1 /* Top-level control of tree optimizations.
2 Copyright 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
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"
54 /* Gate: execute, or not, all of the non-trivial optimizations. */
57 gate_all_optimizations (void)
60 /* Don't bother doing anything if the program has errors.
61 We have to pass down the queue if we already went into SSA */
62 && (!(errorcount || sorrycount) || gimple_in_ssa_p (cfun)));
65 struct gimple_opt_pass pass_all_optimizations =
69 "*all_optimizations", /* name */
70 gate_all_optimizations, /* gate */
74 0, /* static_pass_number */
76 0, /* properties_required */
77 0, /* properties_provided */
78 0, /* properties_destroyed */
79 0, /* todo_flags_start */
80 0 /* todo_flags_finish */
84 /* Gate: execute, or not, all of the non-trivial optimizations. */
87 gate_all_early_local_passes (void)
89 /* Don't bother doing anything if the program has errors. */
90 return (!errorcount && !sorrycount && !in_lto_p);
93 struct simple_ipa_opt_pass pass_early_local_passes =
97 "early_local_cleanups", /* name */
98 gate_all_early_local_passes, /* gate */
102 0, /* static_pass_number */
104 0, /* properties_required */
105 0, /* properties_provided */
106 0, /* properties_destroyed */
107 0, /* todo_flags_start */
108 TODO_remove_functions /* todo_flags_finish */
113 execute_early_local_optimizations (void)
115 /* First time we start with early optimization we need to advance
116 cgraph state so newly inserted functions are also early optimized.
117 However we execute early local optimizations for lately inserted
118 functions, in that case don't reset cgraph state back to IPA_SSA. */
119 if (cgraph_state < CGRAPH_STATE_IPA_SSA)
120 cgraph_state = CGRAPH_STATE_IPA_SSA;
124 /* Gate: execute, or not, all of the non-trivial optimizations. */
127 gate_all_early_optimizations (void)
129 return (optimize >= 1
130 /* Don't bother doing anything if the program has errors. */
131 && !(errorcount || sorrycount));
134 struct gimple_opt_pass pass_all_early_optimizations =
138 "early_optimizations", /* name */
139 gate_all_early_optimizations, /* gate */
140 execute_early_local_optimizations, /* execute */
143 0, /* static_pass_number */
145 0, /* properties_required */
146 0, /* properties_provided */
147 0, /* properties_destroyed */
148 0, /* todo_flags_start */
149 0 /* todo_flags_finish */
153 /* Pass: cleanup the CFG just before expanding trees to RTL.
154 This is just a round of label cleanups and case node grouping
155 because after the tree optimizers have run such cleanups may
159 execute_cleanup_cfg_pre_ipa (void)
165 struct gimple_opt_pass pass_cleanup_cfg =
169 "cleanup_cfg", /* name */
171 execute_cleanup_cfg_pre_ipa, /* 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 TODO_dump_func /* todo_flags_finish */
185 /* Pass: cleanup the CFG just before expanding trees to RTL.
186 This is just a round of label cleanups and case node grouping
187 because after the tree optimizers have run such cleanups may
191 execute_cleanup_cfg_post_optimizing (void)
193 fold_cond_expr_cond ();
195 cleanup_dead_labels ();
196 group_case_labels ();
200 struct gimple_opt_pass pass_cleanup_cfg_post_optimizing =
204 "optimized", /* name */
206 execute_cleanup_cfg_post_optimizing, /* execute */
209 0, /* static_pass_number */
211 PROP_cfg, /* properties_required */
212 0, /* properties_provided */
213 0, /* properties_destroyed */
214 0, /* todo_flags_start */
215 TODO_dump_func /* todo_flags_finish */
216 | TODO_remove_unused_locals
220 /* Pass: do the actions required to finish with tree-ssa optimization
224 execute_free_datastructures (void)
226 free_dominance_info (CDI_DOMINATORS);
227 free_dominance_info (CDI_POST_DOMINATORS);
229 /* And get rid of annotations we no longer need. */
230 delete_tree_cfg_annotations ();
235 /* Pass: fixup_cfg. IPA passes, compilation of earlier functions or inlining
236 might have changed some properties, such as marked functions nothrow.
237 Remove redundant edges and basic blocks, and create new ones if necessary.
239 This pass can't be executed as stand alone pass from pass manager, because
240 in between inlining and this fixup the verify_flow_info would fail. */
243 execute_fixup_cfg (void)
246 gimple_stmt_iterator gsi;
247 int todo = gimple_in_ssa_p (cfun) ? TODO_verify_ssa : 0;
252 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
254 gimple stmt = gsi_stmt (gsi);
255 tree decl = is_gimple_call (stmt)
256 ? gimple_call_fndecl (stmt)
260 && gimple_call_flags (stmt) & (ECF_CONST
262 | ECF_LOOPING_CONST_OR_PURE))
264 if (gimple_in_ssa_p (cfun))
266 todo |= TODO_update_ssa | TODO_cleanup_cfg;
267 mark_symbols_for_renaming (stmt);
272 maybe_clean_eh_stmt (stmt);
275 if (gimple_purge_dead_eh_edges (bb))
276 todo |= TODO_cleanup_cfg;
279 /* Dump a textual representation of the flowgraph. */
281 gimple_dump_cfg (dump_file, dump_flags);
286 struct gimple_opt_pass pass_fixup_cfg =
292 execute_fixup_cfg, /* execute */
295 0, /* static_pass_number */
297 PROP_cfg, /* properties_required */
298 0, /* properties_provided */
299 0, /* properties_destroyed */
300 0, /* todo_flags_start */
301 0 /* todo_flags_finish */
305 /* Do the actions required to initialize internal data structures used
306 in tree-ssa optimization passes. */
309 execute_init_datastructures (void)
311 /* Allocate hash tables, arrays and other structures. */
312 init_tree_ssa (cfun);
316 struct gimple_opt_pass pass_init_datastructures =
322 execute_init_datastructures, /* execute */
325 0, /* static_pass_number */
327 PROP_cfg, /* properties_required */
328 0, /* properties_provided */
329 0, /* properties_destroyed */
330 0, /* todo_flags_start */
331 0 /* todo_flags_finish */
336 tree_lowering_passes (tree fn)
338 tree saved_current_function_decl = current_function_decl;
340 current_function_decl = fn;
341 push_cfun (DECL_STRUCT_FUNCTION (fn));
342 gimple_register_cfg_hooks ();
343 bitmap_obstack_initialize (NULL);
344 execute_pass_list (all_lowering_passes);
345 if (optimize && cgraph_global_info_ready)
346 execute_pass_list (pass_early_local_passes.pass.sub);
347 free_dominance_info (CDI_POST_DOMINATORS);
348 free_dominance_info (CDI_DOMINATORS);
350 current_function_decl = saved_current_function_decl;
351 bitmap_obstack_release (NULL);
355 /* For functions-as-trees languages, this performs all optimization and
356 compilation for FNDECL. */
359 tree_rest_of_compilation (tree fndecl)
361 location_t saved_loc;
362 struct cgraph_node *node;
364 timevar_push (TV_EXPAND);
366 gcc_assert (cgraph_global_info_ready);
368 node = cgraph_node (fndecl);
370 /* Initialize the default bitmap obstack. */
371 bitmap_obstack_initialize (NULL);
373 /* Initialize the RTL code for the function. */
374 current_function_decl = fndecl;
375 saved_loc = input_location;
376 input_location = DECL_SOURCE_LOCATION (fndecl);
377 init_function_start (fndecl);
379 /* Even though we're inside a function body, we still don't want to
380 call expand_expr to calculate the size of a variable-sized array.
381 We haven't necessarily assigned RTL to all variables yet, so it's
382 not safe to try to expand expressions involving them. */
383 cfun->dont_save_pending_sizes_p = 1;
385 gimple_register_cfg_hooks ();
387 bitmap_obstack_initialize (®_obstack); /* FIXME, only at RTL generation*/
389 execute_all_ipa_transforms ();
391 /* Perform all tree transforms and optimizations. */
392 execute_pass_list (all_passes);
394 bitmap_obstack_release (®_obstack);
396 /* Release the default bitmap obstack. */
397 bitmap_obstack_release (NULL);
401 /* If requested, warn about function definitions where the function will
402 return a value (usually of some struct or union type) which itself will
403 take up a lot of stack space. */
404 if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
406 tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
408 if (ret_type && TYPE_SIZE_UNIT (ret_type)
409 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
410 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
413 unsigned int size_as_int
414 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
416 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
417 warning (OPT_Wlarger_than_eq, "size of return value of %q+D is %u bytes",
418 fndecl, size_as_int);
420 warning (OPT_Wlarger_than_eq, "size of return value of %q+D is larger than %wd bytes",
421 fndecl, larger_than_size);
425 gimple_set_body (fndecl, NULL);
426 if (DECL_STRUCT_FUNCTION (fndecl) == 0
427 && !cgraph_node (fndecl)->origin)
429 /* Stop pointing to the local nodes about to be freed.
430 But DECL_INITIAL must remain nonzero so we know this
431 was an actual function definition.
432 For a nested function, this is done in c_pop_function_context.
433 If rest_of_compilation set this to 0, leave it 0. */
434 if (DECL_INITIAL (fndecl) != 0)
435 DECL_INITIAL (fndecl) = error_mark_node;
438 input_location = saved_loc;
441 timevar_pop (TV_EXPAND);