1 /* Top-level control of tree optimizations.
2 Copyright 2001, 2002, 2003, 2004, 2005 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, 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, 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"
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 && !(errorcount
|| sorrycount
));
64 struct tree_opt_pass pass_all_optimizations
=
67 gate_all_optimizations
, /* gate */
71 0, /* static_pass_number */
73 0, /* properties_required */
74 0, /* properties_provided */
75 0, /* properties_destroyed */
76 0, /* todo_flags_start */
77 0, /* todo_flags_finish */
81 struct tree_opt_pass pass_early_local_passes
=
84 gate_all_optimizations
, /* gate */
88 0, /* static_pass_number */
90 0, /* properties_required */
91 0, /* properties_provided */
92 0, /* properties_destroyed */
93 0, /* todo_flags_start */
94 0, /* todo_flags_finish */
98 /* Pass: cleanup the CFG just before expanding trees to RTL.
99 This is just a round of label cleanups and case node grouping
100 because after the tree optimizers have run such cleanups may
104 execute_cleanup_cfg_pre_ipa (void)
109 struct tree_opt_pass pass_cleanup_cfg
=
111 "cleanup_cfg", /* name */
113 execute_cleanup_cfg_pre_ipa
, /* execute */
116 0, /* static_pass_number */
118 PROP_cfg
, /* properties_required */
119 0, /* properties_provided */
120 0, /* properties_destroyed */
121 0, /* todo_flags_start */
122 TODO_dump_func
, /* todo_flags_finish */
127 /* Pass: cleanup the CFG just before expanding trees to RTL.
128 This is just a round of label cleanups and case node grouping
129 because after the tree optimizers have run such cleanups may
133 execute_cleanup_cfg_post_optimizing (void)
135 fold_cond_expr_cond ();
137 cleanup_dead_labels ();
138 group_case_labels ();
141 struct tree_opt_pass pass_cleanup_cfg_post_optimizing
=
143 "final_cleanup", /* name */
145 execute_cleanup_cfg_post_optimizing
, /* execute */
148 0, /* static_pass_number */
150 PROP_cfg
, /* properties_required */
151 0, /* properties_provided */
152 0, /* properties_destroyed */
153 0, /* todo_flags_start */
154 TODO_dump_func
, /* todo_flags_finish */
158 /* Pass: do the actions required to finish with tree-ssa optimization
162 execute_free_datastructures (void)
164 /* ??? This isn't the right place for this. Worse, it got computed
165 more or less at random in various passes. */
166 free_dominance_info (CDI_DOMINATORS
);
167 free_dominance_info (CDI_POST_DOMINATORS
);
169 /* Remove the ssa structures. Do it here since this includes statement
170 annotations that need to be intact during disband_implicit_edges. */
174 struct tree_opt_pass pass_free_datastructures
=
178 execute_free_datastructures
, /* execute */
181 0, /* static_pass_number */
183 PROP_cfg
, /* properties_required */
184 0, /* properties_provided */
185 0, /* properties_destroyed */
186 0, /* todo_flags_start */
187 0, /* todo_flags_finish */
190 /* Pass: free cfg annotations. */
193 execute_free_cfg_annotations (void)
196 block_stmt_iterator bsi
;
198 /* Emit gotos for implicit jumps. */
199 disband_implicit_edges ();
201 /* Remove annotations from every tree in the function. */
203 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
205 tree stmt
= bsi_stmt (bsi
);
206 ggc_free (stmt
->common
.ann
);
207 stmt
->common
.ann
= NULL
;
210 /* And get rid of annotations we no longer need. */
211 delete_tree_cfg_annotations ();
214 struct tree_opt_pass pass_free_cfg_annotations
=
218 execute_free_cfg_annotations
, /* execute */
221 0, /* static_pass_number */
223 PROP_cfg
, /* properties_required */
224 0, /* properties_provided */
225 0, /* properties_destroyed */
226 0, /* todo_flags_start */
227 0, /* todo_flags_finish */
230 /* Pass: fixup_cfg - IPA passes or compilation of earlier functions might've
231 changed some properties - such as marked functions nothrow. Remove now
232 redundant edges and basic blocks. */
235 execute_fixup_cfg (void)
238 block_stmt_iterator bsi
;
243 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
245 tree stmt
= bsi_stmt (bsi
);
246 tree call
= get_call_expr_in (stmt
);
248 if (call
&& call_expr_flags (call
) & (ECF_CONST
| ECF_PURE
))
249 TREE_SIDE_EFFECTS (call
) = 0;
250 if (!tree_could_throw_p (stmt
) && lookup_stmt_eh_region (stmt
))
251 remove_stmt_from_eh_region (stmt
);
253 tree_purge_dead_eh_edges (bb
);
259 struct tree_opt_pass pass_fixup_cfg
=
263 execute_fixup_cfg
, /* execute */
266 0, /* static_pass_number */
268 PROP_cfg
, /* properties_required */
269 0, /* properties_provided */
270 0, /* properties_destroyed */
271 0, /* todo_flags_start */
272 0, /* todo_flags_finish */
276 /* Do the actions required to initialize internal data structures used
277 in tree-ssa optimization passes. */
280 execute_init_datastructures (void)
282 /* Allocate hash tables, arrays and other structures. */
286 struct tree_opt_pass pass_init_datastructures
=
290 execute_init_datastructures
, /* execute */
293 0, /* static_pass_number */
295 PROP_cfg
, /* properties_required */
296 0, /* properties_provided */
297 0, /* properties_destroyed */
298 0, /* todo_flags_start */
299 0, /* todo_flags_finish */
304 tree_lowering_passes (tree fn
)
306 tree saved_current_function_decl
= current_function_decl
;
308 current_function_decl
= fn
;
309 push_cfun (DECL_STRUCT_FUNCTION (fn
));
310 tree_register_cfg_hooks ();
311 bitmap_obstack_initialize (NULL
);
312 execute_pass_list (all_lowering_passes
);
313 free_dominance_info (CDI_POST_DOMINATORS
);
315 current_function_decl
= saved_current_function_decl
;
316 bitmap_obstack_release (NULL
);
320 /* Update recursively all inlined_to pointers of functions
321 inlined into NODE to INLINED_TO. */
323 update_inlined_to_pointers (struct cgraph_node
*node
,
324 struct cgraph_node
*inlined_to
)
326 struct cgraph_edge
*e
;
327 for (e
= node
->callees
; e
; e
= e
->next_callee
)
329 if (e
->callee
->global
.inlined_to
)
331 e
->callee
->global
.inlined_to
= inlined_to
;
332 update_inlined_to_pointers (e
->callee
, inlined_to
);
338 /* For functions-as-trees languages, this performs all optimization and
339 compilation for FNDECL. */
342 tree_rest_of_compilation (tree fndecl
)
344 location_t saved_loc
;
345 struct cgraph_node
*saved_node
= NULL
, *node
;
347 timevar_push (TV_EXPAND
);
349 gcc_assert (!flag_unit_at_a_time
|| cgraph_global_info_ready
);
351 /* Initialize the RTL code for the function. */
352 current_function_decl
= fndecl
;
353 saved_loc
= input_location
;
354 input_location
= DECL_SOURCE_LOCATION (fndecl
);
355 init_function_start (fndecl
);
357 /* Even though we're inside a function body, we still don't want to
358 call expand_expr to calculate the size of a variable-sized array.
359 We haven't necessarily assigned RTL to all variables yet, so it's
360 not safe to try to expand expressions involving them. */
361 cfun
->x_dont_save_pending_sizes_p
= 1;
362 cfun
->after_inlining
= true;
364 node
= cgraph_node (fndecl
);
366 /* We might need the body of this function so that we can expand
367 it inline somewhere else. This means not lowering some constructs
368 such as exception handling. */
369 if (cgraph_preserve_function_body_p (fndecl
))
371 if (!flag_unit_at_a_time
)
373 struct cgraph_edge
*e
;
375 saved_node
= cgraph_clone_node (node
, node
->count
, 1, false);
376 for (e
= saved_node
->callees
; e
; e
= e
->next_callee
)
377 if (!e
->inline_failed
)
378 cgraph_clone_inlined_nodes (e
, true);
380 cfun
->saved_static_chain_decl
= cfun
->static_chain_decl
;
381 save_body (fndecl
, &cfun
->saved_args
, &cfun
->saved_static_chain_decl
);
384 if (flag_inline_trees
)
386 struct cgraph_edge
*e
;
387 for (e
= node
->callees
; e
; e
= e
->next_callee
)
388 if (!e
->inline_failed
|| warn_inline
)
392 timevar_push (TV_INTEGRATION
);
393 optimize_inline_calls (fndecl
);
394 timevar_pop (TV_INTEGRATION
);
397 /* We are not going to maintain the cgraph edges up to date.
398 Kill it so it won't confuse us. */
399 while (node
->callees
)
401 /* In non-unit-at-a-time we must mark all referenced functions as needed.
403 if (node
->callees
->callee
->analyzed
&& !flag_unit_at_a_time
)
404 cgraph_mark_needed_node (node
->callees
->callee
);
405 cgraph_remove_edge (node
->callees
);
408 /* We are not going to maintain the cgraph edges up to date.
409 Kill it so it won't confuse us. */
410 cgraph_node_remove_callees (node
);
413 /* Initialize the default bitmap obstack. */
414 bitmap_obstack_initialize (NULL
);
415 bitmap_obstack_initialize (®_obstack
); /* FIXME, only at RTL generation*/
417 tree_register_cfg_hooks ();
418 /* Perform all tree transforms and optimizations. */
419 execute_pass_list (all_passes
);
421 bitmap_obstack_release (®_obstack
);
423 /* Release the default bitmap obstack. */
424 bitmap_obstack_release (NULL
);
426 /* Restore original body if still needed. */
429 DECL_ARGUMENTS (fndecl
) = cfun
->saved_args
;
430 cfun
->cfg
= cfun
->saved_cfg
;
431 cfun
->eh
= cfun
->saved_eh
;
432 DECL_INITIAL (fndecl
) = cfun
->saved_blocks
;
433 cfun
->unexpanded_var_list
= cfun
->saved_unexpanded_var_list
;
434 cfun
->saved_cfg
= NULL
;
435 cfun
->saved_eh
= NULL
;
436 cfun
->saved_args
= NULL_TREE
;
437 cfun
->saved_blocks
= NULL_TREE
;
438 cfun
->saved_unexpanded_var_list
= NULL_TREE
;
439 cfun
->static_chain_decl
= cfun
->saved_static_chain_decl
;
440 cfun
->saved_static_chain_decl
= NULL
;
441 /* When not in unit-at-a-time mode, we must preserve out of line copy
442 representing node before inlining. Restore original outgoing edges
443 using clone we created earlier. */
444 if (!flag_unit_at_a_time
)
446 struct cgraph_edge
*e
;
448 node
= cgraph_node (current_function_decl
);
449 cgraph_node_remove_callees (node
);
450 node
->callees
= saved_node
->callees
;
451 saved_node
->callees
= NULL
;
452 update_inlined_to_pointers (node
, node
);
453 for (e
= node
->callees
; e
; e
= e
->next_callee
)
455 cgraph_remove_node (saved_node
);
459 DECL_SAVED_TREE (fndecl
) = NULL
;
462 /* If requested, warn about function definitions where the function will
463 return a value (usually of some struct or union type) which itself will
464 take up a lot of stack space. */
465 if (warn_larger_than
&& !DECL_EXTERNAL (fndecl
) && TREE_TYPE (fndecl
))
467 tree ret_type
= TREE_TYPE (TREE_TYPE (fndecl
));
469 if (ret_type
&& TYPE_SIZE_UNIT (ret_type
)
470 && TREE_CODE (TYPE_SIZE_UNIT (ret_type
)) == INTEGER_CST
471 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type
),
474 unsigned int size_as_int
475 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type
));
477 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type
), size_as_int
) == 0)
478 warning (0, "size of return value of %q+D is %u bytes",
479 fndecl
, size_as_int
);
481 warning (0, "size of return value of %q+D is larger than %wd bytes",
482 fndecl
, larger_than_size
);
486 if (!flag_inline_trees
)
488 DECL_SAVED_TREE (fndecl
) = NULL
;
489 if (DECL_STRUCT_FUNCTION (fndecl
) == 0
490 && !cgraph_node (fndecl
)->origin
)
492 /* Stop pointing to the local nodes about to be freed.
493 But DECL_INITIAL must remain nonzero so we know this
494 was an actual function definition.
495 For a nested function, this is done in c_pop_function_context.
496 If rest_of_compilation set this to 0, leave it 0. */
497 if (DECL_INITIAL (fndecl
) != 0)
498 DECL_INITIAL (fndecl
) = error_mark_node
;
502 input_location
= saved_loc
;
505 timevar_pop (TV_EXPAND
);