
249 /* Call all edge removal hooks.  */
250 static void
251 cgraph_call_edge_removal_hooks (struct cgraph_edge *e)
252 {
253   struct cgraph_edge_hook_list *entry = first_cgraph_edge_removal_hook;
254   while (entry)
255   {
256     entry->hook (e, entry->data);
257     entry = entry->next;
258   }
259 }
260 
261 /* Register HOOK to be called with DATA on each removed node.  */
262 struct cgraph_node_hook_list *
263 cgraph_add_node_removal_hook (cgraph_node_hook hook, void *data)
264 {
265   struct cgraph_node_hook_list *entry;
266   struct cgraph_node_hook_list **ptr = &first_cgraph_node_removal_hook;
267 
268   entry = (struct cgraph_node_hook_list *) xmalloc (sizeof (*entry));
269   entry->hook = hook;
270   entry->data = data;
271   entry->next = NULL;
272   while (*ptr)
273     ptr = &(*ptr)->next;
274   *ptr = entry;
275   return entry;
276 }
277 
278 /* Remove ENTRY from the list of hooks called on removing nodes.  */
279 void
280 cgraph_remove_node_removal_hook (struct cgraph_node_hook_list *entry)
281 {
282   struct cgraph_node_hook_list **ptr = &first_cgraph_node_removal_hook;
283 
284   while (*ptr != entry)
285     ptr = &(*ptr)->next;
286   *ptr = entry->next;
287   free (entry);
288 }
289 
290 /* Call all node removal hooks.  */
291 static void
292 cgraph_call_node_removal_hooks (struct cgraph_node *node)
293 {
294   struct cgraph_node_hook_list *entry = first_cgraph_node_removal_hook;
295   while (entry)
296   {
297     entry->hook (node, entry->data);
298     entry = entry->next;
299   }
300 }
301 
302 /* Register HOOK to be called with DATA on each inserted node.  */
303 struct cgraph_node_hook_list *
304 cgraph_add_function_insertion_hook (cgraph_node_hook hook, void *data)
305 {
306   struct cgraph_node_hook_list *entry;
307   struct cgraph_node_hook_list **ptr = &first_cgraph_function_insertion_hook;
308 
309   entry = (struct cgraph_node_hook_list *) xmalloc (sizeof (*entry));
310   entry->hook = hook;
311   entry->data = data;
312   entry->next = NULL;
313   while (*ptr)
314     ptr = &(*ptr)->next;
315   *ptr = entry;
316   return entry;
317 }
318 
319 /* Remove ENTRY from the list of hooks called on inserted nodes.  */
320 void
321 cgraph_remove_function_insertion_hook (struct cgraph_node_hook_list *entry)
322 {
323   struct cgraph_node_hook_list **ptr = &first_cgraph_function_insertion_hook;
324 
325   while (*ptr != entry)
326     ptr = &(*ptr)->next;
327   *ptr = entry->next;
328   free (entry);
329 }
330 
331 /* Call all node insertion hooks.  */
332 void
333 cgraph_call_function_insertion_hooks (struct cgraph_node *node)
334 {
335   struct cgraph_node_hook_list *entry = first_cgraph_function_insertion_hook;
336   while (entry)
337   {
338     entry->hook (node, entry->data);
339     entry = entry->next;
340   }
341 }
342 
343 /* Register HOOK to be called with DATA on each duplicated edge.  */
344 struct cgraph_2edge_hook_list *
345 cgraph_add_edge_duplication_hook (cgraph_2edge_hook hook, void *data)
346 {
347   struct cgraph_2edge_hook_list *entry;
348   struct cgraph_2edge_hook_list **ptr = &first_cgraph_edge_duplicated_hook;
349 
350   entry = (struct cgraph_2edge_hook_list *) xmalloc (sizeof (*entry));
351   entry->hook = hook;
352   entry->data = data;
353   entry->next = NULL;
354   while (*ptr)
355     ptr = &(*ptr)->next;
356   *ptr = entry;
357   return entry;
358 }
359 
360 /* Remove ENTRY from the list of hooks called on duplicating edges.  */
361 void
362 cgraph_remove_edge_duplication_hook (struct cgraph_2edge_hook_list *entry)
363 {
364   struct cgraph_2edge_hook_list **ptr = &first_cgraph_edge_duplicated_hook;
365 
366   while (*ptr != entry)
367     ptr = &(*ptr)->next;
368   *ptr = entry->next;
369   free (entry);
370 }
371 
372 /* Call all edge duplication hooks.  */
373 static void
374 cgraph_call_edge_duplication_hooks (struct cgraph_edge *cs1,
375 				    struct cgraph_edge *cs2)
376 {
377   struct cgraph_2edge_hook_list *entry = first_cgraph_edge_duplicated_hook;
378   while (entry)
379   {
380     entry->hook (cs1, cs2, entry->data);
381     entry = entry->next;
382   }
383 }
384 
385 /* Register HOOK to be called with DATA on each duplicated node.  */
386 struct cgraph_2node_hook_list *
387 cgraph_add_node_duplication_hook (cgraph_2node_hook hook, void *data)
388 {
389   struct cgraph_2node_hook_list *entry;
390   struct cgraph_2node_hook_list **ptr = &first_cgraph_node_duplicated_hook;
391 
392   entry = (struct cgraph_2node_hook_list *) xmalloc (sizeof (*entry));
393   entry->hook = hook;
394   entry->data = data;
395   entry->next = NULL;
396   while (*ptr)
397     ptr = &(*ptr)->next;
398   *ptr = entry;
399   return entry;
400 }
401 
402 /* Remove ENTRY from the list of hooks called on duplicating nodes.  */
403 void
404 cgraph_remove_node_duplication_hook (struct cgraph_2node_hook_list *entry)
405 {
406   struct cgraph_2node_hook_list **ptr = &first_cgraph_node_duplicated_hook;
407 
408   while (*ptr != entry)
409     ptr = &(*ptr)->next;
410   *ptr = entry->next;
411   free (entry);
412 }
413 
414 /* Call all node duplication hooks.  */
415 void
416 cgraph_call_node_duplication_hooks (struct cgraph_node *node1,
417 				    struct cgraph_node *node2)
418 {
419   struct cgraph_2node_hook_list *entry = first_cgraph_node_duplicated_hook;
420   while (entry)
421   {
422     entry->hook (node1, node2, entry->data);
423     entry = entry->next;
424   }
425 }
426 
427 /* Returns a hash code for P.  */
428 
429 static hashval_t
430 hash_node (const void *p)
431 {
432   const struct cgraph_node *n = (const struct cgraph_node *) p;
433   return (hashval_t) DECL_UID (n->decl);
434 }
435 
436 
437 /* Returns nonzero if P1 and P2 are equal.  */
438 
439 static int
440 eq_node (const void *p1, const void *p2)
441 {
442   const struct cgraph_node *n1 = (const struct cgraph_node *) p1;
443   const struct cgraph_node *n2 = (const struct cgraph_node *) p2;
444   return DECL_UID (n1->decl) == DECL_UID (n2->decl);
445 }
446 
447 /* Allocate new callgraph node.  */
448 
449 static inline struct cgraph_node *
450 cgraph_allocate_node (void)
451 {
452   struct cgraph_node *node;
453 
454   if (free_nodes)
455     {
456       node = free_nodes;
457       free_nodes = NEXT_FREE_NODE (node);
458     }
459   else
460     {
461       node = ggc_alloc_cleared_cgraph_node ();
462       node->uid = cgraph_max_uid++;
463     }
464 
465   return node;
466 }
467 
468 /* Allocate new callgraph node and insert it into basic data structures.  */
469 
470 static struct cgraph_node *
471 cgraph_create_node_1 (void)
472 {
473   struct cgraph_node *node = cgraph_allocate_node ();
474 
475   node->next = cgraph_nodes;
476   node->order = cgraph_order++;
477   if (cgraph_nodes)
478     cgraph_nodes->previous = node;
479   node->previous = NULL;
480   node->frequency = NODE_FREQUENCY_NORMAL;
481   node->count_materialization_scale = REG_BR_PROB_BASE;
482   ipa_empty_ref_list (&node->ref_list);
483   cgraph_nodes = node;
484   cgraph_n_nodes++;
485   return node;
486 }
487 
488 /* Return cgraph node assigned to DECL.  Create new one when needed.  */
489 
490 struct cgraph_node *
491 cgraph_create_node (tree decl)
492 {
493   struct cgraph_node key, *node, **slot;
494 
495   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
496 
497   if (!cgraph_hash)
498     cgraph_hash = htab_create_ggc (10, hash_node, eq_node, NULL);
499 
500   key.decl = decl;
501   slot = (struct cgraph_node **) htab_find_slot (cgraph_hash, &key, INSERT);
502   gcc_assert (!*slot);
503 
504   node = cgraph_create_node_1 ();
505   node->decl = decl;
506   *slot = node;
507   if (DECL_CONTEXT (decl) && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL)
508     {
509       node->origin = cgraph_get_create_node (DECL_CONTEXT (decl));
510       node->next_nested = node->origin->nested;
511       node->origin->nested = node;
512     }
513   if (assembler_name_hash)
514     {
515       void **aslot;
516       tree name = DECL_ASSEMBLER_NAME (decl);
517 
518       aslot = htab_find_slot_with_hash (assembler_name_hash, name,
519 					decl_assembler_name_hash (name),
520 					INSERT);
521       /* We can have multiple declarations with same assembler name. For C++
522 	 it is __builtin_strlen and strlen, for instance.  Do we need to
523 	 record them all?  Original implementation marked just first one
524 	 so lets hope for the best.  */
525       if (*aslot == NULL)
526 	*aslot = node;
527     }
528   return node;
529 }
530 
531 /* Try to find a call graph node for declaration DECL and if it does not exist,
532    create it.  */
533 
534 struct cgraph_node *
535 cgraph_get_create_node (tree decl)
536 {
537   struct cgraph_node *node;
538 
539   node = cgraph_get_node (decl);
540   if (node)
541     return node;
542 
543   return cgraph_create_node (decl);
544 }
545 
546 /* Mark ALIAS as an alias to DECL.  DECL_NODE is cgraph node representing
547    the function body is associated with (not neccesarily cgraph_node (DECL).  */
548 
549 struct cgraph_node *
550 cgraph_create_function_alias (tree alias, tree decl)
551 {
552   struct cgraph_node *alias_node;
553 
554   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
555   gcc_assert (TREE_CODE (alias) == FUNCTION_DECL);
556   alias_node = cgraph_get_create_node (alias);
557   gcc_assert (!alias_node->local.finalized);
558   alias_node->thunk.alias = decl;
559   alias_node->local.finalized = true;
560   alias_node->alias = 1;
561 
562   if ((TREE_PUBLIC (alias) && !DECL_COMDAT (alias) && !DECL_EXTERNAL (alias))
563       || (DECL_VIRTUAL_P (alias)
564 	  && (DECL_COMDAT (alias) || DECL_EXTERNAL (alias))))
565     cgraph_mark_reachable_node (alias_node);
566   return alias_node;
567 }
568 
569 /* Attempt to mark ALIAS as an alias to DECL.  Return alias node if successful
570    and NULL otherwise.
571    Same body aliases are output whenever the body of DECL is output,
572    and cgraph_get_node (ALIAS) transparently returns cgraph_get_node (DECL).  */
573 
574 struct cgraph_node *
575 cgraph_same_body_alias (struct cgraph_node *decl_node ATTRIBUTE_UNUSED, tree alias, tree decl)
576 {
577   struct cgraph_node *n;
578 #ifndef ASM_OUTPUT_DEF
579   /* If aliases aren't supported by the assembler, fail.  */
580   return NULL;
581 #endif
582   /* Langhooks can create same body aliases of symbols not defined.
583      Those are useless. Drop them on the floor.  */
584   if (cgraph_global_info_ready)
585     return NULL;
586 
587   n = cgraph_create_function_alias (alias, decl);
588   n->same_body_alias = true;
589   if (same_body_aliases_done)
590     ipa_record_reference (n, NULL, cgraph_get_node (decl), NULL, IPA_REF_ALIAS,
591 			  NULL);
592   return n;
593 }
594 
595 /* Add thunk alias into callgraph.  The alias declaration is ALIAS and it
596    aliases DECL with an adjustments made into the first parameter.
597    See comments in thunk_adjust for detail on the parameters.  */
598 
599 struct cgraph_node *
600 cgraph_add_thunk (struct cgraph_node *decl_node ATTRIBUTE_UNUSED,
601 		  tree alias, tree decl,
602 		  bool this_adjusting,
603 		  HOST_WIDE_INT fixed_offset, HOST_WIDE_INT virtual_value,
604 		  tree virtual_offset,
605 		  tree real_alias)
606 {
607   struct cgraph_node *node;
608 
609   node = cgraph_get_node (alias);
610   if (node)
611     {
612       gcc_assert (node->local.finalized);
613       gcc_assert (!node->alias);
614       gcc_assert (!node->thunk.thunk_p);
615       cgraph_remove_node (node);
616     }
617 
618   node = cgraph_create_node (alias);
619   gcc_checking_assert (!virtual_offset
620 		       || double_int_equal_p
621 		            (tree_to_double_int (virtual_offset),
622 			     shwi_to_double_int (virtual_value)));
623   node->thunk.fixed_offset = fixed_offset;
624   node->thunk.this_adjusting = this_adjusting;
625   node->thunk.virtual_value = virtual_value;
626   node->thunk.virtual_offset_p = virtual_offset != NULL;
627   node->thunk.alias = real_alias;
628   node->thunk.thunk_p = true;
629   node->local.finalized = true;
630 
631   if (cgraph_decide_is_function_needed (node, decl))
632     cgraph_mark_needed_node (node);
633 
634   if ((TREE_PUBLIC (decl) && !DECL_COMDAT (decl) && !DECL_EXTERNAL (decl))
635       || (DECL_VIRTUAL_P (decl)
636 	  && (DECL_COMDAT (decl) || DECL_EXTERNAL (decl))))
637     cgraph_mark_reachable_node (node);
638 
639   return node;
640 }
641 
642 /* Returns the cgraph node assigned to DECL or NULL if no cgraph node
643    is assigned.  */
644 
645 struct cgraph_node *
646 cgraph_get_node (const_tree decl)
647 {
648   struct cgraph_node key, *node = NULL, **slot;
649 
650   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
651 
652   if (!cgraph_hash)
653     return NULL;
654 
655   key.decl = CONST_CAST2 (tree, const_tree, decl);
656 
657   slot = (struct cgraph_node **) htab_find_slot (cgraph_hash, &key,
658 						 NO_INSERT);
659 
660   if (slot && *slot)
661     node = *slot;
662   return node;
663 }
664 
665 /* Insert already constructed node into hashtable.  */
666 
667 void
668 cgraph_insert_node_to_hashtable (struct cgraph_node *node)
669 {
670   struct cgraph_node **slot;
671 
672   slot = (struct cgraph_node **) htab_find_slot (cgraph_hash, node, INSERT);
673 
674   gcc_assert (!*slot);
675   *slot = node;
676 }
677 
678 /* Returns a hash code for P.  */
679 
680 static hashval_t
681 hash_node_by_assembler_name (const void *p)
682 {
683   const struct cgraph_node *n = (const struct cgraph_node *) p;
684   return (hashval_t) decl_assembler_name_hash (DECL_ASSEMBLER_NAME (n->decl));
685 }
686 
687 /* Returns nonzero if P1 and P2 are equal.  */
688 
689 static int
690 eq_assembler_name (const void *p1, const void *p2)
691 {
692   const struct cgraph_node *n1 = (const struct cgraph_node *) p1;
693   const_tree name = (const_tree)p2;
694   return (decl_assembler_name_equal (n1->decl, name));
695 }
696 
697 /* Return the cgraph node that has ASMNAME for its DECL_ASSEMBLER_NAME.
698    Return NULL if there's no such node.  */
699 
700 struct cgraph_node *
701 cgraph_node_for_asm (tree asmname)
702 {
703   struct cgraph_node *node;
704   void **slot;
705 
706   if (!assembler_name_hash)
707     {
708       assembler_name_hash =
709 	htab_create_ggc (10, hash_node_by_assembler_name, eq_assembler_name,
710 			 NULL);
711       for (node = cgraph_nodes; node; node = node->next)
712         if (!node->global.inlined_to)
713 	  {
714 	    tree name = DECL_ASSEMBLER_NAME (node->decl);
715 	    slot = htab_find_slot_with_hash (assembler_name_hash, name,
716 					     decl_assembler_name_hash (name),
717 					     INSERT);
718 	    /* We can have multiple declarations with same assembler name. For C++
719 	       it is __builtin_strlen and strlen, for instance.  Do we need to
720 	       record them all?  Original implementation marked just first one
721 	       so lets hope for the best.  */
722 	    if (!*slot)
723 	      *slot = node;
724 	  }
725     }
726 
727   slot = htab_find_slot_with_hash (assembler_name_hash, asmname,
728 				   decl_assembler_name_hash (asmname),
729 				   NO_INSERT);
730 
731   if (slot)
732     {
733       node = (struct cgraph_node *) *slot;
734       return node;
735     }
736   return NULL;
737 }
738 
739 /* Returns a hash value for X (which really is a die_struct).  */
740 
741 static hashval_t
742 edge_hash (const void *x)
743 {
744   return htab_hash_pointer (((const struct cgraph_edge *) x)->call_stmt);
745 }
746 
747 /* Return nonzero if decl_id of die_struct X is the same as UID of decl *Y.  */
748 
749 static int
750 edge_eq (const void *x, const void *y)
751 {
752   return ((const struct cgraph_edge *) x)->call_stmt == y;
753 }
754 
755 /* Add call graph edge E to call site hash of its caller.  */
756 
757 static inline void
758 cgraph_add_edge_to_call_site_hash (struct cgraph_edge *e)
759 {
760   void **slot;
761   slot = htab_find_slot_with_hash (e->caller->call_site_hash,
762 				   e->call_stmt,
763 				   htab_hash_pointer (e->call_stmt),
764 				   INSERT);
765   gcc_assert (!*slot);
766   *slot = e;
767 }
768 
769 /* Return the callgraph edge representing the GIMPLE_CALL statement
770    CALL_STMT.  */
771 
772 struct cgraph_edge *
773 cgraph_edge (struct cgraph_node *node, gimple call_stmt)
774 {
775   struct cgraph_edge *e, *e2;
776   int n = 0;
777 
778   if (node->call_site_hash)
779     return (struct cgraph_edge *)
780       htab_find_with_hash (node->call_site_hash, call_stmt,
781       	                   htab_hash_pointer (call_stmt));
782 
783   /* This loop may turn out to be performance problem.  In such case adding
784      hashtables into call nodes with very many edges is probably best
785      solution.  It is not good idea to add pointer into CALL_EXPR itself
786      because we want to make possible having multiple cgraph nodes representing
787      different clones of the same body before the body is actually cloned.  */
788   for (e = node->callees; e; e = e->next_callee)
789     {
790       if (e->call_stmt == call_stmt)
791 	break;
792       n++;
793     }
794 
795   if (!e)
796     for (e = node->indirect_calls; e; e = e->next_callee)
797       {
798 	if (e->call_stmt == call_stmt)
799 	  break;
800 	n++;
801       }
802 
803   if (n > 100)
804     {
805       node->call_site_hash = htab_create_ggc (120, edge_hash, edge_eq, NULL);
806       for (e2 = node->callees; e2; e2 = e2->next_callee)
807 	cgraph_add_edge_to_call_site_hash (e2);
808       for (e2 = node->indirect_calls; e2; e2 = e2->next_callee)
809 	cgraph_add_edge_to_call_site_hash (e2);
810     }
811 
812   return e;
813 }
814 
815 
816 /* Change field call_stmt of edge E to NEW_STMT.  */
817 
818 void
819 cgraph_set_call_stmt (struct cgraph_edge *e, gimple new_stmt)
820 {
821   tree decl;
822 
823   if (e->caller->call_site_hash)
824     {
825       htab_remove_elt_with_hash (e->caller->call_site_hash,
826 				 e->call_stmt,
827 				 htab_hash_pointer (e->call_stmt));
828     }
829 
830   e->call_stmt = new_stmt;
831   if (e->indirect_unknown_callee
832       && (decl = gimple_call_fndecl (new_stmt)))
833     {
834       /* Constant propagation (and possibly also inlining?) can turn an
835 	 indirect call into a direct one.  */
836       struct cgraph_node *new_callee = cgraph_get_node (decl);
837 
838       gcc_checking_assert (new_callee);
839       cgraph_make_edge_direct (e, new_callee);
840     }
841 
842   push_cfun (DECL_STRUCT_FUNCTION (e->caller->decl));
843   e->can_throw_external = stmt_can_throw_external (new_stmt);
844   pop_cfun ();
845   if (e->caller->call_site_hash)
846     cgraph_add_edge_to_call_site_hash (e);
847 }
848 
849 /* Like cgraph_set_call_stmt but walk the clone tree and update all
850    clones sharing the same function body.  */
851 
852 void
853 cgraph_set_call_stmt_including_clones (struct cgraph_node *orig,
854 				       gimple old_stmt, gimple new_stmt)
855 {
856   struct cgraph_node *node;
857   struct cgraph_edge *edge = cgraph_edge (orig, old_stmt);
858 
859   if (edge)
860     cgraph_set_call_stmt (edge, new_stmt);
861 
862   node = orig->clones;
863   if (node)
864     while (node != orig)
865       {
866 	struct cgraph_edge *edge = cgraph_edge (node, old_stmt);
867 	if (edge)
868 	  cgraph_set_call_stmt (edge, new_stmt);
869 	if (node->clones)
870 	  node = node->clones;
871 	else if (node->next_sibling_clone)
872 	  node = node->next_sibling_clone;
873 	else
874 	  {
875 	    while (node != orig && !node->next_sibling_clone)
876 	      node = node->clone_of;
877 	    if (node != orig)
878 	      node = node->next_sibling_clone;
879 	  }
880       }
881 }
882 
883 /* Like cgraph_create_edge walk the clone tree and update all clones sharing
884    same function body.  If clones already have edge for OLD_STMT; only
885    update the edge same way as cgraph_set_call_stmt_including_clones does.
886 
887    TODO: COUNT and LOOP_DEPTH should be properly distributed based on relative
888    frequencies of the clones.  */
889 
890 void
891 cgraph_create_edge_including_clones (struct cgraph_node *orig,
892 				     struct cgraph_node *callee,
893 				     gimple old_stmt,
894 				     gimple stmt, gcov_type count,
895 				     int freq,
896 				     cgraph_inline_failed_t reason)
897 {
898   struct cgraph_node *node;
899   struct cgraph_edge *edge;
900 
901   if (!cgraph_edge (orig, stmt))
902     {
903       edge = cgraph_create_edge (orig, callee, stmt, count, freq);
904       edge->inline_failed = reason;
905     }
906 
907   node = orig->clones;
908   if (node)
909     while (node != orig)
910       {
911 	struct cgraph_edge *edge = cgraph_edge (node, old_stmt);
912 
913         /* It is possible that clones already contain the edge while
914 	   master didn't.  Either we promoted indirect call into direct
915 	   call in the clone or we are processing clones of unreachable
916 	   master where edges has been removed.  */
917 	if (edge)
918 	  cgraph_set_call_stmt (edge, stmt);
919 	else if (!cgraph_edge (node, stmt))
920 	  {
921 	    edge = cgraph_create_edge (node, callee, stmt, count,
922 				       freq);
923 	    edge->inline_failed = reason;
924 	  }
925 
926 	if (node->clones)
927 	  node = node->clones;
928 	else if (node->next_sibling_clone)
929 	  node = node->next_sibling_clone;
930 	else
931 	  {
932 	    while (node != orig && !node->next_sibling_clone)
933 	      node = node->clone_of;
934 	    if (node != orig)
935 	      node = node->next_sibling_clone;
936 	  }
937       }
938 }
939 
940 /* Allocate a cgraph_edge structure and fill it with data according to the
941    parameters of which only CALLEE can be NULL (when creating an indirect call
942    edge).  */
943 
944 static struct cgraph_edge *
945 cgraph_create_edge_1 (struct cgraph_node *caller, struct cgraph_node *callee,
946 		       gimple call_stmt, gcov_type count, int freq)
947 {
948   struct cgraph_edge *edge;
949 
950   /* LTO does not actually have access to the call_stmt since these
951      have not been loaded yet.  */
952   if (call_stmt)
953     {
954       /* This is a rather expensive check possibly triggering
955 	 construction of call stmt hashtable.  */
956       gcc_checking_assert (!cgraph_edge (caller, call_stmt));
957 
958       gcc_assert (is_gimple_call (call_stmt));
959     }
960 
961   if (free_edges)
962     {
963       edge = free_edges;
964       free_edges = NEXT_FREE_EDGE (edge);
965     }
966   else
967     {
968       edge = ggc_alloc_cgraph_edge ();
969       edge->uid = cgraph_edge_max_uid++;
970     }
971 
972   edge->aux = NULL;
973   edge->caller = caller;
974   edge->callee = callee;
975   edge->prev_caller = NULL;
976   edge->next_caller = NULL;
977   edge->prev_callee = NULL;
978   edge->next_callee = NULL;
979 
980   edge->count = count;
981   gcc_assert (count >= 0);
982   edge->frequency = freq;
983   gcc_assert (freq >= 0);
984   gcc_assert (freq <= CGRAPH_FREQ_MAX);
985 
986   edge->call_stmt = call_stmt;
987   push_cfun (DECL_STRUCT_FUNCTION (caller->decl));
988   edge->can_throw_external
989     = call_stmt ? stmt_can_throw_external (call_stmt) : false;
990   pop_cfun ();
991   if (call_stmt
992       && callee && callee->decl
993       && !gimple_check_call_matching_types (call_stmt, callee->decl))
994     edge->call_stmt_cannot_inline_p = true;
995   else
996     edge->call_stmt_cannot_inline_p = false;
997   if (call_stmt && caller->call_site_hash)
998     cgraph_add_edge_to_call_site_hash (edge);
999 
1000   edge->indirect_info = NULL;
1001   edge->indirect_inlining_edge = 0;
1002 
1003   return edge;
1004 }
1005 
1006 /* Create edge from CALLER to CALLEE in the cgraph.  */
1007 
1008 struct cgraph_edge *
1009 cgraph_create_edge (struct cgraph_node *caller, struct cgraph_node *callee,
1010 		    gimple call_stmt, gcov_type count, int freq)
1011 {
1012   struct cgraph_edge *edge = cgraph_create_edge_1 (caller, callee, call_stmt,
1013 						   count, freq);
1014 
1015   edge->indirect_unknown_callee = 0;
1016   initialize_inline_failed (edge);
1017 
1018   edge->next_caller = callee->callers;
1019   if (callee->callers)
1020     callee->callers->prev_caller = edge;
1021   edge->next_callee = caller->callees;
1022   if (caller->callees)
1023     caller->callees->prev_callee = edge;
1024   caller->callees = edge;
1025   callee->callers = edge;
1026 
1027   return edge;
1028 }
1029 
1030 /* Allocate cgraph_indirect_call_info and set its fields to default values. */
1031 
1032 struct cgraph_indirect_call_info *
1033 cgraph_allocate_init_indirect_info (void)
1034 {
1035   struct cgraph_indirect_call_info *ii;
1036 
1037   ii = ggc_alloc_cleared_cgraph_indirect_call_info ();
1038   ii->param_index = -1;
1039   return ii;
1040 }
1041 
1042 /* Create an indirect edge with a yet-undetermined callee where the call
1043    statement destination is a formal parameter of the caller with index
1044    PARAM_INDEX. */
1045 
1046 struct cgraph_edge *
1047 cgraph_create_indirect_edge (struct cgraph_node *caller, gimple call_stmt,
1048 			     int ecf_flags,
1049 			     gcov_type count, int freq)
1050 {
1051   struct cgraph_edge *edge = cgraph_create_edge_1 (caller, NULL, call_stmt,
1052 						   count, freq);
1053 
1054   edge->indirect_unknown_callee = 1;
1055   initialize_inline_failed (edge);
1056 
1057   edge->indirect_info = cgraph_allocate_init_indirect_info ();
1058   edge->indirect_info->ecf_flags = ecf_flags;
1059 
1060   edge->next_callee = caller->indirect_calls;
1061   if (caller->indirect_calls)
1062     caller->indirect_calls->prev_callee = edge;
1063   caller->indirect_calls = edge;
1064 
1065   return edge;
1066 }
1067 
1068 /* Remove the edge E from the list of the callers of the callee.  */
1069 
1070 static inline void
1071 cgraph_edge_remove_callee (struct cgraph_edge *e)
1072 {
1073   gcc_assert (!e->indirect_unknown_callee);
1074   if (e->prev_caller)
1075     e->prev_caller->next_caller = e->next_caller;
1076   if (e->next_caller)
1077     e->next_caller->prev_caller = e->prev_caller;
1078   if (!e->prev_caller)
1079     e->callee->callers = e->next_caller;
1080 }
1081 
1082 /* Remove the edge E from the list of the callees of the caller.  */
1083 
1084 static inline void
1085 cgraph_edge_remove_caller (struct cgraph_edge *e)
1086 {
1087   if (e->prev_callee)
1088     e->prev_callee->next_callee = e->next_callee;
1089   if (e->next_callee)
1090     e->next_callee->prev_callee = e->prev_callee;
1091   if (!e->prev_callee)
1092     {
1093       if (e->indirect_unknown_callee)
1094 	e->caller->indirect_calls = e->next_callee;
1095       else
1096 	e->caller->callees = e->next_callee;
1097     }
1098   if (e->caller->call_site_hash)
1099     htab_remove_elt_with_hash (e->caller->call_site_hash,
1100 			       e->call_stmt,
1101 	  		       htab_hash_pointer (e->call_stmt));
1102 }
1103 
1104 /* Put the edge onto the free list.  */
1105 
1106 static void
1107 cgraph_free_edge (struct cgraph_edge *e)
1108 {
1109   int uid = e->uid;
1110 
1111   /* Clear out the edge so we do not dangle pointers.  */
1112   memset (e, 0, sizeof (*e));
1113   e->uid = uid;
1114   NEXT_FREE_EDGE (e) = free_edges;
1115   free_edges = e;
1116 }
1117 
1118 /* Remove the edge E in the cgraph.  */
1119 
1120 void
1121 cgraph_remove_edge (struct cgraph_edge *e)
1122 {
1123   /* Call all edge removal hooks.  */
1124   cgraph_call_edge_removal_hooks (e);
1125 
1126   if (!e->indirect_unknown_callee)
1127     /* Remove from callers list of the callee.  */
1128     cgraph_edge_remove_callee (e);
1129 
1130   /* Remove from callees list of the callers.  */
1131   cgraph_edge_remove_caller (e);
1132 
1133   /* Put the edge onto the free list.  */
1134   cgraph_free_edge (e);
1135 }
1136 
1137 /* Set callee of call graph edge E and add it to the corresponding set of
1138    callers. */
1139 
1140 static void
1141 cgraph_set_edge_callee (struct cgraph_edge *e, struct cgraph_node *n)
1142 {
1143   e->prev_caller = NULL;
1144   if (n->callers)
1145     n->callers->prev_caller = e;
1146   e->next_caller = n->callers;
1147   n->callers = e;
1148   e->callee = n;
1149 }
1150 
1151 /* Redirect callee of E to N.  The function does not update underlying
1152    call expression.  */
1153 
1154 void
1155 cgraph_redirect_edge_callee (struct cgraph_edge *e, struct cgraph_node *n)
1156 {
1157   /* Remove from callers list of the current callee.  */
1158   cgraph_edge_remove_callee (e);
1159 
1160   /* Insert to callers list of the new callee.  */
1161   cgraph_set_edge_callee (e, n);
1162 }
1163 
1164 /* Make an indirect EDGE with an unknown callee an ordinary edge leading to
1165    CALLEE.  DELTA is an integer constant that is to be added to the this
1166    pointer (first parameter) to compensate for skipping a thunk adjustment.  */
1167 
1168 void
1169 cgraph_make_edge_direct (struct cgraph_edge *edge, struct cgraph_node *callee)
1170 {
1171   edge->indirect_unknown_callee = 0;
1172 
1173   /* Get the edge out of the indirect edge list. */
1174   if (edge->prev_callee)
1175     edge->prev_callee->next_callee = edge->next_callee;
1176   if (edge->next_callee)
1177     edge->next_callee->prev_callee = edge->prev_callee;
1178   if (!edge->prev_callee)
1179     edge->caller->indirect_calls = edge->next_callee;
1180 
1181   /* Put it into the normal callee list */
1182   edge->prev_callee = NULL;
1183   edge->next_callee = edge->caller->callees;
1184   if (edge->caller->callees)
1185     edge->caller->callees->prev_callee = edge;
1186   edge->caller->callees = edge;
1187 
1188   /* Insert to callers list of the new callee.  */
1189   cgraph_set_edge_callee (edge, callee);
1190 
1191   if (edge->call_stmt)
1192     edge->call_stmt_cannot_inline_p
1193       = !gimple_check_call_matching_types (edge->call_stmt, callee->decl);
1194 
1195   /* We need to re-determine the inlining status of the edge.  */
1196   initialize_inline_failed (edge);
1197 }
1198 
1199 
1200 /* Update or remove the corresponding cgraph edge if a GIMPLE_CALL
1201    OLD_STMT changed into NEW_STMT.  OLD_CALL is gimple_call_fndecl
1202    of OLD_STMT if it was previously call statement.
1203    If NEW_STMT is NULL, the call has been dropped without any
1204    replacement.  */
1205 
1206 static void
1207 cgraph_update_edges_for_call_stmt_node (struct cgraph_node *node,
1208 					gimple old_stmt, tree old_call,
1209 					gimple new_stmt)
1210 {
1211   tree new_call = (new_stmt && is_gimple_call (new_stmt))
1212 		  ? gimple_call_fndecl (new_stmt) : 0;
1213 
1214   /* We are seeing indirect calls, then there is nothing to update.  */
1215   if (!new_call && !old_call)
1216     return;
1217   /* See if we turned indirect call into direct call or folded call to one builtin
1218      into different builtin.  */
1219   if (old_call != new_call)
1220     {
1221       struct cgraph_edge *e = cgraph_edge (node, old_stmt);
1222       struct cgraph_edge *ne = NULL;
1223       gcov_type count;
1224       int frequency;
1225 
1226       if (e)
1227 	{
1228 	  /* See if the edge is already there and has the correct callee.  It
1229 	     might be so because of indirect inlining has already updated
1230 	     it.  We also might've cloned and redirected the edge.  */
1231 	  if (new_call && e->callee)
1232 	    {
1233 	      struct cgraph_node *callee = e->callee;
1234 	      while (callee)
1235 		{
1236 		  if (callee->decl == new_call
1237 		      || callee->former_clone_of == new_call)
1238 		    return;
1239 		  callee = callee->clone_of;
1240 		}
1241 	    }
1242 
1243 	  /* Otherwise remove edge and create new one; we can't simply redirect
1244 	     since function has changed, so inline plan and other information
1245 	     attached to edge is invalid.  */
1246 	  count = e->count;
1247 	  frequency = e->frequency;
1248 	  cgraph_remove_edge (e);
1249 	}
1250       else if (new_call)
1251 	{
1252 	  /* We are seeing new direct call; compute profile info based on BB.  */
1253 	  basic_block bb = gimple_bb (new_stmt);
1254 	  count = bb->count;
1255 	  frequency = compute_call_stmt_bb_frequency (current_function_decl,
1256 						      bb);
1257 	}
1258 
1259       if (new_call)
1260 	{
1261 	  ne = cgraph_create_edge (node, cgraph_get_create_node (new_call),
1262 				   new_stmt, count, frequency);
1263 	  gcc_assert (ne->inline_failed);
1264 	}
1265     }
1266   /* We only updated the call stmt; update pointer in cgraph edge..  */
1267   else if (old_stmt != new_stmt)
1268     cgraph_set_call_stmt (cgraph_edge (node, old_stmt), new_stmt);
1269 }
1270 
1271 /* Update or remove the corresponding cgraph edge if a GIMPLE_CALL
1272    OLD_STMT changed into NEW_STMT.  OLD_DECL is gimple_call_fndecl
1273    of OLD_STMT before it was updated (updating can happen inplace).  */
1274 
1275 void
1276 cgraph_update_edges_for_call_stmt (gimple old_stmt, tree old_decl, gimple new_stmt)
1277 {
1278   struct cgraph_node *orig = cgraph_get_node (cfun->decl);
1279   struct cgraph_node *node;
1280 
1281   gcc_checking_assert (orig);
1282   cgraph_update_edges_for_call_stmt_node (orig, old_stmt, old_decl, new_stmt);
1283   if (orig->clones)
1284     for (node = orig->clones; node != orig;)
1285       {
1286         cgraph_update_edges_for_call_stmt_node (node, old_stmt, old_decl, new_stmt);
1287 	if (node->clones)
1288 	  node = node->clones;
1289 	else if (node->next_sibling_clone)
1290 	  node = node->next_sibling_clone;
1291 	else
1292 	  {
1293 	    while (node != orig && !node->next_sibling_clone)
1294 	      node = node->clone_of;
1295 	    if (node != orig)
1296 	      node = node->next_sibling_clone;
1297 	  }
1298       }
1299 }
1300 
1301 
1302 /* Remove all callees from the node.  */
1303 
1304 void
1305 cgraph_node_remove_callees (struct cgraph_node *node)
1306 {
1307   struct cgraph_edge *e, *f;
1308 
1309   /* It is sufficient to remove the edges from the lists of callers of
1310      the callees.  The callee list of the node can be zapped with one
1311      assignment.  */
1312   for (e = node->callees; e; e = f)
1313     {
1314       f = e->next_callee;
1315       cgraph_call_edge_removal_hooks (e);
1316       if (!e->indirect_unknown_callee)
1317 	cgraph_edge_remove_callee (e);
1318       cgraph_free_edge (e);
1319     }
1320   for (e = node->indirect_calls; e; e = f)
1321     {
1322       f = e->next_callee;
1323       cgraph_call_edge_removal_hooks (e);
1324       if (!e->indirect_unknown_callee)
1325 	cgraph_edge_remove_callee (e);
1326       cgraph_free_edge (e);
1327     }
1328   node->indirect_calls = NULL;
1329   node->callees = NULL;
1330   if (node->call_site_hash)
1331     {
1332       htab_delete (node->call_site_hash);
1333       node->call_site_hash = NULL;
1334     }
1335 }
1336 
1337 /* Remove all callers from the node.  */
1338 
1339 static void
1340 cgraph_node_remove_callers (struct cgraph_node *node)
1341 {
1342   struct cgraph_edge *e, *f;
1343 
1344   /* It is sufficient to remove the edges from the lists of callees of
1345      the callers.  The caller list of the node can be zapped with one
1346      assignment.  */
1347   for (e = node->callers; e; e = f)
1348     {
1349       f = e->next_caller;
1350       cgraph_call_edge_removal_hooks (e);
1351       cgraph_edge_remove_caller (e);
1352       cgraph_free_edge (e);
1353     }
1354   node->callers = NULL;
1355 }
1356 
1357 /* Release memory used to represent body of function NODE.  */
1358 
1359 void
1360 cgraph_release_function_body (struct cgraph_node *node)
1361 {
1362   if (DECL_STRUCT_FUNCTION (node->decl))
1363     {
1364       tree old_decl = current_function_decl;
1365       push_cfun (DECL_STRUCT_FUNCTION (node->decl));
1366       if (cfun->gimple_df)
1367 	{
1368 	  current_function_decl = node->decl;
1369 	  delete_tree_ssa ();
1370 	  delete_tree_cfg_annotations ();
1371 	  cfun->eh = NULL;
1372 	  current_function_decl = old_decl;
1373 	}
1374       if (cfun->cfg)
1375 	{
1376 	  gcc_assert (dom_computed[0] == DOM_NONE);
1377 	  gcc_assert (dom_computed[1] == DOM_NONE);
1378 	  clear_edges ();
1379 	}
1380       if (cfun->value_histograms)
1381 	free_histograms ();
1382       gcc_assert (!current_loops);
1383       pop_cfun();
1384       gimple_set_body (node->decl, NULL);
1385       VEC_free (ipa_opt_pass, heap,
1386       		node->ipa_transforms_to_apply);
1387       /* Struct function hangs a lot of data that would leak if we didn't
1388          removed all pointers to it.   */
1389       ggc_free (DECL_STRUCT_FUNCTION (node->decl));
1390       DECL_STRUCT_FUNCTION (node->decl) = NULL;
1391     }
1392   DECL_SAVED_TREE (node->decl) = NULL;
1393   /* If the node is abstract and needed, then do not clear DECL_INITIAL
1394      of its associated function function declaration because it's
1395      needed to emit debug info later.  */
1396   if (!node->abstract_and_needed)
1397     DECL_INITIAL (node->decl) = error_mark_node;
1398 }
1399 
1400 /* Remove the node from cgraph.  */
1401 
1402 void
1403 cgraph_remove_node (struct cgraph_node *node)
1404 {
1405   void **slot;
1406   bool kill_body = false;
1407   struct cgraph_node *n;
1408   int uid = node->uid;
1409 
1410   cgraph_call_node_removal_hooks (node);
1411   cgraph_node_remove_callers (node);
1412   cgraph_node_remove_callees (node);
1413   ipa_remove_all_references (&node->ref_list);
1414   ipa_remove_all_refering (&node->ref_list);
1415   VEC_free (ipa_opt_pass, heap,
1416             node->ipa_transforms_to_apply);
1417 
1418   /* Incremental inlining access removed nodes stored in the postorder list.
1419      */
1420   node->needed = node->reachable = false;
1421   for (n = node->nested; n; n = n->next_nested)
1422     n->origin = NULL;
1423   node->nested = NULL;
1424   if (node->origin)
1425     {
1426       struct cgraph_node **node2 = &node->origin->nested;
1427 
1428       while (*node2 != node)
1429 	node2 = &(*node2)->next_nested;
1430       *node2 = node->next_nested;
1431     }
1432   if (node->previous)
1433     node->previous->next = node->next;
1434   else
1435     cgraph_nodes = node->next;
1436   if (node->next)
1437     node->next->previous = node->previous;
1438   node->next = NULL;
1439   node->previous = NULL;
1440   slot = htab_find_slot (cgraph_hash, node, NO_INSERT);
1441   if (*slot == node)
1442     {
1443       struct cgraph_node *next_inline_clone;
1444 
1445       for (next_inline_clone = node->clones;
1446       	   next_inline_clone && next_inline_clone->decl != node->decl;
1447 	   next_inline_clone = next_inline_clone->next_sibling_clone)
1448 	;
1449 
1450       /* If there is inline clone of the node being removed, we need
1451          to put it into the position of removed node and reorganize all
1452 	 other clones to be based on it.  */
1453       if (next_inline_clone)
1454 	{
1455 	  struct cgraph_node *n;
1456 	  struct cgraph_node *new_clones;
1457 
1458 	  *slot = next_inline_clone;
1459 
1460 	  /* Unlink inline clone from the list of clones of removed node.  */
1461 	  if (next_inline_clone->next_sibling_clone)
1462 	    next_inline_clone->next_sibling_clone->prev_sibling_clone
1463 	      = next_inline_clone->prev_sibling_clone;
1464 	  if (next_inline_clone->prev_sibling_clone)
1465 	    {
1466 	      gcc_assert (node->clones != next_inline_clone);
1467 	      next_inline_clone->prev_sibling_clone->next_sibling_clone
1468 	        = next_inline_clone->next_sibling_clone;
1469 	    }
1470 	  else
1471 	    {
1472 	      gcc_assert (node->clones == next_inline_clone);
1473 	      node->clones = next_inline_clone->next_sibling_clone;
1474 	    }
1475 
1476 	  new_clones = node->clones;
1477 	  node->clones = NULL;
1478 
1479 	  /* Copy clone info.  */
1480 	  next_inline_clone->clone = node->clone;
1481 
1482 	  /* Now place it into clone tree at same level at NODE.  */
1483 	  next_inline_clone->clone_of = node->clone_of;
1484 	  next_inline_clone->prev_sibling_clone = NULL;
1485 	  next_inline_clone->next_sibling_clone = NULL;
1486 	  if (node->clone_of)
1487 	    {
1488 	      if (node->clone_of->clones)
1489 	        node->clone_of->clones->prev_sibling_clone = next_inline_clone;
1490 	      next_inline_clone->next_sibling_clone = node->clone_of->clones;
1491 	      node->clone_of->clones = next_inline_clone;
1492 	    }
1493 
1494 	  /* Merge the clone list.  */
1495 	  if (new_clones)
1496 	    {
1497 	      if (!next_inline_clone->clones)
1498 		next_inline_clone->clones = new_clones;
1499 	      else
1500 		{
1501 		  n = next_inline_clone->clones;
1502 		  while (n->next_sibling_clone)
1503 		    n =  n->next_sibling_clone;
1504 		  n->next_sibling_clone = new_clones;
1505 		  new_clones->prev_sibling_clone = n;
1506 		}
1507 	    }
1508 
1509 	  /* Update clone_of pointers.  */
1510 	  n = new_clones;
1511 	  while (n)
1512 	    {
1513 	      n->clone_of = next_inline_clone;
1514 	      n = n->next_sibling_clone;
1515 	    }
1516 	}
1517       else
1518 	{
1519 	  htab_clear_slot (cgraph_hash, slot);
1520 	  kill_body = true;
1521 	}
1522 
1523     }
1524   if (node->prev_sibling_clone)
1525     node->prev_sibling_clone->next_sibling_clone = node->next_sibling_clone;
1526   else if (node->clone_of)
1527     node->clone_of->clones = node->next_sibling_clone;
1528   if (node->next_sibling_clone)
1529     node->next_sibling_clone->prev_sibling_clone = node->prev_sibling_clone;
1530   if (node->clones)
1531     {
1532       struct cgraph_node *n, *next;
1533 
1534       if (node->clone_of)
1535         {
1536 	  for (n = node->clones; n->next_sibling_clone; n = n->next_sibling_clone)
1537 	    n->clone_of = node->clone_of;
1538 	  n->clone_of = node->clone_of;
1539 	  n->next_sibling_clone = node->clone_of->clones;
1540 	  if (node->clone_of->clones)
1541 	    node->clone_of->clones->prev_sibling_clone = n;
1542 	  node->clone_of->clones = node->clones;
1543 	}
1544       else
1545         {
1546 	  /* We are removing node with clones.  this makes clones inconsistent,
1547 	     but assume they will be removed subsequently and just keep clone
1548 	     tree intact.  This can happen in unreachable function removal since
1549 	     we remove unreachable functions in random order, not by bottom-up
1550 	     walk of clone trees.  */
1551 	  for (n = node->clones; n; n = next)
1552 	    {
1553 	       next = n->next_sibling_clone;
1554 	       n->next_sibling_clone = NULL;
1555 	       n->prev_sibling_clone = NULL;
1556 	       n->clone_of = NULL;
1557 	    }
1558 	}
1559     }
1560 
1561   if (node->same_comdat_group)
1562     {
1563       struct cgraph_node *prev;
1564       for (prev = node->same_comdat_group;
1565 	   prev->same_comdat_group != node;
1566 	   prev = prev->same_comdat_group)
1567 	;
1568       if (node->same_comdat_group == prev)
1569 	prev->same_comdat_group = NULL;
1570       else
1571 	prev->same_comdat_group = node->same_comdat_group;
1572       node->same_comdat_group = NULL;
1573     }
1574 
1575   /* While all the clones are removed after being proceeded, the function
1576      itself is kept in the cgraph even after it is compiled.  Check whether
1577      we are done with this body and reclaim it proactively if this is the case.
1578      */
1579   if (!kill_body && *slot)
1580     {
1581       struct cgraph_node *n = (struct cgraph_node *) *slot;
1582       if (!n->clones && !n->clone_of && !n->global.inlined_to
1583 	  && (cgraph_global_info_ready
1584 	      && (TREE_ASM_WRITTEN (n->decl) || DECL_EXTERNAL (n->decl)
1585 		  || n->in_other_partition)))
1586 	kill_body = true;
1587     }
1588   if (assembler_name_hash)
1589     {
1590       tree name = DECL_ASSEMBLER_NAME (node->decl);
1591       slot = htab_find_slot_with_hash (assembler_name_hash, name,
1592 				       decl_assembler_name_hash (name),
1593 				       NO_INSERT);
1594       /* Inline clones are not hashed.  */
1595       if (slot && *slot == node)
1596         htab_clear_slot (assembler_name_hash, slot);
1597     }
1598 
1599   if (kill_body)
1600     cgraph_release_function_body (node);
1601   node->decl = NULL;
1602   if (node->call_site_hash)
1603     {
1604       htab_delete (node->call_site_hash);
1605       node->call_site_hash = NULL;
1606     }
1607   cgraph_n_nodes--;
1608 
1609   /* Clear out the node to NULL all pointers and add the node to the free
1610      list.  */
1611   memset (node, 0, sizeof(*node));
1612   node->uid = uid;
1613   NEXT_FREE_NODE (node) = free_nodes;
1614   free_nodes = node;
1615 }
1616 
1617 /* Add NEW_ to the same comdat group that OLD is in.  */
1618 
1619 void
1620 cgraph_add_to_same_comdat_group (struct cgraph_node *new_,
1621 				 struct cgraph_node *old)
1622 {
1623   gcc_assert (DECL_ONE_ONLY (old->decl));
1624   gcc_assert (!new_->same_comdat_group);
1625   gcc_assert (new_ != old);
1626 
1627   DECL_COMDAT_GROUP (new_->decl) = DECL_COMDAT_GROUP (old->decl);
1628   new_->same_comdat_group = old;
1629   if (!old->same_comdat_group)
1630     old->same_comdat_group = new_;
1631   else
1632     {
1633       struct cgraph_node *n;
1634       for (n = old->same_comdat_group;
1635 	   n->same_comdat_group != old;
1636 	   n = n->same_comdat_group)
1637 	;
1638       n->same_comdat_group = new_;
1639     }
1640 }
1641 
1642 /* Remove the node from cgraph.  */
1643 
1644 void
1645 cgraph_remove_node_and_inline_clones (struct cgraph_node *node)
1646 {
1647   struct cgraph_edge *e, *next;
1648   for (e = node->callees; e; e = next)
1649     {
1650       next = e->next_callee;
1651       if (!e->inline_failed)
1652         cgraph_remove_node_and_inline_clones (e->callee);
1653     }
1654   cgraph_remove_node (node);
1655 }
1656 
1657 /* Notify finalize_compilation_unit that given node is reachable.  */
1658 
1659 void
1660 cgraph_mark_reachable_node (struct cgraph_node *node)
1661 {
1662   if (!node->reachable && node->local.finalized)
1663     {
1664       if (cgraph_global_info_ready)
1665         {
1666 	  /* Verify that function does not appear to be needed out of blue
1667 	     during the optimization process.  This can happen for extern
1668 	     inlines when bodies was removed after inlining.  */
1669 	  gcc_assert ((node->analyzed || node->in_other_partition
1670 		       || DECL_EXTERNAL (node->decl)));
1671 	}
1672       else
1673         notice_global_symbol (node->decl);
1674       node->reachable = 1;
1675 
1676       node->next_needed = cgraph_nodes_queue;
1677       cgraph_nodes_queue = node;
1678     }
1679 }
1680 
1681 /* Likewise indicate that a node is needed, i.e. reachable via some
1682    external means.  */
1683 
1684 void
1685 cgraph_mark_needed_node (struct cgraph_node *node)
1686 {
1687   node->needed = 1;
1688   gcc_assert (!node->global.inlined_to);
1689   cgraph_mark_reachable_node (node);
1690 }
1691 
1692 /* Likewise indicate that a node is having address taken.  */
1693 
1694 void
1695 cgraph_mark_address_taken_node (struct cgraph_node *node)
1696 {
1697   gcc_assert (!node->global.inlined_to);
1698   cgraph_mark_reachable_node (node);
1699   /* FIXME: address_taken flag is used both as a shortcut for testing whether
1700      IPA_REF_ADDR reference exists (and thus it should be set on node
1701      representing alias we take address of) and as a test whether address
1702      of the object was taken (and thus it should be set on node alias is
1703      referring to).  We should remove the first use and the remove the
1704      following set.  */
1705   node->address_taken = 1;
1706   node = cgraph_function_or_thunk_node (node, NULL);
1707   node->address_taken = 1;
1708 }
1709 
1710 /* Return local info for the compiled function.  */
1711 
1712 struct cgraph_local_info *
1713 cgraph_local_info (tree decl)
1714 {
1715   struct cgraph_node *node;
1716 
1717   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
1718   node = cgraph_get_node (decl);
1719   if (!node)
1720     return NULL;
1721   return &node->local;
1722 }
1723 
1724 /* Return local info for the compiled function.  */
1725 
1726 struct cgraph_global_info *
1727 cgraph_global_info (tree decl)
1728 {
1729   struct cgraph_node *node;
1730 
1731   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL && cgraph_global_info_ready);
1732   node = cgraph_get_node (decl);
1733   if (!node)
1734     return NULL;
1735   return &node->global;
1736 }
1737 
1738 /* Return local info for the compiled function.  */
1739 
1740 struct cgraph_rtl_info *
1741 cgraph_rtl_info (tree decl)
1742 {
1743   struct cgraph_node *node;
1744 
1745   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
1746   node = cgraph_get_node (decl);
1747   if (!node
1748       || (decl != current_function_decl
1749 	  && !TREE_ASM_WRITTEN (node->decl)))
1750     return NULL;
1751   return &node->rtl;
1752 }
1753 
1754 /* Return a string describing the failure REASON.  */
1755 
1756 const char*
1757 cgraph_inline_failed_string (cgraph_inline_failed_t reason)
1758 {
1759 #undef DEFCIFCODE
1760 #define DEFCIFCODE(code, string)	string,
1761 
1762   static const char *cif_string_table[CIF_N_REASONS] = {
1763 #include "cif-code.def"
1764   };
1765 
1766   /* Signedness of an enum type is implementation defined, so cast it
1767      to unsigned before testing. */
1768   gcc_assert ((unsigned) reason < CIF_N_REASONS);
1769   return cif_string_table[reason];
1770 }
1771 
1772 /* Return name of the node used in debug output.  */
1773 const char *
1774 cgraph_node_name (struct cgraph_node *node)
1775 {
1776   return lang_hooks.decl_printable_name (node->decl, 2);
1777 }
1778 
1779 /* Names used to print out the availability enum.  */
1780 const char * const cgraph_availability_names[] =
1781   {"unset", "not_available", "overwritable", "available", "local"};
1782 
1783 
1784 /* Dump call graph node NODE to file F.  */
1785 
1786 void
1787 dump_cgraph_node (FILE *f, struct cgraph_node *node)
1788 {
1789   struct cgraph_edge *edge;
1790   int indirect_calls_count = 0;
1791 
1792   fprintf (f, "%s/%i", cgraph_node_name (node), node->uid);
1793   dump_addr (f, " @", (void *)node);
1794   if (DECL_ASSEMBLER_NAME_SET_P (node->decl))
1795     fprintf (f, " (asm: %s)", IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->decl)));
1796   if (node->global.inlined_to)
1797     fprintf (f, " (inline copy in %s/%i)",
1798 	     cgraph_node_name (node->global.inlined_to),
1799 	     node->global.inlined_to->uid);
1800   if (node->same_comdat_group)
1801     fprintf (f, " (same comdat group as %s/%i)",
1802 	     cgraph_node_name (node->same_comdat_group),
1803 	     node->same_comdat_group->uid);
1804   if (node->clone_of)
1805     fprintf (f, " (clone of %s/%i)",
1806 	     cgraph_node_name (node->clone_of),
1807 	     node->clone_of->uid);
1808   if (cgraph_function_flags_ready)
1809     fprintf (f, " availability:%s",
1810 	     cgraph_availability_names [cgraph_function_body_availability (node)]);
1811   if (node->analyzed)
1812     fprintf (f, " analyzed");
1813   if (node->in_other_partition)
1814     fprintf (f, " in_other_partition");
1815   if (node->count)
1816     fprintf (f, " executed "HOST_WIDEST_INT_PRINT_DEC"x",
1817 	     (HOST_WIDEST_INT)node->count);
1818   if (node->origin)
1819     fprintf (f, " nested in: %s", cgraph_node_name (node->origin));
1820   if (node->needed)
1821     fprintf (f, " needed");
1822   if (node->address_taken)
1823     fprintf (f, " address_taken");
1824   else if (node->reachable)
1825     fprintf (f, " reachable");
1826   else if (node->reachable_from_other_partition)
1827     fprintf (f, " reachable_from_other_partition");
1828   if (gimple_has_body_p (node->decl))
1829     fprintf (f, " body");
1830   if (node->process)
1831     fprintf (f, " process");
1832   if (node->local.local)
1833     fprintf (f, " local");
1834   if (node->local.externally_visible)
1835     fprintf (f, " externally_visible");
1836   if (node->resolution != LDPR_UNKNOWN)
1837     fprintf (f, " %s",
1838  	     ld_plugin_symbol_resolution_names[(int)node->resolution]);
1839   if (node->local.finalized)
1840     fprintf (f, " finalized");
1841   if (node->local.redefined_extern_inline)
1842     fprintf (f, " redefined_extern_inline");
1843   if (TREE_ASM_WRITTEN (node->decl))
1844     fprintf (f, " asm_written");
1845   if (node->only_called_at_startup)
1846     fprintf (f, " only_called_at_startup");
1847   if (node->only_called_at_exit)
1848     fprintf (f, " only_called_at_exit");
1849   else if (node->alias)
1850     fprintf (f, " alias");
1851   if (node->tm_clone)
1852     fprintf (f, " tm_clone");
1853 
1854   fprintf (f, "\n");
1855 
1856   if (node->thunk.thunk_p)
1857     {
1858       fprintf (f, "  thunk of %s (asm: %s) fixed offset %i virtual value %i has "
1859 	       "virtual offset %i)\n",
1860 	       lang_hooks.decl_printable_name (node->thunk.alias, 2),
1861 	       IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->thunk.alias)),
1862 	       (int)node->thunk.fixed_offset,
1863 	       (int)node->thunk.virtual_value,
1864 	       (int)node->thunk.virtual_offset_p);
1865     }
1866   if (node->alias && node->thunk.alias)
1867     {
1868       fprintf (f, "  alias of %s",
1869 	       lang_hooks.decl_printable_name (node->thunk.alias, 2));
1870       if (DECL_ASSEMBLER_NAME_SET_P (node->thunk.alias))
1871         fprintf (f, " (asm: %s)",
1872 		 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->thunk.alias)));
1873       fprintf (f, "\n");
1874     }
1875 
1876   fprintf (f, "  called by: ");
1877 
1878   for (edge = node->callers; edge; edge = edge->next_caller)
1879     {
1880       fprintf (f, "%s/%i ", cgraph_node_name (edge->caller),
1881 	       edge->caller->uid);
1882       if (edge->count)
1883 	fprintf (f, "("HOST_WIDEST_INT_PRINT_DEC"x) ",
1884 		 (HOST_WIDEST_INT)edge->count);
1885       if (edge->frequency)
1886 	fprintf (f, "(%.2f per call) ",
1887 		 edge->frequency / (double)CGRAPH_FREQ_BASE);
1888       if (!edge->inline_failed)
1889 	fprintf(f, "(inlined) ");
1890       if (edge->indirect_inlining_edge)
1891 	fprintf(f, "(indirect_inlining) ");
1892       if (edge->can_throw_external)
1893 	fprintf(f, "(can throw external) ");
1894     }
1895 
1896   fprintf (f, "\n  calls: ");
1897   for (edge = node->callees; edge; edge = edge->next_callee)
1898     {
1899       fprintf (f, "%s/%i ", cgraph_node_name (edge->callee),
1900 	       edge->callee->uid);
1901       if (!edge->inline_failed)
1902 	fprintf(f, "(inlined) ");
1903       if (edge->indirect_inlining_edge)
1904 	fprintf(f, "(indirect_inlining) ");
1905       if (edge->count)
1906 	fprintf (f, "("HOST_WIDEST_INT_PRINT_DEC"x) ",
1907 		 (HOST_WIDEST_INT)edge->count);
1908       if (edge->frequency)
1909 	fprintf (f, "(%.2f per call) ",
1910 		 edge->frequency / (double)CGRAPH_FREQ_BASE);
1911       if (edge->can_throw_external)
1912 	fprintf(f, "(can throw external) ");
1913     }
1914   fprintf (f, "\n");
1915   fprintf (f, "  References: ");
1916   ipa_dump_references (f, &node->ref_list);
1917   fprintf (f, "  Refering this function: ");
1918   ipa_dump_refering (f, &node->ref_list);
1919 
1920   for (edge = node->indirect_calls; edge; edge = edge->next_callee)
1921     indirect_calls_count++;
1922   if (indirect_calls_count)
1923     fprintf (f, "  has %i outgoing edges for indirect calls.\n",
1924 	     indirect_calls_count);
1925 }
1926 
1927 
1928 /* Dump call graph node NODE to stderr.  */
1929 
1930 DEBUG_FUNCTION void
1931 debug_cgraph_node (struct cgraph_node *node)
1932 {
1933   dump_cgraph_node (stderr, node);
1934 }
1935 
1936 
1937 /* Dump the callgraph to file F.  */
1938 
1939 void
1940 dump_cgraph (FILE *f)
1941 {
1942   struct cgraph_node *node;
1943 
1944   fprintf (f, "callgraph:\n\n");
1945   for (node = cgraph_nodes; node; node = node->next)
1946     dump_cgraph_node (f, node);
1947 }
1948 
1949 
1950 /* Dump the call graph to stderr.  */
1951 
1952 DEBUG_FUNCTION void
1953 debug_cgraph (void)
1954 {
1955   dump_cgraph (stderr);
1956 }
1957 
1958 
1959 /* Set the DECL_ASSEMBLER_NAME and update cgraph hashtables.  */
1960 
1961 void
1962 change_decl_assembler_name (tree decl, tree name)
1963 {
1964   struct cgraph_node *node;
1965   void **slot;
1966   if (!DECL_ASSEMBLER_NAME_SET_P (decl))
1967     SET_DECL_ASSEMBLER_NAME (decl, name);
1968   else
1969     {
1970       if (name == DECL_ASSEMBLER_NAME (decl))
1971 	return;
1972 
1973       if (assembler_name_hash
1974 	  && TREE_CODE (decl) == FUNCTION_DECL
1975 	  && (node = cgraph_get_node (decl)) != NULL)
1976 	{
1977 	  tree old_name = DECL_ASSEMBLER_NAME (decl);
1978 	  slot = htab_find_slot_with_hash (assembler_name_hash, old_name,
1979 					   decl_assembler_name_hash (old_name),
1980 					   NO_INSERT);
1981 	  /* Inline clones are not hashed.  */
1982 	  if (slot && *slot == node)
1983 	    htab_clear_slot (assembler_name_hash, slot);
1984 	}
1985       if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
1986 	  && DECL_RTL_SET_P (decl))
1987 	warning (0, "%D renamed after being referenced in assembly", decl);
1988 
1989       SET_DECL_ASSEMBLER_NAME (decl, name);
1990     }
1991   if (assembler_name_hash
1992       && TREE_CODE (decl) == FUNCTION_DECL
1993       && (node = cgraph_get_node (decl)) != NULL)
1994     {
1995       slot = htab_find_slot_with_hash (assembler_name_hash, name,
1996 				       decl_assembler_name_hash (name),
1997 				       INSERT);
1998       gcc_assert (!*slot);
1999       *slot = node;
2000     }
2001 }
2002 
2003 /* Add a top-level asm statement to the list.  */
2004 
2005 struct cgraph_asm_node *
2006 cgraph_add_asm_node (tree asm_str)
2007 {
2008   struct cgraph_asm_node *node;
2009 
2010   node = ggc_alloc_cleared_cgraph_asm_node ();
2011   node->asm_str = asm_str;
2012   node->order = cgraph_order++;
2013   node->next = NULL;
2014   if (cgraph_asm_nodes == NULL)
2015     cgraph_asm_nodes = node;
2016   else
2017     cgraph_asm_last_node->next = node;
2018   cgraph_asm_last_node = node;
2019   return node;
2020 }
2021 
2022 /* Return true when the DECL can possibly be inlined.  */
2023 bool
2024 cgraph_function_possibly_inlined_p (tree decl)
2025 {
2026   if (!cgraph_global_info_ready)
2027     return !DECL_UNINLINABLE (decl);
2028   return DECL_POSSIBLY_INLINED (decl);
2029 }
2030 
2031 /* Create clone of E in the node N represented by CALL_EXPR the callgraph.  */
2032 struct cgraph_edge *
2033 cgraph_clone_edge (struct cgraph_edge *e, struct cgraph_node *n,
2034 		   gimple call_stmt, unsigned stmt_uid, gcov_type count_scale,
2035 		   int freq_scale, bool update_original)
2036 {
2037   struct cgraph_edge *new_edge;
2038   gcov_type count = e->count * count_scale / REG_BR_PROB_BASE;
2039   gcov_type freq;
2040 
2041   /* We do not want to ignore loop nest after frequency drops to 0.  */
2042   if (!freq_scale)
2043     freq_scale = 1;
2044   freq = e->frequency * (gcov_type) freq_scale / CGRAPH_FREQ_BASE;
2045   if (freq > CGRAPH_FREQ_MAX)
2046     freq = CGRAPH_FREQ_MAX;
2047 
2048   if (e->indirect_unknown_callee)
2049     {
2050       tree decl;
2051 
2052       if (call_stmt && (decl = gimple_call_fndecl (call_stmt)))
2053 	{
2054 	  struct cgraph_node *callee = cgraph_get_node (decl);
2055 	  gcc_checking_assert (callee);
2056 	  new_edge = cgraph_create_edge (n, callee, call_stmt, count, freq);
2057 	}
2058       else
2059 	{
2060 	  new_edge = cgraph_create_indirect_edge (n, call_stmt,
2061 						  e->indirect_info->ecf_flags,
2062 						  count, freq);
2063 	  *new_edge->indirect_info = *e->indirect_info;
2064 	}
2065     }
2066   else
2067     {
2068       new_edge = cgraph_create_edge (n, e->callee, call_stmt, count, freq);
2069       if (e->indirect_info)
2070 	{
2071 	  new_edge->indirect_info
2072 	    = ggc_alloc_cleared_cgraph_indirect_call_info ();
2073 	  *new_edge->indirect_info = *e->indirect_info;
2074 	}
2075     }
2076 
2077   new_edge->inline_failed = e->inline_failed;
2078   new_edge->indirect_inlining_edge = e->indirect_inlining_edge;
2079   new_edge->lto_stmt_uid = stmt_uid;
2080   /* Clone flags that depend on call_stmt availability manually.  */
2081   new_edge->can_throw_external = e->can_throw_external;
2082   new_edge->call_stmt_cannot_inline_p = e->call_stmt_cannot_inline_p;
2083   if (update_original)
2084     {
2085       e->count -= new_edge->count;
2086       if (e->count < 0)
2087 	e->count = 0;
2088     }
2089   cgraph_call_edge_duplication_hooks (e, new_edge);
2090   return new_edge;
2091 }
2092 
2093 
2094 /* Create node representing clone of N executed COUNT times.  Decrease
2095    the execution counts from original node too.
2096    The new clone will have decl set to DECL that may or may not be the same
2097    as decl of N.
2098 
2099    When UPDATE_ORIGINAL is true, the counts are subtracted from the original
2100    function's profile to reflect the fact that part of execution is handled
2101    by node.
2102    When CALL_DUPLICATOIN_HOOK is true, the ipa passes are acknowledged about
2103    the new clone. Otherwise the caller is responsible for doing so later.  */
2104 
2105 struct cgraph_node *
2106 cgraph_clone_node (struct cgraph_node *n, tree decl, gcov_type count, int freq,
2107 		   bool update_original,
2108 		   VEC(cgraph_edge_p,heap) *redirect_callers,
2109 		   bool call_duplication_hook)
2110 {
2111   struct cgraph_node *new_node = cgraph_create_node_1 ();
2112   struct cgraph_edge *e;
2113   gcov_type count_scale;
2114   unsigned i;
2115 
2116   new_node->decl = decl;
2117   new_node->origin = n->origin;
2118   if (new_node->origin)
2119     {
2120       new_node->next_nested = new_node->origin->nested;
2121       new_node->origin->nested = new_node;
2122     }
2123   new_node->analyzed = n->analyzed;
2124   new_node->local = n->local;
2125   new_node->local.externally_visible = false;
2126   new_node->local.local = true;
2127   new_node->global = n->global;
2128   new_node->rtl = n->rtl;
2129   new_node->count = count;
2130   new_node->frequency = n->frequency;
2131   new_node->clone = n->clone;
2132   new_node->clone.tree_map = 0;
2133   if (n->count)
2134     {
2135       if (new_node->count > n->count)
2136         count_scale = REG_BR_PROB_BASE;
2137       else
2138         count_scale = new_node->count * REG_BR_PROB_BASE / n->count;
2139     }
2140   else
2141     count_scale = 0;
2142   if (update_original)
2143     {
2144       n->count -= count;
2145       if (n->count < 0)
2146 	n->count = 0;
2147     }
2148 
2149   FOR_EACH_VEC_ELT (cgraph_edge_p, redirect_callers, i, e)
2150     {
2151       /* Redirect calls to the old version node to point to its new
2152 	 version.  */
2153       cgraph_redirect_edge_callee (e, new_node);
2154     }
2155 
2156 
2157   for (e = n->callees;e; e=e->next_callee)
2158     cgraph_clone_edge (e, new_node, e->call_stmt, e->lto_stmt_uid,
2159 		       count_scale, freq, update_original);
2160 
2161   for (e = n->indirect_calls; e; e = e->next_callee)
2162     cgraph_clone_edge (e, new_node, e->call_stmt, e->lto_stmt_uid,
2163 		       count_scale, freq, update_original);
2164   ipa_clone_references (new_node, NULL, &n->ref_list);
2165 
2166   new_node->next_sibling_clone = n->clones;
2167   if (n->clones)
2168     n->clones->prev_sibling_clone = new_node;
2169   n->clones = new_node;
2170   new_node->clone_of = n;
2171 
2172   if (n->decl != decl)
2173     {
2174       struct cgraph_node **slot;
2175       slot = (struct cgraph_node **) htab_find_slot (cgraph_hash, new_node, INSERT);
2176       gcc_assert (!*slot);
2177       *slot = new_node;
2178       if (assembler_name_hash)
2179 	{
2180 	  void **aslot;
2181 	  tree name = DECL_ASSEMBLER_NAME (decl);
2182 
2183 	  aslot = htab_find_slot_with_hash (assembler_name_hash, name,
2184 					    decl_assembler_name_hash (name),
2185 					    INSERT);
2186 	  gcc_assert (!*aslot);
2187 	  *aslot = new_node;
2188 	}
2189     }
2190 
2191   if (call_duplication_hook)
2192     cgraph_call_node_duplication_hooks (n, new_node);
2193   return new_node;
2194 }
2195 
2196 /* Create a new name for clone of DECL, add SUFFIX.  Returns an identifier.  */
2197 
2198 static GTY(()) unsigned int clone_fn_id_num;
2199 
2200 tree
2201 clone_function_name (tree decl, const char *suffix)
2202 {
2203   tree name = DECL_ASSEMBLER_NAME (decl);
2204   size_t len = IDENTIFIER_LENGTH (name);
2205   char *tmp_name, *prefix;
2206 
2207   prefix = XALLOCAVEC (char, len + strlen (suffix) + 2);
2208   memcpy (prefix, IDENTIFIER_POINTER (name), len);
2209   strcpy (prefix + len + 1, suffix);
2210 #ifndef NO_DOT_IN_LABEL
2211   prefix[len] = '.';
2212 #elif !defined NO_DOLLAR_IN_LABEL
2213   prefix[len] = '$';
2214 #else
2215   prefix[len] = '_';
2216 #endif
2217   ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix, clone_fn_id_num++);
2218   return get_identifier (tmp_name);
2219 }
2220 
2221 /* Create callgraph node clone with new declaration.  The actual body will
2222    be copied later at compilation stage.
2223 
2224    TODO: after merging in ipa-sra use function call notes instead of args_to_skip
2225    bitmap interface.
2226    */
2227 struct cgraph_node *
2228 cgraph_create_virtual_clone (struct cgraph_node *old_node,
2229 			     VEC(cgraph_edge_p,heap) *redirect_callers,
2230 			     VEC(ipa_replace_map_p,gc) *tree_map,
2231 			     bitmap args_to_skip,
2232 			     const char * suffix)
2233 {
2234   tree old_decl = old_node->decl;
2235   struct cgraph_node *new_node = NULL;
2236   tree new_decl;
2237   size_t i;
2238   struct ipa_replace_map *map;
2239 
2240   if (!flag_wpa)
2241     gcc_checking_assert  (tree_versionable_function_p (old_decl));
2242 
2243   gcc_assert (old_node->local.can_change_signature || !args_to_skip);
2244 
2245   /* Make a new FUNCTION_DECL tree node */
2246   if (!args_to_skip)
2247     new_decl = copy_node (old_decl);
2248   else
2249     new_decl = build_function_decl_skip_args (old_decl, args_to_skip, false);
2250   DECL_STRUCT_FUNCTION (new_decl) = NULL;
2251 
2252   /* Generate a new name for the new version. */
2253   DECL_NAME (new_decl) = clone_function_name (old_decl, suffix);
2254   SET_DECL_ASSEMBLER_NAME (new_decl, DECL_NAME (new_decl));
2255   SET_DECL_RTL (new_decl, NULL);
2256 
2257   new_node = cgraph_clone_node (old_node, new_decl, old_node->count,
2258 				CGRAPH_FREQ_BASE, false,
2259 				redirect_callers, false);
2260   /* Update the properties.
2261      Make clone visible only within this translation unit.  Make sure
2262      that is not weak also.
2263      ??? We cannot use COMDAT linkage because there is no
2264      ABI support for this.  */
2265   DECL_EXTERNAL (new_node->decl) = 0;
2266   if (DECL_ONE_ONLY (old_decl))
2267     DECL_SECTION_NAME (new_node->decl) = NULL;
2268   DECL_COMDAT_GROUP (new_node->decl) = 0;
2269   TREE_PUBLIC (new_node->decl) = 0;
2270   DECL_COMDAT (new_node->decl) = 0;
2271   DECL_WEAK (new_node->decl) = 0;
2272   DECL_VIRTUAL_P (new_node->decl) = 0;
2273   DECL_STATIC_CONSTRUCTOR (new_node->decl) = 0;
2274   DECL_STATIC_DESTRUCTOR (new_node->decl) = 0;
2275   new_node->clone.tree_map = tree_map;
2276   new_node->clone.args_to_skip = args_to_skip;
2277   FOR_EACH_VEC_ELT (ipa_replace_map_p, tree_map, i, map)
2278     {
2279       tree var = map->new_tree;
2280 
2281       STRIP_NOPS (var);
2282       if (TREE_CODE (var) != ADDR_EXPR)
2283 	continue;
2284       var = get_base_var (var);
2285       if (!var)
2286 	continue;
2287 
2288       /* Record references of the future statement initializing the constant
2289 	 argument.  */
2290       if (TREE_CODE (var) == FUNCTION_DECL)
2291 	{
2292 	  struct cgraph_node *ref_node = cgraph_get_node (var);
2293 	  gcc_checking_assert (ref_node);
2294 	  ipa_record_reference (new_node, NULL, ref_node, NULL, IPA_REF_ADDR,
2295 				NULL);
2296 	}
2297       else if (TREE_CODE (var) == VAR_DECL)
2298 	ipa_record_reference (new_node, NULL, NULL, varpool_node (var),
2299 			      IPA_REF_ADDR, NULL);
2300     }
2301   if (!args_to_skip)
2302     new_node->clone.combined_args_to_skip = old_node->clone.combined_args_to_skip;
2303   else if (old_node->clone.combined_args_to_skip)
2304     {
2305       int newi = 0, oldi = 0;
2306       tree arg;
2307       bitmap new_args_to_skip = BITMAP_GGC_ALLOC ();
2308       struct cgraph_node *orig_node;
2309       for (orig_node = old_node; orig_node->clone_of; orig_node = orig_node->clone_of)
2310         ;
2311       for (arg = DECL_ARGUMENTS (orig_node->decl); arg; arg = DECL_CHAIN (arg), oldi++)
2312 	{
2313 	  if (bitmap_bit_p (old_node->clone.combined_args_to_skip, oldi))
2314 	    {
2315 	      bitmap_set_bit (new_args_to_skip, oldi);
2316 	      continue;
2317 	    }
2318 	  if (bitmap_bit_p (args_to_skip, newi))
2319 	    bitmap_set_bit (new_args_to_skip, oldi);
2320 	  newi++;
2321 	}
2322       new_node->clone.combined_args_to_skip = new_args_to_skip;
2323     }
2324   else
2325     new_node->clone.combined_args_to_skip = args_to_skip;
2326   new_node->local.externally_visible = 0;
2327   new_node->local.local = 1;
2328   new_node->lowered = true;
2329   new_node->reachable = true;
2330 
2331   cgraph_call_node_duplication_hooks (old_node, new_node);
2332 
2333 
2334   return new_node;
2335 }
2336 
2337 /* NODE is no longer nested function; update cgraph accordingly.  */
2338 void
2339 cgraph_unnest_node (struct cgraph_node *node)
2340 {
2341   struct cgraph_node **node2 = &node->origin->nested;
2342   gcc_assert (node->origin);
2343 
2344   while (*node2 != node)
2345     node2 = &(*node2)->next_nested;
2346   *node2 = node->next_nested;
2347   node->origin = NULL;
2348 }
2349 
2350 /* Return function availability.  See cgraph.h for description of individual
2351    return values.  */
2352 enum availability
2353 cgraph_function_body_availability (struct cgraph_node *node)
2354 {
2355   enum availability avail;
2356   gcc_assert (cgraph_function_flags_ready);
2357   if (!node->analyzed)
2358     avail = AVAIL_NOT_AVAILABLE;
2359   else if (node->local.local)
2360     avail = AVAIL_LOCAL;
2361   else if (!node->local.externally_visible)
2362     avail = AVAIL_AVAILABLE;
2363   /* Inline functions are safe to be analyzed even if their symbol can
2364      be overwritten at runtime.  It is not meaningful to enforce any sane
2365      behaviour on replacing inline function by different body.  */
2366   else if (DECL_DECLARED_INLINE_P (node->decl))
2367     avail = AVAIL_AVAILABLE;
2368 
2369   /* If the function can be overwritten, return OVERWRITABLE.  Take
2370      care at least of two notable extensions - the COMDAT functions
2371      used to share template instantiations in C++ (this is symmetric
2372      to code cp_cannot_inline_tree_fn and probably shall be shared and
2373      the inlinability hooks completely eliminated).
2374 
2375      ??? Does the C++ one definition rule allow us to always return
2376      AVAIL_AVAILABLE here?  That would be good reason to preserve this
2377      bit.  */
2378 
2379   else if (decl_replaceable_p (node->decl) && !DECL_EXTERNAL (node->decl))
2380     avail = AVAIL_OVERWRITABLE;
2381   else avail = AVAIL_AVAILABLE;
2382 
2383   return avail;
2384 }
2385 
2386 /* Add the function FNDECL to the call graph.
2387    Unlike cgraph_finalize_function, this function is intended to be used
2388    by middle end and allows insertion of new function at arbitrary point
2389    of compilation.  The function can be either in high, low or SSA form
2390    GIMPLE.
2391 
2392    The function is assumed to be reachable and have address taken (so no
2393    API breaking optimizations are performed on it).
2394 
2395    Main work done by this function is to enqueue the function for later
2396    processing to avoid need the passes to be re-entrant.  */
2397 
2398 void
2399 cgraph_add_new_function (tree fndecl, bool lowered)
2400 {
2401   struct cgraph_node *node;
2402   switch (cgraph_state)
2403     {
2404       case CGRAPH_STATE_CONSTRUCTION:
2405 	/* Just enqueue function to be processed at nearest occurrence.  */
2406 	node = cgraph_create_node (fndecl);
2407 	node->next_needed = cgraph_new_nodes;
2408 	if (lowered)
2409 	  node->lowered = true;
2410 	cgraph_new_nodes = node;
2411         break;
2412 
2413       case CGRAPH_STATE_IPA:
2414       case CGRAPH_STATE_IPA_SSA:
2415       case CGRAPH_STATE_EXPANSION:
2416 	/* Bring the function into finalized state and enqueue for later
2417 	   analyzing and compilation.  */
2418 	node = cgraph_get_create_node (fndecl);
2419 	node->local.local = false;
2420 	node->local.finalized = true;
2421 	node->reachable = node->needed = true;
2422 	if (!lowered && cgraph_state == CGRAPH_STATE_EXPANSION)
2423 	  {
2424 	    push_cfun (DECL_STRUCT_FUNCTION (fndecl));
2425 	    current_function_decl = fndecl;
2426 	    gimple_register_cfg_hooks ();
2427 	    tree_lowering_passes (fndecl);
2428 	    bitmap_obstack_initialize (NULL);
2429 	    if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (fndecl)))
2430 	      execute_pass_list (pass_early_local_passes.pass.sub);
2431 	    bitmap_obstack_release (NULL);
2432 	    pop_cfun ();
2433 	    current_function_decl = NULL;
2434 
2435 	    lowered = true;
2436 	  }
2437 	if (lowered)
2438 	  node->lowered = true;
2439 	node->next_needed = cgraph_new_nodes;
2440 	cgraph_new_nodes = node;
2441         break;
2442 
2443       case CGRAPH_STATE_FINISHED:
2444 	/* At the very end of compilation we have to do all the work up
2445 	   to expansion.  */
2446 	node = cgraph_create_node (fndecl);
2447 	if (lowered)
2448 	  node->lowered = true;
2449 	cgraph_analyze_function (node);
2450 	push_cfun (DECL_STRUCT_FUNCTION (fndecl));
2451 	current_function_decl = fndecl;
2452 	gimple_register_cfg_hooks ();
2453 	bitmap_obstack_initialize (NULL);
2454 	if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (fndecl)))
2455 	  execute_pass_list (pass_early_local_passes.pass.sub);
2456 	bitmap_obstack_release (NULL);
2457 	tree_rest_of_compilation (fndecl);
2458 	pop_cfun ();
2459 	current_function_decl = NULL;
2460 	break;
2461     }
2462 
2463   /* Set a personality if required and we already passed EH lowering.  */
2464   if (lowered
2465       && (function_needs_eh_personality (DECL_STRUCT_FUNCTION (fndecl))
2466 	  == eh_personality_lang))
2467     DECL_FUNCTION_PERSONALITY (fndecl) = lang_hooks.eh_personality ();
2468 }
2469 
2470 /* Worker for cgraph_node_can_be_local_p.  */
2471 static bool
2472 cgraph_node_cannot_be_local_p_1 (struct cgraph_node *node,
2473 				 void *data ATTRIBUTE_UNUSED)
2474 {
2475   return !(!node->needed
2476 	   && ((DECL_COMDAT (node->decl) && !node->same_comdat_group)
2477 	       || !node->local.externally_visible));
2478 }
2479 
2480 /* Return true if NODE can be made local for API change.
2481    Extern inline functions and C++ COMDAT functions can be made local
2482    at the expense of possible code size growth if function is used in multiple
2483    compilation units.  */
2484 bool
2485 cgraph_node_can_be_local_p (struct cgraph_node *node)
2486 {
2487   return (!node->address_taken
2488 	  && !cgraph_for_node_and_aliases (node,
2489 					   cgraph_node_cannot_be_local_p_1,
2490 					   NULL, true));
2491 }
2492 
2493 /* Make DECL local.  FIXME: We shouldn't need to mess with rtl this early,
2494    but other code such as notice_global_symbol generates rtl.  */
2495 void
2496 cgraph_make_decl_local (tree decl)
2497 {
2498   rtx rtl, symbol;
2499 
2500   if (TREE_CODE (decl) == VAR_DECL)
2501     DECL_COMMON (decl) = 0;
2502   else gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
2503 
2504   if (DECL_ONE_ONLY (decl) || DECL_COMDAT (decl))
2505     {
2506       /* It is possible that we are linking against library defining same COMDAT
2507 	 function.  To avoid conflict we need to rename our local name of the
2508 	 function just in the case WHOPR partitioning decide to make it hidden
2509 	 to avoid cross partition references.  */
2510       if (flag_wpa)
2511 	{
2512 	  const char *old_name;
2513 
2514 	  old_name  = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2515 	  if (TREE_CODE (decl) == FUNCTION_DECL)
2516 	    {
2517 	      struct cgraph_node *node = cgraph_get_node (decl);
2518 	      change_decl_assembler_name (decl,
2519 					  clone_function_name (decl, "local"));
2520 	      if (node->local.lto_file_data)
2521 		lto_record_renamed_decl (node->local.lto_file_data,
2522 					 old_name,
2523 					 IDENTIFIER_POINTER
2524 					   (DECL_ASSEMBLER_NAME (decl)));
2525 	    }
2526 	  else if (TREE_CODE (decl) == VAR_DECL)
2527 	    {
2528 	      struct varpool_node *vnode = varpool_get_node (decl);
2529 	      /* change_decl_assembler_name will warn here on vtables because
2530 		 C++ frontend still sets TREE_SYMBOL_REFERENCED on them.  */
2531 	      SET_DECL_ASSEMBLER_NAME (decl,
2532 				       clone_function_name (decl, "local"));
2533 	      if (vnode->lto_file_data)
2534 		lto_record_renamed_decl (vnode->lto_file_data,
2535 					 old_name,
2536 					 IDENTIFIER_POINTER
2537 					   (DECL_ASSEMBLER_NAME (decl)));
2538 	    }
2539 	}
2540       DECL_SECTION_NAME (decl) = 0;
2541       DECL_COMDAT (decl) = 0;
2542     }
2543   DECL_COMDAT_GROUP (decl) = 0;
2544   DECL_WEAK (decl) = 0;
2545   DECL_EXTERNAL (decl) = 0;
2546   TREE_PUBLIC (decl) = 0;
2547   if (!DECL_RTL_SET_P (decl))
2548     return;
2549 
2550   /* Update rtl flags.  */
2551   make_decl_rtl (decl);
2552 
2553   rtl = DECL_RTL (decl);
2554   if (!MEM_P (rtl))
2555     return;
2556 
2557   symbol = XEXP (rtl, 0);
2558   if (GET_CODE (symbol) != SYMBOL_REF)
2559     return;
2560 
2561   SYMBOL_REF_WEAK (symbol) = DECL_WEAK (decl);
2562 }
2563 
2564 /* Call calback on NODE, thunks and aliases asociated to NODE.
2565    When INCLUDE_OVERWRITABLE is false, overwritable aliases and thunks are
2566    skipped. */
2567 
2568 bool
2569 cgraph_for_node_thunks_and_aliases (struct cgraph_node *node,
2570 			            bool (*callback) (struct cgraph_node *, void *),
2571 			            void *data,
2572 				    bool include_overwritable)
2573 {
2574   struct cgraph_edge *e;
2575   int i;
2576   struct ipa_ref *ref;
2577 
2578   if (callback (node, data))
2579     return true;
2580   for (e = node->callers; e; e = e->next_caller)
2581     if (e->caller->thunk.thunk_p
2582 	&& (include_overwritable
2583 	    || cgraph_function_body_availability (e->caller) > AVAIL_OVERWRITABLE))
2584       if (cgraph_for_node_thunks_and_aliases (e->caller, callback, data,
2585 					      include_overwritable))
2586 	return true;
2587   for (i = 0; ipa_ref_list_refering_iterate (&node->ref_list, i, ref); i++)
2588     if (ref->use == IPA_REF_ALIAS)
2589       {
2590 	struct cgraph_node *alias = ipa_ref_refering_node (ref);
2591 	if (include_overwritable
2592 	    || cgraph_function_body_availability (alias) > AVAIL_OVERWRITABLE)
2593 	  if (cgraph_for_node_thunks_and_aliases (alias, callback, data,
2594 						  include_overwritable))
2595 	    return true;
2596       }
2597   return false;
2598 }
2599 
2600 /* Call calback on NODE and aliases asociated to NODE.
2601    When INCLUDE_OVERWRITABLE is false, overwritable aliases and thunks are
2602    skipped. */
2603 
2604 bool
2605 cgraph_for_node_and_aliases (struct cgraph_node *node,
2606 			     bool (*callback) (struct cgraph_node *, void *),
2607 			     void *data,
2608 			     bool include_overwritable)
2609 {
2610   int i;
2611   struct ipa_ref *ref;
2612 
2613   if (callback (node, data))
2614     return true;
2615   for (i = 0; ipa_ref_list_refering_iterate (&node->ref_list, i, ref); i++)
2616     if (ref->use == IPA_REF_ALIAS)
2617       {
2618 	struct cgraph_node *alias = ipa_ref_refering_node (ref);
2619 	if (include_overwritable
2620 	    || cgraph_function_body_availability (alias) > AVAIL_OVERWRITABLE)
2621           if (cgraph_for_node_and_aliases (alias, callback, data,
2622 					   include_overwritable))
2623 	    return true;
2624       }
2625   return false;
2626 }
2627 
2628 /* Worker to bring NODE local.  */
2629 
2630 static bool
2631 cgraph_make_node_local_1 (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
2632 {
2633   gcc_checking_assert (cgraph_node_can_be_local_p (node));
2634   if (DECL_COMDAT (node->decl) || DECL_EXTERNAL (node->decl))
2635     {
2636       cgraph_make_decl_local (node->decl);
2637 
2638       node->local.externally_visible = false;
2639       node->local.local = true;
2640       node->resolution = LDPR_PREVAILING_DEF_IRONLY;
2641       gcc_assert (cgraph_function_body_availability (node) == AVAIL_LOCAL);
2642     }
2643   return false;
2644 }
2645 
2646 /* Bring NODE local.  */
2647 
2648 void
2649 cgraph_make_node_local (struct cgraph_node *node)
2650 {
2651   cgraph_for_node_thunks_and_aliases (node, cgraph_make_node_local_1,
2652 				      NULL, true);
2653 }
2654 
2655 /* Worker to set nothrow flag.  */
2656 
2657 static bool
2658 cgraph_set_nothrow_flag_1 (struct cgraph_node *node, void *data)
2659 {
2660   struct cgraph_edge *e;
2661 
2662   TREE_NOTHROW (node->decl) = data != NULL;
2663 
2664   if (data != NULL)
2665     for (e = node->callers; e; e = e->next_caller)
2666       e->can_throw_external = false;
2667   return false;
2668 }
2669 
2670 /* Set TREE_NOTHROW on NODE's decl and on aliases of NODE
2671    if any to NOTHROW.  */
2672 
2673 void
2674 cgraph_set_nothrow_flag (struct cgraph_node *node, bool nothrow)
2675 {
2676   cgraph_for_node_thunks_and_aliases (node, cgraph_set_nothrow_flag_1,
2677 			              (void *)(size_t)nothrow, false);
2678 }
2679 
2680 /* Worker to set const flag.  */
2681 
2682 static bool
2683 cgraph_set_const_flag_1 (struct cgraph_node *node, void *data)
2684 {
2685   /* Static constructors and destructors without a side effect can be
2686      optimized out.  */
2687   if (data && !((size_t)data & 2))
2688     {
2689       if (DECL_STATIC_CONSTRUCTOR (node->decl))
2690 	DECL_STATIC_CONSTRUCTOR (node->decl) = 0;
2691       if (DECL_STATIC_DESTRUCTOR (node->decl))
2692 	DECL_STATIC_DESTRUCTOR (node->decl) = 0;
2693     }
2694   TREE_READONLY (node->decl) = data != NULL;
2695   DECL_LOOPING_CONST_OR_PURE_P (node->decl) = ((size_t)data & 2) != 0;
2696   return false;
2697 }
2698 
2699 /* Set TREE_READONLY on NODE's decl and on aliases of NODE
2700    if any to READONLY.  */
2701 
2702 void
2703 cgraph_set_const_flag (struct cgraph_node *node, bool readonly, bool looping)
2704 {
2705   cgraph_for_node_thunks_and_aliases (node, cgraph_set_const_flag_1,
2706 			              (void *)(size_t)(readonly + (int)looping * 2),
2707 				      false);
2708 }
2709 
2710 /* Worker to set pure flag.  */
2711 
2712 static bool
2713 cgraph_set_pure_flag_1 (struct cgraph_node *node, void *data)
2714 {
2715   /* Static pureructors and destructors without a side effect can be
2716      optimized out.  */
2717   if (data && !((size_t)data & 2))
2718     {
2719       if (DECL_STATIC_CONSTRUCTOR (node->decl))
2720 	DECL_STATIC_CONSTRUCTOR (node->decl) = 0;
2721       if (DECL_STATIC_DESTRUCTOR (node->decl))
2722 	DECL_STATIC_DESTRUCTOR (node->decl) = 0;
2723     }
2724   DECL_PURE_P (node->decl) = data != NULL;
2725   DECL_LOOPING_CONST_OR_PURE_P (node->decl) = ((size_t)data & 2) != 0;
2726   return false;
2727 }
2728 
2729 /* Set DECL_PURE_P on NODE's decl and on aliases of NODE
2730    if any to PURE.  */
2731 
2732 void
2733 cgraph_set_pure_flag (struct cgraph_node *node, bool pure, bool looping)
2734 {
2735   cgraph_for_node_thunks_and_aliases (node, cgraph_set_pure_flag_1,
2736 			              (void *)(size_t)(pure + (int)looping * 2),
2737 				      false);
2738 }
2739 
2740 /* Data used by cgraph_propagate_frequency.  */
2741 
2742 struct cgraph_propagate_frequency_data
2743 {
2744   bool maybe_unlikely_executed;
2745   bool maybe_executed_once;
2746   bool only_called_at_startup;
2747   bool only_called_at_exit;
2748 };
2749 
2750 /* Worker for cgraph_propagate_frequency_1.  */
2751 
2752 static bool
2753 cgraph_propagate_frequency_1 (struct cgraph_node *node, void *data)
2754 {
2755   struct cgraph_propagate_frequency_data *d;
2756   struct cgraph_edge *edge;
2757 
2758   d = (struct cgraph_propagate_frequency_data *)data;
2759   for (edge = node->callers;
2760        edge && (d->maybe_unlikely_executed || d->maybe_executed_once
2761 	        || d->only_called_at_startup || d->only_called_at_exit);
2762        edge = edge->next_caller)
2763     {
2764       if (edge->caller != node)
2765 	{
2766           d->only_called_at_startup &= edge->caller->only_called_at_startup;
2767 	  /* It makes sense to put main() together with the static constructors.
2768 	     It will be executed for sure, but rest of functions called from
2769 	     main are definitely not at startup only.  */
2770 	  if (MAIN_NAME_P (DECL_NAME (edge->caller->decl)))
2771 	    d->only_called_at_startup = 0;
2772           d->only_called_at_exit &= edge->caller->only_called_at_exit;
2773 	}
2774       if (!edge->frequency)
2775 	continue;
2776       switch (edge->caller->frequency)
2777         {
2778 	case NODE_FREQUENCY_UNLIKELY_EXECUTED:
2779 	  break;
2780 	case NODE_FREQUENCY_EXECUTED_ONCE:
2781 	  if (dump_file && (dump_flags & TDF_DETAILS))
2782 	    fprintf (dump_file, "  Called by %s that is executed once\n",
2783 		     cgraph_node_name (edge->caller));
2784 	  d->maybe_unlikely_executed = false;
2785 	  if (inline_edge_summary (edge)->loop_depth)
2786 	    {
2787 	      d->maybe_executed_once = false;
2788 	      if (dump_file && (dump_flags & TDF_DETAILS))
2789 	        fprintf (dump_file, "  Called in loop\n");
2790 	    }
2791 	  break;
2792 	case NODE_FREQUENCY_HOT:
2793 	case NODE_FREQUENCY_NORMAL:
2794 	  if (dump_file && (dump_flags & TDF_DETAILS))
2795 	    fprintf (dump_file, "  Called by %s that is normal or hot\n",
2796 		     cgraph_node_name (edge->caller));
2797 	  d->maybe_unlikely_executed = false;
2798 	  d->maybe_executed_once = false;
2799 	  break;
2800 	}
2801     }
2802   return edge != NULL;
2803 }
2804 
2805 /* See if the frequency of NODE can be updated based on frequencies of its
2806    callers.  */
2807 bool
2808 cgraph_propagate_frequency (struct cgraph_node *node)
2809 {
2810   struct cgraph_propagate_frequency_data d = {true, true, true, true};
2811   bool changed = false;
2812 
2813   if (!node->local.local)
2814     return false;
2815   gcc_assert (node->analyzed);
2816   if (dump_file && (dump_flags & TDF_DETAILS))
2817     fprintf (dump_file, "Processing frequency %s\n", cgraph_node_name (node));
2818 
2819   cgraph_for_node_and_aliases (node, cgraph_propagate_frequency_1, &d, true);
2820 
2821   if ((d.only_called_at_startup && !d.only_called_at_exit)
2822       && !node->only_called_at_startup)
2823     {
2824        node->only_called_at_startup = true;
2825        if (dump_file)
2826          fprintf (dump_file, "Node %s promoted to only called at startup.\n",
2827 		  cgraph_node_name (node));
2828        changed = true;
2829     }
2830   if ((d.only_called_at_exit && !d.only_called_at_startup)
2831       && !node->only_called_at_exit)
2832     {
2833        node->only_called_at_exit = true;
2834        if (dump_file)
2835          fprintf (dump_file, "Node %s promoted to only called at exit.\n",
2836 		  cgraph_node_name (node));
2837        changed = true;
2838     }
2839   /* These come either from profile or user hints; never update them.  */
2840   if (node->frequency == NODE_FREQUENCY_HOT
2841       || node->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED)
2842     return changed;
2843   if (d.maybe_unlikely_executed)
2844     {
2845       node->frequency = NODE_FREQUENCY_UNLIKELY_EXECUTED;
2846       if (dump_file)
2847 	fprintf (dump_file, "Node %s promoted to unlikely executed.\n",
2848 		 cgraph_node_name (node));
2849       changed = true;
2850     }
2851   else if (d.maybe_executed_once && node->frequency != NODE_FREQUENCY_EXECUTED_ONCE)
2852     {
2853       node->frequency = NODE_FREQUENCY_EXECUTED_ONCE;
2854       if (dump_file)
2855 	fprintf (dump_file, "Node %s promoted to executed once.\n",
2856 		 cgraph_node_name (node));
2857       changed = true;
2858     }
2859   return changed;
2860 }
2861 
2862 /* Return true when NODE can not return or throw and thus
2863    it is safe to ignore its side effects for IPA analysis.  */
2864 
2865 bool
2866 cgraph_node_cannot_return (struct cgraph_node *node)
2867 {
2868   int flags = flags_from_decl_or_type (node->decl);
2869   if (!flag_exceptions)
2870     return (flags & ECF_NORETURN) != 0;
2871   else
2872     return ((flags & (ECF_NORETURN | ECF_NOTHROW))
2873 	     == (ECF_NORETURN | ECF_NOTHROW));
2874 }
2875 
2876 /* Return true when call of E can not lead to return from caller
2877    and thus it is safe to ignore its side effects for IPA analysis
2878    when computing side effects of the caller.
2879    FIXME: We could actually mark all edges that have no reaching
2880    patch to EXIT_BLOCK_PTR or throw to get better results.  */
2881 bool
2882 cgraph_edge_cannot_lead_to_return (struct cgraph_edge *e)
2883 {
2884   if (cgraph_node_cannot_return (e->caller))
2885     return true;
2886   if (e->indirect_unknown_callee)
2887     {
2888       int flags = e->indirect_info->ecf_flags;
2889       if (!flag_exceptions)
2890 	return (flags & ECF_NORETURN) != 0;
2891       else
2892 	return ((flags & (ECF_NORETURN | ECF_NOTHROW))
2893 		 == (ECF_NORETURN | ECF_NOTHROW));
2894     }
2895   else
2896     return cgraph_node_cannot_return (e->callee);
2897 }
2898 
2899 /* Return true when function NODE can be removed from callgraph
2900    if all direct calls are eliminated.  */
2901 
2902 bool
2903 cgraph_can_remove_if_no_direct_calls_and_refs_p (struct cgraph_node *node)
2904 {
2905   gcc_assert (!node->global.inlined_to);
2906   /* Extern inlines can always go, we will use the external definition.  */
2907   if (DECL_EXTERNAL (node->decl))
2908     return true;
2909   /* When function is needed, we can not remove it.  */
2910   if (node->needed || node->reachable_from_other_partition)
2911     return false;
2912   if (DECL_STATIC_CONSTRUCTOR (node->decl)
2913       || DECL_STATIC_DESTRUCTOR (node->decl))
2914     return false;
2915   /* Only COMDAT functions can be removed if externally visible.  */
2916   if (node->local.externally_visible
2917       && (!DECL_COMDAT (node->decl)
2918 	  || cgraph_used_from_object_file_p (node)))
2919     return false;
2920   return true;
2921 }
2922 
2923 /* Worker for cgraph_can_remove_if_no_direct_calls_p.  */
2924 
2925 static bool
2926 nonremovable_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
2927 {
2928   return !cgraph_can_remove_if_no_direct_calls_and_refs_p (node);
2929 }
2930 
2931 /* Return true when function NODE and its aliases can be removed from callgraph
2932    if all direct calls are eliminated.  */
2933 
2934 bool
2935 cgraph_can_remove_if_no_direct_calls_p (struct cgraph_node *node)
2936 {
2937   /* Extern inlines can always go, we will use the external definition.  */
2938   if (DECL_EXTERNAL (node->decl))
2939     return true;
2940   if (node->address_taken)
2941     return false;
2942   return !cgraph_for_node_and_aliases (node, nonremovable_p, NULL, true);
2943 }
2944 
2945 /* Worker for cgraph_can_remove_if_no_direct_calls_p.  */
2946 
2947 static bool
2948 used_from_object_file_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
2949 {
2950   return cgraph_used_from_object_file_p (node);
2951 }
2952 
2953 /* Return true when function NODE can be expected to be removed
2954    from program when direct calls in this compilation unit are removed.
2955 
2956    As a special case COMDAT functions are
2957    cgraph_can_remove_if_no_direct_calls_p while the are not
2958    cgraph_only_called_directly_p (it is possible they are called from other
2959    unit)
2960 
2961    This function behaves as cgraph_only_called_directly_p because eliminating
2962    all uses of COMDAT function does not make it necessarily disappear from
2963    the program unless we are compiling whole program or we do LTO.  In this
2964    case we know we win since dynamic linking will not really discard the
2965    linkonce section.  */
2966 
2967 bool
2968 cgraph_will_be_removed_from_program_if_no_direct_calls (struct cgraph_node *node)
2969 {
2970   gcc_assert (!node->global.inlined_to);
2971   if (cgraph_for_node_and_aliases (node, used_from_object_file_p, NULL, true))
2972     return false;
2973   if (!in_lto_p && !flag_whole_program)
2974     return cgraph_only_called_directly_p (node);
2975   else
2976     {
2977        if (DECL_EXTERNAL (node->decl))
2978          return true;
2979       return cgraph_can_remove_if_no_direct_calls_p (node);
2980     }
2981 }
2982 
2983 /* Return true when RESOLUTION indicate that linker will use
2984    the symbol from non-LTO object files.  */
2985 
2986 bool
2987 resolution_used_from_other_file_p (enum ld_plugin_symbol_resolution resolution)
2988 {
2989   return (resolution == LDPR_PREVAILING_DEF
2990           || resolution == LDPR_PREEMPTED_REG
2991           || resolution == LDPR_RESOLVED_EXEC
2992           || resolution == LDPR_RESOLVED_DYN);
2993 }
2994 
2995 
2996 /* Return true when NODE is known to be used from other (non-LTO) object file.
2997    Known only when doing LTO via linker plugin.  */
2998 
2999 bool
3000 cgraph_used_from_object_file_p (struct cgraph_node *node)
3001 {
3002   gcc_assert (!node->global.inlined_to);
3003   if (!TREE_PUBLIC (node->decl) || DECL_EXTERNAL (node->decl))
3004     return false;
3005   if (resolution_used_from_other_file_p (node->resolution))
3006     return true;
3007   return false;
3008 }
3009 
3010 /* Worker for cgraph_only_called_directly_p.  */
3011 
3012 static bool
3013 cgraph_not_only_called_directly_p_1 (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
3014 {
3015   return !cgraph_only_called_directly_or_aliased_p (node);
3016 }
3017 
3018 /* Return true when function NODE and all its aliases are only called
3019    directly.
3020    i.e. it is not externally visible, address was not taken and
3021    it is not used in any other non-standard way.  */
3022 
3023 bool
3024 cgraph_only_called_directly_p (struct cgraph_node *node)
3025 {
3026   gcc_assert (cgraph_function_or_thunk_node (node, NULL) == node);
3027   return !cgraph_for_node_and_aliases (node, cgraph_not_only_called_directly_p_1,
3028 				       NULL, true);
3029 }
3030 
3031 
3032 /* Collect all callers of NODE.  Worker for collect_callers_of_node.  */
3033 
3034 static bool
3035 collect_callers_of_node_1 (struct cgraph_node *node, void *data)
3036 {
3037   VEC (cgraph_edge_p, heap) ** redirect_callers = (VEC (cgraph_edge_p, heap) **)data;
3038   struct cgraph_edge *cs;
3039   enum availability avail;
3040   cgraph_function_or_thunk_node (node, &avail);
3041 
3042   if (avail > AVAIL_OVERWRITABLE)
3043     for (cs = node->callers; cs != NULL; cs = cs->next_caller)
3044       if (!cs->indirect_inlining_edge)
3045         VEC_safe_push (cgraph_edge_p, heap, *redirect_callers, cs);
3046   return false;
3047 }
3048 
3049 /* Collect all callers of NODE and its aliases that are known to lead to NODE
3050    (i.e. are not overwritable).  */
3051 
3052 VEC (cgraph_edge_p, heap) *
3053 collect_callers_of_node (struct cgraph_node *node)
3054 {
3055   VEC (cgraph_edge_p, heap) * redirect_callers = NULL;
3056   cgraph_for_node_and_aliases (node, collect_callers_of_node_1,
3057 			       &redirect_callers, false);
3058   return redirect_callers;
3059 }
3060 
3061 #include "gt-cgraph.h"
3062