/* Control and data flow functions for trees. Copyright 2001, 2002, 2003, 2004 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 "tree-alias-common.h" #include "ggc.h" #include "cgraph.h" /* Global variables used to communicate with passes. */ int dump_flags; bitmap vars_to_rename; /* The root of the compilation pass tree, once constructed. */ static struct tree_opt_pass *all_passes; /* Pass: gimplify the function if it's not been done. */ static void execute_gimple (void) { /* We have this test here rather than as the gate because we always want to dump the original gimplified function. */ if (!lang_hooks.gimple_before_inlining) gimplify_function_tree (current_function_decl); } static struct tree_opt_pass pass_gimple = { "gimple", /* name */ NULL, /* gate */ execute_gimple, /* 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 */ }; /* Pass: replace the outermost BIND_EXPR. We removed all of them while optimizing, but the tree->rtl expander requires it. */ static void execute_rebuild_bind (void) { DECL_SAVED_TREE (current_function_decl) = build (BIND_EXPR, void_type_node, NULL_TREE, DECL_SAVED_TREE (current_function_decl), NULL_TREE); } static struct tree_opt_pass pass_rebuild_bind = { NULL, /* name */ NULL, /* gate */ execute_rebuild_bind, /* 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_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 */ }; /* Pass: do the actions required to finish with tree-ssa optimization passes. */ static void execute_del_cfg (void) { basic_block bb; 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 (); FOR_EACH_BB (bb) { append_to_statement_list_force (bb->stmt_list, chain); } /* And get rid of the cfg. */ delete_tree_cfg (); } static struct tree_opt_pass pass_del_cfg = { NULL, /* name */ NULL, /* gate */ execute_del_cfg, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ 0, /* tv_id */ PROP_cfg, /* properties_required */ 0, /* properties_provided */ PROP_cfg, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ }; /* 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) { char *dot_name, *flag_name; char num[10]; if (!pass->name) return; /* See below in dup_pass_1. */ num[0] = '\0'; if (pass->static_pass_number) sprintf (num, "%d", ((int) pass->static_pass_number < 0 ? 1 : pass->static_pass_number)); dot_name = concat (".", pass->name, num, NULL); flag_name = concat ("tree-", pass->name, num, NULL); pass->static_pass_number = dump_register (dot_name, flag_name); } static void register_dump_files (struct tree_opt_pass *pass) { do { register_one_dump_file (pass); if (pass->sub) register_dump_files (pass->sub); pass = pass->next; } while (pass); } /* Duplicate a pass that's to be run more than once. */ static struct tree_opt_pass * dup_pass_1 (struct tree_opt_pass *pass) { 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 < 0, and be number of duplicates = -static_pass_number + 1. Subsequent instances will be > 0 and just the duplicate number. */ if (pass->name) { int n, p = pass->static_pass_number; if (p) n = -(--p) + 1; else n = 2, p = -1; pass->static_pass_number = p; new->static_pass_number = n; } return new; } /* Construct the pass tree. */ void init_tree_optimization_passes (void) { struct tree_opt_pass **p; #define NEXT_PASS(PASS) (*p = &PASS, p = &(*p)->next) #define DUP_PASS(PASS) (*dup_pass_1 (&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_all_optimizations); NEXT_PASS (pass_mudflap_2); NEXT_PASS (pass_rebuild_bind); *p = NULL; p = &pass_all_optimizations.sub; NEXT_PASS (pass_build_cfg); NEXT_PASS (pass_tree_profile); NEXT_PASS (pass_referenced_vars); NEXT_PASS (pass_build_pta); NEXT_PASS (pass_build_ssa); NEXT_PASS (pass_rename_ssa_copies); NEXT_PASS (pass_early_warn_uninitialized); NEXT_PASS (pass_dce); NEXT_PASS (pass_return); NEXT_PASS (pass_dominator); NEXT_PASS (pass_redundant_phi); NEXT_PASS (DUP_PASS (pass_dce)); 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_del_pta); NEXT_PASS (pass_profile); NEXT_PASS (pass_lower_complex); NEXT_PASS (DUP_PASS (pass_return)); NEXT_PASS (pass_sra); NEXT_PASS (DUP_PASS (pass_rename_ssa_copies)); NEXT_PASS (DUP_PASS (pass_dominator)); NEXT_PASS (DUP_PASS (pass_redundant_phi)); NEXT_PASS (DUP_PASS (pass_dce)); NEXT_PASS (pass_dse); NEXT_PASS (DUP_PASS (pass_forwprop)); NEXT_PASS (DUP_PASS (pass_phiopt)); NEXT_PASS (pass_ccp); NEXT_PASS (DUP_PASS (pass_redundant_phi)); NEXT_PASS (pass_fold_builtins); NEXT_PASS (pass_split_crit_edges); NEXT_PASS (pass_pre); NEXT_PASS (pass_scev); NEXT_PASS (pass_loop); NEXT_PASS (DUP_PASS (pass_dominator)); NEXT_PASS (DUP_PASS (pass_redundant_phi)); NEXT_PASS (pass_cd_dce); NEXT_PASS (DUP_PASS (pass_dse)); NEXT_PASS (DUP_PASS (pass_forwprop)); NEXT_PASS (DUP_PASS (pass_phiopt)); NEXT_PASS (pass_tail_calls); NEXT_PASS (pass_late_warn_uninitialized); NEXT_PASS (pass_warn_function_return); NEXT_PASS (pass_del_ssa); NEXT_PASS (pass_nrv); NEXT_PASS (pass_remove_useless_vars); NEXT_PASS (pass_del_cfg); *p = NULL; p = &pass_scev.sub; NEXT_PASS (pass_scev_init); NEXT_PASS (pass_scev_anal); NEXT_PASS (pass_scev_depend); NEXT_PASS (pass_scev_elim_checks); NEXT_PASS (pass_scev_iv_canon); NEXT_PASS (pass_scev_linear_transform); NEXT_PASS (pass_ddg); NEXT_PASS (pass_scev_vectorize); NEXT_PASS (pass_delete_ddg); NEXT_PASS (pass_scev_done); *p = NULL; #undef NEXT_PASS #undef DUP_PASS /* Register the passes with the tree dump code. */ register_dump_files (all_passes); } static void execute_pass_list (struct tree_opt_pass *); static unsigned int current_properties; static unsigned int last_verified; static void execute_todo (unsigned int flags) { if (flags & TODO_rename_vars) { rewrite_into_ssa (false); bitmap_clear (vars_to_rename); } if ((flags & TODO_dump_func) && dump_file) dump_function_to_file (current_function_decl, dump_file, dump_flags); 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; /* Verify that all required properties are present. */ if (pass->properties_required & ~current_properties) abort (); /* Run pre-pass verification. */ todo = pass->todo_flags_start & ~last_verified; if (todo) execute_todo (todo); /* If a dump file name is present, open it if enabled. */ if (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)\n\n", dname, aname); } } /* If a timevar is present, start it. */ if (pass->tv_id) timevar_push (pass->tv_id); /* Do it! */ if (pass->execute) pass->execute (); /* Run post-pass cleanup and verification. */ todo = pass->todo_flags_finish; last_verified = todo & TODO_verify_all; if (todo) execute_todo (todo); /* Update properties. */ current_properties &= ~pass->properties_destroyed; current_properties |= pass->properties_provided; /* Close down timevar and dump file. */ if (pass->tv_id) timevar_pop (pass->tv_id); 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); } /* Called to move the SAVE_EXPRs for parameter declarations in a nested function into the nested function. DATA is really the nested FUNCTION_DECL. */ static tree set_save_expr_context (tree *tp, int *walk_subtrees, void *data) { if (TREE_CODE (*tp) == SAVE_EXPR && !SAVE_EXPR_CONTEXT (*tp)) SAVE_EXPR_CONTEXT (*tp) = (tree) data; /* Do not walk back into the SAVE_EXPR_CONTEXT; that will cause circularity. */ else if (DECL_P (*tp)) *walk_subtrees = 0; return NULL; } /* For functions-as-trees languages, this performs all optimization and compilation for FNDECL. */ void tree_rest_of_compilation (tree fndecl, bool nested_p) { location_t saved_loc; struct cgraph_node *saved_node = NULL, *node; timevar_push (TV_EXPAND); if (flag_unit_at_a_time && !cgraph_global_info_ready) abort (); /* 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); /* This function is being processed in whole-function mode. */ cfun->x_whole_function_mode_p = 1; /* 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. */ immediate_size_expand = 0; 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_tree = save_body (fndecl, &cfun->saved_args); } 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); } } if (!vars_to_rename) vars_to_rename = BITMAP_XMALLOC (); /* Perform all tree transforms and optimizations. */ execute_pass_list (all_passes); /* If the function has a variably modified type, there may be SAVE_EXPRs in the parameter types. Their context must be set to refer to this function; they cannot be expanded in the containing function. */ if (decl_function_context (fndecl) == current_function_decl && variably_modified_type_p (TREE_TYPE (fndecl))) walk_tree (&TREE_TYPE (fndecl), set_save_expr_context, fndecl, NULL); /* Expand the variables recorded during gimple lowering. This must occur before the call to expand_function_start to ensure that all used variables are expanded before we expand anything on the PENDING_SIZES list. */ expand_used_vars (); /* Set up parameters and prepare for return, for the function. */ expand_function_start (fndecl, 0); /* Allow language dialects to perform special processing. */ (*lang_hooks.rtl_expand.start) (); /* If this function is `main', emit a call to `__main' to run global initializers, etc. */ if (DECL_NAME (fndecl) && MAIN_NAME_P (DECL_NAME (fndecl)) && DECL_FILE_SCOPE_P (fndecl)) expand_main_function (); /* Generate the RTL for this function. */ (*lang_hooks.rtl_expand.stmt) (DECL_SAVED_TREE (fndecl)); /* We hard-wired immediate_size_expand to zero above. expand_function_end will decrement this variable. So, we set the variable to one here, so that after the decrement it will remain zero. */ immediate_size_expand = 1; /* Make sure the locus is set to the end of the function, so that epilogue line numbers and warnings are set properly. */ if (cfun->function_end_locus.file) input_location = cfun->function_end_locus; /* The following insns belong to the top scope. */ record_block_change (DECL_INITIAL (current_function_decl)); /* Allow language dialects to perform special processing. */ (*lang_hooks.rtl_expand.end) (); /* Generate rtl for function exit. */ expand_function_end (); /* If this is a nested function, protect the local variables in the stack above us from being collected while we're compiling this function. */ if (nested_p) ggc_push_context (); /* There's no need to defer outputting this function any more; we know we want to output it. */ DECL_DEFER_OUTPUT (fndecl) = 0; /* Run the optimizers and output the assembler code for this function. */ rest_of_compilation (fndecl); /* Restore original body if still needed. */ if (cfun->saved_tree) { DECL_SAVED_TREE (fndecl) = cfun->saved_tree; DECL_ARGUMENTS (fndecl) = cfun->saved_args; /* 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; while (node->callees) cgraph_remove_edge (node->callees); node->callees = saved_node->callees; saved_node->callees = NULL; for (e = saved_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 '%D' is %u bytes", fndecl, fndecl, size_as_int); else warning ("%Jsize of return value of '%D' is larger than %wd bytes", fndecl, fndecl, larger_than_size); } } if (!nested_p && !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 (); /* Undo the GC context switch. */ if (nested_p) ggc_pop_context (); timevar_pop (TV_EXPAND); }