decl.c (java_expand_body): Kill.
[gcc.git] / gcc / cgraphunit.c
1 /* Callgraph based interprocedural optimizations.
2 Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
3 Contributed by Jan Hubicka
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 /* This module implements main driver of compilation process as well as
22 few basic interprocedural optimizers.
23
24 The main scope of this file is to act as an interface in between
25 tree based frontends and the backend (and middle end)
26
27 The front-end is supposed to use following functionality:
28
29 - cgraph_finalize_function
30
31 This function is called once front-end has parsed whole body of function
32 and it is certain that the function body nor the declaration will change.
33
34 (There is one exception needed for implementing GCC extern inline
35 function.)
36
37 - varpool_finalize_variable
38
39 This function has same behavior as the above but is used for static
40 variables.
41
42 - cgraph_finalize_compilation_unit
43
44 This function is called once (source level) compilation unit is finalized
45 and it will no longer change.
46
47 In the unit-at-a-time the call-graph construction and local function
48 analysis takes place here. Bodies of unreachable functions are released
49 to conserve memory usage.
50
51 The function can be called multiple times when multiple source level
52 compilation units are combined (such as in C frontend)
53
54 - cgraph_optimize
55
56 In this unit-at-a-time compilation the intra procedural analysis takes
57 place here. In particular the static functions whose address is never
58 taken are marked as local. Backend can then use this information to
59 modify calling conventions, do better inlining or similar optimizations.
60
61 - cgraph_mark_needed_node
62 - varpool_mark_needed_node
63
64 When function or variable is referenced by some hidden way the call-graph
65 data structure must be updated accordingly by this function.
66 There should be little need to call this function and all the references
67 should be made explicit to cgraph code. At present these functions are
68 used by C++ frontend to explicitly mark the keyed methods.
69
70 - analyze_expr callback
71
72 This function is responsible for lowering tree nodes not understood by
73 generic code into understandable ones or alternatively marking
74 callgraph and varpool nodes referenced by the as needed.
75
76 ??? On the tree-ssa genericizing should take place here and we will avoid
77 need for these hooks (replacing them by genericizing hook)
78
79 We implement two compilation modes.
80
81 - unit-at-a-time: In this mode analyzing of all functions is deferred
82 to cgraph_finalize_compilation_unit and expansion into cgraph_optimize.
83
84 In cgraph_finalize_compilation_unit the reachable functions are
85 analyzed. During analysis the call-graph edges from reachable
86 functions are constructed and their destinations are marked as
87 reachable. References to functions and variables are discovered too
88 and variables found to be needed output to the assembly file. Via
89 mark_referenced call in assemble_variable functions referenced by
90 static variables are noticed too.
91
92 The intra-procedural information is produced and its existence
93 indicated by global_info_ready. Once this flag is set it is impossible
94 to change function from !reachable to reachable and thus
95 assemble_variable no longer call mark_referenced.
96
97 Finally the call-graph is topologically sorted and all reachable functions
98 that has not been completely inlined or are not external are output.
99
100 ??? It is possible that reference to function or variable is optimized
101 out. We can not deal with this nicely because topological order is not
102 suitable for it. For tree-ssa we may consider another pass doing
103 optimization and re-discovering reachable functions.
104
105 ??? Reorganize code so variables are output very last and only if they
106 really has been referenced by produced code, so we catch more cases
107 where reference has been optimized out.
108
109 - non-unit-at-a-time
110
111 All functions are variables are output as early as possible to conserve
112 memory consumption. This may or may not result in less memory used but
113 it is still needed for some legacy code that rely on particular ordering
114 of things output from the compiler.
115
116 Varpool data structures are not used and variables are output directly.
117
118 Functions are output early using call of
119 cgraph_assemble_pending_function from cgraph_finalize_function. The
120 decision on whether function is needed is made more conservative so
121 uninlininable static functions are needed too. During the call-graph
122 construction the edge destinations are not marked as reachable and it
123 is completely relied upn assemble_variable to mark them. */
124
125
126 #include "config.h"
127 #include "system.h"
128 #include "coretypes.h"
129 #include "tm.h"
130 #include "tree.h"
131 #include "rtl.h"
132 #include "tree-flow.h"
133 #include "tree-inline.h"
134 #include "langhooks.h"
135 #include "pointer-set.h"
136 #include "toplev.h"
137 #include "flags.h"
138 #include "ggc.h"
139 #include "debug.h"
140 #include "target.h"
141 #include "cgraph.h"
142 #include "diagnostic.h"
143 #include "timevar.h"
144 #include "params.h"
145 #include "fibheap.h"
146 #include "c-common.h"
147 #include "intl.h"
148 #include "function.h"
149 #include "ipa-prop.h"
150 #include "tree-gimple.h"
151 #include "tree-pass.h"
152 #include "output.h"
153
154 static void cgraph_expand_all_functions (void);
155 static void cgraph_mark_functions_to_output (void);
156 static void cgraph_expand_function (struct cgraph_node *);
157 static void cgraph_output_pending_asms (void);
158
159 static FILE *cgraph_dump_file;
160
161 static GTY (()) tree static_ctors;
162 static GTY (()) tree static_dtors;
163
164 /* When target does not have ctors and dtors, we call all constructor
165 and destructor by special initialization/destruction function
166 recognized by collect2.
167
168 When we are going to build this function, collect all constructors and
169 destructors and turn them into normal functions. */
170
171 static void
172 record_cdtor_fn (tree fndecl)
173 {
174 struct cgraph_node *node;
175 if (targetm.have_ctors_dtors
176 || (!DECL_STATIC_CONSTRUCTOR (fndecl)
177 && !DECL_STATIC_DESTRUCTOR (fndecl)))
178 return;
179
180 if (DECL_STATIC_CONSTRUCTOR (fndecl))
181 {
182 static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors);
183 DECL_STATIC_CONSTRUCTOR (fndecl) = 0;
184 }
185 if (DECL_STATIC_DESTRUCTOR (fndecl))
186 {
187 static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors);
188 DECL_STATIC_DESTRUCTOR (fndecl) = 0;
189 }
190 DECL_INLINE (fndecl) = 1;
191 node = cgraph_node (fndecl);
192 node->local.disregard_inline_limits = 1;
193 cgraph_mark_reachable_node (node);
194 }
195
196 /* Synthesize a function which calls all the global ctors or global
197 dtors in this file. This is only used for targets which do not
198 support .ctors/.dtors sections. */
199 static void
200 build_cdtor (int method_type, tree cdtors)
201 {
202 tree body = 0;
203
204 if (!cdtors)
205 return;
206
207 for (; cdtors; cdtors = TREE_CHAIN (cdtors))
208 append_to_statement_list (build_function_call_expr (TREE_VALUE (cdtors), 0),
209 &body);
210
211 cgraph_build_static_cdtor (method_type, body, DEFAULT_INIT_PRIORITY);
212 }
213
214 /* Generate functions to call static constructors and destructors
215 for targets that do not support .ctors/.dtors sections. These
216 functions have magic names which are detected by collect2. */
217
218 static void
219 cgraph_build_cdtor_fns (void)
220 {
221 if (!targetm.have_ctors_dtors)
222 {
223 build_cdtor ('I', static_ctors);
224 static_ctors = NULL_TREE;
225 build_cdtor ('D', static_dtors);
226 static_dtors = NULL_TREE;
227 }
228 else
229 {
230 gcc_assert (!static_ctors);
231 gcc_assert (!static_dtors);
232 }
233 }
234
235 /* Determine if function DECL is needed. That is, visible to something
236 either outside this translation unit, something magic in the system
237 configury, or (if not doing unit-at-a-time) to something we havn't
238 seen yet. */
239
240 static bool
241 decide_is_function_needed (struct cgraph_node *node, tree decl)
242 {
243 tree origin;
244 if (MAIN_NAME_P (DECL_NAME (decl))
245 && TREE_PUBLIC (decl))
246 {
247 node->local.externally_visible = true;
248 return true;
249 }
250
251 /* If the user told us it is used, then it must be so. */
252 if (node->local.externally_visible)
253 return true;
254
255 if (!flag_unit_at_a_time && lookup_attribute ("used", DECL_ATTRIBUTES (decl)))
256 return true;
257
258 /* ??? If the assembler name is set by hand, it is possible to assemble
259 the name later after finalizing the function and the fact is noticed
260 in assemble_name then. This is arguably a bug. */
261 if (DECL_ASSEMBLER_NAME_SET_P (decl)
262 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))
263 return true;
264
265 /* With -fkeep-inline-functions we are keeping all inline functions except
266 for extern inline ones. */
267 if (flag_keep_inline_functions
268 && DECL_DECLARED_INLINE_P (decl)
269 && !DECL_EXTERNAL (decl)
270 && !lookup_attribute ("always_inline", DECL_ATTRIBUTES (decl)))
271 return true;
272
273 /* If we decided it was needed before, but at the time we didn't have
274 the body of the function available, then it's still needed. We have
275 to go back and re-check its dependencies now. */
276 if (node->needed)
277 return true;
278
279 /* Externally visible functions must be output. The exception is
280 COMDAT functions that must be output only when they are needed.
281
282 When not optimizing, also output the static functions. (see
283 PR24561), but don't do so for always_inline functions, functions
284 declared inline and nested functions. These was optimized out
285 in the original implementation and it is unclear whether we want
286 to change the behavior here. */
287 if (((TREE_PUBLIC (decl)
288 || (!optimize && !node->local.disregard_inline_limits
289 && !DECL_DECLARED_INLINE_P (decl)
290 && !node->origin))
291 && !flag_whole_program)
292 && !DECL_COMDAT (decl) && !DECL_EXTERNAL (decl))
293 return true;
294
295 /* Constructors and destructors are reachable from the runtime by
296 some mechanism. */
297 if (DECL_STATIC_CONSTRUCTOR (decl) || DECL_STATIC_DESTRUCTOR (decl))
298 return true;
299
300 if (flag_unit_at_a_time)
301 return false;
302
303 /* If not doing unit at a time, then we'll only defer this function
304 if its marked for inlining. Otherwise we want to emit it now. */
305
306 /* "extern inline" functions are never output locally. */
307 if (DECL_EXTERNAL (decl))
308 return false;
309 /* Nested functions of extern inline function shall not be emit unless
310 we inlined the origin. */
311 for (origin = decl_function_context (decl); origin;
312 origin = decl_function_context (origin))
313 if (DECL_EXTERNAL (origin))
314 return false;
315 /* We want to emit COMDAT functions only when absolutely necessary. */
316 if (DECL_COMDAT (decl))
317 return false;
318 if (!DECL_INLINE (decl)
319 || (!node->local.disregard_inline_limits
320 /* When declared inline, defer even the uninlinable functions.
321 This allows them to be eliminated when unused. */
322 && !DECL_DECLARED_INLINE_P (decl)
323 && (!node->local.inlinable || !cgraph_default_inline_p (node, NULL))))
324 return true;
325
326 return false;
327 }
328
329 /* Process CGRAPH_NEW_FUNCTIONS and perform actions necessary to add these
330 functions into callgraph in a way so they look like ordinary reachable
331 functions inserted into callgraph already at construction time. */
332
333 bool
334 cgraph_process_new_functions (void)
335 {
336 bool output = false;
337 tree fndecl;
338 struct cgraph_node *node;
339
340 /* Note that this queue may grow as its being processed, as the new
341 functions may generate new ones. */
342 while (cgraph_new_nodes)
343 {
344 node = cgraph_new_nodes;
345 fndecl = node->decl;
346 cgraph_new_nodes = cgraph_new_nodes->next_needed;
347 switch (cgraph_state)
348 {
349 case CGRAPH_STATE_CONSTRUCTION:
350 /* At construction time we just need to finalize function and move
351 it into reachable functions list. */
352
353 node->next_needed = NULL;
354 node->needed = node->reachable = false;
355 cgraph_finalize_function (fndecl, false);
356 cgraph_mark_reachable_node (node);
357 output = true;
358 break;
359
360 case CGRAPH_STATE_IPA:
361 case CGRAPH_STATE_IPA_SSA:
362 /* When IPA optimization already started, do all essential
363 transformations that has been already performed on the whole
364 cgraph but not on this function. */
365
366 tree_register_cfg_hooks ();
367 if (!node->analyzed)
368 cgraph_analyze_function (node);
369 push_cfun (DECL_STRUCT_FUNCTION (fndecl));
370 current_function_decl = fndecl;
371 node->local.inlinable = tree_inlinable_function_p (fndecl);
372 node->local.self_insns = estimate_num_insns (fndecl,
373 &eni_inlining_weights);
374 node->local.disregard_inline_limits
375 |= DECL_DISREGARD_INLINE_LIMITS (fndecl);
376 /* Inlining characteristics are maintained by the
377 cgraph_mark_inline. */
378 node->global.insns = node->local.self_insns;
379 if (flag_really_no_inline && !node->local.disregard_inline_limits)
380 node->local.inlinable = 0;
381 if ((cgraph_state == CGRAPH_STATE_IPA_SSA
382 && !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (fndecl)))
383 /* When not optimizing, be sure we run early local passes anyway
384 to expand OMP. */
385 || !optimize)
386 execute_pass_list (pass_early_local_passes.sub);
387 free_dominance_info (CDI_POST_DOMINATORS);
388 free_dominance_info (CDI_DOMINATORS);
389 pop_cfun ();
390 current_function_decl = NULL;
391 break;
392
393 case CGRAPH_STATE_EXPANSION:
394 /* Functions created during expansion shall be compiled
395 directly. */
396 node->output = 0;
397 cgraph_expand_function (node);
398 break;
399
400 default:
401 gcc_unreachable ();
402 break;
403 }
404 }
405 return output;
406 }
407
408 /* When not doing unit-at-a-time, output all functions enqueued.
409 Return true when such a functions were found. */
410
411 static bool
412 cgraph_assemble_pending_functions (void)
413 {
414 bool output = false;
415
416 if (flag_unit_at_a_time)
417 return false;
418
419 cgraph_output_pending_asms ();
420
421 while (cgraph_nodes_queue)
422 {
423 struct cgraph_node *n = cgraph_nodes_queue;
424
425 cgraph_nodes_queue = cgraph_nodes_queue->next_needed;
426 n->next_needed = NULL;
427 if (!n->global.inlined_to
428 && !n->alias
429 && !DECL_EXTERNAL (n->decl))
430 {
431 cgraph_expand_function (n);
432 output = true;
433 }
434 output |= cgraph_process_new_functions ();
435 }
436
437 return output;
438 }
439
440
441 /* As an GCC extension we allow redefinition of the function. The
442 semantics when both copies of bodies differ is not well defined.
443 We replace the old body with new body so in unit at a time mode
444 we always use new body, while in normal mode we may end up with
445 old body inlined into some functions and new body expanded and
446 inlined in others.
447
448 ??? It may make more sense to use one body for inlining and other
449 body for expanding the function but this is difficult to do. */
450
451 static void
452 cgraph_reset_node (struct cgraph_node *node)
453 {
454 /* If node->output is set, then this is a unit-at-a-time compilation
455 and we have already begun whole-unit analysis. This is *not*
456 testing for whether we've already emitted the function. That
457 case can be sort-of legitimately seen with real function
458 redefinition errors. I would argue that the front end should
459 never present us with such a case, but don't enforce that for now. */
460 gcc_assert (!node->output);
461
462 /* Reset our data structures so we can analyze the function again. */
463 memset (&node->local, 0, sizeof (node->local));
464 memset (&node->global, 0, sizeof (node->global));
465 memset (&node->rtl, 0, sizeof (node->rtl));
466 node->analyzed = false;
467 node->local.redefined_extern_inline = true;
468 node->local.finalized = false;
469
470 if (!flag_unit_at_a_time)
471 {
472 struct cgraph_node *n, *next;
473
474 for (n = cgraph_nodes; n; n = next)
475 {
476 next = n->next;
477 if (n->global.inlined_to == node)
478 cgraph_remove_node (n);
479 }
480 }
481
482 cgraph_node_remove_callees (node);
483
484 /* We may need to re-queue the node for assembling in case
485 we already proceeded it and ignored as not needed. */
486 if (node->reachable && !flag_unit_at_a_time)
487 {
488 struct cgraph_node *n;
489
490 for (n = cgraph_nodes_queue; n; n = n->next_needed)
491 if (n == node)
492 break;
493 if (!n)
494 node->reachable = 0;
495 }
496 }
497
498 static void
499 cgraph_lower_function (struct cgraph_node *node)
500 {
501 if (node->lowered)
502 return;
503 tree_lowering_passes (node->decl);
504 node->lowered = true;
505 }
506
507 /* DECL has been parsed. Take it, queue it, compile it at the whim of the
508 logic in effect. If NESTED is true, then our caller cannot stand to have
509 the garbage collector run at the moment. We would need to either create
510 a new GC context, or just not compile right now. */
511
512 void
513 cgraph_finalize_function (tree decl, bool nested)
514 {
515 struct cgraph_node *node = cgraph_node (decl);
516
517 if (node->local.finalized)
518 cgraph_reset_node (node);
519
520 node->pid = cgraph_max_pid ++;
521 notice_global_symbol (decl);
522 node->decl = decl;
523 node->local.finalized = true;
524 node->lowered = DECL_STRUCT_FUNCTION (decl)->cfg != NULL;
525 record_cdtor_fn (node->decl);
526 if (node->nested)
527 lower_nested_functions (decl);
528 gcc_assert (!node->nested);
529
530 /* If not unit at a time, then we need to create the call graph
531 now, so that called functions can be queued and emitted now. */
532 if (!flag_unit_at_a_time)
533 cgraph_analyze_function (node);
534
535 if (decide_is_function_needed (node, decl))
536 cgraph_mark_needed_node (node);
537
538 /* Since we reclaim unreachable nodes at the end of every language
539 level unit, we need to be conservative about possible entry points
540 there. */
541 if ((TREE_PUBLIC (decl) && !DECL_COMDAT (decl) && !DECL_EXTERNAL (decl)))
542 cgraph_mark_reachable_node (node);
543
544 /* If not unit at a time, go ahead and emit everything we've found
545 to be reachable at this time. */
546 if (!nested)
547 {
548 if (!cgraph_assemble_pending_functions ())
549 ggc_collect ();
550 }
551
552 /* If we've not yet emitted decl, tell the debug info about it. */
553 if (!TREE_ASM_WRITTEN (decl))
554 (*debug_hooks->deferred_inline_function) (decl);
555
556 /* Possibly warn about unused parameters. */
557 if (warn_unused_parameter)
558 do_warn_unused_parameter (decl);
559 }
560
561 /* Verify cgraph nodes of given cgraph node. */
562 void
563 verify_cgraph_node (struct cgraph_node *node)
564 {
565 struct cgraph_edge *e;
566 struct cgraph_node *main_clone;
567 struct function *this_cfun = DECL_STRUCT_FUNCTION (node->decl);
568 basic_block this_block;
569 block_stmt_iterator bsi;
570 bool error_found = false;
571
572 if (errorcount || sorrycount)
573 return;
574
575 timevar_push (TV_CGRAPH_VERIFY);
576 for (e = node->callees; e; e = e->next_callee)
577 if (e->aux)
578 {
579 error ("aux field set for edge %s->%s",
580 cgraph_node_name (e->caller), cgraph_node_name (e->callee));
581 error_found = true;
582 }
583 if (node->count < 0)
584 {
585 error ("Execution count is negative");
586 error_found = true;
587 }
588 for (e = node->callers; e; e = e->next_caller)
589 {
590 if (e->count < 0)
591 {
592 error ("caller edge count is negative");
593 error_found = true;
594 }
595 if (e->frequency < 0)
596 {
597 error ("caller edge frequency is negative");
598 error_found = true;
599 }
600 if (e->frequency > CGRAPH_FREQ_MAX)
601 {
602 error ("caller edge frequency is too large");
603 error_found = true;
604 }
605 if (!e->inline_failed)
606 {
607 if (node->global.inlined_to
608 != (e->caller->global.inlined_to
609 ? e->caller->global.inlined_to : e->caller))
610 {
611 error ("inlined_to pointer is wrong");
612 error_found = true;
613 }
614 if (node->callers->next_caller)
615 {
616 error ("multiple inline callers");
617 error_found = true;
618 }
619 }
620 else
621 if (node->global.inlined_to)
622 {
623 error ("inlined_to pointer set for noninline callers");
624 error_found = true;
625 }
626 }
627 if (!node->callers && node->global.inlined_to)
628 {
629 error ("inlined_to pointer is set but no predecessors found");
630 error_found = true;
631 }
632 if (node->global.inlined_to == node)
633 {
634 error ("inlined_to pointer refers to itself");
635 error_found = true;
636 }
637
638 for (main_clone = cgraph_node (node->decl); main_clone;
639 main_clone = main_clone->next_clone)
640 if (main_clone == node)
641 break;
642 if (!cgraph_node (node->decl))
643 {
644 error ("node not found in cgraph_hash");
645 error_found = true;
646 }
647
648 if (node->analyzed
649 && DECL_SAVED_TREE (node->decl) && !TREE_ASM_WRITTEN (node->decl)
650 && (!DECL_EXTERNAL (node->decl) || node->global.inlined_to))
651 {
652 if (this_cfun->cfg)
653 {
654 /* The nodes we're interested in are never shared, so walk
655 the tree ignoring duplicates. */
656 struct pointer_set_t *visited_nodes = pointer_set_create ();
657 /* Reach the trees by walking over the CFG, and note the
658 enclosing basic-blocks in the call edges. */
659 FOR_EACH_BB_FN (this_block, this_cfun)
660 for (bsi = bsi_start (this_block); !bsi_end_p (bsi); bsi_next (&bsi))
661 {
662 tree stmt = bsi_stmt (bsi);
663 tree call = get_call_expr_in (stmt);
664 tree decl;
665 if (call && (decl = get_callee_fndecl (call)))
666 {
667 struct cgraph_edge *e = cgraph_edge (node, stmt);
668 if (e)
669 {
670 if (e->aux)
671 {
672 error ("shared call_stmt:");
673 debug_generic_stmt (stmt);
674 error_found = true;
675 }
676 if (e->callee->decl != cgraph_node (decl)->decl
677 && e->inline_failed)
678 {
679 error ("edge points to wrong declaration:");
680 debug_tree (e->callee->decl);
681 fprintf (stderr," Instead of:");
682 debug_tree (decl);
683 }
684 e->aux = (void *)1;
685 }
686 else
687 {
688 error ("missing callgraph edge for call stmt:");
689 debug_generic_stmt (stmt);
690 error_found = true;
691 }
692 }
693 }
694 pointer_set_destroy (visited_nodes);
695 }
696 else
697 /* No CFG available?! */
698 gcc_unreachable ();
699
700 for (e = node->callees; e; e = e->next_callee)
701 {
702 if (!e->aux)
703 {
704 error ("edge %s->%s has no corresponding call_stmt",
705 cgraph_node_name (e->caller),
706 cgraph_node_name (e->callee));
707 debug_generic_stmt (e->call_stmt);
708 error_found = true;
709 }
710 e->aux = 0;
711 }
712 }
713 if (error_found)
714 {
715 dump_cgraph_node (stderr, node);
716 internal_error ("verify_cgraph_node failed");
717 }
718 timevar_pop (TV_CGRAPH_VERIFY);
719 }
720
721 /* Verify whole cgraph structure. */
722 void
723 verify_cgraph (void)
724 {
725 struct cgraph_node *node;
726
727 if (sorrycount || errorcount)
728 return;
729
730 for (node = cgraph_nodes; node; node = node->next)
731 verify_cgraph_node (node);
732 }
733
734 /* Output all asm statements we have stored up to be output. */
735
736 static void
737 cgraph_output_pending_asms (void)
738 {
739 struct cgraph_asm_node *can;
740
741 if (errorcount || sorrycount)
742 return;
743
744 for (can = cgraph_asm_nodes; can; can = can->next)
745 assemble_asm (can->asm_str);
746 cgraph_asm_nodes = NULL;
747 }
748
749 /* Analyze the function scheduled to be output. */
750 void
751 cgraph_analyze_function (struct cgraph_node *node)
752 {
753 tree decl = node->decl;
754
755 current_function_decl = decl;
756 push_cfun (DECL_STRUCT_FUNCTION (decl));
757 cgraph_lower_function (node);
758 node->analyzed = true;
759
760 if (!flag_unit_at_a_time)
761 {
762 bitmap_obstack_initialize (NULL);
763 tree_register_cfg_hooks ();
764 execute_pass_list (pass_early_local_passes.sub);
765 free_dominance_info (CDI_POST_DOMINATORS);
766 free_dominance_info (CDI_DOMINATORS);
767 bitmap_obstack_release (NULL);
768 }
769
770 pop_cfun ();
771 current_function_decl = NULL;
772 }
773
774 /* Look for externally_visible and used attributes and mark cgraph nodes
775 accordingly.
776
777 We cannot mark the nodes at the point the attributes are processed (in
778 handle_*_attribute) because the copy of the declarations available at that
779 point may not be canonical. For example, in:
780
781 void f();
782 void f() __attribute__((used));
783
784 the declaration we see in handle_used_attribute will be the second
785 declaration -- but the front end will subsequently merge that declaration
786 with the original declaration and discard the second declaration.
787
788 Furthermore, we can't mark these nodes in cgraph_finalize_function because:
789
790 void f() {}
791 void f() __attribute__((externally_visible));
792
793 is valid.
794
795 So, we walk the nodes at the end of the translation unit, applying the
796 attributes at that point. */
797
798 static void
799 process_function_and_variable_attributes (struct cgraph_node *first,
800 struct varpool_node *first_var)
801 {
802 struct cgraph_node *node;
803 struct varpool_node *vnode;
804
805 for (node = cgraph_nodes; node != first; node = node->next)
806 {
807 tree decl = node->decl;
808 if (lookup_attribute ("used", DECL_ATTRIBUTES (decl)))
809 {
810 mark_decl_referenced (decl);
811 if (node->local.finalized)
812 cgraph_mark_needed_node (node);
813 }
814 if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (decl)))
815 {
816 if (! TREE_PUBLIC (node->decl))
817 warning (OPT_Wattributes,
818 "%J%<externally_visible%> attribute have effect only on public objects",
819 node->decl);
820 else
821 {
822 if (node->local.finalized)
823 cgraph_mark_needed_node (node);
824 node->local.externally_visible = true;
825 }
826 }
827 }
828 for (vnode = varpool_nodes; vnode != first_var; vnode = vnode->next)
829 {
830 tree decl = vnode->decl;
831 if (lookup_attribute ("used", DECL_ATTRIBUTES (decl)))
832 {
833 mark_decl_referenced (decl);
834 if (vnode->finalized)
835 varpool_mark_needed_node (vnode);
836 }
837 if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (decl)))
838 {
839 if (! TREE_PUBLIC (vnode->decl))
840 warning (OPT_Wattributes,
841 "%J%<externally_visible%> attribute have effect only on public objects",
842 vnode->decl);
843 else
844 {
845 if (vnode->finalized)
846 varpool_mark_needed_node (vnode);
847 vnode->externally_visible = true;
848 }
849 }
850 }
851 }
852
853 /* Process CGRAPH_NODES_NEEDED queue, analyze each function (and transitively
854 each reachable functions) and build cgraph.
855 The function can be called multiple times after inserting new nodes
856 into beginning of queue. Just the new part of queue is re-scanned then. */
857
858 static void
859 cgraph_analyze_functions (void)
860 {
861 /* Keep track of already processed nodes when called multiple times for
862 intermodule optimization. */
863 static struct cgraph_node *first_analyzed;
864 struct cgraph_node *first_processed = first_analyzed;
865 static struct varpool_node *first_analyzed_var;
866 struct cgraph_node *node, *next;
867
868 process_function_and_variable_attributes (first_processed,
869 first_analyzed_var);
870 first_processed = cgraph_nodes;
871 first_analyzed_var = varpool_nodes;
872 varpool_analyze_pending_decls ();
873 if (cgraph_dump_file)
874 {
875 fprintf (cgraph_dump_file, "Initial entry points:");
876 for (node = cgraph_nodes; node != first_analyzed; node = node->next)
877 if (node->needed && DECL_SAVED_TREE (node->decl))
878 fprintf (cgraph_dump_file, " %s", cgraph_node_name (node));
879 fprintf (cgraph_dump_file, "\n");
880 }
881 cgraph_process_new_functions ();
882
883 /* Propagate reachability flag and lower representation of all reachable
884 functions. In the future, lowering will introduce new functions and
885 new entry points on the way (by template instantiation and virtual
886 method table generation for instance). */
887 while (cgraph_nodes_queue)
888 {
889 struct cgraph_edge *edge;
890 tree decl = cgraph_nodes_queue->decl;
891
892 node = cgraph_nodes_queue;
893 cgraph_nodes_queue = cgraph_nodes_queue->next_needed;
894 node->next_needed = NULL;
895
896 /* ??? It is possible to create extern inline function and later using
897 weak alias attribute to kill its body. See
898 gcc.c-torture/compile/20011119-1.c */
899 if (!DECL_SAVED_TREE (decl))
900 {
901 cgraph_reset_node (node);
902 continue;
903 }
904
905 gcc_assert (!node->analyzed && node->reachable);
906 gcc_assert (DECL_SAVED_TREE (decl));
907
908 cgraph_analyze_function (node);
909
910 for (edge = node->callees; edge; edge = edge->next_callee)
911 if (!edge->callee->reachable)
912 cgraph_mark_reachable_node (edge->callee);
913
914 /* We finalize local static variables during constructing callgraph
915 edges. Process their attributes too. */
916 process_function_and_variable_attributes (first_processed,
917 first_analyzed_var);
918 first_processed = cgraph_nodes;
919 first_analyzed_var = varpool_nodes;
920 varpool_analyze_pending_decls ();
921 cgraph_process_new_functions ();
922 }
923
924 /* Collect entry points to the unit. */
925 if (cgraph_dump_file)
926 {
927 fprintf (cgraph_dump_file, "Unit entry points:");
928 for (node = cgraph_nodes; node != first_analyzed; node = node->next)
929 if (node->needed && DECL_SAVED_TREE (node->decl))
930 fprintf (cgraph_dump_file, " %s", cgraph_node_name (node));
931 fprintf (cgraph_dump_file, "\n\nInitial ");
932 dump_cgraph (cgraph_dump_file);
933 }
934
935 if (cgraph_dump_file)
936 fprintf (cgraph_dump_file, "\nReclaiming functions:");
937
938 for (node = cgraph_nodes; node != first_analyzed; node = next)
939 {
940 tree decl = node->decl;
941 next = node->next;
942
943 if (node->local.finalized && !DECL_SAVED_TREE (decl))
944 cgraph_reset_node (node);
945
946 if (!node->reachable && DECL_SAVED_TREE (decl))
947 {
948 if (cgraph_dump_file)
949 fprintf (cgraph_dump_file, " %s", cgraph_node_name (node));
950 cgraph_remove_node (node);
951 continue;
952 }
953 else
954 node->next_needed = NULL;
955 gcc_assert (!node->local.finalized || DECL_SAVED_TREE (decl));
956 gcc_assert (node->analyzed == node->local.finalized);
957 }
958 if (cgraph_dump_file)
959 {
960 fprintf (cgraph_dump_file, "\n\nReclaimed ");
961 dump_cgraph (cgraph_dump_file);
962 }
963 first_analyzed = cgraph_nodes;
964 ggc_collect ();
965 }
966
967 /* Analyze the whole compilation unit once it is parsed completely. */
968
969 void
970 cgraph_finalize_compilation_unit (void)
971 {
972 if (errorcount || sorrycount)
973 return;
974
975 finish_aliases_1 ();
976
977 if (!flag_unit_at_a_time)
978 {
979 cgraph_output_pending_asms ();
980 cgraph_assemble_pending_functions ();
981 varpool_output_debug_info ();
982 return;
983 }
984
985 if (!quiet_flag)
986 {
987 fprintf (stderr, "\nAnalyzing compilation unit\n");
988 fflush (stderr);
989 }
990
991 timevar_push (TV_CGRAPH);
992 cgraph_analyze_functions ();
993 timevar_pop (TV_CGRAPH);
994 }
995 /* Figure out what functions we want to assemble. */
996
997 static void
998 cgraph_mark_functions_to_output (void)
999 {
1000 struct cgraph_node *node;
1001
1002 for (node = cgraph_nodes; node; node = node->next)
1003 {
1004 tree decl = node->decl;
1005 struct cgraph_edge *e;
1006
1007 gcc_assert (!node->output);
1008
1009 for (e = node->callers; e; e = e->next_caller)
1010 if (e->inline_failed)
1011 break;
1012
1013 /* We need to output all local functions that are used and not
1014 always inlined, as well as those that are reachable from
1015 outside the current compilation unit. */
1016 if (DECL_SAVED_TREE (decl)
1017 && !node->global.inlined_to
1018 && (node->needed
1019 || (e && node->reachable))
1020 && !TREE_ASM_WRITTEN (decl)
1021 && !DECL_EXTERNAL (decl))
1022 node->output = 1;
1023 else
1024 {
1025 /* We should've reclaimed all functions that are not needed. */
1026 #ifdef ENABLE_CHECKING
1027 if (!node->global.inlined_to && DECL_SAVED_TREE (decl)
1028 && !DECL_EXTERNAL (decl))
1029 {
1030 dump_cgraph_node (stderr, node);
1031 internal_error ("failed to reclaim unneeded function");
1032 }
1033 #endif
1034 gcc_assert (node->global.inlined_to || !DECL_SAVED_TREE (decl)
1035 || DECL_EXTERNAL (decl));
1036
1037 }
1038
1039 }
1040 }
1041
1042 /* Expand function specified by NODE. */
1043
1044 static void
1045 cgraph_expand_function (struct cgraph_node *node)
1046 {
1047 enum debug_info_type save_write_symbols = NO_DEBUG;
1048 const struct gcc_debug_hooks *save_debug_hooks = NULL;
1049 tree decl = node->decl;
1050
1051 /* We ought to not compile any inline clones. */
1052 gcc_assert (!node->global.inlined_to);
1053
1054 if (flag_unit_at_a_time)
1055 announce_function (decl);
1056
1057 gcc_assert (node->lowered);
1058
1059 if (DECL_IGNORED_P (decl))
1060 {
1061 save_write_symbols = write_symbols;
1062 write_symbols = NO_DEBUG;
1063 save_debug_hooks = debug_hooks;
1064 debug_hooks = &do_nothing_debug_hooks;
1065 }
1066
1067 /* Generate RTL for the body of DECL. */
1068 if (lang_hooks.callgraph.emit_associated_thunks)
1069 lang_hooks.callgraph.emit_associated_thunks (decl);
1070 tree_rest_of_compilation (decl);
1071
1072 /* Make sure that BE didn't give up on compiling. */
1073 /* ??? Can happen with nested function of extern inline. */
1074 gcc_assert (TREE_ASM_WRITTEN (node->decl));
1075
1076 if (DECL_IGNORED_P (decl))
1077 {
1078 write_symbols = save_write_symbols;
1079 debug_hooks = save_debug_hooks;
1080 }
1081
1082 current_function_decl = NULL;
1083 if (!cgraph_preserve_function_body_p (node->decl))
1084 {
1085 cgraph_release_function_body (node);
1086 /* Eliminate all call edges. This is important so the call_expr no longer
1087 points to the dead function body. */
1088 cgraph_node_remove_callees (node);
1089 }
1090
1091 cgraph_function_flags_ready = true;
1092 }
1093
1094 /* Return true when CALLER_DECL should be inlined into CALLEE_DECL. */
1095
1096 bool
1097 cgraph_inline_p (struct cgraph_edge *e, const char **reason)
1098 {
1099 *reason = e->inline_failed;
1100 return !e->inline_failed;
1101 }
1102
1103
1104
1105 /* Expand all functions that must be output.
1106
1107 Attempt to topologically sort the nodes so function is output when
1108 all called functions are already assembled to allow data to be
1109 propagated across the callgraph. Use a stack to get smaller distance
1110 between a function and its callees (later we may choose to use a more
1111 sophisticated algorithm for function reordering; we will likely want
1112 to use subsections to make the output functions appear in top-down
1113 order). */
1114
1115 static void
1116 cgraph_expand_all_functions (void)
1117 {
1118 struct cgraph_node *node;
1119 struct cgraph_node **order = XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
1120 int order_pos = 0, new_order_pos = 0;
1121 int i;
1122
1123 order_pos = cgraph_postorder (order);
1124 gcc_assert (order_pos == cgraph_n_nodes);
1125
1126 /* Garbage collector may remove inline clones we eliminate during
1127 optimization. So we must be sure to not reference them. */
1128 for (i = 0; i < order_pos; i++)
1129 if (order[i]->output)
1130 order[new_order_pos++] = order[i];
1131
1132 for (i = new_order_pos - 1; i >= 0; i--)
1133 {
1134 node = order[i];
1135 if (node->output)
1136 {
1137 gcc_assert (node->reachable);
1138 node->output = 0;
1139 cgraph_expand_function (node);
1140 }
1141 }
1142 cgraph_process_new_functions ();
1143
1144 free (order);
1145
1146 }
1147
1148 /* This is used to sort the node types by the cgraph order number. */
1149
1150 struct cgraph_order_sort
1151 {
1152 enum { ORDER_UNDEFINED = 0, ORDER_FUNCTION, ORDER_VAR, ORDER_ASM } kind;
1153 union
1154 {
1155 struct cgraph_node *f;
1156 struct varpool_node *v;
1157 struct cgraph_asm_node *a;
1158 } u;
1159 };
1160
1161 /* Output all functions, variables, and asm statements in the order
1162 according to their order fields, which is the order in which they
1163 appeared in the file. This implements -fno-toplevel-reorder. In
1164 this mode we may output functions and variables which don't really
1165 need to be output. */
1166
1167 static void
1168 cgraph_output_in_order (void)
1169 {
1170 int max;
1171 size_t size;
1172 struct cgraph_order_sort *nodes;
1173 int i;
1174 struct cgraph_node *pf;
1175 struct varpool_node *pv;
1176 struct cgraph_asm_node *pa;
1177
1178 max = cgraph_order;
1179 size = max * sizeof (struct cgraph_order_sort);
1180 nodes = (struct cgraph_order_sort *) alloca (size);
1181 memset (nodes, 0, size);
1182
1183 varpool_analyze_pending_decls ();
1184
1185 for (pf = cgraph_nodes; pf; pf = pf->next)
1186 {
1187 if (pf->output)
1188 {
1189 i = pf->order;
1190 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1191 nodes[i].kind = ORDER_FUNCTION;
1192 nodes[i].u.f = pf;
1193 }
1194 }
1195
1196 for (pv = varpool_nodes_queue; pv; pv = pv->next_needed)
1197 {
1198 i = pv->order;
1199 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1200 nodes[i].kind = ORDER_VAR;
1201 nodes[i].u.v = pv;
1202 }
1203
1204 for (pa = cgraph_asm_nodes; pa; pa = pa->next)
1205 {
1206 i = pa->order;
1207 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1208 nodes[i].kind = ORDER_ASM;
1209 nodes[i].u.a = pa;
1210 }
1211
1212 for (i = 0; i < max; ++i)
1213 {
1214 switch (nodes[i].kind)
1215 {
1216 case ORDER_FUNCTION:
1217 nodes[i].u.f->output = 0;
1218 cgraph_expand_function (nodes[i].u.f);
1219 break;
1220
1221 case ORDER_VAR:
1222 varpool_assemble_decl (nodes[i].u.v);
1223 break;
1224
1225 case ORDER_ASM:
1226 assemble_asm (nodes[i].u.a->asm_str);
1227 break;
1228
1229 case ORDER_UNDEFINED:
1230 break;
1231
1232 default:
1233 gcc_unreachable ();
1234 }
1235 }
1236
1237 cgraph_asm_nodes = NULL;
1238 }
1239
1240 /* Return true when function body of DECL still needs to be kept around
1241 for later re-use. */
1242 bool
1243 cgraph_preserve_function_body_p (tree decl)
1244 {
1245 struct cgraph_node *node;
1246 if (!cgraph_global_info_ready)
1247 return (flag_really_no_inline
1248 ? DECL_DISREGARD_INLINE_LIMITS (decl)
1249 : DECL_INLINE (decl));
1250 /* Look if there is any clone around. */
1251 for (node = cgraph_node (decl); node; node = node->next_clone)
1252 if (node->global.inlined_to)
1253 return true;
1254 return false;
1255 }
1256
1257 static void
1258 ipa_passes (void)
1259 {
1260 set_cfun (NULL);
1261 current_function_decl = NULL;
1262 tree_register_cfg_hooks ();
1263 bitmap_obstack_initialize (NULL);
1264 execute_ipa_pass_list (all_ipa_passes);
1265 bitmap_obstack_release (NULL);
1266 }
1267
1268 /* Perform simple optimizations based on callgraph. */
1269
1270 void
1271 cgraph_optimize (void)
1272 {
1273 if (errorcount || sorrycount)
1274 return;
1275
1276 #ifdef ENABLE_CHECKING
1277 verify_cgraph ();
1278 #endif
1279
1280 /* Call functions declared with the "constructor" or "destructor"
1281 attribute. */
1282 cgraph_build_cdtor_fns ();
1283 if (!flag_unit_at_a_time)
1284 {
1285 cgraph_assemble_pending_functions ();
1286 cgraph_process_new_functions ();
1287 cgraph_state = CGRAPH_STATE_FINISHED;
1288 cgraph_output_pending_asms ();
1289 varpool_assemble_pending_decls ();
1290 varpool_output_debug_info ();
1291 return;
1292 }
1293
1294 /* Frontend may output common variables after the unit has been finalized.
1295 It is safe to deal with them here as they are always zero initialized. */
1296 varpool_analyze_pending_decls ();
1297 cgraph_analyze_functions ();
1298
1299 timevar_push (TV_CGRAPHOPT);
1300 if (pre_ipa_mem_report)
1301 {
1302 fprintf (stderr, "Memory consumption before IPA\n");
1303 dump_memory_report (false);
1304 }
1305 if (!quiet_flag)
1306 fprintf (stderr, "Performing interprocedural optimizations\n");
1307 cgraph_state = CGRAPH_STATE_IPA;
1308
1309 /* Don't run the IPA passes if there was any error or sorry messages. */
1310 if (errorcount == 0 && sorrycount == 0)
1311 ipa_passes ();
1312
1313 /* This pass remove bodies of extern inline functions we never inlined.
1314 Do this later so other IPA passes see what is really going on. */
1315 cgraph_remove_unreachable_nodes (false, dump_file);
1316 cgraph_global_info_ready = true;
1317 if (cgraph_dump_file)
1318 {
1319 fprintf (cgraph_dump_file, "Optimized ");
1320 dump_cgraph (cgraph_dump_file);
1321 dump_varpool (cgraph_dump_file);
1322 }
1323 if (post_ipa_mem_report)
1324 {
1325 fprintf (stderr, "Memory consumption after IPA\n");
1326 dump_memory_report (false);
1327 }
1328 timevar_pop (TV_CGRAPHOPT);
1329
1330 /* Output everything. */
1331 if (!quiet_flag)
1332 fprintf (stderr, "Assembling functions:\n");
1333 #ifdef ENABLE_CHECKING
1334 verify_cgraph ();
1335 #endif
1336
1337 cgraph_mark_functions_to_output ();
1338
1339 cgraph_state = CGRAPH_STATE_EXPANSION;
1340 if (!flag_toplevel_reorder)
1341 cgraph_output_in_order ();
1342 else
1343 {
1344 cgraph_output_pending_asms ();
1345
1346 cgraph_expand_all_functions ();
1347 varpool_remove_unreferenced_decls ();
1348
1349 varpool_assemble_pending_decls ();
1350 varpool_output_debug_info ();
1351 }
1352 cgraph_process_new_functions ();
1353 cgraph_state = CGRAPH_STATE_FINISHED;
1354
1355 if (cgraph_dump_file)
1356 {
1357 fprintf (cgraph_dump_file, "\nFinal ");
1358 dump_cgraph (cgraph_dump_file);
1359 }
1360 #ifdef ENABLE_CHECKING
1361 verify_cgraph ();
1362 /* Double check that all inline clones are gone and that all
1363 function bodies have been released from memory. */
1364 if (flag_unit_at_a_time
1365 && !(sorrycount || errorcount))
1366 {
1367 struct cgraph_node *node;
1368 bool error_found = false;
1369
1370 for (node = cgraph_nodes; node; node = node->next)
1371 if (node->analyzed
1372 && (node->global.inlined_to
1373 || DECL_SAVED_TREE (node->decl)))
1374 {
1375 error_found = true;
1376 dump_cgraph_node (stderr, node);
1377 }
1378 if (error_found)
1379 internal_error ("nodes with no released memory found");
1380 }
1381 #endif
1382 }
1383 /* Generate and emit a static constructor or destructor. WHICH must be
1384 one of 'I' or 'D'. BODY should be a STATEMENT_LIST containing
1385 GENERIC statements. */
1386
1387 void
1388 cgraph_build_static_cdtor (char which, tree body, int priority)
1389 {
1390 static int counter = 0;
1391 char which_buf[16];
1392 tree decl, name, resdecl;
1393
1394 sprintf (which_buf, "%c_%d", which, counter++);
1395 name = get_file_function_name (which_buf);
1396
1397 decl = build_decl (FUNCTION_DECL, name,
1398 build_function_type (void_type_node, void_list_node));
1399 current_function_decl = decl;
1400
1401 resdecl = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
1402 DECL_ARTIFICIAL (resdecl) = 1;
1403 DECL_IGNORED_P (resdecl) = 1;
1404 DECL_RESULT (decl) = resdecl;
1405
1406 allocate_struct_function (decl);
1407
1408 TREE_STATIC (decl) = 1;
1409 TREE_USED (decl) = 1;
1410 DECL_ARTIFICIAL (decl) = 1;
1411 DECL_IGNORED_P (decl) = 1;
1412 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
1413 DECL_SAVED_TREE (decl) = body;
1414 TREE_PUBLIC (decl) = ! targetm.have_ctors_dtors;
1415 DECL_UNINLINABLE (decl) = 1;
1416
1417 DECL_INITIAL (decl) = make_node (BLOCK);
1418 TREE_USED (DECL_INITIAL (decl)) = 1;
1419
1420 DECL_SOURCE_LOCATION (decl) = input_location;
1421 cfun->function_end_locus = input_location;
1422
1423 switch (which)
1424 {
1425 case 'I':
1426 DECL_STATIC_CONSTRUCTOR (decl) = 1;
1427 decl_init_priority_insert (decl, priority);
1428 break;
1429 case 'D':
1430 DECL_STATIC_DESTRUCTOR (decl) = 1;
1431 decl_fini_priority_insert (decl, priority);
1432 break;
1433 default:
1434 gcc_unreachable ();
1435 }
1436
1437 gimplify_function_tree (decl);
1438
1439 cgraph_add_new_function (decl, false);
1440 cgraph_mark_needed_node (cgraph_node (decl));
1441 }
1442
1443 void
1444 init_cgraph (void)
1445 {
1446 cgraph_dump_file = dump_begin (TDI_cgraph, NULL);
1447 }
1448
1449 /* The edges representing the callers of the NEW_VERSION node were
1450 fixed by cgraph_function_versioning (), now the call_expr in their
1451 respective tree code should be updated to call the NEW_VERSION. */
1452
1453 static void
1454 update_call_expr (struct cgraph_node *new_version)
1455 {
1456 struct cgraph_edge *e;
1457
1458 gcc_assert (new_version);
1459 for (e = new_version->callers; e; e = e->next_caller)
1460 /* Update the call expr on the edges
1461 to call the new version. */
1462 TREE_OPERAND (CALL_EXPR_FN (get_call_expr_in (e->call_stmt)), 0) = new_version->decl;
1463 }
1464
1465
1466 /* Create a new cgraph node which is the new version of
1467 OLD_VERSION node. REDIRECT_CALLERS holds the callers
1468 edges which should be redirected to point to
1469 NEW_VERSION. ALL the callees edges of OLD_VERSION
1470 are cloned to the new version node. Return the new
1471 version node. */
1472
1473 static struct cgraph_node *
1474 cgraph_copy_node_for_versioning (struct cgraph_node *old_version,
1475 tree new_decl,
1476 VEC(cgraph_edge_p,heap) *redirect_callers)
1477 {
1478 struct cgraph_node *new_version;
1479 struct cgraph_edge *e, *new_e;
1480 struct cgraph_edge *next_callee;
1481 unsigned i;
1482
1483 gcc_assert (old_version);
1484
1485 new_version = cgraph_node (new_decl);
1486
1487 new_version->analyzed = true;
1488 new_version->local = old_version->local;
1489 new_version->global = old_version->global;
1490 new_version->rtl = new_version->rtl;
1491 new_version->reachable = true;
1492 new_version->count = old_version->count;
1493
1494 /* Clone the old node callees. Recursive calls are
1495 also cloned. */
1496 for (e = old_version->callees;e; e=e->next_callee)
1497 {
1498 new_e = cgraph_clone_edge (e, new_version, e->call_stmt, 0, e->frequency,
1499 e->loop_nest, true);
1500 new_e->count = e->count;
1501 }
1502 /* Fix recursive calls.
1503 If OLD_VERSION has a recursive call after the
1504 previous edge cloning, the new version will have an edge
1505 pointing to the old version, which is wrong;
1506 Redirect it to point to the new version. */
1507 for (e = new_version->callees ; e; e = next_callee)
1508 {
1509 next_callee = e->next_callee;
1510 if (e->callee == old_version)
1511 cgraph_redirect_edge_callee (e, new_version);
1512
1513 if (!next_callee)
1514 break;
1515 }
1516 for (i = 0; VEC_iterate (cgraph_edge_p, redirect_callers, i, e); i++)
1517 {
1518 /* Redirect calls to the old version node to point to its new
1519 version. */
1520 cgraph_redirect_edge_callee (e, new_version);
1521 }
1522
1523 return new_version;
1524 }
1525
1526 /* Perform function versioning.
1527 Function versioning includes copying of the tree and
1528 a callgraph update (creating a new cgraph node and updating
1529 its callees and callers).
1530
1531 REDIRECT_CALLERS varray includes the edges to be redirected
1532 to the new version.
1533
1534 TREE_MAP is a mapping of tree nodes we want to replace with
1535 new ones (according to results of prior analysis).
1536 OLD_VERSION_NODE is the node that is versioned.
1537 It returns the new version's cgraph node. */
1538
1539 struct cgraph_node *
1540 cgraph_function_versioning (struct cgraph_node *old_version_node,
1541 VEC(cgraph_edge_p,heap) *redirect_callers,
1542 varray_type tree_map)
1543 {
1544 tree old_decl = old_version_node->decl;
1545 struct cgraph_node *new_version_node = NULL;
1546 tree new_decl;
1547
1548 if (!tree_versionable_function_p (old_decl))
1549 return NULL;
1550
1551 /* Make a new FUNCTION_DECL tree node for the
1552 new version. */
1553 new_decl = copy_node (old_decl);
1554
1555 /* Create the new version's call-graph node.
1556 and update the edges of the new node. */
1557 new_version_node =
1558 cgraph_copy_node_for_versioning (old_version_node, new_decl,
1559 redirect_callers);
1560
1561 /* Copy the OLD_VERSION_NODE function tree to the new version. */
1562 tree_function_versioning (old_decl, new_decl, tree_map, false);
1563 /* Update the call_expr on the edges to call the new version node. */
1564 update_call_expr (new_version_node);
1565
1566 /* Update the new version's properties.
1567 Make The new version visible only within this translation unit.
1568 ??? We cannot use COMDAT linkage because there is no
1569 ABI support for this. */
1570 DECL_EXTERNAL (new_version_node->decl) = 0;
1571 DECL_ONE_ONLY (new_version_node->decl) = 0;
1572 TREE_PUBLIC (new_version_node->decl) = 0;
1573 DECL_COMDAT (new_version_node->decl) = 0;
1574 new_version_node->local.externally_visible = 0;
1575 new_version_node->local.local = 1;
1576 new_version_node->lowered = true;
1577 return new_version_node;
1578 }
1579
1580 /* Produce separate function body for inline clones so the offline copy can be
1581 modified without affecting them. */
1582 struct cgraph_node *
1583 save_inline_function_body (struct cgraph_node *node)
1584 {
1585 struct cgraph_node *first_clone;
1586
1587 gcc_assert (node == cgraph_node (node->decl));
1588
1589 cgraph_lower_function (node);
1590
1591 /* In non-unit-at-a-time we construct full fledged clone we never output to
1592 assembly file. This clone is pointed out by inline_decl of original function
1593 and inlining infrastructure knows how to deal with this. */
1594 if (!flag_unit_at_a_time)
1595 {
1596 struct cgraph_edge *e;
1597
1598 first_clone = cgraph_clone_node (node, node->count, 0, CGRAPH_FREQ_BASE,
1599 false);
1600 first_clone->needed = 0;
1601 first_clone->reachable = 1;
1602 /* Recursively clone all bodies. */
1603 for (e = first_clone->callees; e; e = e->next_callee)
1604 if (!e->inline_failed)
1605 cgraph_clone_inlined_nodes (e, true, false);
1606 }
1607 else
1608 first_clone = node->next_clone;
1609
1610 first_clone->decl = copy_node (node->decl);
1611 node->next_clone = NULL;
1612 if (!flag_unit_at_a_time)
1613 node->inline_decl = first_clone->decl;
1614 first_clone->prev_clone = NULL;
1615 cgraph_insert_node_to_hashtable (first_clone);
1616 gcc_assert (first_clone == cgraph_node (first_clone->decl));
1617
1618 /* Copy the OLD_VERSION_NODE function tree to the new version. */
1619 tree_function_versioning (node->decl, first_clone->decl, NULL, true);
1620
1621 DECL_EXTERNAL (first_clone->decl) = 0;
1622 DECL_ONE_ONLY (first_clone->decl) = 0;
1623 TREE_PUBLIC (first_clone->decl) = 0;
1624 DECL_COMDAT (first_clone->decl) = 0;
1625
1626 for (node = first_clone->next_clone; node; node = node->next_clone)
1627 node->decl = first_clone->decl;
1628 #ifdef ENABLE_CHECKING
1629 verify_cgraph_node (first_clone);
1630 #endif
1631 return first_clone;
1632 }
1633
1634 #include "gt-cgraphunit.h"