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);
106 /* Flowgraph optimization and cleanup. */
107 static void tree_merge_blocks (basic_block, basic_block);
108 static bool tree_can_merge_blocks_p (basic_block, basic_block);
109 static void remove_bb (basic_block);
110 static edge find_taken_edge_computed_goto (basic_block, tree);
111 static edge find_taken_edge_cond_expr (basic_block, tree);
112 static edge find_taken_edge_switch_expr (basic_block, tree);
113 static tree find_case_label_for_value (tree, tree);
116 init_empty_tree_cfg (void)
118 /* Initialize the basic block array. */
120 profile_status = PROFILE_ABSENT;
121 n_basic_blocks = NUM_FIXED_BLOCKS;
122 last_basic_block = NUM_FIXED_BLOCKS;
123 basic_block_info = VEC_alloc (basic_block, gc, initial_cfg_capacity);
124 VEC_safe_grow_cleared (basic_block, gc, basic_block_info,
125 initial_cfg_capacity);
127 /* Build a mapping of labels to their associated blocks. */
128 label_to_block_map = VEC_alloc (basic_block, gc, initial_cfg_capacity);
129 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
130 initial_cfg_capacity);
132 SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR);
133 SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR);
134 ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR;
135 EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR;
138 /*---------------------------------------------------------------------------
140 ---------------------------------------------------------------------------*/
142 /* Entry point to the CFG builder for trees. TP points to the list of
143 statements to be added to the flowgraph. */
146 build_tree_cfg (tree *tp)
148 /* Register specific tree functions. */
149 tree_register_cfg_hooks ();
151 memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
153 init_empty_tree_cfg ();
155 found_computed_goto = 0;
158 /* Computed gotos are hell to deal with, especially if there are
159 lots of them with a large number of destinations. So we factor
160 them to a common computed goto location before we build the
161 edge list. After we convert back to normal form, we will un-factor
162 the computed gotos since factoring introduces an unwanted jump. */
163 if (found_computed_goto)
164 factor_computed_gotos ();
166 /* Make sure there is always at least one block, even if it's empty. */
167 if (n_basic_blocks == NUM_FIXED_BLOCKS)
168 create_empty_bb (ENTRY_BLOCK_PTR);
170 /* Adjust the size of the array. */
171 if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
172 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
174 /* To speed up statement iterator walks, we first purge dead labels. */
175 cleanup_dead_labels ();
177 /* Group case nodes to reduce the number of edges.
178 We do this after cleaning up dead labels because otherwise we miss
179 a lot of obvious case merging opportunities. */
180 group_case_labels ();
182 /* Create the edges of the flowgraph. */
184 cleanup_dead_labels ();
186 /* Debugging dumps. */
188 /* Write the flowgraph to a VCG file. */
190 int local_dump_flags;
191 FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
194 tree_cfg2vcg (vcg_file);
195 dump_end (TDI_vcg, vcg_file);
199 #ifdef ENABLE_CHECKING
203 /* Dump a textual representation of the flowgraph. */
205 dump_tree_cfg (dump_file, dump_flags);
209 execute_build_cfg (void)
211 build_tree_cfg (&DECL_SAVED_TREE (current_function_decl));
215 struct tree_opt_pass pass_build_cfg =
219 execute_build_cfg, /* execute */
222 0, /* static_pass_number */
223 TV_TREE_CFG, /* tv_id */
224 PROP_gimple_leh, /* properties_required */
225 PROP_cfg, /* properties_provided */
226 0, /* properties_destroyed */
227 0, /* todo_flags_start */
228 TODO_verify_stmts | TODO_cleanup_cfg, /* todo_flags_finish */
232 /* Search the CFG for any computed gotos. If found, factor them to a
233 common computed goto site. Also record the location of that site so
234 that we can un-factor the gotos after we have converted back to
238 factor_computed_gotos (void)
241 tree factored_label_decl = NULL;
243 tree factored_computed_goto_label = NULL;
244 tree factored_computed_goto = NULL;
246 /* We know there are one or more computed gotos in this function.
247 Examine the last statement in each basic block to see if the block
248 ends with a computed goto. */
252 block_stmt_iterator bsi = bsi_last (bb);
257 last = bsi_stmt (bsi);
259 /* Ignore the computed goto we create when we factor the original
261 if (last == factored_computed_goto)
264 /* If the last statement is a computed goto, factor it. */
265 if (computed_goto_p (last))
269 /* The first time we find a computed goto we need to create
270 the factored goto block and the variable each original
271 computed goto will use for their goto destination. */
272 if (! factored_computed_goto)
274 basic_block new_bb = create_empty_bb (bb);
275 block_stmt_iterator new_bsi = bsi_start (new_bb);
277 /* Create the destination of the factored goto. Each original
278 computed goto will put its desired destination into this
279 variable and jump to the label we create immediately
281 var = create_tmp_var (ptr_type_node, "gotovar");
283 /* Build a label for the new block which will contain the
284 factored computed goto. */
285 factored_label_decl = create_artificial_label ();
286 factored_computed_goto_label
287 = build1 (LABEL_EXPR, void_type_node, factored_label_decl);
288 bsi_insert_after (&new_bsi, factored_computed_goto_label,
291 /* Build our new computed goto. */
292 factored_computed_goto = build1 (GOTO_EXPR, void_type_node, var);
293 bsi_insert_after (&new_bsi, factored_computed_goto,
297 /* Copy the original computed goto's destination into VAR. */
298 assignment = build_gimple_modify_stmt (var,
299 GOTO_DESTINATION (last));
300 bsi_insert_before (&bsi, assignment, BSI_SAME_STMT);
302 /* And re-vector the computed goto to the new destination. */
303 GOTO_DESTINATION (last) = factored_label_decl;
309 /* Build a flowgraph for the statement_list STMT_LIST. */
312 make_blocks (tree stmt_list)
314 tree_stmt_iterator i = tsi_start (stmt_list);
316 bool start_new_block = true;
317 bool first_stmt_of_list = true;
318 basic_block bb = ENTRY_BLOCK_PTR;
320 while (!tsi_end_p (i))
327 /* If the statement starts a new basic block or if we have determined
328 in a previous pass that we need to create a new block for STMT, do
330 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
332 if (!first_stmt_of_list)
333 stmt_list = tsi_split_statement_list_before (&i);
334 bb = create_basic_block (stmt_list, NULL, bb);
335 start_new_block = false;
338 /* Now add STMT to BB and create the subgraphs for special statement
340 set_bb_for_stmt (stmt, bb);
342 if (computed_goto_p (stmt))
343 found_computed_goto = true;
345 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
347 if (stmt_ends_bb_p (stmt))
348 start_new_block = true;
351 first_stmt_of_list = false;
356 /* Create and return a new empty basic block after bb AFTER. */
359 create_bb (void *h, void *e, basic_block after)
365 /* Create and initialize a new basic block. Since alloc_block uses
366 ggc_alloc_cleared to allocate a basic block, we do not have to
367 clear the newly allocated basic block here. */
370 bb->index = last_basic_block;
372 bb->il.tree = GGC_CNEW (struct tree_bb_info);
373 set_bb_stmt_list (bb, h ? (tree) h : alloc_stmt_list ());
375 /* Add the new block to the linked list of blocks. */
376 link_block (bb, after);
378 /* Grow the basic block array if needed. */
379 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
381 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
382 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
385 /* Add the newly created block to the array. */
386 SET_BASIC_BLOCK (last_basic_block, bb);
395 /*---------------------------------------------------------------------------
397 ---------------------------------------------------------------------------*/
399 /* Fold COND_EXPR_COND of each COND_EXPR. */
402 fold_cond_expr_cond (void)
408 tree stmt = last_stmt (bb);
411 && TREE_CODE (stmt) == COND_EXPR)
416 fold_defer_overflow_warnings ();
417 cond = fold (COND_EXPR_COND (stmt));
418 zerop = integer_zerop (cond);
419 onep = integer_onep (cond);
420 fold_undefer_overflow_warnings (zerop || onep,
422 WARN_STRICT_OVERFLOW_CONDITIONAL);
424 COND_EXPR_COND (stmt) = boolean_false_node;
426 COND_EXPR_COND (stmt) = boolean_true_node;
431 /* Join all the blocks in the flowgraph. */
437 struct omp_region *cur_region = NULL;
439 /* Create an edge from entry to the first block with executable
441 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
443 /* Traverse the basic block array placing edges. */
446 tree last = last_stmt (bb);
451 enum tree_code code = TREE_CODE (last);
455 make_goto_expr_edges (bb);
459 make_edge (bb, EXIT_BLOCK_PTR, 0);
463 make_cond_expr_edges (bb);
467 make_switch_expr_edges (bb);
471 make_eh_edges (last);
476 /* If this function receives a nonlocal goto, then we need to
477 make edges from this call site to all the nonlocal goto
479 if (tree_can_make_abnormal_goto (last))
480 make_abnormal_goto_edges (bb, true);
482 /* If this statement has reachable exception handlers, then
483 create abnormal edges to them. */
484 make_eh_edges (last);
486 /* Some calls are known not to return. */
487 fallthru = !(call_expr_flags (last) & ECF_NORETURN);
493 case GIMPLE_MODIFY_STMT:
494 if (is_ctrl_altering_stmt (last))
496 /* A GIMPLE_MODIFY_STMT may have a CALL_EXPR on its RHS and
497 the CALL_EXPR may have an abnormal edge. Search the RHS
498 for this case and create any required edges. */
499 if (tree_can_make_abnormal_goto (last))
500 make_abnormal_goto_edges (bb, true);
502 make_eh_edges (last);
514 cur_region = new_omp_region (bb, code, cur_region);
519 cur_region = new_omp_region (bb, code, cur_region);
523 case OMP_SECTIONS_SWITCH:
528 case OMP_ATOMIC_LOAD:
529 case OMP_ATOMIC_STORE:
535 /* In the case of an OMP_SECTION, the edge will go somewhere
536 other than the next block. This will be created later. */
537 cur_region->exit = bb;
538 fallthru = cur_region->type != OMP_SECTION;
539 cur_region = cur_region->outer;
543 cur_region->cont = bb;
544 switch (cur_region->type)
547 /* Mark all OMP_FOR and OMP_CONTINUE succs edges as abnormal
548 to prevent splitting them. */
549 single_succ_edge (cur_region->entry)->flags |= EDGE_ABNORMAL;
550 /* Make the loopback edge. */
551 make_edge (bb, single_succ (cur_region->entry),
554 /* Create an edge from OMP_FOR to exit, which corresponds to
555 the case that the body of the loop is not executed at
557 make_edge (cur_region->entry, bb->next_bb, EDGE_ABNORMAL);
558 make_edge (bb, bb->next_bb, EDGE_FALLTHRU | EDGE_ABNORMAL);
563 /* Wire up the edges into and out of the nested sections. */
565 basic_block switch_bb = single_succ (cur_region->entry);
567 struct omp_region *i;
568 for (i = cur_region->inner; i ; i = i->next)
570 gcc_assert (i->type == OMP_SECTION);
571 make_edge (switch_bb, i->entry, 0);
572 make_edge (i->exit, bb, EDGE_FALLTHRU);
575 /* Make the loopback edge to the block with
576 OMP_SECTIONS_SWITCH. */
577 make_edge (bb, switch_bb, 0);
579 /* Make the edge from the switch to exit. */
580 make_edge (switch_bb, bb->next_bb, 0);
591 gcc_assert (!stmt_ends_bb_p (last));
599 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
605 /* Fold COND_EXPR_COND of each COND_EXPR. */
606 fold_cond_expr_cond ();
610 /* Create the edges for a COND_EXPR starting at block BB.
611 At this point, both clauses must contain only simple gotos. */
614 make_cond_expr_edges (basic_block bb)
616 tree entry = last_stmt (bb);
617 basic_block then_bb, else_bb;
618 tree then_label, else_label;
622 gcc_assert (TREE_CODE (entry) == COND_EXPR);
624 /* Entry basic blocks for each component. */
625 then_label = GOTO_DESTINATION (COND_EXPR_THEN (entry));
626 else_label = GOTO_DESTINATION (COND_EXPR_ELSE (entry));
627 then_bb = label_to_block (then_label);
628 else_bb = label_to_block (else_label);
630 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
631 e->goto_locus = EXPR_LOCATION (COND_EXPR_THEN (entry));
632 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
634 e->goto_locus = EXPR_LOCATION (COND_EXPR_ELSE (entry));
636 /* We do not need the gotos anymore. */
637 COND_EXPR_THEN (entry) = NULL_TREE;
638 COND_EXPR_ELSE (entry) = NULL_TREE;
642 /* Called for each element in the hash table (P) as we delete the
643 edge to cases hash table.
645 Clear all the TREE_CHAINs to prevent problems with copying of
646 SWITCH_EXPRs and structure sharing rules, then free the hash table
650 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED, void **value,
651 void *data ATTRIBUTE_UNUSED)
655 for (t = (tree) *value; t; t = next)
657 next = TREE_CHAIN (t);
658 TREE_CHAIN (t) = NULL;
665 /* Start recording information mapping edges to case labels. */
668 start_recording_case_labels (void)
670 gcc_assert (edge_to_cases == NULL);
671 edge_to_cases = pointer_map_create ();
674 /* Return nonzero if we are recording information for case labels. */
677 recording_case_labels_p (void)
679 return (edge_to_cases != NULL);
682 /* Stop recording information mapping edges to case labels and
683 remove any information we have recorded. */
685 end_recording_case_labels (void)
687 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
688 pointer_map_destroy (edge_to_cases);
689 edge_to_cases = NULL;
692 /* If we are inside a {start,end}_recording_cases block, then return
693 a chain of CASE_LABEL_EXPRs from T which reference E.
695 Otherwise return NULL. */
698 get_cases_for_edge (edge e, tree t)
704 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
705 chains available. Return NULL so the caller can detect this case. */
706 if (!recording_case_labels_p ())
709 slot = pointer_map_contains (edge_to_cases, e);
713 /* If we did not find E in the hash table, then this must be the first
714 time we have been queried for information about E & T. Add all the
715 elements from T to the hash table then perform the query again. */
717 vec = SWITCH_LABELS (t);
718 n = TREE_VEC_LENGTH (vec);
719 for (i = 0; i < n; i++)
721 tree elt = TREE_VEC_ELT (vec, i);
722 tree lab = CASE_LABEL (elt);
723 basic_block label_bb = label_to_block (lab);
724 edge this_edge = find_edge (e->src, label_bb);
726 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
728 slot = pointer_map_insert (edge_to_cases, this_edge);
729 TREE_CHAIN (elt) = (tree) *slot;
733 return (tree) *pointer_map_contains (edge_to_cases, e);
736 /* Create the edges for a SWITCH_EXPR starting at block BB.
737 At this point, the switch body has been lowered and the
738 SWITCH_LABELS filled in, so this is in effect a multi-way branch. */
741 make_switch_expr_edges (basic_block bb)
743 tree entry = last_stmt (bb);
747 vec = SWITCH_LABELS (entry);
748 n = TREE_VEC_LENGTH (vec);
750 for (i = 0; i < n; ++i)
752 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
753 basic_block label_bb = label_to_block (lab);
754 make_edge (bb, label_bb, 0);
759 /* Return the basic block holding label DEST. */
762 label_to_block_fn (struct function *ifun, tree dest)
764 int uid = LABEL_DECL_UID (dest);
766 /* We would die hard when faced by an undefined label. Emit a label to
767 the very first basic block. This will hopefully make even the dataflow
768 and undefined variable warnings quite right. */
769 if ((errorcount || sorrycount) && uid < 0)
771 block_stmt_iterator bsi =
772 bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS));
775 stmt = build1 (LABEL_EXPR, void_type_node, dest);
776 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
777 uid = LABEL_DECL_UID (dest);
779 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
780 <= (unsigned int) uid)
782 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
785 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
786 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
789 make_abnormal_goto_edges (basic_block bb, bool for_call)
791 basic_block target_bb;
792 block_stmt_iterator bsi;
794 FOR_EACH_BB (target_bb)
795 for (bsi = bsi_start (target_bb); !bsi_end_p (bsi); bsi_next (&bsi))
797 tree target = bsi_stmt (bsi);
799 if (TREE_CODE (target) != LABEL_EXPR)
802 target = LABEL_EXPR_LABEL (target);
804 /* Make an edge to every label block that has been marked as a
805 potential target for a computed goto or a non-local goto. */
806 if ((FORCED_LABEL (target) && !for_call)
807 || (DECL_NONLOCAL (target) && for_call))
809 make_edge (bb, target_bb, EDGE_ABNORMAL);
815 /* Create edges for a goto statement at block BB. */
818 make_goto_expr_edges (basic_block bb)
820 block_stmt_iterator last = bsi_last (bb);
821 tree goto_t = bsi_stmt (last);
823 /* A simple GOTO creates normal edges. */
824 if (simple_goto_p (goto_t))
826 tree dest = GOTO_DESTINATION (goto_t);
827 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
828 e->goto_locus = EXPR_LOCATION (goto_t);
829 bsi_remove (&last, true);
833 /* A computed GOTO creates abnormal edges. */
834 make_abnormal_goto_edges (bb, false);
838 /*---------------------------------------------------------------------------
840 ---------------------------------------------------------------------------*/
842 /* Cleanup useless labels in basic blocks. This is something we wish
843 to do early because it allows us to group case labels before creating
844 the edges for the CFG, and it speeds up block statement iterators in
846 We rerun this pass after CFG is created, to get rid of the labels that
847 are no longer referenced. After then we do not run it any more, since
848 (almost) no new labels should be created. */
850 /* A map from basic block index to the leading label of that block. */
851 static struct label_record
856 /* True if the label is referenced from somewhere. */
860 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
862 update_eh_label (struct eh_region *region)
864 tree old_label = get_eh_region_tree_label (region);
868 basic_block bb = label_to_block (old_label);
870 /* ??? After optimizing, there may be EH regions with labels
871 that have already been removed from the function body, so
872 there is no basic block for them. */
876 new_label = label_for_bb[bb->index].label;
877 label_for_bb[bb->index].used = true;
878 set_eh_region_tree_label (region, new_label);
882 /* Given LABEL return the first label in the same basic block. */
884 main_block_label (tree label)
886 basic_block bb = label_to_block (label);
887 tree main_label = label_for_bb[bb->index].label;
889 /* label_to_block possibly inserted undefined label into the chain. */
892 label_for_bb[bb->index].label = label;
896 label_for_bb[bb->index].used = true;
900 /* Cleanup redundant labels. This is a three-step process:
901 1) Find the leading label for each block.
902 2) Redirect all references to labels to the leading labels.
903 3) Cleanup all useless labels. */
906 cleanup_dead_labels (void)
909 label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
911 /* Find a suitable label for each block. We use the first user-defined
912 label if there is one, or otherwise just the first label we see. */
915 block_stmt_iterator i;
917 for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i))
919 tree label, stmt = bsi_stmt (i);
921 if (TREE_CODE (stmt) != LABEL_EXPR)
924 label = LABEL_EXPR_LABEL (stmt);
926 /* If we have not yet seen a label for the current block,
927 remember this one and see if there are more labels. */
928 if (!label_for_bb[bb->index].label)
930 label_for_bb[bb->index].label = label;
934 /* If we did see a label for the current block already, but it
935 is an artificially created label, replace it if the current
936 label is a user defined label. */
937 if (!DECL_ARTIFICIAL (label)
938 && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
940 label_for_bb[bb->index].label = label;
946 /* Now redirect all jumps/branches to the selected label.
947 First do so for each block ending in a control statement. */
950 tree stmt = last_stmt (bb);
954 switch (TREE_CODE (stmt))
958 tree true_branch, false_branch;
960 true_branch = COND_EXPR_THEN (stmt);
961 false_branch = COND_EXPR_ELSE (stmt);
964 GOTO_DESTINATION (true_branch)
965 = main_block_label (GOTO_DESTINATION (true_branch));
967 GOTO_DESTINATION (false_branch)
968 = main_block_label (GOTO_DESTINATION (false_branch));
976 tree vec = SWITCH_LABELS (stmt);
977 size_t n = TREE_VEC_LENGTH (vec);
979 /* Replace all destination labels. */
980 for (i = 0; i < n; ++i)
982 tree elt = TREE_VEC_ELT (vec, i);
983 tree label = main_block_label (CASE_LABEL (elt));
984 CASE_LABEL (elt) = label;
989 /* We have to handle GOTO_EXPRs until they're removed, and we don't
990 remove them until after we've created the CFG edges. */
992 if (! computed_goto_p (stmt))
994 GOTO_DESTINATION (stmt)
995 = main_block_label (GOTO_DESTINATION (stmt));
1004 for_each_eh_region (update_eh_label);
1006 /* Finally, purge dead labels. All user-defined labels and labels that
1007 can be the target of non-local gotos and labels which have their
1008 address taken are preserved. */
1011 block_stmt_iterator i;
1012 tree label_for_this_bb = label_for_bb[bb->index].label;
1014 if (!label_for_this_bb)
1017 /* If the main label of the block is unused, we may still remove it. */
1018 if (!label_for_bb[bb->index].used)
1019 label_for_this_bb = NULL;
1021 for (i = bsi_start (bb); !bsi_end_p (i); )
1023 tree label, stmt = bsi_stmt (i);
1025 if (TREE_CODE (stmt) != LABEL_EXPR)
1028 label = LABEL_EXPR_LABEL (stmt);
1030 if (label == label_for_this_bb
1031 || ! DECL_ARTIFICIAL (label)
1032 || DECL_NONLOCAL (label)
1033 || FORCED_LABEL (label))
1036 bsi_remove (&i, true);
1040 free (label_for_bb);
1043 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1044 and scan the sorted vector of cases. Combine the ones jumping to the
1046 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1049 group_case_labels (void)
1055 tree stmt = last_stmt (bb);
1056 if (stmt && TREE_CODE (stmt) == SWITCH_EXPR)
1058 tree labels = SWITCH_LABELS (stmt);
1059 int old_size = TREE_VEC_LENGTH (labels);
1060 int i, j, new_size = old_size;
1061 tree default_case = TREE_VEC_ELT (labels, old_size - 1);
1064 /* The default label is always the last case in a switch
1065 statement after gimplification. */
1066 default_label = CASE_LABEL (default_case);
1068 /* Look for possible opportunities to merge cases.
1069 Ignore the last element of the label vector because it
1070 must be the default case. */
1072 while (i < old_size - 1)
1074 tree base_case, base_label, base_high;
1075 base_case = TREE_VEC_ELT (labels, i);
1077 gcc_assert (base_case);
1078 base_label = CASE_LABEL (base_case);
1080 /* Discard cases that have the same destination as the
1082 if (base_label == default_label)
1084 TREE_VEC_ELT (labels, i) = NULL_TREE;
1090 base_high = CASE_HIGH (base_case) ?
1091 CASE_HIGH (base_case) : CASE_LOW (base_case);
1093 /* Try to merge case labels. Break out when we reach the end
1094 of the label vector or when we cannot merge the next case
1095 label with the current one. */
1096 while (i < old_size - 1)
1098 tree merge_case = TREE_VEC_ELT (labels, i);
1099 tree merge_label = CASE_LABEL (merge_case);
1100 tree t = int_const_binop (PLUS_EXPR, base_high,
1101 integer_one_node, 1);
1103 /* Merge the cases if they jump to the same place,
1104 and their ranges are consecutive. */
1105 if (merge_label == base_label
1106 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1108 base_high = CASE_HIGH (merge_case) ?
1109 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1110 CASE_HIGH (base_case) = base_high;
1111 TREE_VEC_ELT (labels, i) = NULL_TREE;
1120 /* Compress the case labels in the label vector, and adjust the
1121 length of the vector. */
1122 for (i = 0, j = 0; i < new_size; i++)
1124 while (! TREE_VEC_ELT (labels, j))
1126 TREE_VEC_ELT (labels, i) = TREE_VEC_ELT (labels, j++);
1128 TREE_VEC_LENGTH (labels) = new_size;
1133 /* Checks whether we can merge block B into block A. */
1136 tree_can_merge_blocks_p (basic_block a, basic_block b)
1139 block_stmt_iterator bsi;
1142 if (!single_succ_p (a))
1145 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1148 if (single_succ (a) != b)
1151 if (!single_pred_p (b))
1154 if (b == EXIT_BLOCK_PTR)
1157 /* If A ends by a statement causing exceptions or something similar, we
1158 cannot merge the blocks. */
1159 /* This CONST_CAST is okay because last_stmt doesn't modify its
1160 argument and the return value is assign to a const_tree. */
1161 stmt = last_stmt (CONST_CAST_BB (a));
1162 if (stmt && stmt_ends_bb_p (stmt))
1165 /* Do not allow a block with only a non-local label to be merged. */
1166 if (stmt && TREE_CODE (stmt) == LABEL_EXPR
1167 && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
1170 /* It must be possible to eliminate all phi nodes in B. If ssa form
1171 is not up-to-date, we cannot eliminate any phis; however, if only
1172 some symbols as whole are marked for renaming, this is not a problem,
1173 as phi nodes for those symbols are irrelevant in updating anyway. */
1174 phi = phi_nodes (b);
1177 if (name_mappings_registered_p ())
1180 for (; phi; phi = PHI_CHAIN (phi))
1181 if (!is_gimple_reg (PHI_RESULT (phi))
1182 && !may_propagate_copy (PHI_RESULT (phi), PHI_ARG_DEF (phi, 0)))
1186 /* Do not remove user labels. */
1187 for (bsi = bsi_start (b); !bsi_end_p (bsi); bsi_next (&bsi))
1189 stmt = bsi_stmt (bsi);
1190 if (TREE_CODE (stmt) != LABEL_EXPR)
1192 if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt)))
1196 /* Protect the loop latches. */
1198 && b->loop_father->latch == b)
1204 /* Replaces all uses of NAME by VAL. */
1207 replace_uses_by (tree name, tree val)
1209 imm_use_iterator imm_iter;
1214 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1216 if (TREE_CODE (stmt) != PHI_NODE)
1217 push_stmt_changes (&stmt);
1219 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1221 replace_exp (use, val);
1223 if (TREE_CODE (stmt) == PHI_NODE)
1225 e = PHI_ARG_EDGE (stmt, PHI_ARG_INDEX_FROM_USE (use));
1226 if (e->flags & EDGE_ABNORMAL)
1228 /* This can only occur for virtual operands, since
1229 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1230 would prevent replacement. */
1231 gcc_assert (!is_gimple_reg (name));
1232 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1237 if (TREE_CODE (stmt) != PHI_NODE)
1241 fold_stmt_inplace (stmt);
1242 if (cfgcleanup_altered_bbs)
1243 bitmap_set_bit (cfgcleanup_altered_bbs, bb_for_stmt (stmt)->index);
1245 /* FIXME. This should go in pop_stmt_changes. */
1246 rhs = get_rhs (stmt);
1247 if (TREE_CODE (rhs) == ADDR_EXPR)
1248 recompute_tree_invariant_for_addr_expr (rhs);
1250 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1252 pop_stmt_changes (&stmt);
1256 gcc_assert (has_zero_uses (name));
1258 /* Also update the trees stored in loop structures. */
1264 FOR_EACH_LOOP (li, loop, 0)
1266 substitute_in_loop_info (loop, name, val);
1271 /* Merge block B into block A. */
1274 tree_merge_blocks (basic_block a, basic_block b)
1276 block_stmt_iterator bsi;
1277 tree_stmt_iterator last;
1281 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1283 /* Remove all single-valued PHI nodes from block B of the form
1284 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1286 for (phi = phi_nodes (b); phi; phi = phi_nodes (b))
1288 tree def = PHI_RESULT (phi), use = PHI_ARG_DEF (phi, 0);
1290 bool may_replace_uses = may_propagate_copy (def, use);
1292 /* In case we maintain loop closed ssa form, do not propagate arguments
1293 of loop exit phi nodes. */
1295 && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1296 && is_gimple_reg (def)
1297 && TREE_CODE (use) == SSA_NAME
1298 && a->loop_father != b->loop_father)
1299 may_replace_uses = false;
1301 if (!may_replace_uses)
1303 gcc_assert (is_gimple_reg (def));
1305 /* Note that just emitting the copies is fine -- there is no problem
1306 with ordering of phi nodes. This is because A is the single
1307 predecessor of B, therefore results of the phi nodes cannot
1308 appear as arguments of the phi nodes. */
1309 copy = build_gimple_modify_stmt (def, use);
1310 bsi_insert_after (&bsi, copy, BSI_NEW_STMT);
1311 SSA_NAME_DEF_STMT (def) = copy;
1312 remove_phi_node (phi, NULL, false);
1316 /* If we deal with a PHI for virtual operands, we can simply
1317 propagate these without fussing with folding or updating
1319 if (!is_gimple_reg (def))
1321 imm_use_iterator iter;
1322 use_operand_p use_p;
1325 FOR_EACH_IMM_USE_STMT (stmt, iter, def)
1326 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1327 SET_USE (use_p, use);
1330 replace_uses_by (def, use);
1331 remove_phi_node (phi, NULL, true);
1335 /* Ensure that B follows A. */
1336 move_block_after (b, a);
1338 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1339 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1341 /* Remove labels from B and set bb_for_stmt to A for other statements. */
1342 for (bsi = bsi_start (b); !bsi_end_p (bsi);)
1344 if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR)
1346 tree label = bsi_stmt (bsi);
1348 bsi_remove (&bsi, false);
1349 /* Now that we can thread computed gotos, we might have
1350 a situation where we have a forced label in block B
1351 However, the label at the start of block B might still be
1352 used in other ways (think about the runtime checking for
1353 Fortran assigned gotos). So we can not just delete the
1354 label. Instead we move the label to the start of block A. */
1355 if (FORCED_LABEL (LABEL_EXPR_LABEL (label)))
1357 block_stmt_iterator dest_bsi = bsi_start (a);
1358 bsi_insert_before (&dest_bsi, label, BSI_NEW_STMT);
1363 change_bb_for_stmt (bsi_stmt (bsi), a);
1368 /* Merge the chains. */
1369 last = tsi_last (bb_stmt_list (a));
1370 tsi_link_after (&last, bb_stmt_list (b), TSI_NEW_STMT);
1371 set_bb_stmt_list (b, NULL_TREE);
1373 if (cfgcleanup_altered_bbs)
1374 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1378 /* Return the one of two successors of BB that is not reachable by a
1379 reached by a complex edge, if there is one. Else, return BB. We use
1380 this in optimizations that use post-dominators for their heuristics,
1381 to catch the cases in C++ where function calls are involved. */
1384 single_noncomplex_succ (basic_block bb)
1387 if (EDGE_COUNT (bb->succs) != 2)
1390 e0 = EDGE_SUCC (bb, 0);
1391 e1 = EDGE_SUCC (bb, 1);
1392 if (e0->flags & EDGE_COMPLEX)
1394 if (e1->flags & EDGE_COMPLEX)
1401 /* Walk the function tree removing unnecessary statements.
1403 * Empty statement nodes are removed
1405 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1407 * Unnecessary COND_EXPRs are removed
1409 * Some unnecessary BIND_EXPRs are removed
1411 Clearly more work could be done. The trick is doing the analysis
1412 and removal fast enough to be a net improvement in compile times.
1414 Note that when we remove a control structure such as a COND_EXPR
1415 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1416 to ensure we eliminate all the useless code. */
1427 static void remove_useless_stmts_1 (tree *, struct rus_data *);
1430 remove_useless_stmts_warn_notreached (tree stmt)
1432 if (EXPR_HAS_LOCATION (stmt))
1434 location_t loc = EXPR_LOCATION (stmt);
1435 if (LOCATION_LINE (loc) > 0)
1437 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
1442 switch (TREE_CODE (stmt))
1444 case STATEMENT_LIST:
1446 tree_stmt_iterator i;
1447 for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i))
1448 if (remove_useless_stmts_warn_notreached (tsi_stmt (i)))
1454 if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt)))
1456 if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt)))
1458 if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt)))
1462 case TRY_FINALLY_EXPR:
1463 case TRY_CATCH_EXPR:
1464 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 0)))
1466 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 1)))
1471 return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt));
1472 case EH_FILTER_EXPR:
1473 return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt));
1475 return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt));
1478 /* Not a live container. */
1486 remove_useless_stmts_cond (tree *stmt_p, struct rus_data *data)
1488 tree then_clause, else_clause, cond;
1489 bool save_has_label, then_has_label, else_has_label;
1491 save_has_label = data->has_label;
1492 data->has_label = false;
1493 data->last_goto = NULL;
1495 remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p), data);
1497 then_has_label = data->has_label;
1498 data->has_label = false;
1499 data->last_goto = NULL;
1501 remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p), data);
1503 else_has_label = data->has_label;
1504 data->has_label = save_has_label | then_has_label | else_has_label;
1506 then_clause = COND_EXPR_THEN (*stmt_p);
1507 else_clause = COND_EXPR_ELSE (*stmt_p);
1508 cond = fold (COND_EXPR_COND (*stmt_p));
1510 /* If neither arm does anything at all, we can remove the whole IF. */
1511 if (!TREE_SIDE_EFFECTS (then_clause) && !TREE_SIDE_EFFECTS (else_clause))
1513 *stmt_p = build_empty_stmt ();
1514 data->repeat = true;
1517 /* If there are no reachable statements in an arm, then we can
1518 zap the entire conditional. */
1519 else if (integer_nonzerop (cond) && !else_has_label)
1521 if (warn_notreached)
1522 remove_useless_stmts_warn_notreached (else_clause);
1523 *stmt_p = then_clause;
1524 data->repeat = true;
1526 else if (integer_zerop (cond) && !then_has_label)
1528 if (warn_notreached)
1529 remove_useless_stmts_warn_notreached (then_clause);
1530 *stmt_p = else_clause;
1531 data->repeat = true;
1534 /* Check a couple of simple things on then/else with single stmts. */
1537 tree then_stmt = expr_only (then_clause);
1538 tree else_stmt = expr_only (else_clause);
1540 /* Notice branches to a common destination. */
1541 if (then_stmt && else_stmt
1542 && TREE_CODE (then_stmt) == GOTO_EXPR
1543 && TREE_CODE (else_stmt) == GOTO_EXPR
1544 && (GOTO_DESTINATION (then_stmt) == GOTO_DESTINATION (else_stmt)))
1546 *stmt_p = then_stmt;
1547 data->repeat = true;
1550 /* If the THEN/ELSE clause merely assigns a value to a variable or
1551 parameter which is already known to contain that value, then
1552 remove the useless THEN/ELSE clause. */
1553 else if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL)
1556 && TREE_CODE (else_stmt) == GIMPLE_MODIFY_STMT
1557 && GIMPLE_STMT_OPERAND (else_stmt, 0) == cond
1558 && integer_zerop (GIMPLE_STMT_OPERAND (else_stmt, 1)))
1559 COND_EXPR_ELSE (*stmt_p) = alloc_stmt_list ();
1561 else if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
1562 && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL
1563 || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL)
1564 && TREE_CONSTANT (TREE_OPERAND (cond, 1)))
1566 tree stmt = (TREE_CODE (cond) == EQ_EXPR
1567 ? then_stmt : else_stmt);
1568 tree *location = (TREE_CODE (cond) == EQ_EXPR
1569 ? &COND_EXPR_THEN (*stmt_p)
1570 : &COND_EXPR_ELSE (*stmt_p));
1573 && TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
1574 && GIMPLE_STMT_OPERAND (stmt, 0) == TREE_OPERAND (cond, 0)
1575 && GIMPLE_STMT_OPERAND (stmt, 1) == TREE_OPERAND (cond, 1))
1576 *location = alloc_stmt_list ();
1580 /* Protect GOTOs in the arm of COND_EXPRs from being removed. They
1581 would be re-introduced during lowering. */
1582 data->last_goto = NULL;
1587 remove_useless_stmts_tf (tree *stmt_p, struct rus_data *data)
1589 bool save_may_branch, save_may_throw;
1590 bool this_may_branch, this_may_throw;
1592 /* Collect may_branch and may_throw information for the body only. */
1593 save_may_branch = data->may_branch;
1594 save_may_throw = data->may_throw;
1595 data->may_branch = false;
1596 data->may_throw = false;
1597 data->last_goto = NULL;
1599 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1601 this_may_branch = data->may_branch;
1602 this_may_throw = data->may_throw;
1603 data->may_branch |= save_may_branch;
1604 data->may_throw |= save_may_throw;
1605 data->last_goto = NULL;
1607 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1609 /* If the body is empty, then we can emit the FINALLY block without
1610 the enclosing TRY_FINALLY_EXPR. */
1611 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 0)))
1613 *stmt_p = TREE_OPERAND (*stmt_p, 1);
1614 data->repeat = true;
1617 /* If the handler is empty, then we can emit the TRY block without
1618 the enclosing TRY_FINALLY_EXPR. */
1619 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1621 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1622 data->repeat = true;
1625 /* If the body neither throws, nor branches, then we can safely
1626 string the TRY and FINALLY blocks together. */
1627 else if (!this_may_branch && !this_may_throw)
1629 tree stmt = *stmt_p;
1630 *stmt_p = TREE_OPERAND (stmt, 0);
1631 append_to_statement_list (TREE_OPERAND (stmt, 1), stmt_p);
1632 data->repeat = true;
1638 remove_useless_stmts_tc (tree *stmt_p, struct rus_data *data)
1640 bool save_may_throw, this_may_throw;
1641 tree_stmt_iterator i;
1644 /* Collect may_throw information for the body only. */
1645 save_may_throw = data->may_throw;
1646 data->may_throw = false;
1647 data->last_goto = NULL;
1649 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1651 this_may_throw = data->may_throw;
1652 data->may_throw = save_may_throw;
1654 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1655 if (!this_may_throw)
1657 if (warn_notreached)
1658 remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p, 1));
1659 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1660 data->repeat = true;
1664 /* Process the catch clause specially. We may be able to tell that
1665 no exceptions propagate past this point. */
1667 this_may_throw = true;
1668 i = tsi_start (TREE_OPERAND (*stmt_p, 1));
1669 stmt = tsi_stmt (i);
1670 data->last_goto = NULL;
1672 switch (TREE_CODE (stmt))
1675 for (; !tsi_end_p (i); tsi_next (&i))
1677 stmt = tsi_stmt (i);
1678 /* If we catch all exceptions, then the body does not
1679 propagate exceptions past this point. */
1680 if (CATCH_TYPES (stmt) == NULL)
1681 this_may_throw = false;
1682 data->last_goto = NULL;
1683 remove_useless_stmts_1 (&CATCH_BODY (stmt), data);
1687 case EH_FILTER_EXPR:
1688 if (EH_FILTER_MUST_NOT_THROW (stmt))
1689 this_may_throw = false;
1690 else if (EH_FILTER_TYPES (stmt) == NULL)
1691 this_may_throw = false;
1692 remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt), data);
1696 /* Otherwise this is a cleanup. */
1697 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1699 /* If the cleanup is empty, then we can emit the TRY block without
1700 the enclosing TRY_CATCH_EXPR. */
1701 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1703 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1704 data->repeat = true;
1708 data->may_throw |= this_may_throw;
1713 remove_useless_stmts_bind (tree *stmt_p, struct rus_data *data)
1717 /* First remove anything underneath the BIND_EXPR. */
1718 remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p), data);
1720 /* If the BIND_EXPR has no variables, then we can pull everything
1721 up one level and remove the BIND_EXPR, unless this is the toplevel
1722 BIND_EXPR for the current function or an inlined function.
1724 When this situation occurs we will want to apply this
1725 optimization again. */
1726 block = BIND_EXPR_BLOCK (*stmt_p);
1727 if (BIND_EXPR_VARS (*stmt_p) == NULL_TREE
1728 && *stmt_p != DECL_SAVED_TREE (current_function_decl)
1730 || ! BLOCK_ABSTRACT_ORIGIN (block)
1731 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1734 *stmt_p = BIND_EXPR_BODY (*stmt_p);
1735 data->repeat = true;
1741 remove_useless_stmts_goto (tree *stmt_p, struct rus_data *data)
1743 tree dest = GOTO_DESTINATION (*stmt_p);
1745 data->may_branch = true;
1746 data->last_goto = NULL;
1748 /* Record the last goto expr, so that we can delete it if unnecessary. */
1749 if (TREE_CODE (dest) == LABEL_DECL)
1750 data->last_goto = stmt_p;
1755 remove_useless_stmts_label (tree *stmt_p, struct rus_data *data)
1757 tree label = LABEL_EXPR_LABEL (*stmt_p);
1759 data->has_label = true;
1761 /* We do want to jump across non-local label receiver code. */
1762 if (DECL_NONLOCAL (label))
1763 data->last_goto = NULL;
1765 else if (data->last_goto && GOTO_DESTINATION (*data->last_goto) == label)
1767 *data->last_goto = build_empty_stmt ();
1768 data->repeat = true;
1771 /* ??? Add something here to delete unused labels. */
1775 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1776 decl. This allows us to eliminate redundant or useless
1777 calls to "const" functions.
1779 Gimplifier already does the same operation, but we may notice functions
1780 being const and pure once their calls has been gimplified, so we need
1781 to update the flag. */
1784 update_call_expr_flags (tree call)
1786 tree decl = get_callee_fndecl (call);
1789 if (call_expr_flags (call) & (ECF_CONST | ECF_PURE))
1790 TREE_SIDE_EFFECTS (call) = 0;
1791 if (TREE_NOTHROW (decl))
1792 TREE_NOTHROW (call) = 1;
1796 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1799 notice_special_calls (tree t)
1801 int flags = call_expr_flags (t);
1803 if (flags & ECF_MAY_BE_ALLOCA)
1804 current_function_calls_alloca = true;
1805 if (flags & ECF_RETURNS_TWICE)
1806 current_function_calls_setjmp = true;
1810 /* Clear flags set by notice_special_calls. Used by dead code removal
1811 to update the flags. */
1814 clear_special_calls (void)
1816 current_function_calls_alloca = false;
1817 current_function_calls_setjmp = false;
1822 remove_useless_stmts_1 (tree *tp, struct rus_data *data)
1826 switch (TREE_CODE (t))
1829 remove_useless_stmts_cond (tp, data);
1832 case TRY_FINALLY_EXPR:
1833 remove_useless_stmts_tf (tp, data);
1836 case TRY_CATCH_EXPR:
1837 remove_useless_stmts_tc (tp, data);
1841 remove_useless_stmts_bind (tp, data);
1845 remove_useless_stmts_goto (tp, data);
1849 remove_useless_stmts_label (tp, data);
1854 data->last_goto = NULL;
1855 data->may_branch = true;
1860 data->last_goto = NULL;
1861 notice_special_calls (t);
1862 update_call_expr_flags (t);
1863 if (tree_could_throw_p (t))
1864 data->may_throw = true;
1870 case GIMPLE_MODIFY_STMT:
1871 data->last_goto = NULL;
1873 op = get_call_expr_in (t);
1876 update_call_expr_flags (op);
1877 notice_special_calls (op);
1879 if (tree_could_throw_p (t))
1880 data->may_throw = true;
1883 case STATEMENT_LIST:
1885 tree_stmt_iterator i = tsi_start (t);
1886 while (!tsi_end_p (i))
1889 if (IS_EMPTY_STMT (t))
1895 remove_useless_stmts_1 (tsi_stmt_ptr (i), data);
1898 if (TREE_CODE (t) == STATEMENT_LIST)
1900 tsi_link_before (&i, t, TSI_SAME_STMT);
1910 data->last_goto = NULL;
1914 data->last_goto = NULL;
1920 remove_useless_stmts (void)
1922 struct rus_data data;
1924 clear_special_calls ();
1928 memset (&data, 0, sizeof (data));
1929 remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl), &data);
1931 while (data.repeat);
1936 struct tree_opt_pass pass_remove_useless_stmts =
1938 "useless", /* name */
1940 remove_useless_stmts, /* execute */
1943 0, /* static_pass_number */
1945 PROP_gimple_any, /* properties_required */
1946 0, /* properties_provided */
1947 0, /* properties_destroyed */
1948 0, /* todo_flags_start */
1949 TODO_dump_func, /* todo_flags_finish */
1953 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
1956 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
1960 /* Since this block is no longer reachable, we can just delete all
1961 of its PHI nodes. */
1962 phi = phi_nodes (bb);
1965 tree next = PHI_CHAIN (phi);
1966 remove_phi_node (phi, NULL_TREE, true);
1970 /* Remove edges to BB's successors. */
1971 while (EDGE_COUNT (bb->succs) > 0)
1972 remove_edge (EDGE_SUCC (bb, 0));
1976 /* Remove statements of basic block BB. */
1979 remove_bb (basic_block bb)
1981 block_stmt_iterator i;
1982 source_location loc = UNKNOWN_LOCATION;
1986 fprintf (dump_file, "Removing basic block %d\n", bb->index);
1987 if (dump_flags & TDF_DETAILS)
1989 dump_bb (bb, dump_file, 0);
1990 fprintf (dump_file, "\n");
1996 struct loop *loop = bb->loop_father;
1998 /* If a loop gets removed, clean up the information associated
2000 if (loop->latch == bb
2001 || loop->header == bb)
2002 free_numbers_of_iterations_estimates_loop (loop);
2005 /* Remove all the instructions in the block. */
2006 if (bb_stmt_list (bb) != NULL_TREE)
2008 for (i = bsi_start (bb); !bsi_end_p (i);)
2010 tree stmt = bsi_stmt (i);
2011 if (TREE_CODE (stmt) == LABEL_EXPR
2012 && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt))
2013 || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))))
2016 block_stmt_iterator new_bsi;
2018 /* A non-reachable non-local label may still be referenced.
2019 But it no longer needs to carry the extra semantics of
2021 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
2023 DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)) = 0;
2024 FORCED_LABEL (LABEL_EXPR_LABEL (stmt)) = 1;
2027 new_bb = bb->prev_bb;
2028 new_bsi = bsi_start (new_bb);
2029 bsi_remove (&i, false);
2030 bsi_insert_before (&new_bsi, stmt, BSI_NEW_STMT);
2034 /* Release SSA definitions if we are in SSA. Note that we
2035 may be called when not in SSA. For example,
2036 final_cleanup calls this function via
2037 cleanup_tree_cfg. */
2038 if (gimple_in_ssa_p (cfun))
2039 release_defs (stmt);
2041 bsi_remove (&i, true);
2044 /* Don't warn for removed gotos. Gotos are often removed due to
2045 jump threading, thus resulting in bogus warnings. Not great,
2046 since this way we lose warnings for gotos in the original
2047 program that are indeed unreachable. */
2048 if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc)
2050 if (EXPR_HAS_LOCATION (stmt))
2051 loc = EXPR_LOCATION (stmt);
2056 /* If requested, give a warning that the first statement in the
2057 block is unreachable. We walk statements backwards in the
2058 loop above, so the last statement we process is the first statement
2060 if (loc > BUILTINS_LOCATION && LOCATION_LINE (loc) > 0)
2061 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2063 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2068 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2069 predicate VAL, return the edge that will be taken out of the block.
2070 If VAL does not match a unique edge, NULL is returned. */
2073 find_taken_edge (basic_block bb, tree val)
2077 stmt = last_stmt (bb);
2080 gcc_assert (is_ctrl_stmt (stmt));
2083 if (! is_gimple_min_invariant (val))
2086 if (TREE_CODE (stmt) == COND_EXPR)
2087 return find_taken_edge_cond_expr (bb, val);
2089 if (TREE_CODE (stmt) == SWITCH_EXPR)
2090 return find_taken_edge_switch_expr (bb, val);
2092 if (computed_goto_p (stmt))
2094 /* Only optimize if the argument is a label, if the argument is
2095 not a label then we can not construct a proper CFG.
2097 It may be the case that we only need to allow the LABEL_REF to
2098 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2099 appear inside a LABEL_EXPR just to be safe. */
2100 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2101 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2102 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2109 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2110 statement, determine which of the outgoing edges will be taken out of the
2111 block. Return NULL if either edge may be taken. */
2114 find_taken_edge_computed_goto (basic_block bb, tree val)
2119 dest = label_to_block (val);
2122 e = find_edge (bb, dest);
2123 gcc_assert (e != NULL);
2129 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2130 statement, determine which of the two edges will be taken out of the
2131 block. Return NULL if either edge may be taken. */
2134 find_taken_edge_cond_expr (basic_block bb, tree val)
2136 edge true_edge, false_edge;
2138 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2140 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2141 return (integer_zerop (val) ? false_edge : true_edge);
2144 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2145 statement, determine which edge will be taken out of the block. Return
2146 NULL if any edge may be taken. */
2149 find_taken_edge_switch_expr (basic_block bb, tree val)
2151 tree switch_expr, taken_case;
2152 basic_block dest_bb;
2155 switch_expr = last_stmt (bb);
2156 taken_case = find_case_label_for_value (switch_expr, val);
2157 dest_bb = label_to_block (CASE_LABEL (taken_case));
2159 e = find_edge (bb, dest_bb);
2165 /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL.
2166 We can make optimal use here of the fact that the case labels are
2167 sorted: We can do a binary search for a case matching VAL. */
2170 find_case_label_for_value (tree switch_expr, tree val)
2172 tree vec = SWITCH_LABELS (switch_expr);
2173 size_t low, high, n = TREE_VEC_LENGTH (vec);
2174 tree default_case = TREE_VEC_ELT (vec, n - 1);
2176 for (low = -1, high = n - 1; high - low > 1; )
2178 size_t i = (high + low) / 2;
2179 tree t = TREE_VEC_ELT (vec, i);
2182 /* Cache the result of comparing CASE_LOW and val. */
2183 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2190 if (CASE_HIGH (t) == NULL)
2192 /* A singe-valued case label. */
2198 /* A case range. We can only handle integer ranges. */
2199 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2204 return default_case;
2210 /*---------------------------------------------------------------------------
2212 ---------------------------------------------------------------------------*/
2214 /* Dump tree-specific information of block BB to file OUTF. */
2217 tree_dump_bb (basic_block bb, FILE *outf, int indent)
2219 dump_generic_bb (outf, bb, indent, TDF_VOPS|TDF_MEMSYMS);
2223 /* Dump a basic block on stderr. */
2226 debug_tree_bb (basic_block bb)
2228 dump_bb (bb, stderr, 0);
2232 /* Dump basic block with index N on stderr. */
2235 debug_tree_bb_n (int n)
2237 debug_tree_bb (BASIC_BLOCK (n));
2238 return BASIC_BLOCK (n);
2242 /* Dump the CFG on stderr.
2244 FLAGS are the same used by the tree dumping functions
2245 (see TDF_* in tree-pass.h). */
2248 debug_tree_cfg (int flags)
2250 dump_tree_cfg (stderr, flags);
2254 /* Dump the program showing basic block boundaries on the given FILE.
2256 FLAGS are the same used by the tree dumping functions (see TDF_* in
2260 dump_tree_cfg (FILE *file, int flags)
2262 if (flags & TDF_DETAILS)
2264 const char *funcname
2265 = lang_hooks.decl_printable_name (current_function_decl, 2);
2268 fprintf (file, ";; Function %s\n\n", funcname);
2269 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2270 n_basic_blocks, n_edges, last_basic_block);
2272 brief_dump_cfg (file);
2273 fprintf (file, "\n");
2276 if (flags & TDF_STATS)
2277 dump_cfg_stats (file);
2279 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2283 /* Dump CFG statistics on FILE. */
2286 dump_cfg_stats (FILE *file)
2288 static long max_num_merged_labels = 0;
2289 unsigned long size, total = 0;
2292 const char * const fmt_str = "%-30s%-13s%12s\n";
2293 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2294 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2295 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2296 const char *funcname
2297 = lang_hooks.decl_printable_name (current_function_decl, 2);
2300 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2302 fprintf (file, "---------------------------------------------------------\n");
2303 fprintf (file, fmt_str, "", " Number of ", "Memory");
2304 fprintf (file, fmt_str, "", " instances ", "used ");
2305 fprintf (file, "---------------------------------------------------------\n");
2307 size = n_basic_blocks * sizeof (struct basic_block_def);
2309 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2310 SCALE (size), LABEL (size));
2314 num_edges += EDGE_COUNT (bb->succs);
2315 size = num_edges * sizeof (struct edge_def);
2317 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2319 fprintf (file, "---------------------------------------------------------\n");
2320 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2322 fprintf (file, "---------------------------------------------------------\n");
2323 fprintf (file, "\n");
2325 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2326 max_num_merged_labels = cfg_stats.num_merged_labels;
2328 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2329 cfg_stats.num_merged_labels, max_num_merged_labels);
2331 fprintf (file, "\n");
2335 /* Dump CFG statistics on stderr. Keep extern so that it's always
2336 linked in the final executable. */
2339 debug_cfg_stats (void)
2341 dump_cfg_stats (stderr);
2345 /* Dump the flowgraph to a .vcg FILE. */
2348 tree_cfg2vcg (FILE *file)
2353 const char *funcname
2354 = lang_hooks.decl_printable_name (current_function_decl, 2);
2356 /* Write the file header. */
2357 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2358 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2359 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2361 /* Write blocks and edges. */
2362 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2364 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2367 if (e->flags & EDGE_FAKE)
2368 fprintf (file, " linestyle: dotted priority: 10");
2370 fprintf (file, " linestyle: solid priority: 100");
2372 fprintf (file, " }\n");
2378 enum tree_code head_code, end_code;
2379 const char *head_name, *end_name;
2382 tree first = first_stmt (bb);
2383 tree last = last_stmt (bb);
2387 head_code = TREE_CODE (first);
2388 head_name = tree_code_name[head_code];
2389 head_line = get_lineno (first);
2392 head_name = "no-statement";
2396 end_code = TREE_CODE (last);
2397 end_name = tree_code_name[end_code];
2398 end_line = get_lineno (last);
2401 end_name = "no-statement";
2403 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2404 bb->index, bb->index, head_name, head_line, end_name,
2407 FOR_EACH_EDGE (e, ei, bb->succs)
2409 if (e->dest == EXIT_BLOCK_PTR)
2410 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2412 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2414 if (e->flags & EDGE_FAKE)
2415 fprintf (file, " priority: 10 linestyle: dotted");
2417 fprintf (file, " priority: 100 linestyle: solid");
2419 fprintf (file, " }\n");
2422 if (bb->next_bb != EXIT_BLOCK_PTR)
2426 fputs ("}\n\n", file);
2431 /*---------------------------------------------------------------------------
2432 Miscellaneous helpers
2433 ---------------------------------------------------------------------------*/
2435 /* Return true if T represents a stmt that always transfers control. */
2438 is_ctrl_stmt (const_tree t)
2440 return (TREE_CODE (t) == COND_EXPR
2441 || TREE_CODE (t) == SWITCH_EXPR
2442 || TREE_CODE (t) == GOTO_EXPR
2443 || TREE_CODE (t) == RETURN_EXPR
2444 || TREE_CODE (t) == RESX_EXPR);
2448 /* Return true if T is a statement that may alter the flow of control
2449 (e.g., a call to a non-returning function). */
2452 is_ctrl_altering_stmt (const_tree t)
2457 call = get_call_expr_in (CONST_CAST_TREE (t));
2460 /* A non-pure/const CALL_EXPR alters flow control if the current
2461 function has nonlocal labels. */
2462 if (TREE_SIDE_EFFECTS (call) && current_function_has_nonlocal_label)
2465 /* A CALL_EXPR also alters control flow if it does not return. */
2466 if (call_expr_flags (call) & ECF_NORETURN)
2470 /* OpenMP directives alter control flow. */
2471 if (OMP_DIRECTIVE_P (t))
2474 /* If a statement can throw, it alters control flow. */
2475 return tree_can_throw_internal (t);
2479 /* Return true if T is a computed goto. */
2482 computed_goto_p (const_tree t)
2484 return (TREE_CODE (t) == GOTO_EXPR
2485 && TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL);
2489 /* Return true if T is a simple local goto. */
2492 simple_goto_p (const_tree t)
2494 return (TREE_CODE (t) == GOTO_EXPR
2495 && TREE_CODE (GOTO_DESTINATION (t)) == LABEL_DECL);
2499 /* Return true if T can make an abnormal transfer of control flow.
2500 Transfers of control flow associated with EH are excluded. */
2503 tree_can_make_abnormal_goto (const_tree t)
2505 if (computed_goto_p (t))
2507 if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
2508 t = GIMPLE_STMT_OPERAND (t, 1);
2509 if (TREE_CODE (t) == WITH_SIZE_EXPR)
2510 t = TREE_OPERAND (t, 0);
2511 if (TREE_CODE (t) == CALL_EXPR)
2512 return TREE_SIDE_EFFECTS (t) && current_function_has_nonlocal_label;
2517 /* Return true if T should start a new basic block. PREV_T is the
2518 statement preceding T. It is used when T is a label or a case label.
2519 Labels should only start a new basic block if their previous statement
2520 wasn't a label. Otherwise, sequence of labels would generate
2521 unnecessary basic blocks that only contain a single label. */
2524 stmt_starts_bb_p (const_tree t, const_tree prev_t)
2529 /* LABEL_EXPRs start a new basic block only if the preceding
2530 statement wasn't a label of the same type. This prevents the
2531 creation of consecutive blocks that have nothing but a single
2533 if (TREE_CODE (t) == LABEL_EXPR)
2535 /* Nonlocal and computed GOTO targets always start a new block. */
2536 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t))
2537 || FORCED_LABEL (LABEL_EXPR_LABEL (t)))
2540 if (prev_t && TREE_CODE (prev_t) == LABEL_EXPR)
2542 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t)))
2545 cfg_stats.num_merged_labels++;
2556 /* Return true if T should end a basic block. */
2559 stmt_ends_bb_p (const_tree t)
2561 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2564 /* Remove block annotations and other datastructures. */
2567 delete_tree_cfg_annotations (void)
2570 block_stmt_iterator bsi;
2572 /* Remove annotations from every tree in the function. */
2574 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
2576 tree stmt = bsi_stmt (bsi);
2577 ggc_free (stmt->base.ann);
2578 stmt->base.ann = NULL;
2580 label_to_block_map = NULL;
2584 /* Return the first statement in basic block BB. */
2587 first_stmt (basic_block bb)
2589 block_stmt_iterator i = bsi_start (bb);
2590 return !bsi_end_p (i) ? bsi_stmt (i) : NULL_TREE;
2593 /* Return the last statement in basic block BB. */
2596 last_stmt (basic_block bb)
2598 block_stmt_iterator b = bsi_last (bb);
2599 return !bsi_end_p (b) ? bsi_stmt (b) : NULL_TREE;
2602 /* Return the last statement of an otherwise empty block. Return NULL
2603 if the block is totally empty, or if it contains more than one
2607 last_and_only_stmt (basic_block bb)
2609 block_stmt_iterator i = bsi_last (bb);
2615 last = bsi_stmt (i);
2620 /* Empty statements should no longer appear in the instruction stream.
2621 Everything that might have appeared before should be deleted by
2622 remove_useless_stmts, and the optimizers should just bsi_remove
2623 instead of smashing with build_empty_stmt.
2625 Thus the only thing that should appear here in a block containing
2626 one executable statement is a label. */
2627 prev = bsi_stmt (i);
2628 if (TREE_CODE (prev) == LABEL_EXPR)
2635 /* Mark BB as the basic block holding statement T. */
2638 set_bb_for_stmt (tree t, basic_block bb)
2640 if (TREE_CODE (t) == PHI_NODE)
2642 else if (TREE_CODE (t) == STATEMENT_LIST)
2644 tree_stmt_iterator i;
2645 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2646 set_bb_for_stmt (tsi_stmt (i), bb);
2650 stmt_ann_t ann = get_stmt_ann (t);
2653 /* If the statement is a label, add the label to block-to-labels map
2654 so that we can speed up edge creation for GOTO_EXPRs. */
2655 if (TREE_CODE (t) == LABEL_EXPR)
2659 t = LABEL_EXPR_LABEL (t);
2660 uid = LABEL_DECL_UID (t);
2663 unsigned old_len = VEC_length (basic_block, label_to_block_map);
2664 LABEL_DECL_UID (t) = uid = cfun->last_label_uid++;
2665 if (old_len <= (unsigned) uid)
2667 unsigned new_len = 3 * uid / 2;
2669 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
2674 /* We're moving an existing label. Make sure that we've
2675 removed it from the old block. */
2677 || !VEC_index (basic_block, label_to_block_map, uid));
2678 VEC_replace (basic_block, label_to_block_map, uid, bb);
2683 /* Faster version of set_bb_for_stmt that assume that statement is being moved
2684 from one basic block to another.
2685 For BB splitting we can run into quadratic case, so performance is quite
2686 important and knowing that the tables are big enough, change_bb_for_stmt
2687 can inline as leaf function. */
2689 change_bb_for_stmt (tree t, basic_block bb)
2691 get_stmt_ann (t)->bb = bb;
2692 if (TREE_CODE (t) == LABEL_EXPR)
2693 VEC_replace (basic_block, label_to_block_map,
2694 LABEL_DECL_UID (LABEL_EXPR_LABEL (t)), bb);
2697 /* Finds iterator for STMT. */
2699 extern block_stmt_iterator
2700 bsi_for_stmt (tree stmt)
2702 block_stmt_iterator bsi;
2704 for (bsi = bsi_start (bb_for_stmt (stmt)); !bsi_end_p (bsi); bsi_next (&bsi))
2705 if (bsi_stmt (bsi) == stmt)
2711 /* Mark statement T as modified, and update it. */
2713 update_modified_stmts (tree t)
2715 if (!ssa_operands_active ())
2717 if (TREE_CODE (t) == STATEMENT_LIST)
2719 tree_stmt_iterator i;
2721 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2723 stmt = tsi_stmt (i);
2724 update_stmt_if_modified (stmt);
2728 update_stmt_if_modified (t);
2731 /* Insert statement (or statement list) T before the statement
2732 pointed-to by iterator I. M specifies how to update iterator I
2733 after insertion (see enum bsi_iterator_update). */
2736 bsi_insert_before (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2738 set_bb_for_stmt (t, i->bb);
2739 update_modified_stmts (t);
2740 tsi_link_before (&i->tsi, t, m);
2744 /* Insert statement (or statement list) T after the statement
2745 pointed-to by iterator I. M specifies how to update iterator I
2746 after insertion (see enum bsi_iterator_update). */
2749 bsi_insert_after (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2751 set_bb_for_stmt (t, i->bb);
2752 update_modified_stmts (t);
2753 tsi_link_after (&i->tsi, t, m);
2757 /* Remove the statement pointed to by iterator I. The iterator is updated
2758 to the next statement.
2760 When REMOVE_EH_INFO is true we remove the statement pointed to by
2761 iterator I from the EH tables. Otherwise we do not modify the EH
2764 Generally, REMOVE_EH_INFO should be true when the statement is going to
2765 be removed from the IL and not reinserted elsewhere. */
2768 bsi_remove (block_stmt_iterator *i, bool remove_eh_info)
2770 tree t = bsi_stmt (*i);
2771 set_bb_for_stmt (t, NULL);
2772 delink_stmt_imm_use (t);
2773 tsi_delink (&i->tsi);
2774 mark_stmt_modified (t);
2777 remove_stmt_from_eh_region (t);
2778 gimple_remove_stmt_histograms (cfun, t);
2783 /* Move the statement at FROM so it comes right after the statement at TO. */
2786 bsi_move_after (block_stmt_iterator *from, block_stmt_iterator *to)
2788 tree stmt = bsi_stmt (*from);
2789 bsi_remove (from, false);
2790 /* We must have BSI_NEW_STMT here, as bsi_move_after is sometimes used to
2791 move statements to an empty block. */
2792 bsi_insert_after (to, stmt, BSI_NEW_STMT);
2796 /* Move the statement at FROM so it comes right before the statement at TO. */
2799 bsi_move_before (block_stmt_iterator *from, block_stmt_iterator *to)
2801 tree stmt = bsi_stmt (*from);
2802 bsi_remove (from, false);
2803 /* For consistency with bsi_move_after, it might be better to have
2804 BSI_NEW_STMT here; however, that breaks several places that expect
2805 that TO does not change. */
2806 bsi_insert_before (to, stmt, BSI_SAME_STMT);
2810 /* Move the statement at FROM to the end of basic block BB. */
2813 bsi_move_to_bb_end (block_stmt_iterator *from, basic_block bb)
2815 block_stmt_iterator last = bsi_last (bb);
2817 /* Have to check bsi_end_p because it could be an empty block. */
2818 if (!bsi_end_p (last) && is_ctrl_stmt (bsi_stmt (last)))
2819 bsi_move_before (from, &last);
2821 bsi_move_after (from, &last);
2825 /* Replace the contents of the statement pointed to by iterator BSI
2826 with STMT. If UPDATE_EH_INFO is true, the exception handling
2827 information of the original statement is moved to the new statement. */
2830 bsi_replace (const block_stmt_iterator *bsi, tree stmt, bool update_eh_info)
2833 tree orig_stmt = bsi_stmt (*bsi);
2835 if (stmt == orig_stmt)
2837 SET_EXPR_LOCUS (stmt, EXPR_LOCUS (orig_stmt));
2838 set_bb_for_stmt (stmt, bsi->bb);
2840 /* Preserve EH region information from the original statement, if
2841 requested by the caller. */
2844 eh_region = lookup_stmt_eh_region (orig_stmt);
2847 remove_stmt_from_eh_region (orig_stmt);
2848 add_stmt_to_eh_region (stmt, eh_region);
2852 gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
2853 gimple_remove_stmt_histograms (cfun, orig_stmt);
2854 delink_stmt_imm_use (orig_stmt);
2855 *bsi_stmt_ptr (*bsi) = stmt;
2856 mark_stmt_modified (stmt);
2857 update_modified_stmts (stmt);
2861 /* Insert the statement pointed-to by BSI into edge E. Every attempt
2862 is made to place the statement in an existing basic block, but
2863 sometimes that isn't possible. When it isn't possible, the edge is
2864 split and the statement is added to the new block.
2866 In all cases, the returned *BSI points to the correct location. The
2867 return value is true if insertion should be done after the location,
2868 or false if it should be done before the location. If new basic block
2869 has to be created, it is stored in *NEW_BB. */
2872 tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi,
2873 basic_block *new_bb)
2875 basic_block dest, src;
2881 /* If the destination has one predecessor which has no PHI nodes,
2882 insert there. Except for the exit block.
2884 The requirement for no PHI nodes could be relaxed. Basically we
2885 would have to examine the PHIs to prove that none of them used
2886 the value set by the statement we want to insert on E. That
2887 hardly seems worth the effort. */
2888 if (single_pred_p (dest)
2889 && ! phi_nodes (dest)
2890 && dest != EXIT_BLOCK_PTR)
2892 *bsi = bsi_start (dest);
2893 if (bsi_end_p (*bsi))
2896 /* Make sure we insert after any leading labels. */
2897 tmp = bsi_stmt (*bsi);
2898 while (TREE_CODE (tmp) == LABEL_EXPR)
2901 if (bsi_end_p (*bsi))
2903 tmp = bsi_stmt (*bsi);
2906 if (bsi_end_p (*bsi))
2908 *bsi = bsi_last (dest);
2915 /* If the source has one successor, the edge is not abnormal and
2916 the last statement does not end a basic block, insert there.
2917 Except for the entry block. */
2919 if ((e->flags & EDGE_ABNORMAL) == 0
2920 && single_succ_p (src)
2921 && src != ENTRY_BLOCK_PTR)
2923 *bsi = bsi_last (src);
2924 if (bsi_end_p (*bsi))
2927 tmp = bsi_stmt (*bsi);
2928 if (!stmt_ends_bb_p (tmp))
2931 /* Insert code just before returning the value. We may need to decompose
2932 the return in the case it contains non-trivial operand. */
2933 if (TREE_CODE (tmp) == RETURN_EXPR)
2935 tree op = TREE_OPERAND (tmp, 0);
2936 if (op && !is_gimple_val (op))
2938 gcc_assert (TREE_CODE (op) == GIMPLE_MODIFY_STMT);
2939 bsi_insert_before (bsi, op, BSI_NEW_STMT);
2940 TREE_OPERAND (tmp, 0) = GIMPLE_STMT_OPERAND (op, 0);
2947 /* Otherwise, create a new basic block, and split this edge. */
2948 dest = split_edge (e);
2951 e = single_pred_edge (dest);
2956 /* This routine will commit all pending edge insertions, creating any new
2957 basic blocks which are necessary. */
2960 bsi_commit_edge_inserts (void)
2966 bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL);
2969 FOR_EACH_EDGE (e, ei, bb->succs)
2970 bsi_commit_one_edge_insert (e, NULL);
2974 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
2975 to this block, otherwise set it to NULL. */
2978 bsi_commit_one_edge_insert (edge e, basic_block *new_bb)
2982 if (PENDING_STMT (e))
2984 block_stmt_iterator bsi;
2985 tree stmt = PENDING_STMT (e);
2987 PENDING_STMT (e) = NULL_TREE;
2989 if (tree_find_edge_insert_loc (e, &bsi, new_bb))
2990 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
2992 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
2997 /* Add STMT to the pending list of edge E. No actual insertion is
2998 made until a call to bsi_commit_edge_inserts () is made. */
3001 bsi_insert_on_edge (edge e, tree stmt)
3003 append_to_statement_list (stmt, &PENDING_STMT (e));
3006 /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new
3007 block has to be created, it is returned. */
3010 bsi_insert_on_edge_immediate (edge e, tree stmt)
3012 block_stmt_iterator bsi;
3013 basic_block new_bb = NULL;
3015 gcc_assert (!PENDING_STMT (e));
3017 if (tree_find_edge_insert_loc (e, &bsi, &new_bb))
3018 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3020 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3025 /*---------------------------------------------------------------------------
3026 Tree specific functions for CFG manipulation
3027 ---------------------------------------------------------------------------*/
3029 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
3032 reinstall_phi_args (edge new_edge, edge old_edge)
3035 edge_var_map_vector v;
3039 v = redirect_edge_var_map_vector (old_edge);
3043 for (i = 0, phi = phi_nodes (new_edge->dest);
3044 VEC_iterate (edge_var_map, v, i, vm) && phi;
3045 i++, phi = PHI_CHAIN (phi))
3047 tree result = redirect_edge_var_map_result (vm);
3048 tree arg = redirect_edge_var_map_def (vm);
3050 gcc_assert (result == PHI_RESULT (phi));
3052 add_phi_arg (phi, arg, new_edge);
3055 redirect_edge_var_map_clear (old_edge);
3058 /* Returns the basic block after which the new basic block created
3059 by splitting edge EDGE_IN should be placed. Tries to keep the new block
3060 near its "logical" location. This is of most help to humans looking
3061 at debugging dumps. */
3064 split_edge_bb_loc (edge edge_in)
3066 basic_block dest = edge_in->dest;
3068 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
3069 return edge_in->src;
3071 return dest->prev_bb;
3074 /* Split a (typically critical) edge EDGE_IN. Return the new block.
3075 Abort on abnormal edges. */
3078 tree_split_edge (edge edge_in)
3080 basic_block new_bb, after_bb, dest;
3083 /* Abnormal edges cannot be split. */
3084 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
3086 dest = edge_in->dest;
3088 after_bb = split_edge_bb_loc (edge_in);
3090 new_bb = create_empty_bb (after_bb);
3091 new_bb->frequency = EDGE_FREQUENCY (edge_in);
3092 new_bb->count = edge_in->count;
3093 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
3094 new_edge->probability = REG_BR_PROB_BASE;
3095 new_edge->count = edge_in->count;
3097 e = redirect_edge_and_branch (edge_in, new_bb);
3098 gcc_assert (e == edge_in);
3099 reinstall_phi_args (new_edge, e);
3104 /* Callback for walk_tree, check that all elements with address taken are
3105 properly noticed as such. The DATA is an int* that is 1 if TP was seen
3106 inside a PHI node. */
3109 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
3112 bool in_phi = (data != NULL);
3117 /* Check operand N for being valid GIMPLE and give error MSG if not. */
3118 #define CHECK_OP(N, MSG) \
3119 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
3120 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
3122 switch (TREE_CODE (t))
3125 if (SSA_NAME_IN_FREE_LIST (t))
3127 error ("SSA name in freelist but still referenced");
3133 x = fold (ASSERT_EXPR_COND (t));
3134 if (x == boolean_false_node)
3136 error ("ASSERT_EXPR with an always-false condition");
3144 case GIMPLE_MODIFY_STMT:
3145 x = GIMPLE_STMT_OPERAND (t, 0);
3146 if (TREE_CODE (x) == BIT_FIELD_REF
3147 && is_gimple_reg (TREE_OPERAND (x, 0)))
3149 error ("GIMPLE register modified with BIT_FIELD_REF");
3158 bool old_side_effects;
3161 bool new_side_effects;
3163 /* ??? tree-ssa-alias.c may have overlooked dead PHI nodes, missing
3164 dead PHIs that take the address of something. But if the PHI
3165 result is dead, the fact that it takes the address of anything
3166 is irrelevant. Because we can not tell from here if a PHI result
3167 is dead, we just skip this check for PHIs altogether. This means
3168 we may be missing "valid" checks, but what can you do?
3169 This was PR19217. */
3173 old_invariant = TREE_INVARIANT (t);
3174 old_constant = TREE_CONSTANT (t);
3175 old_side_effects = TREE_SIDE_EFFECTS (t);
3177 recompute_tree_invariant_for_addr_expr (t);
3178 new_invariant = TREE_INVARIANT (t);
3179 new_side_effects = TREE_SIDE_EFFECTS (t);
3180 new_constant = TREE_CONSTANT (t);
3182 if (old_invariant != new_invariant)
3184 error ("invariant not recomputed when ADDR_EXPR changed");
3188 if (old_constant != new_constant)
3190 error ("constant not recomputed when ADDR_EXPR changed");
3193 if (old_side_effects != new_side_effects)
3195 error ("side effects not recomputed when ADDR_EXPR changed");
3199 /* Skip any references (they will be checked when we recurse down the
3200 tree) and ensure that any variable used as a prefix is marked
3202 for (x = TREE_OPERAND (t, 0);
3203 handled_component_p (x);
3204 x = TREE_OPERAND (x, 0))
3207 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
3209 if (!TREE_ADDRESSABLE (x))
3211 error ("address taken, but ADDRESSABLE bit not set");
3215 /* Stop recursing and verifying invariant ADDR_EXPRs, they tend
3216 to become arbitrary complicated. */
3217 if (is_gimple_min_invariant (t))
3223 x = COND_EXPR_COND (t);
3224 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
3226 error ("non-integral used in condition");
3229 if (!is_gimple_condexpr (x))
3231 error ("invalid conditional operand");
3238 case FIX_TRUNC_EXPR:
3243 case NON_LVALUE_EXPR:
3244 case TRUTH_NOT_EXPR:
3245 CHECK_OP (0, "invalid operand to unary operator");
3252 case ARRAY_RANGE_REF:
3254 case VIEW_CONVERT_EXPR:
3255 /* We have a nest of references. Verify that each of the operands
3256 that determine where to reference is either a constant or a variable,
3257 verify that the base is valid, and then show we've already checked
3259 while (handled_component_p (t))
3261 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
3262 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
3263 else if (TREE_CODE (t) == ARRAY_REF
3264 || TREE_CODE (t) == ARRAY_RANGE_REF)
3266 CHECK_OP (1, "invalid array index");
3267 if (TREE_OPERAND (t, 2))
3268 CHECK_OP (2, "invalid array lower bound");
3269 if (TREE_OPERAND (t, 3))
3270 CHECK_OP (3, "invalid array stride");
3272 else if (TREE_CODE (t) == BIT_FIELD_REF)
3274 if (!host_integerp (TREE_OPERAND (t, 1), 1)
3275 || !host_integerp (TREE_OPERAND (t, 2), 1))
3277 error ("invalid position or size operand to BIT_FIELD_REF");
3280 else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
3281 && (TYPE_PRECISION (TREE_TYPE (t))
3282 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
3284 error ("integral result type precision does not match "
3285 "field size of BIT_FIELD_REF");
3288 if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
3289 && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
3290 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
3292 error ("mode precision of non-integral result does not "
3293 "match field size of BIT_FIELD_REF");
3298 t = TREE_OPERAND (t, 0);
3301 if (!is_gimple_min_invariant (t) && !is_gimple_lvalue (t))
3303 error ("invalid reference prefix");
3310 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
3311 POINTER_PLUS_EXPR. */
3312 if (POINTER_TYPE_P (TREE_TYPE (t)))
3314 error ("invalid operand to plus/minus, type is a pointer");
3317 CHECK_OP (0, "invalid operand to binary operator");
3318 CHECK_OP (1, "invalid operand to binary operator");
3321 case POINTER_PLUS_EXPR:
3322 /* Check to make sure the first operand is a pointer or reference type. */
3323 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
3325 error ("invalid operand to pointer plus, first operand is not a pointer");
3328 /* Check to make sure the second operand is an integer with type of
3330 if (!useless_type_conversion_p (sizetype,
3331 TREE_TYPE (TREE_OPERAND (t, 1))))
3333 error ("invalid operand to pointer plus, second operand is not an "
3334 "integer with type of sizetype.");
3344 case UNORDERED_EXPR:
3353 case TRUNC_DIV_EXPR:
3355 case FLOOR_DIV_EXPR:
3356 case ROUND_DIV_EXPR:
3357 case TRUNC_MOD_EXPR:
3359 case FLOOR_MOD_EXPR:
3360 case ROUND_MOD_EXPR:
3362 case EXACT_DIV_EXPR:
3372 CHECK_OP (0, "invalid operand to binary operator");
3373 CHECK_OP (1, "invalid operand to binary operator");
3377 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3389 /* Verifies if EXPR is a valid GIMPLE unary expression. Returns true
3390 if there is an error, otherwise false. */
3393 verify_gimple_unary_expr (const_tree expr)
3395 tree op = TREE_OPERAND (expr, 0);
3396 tree type = TREE_TYPE (expr);
3398 if (!is_gimple_val (op))
3400 error ("invalid operand in unary expression");
3404 /* For general unary expressions we have the operations type
3405 as the effective type the operation is carried out on. So all
3406 we need to require is that the operand is trivially convertible
3408 if (!useless_type_conversion_p (type, TREE_TYPE (op)))
3410 error ("type mismatch in unary expression");
3411 debug_generic_expr (type);
3412 debug_generic_expr (TREE_TYPE (op));
3419 /* Verifies if EXPR is a valid GIMPLE binary expression. Returns true
3420 if there is an error, otherwise false. */
3423 verify_gimple_binary_expr (const_tree expr)
3425 tree op0 = TREE_OPERAND (expr, 0);
3426 tree op1 = TREE_OPERAND (expr, 1);
3427 tree type = TREE_TYPE (expr);
3429 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3431 error ("invalid operands in binary expression");
3435 /* For general binary expressions we have the operations type
3436 as the effective type the operation is carried out on. So all
3437 we need to require is that both operands are trivially convertible
3439 if (!useless_type_conversion_p (type, TREE_TYPE (op0))
3440 || !useless_type_conversion_p (type, TREE_TYPE (op1)))
3442 error ("type mismatch in binary expression");
3443 debug_generic_stmt (type);
3444 debug_generic_stmt (TREE_TYPE (op0));
3445 debug_generic_stmt (TREE_TYPE (op1));
3452 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3453 Returns true if there is an error, otherwise false. */
3456 verify_gimple_min_lval (tree expr)
3460 if (is_gimple_id (expr))
3463 if (TREE_CODE (expr) != INDIRECT_REF
3464 && TREE_CODE (expr) != ALIGN_INDIRECT_REF
3465 && TREE_CODE (expr) != MISALIGNED_INDIRECT_REF)
3467 error ("invalid expression for min lvalue");
3471 op = TREE_OPERAND (expr, 0);
3472 if (!is_gimple_val (op))
3474 error ("invalid operand in indirect reference");
3475 debug_generic_stmt (op);
3478 if (!useless_type_conversion_p (TREE_TYPE (expr),
3479 TREE_TYPE (TREE_TYPE (op))))
3481 error ("type mismatch in indirect reference");
3482 debug_generic_stmt (TREE_TYPE (expr));
3483 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3490 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3491 if there is an error, otherwise false. */
3494 verify_gimple_reference (tree expr)
3496 while (handled_component_p (expr))
3498 tree op = TREE_OPERAND (expr, 0);
3500 if (TREE_CODE (expr) == ARRAY_REF
3501 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3503 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3504 || (TREE_OPERAND (expr, 2)
3505 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3506 || (TREE_OPERAND (expr, 3)
3507 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3509 error ("invalid operands to array reference");
3510 debug_generic_stmt (expr);
3515 /* Verify if the reference array element types are compatible. */
3516 if (TREE_CODE (expr) == ARRAY_REF
3517 && !useless_type_conversion_p (TREE_TYPE (expr),
3518 TREE_TYPE (TREE_TYPE (op))))
3520 error ("type mismatch in array reference");
3521 debug_generic_stmt (TREE_TYPE (expr));
3522 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3525 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3526 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3527 TREE_TYPE (TREE_TYPE (op))))
3529 error ("type mismatch in array range reference");
3530 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3531 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3535 if ((TREE_CODE (expr) == REALPART_EXPR
3536 || TREE_CODE (expr) == IMAGPART_EXPR)
3537 && !useless_type_conversion_p (TREE_TYPE (expr),
3538 TREE_TYPE (TREE_TYPE (op))))
3540 error ("type mismatch in real/imagpart reference");
3541 debug_generic_stmt (TREE_TYPE (expr));
3542 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3546 if (TREE_CODE (expr) == COMPONENT_REF
3547 && !useless_type_conversion_p (TREE_TYPE (expr),
3548 TREE_TYPE (TREE_OPERAND (expr, 1))))
3550 error ("type mismatch in component reference");
3551 debug_generic_stmt (TREE_TYPE (expr));
3552 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3556 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3557 is nothing to verify. Gross mismatches at most invoke
3558 undefined behavior. */
3563 return verify_gimple_min_lval (expr);
3566 /* Returns true if there is one pointer type in TYPE_POINTER_TO (SRC_OBJ)
3567 list of pointer-to types that is trivially convertible to DEST. */
3570 one_pointer_to_useless_type_conversion_p (tree dest, tree src_obj)
3574 if (!TYPE_POINTER_TO (src_obj))
3577 for (src = TYPE_POINTER_TO (src_obj); src; src = TYPE_NEXT_PTR_TO (src))
3578 if (useless_type_conversion_p (dest, src))
3584 /* Verify the GIMPLE expression EXPR. Returns true if there is an
3585 error, otherwise false. */
3588 verify_gimple_expr (tree expr)
3590 tree type = TREE_TYPE (expr);
3592 if (is_gimple_val (expr))
3595 /* Special codes we cannot handle via their class. */
3596 switch (TREE_CODE (expr))
3601 tree op = TREE_OPERAND (expr, 0);
3602 if (!is_gimple_val (op))
3604 error ("invalid operand in conversion");
3608 /* Allow conversions between integral types and between
3610 if ((INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3611 || (POINTER_TYPE_P (type) && POINTER_TYPE_P (TREE_TYPE (op))))
3614 /* Allow conversions between integral types and pointers only if
3615 there is no sign or zero extension involved. */
3616 if (((POINTER_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3617 || (POINTER_TYPE_P (TREE_TYPE (op)) && INTEGRAL_TYPE_P (type)))
3618 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op)))
3621 /* Allow conversion from integer to offset type and vice versa. */
3622 if ((TREE_CODE (type) == OFFSET_TYPE
3623 && TREE_CODE (TREE_TYPE (op)) == INTEGER_TYPE)
3624 || (TREE_CODE (type) == INTEGER_TYPE
3625 && TREE_CODE (TREE_TYPE (op)) == OFFSET_TYPE))
3628 /* Otherwise assert we are converting between types of the
3630 if (TREE_CODE (type) != TREE_CODE (TREE_TYPE (op)))
3632 error ("invalid types in nop conversion");
3633 debug_generic_expr (type);
3634 debug_generic_expr (TREE_TYPE (op));
3643 tree op = TREE_OPERAND (expr, 0);
3644 if (!is_gimple_val (op))
3646 error ("invalid operand in int to float conversion");
3649 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3650 || !SCALAR_FLOAT_TYPE_P (type))
3652 error ("invalid types in conversion to floating point");
3653 debug_generic_expr (type);
3654 debug_generic_expr (TREE_TYPE (op));
3660 case FIX_TRUNC_EXPR:
3662 tree op = TREE_OPERAND (expr, 0);
3663 if (!is_gimple_val (op))
3665 error ("invalid operand in float to int conversion");
3668 if (!INTEGRAL_TYPE_P (type)
3669 || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (op)))
3671 error ("invalid types in conversion to integer");
3672 debug_generic_expr (type);
3673 debug_generic_expr (TREE_TYPE (op));
3681 tree op0 = TREE_OPERAND (expr, 0);
3682 tree op1 = TREE_OPERAND (expr, 1);
3683 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3685 error ("invalid operands in complex expression");
3688 if (!TREE_CODE (type) == COMPLEX_TYPE
3689 || !(TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
3690 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0)))
3691 || !(TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3692 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op1)))
3693 || !useless_type_conversion_p (TREE_TYPE (type),
3695 || !useless_type_conversion_p (TREE_TYPE (type),
3698 error ("type mismatch in complex expression");
3699 debug_generic_stmt (TREE_TYPE (expr));
3700 debug_generic_stmt (TREE_TYPE (op0));
3701 debug_generic_stmt (TREE_TYPE (op1));
3709 /* This is used like COMPLEX_EXPR but for vectors. */
3710 if (TREE_CODE (type) != VECTOR_TYPE)
3712 error ("constructor not allowed for non-vector types");
3713 debug_generic_stmt (type);
3716 /* FIXME: verify constructor arguments. */
3725 tree op0 = TREE_OPERAND (expr, 0);
3726 tree op1 = TREE_OPERAND (expr, 1);
3727 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3729 error ("invalid operands in shift expression");
3732 if (!TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3733 || !useless_type_conversion_p (type, TREE_TYPE (op0)))
3735 error ("type mismatch in shift expression");
3736 debug_generic_stmt (TREE_TYPE (expr));
3737 debug_generic_stmt (TREE_TYPE (op0));
3738 debug_generic_stmt (TREE_TYPE (op1));
3747 tree op0 = TREE_OPERAND (expr, 0);
3748 tree op1 = TREE_OPERAND (expr, 1);
3749 if (POINTER_TYPE_P (type)
3750 || POINTER_TYPE_P (TREE_TYPE (op0))
3751 || POINTER_TYPE_P (TREE_TYPE (op1)))
3753 error ("invalid (pointer) operands to plus/minus");
3756 /* Continue with generic binary expression handling. */
3760 case POINTER_PLUS_EXPR:
3762 tree op0 = TREE_OPERAND (expr, 0);
3763 tree op1 = TREE_OPERAND (expr, 1);
3764 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3766 error ("invalid operands in pointer plus expression");
3769 if (!POINTER_TYPE_P (TREE_TYPE (op0))
3770 || !useless_type_conversion_p (type, TREE_TYPE (op0))
3771 || !useless_type_conversion_p (sizetype, TREE_TYPE (op1)))
3773 error ("type mismatch in pointer plus expression");
3774 debug_generic_stmt (type);
3775 debug_generic_stmt (TREE_TYPE (op0));
3776 debug_generic_stmt (TREE_TYPE (op1));
3784 tree op0 = TREE_OPERAND (expr, 0);
3785 tree op1 = TREE_OPERAND (expr, 1);
3786 tree op2 = TREE_OPERAND (expr, 2);
3787 if ((!is_gimple_val (op1)
3788 && TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3789 || (!is_gimple_val (op2)
3790 && TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE))
3792 error ("invalid operands in conditional expression");
3795 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3796 || (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE
3797 && !useless_type_conversion_p (type, TREE_TYPE (op1)))
3798 || (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE
3799 && !useless_type_conversion_p (type, TREE_TYPE (op2))))
3801 error ("type mismatch in conditional expression");
3802 debug_generic_stmt (type);
3803 debug_generic_stmt (TREE_TYPE (op0));
3804 debug_generic_stmt (TREE_TYPE (op1));
3805 debug_generic_stmt (TREE_TYPE (op2));
3808 return verify_gimple_expr (op0);
3813 tree op = TREE_OPERAND (expr, 0);
3814 if (!is_gimple_addressable (op))
3816 error ("invalid operand in unary expression");
3819 if (!one_pointer_to_useless_type_conversion_p (type, TREE_TYPE (op))
3820 /* FIXME: a longstanding wart, &a == &a[0]. */
3821 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3822 || !one_pointer_to_useless_type_conversion_p (type,
3823 TREE_TYPE (TREE_TYPE (op)))))
3825 error ("type mismatch in address expression");
3826 debug_generic_stmt (TREE_TYPE (expr));
3827 debug_generic_stmt (TYPE_POINTER_TO (TREE_TYPE (op)));
3831 return verify_gimple_reference (op);
3834 case TRUTH_ANDIF_EXPR:
3835 case TRUTH_ORIF_EXPR:
3836 case TRUTH_AND_EXPR:
3838 case TRUTH_XOR_EXPR:
3840 tree op0 = TREE_OPERAND (expr, 0);
3841 tree op1 = TREE_OPERAND (expr, 1);
3843 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3845 error ("invalid operands in truth expression");
3849 /* We allow any kind of integral typed argument and result. */
3850 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3851 || !INTEGRAL_TYPE_P (TREE_TYPE (op1))
3852 || !INTEGRAL_TYPE_P (type))
3854 error ("type mismatch in binary truth expression");
3855 debug_generic_stmt (type);
3856 debug_generic_stmt (TREE_TYPE (op0));
3857 debug_generic_stmt (TREE_TYPE (op1));
3864 case TRUTH_NOT_EXPR:
3866 tree op = TREE_OPERAND (expr, 0);
3868 if (!is_gimple_val (op))
3870 error ("invalid operand in unary not");
3874 /* For TRUTH_NOT_EXPR we can have any kind of integral
3875 typed arguments and results. */
3876 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3877 || !INTEGRAL_TYPE_P (type))
3879 error ("type mismatch in not expression");
3880 debug_generic_expr (TREE_TYPE (expr));
3881 debug_generic_expr (TREE_TYPE (op));
3889 /* FIXME. The C frontend passes unpromoted arguments in case it
3890 didn't see a function declaration before the call. */
3900 /* Generic handling via classes. */
3901 switch (TREE_CODE_CLASS (TREE_CODE (expr)))
3904 return verify_gimple_unary_expr (expr);
3907 return verify_gimple_binary_expr (expr);
3910 return verify_gimple_reference (expr);
3912 case tcc_comparison:
3914 tree op0 = TREE_OPERAND (expr, 0);
3915 tree op1 = TREE_OPERAND (expr, 1);
3916 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3918 error ("invalid operands in comparison expression");
3921 /* For comparisons we do not have the operations type as the
3922 effective type the comparison is carried out in. Instead
3923 we require that either the first operand is trivially
3924 convertible into the second, or the other way around.
3925 The resulting type of a comparison may be any integral type.
3926 Because we special-case pointers to void we allow
3927 comparisons of pointers with the same mode as well. */
3928 if ((!useless_type_conversion_p (TREE_TYPE (op0), TREE_TYPE (op1))
3929 && !useless_type_conversion_p (TREE_TYPE (op1), TREE_TYPE (op0))
3930 && (!POINTER_TYPE_P (TREE_TYPE (op0))
3931 || !POINTER_TYPE_P (TREE_TYPE (op1))
3932 || TYPE_MODE (TREE_TYPE (op0)) != TYPE_MODE (TREE_TYPE (op1))))
3933 || !INTEGRAL_TYPE_P (type))
3935 error ("type mismatch in comparison expression");
3936 debug_generic_stmt (TREE_TYPE (expr));
3937 debug_generic_stmt (TREE_TYPE (op0));
3938 debug_generic_stmt (TREE_TYPE (op1));
3951 /* Verify the GIMPLE assignment statement STMT. Returns true if there
3952 is an error, otherwise false. */
3955 verify_gimple_modify_stmt (const_tree stmt)
3957 tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
3958 tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
3960 gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
3962 if (!useless_type_conversion_p (TREE_TYPE (lhs),
3965 error ("non-trivial conversion at assignment");
3966 debug_generic_expr (TREE_TYPE (lhs));
3967 debug_generic_expr (TREE_TYPE (rhs));
3971 /* Loads/stores from/to a variable are ok. */
3972 if ((is_gimple_val (lhs)
3973 && is_gimple_variable (rhs))
3974 || (is_gimple_val (rhs)
3975 && is_gimple_variable (lhs)))
3978 /* Aggregate copies are ok. */
3979 if (!is_gimple_reg_type (TREE_TYPE (lhs))
3980 && !is_gimple_reg_type (TREE_TYPE (rhs)))
3983 /* We might get 'loads' from a parameter which is not a gimple value. */
3984 if (TREE_CODE (rhs) == PARM_DECL)
3985 return verify_gimple_expr (lhs);
3987 if (!is_gimple_variable (lhs)
3988 && verify_gimple_expr (lhs))
3991 if (!is_gimple_variable (rhs)
3992 && verify_gimple_expr (rhs))
3998 /* Verify the GIMPLE statement STMT. Returns true if there is an
3999 error, otherwise false. */
4002 verify_gimple_stmt (tree stmt)
4004 if (!is_gimple_stmt (stmt))
4006 error ("is not a valid GIMPLE statement");
4010 if (OMP_DIRECTIVE_P (stmt))
4012 /* OpenMP directives are validated by the FE and never operated
4013 on by the optimizers. Furthermore, OMP_FOR may contain
4014 non-gimple expressions when the main index variable has had
4015 its address taken. This does not affect the loop itself
4016 because the header of an OMP_FOR is merely used to determine
4017 how to setup the parallel iteration. */
4021 switch (TREE_CODE (stmt))
4023 case GIMPLE_MODIFY_STMT:
4024 return verify_gimple_modify_stmt (stmt);
4031 if (!is_gimple_val (TREE_OPERAND (stmt, 0)))
4033 error ("invalid operand to switch statement");
4034 debug_generic_expr (TREE_OPERAND (stmt, 0));
4040 tree op = TREE_OPERAND (stmt, 0);
4042 if (TREE_CODE (TREE_TYPE (stmt)) != VOID_TYPE)
4044 error ("type error in return expression");
4049 || TREE_CODE (op) == RESULT_DECL)
4052 return verify_gimple_modify_stmt (op);
4057 return verify_gimple_expr (stmt);
4060 case CHANGE_DYNAMIC_TYPE_EXPR:
4069 /* Verify the GIMPLE statements inside the statement list STMTS.
4070 Returns true if there were any errors. */
4073 verify_gimple_2 (tree stmts)
4075 tree_stmt_iterator tsi;
4078 for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi))
4080 tree stmt = tsi_stmt (tsi);
4082 switch (TREE_CODE (stmt))
4085 err |= verify_gimple_2 (BIND_EXPR_BODY (stmt));
4088 case TRY_CATCH_EXPR:
4089 case TRY_FINALLY_EXPR:
4090 err |= verify_gimple_2 (TREE_OPERAND (stmt, 0));
4091 err |= verify_gimple_2 (TREE_OPERAND (stmt, 1));
4095 err |= verify_gimple_2 (CATCH_BODY (stmt));
4098 case EH_FILTER_EXPR:
4099 err |= verify_gimple_2 (EH_FILTER_FAILURE (stmt));
4104 bool err2 = verify_gimple_stmt (stmt);
4106 debug_generic_expr (stmt);
4116 /* Verify the GIMPLE statements inside the statement list STMTS. */
4119 verify_gimple_1 (tree stmts)
4121 if (verify_gimple_2 (stmts))
4122 internal_error ("verify_gimple failed");
4125 /* Verify the GIMPLE statements inside the current function. */
4128 verify_gimple (void)
4130 verify_gimple_1 (BIND_EXPR_BODY (DECL_SAVED_TREE (cfun->decl)));
4133 /* Verify STMT, return true if STMT is not in GIMPLE form.
4134 TODO: Implement type checking. */
4137 verify_stmt (tree stmt, bool last_in_block)
4141 if (OMP_DIRECTIVE_P (stmt))
4143 /* OpenMP directives are validated by the FE and never operated
4144 on by the optimizers. Furthermore, OMP_FOR may contain
4145 non-gimple expressions when the main index variable has had
4146 its address taken. This does not affect the loop itself
4147 because the header of an OMP_FOR is merely used to determine
4148 how to setup the parallel iteration. */
4152 if (!is_gimple_stmt (stmt))
4154 error ("is not a valid GIMPLE statement");
4158 addr = walk_tree (&stmt, verify_expr, NULL, NULL);
4161 debug_generic_stmt (addr);
4165 /* If the statement is marked as part of an EH region, then it is
4166 expected that the statement could throw. Verify that when we
4167 have optimizations that simplify statements such that we prove
4168 that they cannot throw, that we update other data structures
4170 if (lookup_stmt_eh_region (stmt) >= 0)
4172 if (!tree_could_throw_p (stmt))
4174 error ("statement marked for throw, but doesn%'t");
4177 if (!last_in_block && tree_can_throw_internal (stmt))
4179 error ("statement marked for throw in middle of block");
4187 debug_generic_stmt (stmt);
4192 /* Return true when the T can be shared. */
4195 tree_node_can_be_shared (tree t)
4197 if (IS_TYPE_OR_DECL_P (t)
4198 || is_gimple_min_invariant (t)
4199 || TREE_CODE (t) == SSA_NAME
4200 || t == error_mark_node
4201 || TREE_CODE (t) == IDENTIFIER_NODE)
4204 if (TREE_CODE (t) == CASE_LABEL_EXPR)
4207 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4208 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4209 || TREE_CODE (t) == COMPONENT_REF
4210 || TREE_CODE (t) == REALPART_EXPR
4211 || TREE_CODE (t) == IMAGPART_EXPR)
4212 t = TREE_OPERAND (t, 0);
4221 /* Called via walk_trees. Verify tree sharing. */
4224 verify_node_sharing (tree * tp, int *walk_subtrees, void *data)
4226 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4228 if (tree_node_can_be_shared (*tp))
4230 *walk_subtrees = false;
4234 if (pointer_set_insert (visited, *tp))
4241 /* Helper function for verify_gimple_tuples. */
4244 verify_gimple_tuples_1 (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4245 void *data ATTRIBUTE_UNUSED)
4247 switch (TREE_CODE (*tp))
4250 error ("unexpected non-tuple");
4260 /* Verify that there are no trees that should have been converted to
4261 gimple tuples. Return true if T contains a node that should have
4262 been converted to a gimple tuple, but hasn't. */
4265 verify_gimple_tuples (tree t)
4267 return walk_tree (&t, verify_gimple_tuples_1, NULL, NULL) != NULL;
4270 static bool eh_error_found;
4272 verify_eh_throw_stmt_node (void **slot, void *data)
4274 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4275 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4277 if (!pointer_set_contains (visited, node->stmt))
4279 error ("Dead STMT in EH table");
4280 debug_generic_stmt (node->stmt);
4281 eh_error_found = true;
4286 /* Verify the GIMPLE statement chain. */
4292 block_stmt_iterator bsi;
4294 struct pointer_set_t *visited, *visited_stmts;
4297 timevar_push (TV_TREE_STMT_VERIFY);
4298 visited = pointer_set_create ();
4299 visited_stmts = pointer_set_create ();
4306 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4308 int phi_num_args = PHI_NUM_ARGS (phi);
4310 pointer_set_insert (visited_stmts, phi);
4311 if (bb_for_stmt (phi) != bb)
4313 error ("bb_for_stmt (phi) is set to a wrong basic block");
4317 for (i = 0; i < phi_num_args; i++)
4319 tree t = PHI_ARG_DEF (phi, i);
4324 error ("missing PHI def");
4325 debug_generic_stmt (phi);
4329 /* Addressable variables do have SSA_NAMEs but they
4330 are not considered gimple values. */
4331 else if (TREE_CODE (t) != SSA_NAME
4332 && TREE_CODE (t) != FUNCTION_DECL
4333 && !is_gimple_val (t))
4335 error ("PHI def is not a GIMPLE value");
4336 debug_generic_stmt (phi);
4337 debug_generic_stmt (t);
4341 addr = walk_tree (&t, verify_expr, (void *) 1, NULL);
4344 debug_generic_stmt (addr);
4348 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4351 error ("incorrect sharing of tree nodes");
4352 debug_generic_stmt (phi);
4353 debug_generic_stmt (addr);
4359 for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
4361 tree stmt = bsi_stmt (bsi);
4363 pointer_set_insert (visited_stmts, stmt);
4364 err |= verify_gimple_tuples (stmt);
4366 if (bb_for_stmt (stmt) != bb)
4368 error ("bb_for_stmt (stmt) is set to a wrong basic block");
4373 err |= verify_stmt (stmt, bsi_end_p (bsi));
4374 addr = walk_tree (&stmt, verify_node_sharing, visited, NULL);
4377 error ("incorrect sharing of tree nodes");
4378 debug_generic_stmt (stmt);
4379 debug_generic_stmt (addr);
4384 eh_error_found = false;
4385 if (get_eh_throw_stmt_table (cfun))
4386 htab_traverse (get_eh_throw_stmt_table (cfun),
4387 verify_eh_throw_stmt_node,
4390 if (err | eh_error_found)
4391 internal_error ("verify_stmts failed");
4393 pointer_set_destroy (visited);
4394 pointer_set_destroy (visited_stmts);
4395 verify_histograms ();
4396 timevar_pop (TV_TREE_STMT_VERIFY);
4400 /* Verifies that the flow information is OK. */
4403 tree_verify_flow_info (void)
4407 block_stmt_iterator bsi;
4412 if (ENTRY_BLOCK_PTR->il.tree)
4414 error ("ENTRY_BLOCK has IL associated with it");
4418 if (EXIT_BLOCK_PTR->il.tree)
4420 error ("EXIT_BLOCK has IL associated with it");
4424 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4425 if (e->flags & EDGE_FALLTHRU)
4427 error ("fallthru to exit from bb %d", e->src->index);
4433 bool found_ctrl_stmt = false;
4437 /* Skip labels on the start of basic block. */
4438 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4440 tree prev_stmt = stmt;
4442 stmt = bsi_stmt (bsi);
4444 if (TREE_CODE (stmt) != LABEL_EXPR)
4447 if (prev_stmt && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
4449 error ("nonlocal label ");
4450 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4451 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4456 if (label_to_block (LABEL_EXPR_LABEL (stmt)) != bb)
4459 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4460 fprintf (stderr, " to block does not match in bb %d",
4465 if (decl_function_context (LABEL_EXPR_LABEL (stmt))
4466 != current_function_decl)
4469 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4470 fprintf (stderr, " has incorrect context in bb %d",
4476 /* Verify that body of basic block BB is free of control flow. */
4477 for (; !bsi_end_p (bsi); bsi_next (&bsi))
4479 tree stmt = bsi_stmt (bsi);
4481 if (found_ctrl_stmt)
4483 error ("control flow in the middle of basic block %d",
4488 if (stmt_ends_bb_p (stmt))
4489 found_ctrl_stmt = true;
4491 if (TREE_CODE (stmt) == LABEL_EXPR)
4494 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4495 fprintf (stderr, " in the middle of basic block %d", bb->index);
4500 bsi = bsi_last (bb);
4501 if (bsi_end_p (bsi))
4504 stmt = bsi_stmt (bsi);
4506 err |= verify_eh_edges (stmt);
4508 if (is_ctrl_stmt (stmt))
4510 FOR_EACH_EDGE (e, ei, bb->succs)
4511 if (e->flags & EDGE_FALLTHRU)
4513 error ("fallthru edge after a control statement in bb %d",
4519 if (TREE_CODE (stmt) != COND_EXPR)
4521 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4522 after anything else but if statement. */
4523 FOR_EACH_EDGE (e, ei, bb->succs)
4524 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4526 error ("true/false edge after a non-COND_EXPR in bb %d",
4532 switch (TREE_CODE (stmt))
4539 if (COND_EXPR_THEN (stmt) != NULL_TREE
4540 || COND_EXPR_ELSE (stmt) != NULL_TREE)
4542 error ("COND_EXPR with code in branches at the end of bb %d",
4547 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4549 if (!true_edge || !false_edge
4550 || !(true_edge->flags & EDGE_TRUE_VALUE)
4551 || !(false_edge->flags & EDGE_FALSE_VALUE)
4552 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4553 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4554 || EDGE_COUNT (bb->succs) >= 3)
4556 error ("wrong outgoing edge flags at end of bb %d",
4564 if (simple_goto_p (stmt))
4566 error ("explicit goto at end of bb %d", bb->index);
4571 /* FIXME. We should double check that the labels in the
4572 destination blocks have their address taken. */
4573 FOR_EACH_EDGE (e, ei, bb->succs)
4574 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4575 | EDGE_FALSE_VALUE))
4576 || !(e->flags & EDGE_ABNORMAL))
4578 error ("wrong outgoing edge flags at end of bb %d",
4586 if (!single_succ_p (bb)
4587 || (single_succ_edge (bb)->flags
4588 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4589 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4591 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4594 if (single_succ (bb) != EXIT_BLOCK_PTR)
4596 error ("return edge does not point to exit in bb %d",
4609 vec = SWITCH_LABELS (stmt);
4610 n = TREE_VEC_LENGTH (vec);
4612 /* Mark all the destination basic blocks. */
4613 for (i = 0; i < n; ++i)
4615 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4616 basic_block label_bb = label_to_block (lab);
4618 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4619 label_bb->aux = (void *)1;
4622 /* Verify that the case labels are sorted. */
4623 prev = TREE_VEC_ELT (vec, 0);
4624 for (i = 1; i < n - 1; ++i)
4626 tree c = TREE_VEC_ELT (vec, i);
4629 error ("found default case not at end of case vector");
4633 if (! tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4635 error ("case labels not sorted: ");
4636 print_generic_expr (stderr, prev, 0);
4637 fprintf (stderr," is greater than ");
4638 print_generic_expr (stderr, c, 0);
4639 fprintf (stderr," but comes before it.\n");
4644 if (CASE_LOW (TREE_VEC_ELT (vec, n - 1)))
4646 error ("no default case found at end of case vector");
4650 FOR_EACH_EDGE (e, ei, bb->succs)
4654 error ("extra outgoing edge %d->%d",
4655 bb->index, e->dest->index);
4658 e->dest->aux = (void *)2;
4659 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4660 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4662 error ("wrong outgoing edge flags at end of bb %d",
4668 /* Check that we have all of them. */
4669 for (i = 0; i < n; ++i)
4671 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4672 basic_block label_bb = label_to_block (lab);
4674 if (label_bb->aux != (void *)2)
4676 error ("missing edge %i->%i",
4677 bb->index, label_bb->index);
4682 FOR_EACH_EDGE (e, ei, bb->succs)
4683 e->dest->aux = (void *)0;
4690 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4691 verify_dominators (CDI_DOMINATORS);
4697 /* Updates phi nodes after creating a forwarder block joined
4698 by edge FALLTHRU. */
4701 tree_make_forwarder_block (edge fallthru)
4705 basic_block dummy, bb;
4706 tree phi, new_phi, var;
4708 dummy = fallthru->src;
4709 bb = fallthru->dest;
4711 if (single_pred_p (bb))
4714 /* If we redirected a branch we must create new PHI nodes at the
4716 for (phi = phi_nodes (dummy); phi; phi = PHI_CHAIN (phi))
4718 var = PHI_RESULT (phi);
4719 new_phi = create_phi_node (var, bb);
4720 SSA_NAME_DEF_STMT (var) = new_phi;
4721 SET_PHI_RESULT (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4722 add_phi_arg (new_phi, PHI_RESULT (phi), fallthru);
4725 /* Ensure that the PHI node chain is in the same order. */
4726 set_phi_nodes (bb, phi_reverse (phi_nodes (bb)));
4728 /* Add the arguments we have stored on edges. */
4729 FOR_EACH_EDGE (e, ei, bb->preds)
4734 flush_pending_stmts (e);
4739 /* Return a non-special label in the head of basic block BLOCK.
4740 Create one if it doesn't exist. */
4743 tree_block_label (basic_block bb)
4745 block_stmt_iterator i, s = bsi_start (bb);
4749 for (i = s; !bsi_end_p (i); first = false, bsi_next (&i))
4751 stmt = bsi_stmt (i);
4752 if (TREE_CODE (stmt) != LABEL_EXPR)
4754 label = LABEL_EXPR_LABEL (stmt);
4755 if (!DECL_NONLOCAL (label))
4758 bsi_move_before (&i, &s);
4763 label = create_artificial_label ();
4764 stmt = build1 (LABEL_EXPR, void_type_node, label);
4765 bsi_insert_before (&s, stmt, BSI_NEW_STMT);
4770 /* Attempt to perform edge redirection by replacing a possibly complex
4771 jump instruction by a goto or by removing the jump completely.
4772 This can apply only if all edges now point to the same block. The
4773 parameters and return values are equivalent to
4774 redirect_edge_and_branch. */
4777 tree_try_redirect_by_replacing_jump (edge e, basic_block target)
4779 basic_block src = e->src;
4780 block_stmt_iterator b;
4783 /* We can replace or remove a complex jump only when we have exactly
4785 if (EDGE_COUNT (src->succs) != 2
4786 /* Verify that all targets will be TARGET. Specifically, the
4787 edge that is not E must also go to TARGET. */
4788 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4794 stmt = bsi_stmt (b);
4796 if (TREE_CODE (stmt) == COND_EXPR
4797 || TREE_CODE (stmt) == SWITCH_EXPR)
4799 bsi_remove (&b, true);
4800 e = ssa_redirect_edge (e, target);
4801 e->flags = EDGE_FALLTHRU;
4809 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4810 edge representing the redirected branch. */
4813 tree_redirect_edge_and_branch (edge e, basic_block dest)
4815 basic_block bb = e->src;
4816 block_stmt_iterator bsi;
4820 if (e->flags & EDGE_ABNORMAL)
4823 if (e->src != ENTRY_BLOCK_PTR
4824 && (ret = tree_try_redirect_by_replacing_jump (e, dest)))
4827 if (e->dest == dest)
4830 bsi = bsi_last (bb);
4831 stmt = bsi_end_p (bsi) ? NULL : bsi_stmt (bsi);
4833 switch (stmt ? TREE_CODE (stmt) : ERROR_MARK)
4836 /* For COND_EXPR, we only need to redirect the edge. */
4840 /* No non-abnormal edges should lead from a non-simple goto, and
4841 simple ones should be represented implicitly. */
4846 tree cases = get_cases_for_edge (e, stmt);
4847 tree label = tree_block_label (dest);
4849 /* If we have a list of cases associated with E, then use it
4850 as it's a lot faster than walking the entire case vector. */
4853 edge e2 = find_edge (e->src, dest);
4860 CASE_LABEL (cases) = label;
4861 cases = TREE_CHAIN (cases);
4864 /* If there was already an edge in the CFG, then we need
4865 to move all the cases associated with E to E2. */
4868 tree cases2 = get_cases_for_edge (e2, stmt);
4870 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4871 TREE_CHAIN (cases2) = first;
4876 tree vec = SWITCH_LABELS (stmt);
4877 size_t i, n = TREE_VEC_LENGTH (vec);
4879 for (i = 0; i < n; i++)
4881 tree elt = TREE_VEC_ELT (vec, i);
4883 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4884 CASE_LABEL (elt) = label;
4892 bsi_remove (&bsi, true);
4893 e->flags |= EDGE_FALLTHRU;
4898 case OMP_SECTIONS_SWITCH:
4900 /* The edges from OMP constructs can be simply redirected. */
4904 /* Otherwise it must be a fallthru edge, and we don't need to
4905 do anything besides redirecting it. */
4906 gcc_assert (e->flags & EDGE_FALLTHRU);
4910 /* Update/insert PHI nodes as necessary. */
4912 /* Now update the edges in the CFG. */
4913 e = ssa_redirect_edge (e, dest);
4918 /* Returns true if it is possible to remove edge E by redirecting
4919 it to the destination of the other edge from E->src. */
4922 tree_can_remove_branch_p (const_edge e)
4924 if (e->flags & EDGE_ABNORMAL)
4930 /* Simple wrapper, as we can always redirect fallthru edges. */
4933 tree_redirect_edge_and_branch_force (edge e, basic_block dest)
4935 e = tree_redirect_edge_and_branch (e, dest);
4942 /* Splits basic block BB after statement STMT (but at least after the
4943 labels). If STMT is NULL, BB is split just after the labels. */
4946 tree_split_block (basic_block bb, void *stmt)
4948 block_stmt_iterator bsi;
4949 tree_stmt_iterator tsi_tgt;
4955 new_bb = create_empty_bb (bb);
4957 /* Redirect the outgoing edges. */
4958 new_bb->succs = bb->succs;
4960 FOR_EACH_EDGE (e, ei, new_bb->succs)
4963 if (stmt && TREE_CODE ((tree) stmt) == LABEL_EXPR)
4966 /* Move everything from BSI to the new basic block. */
4967 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4969 act = bsi_stmt (bsi);
4970 if (TREE_CODE (act) == LABEL_EXPR)
4983 if (bsi_end_p (bsi))
4986 /* Split the statement list - avoid re-creating new containers as this
4987 brings ugly quadratic memory consumption in the inliner.
4988 (We are still quadratic since we need to update stmt BB pointers,
4990 list = tsi_split_statement_list_before (&bsi.tsi);
4991 set_bb_stmt_list (new_bb, list);
4992 for (tsi_tgt = tsi_start (list);
4993 !tsi_end_p (tsi_tgt); tsi_next (&tsi_tgt))
4994 change_bb_for_stmt (tsi_stmt (tsi_tgt), new_bb);
5000 /* Moves basic block BB after block AFTER. */
5003 tree_move_block_after (basic_block bb, basic_block after)
5005 if (bb->prev_bb == after)
5009 link_block (bb, after);
5015 /* Return true if basic_block can be duplicated. */
5018 tree_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
5024 /* Create a duplicate of the basic block BB. NOTE: This does not
5025 preserve SSA form. */
5028 tree_duplicate_bb (basic_block bb)
5031 block_stmt_iterator bsi, bsi_tgt;
5034 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
5036 /* Copy the PHI nodes. We ignore PHI node arguments here because
5037 the incoming edges have not been setup yet. */
5038 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5040 tree copy = create_phi_node (PHI_RESULT (phi), new_bb);
5041 create_new_def_for (PHI_RESULT (copy), copy, PHI_RESULT_PTR (copy));
5044 /* Keep the chain of PHI nodes in the same order so that they can be
5045 updated by ssa_redirect_edge. */
5046 set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb)));
5048 bsi_tgt = bsi_start (new_bb);
5049 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5051 def_operand_p def_p;
5052 ssa_op_iter op_iter;
5056 stmt = bsi_stmt (bsi);
5057 if (TREE_CODE (stmt) == LABEL_EXPR)
5060 /* Create a new copy of STMT and duplicate STMT's virtual
5062 copy = unshare_expr (stmt);
5063 bsi_insert_after (&bsi_tgt, copy, BSI_NEW_STMT);
5064 copy_virtual_operands (copy, stmt);
5065 region = lookup_stmt_eh_region (stmt);
5067 add_stmt_to_eh_region (copy, region);
5068 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
5070 /* Create new names for all the definitions created by COPY and
5071 add replacement mappings for each new name. */
5072 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
5073 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
5079 /* Adds phi node arguments for edge E_COPY after basic block duplication. */
5082 add_phi_args_after_copy_edge (edge e_copy)
5084 basic_block bb, bb_copy = e_copy->src, dest;
5087 tree phi, phi_copy, phi_next, def;
5089 if (!phi_nodes (e_copy->dest))
5092 bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
5094 if (e_copy->dest->flags & BB_DUPLICATED)
5095 dest = get_bb_original (e_copy->dest);
5097 dest = e_copy->dest;
5099 e = find_edge (bb, dest);
5102 /* During loop unrolling the target of the latch edge is copied.
5103 In this case we are not looking for edge to dest, but to
5104 duplicated block whose original was dest. */
5105 FOR_EACH_EDGE (e, ei, bb->succs)
5107 if ((e->dest->flags & BB_DUPLICATED)
5108 && get_bb_original (e->dest) == dest)
5112 gcc_assert (e != NULL);
5115 for (phi = phi_nodes (e->dest), phi_copy = phi_nodes (e_copy->dest);
5117 phi = phi_next, phi_copy = PHI_CHAIN (phi_copy))
5119 phi_next = PHI_CHAIN (phi);
5120 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5121 add_phi_arg (phi_copy, def, e_copy);
5126 /* Basic block BB_COPY was created by code duplication. Add phi node
5127 arguments for edges going out of BB_COPY. The blocks that were
5128 duplicated have BB_DUPLICATED set. */
5131 add_phi_args_after_copy_bb (basic_block bb_copy)
5136 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5138 add_phi_args_after_copy_edge (e_copy);
5142 /* Blocks in REGION_COPY array of length N_REGION were created by
5143 duplication of basic blocks. Add phi node arguments for edges
5144 going from these blocks. If E_COPY is not NULL, also add
5145 phi node arguments for its destination.*/
5148 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
5153 for (i = 0; i < n_region; i++)
5154 region_copy[i]->flags |= BB_DUPLICATED;
5156 for (i = 0; i < n_region; i++)
5157 add_phi_args_after_copy_bb (region_copy[i]);
5159 add_phi_args_after_copy_edge (e_copy);
5161 for (i = 0; i < n_region; i++)
5162 region_copy[i]->flags &= ~BB_DUPLICATED;
5165 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5166 important exit edge EXIT. By important we mean that no SSA name defined
5167 inside region is live over the other exit edges of the region. All entry
5168 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5169 to the duplicate of the region. SSA form, dominance and loop information
5170 is updated. The new basic blocks are stored to REGION_COPY in the same
5171 order as they had in REGION, provided that REGION_COPY is not NULL.
5172 The function returns false if it is unable to copy the region,
5176 tree_duplicate_sese_region (edge entry, edge exit,
5177 basic_block *region, unsigned n_region,
5178 basic_block *region_copy)
5181 bool free_region_copy = false, copying_header = false;
5182 struct loop *loop = entry->dest->loop_father;
5184 VEC (basic_block, heap) *doms;
5186 int total_freq = 0, entry_freq = 0;
5187 gcov_type total_count = 0, entry_count = 0;
5189 if (!can_copy_bbs_p (region, n_region))
5192 /* Some sanity checking. Note that we do not check for all possible
5193 missuses of the functions. I.e. if you ask to copy something weird,
5194 it will work, but the state of structures probably will not be
5196 for (i = 0; i < n_region; i++)
5198 /* We do not handle subloops, i.e. all the blocks must belong to the
5200 if (region[i]->loop_father != loop)
5203 if (region[i] != entry->dest
5204 && region[i] == loop->header)
5208 set_loop_copy (loop, loop);
5210 /* In case the function is used for loop header copying (which is the primary
5211 use), ensure that EXIT and its copy will be new latch and entry edges. */
5212 if (loop->header == entry->dest)
5214 copying_header = true;
5215 set_loop_copy (loop, loop_outer (loop));
5217 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5220 for (i = 0; i < n_region; i++)
5221 if (region[i] != exit->src
5222 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5228 region_copy = XNEWVEC (basic_block, n_region);
5229 free_region_copy = true;
5232 gcc_assert (!need_ssa_update_p ());
5234 /* Record blocks outside the region that are dominated by something
5237 initialize_original_copy_tables ();
5239 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5241 if (entry->dest->count)
5243 total_count = entry->dest->count;
5244 entry_count = entry->count;
5245 /* Fix up corner cases, to avoid division by zero or creation of negative
5247 if (entry_count > total_count)
5248 entry_count = total_count;
5252 total_freq = entry->dest->frequency;
5253 entry_freq = EDGE_FREQUENCY (entry);
5254 /* Fix up corner cases, to avoid division by zero or creation of negative
5256 if (total_freq == 0)
5258 else if (entry_freq > total_freq)
5259 entry_freq = total_freq;
5262 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5263 split_edge_bb_loc (entry));
5266 scale_bbs_frequencies_gcov_type (region, n_region,
5267 total_count - entry_count,
5269 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5274 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5276 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5281 loop->header = exit->dest;
5282 loop->latch = exit->src;
5285 /* Redirect the entry and add the phi node arguments. */
5286 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5287 gcc_assert (redirected != NULL);
5288 flush_pending_stmts (entry);
5290 /* Concerning updating of dominators: We must recount dominators
5291 for entry block and its copy. Anything that is outside of the
5292 region, but was dominated by something inside needs recounting as
5294 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5295 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5296 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5297 VEC_free (basic_block, heap, doms);
5299 /* Add the other PHI node arguments. */
5300 add_phi_args_after_copy (region_copy, n_region, NULL);
5302 /* Update the SSA web. */
5303 update_ssa (TODO_update_ssa);
5305 if (free_region_copy)
5308 free_original_copy_tables ();
5312 /* Duplicates REGION consisting of N_REGION blocks. The new blocks
5313 are stored to REGION_COPY in the same order in that they appear
5314 in REGION, if REGION_COPY is not NULL. ENTRY is the entry to
5315 the region, EXIT an exit from it. The condition guarding EXIT
5316 is moved to ENTRY. Returns true if duplication succeeds, false
5342 tree_duplicate_sese_tail (edge entry, edge exit,
5343 basic_block *region, unsigned n_region,
5344 basic_block *region_copy)
5347 bool free_region_copy = false;
5348 struct loop *loop = exit->dest->loop_father;
5349 struct loop *orig_loop = entry->dest->loop_father;
5350 basic_block switch_bb, entry_bb, nentry_bb;
5351 VEC (basic_block, heap) *doms;
5352 int total_freq = 0, exit_freq = 0;
5353 gcov_type total_count = 0, exit_count = 0;
5354 edge exits[2], nexits[2], e;
5355 block_stmt_iterator bsi;
5359 gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5361 exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5363 if (!can_copy_bbs_p (region, n_region))
5366 /* Some sanity checking. Note that we do not check for all possible
5367 missuses of the functions. I.e. if you ask to copy something weird
5368 (e.g., in the example, if there is a jump from inside to the middle
5369 of some_code, or come_code defines some of the values used in cond)
5370 it will work, but the resulting code will not be correct. */
5371 for (i = 0; i < n_region; i++)
5373 /* We do not handle subloops, i.e. all the blocks must belong to the
5375 if (region[i]->loop_father != orig_loop)
5378 if (region[i] == orig_loop->latch)
5382 initialize_original_copy_tables ();
5383 set_loop_copy (orig_loop, loop);
5387 region_copy = XNEWVEC (basic_block, n_region);
5388 free_region_copy = true;
5391 gcc_assert (!need_ssa_update_p ());
5393 /* Record blocks outside the region that are dominated by something
5395 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5397 if (exit->src->count)
5399 total_count = exit->src->count;
5400 exit_count = exit->count;
5401 /* Fix up corner cases, to avoid division by zero or creation of negative
5403 if (exit_count > total_count)
5404 exit_count = total_count;
5408 total_freq = exit->src->frequency;
5409 exit_freq = EDGE_FREQUENCY (exit);
5410 /* Fix up corner cases, to avoid division by zero or creation of negative
5412 if (total_freq == 0)
5414 if (exit_freq > total_freq)
5415 exit_freq = total_freq;
5418 copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5419 split_edge_bb_loc (exit));
5422 scale_bbs_frequencies_gcov_type (region, n_region,
5423 total_count - exit_count,
5425 scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5430 scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5432 scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5435 /* Create the switch block, and put the exit condition to it. */
5436 entry_bb = entry->dest;
5437 nentry_bb = get_bb_copy (entry_bb);
5438 if (!last_stmt (entry->src)
5439 || !stmt_ends_bb_p (last_stmt (entry->src)))
5440 switch_bb = entry->src;
5442 switch_bb = split_edge (entry);
5443 set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5445 bsi = bsi_last (switch_bb);
5446 cond = last_stmt (exit->src);
5447 gcc_assert (TREE_CODE (cond) == COND_EXPR);
5448 bsi_insert_after (&bsi, unshare_expr (cond), BSI_NEW_STMT);
5450 sorig = single_succ_edge (switch_bb);
5451 sorig->flags = exits[1]->flags;
5452 snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5454 /* Register the new edge from SWITCH_BB in loop exit lists. */
5455 rescan_loop_exit (snew, true, false);
5457 /* Add the PHI node arguments. */
5458 add_phi_args_after_copy (region_copy, n_region, snew);
5460 /* Get rid of now superfluous conditions and associated edges (and phi node
5462 e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5463 PENDING_STMT (e) = NULL_TREE;
5464 e = redirect_edge_and_branch (nexits[1], nexits[0]->dest);
5465 PENDING_STMT (e) = NULL_TREE;
5467 /* Anything that is outside of the region, but was dominated by something
5468 inside needs to update dominance info. */
5469 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5470 VEC_free (basic_block, heap, doms);
5472 /* Update the SSA web. */
5473 update_ssa (TODO_update_ssa);
5475 if (free_region_copy)
5478 free_original_copy_tables ();
5483 DEF_VEC_P(basic_block);
5484 DEF_VEC_ALLOC_P(basic_block,heap);
5487 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5488 adding blocks when the dominator traversal reaches EXIT. This
5489 function silently assumes that ENTRY strictly dominates EXIT. */
5492 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5493 VEC(basic_block,heap) **bbs_p)
5497 for (son = first_dom_son (CDI_DOMINATORS, entry);
5499 son = next_dom_son (CDI_DOMINATORS, son))
5501 VEC_safe_push (basic_block, heap, *bbs_p, son);
5503 gather_blocks_in_sese_region (son, exit, bbs_p);
5507 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5508 The duplicates are recorded in VARS_MAP. */
5511 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5514 tree t = *tp, new_t;
5515 struct function *f = DECL_STRUCT_FUNCTION (to_context);
5518 if (DECL_CONTEXT (t) == to_context)
5521 loc = pointer_map_contains (vars_map, t);
5525 loc = pointer_map_insert (vars_map, t);
5529 new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5530 f->unexpanded_var_list
5531 = tree_cons (NULL_TREE, new_t, f->unexpanded_var_list);
5535 gcc_assert (TREE_CODE (t) == CONST_DECL);
5536 new_t = copy_node (t);
5538 DECL_CONTEXT (new_t) = to_context;
5548 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5549 VARS_MAP maps old ssa names and var_decls to the new ones. */
5552 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5556 tree new_name, decl = SSA_NAME_VAR (name);
5558 gcc_assert (is_gimple_reg (name));
5560 loc = pointer_map_contains (vars_map, name);
5564 replace_by_duplicate_decl (&decl, vars_map, to_context);
5566 push_cfun (DECL_STRUCT_FUNCTION (to_context));
5567 if (gimple_in_ssa_p (cfun))
5568 add_referenced_var (decl);
5570 new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5571 if (SSA_NAME_IS_DEFAULT_DEF (name))
5572 set_default_def (decl, new_name);
5575 loc = pointer_map_insert (vars_map, name);
5589 struct pointer_map_t *vars_map;
5590 htab_t new_label_map;
5594 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5595 contained in *TP and change the DECL_CONTEXT of every local
5596 variable referenced in *TP. */
5599 move_stmt_r (tree *tp, int *walk_subtrees, void *data)
5601 struct move_stmt_d *p = (struct move_stmt_d *) data;
5605 && (EXPR_P (t) || GIMPLE_STMT_P (t)))
5606 TREE_BLOCK (t) = p->block;
5608 if (OMP_DIRECTIVE_P (t)
5609 && TREE_CODE (t) != OMP_RETURN
5610 && TREE_CODE (t) != OMP_CONTINUE)
5612 /* Do not remap variables inside OMP directives. Variables
5613 referenced in clauses and directive header belong to the
5614 parent function and should not be moved into the child
5616 bool save_remap_decls_p = p->remap_decls_p;
5617 p->remap_decls_p = false;
5620 walk_tree (&OMP_BODY (t), move_stmt_r, p, NULL);
5622 p->remap_decls_p = save_remap_decls_p;
5624 else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5626 if (TREE_CODE (t) == SSA_NAME)
5627 *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5628 else if (TREE_CODE (t) == LABEL_DECL)
5630 if (p->new_label_map)
5632 struct tree_map in, *out;
5634 out = htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5639 DECL_CONTEXT (t) = p->to_context;
5641 else if (p->remap_decls_p)
5643 /* Replace T with its duplicate. T should no longer appear in the
5644 parent function, so this looks wasteful; however, it may appear
5645 in referenced_vars, and more importantly, as virtual operands of
5646 statements, and in alias lists of other variables. It would be
5647 quite difficult to expunge it from all those places. ??? It might
5648 suffice to do this for addressable variables. */
5649 if ((TREE_CODE (t) == VAR_DECL
5650 && !is_global_var (t))
5651 || TREE_CODE (t) == CONST_DECL)
5652 replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5655 && gimple_in_ssa_p (cfun))
5657 push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5658 add_referenced_var (*tp);
5664 else if (TYPE_P (t))
5670 /* Marks virtual operands of all statements in basic blocks BBS for
5674 mark_virtual_ops_in_bb (basic_block bb)
5677 block_stmt_iterator bsi;
5679 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5680 mark_virtual_ops_for_renaming (phi);
5682 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5683 mark_virtual_ops_for_renaming (bsi_stmt (bsi));
5686 /* Marks virtual operands of all statements in basic blocks BBS for
5690 mark_virtual_ops_in_region (VEC (basic_block,heap) *bbs)
5695 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5696 mark_virtual_ops_in_bb (bb);
5699 /* Move basic block BB from function CFUN to function DEST_FN. The
5700 block is moved out of the original linked list and placed after
5701 block AFTER in the new list. Also, the block is removed from the
5702 original array of blocks and placed in DEST_FN's array of blocks.
5703 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5704 updated to reflect the moved edges.
5706 The local variables are remapped to new instances, VARS_MAP is used
5707 to record the mapping. */
5710 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5711 basic_block after, bool update_edge_count_p,
5712 struct pointer_map_t *vars_map, htab_t new_label_map,
5715 struct control_flow_graph *cfg;
5718 block_stmt_iterator si;
5719 struct move_stmt_d d;
5720 unsigned old_len, new_len;
5723 /* Remove BB from dominance structures. */
5724 delete_from_dominance_info (CDI_DOMINATORS, bb);
5726 remove_bb_from_loops (bb);
5728 /* Link BB to the new linked list. */
5729 move_block_after (bb, after);
5731 /* Update the edge count in the corresponding flowgraphs. */
5732 if (update_edge_count_p)
5733 FOR_EACH_EDGE (e, ei, bb->succs)
5735 cfun->cfg->x_n_edges--;
5736 dest_cfun->cfg->x_n_edges++;
5739 /* Remove BB from the original basic block array. */
5740 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5741 cfun->cfg->x_n_basic_blocks--;
5743 /* Grow DEST_CFUN's basic block array if needed. */
5744 cfg = dest_cfun->cfg;
5745 cfg->x_n_basic_blocks++;
5746 if (bb->index >= cfg->x_last_basic_block)
5747 cfg->x_last_basic_block = bb->index + 1;
5749 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5750 if ((unsigned) cfg->x_last_basic_block >= old_len)
5752 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5753 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5757 VEC_replace (basic_block, cfg->x_basic_block_info,
5760 /* Remap the variables in phi nodes. */
5761 for (phi = phi_nodes (bb); phi; phi = next_phi)
5764 tree op = PHI_RESULT (phi);
5767 next_phi = PHI_CHAIN (phi);
5768 if (!is_gimple_reg (op))
5770 /* Remove the phi nodes for virtual operands (alias analysis will be
5771 run for the new function, anyway). */
5772 remove_phi_node (phi, NULL, true);
5776 SET_PHI_RESULT (phi, replace_ssa_name (op, vars_map, dest_cfun->decl));
5777 FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5779 op = USE_FROM_PTR (use);
5780 if (TREE_CODE (op) == SSA_NAME)
5781 SET_USE (use, replace_ssa_name (op, vars_map, dest_cfun->decl));
5785 /* The statements in BB need to be associated with a new TREE_BLOCK.
5786 Labels need to be associated with a new label-to-block map. */
5787 memset (&d, 0, sizeof (d));
5788 d.vars_map = vars_map;
5789 d.from_context = cfun->decl;
5790 d.to_context = dest_cfun->decl;
5791 d.new_label_map = new_label_map;
5793 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5795 tree stmt = bsi_stmt (si);
5798 d.remap_decls_p = true;
5799 if (TREE_BLOCK (stmt))
5800 d.block = DECL_INITIAL (dest_cfun->decl);
5802 walk_tree (&stmt, move_stmt_r, &d, NULL);
5804 if (TREE_CODE (stmt) == LABEL_EXPR)
5806 tree label = LABEL_EXPR_LABEL (stmt);
5807 int uid = LABEL_DECL_UID (label);
5809 gcc_assert (uid > -1);
5811 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5812 if (old_len <= (unsigned) uid)
5814 new_len = 3 * uid / 2;
5815 VEC_safe_grow_cleared (basic_block, gc,
5816 cfg->x_label_to_block_map, new_len);
5819 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5820 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5822 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5824 if (uid >= dest_cfun->last_label_uid)
5825 dest_cfun->last_label_uid = uid + 1;
5827 else if (TREE_CODE (stmt) == RESX_EXPR && eh_offset != 0)
5828 TREE_OPERAND (stmt, 0) =
5829 build_int_cst (NULL_TREE,
5830 TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0))
5833 region = lookup_stmt_eh_region (stmt);
5836 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5837 remove_stmt_from_eh_region (stmt);
5838 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5839 gimple_remove_stmt_histograms (cfun, stmt);
5842 /* We cannot leave any operands allocated from the operand caches of
5843 the current function. */
5844 free_stmt_operands (stmt);
5845 push_cfun (dest_cfun);
5851 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5852 the outermost EH region. Use REGION as the incoming base EH region. */
5855 find_outermost_region_in_block (struct function *src_cfun,
5856 basic_block bb, int region)
5858 block_stmt_iterator si;
5860 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5862 tree stmt = bsi_stmt (si);
5865 if (TREE_CODE (stmt) == RESX_EXPR)
5866 stmt_region = TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0));
5868 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5869 if (stmt_region > 0)
5872 region = stmt_region;
5873 else if (stmt_region != region)
5875 region = eh_region_outermost (src_cfun, stmt_region, region);
5876 gcc_assert (region != -1);
5885 new_label_mapper (tree decl, void *data)
5887 htab_t hash = (htab_t) data;
5891 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5893 m = xmalloc (sizeof (struct tree_map));
5894 m->hash = DECL_UID (decl);
5895 m->base.from = decl;
5896 m->to = create_artificial_label ();
5897 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5898 if (LABEL_DECL_UID (m->to) >= cfun->last_label_uid)
5899 cfun->last_label_uid = LABEL_DECL_UID (m->to) + 1;
5901 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5902 gcc_assert (*slot == NULL);
5909 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5910 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5911 single basic block in the original CFG and the new basic block is
5912 returned. DEST_CFUN must not have a CFG yet.
5914 Note that the region need not be a pure SESE region. Blocks inside
5915 the region may contain calls to abort/exit. The only restriction
5916 is that ENTRY_BB should be the only entry point and it must
5919 All local variables referenced in the region are assumed to be in
5920 the corresponding BLOCK_VARS and unexpanded variable lists
5921 associated with DEST_CFUN. */
5924 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5925 basic_block exit_bb)
5927 VEC(basic_block,heap) *bbs, *dom_bbs;
5928 basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
5929 basic_block after, bb, *entry_pred, *exit_succ, abb;
5930 struct function *saved_cfun = cfun;
5931 int *entry_flag, *exit_flag, eh_offset;
5932 unsigned *entry_prob, *exit_prob;
5933 unsigned i, num_entry_edges, num_exit_edges;
5936 htab_t new_label_map;
5937 struct pointer_map_t *vars_map;
5938 struct loop *loop = entry_bb->loop_father;
5940 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5942 gcc_assert (entry_bb != exit_bb
5944 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
5946 /* Collect all the blocks in the region. Manually add ENTRY_BB
5947 because it won't be added by dfs_enumerate_from. */
5949 VEC_safe_push (basic_block, heap, bbs, entry_bb);
5950 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
5952 /* The blocks that used to be dominated by something in BBS will now be
5953 dominated by the new block. */
5954 dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
5955 VEC_address (basic_block, bbs),
5956 VEC_length (basic_block, bbs));
5958 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5959 the predecessor edges to ENTRY_BB and the successor edges to
5960 EXIT_BB so that we can re-attach them to the new basic block that
5961 will replace the region. */
5962 num_entry_edges = EDGE_COUNT (entry_bb->preds);
5963 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
5964 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
5965 entry_prob = XNEWVEC (unsigned, num_entry_edges);
5967 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
5969 entry_prob[i] = e->probability;
5970 entry_flag[i] = e->flags;
5971 entry_pred[i++] = e->src;
5977 num_exit_edges = EDGE_COUNT (exit_bb->succs);
5978 exit_succ = (basic_block *) xcalloc (num_exit_edges,
5979 sizeof (basic_block));
5980 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
5981 exit_prob = XNEWVEC (unsigned, num_exit_edges);
5983 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
5985 exit_prob[i] = e->probability;
5986 exit_flag[i] = e->flags;
5987 exit_succ[i++] = e->dest;
5999 /* Switch context to the child function to initialize DEST_FN's CFG. */
6000 gcc_assert (dest_cfun->cfg == NULL);
6001 push_cfun (dest_cfun);
6003 init_empty_tree_cfg ();
6005 /* Initialize EH information for the new function. */
6007 new_label_map = NULL;
6012 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6013 region = find_outermost_region_in_block (saved_cfun, bb, region);
6015 init_eh_for_function ();
6018 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
6019 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
6020 new_label_map, region, 0);
6026 /* The ssa form for virtual operands in the source function will have to
6027 be repaired. We do not care for the real operands -- the sese region
6028 must be closed with respect to those. */
6029 mark_virtual_ops_in_region (bbs);
6031 /* Move blocks from BBS into DEST_CFUN. */
6032 gcc_assert (VEC_length (basic_block, bbs) >= 2);
6033 after = dest_cfun->cfg->x_entry_block_ptr;
6034 vars_map = pointer_map_create ();
6035 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6037 /* No need to update edge counts on the last block. It has
6038 already been updated earlier when we detached the region from
6039 the original CFG. */
6040 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, vars_map,
6041 new_label_map, eh_offset);
6046 htab_delete (new_label_map);
6047 pointer_map_destroy (vars_map);
6049 /* Rewire the entry and exit blocks. The successor to the entry
6050 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
6051 the child function. Similarly, the predecessor of DEST_FN's
6052 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
6053 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
6054 various CFG manipulation function get to the right CFG.
6056 FIXME, this is silly. The CFG ought to become a parameter to
6058 push_cfun (dest_cfun);
6059 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
6061 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
6064 /* Back in the original function, the SESE region has disappeared,
6065 create a new basic block in its place. */
6066 bb = create_empty_bb (entry_pred[0]);
6068 add_bb_to_loop (bb, loop);
6069 for (i = 0; i < num_entry_edges; i++)
6071 e = make_edge (entry_pred[i], bb, entry_flag[i]);
6072 e->probability = entry_prob[i];
6075 for (i = 0; i < num_exit_edges; i++)
6077 e = make_edge (bb, exit_succ[i], exit_flag[i]);
6078 e->probability = exit_prob[i];
6081 set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
6082 for (i = 0; VEC_iterate (basic_block, dom_bbs, i, abb); i++)
6083 set_immediate_dominator (CDI_DOMINATORS, abb, bb);
6084 VEC_free (basic_block, heap, dom_bbs);
6095 VEC_free (basic_block, heap, bbs);
6101 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */
6104 dump_function_to_file (tree fn, FILE *file, int flags)
6106 tree arg, vars, var;
6107 struct function *dsf;
6108 bool ignore_topmost_bind = false, any_var = false;
6112 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
6114 arg = DECL_ARGUMENTS (fn);
6117 print_generic_expr (file, arg, dump_flags);
6118 if (TREE_CHAIN (arg))
6119 fprintf (file, ", ");
6120 arg = TREE_CHAIN (arg);
6122 fprintf (file, ")\n");
6124 dsf = DECL_STRUCT_FUNCTION (fn);
6125 if (dsf && (flags & TDF_DETAILS))
6126 dump_eh_tree (file, dsf);
6128 if (flags & TDF_RAW)
6130 dump_node (fn, TDF_SLIM | flags, file);
6134 /* Switch CFUN to point to FN. */
6135 push_cfun (DECL_STRUCT_FUNCTION (fn));
6137 /* When GIMPLE is lowered, the variables are no longer available in
6138 BIND_EXPRs, so display them separately. */
6139 if (cfun && cfun->decl == fn && cfun->unexpanded_var_list)
6141 ignore_topmost_bind = true;
6143 fprintf (file, "{\n");
6144 for (vars = cfun->unexpanded_var_list; vars; vars = TREE_CHAIN (vars))
6146 var = TREE_VALUE (vars);
6148 print_generic_decl (file, var, flags);
6149 fprintf (file, "\n");
6155 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
6157 /* Make a CFG based dump. */
6158 check_bb_profile (ENTRY_BLOCK_PTR, file);
6159 if (!ignore_topmost_bind)
6160 fprintf (file, "{\n");
6162 if (any_var && n_basic_blocks)
6163 fprintf (file, "\n");
6166 dump_generic_bb (file, bb, 2, flags);
6168 fprintf (file, "}\n");
6169 check_bb_profile (EXIT_BLOCK_PTR, file);
6175 /* Make a tree based dump. */
6176 chain = DECL_SAVED_TREE (fn);
6178 if (chain && TREE_CODE (chain) == BIND_EXPR)
6180 if (ignore_topmost_bind)
6182 chain = BIND_EXPR_BODY (chain);
6190 if (!ignore_topmost_bind)
6191 fprintf (file, "{\n");
6196 fprintf (file, "\n");
6198 print_generic_stmt_indented (file, chain, flags, indent);
6199 if (ignore_topmost_bind)
6200 fprintf (file, "}\n");
6203 fprintf (file, "\n\n");
6210 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
6213 debug_function (tree fn, int flags)
6215 dump_function_to_file (fn, stderr, flags);
6219 /* Print on FILE the indexes for the predecessors of basic_block BB. */
6222 print_pred_bbs (FILE *file, basic_block bb)
6227 FOR_EACH_EDGE (e, ei, bb->preds)
6228 fprintf (file, "bb_%d ", e->src->index);
6232 /* Print on FILE the indexes for the successors of basic_block BB. */
6235 print_succ_bbs (FILE *file, basic_block bb)
6240 FOR_EACH_EDGE (e, ei, bb->succs)
6241 fprintf (file, "bb_%d ", e->dest->index);
6244 /* Print to FILE the basic block BB following the VERBOSITY level. */
6247 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6249 char *s_indent = (char *) alloca ((size_t) indent + 1);
6250 memset ((void *) s_indent, ' ', (size_t) indent);
6251 s_indent[indent] = '\0';
6253 /* Print basic_block's header. */
6256 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
6257 print_pred_bbs (file, bb);
6258 fprintf (file, "}, succs = {");
6259 print_succ_bbs (file, bb);
6260 fprintf (file, "})\n");
6263 /* Print basic_block's body. */
6266 fprintf (file, "%s {\n", s_indent);
6267 tree_dump_bb (bb, file, indent + 4);
6268 fprintf (file, "%s }\n", s_indent);
6272 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6274 /* Pretty print LOOP on FILE, indented INDENT spaces. Following
6275 VERBOSITY level this outputs the contents of the loop, or just its
6279 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6287 s_indent = (char *) alloca ((size_t) indent + 1);
6288 memset ((void *) s_indent, ' ', (size_t) indent);
6289 s_indent[indent] = '\0';
6291 /* Print loop's header. */
6292 fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6293 loop->num, loop->header->index, loop->latch->index);
6294 fprintf (file, ", niter = ");
6295 print_generic_expr (file, loop->nb_iterations, 0);
6297 if (loop->any_upper_bound)
6299 fprintf (file, ", upper_bound = ");
6300 dump_double_int (file, loop->nb_iterations_upper_bound, true);
6303 if (loop->any_estimate)
6305 fprintf (file, ", estimate = ");
6306 dump_double_int (file, loop->nb_iterations_estimate, true);
6308 fprintf (file, ")\n");
6310 /* Print loop's body. */
6313 fprintf (file, "%s{\n", s_indent);
6315 if (bb->loop_father == loop)
6316 print_loops_bb (file, bb, indent, verbosity);
6318 print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6319 fprintf (file, "%s}\n", s_indent);
6323 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6324 spaces. Following VERBOSITY level this outputs the contents of the
6325 loop, or just its structure. */
6328 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6333 print_loop (file, loop, indent, verbosity);
6334 print_loop_and_siblings (file, loop->next, indent, verbosity);
6337 /* Follow a CFG edge from the entry point of the program, and on entry
6338 of a loop, pretty print the loop structure on FILE. */
6341 print_loops (FILE *file, int verbosity)
6345 bb = BASIC_BLOCK (NUM_FIXED_BLOCKS);
6346 if (bb && bb->loop_father)
6347 print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6351 /* Debugging loops structure at tree level, at some VERBOSITY level. */
6354 debug_loops (int verbosity)
6356 print_loops (stderr, verbosity);
6359 /* Print on stderr the code of LOOP, at some VERBOSITY level. */
6362 debug_loop (struct loop *loop, int verbosity)
6364 print_loop (stderr, loop, 0, verbosity);
6367 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6371 debug_loop_num (unsigned num, int verbosity)
6373 debug_loop (get_loop (num), verbosity);
6376 /* Return true if BB ends with a call, possibly followed by some
6377 instructions that must stay with the call. Return false,
6381 tree_block_ends_with_call_p (basic_block bb)
6383 block_stmt_iterator bsi = bsi_last (bb);
6384 return get_call_expr_in (bsi_stmt (bsi)) != NULL;
6388 /* Return true if BB ends with a conditional branch. Return false,
6392 tree_block_ends_with_condjump_p (const_basic_block bb)
6394 /* This CONST_CAST is okay because last_stmt doesn't modify its
6395 argument and the return value is not modified. */
6396 const_tree stmt = last_stmt (CONST_CAST_BB(bb));
6397 return (stmt && TREE_CODE (stmt) == COND_EXPR);
6401 /* Return true if we need to add fake edge to exit at statement T.
6402 Helper function for tree_flow_call_edges_add. */
6405 need_fake_edge_p (tree t)
6409 /* NORETURN and LONGJMP calls already have an edge to exit.
6410 CONST and PURE calls do not need one.
6411 We don't currently check for CONST and PURE here, although
6412 it would be a good idea, because those attributes are
6413 figured out from the RTL in mark_constant_function, and
6414 the counter incrementation code from -fprofile-arcs
6415 leads to different results from -fbranch-probabilities. */
6416 call = get_call_expr_in (t);
6418 && !(call_expr_flags (call) & ECF_NORETURN))
6421 if (TREE_CODE (t) == ASM_EXPR
6422 && (ASM_VOLATILE_P (t) || ASM_INPUT_P (t)))
6429 /* Add fake edges to the function exit for any non constant and non
6430 noreturn calls, volatile inline assembly in the bitmap of blocks
6431 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
6432 the number of blocks that were split.
6434 The goal is to expose cases in which entering a basic block does
6435 not imply that all subsequent instructions must be executed. */
6438 tree_flow_call_edges_add (sbitmap blocks)
6441 int blocks_split = 0;
6442 int last_bb = last_basic_block;
6443 bool check_last_block = false;
6445 if (n_basic_blocks == NUM_FIXED_BLOCKS)
6449 check_last_block = true;
6451 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6453 /* In the last basic block, before epilogue generation, there will be
6454 a fallthru edge to EXIT. Special care is required if the last insn
6455 of the last basic block is a call because make_edge folds duplicate
6456 edges, which would result in the fallthru edge also being marked
6457 fake, which would result in the fallthru edge being removed by
6458 remove_fake_edges, which would result in an invalid CFG.
6460 Moreover, we can't elide the outgoing fake edge, since the block
6461 profiler needs to take this into account in order to solve the minimal
6462 spanning tree in the case that the call doesn't return.
6464 Handle this by adding a dummy instruction in a new last basic block. */
6465 if (check_last_block)
6467 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6468 block_stmt_iterator bsi = bsi_last (bb);
6470 if (!bsi_end_p (bsi))
6473 if (t && need_fake_edge_p (t))
6477 e = find_edge (bb, EXIT_BLOCK_PTR);
6480 bsi_insert_on_edge (e, build_empty_stmt ());
6481 bsi_commit_edge_inserts ();
6486 /* Now add fake edges to the function exit for any non constant
6487 calls since there is no way that we can determine if they will
6489 for (i = 0; i < last_bb; i++)
6491 basic_block bb = BASIC_BLOCK (i);
6492 block_stmt_iterator bsi;
6493 tree stmt, last_stmt;
6498 if (blocks && !TEST_BIT (blocks, i))
6501 bsi = bsi_last (bb);
6502 if (!bsi_end_p (bsi))
6504 last_stmt = bsi_stmt (bsi);
6507 stmt = bsi_stmt (bsi);
6508 if (need_fake_edge_p (stmt))
6511 /* The handling above of the final block before the
6512 epilogue should be enough to verify that there is
6513 no edge to the exit block in CFG already.
6514 Calling make_edge in such case would cause us to
6515 mark that edge as fake and remove it later. */
6516 #ifdef ENABLE_CHECKING
6517 if (stmt == last_stmt)
6519 e = find_edge (bb, EXIT_BLOCK_PTR);
6520 gcc_assert (e == NULL);
6524 /* Note that the following may create a new basic block
6525 and renumber the existing basic blocks. */
6526 if (stmt != last_stmt)
6528 e = split_block (bb, stmt);
6532 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6536 while (!bsi_end_p (bsi));
6541 verify_flow_info ();
6543 return blocks_split;
6546 /* Purge dead abnormal call edges from basic block BB. */
6549 tree_purge_dead_abnormal_call_edges (basic_block bb)
6551 bool changed = tree_purge_dead_eh_edges (bb);
6553 if (current_function_has_nonlocal_label)
6555 tree stmt = last_stmt (bb);
6559 if (!(stmt && tree_can_make_abnormal_goto (stmt)))
6560 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6562 if (e->flags & EDGE_ABNORMAL)
6571 /* See tree_purge_dead_eh_edges below. */
6573 free_dominance_info (CDI_DOMINATORS);
6579 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6582 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6586 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6587 for (son = first_dom_son (CDI_DOMINATORS, bb);
6589 son = next_dom_son (CDI_DOMINATORS, son))
6590 get_all_dominated_blocks (son, dom_bbs);
6593 /* Removes edge E and all the blocks dominated by it, and updates dominance
6594 information. The IL in E->src needs to be updated separately.
6595 If dominance info is not available, only the edge E is removed.*/
6598 remove_edge_and_dominated_blocks (edge e)
6600 VEC (basic_block, heap) *bbs_to_remove = NULL;
6601 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6605 bool none_removed = false;
6607 basic_block bb, dbb;
6610 if (!dom_info_available_p (CDI_DOMINATORS))
6616 /* No updating is needed for edges to exit. */
6617 if (e->dest == EXIT_BLOCK_PTR)
6619 if (cfgcleanup_altered_bbs)
6620 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6625 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6626 that is not dominated by E->dest, then this set is empty. Otherwise,
6627 all the basic blocks dominated by E->dest are removed.
6629 Also, to DF_IDOM we store the immediate dominators of the blocks in
6630 the dominance frontier of E (i.e., of the successors of the
6631 removed blocks, if there are any, and of E->dest otherwise). */
6632 FOR_EACH_EDGE (f, ei, e->dest->preds)
6637 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6639 none_removed = true;
6644 df = BITMAP_ALLOC (NULL);
6645 df_idom = BITMAP_ALLOC (NULL);
6648 bitmap_set_bit (df_idom,
6649 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6652 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6653 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6655 FOR_EACH_EDGE (f, ei, bb->succs)
6657 if (f->dest != EXIT_BLOCK_PTR)
6658 bitmap_set_bit (df, f->dest->index);
6661 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6662 bitmap_clear_bit (df, bb->index);
6664 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6666 bb = BASIC_BLOCK (i);
6667 bitmap_set_bit (df_idom,
6668 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6672 if (cfgcleanup_altered_bbs)
6674 /* Record the set of the altered basic blocks. */
6675 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6676 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6679 /* Remove E and the cancelled blocks. */
6684 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6685 delete_basic_block (bb);
6688 /* Update the dominance information. The immediate dominator may change only
6689 for blocks whose immediate dominator belongs to DF_IDOM:
6691 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6692 removal. Let Z the arbitrary block such that idom(Z) = Y and
6693 Z dominates X after the removal. Before removal, there exists a path P
6694 from Y to X that avoids Z. Let F be the last edge on P that is
6695 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6696 dominates W, and because of P, Z does not dominate W), and W belongs to
6697 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6698 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6700 bb = BASIC_BLOCK (i);
6701 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6703 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6704 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6707 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6710 BITMAP_FREE (df_idom);
6711 VEC_free (basic_block, heap, bbs_to_remove);
6712 VEC_free (basic_block, heap, bbs_to_fix_dom);
6715 /* Purge dead EH edges from basic block BB. */
6718 tree_purge_dead_eh_edges (basic_block bb)
6720 bool changed = false;
6723 tree stmt = last_stmt (bb);
6725 if (stmt && tree_can_throw_internal (stmt))
6728 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6730 if (e->flags & EDGE_EH)
6732 remove_edge_and_dominated_blocks (e);
6743 tree_purge_all_dead_eh_edges (const_bitmap blocks)
6745 bool changed = false;
6749 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6751 changed |= tree_purge_dead_eh_edges (BASIC_BLOCK (i));
6757 /* This function is called whenever a new edge is created or
6761 tree_execute_on_growing_pred (edge e)
6763 basic_block bb = e->dest;
6766 reserve_phi_args_for_new_edge (bb);
6769 /* This function is called immediately before edge E is removed from
6770 the edge vector E->dest->preds. */
6773 tree_execute_on_shrinking_pred (edge e)
6775 if (phi_nodes (e->dest))
6776 remove_phi_args (e);
6779 /*---------------------------------------------------------------------------
6780 Helper functions for Loop versioning
6781 ---------------------------------------------------------------------------*/
6783 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6784 of 'first'. Both of them are dominated by 'new_head' basic block. When
6785 'new_head' was created by 'second's incoming edge it received phi arguments
6786 on the edge by split_edge(). Later, additional edge 'e' was created to
6787 connect 'new_head' and 'first'. Now this routine adds phi args on this
6788 additional edge 'e' that new_head to second edge received as part of edge
6793 tree_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6794 basic_block new_head, edge e)
6797 edge e2 = find_edge (new_head, second);
6799 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6800 edge, we should always have an edge from NEW_HEAD to SECOND. */
6801 gcc_assert (e2 != NULL);
6803 /* Browse all 'second' basic block phi nodes and add phi args to
6804 edge 'e' for 'first' head. PHI args are always in correct order. */
6806 for (phi2 = phi_nodes (second), phi1 = phi_nodes (first);
6808 phi2 = PHI_CHAIN (phi2), phi1 = PHI_CHAIN (phi1))
6810 tree def = PHI_ARG_DEF (phi2, e2->dest_idx);
6811 add_phi_arg (phi1, def, e);
6815 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6816 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6817 the destination of the ELSE part. */
6819 tree_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6820 basic_block second_head ATTRIBUTE_UNUSED,
6821 basic_block cond_bb, void *cond_e)
6823 block_stmt_iterator bsi;
6824 tree new_cond_expr = NULL_TREE;
6825 tree cond_expr = (tree) cond_e;
6828 /* Build new conditional expr */
6829 new_cond_expr = build3 (COND_EXPR, void_type_node, cond_expr,
6830 NULL_TREE, NULL_TREE);
6832 /* Add new cond in cond_bb. */
6833 bsi = bsi_start (cond_bb);
6834 bsi_insert_after (&bsi, new_cond_expr, BSI_NEW_STMT);
6835 /* Adjust edges appropriately to connect new head with first head
6836 as well as second head. */
6837 e0 = single_succ_edge (cond_bb);
6838 e0->flags &= ~EDGE_FALLTHRU;
6839 e0->flags |= EDGE_FALSE_VALUE;
6842 struct cfg_hooks tree_cfg_hooks = {
6844 tree_verify_flow_info,
6845 tree_dump_bb, /* dump_bb */
6846 create_bb, /* create_basic_block */
6847 tree_redirect_edge_and_branch,/* redirect_edge_and_branch */
6848 tree_redirect_edge_and_branch_force,/* redirect_edge_and_branch_force */
6849 tree_can_remove_branch_p, /* can_remove_branch_p */
6850 remove_bb, /* delete_basic_block */
6851 tree_split_block, /* split_block */
6852 tree_move_block_after, /* move_block_after */
6853 tree_can_merge_blocks_p, /* can_merge_blocks_p */
6854 tree_merge_blocks, /* merge_blocks */
6855 tree_predict_edge, /* predict_edge */
6856 tree_predicted_by_p, /* predicted_by_p */
6857 tree_can_duplicate_bb_p, /* can_duplicate_block_p */
6858 tree_duplicate_bb, /* duplicate_block */
6859 tree_split_edge, /* split_edge */
6860 tree_make_forwarder_block, /* make_forward_block */
6861 NULL, /* tidy_fallthru_edge */
6862 tree_block_ends_with_call_p, /* block_ends_with_call_p */
6863 tree_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6864 tree_flow_call_edges_add, /* flow_call_edges_add */
6865 tree_execute_on_growing_pred, /* execute_on_growing_pred */
6866 tree_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6867 tree_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6868 tree_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6869 tree_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6870 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6871 flush_pending_stmts /* flush_pending_stmts */
6875 /* Split all critical edges. */
6878 split_critical_edges (void)
6884 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6885 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6886 mappings around the calls to split_edge. */
6887 start_recording_case_labels ();
6890 FOR_EACH_EDGE (e, ei, bb->succs)
6891 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6896 end_recording_case_labels ();
6900 struct tree_opt_pass pass_split_crit_edges =
6902 "crited", /* name */
6904 split_critical_edges, /* execute */
6907 0, /* static_pass_number */
6908 TV_TREE_SPLIT_EDGES, /* tv_id */
6909 PROP_cfg, /* properties required */
6910 PROP_no_crit_edges, /* properties_provided */
6911 0, /* properties_destroyed */
6912 0, /* todo_flags_start */
6913 TODO_dump_func, /* todo_flags_finish */
6918 /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into
6919 a temporary, make sure and register it to be renamed if necessary,
6920 and finally return the temporary. Put the statements to compute
6921 EXP before the current statement in BSI. */
6924 gimplify_val (block_stmt_iterator *bsi, tree type, tree exp)
6926 tree t, new_stmt, orig_stmt;
6928 if (is_gimple_val (exp))
6931 t = make_rename_temp (type, NULL);
6932 new_stmt = build_gimple_modify_stmt (t, exp);
6934 orig_stmt = bsi_stmt (*bsi);
6935 SET_EXPR_LOCUS (new_stmt, EXPR_LOCUS (orig_stmt));
6936 TREE_BLOCK (new_stmt) = TREE_BLOCK (orig_stmt);
6938 bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
6939 if (gimple_in_ssa_p (cfun))
6940 mark_symbols_for_renaming (new_stmt);
6945 /* Build a ternary operation and gimplify it. Emit code before BSI.
6946 Return the gimple_val holding the result. */
6949 gimplify_build3 (block_stmt_iterator *bsi, enum tree_code code,
6950 tree type, tree a, tree b, tree c)
6954 ret = fold_build3 (code, type, a, b, c);
6957 return gimplify_val (bsi, type, ret);
6960 /* Build a binary operation and gimplify it. Emit code before BSI.
6961 Return the gimple_val holding the result. */
6964 gimplify_build2 (block_stmt_iterator *bsi, enum tree_code code,
6965 tree type, tree a, tree b)
6969 ret = fold_build2 (code, type, a, b);
6972 return gimplify_val (bsi, type, ret);
6975 /* Build a unary operation and gimplify it. Emit code before BSI.
6976 Return the gimple_val holding the result. */
6979 gimplify_build1 (block_stmt_iterator *bsi, enum tree_code code, tree type,
6984 ret = fold_build1 (code, type, a);
6987 return gimplify_val (bsi, type, ret);
6992 /* Emit return warnings. */
6995 execute_warn_function_return (void)
6997 source_location location;
7002 /* If we have a path to EXIT, then we do return. */
7003 if (TREE_THIS_VOLATILE (cfun->decl)
7004 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
7006 location = UNKNOWN_LOCATION;
7007 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7009 last = last_stmt (e->src);
7010 if (TREE_CODE (last) == RETURN_EXPR
7011 && (location = EXPR_LOCATION (last)) != UNKNOWN_LOCATION)
7014 if (location == UNKNOWN_LOCATION)
7015 location = cfun->function_end_locus;
7016 warning (0, "%H%<noreturn%> function does return", &location);
7019 /* If we see "return;" in some basic block, then we do reach the end
7020 without returning a value. */
7021 else if (warn_return_type
7022 && !TREE_NO_WARNING (cfun->decl)
7023 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
7024 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
7026 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7028 tree last = last_stmt (e->src);
7029 if (TREE_CODE (last) == RETURN_EXPR
7030 && TREE_OPERAND (last, 0) == NULL
7031 && !TREE_NO_WARNING (last))
7033 location = EXPR_LOCATION (last);
7034 if (location == UNKNOWN_LOCATION)
7035 location = cfun->function_end_locus;
7036 warning (OPT_Wreturn_type, "%Hcontrol reaches end of non-void function", &location);
7037 TREE_NO_WARNING (cfun->decl) = 1;
7046 /* Given a basic block B which ends with a conditional and has
7047 precisely two successors, determine which of the edges is taken if
7048 the conditional is true and which is taken if the conditional is
7049 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
7052 extract_true_false_edges_from_block (basic_block b,
7056 edge e = EDGE_SUCC (b, 0);
7058 if (e->flags & EDGE_TRUE_VALUE)
7061 *false_edge = EDGE_SUCC (b, 1);
7066 *true_edge = EDGE_SUCC (b, 1);
7070 struct tree_opt_pass pass_warn_function_return =
7074 execute_warn_function_return, /* execute */
7077 0, /* static_pass_number */
7079 PROP_cfg, /* properties_required */
7080 0, /* properties_provided */
7081 0, /* properties_destroyed */
7082 0, /* todo_flags_start */
7083 0, /* todo_flags_finish */
7087 /* Emit noreturn warnings. */
7090 execute_warn_function_noreturn (void)
7092 if (warn_missing_noreturn
7093 && !TREE_THIS_VOLATILE (cfun->decl)
7094 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
7095 && !lang_hooks.function.missing_noreturn_ok_p (cfun->decl))
7096 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
7097 "for attribute %<noreturn%>",
7102 struct tree_opt_pass pass_warn_function_noreturn =
7106 execute_warn_function_noreturn, /* execute */
7109 0, /* static_pass_number */
7111 PROP_cfg, /* properties_required */
7112 0, /* properties_provided */
7113 0, /* properties_destroyed */
7114 0, /* todo_flags_start */
7115 0, /* todo_flags_finish */