1 /* Top-level control of tree optimizations.
2 Copyright 2001, 2002, 2003, 2004 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"
47 #include "tree-alias-common.h"
52 /* Global variables used to communicate with passes. */
54 bitmap vars_to_rename;
57 /* The root of the compilation pass tree, once constructed. */
58 static struct tree_opt_pass *all_passes;
60 /* Pass: dump the gimplified, inlined, functions. */
62 static struct tree_opt_pass pass_gimple =
69 0, /* static_pass_number */
71 0, /* properties_required */
72 PROP_gimple_any, /* properties_provided */
73 0, /* properties_destroyed */
74 0, /* todo_flags_start */
75 TODO_dump_func /* todo_flags_finish */
78 /* Gate: execute, or not, all of the non-trivial optimizations. */
81 gate_all_optimizations (void)
84 /* Don't bother doing anything if the program has errors. */
85 && !(errorcount || sorrycount));
88 static struct tree_opt_pass pass_all_optimizations =
91 gate_all_optimizations, /* gate */
95 0, /* static_pass_number */
97 0, /* properties_required */
98 0, /* properties_provided */
99 0, /* properties_destroyed */
100 0, /* todo_flags_start */
101 0 /* todo_flags_finish */
104 /* Pass: cleanup the CFG just before expanding trees to RTL.
105 This is just a round of label cleanups and case node grouping
106 because after the tree optimizers have run such cleanups may
110 execute_cleanup_cfg_post_optimizing (void)
113 cleanup_dead_labels ();
114 group_case_labels ();
117 static struct tree_opt_pass pass_cleanup_cfg_post_optimizing =
121 execute_cleanup_cfg_post_optimizing, /* execute */
124 0, /* static_pass_number */
126 PROP_cfg, /* properties_required */
127 0, /* properties_provided */
128 0, /* properties_destroyed */
129 0, /* todo_flags_start */
130 0 /* todo_flags_finish */
133 /* Pass: do the actions required to finish with tree-ssa optimization
137 execute_free_datastructures (void)
141 /* ??? This isn't the right place for this. Worse, it got computed
142 more or less at random in various passes. */
143 free_dominance_info (CDI_DOMINATORS);
145 /* Emit gotos for implicit jumps. */
146 disband_implicit_edges ();
148 /* Remove the ssa structures. Do it here since this includes statement
149 annotations that need to be intact during disband_implicit_edges. */
152 /* Re-chain the statements from the blocks. */
153 chain = &DECL_SAVED_TREE (current_function_decl);
154 *chain = alloc_stmt_list ();
156 /* And get rid of annotations we no longer need. */
157 delete_tree_cfg_annotations ();
160 static struct tree_opt_pass pass_free_datastructures =
164 execute_free_datastructures, /* execute */
167 0, /* static_pass_number */
169 PROP_cfg, /* properties_required */
170 0, /* properties_provided */
171 0, /* properties_destroyed */
172 0, /* todo_flags_start */
173 0 /* todo_flags_finish */
177 /* Do the actions required to initialize internal data structures used
178 in tree-ssa optimization passes. */
181 execute_init_datastructures (void)
183 /* Allocate hash tables, arrays and other structures. */
187 static struct tree_opt_pass pass_init_datastructures =
191 execute_init_datastructures, /* execute */
194 0, /* static_pass_number */
196 PROP_cfg, /* properties_required */
197 0, /* properties_provided */
198 0, /* properties_destroyed */
199 0, /* todo_flags_start */
200 0 /* todo_flags_finish */
203 /* Iterate over the pass tree allocating dump file numbers. We want
204 to do this depth first, and independent of whether the pass is
208 register_one_dump_file (struct tree_opt_pass *pass)
210 char *dot_name, *flag_name;
216 /* See below in next_pass_1. */
218 if (pass->static_pass_number != -1)
219 sprintf (num, "%d", ((int) pass->static_pass_number < 0
220 ? 1 : pass->static_pass_number));
222 dot_name = concat (".", pass->name, num, NULL);
223 flag_name = concat ("tree-", pass->name, num, NULL);
225 pass->static_pass_number = dump_register (dot_name, flag_name);
229 register_dump_files (struct tree_opt_pass *pass, int properties)
233 /* Verify that all required properties are present. */
234 if (pass->properties_required & ~properties)
237 if (pass->properties_destroyed & pass->properties_provided)
240 pass->properties_required = properties;
241 pass->properties_provided = properties =
242 (properties | pass->properties_provided) & ~pass->properties_destroyed;
244 if (properties & PROP_trees)
245 register_one_dump_file (pass);
247 properties = register_dump_files (pass->sub, properties);
255 /* Add a pass to the pass list. Duplicate the pass if it's already
258 static struct tree_opt_pass **
259 next_pass_1 (struct tree_opt_pass **list, struct tree_opt_pass *pass)
262 /* A non-zero static_pass_number indicates that the
263 pass is already in the list. */
264 if (pass->static_pass_number)
266 struct tree_opt_pass *new;
268 new = xmalloc (sizeof (*new));
269 memcpy (new, pass, sizeof (*new));
271 /* Indicate to register_dump_files that this pass has duplicates,
272 and so it should rename the dump file. The first instance will
273 be -1, and be number of duplicates = -static_pass_number - 1.
274 Subsequent instances will be > 0 and just the duplicate number. */
277 pass->static_pass_number -= 1;
278 new->static_pass_number = -pass->static_pass_number;
285 pass->static_pass_number = -1;
289 return &(*list)->next;
293 /* Construct the pass tree. */
296 init_tree_optimization_passes (void)
298 struct tree_opt_pass **p;
300 #define NEXT_PASS(PASS) (p = next_pass_1 (p, &PASS))
303 NEXT_PASS (pass_gimple);
304 NEXT_PASS (pass_remove_useless_stmts);
305 NEXT_PASS (pass_mudflap_1);
306 NEXT_PASS (pass_lower_cf);
307 NEXT_PASS (pass_lower_eh);
308 NEXT_PASS (pass_build_cfg);
309 NEXT_PASS (pass_pre_expand);
310 NEXT_PASS (pass_tree_profile);
311 NEXT_PASS (pass_init_datastructures);
312 NEXT_PASS (pass_all_optimizations);
313 NEXT_PASS (pass_warn_function_return);
314 NEXT_PASS (pass_mudflap_2);
315 NEXT_PASS (pass_free_datastructures);
316 NEXT_PASS (pass_expand);
317 NEXT_PASS (pass_rest_of_compilation);
320 p = &pass_all_optimizations.sub;
321 NEXT_PASS (pass_referenced_vars);
322 NEXT_PASS (pass_build_pta);
323 NEXT_PASS (pass_build_ssa);
324 NEXT_PASS (pass_may_alias);
325 NEXT_PASS (pass_rename_ssa_copies);
326 NEXT_PASS (pass_early_warn_uninitialized);
327 NEXT_PASS (pass_dce);
328 NEXT_PASS (pass_dominator);
329 NEXT_PASS (pass_redundant_phi);
330 NEXT_PASS (pass_dce);
331 NEXT_PASS (pass_forwprop);
332 NEXT_PASS (pass_phiopt);
333 NEXT_PASS (pass_may_alias);
334 NEXT_PASS (pass_tail_recursion);
336 NEXT_PASS (pass_profile);
337 NEXT_PASS (pass_sra);
338 NEXT_PASS (pass_rename_ssa_copies);
339 NEXT_PASS (pass_dominator);
340 NEXT_PASS (pass_redundant_phi);
341 NEXT_PASS (pass_dce);
342 NEXT_PASS (pass_dse);
343 NEXT_PASS (pass_may_alias);
344 NEXT_PASS (pass_forwprop);
345 NEXT_PASS (pass_phiopt);
346 NEXT_PASS (pass_ccp);
347 NEXT_PASS (pass_redundant_phi);
348 NEXT_PASS (pass_fold_builtins);
349 NEXT_PASS (pass_split_crit_edges);
350 NEXT_PASS (pass_pre);
351 NEXT_PASS (pass_loop);
352 NEXT_PASS (pass_dominator);
353 NEXT_PASS (pass_redundant_phi);
354 NEXT_PASS (pass_cd_dce);
355 NEXT_PASS (pass_dse);
356 NEXT_PASS (pass_forwprop);
357 NEXT_PASS (pass_phiopt);
358 NEXT_PASS (pass_tail_calls);
359 NEXT_PASS (pass_late_warn_uninitialized);
360 NEXT_PASS (pass_del_pta);
361 NEXT_PASS (pass_del_ssa);
362 NEXT_PASS (pass_nrv);
363 NEXT_PASS (pass_remove_useless_vars);
364 NEXT_PASS (pass_cleanup_cfg_post_optimizing);
368 NEXT_PASS (pass_loop_init);
369 NEXT_PASS (pass_lim);
370 NEXT_PASS (pass_iv_canon);
371 NEXT_PASS (pass_vectorize);
372 NEXT_PASS (pass_complete_unroll);
373 NEXT_PASS (pass_loop_done);
378 /* Register the passes with the tree dump code. */
379 register_dump_files (all_passes, 0);
382 static void execute_pass_list (struct tree_opt_pass *);
384 static unsigned int last_verified;
387 execute_todo (unsigned int flags)
389 if (flags & TODO_rename_vars)
391 rewrite_into_ssa (false);
392 bitmap_clear (vars_to_rename);
395 if ((flags & TODO_dump_func) && dump_file)
397 dump_function_to_file (current_function_decl,
398 dump_file, dump_flags);
400 /* Flush the file. If verification fails, we won't be able to
401 close the file before aborting. */
405 if (flags & TODO_ggc_collect)
408 #ifdef ENABLE_CHECKING
409 if (flags & TODO_verify_ssa)
411 if (flags & TODO_verify_flow)
413 if (flags & TODO_verify_stmts)
419 execute_one_pass (struct tree_opt_pass *pass)
423 /* See if we're supposed to run this pass. */
424 if (pass->gate && !pass->gate ())
427 /* Note that the folders should only create gimple expressions.
428 This is a hack until the new folder is ready. */
429 in_gimple_form = (pass->properties_provided & PROP_trees) != 0;
431 /* Run pre-pass verification. */
432 todo = pass->todo_flags_start & ~last_verified;
436 /* If a dump file name is present, open it if enabled. */
437 if (pass->static_pass_number != -1)
439 dump_file = dump_begin (pass->static_pass_number, &dump_flags);
442 const char *dname, *aname;
443 dname = lang_hooks.decl_printable_name (current_function_decl, 2);
444 aname = (IDENTIFIER_POINTER
445 (DECL_ASSEMBLER_NAME (current_function_decl)));
446 fprintf (dump_file, "\n;; Function %s (%s)\n\n", dname, aname);
450 /* If a timevar is present, start it. */
452 timevar_push (pass->tv_id);
458 /* Run post-pass cleanup and verification. */
459 todo = pass->todo_flags_finish;
460 last_verified = todo & TODO_verify_all;
464 /* Close down timevar and dump file. */
466 timevar_pop (pass->tv_id);
469 dump_end (pass->static_pass_number, dump_file);
477 execute_pass_list (struct tree_opt_pass *pass)
481 if (execute_one_pass (pass) && pass->sub)
482 execute_pass_list (pass->sub);
489 /* For functions-as-trees languages, this performs all optimization and
490 compilation for FNDECL. */
493 tree_rest_of_compilation (tree fndecl, bool nested_p)
495 location_t saved_loc;
496 struct cgraph_node *saved_node = NULL, *node;
498 timevar_push (TV_EXPAND);
500 if (flag_unit_at_a_time && !cgraph_global_info_ready)
503 /* Initialize the RTL code for the function. */
504 current_function_decl = fndecl;
505 saved_loc = input_location;
506 input_location = DECL_SOURCE_LOCATION (fndecl);
507 init_function_start (fndecl);
509 /* Even though we're inside a function body, we still don't want to
510 call expand_expr to calculate the size of a variable-sized array.
511 We haven't necessarily assigned RTL to all variables yet, so it's
512 not safe to try to expand expressions involving them. */
513 cfun->x_dont_save_pending_sizes_p = 1;
515 node = cgraph_node (fndecl);
517 /* We might need the body of this function so that we can expand
518 it inline somewhere else. This means not lowering some constructs
519 such as exception handling. */
520 if (cgraph_preserve_function_body_p (fndecl))
522 if (!flag_unit_at_a_time)
524 struct cgraph_edge *e;
526 saved_node = cgraph_clone_node (node);
527 for (e = saved_node->callees; e; e = e->next_callee)
528 if (!e->inline_failed)
529 cgraph_clone_inlined_nodes (e, true);
531 cfun->saved_static_chain_decl = cfun->static_chain_decl;
532 cfun->saved_tree = save_body (fndecl, &cfun->saved_args,
533 &cfun->saved_static_chain_decl);
536 if (flag_inline_trees)
538 struct cgraph_edge *e;
539 for (e = node->callees; e; e = e->next_callee)
540 if (!e->inline_failed || warn_inline)
544 timevar_push (TV_INTEGRATION);
545 optimize_inline_calls (fndecl);
546 timevar_pop (TV_INTEGRATION);
551 vars_to_rename = BITMAP_XMALLOC ();
553 /* If this is a nested function, protect the local variables in the stack
554 above us from being collected while we're compiling this function. */
558 /* Perform all tree transforms and optimizations. */
559 execute_pass_list (all_passes);
561 /* Restore original body if still needed. */
562 if (cfun->saved_tree)
564 DECL_SAVED_TREE (fndecl) = cfun->saved_tree;
565 DECL_ARGUMENTS (fndecl) = cfun->saved_args;
566 cfun->static_chain_decl = cfun->saved_static_chain_decl;
568 /* When not in unit-at-a-time mode, we must preserve out of line copy
569 representing node before inlining. Restore original outgoing edges
570 using clone we created earlier. */
571 if (!flag_unit_at_a_time)
573 struct cgraph_edge *e;
574 while (node->callees)
575 cgraph_remove_edge (node->callees);
576 node->callees = saved_node->callees;
577 saved_node->callees = NULL;
578 for (e = saved_node->callees; e; e = e->next_callee)
580 cgraph_remove_node (saved_node);
584 DECL_SAVED_TREE (fndecl) = NULL;
587 /* If requested, warn about function definitions where the function will
588 return a value (usually of some struct or union type) which itself will
589 take up a lot of stack space. */
590 if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
592 tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
594 if (ret_type && TYPE_SIZE_UNIT (ret_type)
595 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
596 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
599 unsigned int size_as_int
600 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
602 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
603 warning ("%Jsize of return value of '%D' is %u bytes",
604 fndecl, fndecl, size_as_int);
606 warning ("%Jsize of return value of '%D' is larger than %wd bytes",
607 fndecl, fndecl, larger_than_size);
611 if (!nested_p && !flag_inline_trees)
613 DECL_SAVED_TREE (fndecl) = NULL;
614 if (DECL_STRUCT_FUNCTION (fndecl) == 0
615 && !cgraph_node (fndecl)->origin)
617 /* Stop pointing to the local nodes about to be freed.
618 But DECL_INITIAL must remain nonzero so we know this
619 was an actual function definition.
620 For a nested function, this is done in c_pop_function_context.
621 If rest_of_compilation set this to 0, leave it 0. */
622 if (DECL_INITIAL (fndecl) != 0)
623 DECL_INITIAL (fndecl) = error_mark_node;
627 input_location = saved_loc;
631 /* Undo the GC context switch. */
634 timevar_pop (TV_EXPAND);