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: gimplify the function if it's not been done. */
65 /* We have this test here rather than as the gate because we always
66 want to dump the original gimplified function. */
67 if (!lang_hooks.gimple_before_inlining)
68 gimplify_function_tree (current_function_decl);
71 static struct tree_opt_pass pass_gimple =
75 execute_gimple, /* execute */
78 0, /* static_pass_number */
80 0, /* properties_required */
81 PROP_gimple_any, /* properties_provided */
82 0, /* properties_destroyed */
83 0, /* todo_flags_start */
84 TODO_dump_func /* todo_flags_finish */
87 /* Gate: execute, or not, all of the non-trivial optimizations. */
90 gate_all_optimizations (void)
93 /* Don't bother doing anything if the program has errors. */
94 && !(errorcount || sorrycount));
97 static struct tree_opt_pass pass_all_optimizations =
100 gate_all_optimizations, /* gate */
104 0, /* static_pass_number */
106 0, /* properties_required */
107 0, /* properties_provided */
108 0, /* properties_destroyed */
109 0, /* todo_flags_start */
110 0 /* todo_flags_finish */
113 /* Pass: do the actions required to finish with tree-ssa optimization
117 execute_free_datastructures (void)
121 /* ??? This isn't the right place for this. Worse, it got computed
122 more or less at random in various passes. */
123 free_dominance_info (CDI_DOMINATORS);
125 /* Emit gotos for implicit jumps. */
126 disband_implicit_edges ();
128 /* Remove the ssa structures. Do it here since this includes statement
129 annotations that need to be intact during disband_implicit_edges. */
132 /* Re-chain the statements from the blocks. */
133 chain = &DECL_SAVED_TREE (current_function_decl);
134 *chain = alloc_stmt_list ();
136 /* And get rid of annotations we no longer need. */
137 delete_tree_cfg_annotations ();
140 static struct tree_opt_pass pass_free_datastructures =
144 execute_free_datastructures, /* execute */
147 0, /* static_pass_number */
149 PROP_cfg, /* properties_required */
150 0, /* properties_provided */
151 0, /* properties_destroyed */
152 0, /* todo_flags_start */
153 0 /* todo_flags_finish */
157 /* Do the actions required to initialize internal data structures used
158 in tree-ssa optimization passes. */
161 execute_init_datastructures (void)
163 /* Allocate hash tables, arrays and other structures. */
167 static struct tree_opt_pass pass_init_datastructures =
171 execute_init_datastructures, /* execute */
174 0, /* static_pass_number */
176 PROP_cfg, /* properties_required */
177 0, /* properties_provided */
178 0, /* properties_destroyed */
179 0, /* todo_flags_start */
180 0 /* todo_flags_finish */
183 /* Iterate over the pass tree allocating dump file numbers. We want
184 to do this depth first, and independent of whether the pass is
188 register_one_dump_file (struct tree_opt_pass *pass)
190 char *dot_name, *flag_name;
196 /* See below in dup_pass_1. */
198 if (pass->static_pass_number)
199 sprintf (num, "%d", ((int) pass->static_pass_number < 0
200 ? 1 : pass->static_pass_number));
202 dot_name = concat (".", pass->name, num, NULL);
203 flag_name = concat ("tree-", pass->name, num, NULL);
205 pass->static_pass_number = dump_register (dot_name, flag_name);
209 register_dump_files (struct tree_opt_pass *pass, int properties)
213 /* Verify that all required properties are present. */
214 if (pass->properties_required & ~properties)
217 if (pass->properties_destroyed & pass->properties_provided)
220 pass->properties_required = properties;
221 pass->properties_provided = properties =
222 (properties | pass->properties_provided) & ~pass->properties_destroyed;
224 if (properties & PROP_trees)
225 register_one_dump_file (pass);
227 properties = register_dump_files (pass->sub, properties);
235 /* Duplicate a pass that's to be run more than once. */
237 static struct tree_opt_pass *
238 dup_pass_1 (struct tree_opt_pass *pass)
240 struct tree_opt_pass *new;
242 new = xmalloc (sizeof (*new));
243 memcpy (new, pass, sizeof (*new));
245 /* Indicate to register_dump_files that this pass has duplicates,
246 and so it should rename the dump file. The first instance will
247 be < 0, and be number of duplicates = -static_pass_number + 1.
248 Subsequent instances will be > 0 and just the duplicate number. */
251 int n, p = pass->static_pass_number;
258 pass->static_pass_number = p;
259 new->static_pass_number = n;
265 /* Construct the pass tree. */
268 init_tree_optimization_passes (void)
270 struct tree_opt_pass **p;
272 #define NEXT_PASS(PASS) (*p = &PASS, p = &(*p)->next)
273 #define DUP_PASS(PASS) (*dup_pass_1 (&PASS))
276 NEXT_PASS (pass_gimple);
277 NEXT_PASS (pass_remove_useless_stmts);
278 NEXT_PASS (pass_mudflap_1);
279 NEXT_PASS (pass_lower_cf);
280 NEXT_PASS (pass_lower_eh);
281 NEXT_PASS (pass_build_cfg);
282 NEXT_PASS (pass_tree_profile);
283 NEXT_PASS (pass_init_datastructures);
284 NEXT_PASS (pass_all_optimizations);
285 NEXT_PASS (pass_mudflap_2);
286 NEXT_PASS (pass_free_datastructures);
287 NEXT_PASS (pass_expand);
288 NEXT_PASS (pass_rest_of_compilation);
291 p = &pass_all_optimizations.sub;
292 NEXT_PASS (pass_referenced_vars);
293 NEXT_PASS (pass_build_pta);
294 NEXT_PASS (pass_build_ssa);
295 NEXT_PASS (pass_rename_ssa_copies);
296 NEXT_PASS (pass_early_warn_uninitialized);
297 NEXT_PASS (pass_dce);
298 NEXT_PASS (pass_dominator);
299 NEXT_PASS (pass_redundant_phi);
300 NEXT_PASS (DUP_PASS (pass_dce));
301 NEXT_PASS (pass_forwprop);
302 NEXT_PASS (pass_phiopt);
303 NEXT_PASS (pass_may_alias);
304 NEXT_PASS (pass_tail_recursion);
306 NEXT_PASS (pass_del_pta);
307 NEXT_PASS (pass_profile);
308 NEXT_PASS (pass_lower_complex);
309 NEXT_PASS (pass_sra);
310 NEXT_PASS (DUP_PASS (pass_rename_ssa_copies));
311 NEXT_PASS (DUP_PASS (pass_dominator));
312 NEXT_PASS (DUP_PASS (pass_redundant_phi));
313 NEXT_PASS (DUP_PASS (pass_dce));
314 NEXT_PASS (pass_dse);
315 NEXT_PASS (DUP_PASS (pass_forwprop));
316 NEXT_PASS (DUP_PASS (pass_phiopt));
317 NEXT_PASS (pass_ccp);
318 NEXT_PASS (DUP_PASS (pass_redundant_phi));
319 NEXT_PASS (pass_fold_builtins);
320 NEXT_PASS (pass_split_crit_edges);
321 NEXT_PASS (pass_pre);
322 NEXT_PASS (pass_loop);
323 NEXT_PASS (DUP_PASS (pass_dominator));
324 NEXT_PASS (DUP_PASS (pass_redundant_phi));
325 NEXT_PASS (pass_cd_dce);
326 NEXT_PASS (DUP_PASS (pass_dse));
327 NEXT_PASS (DUP_PASS (pass_forwprop));
328 NEXT_PASS (DUP_PASS (pass_phiopt));
329 NEXT_PASS (pass_tail_calls);
330 NEXT_PASS (pass_late_warn_uninitialized);
331 NEXT_PASS (pass_warn_function_return);
332 NEXT_PASS (pass_del_ssa);
333 NEXT_PASS (pass_nrv);
334 NEXT_PASS (pass_remove_useless_vars);
338 NEXT_PASS (pass_loop_init);
339 NEXT_PASS (pass_loop_done);
345 /* Register the passes with the tree dump code. */
346 register_dump_files (all_passes, 0);
349 static void execute_pass_list (struct tree_opt_pass *);
351 static unsigned int last_verified;
354 execute_todo (unsigned int flags)
356 if (flags & TODO_rename_vars)
358 rewrite_into_ssa (false);
359 bitmap_clear (vars_to_rename);
362 if ((flags & TODO_dump_func) && dump_file)
363 dump_function_to_file (current_function_decl,
364 dump_file, dump_flags);
366 if (flags & TODO_ggc_collect)
369 #ifdef ENABLE_CHECKING
370 if (flags & TODO_verify_ssa)
372 if (flags & TODO_verify_flow)
374 if (flags & TODO_verify_stmts)
380 execute_one_pass (struct tree_opt_pass *pass)
384 /* See if we're supposed to run this pass. */
385 if (pass->gate && !pass->gate ())
388 /* Note that the folders should only create gimple expressions.
389 This is a hack until the new folder is ready. */
390 in_gimple_form = (pass->properties_provided & PROP_trees) != 0;
392 /* Run pre-pass verification. */
393 todo = pass->todo_flags_start & ~last_verified;
397 /* If a dump file name is present, open it if enabled. */
398 if (pass->static_pass_number)
400 dump_file = dump_begin (pass->static_pass_number, &dump_flags);
403 const char *dname, *aname;
404 dname = lang_hooks.decl_printable_name (current_function_decl, 2);
405 aname = (IDENTIFIER_POINTER
406 (DECL_ASSEMBLER_NAME (current_function_decl)));
407 fprintf (dump_file, "\n;; Function %s (%s)\n\n", dname, aname);
411 /* If a timevar is present, start it. */
413 timevar_push (pass->tv_id);
419 /* Run post-pass cleanup and verification. */
420 todo = pass->todo_flags_finish;
421 last_verified = todo & TODO_verify_all;
425 /* Close down timevar and dump file. */
427 timevar_pop (pass->tv_id);
430 dump_end (pass->static_pass_number, dump_file);
438 execute_pass_list (struct tree_opt_pass *pass)
442 if (execute_one_pass (pass) && pass->sub)
443 execute_pass_list (pass->sub);
450 /* For functions-as-trees languages, this performs all optimization and
451 compilation for FNDECL. */
454 tree_rest_of_compilation (tree fndecl, bool nested_p)
456 location_t saved_loc;
457 struct cgraph_node *saved_node = NULL, *node;
459 timevar_push (TV_EXPAND);
461 if (flag_unit_at_a_time && !cgraph_global_info_ready)
464 /* Initialize the RTL code for the function. */
465 current_function_decl = fndecl;
466 saved_loc = input_location;
467 input_location = DECL_SOURCE_LOCATION (fndecl);
468 init_function_start (fndecl);
470 /* This function is being processed in whole-function mode. */
471 cfun->x_whole_function_mode_p = 1;
473 /* Even though we're inside a function body, we still don't want to
474 call expand_expr to calculate the size of a variable-sized array.
475 We haven't necessarily assigned RTL to all variables yet, so it's
476 not safe to try to expand expressions involving them. */
477 cfun->x_dont_save_pending_sizes_p = 1;
479 node = cgraph_node (fndecl);
481 /* We might need the body of this function so that we can expand
482 it inline somewhere else. This means not lowering some constructs
483 such as exception handling. */
484 if (cgraph_preserve_function_body_p (fndecl))
486 if (!flag_unit_at_a_time)
488 struct cgraph_edge *e;
490 saved_node = cgraph_clone_node (node);
491 for (e = saved_node->callees; e; e = e->next_callee)
492 if (!e->inline_failed)
493 cgraph_clone_inlined_nodes (e, true);
495 cfun->saved_tree = save_body (fndecl, &cfun->saved_args);
498 if (flag_inline_trees)
500 struct cgraph_edge *e;
501 for (e = node->callees; e; e = e->next_callee)
502 if (!e->inline_failed || warn_inline)
506 timevar_push (TV_INTEGRATION);
507 optimize_inline_calls (fndecl);
508 timevar_pop (TV_INTEGRATION);
513 vars_to_rename = BITMAP_XMALLOC ();
515 /* If this is a nested function, protect the local variables in the stack
516 above us from being collected while we're compiling this function. */
520 /* Perform all tree transforms and optimizations. */
521 execute_pass_list (all_passes);
523 /* Restore original body if still needed. */
524 if (cfun->saved_tree)
526 DECL_SAVED_TREE (fndecl) = cfun->saved_tree;
527 DECL_ARGUMENTS (fndecl) = cfun->saved_args;
529 /* When not in unit-at-a-time mode, we must preserve out of line copy
530 representing node before inlining. Restore original outgoing edges
531 using clone we created earlier. */
532 if (!flag_unit_at_a_time)
534 struct cgraph_edge *e;
535 while (node->callees)
536 cgraph_remove_edge (node->callees);
537 node->callees = saved_node->callees;
538 saved_node->callees = NULL;
539 for (e = saved_node->callees; e; e = e->next_callee)
541 cgraph_remove_node (saved_node);
545 DECL_SAVED_TREE (fndecl) = NULL;
548 /* If requested, warn about function definitions where the function will
549 return a value (usually of some struct or union type) which itself will
550 take up a lot of stack space. */
551 if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
553 tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
555 if (ret_type && TYPE_SIZE_UNIT (ret_type)
556 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
557 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
560 unsigned int size_as_int
561 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
563 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
564 warning ("%Jsize of return value of '%D' is %u bytes",
565 fndecl, fndecl, size_as_int);
567 warning ("%Jsize of return value of '%D' is larger than %wd bytes",
568 fndecl, fndecl, larger_than_size);
572 if (!nested_p && !flag_inline_trees)
574 DECL_SAVED_TREE (fndecl) = NULL;
575 if (DECL_STRUCT_FUNCTION (fndecl) == 0
576 && !cgraph_node (fndecl)->origin)
578 /* Stop pointing to the local nodes about to be freed.
579 But DECL_INITIAL must remain nonzero so we know this
580 was an actual function definition.
581 For a nested function, this is done in c_pop_function_context.
582 If rest_of_compilation set this to 0, leave it 0. */
583 if (DECL_INITIAL (fndecl) != 0)
584 DECL_INITIAL (fndecl) = error_mark_node;
588 input_location = saved_loc;
592 /* Undo the GC context switch. */
595 timevar_pop (TV_EXPAND);