1 /* Control flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
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"
29 #include "hard-reg-set.h"
30 #include "basic-block.h"
36 #include "langhooks.h"
37 #include "diagnostic.h"
38 #include "tree-flow.h"
40 #include "tree-dump.h"
41 #include "tree-pass.h"
45 #include "cfglayout.h"
46 #include "tree-ssa-propagate.h"
47 #include "value-prof.h"
48 #include "pointer-set.h"
49 #include "tree-inline.h"
51 /* This file contains functions for building the Control Flow Graph (CFG)
52 for a function tree. */
54 /* Local declarations. */
56 /* Initial capacity for the basic block array. */
57 static const int initial_cfg_capacity = 20;
59 /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs
60 which use a particular edge. The CASE_LABEL_EXPRs are chained together
61 via their TREE_CHAIN field, which we clear after we're done with the
62 hash table to prevent problems with duplication of SWITCH_EXPRs.
64 Access to this list of CASE_LABEL_EXPRs allows us to efficiently
65 update the case vector in response to edge redirections.
67 Right now this table is set up and torn down at key points in the
68 compilation process. It would be nice if we could make the table
69 more persistent. The key is getting notification of changes to
70 the CFG (particularly edge removal, creation and redirection). */
72 static struct pointer_map_t *edge_to_cases;
77 long num_merged_labels;
80 static struct cfg_stats_d cfg_stats;
82 /* Nonzero if we found a computed goto while building basic blocks. */
83 static bool found_computed_goto;
85 /* Basic blocks and flowgraphs. */
86 static basic_block create_bb (void *, void *, basic_block);
87 static void make_blocks (tree);
88 static void factor_computed_gotos (void);
91 static void make_edges (void);
92 static void make_cond_expr_edges (basic_block);
93 static void make_switch_expr_edges (basic_block);
94 static void make_goto_expr_edges (basic_block);
95 static edge tree_redirect_edge_and_branch (edge, basic_block);
96 static edge tree_try_redirect_by_replacing_jump (edge, basic_block);
97 static unsigned int split_critical_edges (void);
99 /* Various helpers. */
100 static inline bool stmt_starts_bb_p (const_tree, const_tree);
101 static int tree_verify_flow_info (void);
102 static void tree_make_forwarder_block (edge);
103 static void tree_cfg2vcg (FILE *);
104 static inline void change_bb_for_stmt (tree t, basic_block bb);
105 static bool computed_goto_p (const_tree);
107 /* Flowgraph optimization and cleanup. */
108 static void tree_merge_blocks (basic_block, basic_block);
109 static bool tree_can_merge_blocks_p (basic_block, basic_block);
110 static void remove_bb (basic_block);
111 static edge find_taken_edge_computed_goto (basic_block, tree);
112 static edge find_taken_edge_cond_expr (basic_block, tree);
113 static edge find_taken_edge_switch_expr (basic_block, tree);
114 static tree find_case_label_for_value (tree, tree);
117 init_empty_tree_cfg (void)
119 /* Initialize the basic block array. */
121 profile_status = PROFILE_ABSENT;
122 n_basic_blocks = NUM_FIXED_BLOCKS;
123 last_basic_block = NUM_FIXED_BLOCKS;
124 basic_block_info = VEC_alloc (basic_block, gc, initial_cfg_capacity);
125 VEC_safe_grow_cleared (basic_block, gc, basic_block_info,
126 initial_cfg_capacity);
128 /* Build a mapping of labels to their associated blocks. */
129 label_to_block_map = VEC_alloc (basic_block, gc, initial_cfg_capacity);
130 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
131 initial_cfg_capacity);
133 SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR);
134 SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR);
135 ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR;
136 EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR;
139 /*---------------------------------------------------------------------------
141 ---------------------------------------------------------------------------*/
143 /* Entry point to the CFG builder for trees. TP points to the list of
144 statements to be added to the flowgraph. */
147 build_tree_cfg (tree *tp)
149 /* Register specific tree functions. */
150 tree_register_cfg_hooks ();
152 memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
154 init_empty_tree_cfg ();
156 found_computed_goto = 0;
159 /* Computed gotos are hell to deal with, especially if there are
160 lots of them with a large number of destinations. So we factor
161 them to a common computed goto location before we build the
162 edge list. After we convert back to normal form, we will un-factor
163 the computed gotos since factoring introduces an unwanted jump. */
164 if (found_computed_goto)
165 factor_computed_gotos ();
167 /* Make sure there is always at least one block, even if it's empty. */
168 if (n_basic_blocks == NUM_FIXED_BLOCKS)
169 create_empty_bb (ENTRY_BLOCK_PTR);
171 /* Adjust the size of the array. */
172 if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
173 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
175 /* To speed up statement iterator walks, we first purge dead labels. */
176 cleanup_dead_labels ();
178 /* Group case nodes to reduce the number of edges.
179 We do this after cleaning up dead labels because otherwise we miss
180 a lot of obvious case merging opportunities. */
181 group_case_labels ();
183 /* Create the edges of the flowgraph. */
185 cleanup_dead_labels ();
187 /* Debugging dumps. */
189 /* Write the flowgraph to a VCG file. */
191 int local_dump_flags;
192 FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
195 tree_cfg2vcg (vcg_file);
196 dump_end (TDI_vcg, vcg_file);
200 #ifdef ENABLE_CHECKING
204 /* Dump a textual representation of the flowgraph. */
206 dump_tree_cfg (dump_file, dump_flags);
210 execute_build_cfg (void)
212 build_tree_cfg (&DECL_SAVED_TREE (current_function_decl));
216 struct gimple_opt_pass pass_build_cfg =
222 execute_build_cfg, /* execute */
225 0, /* static_pass_number */
226 TV_TREE_CFG, /* tv_id */
227 PROP_gimple_leh, /* properties_required */
228 PROP_cfg, /* properties_provided */
229 0, /* properties_destroyed */
230 0, /* todo_flags_start */
231 TODO_verify_stmts | TODO_cleanup_cfg /* todo_flags_finish */
235 /* Search the CFG for any computed gotos. If found, factor them to a
236 common computed goto site. Also record the location of that site so
237 that we can un-factor the gotos after we have converted back to
241 factor_computed_gotos (void)
244 tree factored_label_decl = NULL;
246 tree factored_computed_goto_label = NULL;
247 tree factored_computed_goto = NULL;
249 /* We know there are one or more computed gotos in this function.
250 Examine the last statement in each basic block to see if the block
251 ends with a computed goto. */
255 block_stmt_iterator bsi = bsi_last (bb);
260 last = bsi_stmt (bsi);
262 /* Ignore the computed goto we create when we factor the original
264 if (last == factored_computed_goto)
267 /* If the last statement is a computed goto, factor it. */
268 if (computed_goto_p (last))
272 /* The first time we find a computed goto we need to create
273 the factored goto block and the variable each original
274 computed goto will use for their goto destination. */
275 if (! factored_computed_goto)
277 basic_block new_bb = create_empty_bb (bb);
278 block_stmt_iterator new_bsi = bsi_start (new_bb);
280 /* Create the destination of the factored goto. Each original
281 computed goto will put its desired destination into this
282 variable and jump to the label we create immediately
284 var = create_tmp_var (ptr_type_node, "gotovar");
286 /* Build a label for the new block which will contain the
287 factored computed goto. */
288 factored_label_decl = create_artificial_label ();
289 factored_computed_goto_label
290 = build1 (LABEL_EXPR, void_type_node, factored_label_decl);
291 bsi_insert_after (&new_bsi, factored_computed_goto_label,
294 /* Build our new computed goto. */
295 factored_computed_goto = build1 (GOTO_EXPR, void_type_node, var);
296 bsi_insert_after (&new_bsi, factored_computed_goto,
300 /* Copy the original computed goto's destination into VAR. */
301 assignment = build_gimple_modify_stmt (var,
302 GOTO_DESTINATION (last));
303 bsi_insert_before (&bsi, assignment, BSI_SAME_STMT);
305 /* And re-vector the computed goto to the new destination. */
306 GOTO_DESTINATION (last) = factored_label_decl;
312 /* Build a flowgraph for the statement_list STMT_LIST. */
315 make_blocks (tree stmt_list)
317 tree_stmt_iterator i = tsi_start (stmt_list);
319 bool start_new_block = true;
320 bool first_stmt_of_list = true;
321 basic_block bb = ENTRY_BLOCK_PTR;
323 while (!tsi_end_p (i))
330 /* If the statement starts a new basic block or if we have determined
331 in a previous pass that we need to create a new block for STMT, do
333 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
335 if (!first_stmt_of_list)
336 stmt_list = tsi_split_statement_list_before (&i);
337 bb = create_basic_block (stmt_list, NULL, bb);
338 start_new_block = false;
341 /* Now add STMT to BB and create the subgraphs for special statement
343 set_bb_for_stmt (stmt, bb);
345 if (computed_goto_p (stmt))
346 found_computed_goto = true;
348 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
350 if (stmt_ends_bb_p (stmt))
351 start_new_block = true;
354 first_stmt_of_list = false;
359 /* Create and return a new empty basic block after bb AFTER. */
362 create_bb (void *h, void *e, basic_block after)
368 /* Create and initialize a new basic block. Since alloc_block uses
369 ggc_alloc_cleared to allocate a basic block, we do not have to
370 clear the newly allocated basic block here. */
373 bb->index = last_basic_block;
375 bb->il.tree = GGC_CNEW (struct tree_bb_info);
376 set_bb_stmt_list (bb, h ? (tree) h : alloc_stmt_list ());
378 /* Add the new block to the linked list of blocks. */
379 link_block (bb, after);
381 /* Grow the basic block array if needed. */
382 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
384 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
385 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
388 /* Add the newly created block to the array. */
389 SET_BASIC_BLOCK (last_basic_block, bb);
398 /*---------------------------------------------------------------------------
400 ---------------------------------------------------------------------------*/
402 /* Fold COND_EXPR_COND of each COND_EXPR. */
405 fold_cond_expr_cond (void)
411 tree stmt = last_stmt (bb);
414 && TREE_CODE (stmt) == COND_EXPR)
419 fold_defer_overflow_warnings ();
420 cond = fold (COND_EXPR_COND (stmt));
421 zerop = integer_zerop (cond);
422 onep = integer_onep (cond);
423 fold_undefer_overflow_warnings (zerop || onep,
425 WARN_STRICT_OVERFLOW_CONDITIONAL);
427 COND_EXPR_COND (stmt) = boolean_false_node;
429 COND_EXPR_COND (stmt) = boolean_true_node;
434 /* Join all the blocks in the flowgraph. */
440 struct omp_region *cur_region = NULL;
442 /* Create an edge from entry to the first block with executable
444 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
446 /* Traverse the basic block array placing edges. */
449 tree last = last_stmt (bb);
454 enum tree_code code = TREE_CODE (last);
458 make_goto_expr_edges (bb);
462 make_edge (bb, EXIT_BLOCK_PTR, 0);
466 make_cond_expr_edges (bb);
470 make_switch_expr_edges (bb);
474 make_eh_edges (last);
479 /* If this function receives a nonlocal goto, then we need to
480 make edges from this call site to all the nonlocal goto
482 if (tree_can_make_abnormal_goto (last))
483 make_abnormal_goto_edges (bb, true);
485 /* If this statement has reachable exception handlers, then
486 create abnormal edges to them. */
487 make_eh_edges (last);
489 /* Some calls are known not to return. */
490 fallthru = !(call_expr_flags (last) & ECF_NORETURN);
496 case GIMPLE_MODIFY_STMT:
497 if (is_ctrl_altering_stmt (last))
499 /* A GIMPLE_MODIFY_STMT may have a CALL_EXPR on its RHS and
500 the CALL_EXPR may have an abnormal edge. Search the RHS
501 for this case and create any required edges. */
502 if (tree_can_make_abnormal_goto (last))
503 make_abnormal_goto_edges (bb, true);
505 make_eh_edges (last);
517 cur_region = new_omp_region (bb, code, cur_region);
522 cur_region = new_omp_region (bb, code, cur_region);
526 case OMP_SECTIONS_SWITCH:
531 case OMP_ATOMIC_LOAD:
532 case OMP_ATOMIC_STORE:
538 /* In the case of an OMP_SECTION, the edge will go somewhere
539 other than the next block. This will be created later. */
540 cur_region->exit = bb;
541 fallthru = cur_region->type != OMP_SECTION;
542 cur_region = cur_region->outer;
546 cur_region->cont = bb;
547 switch (cur_region->type)
550 /* Mark all OMP_FOR and OMP_CONTINUE succs edges as abnormal
551 to prevent splitting them. */
552 single_succ_edge (cur_region->entry)->flags |= EDGE_ABNORMAL;
553 /* Make the loopback edge. */
554 make_edge (bb, single_succ (cur_region->entry),
557 /* Create an edge from OMP_FOR to exit, which corresponds to
558 the case that the body of the loop is not executed at
560 make_edge (cur_region->entry, bb->next_bb, EDGE_ABNORMAL);
561 make_edge (bb, bb->next_bb, EDGE_FALLTHRU | EDGE_ABNORMAL);
566 /* Wire up the edges into and out of the nested sections. */
568 basic_block switch_bb = single_succ (cur_region->entry);
570 struct omp_region *i;
571 for (i = cur_region->inner; i ; i = i->next)
573 gcc_assert (i->type == OMP_SECTION);
574 make_edge (switch_bb, i->entry, 0);
575 make_edge (i->exit, bb, EDGE_FALLTHRU);
578 /* Make the loopback edge to the block with
579 OMP_SECTIONS_SWITCH. */
580 make_edge (bb, switch_bb, 0);
582 /* Make the edge from the switch to exit. */
583 make_edge (switch_bb, bb->next_bb, 0);
594 gcc_assert (!stmt_ends_bb_p (last));
602 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
608 /* Fold COND_EXPR_COND of each COND_EXPR. */
609 fold_cond_expr_cond ();
613 /* Create the edges for a COND_EXPR starting at block BB.
614 At this point, both clauses must contain only simple gotos. */
617 make_cond_expr_edges (basic_block bb)
619 tree entry = last_stmt (bb);
620 basic_block then_bb, else_bb;
621 tree then_label, else_label;
625 gcc_assert (TREE_CODE (entry) == COND_EXPR);
627 /* Entry basic blocks for each component. */
628 then_label = GOTO_DESTINATION (COND_EXPR_THEN (entry));
629 else_label = GOTO_DESTINATION (COND_EXPR_ELSE (entry));
630 then_bb = label_to_block (then_label);
631 else_bb = label_to_block (else_label);
633 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
634 e->goto_locus = EXPR_LOCATION (COND_EXPR_THEN (entry));
635 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
637 e->goto_locus = EXPR_LOCATION (COND_EXPR_ELSE (entry));
639 /* We do not need the gotos anymore. */
640 COND_EXPR_THEN (entry) = NULL_TREE;
641 COND_EXPR_ELSE (entry) = NULL_TREE;
645 /* Called for each element in the hash table (P) as we delete the
646 edge to cases hash table.
648 Clear all the TREE_CHAINs to prevent problems with copying of
649 SWITCH_EXPRs and structure sharing rules, then free the hash table
653 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED, void **value,
654 void *data ATTRIBUTE_UNUSED)
658 for (t = (tree) *value; t; t = next)
660 next = TREE_CHAIN (t);
661 TREE_CHAIN (t) = NULL;
668 /* Start recording information mapping edges to case labels. */
671 start_recording_case_labels (void)
673 gcc_assert (edge_to_cases == NULL);
674 edge_to_cases = pointer_map_create ();
677 /* Return nonzero if we are recording information for case labels. */
680 recording_case_labels_p (void)
682 return (edge_to_cases != NULL);
685 /* Stop recording information mapping edges to case labels and
686 remove any information we have recorded. */
688 end_recording_case_labels (void)
690 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
691 pointer_map_destroy (edge_to_cases);
692 edge_to_cases = NULL;
695 /* If we are inside a {start,end}_recording_cases block, then return
696 a chain of CASE_LABEL_EXPRs from T which reference E.
698 Otherwise return NULL. */
701 get_cases_for_edge (edge e, tree t)
707 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
708 chains available. Return NULL so the caller can detect this case. */
709 if (!recording_case_labels_p ())
712 slot = pointer_map_contains (edge_to_cases, e);
716 /* If we did not find E in the hash table, then this must be the first
717 time we have been queried for information about E & T. Add all the
718 elements from T to the hash table then perform the query again. */
720 vec = SWITCH_LABELS (t);
721 n = TREE_VEC_LENGTH (vec);
722 for (i = 0; i < n; i++)
724 tree elt = TREE_VEC_ELT (vec, i);
725 tree lab = CASE_LABEL (elt);
726 basic_block label_bb = label_to_block (lab);
727 edge this_edge = find_edge (e->src, label_bb);
729 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
731 slot = pointer_map_insert (edge_to_cases, this_edge);
732 TREE_CHAIN (elt) = (tree) *slot;
736 return (tree) *pointer_map_contains (edge_to_cases, e);
739 /* Create the edges for a SWITCH_EXPR starting at block BB.
740 At this point, the switch body has been lowered and the
741 SWITCH_LABELS filled in, so this is in effect a multi-way branch. */
744 make_switch_expr_edges (basic_block bb)
746 tree entry = last_stmt (bb);
750 vec = SWITCH_LABELS (entry);
751 n = TREE_VEC_LENGTH (vec);
753 for (i = 0; i < n; ++i)
755 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
756 basic_block label_bb = label_to_block (lab);
757 make_edge (bb, label_bb, 0);
762 /* Return the basic block holding label DEST. */
765 label_to_block_fn (struct function *ifun, tree dest)
767 int uid = LABEL_DECL_UID (dest);
769 /* We would die hard when faced by an undefined label. Emit a label to
770 the very first basic block. This will hopefully make even the dataflow
771 and undefined variable warnings quite right. */
772 if ((errorcount || sorrycount) && uid < 0)
774 block_stmt_iterator bsi =
775 bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS));
778 stmt = build1 (LABEL_EXPR, void_type_node, dest);
779 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
780 uid = LABEL_DECL_UID (dest);
782 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
783 <= (unsigned int) uid)
785 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
788 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
789 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
792 make_abnormal_goto_edges (basic_block bb, bool for_call)
794 basic_block target_bb;
795 block_stmt_iterator bsi;
797 FOR_EACH_BB (target_bb)
798 for (bsi = bsi_start (target_bb); !bsi_end_p (bsi); bsi_next (&bsi))
800 tree target = bsi_stmt (bsi);
802 if (TREE_CODE (target) != LABEL_EXPR)
805 target = LABEL_EXPR_LABEL (target);
807 /* Make an edge to every label block that has been marked as a
808 potential target for a computed goto or a non-local goto. */
809 if ((FORCED_LABEL (target) && !for_call)
810 || (DECL_NONLOCAL (target) && for_call))
812 make_edge (bb, target_bb, EDGE_ABNORMAL);
818 /* Create edges for a goto statement at block BB. */
821 make_goto_expr_edges (basic_block bb)
823 block_stmt_iterator last = bsi_last (bb);
824 tree goto_t = bsi_stmt (last);
826 /* A simple GOTO creates normal edges. */
827 if (simple_goto_p (goto_t))
829 tree dest = GOTO_DESTINATION (goto_t);
830 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
831 e->goto_locus = EXPR_LOCATION (goto_t);
832 bsi_remove (&last, true);
836 /* A computed GOTO creates abnormal edges. */
837 make_abnormal_goto_edges (bb, false);
841 /*---------------------------------------------------------------------------
843 ---------------------------------------------------------------------------*/
845 /* Cleanup useless labels in basic blocks. This is something we wish
846 to do early because it allows us to group case labels before creating
847 the edges for the CFG, and it speeds up block statement iterators in
849 We rerun this pass after CFG is created, to get rid of the labels that
850 are no longer referenced. After then we do not run it any more, since
851 (almost) no new labels should be created. */
853 /* A map from basic block index to the leading label of that block. */
854 static struct label_record
859 /* True if the label is referenced from somewhere. */
863 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
865 update_eh_label (struct eh_region *region)
867 tree old_label = get_eh_region_tree_label (region);
871 basic_block bb = label_to_block (old_label);
873 /* ??? After optimizing, there may be EH regions with labels
874 that have already been removed from the function body, so
875 there is no basic block for them. */
879 new_label = label_for_bb[bb->index].label;
880 label_for_bb[bb->index].used = true;
881 set_eh_region_tree_label (region, new_label);
885 /* Given LABEL return the first label in the same basic block. */
887 main_block_label (tree label)
889 basic_block bb = label_to_block (label);
890 tree main_label = label_for_bb[bb->index].label;
892 /* label_to_block possibly inserted undefined label into the chain. */
895 label_for_bb[bb->index].label = label;
899 label_for_bb[bb->index].used = true;
903 /* Cleanup redundant labels. This is a three-step process:
904 1) Find the leading label for each block.
905 2) Redirect all references to labels to the leading labels.
906 3) Cleanup all useless labels. */
909 cleanup_dead_labels (void)
912 label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
914 /* Find a suitable label for each block. We use the first user-defined
915 label if there is one, or otherwise just the first label we see. */
918 block_stmt_iterator i;
920 for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i))
922 tree label, stmt = bsi_stmt (i);
924 if (TREE_CODE (stmt) != LABEL_EXPR)
927 label = LABEL_EXPR_LABEL (stmt);
929 /* If we have not yet seen a label for the current block,
930 remember this one and see if there are more labels. */
931 if (!label_for_bb[bb->index].label)
933 label_for_bb[bb->index].label = label;
937 /* If we did see a label for the current block already, but it
938 is an artificially created label, replace it if the current
939 label is a user defined label. */
940 if (!DECL_ARTIFICIAL (label)
941 && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
943 label_for_bb[bb->index].label = label;
949 /* Now redirect all jumps/branches to the selected label.
950 First do so for each block ending in a control statement. */
953 tree stmt = last_stmt (bb);
957 switch (TREE_CODE (stmt))
961 tree true_branch, false_branch;
963 true_branch = COND_EXPR_THEN (stmt);
964 false_branch = COND_EXPR_ELSE (stmt);
967 GOTO_DESTINATION (true_branch)
968 = main_block_label (GOTO_DESTINATION (true_branch));
970 GOTO_DESTINATION (false_branch)
971 = main_block_label (GOTO_DESTINATION (false_branch));
979 tree vec = SWITCH_LABELS (stmt);
980 size_t n = TREE_VEC_LENGTH (vec);
982 /* Replace all destination labels. */
983 for (i = 0; i < n; ++i)
985 tree elt = TREE_VEC_ELT (vec, i);
986 tree label = main_block_label (CASE_LABEL (elt));
987 CASE_LABEL (elt) = label;
992 /* We have to handle GOTO_EXPRs until they're removed, and we don't
993 remove them until after we've created the CFG edges. */
995 if (! computed_goto_p (stmt))
997 GOTO_DESTINATION (stmt)
998 = main_block_label (GOTO_DESTINATION (stmt));
1007 for_each_eh_region (update_eh_label);
1009 /* Finally, purge dead labels. All user-defined labels and labels that
1010 can be the target of non-local gotos and labels which have their
1011 address taken are preserved. */
1014 block_stmt_iterator i;
1015 tree label_for_this_bb = label_for_bb[bb->index].label;
1017 if (!label_for_this_bb)
1020 /* If the main label of the block is unused, we may still remove it. */
1021 if (!label_for_bb[bb->index].used)
1022 label_for_this_bb = NULL;
1024 for (i = bsi_start (bb); !bsi_end_p (i); )
1026 tree label, stmt = bsi_stmt (i);
1028 if (TREE_CODE (stmt) != LABEL_EXPR)
1031 label = LABEL_EXPR_LABEL (stmt);
1033 if (label == label_for_this_bb
1034 || ! DECL_ARTIFICIAL (label)
1035 || DECL_NONLOCAL (label)
1036 || FORCED_LABEL (label))
1039 bsi_remove (&i, true);
1043 free (label_for_bb);
1046 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1047 and scan the sorted vector of cases. Combine the ones jumping to the
1049 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1052 group_case_labels (void)
1058 tree stmt = last_stmt (bb);
1059 if (stmt && TREE_CODE (stmt) == SWITCH_EXPR)
1061 tree labels = SWITCH_LABELS (stmt);
1062 int old_size = TREE_VEC_LENGTH (labels);
1063 int i, j, new_size = old_size;
1064 tree default_case = NULL_TREE;
1065 tree default_label = NULL_TREE;
1067 /* The default label is always the last case in a switch
1068 statement after gimplification if it was not optimized
1070 if (!CASE_LOW (TREE_VEC_ELT (labels, old_size - 1))
1071 && !CASE_HIGH (TREE_VEC_ELT (labels, old_size - 1)))
1073 default_case = TREE_VEC_ELT (labels, old_size - 1);
1074 default_label = CASE_LABEL (default_case);
1078 /* Look for possible opportunities to merge cases. */
1080 while (i < old_size)
1082 tree base_case, base_label, base_high;
1083 base_case = TREE_VEC_ELT (labels, i);
1085 gcc_assert (base_case);
1086 base_label = CASE_LABEL (base_case);
1088 /* Discard cases that have the same destination as the
1090 if (base_label == default_label)
1092 TREE_VEC_ELT (labels, i) = NULL_TREE;
1098 base_high = CASE_HIGH (base_case) ?
1099 CASE_HIGH (base_case) : CASE_LOW (base_case);
1101 /* Try to merge case labels. Break out when we reach the end
1102 of the label vector or when we cannot merge the next case
1103 label with the current one. */
1104 while (i < old_size)
1106 tree merge_case = TREE_VEC_ELT (labels, i);
1107 tree merge_label = CASE_LABEL (merge_case);
1108 tree t = int_const_binop (PLUS_EXPR, base_high,
1109 integer_one_node, 1);
1111 /* Merge the cases if they jump to the same place,
1112 and their ranges are consecutive. */
1113 if (merge_label == base_label
1114 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1116 base_high = CASE_HIGH (merge_case) ?
1117 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1118 CASE_HIGH (base_case) = base_high;
1119 TREE_VEC_ELT (labels, i) = NULL_TREE;
1128 /* Compress the case labels in the label vector, and adjust the
1129 length of the vector. */
1130 for (i = 0, j = 0; i < new_size; i++)
1132 while (! TREE_VEC_ELT (labels, j))
1134 TREE_VEC_ELT (labels, i) = TREE_VEC_ELT (labels, j++);
1136 TREE_VEC_LENGTH (labels) = new_size;
1141 /* Checks whether we can merge block B into block A. */
1144 tree_can_merge_blocks_p (basic_block a, basic_block b)
1147 block_stmt_iterator bsi;
1150 if (!single_succ_p (a))
1153 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1156 if (single_succ (a) != b)
1159 if (!single_pred_p (b))
1162 if (b == EXIT_BLOCK_PTR)
1165 /* If A ends by a statement causing exceptions or something similar, we
1166 cannot merge the blocks. */
1167 /* This CONST_CAST is okay because last_stmt doesn't modify its
1168 argument and the return value is assign to a const_tree. */
1169 stmt = last_stmt (CONST_CAST_BB (a));
1170 if (stmt && stmt_ends_bb_p (stmt))
1173 /* Do not allow a block with only a non-local label to be merged. */
1174 if (stmt && TREE_CODE (stmt) == LABEL_EXPR
1175 && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
1178 /* It must be possible to eliminate all phi nodes in B. If ssa form
1179 is not up-to-date, we cannot eliminate any phis; however, if only
1180 some symbols as whole are marked for renaming, this is not a problem,
1181 as phi nodes for those symbols are irrelevant in updating anyway. */
1182 phi = phi_nodes (b);
1185 if (name_mappings_registered_p ())
1188 for (; phi; phi = PHI_CHAIN (phi))
1189 if (!is_gimple_reg (PHI_RESULT (phi))
1190 && !may_propagate_copy (PHI_RESULT (phi), PHI_ARG_DEF (phi, 0)))
1194 /* Do not remove user labels. */
1195 for (bsi = bsi_start (b); !bsi_end_p (bsi); bsi_next (&bsi))
1197 stmt = bsi_stmt (bsi);
1198 if (TREE_CODE (stmt) != LABEL_EXPR)
1200 if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt)))
1204 /* Protect the loop latches. */
1206 && b->loop_father->latch == b)
1212 /* Replaces all uses of NAME by VAL. */
1215 replace_uses_by (tree name, tree val)
1217 imm_use_iterator imm_iter;
1222 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1224 if (TREE_CODE (stmt) != PHI_NODE)
1225 push_stmt_changes (&stmt);
1227 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1229 replace_exp (use, val);
1231 if (TREE_CODE (stmt) == PHI_NODE)
1233 e = PHI_ARG_EDGE (stmt, PHI_ARG_INDEX_FROM_USE (use));
1234 if (e->flags & EDGE_ABNORMAL)
1236 /* This can only occur for virtual operands, since
1237 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1238 would prevent replacement. */
1239 gcc_assert (!is_gimple_reg (name));
1240 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1245 if (TREE_CODE (stmt) != PHI_NODE)
1249 fold_stmt_inplace (stmt);
1250 if (cfgcleanup_altered_bbs)
1251 bitmap_set_bit (cfgcleanup_altered_bbs, bb_for_stmt (stmt)->index);
1253 /* FIXME. This should go in pop_stmt_changes. */
1254 rhs = get_rhs (stmt);
1255 if (TREE_CODE (rhs) == ADDR_EXPR)
1256 recompute_tree_invariant_for_addr_expr (rhs);
1258 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1260 pop_stmt_changes (&stmt);
1264 gcc_assert (has_zero_uses (name));
1266 /* Also update the trees stored in loop structures. */
1272 FOR_EACH_LOOP (li, loop, 0)
1274 substitute_in_loop_info (loop, name, val);
1279 /* Merge block B into block A. */
1282 tree_merge_blocks (basic_block a, basic_block b)
1284 block_stmt_iterator bsi;
1285 tree_stmt_iterator last;
1289 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1291 /* Remove all single-valued PHI nodes from block B of the form
1292 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1294 for (phi = phi_nodes (b); phi; phi = phi_nodes (b))
1296 tree def = PHI_RESULT (phi), use = PHI_ARG_DEF (phi, 0);
1298 bool may_replace_uses = may_propagate_copy (def, use);
1300 /* In case we maintain loop closed ssa form, do not propagate arguments
1301 of loop exit phi nodes. */
1303 && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1304 && is_gimple_reg (def)
1305 && TREE_CODE (use) == SSA_NAME
1306 && a->loop_father != b->loop_father)
1307 may_replace_uses = false;
1309 if (!may_replace_uses)
1311 gcc_assert (is_gimple_reg (def));
1313 /* Note that just emitting the copies is fine -- there is no problem
1314 with ordering of phi nodes. This is because A is the single
1315 predecessor of B, therefore results of the phi nodes cannot
1316 appear as arguments of the phi nodes. */
1317 copy = build_gimple_modify_stmt (def, use);
1318 bsi_insert_after (&bsi, copy, BSI_NEW_STMT);
1319 SSA_NAME_DEF_STMT (def) = copy;
1320 remove_phi_node (phi, NULL, false);
1324 /* If we deal with a PHI for virtual operands, we can simply
1325 propagate these without fussing with folding or updating
1327 if (!is_gimple_reg (def))
1329 imm_use_iterator iter;
1330 use_operand_p use_p;
1333 FOR_EACH_IMM_USE_STMT (stmt, iter, def)
1334 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1335 SET_USE (use_p, use);
1338 replace_uses_by (def, use);
1339 remove_phi_node (phi, NULL, true);
1343 /* Ensure that B follows A. */
1344 move_block_after (b, a);
1346 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1347 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1349 /* Remove labels from B and set bb_for_stmt to A for other statements. */
1350 for (bsi = bsi_start (b); !bsi_end_p (bsi);)
1352 if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR)
1354 tree label = bsi_stmt (bsi);
1356 bsi_remove (&bsi, false);
1357 /* Now that we can thread computed gotos, we might have
1358 a situation where we have a forced label in block B
1359 However, the label at the start of block B might still be
1360 used in other ways (think about the runtime checking for
1361 Fortran assigned gotos). So we can not just delete the
1362 label. Instead we move the label to the start of block A. */
1363 if (FORCED_LABEL (LABEL_EXPR_LABEL (label)))
1365 block_stmt_iterator dest_bsi = bsi_start (a);
1366 bsi_insert_before (&dest_bsi, label, BSI_NEW_STMT);
1371 change_bb_for_stmt (bsi_stmt (bsi), a);
1376 /* Merge the chains. */
1377 last = tsi_last (bb_stmt_list (a));
1378 tsi_link_after (&last, bb_stmt_list (b), TSI_NEW_STMT);
1379 set_bb_stmt_list (b, NULL_TREE);
1381 if (cfgcleanup_altered_bbs)
1382 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1386 /* Return the one of two successors of BB that is not reachable by a
1387 reached by a complex edge, if there is one. Else, return BB. We use
1388 this in optimizations that use post-dominators for their heuristics,
1389 to catch the cases in C++ where function calls are involved. */
1392 single_noncomplex_succ (basic_block bb)
1395 if (EDGE_COUNT (bb->succs) != 2)
1398 e0 = EDGE_SUCC (bb, 0);
1399 e1 = EDGE_SUCC (bb, 1);
1400 if (e0->flags & EDGE_COMPLEX)
1402 if (e1->flags & EDGE_COMPLEX)
1409 /* Walk the function tree removing unnecessary statements.
1411 * Empty statement nodes are removed
1413 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1415 * Unnecessary COND_EXPRs are removed
1417 * Some unnecessary BIND_EXPRs are removed
1419 Clearly more work could be done. The trick is doing the analysis
1420 and removal fast enough to be a net improvement in compile times.
1422 Note that when we remove a control structure such as a COND_EXPR
1423 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1424 to ensure we eliminate all the useless code. */
1435 static void remove_useless_stmts_1 (tree *, struct rus_data *);
1438 remove_useless_stmts_warn_notreached (tree stmt)
1440 if (EXPR_HAS_LOCATION (stmt))
1442 location_t loc = EXPR_LOCATION (stmt);
1443 if (LOCATION_LINE (loc) > 0)
1445 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
1450 switch (TREE_CODE (stmt))
1452 case STATEMENT_LIST:
1454 tree_stmt_iterator i;
1455 for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i))
1456 if (remove_useless_stmts_warn_notreached (tsi_stmt (i)))
1462 if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt)))
1464 if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt)))
1466 if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt)))
1470 case TRY_FINALLY_EXPR:
1471 case TRY_CATCH_EXPR:
1472 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 0)))
1474 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 1)))
1479 return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt));
1480 case EH_FILTER_EXPR:
1481 return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt));
1483 return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt));
1486 /* Not a live container. */
1494 remove_useless_stmts_cond (tree *stmt_p, struct rus_data *data)
1496 tree then_clause, else_clause, cond;
1497 bool save_has_label, then_has_label, else_has_label;
1499 save_has_label = data->has_label;
1500 data->has_label = false;
1501 data->last_goto = NULL;
1503 remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p), data);
1505 then_has_label = data->has_label;
1506 data->has_label = false;
1507 data->last_goto = NULL;
1509 remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p), data);
1511 else_has_label = data->has_label;
1512 data->has_label = save_has_label | then_has_label | else_has_label;
1514 then_clause = COND_EXPR_THEN (*stmt_p);
1515 else_clause = COND_EXPR_ELSE (*stmt_p);
1516 cond = fold (COND_EXPR_COND (*stmt_p));
1518 /* If neither arm does anything at all, we can remove the whole IF. */
1519 if (!TREE_SIDE_EFFECTS (then_clause) && !TREE_SIDE_EFFECTS (else_clause))
1521 *stmt_p = build_empty_stmt ();
1522 data->repeat = true;
1525 /* If there are no reachable statements in an arm, then we can
1526 zap the entire conditional. */
1527 else if (integer_nonzerop (cond) && !else_has_label)
1529 if (warn_notreached)
1530 remove_useless_stmts_warn_notreached (else_clause);
1531 *stmt_p = then_clause;
1532 data->repeat = true;
1534 else if (integer_zerop (cond) && !then_has_label)
1536 if (warn_notreached)
1537 remove_useless_stmts_warn_notreached (then_clause);
1538 *stmt_p = else_clause;
1539 data->repeat = true;
1542 /* Check a couple of simple things on then/else with single stmts. */
1545 tree then_stmt = expr_only (then_clause);
1546 tree else_stmt = expr_only (else_clause);
1548 /* Notice branches to a common destination. */
1549 if (then_stmt && else_stmt
1550 && TREE_CODE (then_stmt) == GOTO_EXPR
1551 && TREE_CODE (else_stmt) == GOTO_EXPR
1552 && (GOTO_DESTINATION (then_stmt) == GOTO_DESTINATION (else_stmt)))
1554 *stmt_p = then_stmt;
1555 data->repeat = true;
1558 /* If the THEN/ELSE clause merely assigns a value to a variable or
1559 parameter which is already known to contain that value, then
1560 remove the useless THEN/ELSE clause. */
1561 else if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL)
1564 && TREE_CODE (else_stmt) == GIMPLE_MODIFY_STMT
1565 && GIMPLE_STMT_OPERAND (else_stmt, 0) == cond
1566 && integer_zerop (GIMPLE_STMT_OPERAND (else_stmt, 1)))
1567 COND_EXPR_ELSE (*stmt_p) = alloc_stmt_list ();
1569 else if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
1570 && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL
1571 || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL)
1572 && TREE_CONSTANT (TREE_OPERAND (cond, 1)))
1574 tree stmt = (TREE_CODE (cond) == EQ_EXPR
1575 ? then_stmt : else_stmt);
1576 tree *location = (TREE_CODE (cond) == EQ_EXPR
1577 ? &COND_EXPR_THEN (*stmt_p)
1578 : &COND_EXPR_ELSE (*stmt_p));
1581 && TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
1582 && GIMPLE_STMT_OPERAND (stmt, 0) == TREE_OPERAND (cond, 0)
1583 && GIMPLE_STMT_OPERAND (stmt, 1) == TREE_OPERAND (cond, 1))
1584 *location = alloc_stmt_list ();
1588 /* Protect GOTOs in the arm of COND_EXPRs from being removed. They
1589 would be re-introduced during lowering. */
1590 data->last_goto = NULL;
1595 remove_useless_stmts_tf (tree *stmt_p, struct rus_data *data)
1597 bool save_may_branch, save_may_throw;
1598 bool this_may_branch, this_may_throw;
1600 /* Collect may_branch and may_throw information for the body only. */
1601 save_may_branch = data->may_branch;
1602 save_may_throw = data->may_throw;
1603 data->may_branch = false;
1604 data->may_throw = false;
1605 data->last_goto = NULL;
1607 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1609 this_may_branch = data->may_branch;
1610 this_may_throw = data->may_throw;
1611 data->may_branch |= save_may_branch;
1612 data->may_throw |= save_may_throw;
1613 data->last_goto = NULL;
1615 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1617 /* If the body is empty, then we can emit the FINALLY block without
1618 the enclosing TRY_FINALLY_EXPR. */
1619 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 0)))
1621 *stmt_p = TREE_OPERAND (*stmt_p, 1);
1622 data->repeat = true;
1625 /* If the handler is empty, then we can emit the TRY block without
1626 the enclosing TRY_FINALLY_EXPR. */
1627 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1629 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1630 data->repeat = true;
1633 /* If the body neither throws, nor branches, then we can safely
1634 string the TRY and FINALLY blocks together. */
1635 else if (!this_may_branch && !this_may_throw)
1637 tree stmt = *stmt_p;
1638 *stmt_p = TREE_OPERAND (stmt, 0);
1639 append_to_statement_list (TREE_OPERAND (stmt, 1), stmt_p);
1640 data->repeat = true;
1646 remove_useless_stmts_tc (tree *stmt_p, struct rus_data *data)
1648 bool save_may_throw, this_may_throw;
1649 tree_stmt_iterator i;
1652 /* Collect may_throw information for the body only. */
1653 save_may_throw = data->may_throw;
1654 data->may_throw = false;
1655 data->last_goto = NULL;
1657 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1659 this_may_throw = data->may_throw;
1660 data->may_throw = save_may_throw;
1662 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1663 if (!this_may_throw)
1665 if (warn_notreached)
1666 remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p, 1));
1667 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1668 data->repeat = true;
1672 /* Process the catch clause specially. We may be able to tell that
1673 no exceptions propagate past this point. */
1675 this_may_throw = true;
1676 i = tsi_start (TREE_OPERAND (*stmt_p, 1));
1677 stmt = tsi_stmt (i);
1678 data->last_goto = NULL;
1680 switch (TREE_CODE (stmt))
1683 for (; !tsi_end_p (i); tsi_next (&i))
1685 stmt = tsi_stmt (i);
1686 /* If we catch all exceptions, then the body does not
1687 propagate exceptions past this point. */
1688 if (CATCH_TYPES (stmt) == NULL)
1689 this_may_throw = false;
1690 data->last_goto = NULL;
1691 remove_useless_stmts_1 (&CATCH_BODY (stmt), data);
1695 case EH_FILTER_EXPR:
1696 if (EH_FILTER_MUST_NOT_THROW (stmt))
1697 this_may_throw = false;
1698 else if (EH_FILTER_TYPES (stmt) == NULL)
1699 this_may_throw = false;
1700 remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt), data);
1704 /* Otherwise this is a cleanup. */
1705 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1707 /* If the cleanup is empty, then we can emit the TRY block without
1708 the enclosing TRY_CATCH_EXPR. */
1709 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1711 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1712 data->repeat = true;
1716 data->may_throw |= this_may_throw;
1721 remove_useless_stmts_bind (tree *stmt_p, struct rus_data *data)
1725 /* First remove anything underneath the BIND_EXPR. */
1726 remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p), data);
1728 /* If the BIND_EXPR has no variables, then we can pull everything
1729 up one level and remove the BIND_EXPR, unless this is the toplevel
1730 BIND_EXPR for the current function or an inlined function.
1732 When this situation occurs we will want to apply this
1733 optimization again. */
1734 block = BIND_EXPR_BLOCK (*stmt_p);
1735 if (BIND_EXPR_VARS (*stmt_p) == NULL_TREE
1736 && *stmt_p != DECL_SAVED_TREE (current_function_decl)
1738 || ! BLOCK_ABSTRACT_ORIGIN (block)
1739 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1742 *stmt_p = BIND_EXPR_BODY (*stmt_p);
1743 data->repeat = true;
1749 remove_useless_stmts_goto (tree *stmt_p, struct rus_data *data)
1751 tree dest = GOTO_DESTINATION (*stmt_p);
1753 data->may_branch = true;
1754 data->last_goto = NULL;
1756 /* Record the last goto expr, so that we can delete it if unnecessary. */
1757 if (TREE_CODE (dest) == LABEL_DECL)
1758 data->last_goto = stmt_p;
1763 remove_useless_stmts_label (tree *stmt_p, struct rus_data *data)
1765 tree label = LABEL_EXPR_LABEL (*stmt_p);
1767 data->has_label = true;
1769 /* We do want to jump across non-local label receiver code. */
1770 if (DECL_NONLOCAL (label))
1771 data->last_goto = NULL;
1773 else if (data->last_goto && GOTO_DESTINATION (*data->last_goto) == label)
1775 *data->last_goto = build_empty_stmt ();
1776 data->repeat = true;
1779 /* ??? Add something here to delete unused labels. */
1783 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1784 decl. This allows us to eliminate redundant or useless
1785 calls to "const" functions.
1787 Gimplifier already does the same operation, but we may notice functions
1788 being const and pure once their calls has been gimplified, so we need
1789 to update the flag. */
1792 update_call_expr_flags (tree call)
1794 tree decl = get_callee_fndecl (call);
1798 flags = call_expr_flags (call);
1799 if (flags & (ECF_CONST | ECF_PURE) && !(flags & ECF_LOOPING_CONST_OR_PURE))
1800 TREE_SIDE_EFFECTS (call) = 0;
1801 if (TREE_NOTHROW (decl))
1802 TREE_NOTHROW (call) = 1;
1806 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1809 notice_special_calls (tree t)
1811 int flags = call_expr_flags (t);
1813 if (flags & ECF_MAY_BE_ALLOCA)
1814 cfun->calls_alloca = true;
1815 if (flags & ECF_RETURNS_TWICE)
1816 cfun->calls_setjmp = true;
1820 /* Clear flags set by notice_special_calls. Used by dead code removal
1821 to update the flags. */
1824 clear_special_calls (void)
1826 cfun->calls_alloca = false;
1827 cfun->calls_setjmp = false;
1832 remove_useless_stmts_1 (tree *tp, struct rus_data *data)
1836 switch (TREE_CODE (t))
1839 remove_useless_stmts_cond (tp, data);
1842 case TRY_FINALLY_EXPR:
1843 remove_useless_stmts_tf (tp, data);
1846 case TRY_CATCH_EXPR:
1847 remove_useless_stmts_tc (tp, data);
1851 remove_useless_stmts_bind (tp, data);
1855 remove_useless_stmts_goto (tp, data);
1859 remove_useless_stmts_label (tp, data);
1864 data->last_goto = NULL;
1865 data->may_branch = true;
1870 data->last_goto = NULL;
1871 notice_special_calls (t);
1872 update_call_expr_flags (t);
1873 if (tree_could_throw_p (t))
1874 data->may_throw = true;
1880 case GIMPLE_MODIFY_STMT:
1881 data->last_goto = NULL;
1883 op = get_call_expr_in (t);
1886 update_call_expr_flags (op);
1887 notice_special_calls (op);
1889 if (tree_could_throw_p (t))
1890 data->may_throw = true;
1893 case STATEMENT_LIST:
1895 tree_stmt_iterator i = tsi_start (t);
1896 while (!tsi_end_p (i))
1899 if (IS_EMPTY_STMT (t))
1905 remove_useless_stmts_1 (tsi_stmt_ptr (i), data);
1908 if (TREE_CODE (t) == STATEMENT_LIST)
1910 tsi_link_before (&i, t, TSI_SAME_STMT);
1920 data->last_goto = NULL;
1924 /* Make sure the outermost BIND_EXPR in OMP_BODY isn't removed
1926 remove_useless_stmts_1 (&BIND_EXPR_BODY (OMP_BODY (*tp)), data);
1927 data->last_goto = NULL;
1936 remove_useless_stmts_1 (&OMP_BODY (*tp), data);
1937 data->last_goto = NULL;
1941 remove_useless_stmts_1 (&OMP_FOR_BODY (*tp), data);
1942 data->last_goto = NULL;
1943 if (OMP_FOR_PRE_BODY (*tp))
1945 remove_useless_stmts_1 (&OMP_FOR_PRE_BODY (*tp), data);
1946 data->last_goto = NULL;
1951 data->last_goto = NULL;
1957 remove_useless_stmts (void)
1959 struct rus_data data;
1961 clear_special_calls ();
1965 memset (&data, 0, sizeof (data));
1966 remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl), &data);
1968 while (data.repeat);
1973 struct gimple_opt_pass pass_remove_useless_stmts =
1977 "useless", /* name */
1979 remove_useless_stmts, /* execute */
1982 0, /* static_pass_number */
1984 PROP_gimple_any, /* properties_required */
1985 0, /* properties_provided */
1986 0, /* properties_destroyed */
1987 0, /* todo_flags_start */
1988 TODO_dump_func /* todo_flags_finish */
1992 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
1995 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
1999 /* Since this block is no longer reachable, we can just delete all
2000 of its PHI nodes. */
2001 phi = phi_nodes (bb);
2004 tree next = PHI_CHAIN (phi);
2005 remove_phi_node (phi, NULL_TREE, true);
2009 /* Remove edges to BB's successors. */
2010 while (EDGE_COUNT (bb->succs) > 0)
2011 remove_edge (EDGE_SUCC (bb, 0));
2015 /* Remove statements of basic block BB. */
2018 remove_bb (basic_block bb)
2020 block_stmt_iterator i;
2021 source_location loc = UNKNOWN_LOCATION;
2025 fprintf (dump_file, "Removing basic block %d\n", bb->index);
2026 if (dump_flags & TDF_DETAILS)
2028 dump_bb (bb, dump_file, 0);
2029 fprintf (dump_file, "\n");
2035 struct loop *loop = bb->loop_father;
2037 /* If a loop gets removed, clean up the information associated
2039 if (loop->latch == bb
2040 || loop->header == bb)
2041 free_numbers_of_iterations_estimates_loop (loop);
2044 /* Remove all the instructions in the block. */
2045 if (bb_stmt_list (bb) != NULL_TREE)
2047 for (i = bsi_start (bb); !bsi_end_p (i);)
2049 tree stmt = bsi_stmt (i);
2050 if (TREE_CODE (stmt) == LABEL_EXPR
2051 && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt))
2052 || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))))
2055 block_stmt_iterator new_bsi;
2057 /* A non-reachable non-local label may still be referenced.
2058 But it no longer needs to carry the extra semantics of
2060 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
2062 DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)) = 0;
2063 FORCED_LABEL (LABEL_EXPR_LABEL (stmt)) = 1;
2066 new_bb = bb->prev_bb;
2067 new_bsi = bsi_start (new_bb);
2068 bsi_remove (&i, false);
2069 bsi_insert_before (&new_bsi, stmt, BSI_NEW_STMT);
2073 /* Release SSA definitions if we are in SSA. Note that we
2074 may be called when not in SSA. For example,
2075 final_cleanup calls this function via
2076 cleanup_tree_cfg. */
2077 if (gimple_in_ssa_p (cfun))
2078 release_defs (stmt);
2080 bsi_remove (&i, true);
2083 /* Don't warn for removed gotos. Gotos are often removed due to
2084 jump threading, thus resulting in bogus warnings. Not great,
2085 since this way we lose warnings for gotos in the original
2086 program that are indeed unreachable. */
2087 if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc)
2089 if (EXPR_HAS_LOCATION (stmt))
2090 loc = EXPR_LOCATION (stmt);
2095 /* If requested, give a warning that the first statement in the
2096 block is unreachable. We walk statements backwards in the
2097 loop above, so the last statement we process is the first statement
2099 if (loc > BUILTINS_LOCATION && LOCATION_LINE (loc) > 0)
2100 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2102 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2107 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2108 predicate VAL, return the edge that will be taken out of the block.
2109 If VAL does not match a unique edge, NULL is returned. */
2112 find_taken_edge (basic_block bb, tree val)
2116 stmt = last_stmt (bb);
2119 gcc_assert (is_ctrl_stmt (stmt));
2122 if (! is_gimple_min_invariant (val))
2125 if (TREE_CODE (stmt) == COND_EXPR)
2126 return find_taken_edge_cond_expr (bb, val);
2128 if (TREE_CODE (stmt) == SWITCH_EXPR)
2129 return find_taken_edge_switch_expr (bb, val);
2131 if (computed_goto_p (stmt))
2133 /* Only optimize if the argument is a label, if the argument is
2134 not a label then we can not construct a proper CFG.
2136 It may be the case that we only need to allow the LABEL_REF to
2137 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2138 appear inside a LABEL_EXPR just to be safe. */
2139 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2140 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2141 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2148 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2149 statement, determine which of the outgoing edges will be taken out of the
2150 block. Return NULL if either edge may be taken. */
2153 find_taken_edge_computed_goto (basic_block bb, tree val)
2158 dest = label_to_block (val);
2161 e = find_edge (bb, dest);
2162 gcc_assert (e != NULL);
2168 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2169 statement, determine which of the two edges will be taken out of the
2170 block. Return NULL if either edge may be taken. */
2173 find_taken_edge_cond_expr (basic_block bb, tree val)
2175 edge true_edge, false_edge;
2177 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2179 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2180 return (integer_zerop (val) ? false_edge : true_edge);
2183 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2184 statement, determine which edge will be taken out of the block. Return
2185 NULL if any edge may be taken. */
2188 find_taken_edge_switch_expr (basic_block bb, tree val)
2190 tree switch_expr, taken_case;
2191 basic_block dest_bb;
2194 switch_expr = last_stmt (bb);
2195 taken_case = find_case_label_for_value (switch_expr, val);
2196 dest_bb = label_to_block (CASE_LABEL (taken_case));
2198 e = find_edge (bb, dest_bb);
2204 /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL.
2205 We can make optimal use here of the fact that the case labels are
2206 sorted: We can do a binary search for a case matching VAL. */
2209 find_case_label_for_value (tree switch_expr, tree val)
2211 tree vec = SWITCH_LABELS (switch_expr);
2212 size_t low, high, n = TREE_VEC_LENGTH (vec);
2213 tree default_case = TREE_VEC_ELT (vec, n - 1);
2215 for (low = -1, high = n - 1; high - low > 1; )
2217 size_t i = (high + low) / 2;
2218 tree t = TREE_VEC_ELT (vec, i);
2221 /* Cache the result of comparing CASE_LOW and val. */
2222 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2229 if (CASE_HIGH (t) == NULL)
2231 /* A singe-valued case label. */
2237 /* A case range. We can only handle integer ranges. */
2238 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2243 return default_case;
2249 /*---------------------------------------------------------------------------
2251 ---------------------------------------------------------------------------*/
2253 /* Dump tree-specific information of block BB to file OUTF. */
2256 tree_dump_bb (basic_block bb, FILE *outf, int indent)
2258 dump_generic_bb (outf, bb, indent, TDF_VOPS|TDF_MEMSYMS);
2262 /* Dump a basic block on stderr. */
2265 debug_tree_bb (basic_block bb)
2267 dump_bb (bb, stderr, 0);
2271 /* Dump basic block with index N on stderr. */
2274 debug_tree_bb_n (int n)
2276 debug_tree_bb (BASIC_BLOCK (n));
2277 return BASIC_BLOCK (n);
2281 /* Dump the CFG on stderr.
2283 FLAGS are the same used by the tree dumping functions
2284 (see TDF_* in tree-pass.h). */
2287 debug_tree_cfg (int flags)
2289 dump_tree_cfg (stderr, flags);
2293 /* Dump the program showing basic block boundaries on the given FILE.
2295 FLAGS are the same used by the tree dumping functions (see TDF_* in
2299 dump_tree_cfg (FILE *file, int flags)
2301 if (flags & TDF_DETAILS)
2303 const char *funcname
2304 = lang_hooks.decl_printable_name (current_function_decl, 2);
2307 fprintf (file, ";; Function %s\n\n", funcname);
2308 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2309 n_basic_blocks, n_edges, last_basic_block);
2311 brief_dump_cfg (file);
2312 fprintf (file, "\n");
2315 if (flags & TDF_STATS)
2316 dump_cfg_stats (file);
2318 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2322 /* Dump CFG statistics on FILE. */
2325 dump_cfg_stats (FILE *file)
2327 static long max_num_merged_labels = 0;
2328 unsigned long size, total = 0;
2331 const char * const fmt_str = "%-30s%-13s%12s\n";
2332 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2333 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2334 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2335 const char *funcname
2336 = lang_hooks.decl_printable_name (current_function_decl, 2);
2339 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2341 fprintf (file, "---------------------------------------------------------\n");
2342 fprintf (file, fmt_str, "", " Number of ", "Memory");
2343 fprintf (file, fmt_str, "", " instances ", "used ");
2344 fprintf (file, "---------------------------------------------------------\n");
2346 size = n_basic_blocks * sizeof (struct basic_block_def);
2348 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2349 SCALE (size), LABEL (size));
2353 num_edges += EDGE_COUNT (bb->succs);
2354 size = num_edges * sizeof (struct edge_def);
2356 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2358 fprintf (file, "---------------------------------------------------------\n");
2359 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2361 fprintf (file, "---------------------------------------------------------\n");
2362 fprintf (file, "\n");
2364 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2365 max_num_merged_labels = cfg_stats.num_merged_labels;
2367 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2368 cfg_stats.num_merged_labels, max_num_merged_labels);
2370 fprintf (file, "\n");
2374 /* Dump CFG statistics on stderr. Keep extern so that it's always
2375 linked in the final executable. */
2378 debug_cfg_stats (void)
2380 dump_cfg_stats (stderr);
2384 /* Dump the flowgraph to a .vcg FILE. */
2387 tree_cfg2vcg (FILE *file)
2392 const char *funcname
2393 = lang_hooks.decl_printable_name (current_function_decl, 2);
2395 /* Write the file header. */
2396 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2397 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2398 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2400 /* Write blocks and edges. */
2401 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2403 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2406 if (e->flags & EDGE_FAKE)
2407 fprintf (file, " linestyle: dotted priority: 10");
2409 fprintf (file, " linestyle: solid priority: 100");
2411 fprintf (file, " }\n");
2417 enum tree_code head_code, end_code;
2418 const char *head_name, *end_name;
2421 tree first = first_stmt (bb);
2422 tree last = last_stmt (bb);
2426 head_code = TREE_CODE (first);
2427 head_name = tree_code_name[head_code];
2428 head_line = get_lineno (first);
2431 head_name = "no-statement";
2435 end_code = TREE_CODE (last);
2436 end_name = tree_code_name[end_code];
2437 end_line = get_lineno (last);
2440 end_name = "no-statement";
2442 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2443 bb->index, bb->index, head_name, head_line, end_name,
2446 FOR_EACH_EDGE (e, ei, bb->succs)
2448 if (e->dest == EXIT_BLOCK_PTR)
2449 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2451 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2453 if (e->flags & EDGE_FAKE)
2454 fprintf (file, " priority: 10 linestyle: dotted");
2456 fprintf (file, " priority: 100 linestyle: solid");
2458 fprintf (file, " }\n");
2461 if (bb->next_bb != EXIT_BLOCK_PTR)
2465 fputs ("}\n\n", file);
2470 /*---------------------------------------------------------------------------
2471 Miscellaneous helpers
2472 ---------------------------------------------------------------------------*/
2474 /* Return true if T represents a stmt that always transfers control. */
2477 is_ctrl_stmt (const_tree t)
2479 return (TREE_CODE (t) == COND_EXPR
2480 || TREE_CODE (t) == SWITCH_EXPR
2481 || TREE_CODE (t) == GOTO_EXPR
2482 || TREE_CODE (t) == RETURN_EXPR
2483 || TREE_CODE (t) == RESX_EXPR);
2487 /* Return true if T is a statement that may alter the flow of control
2488 (e.g., a call to a non-returning function). */
2491 is_ctrl_altering_stmt (const_tree t)
2496 call = get_call_expr_in (CONST_CAST_TREE (t));
2499 /* A non-pure/const CALL_EXPR alters flow control if the current
2500 function has nonlocal labels. */
2501 if (TREE_SIDE_EFFECTS (call) && cfun->has_nonlocal_label)
2504 /* A CALL_EXPR also alters control flow if it does not return. */
2505 if (call_expr_flags (call) & ECF_NORETURN)
2509 /* OpenMP directives alter control flow. */
2510 if (OMP_DIRECTIVE_P (t))
2513 /* If a statement can throw, it alters control flow. */
2514 return tree_can_throw_internal (t);
2518 /* Return true if T is a computed goto. */
2521 computed_goto_p (const_tree t)
2523 return (TREE_CODE (t) == GOTO_EXPR
2524 && TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL);
2528 /* Return true if T is a simple local goto. */
2531 simple_goto_p (const_tree t)
2533 return (TREE_CODE (t) == GOTO_EXPR
2534 && TREE_CODE (GOTO_DESTINATION (t)) == LABEL_DECL);
2538 /* Return true if T can make an abnormal transfer of control flow.
2539 Transfers of control flow associated with EH are excluded. */
2542 tree_can_make_abnormal_goto (const_tree t)
2544 if (computed_goto_p (t))
2546 if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
2547 t = GIMPLE_STMT_OPERAND (t, 1);
2548 if (TREE_CODE (t) == WITH_SIZE_EXPR)
2549 t = TREE_OPERAND (t, 0);
2550 if (TREE_CODE (t) == CALL_EXPR)
2551 return TREE_SIDE_EFFECTS (t) && cfun->has_nonlocal_label;
2556 /* Return true if T should start a new basic block. PREV_T is the
2557 statement preceding T. It is used when T is a label or a case label.
2558 Labels should only start a new basic block if their previous statement
2559 wasn't a label. Otherwise, sequence of labels would generate
2560 unnecessary basic blocks that only contain a single label. */
2563 stmt_starts_bb_p (const_tree t, const_tree prev_t)
2568 /* LABEL_EXPRs start a new basic block only if the preceding
2569 statement wasn't a label of the same type. This prevents the
2570 creation of consecutive blocks that have nothing but a single
2572 if (TREE_CODE (t) == LABEL_EXPR)
2574 /* Nonlocal and computed GOTO targets always start a new block. */
2575 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t))
2576 || FORCED_LABEL (LABEL_EXPR_LABEL (t)))
2579 if (prev_t && TREE_CODE (prev_t) == LABEL_EXPR)
2581 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t)))
2584 cfg_stats.num_merged_labels++;
2595 /* Return true if T should end a basic block. */
2598 stmt_ends_bb_p (const_tree t)
2600 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2603 /* Remove block annotations and other datastructures. */
2606 delete_tree_cfg_annotations (void)
2609 block_stmt_iterator bsi;
2611 /* Remove annotations from every tree in the function. */
2613 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
2615 tree stmt = bsi_stmt (bsi);
2616 ggc_free (stmt->base.ann);
2617 stmt->base.ann = NULL;
2619 label_to_block_map = NULL;
2623 /* Return the first statement in basic block BB. */
2626 first_stmt (basic_block bb)
2628 block_stmt_iterator i = bsi_start (bb);
2629 return !bsi_end_p (i) ? bsi_stmt (i) : NULL_TREE;
2632 /* Return the last statement in basic block BB. */
2635 last_stmt (basic_block bb)
2637 block_stmt_iterator b = bsi_last (bb);
2638 return !bsi_end_p (b) ? bsi_stmt (b) : NULL_TREE;
2641 /* Return the last statement of an otherwise empty block. Return NULL
2642 if the block is totally empty, or if it contains more than one
2646 last_and_only_stmt (basic_block bb)
2648 block_stmt_iterator i = bsi_last (bb);
2654 last = bsi_stmt (i);
2659 /* Empty statements should no longer appear in the instruction stream.
2660 Everything that might have appeared before should be deleted by
2661 remove_useless_stmts, and the optimizers should just bsi_remove
2662 instead of smashing with build_empty_stmt.
2664 Thus the only thing that should appear here in a block containing
2665 one executable statement is a label. */
2666 prev = bsi_stmt (i);
2667 if (TREE_CODE (prev) == LABEL_EXPR)
2674 /* Mark BB as the basic block holding statement T. */
2677 set_bb_for_stmt (tree t, basic_block bb)
2679 if (TREE_CODE (t) == PHI_NODE)
2681 else if (TREE_CODE (t) == STATEMENT_LIST)
2683 tree_stmt_iterator i;
2684 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2685 set_bb_for_stmt (tsi_stmt (i), bb);
2689 stmt_ann_t ann = get_stmt_ann (t);
2692 /* If the statement is a label, add the label to block-to-labels map
2693 so that we can speed up edge creation for GOTO_EXPRs. */
2694 if (TREE_CODE (t) == LABEL_EXPR)
2698 t = LABEL_EXPR_LABEL (t);
2699 uid = LABEL_DECL_UID (t);
2702 unsigned old_len = VEC_length (basic_block, label_to_block_map);
2703 LABEL_DECL_UID (t) = uid = cfun->cfg->last_label_uid++;
2704 if (old_len <= (unsigned) uid)
2706 unsigned new_len = 3 * uid / 2;
2708 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
2713 /* We're moving an existing label. Make sure that we've
2714 removed it from the old block. */
2716 || !VEC_index (basic_block, label_to_block_map, uid));
2717 VEC_replace (basic_block, label_to_block_map, uid, bb);
2722 /* Faster version of set_bb_for_stmt that assume that statement is being moved
2723 from one basic block to another.
2724 For BB splitting we can run into quadratic case, so performance is quite
2725 important and knowing that the tables are big enough, change_bb_for_stmt
2726 can inline as leaf function. */
2728 change_bb_for_stmt (tree t, basic_block bb)
2730 get_stmt_ann (t)->bb = bb;
2731 if (TREE_CODE (t) == LABEL_EXPR)
2732 VEC_replace (basic_block, label_to_block_map,
2733 LABEL_DECL_UID (LABEL_EXPR_LABEL (t)), bb);
2736 /* Finds iterator for STMT. */
2738 extern block_stmt_iterator
2739 bsi_for_stmt (tree stmt)
2741 block_stmt_iterator bsi;
2743 for (bsi = bsi_start (bb_for_stmt (stmt)); !bsi_end_p (bsi); bsi_next (&bsi))
2744 if (bsi_stmt (bsi) == stmt)
2750 /* Mark statement T as modified, and update it. */
2752 update_modified_stmts (tree t)
2754 if (!ssa_operands_active ())
2756 if (TREE_CODE (t) == STATEMENT_LIST)
2758 tree_stmt_iterator i;
2760 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2762 stmt = tsi_stmt (i);
2763 update_stmt_if_modified (stmt);
2767 update_stmt_if_modified (t);
2770 /* Insert statement (or statement list) T before the statement
2771 pointed-to by iterator I. M specifies how to update iterator I
2772 after insertion (see enum bsi_iterator_update). */
2775 bsi_insert_before (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2777 set_bb_for_stmt (t, i->bb);
2778 update_modified_stmts (t);
2779 tsi_link_before (&i->tsi, t, m);
2783 /* Insert statement (or statement list) T after the statement
2784 pointed-to by iterator I. M specifies how to update iterator I
2785 after insertion (see enum bsi_iterator_update). */
2788 bsi_insert_after (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2790 set_bb_for_stmt (t, i->bb);
2791 update_modified_stmts (t);
2792 tsi_link_after (&i->tsi, t, m);
2796 /* Remove the statement pointed to by iterator I. The iterator is updated
2797 to the next statement.
2799 When REMOVE_EH_INFO is true we remove the statement pointed to by
2800 iterator I from the EH tables. Otherwise we do not modify the EH
2803 Generally, REMOVE_EH_INFO should be true when the statement is going to
2804 be removed from the IL and not reinserted elsewhere. */
2807 bsi_remove (block_stmt_iterator *i, bool remove_eh_info)
2809 tree t = bsi_stmt (*i);
2810 set_bb_for_stmt (t, NULL);
2811 delink_stmt_imm_use (t);
2812 tsi_delink (&i->tsi);
2813 mark_stmt_modified (t);
2816 remove_stmt_from_eh_region (t);
2817 gimple_remove_stmt_histograms (cfun, t);
2822 /* Move the statement at FROM so it comes right after the statement at TO. */
2825 bsi_move_after (block_stmt_iterator *from, block_stmt_iterator *to)
2827 tree stmt = bsi_stmt (*from);
2828 bsi_remove (from, false);
2829 /* We must have BSI_NEW_STMT here, as bsi_move_after is sometimes used to
2830 move statements to an empty block. */
2831 bsi_insert_after (to, stmt, BSI_NEW_STMT);
2835 /* Move the statement at FROM so it comes right before the statement at TO. */
2838 bsi_move_before (block_stmt_iterator *from, block_stmt_iterator *to)
2840 tree stmt = bsi_stmt (*from);
2841 bsi_remove (from, false);
2842 /* For consistency with bsi_move_after, it might be better to have
2843 BSI_NEW_STMT here; however, that breaks several places that expect
2844 that TO does not change. */
2845 bsi_insert_before (to, stmt, BSI_SAME_STMT);
2849 /* Move the statement at FROM to the end of basic block BB. */
2852 bsi_move_to_bb_end (block_stmt_iterator *from, basic_block bb)
2854 block_stmt_iterator last = bsi_last (bb);
2856 /* Have to check bsi_end_p because it could be an empty block. */
2857 if (!bsi_end_p (last) && is_ctrl_stmt (bsi_stmt (last)))
2858 bsi_move_before (from, &last);
2860 bsi_move_after (from, &last);
2864 /* Replace the contents of the statement pointed to by iterator BSI
2865 with STMT. If UPDATE_EH_INFO is true, the exception handling
2866 information of the original statement is moved to the new statement. */
2869 bsi_replace (const block_stmt_iterator *bsi, tree stmt, bool update_eh_info)
2872 tree orig_stmt = bsi_stmt (*bsi);
2874 if (stmt == orig_stmt)
2876 SET_EXPR_LOCUS (stmt, EXPR_LOCUS (orig_stmt));
2877 set_bb_for_stmt (stmt, bsi->bb);
2879 /* Preserve EH region information from the original statement, if
2880 requested by the caller. */
2883 eh_region = lookup_stmt_eh_region (orig_stmt);
2886 remove_stmt_from_eh_region (orig_stmt);
2887 add_stmt_to_eh_region (stmt, eh_region);
2891 gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
2892 gimple_remove_stmt_histograms (cfun, orig_stmt);
2893 delink_stmt_imm_use (orig_stmt);
2894 *bsi_stmt_ptr (*bsi) = stmt;
2895 mark_stmt_modified (stmt);
2896 update_modified_stmts (stmt);
2900 /* Insert the statement pointed-to by BSI into edge E. Every attempt
2901 is made to place the statement in an existing basic block, but
2902 sometimes that isn't possible. When it isn't possible, the edge is
2903 split and the statement is added to the new block.
2905 In all cases, the returned *BSI points to the correct location. The
2906 return value is true if insertion should be done after the location,
2907 or false if it should be done before the location. If new basic block
2908 has to be created, it is stored in *NEW_BB. */
2911 tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi,
2912 basic_block *new_bb)
2914 basic_block dest, src;
2920 /* If the destination has one predecessor which has no PHI nodes,
2921 insert there. Except for the exit block.
2923 The requirement for no PHI nodes could be relaxed. Basically we
2924 would have to examine the PHIs to prove that none of them used
2925 the value set by the statement we want to insert on E. That
2926 hardly seems worth the effort. */
2927 if (single_pred_p (dest)
2928 && ! phi_nodes (dest)
2929 && dest != EXIT_BLOCK_PTR)
2931 *bsi = bsi_start (dest);
2932 if (bsi_end_p (*bsi))
2935 /* Make sure we insert after any leading labels. */
2936 tmp = bsi_stmt (*bsi);
2937 while (TREE_CODE (tmp) == LABEL_EXPR)
2940 if (bsi_end_p (*bsi))
2942 tmp = bsi_stmt (*bsi);
2945 if (bsi_end_p (*bsi))
2947 *bsi = bsi_last (dest);
2954 /* If the source has one successor, the edge is not abnormal and
2955 the last statement does not end a basic block, insert there.
2956 Except for the entry block. */
2958 if ((e->flags & EDGE_ABNORMAL) == 0
2959 && single_succ_p (src)
2960 && src != ENTRY_BLOCK_PTR)
2962 *bsi = bsi_last (src);
2963 if (bsi_end_p (*bsi))
2966 tmp = bsi_stmt (*bsi);
2967 if (!stmt_ends_bb_p (tmp))
2970 /* Insert code just before returning the value. We may need to decompose
2971 the return in the case it contains non-trivial operand. */
2972 if (TREE_CODE (tmp) == RETURN_EXPR)
2974 tree op = TREE_OPERAND (tmp, 0);
2975 if (op && !is_gimple_val (op))
2977 gcc_assert (TREE_CODE (op) == GIMPLE_MODIFY_STMT);
2978 bsi_insert_before (bsi, op, BSI_NEW_STMT);
2979 TREE_OPERAND (tmp, 0) = GIMPLE_STMT_OPERAND (op, 0);
2986 /* Otherwise, create a new basic block, and split this edge. */
2987 dest = split_edge (e);
2990 e = single_pred_edge (dest);
2995 /* This routine will commit all pending edge insertions, creating any new
2996 basic blocks which are necessary. */
2999 bsi_commit_edge_inserts (void)
3005 bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL);
3008 FOR_EACH_EDGE (e, ei, bb->succs)
3009 bsi_commit_one_edge_insert (e, NULL);
3013 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
3014 to this block, otherwise set it to NULL. */
3017 bsi_commit_one_edge_insert (edge e, basic_block *new_bb)
3021 if (PENDING_STMT (e))
3023 block_stmt_iterator bsi;
3024 tree stmt = PENDING_STMT (e);
3026 PENDING_STMT (e) = NULL_TREE;
3028 if (tree_find_edge_insert_loc (e, &bsi, new_bb))
3029 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3031 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3036 /* Add STMT to the pending list of edge E. No actual insertion is
3037 made until a call to bsi_commit_edge_inserts () is made. */
3040 bsi_insert_on_edge (edge e, tree stmt)
3042 append_to_statement_list (stmt, &PENDING_STMT (e));
3045 /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new
3046 block has to be created, it is returned. */
3049 bsi_insert_on_edge_immediate (edge e, tree stmt)
3051 block_stmt_iterator bsi;
3052 basic_block new_bb = NULL;
3054 gcc_assert (!PENDING_STMT (e));
3056 if (tree_find_edge_insert_loc (e, &bsi, &new_bb))
3057 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3059 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3064 /*---------------------------------------------------------------------------
3065 Tree specific functions for CFG manipulation
3066 ---------------------------------------------------------------------------*/
3068 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
3071 reinstall_phi_args (edge new_edge, edge old_edge)
3074 edge_var_map_vector v;
3078 v = redirect_edge_var_map_vector (old_edge);
3082 for (i = 0, phi = phi_nodes (new_edge->dest);
3083 VEC_iterate (edge_var_map, v, i, vm) && phi;
3084 i++, phi = PHI_CHAIN (phi))
3086 tree result = redirect_edge_var_map_result (vm);
3087 tree arg = redirect_edge_var_map_def (vm);
3089 gcc_assert (result == PHI_RESULT (phi));
3091 add_phi_arg (phi, arg, new_edge);
3094 redirect_edge_var_map_clear (old_edge);
3097 /* Returns the basic block after which the new basic block created
3098 by splitting edge EDGE_IN should be placed. Tries to keep the new block
3099 near its "logical" location. This is of most help to humans looking
3100 at debugging dumps. */
3103 split_edge_bb_loc (edge edge_in)
3105 basic_block dest = edge_in->dest;
3107 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
3108 return edge_in->src;
3110 return dest->prev_bb;
3113 /* Split a (typically critical) edge EDGE_IN. Return the new block.
3114 Abort on abnormal edges. */
3117 tree_split_edge (edge edge_in)
3119 basic_block new_bb, after_bb, dest;
3122 /* Abnormal edges cannot be split. */
3123 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
3125 dest = edge_in->dest;
3127 after_bb = split_edge_bb_loc (edge_in);
3129 new_bb = create_empty_bb (after_bb);
3130 new_bb->frequency = EDGE_FREQUENCY (edge_in);
3131 new_bb->count = edge_in->count;
3132 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
3133 new_edge->probability = REG_BR_PROB_BASE;
3134 new_edge->count = edge_in->count;
3136 e = redirect_edge_and_branch (edge_in, new_bb);
3137 gcc_assert (e == edge_in);
3138 reinstall_phi_args (new_edge, e);
3143 /* Callback for walk_tree, check that all elements with address taken are
3144 properly noticed as such. The DATA is an int* that is 1 if TP was seen
3145 inside a PHI node. */
3148 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
3155 /* Check operand N for being valid GIMPLE and give error MSG if not. */
3156 #define CHECK_OP(N, MSG) \
3157 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
3158 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
3160 switch (TREE_CODE (t))
3163 if (SSA_NAME_IN_FREE_LIST (t))
3165 error ("SSA name in freelist but still referenced");
3171 x = fold (ASSERT_EXPR_COND (t));
3172 if (x == boolean_false_node)
3174 error ("ASSERT_EXPR with an always-false condition");
3182 case GIMPLE_MODIFY_STMT:
3183 x = GIMPLE_STMT_OPERAND (t, 0);
3184 if (TREE_CODE (x) == BIT_FIELD_REF
3185 && is_gimple_reg (TREE_OPERAND (x, 0)))
3187 error ("GIMPLE register modified with BIT_FIELD_REF");
3195 bool old_side_effects;
3197 bool new_side_effects;
3199 gcc_assert (is_gimple_address (t));
3201 old_constant = TREE_CONSTANT (t);
3202 old_side_effects = TREE_SIDE_EFFECTS (t);
3204 recompute_tree_invariant_for_addr_expr (t);
3205 new_side_effects = TREE_SIDE_EFFECTS (t);
3206 new_constant = TREE_CONSTANT (t);
3208 if (old_constant != new_constant)
3210 error ("constant not recomputed when ADDR_EXPR changed");
3213 if (old_side_effects != new_side_effects)
3215 error ("side effects not recomputed when ADDR_EXPR changed");
3219 /* Skip any references (they will be checked when we recurse down the
3220 tree) and ensure that any variable used as a prefix is marked
3222 for (x = TREE_OPERAND (t, 0);
3223 handled_component_p (x);
3224 x = TREE_OPERAND (x, 0))
3227 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
3229 if (!TREE_ADDRESSABLE (x))
3231 error ("address taken, but ADDRESSABLE bit not set");
3239 x = COND_EXPR_COND (t);
3240 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
3242 error ("non-integral used in condition");
3245 if (!is_gimple_condexpr (x))
3247 error ("invalid conditional operand");
3252 case NON_LVALUE_EXPR:
3257 case FIX_TRUNC_EXPR:
3262 case TRUTH_NOT_EXPR:
3263 CHECK_OP (0, "invalid operand to unary operator");
3270 case ARRAY_RANGE_REF:
3272 case VIEW_CONVERT_EXPR:
3273 /* We have a nest of references. Verify that each of the operands
3274 that determine where to reference is either a constant or a variable,
3275 verify that the base is valid, and then show we've already checked
3277 while (handled_component_p (t))
3279 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
3280 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
3281 else if (TREE_CODE (t) == ARRAY_REF
3282 || TREE_CODE (t) == ARRAY_RANGE_REF)
3284 CHECK_OP (1, "invalid array index");
3285 if (TREE_OPERAND (t, 2))
3286 CHECK_OP (2, "invalid array lower bound");
3287 if (TREE_OPERAND (t, 3))
3288 CHECK_OP (3, "invalid array stride");
3290 else if (TREE_CODE (t) == BIT_FIELD_REF)
3292 if (!host_integerp (TREE_OPERAND (t, 1), 1)
3293 || !host_integerp (TREE_OPERAND (t, 2), 1))
3295 error ("invalid position or size operand to BIT_FIELD_REF");
3298 else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
3299 && (TYPE_PRECISION (TREE_TYPE (t))
3300 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
3302 error ("integral result type precision does not match "
3303 "field size of BIT_FIELD_REF");
3306 if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
3307 && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
3308 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
3310 error ("mode precision of non-integral result does not "
3311 "match field size of BIT_FIELD_REF");
3316 t = TREE_OPERAND (t, 0);
3319 if (!is_gimple_min_invariant (t) && !is_gimple_lvalue (t))
3321 error ("invalid reference prefix");
3328 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
3329 POINTER_PLUS_EXPR. */
3330 if (POINTER_TYPE_P (TREE_TYPE (t)))
3332 error ("invalid operand to plus/minus, type is a pointer");
3335 CHECK_OP (0, "invalid operand to binary operator");
3336 CHECK_OP (1, "invalid operand to binary operator");
3339 case POINTER_PLUS_EXPR:
3340 /* Check to make sure the first operand is a pointer or reference type. */
3341 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
3343 error ("invalid operand to pointer plus, first operand is not a pointer");
3346 /* Check to make sure the second operand is an integer with type of
3348 if (!useless_type_conversion_p (sizetype,
3349 TREE_TYPE (TREE_OPERAND (t, 1))))
3351 error ("invalid operand to pointer plus, second operand is not an "
3352 "integer with type of sizetype.");
3362 case UNORDERED_EXPR:
3371 case TRUNC_DIV_EXPR:
3373 case FLOOR_DIV_EXPR:
3374 case ROUND_DIV_EXPR:
3375 case TRUNC_MOD_EXPR:
3377 case FLOOR_MOD_EXPR:
3378 case ROUND_MOD_EXPR:
3380 case EXACT_DIV_EXPR:
3390 CHECK_OP (0, "invalid operand to binary operator");
3391 CHECK_OP (1, "invalid operand to binary operator");
3395 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3407 /* Verifies if EXPR is a valid GIMPLE unary expression. Returns true
3408 if there is an error, otherwise false. */
3411 verify_gimple_unary_expr (const_tree expr)
3413 tree op = TREE_OPERAND (expr, 0);
3414 tree type = TREE_TYPE (expr);
3416 if (!is_gimple_val (op))
3418 error ("invalid operand in unary expression");
3422 /* For general unary expressions we have the operations type
3423 as the effective type the operation is carried out on. So all
3424 we need to require is that the operand is trivially convertible
3426 if (!useless_type_conversion_p (type, TREE_TYPE (op)))
3428 error ("type mismatch in unary expression");
3429 debug_generic_expr (type);
3430 debug_generic_expr (TREE_TYPE (op));
3437 /* Verifies if EXPR is a valid GIMPLE binary expression. Returns true
3438 if there is an error, otherwise false. */
3441 verify_gimple_binary_expr (const_tree expr)
3443 tree op0 = TREE_OPERAND (expr, 0);
3444 tree op1 = TREE_OPERAND (expr, 1);
3445 tree type = TREE_TYPE (expr);
3447 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3449 error ("invalid operands in binary expression");
3453 /* For general binary expressions we have the operations type
3454 as the effective type the operation is carried out on. So all
3455 we need to require is that both operands are trivially convertible
3457 if (!useless_type_conversion_p (type, TREE_TYPE (op0))
3458 || !useless_type_conversion_p (type, TREE_TYPE (op1)))
3460 error ("type mismatch in binary expression");
3461 debug_generic_stmt (type);
3462 debug_generic_stmt (TREE_TYPE (op0));
3463 debug_generic_stmt (TREE_TYPE (op1));
3470 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3471 Returns true if there is an error, otherwise false. */
3474 verify_gimple_min_lval (tree expr)
3478 if (is_gimple_id (expr))
3481 if (TREE_CODE (expr) != INDIRECT_REF
3482 && TREE_CODE (expr) != ALIGN_INDIRECT_REF
3483 && TREE_CODE (expr) != MISALIGNED_INDIRECT_REF)
3485 error ("invalid expression for min lvalue");
3489 op = TREE_OPERAND (expr, 0);
3490 if (!is_gimple_val (op))
3492 error ("invalid operand in indirect reference");
3493 debug_generic_stmt (op);
3496 if (!useless_type_conversion_p (TREE_TYPE (expr),
3497 TREE_TYPE (TREE_TYPE (op))))
3499 error ("type mismatch in indirect reference");
3500 debug_generic_stmt (TREE_TYPE (expr));
3501 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3508 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3509 if there is an error, otherwise false. */
3512 verify_gimple_reference (tree expr)
3514 while (handled_component_p (expr))
3516 tree op = TREE_OPERAND (expr, 0);
3518 if (TREE_CODE (expr) == ARRAY_REF
3519 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3521 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3522 || (TREE_OPERAND (expr, 2)
3523 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3524 || (TREE_OPERAND (expr, 3)
3525 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3527 error ("invalid operands to array reference");
3528 debug_generic_stmt (expr);
3533 /* Verify if the reference array element types are compatible. */
3534 if (TREE_CODE (expr) == ARRAY_REF
3535 && !useless_type_conversion_p (TREE_TYPE (expr),
3536 TREE_TYPE (TREE_TYPE (op))))
3538 error ("type mismatch in array reference");
3539 debug_generic_stmt (TREE_TYPE (expr));
3540 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3543 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3544 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3545 TREE_TYPE (TREE_TYPE (op))))
3547 error ("type mismatch in array range reference");
3548 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3549 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3553 if ((TREE_CODE (expr) == REALPART_EXPR
3554 || TREE_CODE (expr) == IMAGPART_EXPR)
3555 && !useless_type_conversion_p (TREE_TYPE (expr),
3556 TREE_TYPE (TREE_TYPE (op))))
3558 error ("type mismatch in real/imagpart reference");
3559 debug_generic_stmt (TREE_TYPE (expr));
3560 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3564 if (TREE_CODE (expr) == COMPONENT_REF
3565 && !useless_type_conversion_p (TREE_TYPE (expr),
3566 TREE_TYPE (TREE_OPERAND (expr, 1))))
3568 error ("type mismatch in component reference");
3569 debug_generic_stmt (TREE_TYPE (expr));
3570 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3574 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3575 is nothing to verify. Gross mismatches at most invoke
3576 undefined behavior. */
3581 return verify_gimple_min_lval (expr);
3584 /* Returns true if there is one pointer type in TYPE_POINTER_TO (SRC_OBJ)
3585 list of pointer-to types that is trivially convertible to DEST. */
3588 one_pointer_to_useless_type_conversion_p (tree dest, tree src_obj)
3592 if (!TYPE_POINTER_TO (src_obj))
3595 for (src = TYPE_POINTER_TO (src_obj); src; src = TYPE_NEXT_PTR_TO (src))
3596 if (useless_type_conversion_p (dest, src))
3602 /* Verify the GIMPLE expression EXPR. Returns true if there is an
3603 error, otherwise false. */
3606 verify_gimple_expr (tree expr)
3608 tree type = TREE_TYPE (expr);
3610 if (is_gimple_val (expr))
3613 /* Special codes we cannot handle via their class. */
3614 switch (TREE_CODE (expr))
3619 tree op = TREE_OPERAND (expr, 0);
3620 if (!is_gimple_val (op))
3622 error ("invalid operand in conversion");
3626 /* Allow conversions between integral types and between
3628 if ((INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3629 || (POINTER_TYPE_P (type) && POINTER_TYPE_P (TREE_TYPE (op))))
3632 /* Allow conversions between integral types and pointers only if
3633 there is no sign or zero extension involved. */
3634 if (((POINTER_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3635 || (POINTER_TYPE_P (TREE_TYPE (op)) && INTEGRAL_TYPE_P (type)))
3636 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op)))
3639 /* Allow conversion from integer to offset type and vice versa. */
3640 if ((TREE_CODE (type) == OFFSET_TYPE
3641 && TREE_CODE (TREE_TYPE (op)) == INTEGER_TYPE)
3642 || (TREE_CODE (type) == INTEGER_TYPE
3643 && TREE_CODE (TREE_TYPE (op)) == OFFSET_TYPE))
3646 /* Otherwise assert we are converting between types of the
3648 if (TREE_CODE (type) != TREE_CODE (TREE_TYPE (op)))
3650 error ("invalid types in nop conversion");
3651 debug_generic_expr (type);
3652 debug_generic_expr (TREE_TYPE (op));
3661 tree op = TREE_OPERAND (expr, 0);
3662 if (!is_gimple_val (op))
3664 error ("invalid operand in int to float conversion");
3667 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3668 || !SCALAR_FLOAT_TYPE_P (type))
3670 error ("invalid types in conversion to floating point");
3671 debug_generic_expr (type);
3672 debug_generic_expr (TREE_TYPE (op));
3678 case FIX_TRUNC_EXPR:
3680 tree op = TREE_OPERAND (expr, 0);
3681 if (!is_gimple_val (op))
3683 error ("invalid operand in float to int conversion");
3686 if (!INTEGRAL_TYPE_P (type)
3687 || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (op)))
3689 error ("invalid types in conversion to integer");
3690 debug_generic_expr (type);
3691 debug_generic_expr (TREE_TYPE (op));
3699 tree op0 = TREE_OPERAND (expr, 0);
3700 tree op1 = TREE_OPERAND (expr, 1);
3701 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3703 error ("invalid operands in complex expression");
3706 if (!TREE_CODE (type) == COMPLEX_TYPE
3707 || !(TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
3708 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0)))
3709 || !(TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3710 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op1)))
3711 || !useless_type_conversion_p (TREE_TYPE (type),
3713 || !useless_type_conversion_p (TREE_TYPE (type),
3716 error ("type mismatch in complex expression");
3717 debug_generic_stmt (TREE_TYPE (expr));
3718 debug_generic_stmt (TREE_TYPE (op0));
3719 debug_generic_stmt (TREE_TYPE (op1));
3727 /* This is used like COMPLEX_EXPR but for vectors. */
3728 if (TREE_CODE (type) != VECTOR_TYPE)
3730 error ("constructor not allowed for non-vector types");
3731 debug_generic_stmt (type);
3734 /* FIXME: verify constructor arguments. */
3743 tree op0 = TREE_OPERAND (expr, 0);
3744 tree op1 = TREE_OPERAND (expr, 1);
3745 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3747 error ("invalid operands in shift expression");
3750 if (!TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3751 || !useless_type_conversion_p (type, TREE_TYPE (op0)))
3753 error ("type mismatch in shift expression");
3754 debug_generic_stmt (TREE_TYPE (expr));
3755 debug_generic_stmt (TREE_TYPE (op0));
3756 debug_generic_stmt (TREE_TYPE (op1));
3765 tree op0 = TREE_OPERAND (expr, 0);
3766 tree op1 = TREE_OPERAND (expr, 1);
3767 if (POINTER_TYPE_P (type)
3768 || POINTER_TYPE_P (TREE_TYPE (op0))
3769 || POINTER_TYPE_P (TREE_TYPE (op1)))
3771 error ("invalid (pointer) operands to plus/minus");
3774 /* Continue with generic binary expression handling. */
3778 case POINTER_PLUS_EXPR:
3780 tree op0 = TREE_OPERAND (expr, 0);
3781 tree op1 = TREE_OPERAND (expr, 1);
3782 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3784 error ("invalid operands in pointer plus expression");
3787 if (!POINTER_TYPE_P (TREE_TYPE (op0))
3788 || !useless_type_conversion_p (type, TREE_TYPE (op0))
3789 || !useless_type_conversion_p (sizetype, TREE_TYPE (op1)))
3791 error ("type mismatch in pointer plus expression");
3792 debug_generic_stmt (type);
3793 debug_generic_stmt (TREE_TYPE (op0));
3794 debug_generic_stmt (TREE_TYPE (op1));
3802 tree op0 = TREE_OPERAND (expr, 0);
3803 tree op1 = TREE_OPERAND (expr, 1);
3804 tree op2 = TREE_OPERAND (expr, 2);
3805 if ((!is_gimple_val (op1)
3806 && TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3807 || (!is_gimple_val (op2)
3808 && TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE))
3810 error ("invalid operands in conditional expression");
3813 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3814 || (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE
3815 && !useless_type_conversion_p (type, TREE_TYPE (op1)))
3816 || (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE
3817 && !useless_type_conversion_p (type, TREE_TYPE (op2))))
3819 error ("type mismatch in conditional expression");
3820 debug_generic_stmt (type);
3821 debug_generic_stmt (TREE_TYPE (op0));
3822 debug_generic_stmt (TREE_TYPE (op1));
3823 debug_generic_stmt (TREE_TYPE (op2));
3826 return verify_gimple_expr (op0);
3831 tree op = TREE_OPERAND (expr, 0);
3832 if (!is_gimple_addressable (op))
3834 error ("invalid operand in unary expression");
3837 if (!one_pointer_to_useless_type_conversion_p (type, TREE_TYPE (op))
3838 /* FIXME: a longstanding wart, &a == &a[0]. */
3839 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3840 || !one_pointer_to_useless_type_conversion_p (type,
3841 TREE_TYPE (TREE_TYPE (op)))))
3843 error ("type mismatch in address expression");
3844 debug_generic_stmt (TREE_TYPE (expr));
3845 debug_generic_stmt (TYPE_POINTER_TO (TREE_TYPE (op)));
3849 return verify_gimple_reference (op);
3852 case TRUTH_ANDIF_EXPR:
3853 case TRUTH_ORIF_EXPR:
3856 case TRUTH_AND_EXPR:
3858 case TRUTH_XOR_EXPR:
3860 tree op0 = TREE_OPERAND (expr, 0);
3861 tree op1 = TREE_OPERAND (expr, 1);
3863 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3865 error ("invalid operands in truth expression");
3869 /* We allow any kind of integral typed argument and result. */
3870 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3871 || !INTEGRAL_TYPE_P (TREE_TYPE (op1))
3872 || !INTEGRAL_TYPE_P (type))
3874 error ("type mismatch in binary truth expression");
3875 debug_generic_stmt (type);
3876 debug_generic_stmt (TREE_TYPE (op0));
3877 debug_generic_stmt (TREE_TYPE (op1));
3884 case TRUTH_NOT_EXPR:
3886 tree op = TREE_OPERAND (expr, 0);
3888 if (!is_gimple_val (op))
3890 error ("invalid operand in unary not");
3894 /* For TRUTH_NOT_EXPR we can have any kind of integral
3895 typed arguments and results. */
3896 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3897 || !INTEGRAL_TYPE_P (type))
3899 error ("type mismatch in not expression");
3900 debug_generic_expr (TREE_TYPE (expr));
3901 debug_generic_expr (TREE_TYPE (op));
3909 /* FIXME. The C frontend passes unpromoted arguments in case it
3910 didn't see a function declaration before the call. */
3912 tree decl = CALL_EXPR_FN (expr);
3914 if (TREE_CODE (decl) == FUNCTION_DECL
3915 && DECL_LOOPING_CONST_OR_PURE_P (decl)
3916 && (!DECL_PURE_P (decl))
3917 && (!TREE_READONLY (decl)))
3919 error ("invalid pure const state for function");
3932 /* Generic handling via classes. */
3933 switch (TREE_CODE_CLASS (TREE_CODE (expr)))
3936 return verify_gimple_unary_expr (expr);
3939 return verify_gimple_binary_expr (expr);
3942 return verify_gimple_reference (expr);
3944 case tcc_comparison:
3946 tree op0 = TREE_OPERAND (expr, 0);
3947 tree op1 = TREE_OPERAND (expr, 1);
3948 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3950 error ("invalid operands in comparison expression");
3953 /* For comparisons we do not have the operations type as the
3954 effective type the comparison is carried out in. Instead
3955 we require that either the first operand is trivially
3956 convertible into the second, or the other way around.
3957 The resulting type of a comparison may be any integral type.
3958 Because we special-case pointers to void we allow
3959 comparisons of pointers with the same mode as well. */
3960 if ((!useless_type_conversion_p (TREE_TYPE (op0), TREE_TYPE (op1))
3961 && !useless_type_conversion_p (TREE_TYPE (op1), TREE_TYPE (op0))
3962 && (!POINTER_TYPE_P (TREE_TYPE (op0))
3963 || !POINTER_TYPE_P (TREE_TYPE (op1))
3964 || TYPE_MODE (TREE_TYPE (op0)) != TYPE_MODE (TREE_TYPE (op1))))
3965 || !INTEGRAL_TYPE_P (type))
3967 error ("type mismatch in comparison expression");
3968 debug_generic_stmt (TREE_TYPE (expr));
3969 debug_generic_stmt (TREE_TYPE (op0));
3970 debug_generic_stmt (TREE_TYPE (op1));
3983 /* Verify the GIMPLE assignment statement STMT. Returns true if there
3984 is an error, otherwise false. */
3987 verify_gimple_modify_stmt (const_tree stmt)
3989 tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
3990 tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
3992 gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
3994 if (!useless_type_conversion_p (TREE_TYPE (lhs),
3997 error ("non-trivial conversion at assignment");
3998 debug_generic_expr (TREE_TYPE (lhs));
3999 debug_generic_expr (TREE_TYPE (rhs));
4003 /* Loads/stores from/to a variable are ok. */
4004 if ((is_gimple_val (lhs)
4005 && is_gimple_variable (rhs))
4006 || (is_gimple_val (rhs)
4007 && is_gimple_variable (lhs)))
4010 /* Aggregate copies are ok. */
4011 if (!is_gimple_reg_type (TREE_TYPE (lhs))
4012 && !is_gimple_reg_type (TREE_TYPE (rhs)))
4015 /* We might get 'loads' from a parameter which is not a gimple value. */
4016 if (TREE_CODE (rhs) == PARM_DECL)
4017 return verify_gimple_expr (lhs);
4019 if (!is_gimple_variable (lhs)
4020 && verify_gimple_expr (lhs))
4023 if (!is_gimple_variable (rhs)
4024 && verify_gimple_expr (rhs))
4030 /* Verify the GIMPLE statement STMT. Returns true if there is an
4031 error, otherwise false. */
4034 verify_gimple_stmt (tree stmt)
4036 if (!is_gimple_stmt (stmt))
4038 error ("is not a valid GIMPLE statement");
4042 if (OMP_DIRECTIVE_P (stmt))
4044 /* OpenMP directives are validated by the FE and never operated
4045 on by the optimizers. Furthermore, OMP_FOR may contain
4046 non-gimple expressions when the main index variable has had
4047 its address taken. This does not affect the loop itself
4048 because the header of an OMP_FOR is merely used to determine
4049 how to setup the parallel iteration. */
4053 switch (TREE_CODE (stmt))
4055 case GIMPLE_MODIFY_STMT:
4056 return verify_gimple_modify_stmt (stmt);
4063 if (!is_gimple_val (TREE_OPERAND (stmt, 0)))
4065 error ("invalid operand to switch statement");
4066 debug_generic_expr (TREE_OPERAND (stmt, 0));
4072 tree op = TREE_OPERAND (stmt, 0);
4074 if (TREE_CODE (TREE_TYPE (stmt)) != VOID_TYPE)
4076 error ("type error in return expression");
4081 || TREE_CODE (op) == RESULT_DECL)
4084 return verify_gimple_modify_stmt (op);
4089 return verify_gimple_expr (stmt);
4092 case CHANGE_DYNAMIC_TYPE_EXPR:
4102 /* Verify the GIMPLE statements inside the statement list STMTS.
4103 Returns true if there were any errors. */
4106 verify_gimple_2 (tree stmts)
4108 tree_stmt_iterator tsi;
4111 for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi))
4113 tree stmt = tsi_stmt (tsi);
4115 switch (TREE_CODE (stmt))
4118 err |= verify_gimple_2 (BIND_EXPR_BODY (stmt));
4121 case TRY_CATCH_EXPR:
4122 case TRY_FINALLY_EXPR:
4123 err |= verify_gimple_2 (TREE_OPERAND (stmt, 0));
4124 err |= verify_gimple_2 (TREE_OPERAND (stmt, 1));
4128 err |= verify_gimple_2 (CATCH_BODY (stmt));
4131 case EH_FILTER_EXPR:
4132 err |= verify_gimple_2 (EH_FILTER_FAILURE (stmt));
4137 bool err2 = verify_gimple_stmt (stmt);
4139 debug_generic_expr (stmt);
4149 /* Verify the GIMPLE statements inside the statement list STMTS. */
4152 verify_gimple_1 (tree stmts)
4154 if (verify_gimple_2 (stmts))
4155 internal_error ("verify_gimple failed");
4158 /* Verify the GIMPLE statements inside the current function. */
4161 verify_gimple (void)
4163 verify_gimple_1 (BIND_EXPR_BODY (DECL_SAVED_TREE (cfun->decl)));
4166 /* Verify STMT, return true if STMT is not in GIMPLE form.
4167 TODO: Implement type checking. */
4170 verify_stmt (tree stmt, bool last_in_block)
4174 if (OMP_DIRECTIVE_P (stmt))
4176 /* OpenMP directives are validated by the FE and never operated
4177 on by the optimizers. Furthermore, OMP_FOR may contain
4178 non-gimple expressions when the main index variable has had
4179 its address taken. This does not affect the loop itself
4180 because the header of an OMP_FOR is merely used to determine
4181 how to setup the parallel iteration. */
4185 if (!is_gimple_stmt (stmt))
4187 error ("is not a valid GIMPLE statement");
4191 addr = walk_tree (&stmt, verify_expr, NULL, NULL);
4194 debug_generic_stmt (addr);
4197 inform ("in statement");
4198 debug_generic_stmt (stmt);
4203 /* If the statement is marked as part of an EH region, then it is
4204 expected that the statement could throw. Verify that when we
4205 have optimizations that simplify statements such that we prove
4206 that they cannot throw, that we update other data structures
4208 if (lookup_stmt_eh_region (stmt) >= 0)
4210 if (!tree_could_throw_p (stmt))
4212 error ("statement marked for throw, but doesn%'t");
4215 if (!last_in_block && tree_can_throw_internal (stmt))
4217 error ("statement marked for throw in middle of block");
4225 debug_generic_stmt (stmt);
4230 /* Return true when the T can be shared. */
4233 tree_node_can_be_shared (tree t)
4235 if (IS_TYPE_OR_DECL_P (t)
4236 || is_gimple_min_invariant (t)
4237 || TREE_CODE (t) == SSA_NAME
4238 || t == error_mark_node
4239 || TREE_CODE (t) == IDENTIFIER_NODE)
4242 if (TREE_CODE (t) == CASE_LABEL_EXPR)
4245 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4246 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4247 || TREE_CODE (t) == COMPONENT_REF
4248 || TREE_CODE (t) == REALPART_EXPR
4249 || TREE_CODE (t) == IMAGPART_EXPR)
4250 t = TREE_OPERAND (t, 0);
4259 /* Called via walk_trees. Verify tree sharing. */
4262 verify_node_sharing (tree * tp, int *walk_subtrees, void *data)
4264 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4266 if (tree_node_can_be_shared (*tp))
4268 *walk_subtrees = false;
4272 if (pointer_set_insert (visited, *tp))
4279 /* Helper function for verify_gimple_tuples. */
4282 verify_gimple_tuples_1 (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4283 void *data ATTRIBUTE_UNUSED)
4285 switch (TREE_CODE (*tp))
4288 error ("unexpected non-tuple");
4298 /* Verify that there are no trees that should have been converted to
4299 gimple tuples. Return true if T contains a node that should have
4300 been converted to a gimple tuple, but hasn't. */
4303 verify_gimple_tuples (tree t)
4305 return walk_tree (&t, verify_gimple_tuples_1, NULL, NULL) != NULL;
4308 static bool eh_error_found;
4310 verify_eh_throw_stmt_node (void **slot, void *data)
4312 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4313 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4315 if (!pointer_set_contains (visited, node->stmt))
4317 error ("Dead STMT in EH table");
4318 debug_generic_stmt (node->stmt);
4319 eh_error_found = true;
4324 /* Verify the GIMPLE statement chain. */
4330 block_stmt_iterator bsi;
4332 struct pointer_set_t *visited, *visited_stmts;
4335 timevar_push (TV_TREE_STMT_VERIFY);
4336 visited = pointer_set_create ();
4337 visited_stmts = pointer_set_create ();
4344 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4346 int phi_num_args = PHI_NUM_ARGS (phi);
4348 pointer_set_insert (visited_stmts, phi);
4349 if (bb_for_stmt (phi) != bb)
4351 error ("bb_for_stmt (phi) is set to a wrong basic block");
4355 for (i = 0; i < phi_num_args; i++)
4357 tree t = PHI_ARG_DEF (phi, i);
4362 error ("missing PHI def");
4363 debug_generic_stmt (phi);
4367 /* Addressable variables do have SSA_NAMEs but they
4368 are not considered gimple values. */
4369 else if (TREE_CODE (t) != SSA_NAME
4370 && TREE_CODE (t) != FUNCTION_DECL
4371 && !is_gimple_min_invariant (t))
4373 error ("PHI def is not a GIMPLE value");
4374 debug_generic_stmt (phi);
4375 debug_generic_stmt (t);
4379 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4382 error ("incorrect sharing of tree nodes");
4383 debug_generic_stmt (phi);
4384 debug_generic_stmt (addr);
4390 for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
4392 tree stmt = bsi_stmt (bsi);
4394 pointer_set_insert (visited_stmts, stmt);
4395 err |= verify_gimple_tuples (stmt);
4397 if (bb_for_stmt (stmt) != bb)
4399 error ("bb_for_stmt (stmt) is set to a wrong basic block");
4404 err |= verify_stmt (stmt, bsi_end_p (bsi));
4405 addr = walk_tree (&stmt, verify_node_sharing, visited, NULL);
4408 error ("incorrect sharing of tree nodes");
4409 debug_generic_stmt (stmt);
4410 debug_generic_stmt (addr);
4415 eh_error_found = false;
4416 if (get_eh_throw_stmt_table (cfun))
4417 htab_traverse (get_eh_throw_stmt_table (cfun),
4418 verify_eh_throw_stmt_node,
4421 if (err | eh_error_found)
4422 internal_error ("verify_stmts failed");
4424 pointer_set_destroy (visited);
4425 pointer_set_destroy (visited_stmts);
4426 verify_histograms ();
4427 timevar_pop (TV_TREE_STMT_VERIFY);
4431 /* Verifies that the flow information is OK. */
4434 tree_verify_flow_info (void)
4438 block_stmt_iterator bsi;
4443 if (ENTRY_BLOCK_PTR->il.tree)
4445 error ("ENTRY_BLOCK has IL associated with it");
4449 if (EXIT_BLOCK_PTR->il.tree)
4451 error ("EXIT_BLOCK has IL associated with it");
4455 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4456 if (e->flags & EDGE_FALLTHRU)
4458 error ("fallthru to exit from bb %d", e->src->index);
4464 bool found_ctrl_stmt = false;
4468 /* Skip labels on the start of basic block. */
4469 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4471 tree prev_stmt = stmt;
4473 stmt = bsi_stmt (bsi);
4475 if (TREE_CODE (stmt) != LABEL_EXPR)
4478 if (prev_stmt && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
4480 error ("nonlocal label ");
4481 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4482 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4487 if (label_to_block (LABEL_EXPR_LABEL (stmt)) != bb)
4490 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4491 fprintf (stderr, " to block does not match in bb %d",
4496 if (decl_function_context (LABEL_EXPR_LABEL (stmt))
4497 != current_function_decl)
4500 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4501 fprintf (stderr, " has incorrect context in bb %d",
4507 /* Verify that body of basic block BB is free of control flow. */
4508 for (; !bsi_end_p (bsi); bsi_next (&bsi))
4510 tree stmt = bsi_stmt (bsi);
4512 if (found_ctrl_stmt)
4514 error ("control flow in the middle of basic block %d",
4519 if (stmt_ends_bb_p (stmt))
4520 found_ctrl_stmt = true;
4522 if (TREE_CODE (stmt) == LABEL_EXPR)
4525 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4526 fprintf (stderr, " in the middle of basic block %d", bb->index);
4531 bsi = bsi_last (bb);
4532 if (bsi_end_p (bsi))
4535 stmt = bsi_stmt (bsi);
4537 err |= verify_eh_edges (stmt);
4539 if (is_ctrl_stmt (stmt))
4541 FOR_EACH_EDGE (e, ei, bb->succs)
4542 if (e->flags & EDGE_FALLTHRU)
4544 error ("fallthru edge after a control statement in bb %d",
4550 if (TREE_CODE (stmt) != COND_EXPR)
4552 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4553 after anything else but if statement. */
4554 FOR_EACH_EDGE (e, ei, bb->succs)
4555 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4557 error ("true/false edge after a non-COND_EXPR in bb %d",
4563 switch (TREE_CODE (stmt))
4570 if (COND_EXPR_THEN (stmt) != NULL_TREE
4571 || COND_EXPR_ELSE (stmt) != NULL_TREE)
4573 error ("COND_EXPR with code in branches at the end of bb %d",
4578 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4580 if (!true_edge || !false_edge
4581 || !(true_edge->flags & EDGE_TRUE_VALUE)
4582 || !(false_edge->flags & EDGE_FALSE_VALUE)
4583 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4584 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4585 || EDGE_COUNT (bb->succs) >= 3)
4587 error ("wrong outgoing edge flags at end of bb %d",
4595 if (simple_goto_p (stmt))
4597 error ("explicit goto at end of bb %d", bb->index);
4602 /* FIXME. We should double check that the labels in the
4603 destination blocks have their address taken. */
4604 FOR_EACH_EDGE (e, ei, bb->succs)
4605 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4606 | EDGE_FALSE_VALUE))
4607 || !(e->flags & EDGE_ABNORMAL))
4609 error ("wrong outgoing edge flags at end of bb %d",
4617 if (!single_succ_p (bb)
4618 || (single_succ_edge (bb)->flags
4619 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4620 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4622 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4625 if (single_succ (bb) != EXIT_BLOCK_PTR)
4627 error ("return edge does not point to exit in bb %d",
4640 vec = SWITCH_LABELS (stmt);
4641 n = TREE_VEC_LENGTH (vec);
4643 /* Mark all the destination basic blocks. */
4644 for (i = 0; i < n; ++i)
4646 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4647 basic_block label_bb = label_to_block (lab);
4649 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4650 label_bb->aux = (void *)1;
4653 /* Verify that the case labels are sorted. */
4654 prev = TREE_VEC_ELT (vec, 0);
4655 for (i = 1; i < n; ++i)
4657 tree c = TREE_VEC_ELT (vec, i);
4662 error ("found default case not at end of case vector");
4667 if (! tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4669 error ("case labels not sorted: ");
4670 print_generic_expr (stderr, prev, 0);
4671 fprintf (stderr," is greater than ");
4672 print_generic_expr (stderr, c, 0);
4673 fprintf (stderr," but comes before it.\n");
4678 /* VRP will remove the default case if it can prove it will
4679 never be executed. So do not verify there always exists
4680 a default case here. */
4682 FOR_EACH_EDGE (e, ei, bb->succs)
4686 error ("extra outgoing edge %d->%d",
4687 bb->index, e->dest->index);
4690 e->dest->aux = (void *)2;
4691 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4692 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4694 error ("wrong outgoing edge flags at end of bb %d",
4700 /* Check that we have all of them. */
4701 for (i = 0; i < n; ++i)
4703 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4704 basic_block label_bb = label_to_block (lab);
4706 if (label_bb->aux != (void *)2)
4708 error ("missing edge %i->%i",
4709 bb->index, label_bb->index);
4714 FOR_EACH_EDGE (e, ei, bb->succs)
4715 e->dest->aux = (void *)0;
4722 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4723 verify_dominators (CDI_DOMINATORS);
4729 /* Updates phi nodes after creating a forwarder block joined
4730 by edge FALLTHRU. */
4733 tree_make_forwarder_block (edge fallthru)
4737 basic_block dummy, bb;
4738 tree phi, new_phi, var;
4740 dummy = fallthru->src;
4741 bb = fallthru->dest;
4743 if (single_pred_p (bb))
4746 /* If we redirected a branch we must create new PHI nodes at the
4748 for (phi = phi_nodes (dummy); phi; phi = PHI_CHAIN (phi))
4750 var = PHI_RESULT (phi);
4751 new_phi = create_phi_node (var, bb);
4752 SSA_NAME_DEF_STMT (var) = new_phi;
4753 SET_PHI_RESULT (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4754 add_phi_arg (new_phi, PHI_RESULT (phi), fallthru);
4757 /* Ensure that the PHI node chain is in the same order. */
4758 set_phi_nodes (bb, phi_reverse (phi_nodes (bb)));
4760 /* Add the arguments we have stored on edges. */
4761 FOR_EACH_EDGE (e, ei, bb->preds)
4766 flush_pending_stmts (e);
4771 /* Return a non-special label in the head of basic block BLOCK.
4772 Create one if it doesn't exist. */
4775 tree_block_label (basic_block bb)
4777 block_stmt_iterator i, s = bsi_start (bb);
4781 for (i = s; !bsi_end_p (i); first = false, bsi_next (&i))
4783 stmt = bsi_stmt (i);
4784 if (TREE_CODE (stmt) != LABEL_EXPR)
4786 label = LABEL_EXPR_LABEL (stmt);
4787 if (!DECL_NONLOCAL (label))
4790 bsi_move_before (&i, &s);
4795 label = create_artificial_label ();
4796 stmt = build1 (LABEL_EXPR, void_type_node, label);
4797 bsi_insert_before (&s, stmt, BSI_NEW_STMT);
4802 /* Attempt to perform edge redirection by replacing a possibly complex
4803 jump instruction by a goto or by removing the jump completely.
4804 This can apply only if all edges now point to the same block. The
4805 parameters and return values are equivalent to
4806 redirect_edge_and_branch. */
4809 tree_try_redirect_by_replacing_jump (edge e, basic_block target)
4811 basic_block src = e->src;
4812 block_stmt_iterator b;
4815 /* We can replace or remove a complex jump only when we have exactly
4817 if (EDGE_COUNT (src->succs) != 2
4818 /* Verify that all targets will be TARGET. Specifically, the
4819 edge that is not E must also go to TARGET. */
4820 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4826 stmt = bsi_stmt (b);
4828 if (TREE_CODE (stmt) == COND_EXPR
4829 || TREE_CODE (stmt) == SWITCH_EXPR)
4831 bsi_remove (&b, true);
4832 e = ssa_redirect_edge (e, target);
4833 e->flags = EDGE_FALLTHRU;
4841 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4842 edge representing the redirected branch. */
4845 tree_redirect_edge_and_branch (edge e, basic_block dest)
4847 basic_block bb = e->src;
4848 block_stmt_iterator bsi;
4852 if (e->flags & EDGE_ABNORMAL)
4855 if (e->src != ENTRY_BLOCK_PTR
4856 && (ret = tree_try_redirect_by_replacing_jump (e, dest)))
4859 if (e->dest == dest)
4862 bsi = bsi_last (bb);
4863 stmt = bsi_end_p (bsi) ? NULL : bsi_stmt (bsi);
4865 switch (stmt ? TREE_CODE (stmt) : ERROR_MARK)
4868 /* For COND_EXPR, we only need to redirect the edge. */
4872 /* No non-abnormal edges should lead from a non-simple goto, and
4873 simple ones should be represented implicitly. */
4878 tree cases = get_cases_for_edge (e, stmt);
4879 tree label = tree_block_label (dest);
4881 /* If we have a list of cases associated with E, then use it
4882 as it's a lot faster than walking the entire case vector. */
4885 edge e2 = find_edge (e->src, dest);
4892 CASE_LABEL (cases) = label;
4893 cases = TREE_CHAIN (cases);
4896 /* If there was already an edge in the CFG, then we need
4897 to move all the cases associated with E to E2. */
4900 tree cases2 = get_cases_for_edge (e2, stmt);
4902 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4903 TREE_CHAIN (cases2) = first;
4908 tree vec = SWITCH_LABELS (stmt);
4909 size_t i, n = TREE_VEC_LENGTH (vec);
4911 for (i = 0; i < n; i++)
4913 tree elt = TREE_VEC_ELT (vec, i);
4915 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4916 CASE_LABEL (elt) = label;
4924 bsi_remove (&bsi, true);
4925 e->flags |= EDGE_FALLTHRU;
4930 case OMP_SECTIONS_SWITCH:
4932 /* The edges from OMP constructs can be simply redirected. */
4936 /* Otherwise it must be a fallthru edge, and we don't need to
4937 do anything besides redirecting it. */
4938 gcc_assert (e->flags & EDGE_FALLTHRU);
4942 /* Update/insert PHI nodes as necessary. */
4944 /* Now update the edges in the CFG. */
4945 e = ssa_redirect_edge (e, dest);
4950 /* Returns true if it is possible to remove edge E by redirecting
4951 it to the destination of the other edge from E->src. */
4954 tree_can_remove_branch_p (const_edge e)
4956 if (e->flags & EDGE_ABNORMAL)
4962 /* Simple wrapper, as we can always redirect fallthru edges. */
4965 tree_redirect_edge_and_branch_force (edge e, basic_block dest)
4967 e = tree_redirect_edge_and_branch (e, dest);
4974 /* Splits basic block BB after statement STMT (but at least after the
4975 labels). If STMT is NULL, BB is split just after the labels. */
4978 tree_split_block (basic_block bb, void *stmt)
4980 block_stmt_iterator bsi;
4981 tree_stmt_iterator tsi_tgt;
4987 new_bb = create_empty_bb (bb);
4989 /* Redirect the outgoing edges. */
4990 new_bb->succs = bb->succs;
4992 FOR_EACH_EDGE (e, ei, new_bb->succs)
4995 if (stmt && TREE_CODE ((tree) stmt) == LABEL_EXPR)
4998 /* Move everything from BSI to the new basic block. */
4999 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5001 act = bsi_stmt (bsi);
5002 if (TREE_CODE (act) == LABEL_EXPR)
5015 if (bsi_end_p (bsi))
5018 /* Split the statement list - avoid re-creating new containers as this
5019 brings ugly quadratic memory consumption in the inliner.
5020 (We are still quadratic since we need to update stmt BB pointers,
5022 list = tsi_split_statement_list_before (&bsi.tsi);
5023 set_bb_stmt_list (new_bb, list);
5024 for (tsi_tgt = tsi_start (list);
5025 !tsi_end_p (tsi_tgt); tsi_next (&tsi_tgt))
5026 change_bb_for_stmt (tsi_stmt (tsi_tgt), new_bb);
5032 /* Moves basic block BB after block AFTER. */
5035 tree_move_block_after (basic_block bb, basic_block after)
5037 if (bb->prev_bb == after)
5041 link_block (bb, after);
5047 /* Return true if basic_block can be duplicated. */
5050 tree_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
5056 /* Create a duplicate of the basic block BB. NOTE: This does not
5057 preserve SSA form. */
5060 tree_duplicate_bb (basic_block bb)
5063 block_stmt_iterator bsi, bsi_tgt;
5066 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
5068 /* Copy the PHI nodes. We ignore PHI node arguments here because
5069 the incoming edges have not been setup yet. */
5070 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5072 tree copy = create_phi_node (PHI_RESULT (phi), new_bb);
5073 create_new_def_for (PHI_RESULT (copy), copy, PHI_RESULT_PTR (copy));
5076 /* Keep the chain of PHI nodes in the same order so that they can be
5077 updated by ssa_redirect_edge. */
5078 set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb)));
5080 bsi_tgt = bsi_start (new_bb);
5081 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5083 def_operand_p def_p;
5084 ssa_op_iter op_iter;
5088 stmt = bsi_stmt (bsi);
5089 if (TREE_CODE (stmt) == LABEL_EXPR)
5092 /* Create a new copy of STMT and duplicate STMT's virtual
5094 copy = unshare_expr (stmt);
5095 bsi_insert_after (&bsi_tgt, copy, BSI_NEW_STMT);
5096 copy_virtual_operands (copy, stmt);
5097 region = lookup_stmt_eh_region (stmt);
5099 add_stmt_to_eh_region (copy, region);
5100 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
5102 /* Create new names for all the definitions created by COPY and
5103 add replacement mappings for each new name. */
5104 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
5105 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
5111 /* Adds phi node arguments for edge E_COPY after basic block duplication. */
5114 add_phi_args_after_copy_edge (edge e_copy)
5116 basic_block bb, bb_copy = e_copy->src, dest;
5119 tree phi, phi_copy, phi_next, def;
5121 if (!phi_nodes (e_copy->dest))
5124 bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
5126 if (e_copy->dest->flags & BB_DUPLICATED)
5127 dest = get_bb_original (e_copy->dest);
5129 dest = e_copy->dest;
5131 e = find_edge (bb, dest);
5134 /* During loop unrolling the target of the latch edge is copied.
5135 In this case we are not looking for edge to dest, but to
5136 duplicated block whose original was dest. */
5137 FOR_EACH_EDGE (e, ei, bb->succs)
5139 if ((e->dest->flags & BB_DUPLICATED)
5140 && get_bb_original (e->dest) == dest)
5144 gcc_assert (e != NULL);
5147 for (phi = phi_nodes (e->dest), phi_copy = phi_nodes (e_copy->dest);
5149 phi = phi_next, phi_copy = PHI_CHAIN (phi_copy))
5151 phi_next = PHI_CHAIN (phi);
5152 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5153 add_phi_arg (phi_copy, def, e_copy);
5158 /* Basic block BB_COPY was created by code duplication. Add phi node
5159 arguments for edges going out of BB_COPY. The blocks that were
5160 duplicated have BB_DUPLICATED set. */
5163 add_phi_args_after_copy_bb (basic_block bb_copy)
5168 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5170 add_phi_args_after_copy_edge (e_copy);
5174 /* Blocks in REGION_COPY array of length N_REGION were created by
5175 duplication of basic blocks. Add phi node arguments for edges
5176 going from these blocks. If E_COPY is not NULL, also add
5177 phi node arguments for its destination.*/
5180 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
5185 for (i = 0; i < n_region; i++)
5186 region_copy[i]->flags |= BB_DUPLICATED;
5188 for (i = 0; i < n_region; i++)
5189 add_phi_args_after_copy_bb (region_copy[i]);
5191 add_phi_args_after_copy_edge (e_copy);
5193 for (i = 0; i < n_region; i++)
5194 region_copy[i]->flags &= ~BB_DUPLICATED;
5197 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5198 important exit edge EXIT. By important we mean that no SSA name defined
5199 inside region is live over the other exit edges of the region. All entry
5200 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5201 to the duplicate of the region. SSA form, dominance and loop information
5202 is updated. The new basic blocks are stored to REGION_COPY in the same
5203 order as they had in REGION, provided that REGION_COPY is not NULL.
5204 The function returns false if it is unable to copy the region,
5208 tree_duplicate_sese_region (edge entry, edge exit,
5209 basic_block *region, unsigned n_region,
5210 basic_block *region_copy)
5213 bool free_region_copy = false, copying_header = false;
5214 struct loop *loop = entry->dest->loop_father;
5216 VEC (basic_block, heap) *doms;
5218 int total_freq = 0, entry_freq = 0;
5219 gcov_type total_count = 0, entry_count = 0;
5221 if (!can_copy_bbs_p (region, n_region))
5224 /* Some sanity checking. Note that we do not check for all possible
5225 missuses of the functions. I.e. if you ask to copy something weird,
5226 it will work, but the state of structures probably will not be
5228 for (i = 0; i < n_region; i++)
5230 /* We do not handle subloops, i.e. all the blocks must belong to the
5232 if (region[i]->loop_father != loop)
5235 if (region[i] != entry->dest
5236 && region[i] == loop->header)
5240 set_loop_copy (loop, loop);
5242 /* In case the function is used for loop header copying (which is the primary
5243 use), ensure that EXIT and its copy will be new latch and entry edges. */
5244 if (loop->header == entry->dest)
5246 copying_header = true;
5247 set_loop_copy (loop, loop_outer (loop));
5249 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5252 for (i = 0; i < n_region; i++)
5253 if (region[i] != exit->src
5254 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5260 region_copy = XNEWVEC (basic_block, n_region);
5261 free_region_copy = true;
5264 gcc_assert (!need_ssa_update_p ());
5266 /* Record blocks outside the region that are dominated by something
5269 initialize_original_copy_tables ();
5271 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5273 if (entry->dest->count)
5275 total_count = entry->dest->count;
5276 entry_count = entry->count;
5277 /* Fix up corner cases, to avoid division by zero or creation of negative
5279 if (entry_count > total_count)
5280 entry_count = total_count;
5284 total_freq = entry->dest->frequency;
5285 entry_freq = EDGE_FREQUENCY (entry);
5286 /* Fix up corner cases, to avoid division by zero or creation of negative
5288 if (total_freq == 0)
5290 else if (entry_freq > total_freq)
5291 entry_freq = total_freq;
5294 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5295 split_edge_bb_loc (entry));
5298 scale_bbs_frequencies_gcov_type (region, n_region,
5299 total_count - entry_count,
5301 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5306 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5308 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5313 loop->header = exit->dest;
5314 loop->latch = exit->src;
5317 /* Redirect the entry and add the phi node arguments. */
5318 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5319 gcc_assert (redirected != NULL);
5320 flush_pending_stmts (entry);
5322 /* Concerning updating of dominators: We must recount dominators
5323 for entry block and its copy. Anything that is outside of the
5324 region, but was dominated by something inside needs recounting as
5326 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5327 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5328 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5329 VEC_free (basic_block, heap, doms);
5331 /* Add the other PHI node arguments. */
5332 add_phi_args_after_copy (region_copy, n_region, NULL);
5334 /* Update the SSA web. */
5335 update_ssa (TODO_update_ssa);
5337 if (free_region_copy)
5340 free_original_copy_tables ();
5344 /* Duplicates REGION consisting of N_REGION blocks. The new blocks
5345 are stored to REGION_COPY in the same order in that they appear
5346 in REGION, if REGION_COPY is not NULL. ENTRY is the entry to
5347 the region, EXIT an exit from it. The condition guarding EXIT
5348 is moved to ENTRY. Returns true if duplication succeeds, false
5374 tree_duplicate_sese_tail (edge entry, edge exit,
5375 basic_block *region, unsigned n_region,
5376 basic_block *region_copy)
5379 bool free_region_copy = false;
5380 struct loop *loop = exit->dest->loop_father;
5381 struct loop *orig_loop = entry->dest->loop_father;
5382 basic_block switch_bb, entry_bb, nentry_bb;
5383 VEC (basic_block, heap) *doms;
5384 int total_freq = 0, exit_freq = 0;
5385 gcov_type total_count = 0, exit_count = 0;
5386 edge exits[2], nexits[2], e;
5387 block_stmt_iterator bsi;
5391 gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5393 exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5395 if (!can_copy_bbs_p (region, n_region))
5398 /* Some sanity checking. Note that we do not check for all possible
5399 missuses of the functions. I.e. if you ask to copy something weird
5400 (e.g., in the example, if there is a jump from inside to the middle
5401 of some_code, or come_code defines some of the values used in cond)
5402 it will work, but the resulting code will not be correct. */
5403 for (i = 0; i < n_region; i++)
5405 /* We do not handle subloops, i.e. all the blocks must belong to the
5407 if (region[i]->loop_father != orig_loop)
5410 if (region[i] == orig_loop->latch)
5414 initialize_original_copy_tables ();
5415 set_loop_copy (orig_loop, loop);
5419 region_copy = XNEWVEC (basic_block, n_region);
5420 free_region_copy = true;
5423 gcc_assert (!need_ssa_update_p ());
5425 /* Record blocks outside the region that are dominated by something
5427 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5429 if (exit->src->count)
5431 total_count = exit->src->count;
5432 exit_count = exit->count;
5433 /* Fix up corner cases, to avoid division by zero or creation of negative
5435 if (exit_count > total_count)
5436 exit_count = total_count;
5440 total_freq = exit->src->frequency;
5441 exit_freq = EDGE_FREQUENCY (exit);
5442 /* Fix up corner cases, to avoid division by zero or creation of negative
5444 if (total_freq == 0)
5446 if (exit_freq > total_freq)
5447 exit_freq = total_freq;
5450 copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5451 split_edge_bb_loc (exit));
5454 scale_bbs_frequencies_gcov_type (region, n_region,
5455 total_count - exit_count,
5457 scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5462 scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5464 scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5467 /* Create the switch block, and put the exit condition to it. */
5468 entry_bb = entry->dest;
5469 nentry_bb = get_bb_copy (entry_bb);
5470 if (!last_stmt (entry->src)
5471 || !stmt_ends_bb_p (last_stmt (entry->src)))
5472 switch_bb = entry->src;
5474 switch_bb = split_edge (entry);
5475 set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5477 bsi = bsi_last (switch_bb);
5478 cond = last_stmt (exit->src);
5479 gcc_assert (TREE_CODE (cond) == COND_EXPR);
5480 bsi_insert_after (&bsi, unshare_expr (cond), BSI_NEW_STMT);
5482 sorig = single_succ_edge (switch_bb);
5483 sorig->flags = exits[1]->flags;
5484 snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5486 /* Register the new edge from SWITCH_BB in loop exit lists. */
5487 rescan_loop_exit (snew, true, false);
5489 /* Add the PHI node arguments. */
5490 add_phi_args_after_copy (region_copy, n_region, snew);
5492 /* Get rid of now superfluous conditions and associated edges (and phi node
5494 e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5495 PENDING_STMT (e) = NULL_TREE;
5496 e = redirect_edge_and_branch (nexits[1], nexits[0]->dest);
5497 PENDING_STMT (e) = NULL_TREE;
5499 /* Anything that is outside of the region, but was dominated by something
5500 inside needs to update dominance info. */
5501 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5502 VEC_free (basic_block, heap, doms);
5504 /* Update the SSA web. */
5505 update_ssa (TODO_update_ssa);
5507 if (free_region_copy)
5510 free_original_copy_tables ();
5515 DEF_VEC_P(basic_block);
5516 DEF_VEC_ALLOC_P(basic_block,heap);
5519 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5520 adding blocks when the dominator traversal reaches EXIT. This
5521 function silently assumes that ENTRY strictly dominates EXIT. */
5524 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5525 VEC(basic_block,heap) **bbs_p)
5529 for (son = first_dom_son (CDI_DOMINATORS, entry);
5531 son = next_dom_son (CDI_DOMINATORS, son))
5533 VEC_safe_push (basic_block, heap, *bbs_p, son);
5535 gather_blocks_in_sese_region (son, exit, bbs_p);
5539 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5540 The duplicates are recorded in VARS_MAP. */
5543 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5546 tree t = *tp, new_t;
5547 struct function *f = DECL_STRUCT_FUNCTION (to_context);
5550 if (DECL_CONTEXT (t) == to_context)
5553 loc = pointer_map_contains (vars_map, t);
5557 loc = pointer_map_insert (vars_map, t);
5561 new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5562 f->local_decls = tree_cons (NULL_TREE, new_t, f->local_decls);
5566 gcc_assert (TREE_CODE (t) == CONST_DECL);
5567 new_t = copy_node (t);
5569 DECL_CONTEXT (new_t) = to_context;
5579 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5580 VARS_MAP maps old ssa names and var_decls to the new ones. */
5583 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5587 tree new_name, decl = SSA_NAME_VAR (name);
5589 gcc_assert (is_gimple_reg (name));
5591 loc = pointer_map_contains (vars_map, name);
5595 replace_by_duplicate_decl (&decl, vars_map, to_context);
5597 push_cfun (DECL_STRUCT_FUNCTION (to_context));
5598 if (gimple_in_ssa_p (cfun))
5599 add_referenced_var (decl);
5601 new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5602 if (SSA_NAME_IS_DEFAULT_DEF (name))
5603 set_default_def (decl, new_name);
5606 loc = pointer_map_insert (vars_map, name);
5620 struct pointer_map_t *vars_map;
5621 htab_t new_label_map;
5625 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5626 contained in *TP and change the DECL_CONTEXT of every local
5627 variable referenced in *TP. */
5630 move_stmt_r (tree *tp, int *walk_subtrees, void *data)
5632 struct move_stmt_d *p = (struct move_stmt_d *) data;
5636 && (EXPR_P (t) || GIMPLE_STMT_P (t)))
5637 TREE_BLOCK (t) = p->block;
5639 if (OMP_DIRECTIVE_P (t)
5640 && TREE_CODE (t) != OMP_RETURN
5641 && TREE_CODE (t) != OMP_CONTINUE)
5643 /* Do not remap variables inside OMP directives. Variables
5644 referenced in clauses and directive header belong to the
5645 parent function and should not be moved into the child
5647 bool save_remap_decls_p = p->remap_decls_p;
5648 p->remap_decls_p = false;
5651 walk_tree (&OMP_BODY (t), move_stmt_r, p, NULL);
5653 p->remap_decls_p = save_remap_decls_p;
5655 else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5657 if (TREE_CODE (t) == SSA_NAME)
5658 *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5659 else if (TREE_CODE (t) == LABEL_DECL)
5661 if (p->new_label_map)
5663 struct tree_map in, *out;
5665 out = htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5670 DECL_CONTEXT (t) = p->to_context;
5672 else if (p->remap_decls_p)
5674 /* Replace T with its duplicate. T should no longer appear in the
5675 parent function, so this looks wasteful; however, it may appear
5676 in referenced_vars, and more importantly, as virtual operands of
5677 statements, and in alias lists of other variables. It would be
5678 quite difficult to expunge it from all those places. ??? It might
5679 suffice to do this for addressable variables. */
5680 if ((TREE_CODE (t) == VAR_DECL
5681 && !is_global_var (t))
5682 || TREE_CODE (t) == CONST_DECL)
5683 replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5686 && gimple_in_ssa_p (cfun))
5688 push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5689 add_referenced_var (*tp);
5695 else if (TYPE_P (t))
5701 /* Marks virtual operands of all statements in basic blocks BBS for
5705 mark_virtual_ops_in_bb (basic_block bb)
5708 block_stmt_iterator bsi;
5710 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5711 mark_virtual_ops_for_renaming (phi);
5713 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5714 mark_virtual_ops_for_renaming (bsi_stmt (bsi));
5717 /* Marks virtual operands of all statements in basic blocks BBS for
5721 mark_virtual_ops_in_region (VEC (basic_block,heap) *bbs)
5726 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5727 mark_virtual_ops_in_bb (bb);
5730 /* Move basic block BB from function CFUN to function DEST_FN. The
5731 block is moved out of the original linked list and placed after
5732 block AFTER in the new list. Also, the block is removed from the
5733 original array of blocks and placed in DEST_FN's array of blocks.
5734 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5735 updated to reflect the moved edges.
5737 The local variables are remapped to new instances, VARS_MAP is used
5738 to record the mapping. */
5741 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5742 basic_block after, bool update_edge_count_p,
5743 struct pointer_map_t *vars_map, htab_t new_label_map,
5746 struct control_flow_graph *cfg;
5749 block_stmt_iterator si;
5750 struct move_stmt_d d;
5751 unsigned old_len, new_len;
5754 /* Remove BB from dominance structures. */
5755 delete_from_dominance_info (CDI_DOMINATORS, bb);
5757 remove_bb_from_loops (bb);
5759 /* Link BB to the new linked list. */
5760 move_block_after (bb, after);
5762 /* Update the edge count in the corresponding flowgraphs. */
5763 if (update_edge_count_p)
5764 FOR_EACH_EDGE (e, ei, bb->succs)
5766 cfun->cfg->x_n_edges--;
5767 dest_cfun->cfg->x_n_edges++;
5770 /* Remove BB from the original basic block array. */
5771 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5772 cfun->cfg->x_n_basic_blocks--;
5774 /* Grow DEST_CFUN's basic block array if needed. */
5775 cfg = dest_cfun->cfg;
5776 cfg->x_n_basic_blocks++;
5777 if (bb->index >= cfg->x_last_basic_block)
5778 cfg->x_last_basic_block = bb->index + 1;
5780 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5781 if ((unsigned) cfg->x_last_basic_block >= old_len)
5783 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5784 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5788 VEC_replace (basic_block, cfg->x_basic_block_info,
5791 /* Remap the variables in phi nodes. */
5792 for (phi = phi_nodes (bb); phi; phi = next_phi)
5795 tree op = PHI_RESULT (phi);
5798 next_phi = PHI_CHAIN (phi);
5799 if (!is_gimple_reg (op))
5801 /* Remove the phi nodes for virtual operands (alias analysis will be
5802 run for the new function, anyway). */
5803 remove_phi_node (phi, NULL, true);
5807 SET_PHI_RESULT (phi, replace_ssa_name (op, vars_map, dest_cfun->decl));
5808 FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5810 op = USE_FROM_PTR (use);
5811 if (TREE_CODE (op) == SSA_NAME)
5812 SET_USE (use, replace_ssa_name (op, vars_map, dest_cfun->decl));
5816 /* The statements in BB need to be associated with a new TREE_BLOCK.
5817 Labels need to be associated with a new label-to-block map. */
5818 memset (&d, 0, sizeof (d));
5819 d.vars_map = vars_map;
5820 d.from_context = cfun->decl;
5821 d.to_context = dest_cfun->decl;
5822 d.new_label_map = new_label_map;
5824 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5826 tree stmt = bsi_stmt (si);
5829 d.remap_decls_p = true;
5830 if (TREE_BLOCK (stmt))
5831 d.block = DECL_INITIAL (dest_cfun->decl);
5833 walk_tree (&stmt, move_stmt_r, &d, NULL);
5835 if (TREE_CODE (stmt) == LABEL_EXPR)
5837 tree label = LABEL_EXPR_LABEL (stmt);
5838 int uid = LABEL_DECL_UID (label);
5840 gcc_assert (uid > -1);
5842 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5843 if (old_len <= (unsigned) uid)
5845 new_len = 3 * uid / 2;
5846 VEC_safe_grow_cleared (basic_block, gc,
5847 cfg->x_label_to_block_map, new_len);
5850 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5851 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5853 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5855 if (uid >= dest_cfun->cfg->last_label_uid)
5856 dest_cfun->cfg->last_label_uid = uid + 1;
5858 else if (TREE_CODE (stmt) == RESX_EXPR && eh_offset != 0)
5859 TREE_OPERAND (stmt, 0) =
5860 build_int_cst (NULL_TREE,
5861 TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0))
5864 region = lookup_stmt_eh_region (stmt);
5867 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5868 remove_stmt_from_eh_region (stmt);
5869 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5870 gimple_remove_stmt_histograms (cfun, stmt);
5873 /* We cannot leave any operands allocated from the operand caches of
5874 the current function. */
5875 free_stmt_operands (stmt);
5876 push_cfun (dest_cfun);
5882 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5883 the outermost EH region. Use REGION as the incoming base EH region. */
5886 find_outermost_region_in_block (struct function *src_cfun,
5887 basic_block bb, int region)
5889 block_stmt_iterator si;
5891 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5893 tree stmt = bsi_stmt (si);
5896 if (TREE_CODE (stmt) == RESX_EXPR)
5897 stmt_region = TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0));
5899 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5900 if (stmt_region > 0)
5903 region = stmt_region;
5904 else if (stmt_region != region)
5906 region = eh_region_outermost (src_cfun, stmt_region, region);
5907 gcc_assert (region != -1);
5916 new_label_mapper (tree decl, void *data)
5918 htab_t hash = (htab_t) data;
5922 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5924 m = xmalloc (sizeof (struct tree_map));
5925 m->hash = DECL_UID (decl);
5926 m->base.from = decl;
5927 m->to = create_artificial_label ();
5928 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5929 if (LABEL_DECL_UID (m->to) >= cfun->cfg->last_label_uid)
5930 cfun->cfg->last_label_uid = LABEL_DECL_UID (m->to) + 1;
5932 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5933 gcc_assert (*slot == NULL);
5940 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5941 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5942 single basic block in the original CFG and the new basic block is
5943 returned. DEST_CFUN must not have a CFG yet.
5945 Note that the region need not be a pure SESE region. Blocks inside
5946 the region may contain calls to abort/exit. The only restriction
5947 is that ENTRY_BB should be the only entry point and it must
5950 All local variables referenced in the region are assumed to be in
5951 the corresponding BLOCK_VARS and unexpanded variable lists
5952 associated with DEST_CFUN. */
5955 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5956 basic_block exit_bb)
5958 VEC(basic_block,heap) *bbs, *dom_bbs;
5959 basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
5960 basic_block after, bb, *entry_pred, *exit_succ, abb;
5961 struct function *saved_cfun = cfun;
5962 int *entry_flag, *exit_flag, eh_offset;
5963 unsigned *entry_prob, *exit_prob;
5964 unsigned i, num_entry_edges, num_exit_edges;
5967 htab_t new_label_map;
5968 struct pointer_map_t *vars_map;
5969 struct loop *loop = entry_bb->loop_father;
5971 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5973 gcc_assert (entry_bb != exit_bb
5975 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
5977 /* Collect all the blocks in the region. Manually add ENTRY_BB
5978 because it won't be added by dfs_enumerate_from. */
5980 VEC_safe_push (basic_block, heap, bbs, entry_bb);
5981 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
5983 /* The blocks that used to be dominated by something in BBS will now be
5984 dominated by the new block. */
5985 dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
5986 VEC_address (basic_block, bbs),
5987 VEC_length (basic_block, bbs));
5989 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5990 the predecessor edges to ENTRY_BB and the successor edges to
5991 EXIT_BB so that we can re-attach them to the new basic block that
5992 will replace the region. */
5993 num_entry_edges = EDGE_COUNT (entry_bb->preds);
5994 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
5995 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
5996 entry_prob = XNEWVEC (unsigned, num_entry_edges);
5998 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
6000 entry_prob[i] = e->probability;
6001 entry_flag[i] = e->flags;
6002 entry_pred[i++] = e->src;
6008 num_exit_edges = EDGE_COUNT (exit_bb->succs);
6009 exit_succ = (basic_block *) xcalloc (num_exit_edges,
6010 sizeof (basic_block));
6011 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
6012 exit_prob = XNEWVEC (unsigned, num_exit_edges);
6014 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
6016 exit_prob[i] = e->probability;
6017 exit_flag[i] = e->flags;
6018 exit_succ[i++] = e->dest;
6030 /* Switch context to the child function to initialize DEST_FN's CFG. */
6031 gcc_assert (dest_cfun->cfg == NULL);
6032 push_cfun (dest_cfun);
6034 init_empty_tree_cfg ();
6036 /* Initialize EH information for the new function. */
6038 new_label_map = NULL;
6043 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6044 region = find_outermost_region_in_block (saved_cfun, bb, region);
6046 init_eh_for_function ();
6049 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
6050 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
6051 new_label_map, region, 0);
6057 /* The ssa form for virtual operands in the source function will have to
6058 be repaired. We do not care for the real operands -- the sese region
6059 must be closed with respect to those. */
6060 mark_virtual_ops_in_region (bbs);
6062 /* Move blocks from BBS into DEST_CFUN. */
6063 gcc_assert (VEC_length (basic_block, bbs) >= 2);
6064 after = dest_cfun->cfg->x_entry_block_ptr;
6065 vars_map = pointer_map_create ();
6066 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6068 /* No need to update edge counts on the last block. It has
6069 already been updated earlier when we detached the region from
6070 the original CFG. */
6071 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, vars_map,
6072 new_label_map, eh_offset);
6077 htab_delete (new_label_map);
6078 pointer_map_destroy (vars_map);
6080 /* Rewire the entry and exit blocks. The successor to the entry
6081 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
6082 the child function. Similarly, the predecessor of DEST_FN's
6083 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
6084 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
6085 various CFG manipulation function get to the right CFG.
6087 FIXME, this is silly. The CFG ought to become a parameter to
6089 push_cfun (dest_cfun);
6090 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
6092 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
6095 /* Back in the original function, the SESE region has disappeared,
6096 create a new basic block in its place. */
6097 bb = create_empty_bb (entry_pred[0]);
6099 add_bb_to_loop (bb, loop);
6100 for (i = 0; i < num_entry_edges; i++)
6102 e = make_edge (entry_pred[i], bb, entry_flag[i]);
6103 e->probability = entry_prob[i];
6106 for (i = 0; i < num_exit_edges; i++)
6108 e = make_edge (bb, exit_succ[i], exit_flag[i]);
6109 e->probability = exit_prob[i];
6112 set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
6113 for (i = 0; VEC_iterate (basic_block, dom_bbs, i, abb); i++)
6114 set_immediate_dominator (CDI_DOMINATORS, abb, bb);
6115 VEC_free (basic_block, heap, dom_bbs);
6126 VEC_free (basic_block, heap, bbs);
6132 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */
6135 dump_function_to_file (tree fn, FILE *file, int flags)
6137 tree arg, vars, var;
6138 struct function *dsf;
6139 bool ignore_topmost_bind = false, any_var = false;
6143 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
6145 arg = DECL_ARGUMENTS (fn);
6148 print_generic_expr (file, TREE_TYPE (arg), dump_flags);
6149 fprintf (file, " ");
6150 print_generic_expr (file, arg, dump_flags);
6151 if (TREE_CHAIN (arg))
6152 fprintf (file, ", ");
6153 arg = TREE_CHAIN (arg);
6155 fprintf (file, ")\n");
6157 dsf = DECL_STRUCT_FUNCTION (fn);
6158 if (dsf && (flags & TDF_DETAILS))
6159 dump_eh_tree (file, dsf);
6161 if (flags & TDF_RAW)
6163 dump_node (fn, TDF_SLIM | flags, file);
6167 /* Switch CFUN to point to FN. */
6168 push_cfun (DECL_STRUCT_FUNCTION (fn));
6170 /* When GIMPLE is lowered, the variables are no longer available in
6171 BIND_EXPRs, so display them separately. */
6172 if (cfun && cfun->decl == fn && cfun->local_decls)
6174 ignore_topmost_bind = true;
6176 fprintf (file, "{\n");
6177 for (vars = cfun->local_decls; vars; vars = TREE_CHAIN (vars))
6179 var = TREE_VALUE (vars);
6181 print_generic_decl (file, var, flags);
6182 fprintf (file, "\n");
6188 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
6190 /* Make a CFG based dump. */
6191 check_bb_profile (ENTRY_BLOCK_PTR, file);
6192 if (!ignore_topmost_bind)
6193 fprintf (file, "{\n");
6195 if (any_var && n_basic_blocks)
6196 fprintf (file, "\n");
6199 dump_generic_bb (file, bb, 2, flags);
6201 fprintf (file, "}\n");
6202 check_bb_profile (EXIT_BLOCK_PTR, file);
6208 /* Make a tree based dump. */
6209 chain = DECL_SAVED_TREE (fn);
6211 if (chain && TREE_CODE (chain) == BIND_EXPR)
6213 if (ignore_topmost_bind)
6215 chain = BIND_EXPR_BODY (chain);
6223 if (!ignore_topmost_bind)
6224 fprintf (file, "{\n");
6229 fprintf (file, "\n");
6231 print_generic_stmt_indented (file, chain, flags, indent);
6232 if (ignore_topmost_bind)
6233 fprintf (file, "}\n");
6236 fprintf (file, "\n\n");
6243 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
6246 debug_function (tree fn, int flags)
6248 dump_function_to_file (fn, stderr, flags);
6252 /* Print on FILE the indexes for the predecessors of basic_block BB. */
6255 print_pred_bbs (FILE *file, basic_block bb)
6260 FOR_EACH_EDGE (e, ei, bb->preds)
6261 fprintf (file, "bb_%d ", e->src->index);
6265 /* Print on FILE the indexes for the successors of basic_block BB. */
6268 print_succ_bbs (FILE *file, basic_block bb)
6273 FOR_EACH_EDGE (e, ei, bb->succs)
6274 fprintf (file, "bb_%d ", e->dest->index);
6277 /* Print to FILE the basic block BB following the VERBOSITY level. */
6280 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6282 char *s_indent = (char *) alloca ((size_t) indent + 1);
6283 memset ((void *) s_indent, ' ', (size_t) indent);
6284 s_indent[indent] = '\0';
6286 /* Print basic_block's header. */
6289 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
6290 print_pred_bbs (file, bb);
6291 fprintf (file, "}, succs = {");
6292 print_succ_bbs (file, bb);
6293 fprintf (file, "})\n");
6296 /* Print basic_block's body. */
6299 fprintf (file, "%s {\n", s_indent);
6300 tree_dump_bb (bb, file, indent + 4);
6301 fprintf (file, "%s }\n", s_indent);
6305 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6307 /* Pretty print LOOP on FILE, indented INDENT spaces. Following
6308 VERBOSITY level this outputs the contents of the loop, or just its
6312 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6320 s_indent = (char *) alloca ((size_t) indent + 1);
6321 memset ((void *) s_indent, ' ', (size_t) indent);
6322 s_indent[indent] = '\0';
6324 /* Print loop's header. */
6325 fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6326 loop->num, loop->header->index, loop->latch->index);
6327 fprintf (file, ", niter = ");
6328 print_generic_expr (file, loop->nb_iterations, 0);
6330 if (loop->any_upper_bound)
6332 fprintf (file, ", upper_bound = ");
6333 dump_double_int (file, loop->nb_iterations_upper_bound, true);
6336 if (loop->any_estimate)
6338 fprintf (file, ", estimate = ");
6339 dump_double_int (file, loop->nb_iterations_estimate, true);
6341 fprintf (file, ")\n");
6343 /* Print loop's body. */
6346 fprintf (file, "%s{\n", s_indent);
6348 if (bb->loop_father == loop)
6349 print_loops_bb (file, bb, indent, verbosity);
6351 print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6352 fprintf (file, "%s}\n", s_indent);
6356 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6357 spaces. Following VERBOSITY level this outputs the contents of the
6358 loop, or just its structure. */
6361 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6366 print_loop (file, loop, indent, verbosity);
6367 print_loop_and_siblings (file, loop->next, indent, verbosity);
6370 /* Follow a CFG edge from the entry point of the program, and on entry
6371 of a loop, pretty print the loop structure on FILE. */
6374 print_loops (FILE *file, int verbosity)
6378 bb = BASIC_BLOCK (NUM_FIXED_BLOCKS);
6379 if (bb && bb->loop_father)
6380 print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6384 /* Debugging loops structure at tree level, at some VERBOSITY level. */
6387 debug_loops (int verbosity)
6389 print_loops (stderr, verbosity);
6392 /* Print on stderr the code of LOOP, at some VERBOSITY level. */
6395 debug_loop (struct loop *loop, int verbosity)
6397 print_loop (stderr, loop, 0, verbosity);
6400 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6404 debug_loop_num (unsigned num, int verbosity)
6406 debug_loop (get_loop (num), verbosity);
6409 /* Return true if BB ends with a call, possibly followed by some
6410 instructions that must stay with the call. Return false,
6414 tree_block_ends_with_call_p (basic_block bb)
6416 block_stmt_iterator bsi = bsi_last (bb);
6417 return get_call_expr_in (bsi_stmt (bsi)) != NULL;
6421 /* Return true if BB ends with a conditional branch. Return false,
6425 tree_block_ends_with_condjump_p (const_basic_block bb)
6427 /* This CONST_CAST is okay because last_stmt doesn't modify its
6428 argument and the return value is not modified. */
6429 const_tree stmt = last_stmt (CONST_CAST_BB(bb));
6430 return (stmt && TREE_CODE (stmt) == COND_EXPR);
6434 /* Return true if we need to add fake edge to exit at statement T.
6435 Helper function for tree_flow_call_edges_add. */
6438 need_fake_edge_p (tree t)
6440 tree call, fndecl = NULL_TREE;
6443 /* NORETURN and LONGJMP calls already have an edge to exit.
6444 CONST and PURE calls do not need one.
6445 We don't currently check for CONST and PURE here, although
6446 it would be a good idea, because those attributes are
6447 figured out from the RTL in mark_constant_function, and
6448 the counter incrementation code from -fprofile-arcs
6449 leads to different results from -fbranch-probabilities. */
6450 call = get_call_expr_in (t);
6453 fndecl = get_callee_fndecl (call);
6454 call_flags = call_expr_flags (call);
6457 if (call && fndecl && DECL_BUILT_IN (fndecl)
6458 && (call_flags & ECF_NOTHROW)
6459 && !(call_flags & ECF_NORETURN)
6460 && !(call_flags & ECF_RETURNS_TWICE))
6463 if (call && !(call_flags & ECF_NORETURN))
6466 if (TREE_CODE (t) == ASM_EXPR
6467 && (ASM_VOLATILE_P (t) || ASM_INPUT_P (t)))
6474 /* Add fake edges to the function exit for any non constant and non
6475 noreturn calls, volatile inline assembly in the bitmap of blocks
6476 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
6477 the number of blocks that were split.
6479 The goal is to expose cases in which entering a basic block does
6480 not imply that all subsequent instructions must be executed. */
6483 tree_flow_call_edges_add (sbitmap blocks)
6486 int blocks_split = 0;
6487 int last_bb = last_basic_block;
6488 bool check_last_block = false;
6490 if (n_basic_blocks == NUM_FIXED_BLOCKS)
6494 check_last_block = true;
6496 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6498 /* In the last basic block, before epilogue generation, there will be
6499 a fallthru edge to EXIT. Special care is required if the last insn
6500 of the last basic block is a call because make_edge folds duplicate
6501 edges, which would result in the fallthru edge also being marked
6502 fake, which would result in the fallthru edge being removed by
6503 remove_fake_edges, which would result in an invalid CFG.
6505 Moreover, we can't elide the outgoing fake edge, since the block
6506 profiler needs to take this into account in order to solve the minimal
6507 spanning tree in the case that the call doesn't return.
6509 Handle this by adding a dummy instruction in a new last basic block. */
6510 if (check_last_block)
6512 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6513 block_stmt_iterator bsi = bsi_last (bb);
6515 if (!bsi_end_p (bsi))
6518 if (t && need_fake_edge_p (t))
6522 e = find_edge (bb, EXIT_BLOCK_PTR);
6525 bsi_insert_on_edge (e, build_empty_stmt ());
6526 bsi_commit_edge_inserts ();
6531 /* Now add fake edges to the function exit for any non constant
6532 calls since there is no way that we can determine if they will
6534 for (i = 0; i < last_bb; i++)
6536 basic_block bb = BASIC_BLOCK (i);
6537 block_stmt_iterator bsi;
6538 tree stmt, last_stmt;
6543 if (blocks && !TEST_BIT (blocks, i))
6546 bsi = bsi_last (bb);
6547 if (!bsi_end_p (bsi))
6549 last_stmt = bsi_stmt (bsi);
6552 stmt = bsi_stmt (bsi);
6553 if (need_fake_edge_p (stmt))
6556 /* The handling above of the final block before the
6557 epilogue should be enough to verify that there is
6558 no edge to the exit block in CFG already.
6559 Calling make_edge in such case would cause us to
6560 mark that edge as fake and remove it later. */
6561 #ifdef ENABLE_CHECKING
6562 if (stmt == last_stmt)
6564 e = find_edge (bb, EXIT_BLOCK_PTR);
6565 gcc_assert (e == NULL);
6569 /* Note that the following may create a new basic block
6570 and renumber the existing basic blocks. */
6571 if (stmt != last_stmt)
6573 e = split_block (bb, stmt);
6577 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6581 while (!bsi_end_p (bsi));
6586 verify_flow_info ();
6588 return blocks_split;
6591 /* Purge dead abnormal call edges from basic block BB. */
6594 tree_purge_dead_abnormal_call_edges (basic_block bb)
6596 bool changed = tree_purge_dead_eh_edges (bb);
6598 if (cfun->has_nonlocal_label)
6600 tree stmt = last_stmt (bb);
6604 if (!(stmt && tree_can_make_abnormal_goto (stmt)))
6605 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6607 if (e->flags & EDGE_ABNORMAL)
6616 /* See tree_purge_dead_eh_edges below. */
6618 free_dominance_info (CDI_DOMINATORS);
6624 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6627 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6631 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6632 for (son = first_dom_son (CDI_DOMINATORS, bb);
6634 son = next_dom_son (CDI_DOMINATORS, son))
6635 get_all_dominated_blocks (son, dom_bbs);
6638 /* Removes edge E and all the blocks dominated by it, and updates dominance
6639 information. The IL in E->src needs to be updated separately.
6640 If dominance info is not available, only the edge E is removed.*/
6643 remove_edge_and_dominated_blocks (edge e)
6645 VEC (basic_block, heap) *bbs_to_remove = NULL;
6646 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6650 bool none_removed = false;
6652 basic_block bb, dbb;
6655 if (!dom_info_available_p (CDI_DOMINATORS))
6661 /* No updating is needed for edges to exit. */
6662 if (e->dest == EXIT_BLOCK_PTR)
6664 if (cfgcleanup_altered_bbs)
6665 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6670 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6671 that is not dominated by E->dest, then this set is empty. Otherwise,
6672 all the basic blocks dominated by E->dest are removed.
6674 Also, to DF_IDOM we store the immediate dominators of the blocks in
6675 the dominance frontier of E (i.e., of the successors of the
6676 removed blocks, if there are any, and of E->dest otherwise). */
6677 FOR_EACH_EDGE (f, ei, e->dest->preds)
6682 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6684 none_removed = true;
6689 df = BITMAP_ALLOC (NULL);
6690 df_idom = BITMAP_ALLOC (NULL);
6693 bitmap_set_bit (df_idom,
6694 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6697 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6698 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6700 FOR_EACH_EDGE (f, ei, bb->succs)
6702 if (f->dest != EXIT_BLOCK_PTR)
6703 bitmap_set_bit (df, f->dest->index);
6706 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6707 bitmap_clear_bit (df, bb->index);
6709 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6711 bb = BASIC_BLOCK (i);
6712 bitmap_set_bit (df_idom,
6713 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6717 if (cfgcleanup_altered_bbs)
6719 /* Record the set of the altered basic blocks. */
6720 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6721 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6724 /* Remove E and the cancelled blocks. */
6729 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6730 delete_basic_block (bb);
6733 /* Update the dominance information. The immediate dominator may change only
6734 for blocks whose immediate dominator belongs to DF_IDOM:
6736 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6737 removal. Let Z the arbitrary block such that idom(Z) = Y and
6738 Z dominates X after the removal. Before removal, there exists a path P
6739 from Y to X that avoids Z. Let F be the last edge on P that is
6740 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6741 dominates W, and because of P, Z does not dominate W), and W belongs to
6742 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6743 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6745 bb = BASIC_BLOCK (i);
6746 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6748 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6749 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6752 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6755 BITMAP_FREE (df_idom);
6756 VEC_free (basic_block, heap, bbs_to_remove);
6757 VEC_free (basic_block, heap, bbs_to_fix_dom);
6760 /* Purge dead EH edges from basic block BB. */
6763 tree_purge_dead_eh_edges (basic_block bb)
6765 bool changed = false;
6768 tree stmt = last_stmt (bb);
6770 if (stmt && tree_can_throw_internal (stmt))
6773 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6775 if (e->flags & EDGE_EH)
6777 remove_edge_and_dominated_blocks (e);
6788 tree_purge_all_dead_eh_edges (const_bitmap blocks)
6790 bool changed = false;
6794 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6796 changed |= tree_purge_dead_eh_edges (BASIC_BLOCK (i));
6802 /* This function is called whenever a new edge is created or
6806 tree_execute_on_growing_pred (edge e)
6808 basic_block bb = e->dest;
6811 reserve_phi_args_for_new_edge (bb);
6814 /* This function is called immediately before edge E is removed from
6815 the edge vector E->dest->preds. */
6818 tree_execute_on_shrinking_pred (edge e)
6820 if (phi_nodes (e->dest))
6821 remove_phi_args (e);
6824 /*---------------------------------------------------------------------------
6825 Helper functions for Loop versioning
6826 ---------------------------------------------------------------------------*/
6828 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6829 of 'first'. Both of them are dominated by 'new_head' basic block. When
6830 'new_head' was created by 'second's incoming edge it received phi arguments
6831 on the edge by split_edge(). Later, additional edge 'e' was created to
6832 connect 'new_head' and 'first'. Now this routine adds phi args on this
6833 additional edge 'e' that new_head to second edge received as part of edge
6838 tree_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6839 basic_block new_head, edge e)
6842 edge e2 = find_edge (new_head, second);
6844 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6845 edge, we should always have an edge from NEW_HEAD to SECOND. */
6846 gcc_assert (e2 != NULL);
6848 /* Browse all 'second' basic block phi nodes and add phi args to
6849 edge 'e' for 'first' head. PHI args are always in correct order. */
6851 for (phi2 = phi_nodes (second), phi1 = phi_nodes (first);
6853 phi2 = PHI_CHAIN (phi2), phi1 = PHI_CHAIN (phi1))
6855 tree def = PHI_ARG_DEF (phi2, e2->dest_idx);
6856 add_phi_arg (phi1, def, e);
6860 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6861 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6862 the destination of the ELSE part. */
6864 tree_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6865 basic_block second_head ATTRIBUTE_UNUSED,
6866 basic_block cond_bb, void *cond_e)
6868 block_stmt_iterator bsi;
6869 tree new_cond_expr = NULL_TREE;
6870 tree cond_expr = (tree) cond_e;
6873 /* Build new conditional expr */
6874 new_cond_expr = build3 (COND_EXPR, void_type_node, cond_expr,
6875 NULL_TREE, NULL_TREE);
6877 /* Add new cond in cond_bb. */
6878 bsi = bsi_start (cond_bb);
6879 bsi_insert_after (&bsi, new_cond_expr, BSI_NEW_STMT);
6880 /* Adjust edges appropriately to connect new head with first head
6881 as well as second head. */
6882 e0 = single_succ_edge (cond_bb);
6883 e0->flags &= ~EDGE_FALLTHRU;
6884 e0->flags |= EDGE_FALSE_VALUE;
6887 struct cfg_hooks tree_cfg_hooks = {
6889 tree_verify_flow_info,
6890 tree_dump_bb, /* dump_bb */
6891 create_bb, /* create_basic_block */
6892 tree_redirect_edge_and_branch,/* redirect_edge_and_branch */
6893 tree_redirect_edge_and_branch_force,/* redirect_edge_and_branch_force */
6894 tree_can_remove_branch_p, /* can_remove_branch_p */
6895 remove_bb, /* delete_basic_block */
6896 tree_split_block, /* split_block */
6897 tree_move_block_after, /* move_block_after */
6898 tree_can_merge_blocks_p, /* can_merge_blocks_p */
6899 tree_merge_blocks, /* merge_blocks */
6900 tree_predict_edge, /* predict_edge */
6901 tree_predicted_by_p, /* predicted_by_p */
6902 tree_can_duplicate_bb_p, /* can_duplicate_block_p */
6903 tree_duplicate_bb, /* duplicate_block */
6904 tree_split_edge, /* split_edge */
6905 tree_make_forwarder_block, /* make_forward_block */
6906 NULL, /* tidy_fallthru_edge */
6907 tree_block_ends_with_call_p, /* block_ends_with_call_p */
6908 tree_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6909 tree_flow_call_edges_add, /* flow_call_edges_add */
6910 tree_execute_on_growing_pred, /* execute_on_growing_pred */
6911 tree_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6912 tree_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6913 tree_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6914 tree_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6915 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6916 flush_pending_stmts /* flush_pending_stmts */
6920 /* Split all critical edges. */
6923 split_critical_edges (void)
6929 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6930 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6931 mappings around the calls to split_edge. */
6932 start_recording_case_labels ();
6935 FOR_EACH_EDGE (e, ei, bb->succs)
6936 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6941 end_recording_case_labels ();
6945 struct gimple_opt_pass pass_split_crit_edges =
6949 "crited", /* name */
6951 split_critical_edges, /* execute */
6954 0, /* static_pass_number */
6955 TV_TREE_SPLIT_EDGES, /* tv_id */
6956 PROP_cfg, /* properties required */
6957 PROP_no_crit_edges, /* properties_provided */
6958 0, /* properties_destroyed */
6959 0, /* todo_flags_start */
6960 TODO_dump_func /* todo_flags_finish */
6965 /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into
6966 a temporary, make sure and register it to be renamed if necessary,
6967 and finally return the temporary. Put the statements to compute
6968 EXP before the current statement in BSI. */
6971 gimplify_val (block_stmt_iterator *bsi, tree type, tree exp)
6973 tree t, new_stmt, orig_stmt;
6975 if (is_gimple_val (exp))
6978 t = make_rename_temp (type, NULL);
6979 new_stmt = build_gimple_modify_stmt (t, exp);
6981 orig_stmt = bsi_stmt (*bsi);
6982 SET_EXPR_LOCUS (new_stmt, EXPR_LOCUS (orig_stmt));
6983 TREE_BLOCK (new_stmt) = TREE_BLOCK (orig_stmt);
6985 bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
6986 if (gimple_in_ssa_p (cfun))
6987 mark_symbols_for_renaming (new_stmt);
6992 /* Build a ternary operation and gimplify it. Emit code before BSI.
6993 Return the gimple_val holding the result. */
6996 gimplify_build3 (block_stmt_iterator *bsi, enum tree_code code,
6997 tree type, tree a, tree b, tree c)
7001 ret = fold_build3 (code, type, a, b, c);
7004 return gimplify_val (bsi, type, ret);
7007 /* Build a binary operation and gimplify it. Emit code before BSI.
7008 Return the gimple_val holding the result. */
7011 gimplify_build2 (block_stmt_iterator *bsi, enum tree_code code,
7012 tree type, tree a, tree b)
7016 ret = fold_build2 (code, type, a, b);
7019 return gimplify_val (bsi, type, ret);
7022 /* Build a unary operation and gimplify it. Emit code before BSI.
7023 Return the gimple_val holding the result. */
7026 gimplify_build1 (block_stmt_iterator *bsi, enum tree_code code, tree type,
7031 ret = fold_build1 (code, type, a);
7034 return gimplify_val (bsi, type, ret);
7039 /* Emit return warnings. */
7042 execute_warn_function_return (void)
7044 source_location location;
7049 /* If we have a path to EXIT, then we do return. */
7050 if (TREE_THIS_VOLATILE (cfun->decl)
7051 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
7053 location = UNKNOWN_LOCATION;
7054 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7056 last = last_stmt (e->src);
7057 if (TREE_CODE (last) == RETURN_EXPR
7058 && (location = EXPR_LOCATION (last)) != UNKNOWN_LOCATION)
7061 if (location == UNKNOWN_LOCATION)
7062 location = cfun->function_end_locus;
7063 warning (0, "%H%<noreturn%> function does return", &location);
7066 /* If we see "return;" in some basic block, then we do reach the end
7067 without returning a value. */
7068 else if (warn_return_type
7069 && !TREE_NO_WARNING (cfun->decl)
7070 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
7071 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
7073 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7075 tree last = last_stmt (e->src);
7076 if (TREE_CODE (last) == RETURN_EXPR
7077 && TREE_OPERAND (last, 0) == NULL
7078 && !TREE_NO_WARNING (last))
7080 location = EXPR_LOCATION (last);
7081 if (location == UNKNOWN_LOCATION)
7082 location = cfun->function_end_locus;
7083 warning (OPT_Wreturn_type, "%Hcontrol reaches end of non-void function", &location);
7084 TREE_NO_WARNING (cfun->decl) = 1;
7093 /* Given a basic block B which ends with a conditional and has
7094 precisely two successors, determine which of the edges is taken if
7095 the conditional is true and which is taken if the conditional is
7096 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
7099 extract_true_false_edges_from_block (basic_block b,
7103 edge e = EDGE_SUCC (b, 0);
7105 if (e->flags & EDGE_TRUE_VALUE)
7108 *false_edge = EDGE_SUCC (b, 1);
7113 *true_edge = EDGE_SUCC (b, 1);
7117 struct gimple_opt_pass pass_warn_function_return =
7123 execute_warn_function_return, /* execute */
7126 0, /* static_pass_number */
7128 PROP_cfg, /* properties_required */
7129 0, /* properties_provided */
7130 0, /* properties_destroyed */
7131 0, /* todo_flags_start */
7132 0 /* todo_flags_finish */
7136 /* Emit noreturn warnings. */
7139 execute_warn_function_noreturn (void)
7141 if (warn_missing_noreturn
7142 && !TREE_THIS_VOLATILE (cfun->decl)
7143 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
7144 && !lang_hooks.missing_noreturn_ok_p (cfun->decl))
7145 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
7146 "for attribute %<noreturn%>",
7151 struct gimple_opt_pass pass_warn_function_noreturn =
7157 execute_warn_function_noreturn, /* execute */
7160 0, /* static_pass_number */
7162 PROP_cfg, /* properties_required */
7163 0, /* properties_provided */
7164 0, /* properties_destroyed */
7165 0, /* todo_flags_start */
7166 0 /* todo_flags_finish */