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Diffstat (limited to 'gcc/tree-optimize.c')
| -rw-r--r-- | gcc/tree-optimize.c | 517 |
1 files changed, 517 insertions, 0 deletions
diff --git a/gcc/tree-optimize.c b/gcc/tree-optimize.c new file mode 100644 index 0000000..50dd22b --- /dev/null +++ b/gcc/tree-optimize.c @@ -0,0 +1,517 @@ +/* Top-level control of tree optimizations. + Copyright 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. + Contributed by Diego Novillo <dnovillo@redhat.com> + +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, 51 Franklin Street, Fifth Floor, +Boston, MA 02110-1301, 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" +#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. */ + && !(errorcount || sorrycount)); +} + +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 */ +}; + +struct tree_opt_pass pass_early_local_passes = +{ + 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 unsigned int +execute_cleanup_cfg_pre_ipa (void) +{ + cleanup_tree_cfg (); + return 0; +} + +struct tree_opt_pass pass_cleanup_cfg = +{ + "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 */ + 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 unsigned int +execute_cleanup_cfg_post_optimizing (void) +{ + fold_cond_expr_cond (); + cleanup_tree_cfg (); + cleanup_dead_labels (); + group_case_labels (); + return 0; +} + +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 unsigned int +execute_free_datastructures (void) +{ + /* ??? 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); + free_dominance_info (CDI_POST_DOMINATORS); + + /* Remove the ssa structures. Do it here since this includes statement + annotations that need to be intact during disband_implicit_edges. */ + delete_tree_ssa (); + return 0; +} + +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 */ +}; +/* Pass: free cfg annotations. */ + +static unsigned int +execute_free_cfg_annotations (void) +{ + basic_block bb; + block_stmt_iterator bsi; + + /* Emit gotos for implicit jumps. */ + disband_implicit_edges (); + + /* Remove annotations from every tree in the function. */ + FOR_EACH_BB (bb) + for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) + { + tree stmt = bsi_stmt (bsi); + ggc_free (stmt->common.ann); + stmt->common.ann = NULL; + } + + /* And get rid of annotations we no longer need. */ + delete_tree_cfg_annotations (); + +#ifdef ENABLE_CHECKING + /* Once the statement annotations have been removed, we can verify + the integrity of statements in the EH throw table. */ + verify_eh_throw_table_statements (); +#endif + return 0; +} + +struct tree_opt_pass pass_free_cfg_annotations = +{ + 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 */ + 0 /* letter */ +}; + +/* Return true if BB has at least one abnormal outgoing edge. */ + +static inline bool +has_abnormal_outgoing_edge_p (basic_block bb) +{ + edge e; + edge_iterator ei; + + FOR_EACH_EDGE (e, ei, bb->succs) + if (e->flags & EDGE_ABNORMAL) + return true; + + return false; +} + +/* Pass: fixup_cfg. IPA passes, compilation of earlier functions or inlining + might have changed some properties, such as marked functions nothrow or + added calls that can potentially go to non-local labels. Remove redundant + edges and basic blocks, and create new ones if necessary. */ + +static unsigned int +execute_fixup_cfg (void) +{ + basic_block bb; + block_stmt_iterator bsi; + + if (cfun->eh) + FOR_EACH_BB (bb) + { + for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) + { + tree stmt = bsi_stmt (bsi); + tree call = get_call_expr_in (stmt); + + if (call && call_expr_flags (call) & (ECF_CONST | ECF_PURE)) + TREE_SIDE_EFFECTS (call) = 0; + if (!tree_could_throw_p (stmt) && lookup_stmt_eh_region (stmt)) + remove_stmt_from_eh_region (stmt); + } + tree_purge_dead_eh_edges (bb); + } + + if (current_function_has_nonlocal_label) + FOR_EACH_BB (bb) + { + for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) + { + tree stmt = bsi_stmt (bsi); + if (tree_can_make_abnormal_goto (stmt)) + { + if (stmt == bsi_stmt (bsi_last (bb))) + { + if (!has_abnormal_outgoing_edge_p (bb)) + make_abnormal_goto_edges (bb, true); + } + else + { + edge e = split_block (bb, stmt); + bb = e->src; + make_abnormal_goto_edges (bb, true); + } + break; + } + } + } + + cleanup_tree_cfg (); + + /* Dump a textual representation of the flowgraph. */ + if (dump_file) + dump_tree_cfg (dump_file, dump_flags); + + return 0; +} + +struct tree_opt_pass pass_fixup_cfg = +{ + "fixupcfg", /* name */ + NULL, /* gate */ + execute_fixup_cfg, /* 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 unsigned int +execute_init_datastructures (void) +{ + /* Allocate hash tables, arrays and other structures. */ + init_tree_ssa (); + return 0; +} + +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 */ +}; + +void +tree_lowering_passes (tree fn) +{ + tree saved_current_function_decl = current_function_decl; + + current_function_decl = fn; + push_cfun (DECL_STRUCT_FUNCTION (fn)); + tree_register_cfg_hooks (); + bitmap_obstack_initialize (NULL); + execute_pass_list (all_lowering_passes); + free_dominance_info (CDI_POST_DOMINATORS); + compact_blocks (); + current_function_decl = saved_current_function_decl; + bitmap_obstack_release (NULL); + pop_cfun (); +} + +/* 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 *node; + + timevar_push (TV_EXPAND); + + gcc_assert (!flag_unit_at_a_time || cgraph_global_info_ready); + + node = cgraph_node (fndecl); + + /* We might need the body of this function so that we can expand + it inline somewhere else. */ + if (cgraph_preserve_function_body_p (fndecl)) + save_inline_function_body (node); + + /* 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; + cfun->after_inlining = true; + + 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); + } + } + /* In non-unit-at-a-time we must mark all referenced functions as needed. + */ + if (!flag_unit_at_a_time) + { + struct cgraph_edge *e; + for (e = node->callees; e; e = e->next_callee) + if (e->callee->analyzed) + cgraph_mark_needed_node (e->callee); + } + + /* 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*/ + + tree_register_cfg_hooks (); + /* Perform all tree transforms and optimizations. */ + execute_pass_list (all_passes); + + bitmap_obstack_release (®_obstack); + + /* Release the default bitmap obstack. */ + bitmap_obstack_release (NULL); + + 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 (0, "size of return value of %q+D is %u bytes", + fndecl, size_as_int); + else + warning (0, "size of return value of %q+D is larger than %wd bytes", + 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); +} |
