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: do the actions required to finish with tree-ssa optimization
108 execute_free_datastructures (void)
112 /* ??? This isn't the right place for this. Worse, it got computed
113 more or less at random in various passes. */
114 free_dominance_info (CDI_DOMINATORS);
116 /* Emit gotos for implicit jumps. */
117 disband_implicit_edges ();
119 /* Remove the ssa structures. Do it here since this includes statement
120 annotations that need to be intact during disband_implicit_edges. */
123 /* Re-chain the statements from the blocks. */
124 chain = &DECL_SAVED_TREE (current_function_decl);
125 *chain = alloc_stmt_list ();
127 /* And get rid of annotations we no longer need. */
128 delete_tree_cfg_annotations ();
131 static struct tree_opt_pass pass_free_datastructures =
135 execute_free_datastructures, /* execute */
138 0, /* static_pass_number */
140 PROP_cfg, /* properties_required */
141 0, /* properties_provided */
142 0, /* properties_destroyed */
143 0, /* todo_flags_start */
144 0 /* todo_flags_finish */
148 /* Do the actions required to initialize internal data structures used
149 in tree-ssa optimization passes. */
152 execute_init_datastructures (void)
154 /* Allocate hash tables, arrays and other structures. */
158 static struct tree_opt_pass pass_init_datastructures =
162 execute_init_datastructures, /* execute */
165 0, /* static_pass_number */
167 PROP_cfg, /* properties_required */
168 0, /* properties_provided */
169 0, /* properties_destroyed */
170 0, /* todo_flags_start */
171 0 /* todo_flags_finish */
174 /* Iterate over the pass tree allocating dump file numbers. We want
175 to do this depth first, and independent of whether the pass is
179 register_one_dump_file (struct tree_opt_pass *pass)
181 char *dot_name, *flag_name;
187 /* See below in dup_pass_1. */
189 if (pass->static_pass_number)
190 sprintf (num, "%d", ((int) pass->static_pass_number < 0
191 ? 1 : pass->static_pass_number));
193 dot_name = concat (".", pass->name, num, NULL);
194 flag_name = concat ("tree-", pass->name, num, NULL);
196 pass->static_pass_number = dump_register (dot_name, flag_name);
200 register_dump_files (struct tree_opt_pass *pass, int properties)
204 /* Verify that all required properties are present. */
205 if (pass->properties_required & ~properties)
208 if (pass->properties_destroyed & pass->properties_provided)
211 pass->properties_required = properties;
212 pass->properties_provided = properties =
213 (properties | pass->properties_provided) & ~pass->properties_destroyed;
215 if (properties & PROP_trees)
216 register_one_dump_file (pass);
218 properties = register_dump_files (pass->sub, properties);
226 /* Duplicate a pass that's to be run more than once. */
228 static struct tree_opt_pass *
229 dup_pass_1 (struct tree_opt_pass *pass)
231 struct tree_opt_pass *new;
233 new = xmalloc (sizeof (*new));
234 memcpy (new, pass, sizeof (*new));
236 /* Indicate to register_dump_files that this pass has duplicates,
237 and so it should rename the dump file. The first instance will
238 be < 0, and be number of duplicates = -static_pass_number + 1.
239 Subsequent instances will be > 0 and just the duplicate number. */
242 int n, p = pass->static_pass_number;
249 pass->static_pass_number = p;
250 new->static_pass_number = n;
256 /* Construct the pass tree. */
259 init_tree_optimization_passes (void)
261 struct tree_opt_pass **p;
263 #define NEXT_PASS(PASS) (*p = &PASS, p = &(*p)->next)
264 #define DUP_PASS(PASS) (*dup_pass_1 (&PASS))
267 NEXT_PASS (pass_gimple);
268 NEXT_PASS (pass_remove_useless_stmts);
269 NEXT_PASS (pass_mudflap_1);
270 NEXT_PASS (pass_lower_cf);
271 NEXT_PASS (pass_lower_eh);
272 NEXT_PASS (pass_build_cfg);
273 NEXT_PASS (pass_tree_profile);
274 NEXT_PASS (pass_init_datastructures);
275 NEXT_PASS (pass_all_optimizations);
276 NEXT_PASS (pass_warn_function_return);
277 NEXT_PASS (pass_mudflap_2);
278 NEXT_PASS (pass_free_datastructures);
279 NEXT_PASS (pass_expand);
280 NEXT_PASS (pass_rest_of_compilation);
283 p = &pass_all_optimizations.sub;
284 NEXT_PASS (pass_referenced_vars);
285 NEXT_PASS (pass_build_pta);
286 NEXT_PASS (pass_build_ssa);
287 NEXT_PASS (pass_rename_ssa_copies);
288 NEXT_PASS (pass_early_warn_uninitialized);
289 NEXT_PASS (pass_dce);
290 NEXT_PASS (pass_dominator);
291 NEXT_PASS (pass_redundant_phi);
292 NEXT_PASS (DUP_PASS (pass_dce));
293 NEXT_PASS (pass_forwprop);
294 NEXT_PASS (pass_phiopt);
295 NEXT_PASS (pass_may_alias);
296 NEXT_PASS (pass_tail_recursion);
298 NEXT_PASS (pass_profile);
299 NEXT_PASS (pass_lower_complex);
300 NEXT_PASS (pass_sra);
301 NEXT_PASS (DUP_PASS (pass_rename_ssa_copies));
302 NEXT_PASS (DUP_PASS (pass_dominator));
303 NEXT_PASS (DUP_PASS (pass_redundant_phi));
304 NEXT_PASS (DUP_PASS (pass_dce));
305 NEXT_PASS (pass_dse);
306 NEXT_PASS (DUP_PASS (pass_may_alias));
307 NEXT_PASS (DUP_PASS (pass_forwprop));
308 NEXT_PASS (DUP_PASS (pass_phiopt));
309 NEXT_PASS (pass_ccp);
310 NEXT_PASS (DUP_PASS (pass_redundant_phi));
311 NEXT_PASS (pass_fold_builtins);
312 NEXT_PASS (pass_split_crit_edges);
313 NEXT_PASS (pass_pre);
314 NEXT_PASS (pass_loop);
315 NEXT_PASS (DUP_PASS (pass_dominator));
316 NEXT_PASS (DUP_PASS (pass_redundant_phi));
317 NEXT_PASS (pass_cd_dce);
318 NEXT_PASS (DUP_PASS (pass_dse));
319 NEXT_PASS (DUP_PASS (pass_forwprop));
320 NEXT_PASS (DUP_PASS (pass_phiopt));
321 NEXT_PASS (pass_tail_calls);
322 NEXT_PASS (pass_late_warn_uninitialized);
323 NEXT_PASS (pass_del_pta);
324 NEXT_PASS (pass_del_ssa);
325 NEXT_PASS (pass_nrv);
326 NEXT_PASS (pass_remove_useless_vars);
330 NEXT_PASS (pass_loop_init);
331 NEXT_PASS (pass_lim);
332 NEXT_PASS (pass_loop_done);
338 /* Register the passes with the tree dump code. */
339 register_dump_files (all_passes, 0);
342 static void execute_pass_list (struct tree_opt_pass *);
344 static unsigned int last_verified;
347 execute_todo (unsigned int flags)
349 if (flags & TODO_rename_vars)
351 rewrite_into_ssa (false);
352 bitmap_clear (vars_to_rename);
355 if ((flags & TODO_dump_func) && dump_file)
357 dump_function_to_file (current_function_decl,
358 dump_file, dump_flags);
360 /* Flush the file. If verification fails, we won't be able to
361 close the file before aborting. */
365 if (flags & TODO_ggc_collect)
368 #ifdef ENABLE_CHECKING
369 if (flags & TODO_verify_ssa)
371 if (flags & TODO_verify_flow)
373 if (flags & TODO_verify_stmts)
379 execute_one_pass (struct tree_opt_pass *pass)
383 /* See if we're supposed to run this pass. */
384 if (pass->gate && !pass->gate ())
387 /* Note that the folders should only create gimple expressions.
388 This is a hack until the new folder is ready. */
389 in_gimple_form = (pass->properties_provided & PROP_trees) != 0;
391 /* Run pre-pass verification. */
392 todo = pass->todo_flags_start & ~last_verified;
396 /* If a dump file name is present, open it if enabled. */
397 if (pass->static_pass_number)
399 dump_file = dump_begin (pass->static_pass_number, &dump_flags);
402 const char *dname, *aname;
403 dname = lang_hooks.decl_printable_name (current_function_decl, 2);
404 aname = (IDENTIFIER_POINTER
405 (DECL_ASSEMBLER_NAME (current_function_decl)));
406 fprintf (dump_file, "\n;; Function %s (%s)\n\n", dname, aname);
410 /* If a timevar is present, start it. */
412 timevar_push (pass->tv_id);
418 /* Run post-pass cleanup and verification. */
419 todo = pass->todo_flags_finish;
420 last_verified = todo & TODO_verify_all;
424 /* Close down timevar and dump file. */
426 timevar_pop (pass->tv_id);
429 dump_end (pass->static_pass_number, dump_file);
437 execute_pass_list (struct tree_opt_pass *pass)
441 if (execute_one_pass (pass) && pass->sub)
442 execute_pass_list (pass->sub);
449 /* For functions-as-trees languages, this performs all optimization and
450 compilation for FNDECL. */
453 tree_rest_of_compilation (tree fndecl, bool nested_p)
455 location_t saved_loc;
456 struct cgraph_node *saved_node = NULL, *node;
458 timevar_push (TV_EXPAND);
460 if (flag_unit_at_a_time && !cgraph_global_info_ready)
463 /* Initialize the RTL code for the function. */
464 current_function_decl = fndecl;
465 saved_loc = input_location;
466 input_location = DECL_SOURCE_LOCATION (fndecl);
467 init_function_start (fndecl);
469 /* Even though we're inside a function body, we still don't want to
470 call expand_expr to calculate the size of a variable-sized array.
471 We haven't necessarily assigned RTL to all variables yet, so it's
472 not safe to try to expand expressions involving them. */
473 cfun->x_dont_save_pending_sizes_p = 1;
475 node = cgraph_node (fndecl);
477 /* We might need the body of this function so that we can expand
478 it inline somewhere else. This means not lowering some constructs
479 such as exception handling. */
480 if (cgraph_preserve_function_body_p (fndecl))
482 if (!flag_unit_at_a_time)
484 struct cgraph_edge *e;
486 saved_node = cgraph_clone_node (node);
487 for (e = saved_node->callees; e; e = e->next_callee)
488 if (!e->inline_failed)
489 cgraph_clone_inlined_nodes (e, true);
491 cfun->saved_tree = save_body (fndecl, &cfun->saved_args);
494 if (flag_inline_trees)
496 struct cgraph_edge *e;
497 for (e = node->callees; e; e = e->next_callee)
498 if (!e->inline_failed || warn_inline)
502 timevar_push (TV_INTEGRATION);
503 optimize_inline_calls (fndecl);
504 timevar_pop (TV_INTEGRATION);
509 vars_to_rename = BITMAP_XMALLOC ();
511 /* If this is a nested function, protect the local variables in the stack
512 above us from being collected while we're compiling this function. */
516 /* Perform all tree transforms and optimizations. */
517 execute_pass_list (all_passes);
519 /* Restore original body if still needed. */
520 if (cfun->saved_tree)
522 DECL_SAVED_TREE (fndecl) = cfun->saved_tree;
523 DECL_ARGUMENTS (fndecl) = cfun->saved_args;
525 /* When not in unit-at-a-time mode, we must preserve out of line copy
526 representing node before inlining. Restore original outgoing edges
527 using clone we created earlier. */
528 if (!flag_unit_at_a_time)
530 struct cgraph_edge *e;
531 while (node->callees)
532 cgraph_remove_edge (node->callees);
533 node->callees = saved_node->callees;
534 saved_node->callees = NULL;
535 for (e = saved_node->callees; e; e = e->next_callee)
537 cgraph_remove_node (saved_node);
541 DECL_SAVED_TREE (fndecl) = NULL;
544 /* If requested, warn about function definitions where the function will
545 return a value (usually of some struct or union type) which itself will
546 take up a lot of stack space. */
547 if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
549 tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
551 if (ret_type && TYPE_SIZE_UNIT (ret_type)
552 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
553 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
556 unsigned int size_as_int
557 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
559 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
560 warning ("%Jsize of return value of '%D' is %u bytes",
561 fndecl, fndecl, size_as_int);
563 warning ("%Jsize of return value of '%D' is larger than %wd bytes",
564 fndecl, fndecl, larger_than_size);
568 if (!nested_p && !flag_inline_trees)
570 DECL_SAVED_TREE (fndecl) = NULL;
571 if (DECL_STRUCT_FUNCTION (fndecl) == 0
572 && !cgraph_node (fndecl)->origin)
574 /* Stop pointing to the local nodes about to be freed.
575 But DECL_INITIAL must remain nonzero so we know this
576 was an actual function definition.
577 For a nested function, this is done in c_pop_function_context.
578 If rest_of_compilation set this to 0, leave it 0. */
579 if (DECL_INITIAL (fndecl) != 0)
580 DECL_INITIAL (fndecl) = error_mark_node;
584 input_location = saved_loc;
588 /* Undo the GC context switch. */
591 timevar_pop (TV_EXPAND);