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;
248 gcov_type count_scale
;
252 if (ENTRY_BLOCK_PTR
->count
)
253 count_scale
= (cgraph_node (current_function_decl
)->count
* REG_BR_PROB_BASE
254 + ENTRY_BLOCK_PTR
->count
/ 2) / ENTRY_BLOCK_PTR
->count
;
256 count_scale
= REG_BR_PROB_BASE
;
258 ENTRY_BLOCK_PTR
->count
= cgraph_node (current_function_decl
)->count
;
259 EXIT_BLOCK_PTR
->count
= (EXIT_BLOCK_PTR
->count
* count_scale
260 + REG_BR_PROB_BASE
/ 2) / REG_BR_PROB_BASE
;
264 bb
->count
= (bb
->count
* count_scale
265 + REG_BR_PROB_BASE
/ 2) / REG_BR_PROB_BASE
;
266 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
268 gimple stmt
= gsi_stmt (gsi
);
269 tree decl
= is_gimple_call (stmt
)
270 ? gimple_call_fndecl (stmt
)
274 && gimple_call_flags (stmt
) & (ECF_CONST
276 | ECF_LOOPING_CONST_OR_PURE
))
278 if (gimple_in_ssa_p (cfun
))
280 todo
|= TODO_update_ssa
| TODO_cleanup_cfg
;
281 mark_symbols_for_renaming (stmt
);
286 maybe_clean_eh_stmt (stmt
);
289 if (gimple_purge_dead_eh_edges (bb
))
290 todo
|= TODO_cleanup_cfg
;
291 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
292 e
->count
= (e
->count
* count_scale
293 + REG_BR_PROB_BASE
/ 2) / REG_BR_PROB_BASE
;
295 if (count_scale
!= REG_BR_PROB_BASE
)
296 compute_function_frequency ();
298 /* Dump a textual representation of the flowgraph. */
300 gimple_dump_cfg (dump_file
, dump_flags
);
305 struct gimple_opt_pass pass_fixup_cfg
=
309 "*free_cfg_annotations", /* name */
311 execute_fixup_cfg
, /* execute */
314 0, /* static_pass_number */
316 PROP_cfg
, /* properties_required */
317 0, /* properties_provided */
318 0, /* properties_destroyed */
319 0, /* todo_flags_start */
320 0 /* todo_flags_finish */
324 /* Do the actions required to initialize internal data structures used
325 in tree-ssa optimization passes. */
328 execute_init_datastructures (void)
330 /* Allocate hash tables, arrays and other structures. */
331 init_tree_ssa (cfun
);
335 struct gimple_opt_pass pass_init_datastructures
=
339 "*init_datastructures", /* name */
341 execute_init_datastructures
, /* execute */
344 0, /* static_pass_number */
346 PROP_cfg
, /* properties_required */
347 0, /* properties_provided */
348 0, /* properties_destroyed */
349 0, /* todo_flags_start */
350 0 /* todo_flags_finish */
355 tree_lowering_passes (tree fn
)
357 tree saved_current_function_decl
= current_function_decl
;
359 current_function_decl
= fn
;
360 push_cfun (DECL_STRUCT_FUNCTION (fn
));
361 gimple_register_cfg_hooks ();
362 bitmap_obstack_initialize (NULL
);
363 execute_pass_list (all_lowering_passes
);
364 if (optimize
&& cgraph_global_info_ready
)
365 execute_pass_list (pass_early_local_passes
.pass
.sub
);
366 free_dominance_info (CDI_POST_DOMINATORS
);
367 free_dominance_info (CDI_DOMINATORS
);
369 current_function_decl
= saved_current_function_decl
;
370 bitmap_obstack_release (NULL
);
374 /* For functions-as-trees languages, this performs all optimization and
375 compilation for FNDECL. */
378 tree_rest_of_compilation (tree fndecl
)
380 location_t saved_loc
;
382 timevar_push (TV_EXPAND
);
384 gcc_assert (cgraph_global_info_ready
);
386 /* Initialize the default bitmap obstack. */
387 bitmap_obstack_initialize (NULL
);
389 /* Initialize the RTL code for the function. */
390 current_function_decl
= fndecl
;
391 saved_loc
= input_location
;
392 input_location
= DECL_SOURCE_LOCATION (fndecl
);
393 init_function_start (fndecl
);
395 /* Even though we're inside a function body, we still don't want to
396 call expand_expr to calculate the size of a variable-sized array.
397 We haven't necessarily assigned RTL to all variables yet, so it's
398 not safe to try to expand expressions involving them. */
399 cfun
->dont_save_pending_sizes_p
= 1;
401 gimple_register_cfg_hooks ();
403 bitmap_obstack_initialize (®_obstack
); /* FIXME, only at RTL generation*/
405 execute_all_ipa_transforms ();
407 /* Perform all tree transforms and optimizations. */
408 execute_pass_list (all_passes
);
410 bitmap_obstack_release (®_obstack
);
412 /* Release the default bitmap obstack. */
413 bitmap_obstack_release (NULL
);
417 /* If requested, warn about function definitions where the function will
418 return a value (usually of some struct or union type) which itself will
419 take up a lot of stack space. */
420 if (warn_larger_than
&& !DECL_EXTERNAL (fndecl
) && TREE_TYPE (fndecl
))
422 tree ret_type
= TREE_TYPE (TREE_TYPE (fndecl
));
424 if (ret_type
&& TYPE_SIZE_UNIT (ret_type
)
425 && TREE_CODE (TYPE_SIZE_UNIT (ret_type
)) == INTEGER_CST
426 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type
),
429 unsigned int size_as_int
430 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type
));
432 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type
), size_as_int
) == 0)
433 warning (OPT_Wlarger_than_eq
, "size of return value of %q+D is %u bytes",
434 fndecl
, size_as_int
);
436 warning (OPT_Wlarger_than_eq
, "size of return value of %q+D is larger than %wd bytes",
437 fndecl
, larger_than_size
);
441 gimple_set_body (fndecl
, NULL
);
442 if (DECL_STRUCT_FUNCTION (fndecl
) == 0
443 && !cgraph_node (fndecl
)->origin
)
445 /* Stop pointing to the local nodes about to be freed.
446 But DECL_INITIAL must remain nonzero so we know this
447 was an actual function definition.
448 For a nested function, this is done in c_pop_function_context.
449 If rest_of_compilation set this to 0, leave it 0. */
450 if (DECL_INITIAL (fndecl
) != 0)
451 DECL_INITIAL (fndecl
) = error_mark_node
;
454 input_location
= saved_loc
;
457 timevar_pop (TV_EXPAND
);