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"
53 /* Global variables used to communicate with passes. */
55 bitmap vars_to_rename;
58 /* The root of the compilation pass tree, once constructed. */
59 static struct tree_opt_pass *all_passes;
61 /* Pass: dump the gimplified, inlined, functions. */
63 static struct tree_opt_pass pass_gimple =
70 0, /* static_pass_number */
72 0, /* properties_required */
73 PROP_gimple_any, /* properties_provided */
74 0, /* properties_destroyed */
75 0, /* todo_flags_start */
76 TODO_dump_func, /* todo_flags_finish */
80 /* Gate: execute, or not, all of the non-trivial optimizations. */
83 gate_all_optimizations (void)
86 /* Don't bother doing anything if the program has errors. */
87 && !(errorcount || sorrycount));
90 static struct tree_opt_pass pass_all_optimizations =
93 gate_all_optimizations, /* gate */
97 0, /* static_pass_number */
99 0, /* properties_required */
100 0, /* properties_provided */
101 0, /* properties_destroyed */
102 0, /* todo_flags_start */
103 0, /* todo_flags_finish */
107 /* Pass: cleanup the CFG just before expanding trees to RTL.
108 This is just a round of label cleanups and case node grouping
109 because after the tree optimizers have run such cleanups may
113 execute_cleanup_cfg_post_optimizing (void)
116 cleanup_dead_labels ();
117 group_case_labels ();
120 static struct tree_opt_pass pass_cleanup_cfg_post_optimizing =
124 execute_cleanup_cfg_post_optimizing, /* execute */
127 0, /* static_pass_number */
129 PROP_cfg, /* properties_required */
130 0, /* properties_provided */
131 0, /* properties_destroyed */
132 0, /* todo_flags_start */
133 0, /* todo_flags_finish */
137 /* Pass: do the actions required to finish with tree-ssa optimization
141 execute_free_datastructures (void)
145 /* ??? This isn't the right place for this. Worse, it got computed
146 more or less at random in various passes. */
147 free_dominance_info (CDI_DOMINATORS);
149 /* Emit gotos for implicit jumps. */
150 disband_implicit_edges ();
152 /* Remove the ssa structures. Do it here since this includes statement
153 annotations that need to be intact during disband_implicit_edges. */
156 /* Re-chain the statements from the blocks. */
157 chain = &DECL_SAVED_TREE (current_function_decl);
158 *chain = alloc_stmt_list ();
160 /* And get rid of annotations we no longer need. */
161 delete_tree_cfg_annotations ();
164 static struct tree_opt_pass pass_free_datastructures =
168 execute_free_datastructures, /* execute */
171 0, /* static_pass_number */
173 PROP_cfg, /* properties_required */
174 0, /* properties_provided */
175 0, /* properties_destroyed */
176 0, /* todo_flags_start */
177 0, /* todo_flags_finish */
182 /* Do the actions required to initialize internal data structures used
183 in tree-ssa optimization passes. */
186 execute_init_datastructures (void)
188 /* Allocate hash tables, arrays and other structures. */
192 static struct tree_opt_pass pass_init_datastructures =
196 execute_init_datastructures, /* execute */
199 0, /* static_pass_number */
201 PROP_cfg, /* properties_required */
202 0, /* properties_provided */
203 0, /* properties_destroyed */
204 0, /* todo_flags_start */
205 0, /* todo_flags_finish */
209 /* Iterate over the pass tree allocating dump file numbers. We want
210 to do this depth first, and independent of whether the pass is
214 register_one_dump_file (struct tree_opt_pass *pass, int n)
216 char *dot_name, *flag_name;
219 /* See below in next_pass_1. */
221 if (pass->static_pass_number != -1)
222 sprintf (num, "%d", ((int) pass->static_pass_number < 0
223 ? 1 : pass->static_pass_number));
225 dot_name = concat (".", pass->name, num, NULL);
226 if (pass->properties_provided & PROP_trees)
228 flag_name = concat ("tree-", pass->name, num, NULL);
229 pass->static_pass_number = dump_register (dot_name, flag_name,
230 TDF_TREE, n + TDI_tree_all, 0);
234 flag_name = concat ("rtl-", pass->name, num, NULL);
235 pass->static_pass_number = dump_register (dot_name, flag_name,
236 TDF_RTL, n, pass->letter);
241 register_dump_files (struct tree_opt_pass *pass, int properties)
249 pass->properties_required = properties;
251 (properties | pass->properties_provided) & ~pass->properties_destroyed;
253 /* Reset the counter when we reach RTL-based passes. */
254 if ((pass->properties_provided ^ pass->properties_required) & PROP_rtl)
262 new_properties = register_dump_files (pass->sub, new_properties);
264 /* If we have a gate, combine the properties that we could have with
265 and without the pass being examined. */
267 properties &= new_properties;
269 properties = new_properties;
271 pass->properties_provided = properties;
273 register_one_dump_file (pass, pass_number);
282 /* Add a pass to the pass list. Duplicate the pass if it's already
285 static struct tree_opt_pass **
286 next_pass_1 (struct tree_opt_pass **list, struct tree_opt_pass *pass)
289 /* A non-zero static_pass_number indicates that the
290 pass is already in the list. */
291 if (pass->static_pass_number)
293 struct tree_opt_pass *new;
295 new = xmalloc (sizeof (*new));
296 memcpy (new, pass, sizeof (*new));
298 /* Indicate to register_dump_files that this pass has duplicates,
299 and so it should rename the dump file. The first instance will
300 be -1, and be number of duplicates = -static_pass_number - 1.
301 Subsequent instances will be > 0 and just the duplicate number. */
304 pass->static_pass_number -= 1;
305 new->static_pass_number = -pass->static_pass_number;
312 pass->static_pass_number = -1;
316 return &(*list)->next;
320 /* Construct the pass tree. */
323 init_tree_optimization_passes (void)
325 struct tree_opt_pass **p;
327 #define NEXT_PASS(PASS) (p = next_pass_1 (p, &PASS))
330 NEXT_PASS (pass_gimple);
331 NEXT_PASS (pass_remove_useless_stmts);
332 NEXT_PASS (pass_mudflap_1);
333 NEXT_PASS (pass_lower_cf);
334 NEXT_PASS (pass_lower_eh);
335 NEXT_PASS (pass_build_cfg);
336 NEXT_PASS (pass_pre_expand);
337 NEXT_PASS (pass_tree_profile);
338 NEXT_PASS (pass_init_datastructures);
339 NEXT_PASS (pass_all_optimizations);
340 NEXT_PASS (pass_warn_function_return);
341 NEXT_PASS (pass_mudflap_2);
342 NEXT_PASS (pass_free_datastructures);
343 NEXT_PASS (pass_expand);
344 NEXT_PASS (pass_rest_of_compilation);
347 p = &pass_all_optimizations.sub;
348 NEXT_PASS (pass_referenced_vars);
349 NEXT_PASS (pass_build_pta);
350 NEXT_PASS (pass_build_ssa);
351 NEXT_PASS (pass_may_alias);
352 NEXT_PASS (pass_rename_ssa_copies);
353 NEXT_PASS (pass_early_warn_uninitialized);
354 NEXT_PASS (pass_dce);
355 NEXT_PASS (pass_dominator);
356 NEXT_PASS (pass_redundant_phi);
357 NEXT_PASS (pass_dce);
358 NEXT_PASS (pass_forwprop);
359 NEXT_PASS (pass_phiopt);
360 NEXT_PASS (pass_may_alias);
361 NEXT_PASS (pass_tail_recursion);
363 NEXT_PASS (pass_profile);
364 NEXT_PASS (pass_sra);
365 NEXT_PASS (pass_rename_ssa_copies);
366 NEXT_PASS (pass_dominator);
367 NEXT_PASS (pass_redundant_phi);
368 NEXT_PASS (pass_dce);
369 NEXT_PASS (pass_dse);
370 NEXT_PASS (pass_may_alias);
371 NEXT_PASS (pass_forwprop);
372 NEXT_PASS (pass_phiopt);
373 NEXT_PASS (pass_ccp);
374 NEXT_PASS (pass_redundant_phi);
375 NEXT_PASS (pass_fold_builtins);
376 NEXT_PASS (pass_split_crit_edges);
377 NEXT_PASS (pass_pre);
378 NEXT_PASS (pass_loop);
379 NEXT_PASS (pass_dominator);
380 NEXT_PASS (pass_redundant_phi);
381 NEXT_PASS (pass_cd_dce);
382 NEXT_PASS (pass_dse);
383 NEXT_PASS (pass_forwprop);
384 NEXT_PASS (pass_phiopt);
385 NEXT_PASS (pass_tail_calls);
386 NEXT_PASS (pass_late_warn_uninitialized);
387 NEXT_PASS (pass_del_pta);
388 NEXT_PASS (pass_del_ssa);
389 NEXT_PASS (pass_nrv);
390 NEXT_PASS (pass_remove_useless_vars);
391 NEXT_PASS (pass_cleanup_cfg_post_optimizing);
395 NEXT_PASS (pass_loop_init);
396 NEXT_PASS (pass_lim);
397 NEXT_PASS (pass_iv_canon);
398 NEXT_PASS (pass_if_conversion);
399 NEXT_PASS (pass_vectorize);
400 NEXT_PASS (pass_complete_unroll);
401 NEXT_PASS (pass_iv_optimize);
402 NEXT_PASS (pass_loop_done);
407 /* Register the passes with the tree dump code. */
408 register_dump_files (all_passes, 0);
411 static void execute_pass_list (struct tree_opt_pass *);
413 static unsigned int last_verified;
416 execute_todo (int properties, unsigned int flags)
418 if (flags & TODO_rename_vars)
420 rewrite_into_ssa (false);
421 bitmap_clear (vars_to_rename);
424 if ((flags & TODO_dump_func) && dump_file)
426 if (properties & PROP_trees)
427 dump_function_to_file (current_function_decl,
428 dump_file, dump_flags);
429 else if (properties & PROP_cfg)
430 print_rtl_with_bb (dump_file, get_insns ());
432 print_rtl (dump_file, get_insns ());
434 /* Flush the file. If verification fails, we won't be able to
435 close the file before aborting. */
439 if (flags & TODO_ggc_collect)
442 #ifdef ENABLE_CHECKING
443 if (flags & TODO_verify_ssa)
445 if (flags & TODO_verify_flow)
447 if (flags & TODO_verify_stmts)
453 execute_one_pass (struct tree_opt_pass *pass)
457 /* See if we're supposed to run this pass. */
458 if (pass->gate && !pass->gate ())
461 /* Note that the folders should only create gimple expressions.
462 This is a hack until the new folder is ready. */
463 in_gimple_form = (pass->properties_provided & PROP_trees) != 0;
465 /* Run pre-pass verification. */
466 todo = pass->todo_flags_start & ~last_verified;
468 execute_todo (pass->properties_required, todo);
470 /* If a dump file name is present, open it if enabled. */
471 if (pass->static_pass_number != -1)
473 bool initializing_dump = !dump_initialized_p (pass->static_pass_number);
474 dump_file_name = get_dump_file_name (pass->static_pass_number);
475 dump_file = dump_begin (pass->static_pass_number, &dump_flags);
478 const char *dname, *aname;
479 dname = lang_hooks.decl_printable_name (current_function_decl, 2);
480 aname = (IDENTIFIER_POINTER
481 (DECL_ASSEMBLER_NAME (current_function_decl)));
482 fprintf (dump_file, "\n;; Function %s (%s)%s\n\n", dname, aname,
483 cfun->function_frequency == FUNCTION_FREQUENCY_HOT
485 : cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED
486 ? " (unlikely executed)"
490 if (initializing_dump
491 && graph_dump_format != no_graph
492 && (pass->properties_provided & (PROP_cfg | PROP_rtl))
493 == (PROP_cfg | PROP_rtl))
494 clean_graph_dump_file (dump_file_name);
497 /* If a timevar is present, start it. */
499 timevar_push (pass->tv_id);
506 && (pass->properties_provided & (PROP_cfg | PROP_rtl))
507 == (PROP_cfg | PROP_rtl))
508 print_rtl_graph_with_bb (dump_file_name, get_insns ());
510 /* Run post-pass cleanup and verification. */
511 todo = pass->todo_flags_finish;
512 last_verified = todo & TODO_verify_all;
514 execute_todo (pass->properties_provided, todo);
516 /* Close down timevar and dump file. */
518 timevar_pop (pass->tv_id);
521 free ((char *) dump_file_name);
522 dump_file_name = NULL;
526 dump_end (pass->static_pass_number, dump_file);
534 execute_pass_list (struct tree_opt_pass *pass)
538 if (execute_one_pass (pass) && pass->sub)
539 execute_pass_list (pass->sub);
546 /* For functions-as-trees languages, this performs all optimization and
547 compilation for FNDECL. */
550 tree_rest_of_compilation (tree fndecl, bool nested_p)
552 location_t saved_loc;
553 struct cgraph_node *saved_node = NULL, *node;
555 timevar_push (TV_EXPAND);
557 if (flag_unit_at_a_time && !cgraph_global_info_ready)
560 /* Initialize the RTL code for the function. */
561 current_function_decl = fndecl;
562 saved_loc = input_location;
563 input_location = DECL_SOURCE_LOCATION (fndecl);
564 init_function_start (fndecl);
566 /* Even though we're inside a function body, we still don't want to
567 call expand_expr to calculate the size of a variable-sized array.
568 We haven't necessarily assigned RTL to all variables yet, so it's
569 not safe to try to expand expressions involving them. */
570 cfun->x_dont_save_pending_sizes_p = 1;
572 node = cgraph_node (fndecl);
574 /* We might need the body of this function so that we can expand
575 it inline somewhere else. This means not lowering some constructs
576 such as exception handling. */
577 if (cgraph_preserve_function_body_p (fndecl))
579 if (!flag_unit_at_a_time)
581 struct cgraph_edge *e;
583 saved_node = cgraph_clone_node (node);
584 for (e = saved_node->callees; e; e = e->next_callee)
585 if (!e->inline_failed)
586 cgraph_clone_inlined_nodes (e, true);
588 cfun->saved_static_chain_decl = cfun->static_chain_decl;
589 cfun->saved_tree = save_body (fndecl, &cfun->saved_args,
590 &cfun->saved_static_chain_decl);
593 if (flag_inline_trees)
595 struct cgraph_edge *e;
596 for (e = node->callees; e; e = e->next_callee)
597 if (!e->inline_failed || warn_inline)
601 timevar_push (TV_INTEGRATION);
602 optimize_inline_calls (fndecl);
603 timevar_pop (TV_INTEGRATION);
608 vars_to_rename = BITMAP_XMALLOC ();
610 /* If this is a nested function, protect the local variables in the stack
611 above us from being collected while we're compiling this function. */
615 /* Perform all tree transforms and optimizations. */
616 execute_pass_list (all_passes);
618 /* Restore original body if still needed. */
619 if (cfun->saved_tree)
621 DECL_SAVED_TREE (fndecl) = cfun->saved_tree;
622 DECL_ARGUMENTS (fndecl) = cfun->saved_args;
623 cfun->static_chain_decl = cfun->saved_static_chain_decl;
625 /* When not in unit-at-a-time mode, we must preserve out of line copy
626 representing node before inlining. Restore original outgoing edges
627 using clone we created earlier. */
628 if (!flag_unit_at_a_time)
630 struct cgraph_edge *e;
631 while (node->callees)
632 cgraph_remove_edge (node->callees);
633 node->callees = saved_node->callees;
634 saved_node->callees = NULL;
635 for (e = saved_node->callees; e; e = e->next_callee)
637 cgraph_remove_node (saved_node);
641 DECL_SAVED_TREE (fndecl) = NULL;
644 /* If requested, warn about function definitions where the function will
645 return a value (usually of some struct or union type) which itself will
646 take up a lot of stack space. */
647 if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
649 tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
651 if (ret_type && TYPE_SIZE_UNIT (ret_type)
652 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
653 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
656 unsigned int size_as_int
657 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
659 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
660 warning ("%Jsize of return value of '%D' is %u bytes",
661 fndecl, fndecl, size_as_int);
663 warning ("%Jsize of return value of '%D' is larger than %wd bytes",
664 fndecl, fndecl, larger_than_size);
668 if (!nested_p && !flag_inline_trees)
670 DECL_SAVED_TREE (fndecl) = NULL;
671 if (DECL_STRUCT_FUNCTION (fndecl) == 0
672 && !cgraph_node (fndecl)->origin)
674 /* Stop pointing to the local nodes about to be freed.
675 But DECL_INITIAL must remain nonzero so we know this
676 was an actual function definition.
677 For a nested function, this is done in c_pop_function_context.
678 If rest_of_compilation set this to 0, leave it 0. */
679 if (DECL_INITIAL (fndecl) != 0)
680 DECL_INITIAL (fndecl) = error_mark_node;
684 input_location = saved_loc;
688 /* Undo the GC context switch. */
691 timevar_pop (TV_EXPAND);