/* Top-level control of tree optimizations. Copyright 2001, 2002, 2003, 2004, 2005 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 2, 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 COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #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" /* Global variables used to communicate with passes. */ int dump_flags; bitmap vars_to_rename; bool in_gimple_form; /* The root of the compilation pass tree, once constructed. */ static struct tree_opt_pass *all_passes; /* Pass: dump the gimplified, inlined, functions. */ static struct tree_opt_pass pass_gimple = { "gimple", /* name */ NULL, /* gate */ NULL, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ 0, /* properties_required */ PROP_gimple_any, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_dump_func, /* todo_flags_finish */ 0 /* letter */ }; /* 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. */ && !(errorcount || sorrycount)); } static struct tree_opt_pass pass_all_optimizations = { 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 */ 0 /* letter */ }; /* 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 void execute_cleanup_cfg_post_optimizing (void) { cleanup_tree_cfg (); cleanup_dead_labels (); group_case_labels (); } static struct tree_opt_pass pass_cleanup_cfg_post_optimizing = { "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 */ 0 /* letter */ }; /* Pass: do the actions required to finish with tree-ssa optimization passes. */ static void execute_free_datastructures (void) { tree *chain; /* ??? This isn't the right place for this. Worse, it got computed more or less at random in various passes. */ free_dominance_info (CDI_DOMINATORS); /* Emit gotos for implicit jumps. */ disband_implicit_edges (); /* Remove the ssa structures. Do it here since this includes statement annotations that need to be intact during disband_implicit_edges. */ delete_tree_ssa (); /* Re-chain the statements from the blocks. */ chain = &DECL_SAVED_TREE (current_function_decl); *chain = alloc_stmt_list (); /* And get rid of annotations we no longer need. */ delete_tree_cfg_annotations (); } static struct tree_opt_pass pass_free_datastructures = { 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 */ 0 /* letter */ }; /* Do the actions required to initialize internal data structures used in tree-ssa optimization passes. */ static void execute_init_datastructures (void) { /* Allocate hash tables, arrays and other structures. */ init_tree_ssa (); } static struct tree_opt_pass pass_init_datastructures = { 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 */ 0 /* letter */ }; /* Iterate over the pass tree allocating dump file numbers. We want to do this depth first, and independent of whether the pass is enabled or not. */ static void register_one_dump_file (struct tree_opt_pass *pass, int n) { char *dot_name, *flag_name, *glob_name; char num[10]; /* See below in next_pass_1. */ num[0] = '\0'; if (pass->static_pass_number != -1) sprintf (num, "%d", ((int) pass->static_pass_number < 0 ? 1 : pass->static_pass_number)); dot_name = concat (".", pass->name, num, NULL); if (pass->properties_provided & PROP_trees) { flag_name = concat ("tree-", pass->name, num, NULL); glob_name = concat ("tree-", pass->name, NULL); pass->static_pass_number = dump_register (dot_name, flag_name, glob_name, TDF_TREE, n + TDI_tree_all, 0); } else { flag_name = concat ("rtl-", pass->name, num, NULL); glob_name = concat ("rtl-", pass->name, NULL); pass->static_pass_number = dump_register (dot_name, flag_name, glob_name, TDF_RTL, n, pass->letter); } } static int register_dump_files (struct tree_opt_pass *pass, int properties) { static int n = 0; do { int new_properties; int pass_number; pass->properties_required = properties; new_properties = (properties | pass->properties_provided) & ~pass->properties_destroyed; /* Reset the counter when we reach RTL-based passes. */ if ((pass->properties_provided ^ pass->properties_required) & PROP_rtl) n = 0; pass_number = n; if (pass->name) n++; if (pass->sub) new_properties = register_dump_files (pass->sub, new_properties); /* If we have a gate, combine the properties that we could have with and without the pass being examined. */ if (pass->gate) properties &= new_properties; else properties = new_properties; pass->properties_provided = properties; if (pass->name) register_one_dump_file (pass, pass_number); pass = pass->next; } while (pass); return properties; } /* Add a pass to the pass list. Duplicate the pass if it's already in the list. */ static struct tree_opt_pass ** next_pass_1 (struct tree_opt_pass **list, struct tree_opt_pass *pass) { /* A nonzero static_pass_number indicates that the pass is already in the list. */ if (pass->static_pass_number) { struct tree_opt_pass *new; new = xmalloc (sizeof (*new)); memcpy (new, pass, sizeof (*new)); /* Indicate to register_dump_files that this pass has duplicates, and so it should rename the dump file. The first instance will be -1, and be number of duplicates = -static_pass_number - 1. Subsequent instances will be > 0 and just the duplicate number. */ if (pass->name) { pass->static_pass_number -= 1; new->static_pass_number = -pass->static_pass_number; } *list = new; } else { pass->static_pass_number = -1; *list = pass; } return &(*list)->next; } /* Construct the pass tree. */ void init_tree_optimization_passes (void) { struct tree_opt_pass **p; #define NEXT_PASS(PASS) (p = next_pass_1 (p, &PASS)) p = &all_passes; NEXT_PASS (pass_gimple); NEXT_PASS (pass_remove_useless_stmts); NEXT_PASS (pass_mudflap_1); NEXT_PASS (pass_lower_cf); NEXT_PASS (pass_lower_eh); NEXT_PASS (pass_build_cfg); NEXT_PASS (pass_pre_expand); NEXT_PASS (pass_tree_profile); NEXT_PASS (pass_init_datastructures); NEXT_PASS (pass_all_optimizations); NEXT_PASS (pass_warn_function_return); NEXT_PASS (pass_mudflap_2); NEXT_PASS (pass_free_datastructures); NEXT_PASS (pass_expand); NEXT_PASS (pass_rest_of_compilation); *p = NULL; p = &pass_all_optimizations.sub; NEXT_PASS (pass_referenced_vars); NEXT_PASS (pass_build_ssa); NEXT_PASS (pass_may_alias); NEXT_PASS (pass_rename_ssa_copies); NEXT_PASS (pass_early_warn_uninitialized); NEXT_PASS (pass_dce); NEXT_PASS (pass_dominator); NEXT_PASS (pass_redundant_phi); NEXT_PASS (pass_dce); NEXT_PASS (pass_merge_phi); NEXT_PASS (pass_forwprop); NEXT_PASS (pass_phiopt); NEXT_PASS (pass_may_alias); NEXT_PASS (pass_tail_recursion); NEXT_PASS (pass_ch); NEXT_PASS (pass_profile); NEXT_PASS (pass_sra); /* FIXME: SRA may generate arbitrary gimple code, exposing new aliased and call-clobbered variables. As mentioned below, pass_may_alias should be a TODO item. */ NEXT_PASS (pass_may_alias); NEXT_PASS (pass_rename_ssa_copies); NEXT_PASS (pass_dominator); NEXT_PASS (pass_redundant_phi); NEXT_PASS (pass_dce); NEXT_PASS (pass_dse); NEXT_PASS (pass_may_alias); NEXT_PASS (pass_forwprop); NEXT_PASS (pass_phiopt); NEXT_PASS (pass_ccp); NEXT_PASS (pass_redundant_phi); NEXT_PASS (pass_fold_builtins); /* FIXME: May alias should a TODO but for 4.0.0, we add may_alias right after fold builtins which can create arbitrary GIMPLE. */ NEXT_PASS (pass_may_alias); NEXT_PASS (pass_split_crit_edges); NEXT_PASS (pass_pre); NEXT_PASS (pass_loop); NEXT_PASS (pass_dominator); NEXT_PASS (pass_redundant_phi); /* FIXME: If DCE is not run before checking for uninitialized uses, we may get false warnings (e.g., testsuite/gcc.dg/uninit-5.c). However, this also causes us to misdiagnose cases that should be real warnings (e.g., testsuite/gcc.dg/pr18501.c). To fix the false positives in uninit-5.c, we would have to account for the predicates protecting the set and the use of each variable. Using a representation like Gated Single Assignment may help. */ NEXT_PASS (pass_late_warn_uninitialized); NEXT_PASS (pass_cd_dce); NEXT_PASS (pass_dse); NEXT_PASS (pass_forwprop); NEXT_PASS (pass_phiopt); NEXT_PASS (pass_tail_calls); NEXT_PASS (pass_rename_ssa_copies); NEXT_PASS (pass_del_ssa); NEXT_PASS (pass_nrv); NEXT_PASS (pass_remove_useless_vars); NEXT_PASS (pass_mark_used_blocks); NEXT_PASS (pass_cleanup_cfg_post_optimizing); *p = NULL; p = &pass_loop.sub; NEXT_PASS (pass_loop_init); NEXT_PASS (pass_lim); NEXT_PASS (pass_unswitch); NEXT_PASS (pass_record_bounds); NEXT_PASS (pass_linear_transform); NEXT_PASS (pass_iv_canon); NEXT_PASS (pass_if_conversion); NEXT_PASS (pass_vectorize); NEXT_PASS (pass_complete_unroll); NEXT_PASS (pass_iv_optimize); NEXT_PASS (pass_loop_done); *p = NULL; #undef NEXT_PASS /* Register the passes with the tree dump code. */ register_dump_files (all_passes, 0); } static void execute_pass_list (struct tree_opt_pass *); static unsigned int last_verified; static void execute_todo (int properties, unsigned int flags) { if (flags & TODO_rename_vars) { rewrite_into_ssa (false); bitmap_clear (vars_to_rename); } if (flags & TODO_fix_def_def_chains) { rewrite_def_def_chains (); bitmap_clear (vars_to_rename); } if (flags & TODO_cleanup_cfg) cleanup_tree_cfg (); if ((flags & TODO_dump_func) && dump_file) { if (properties & PROP_trees) dump_function_to_file (current_function_decl, dump_file, dump_flags); else if (properties & PROP_cfg) print_rtl_with_bb (dump_file, get_insns ()); else print_rtl (dump_file, get_insns ()); /* Flush the file. If verification fails, we won't be able to close the file before aborting. */ fflush (dump_file); } if (flags & TODO_ggc_collect) ggc_collect (); #ifdef ENABLE_CHECKING if (flags & TODO_verify_ssa) verify_ssa (); if (flags & TODO_verify_flow) verify_flow_info (); if (flags & TODO_verify_stmts) verify_stmts (); #endif } static bool execute_one_pass (struct tree_opt_pass *pass) { unsigned int todo; /* See if we're supposed to run this pass. */ if (pass->gate && !pass->gate ()) return false; /* Note that the folders should only create gimple expressions. This is a hack until the new folder is ready. */ in_gimple_form = (pass->properties_provided & PROP_trees) != 0; /* Run pre-pass verification. */ todo = pass->todo_flags_start & ~last_verified; if (todo) execute_todo (pass->properties_required, todo); /* If a dump file name is present, open it if enabled. */ if (pass->static_pass_number != -1) { bool initializing_dump = !dump_initialized_p (pass->static_pass_number); dump_file_name = get_dump_file_name (pass->static_pass_number); dump_file = dump_begin (pass->static_pass_number, &dump_flags); if (dump_file) { const char *dname, *aname; dname = lang_hooks.decl_printable_name (current_function_decl, 2); aname = (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (current_function_decl))); fprintf (dump_file, "\n;; Function %s (%s)%s\n\n", dname, aname, cfun->function_frequency == FUNCTION_FREQUENCY_HOT ? " (hot)" : cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED ? " (unlikely executed)" : ""); } if (initializing_dump && graph_dump_format != no_graph && (pass->properties_provided & (PROP_cfg | PROP_rtl)) == (PROP_cfg | PROP_rtl)) clean_graph_dump_file (dump_file_name); } /* If a timevar is present, start it. */ if (pass->tv_id) timevar_push (pass->tv_id); /* Do it! */ if (pass->execute) pass->execute (); /* Stop timevar. */ if (pass->tv_id) timevar_pop (pass->tv_id); if (dump_file && (pass->properties_provided & (PROP_cfg | PROP_rtl)) == (PROP_cfg | PROP_rtl)) print_rtl_with_bb (dump_file, get_insns ()); /* Run post-pass cleanup and verification. */ todo = pass->todo_flags_finish; last_verified = todo & TODO_verify_all; if (todo) execute_todo (pass->properties_provided, todo); /* Flush and close dump file. */ if (dump_file_name) { free ((char *) dump_file_name); dump_file_name = NULL; } if (dump_file) { dump_end (pass->static_pass_number, dump_file); dump_file = NULL; } return true; } static void execute_pass_list (struct tree_opt_pass *pass) { do { if (execute_one_pass (pass) && pass->sub) execute_pass_list (pass->sub); pass = pass->next; } while (pass); } /* Update recursively all inlined_to pointers of functions inlined into NODE to INLINED_TO. */ static void update_inlined_to_pointers (struct cgraph_node *node, struct cgraph_node *inlined_to) { struct cgraph_edge *e; for (e = node->callees; e; e = e->next_callee) { if (e->callee->global.inlined_to) { e->callee->global.inlined_to = inlined_to; update_inlined_to_pointers (e->callee, inlined_to); } } } /* 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 *saved_node = NULL, *node; timevar_push (TV_EXPAND); gcc_assert (!flag_unit_at_a_time || cgraph_global_info_ready); /* 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->x_dont_save_pending_sizes_p = 1; node = cgraph_node (fndecl); /* We might need the body of this function so that we can expand it inline somewhere else. This means not lowering some constructs such as exception handling. */ if (cgraph_preserve_function_body_p (fndecl)) { if (!flag_unit_at_a_time) { struct cgraph_edge *e; saved_node = cgraph_clone_node (node); for (e = saved_node->callees; e; e = e->next_callee) if (!e->inline_failed) cgraph_clone_inlined_nodes (e, true); } cfun->saved_static_chain_decl = cfun->static_chain_decl; cfun->saved_tree = save_body (fndecl, &cfun->saved_args, &cfun->saved_static_chain_decl); } if (flag_inline_trees) { struct cgraph_edge *e; for (e = node->callees; e; e = e->next_callee) if (!e->inline_failed || warn_inline) break; if (e) { timevar_push (TV_INTEGRATION); optimize_inline_calls (fndecl); timevar_pop (TV_INTEGRATION); } } /* We are not going to maintain the cgraph edges up to date. Kill it so it won't confuse us. */ cgraph_node_remove_callees (node); /* Initialize the default bitmap obstack. */ bitmap_obstack_initialize (NULL); bitmap_obstack_initialize (®_obstack); /* FIXME, only at RTL generation*/ vars_to_rename = BITMAP_ALLOC (NULL); /* Perform all tree transforms and optimizations. */ execute_pass_list (all_passes); bitmap_obstack_release (®_obstack); /* Release the default bitmap obstack. */ bitmap_obstack_release (NULL); /* Restore original body if still needed. */ if (cfun->saved_tree) { DECL_SAVED_TREE (fndecl) = cfun->saved_tree; DECL_ARGUMENTS (fndecl) = cfun->saved_args; cfun->static_chain_decl = cfun->saved_static_chain_decl; /* When not in unit-at-a-time mode, we must preserve out of line copy representing node before inlining. Restore original outgoing edges using clone we created earlier. */ if (!flag_unit_at_a_time) { struct cgraph_edge *e; cgraph_node_remove_callees (node); node->callees = saved_node->callees; saved_node->callees = NULL; update_inlined_to_pointers (node, node); for (e = node->callees; e; e = e->next_callee) e->caller = node; cgraph_remove_node (saved_node); } } else DECL_SAVED_TREE (fndecl) = NULL; cfun = 0; /* 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 ("%Jsize of return value of %qD is %u bytes", fndecl, fndecl, size_as_int); else warning ("%Jsize of return value of %qD is larger than %wd bytes", fndecl, fndecl, larger_than_size); } } if (!flag_inline_trees) { DECL_SAVED_TREE (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); }