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_if_conversion);
372 NEXT_PASS (pass_vectorize);
373 NEXT_PASS (pass_complete_unroll);
374 NEXT_PASS (pass_iv_optimize);
375 NEXT_PASS (pass_loop_done);
380 /* Register the passes with the tree dump code. */
381 register_dump_files (all_passes, 0);
384 static void execute_pass_list (struct tree_opt_pass *);
386 static unsigned int last_verified;
389 execute_todo (unsigned int flags)
391 if (flags & TODO_rename_vars)
393 rewrite_into_ssa (false);
394 bitmap_clear (vars_to_rename);
397 if ((flags & TODO_dump_func) && dump_file)
399 dump_function_to_file (current_function_decl,
400 dump_file, dump_flags);
402 /* Flush the file. If verification fails, we won't be able to
403 close the file before aborting. */
407 if (flags & TODO_ggc_collect)
410 #ifdef ENABLE_CHECKING
411 if (flags & TODO_verify_ssa)
413 if (flags & TODO_verify_flow)
415 if (flags & TODO_verify_stmts)
421 execute_one_pass (struct tree_opt_pass *pass)
425 /* See if we're supposed to run this pass. */
426 if (pass->gate && !pass->gate ())
429 /* Note that the folders should only create gimple expressions.
430 This is a hack until the new folder is ready. */
431 in_gimple_form = (pass->properties_provided & PROP_trees) != 0;
433 /* Run pre-pass verification. */
434 todo = pass->todo_flags_start & ~last_verified;
438 /* If a dump file name is present, open it if enabled. */
439 if (pass->static_pass_number != -1)
441 dump_file = dump_begin (pass->static_pass_number, &dump_flags);
444 const char *dname, *aname;
445 dname = lang_hooks.decl_printable_name (current_function_decl, 2);
446 aname = (IDENTIFIER_POINTER
447 (DECL_ASSEMBLER_NAME (current_function_decl)));
448 fprintf (dump_file, "\n;; Function %s (%s)\n\n", dname, aname);
452 /* If a timevar is present, start it. */
454 timevar_push (pass->tv_id);
460 /* Run post-pass cleanup and verification. */
461 todo = pass->todo_flags_finish;
462 last_verified = todo & TODO_verify_all;
466 /* Close down timevar and dump file. */
468 timevar_pop (pass->tv_id);
471 dump_end (pass->static_pass_number, dump_file);
479 execute_pass_list (struct tree_opt_pass *pass)
483 if (execute_one_pass (pass) && pass->sub)
484 execute_pass_list (pass->sub);
491 /* For functions-as-trees languages, this performs all optimization and
492 compilation for FNDECL. */
495 tree_rest_of_compilation (tree fndecl, bool nested_p)
497 location_t saved_loc;
498 struct cgraph_node *saved_node = NULL, *node;
500 timevar_push (TV_EXPAND);
502 if (flag_unit_at_a_time && !cgraph_global_info_ready)
505 /* Initialize the RTL code for the function. */
506 current_function_decl = fndecl;
507 saved_loc = input_location;
508 input_location = DECL_SOURCE_LOCATION (fndecl);
509 init_function_start (fndecl);
511 /* Even though we're inside a function body, we still don't want to
512 call expand_expr to calculate the size of a variable-sized array.
513 We haven't necessarily assigned RTL to all variables yet, so it's
514 not safe to try to expand expressions involving them. */
515 cfun->x_dont_save_pending_sizes_p = 1;
517 node = cgraph_node (fndecl);
519 /* We might need the body of this function so that we can expand
520 it inline somewhere else. This means not lowering some constructs
521 such as exception handling. */
522 if (cgraph_preserve_function_body_p (fndecl))
524 if (!flag_unit_at_a_time)
526 struct cgraph_edge *e;
528 saved_node = cgraph_clone_node (node);
529 for (e = saved_node->callees; e; e = e->next_callee)
530 if (!e->inline_failed)
531 cgraph_clone_inlined_nodes (e, true);
533 cfun->saved_static_chain_decl = cfun->static_chain_decl;
534 cfun->saved_tree = save_body (fndecl, &cfun->saved_args,
535 &cfun->saved_static_chain_decl);
538 if (flag_inline_trees)
540 struct cgraph_edge *e;
541 for (e = node->callees; e; e = e->next_callee)
542 if (!e->inline_failed || warn_inline)
546 timevar_push (TV_INTEGRATION);
547 optimize_inline_calls (fndecl);
548 timevar_pop (TV_INTEGRATION);
553 vars_to_rename = BITMAP_XMALLOC ();
555 /* If this is a nested function, protect the local variables in the stack
556 above us from being collected while we're compiling this function. */
560 /* Perform all tree transforms and optimizations. */
561 execute_pass_list (all_passes);
563 /* Restore original body if still needed. */
564 if (cfun->saved_tree)
566 DECL_SAVED_TREE (fndecl) = cfun->saved_tree;
567 DECL_ARGUMENTS (fndecl) = cfun->saved_args;
568 cfun->static_chain_decl = cfun->saved_static_chain_decl;
570 /* When not in unit-at-a-time mode, we must preserve out of line copy
571 representing node before inlining. Restore original outgoing edges
572 using clone we created earlier. */
573 if (!flag_unit_at_a_time)
575 struct cgraph_edge *e;
576 while (node->callees)
577 cgraph_remove_edge (node->callees);
578 node->callees = saved_node->callees;
579 saved_node->callees = NULL;
580 for (e = saved_node->callees; e; e = e->next_callee)
582 cgraph_remove_node (saved_node);
586 DECL_SAVED_TREE (fndecl) = NULL;
589 /* If requested, warn about function definitions where the function will
590 return a value (usually of some struct or union type) which itself will
591 take up a lot of stack space. */
592 if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
594 tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
596 if (ret_type && TYPE_SIZE_UNIT (ret_type)
597 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
598 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
601 unsigned int size_as_int
602 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
604 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
605 warning ("%Jsize of return value of '%D' is %u bytes",
606 fndecl, fndecl, size_as_int);
608 warning ("%Jsize of return value of '%D' is larger than %wd bytes",
609 fndecl, fndecl, larger_than_size);
613 if (!nested_p && !flag_inline_trees)
615 DECL_SAVED_TREE (fndecl) = NULL;
616 if (DECL_STRUCT_FUNCTION (fndecl) == 0
617 && !cgraph_node (fndecl)->origin)
619 /* Stop pointing to the local nodes about to be freed.
620 But DECL_INITIAL must remain nonzero so we know this
621 was an actual function definition.
622 For a nested function, this is done in c_pop_function_context.
623 If rest_of_compilation set this to 0, leave it 0. */
624 if (DECL_INITIAL (fndecl) != 0)
625 DECL_INITIAL (fndecl) = error_mark_node;
629 input_location = saved_loc;
633 /* Undo the GC context switch. */
636 timevar_pop (TV_EXPAND);