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_remove_unused_locals /* todo_flags_finish */
215 /* Pass: do the actions required to finish with tree-ssa optimization
219 execute_free_datastructures (void)
221 free_dominance_info (CDI_DOMINATORS);
222 free_dominance_info (CDI_POST_DOMINATORS);
224 /* And get rid of annotations we no longer need. */
225 delete_tree_cfg_annotations ();
230 /* IPA passes, compilation of earlier functions or inlining
231 might have changed some properties, such as marked functions nothrow,
232 pure, const or noreturn.
233 Remove redundant edges and basic blocks, and create new ones if necessary.
235 This pass can't be executed as stand alone pass from pass manager, because
236 in between inlining and this fixup the verify_flow_info would fail. */
239 execute_fixup_cfg (void)
242 gimple_stmt_iterator gsi;
243 int todo = gimple_in_ssa_p (cfun) ? TODO_verify_ssa : 0;
244 gcov_type count_scale;
248 if (ENTRY_BLOCK_PTR->count)
249 count_scale = ((cgraph_get_node (current_function_decl)->count
250 * REG_BR_PROB_BASE + ENTRY_BLOCK_PTR->count / 2)
251 / ENTRY_BLOCK_PTR->count);
253 count_scale = REG_BR_PROB_BASE;
255 ENTRY_BLOCK_PTR->count = cgraph_get_node (current_function_decl)->count;
256 EXIT_BLOCK_PTR->count = (EXIT_BLOCK_PTR->count * count_scale
257 + REG_BR_PROB_BASE / 2) / REG_BR_PROB_BASE;
261 bb->count = (bb->count * count_scale
262 + REG_BR_PROB_BASE / 2) / REG_BR_PROB_BASE;
263 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
265 gimple stmt = gsi_stmt (gsi);
266 tree decl = is_gimple_call (stmt)
267 ? gimple_call_fndecl (stmt)
271 int flags = gimple_call_flags (stmt);
272 if (flags & (ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE))
274 if (gimple_purge_dead_abnormal_call_edges (bb))
275 todo |= TODO_cleanup_cfg;
277 if (gimple_in_ssa_p (cfun))
279 todo |= TODO_update_ssa | TODO_cleanup_cfg;
284 if (flags & ECF_NORETURN
285 && fixup_noreturn_call (stmt))
286 todo |= TODO_cleanup_cfg;
289 if (maybe_clean_eh_stmt (stmt)
290 && gimple_purge_dead_eh_edges (bb))
291 todo |= TODO_cleanup_cfg;
294 FOR_EACH_EDGE (e, ei, bb->succs)
295 e->count = (e->count * count_scale
296 + REG_BR_PROB_BASE / 2) / REG_BR_PROB_BASE;
298 if (count_scale != REG_BR_PROB_BASE)
299 compute_function_frequency ();
301 /* We just processed all calls. */
304 VEC_free (gimple, gc, MODIFIED_NORETURN_CALLS (cfun));
305 MODIFIED_NORETURN_CALLS (cfun) = NULL;
308 /* Dump a textual representation of the flowgraph. */
310 gimple_dump_cfg (dump_file, dump_flags);
315 struct gimple_opt_pass pass_fixup_cfg =
319 "*free_cfg_annotations", /* name */
321 execute_fixup_cfg, /* execute */
324 0, /* static_pass_number */
326 PROP_cfg, /* properties_required */
327 0, /* properties_provided */
328 0, /* properties_destroyed */
329 0, /* todo_flags_start */
330 0 /* todo_flags_finish */
334 /* Do the actions required to initialize internal data structures used
335 in tree-ssa optimization passes. */
338 execute_init_datastructures (void)
340 /* Allocate hash tables, arrays and other structures. */
341 init_tree_ssa (cfun);
345 struct gimple_opt_pass pass_init_datastructures =
349 "*init_datastructures", /* name */
351 execute_init_datastructures, /* execute */
354 0, /* static_pass_number */
356 PROP_cfg, /* properties_required */
357 0, /* properties_provided */
358 0, /* properties_destroyed */
359 0, /* todo_flags_start */
360 0 /* todo_flags_finish */
365 tree_lowering_passes (tree fn)
367 tree saved_current_function_decl = current_function_decl;
369 current_function_decl = fn;
370 push_cfun (DECL_STRUCT_FUNCTION (fn));
371 gimple_register_cfg_hooks ();
372 bitmap_obstack_initialize (NULL);
373 execute_pass_list (all_lowering_passes);
374 if (optimize && cgraph_global_info_ready)
375 execute_pass_list (pass_early_local_passes.pass.sub);
376 free_dominance_info (CDI_POST_DOMINATORS);
377 free_dominance_info (CDI_DOMINATORS);
379 current_function_decl = saved_current_function_decl;
380 bitmap_obstack_release (NULL);
384 /* For functions-as-trees languages, this performs all optimization and
385 compilation for FNDECL. */
388 tree_rest_of_compilation (tree fndecl)
390 location_t saved_loc;
392 timevar_push (TV_REST_OF_COMPILATION);
394 gcc_assert (cgraph_global_info_ready);
396 /* Initialize the default bitmap obstack. */
397 bitmap_obstack_initialize (NULL);
399 /* Initialize the RTL code for the function. */
400 current_function_decl = fndecl;
401 saved_loc = input_location;
402 input_location = DECL_SOURCE_LOCATION (fndecl);
403 init_function_start (fndecl);
405 gimple_register_cfg_hooks ();
407 bitmap_obstack_initialize (®_obstack); /* FIXME, only at RTL generation*/
409 execute_all_ipa_transforms ();
411 /* Perform all tree transforms and optimizations. */
413 /* Signal the start of passes. */
414 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_START, NULL);
416 execute_pass_list (all_passes);
418 /* Signal the end of passes. */
419 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_END, NULL);
421 bitmap_obstack_release (®_obstack);
423 /* Release the default bitmap obstack. */
424 bitmap_obstack_release (NULL);
428 /* If requested, warn about function definitions where the function will
429 return a value (usually of some struct or union type) which itself will
430 take up a lot of stack space. */
431 if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
433 tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
435 if (ret_type && TYPE_SIZE_UNIT (ret_type)
436 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
437 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
440 unsigned int size_as_int
441 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
443 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
444 warning (OPT_Wlarger_than_, "size of return value of %q+D is %u bytes",
445 fndecl, size_as_int);
447 warning (OPT_Wlarger_than_, "size of return value of %q+D is larger than %wd bytes",
448 fndecl, larger_than_size);
452 gimple_set_body (fndecl, NULL);
453 if (DECL_STRUCT_FUNCTION (fndecl) == 0
454 && !cgraph_get_node (fndecl)->origin)
456 /* Stop pointing to the local nodes about to be freed.
457 But DECL_INITIAL must remain nonzero so we know this
458 was an actual function definition.
459 For a nested function, this is done in c_pop_function_context.
460 If rest_of_compilation set this to 0, leave it 0. */
461 if (DECL_INITIAL (fndecl) != 0)
462 DECL_INITIAL (fndecl) = error_mark_node;
465 input_location = saved_loc;
468 timevar_pop (TV_REST_OF_COMPILATION);