1 /* Basic IPA optimizations and utilities.
2 Copyright (C) 2003, 2004, 2005, 2007, 2008 Free Software Foundation,
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
26 #include "tree-pass.h"
31 /* Fill array order with all nodes with output flag set in the reverse
35 cgraph_postorder (struct cgraph_node **order)
37 struct cgraph_node *node, *node2;
40 struct cgraph_edge *edge, last;
43 struct cgraph_node **stack =
44 XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
46 /* We have to deal with cycles nicely, so use a depth first traversal
47 output algorithm. Ignore the fact that some functions won't need
48 to be output and put them into order as well, so we get dependencies
49 right through inline functions. */
50 for (node = cgraph_nodes; node; node = node->next)
52 for (pass = 0; pass < 2; pass++)
53 for (node = cgraph_nodes; node; node = node->next)
56 || (!cgraph_only_called_directly_p (node)
57 && !node->address_taken)))
63 node->aux = node->callers;
66 while (node2->aux != &last)
68 edge = (struct cgraph_edge *) node2->aux;
69 if (edge->next_caller)
70 node2->aux = edge->next_caller;
73 if (!edge->caller->aux)
75 if (!edge->caller->callers)
76 edge->caller->aux = &last;
78 edge->caller->aux = edge->caller->callers;
79 stack[stack_size++] = node2;
84 if (node2->aux == &last)
86 order[order_pos++] = node2;
88 node2 = stack[--stack_size];
95 for (node = cgraph_nodes; node; node = node->next)
100 /* Look for all functions inlined to NODE and update their inlined_to pointers
104 update_inlined_to_pointer (struct cgraph_node *node, struct cgraph_node *inlined_to)
106 struct cgraph_edge *e;
107 for (e = node->callees; e; e = e->next_callee)
108 if (e->callee->global.inlined_to)
110 e->callee->global.inlined_to = inlined_to;
111 update_inlined_to_pointer (e->callee, inlined_to);
115 /* Perform reachability analysis and reclaim all unreachable nodes.
116 If BEFORE_INLINING_P is true this function is called before inlining
117 decisions has been made. If BEFORE_INLINING_P is false this function also
118 removes unneeded bodies of extern inline functions. */
121 cgraph_remove_unreachable_nodes (bool before_inlining_p, FILE *file)
123 struct cgraph_node *first = (struct cgraph_node *) (void *) 1;
124 struct cgraph_node *node, *next;
125 bool changed = false;
127 #ifdef ENABLE_CHECKING
131 fprintf (file, "\nReclaiming functions:");
132 #ifdef ENABLE_CHECKING
133 for (node = cgraph_nodes; node; node = node->next)
134 gcc_assert (!node->aux);
136 for (node = cgraph_nodes; node; node = node->next)
137 if (!cgraph_can_remove_if_no_direct_calls_p (node)
138 && ((!DECL_EXTERNAL (node->decl))
140 || before_inlining_p))
142 gcc_assert (!node->global.inlined_to);
147 gcc_assert (!node->aux);
149 /* Perform reachability analysis. As a special case do not consider
150 extern inline functions not inlined as live because we won't output
152 while (first != (void *) 1)
154 struct cgraph_edge *e;
156 first = (struct cgraph_node *) first->aux;
158 for (e = node->callees; e; e = e->next_callee)
161 && (!e->inline_failed || !e->callee->analyzed
162 || (!DECL_EXTERNAL (e->callee->decl))
163 || before_inlining_p))
165 e->callee->aux = first;
168 while (node->clone_of && !node->clone_of->aux && !gimple_has_body_p (node->decl))
170 node = node->clone_of;
176 /* Remove unreachable nodes. Extern inline functions need special care;
177 Unreachable extern inline functions shall be removed.
178 Reachable extern inline functions we never inlined shall get their bodies
180 Reachable extern inline functions we sometimes inlined will be turned into
181 unanalyzed nodes so they look like for true extern functions to the rest
182 of code. Body of such functions is released via remove_node once the
183 inline clones are eliminated. */
184 for (node = cgraph_nodes; node; node = next)
189 node->global.inlined_to = NULL;
191 fprintf (file, " %s", cgraph_node_name (node));
192 if (!node->analyzed || !DECL_EXTERNAL (node->decl)
193 || before_inlining_p)
194 cgraph_remove_node (node);
197 struct cgraph_edge *e;
199 /* See if there is reachable caller. */
200 for (e = node->callers; e; e = e->next_caller)
204 /* If so, we need to keep node in the callgraph. */
205 if (e || node->needed)
207 struct cgraph_node *clone;
209 /* If there are still clones, we must keep body around.
210 Otherwise we can just remove the body but keep the clone. */
211 for (clone = node->clones; clone;
212 clone = clone->next_sibling_clone)
217 cgraph_release_function_body (node);
218 cgraph_node_remove_callees (node);
219 node->analyzed = false;
220 node->local.inlinable = false;
224 cgraph_remove_node (node);
229 for (node = cgraph_nodes; node; node = node->next)
231 /* Inline clones might be kept around so their materializing allows further
232 cloning. If the function the clone is inlined into is removed, we need
233 to turn it into normal cone. */
234 if (node->global.inlined_to
237 gcc_assert (node->clones);
238 node->global.inlined_to = NULL;
239 update_inlined_to_pointer (node, node);
243 #ifdef ENABLE_CHECKING
247 /* Reclaim alias pairs for functions that have disappeared from the
249 remove_unreachable_alias_pairs ();
255 cgraph_externally_visible_p (struct cgraph_node *node, bool whole_program)
257 if (!DECL_COMDAT (node->decl)
258 && (!TREE_PUBLIC (node->decl) || DECL_EXTERNAL (node->decl)))
262 /* COMDAT functions must be shared only if they have address taken,
263 otherwise we can produce our own private implementation with
265 if (DECL_COMDAT (node->decl) && (node->address_taken || !node->analyzed))
267 if (MAIN_NAME_P (DECL_NAME (node->decl)))
269 if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (node->decl)))
274 /* Mark visibility of all functions.
276 A local function is one whose calls can occur only in the current
277 compilation unit and all its calls are explicit, so we can change
278 its calling convention. We simply mark all static functions whose
279 address is not taken as local.
281 We also change the TREE_PUBLIC flag of all declarations that are public
282 in language point of view but we want to overwrite this default
283 via visibilities for the backend point of view. */
286 function_and_variable_visibility (bool whole_program)
288 struct cgraph_node *node;
289 struct varpool_node *vnode;
291 for (node = cgraph_nodes; node; node = node->next)
293 if (cgraph_externally_visible_p (node, whole_program))
295 gcc_assert (!node->global.inlined_to);
296 node->local.externally_visible = true;
299 node->local.externally_visible = false;
300 if (!node->local.externally_visible && node->analyzed
301 && !DECL_EXTERNAL (node->decl))
303 gcc_assert (whole_program || !TREE_PUBLIC (node->decl));
304 TREE_PUBLIC (node->decl) = 0;
305 DECL_COMDAT (node->decl) = 0;
306 DECL_WEAK (node->decl) = 0;
308 node->local.local = (cgraph_only_called_directly_p (node)
310 && !DECL_EXTERNAL (node->decl)
311 && !node->local.externally_visible);
313 for (vnode = varpool_nodes_queue; vnode; vnode = vnode->next_needed)
316 && (DECL_COMDAT (vnode->decl) || TREE_PUBLIC (vnode->decl))
318 || lookup_attribute ("externally_visible",
319 DECL_ATTRIBUTES (vnode->decl))))
320 vnode->externally_visible = true;
322 vnode->externally_visible = false;
323 if (!vnode->externally_visible)
325 gcc_assert (whole_program || !TREE_PUBLIC (vnode->decl));
326 TREE_PUBLIC (vnode->decl) = 0;
328 gcc_assert (TREE_STATIC (vnode->decl));
333 fprintf (dump_file, "\nMarking local functions:");
334 for (node = cgraph_nodes; node; node = node->next)
335 if (node->local.local)
336 fprintf (dump_file, " %s", cgraph_node_name (node));
337 fprintf (dump_file, "\n\n");
338 fprintf (dump_file, "\nMarking externally visible functions:");
339 for (node = cgraph_nodes; node; node = node->next)
340 if (node->local.externally_visible)
341 fprintf (dump_file, " %s", cgraph_node_name (node));
342 fprintf (dump_file, "\n\n");
344 cgraph_function_flags_ready = true;
348 /* Local function pass handling visibilities. This happens before LTO streaming
349 so in particular -fwhole-program should be ignored at this level. */
352 local_function_and_variable_visibility (void)
354 return function_and_variable_visibility (flag_whole_program && !flag_lto && !flag_whopr);
357 struct simple_ipa_opt_pass pass_ipa_function_and_variable_visibility =
361 "visibility", /* name */
363 local_function_and_variable_visibility,/* execute */
366 0, /* static_pass_number */
367 TV_CGRAPHOPT, /* tv_id */
368 0, /* properties_required */
369 0, /* properties_provided */
370 0, /* properties_destroyed */
371 0, /* todo_flags_start */
372 TODO_remove_functions | TODO_dump_cgraph/* todo_flags_finish */
376 /* Do not re-run on ltrans stage. */
379 gate_whole_program_function_and_variable_visibility (void)
384 /* Bring functionss local at LTO time whith -fwhole-program. */
387 whole_program_function_and_variable_visibility (void)
389 struct cgraph_node *node;
390 struct varpool_node *vnode;
392 function_and_variable_visibility (flag_whole_program);
394 for (node = cgraph_nodes; node; node = node->next)
395 if (node->local.externally_visible)
396 cgraph_mark_needed_node (node);
397 for (vnode = varpool_nodes_queue; vnode; vnode = vnode->next_needed)
398 if (vnode->externally_visible)
399 varpool_mark_needed_node (vnode);
403 struct ipa_opt_pass_d pass_ipa_whole_program_visibility =
407 "whole-program", /* name */
408 gate_whole_program_function_and_variable_visibility,/* gate */
409 whole_program_function_and_variable_visibility,/* execute */
412 0, /* static_pass_number */
413 TV_CGRAPHOPT, /* tv_id */
414 0, /* properties_required */
415 0, /* properties_provided */
416 0, /* properties_destroyed */
417 0, /* todo_flags_start */
418 TODO_dump_cgraph | TODO_remove_functions/* todo_flags_finish */
420 NULL, /* generate_summary */
421 NULL, /* write_summary */
422 NULL, /* read_summary */
423 NULL, /* function_read_summary */
425 NULL, /* function_transform */
426 NULL, /* variable_transform */
429 /* Hash a cgraph node set element. */
432 hash_cgraph_node_set_element (const void *p)
434 const_cgraph_node_set_element element = (const_cgraph_node_set_element) p;
435 return htab_hash_pointer (element->node);
438 /* Compare two cgraph node set elements. */
441 eq_cgraph_node_set_element (const void *p1, const void *p2)
443 const_cgraph_node_set_element e1 = (const_cgraph_node_set_element) p1;
444 const_cgraph_node_set_element e2 = (const_cgraph_node_set_element) p2;
446 return e1->node == e2->node;
449 /* Create a new cgraph node set. */
452 cgraph_node_set_new (void)
454 cgraph_node_set new_node_set;
456 new_node_set = GGC_NEW (struct cgraph_node_set_def);
457 new_node_set->hashtab = htab_create_ggc (10,
458 hash_cgraph_node_set_element,
459 eq_cgraph_node_set_element,
461 new_node_set->nodes = NULL;
465 /* Add cgraph_node NODE to cgraph_node_set SET. */
468 cgraph_node_set_add (cgraph_node_set set, struct cgraph_node *node)
471 cgraph_node_set_element element;
472 struct cgraph_node_set_element_def dummy;
475 slot = htab_find_slot (set->hashtab, &dummy, INSERT);
477 if (*slot != HTAB_EMPTY_ENTRY)
479 element = (cgraph_node_set_element) *slot;
480 gcc_assert (node == element->node
481 && (VEC_index (cgraph_node_ptr, set->nodes, element->index)
486 /* Insert node into hash table. */
488 (cgraph_node_set_element) GGC_NEW (struct cgraph_node_set_element_def);
489 element->node = node;
490 element->index = VEC_length (cgraph_node_ptr, set->nodes);
493 /* Insert into node vector. */
494 VEC_safe_push (cgraph_node_ptr, gc, set->nodes, node);
497 /* Remove cgraph_node NODE from cgraph_node_set SET. */
500 cgraph_node_set_remove (cgraph_node_set set, struct cgraph_node *node)
502 void **slot, **last_slot;
503 cgraph_node_set_element element, last_element;
504 struct cgraph_node *last_node;
505 struct cgraph_node_set_element_def dummy;
508 slot = htab_find_slot (set->hashtab, &dummy, NO_INSERT);
512 element = (cgraph_node_set_element) *slot;
513 gcc_assert (VEC_index (cgraph_node_ptr, set->nodes, element->index)
516 /* Remove from vector. We do this by swapping node with the last element
518 last_node = VEC_pop (cgraph_node_ptr, set->nodes);
519 if (last_node != node)
521 dummy.node = last_node;
522 last_slot = htab_find_slot (set->hashtab, &dummy, NO_INSERT);
523 last_element = (cgraph_node_set_element) *last_slot;
524 gcc_assert (last_element);
526 /* Move the last element to the original spot of NODE. */
527 last_element->index = element->index;
528 VEC_replace (cgraph_node_ptr, set->nodes, last_element->index,
532 /* Remove element from hash table. */
533 htab_clear_slot (set->hashtab, slot);
537 /* Find NODE in SET and return an iterator to it if found. A null iterator
538 is returned if NODE is not in SET. */
540 cgraph_node_set_iterator
541 cgraph_node_set_find (cgraph_node_set set, struct cgraph_node *node)
544 struct cgraph_node_set_element_def dummy;
545 cgraph_node_set_element element;
546 cgraph_node_set_iterator csi;
549 slot = htab_find_slot (set->hashtab, &dummy, NO_INSERT);
551 csi.index = (unsigned) ~0;
554 element = (cgraph_node_set_element) *slot;
555 gcc_assert (VEC_index (cgraph_node_ptr, set->nodes, element->index)
557 csi.index = element->index;
564 /* Dump content of SET to file F. */
567 dump_cgraph_node_set (FILE *f, cgraph_node_set set)
569 cgraph_node_set_iterator iter;
571 for (iter = csi_start (set); !csi_end_p (iter); csi_next (&iter))
573 struct cgraph_node *node = csi_node (iter);
574 dump_cgraph_node (f, node);
578 /* Dump content of SET to stderr. */
581 debug_cgraph_node_set (cgraph_node_set set)
583 dump_cgraph_node_set (stderr, set);