1 /* Top-level control of tree optimizations.
2 Copyright 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3 Contributed by Diego Novillo <dnovillo@redhat.com>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
24 #include "coretypes.h"
29 #include "hard-reg-set.h"
30 #include "basic-block.h"
33 #include "diagnostic.h"
34 #include "basic-block.h"
36 #include "tree-flow.h"
37 #include "tree-dump.h"
40 #include "langhooks.h"
44 #include "tree-inline.h"
45 #include "tree-mudflap.h"
46 #include "tree-pass.h"
53 /* Global variables used to communicate with passes. */
57 /* The root of the compilation pass tree, once constructed. */
58 static struct tree_opt_pass *all_passes, *all_ipa_passes;
60 /* Gate: execute, or not, all of the non-trivial optimizations. */
63 gate_all_optimizations (void)
66 /* Don't bother doing anything if the program has errors. */
67 && !(errorcount || sorrycount));
70 static struct tree_opt_pass pass_all_optimizations =
73 gate_all_optimizations, /* gate */
77 0, /* static_pass_number */
79 0, /* properties_required */
80 0, /* properties_provided */
81 0, /* properties_destroyed */
82 0, /* todo_flags_start */
83 0, /* todo_flags_finish */
87 /* Pass: cleanup the CFG just before expanding trees to RTL.
88 This is just a round of label cleanups and case node grouping
89 because after the tree optimizers have run such cleanups may
93 execute_cleanup_cfg_post_optimizing (void)
96 cleanup_dead_labels ();
100 static struct tree_opt_pass pass_cleanup_cfg_post_optimizing =
102 "final_cleanup", /* name */
104 execute_cleanup_cfg_post_optimizing, /* execute */
107 0, /* static_pass_number */
109 PROP_cfg, /* properties_required */
110 0, /* properties_provided */
111 0, /* properties_destroyed */
112 0, /* todo_flags_start */
113 TODO_dump_func, /* todo_flags_finish */
117 /* Pass: do the actions required to finish with tree-ssa optimization
121 execute_free_datastructures (void)
125 /* ??? This isn't the right place for this. Worse, it got computed
126 more or less at random in various passes. */
127 free_dominance_info (CDI_DOMINATORS);
129 /* Emit gotos for implicit jumps. */
130 disband_implicit_edges ();
132 /* Remove the ssa structures. Do it here since this includes statement
133 annotations that need to be intact during disband_implicit_edges. */
136 /* Re-chain the statements from the blocks. */
137 chain = &DECL_SAVED_TREE (current_function_decl);
138 *chain = alloc_stmt_list ();
140 /* And get rid of annotations we no longer need. */
141 delete_tree_cfg_annotations ();
144 static struct tree_opt_pass pass_free_datastructures =
148 execute_free_datastructures, /* execute */
151 0, /* static_pass_number */
153 PROP_cfg, /* properties_required */
154 0, /* properties_provided */
155 0, /* properties_destroyed */
156 0, /* todo_flags_start */
157 0, /* todo_flags_finish */
162 /* Do the actions required to initialize internal data structures used
163 in tree-ssa optimization passes. */
166 execute_init_datastructures (void)
168 /* Allocate hash tables, arrays and other structures. */
172 static struct tree_opt_pass pass_init_datastructures =
176 execute_init_datastructures, /* execute */
179 0, /* static_pass_number */
181 PROP_cfg, /* properties_required */
182 0, /* properties_provided */
183 0, /* properties_destroyed */
184 0, /* todo_flags_start */
185 0, /* todo_flags_finish */
189 /* Iterate over the pass tree allocating dump file numbers. We want
190 to do this depth first, and independent of whether the pass is
194 register_one_dump_file (struct tree_opt_pass *pass, bool ipa, int n)
196 char *dot_name, *flag_name, *glob_name;
199 /* See below in next_pass_1. */
201 if (pass->static_pass_number != -1)
202 sprintf (num, "%d", ((int) pass->static_pass_number < 0
203 ? 1 : pass->static_pass_number));
205 dot_name = concat (".", pass->name, num, NULL);
208 flag_name = concat ("ipa-", pass->name, num, NULL);
209 glob_name = concat ("ipa-", pass->name, NULL);
210 /* First IPA dump is cgraph that is dumped via separate channels. */
211 pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
214 else if (pass->properties_provided & PROP_trees)
216 flag_name = concat ("tree-", pass->name, num, NULL);
217 glob_name = concat ("tree-", pass->name, NULL);
218 pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
219 TDF_TREE, n + TDI_tree_all, 0);
223 flag_name = concat ("rtl-", pass->name, num, NULL);
224 glob_name = concat ("rtl-", pass->name, NULL);
225 pass->static_pass_number = dump_register (dot_name, flag_name, glob_name,
226 TDF_RTL, n, pass->letter);
231 register_dump_files (struct tree_opt_pass *pass, bool ipa, int properties)
239 pass->properties_required = properties;
241 (properties | pass->properties_provided) & ~pass->properties_destroyed;
243 /* Reset the counter when we reach RTL-based passes. */
244 if ((pass->properties_provided ^ pass->properties_required) & PROP_rtl)
252 new_properties = register_dump_files (pass->sub, ipa, new_properties);
254 /* If we have a gate, combine the properties that we could have with
255 and without the pass being examined. */
257 properties &= new_properties;
259 properties = new_properties;
261 pass->properties_provided = properties;
263 register_one_dump_file (pass, ipa, pass_number);
272 /* Add a pass to the pass list. Duplicate the pass if it's already
275 static struct tree_opt_pass **
276 next_pass_1 (struct tree_opt_pass **list, struct tree_opt_pass *pass)
279 /* A nonzero static_pass_number indicates that the
280 pass is already in the list. */
281 if (pass->static_pass_number)
283 struct tree_opt_pass *new;
285 new = xmalloc (sizeof (*new));
286 memcpy (new, pass, sizeof (*new));
288 /* Indicate to register_dump_files that this pass has duplicates,
289 and so it should rename the dump file. The first instance will
290 be -1, and be number of duplicates = -static_pass_number - 1.
291 Subsequent instances will be > 0 and just the duplicate number. */
294 pass->static_pass_number -= 1;
295 new->static_pass_number = -pass->static_pass_number;
302 pass->static_pass_number = -1;
306 return &(*list)->next;
310 /* Construct the pass tree. */
313 init_tree_optimization_passes (void)
315 struct tree_opt_pass **p;
317 #define NEXT_PASS(PASS) (p = next_pass_1 (p, &PASS))
318 /* Intraprocedural optimization passes. */
320 NEXT_PASS (pass_ipa_inline);
324 NEXT_PASS (pass_remove_useless_stmts);
325 NEXT_PASS (pass_mudflap_1);
326 NEXT_PASS (pass_lower_cf);
327 NEXT_PASS (pass_lower_eh);
328 NEXT_PASS (pass_build_cfg);
329 NEXT_PASS (pass_pre_expand);
330 NEXT_PASS (pass_tree_profile);
331 NEXT_PASS (pass_init_datastructures);
332 NEXT_PASS (pass_all_optimizations);
333 NEXT_PASS (pass_warn_function_return);
334 NEXT_PASS (pass_mudflap_2);
335 NEXT_PASS (pass_free_datastructures);
336 NEXT_PASS (pass_expand);
337 NEXT_PASS (pass_rest_of_compilation);
340 p = &pass_all_optimizations.sub;
341 NEXT_PASS (pass_referenced_vars);
342 NEXT_PASS (pass_create_structure_vars);
343 NEXT_PASS (pass_build_ssa);
344 NEXT_PASS (pass_may_alias);
345 NEXT_PASS (pass_rename_ssa_copies);
346 NEXT_PASS (pass_early_warn_uninitialized);
348 /* Initial scalar cleanups. */
349 NEXT_PASS (pass_ccp);
350 NEXT_PASS (pass_fre);
351 NEXT_PASS (pass_dce);
352 NEXT_PASS (pass_forwprop);
353 NEXT_PASS (pass_vrp);
354 NEXT_PASS (pass_copy_prop);
355 NEXT_PASS (pass_dce);
356 NEXT_PASS (pass_dominator);
358 NEXT_PASS (pass_merge_phi);
359 NEXT_PASS (pass_phiopt);
360 NEXT_PASS (pass_may_alias);
361 NEXT_PASS (pass_tail_recursion);
362 NEXT_PASS (pass_profile);
364 NEXT_PASS (pass_stdarg);
365 NEXT_PASS (pass_sra);
366 /* FIXME: SRA may generate arbitrary gimple code, exposing new
367 aliased and call-clobbered variables. As mentioned below,
368 pass_may_alias should be a TODO item. */
369 NEXT_PASS (pass_may_alias);
370 NEXT_PASS (pass_rename_ssa_copies);
371 NEXT_PASS (pass_dominator);
372 NEXT_PASS (pass_copy_prop);
373 NEXT_PASS (pass_dce);
374 NEXT_PASS (pass_dse);
375 NEXT_PASS (pass_may_alias);
376 NEXT_PASS (pass_forwprop);
377 NEXT_PASS (pass_phiopt);
378 NEXT_PASS (pass_store_ccp);
379 NEXT_PASS (pass_store_copy_prop);
380 NEXT_PASS (pass_fold_builtins);
381 /* FIXME: May alias should a TODO but for 4.0.0,
382 we add may_alias right after fold builtins
383 which can create arbitrary GIMPLE. */
384 NEXT_PASS (pass_may_alias);
385 NEXT_PASS (pass_split_crit_edges);
386 NEXT_PASS (pass_pre);
387 NEXT_PASS (pass_sink_code);
388 NEXT_PASS (pass_loop);
389 NEXT_PASS (pass_dominator);
390 NEXT_PASS (pass_copy_prop);
391 NEXT_PASS (pass_dce);
392 /* FIXME: If DCE is not run before checking for uninitialized uses,
393 we may get false warnings (e.g., testsuite/gcc.dg/uninit-5.c).
394 However, this also causes us to misdiagnose cases that should be
395 real warnings (e.g., testsuite/gcc.dg/pr18501.c).
397 To fix the false positives in uninit-5.c, we would have to
398 account for the predicates protecting the set and the use of each
399 variable. Using a representation like Gated Single Assignment
401 NEXT_PASS (pass_late_warn_uninitialized);
402 NEXT_PASS (pass_cd_dce);
403 NEXT_PASS (pass_dse);
404 NEXT_PASS (pass_forwprop);
405 NEXT_PASS (pass_phiopt);
406 NEXT_PASS (pass_tail_calls);
407 NEXT_PASS (pass_rename_ssa_copies);
408 NEXT_PASS (pass_uncprop);
409 NEXT_PASS (pass_del_ssa);
410 NEXT_PASS (pass_nrv);
411 NEXT_PASS (pass_remove_useless_vars);
412 NEXT_PASS (pass_mark_used_blocks);
413 NEXT_PASS (pass_cleanup_cfg_post_optimizing);
417 NEXT_PASS (pass_loop_init);
418 NEXT_PASS (pass_copy_prop);
419 NEXT_PASS (pass_lim);
420 NEXT_PASS (pass_unswitch);
421 NEXT_PASS (pass_record_bounds);
422 NEXT_PASS (pass_linear_transform);
423 NEXT_PASS (pass_iv_canon);
424 NEXT_PASS (pass_if_conversion);
425 NEXT_PASS (pass_vectorize);
426 NEXT_PASS (pass_lower_vector_ssa);
427 NEXT_PASS (pass_complete_unroll);
428 NEXT_PASS (pass_iv_optimize);
429 NEXT_PASS (pass_loop_done);
434 register_dump_files (all_passes, false, PROP_gimple_any
438 register_dump_files (all_ipa_passes, true, PROP_gimple_any
444 static unsigned int last_verified;
447 execute_todo (struct tree_opt_pass *pass, unsigned int flags, bool use_required)
450 = use_required ? pass->properties_required : pass->properties_provided;
452 #if defined ENABLE_CHECKING
453 if (need_ssa_update_p ())
454 gcc_assert (flags & TODO_update_ssa_any);
457 if (flags & TODO_update_ssa_any)
459 unsigned update_flags = flags & TODO_update_ssa_any;
460 update_ssa (update_flags);
463 if (flags & TODO_cleanup_cfg)
466 cleanup_tree_cfg_loop ();
471 if ((flags & TODO_dump_func)
472 && dump_file && current_function_decl)
474 if (properties & PROP_trees)
475 dump_function_to_file (current_function_decl,
476 dump_file, dump_flags);
477 else if (properties & PROP_cfg)
478 print_rtl_with_bb (dump_file, get_insns ());
480 print_rtl (dump_file, get_insns ());
482 /* Flush the file. If verification fails, we won't be able to
483 close the file before dieing. */
486 if ((flags & TODO_dump_cgraph)
487 && dump_file && !current_function_decl)
489 dump_cgraph (dump_file);
490 /* Flush the file. If verification fails, we won't be able to
491 close the file before aborting. */
495 if (flags & TODO_ggc_collect)
500 #if defined ENABLE_CHECKING
501 if ((pass->properties_required & PROP_ssa)
502 && !(pass->properties_destroyed & PROP_ssa))
504 if (flags & TODO_verify_flow)
506 if (flags & TODO_verify_stmts)
508 if (flags & TODO_verify_loops)
509 verify_loop_closed_ssa ();
514 execute_one_pass (struct tree_opt_pass *pass)
518 /* See if we're supposed to run this pass. */
519 if (pass->gate && !pass->gate ())
522 /* Note that the folders should only create gimple expressions.
523 This is a hack until the new folder is ready. */
524 in_gimple_form = (pass->properties_provided & PROP_trees) != 0;
526 /* Run pre-pass verification. */
527 todo = pass->todo_flags_start & ~last_verified;
529 execute_todo (pass, todo, true);
531 /* If a dump file name is present, open it if enabled. */
532 if (pass->static_pass_number != -1)
534 bool initializing_dump = !dump_initialized_p (pass->static_pass_number);
535 dump_file_name = get_dump_file_name (pass->static_pass_number);
536 dump_file = dump_begin (pass->static_pass_number, &dump_flags);
537 if (dump_file && current_function_decl)
539 const char *dname, *aname;
540 dname = lang_hooks.decl_printable_name (current_function_decl, 2);
541 aname = (IDENTIFIER_POINTER
542 (DECL_ASSEMBLER_NAME (current_function_decl)));
543 fprintf (dump_file, "\n;; Function %s (%s)%s\n\n", dname, aname,
544 cfun->function_frequency == FUNCTION_FREQUENCY_HOT
546 : cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED
547 ? " (unlikely executed)"
551 if (initializing_dump
552 && graph_dump_format != no_graph
553 && (pass->properties_provided & (PROP_cfg | PROP_rtl))
554 == (PROP_cfg | PROP_rtl))
555 clean_graph_dump_file (dump_file_name);
558 /* If a timevar is present, start it. */
560 timevar_push (pass->tv_id);
568 timevar_pop (pass->tv_id);
571 && (pass->properties_provided & (PROP_cfg | PROP_rtl))
572 == (PROP_cfg | PROP_rtl))
573 print_rtl_with_bb (dump_file, get_insns ());
575 /* Run post-pass cleanup and verification. */
576 todo = pass->todo_flags_finish;
577 last_verified = todo & TODO_verify_all;
579 execute_todo (pass, todo, false);
581 /* Flush and close dump file. */
584 free ((char *) dump_file_name);
585 dump_file_name = NULL;
589 dump_end (pass->static_pass_number, dump_file);
597 execute_pass_list (struct tree_opt_pass *pass)
601 if (execute_one_pass (pass) && pass->sub)
602 execute_pass_list (pass->sub);
608 /* Execute all IPA passes. */
612 execute_pass_list (all_ipa_passes);
616 /* Update recursively all inlined_to pointers of functions
617 inlined into NODE to INLINED_TO. */
619 update_inlined_to_pointers (struct cgraph_node *node,
620 struct cgraph_node *inlined_to)
622 struct cgraph_edge *e;
623 for (e = node->callees; e; e = e->next_callee)
625 if (e->callee->global.inlined_to)
627 e->callee->global.inlined_to = inlined_to;
628 update_inlined_to_pointers (e->callee, inlined_to);
634 /* For functions-as-trees languages, this performs all optimization and
635 compilation for FNDECL. */
638 tree_rest_of_compilation (tree fndecl)
640 location_t saved_loc;
641 struct cgraph_node *saved_node = NULL, *node;
643 timevar_push (TV_EXPAND);
645 gcc_assert (!flag_unit_at_a_time || cgraph_global_info_ready);
647 /* Initialize the RTL code for the function. */
648 current_function_decl = fndecl;
649 saved_loc = input_location;
650 input_location = DECL_SOURCE_LOCATION (fndecl);
651 init_function_start (fndecl);
653 /* Even though we're inside a function body, we still don't want to
654 call expand_expr to calculate the size of a variable-sized array.
655 We haven't necessarily assigned RTL to all variables yet, so it's
656 not safe to try to expand expressions involving them. */
657 cfun->x_dont_save_pending_sizes_p = 1;
658 cfun->after_inlining = true;
660 node = cgraph_node (fndecl);
662 /* We might need the body of this function so that we can expand
663 it inline somewhere else. This means not lowering some constructs
664 such as exception handling. */
665 if (cgraph_preserve_function_body_p (fndecl))
667 if (!flag_unit_at_a_time)
669 struct cgraph_edge *e;
671 saved_node = cgraph_clone_node (node);
672 for (e = saved_node->callees; e; e = e->next_callee)
673 if (!e->inline_failed)
674 cgraph_clone_inlined_nodes (e, true);
676 cfun->saved_static_chain_decl = cfun->static_chain_decl;
677 cfun->saved_tree = save_body (fndecl, &cfun->saved_args,
678 &cfun->saved_static_chain_decl);
681 if (flag_inline_trees)
683 struct cgraph_edge *e;
684 for (e = node->callees; e; e = e->next_callee)
685 if (!e->inline_failed || warn_inline)
689 timevar_push (TV_INTEGRATION);
690 optimize_inline_calls (fndecl);
691 timevar_pop (TV_INTEGRATION);
694 /* We are not going to maintain the cgraph edges up to date.
695 Kill it so it won't confuse us. */
696 while (node->callees)
698 /* In non-unit-at-a-time we must mark all referenced functions as needed.
700 if (node->callees->callee->analyzed && !flag_unit_at_a_time)
701 cgraph_mark_needed_node (node->callees->callee);
702 cgraph_remove_edge (node->callees);
705 /* We are not going to maintain the cgraph edges up to date.
706 Kill it so it won't confuse us. */
707 cgraph_node_remove_callees (node);
710 /* Initialize the default bitmap obstack. */
711 bitmap_obstack_initialize (NULL);
712 bitmap_obstack_initialize (®_obstack); /* FIXME, only at RTL generation*/
714 /* Perform all tree transforms and optimizations. */
715 execute_pass_list (all_passes);
717 bitmap_obstack_release (®_obstack);
719 /* Release the default bitmap obstack. */
720 bitmap_obstack_release (NULL);
722 /* Restore original body if still needed. */
723 if (cfun->saved_tree)
725 DECL_SAVED_TREE (fndecl) = cfun->saved_tree;
726 DECL_ARGUMENTS (fndecl) = cfun->saved_args;
727 cfun->static_chain_decl = cfun->saved_static_chain_decl;
729 /* When not in unit-at-a-time mode, we must preserve out of line copy
730 representing node before inlining. Restore original outgoing edges
731 using clone we created earlier. */
732 if (!flag_unit_at_a_time)
734 struct cgraph_edge *e;
736 cgraph_node_remove_callees (node);
737 node->callees = saved_node->callees;
738 saved_node->callees = NULL;
739 update_inlined_to_pointers (node, node);
740 for (e = node->callees; e; e = e->next_callee)
742 cgraph_remove_node (saved_node);
746 DECL_SAVED_TREE (fndecl) = NULL;
749 /* If requested, warn about function definitions where the function will
750 return a value (usually of some struct or union type) which itself will
751 take up a lot of stack space. */
752 if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
754 tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
756 if (ret_type && TYPE_SIZE_UNIT (ret_type)
757 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
758 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
761 unsigned int size_as_int
762 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
764 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
765 warning (0, "%Jsize of return value of %qD is %u bytes",
766 fndecl, fndecl, size_as_int);
768 warning (0, "%Jsize of return value of %qD is larger than %wd bytes",
769 fndecl, fndecl, larger_than_size);
773 if (!flag_inline_trees)
775 DECL_SAVED_TREE (fndecl) = NULL;
776 if (DECL_STRUCT_FUNCTION (fndecl) == 0
777 && !cgraph_node (fndecl)->origin)
779 /* Stop pointing to the local nodes about to be freed.
780 But DECL_INITIAL must remain nonzero so we know this
781 was an actual function definition.
782 For a nested function, this is done in c_pop_function_context.
783 If rest_of_compilation set this to 0, leave it 0. */
784 if (DECL_INITIAL (fndecl) != 0)
785 DECL_INITIAL (fndecl) = error_mark_node;
789 input_location = saved_loc;
792 timevar_pop (TV_EXPAND);