1 /* Top-level control of tree optimizations.
2 Copyright 2001, 2002, 2003, 2004, 2005, 2007 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 3, 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 COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
28 #include "hard-reg-set.h"
29 #include "basic-block.h"
32 #include "diagnostic.h"
33 #include "basic-block.h"
35 #include "tree-flow.h"
36 #include "tree-dump.h"
39 #include "langhooks.h"
43 #include "tree-inline.h"
44 #include "tree-mudflap.h"
45 #include "tree-pass.h"
53 /* Gate: execute, or not, all of the non-trivial optimizations. */
56 gate_all_optimizations (void)
59 /* Don't bother doing anything if the program has errors.
60 We have to pass down the queue if we already went into SSA */
61 && (!(errorcount
|| sorrycount
) || gimple_in_ssa_p (cfun
)));
64 struct gimple_opt_pass pass_all_optimizations
=
69 gate_all_optimizations
, /* gate */
73 0, /* static_pass_number */
75 0, /* properties_required */
76 0, /* properties_provided */
77 0, /* properties_destroyed */
78 0, /* todo_flags_start */
79 0 /* todo_flags_finish */
83 /* Gate: execute, or not, all of the non-trivial optimizations. */
86 gate_all_early_local_passes (void)
88 /* Don't bother doing anything if the program has errors. */
89 return (!errorcount
&& !sorrycount
);
92 struct simple_ipa_opt_pass pass_early_local_passes
=
96 "early_local_cleanups", /* name */
97 gate_all_early_local_passes
, /* gate */
101 0, /* static_pass_number */
103 0, /* properties_required */
104 0, /* properties_provided */
105 0, /* properties_destroyed */
106 0, /* todo_flags_start */
107 TODO_remove_functions
/* todo_flags_finish */
112 execute_early_local_optimizations (void)
114 if (flag_unit_at_a_time
)
115 cgraph_state
= CGRAPH_STATE_IPA_SSA
;
119 /* Gate: execute, or not, all of the non-trivial optimizations. */
122 gate_all_early_optimizations (void)
124 return (optimize
>= 1
125 /* Don't bother doing anything if the program has errors. */
126 && !(errorcount
|| sorrycount
));
129 struct gimple_opt_pass pass_all_early_optimizations
=
133 "early_optimizations", /* name */
134 gate_all_early_optimizations
, /* gate */
135 execute_early_local_optimizations
, /* execute */
138 0, /* static_pass_number */
140 0, /* properties_required */
141 0, /* properties_provided */
142 0, /* properties_destroyed */
143 0, /* todo_flags_start */
144 0 /* todo_flags_finish */
148 /* Pass: cleanup the CFG just before expanding trees to RTL.
149 This is just a round of label cleanups and case node grouping
150 because after the tree optimizers have run such cleanups may
154 execute_cleanup_cfg_pre_ipa (void)
160 struct gimple_opt_pass pass_cleanup_cfg
=
164 "cleanup_cfg", /* name */
166 execute_cleanup_cfg_pre_ipa
, /* execute */
169 0, /* static_pass_number */
171 PROP_cfg
, /* properties_required */
172 0, /* properties_provided */
173 0, /* properties_destroyed */
174 0, /* todo_flags_start */
175 TODO_dump_func
/* todo_flags_finish */
180 /* Pass: cleanup the CFG just before expanding trees to RTL.
181 This is just a round of label cleanups and case node grouping
182 because after the tree optimizers have run such cleanups may
186 execute_cleanup_cfg_post_optimizing (void)
188 fold_cond_expr_cond ();
190 cleanup_dead_labels ();
191 group_case_labels ();
195 struct gimple_opt_pass pass_cleanup_cfg_post_optimizing
=
199 "final_cleanup", /* name */
201 execute_cleanup_cfg_post_optimizing
, /* execute */
204 0, /* static_pass_number */
206 PROP_cfg
, /* properties_required */
207 0, /* properties_provided */
208 0, /* properties_destroyed */
209 0, /* todo_flags_start */
210 TODO_dump_func
/* todo_flags_finish */
214 /* Pass: do the actions required to finish with tree-ssa optimization
218 execute_free_datastructures (void)
220 free_dominance_info (CDI_DOMINATORS
);
221 free_dominance_info (CDI_POST_DOMINATORS
);
223 /* Remove the ssa structures. */
229 struct gimple_opt_pass pass_free_datastructures
=
235 execute_free_datastructures
, /* execute */
238 0, /* static_pass_number */
240 PROP_cfg
, /* properties_required */
241 0, /* properties_provided */
242 0, /* properties_destroyed */
243 0, /* todo_flags_start */
244 0 /* todo_flags_finish */
247 /* Pass: free cfg annotations. */
250 execute_free_cfg_annotations (void)
252 /* And get rid of annotations we no longer need. */
253 delete_tree_cfg_annotations ();
258 struct gimple_opt_pass pass_free_cfg_annotations
=
264 execute_free_cfg_annotations
, /* execute */
267 0, /* static_pass_number */
269 PROP_cfg
, /* properties_required */
270 0, /* properties_provided */
271 0, /* properties_destroyed */
272 0, /* todo_flags_start */
273 0 /* todo_flags_finish */
277 /* Pass: fixup_cfg. IPA passes, compilation of earlier functions or inlining
278 might have changed some properties, such as marked functions nothrow.
279 Remove redundant edges and basic blocks, and create new ones if necessary.
281 This pass can't be executed as stand alone pass from pass manager, because
282 in between inlining and this fixup the verify_flow_info would fail. */
285 execute_fixup_cfg (void)
288 block_stmt_iterator bsi
;
289 int todo
= gimple_in_ssa_p (cfun
) ? TODO_verify_ssa
: 0;
291 cfun
->after_inlining
= true;
296 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
298 tree stmt
= bsi_stmt (bsi
);
299 tree call
= get_call_expr_in (stmt
);
300 tree decl
= call
? get_callee_fndecl (call
) : NULL
;
302 if (decl
&& call_expr_flags (call
) & (ECF_CONST
| ECF_PURE
303 | ECF_LOOPING_CONST_OR_PURE
)
304 && TREE_SIDE_EFFECTS (call
))
306 if (gimple_in_ssa_p (cfun
))
308 todo
|= TODO_update_ssa
| TODO_cleanup_cfg
;
311 TREE_SIDE_EFFECTS (call
) = 0;
313 if (decl
&& TREE_NOTHROW (decl
))
314 TREE_NOTHROW (call
) = 1;
315 if (!tree_could_throw_p (stmt
) && lookup_stmt_eh_region (stmt
))
316 remove_stmt_from_eh_region (stmt
);
318 if (tree_purge_dead_eh_edges (bb
))
319 todo
|= TODO_cleanup_cfg
;
322 /* Dump a textual representation of the flowgraph. */
324 dump_tree_cfg (dump_file
, dump_flags
);
329 /* Do the actions required to initialize internal data structures used
330 in tree-ssa optimization passes. */
333 execute_init_datastructures (void)
335 /* Allocate hash tables, arrays and other structures. */
340 /* Gate: initialize or not the SSA datastructures. */
343 gate_init_datastructures (void)
345 return (optimize
>= 1);
348 struct gimple_opt_pass pass_init_datastructures
=
353 gate_init_datastructures
, /* gate */
354 execute_init_datastructures
, /* execute */
357 0, /* static_pass_number */
359 PROP_cfg
, /* properties_required */
360 0, /* properties_provided */
361 0, /* properties_destroyed */
362 0, /* todo_flags_start */
363 0 /* todo_flags_finish */
368 tree_lowering_passes (tree fn
)
370 tree saved_current_function_decl
= current_function_decl
;
372 current_function_decl
= fn
;
373 push_cfun (DECL_STRUCT_FUNCTION (fn
));
374 tree_register_cfg_hooks ();
375 bitmap_obstack_initialize (NULL
);
376 execute_pass_list (all_lowering_passes
);
377 if (optimize
&& cgraph_global_info_ready
)
378 execute_pass_list (pass_early_local_passes
.pass
.sub
);
379 free_dominance_info (CDI_POST_DOMINATORS
);
380 free_dominance_info (CDI_DOMINATORS
);
382 current_function_decl
= saved_current_function_decl
;
383 bitmap_obstack_release (NULL
);
387 /* For functions-as-trees languages, this performs all optimization and
388 compilation for FNDECL. */
391 tree_rest_of_compilation (tree fndecl
)
393 location_t saved_loc
;
394 struct cgraph_node
*node
;
396 timevar_push (TV_EXPAND
);
398 gcc_assert (!flag_unit_at_a_time
|| cgraph_global_info_ready
);
400 node
= cgraph_node (fndecl
);
402 /* Initialize the default bitmap obstack. */
403 bitmap_obstack_initialize (NULL
);
405 /* Initialize the RTL code for the function. */
406 current_function_decl
= fndecl
;
407 saved_loc
= input_location
;
408 input_location
= DECL_SOURCE_LOCATION (fndecl
);
409 init_function_start (fndecl
);
411 /* Even though we're inside a function body, we still don't want to
412 call expand_expr to calculate the size of a variable-sized array.
413 We haven't necessarily assigned RTL to all variables yet, so it's
414 not safe to try to expand expressions involving them. */
415 cfun
->dont_save_pending_sizes_p
= 1;
417 tree_register_cfg_hooks ();
419 bitmap_obstack_initialize (®_obstack
); /* FIXME, only at RTL generation*/
420 /* Perform all tree transforms and optimizations. */
421 execute_pass_list (all_passes
);
423 bitmap_obstack_release (®_obstack
);
425 /* Release the default bitmap obstack. */
426 bitmap_obstack_release (NULL
);
428 DECL_SAVED_TREE (fndecl
) = NULL
;
431 /* If requested, warn about function definitions where the function will
432 return a value (usually of some struct or union type) which itself will
433 take up a lot of stack space. */
434 if (warn_larger_than
&& !DECL_EXTERNAL (fndecl
) && TREE_TYPE (fndecl
))
436 tree ret_type
= TREE_TYPE (TREE_TYPE (fndecl
));
438 if (ret_type
&& TYPE_SIZE_UNIT (ret_type
)
439 && TREE_CODE (TYPE_SIZE_UNIT (ret_type
)) == INTEGER_CST
440 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type
),
443 unsigned int size_as_int
444 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type
));
446 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type
), size_as_int
) == 0)
447 warning (OPT_Wlarger_than_eq
, "size of return value of %q+D is %u bytes",
448 fndecl
, size_as_int
);
450 warning (OPT_Wlarger_than_eq
, "size of return value of %q+D is larger than %wd bytes",
451 fndecl
, larger_than_size
);
455 if (!flag_inline_trees
)
457 DECL_SAVED_TREE (fndecl
) = NULL
;
458 if (DECL_STRUCT_FUNCTION (fndecl
) == 0
459 && !cgraph_node (fndecl
)->origin
)
461 /* Stop pointing to the local nodes about to be freed.
462 But DECL_INITIAL must remain nonzero so we know this
463 was an actual function definition.
464 For a nested function, this is done in c_pop_function_context.
465 If rest_of_compilation set this to 0, leave it 0. */
466 if (DECL_INITIAL (fndecl
) != 0)
467 DECL_INITIAL (fndecl
) = error_mark_node
;
471 input_location
= saved_loc
;
474 timevar_pop (TV_EXPAND
);