1 /* Top-level control of tree optimizations.
2 Copyright 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
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"
28 #include "basic-block.h"
31 #include "tree-flow.h"
32 #include "tree-dump.h"
35 #include "langhooks.h"
36 #include "diagnostic-core.h"
40 #include "tree-inline.h"
41 #include "tree-mudflap.h"
42 #include "tree-pass.h"
49 #include "regset.h" /* FIXME: For reg_obstack. */
51 /* Gate: execute, or not, all of the non-trivial optimizations. */
54 gate_all_optimizations (void)
57 /* Don't bother doing anything if the program has errors.
58 We have to pass down the queue if we already went into SSA */
59 && (!seen_error () || gimple_in_ssa_p (cfun)));
62 struct gimple_opt_pass pass_all_optimizations =
66 "*all_optimizations", /* name */
67 gate_all_optimizations, /* gate */
71 0, /* static_pass_number */
72 TV_OPTIMIZE, /* tv_id */
73 0, /* properties_required */
74 0, /* properties_provided */
75 0, /* properties_destroyed */
76 0, /* todo_flags_start */
77 0 /* todo_flags_finish */
81 /* Gate: execute, or not, all of the non-trivial optimizations. */
84 gate_all_early_local_passes (void)
86 /* Don't bother doing anything if the program has errors. */
87 return (!seen_error () && !in_lto_p);
91 execute_all_early_local_passes (void)
93 /* Once this pass (and its sub-passes) are complete, all functions
94 will be in SSA form. Technically this state change is happening
95 a tad early, since the sub-passes have not yet run, but since
96 none of the sub-passes are IPA passes and do not create new
97 functions, this is ok. We're setting this value for the benefit
98 of IPA passes that follow. */
99 if (cgraph_state < CGRAPH_STATE_IPA_SSA)
100 cgraph_state = CGRAPH_STATE_IPA_SSA;
104 struct simple_ipa_opt_pass pass_early_local_passes =
108 "early_local_cleanups", /* name */
109 gate_all_early_local_passes, /* gate */
110 execute_all_early_local_passes, /* execute */
113 0, /* static_pass_number */
114 TV_EARLY_LOCAL, /* tv_id */
115 0, /* properties_required */
116 0, /* properties_provided */
117 0, /* properties_destroyed */
118 0, /* todo_flags_start */
119 TODO_remove_functions /* todo_flags_finish */
123 /* Gate: execute, or not, all of the non-trivial optimizations. */
126 gate_all_early_optimizations (void)
128 return (optimize >= 1
129 /* Don't bother doing anything if the program has errors. */
133 struct gimple_opt_pass pass_all_early_optimizations =
137 "early_optimizations", /* name */
138 gate_all_early_optimizations, /* gate */
142 0, /* static_pass_number */
144 0, /* properties_required */
145 0, /* properties_provided */
146 0, /* properties_destroyed */
147 0, /* todo_flags_start */
148 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_post_optimizing (void)
162 cleanup_dead_labels ();
163 group_case_labels ();
164 if ((flag_compare_debug_opt || flag_compare_debug)
165 && flag_dump_final_insns)
167 FILE *final_output = fopen (flag_dump_final_insns, "a");
171 error ("could not open final insn dump file %qs: %m",
172 flag_dump_final_insns);
173 flag_dump_final_insns = NULL;
177 int save_unnumbered = flag_dump_unnumbered;
178 int save_noaddr = flag_dump_noaddr;
180 flag_dump_noaddr = flag_dump_unnumbered = 1;
181 fprintf (final_output, "\n");
182 dump_enumerated_decls (final_output, dump_flags | TDF_NOUID);
183 flag_dump_noaddr = save_noaddr;
184 flag_dump_unnumbered = save_unnumbered;
185 if (fclose (final_output))
187 error ("could not close final insn dump file %qs: %m",
188 flag_dump_final_insns);
189 flag_dump_final_insns = NULL;
196 struct gimple_opt_pass pass_cleanup_cfg_post_optimizing =
200 "optimized", /* name */
202 execute_cleanup_cfg_post_optimizing, /* execute */
205 0, /* static_pass_number */
206 TV_TREE_CLEANUP_CFG, /* tv_id */
207 PROP_cfg, /* properties_required */
208 0, /* properties_provided */
209 0, /* properties_destroyed */
210 0, /* todo_flags_start */
211 TODO_dump_func /* todo_flags_finish */
212 | TODO_remove_unused_locals
216 /* Pass: do the actions required to finish with tree-ssa optimization
220 execute_free_datastructures (void)
222 free_dominance_info (CDI_DOMINATORS);
223 free_dominance_info (CDI_POST_DOMINATORS);
225 /* And get rid of annotations we no longer need. */
226 delete_tree_cfg_annotations ();
231 /* IPA passes, compilation of earlier functions or inlining
232 might have changed some properties, such as marked functions nothrow,
233 pure, const or noreturn.
234 Remove redundant edges and basic blocks, and create new ones if necessary.
236 This pass can't be executed as stand alone pass from pass manager, because
237 in between inlining and this fixup the verify_flow_info would fail. */
240 execute_fixup_cfg (void)
243 gimple_stmt_iterator gsi;
244 int todo = gimple_in_ssa_p (cfun) ? TODO_verify_ssa : 0;
245 gcov_type count_scale;
249 if (ENTRY_BLOCK_PTR->count)
250 count_scale = ((cgraph_get_node (current_function_decl)->count
251 * REG_BR_PROB_BASE + ENTRY_BLOCK_PTR->count / 2)
252 / ENTRY_BLOCK_PTR->count);
254 count_scale = REG_BR_PROB_BASE;
256 ENTRY_BLOCK_PTR->count = cgraph_get_node (current_function_decl)->count;
257 EXIT_BLOCK_PTR->count = (EXIT_BLOCK_PTR->count * count_scale
258 + REG_BR_PROB_BASE / 2) / REG_BR_PROB_BASE;
262 bb->count = (bb->count * count_scale
263 + REG_BR_PROB_BASE / 2) / REG_BR_PROB_BASE;
264 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
266 gimple stmt = gsi_stmt (gsi);
267 tree decl = is_gimple_call (stmt)
268 ? gimple_call_fndecl (stmt)
272 int flags = gimple_call_flags (stmt);
273 if (flags & (ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE))
275 if (gimple_purge_dead_abnormal_call_edges (bb))
276 todo |= TODO_cleanup_cfg;
278 if (gimple_in_ssa_p (cfun))
280 todo |= TODO_update_ssa | TODO_cleanup_cfg;
285 if (flags & ECF_NORETURN
286 && fixup_noreturn_call (stmt))
287 todo |= TODO_cleanup_cfg;
290 if (maybe_clean_eh_stmt (stmt)
291 && gimple_purge_dead_eh_edges (bb))
292 todo |= TODO_cleanup_cfg;
295 FOR_EACH_EDGE (e, ei, bb->succs)
296 e->count = (e->count * count_scale
297 + REG_BR_PROB_BASE / 2) / REG_BR_PROB_BASE;
299 if (count_scale != REG_BR_PROB_BASE)
300 compute_function_frequency ();
302 /* We just processed all calls. */
305 VEC_free (gimple, gc, MODIFIED_NORETURN_CALLS (cfun));
306 MODIFIED_NORETURN_CALLS (cfun) = NULL;
309 /* Dump a textual representation of the flowgraph. */
311 gimple_dump_cfg (dump_file, dump_flags);
316 struct gimple_opt_pass pass_fixup_cfg =
320 "*free_cfg_annotations", /* name */
322 execute_fixup_cfg, /* 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 */
335 /* Do the actions required to initialize internal data structures used
336 in tree-ssa optimization passes. */
339 execute_init_datastructures (void)
341 /* Allocate hash tables, arrays and other structures. */
342 init_tree_ssa (cfun);
346 struct gimple_opt_pass pass_init_datastructures =
350 "*init_datastructures", /* name */
352 execute_init_datastructures, /* execute */
355 0, /* static_pass_number */
357 PROP_cfg, /* properties_required */
358 0, /* properties_provided */
359 0, /* properties_destroyed */
360 0, /* todo_flags_start */
361 0 /* todo_flags_finish */
366 tree_lowering_passes (tree fn)
368 tree saved_current_function_decl = current_function_decl;
370 current_function_decl = fn;
371 push_cfun (DECL_STRUCT_FUNCTION (fn));
372 gimple_register_cfg_hooks ();
373 bitmap_obstack_initialize (NULL);
374 execute_pass_list (all_lowering_passes);
375 if (optimize && cgraph_global_info_ready)
376 execute_pass_list (pass_early_local_passes.pass.sub);
377 free_dominance_info (CDI_POST_DOMINATORS);
378 free_dominance_info (CDI_DOMINATORS);
380 current_function_decl = saved_current_function_decl;
381 bitmap_obstack_release (NULL);
385 /* For functions-as-trees languages, this performs all optimization and
386 compilation for FNDECL. */
389 tree_rest_of_compilation (tree fndecl)
391 location_t saved_loc;
393 timevar_push (TV_REST_OF_COMPILATION);
395 gcc_assert (cgraph_global_info_ready);
397 /* Initialize the default bitmap obstack. */
398 bitmap_obstack_initialize (NULL);
400 /* Initialize the RTL code for the function. */
401 current_function_decl = fndecl;
402 saved_loc = input_location;
403 input_location = DECL_SOURCE_LOCATION (fndecl);
404 init_function_start (fndecl);
406 gimple_register_cfg_hooks ();
408 bitmap_obstack_initialize (®_obstack); /* FIXME, only at RTL generation*/
410 execute_all_ipa_transforms ();
412 /* Perform all tree transforms and optimizations. */
414 /* Signal the start of passes. */
415 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_START, NULL);
417 execute_pass_list (all_passes);
419 /* Signal the end of passes. */
420 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_END, NULL);
422 bitmap_obstack_release (®_obstack);
424 /* Release the default bitmap obstack. */
425 bitmap_obstack_release (NULL);
429 /* If requested, warn about function definitions where the function will
430 return a value (usually of some struct or union type) which itself will
431 take up a lot of stack space. */
432 if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
434 tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
436 if (ret_type && TYPE_SIZE_UNIT (ret_type)
437 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
438 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
441 unsigned int size_as_int
442 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
444 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
445 warning (OPT_Wlarger_than_, "size of return value of %q+D is %u bytes",
446 fndecl, size_as_int);
448 warning (OPT_Wlarger_than_, "size of return value of %q+D is larger than %wd bytes",
449 fndecl, larger_than_size);
453 gimple_set_body (fndecl, NULL);
454 if (DECL_STRUCT_FUNCTION (fndecl) == 0
455 && !cgraph_get_node (fndecl)->origin)
457 /* Stop pointing to the local nodes about to be freed.
458 But DECL_INITIAL must remain nonzero so we know this
459 was an actual function definition.
460 For a nested function, this is done in c_pop_function_context.
461 If rest_of_compilation set this to 0, leave it 0. */
462 if (DECL_INITIAL (fndecl) != 0)
463 DECL_INITIAL (fndecl) = error_mark_node;
466 input_location = saved_loc;
469 timevar_pop (TV_REST_OF_COMPILATION);