/* Top-level control of tree optimizations. Copyright 2001, 2002, 2003, 2004, 2005, 2007, 2008 Free Software Foundation, Inc. Contributed by Diego Novillo This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see . */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "tree.h" #include "rtl.h" #include "tm_p.h" #include "hard-reg-set.h" #include "basic-block.h" #include "output.h" #include "expr.h" #include "diagnostic.h" #include "basic-block.h" #include "flags.h" #include "tree-flow.h" #include "tree-dump.h" #include "timevar.h" #include "function.h" #include "langhooks.h" #include "toplev.h" #include "flags.h" #include "cgraph.h" #include "tree-inline.h" #include "tree-mudflap.h" #include "tree-pass.h" #include "ggc.h" #include "cgraph.h" #include "graph.h" #include "cfgloop.h" #include "except.h" /* Gate: execute, or not, all of the non-trivial optimizations. */ static bool gate_all_optimizations (void) { return (optimize >= 1 /* Don't bother doing anything if the program has errors. We have to pass down the queue if we already went into SSA */ && (!(errorcount || sorrycount) || gimple_in_ssa_p (cfun))); } struct gimple_opt_pass pass_all_optimizations = { { GIMPLE_PASS, NULL, /* name */ gate_all_optimizations, /* gate */ NULL, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ } }; /* Gate: execute, or not, all of the non-trivial optimizations. */ static bool gate_all_early_local_passes (void) { /* Don't bother doing anything if the program has errors. */ return (!errorcount && !sorrycount); } struct simple_ipa_opt_pass pass_early_local_passes = { { SIMPLE_IPA_PASS, "early_local_cleanups", /* name */ gate_all_early_local_passes, /* gate */ NULL, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_remove_functions /* todo_flags_finish */ } }; static unsigned int execute_early_local_optimizations (void) { /* First time we start with early optimization we need to advance cgraph state so newly inserted functions are also early optimized. However we execute early local optimizations for lately inserted functions, in that case don't reset cgraph state back to IPA_SSA. */ if (cgraph_state < CGRAPH_STATE_IPA_SSA) cgraph_state = CGRAPH_STATE_IPA_SSA; return 0; } /* Gate: execute, or not, all of the non-trivial optimizations. */ static bool gate_all_early_optimizations (void) { return (optimize >= 1 /* Don't bother doing anything if the program has errors. */ && !(errorcount || sorrycount)); } struct gimple_opt_pass pass_all_early_optimizations = { { GIMPLE_PASS, "early_optimizations", /* name */ gate_all_early_optimizations, /* gate */ execute_early_local_optimizations, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ } }; /* Pass: cleanup the CFG just before expanding trees to RTL. This is just a round of label cleanups and case node grouping because after the tree optimizers have run such cleanups may be necessary. */ static unsigned int execute_cleanup_cfg_pre_ipa (void) { cleanup_tree_cfg (); return 0; } struct gimple_opt_pass pass_cleanup_cfg = { { GIMPLE_PASS, "cleanup_cfg", /* name */ NULL, /* gate */ execute_cleanup_cfg_pre_ipa, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ PROP_cfg, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_dump_func /* todo_flags_finish */ } }; /* Pass: cleanup the CFG just before expanding trees to RTL. This is just a round of label cleanups and case node grouping because after the tree optimizers have run such cleanups may be necessary. */ static unsigned int execute_cleanup_cfg_post_optimizing (void) { fold_cond_expr_cond (); cleanup_tree_cfg (); cleanup_dead_labels (); group_case_labels (); return 0; } struct gimple_opt_pass pass_cleanup_cfg_post_optimizing = { { GIMPLE_PASS, "final_cleanup", /* name */ NULL, /* gate */ execute_cleanup_cfg_post_optimizing, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ PROP_cfg, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_dump_func /* todo_flags_finish */ } }; /* Pass: do the actions required to finish with tree-ssa optimization passes. */ static unsigned int execute_free_datastructures (void) { free_dominance_info (CDI_DOMINATORS); free_dominance_info (CDI_POST_DOMINATORS); /* Remove the ssa structures. */ if (cfun->gimple_df) delete_tree_ssa (); return 0; } struct gimple_opt_pass pass_free_datastructures = { { GIMPLE_PASS, NULL, /* name */ NULL, /* gate */ execute_free_datastructures, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ PROP_cfg, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ } }; /* Pass: free cfg annotations. */ static unsigned int execute_free_cfg_annotations (void) { /* And get rid of annotations we no longer need. */ delete_tree_cfg_annotations (); return 0; } struct gimple_opt_pass pass_free_cfg_annotations = { { GIMPLE_PASS, NULL, /* name */ NULL, /* gate */ execute_free_cfg_annotations, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ PROP_cfg, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ } }; /* Pass: fixup_cfg. IPA passes, compilation of earlier functions or inlining might have changed some properties, such as marked functions nothrow. Remove redundant edges and basic blocks, and create new ones if necessary. This pass can't be executed as stand alone pass from pass manager, because in between inlining and this fixup the verify_flow_info would fail. */ unsigned int execute_fixup_cfg (void) { basic_block bb; gimple_stmt_iterator gsi; int todo = gimple_in_ssa_p (cfun) ? TODO_verify_ssa : 0; cfun->after_inlining = true; cfun->always_inline_functions_inlined = true; if (cfun->eh) FOR_EACH_BB (bb) { for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { gimple stmt = gsi_stmt (gsi); tree decl = is_gimple_call (stmt) ? gimple_call_fndecl (stmt) : NULL; if (decl && gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE)) { if (gimple_in_ssa_p (cfun)) { todo |= TODO_update_ssa | TODO_cleanup_cfg; update_stmt (stmt); } } if (!stmt_could_throw_p (stmt) && lookup_stmt_eh_region (stmt)) remove_stmt_from_eh_region (stmt); } if (gimple_purge_dead_eh_edges (bb)) todo |= TODO_cleanup_cfg; } /* Dump a textual representation of the flowgraph. */ if (dump_file) gimple_dump_cfg (dump_file, dump_flags); return todo; } /* Do the actions required to initialize internal data structures used in tree-ssa optimization passes. */ static unsigned int execute_init_datastructures (void) { /* Allocate hash tables, arrays and other structures. */ init_tree_ssa (cfun); return 0; } struct gimple_opt_pass pass_init_datastructures = { { GIMPLE_PASS, NULL, /* name */ NULL, /* gate */ execute_init_datastructures, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ PROP_cfg, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ } }; void tree_lowering_passes (tree fn) { tree saved_current_function_decl = current_function_decl; current_function_decl = fn; push_cfun (DECL_STRUCT_FUNCTION (fn)); gimple_register_cfg_hooks (); bitmap_obstack_initialize (NULL); execute_pass_list (all_lowering_passes); if (optimize && cgraph_global_info_ready) execute_pass_list (pass_early_local_passes.pass.sub); free_dominance_info (CDI_POST_DOMINATORS); free_dominance_info (CDI_DOMINATORS); compact_blocks (); current_function_decl = saved_current_function_decl; bitmap_obstack_release (NULL); pop_cfun (); } /* For functions-as-trees languages, this performs all optimization and compilation for FNDECL. */ void tree_rest_of_compilation (tree fndecl) { location_t saved_loc; struct cgraph_node *node; timevar_push (TV_EXPAND); gcc_assert (cgraph_global_info_ready); node = cgraph_node (fndecl); /* Initialize the default bitmap obstack. */ bitmap_obstack_initialize (NULL); /* Initialize the RTL code for the function. */ current_function_decl = fndecl; saved_loc = input_location; input_location = DECL_SOURCE_LOCATION (fndecl); init_function_start (fndecl); /* Even though we're inside a function body, we still don't want to call expand_expr to calculate the size of a variable-sized array. We haven't necessarily assigned RTL to all variables yet, so it's not safe to try to expand expressions involving them. */ cfun->dont_save_pending_sizes_p = 1; gimple_register_cfg_hooks (); bitmap_obstack_initialize (®_obstack); /* FIXME, only at RTL generation*/ /* Perform all tree transforms and optimizations. */ execute_pass_list (all_passes); bitmap_obstack_release (®_obstack); /* Release the default bitmap obstack. */ bitmap_obstack_release (NULL); set_cfun (NULL); /* If requested, warn about function definitions where the function will return a value (usually of some struct or union type) which itself will take up a lot of stack space. */ if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl)) { tree ret_type = TREE_TYPE (TREE_TYPE (fndecl)); if (ret_type && TYPE_SIZE_UNIT (ret_type) && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type), larger_than_size)) { unsigned int size_as_int = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type)); if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0) warning (OPT_Wlarger_than_eq, "size of return value of %q+D is %u bytes", fndecl, size_as_int); else warning (OPT_Wlarger_than_eq, "size of return value of %q+D is larger than %wd bytes", fndecl, larger_than_size); } } gimple_set_body (fndecl, NULL); if (DECL_STRUCT_FUNCTION (fndecl) == 0 && !cgraph_node (fndecl)->origin) { /* Stop pointing to the local nodes about to be freed. But DECL_INITIAL must remain nonzero so we know this was an actual function definition. For a nested function, this is done in c_pop_function_context. If rest_of_compilation set this to 0, leave it 0. */ if (DECL_INITIAL (fndecl) != 0) DECL_INITIAL (fndecl) = error_mark_node; } input_location = saved_loc; ggc_collect (); timevar_pop (TV_EXPAND); }