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 GIMPLE_SWITCHes.
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 void make_blocks (gimple_seq);
87 static void factor_computed_gotos (void);
90 static void make_edges (void);
91 static void make_cond_expr_edges (basic_block);
92 static void make_gimple_switch_edges (basic_block);
93 static void make_goto_expr_edges (basic_block);
94 static edge gimple_redirect_edge_and_branch (edge, basic_block);
95 static edge gimple_try_redirect_by_replacing_jump (edge, basic_block);
96 static unsigned int split_critical_edges (void);
98 /* Various helpers. */
99 static inline bool stmt_starts_bb_p (gimple, gimple);
100 static int gimple_verify_flow_info (void);
101 static void gimple_make_forwarder_block (edge);
102 static void gimple_cfg2vcg (FILE *);
104 /* Flowgraph optimization and cleanup. */
105 static void gimple_merge_blocks (basic_block, basic_block);
106 static bool gimple_can_merge_blocks_p (basic_block, basic_block);
107 static void remove_bb (basic_block);
108 static edge find_taken_edge_computed_goto (basic_block, tree);
109 static edge find_taken_edge_cond_expr (basic_block, tree);
110 static edge find_taken_edge_switch_expr (basic_block, tree);
111 static tree find_case_label_for_value (gimple, tree);
114 init_empty_tree_cfg_for_function (struct function *fn)
116 /* Initialize the basic block array. */
118 profile_status_for_function (fn) = PROFILE_ABSENT;
119 n_basic_blocks_for_function (fn) = NUM_FIXED_BLOCKS;
120 last_basic_block_for_function (fn) = NUM_FIXED_BLOCKS;
121 basic_block_info_for_function (fn)
122 = VEC_alloc (basic_block, gc, initial_cfg_capacity);
123 VEC_safe_grow_cleared (basic_block, gc,
124 basic_block_info_for_function (fn),
125 initial_cfg_capacity);
127 /* Build a mapping of labels to their associated blocks. */
128 label_to_block_map_for_function (fn)
129 = VEC_alloc (basic_block, gc, initial_cfg_capacity);
130 VEC_safe_grow_cleared (basic_block, gc,
131 label_to_block_map_for_function (fn),
132 initial_cfg_capacity);
134 SET_BASIC_BLOCK_FOR_FUNCTION (fn, ENTRY_BLOCK,
135 ENTRY_BLOCK_PTR_FOR_FUNCTION (fn));
136 SET_BASIC_BLOCK_FOR_FUNCTION (fn, EXIT_BLOCK,
137 EXIT_BLOCK_PTR_FOR_FUNCTION (fn));
139 ENTRY_BLOCK_PTR_FOR_FUNCTION (fn)->next_bb
140 = EXIT_BLOCK_PTR_FOR_FUNCTION (fn);
141 EXIT_BLOCK_PTR_FOR_FUNCTION (fn)->prev_bb
142 = ENTRY_BLOCK_PTR_FOR_FUNCTION (fn);
146 init_empty_tree_cfg (void)
148 init_empty_tree_cfg_for_function (cfun);
151 /*---------------------------------------------------------------------------
153 ---------------------------------------------------------------------------*/
155 /* Entry point to the CFG builder for trees. SEQ is the sequence of
156 statements to be added to the flowgraph. */
159 build_gimple_cfg (gimple_seq seq)
161 /* Register specific gimple functions. */
162 gimple_register_cfg_hooks ();
164 memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
166 init_empty_tree_cfg ();
168 found_computed_goto = 0;
171 /* Computed gotos are hell to deal with, especially if there are
172 lots of them with a large number of destinations. So we factor
173 them to a common computed goto location before we build the
174 edge list. After we convert back to normal form, we will un-factor
175 the computed gotos since factoring introduces an unwanted jump. */
176 if (found_computed_goto)
177 factor_computed_gotos ();
179 /* Make sure there is always at least one block, even if it's empty. */
180 if (n_basic_blocks == NUM_FIXED_BLOCKS)
181 create_empty_bb (ENTRY_BLOCK_PTR);
183 /* Adjust the size of the array. */
184 if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
185 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
187 /* To speed up statement iterator walks, we first purge dead labels. */
188 cleanup_dead_labels ();
190 /* Group case nodes to reduce the number of edges.
191 We do this after cleaning up dead labels because otherwise we miss
192 a lot of obvious case merging opportunities. */
193 group_case_labels ();
195 /* Create the edges of the flowgraph. */
197 cleanup_dead_labels ();
199 /* Debugging dumps. */
201 /* Write the flowgraph to a VCG file. */
203 int local_dump_flags;
204 FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
207 gimple_cfg2vcg (vcg_file);
208 dump_end (TDI_vcg, vcg_file);
212 #ifdef ENABLE_CHECKING
218 execute_build_cfg (void)
220 gimple_seq body = gimple_body (current_function_decl);
222 build_gimple_cfg (body);
223 gimple_set_body (current_function_decl, NULL);
227 struct gimple_opt_pass pass_build_cfg =
233 execute_build_cfg, /* execute */
236 0, /* static_pass_number */
237 TV_TREE_CFG, /* tv_id */
238 PROP_gimple_leh, /* properties_required */
239 PROP_cfg, /* properties_provided */
240 0, /* properties_destroyed */
241 0, /* todo_flags_start */
242 TODO_verify_stmts | TODO_cleanup_cfg
243 | TODO_dump_func /* todo_flags_finish */
248 /* Return true if T is a computed goto. */
251 computed_goto_p (gimple t)
253 return (gimple_code (t) == GIMPLE_GOTO
254 && TREE_CODE (gimple_goto_dest (t)) != LABEL_DECL);
258 /* Search the CFG for any computed gotos. If found, factor them to a
259 common computed goto site. Also record the location of that site so
260 that we can un-factor the gotos after we have converted back to
264 factor_computed_gotos (void)
267 tree factored_label_decl = NULL;
269 gimple factored_computed_goto_label = NULL;
270 gimple factored_computed_goto = NULL;
272 /* We know there are one or more computed gotos in this function.
273 Examine the last statement in each basic block to see if the block
274 ends with a computed goto. */
278 gimple_stmt_iterator gsi = gsi_last_bb (bb);
284 last = gsi_stmt (gsi);
286 /* Ignore the computed goto we create when we factor the original
288 if (last == factored_computed_goto)
291 /* If the last statement is a computed goto, factor it. */
292 if (computed_goto_p (last))
296 /* The first time we find a computed goto we need to create
297 the factored goto block and the variable each original
298 computed goto will use for their goto destination. */
299 if (!factored_computed_goto)
301 basic_block new_bb = create_empty_bb (bb);
302 gimple_stmt_iterator new_gsi = gsi_start_bb (new_bb);
304 /* Create the destination of the factored goto. Each original
305 computed goto will put its desired destination into this
306 variable and jump to the label we create immediately
308 var = create_tmp_var (ptr_type_node, "gotovar");
310 /* Build a label for the new block which will contain the
311 factored computed goto. */
312 factored_label_decl = create_artificial_label ();
313 factored_computed_goto_label
314 = gimple_build_label (factored_label_decl);
315 gsi_insert_after (&new_gsi, factored_computed_goto_label,
318 /* Build our new computed goto. */
319 factored_computed_goto = gimple_build_goto (var);
320 gsi_insert_after (&new_gsi, factored_computed_goto, GSI_NEW_STMT);
323 /* Copy the original computed goto's destination into VAR. */
324 assignment = gimple_build_assign (var, gimple_goto_dest (last));
325 gsi_insert_before (&gsi, assignment, GSI_SAME_STMT);
327 /* And re-vector the computed goto to the new destination. */
328 gimple_goto_set_dest (last, factored_label_decl);
334 /* Build a flowgraph for the sequence of stmts SEQ. */
337 make_blocks (gimple_seq seq)
339 gimple_stmt_iterator i = gsi_start (seq);
341 bool start_new_block = true;
342 bool first_stmt_of_seq = true;
343 basic_block bb = ENTRY_BLOCK_PTR;
345 while (!gsi_end_p (i))
352 /* If the statement starts a new basic block or if we have determined
353 in a previous pass that we need to create a new block for STMT, do
355 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
357 if (!first_stmt_of_seq)
358 seq = gsi_split_seq_before (&i);
359 bb = create_basic_block (seq, NULL, bb);
360 start_new_block = false;
363 /* Now add STMT to BB and create the subgraphs for special statement
365 gimple_set_bb (stmt, bb);
367 if (computed_goto_p (stmt))
368 found_computed_goto = true;
370 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
372 if (stmt_ends_bb_p (stmt))
373 start_new_block = true;
376 first_stmt_of_seq = false;
381 /* Create and return a new empty basic block after bb AFTER. */
384 create_bb (void *h, void *e, basic_block after)
390 /* Create and initialize a new basic block. Since alloc_block uses
391 ggc_alloc_cleared to allocate a basic block, we do not have to
392 clear the newly allocated basic block here. */
395 bb->index = last_basic_block;
397 bb->il.gimple = GGC_CNEW (struct gimple_bb_info);
398 set_bb_seq (bb, h ? (gimple_seq) h : gimple_seq_alloc ());
400 /* Add the new block to the linked list of blocks. */
401 link_block (bb, after);
403 /* Grow the basic block array if needed. */
404 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
406 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
407 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
410 /* Add the newly created block to the array. */
411 SET_BASIC_BLOCK (last_basic_block, bb);
420 /*---------------------------------------------------------------------------
422 ---------------------------------------------------------------------------*/
424 /* Fold COND_EXPR_COND of each COND_EXPR. */
427 fold_cond_expr_cond (void)
433 gimple stmt = last_stmt (bb);
435 if (stmt && gimple_code (stmt) == GIMPLE_COND)
440 fold_defer_overflow_warnings ();
441 cond = fold_binary (gimple_cond_code (stmt), boolean_type_node,
442 gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
445 zerop = integer_zerop (cond);
446 onep = integer_onep (cond);
449 zerop = onep = false;
451 fold_undefer_overflow_warnings (zerop || onep,
453 WARN_STRICT_OVERFLOW_CONDITIONAL);
455 gimple_cond_make_false (stmt);
457 gimple_cond_make_true (stmt);
462 /* Join all the blocks in the flowgraph. */
468 struct omp_region *cur_region = NULL;
470 /* Create an edge from entry to the first block with executable
472 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
474 /* Traverse the basic block array placing edges. */
477 gimple last = last_stmt (bb);
482 enum gimple_code code = gimple_code (last);
486 make_goto_expr_edges (bb);
490 make_edge (bb, EXIT_BLOCK_PTR, 0);
494 make_cond_expr_edges (bb);
498 make_gimple_switch_edges (bb);
502 make_eh_edges (last);
507 /* If this function receives a nonlocal goto, then we need to
508 make edges from this call site to all the nonlocal goto
510 if (stmt_can_make_abnormal_goto (last))
511 make_abnormal_goto_edges (bb, true);
513 /* If this statement has reachable exception handlers, then
514 create abnormal edges to them. */
515 make_eh_edges (last);
517 /* Some calls are known not to return. */
518 fallthru = !(gimple_call_flags (last) & ECF_NORETURN);
522 /* A GIMPLE_ASSIGN may throw internally and thus be considered
524 if (is_ctrl_altering_stmt (last))
526 make_eh_edges (last);
531 case GIMPLE_OMP_PARALLEL:
532 case GIMPLE_OMP_TASK:
534 case GIMPLE_OMP_SINGLE:
535 case GIMPLE_OMP_MASTER:
536 case GIMPLE_OMP_ORDERED:
537 case GIMPLE_OMP_CRITICAL:
538 case GIMPLE_OMP_SECTION:
539 cur_region = new_omp_region (bb, code, cur_region);
543 case GIMPLE_OMP_SECTIONS:
544 cur_region = new_omp_region (bb, code, cur_region);
548 case GIMPLE_OMP_SECTIONS_SWITCH:
553 case GIMPLE_OMP_ATOMIC_LOAD:
554 case GIMPLE_OMP_ATOMIC_STORE:
559 case GIMPLE_OMP_RETURN:
560 /* In the case of a GIMPLE_OMP_SECTION, the edge will go
561 somewhere other than the next block. This will be
563 cur_region->exit = bb;
564 fallthru = cur_region->type != GIMPLE_OMP_SECTION;
565 cur_region = cur_region->outer;
568 case GIMPLE_OMP_CONTINUE:
569 cur_region->cont = bb;
570 switch (cur_region->type)
573 /* Mark all GIMPLE_OMP_FOR and GIMPLE_OMP_CONTINUE
574 succs edges as abnormal to prevent splitting
576 single_succ_edge (cur_region->entry)->flags |= EDGE_ABNORMAL;
577 /* Make the loopback edge. */
578 make_edge (bb, single_succ (cur_region->entry),
581 /* Create an edge from GIMPLE_OMP_FOR to exit, which
582 corresponds to the case that the body of the loop
583 is not executed at all. */
584 make_edge (cur_region->entry, bb->next_bb, EDGE_ABNORMAL);
585 make_edge (bb, bb->next_bb, EDGE_FALLTHRU | EDGE_ABNORMAL);
589 case GIMPLE_OMP_SECTIONS:
590 /* Wire up the edges into and out of the nested sections. */
592 basic_block switch_bb = single_succ (cur_region->entry);
594 struct omp_region *i;
595 for (i = cur_region->inner; i ; i = i->next)
597 gcc_assert (i->type == GIMPLE_OMP_SECTION);
598 make_edge (switch_bb, i->entry, 0);
599 make_edge (i->exit, bb, EDGE_FALLTHRU);
602 /* Make the loopback edge to the block with
603 GIMPLE_OMP_SECTIONS_SWITCH. */
604 make_edge (bb, switch_bb, 0);
606 /* Make the edge from the switch to exit. */
607 make_edge (switch_bb, bb->next_bb, 0);
618 gcc_assert (!stmt_ends_bb_p (last));
626 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
632 /* Fold COND_EXPR_COND of each COND_EXPR. */
633 fold_cond_expr_cond ();
637 /* Create the edges for a GIMPLE_COND starting at block BB. */
640 make_cond_expr_edges (basic_block bb)
642 gimple entry = last_stmt (bb);
643 gimple then_stmt, else_stmt;
644 basic_block then_bb, else_bb;
645 tree then_label, else_label;
649 gcc_assert (gimple_code (entry) == GIMPLE_COND);
651 /* Entry basic blocks for each component. */
652 then_label = gimple_cond_true_label (entry);
653 else_label = gimple_cond_false_label (entry);
654 then_bb = label_to_block (then_label);
655 else_bb = label_to_block (else_label);
656 then_stmt = first_stmt (then_bb);
657 else_stmt = first_stmt (else_bb);
659 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
660 e->goto_locus = gimple_location (then_stmt);
662 e->goto_block = gimple_block (then_stmt);
663 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
666 e->goto_locus = gimple_location (else_stmt);
668 e->goto_block = gimple_block (else_stmt);
671 /* We do not need the labels anymore. */
672 gimple_cond_set_true_label (entry, NULL_TREE);
673 gimple_cond_set_false_label (entry, NULL_TREE);
677 /* Called for each element in the hash table (P) as we delete the
678 edge to cases hash table.
680 Clear all the TREE_CHAINs to prevent problems with copying of
681 SWITCH_EXPRs and structure sharing rules, then free the hash table
685 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED, void **value,
686 void *data ATTRIBUTE_UNUSED)
690 for (t = (tree) *value; t; t = next)
692 next = TREE_CHAIN (t);
693 TREE_CHAIN (t) = NULL;
700 /* Start recording information mapping edges to case labels. */
703 start_recording_case_labels (void)
705 gcc_assert (edge_to_cases == NULL);
706 edge_to_cases = pointer_map_create ();
709 /* Return nonzero if we are recording information for case labels. */
712 recording_case_labels_p (void)
714 return (edge_to_cases != NULL);
717 /* Stop recording information mapping edges to case labels and
718 remove any information we have recorded. */
720 end_recording_case_labels (void)
722 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
723 pointer_map_destroy (edge_to_cases);
724 edge_to_cases = NULL;
727 /* If we are inside a {start,end}_recording_cases block, then return
728 a chain of CASE_LABEL_EXPRs from T which reference E.
730 Otherwise return NULL. */
733 get_cases_for_edge (edge e, gimple t)
738 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
739 chains available. Return NULL so the caller can detect this case. */
740 if (!recording_case_labels_p ())
743 slot = pointer_map_contains (edge_to_cases, e);
747 /* If we did not find E in the hash table, then this must be the first
748 time we have been queried for information about E & T. Add all the
749 elements from T to the hash table then perform the query again. */
751 n = gimple_switch_num_labels (t);
752 for (i = 0; i < n; i++)
754 tree elt = gimple_switch_label (t, i);
755 tree lab = CASE_LABEL (elt);
756 basic_block label_bb = label_to_block (lab);
757 edge this_edge = find_edge (e->src, label_bb);
759 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
761 slot = pointer_map_insert (edge_to_cases, this_edge);
762 TREE_CHAIN (elt) = (tree) *slot;
766 return (tree) *pointer_map_contains (edge_to_cases, e);
769 /* Create the edges for a GIMPLE_SWITCH starting at block BB. */
772 make_gimple_switch_edges (basic_block bb)
774 gimple entry = last_stmt (bb);
777 n = gimple_switch_num_labels (entry);
779 for (i = 0; i < n; ++i)
781 tree lab = CASE_LABEL (gimple_switch_label (entry, i));
782 basic_block label_bb = label_to_block (lab);
783 make_edge (bb, label_bb, 0);
788 /* Return the basic block holding label DEST. */
791 label_to_block_fn (struct function *ifun, tree dest)
793 int uid = LABEL_DECL_UID (dest);
795 /* We would die hard when faced by an undefined label. Emit a label to
796 the very first basic block. This will hopefully make even the dataflow
797 and undefined variable warnings quite right. */
798 if ((errorcount || sorrycount) && uid < 0)
800 gimple_stmt_iterator gsi = gsi_start_bb (BASIC_BLOCK (NUM_FIXED_BLOCKS));
803 stmt = gimple_build_label (dest);
804 gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
805 uid = LABEL_DECL_UID (dest);
807 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
808 <= (unsigned int) uid)
810 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
813 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
814 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
817 make_abnormal_goto_edges (basic_block bb, bool for_call)
819 basic_block target_bb;
820 gimple_stmt_iterator gsi;
822 FOR_EACH_BB (target_bb)
823 for (gsi = gsi_start_bb (target_bb); !gsi_end_p (gsi); gsi_next (&gsi))
825 gimple label_stmt = gsi_stmt (gsi);
828 if (gimple_code (label_stmt) != GIMPLE_LABEL)
831 target = gimple_label_label (label_stmt);
833 /* Make an edge to every label block that has been marked as a
834 potential target for a computed goto or a non-local goto. */
835 if ((FORCED_LABEL (target) && !for_call)
836 || (DECL_NONLOCAL (target) && for_call))
838 make_edge (bb, target_bb, EDGE_ABNORMAL);
844 /* Create edges for a goto statement at block BB. */
847 make_goto_expr_edges (basic_block bb)
849 gimple_stmt_iterator last = gsi_last_bb (bb);
850 gimple goto_t = gsi_stmt (last);
852 /* A simple GOTO creates normal edges. */
853 if (simple_goto_p (goto_t))
855 tree dest = gimple_goto_dest (goto_t);
856 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
857 e->goto_locus = gimple_location (goto_t);
859 e->goto_block = gimple_block (goto_t);
860 gsi_remove (&last, true);
864 /* A computed GOTO creates abnormal edges. */
865 make_abnormal_goto_edges (bb, false);
869 /*---------------------------------------------------------------------------
871 ---------------------------------------------------------------------------*/
873 /* Cleanup useless labels in basic blocks. This is something we wish
874 to do early because it allows us to group case labels before creating
875 the edges for the CFG, and it speeds up block statement iterators in
877 We rerun this pass after CFG is created, to get rid of the labels that
878 are no longer referenced. After then we do not run it any more, since
879 (almost) no new labels should be created. */
881 /* A map from basic block index to the leading label of that block. */
882 static struct label_record
887 /* True if the label is referenced from somewhere. */
891 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
893 update_eh_label (struct eh_region *region)
895 tree old_label = get_eh_region_tree_label (region);
899 basic_block bb = label_to_block (old_label);
901 /* ??? After optimizing, there may be EH regions with labels
902 that have already been removed from the function body, so
903 there is no basic block for them. */
907 new_label = label_for_bb[bb->index].label;
908 label_for_bb[bb->index].used = true;
909 set_eh_region_tree_label (region, new_label);
914 /* Given LABEL return the first label in the same basic block. */
917 main_block_label (tree label)
919 basic_block bb = label_to_block (label);
920 tree main_label = label_for_bb[bb->index].label;
922 /* label_to_block possibly inserted undefined label into the chain. */
925 label_for_bb[bb->index].label = label;
929 label_for_bb[bb->index].used = true;
933 /* Cleanup redundant labels. This is a three-step process:
934 1) Find the leading label for each block.
935 2) Redirect all references to labels to the leading labels.
936 3) Cleanup all useless labels. */
939 cleanup_dead_labels (void)
942 label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
944 /* Find a suitable label for each block. We use the first user-defined
945 label if there is one, or otherwise just the first label we see. */
948 gimple_stmt_iterator i;
950 for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
953 gimple stmt = gsi_stmt (i);
955 if (gimple_code (stmt) != GIMPLE_LABEL)
958 label = gimple_label_label (stmt);
960 /* If we have not yet seen a label for the current block,
961 remember this one and see if there are more labels. */
962 if (!label_for_bb[bb->index].label)
964 label_for_bb[bb->index].label = label;
968 /* If we did see a label for the current block already, but it
969 is an artificially created label, replace it if the current
970 label is a user defined label. */
971 if (!DECL_ARTIFICIAL (label)
972 && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
974 label_for_bb[bb->index].label = label;
980 /* Now redirect all jumps/branches to the selected label.
981 First do so for each block ending in a control statement. */
984 gimple stmt = last_stmt (bb);
988 switch (gimple_code (stmt))
992 tree true_label = gimple_cond_true_label (stmt);
993 tree false_label = gimple_cond_false_label (stmt);
996 gimple_cond_set_true_label (stmt, main_block_label (true_label));
998 gimple_cond_set_false_label (stmt, main_block_label (false_label));
1004 size_t i, n = gimple_switch_num_labels (stmt);
1006 /* Replace all destination labels. */
1007 for (i = 0; i < n; ++i)
1009 tree case_label = gimple_switch_label (stmt, i);
1010 tree label = main_block_label (CASE_LABEL (case_label));
1011 CASE_LABEL (case_label) = label;
1016 /* We have to handle gotos until they're removed, and we don't
1017 remove them until after we've created the CFG edges. */
1019 if (!computed_goto_p (stmt))
1021 tree new_dest = main_block_label (gimple_goto_dest (stmt));
1022 gimple_goto_set_dest (stmt, new_dest);
1031 for_each_eh_region (update_eh_label);
1033 /* Finally, purge dead labels. All user-defined labels and labels that
1034 can be the target of non-local gotos and labels which have their
1035 address taken are preserved. */
1038 gimple_stmt_iterator i;
1039 tree label_for_this_bb = label_for_bb[bb->index].label;
1041 if (!label_for_this_bb)
1044 /* If the main label of the block is unused, we may still remove it. */
1045 if (!label_for_bb[bb->index].used)
1046 label_for_this_bb = NULL;
1048 for (i = gsi_start_bb (bb); !gsi_end_p (i); )
1051 gimple stmt = gsi_stmt (i);
1053 if (gimple_code (stmt) != GIMPLE_LABEL)
1056 label = gimple_label_label (stmt);
1058 if (label == label_for_this_bb
1059 || !DECL_ARTIFICIAL (label)
1060 || DECL_NONLOCAL (label)
1061 || FORCED_LABEL (label))
1064 gsi_remove (&i, true);
1068 free (label_for_bb);
1071 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1072 and scan the sorted vector of cases. Combine the ones jumping to the
1074 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1077 group_case_labels (void)
1083 gimple stmt = last_stmt (bb);
1084 if (stmt && gimple_code (stmt) == GIMPLE_SWITCH)
1086 int old_size = gimple_switch_num_labels (stmt);
1087 int i, j, new_size = old_size;
1088 tree default_case = NULL_TREE;
1089 tree default_label = NULL_TREE;
1092 /* The default label is always the first case in a switch
1093 statement after gimplification if it was not optimized
1095 if (!CASE_LOW (gimple_switch_default_label (stmt))
1096 && !CASE_HIGH (gimple_switch_default_label (stmt)))
1098 default_case = gimple_switch_default_label (stmt);
1099 default_label = CASE_LABEL (default_case);
1103 has_default = false;
1105 /* Look for possible opportunities to merge cases. */
1110 while (i < old_size)
1112 tree base_case, base_label, base_high;
1113 base_case = gimple_switch_label (stmt, i);
1115 gcc_assert (base_case);
1116 base_label = CASE_LABEL (base_case);
1118 /* Discard cases that have the same destination as the
1120 if (base_label == default_label)
1122 gimple_switch_set_label (stmt, i, NULL_TREE);
1128 base_high = CASE_HIGH (base_case)
1129 ? CASE_HIGH (base_case)
1130 : CASE_LOW (base_case);
1133 /* Try to merge case labels. Break out when we reach the end
1134 of the label vector or when we cannot merge the next case
1135 label with the current one. */
1136 while (i < old_size)
1138 tree merge_case = gimple_switch_label (stmt, i);
1139 tree merge_label = CASE_LABEL (merge_case);
1140 tree t = int_const_binop (PLUS_EXPR, base_high,
1141 integer_one_node, 1);
1143 /* Merge the cases if they jump to the same place,
1144 and their ranges are consecutive. */
1145 if (merge_label == base_label
1146 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1148 base_high = CASE_HIGH (merge_case) ?
1149 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1150 CASE_HIGH (base_case) = base_high;
1151 gimple_switch_set_label (stmt, i, NULL_TREE);
1160 /* Compress the case labels in the label vector, and adjust the
1161 length of the vector. */
1162 for (i = 0, j = 0; i < new_size; i++)
1164 while (! gimple_switch_label (stmt, j))
1166 gimple_switch_set_label (stmt, i,
1167 gimple_switch_label (stmt, j++));
1170 gcc_assert (new_size <= old_size);
1171 gimple_switch_set_num_labels (stmt, new_size);
1176 /* Checks whether we can merge block B into block A. */
1179 gimple_can_merge_blocks_p (basic_block a, basic_block b)
1182 gimple_stmt_iterator gsi;
1185 if (!single_succ_p (a))
1188 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1191 if (single_succ (a) != b)
1194 if (!single_pred_p (b))
1197 if (b == EXIT_BLOCK_PTR)
1200 /* If A ends by a statement causing exceptions or something similar, we
1201 cannot merge the blocks. */
1202 stmt = last_stmt (a);
1203 if (stmt && stmt_ends_bb_p (stmt))
1206 /* Do not allow a block with only a non-local label to be merged. */
1208 && gimple_code (stmt) == GIMPLE_LABEL
1209 && DECL_NONLOCAL (gimple_label_label (stmt)))
1212 /* It must be possible to eliminate all phi nodes in B. If ssa form
1213 is not up-to-date, we cannot eliminate any phis; however, if only
1214 some symbols as whole are marked for renaming, this is not a problem,
1215 as phi nodes for those symbols are irrelevant in updating anyway. */
1216 phis = phi_nodes (b);
1217 if (!gimple_seq_empty_p (phis))
1219 gimple_stmt_iterator i;
1221 if (name_mappings_registered_p ())
1224 for (i = gsi_start (phis); !gsi_end_p (i); gsi_next (&i))
1226 gimple phi = gsi_stmt (i);
1228 if (!is_gimple_reg (gimple_phi_result (phi))
1229 && !may_propagate_copy (gimple_phi_result (phi),
1230 gimple_phi_arg_def (phi, 0)))
1235 /* Do not remove user labels. */
1236 for (gsi = gsi_start_bb (b); !gsi_end_p (gsi); gsi_next (&gsi))
1238 stmt = gsi_stmt (gsi);
1239 if (gimple_code (stmt) != GIMPLE_LABEL)
1241 if (!DECL_ARTIFICIAL (gimple_label_label (stmt)))
1245 /* Protect the loop latches. */
1247 && b->loop_father->latch == b)
1253 /* Replaces all uses of NAME by VAL. */
1256 replace_uses_by (tree name, tree val)
1258 imm_use_iterator imm_iter;
1263 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1265 if (gimple_code (stmt) != GIMPLE_PHI)
1266 push_stmt_changes (&stmt);
1268 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1270 replace_exp (use, val);
1272 if (gimple_code (stmt) == GIMPLE_PHI)
1274 e = gimple_phi_arg_edge (stmt, PHI_ARG_INDEX_FROM_USE (use));
1275 if (e->flags & EDGE_ABNORMAL)
1277 /* This can only occur for virtual operands, since
1278 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1279 would prevent replacement. */
1280 gcc_assert (!is_gimple_reg (name));
1281 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1286 if (gimple_code (stmt) != GIMPLE_PHI)
1290 fold_stmt_inplace (stmt);
1291 if (cfgcleanup_altered_bbs)
1292 bitmap_set_bit (cfgcleanup_altered_bbs, gimple_bb (stmt)->index);
1294 /* FIXME. This should go in pop_stmt_changes. */
1295 for (i = 0; i < gimple_num_ops (stmt); i++)
1297 tree op = gimple_op (stmt, i);
1298 /* Operands may be empty here. For example, the labels
1299 of a GIMPLE_COND are nulled out following the creation
1300 of the corresponding CFG edges. */
1301 if (op && TREE_CODE (op) == ADDR_EXPR)
1302 recompute_tree_invariant_for_addr_expr (op);
1305 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1307 pop_stmt_changes (&stmt);
1311 gcc_assert (has_zero_uses (name));
1313 /* Also update the trees stored in loop structures. */
1319 FOR_EACH_LOOP (li, loop, 0)
1321 substitute_in_loop_info (loop, name, val);
1326 /* Merge block B into block A. */
1329 gimple_merge_blocks (basic_block a, basic_block b)
1331 gimple_stmt_iterator last, gsi, psi;
1332 gimple_seq phis = phi_nodes (b);
1335 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1337 /* Remove all single-valued PHI nodes from block B of the form
1338 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1339 gsi = gsi_last_bb (a);
1340 for (psi = gsi_start (phis); !gsi_end_p (psi); )
1342 gimple phi = gsi_stmt (psi);
1343 tree def = gimple_phi_result (phi), use = gimple_phi_arg_def (phi, 0);
1345 bool may_replace_uses = !is_gimple_reg (def)
1346 || may_propagate_copy (def, use);
1348 /* In case we maintain loop closed ssa form, do not propagate arguments
1349 of loop exit phi nodes. */
1351 && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1352 && is_gimple_reg (def)
1353 && TREE_CODE (use) == SSA_NAME
1354 && a->loop_father != b->loop_father)
1355 may_replace_uses = false;
1357 if (!may_replace_uses)
1359 gcc_assert (is_gimple_reg (def));
1361 /* Note that just emitting the copies is fine -- there is no problem
1362 with ordering of phi nodes. This is because A is the single
1363 predecessor of B, therefore results of the phi nodes cannot
1364 appear as arguments of the phi nodes. */
1365 copy = gimple_build_assign (def, use);
1366 gsi_insert_after (&gsi, copy, GSI_NEW_STMT);
1367 remove_phi_node (&psi, false);
1371 /* If we deal with a PHI for virtual operands, we can simply
1372 propagate these without fussing with folding or updating
1374 if (!is_gimple_reg (def))
1376 imm_use_iterator iter;
1377 use_operand_p use_p;
1380 FOR_EACH_IMM_USE_STMT (stmt, iter, def)
1381 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1382 SET_USE (use_p, use);
1385 replace_uses_by (def, use);
1387 remove_phi_node (&psi, true);
1391 /* Ensure that B follows A. */
1392 move_block_after (b, a);
1394 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1395 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1397 /* Remove labels from B and set gimple_bb to A for other statements. */
1398 for (gsi = gsi_start_bb (b); !gsi_end_p (gsi);)
1400 if (gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL)
1402 gimple label = gsi_stmt (gsi);
1404 gsi_remove (&gsi, false);
1406 /* Now that we can thread computed gotos, we might have
1407 a situation where we have a forced label in block B
1408 However, the label at the start of block B might still be
1409 used in other ways (think about the runtime checking for
1410 Fortran assigned gotos). So we can not just delete the
1411 label. Instead we move the label to the start of block A. */
1412 if (FORCED_LABEL (gimple_label_label (label)))
1414 gimple_stmt_iterator dest_gsi = gsi_start_bb (a);
1415 gsi_insert_before (&dest_gsi, label, GSI_NEW_STMT);
1420 gimple_set_bb (gsi_stmt (gsi), a);
1425 /* Merge the sequences. */
1426 last = gsi_last_bb (a);
1427 gsi_insert_seq_after (&last, bb_seq (b), GSI_NEW_STMT);
1428 set_bb_seq (b, NULL);
1430 if (cfgcleanup_altered_bbs)
1431 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1435 /* Return the one of two successors of BB that is not reachable by a
1436 reached by a complex edge, if there is one. Else, return BB. We use
1437 this in optimizations that use post-dominators for their heuristics,
1438 to catch the cases in C++ where function calls are involved. */
1441 single_noncomplex_succ (basic_block bb)
1444 if (EDGE_COUNT (bb->succs) != 2)
1447 e0 = EDGE_SUCC (bb, 0);
1448 e1 = EDGE_SUCC (bb, 1);
1449 if (e0->flags & EDGE_COMPLEX)
1451 if (e1->flags & EDGE_COMPLEX)
1458 /* Walk the function tree removing unnecessary statements.
1460 * Empty statement nodes are removed
1462 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1464 * Unnecessary COND_EXPRs are removed
1466 * Some unnecessary BIND_EXPRs are removed
1468 * GOTO_EXPRs immediately preceding destination are removed.
1470 Clearly more work could be done. The trick is doing the analysis
1471 and removal fast enough to be a net improvement in compile times.
1473 Note that when we remove a control structure such as a COND_EXPR
1474 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1475 to ensure we eliminate all the useless code. */
1484 gimple_stmt_iterator last_goto_gsi;
1488 static void remove_useless_stmts_1 (gimple_stmt_iterator *gsi, struct rus_data *);
1490 /* Given a statement sequence, find the first executable statement with
1491 location information, and warn that it is unreachable. When searching,
1492 descend into containers in execution order. */
1495 remove_useless_stmts_warn_notreached (gimple_seq stmts)
1497 gimple_stmt_iterator gsi;
1499 for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
1501 gimple stmt = gsi_stmt (gsi);
1503 if (gimple_has_location (stmt))
1505 location_t loc = gimple_location (stmt);
1506 if (LOCATION_LINE (loc) > 0)
1508 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
1513 switch (gimple_code (stmt))
1515 /* Unfortunately, we need the CFG now to detect unreachable
1516 branches in a conditional, so conditionals are not handled here. */
1519 if (remove_useless_stmts_warn_notreached (gimple_try_eval (stmt)))
1521 if (remove_useless_stmts_warn_notreached (gimple_try_cleanup (stmt)))
1526 return remove_useless_stmts_warn_notreached (gimple_catch_handler (stmt));
1528 case GIMPLE_EH_FILTER:
1529 return remove_useless_stmts_warn_notreached (gimple_eh_filter_failure (stmt));
1532 return remove_useless_stmts_warn_notreached (gimple_bind_body (stmt));
1542 /* Helper for remove_useless_stmts_1. Handle GIMPLE_COND statements. */
1545 remove_useless_stmts_cond (gimple_stmt_iterator *gsi, struct rus_data *data)
1547 gimple stmt = gsi_stmt (*gsi);
1549 /* The folded result must still be a conditional statement. */
1550 fold_stmt_inplace (stmt);
1552 data->may_branch = true;
1554 /* Replace trivial conditionals with gotos. */
1555 if (gimple_cond_true_p (stmt))
1557 /* Goto THEN label. */
1558 tree then_label = gimple_cond_true_label (stmt);
1560 gsi_replace (gsi, gimple_build_goto (then_label), false);
1561 data->last_goto_gsi = *gsi;
1562 data->last_was_goto = true;
1563 data->repeat = true;
1565 else if (gimple_cond_false_p (stmt))
1567 /* Goto ELSE label. */
1568 tree else_label = gimple_cond_false_label (stmt);
1570 gsi_replace (gsi, gimple_build_goto (else_label), false);
1571 data->last_goto_gsi = *gsi;
1572 data->last_was_goto = true;
1573 data->repeat = true;
1577 tree then_label = gimple_cond_true_label (stmt);
1578 tree else_label = gimple_cond_false_label (stmt);
1580 if (then_label == else_label)
1582 /* Goto common destination. */
1583 gsi_replace (gsi, gimple_build_goto (then_label), false);
1584 data->last_goto_gsi = *gsi;
1585 data->last_was_goto = true;
1586 data->repeat = true;
1592 data->last_was_goto = false;
1595 /* Helper for remove_useless_stmts_1.
1596 Handle the try-finally case for GIMPLE_TRY statements. */
1599 remove_useless_stmts_tf (gimple_stmt_iterator *gsi, struct rus_data *data)
1601 bool save_may_branch, save_may_throw;
1602 bool this_may_branch, this_may_throw;
1604 gimple_seq eval_seq, cleanup_seq;
1605 gimple_stmt_iterator eval_gsi, cleanup_gsi;
1607 gimple stmt = gsi_stmt (*gsi);
1609 /* Collect may_branch and may_throw information for the body only. */
1610 save_may_branch = data->may_branch;
1611 save_may_throw = data->may_throw;
1612 data->may_branch = false;
1613 data->may_throw = false;
1614 data->last_was_goto = false;
1616 eval_seq = gimple_try_eval (stmt);
1617 eval_gsi = gsi_start (eval_seq);
1618 remove_useless_stmts_1 (&eval_gsi, data);
1620 this_may_branch = data->may_branch;
1621 this_may_throw = data->may_throw;
1622 data->may_branch |= save_may_branch;
1623 data->may_throw |= save_may_throw;
1624 data->last_was_goto = false;
1626 cleanup_seq = gimple_try_cleanup (stmt);
1627 cleanup_gsi = gsi_start (cleanup_seq);
1628 remove_useless_stmts_1 (&cleanup_gsi, data);
1630 /* If the body is empty, then we can emit the FINALLY block without
1631 the enclosing TRY_FINALLY_EXPR. */
1632 if (gimple_seq_empty_p (eval_seq))
1634 gsi_insert_seq_before (gsi, cleanup_seq, GSI_SAME_STMT);
1635 gsi_remove (gsi, false);
1636 data->repeat = true;
1639 /* If the handler is empty, then we can emit the TRY block without
1640 the enclosing TRY_FINALLY_EXPR. */
1641 else if (gimple_seq_empty_p (cleanup_seq))
1643 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1644 gsi_remove (gsi, false);
1645 data->repeat = true;
1648 /* If the body neither throws, nor branches, then we can safely
1649 string the TRY and FINALLY blocks together. */
1650 else if (!this_may_branch && !this_may_throw)
1652 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1653 gsi_insert_seq_before (gsi, cleanup_seq, GSI_SAME_STMT);
1654 gsi_remove (gsi, false);
1655 data->repeat = true;
1661 /* Helper for remove_useless_stmts_1.
1662 Handle the try-catch case for GIMPLE_TRY statements. */
1665 remove_useless_stmts_tc (gimple_stmt_iterator *gsi, struct rus_data *data)
1667 bool save_may_throw, this_may_throw;
1669 gimple_seq eval_seq, cleanup_seq, handler_seq, failure_seq;
1670 gimple_stmt_iterator eval_gsi, cleanup_gsi, handler_gsi, failure_gsi;
1672 gimple stmt = gsi_stmt (*gsi);
1674 /* Collect may_throw information for the body only. */
1675 save_may_throw = data->may_throw;
1676 data->may_throw = false;
1677 data->last_was_goto = false;
1679 eval_seq = gimple_try_eval (stmt);
1680 eval_gsi = gsi_start (eval_seq);
1681 remove_useless_stmts_1 (&eval_gsi, data);
1683 this_may_throw = data->may_throw;
1684 data->may_throw = save_may_throw;
1686 cleanup_seq = gimple_try_cleanup (stmt);
1688 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1689 if (!this_may_throw)
1691 if (warn_notreached)
1693 remove_useless_stmts_warn_notreached (cleanup_seq);
1695 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1696 gsi_remove (gsi, false);
1697 data->repeat = true;
1701 /* Process the catch clause specially. We may be able to tell that
1702 no exceptions propagate past this point. */
1704 this_may_throw = true;
1705 cleanup_gsi = gsi_start (cleanup_seq);
1706 stmt = gsi_stmt (cleanup_gsi);
1707 data->last_was_goto = false;
1709 switch (gimple_code (stmt))
1712 /* If the first element is a catch, they all must be. */
1713 while (!gsi_end_p (cleanup_gsi))
1715 stmt = gsi_stmt (cleanup_gsi);
1716 /* If we catch all exceptions, then the body does not
1717 propagate exceptions past this point. */
1718 if (gimple_catch_types (stmt) == NULL)
1719 this_may_throw = false;
1720 data->last_was_goto = false;
1721 handler_seq = gimple_catch_handler (stmt);
1722 handler_gsi = gsi_start (handler_seq);
1723 remove_useless_stmts_1 (&handler_gsi, data);
1724 gsi_next (&cleanup_gsi);
1729 case GIMPLE_EH_FILTER:
1730 /* If the first element is an eh_filter, it should stand alone. */
1731 if (gimple_eh_filter_must_not_throw (stmt))
1732 this_may_throw = false;
1733 else if (gimple_eh_filter_types (stmt) == NULL)
1734 this_may_throw = false;
1735 failure_seq = gimple_eh_filter_failure (stmt);
1736 failure_gsi = gsi_start (failure_seq);
1737 remove_useless_stmts_1 (&failure_gsi, data);
1742 /* Otherwise this is a list of cleanup statements. */
1743 remove_useless_stmts_1 (&cleanup_gsi, data);
1745 /* If the cleanup is empty, then we can emit the TRY block without
1746 the enclosing TRY_CATCH_EXPR. */
1747 if (gimple_seq_empty_p (cleanup_seq))
1749 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1750 gsi_remove(gsi, false);
1751 data->repeat = true;
1758 data->may_throw |= this_may_throw;
1761 /* Helper for remove_useless_stmts_1. Handle GIMPLE_BIND statements. */
1764 remove_useless_stmts_bind (gimple_stmt_iterator *gsi, struct rus_data *data ATTRIBUTE_UNUSED)
1767 gimple_seq body_seq, fn_body_seq;
1768 gimple_stmt_iterator body_gsi;
1770 gimple stmt = gsi_stmt (*gsi);
1772 /* First remove anything underneath the BIND_EXPR. */
1774 body_seq = gimple_bind_body (stmt);
1775 body_gsi = gsi_start (body_seq);
1776 remove_useless_stmts_1 (&body_gsi, data);
1778 /* If the GIMPLE_BIND has no variables, then we can pull everything
1779 up one level and remove the GIMPLE_BIND, unless this is the toplevel
1780 GIMPLE_BIND for the current function or an inlined function.
1782 When this situation occurs we will want to apply this
1783 optimization again. */
1784 block = gimple_bind_block (stmt);
1785 fn_body_seq = gimple_body (current_function_decl);
1786 if (gimple_bind_vars (stmt) == NULL_TREE
1787 && (gimple_seq_empty_p (fn_body_seq)
1788 || stmt != gimple_seq_first_stmt (fn_body_seq))
1790 || ! BLOCK_ABSTRACT_ORIGIN (block)
1791 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1794 gsi_insert_seq_before (gsi, body_seq, GSI_SAME_STMT);
1795 gsi_remove (gsi, false);
1796 data->repeat = true;
1802 /* Helper for remove_useless_stmts_1. Handle GIMPLE_GOTO statements. */
1805 remove_useless_stmts_goto (gimple_stmt_iterator *gsi, struct rus_data *data)
1807 gimple stmt = gsi_stmt (*gsi);
1809 tree dest = gimple_goto_dest (stmt);
1811 data->may_branch = true;
1812 data->last_was_goto = false;
1814 /* Record iterator for last goto expr, so that we can delete it if unnecessary. */
1815 if (TREE_CODE (dest) == LABEL_DECL)
1817 data->last_goto_gsi = *gsi;
1818 data->last_was_goto = true;
1824 /* Helper for remove_useless_stmts_1. Handle GIMPLE_LABEL statements. */
1827 remove_useless_stmts_label (gimple_stmt_iterator *gsi, struct rus_data *data)
1829 gimple stmt = gsi_stmt (*gsi);
1831 tree label = gimple_label_label (stmt);
1833 data->has_label = true;
1835 /* We do want to jump across non-local label receiver code. */
1836 if (DECL_NONLOCAL (label))
1837 data->last_was_goto = false;
1839 else if (data->last_was_goto
1840 && gimple_goto_dest (gsi_stmt (data->last_goto_gsi)) == label)
1842 /* Replace the preceding GIMPLE_GOTO statement with
1843 a GIMPLE_NOP, which will be subsequently removed.
1844 In this way, we avoid invalidating other iterators
1845 active on the statement sequence. */
1846 gsi_replace(&data->last_goto_gsi, gimple_build_nop(), false);
1847 data->last_was_goto = false;
1848 data->repeat = true;
1851 /* ??? Add something here to delete unused labels. */
1857 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1860 notice_special_calls (gimple call)
1862 int flags = gimple_call_flags (call);
1864 if (flags & ECF_MAY_BE_ALLOCA)
1865 cfun->calls_alloca = true;
1866 if (flags & ECF_RETURNS_TWICE)
1867 cfun->calls_setjmp = true;
1871 /* Clear flags set by notice_special_calls. Used by dead code removal
1872 to update the flags. */
1875 clear_special_calls (void)
1877 cfun->calls_alloca = false;
1878 cfun->calls_setjmp = false;
1881 /* Remove useless statements from a statement sequence, and perform
1882 some preliminary simplifications. */
1885 remove_useless_stmts_1 (gimple_stmt_iterator *gsi, struct rus_data *data)
1887 while (!gsi_end_p (*gsi))
1889 gimple stmt = gsi_stmt (*gsi);
1891 switch (gimple_code (stmt))
1894 remove_useless_stmts_cond (gsi, data);
1898 remove_useless_stmts_goto (gsi, data);
1902 remove_useless_stmts_label (gsi, data);
1907 stmt = gsi_stmt (*gsi);
1908 data->last_was_goto = false;
1909 if (stmt_could_throw_p (stmt))
1910 data->may_throw = true;
1916 data->last_was_goto = false;
1922 stmt = gsi_stmt (*gsi);
1923 data->last_was_goto = false;
1924 if (is_gimple_call (stmt))
1925 notice_special_calls (stmt);
1927 /* We used to call update_gimple_call_flags here,
1928 which copied side-effects and nothrows status
1929 from the function decl to the call. In the new
1930 tuplified GIMPLE, the accessors for this information
1931 always consult the function decl, so this copying
1932 is no longer necessary. */
1933 if (stmt_could_throw_p (stmt))
1934 data->may_throw = true;
1940 data->last_was_goto = false;
1941 data->may_branch = true;
1946 remove_useless_stmts_bind (gsi, data);
1950 if (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH)
1951 remove_useless_stmts_tc (gsi, data);
1952 else if (gimple_try_kind (stmt) == GIMPLE_TRY_FINALLY)
1953 remove_useless_stmts_tf (gsi, data);
1963 gsi_remove (gsi, false);
1966 case GIMPLE_OMP_FOR:
1968 gimple_seq pre_body_seq = gimple_omp_for_pre_body (stmt);
1969 gimple_stmt_iterator pre_body_gsi = gsi_start (pre_body_seq);
1971 remove_useless_stmts_1 (&pre_body_gsi, data);
1972 data->last_was_goto = false;
1975 case GIMPLE_OMP_CRITICAL:
1976 case GIMPLE_OMP_CONTINUE:
1977 case GIMPLE_OMP_MASTER:
1978 case GIMPLE_OMP_ORDERED:
1979 case GIMPLE_OMP_SECTION:
1980 case GIMPLE_OMP_SECTIONS:
1981 case GIMPLE_OMP_SINGLE:
1983 gimple_seq body_seq = gimple_omp_body (stmt);
1984 gimple_stmt_iterator body_gsi = gsi_start (body_seq);
1986 remove_useless_stmts_1 (&body_gsi, data);
1987 data->last_was_goto = false;
1992 case GIMPLE_OMP_PARALLEL:
1993 case GIMPLE_OMP_TASK:
1995 /* Make sure the outermost GIMPLE_BIND isn't removed
1997 gimple_seq body_seq = gimple_omp_body (stmt);
1998 gimple bind = gimple_seq_first_stmt (body_seq);
1999 gimple_seq bind_seq = gimple_bind_body (bind);
2000 gimple_stmt_iterator bind_gsi = gsi_start (bind_seq);
2002 remove_useless_stmts_1 (&bind_gsi, data);
2003 data->last_was_goto = false;
2008 case GIMPLE_CHANGE_DYNAMIC_TYPE:
2009 /* If we do not optimize remove GIMPLE_CHANGE_DYNAMIC_TYPE as
2010 expansion is confused about them and we only remove them
2011 during alias computation otherwise. */
2014 data->last_was_goto = false;
2015 gsi_remove (gsi, false);
2021 data->last_was_goto = false;
2028 /* Walk the function tree, removing useless statements and performing
2029 some preliminary simplifications. */
2032 remove_useless_stmts (void)
2034 struct rus_data data;
2036 clear_special_calls ();
2040 gimple_stmt_iterator gsi;
2042 gsi = gsi_start (gimple_body (current_function_decl));
2043 memset (&data, 0, sizeof (data));
2044 remove_useless_stmts_1 (&gsi, &data);
2046 while (data.repeat);
2051 struct gimple_opt_pass pass_remove_useless_stmts =
2055 "useless", /* name */
2057 remove_useless_stmts, /* execute */
2060 0, /* static_pass_number */
2062 PROP_gimple_any, /* properties_required */
2063 0, /* properties_provided */
2064 0, /* properties_destroyed */
2065 0, /* todo_flags_start */
2066 TODO_dump_func /* todo_flags_finish */
2070 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
2073 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
2075 /* Since this block is no longer reachable, we can just delete all
2076 of its PHI nodes. */
2077 remove_phi_nodes (bb);
2079 /* Remove edges to BB's successors. */
2080 while (EDGE_COUNT (bb->succs) > 0)
2081 remove_edge (EDGE_SUCC (bb, 0));
2085 /* Remove statements of basic block BB. */
2088 remove_bb (basic_block bb)
2090 gimple_stmt_iterator i;
2091 source_location loc = UNKNOWN_LOCATION;
2095 fprintf (dump_file, "Removing basic block %d\n", bb->index);
2096 if (dump_flags & TDF_DETAILS)
2098 dump_bb (bb, dump_file, 0);
2099 fprintf (dump_file, "\n");
2105 struct loop *loop = bb->loop_father;
2107 /* If a loop gets removed, clean up the information associated
2109 if (loop->latch == bb
2110 || loop->header == bb)
2111 free_numbers_of_iterations_estimates_loop (loop);
2114 /* Remove all the instructions in the block. */
2115 if (bb_seq (bb) != NULL)
2117 for (i = gsi_start_bb (bb); !gsi_end_p (i);)
2119 gimple stmt = gsi_stmt (i);
2120 if (gimple_code (stmt) == GIMPLE_LABEL
2121 && (FORCED_LABEL (gimple_label_label (stmt))
2122 || DECL_NONLOCAL (gimple_label_label (stmt))))
2125 gimple_stmt_iterator new_gsi;
2127 /* A non-reachable non-local label may still be referenced.
2128 But it no longer needs to carry the extra semantics of
2130 if (DECL_NONLOCAL (gimple_label_label (stmt)))
2132 DECL_NONLOCAL (gimple_label_label (stmt)) = 0;
2133 FORCED_LABEL (gimple_label_label (stmt)) = 1;
2136 new_bb = bb->prev_bb;
2137 new_gsi = gsi_start_bb (new_bb);
2138 gsi_remove (&i, false);
2139 gsi_insert_before (&new_gsi, stmt, GSI_NEW_STMT);
2143 /* Release SSA definitions if we are in SSA. Note that we
2144 may be called when not in SSA. For example,
2145 final_cleanup calls this function via
2146 cleanup_tree_cfg. */
2147 if (gimple_in_ssa_p (cfun))
2148 release_defs (stmt);
2150 gsi_remove (&i, true);
2153 /* Don't warn for removed gotos. Gotos are often removed due to
2154 jump threading, thus resulting in bogus warnings. Not great,
2155 since this way we lose warnings for gotos in the original
2156 program that are indeed unreachable. */
2157 if (gimple_code (stmt) != GIMPLE_GOTO
2158 && gimple_has_location (stmt)
2160 loc = gimple_location (stmt);
2164 /* If requested, give a warning that the first statement in the
2165 block is unreachable. We walk statements backwards in the
2166 loop above, so the last statement we process is the first statement
2168 if (loc > BUILTINS_LOCATION && LOCATION_LINE (loc) > 0)
2169 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2171 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2172 bb->il.gimple = NULL;
2176 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2177 predicate VAL, return the edge that will be taken out of the block.
2178 If VAL does not match a unique edge, NULL is returned. */
2181 find_taken_edge (basic_block bb, tree val)
2185 stmt = last_stmt (bb);
2188 gcc_assert (is_ctrl_stmt (stmt));
2193 if (!is_gimple_min_invariant (val))
2196 if (gimple_code (stmt) == GIMPLE_COND)
2197 return find_taken_edge_cond_expr (bb, val);
2199 if (gimple_code (stmt) == GIMPLE_SWITCH)
2200 return find_taken_edge_switch_expr (bb, val);
2202 if (computed_goto_p (stmt))
2204 /* Only optimize if the argument is a label, if the argument is
2205 not a label then we can not construct a proper CFG.
2207 It may be the case that we only need to allow the LABEL_REF to
2208 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2209 appear inside a LABEL_EXPR just to be safe. */
2210 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2211 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2212 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2219 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2220 statement, determine which of the outgoing edges will be taken out of the
2221 block. Return NULL if either edge may be taken. */
2224 find_taken_edge_computed_goto (basic_block bb, tree val)
2229 dest = label_to_block (val);
2232 e = find_edge (bb, dest);
2233 gcc_assert (e != NULL);
2239 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2240 statement, determine which of the two edges will be taken out of the
2241 block. Return NULL if either edge may be taken. */
2244 find_taken_edge_cond_expr (basic_block bb, tree val)
2246 edge true_edge, false_edge;
2248 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2250 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2251 return (integer_zerop (val) ? false_edge : true_edge);
2254 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2255 statement, determine which edge will be taken out of the block. Return
2256 NULL if any edge may be taken. */
2259 find_taken_edge_switch_expr (basic_block bb, tree val)
2261 basic_block dest_bb;
2266 switch_stmt = last_stmt (bb);
2267 taken_case = find_case_label_for_value (switch_stmt, val);
2268 dest_bb = label_to_block (CASE_LABEL (taken_case));
2270 e = find_edge (bb, dest_bb);
2276 /* Return the CASE_LABEL_EXPR that SWITCH_STMT will take for VAL.
2277 We can make optimal use here of the fact that the case labels are
2278 sorted: We can do a binary search for a case matching VAL. */
2281 find_case_label_for_value (gimple switch_stmt, tree val)
2283 size_t low, high, n = gimple_switch_num_labels (switch_stmt);
2284 tree default_case = gimple_switch_default_label (switch_stmt);
2286 for (low = 0, high = n; high - low > 1; )
2288 size_t i = (high + low) / 2;
2289 tree t = gimple_switch_label (switch_stmt, i);
2292 /* Cache the result of comparing CASE_LOW and val. */
2293 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2300 if (CASE_HIGH (t) == NULL)
2302 /* A singe-valued case label. */
2308 /* A case range. We can only handle integer ranges. */
2309 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2314 return default_case;
2318 /* Dump a basic block on stderr. */
2321 gimple_debug_bb (basic_block bb)
2323 gimple_dump_bb (bb, stderr, 0, TDF_VOPS|TDF_MEMSYMS);
2327 /* Dump basic block with index N on stderr. */
2330 gimple_debug_bb_n (int n)
2332 gimple_debug_bb (BASIC_BLOCK (n));
2333 return BASIC_BLOCK (n);
2337 /* Dump the CFG on stderr.
2339 FLAGS are the same used by the tree dumping functions
2340 (see TDF_* in tree-pass.h). */
2343 gimple_debug_cfg (int flags)
2345 gimple_dump_cfg (stderr, flags);
2349 /* Dump the program showing basic block boundaries on the given FILE.
2351 FLAGS are the same used by the tree dumping functions (see TDF_* in
2355 gimple_dump_cfg (FILE *file, int flags)
2357 if (flags & TDF_DETAILS)
2359 const char *funcname
2360 = lang_hooks.decl_printable_name (current_function_decl, 2);
2363 fprintf (file, ";; Function %s\n\n", funcname);
2364 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2365 n_basic_blocks, n_edges, last_basic_block);
2367 brief_dump_cfg (file);
2368 fprintf (file, "\n");
2371 if (flags & TDF_STATS)
2372 dump_cfg_stats (file);
2374 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2378 /* Dump CFG statistics on FILE. */
2381 dump_cfg_stats (FILE *file)
2383 static long max_num_merged_labels = 0;
2384 unsigned long size, total = 0;
2387 const char * const fmt_str = "%-30s%-13s%12s\n";
2388 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2389 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2390 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2391 const char *funcname
2392 = lang_hooks.decl_printable_name (current_function_decl, 2);
2395 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2397 fprintf (file, "---------------------------------------------------------\n");
2398 fprintf (file, fmt_str, "", " Number of ", "Memory");
2399 fprintf (file, fmt_str, "", " instances ", "used ");
2400 fprintf (file, "---------------------------------------------------------\n");
2402 size = n_basic_blocks * sizeof (struct basic_block_def);
2404 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2405 SCALE (size), LABEL (size));
2409 num_edges += EDGE_COUNT (bb->succs);
2410 size = num_edges * sizeof (struct edge_def);
2412 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2414 fprintf (file, "---------------------------------------------------------\n");
2415 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2417 fprintf (file, "---------------------------------------------------------\n");
2418 fprintf (file, "\n");
2420 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2421 max_num_merged_labels = cfg_stats.num_merged_labels;
2423 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2424 cfg_stats.num_merged_labels, max_num_merged_labels);
2426 fprintf (file, "\n");
2430 /* Dump CFG statistics on stderr. Keep extern so that it's always
2431 linked in the final executable. */
2434 debug_cfg_stats (void)
2436 dump_cfg_stats (stderr);
2440 /* Dump the flowgraph to a .vcg FILE. */
2443 gimple_cfg2vcg (FILE *file)
2448 const char *funcname
2449 = lang_hooks.decl_printable_name (current_function_decl, 2);
2451 /* Write the file header. */
2452 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2453 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2454 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2456 /* Write blocks and edges. */
2457 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2459 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2462 if (e->flags & EDGE_FAKE)
2463 fprintf (file, " linestyle: dotted priority: 10");
2465 fprintf (file, " linestyle: solid priority: 100");
2467 fprintf (file, " }\n");
2473 enum gimple_code head_code, end_code;
2474 const char *head_name, *end_name;
2477 gimple first = first_stmt (bb);
2478 gimple last = last_stmt (bb);
2482 head_code = gimple_code (first);
2483 head_name = gimple_code_name[head_code];
2484 head_line = get_lineno (first);
2487 head_name = "no-statement";
2491 end_code = gimple_code (last);
2492 end_name = gimple_code_name[end_code];
2493 end_line = get_lineno (last);
2496 end_name = "no-statement";
2498 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2499 bb->index, bb->index, head_name, head_line, end_name,
2502 FOR_EACH_EDGE (e, ei, bb->succs)
2504 if (e->dest == EXIT_BLOCK_PTR)
2505 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2507 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2509 if (e->flags & EDGE_FAKE)
2510 fprintf (file, " priority: 10 linestyle: dotted");
2512 fprintf (file, " priority: 100 linestyle: solid");
2514 fprintf (file, " }\n");
2517 if (bb->next_bb != EXIT_BLOCK_PTR)
2521 fputs ("}\n\n", file);
2526 /*---------------------------------------------------------------------------
2527 Miscellaneous helpers
2528 ---------------------------------------------------------------------------*/
2530 /* Return true if T represents a stmt that always transfers control. */
2533 is_ctrl_stmt (gimple t)
2535 return gimple_code (t) == GIMPLE_COND
2536 || gimple_code (t) == GIMPLE_SWITCH
2537 || gimple_code (t) == GIMPLE_GOTO
2538 || gimple_code (t) == GIMPLE_RETURN
2539 || gimple_code (t) == GIMPLE_RESX;
2543 /* Return true if T is a statement that may alter the flow of control
2544 (e.g., a call to a non-returning function). */
2547 is_ctrl_altering_stmt (gimple t)
2551 if (is_gimple_call (t))
2553 int flags = gimple_call_flags (t);
2555 /* A non-pure/const call alters flow control if the current
2556 function has nonlocal labels. */
2557 if (!(flags & (ECF_CONST | ECF_PURE))
2558 && cfun->has_nonlocal_label)
2561 /* A call also alters control flow if it does not return. */
2562 if (gimple_call_flags (t) & ECF_NORETURN)
2566 /* OpenMP directives alter control flow. */
2567 if (is_gimple_omp (t))
2570 /* If a statement can throw, it alters control flow. */
2571 return stmt_can_throw_internal (t);
2575 /* Return true if T is a simple local goto. */
2578 simple_goto_p (gimple t)
2580 return (gimple_code (t) == GIMPLE_GOTO
2581 && TREE_CODE (gimple_goto_dest (t)) == LABEL_DECL);
2585 /* Return true if T can make an abnormal transfer of control flow.
2586 Transfers of control flow associated with EH are excluded. */
2589 stmt_can_make_abnormal_goto (gimple t)
2591 if (computed_goto_p (t))
2593 if (is_gimple_call (t))
2594 return gimple_has_side_effects (t) && cfun->has_nonlocal_label;
2599 /* Return true if STMT should start a new basic block. PREV_STMT is
2600 the statement preceding STMT. It is used when STMT is a label or a
2601 case label. Labels should only start a new basic block if their
2602 previous statement wasn't a label. Otherwise, sequence of labels
2603 would generate unnecessary basic blocks that only contain a single
2607 stmt_starts_bb_p (gimple stmt, gimple prev_stmt)
2612 /* Labels start a new basic block only if the preceding statement
2613 wasn't a label of the same type. This prevents the creation of
2614 consecutive blocks that have nothing but a single label. */
2615 if (gimple_code (stmt) == GIMPLE_LABEL)
2617 /* Nonlocal and computed GOTO targets always start a new block. */
2618 if (DECL_NONLOCAL (gimple_label_label (stmt))
2619 || FORCED_LABEL (gimple_label_label (stmt)))
2622 if (prev_stmt && gimple_code (prev_stmt) == GIMPLE_LABEL)
2624 if (DECL_NONLOCAL (gimple_label_label (prev_stmt)))
2627 cfg_stats.num_merged_labels++;
2638 /* Return true if T should end a basic block. */
2641 stmt_ends_bb_p (gimple t)
2643 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2646 /* Remove block annotations and other data structures. */
2649 delete_tree_cfg_annotations (void)
2651 label_to_block_map = NULL;
2655 /* Return the first statement in basic block BB. */
2658 first_stmt (basic_block bb)
2660 gimple_stmt_iterator i = gsi_start_bb (bb);
2661 return !gsi_end_p (i) ? gsi_stmt (i) : NULL;
2664 /* Return the last statement in basic block BB. */
2667 last_stmt (basic_block bb)
2669 gimple_stmt_iterator b = gsi_last_bb (bb);
2670 return !gsi_end_p (b) ? gsi_stmt (b) : NULL;
2673 /* Return the last statement of an otherwise empty block. Return NULL
2674 if the block is totally empty, or if it contains more than one
2678 last_and_only_stmt (basic_block bb)
2680 gimple_stmt_iterator i = gsi_last_bb (bb);
2686 last = gsi_stmt (i);
2691 /* Empty statements should no longer appear in the instruction stream.
2692 Everything that might have appeared before should be deleted by
2693 remove_useless_stmts, and the optimizers should just gsi_remove
2694 instead of smashing with build_empty_stmt.
2696 Thus the only thing that should appear here in a block containing
2697 one executable statement is a label. */
2698 prev = gsi_stmt (i);
2699 if (gimple_code (prev) == GIMPLE_LABEL)
2705 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
2708 reinstall_phi_args (edge new_edge, edge old_edge)
2710 edge_var_map_vector v;
2713 gimple_stmt_iterator phis;
2715 v = redirect_edge_var_map_vector (old_edge);
2719 for (i = 0, phis = gsi_start_phis (new_edge->dest);
2720 VEC_iterate (edge_var_map, v, i, vm) && !gsi_end_p (phis);
2721 i++, gsi_next (&phis))
2723 gimple phi = gsi_stmt (phis);
2724 tree result = redirect_edge_var_map_result (vm);
2725 tree arg = redirect_edge_var_map_def (vm);
2727 gcc_assert (result == gimple_phi_result (phi));
2729 add_phi_arg (phi, arg, new_edge);
2732 redirect_edge_var_map_clear (old_edge);
2735 /* Returns the basic block after which the new basic block created
2736 by splitting edge EDGE_IN should be placed. Tries to keep the new block
2737 near its "logical" location. This is of most help to humans looking
2738 at debugging dumps. */
2741 split_edge_bb_loc (edge edge_in)
2743 basic_block dest = edge_in->dest;
2745 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
2746 return edge_in->src;
2748 return dest->prev_bb;
2751 /* Split a (typically critical) edge EDGE_IN. Return the new block.
2752 Abort on abnormal edges. */
2755 gimple_split_edge (edge edge_in)
2757 basic_block new_bb, after_bb, dest;
2760 /* Abnormal edges cannot be split. */
2761 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
2763 dest = edge_in->dest;
2765 after_bb = split_edge_bb_loc (edge_in);
2767 new_bb = create_empty_bb (after_bb);
2768 new_bb->frequency = EDGE_FREQUENCY (edge_in);
2769 new_bb->count = edge_in->count;
2770 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
2771 new_edge->probability = REG_BR_PROB_BASE;
2772 new_edge->count = edge_in->count;
2774 e = redirect_edge_and_branch (edge_in, new_bb);
2775 gcc_assert (e == edge_in);
2776 reinstall_phi_args (new_edge, e);
2781 /* Callback for walk_tree, check that all elements with address taken are
2782 properly noticed as such. The DATA is an int* that is 1 if TP was seen
2783 inside a PHI node. */
2786 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
2793 /* Check operand N for being valid GIMPLE and give error MSG if not. */
2794 #define CHECK_OP(N, MSG) \
2795 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
2796 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
2798 switch (TREE_CODE (t))
2801 if (SSA_NAME_IN_FREE_LIST (t))
2803 error ("SSA name in freelist but still referenced");
2809 x = TREE_OPERAND (t, 0);
2810 if (!is_gimple_reg (x) && !is_gimple_min_invariant (x))
2812 error ("Indirect reference's operand is not a register or a constant.");
2818 x = fold (ASSERT_EXPR_COND (t));
2819 if (x == boolean_false_node)
2821 error ("ASSERT_EXPR with an always-false condition");
2827 error ("MODIFY_EXPR not expected while having tuples.");
2833 bool old_side_effects;
2835 bool new_side_effects;
2837 gcc_assert (is_gimple_address (t));
2839 old_constant = TREE_CONSTANT (t);
2840 old_side_effects = TREE_SIDE_EFFECTS (t);
2842 recompute_tree_invariant_for_addr_expr (t);
2843 new_side_effects = TREE_SIDE_EFFECTS (t);
2844 new_constant = TREE_CONSTANT (t);
2846 if (old_constant != new_constant)
2848 error ("constant not recomputed when ADDR_EXPR changed");
2851 if (old_side_effects != new_side_effects)
2853 error ("side effects not recomputed when ADDR_EXPR changed");
2857 /* Skip any references (they will be checked when we recurse down the
2858 tree) and ensure that any variable used as a prefix is marked
2860 for (x = TREE_OPERAND (t, 0);
2861 handled_component_p (x);
2862 x = TREE_OPERAND (x, 0))
2865 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
2867 if (!TREE_ADDRESSABLE (x))
2869 error ("address taken, but ADDRESSABLE bit not set");
2877 x = COND_EXPR_COND (t);
2878 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
2880 error ("non-integral used in condition");
2883 if (!is_gimple_condexpr (x))
2885 error ("invalid conditional operand");
2890 case NON_LVALUE_EXPR:
2894 case FIX_TRUNC_EXPR:
2899 case TRUTH_NOT_EXPR:
2900 CHECK_OP (0, "invalid operand to unary operator");
2907 case ARRAY_RANGE_REF:
2909 case VIEW_CONVERT_EXPR:
2910 /* We have a nest of references. Verify that each of the operands
2911 that determine where to reference is either a constant or a variable,
2912 verify that the base is valid, and then show we've already checked
2914 while (handled_component_p (t))
2916 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
2917 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
2918 else if (TREE_CODE (t) == ARRAY_REF
2919 || TREE_CODE (t) == ARRAY_RANGE_REF)
2921 CHECK_OP (1, "invalid array index");
2922 if (TREE_OPERAND (t, 2))
2923 CHECK_OP (2, "invalid array lower bound");
2924 if (TREE_OPERAND (t, 3))
2925 CHECK_OP (3, "invalid array stride");
2927 else if (TREE_CODE (t) == BIT_FIELD_REF)
2929 if (!host_integerp (TREE_OPERAND (t, 1), 1)
2930 || !host_integerp (TREE_OPERAND (t, 2), 1))
2932 error ("invalid position or size operand to BIT_FIELD_REF");
2935 else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
2936 && (TYPE_PRECISION (TREE_TYPE (t))
2937 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2939 error ("integral result type precision does not match "
2940 "field size of BIT_FIELD_REF");
2943 if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
2944 && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
2945 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2947 error ("mode precision of non-integral result does not "
2948 "match field size of BIT_FIELD_REF");
2953 t = TREE_OPERAND (t, 0);
2956 if (!is_gimple_min_invariant (t) && !is_gimple_lvalue (t))
2958 error ("invalid reference prefix");
2965 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
2966 POINTER_PLUS_EXPR. */
2967 if (POINTER_TYPE_P (TREE_TYPE (t)))
2969 error ("invalid operand to plus/minus, type is a pointer");
2972 CHECK_OP (0, "invalid operand to binary operator");
2973 CHECK_OP (1, "invalid operand to binary operator");
2976 case POINTER_PLUS_EXPR:
2977 /* Check to make sure the first operand is a pointer or reference type. */
2978 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
2980 error ("invalid operand to pointer plus, first operand is not a pointer");
2983 /* Check to make sure the second operand is an integer with type of
2985 if (!useless_type_conversion_p (sizetype,
2986 TREE_TYPE (TREE_OPERAND (t, 1))))
2988 error ("invalid operand to pointer plus, second operand is not an "
2989 "integer with type of sizetype.");
2999 case UNORDERED_EXPR:
3008 case TRUNC_DIV_EXPR:
3010 case FLOOR_DIV_EXPR:
3011 case ROUND_DIV_EXPR:
3012 case TRUNC_MOD_EXPR:
3014 case FLOOR_MOD_EXPR:
3015 case ROUND_MOD_EXPR:
3017 case EXACT_DIV_EXPR:
3027 CHECK_OP (0, "invalid operand to binary operator");
3028 CHECK_OP (1, "invalid operand to binary operator");
3032 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3045 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3046 Returns true if there is an error, otherwise false. */
3049 verify_types_in_gimple_min_lval (tree expr)
3053 if (is_gimple_id (expr))
3056 if (!INDIRECT_REF_P (expr)
3057 && TREE_CODE (expr) != TARGET_MEM_REF)
3059 error ("invalid expression for min lvalue");
3063 /* TARGET_MEM_REFs are strange beasts. */
3064 if (TREE_CODE (expr) == TARGET_MEM_REF)
3067 op = TREE_OPERAND (expr, 0);
3068 if (!is_gimple_val (op))
3070 error ("invalid operand in indirect reference");
3071 debug_generic_stmt (op);
3074 if (!useless_type_conversion_p (TREE_TYPE (expr),
3075 TREE_TYPE (TREE_TYPE (op))))
3077 error ("type mismatch in indirect reference");
3078 debug_generic_stmt (TREE_TYPE (expr));
3079 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3086 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3087 if there is an error, otherwise false. */
3090 verify_types_in_gimple_reference (tree expr)
3092 while (handled_component_p (expr))
3094 tree op = TREE_OPERAND (expr, 0);
3096 if (TREE_CODE (expr) == ARRAY_REF
3097 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3099 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3100 || (TREE_OPERAND (expr, 2)
3101 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3102 || (TREE_OPERAND (expr, 3)
3103 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3105 error ("invalid operands to array reference");
3106 debug_generic_stmt (expr);
3111 /* Verify if the reference array element types are compatible. */
3112 if (TREE_CODE (expr) == ARRAY_REF
3113 && !useless_type_conversion_p (TREE_TYPE (expr),
3114 TREE_TYPE (TREE_TYPE (op))))
3116 error ("type mismatch in array reference");
3117 debug_generic_stmt (TREE_TYPE (expr));
3118 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3121 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3122 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3123 TREE_TYPE (TREE_TYPE (op))))
3125 error ("type mismatch in array range reference");
3126 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3127 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3131 if ((TREE_CODE (expr) == REALPART_EXPR
3132 || TREE_CODE (expr) == IMAGPART_EXPR)
3133 && !useless_type_conversion_p (TREE_TYPE (expr),
3134 TREE_TYPE (TREE_TYPE (op))))
3136 error ("type mismatch in real/imagpart reference");
3137 debug_generic_stmt (TREE_TYPE (expr));
3138 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3142 if (TREE_CODE (expr) == COMPONENT_REF
3143 && !useless_type_conversion_p (TREE_TYPE (expr),
3144 TREE_TYPE (TREE_OPERAND (expr, 1))))
3146 error ("type mismatch in component reference");
3147 debug_generic_stmt (TREE_TYPE (expr));
3148 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3152 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3153 is nothing to verify. Gross mismatches at most invoke
3154 undefined behavior. */
3155 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
3156 && !handled_component_p (op))
3162 return verify_types_in_gimple_min_lval (expr);
3165 /* Returns true if there is one pointer type in TYPE_POINTER_TO (SRC_OBJ)
3166 list of pointer-to types that is trivially convertible to DEST. */
3169 one_pointer_to_useless_type_conversion_p (tree dest, tree src_obj)
3173 if (!TYPE_POINTER_TO (src_obj))
3176 for (src = TYPE_POINTER_TO (src_obj); src; src = TYPE_NEXT_PTR_TO (src))
3177 if (useless_type_conversion_p (dest, src))
3183 /* Return true if TYPE1 is a fixed-point type and if conversions to and
3184 from TYPE2 can be handled by FIXED_CONVERT_EXPR. */
3187 valid_fixed_convert_types_p (tree type1, tree type2)
3189 return (FIXED_POINT_TYPE_P (type1)
3190 && (INTEGRAL_TYPE_P (type2)
3191 || SCALAR_FLOAT_TYPE_P (type2)
3192 || FIXED_POINT_TYPE_P (type2)));
3195 /* Verify the contents of a GIMPLE_CALL STMT. Returns true when there
3196 is a problem, otherwise false. */
3199 verify_gimple_call (gimple stmt)
3201 tree fn = gimple_call_fn (stmt);
3204 if (!POINTER_TYPE_P (TREE_TYPE (fn))
3205 || (TREE_CODE (TREE_TYPE (TREE_TYPE (fn))) != FUNCTION_TYPE
3206 && TREE_CODE (TREE_TYPE (TREE_TYPE (fn))) != METHOD_TYPE))
3208 error ("non-function in gimple call");
3212 if (gimple_call_lhs (stmt)
3213 && !is_gimple_lvalue (gimple_call_lhs (stmt)))
3215 error ("invalid LHS in gimple call");
3219 fntype = TREE_TYPE (TREE_TYPE (fn));
3220 if (gimple_call_lhs (stmt)
3221 && !useless_type_conversion_p (TREE_TYPE (gimple_call_lhs (stmt)),
3223 /* ??? At least C++ misses conversions at assignments from
3224 void * call results.
3225 ??? Java is completely off. Especially with functions
3226 returning java.lang.Object.
3227 For now simply allow arbitrary pointer type conversions. */
3228 && !(POINTER_TYPE_P (TREE_TYPE (gimple_call_lhs (stmt)))
3229 && POINTER_TYPE_P (TREE_TYPE (fntype))))
3231 error ("invalid conversion in gimple call");
3232 debug_generic_stmt (TREE_TYPE (gimple_call_lhs (stmt)));
3233 debug_generic_stmt (TREE_TYPE (fntype));
3237 /* ??? The C frontend passes unpromoted arguments in case it
3238 didn't see a function declaration before the call. So for now
3239 leave the call arguments unverified. Once we gimplify
3240 unit-at-a-time we have a chance to fix this. */
3245 /* Verifies the gimple comparison with the result type TYPE and
3246 the operands OP0 and OP1. */
3249 verify_gimple_comparison (tree type, tree op0, tree op1)
3251 tree op0_type = TREE_TYPE (op0);
3252 tree op1_type = TREE_TYPE (op1);
3254 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3256 error ("invalid operands in gimple comparison");
3260 /* For comparisons we do not have the operations type as the
3261 effective type the comparison is carried out in. Instead
3262 we require that either the first operand is trivially
3263 convertible into the second, or the other way around.
3264 The resulting type of a comparison may be any integral type.
3265 Because we special-case pointers to void we allow
3266 comparisons of pointers with the same mode as well. */
3267 if ((!useless_type_conversion_p (op0_type, op1_type)
3268 && !useless_type_conversion_p (op1_type, op0_type)
3269 && (!POINTER_TYPE_P (op0_type)
3270 || !POINTER_TYPE_P (op1_type)
3271 || TYPE_MODE (op0_type) != TYPE_MODE (op1_type)))
3272 || !INTEGRAL_TYPE_P (type))
3274 error ("type mismatch in comparison expression");
3275 debug_generic_expr (type);
3276 debug_generic_expr (op0_type);
3277 debug_generic_expr (op1_type);
3284 /* Verify a gimple assignment statement STMT with an unary rhs.
3285 Returns true if anything is wrong. */
3288 verify_gimple_assign_unary (gimple stmt)
3290 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3291 tree lhs = gimple_assign_lhs (stmt);
3292 tree lhs_type = TREE_TYPE (lhs);
3293 tree rhs1 = gimple_assign_rhs1 (stmt);
3294 tree rhs1_type = TREE_TYPE (rhs1);
3296 if (!is_gimple_reg (lhs)
3298 && TREE_CODE (lhs_type) == COMPLEX_TYPE))
3300 error ("non-register as LHS of unary operation");
3304 if (!is_gimple_val (rhs1))
3306 error ("invalid operand in unary operation");
3310 /* First handle conversions. */
3315 /* Allow conversions between integral types and pointers only if
3316 there is no sign or zero extension involved.
3317 For targets were the precision of sizetype doesn't match that
3318 of pointers we need to allow arbitrary conversions from and
3320 if ((POINTER_TYPE_P (lhs_type)
3321 && INTEGRAL_TYPE_P (rhs1_type)
3322 && (TYPE_PRECISION (lhs_type) >= TYPE_PRECISION (rhs1_type)
3323 || rhs1_type == sizetype))
3324 || (POINTER_TYPE_P (rhs1_type)
3325 && INTEGRAL_TYPE_P (lhs_type)
3326 && (TYPE_PRECISION (rhs1_type) >= TYPE_PRECISION (lhs_type)
3327 || lhs_type == sizetype)))
3330 /* Allow conversion from integer to offset type and vice versa. */
3331 if ((TREE_CODE (lhs_type) == OFFSET_TYPE
3332 && TREE_CODE (rhs1_type) == INTEGER_TYPE)
3333 || (TREE_CODE (lhs_type) == INTEGER_TYPE
3334 && TREE_CODE (rhs1_type) == OFFSET_TYPE))
3337 /* Otherwise assert we are converting between types of the
3339 if (INTEGRAL_TYPE_P (lhs_type) != INTEGRAL_TYPE_P (rhs1_type))
3341 error ("invalid types in nop conversion");
3342 debug_generic_expr (lhs_type);
3343 debug_generic_expr (rhs1_type);
3350 case FIXED_CONVERT_EXPR:
3352 if (!valid_fixed_convert_types_p (lhs_type, rhs1_type)
3353 && !valid_fixed_convert_types_p (rhs1_type, lhs_type))
3355 error ("invalid types in fixed-point conversion");
3356 debug_generic_expr (lhs_type);
3357 debug_generic_expr (rhs1_type);
3366 if (!INTEGRAL_TYPE_P (rhs1_type) || !SCALAR_FLOAT_TYPE_P (lhs_type))
3368 error ("invalid types in conversion to floating point");
3369 debug_generic_expr (lhs_type);
3370 debug_generic_expr (rhs1_type);
3377 case FIX_TRUNC_EXPR:
3379 if (!INTEGRAL_TYPE_P (lhs_type) || !SCALAR_FLOAT_TYPE_P (rhs1_type))
3381 error ("invalid types in conversion to integer");
3382 debug_generic_expr (lhs_type);
3383 debug_generic_expr (rhs1_type);
3390 case TRUTH_NOT_EXPR:
3398 case NON_LVALUE_EXPR:
3400 case REDUC_MAX_EXPR:
3401 case REDUC_MIN_EXPR:
3402 case REDUC_PLUS_EXPR:
3403 case VEC_UNPACK_HI_EXPR:
3404 case VEC_UNPACK_LO_EXPR:
3405 case VEC_UNPACK_FLOAT_HI_EXPR:
3406 case VEC_UNPACK_FLOAT_LO_EXPR:
3413 /* For the remaining codes assert there is no conversion involved. */
3414 if (!useless_type_conversion_p (lhs_type, rhs1_type))
3416 error ("non-trivial conversion in unary operation");
3417 debug_generic_expr (lhs_type);
3418 debug_generic_expr (rhs1_type);
3425 /* Verify a gimple assignment statement STMT with a binary rhs.
3426 Returns true if anything is wrong. */
3429 verify_gimple_assign_binary (gimple stmt)
3431 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3432 tree lhs = gimple_assign_lhs (stmt);
3433 tree lhs_type = TREE_TYPE (lhs);
3434 tree rhs1 = gimple_assign_rhs1 (stmt);
3435 tree rhs1_type = TREE_TYPE (rhs1);
3436 tree rhs2 = gimple_assign_rhs2 (stmt);
3437 tree rhs2_type = TREE_TYPE (rhs2);
3439 if (!is_gimple_reg (lhs)
3441 && TREE_CODE (lhs_type) == COMPLEX_TYPE))
3443 error ("non-register as LHS of binary operation");
3447 if (!is_gimple_val (rhs1)
3448 || !is_gimple_val (rhs2))
3450 error ("invalid operands in binary operation");
3454 /* First handle operations that involve different types. */
3459 if (TREE_CODE (lhs_type) != COMPLEX_TYPE
3460 || !(INTEGRAL_TYPE_P (rhs1_type)
3461 || SCALAR_FLOAT_TYPE_P (rhs1_type))
3462 || !(INTEGRAL_TYPE_P (rhs2_type)
3463 || SCALAR_FLOAT_TYPE_P (rhs2_type)))
3465 error ("type mismatch in complex expression");
3466 debug_generic_expr (lhs_type);
3467 debug_generic_expr (rhs1_type);
3468 debug_generic_expr (rhs2_type);
3480 if (!INTEGRAL_TYPE_P (rhs1_type)
3481 || !INTEGRAL_TYPE_P (rhs2_type)
3482 || !useless_type_conversion_p (lhs_type, rhs1_type))
3484 error ("type mismatch in shift expression");
3485 debug_generic_expr (lhs_type);
3486 debug_generic_expr (rhs1_type);
3487 debug_generic_expr (rhs2_type);
3494 case VEC_LSHIFT_EXPR:
3495 case VEC_RSHIFT_EXPR:
3497 if (TREE_CODE (rhs1_type) != VECTOR_TYPE
3498 || !INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
3499 || (!INTEGRAL_TYPE_P (rhs2_type)
3500 && (TREE_CODE (rhs2_type) != VECTOR_TYPE
3501 || !INTEGRAL_TYPE_P (TREE_TYPE (rhs2_type))))
3502 || !useless_type_conversion_p (lhs_type, rhs1_type))
3504 error ("type mismatch in vector shift expression");
3505 debug_generic_expr (lhs_type);
3506 debug_generic_expr (rhs1_type);
3507 debug_generic_expr (rhs2_type);
3514 case POINTER_PLUS_EXPR:
3516 if (!POINTER_TYPE_P (rhs1_type)
3517 || !useless_type_conversion_p (lhs_type, rhs1_type)
3518 || !useless_type_conversion_p (sizetype, rhs2_type))
3520 error ("type mismatch in pointer plus expression");
3521 debug_generic_stmt (lhs_type);
3522 debug_generic_stmt (rhs1_type);
3523 debug_generic_stmt (rhs2_type);
3530 case TRUTH_ANDIF_EXPR:
3531 case TRUTH_ORIF_EXPR:
3534 case TRUTH_AND_EXPR:
3536 case TRUTH_XOR_EXPR:
3538 /* We allow any kind of integral typed argument and result. */
3539 if (!INTEGRAL_TYPE_P (rhs1_type)
3540 || !INTEGRAL_TYPE_P (rhs2_type)
3541 || !INTEGRAL_TYPE_P (lhs_type))
3543 error ("type mismatch in binary truth expression");
3544 debug_generic_expr (lhs_type);
3545 debug_generic_expr (rhs1_type);
3546 debug_generic_expr (rhs2_type);
3559 case UNORDERED_EXPR:
3567 /* Comparisons are also binary, but the result type is not
3568 connected to the operand types. */
3569 return verify_gimple_comparison (lhs_type, rhs1, rhs2);
3574 if (POINTER_TYPE_P (lhs_type)
3575 || POINTER_TYPE_P (rhs1_type)
3576 || POINTER_TYPE_P (rhs2_type))
3578 error ("invalid (pointer) operands to plus/minus");
3582 /* Continue with generic binary expression handling. */
3587 case TRUNC_DIV_EXPR:
3589 case FLOOR_DIV_EXPR:
3590 case ROUND_DIV_EXPR:
3591 case TRUNC_MOD_EXPR:
3593 case FLOOR_MOD_EXPR:
3594 case ROUND_MOD_EXPR:
3596 case EXACT_DIV_EXPR:
3602 case WIDEN_SUM_EXPR:
3603 case WIDEN_MULT_EXPR:
3604 case VEC_WIDEN_MULT_HI_EXPR:
3605 case VEC_WIDEN_MULT_LO_EXPR:
3606 case VEC_PACK_TRUNC_EXPR:
3607 case VEC_PACK_SAT_EXPR:
3608 case VEC_PACK_FIX_TRUNC_EXPR:
3609 case VEC_EXTRACT_EVEN_EXPR:
3610 case VEC_EXTRACT_ODD_EXPR:
3611 case VEC_INTERLEAVE_HIGH_EXPR:
3612 case VEC_INTERLEAVE_LOW_EXPR:
3613 /* Continue with generic binary expression handling. */
3620 if (!useless_type_conversion_p (lhs_type, rhs1_type)
3621 || !useless_type_conversion_p (lhs_type, rhs2_type))
3623 error ("type mismatch in binary expression");
3624 debug_generic_stmt (lhs_type);
3625 debug_generic_stmt (rhs1_type);
3626 debug_generic_stmt (rhs2_type);
3633 /* Verify a gimple assignment statement STMT with a single rhs.
3634 Returns true if anything is wrong. */
3637 verify_gimple_assign_single (gimple stmt)
3639 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3640 tree lhs = gimple_assign_lhs (stmt);
3641 tree lhs_type = TREE_TYPE (lhs);
3642 tree rhs1 = gimple_assign_rhs1 (stmt);
3643 tree rhs1_type = TREE_TYPE (rhs1);
3646 if (!useless_type_conversion_p (lhs_type, rhs1_type))
3648 error ("non-trivial conversion at assignment");
3649 debug_generic_expr (lhs_type);
3650 debug_generic_expr (rhs1_type);
3654 if (handled_component_p (lhs))
3655 res |= verify_types_in_gimple_reference (lhs);
3657 /* Special codes we cannot handle via their class. */
3662 tree op = TREE_OPERAND (rhs1, 0);
3663 if (!is_gimple_addressable (op))
3665 error ("invalid operand in unary expression");
3669 if (!one_pointer_to_useless_type_conversion_p (lhs_type, TREE_TYPE (op))
3670 /* FIXME: a longstanding wart, &a == &a[0]. */
3671 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3672 || !one_pointer_to_useless_type_conversion_p (lhs_type,
3673 TREE_TYPE (TREE_TYPE (op)))))
3675 error ("type mismatch in address expression");
3676 debug_generic_stmt (lhs_type);
3677 debug_generic_stmt (TYPE_POINTER_TO (TREE_TYPE (op)));
3681 return verify_types_in_gimple_reference (op);
3688 case ALIGN_INDIRECT_REF:
3689 case MISALIGNED_INDIRECT_REF:
3691 case ARRAY_RANGE_REF:
3692 case VIEW_CONVERT_EXPR:
3695 case TARGET_MEM_REF:
3696 if (!is_gimple_reg (lhs)
3697 && is_gimple_reg_type (TREE_TYPE (lhs)))
3699 error ("invalid rhs for gimple memory store");
3700 debug_generic_stmt (lhs);
3701 debug_generic_stmt (rhs1);
3704 return res || verify_types_in_gimple_reference (rhs1);
3716 /* tcc_declaration */
3721 if (!is_gimple_reg (lhs)
3722 && !is_gimple_reg (rhs1)
3723 && is_gimple_reg_type (TREE_TYPE (lhs)))
3725 error ("invalid rhs for gimple memory store");
3726 debug_generic_stmt (lhs);
3727 debug_generic_stmt (rhs1);
3736 case WITH_SIZE_EXPR:
3739 case POLYNOMIAL_CHREC:
3742 case REALIGN_LOAD_EXPR:
3752 /* Verify the contents of a GIMPLE_ASSIGN STMT. Returns true when there
3753 is a problem, otherwise false. */
3756 verify_gimple_assign (gimple stmt)
3758 switch (gimple_assign_rhs_class (stmt))
3760 case GIMPLE_SINGLE_RHS:
3761 return verify_gimple_assign_single (stmt);
3763 case GIMPLE_UNARY_RHS:
3764 return verify_gimple_assign_unary (stmt);
3766 case GIMPLE_BINARY_RHS:
3767 return verify_gimple_assign_binary (stmt);
3774 /* Verify the contents of a GIMPLE_RETURN STMT. Returns true when there
3775 is a problem, otherwise false. */
3778 verify_gimple_return (gimple stmt)
3780 tree op = gimple_return_retval (stmt);
3781 tree restype = TREE_TYPE (TREE_TYPE (cfun->decl));
3783 /* We cannot test for present return values as we do not fix up missing
3784 return values from the original source. */
3788 if (!is_gimple_val (op)
3789 && TREE_CODE (op) != RESULT_DECL)
3791 error ("invalid operand in return statement");
3792 debug_generic_stmt (op);
3796 if (!useless_type_conversion_p (restype, TREE_TYPE (op))
3797 /* ??? With C++ we can have the situation that the result
3798 decl is a reference type while the return type is an aggregate. */
3799 && !(TREE_CODE (op) == RESULT_DECL
3800 && TREE_CODE (TREE_TYPE (op)) == REFERENCE_TYPE
3801 && useless_type_conversion_p (restype, TREE_TYPE (TREE_TYPE (op)))))
3803 error ("invalid conversion in return statement");
3804 debug_generic_stmt (restype);
3805 debug_generic_stmt (TREE_TYPE (op));
3813 /* Verify the contents of a GIMPLE_GOTO STMT. Returns true when there
3814 is a problem, otherwise false. */
3817 verify_gimple_goto (gimple stmt)
3819 tree dest = gimple_goto_dest (stmt);
3821 /* ??? We have two canonical forms of direct goto destinations, a
3822 bare LABEL_DECL and an ADDR_EXPR of a LABEL_DECL. */
3823 if (TREE_CODE (dest) != LABEL_DECL
3824 && (!is_gimple_val (dest)
3825 || !POINTER_TYPE_P (TREE_TYPE (dest))))
3827 error ("goto destination is neither a label nor a pointer");
3834 /* Verify the contents of a GIMPLE_SWITCH STMT. Returns true when there
3835 is a problem, otherwise false. */
3838 verify_gimple_switch (gimple stmt)
3840 if (!is_gimple_val (gimple_switch_index (stmt)))
3842 error ("invalid operand to switch statement");
3843 debug_generic_stmt (gimple_switch_index (stmt));
3851 /* Verify the contents of a GIMPLE_PHI. Returns true if there is a problem,
3852 and false otherwise. */
3855 verify_gimple_phi (gimple stmt)
3857 tree type = TREE_TYPE (gimple_phi_result (stmt));
3860 if (!is_gimple_variable (gimple_phi_result (stmt)))
3862 error ("Invalid PHI result");
3866 for (i = 0; i < gimple_phi_num_args (stmt); i++)
3868 tree arg = gimple_phi_arg_def (stmt, i);
3869 if ((is_gimple_reg (gimple_phi_result (stmt))
3870 && !is_gimple_val (arg))
3871 || (!is_gimple_reg (gimple_phi_result (stmt))
3872 && !is_gimple_addressable (arg)))
3874 error ("Invalid PHI argument");
3875 debug_generic_stmt (arg);
3878 if (!useless_type_conversion_p (type, TREE_TYPE (arg)))
3880 error ("Incompatible types in PHI argument");
3881 debug_generic_stmt (type);
3882 debug_generic_stmt (TREE_TYPE (arg));
3891 /* Verify the GIMPLE statement STMT. Returns true if there is an
3892 error, otherwise false. */
3895 verify_types_in_gimple_stmt (gimple stmt)
3897 if (is_gimple_omp (stmt))
3899 /* OpenMP directives are validated by the FE and never operated
3900 on by the optimizers. Furthermore, GIMPLE_OMP_FOR may contain
3901 non-gimple expressions when the main index variable has had
3902 its address taken. This does not affect the loop itself
3903 because the header of an GIMPLE_OMP_FOR is merely used to determine
3904 how to setup the parallel iteration. */
3908 switch (gimple_code (stmt))
3911 return verify_gimple_assign (stmt);
3914 return TREE_CODE (gimple_label_label (stmt)) != LABEL_DECL;
3917 return verify_gimple_call (stmt);
3920 return verify_gimple_comparison (boolean_type_node,
3921 gimple_cond_lhs (stmt),
3922 gimple_cond_rhs (stmt));
3925 return verify_gimple_goto (stmt);
3928 return verify_gimple_switch (stmt);
3931 return verify_gimple_return (stmt);
3936 case GIMPLE_CHANGE_DYNAMIC_TYPE:
3937 return (!is_gimple_val (gimple_cdt_location (stmt))
3938 || !POINTER_TYPE_P (TREE_TYPE (gimple_cdt_location (stmt))));
3941 return verify_gimple_phi (stmt);
3943 /* Tuples that do not have tree operands. */
3946 case GIMPLE_PREDICT:
3954 /* Verify the GIMPLE statements inside the sequence STMTS. */
3957 verify_types_in_gimple_seq_2 (gimple_seq stmts)
3959 gimple_stmt_iterator ittr;
3962 for (ittr = gsi_start (stmts); !gsi_end_p (ittr); gsi_next (&ittr))
3964 gimple stmt = gsi_stmt (ittr);
3966 switch (gimple_code (stmt))
3969 err |= verify_types_in_gimple_seq_2 (gimple_bind_body (stmt));
3973 err |= verify_types_in_gimple_seq_2 (gimple_try_eval (stmt));
3974 err |= verify_types_in_gimple_seq_2 (gimple_try_cleanup (stmt));
3977 case GIMPLE_EH_FILTER:
3978 err |= verify_types_in_gimple_seq_2 (gimple_eh_filter_failure (stmt));
3982 err |= verify_types_in_gimple_seq_2 (gimple_catch_handler (stmt));
3987 bool err2 = verify_types_in_gimple_stmt (stmt);
3989 debug_gimple_stmt (stmt);
3999 /* Verify the GIMPLE statements inside the statement list STMTS. */
4002 verify_types_in_gimple_seq (gimple_seq stmts)
4004 if (verify_types_in_gimple_seq_2 (stmts))
4005 internal_error ("verify_gimple failed");
4009 /* Verify STMT, return true if STMT is not in GIMPLE form.
4010 TODO: Implement type checking. */
4013 verify_stmt (gimple_stmt_iterator *gsi)
4016 struct walk_stmt_info wi;
4017 bool last_in_block = gsi_one_before_end_p (*gsi);
4018 gimple stmt = gsi_stmt (*gsi);
4020 if (is_gimple_omp (stmt))
4022 /* OpenMP directives are validated by the FE and never operated
4023 on by the optimizers. Furthermore, GIMPLE_OMP_FOR may contain
4024 non-gimple expressions when the main index variable has had
4025 its address taken. This does not affect the loop itself
4026 because the header of an GIMPLE_OMP_FOR is merely used to determine
4027 how to setup the parallel iteration. */
4031 /* FIXME. The C frontend passes unpromoted arguments in case it
4032 didn't see a function declaration before the call. */
4033 if (is_gimple_call (stmt))
4037 if (!is_gimple_call_addr (gimple_call_fn (stmt)))
4039 error ("invalid function in call statement");
4043 decl = gimple_call_fndecl (stmt);
4045 && TREE_CODE (decl) == FUNCTION_DECL
4046 && DECL_LOOPING_CONST_OR_PURE_P (decl)
4047 && (!DECL_PURE_P (decl))
4048 && (!TREE_READONLY (decl)))
4050 error ("invalid pure const state for function");
4055 memset (&wi, 0, sizeof (wi));
4056 addr = walk_gimple_op (gsi_stmt (*gsi), verify_expr, &wi);
4059 debug_generic_expr (addr);
4060 inform (input_location, "in statement");
4061 debug_gimple_stmt (stmt);
4065 /* If the statement is marked as part of an EH region, then it is
4066 expected that the statement could throw. Verify that when we
4067 have optimizations that simplify statements such that we prove
4068 that they cannot throw, that we update other data structures
4070 if (lookup_stmt_eh_region (stmt) >= 0)
4072 if (!stmt_could_throw_p (stmt))
4074 error ("statement marked for throw, but doesn%'t");
4077 if (!last_in_block && stmt_can_throw_internal (stmt))
4079 error ("statement marked for throw in middle of block");
4087 debug_gimple_stmt (stmt);
4092 /* Return true when the T can be shared. */
4095 tree_node_can_be_shared (tree t)
4097 if (IS_TYPE_OR_DECL_P (t)
4098 || is_gimple_min_invariant (t)
4099 || TREE_CODE (t) == SSA_NAME
4100 || t == error_mark_node
4101 || TREE_CODE (t) == IDENTIFIER_NODE)
4104 if (TREE_CODE (t) == CASE_LABEL_EXPR)
4107 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4108 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4109 || TREE_CODE (t) == COMPONENT_REF
4110 || TREE_CODE (t) == REALPART_EXPR
4111 || TREE_CODE (t) == IMAGPART_EXPR)
4112 t = TREE_OPERAND (t, 0);
4121 /* Called via walk_gimple_stmt. Verify tree sharing. */
4124 verify_node_sharing (tree *tp, int *walk_subtrees, void *data)
4126 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
4127 struct pointer_set_t *visited = (struct pointer_set_t *) wi->info;
4129 if (tree_node_can_be_shared (*tp))
4131 *walk_subtrees = false;
4135 if (pointer_set_insert (visited, *tp))
4142 static bool eh_error_found;
4144 verify_eh_throw_stmt_node (void **slot, void *data)
4146 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4147 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4149 if (!pointer_set_contains (visited, node->stmt))
4151 error ("Dead STMT in EH table");
4152 debug_gimple_stmt (node->stmt);
4153 eh_error_found = true;
4159 /* Verify the GIMPLE statements in every basic block. */
4165 gimple_stmt_iterator gsi;
4167 struct pointer_set_t *visited, *visited_stmts;
4169 struct walk_stmt_info wi;
4171 timevar_push (TV_TREE_STMT_VERIFY);
4172 visited = pointer_set_create ();
4173 visited_stmts = pointer_set_create ();
4175 memset (&wi, 0, sizeof (wi));
4176 wi.info = (void *) visited;
4183 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4185 phi = gsi_stmt (gsi);
4186 pointer_set_insert (visited_stmts, phi);
4187 if (gimple_bb (phi) != bb)
4189 error ("gimple_bb (phi) is set to a wrong basic block");
4193 for (i = 0; i < gimple_phi_num_args (phi); i++)
4195 tree t = gimple_phi_arg_def (phi, i);
4200 error ("missing PHI def");
4201 debug_gimple_stmt (phi);
4205 /* Addressable variables do have SSA_NAMEs but they
4206 are not considered gimple values. */
4207 else if (TREE_CODE (t) != SSA_NAME
4208 && TREE_CODE (t) != FUNCTION_DECL
4209 && !is_gimple_min_invariant (t))
4211 error ("PHI argument is not a GIMPLE value");
4212 debug_gimple_stmt (phi);
4213 debug_generic_expr (t);
4217 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4220 error ("incorrect sharing of tree nodes");
4221 debug_gimple_stmt (phi);
4222 debug_generic_expr (addr);
4228 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
4230 gimple stmt = gsi_stmt (gsi);
4232 if (gimple_code (stmt) == GIMPLE_WITH_CLEANUP_EXPR
4233 || gimple_code (stmt) == GIMPLE_BIND)
4235 error ("invalid GIMPLE statement");
4236 debug_gimple_stmt (stmt);
4240 pointer_set_insert (visited_stmts, stmt);
4242 if (gimple_bb (stmt) != bb)
4244 error ("gimple_bb (stmt) is set to a wrong basic block");
4248 if (gimple_code (stmt) == GIMPLE_LABEL)
4250 tree decl = gimple_label_label (stmt);
4251 int uid = LABEL_DECL_UID (decl);
4254 || VEC_index (basic_block, label_to_block_map, uid) != bb)
4256 error ("incorrect entry in label_to_block_map.\n");
4261 err |= verify_stmt (&gsi);
4262 addr = walk_gimple_op (gsi_stmt (gsi), verify_node_sharing, &wi);
4265 error ("incorrect sharing of tree nodes");
4266 debug_gimple_stmt (stmt);
4267 debug_generic_expr (addr);
4274 eh_error_found = false;
4275 if (get_eh_throw_stmt_table (cfun))
4276 htab_traverse (get_eh_throw_stmt_table (cfun),
4277 verify_eh_throw_stmt_node,
4280 if (err | eh_error_found)
4281 internal_error ("verify_stmts failed");
4283 pointer_set_destroy (visited);
4284 pointer_set_destroy (visited_stmts);
4285 verify_histograms ();
4286 timevar_pop (TV_TREE_STMT_VERIFY);
4290 /* Verifies that the flow information is OK. */
4293 gimple_verify_flow_info (void)
4297 gimple_stmt_iterator gsi;
4302 if (ENTRY_BLOCK_PTR->il.gimple)
4304 error ("ENTRY_BLOCK has IL associated with it");
4308 if (EXIT_BLOCK_PTR->il.gimple)
4310 error ("EXIT_BLOCK has IL associated with it");
4314 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4315 if (e->flags & EDGE_FALLTHRU)
4317 error ("fallthru to exit from bb %d", e->src->index);
4323 bool found_ctrl_stmt = false;
4327 /* Skip labels on the start of basic block. */
4328 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4331 gimple prev_stmt = stmt;
4333 stmt = gsi_stmt (gsi);
4335 if (gimple_code (stmt) != GIMPLE_LABEL)
4338 label = gimple_label_label (stmt);
4339 if (prev_stmt && DECL_NONLOCAL (label))
4341 error ("nonlocal label ");
4342 print_generic_expr (stderr, label, 0);
4343 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4348 if (label_to_block (label) != bb)
4351 print_generic_expr (stderr, label, 0);
4352 fprintf (stderr, " to block does not match in bb %d",
4357 if (decl_function_context (label) != current_function_decl)
4360 print_generic_expr (stderr, label, 0);
4361 fprintf (stderr, " has incorrect context in bb %d",
4367 /* Verify that body of basic block BB is free of control flow. */
4368 for (; !gsi_end_p (gsi); gsi_next (&gsi))
4370 gimple stmt = gsi_stmt (gsi);
4372 if (found_ctrl_stmt)
4374 error ("control flow in the middle of basic block %d",
4379 if (stmt_ends_bb_p (stmt))
4380 found_ctrl_stmt = true;
4382 if (gimple_code (stmt) == GIMPLE_LABEL)
4385 print_generic_expr (stderr, gimple_label_label (stmt), 0);
4386 fprintf (stderr, " in the middle of basic block %d", bb->index);
4391 gsi = gsi_last_bb (bb);
4392 if (gsi_end_p (gsi))
4395 stmt = gsi_stmt (gsi);
4397 err |= verify_eh_edges (stmt);
4399 if (is_ctrl_stmt (stmt))
4401 FOR_EACH_EDGE (e, ei, bb->succs)
4402 if (e->flags & EDGE_FALLTHRU)
4404 error ("fallthru edge after a control statement in bb %d",
4410 if (gimple_code (stmt) != GIMPLE_COND)
4412 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4413 after anything else but if statement. */
4414 FOR_EACH_EDGE (e, ei, bb->succs)
4415 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4417 error ("true/false edge after a non-GIMPLE_COND in bb %d",
4423 switch (gimple_code (stmt))
4430 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4434 || !(true_edge->flags & EDGE_TRUE_VALUE)
4435 || !(false_edge->flags & EDGE_FALSE_VALUE)
4436 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4437 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4438 || EDGE_COUNT (bb->succs) >= 3)
4440 error ("wrong outgoing edge flags at end of bb %d",
4448 if (simple_goto_p (stmt))
4450 error ("explicit goto at end of bb %d", bb->index);
4455 /* FIXME. We should double check that the labels in the
4456 destination blocks have their address taken. */
4457 FOR_EACH_EDGE (e, ei, bb->succs)
4458 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4459 | EDGE_FALSE_VALUE))
4460 || !(e->flags & EDGE_ABNORMAL))
4462 error ("wrong outgoing edge flags at end of bb %d",
4470 if (!single_succ_p (bb)
4471 || (single_succ_edge (bb)->flags
4472 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4473 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4475 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4478 if (single_succ (bb) != EXIT_BLOCK_PTR)
4480 error ("return edge does not point to exit in bb %d",
4492 n = gimple_switch_num_labels (stmt);
4494 /* Mark all the destination basic blocks. */
4495 for (i = 0; i < n; ++i)
4497 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4498 basic_block label_bb = label_to_block (lab);
4499 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4500 label_bb->aux = (void *)1;
4503 /* Verify that the case labels are sorted. */
4504 prev = gimple_switch_label (stmt, 0);
4505 for (i = 1; i < n; ++i)
4507 tree c = gimple_switch_label (stmt, i);
4510 error ("found default case not at the start of "
4516 && !tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4518 error ("case labels not sorted: ");
4519 print_generic_expr (stderr, prev, 0);
4520 fprintf (stderr," is greater than ");
4521 print_generic_expr (stderr, c, 0);
4522 fprintf (stderr," but comes before it.\n");
4527 /* VRP will remove the default case if it can prove it will
4528 never be executed. So do not verify there always exists
4529 a default case here. */
4531 FOR_EACH_EDGE (e, ei, bb->succs)
4535 error ("extra outgoing edge %d->%d",
4536 bb->index, e->dest->index);
4540 e->dest->aux = (void *)2;
4541 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4542 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4544 error ("wrong outgoing edge flags at end of bb %d",
4550 /* Check that we have all of them. */
4551 for (i = 0; i < n; ++i)
4553 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4554 basic_block label_bb = label_to_block (lab);
4556 if (label_bb->aux != (void *)2)
4558 error ("missing edge %i->%i", bb->index, label_bb->index);
4563 FOR_EACH_EDGE (e, ei, bb->succs)
4564 e->dest->aux = (void *)0;
4571 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4572 verify_dominators (CDI_DOMINATORS);
4578 /* Updates phi nodes after creating a forwarder block joined
4579 by edge FALLTHRU. */
4582 gimple_make_forwarder_block (edge fallthru)
4586 basic_block dummy, bb;
4588 gimple_stmt_iterator gsi;
4590 dummy = fallthru->src;
4591 bb = fallthru->dest;
4593 if (single_pred_p (bb))
4596 /* If we redirected a branch we must create new PHI nodes at the
4598 for (gsi = gsi_start_phis (dummy); !gsi_end_p (gsi); gsi_next (&gsi))
4600 gimple phi, new_phi;
4602 phi = gsi_stmt (gsi);
4603 var = gimple_phi_result (phi);
4604 new_phi = create_phi_node (var, bb);
4605 SSA_NAME_DEF_STMT (var) = new_phi;
4606 gimple_phi_set_result (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4607 add_phi_arg (new_phi, gimple_phi_result (phi), fallthru);
4610 /* Add the arguments we have stored on edges. */
4611 FOR_EACH_EDGE (e, ei, bb->preds)
4616 flush_pending_stmts (e);
4621 /* Return a non-special label in the head of basic block BLOCK.
4622 Create one if it doesn't exist. */
4625 gimple_block_label (basic_block bb)
4627 gimple_stmt_iterator i, s = gsi_start_bb (bb);
4632 for (i = s; !gsi_end_p (i); first = false, gsi_next (&i))
4634 stmt = gsi_stmt (i);
4635 if (gimple_code (stmt) != GIMPLE_LABEL)
4637 label = gimple_label_label (stmt);
4638 if (!DECL_NONLOCAL (label))
4641 gsi_move_before (&i, &s);
4646 label = create_artificial_label ();
4647 stmt = gimple_build_label (label);
4648 gsi_insert_before (&s, stmt, GSI_NEW_STMT);
4653 /* Attempt to perform edge redirection by replacing a possibly complex
4654 jump instruction by a goto or by removing the jump completely.
4655 This can apply only if all edges now point to the same block. The
4656 parameters and return values are equivalent to
4657 redirect_edge_and_branch. */
4660 gimple_try_redirect_by_replacing_jump (edge e, basic_block target)
4662 basic_block src = e->src;
4663 gimple_stmt_iterator i;
4666 /* We can replace or remove a complex jump only when we have exactly
4668 if (EDGE_COUNT (src->succs) != 2
4669 /* Verify that all targets will be TARGET. Specifically, the
4670 edge that is not E must also go to TARGET. */
4671 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4674 i = gsi_last_bb (src);
4678 stmt = gsi_stmt (i);
4680 if (gimple_code (stmt) == GIMPLE_COND || gimple_code (stmt) == GIMPLE_SWITCH)
4682 gsi_remove (&i, true);
4683 e = ssa_redirect_edge (e, target);
4684 e->flags = EDGE_FALLTHRU;
4692 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4693 edge representing the redirected branch. */
4696 gimple_redirect_edge_and_branch (edge e, basic_block dest)
4698 basic_block bb = e->src;
4699 gimple_stmt_iterator gsi;
4703 if (e->flags & EDGE_ABNORMAL)
4706 if (e->src != ENTRY_BLOCK_PTR
4707 && (ret = gimple_try_redirect_by_replacing_jump (e, dest)))
4710 if (e->dest == dest)
4713 gsi = gsi_last_bb (bb);
4714 stmt = gsi_end_p (gsi) ? NULL : gsi_stmt (gsi);
4716 switch (stmt ? gimple_code (stmt) : ERROR_MARK)
4719 /* For COND_EXPR, we only need to redirect the edge. */
4723 /* No non-abnormal edges should lead from a non-simple goto, and
4724 simple ones should be represented implicitly. */
4729 tree label = gimple_block_label (dest);
4730 tree cases = get_cases_for_edge (e, stmt);
4732 /* If we have a list of cases associated with E, then use it
4733 as it's a lot faster than walking the entire case vector. */
4736 edge e2 = find_edge (e->src, dest);
4743 CASE_LABEL (cases) = label;
4744 cases = TREE_CHAIN (cases);
4747 /* If there was already an edge in the CFG, then we need
4748 to move all the cases associated with E to E2. */
4751 tree cases2 = get_cases_for_edge (e2, stmt);
4753 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4754 TREE_CHAIN (cases2) = first;
4759 size_t i, n = gimple_switch_num_labels (stmt);
4761 for (i = 0; i < n; i++)
4763 tree elt = gimple_switch_label (stmt, i);
4764 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4765 CASE_LABEL (elt) = label;
4773 gsi_remove (&gsi, true);
4774 e->flags |= EDGE_FALLTHRU;
4777 case GIMPLE_OMP_RETURN:
4778 case GIMPLE_OMP_CONTINUE:
4779 case GIMPLE_OMP_SECTIONS_SWITCH:
4780 case GIMPLE_OMP_FOR:
4781 /* The edges from OMP constructs can be simply redirected. */
4785 /* Otherwise it must be a fallthru edge, and we don't need to
4786 do anything besides redirecting it. */
4787 gcc_assert (e->flags & EDGE_FALLTHRU);
4791 /* Update/insert PHI nodes as necessary. */
4793 /* Now update the edges in the CFG. */
4794 e = ssa_redirect_edge (e, dest);
4799 /* Returns true if it is possible to remove edge E by redirecting
4800 it to the destination of the other edge from E->src. */
4803 gimple_can_remove_branch_p (const_edge e)
4805 if (e->flags & EDGE_ABNORMAL)
4811 /* Simple wrapper, as we can always redirect fallthru edges. */
4814 gimple_redirect_edge_and_branch_force (edge e, basic_block dest)
4816 e = gimple_redirect_edge_and_branch (e, dest);
4823 /* Splits basic block BB after statement STMT (but at least after the
4824 labels). If STMT is NULL, BB is split just after the labels. */
4827 gimple_split_block (basic_block bb, void *stmt)
4829 gimple_stmt_iterator gsi;
4830 gimple_stmt_iterator gsi_tgt;
4837 new_bb = create_empty_bb (bb);
4839 /* Redirect the outgoing edges. */
4840 new_bb->succs = bb->succs;
4842 FOR_EACH_EDGE (e, ei, new_bb->succs)
4845 if (stmt && gimple_code ((gimple) stmt) == GIMPLE_LABEL)
4848 /* Move everything from GSI to the new basic block. */
4849 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4851 act = gsi_stmt (gsi);
4852 if (gimple_code (act) == GIMPLE_LABEL)
4865 if (gsi_end_p (gsi))
4868 /* Split the statement list - avoid re-creating new containers as this
4869 brings ugly quadratic memory consumption in the inliner.
4870 (We are still quadratic since we need to update stmt BB pointers,
4872 list = gsi_split_seq_before (&gsi);
4873 set_bb_seq (new_bb, list);
4874 for (gsi_tgt = gsi_start (list);
4875 !gsi_end_p (gsi_tgt); gsi_next (&gsi_tgt))
4876 gimple_set_bb (gsi_stmt (gsi_tgt), new_bb);
4882 /* Moves basic block BB after block AFTER. */
4885 gimple_move_block_after (basic_block bb, basic_block after)
4887 if (bb->prev_bb == after)
4891 link_block (bb, after);
4897 /* Return true if basic_block can be duplicated. */
4900 gimple_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
4905 /* Create a duplicate of the basic block BB. NOTE: This does not
4906 preserve SSA form. */
4909 gimple_duplicate_bb (basic_block bb)
4912 gimple_stmt_iterator gsi, gsi_tgt;
4913 gimple_seq phis = phi_nodes (bb);
4914 gimple phi, stmt, copy;
4916 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
4918 /* Copy the PHI nodes. We ignore PHI node arguments here because
4919 the incoming edges have not been setup yet. */
4920 for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi))
4922 phi = gsi_stmt (gsi);
4923 copy = create_phi_node (gimple_phi_result (phi), new_bb);
4924 create_new_def_for (gimple_phi_result (copy), copy,
4925 gimple_phi_result_ptr (copy));
4928 gsi_tgt = gsi_start_bb (new_bb);
4929 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4931 def_operand_p def_p;
4932 ssa_op_iter op_iter;
4935 stmt = gsi_stmt (gsi);
4936 if (gimple_code (stmt) == GIMPLE_LABEL)
4939 /* Create a new copy of STMT and duplicate STMT's virtual
4941 copy = gimple_copy (stmt);
4942 gsi_insert_after (&gsi_tgt, copy, GSI_NEW_STMT);
4943 copy_virtual_operands (copy, stmt);
4944 region = lookup_stmt_eh_region (stmt);
4946 add_stmt_to_eh_region (copy, region);
4947 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
4949 /* Create new names for all the definitions created by COPY and
4950 add replacement mappings for each new name. */
4951 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
4952 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
4958 /* Adds phi node arguments for edge E_COPY after basic block duplication. */
4961 add_phi_args_after_copy_edge (edge e_copy)
4963 basic_block bb, bb_copy = e_copy->src, dest;
4966 gimple phi, phi_copy;
4968 gimple_stmt_iterator psi, psi_copy;
4970 if (gimple_seq_empty_p (phi_nodes (e_copy->dest)))
4973 bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
4975 if (e_copy->dest->flags & BB_DUPLICATED)
4976 dest = get_bb_original (e_copy->dest);
4978 dest = e_copy->dest;
4980 e = find_edge (bb, dest);
4983 /* During loop unrolling the target of the latch edge is copied.
4984 In this case we are not looking for edge to dest, but to
4985 duplicated block whose original was dest. */
4986 FOR_EACH_EDGE (e, ei, bb->succs)
4988 if ((e->dest->flags & BB_DUPLICATED)
4989 && get_bb_original (e->dest) == dest)
4993 gcc_assert (e != NULL);
4996 for (psi = gsi_start_phis (e->dest),
4997 psi_copy = gsi_start_phis (e_copy->dest);
4999 gsi_next (&psi), gsi_next (&psi_copy))
5001 phi = gsi_stmt (psi);
5002 phi_copy = gsi_stmt (psi_copy);
5003 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5004 add_phi_arg (phi_copy, def, e_copy);
5009 /* Basic block BB_COPY was created by code duplication. Add phi node
5010 arguments for edges going out of BB_COPY. The blocks that were
5011 duplicated have BB_DUPLICATED set. */
5014 add_phi_args_after_copy_bb (basic_block bb_copy)
5019 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5021 add_phi_args_after_copy_edge (e_copy);
5025 /* Blocks in REGION_COPY array of length N_REGION were created by
5026 duplication of basic blocks. Add phi node arguments for edges
5027 going from these blocks. If E_COPY is not NULL, also add
5028 phi node arguments for its destination.*/
5031 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
5036 for (i = 0; i < n_region; i++)
5037 region_copy[i]->flags |= BB_DUPLICATED;
5039 for (i = 0; i < n_region; i++)
5040 add_phi_args_after_copy_bb (region_copy[i]);
5042 add_phi_args_after_copy_edge (e_copy);
5044 for (i = 0; i < n_region; i++)
5045 region_copy[i]->flags &= ~BB_DUPLICATED;
5048 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5049 important exit edge EXIT. By important we mean that no SSA name defined
5050 inside region is live over the other exit edges of the region. All entry
5051 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5052 to the duplicate of the region. SSA form, dominance and loop information
5053 is updated. The new basic blocks are stored to REGION_COPY in the same
5054 order as they had in REGION, provided that REGION_COPY is not NULL.
5055 The function returns false if it is unable to copy the region,
5059 gimple_duplicate_sese_region (edge entry, edge exit,
5060 basic_block *region, unsigned n_region,
5061 basic_block *region_copy)
5064 bool free_region_copy = false, copying_header = false;
5065 struct loop *loop = entry->dest->loop_father;
5067 VEC (basic_block, heap) *doms;
5069 int total_freq = 0, entry_freq = 0;
5070 gcov_type total_count = 0, entry_count = 0;
5072 if (!can_copy_bbs_p (region, n_region))
5075 /* Some sanity checking. Note that we do not check for all possible
5076 missuses of the functions. I.e. if you ask to copy something weird,
5077 it will work, but the state of structures probably will not be
5079 for (i = 0; i < n_region; i++)
5081 /* We do not handle subloops, i.e. all the blocks must belong to the
5083 if (region[i]->loop_father != loop)
5086 if (region[i] != entry->dest
5087 && region[i] == loop->header)
5091 set_loop_copy (loop, loop);
5093 /* In case the function is used for loop header copying (which is the primary
5094 use), ensure that EXIT and its copy will be new latch and entry edges. */
5095 if (loop->header == entry->dest)
5097 copying_header = true;
5098 set_loop_copy (loop, loop_outer (loop));
5100 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5103 for (i = 0; i < n_region; i++)
5104 if (region[i] != exit->src
5105 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5111 region_copy = XNEWVEC (basic_block, n_region);
5112 free_region_copy = true;
5115 gcc_assert (!need_ssa_update_p ());
5117 /* Record blocks outside the region that are dominated by something
5120 initialize_original_copy_tables ();
5122 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5124 if (entry->dest->count)
5126 total_count = entry->dest->count;
5127 entry_count = entry->count;
5128 /* Fix up corner cases, to avoid division by zero or creation of negative
5130 if (entry_count > total_count)
5131 entry_count = total_count;
5135 total_freq = entry->dest->frequency;
5136 entry_freq = EDGE_FREQUENCY (entry);
5137 /* Fix up corner cases, to avoid division by zero or creation of negative
5139 if (total_freq == 0)
5141 else if (entry_freq > total_freq)
5142 entry_freq = total_freq;
5145 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5146 split_edge_bb_loc (entry));
5149 scale_bbs_frequencies_gcov_type (region, n_region,
5150 total_count - entry_count,
5152 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5157 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5159 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5164 loop->header = exit->dest;
5165 loop->latch = exit->src;
5168 /* Redirect the entry and add the phi node arguments. */
5169 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5170 gcc_assert (redirected != NULL);
5171 flush_pending_stmts (entry);
5173 /* Concerning updating of dominators: We must recount dominators
5174 for entry block and its copy. Anything that is outside of the
5175 region, but was dominated by something inside needs recounting as
5177 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5178 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5179 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5180 VEC_free (basic_block, heap, doms);
5182 /* Add the other PHI node arguments. */
5183 add_phi_args_after_copy (region_copy, n_region, NULL);
5185 /* Update the SSA web. */
5186 update_ssa (TODO_update_ssa);
5188 if (free_region_copy)
5191 free_original_copy_tables ();
5195 /* Duplicates REGION consisting of N_REGION blocks. The new blocks
5196 are stored to REGION_COPY in the same order in that they appear
5197 in REGION, if REGION_COPY is not NULL. ENTRY is the entry to
5198 the region, EXIT an exit from it. The condition guarding EXIT
5199 is moved to ENTRY. Returns true if duplication succeeds, false
5225 gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNUSED,
5226 basic_block *region ATTRIBUTE_UNUSED, unsigned n_region ATTRIBUTE_UNUSED,
5227 basic_block *region_copy ATTRIBUTE_UNUSED)
5230 bool free_region_copy = false;
5231 struct loop *loop = exit->dest->loop_father;
5232 struct loop *orig_loop = entry->dest->loop_father;
5233 basic_block switch_bb, entry_bb, nentry_bb;
5234 VEC (basic_block, heap) *doms;
5235 int total_freq = 0, exit_freq = 0;
5236 gcov_type total_count = 0, exit_count = 0;
5237 edge exits[2], nexits[2], e;
5238 gimple_stmt_iterator gsi;
5242 gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5244 exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5246 if (!can_copy_bbs_p (region, n_region))
5249 /* Some sanity checking. Note that we do not check for all possible
5250 missuses of the functions. I.e. if you ask to copy something weird
5251 (e.g., in the example, if there is a jump from inside to the middle
5252 of some_code, or come_code defines some of the values used in cond)
5253 it will work, but the resulting code will not be correct. */
5254 for (i = 0; i < n_region; i++)
5256 /* We do not handle subloops, i.e. all the blocks must belong to the
5258 if (region[i]->loop_father != orig_loop)
5261 if (region[i] == orig_loop->latch)
5265 initialize_original_copy_tables ();
5266 set_loop_copy (orig_loop, loop);
5270 region_copy = XNEWVEC (basic_block, n_region);
5271 free_region_copy = true;
5274 gcc_assert (!need_ssa_update_p ());
5276 /* Record blocks outside the region that are dominated by something
5278 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5280 if (exit->src->count)
5282 total_count = exit->src->count;
5283 exit_count = exit->count;
5284 /* Fix up corner cases, to avoid division by zero or creation of negative
5286 if (exit_count > total_count)
5287 exit_count = total_count;
5291 total_freq = exit->src->frequency;
5292 exit_freq = EDGE_FREQUENCY (exit);
5293 /* Fix up corner cases, to avoid division by zero or creation of negative
5295 if (total_freq == 0)
5297 if (exit_freq > total_freq)
5298 exit_freq = total_freq;
5301 copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5302 split_edge_bb_loc (exit));
5305 scale_bbs_frequencies_gcov_type (region, n_region,
5306 total_count - exit_count,
5308 scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5313 scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5315 scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5318 /* Create the switch block, and put the exit condition to it. */
5319 entry_bb = entry->dest;
5320 nentry_bb = get_bb_copy (entry_bb);
5321 if (!last_stmt (entry->src)
5322 || !stmt_ends_bb_p (last_stmt (entry->src)))
5323 switch_bb = entry->src;
5325 switch_bb = split_edge (entry);
5326 set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5328 gsi = gsi_last_bb (switch_bb);
5329 cond_stmt = last_stmt (exit->src);
5330 gcc_assert (gimple_code (cond_stmt) == GIMPLE_COND);
5331 cond_stmt = gimple_copy (cond_stmt);
5332 gimple_cond_set_lhs (cond_stmt, unshare_expr (gimple_cond_lhs (cond_stmt)));
5333 gimple_cond_set_rhs (cond_stmt, unshare_expr (gimple_cond_rhs (cond_stmt)));
5334 gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
5336 sorig = single_succ_edge (switch_bb);
5337 sorig->flags = exits[1]->flags;
5338 snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5340 /* Register the new edge from SWITCH_BB in loop exit lists. */
5341 rescan_loop_exit (snew, true, false);
5343 /* Add the PHI node arguments. */
5344 add_phi_args_after_copy (region_copy, n_region, snew);
5346 /* Get rid of now superfluous conditions and associated edges (and phi node
5348 e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5349 PENDING_STMT (e) = NULL;
5350 e = redirect_edge_and_branch (nexits[1], nexits[0]->dest);
5351 PENDING_STMT (e) = NULL;
5353 /* Anything that is outside of the region, but was dominated by something
5354 inside needs to update dominance info. */
5355 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5356 VEC_free (basic_block, heap, doms);
5358 /* Update the SSA web. */
5359 update_ssa (TODO_update_ssa);
5361 if (free_region_copy)
5364 free_original_copy_tables ();
5368 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5369 adding blocks when the dominator traversal reaches EXIT. This
5370 function silently assumes that ENTRY strictly dominates EXIT. */
5373 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5374 VEC(basic_block,heap) **bbs_p)
5378 for (son = first_dom_son (CDI_DOMINATORS, entry);
5380 son = next_dom_son (CDI_DOMINATORS, son))
5382 VEC_safe_push (basic_block, heap, *bbs_p, son);
5384 gather_blocks_in_sese_region (son, exit, bbs_p);
5388 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5389 The duplicates are recorded in VARS_MAP. */
5392 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5395 tree t = *tp, new_t;
5396 struct function *f = DECL_STRUCT_FUNCTION (to_context);
5399 if (DECL_CONTEXT (t) == to_context)
5402 loc = pointer_map_contains (vars_map, t);
5406 loc = pointer_map_insert (vars_map, t);
5410 new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5411 f->local_decls = tree_cons (NULL_TREE, new_t, f->local_decls);
5415 gcc_assert (TREE_CODE (t) == CONST_DECL);
5416 new_t = copy_node (t);
5418 DECL_CONTEXT (new_t) = to_context;
5423 new_t = (tree) *loc;
5429 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5430 VARS_MAP maps old ssa names and var_decls to the new ones. */
5433 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5437 tree new_name, decl = SSA_NAME_VAR (name);
5439 gcc_assert (is_gimple_reg (name));
5441 loc = pointer_map_contains (vars_map, name);
5445 replace_by_duplicate_decl (&decl, vars_map, to_context);
5447 push_cfun (DECL_STRUCT_FUNCTION (to_context));
5448 if (gimple_in_ssa_p (cfun))
5449 add_referenced_var (decl);
5451 new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5452 if (SSA_NAME_IS_DEFAULT_DEF (name))
5453 set_default_def (decl, new_name);
5456 loc = pointer_map_insert (vars_map, name);
5460 new_name = (tree) *loc;
5471 struct pointer_map_t *vars_map;
5472 htab_t new_label_map;
5476 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5477 contained in *TP if it has been ORIG_BLOCK previously and change the
5478 DECL_CONTEXT of every local variable referenced in *TP. */
5481 move_stmt_op (tree *tp, int *walk_subtrees, void *data)
5483 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
5484 struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5488 /* We should never have TREE_BLOCK set on non-statements. */
5489 gcc_assert (!TREE_BLOCK (t));
5491 else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5493 if (TREE_CODE (t) == SSA_NAME)
5494 *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5495 else if (TREE_CODE (t) == LABEL_DECL)
5497 if (p->new_label_map)
5499 struct tree_map in, *out;
5501 out = (struct tree_map *)
5502 htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5507 DECL_CONTEXT (t) = p->to_context;
5509 else if (p->remap_decls_p)
5511 /* Replace T with its duplicate. T should no longer appear in the
5512 parent function, so this looks wasteful; however, it may appear
5513 in referenced_vars, and more importantly, as virtual operands of
5514 statements, and in alias lists of other variables. It would be
5515 quite difficult to expunge it from all those places. ??? It might
5516 suffice to do this for addressable variables. */
5517 if ((TREE_CODE (t) == VAR_DECL
5518 && !is_global_var (t))
5519 || TREE_CODE (t) == CONST_DECL)
5520 replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5523 && gimple_in_ssa_p (cfun))
5525 push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5526 add_referenced_var (*tp);
5532 else if (TYPE_P (t))
5538 /* Like move_stmt_op, but for gimple statements.
5540 Helper for move_block_to_fn. Set GIMPLE_BLOCK in every expression
5541 contained in the current statement in *GSI_P and change the
5542 DECL_CONTEXT of every local variable referenced in the current
5546 move_stmt_r (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
5547 struct walk_stmt_info *wi)
5549 struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5550 gimple stmt = gsi_stmt (*gsi_p);
5551 tree block = gimple_block (stmt);
5553 if (p->orig_block == NULL_TREE
5554 || block == p->orig_block
5555 || block == NULL_TREE)
5556 gimple_set_block (stmt, p->new_block);
5557 #ifdef ENABLE_CHECKING
5558 else if (block != p->new_block)
5560 while (block && block != p->orig_block)
5561 block = BLOCK_SUPERCONTEXT (block);
5566 if (is_gimple_omp (stmt)
5567 && gimple_code (stmt) != GIMPLE_OMP_RETURN
5568 && gimple_code (stmt) != GIMPLE_OMP_CONTINUE)
5570 /* Do not remap variables inside OMP directives. Variables
5571 referenced in clauses and directive header belong to the
5572 parent function and should not be moved into the child
5574 bool save_remap_decls_p = p->remap_decls_p;
5575 p->remap_decls_p = false;
5576 *handled_ops_p = true;
5578 walk_gimple_seq (gimple_omp_body (stmt), move_stmt_r, move_stmt_op, wi);
5580 p->remap_decls_p = save_remap_decls_p;
5586 /* Marks virtual operands of all statements in basic blocks BBS for
5590 mark_virtual_ops_in_bb (basic_block bb)
5592 gimple_stmt_iterator gsi;
5594 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5595 mark_virtual_ops_for_renaming (gsi_stmt (gsi));
5597 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5598 mark_virtual_ops_for_renaming (gsi_stmt (gsi));
5601 /* Marks virtual operands of all statements in basic blocks BBS for
5605 mark_virtual_ops_in_region (VEC (basic_block,heap) *bbs)
5610 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5611 mark_virtual_ops_in_bb (bb);
5614 /* Move basic block BB from function CFUN to function DEST_FN. The
5615 block is moved out of the original linked list and placed after
5616 block AFTER in the new list. Also, the block is removed from the
5617 original array of blocks and placed in DEST_FN's array of blocks.
5618 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5619 updated to reflect the moved edges.
5621 The local variables are remapped to new instances, VARS_MAP is used
5622 to record the mapping. */
5625 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5626 basic_block after, bool update_edge_count_p,
5627 struct move_stmt_d *d, int eh_offset)
5629 struct control_flow_graph *cfg;
5632 gimple_stmt_iterator si;
5633 unsigned old_len, new_len;
5635 /* Remove BB from dominance structures. */
5636 delete_from_dominance_info (CDI_DOMINATORS, bb);
5638 remove_bb_from_loops (bb);
5640 /* Link BB to the new linked list. */
5641 move_block_after (bb, after);
5643 /* Update the edge count in the corresponding flowgraphs. */
5644 if (update_edge_count_p)
5645 FOR_EACH_EDGE (e, ei, bb->succs)
5647 cfun->cfg->x_n_edges--;
5648 dest_cfun->cfg->x_n_edges++;
5651 /* Remove BB from the original basic block array. */
5652 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5653 cfun->cfg->x_n_basic_blocks--;
5655 /* Grow DEST_CFUN's basic block array if needed. */
5656 cfg = dest_cfun->cfg;
5657 cfg->x_n_basic_blocks++;
5658 if (bb->index >= cfg->x_last_basic_block)
5659 cfg->x_last_basic_block = bb->index + 1;
5661 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5662 if ((unsigned) cfg->x_last_basic_block >= old_len)
5664 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5665 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5669 VEC_replace (basic_block, cfg->x_basic_block_info,
5672 /* Remap the variables in phi nodes. */
5673 for (si = gsi_start_phis (bb); !gsi_end_p (si); )
5675 gimple phi = gsi_stmt (si);
5677 tree op = PHI_RESULT (phi);
5680 if (!is_gimple_reg (op))
5682 /* Remove the phi nodes for virtual operands (alias analysis will be
5683 run for the new function, anyway). */
5684 remove_phi_node (&si, true);
5688 SET_PHI_RESULT (phi,
5689 replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5690 FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5692 op = USE_FROM_PTR (use);
5693 if (TREE_CODE (op) == SSA_NAME)
5694 SET_USE (use, replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5700 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5702 gimple stmt = gsi_stmt (si);
5704 struct walk_stmt_info wi;
5706 memset (&wi, 0, sizeof (wi));
5708 walk_gimple_stmt (&si, move_stmt_r, move_stmt_op, &wi);
5710 if (gimple_code (stmt) == GIMPLE_LABEL)
5712 tree label = gimple_label_label (stmt);
5713 int uid = LABEL_DECL_UID (label);
5715 gcc_assert (uid > -1);
5717 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5718 if (old_len <= (unsigned) uid)
5720 new_len = 3 * uid / 2;
5721 VEC_safe_grow_cleared (basic_block, gc,
5722 cfg->x_label_to_block_map, new_len);
5725 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5726 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5728 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5730 if (uid >= dest_cfun->cfg->last_label_uid)
5731 dest_cfun->cfg->last_label_uid = uid + 1;
5733 else if (gimple_code (stmt) == GIMPLE_RESX && eh_offset != 0)
5734 gimple_resx_set_region (stmt, gimple_resx_region (stmt) + eh_offset);
5736 region = lookup_stmt_eh_region (stmt);
5739 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5740 remove_stmt_from_eh_region (stmt);
5741 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5742 gimple_remove_stmt_histograms (cfun, stmt);
5745 /* We cannot leave any operands allocated from the operand caches of
5746 the current function. */
5747 free_stmt_operands (stmt);
5748 push_cfun (dest_cfun);
5753 FOR_EACH_EDGE (e, ei, bb->succs)
5756 tree block = e->goto_block;
5757 if (d->orig_block == NULL_TREE
5758 || block == d->orig_block)
5759 e->goto_block = d->new_block;
5760 #ifdef ENABLE_CHECKING
5761 else if (block != d->new_block)
5763 while (block && block != d->orig_block)
5764 block = BLOCK_SUPERCONTEXT (block);
5771 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5772 the outermost EH region. Use REGION as the incoming base EH region. */
5775 find_outermost_region_in_block (struct function *src_cfun,
5776 basic_block bb, int region)
5778 gimple_stmt_iterator si;
5780 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5782 gimple stmt = gsi_stmt (si);
5785 if (gimple_code (stmt) == GIMPLE_RESX)
5786 stmt_region = gimple_resx_region (stmt);
5788 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5789 if (stmt_region > 0)
5792 region = stmt_region;
5793 else if (stmt_region != region)
5795 region = eh_region_outermost (src_cfun, stmt_region, region);
5796 gcc_assert (region != -1);
5805 new_label_mapper (tree decl, void *data)
5807 htab_t hash = (htab_t) data;
5811 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5813 m = XNEW (struct tree_map);
5814 m->hash = DECL_UID (decl);
5815 m->base.from = decl;
5816 m->to = create_artificial_label ();
5817 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5818 if (LABEL_DECL_UID (m->to) >= cfun->cfg->last_label_uid)
5819 cfun->cfg->last_label_uid = LABEL_DECL_UID (m->to) + 1;
5821 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5822 gcc_assert (*slot == NULL);
5829 /* Change DECL_CONTEXT of all BLOCK_VARS in block, including
5833 replace_block_vars_by_duplicates (tree block, struct pointer_map_t *vars_map,
5838 for (tp = &BLOCK_VARS (block); *tp; tp = &TREE_CHAIN (*tp))
5841 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != CONST_DECL)
5843 replace_by_duplicate_decl (&t, vars_map, to_context);
5846 if (TREE_CODE (*tp) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (*tp))
5848 SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (*tp));
5849 DECL_HAS_VALUE_EXPR_P (t) = 1;
5851 TREE_CHAIN (t) = TREE_CHAIN (*tp);
5856 for (block = BLOCK_SUBBLOCKS (block); block; block = BLOCK_CHAIN (block))
5857 replace_block_vars_by_duplicates (block, vars_map, to_context);
5860 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5861 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5862 single basic block in the original CFG and the new basic block is
5863 returned. DEST_CFUN must not have a CFG yet.
5865 Note that the region need not be a pure SESE region. Blocks inside
5866 the region may contain calls to abort/exit. The only restriction
5867 is that ENTRY_BB should be the only entry point and it must
5870 Change TREE_BLOCK of all statements in ORIG_BLOCK to the new
5871 functions outermost BLOCK, move all subblocks of ORIG_BLOCK
5872 to the new function.
5874 All local variables referenced in the region are assumed to be in
5875 the corresponding BLOCK_VARS and unexpanded variable lists
5876 associated with DEST_CFUN. */
5879 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5880 basic_block exit_bb, tree orig_block)
5882 VEC(basic_block,heap) *bbs, *dom_bbs;
5883 basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
5884 basic_block after, bb, *entry_pred, *exit_succ, abb;
5885 struct function *saved_cfun = cfun;
5886 int *entry_flag, *exit_flag, eh_offset;
5887 unsigned *entry_prob, *exit_prob;
5888 unsigned i, num_entry_edges, num_exit_edges;
5891 htab_t new_label_map;
5892 struct pointer_map_t *vars_map;
5893 struct loop *loop = entry_bb->loop_father;
5894 struct move_stmt_d d;
5896 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5898 gcc_assert (entry_bb != exit_bb
5900 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
5902 /* Collect all the blocks in the region. Manually add ENTRY_BB
5903 because it won't be added by dfs_enumerate_from. */
5905 VEC_safe_push (basic_block, heap, bbs, entry_bb);
5906 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
5908 /* The blocks that used to be dominated by something in BBS will now be
5909 dominated by the new block. */
5910 dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
5911 VEC_address (basic_block, bbs),
5912 VEC_length (basic_block, bbs));
5914 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5915 the predecessor edges to ENTRY_BB and the successor edges to
5916 EXIT_BB so that we can re-attach them to the new basic block that
5917 will replace the region. */
5918 num_entry_edges = EDGE_COUNT (entry_bb->preds);
5919 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
5920 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
5921 entry_prob = XNEWVEC (unsigned, num_entry_edges);
5923 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
5925 entry_prob[i] = e->probability;
5926 entry_flag[i] = e->flags;
5927 entry_pred[i++] = e->src;
5933 num_exit_edges = EDGE_COUNT (exit_bb->succs);
5934 exit_succ = (basic_block *) xcalloc (num_exit_edges,
5935 sizeof (basic_block));
5936 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
5937 exit_prob = XNEWVEC (unsigned, num_exit_edges);
5939 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
5941 exit_prob[i] = e->probability;
5942 exit_flag[i] = e->flags;
5943 exit_succ[i++] = e->dest;
5955 /* Switch context to the child function to initialize DEST_FN's CFG. */
5956 gcc_assert (dest_cfun->cfg == NULL);
5957 push_cfun (dest_cfun);
5959 init_empty_tree_cfg ();
5961 /* Initialize EH information for the new function. */
5963 new_label_map = NULL;
5968 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5969 region = find_outermost_region_in_block (saved_cfun, bb, region);
5971 init_eh_for_function ();
5974 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
5975 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
5976 new_label_map, region, 0);
5982 /* The ssa form for virtual operands in the source function will have to
5983 be repaired. We do not care for the real operands -- the sese region
5984 must be closed with respect to those. */
5985 mark_virtual_ops_in_region (bbs);
5987 /* Move blocks from BBS into DEST_CFUN. */
5988 gcc_assert (VEC_length (basic_block, bbs) >= 2);
5989 after = dest_cfun->cfg->x_entry_block_ptr;
5990 vars_map = pointer_map_create ();
5992 memset (&d, 0, sizeof (d));
5993 d.vars_map = vars_map;
5994 d.from_context = cfun->decl;
5995 d.to_context = dest_cfun->decl;
5996 d.new_label_map = new_label_map;
5997 d.remap_decls_p = true;
5998 d.orig_block = orig_block;
5999 d.new_block = DECL_INITIAL (dest_cfun->decl);
6001 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6003 /* No need to update edge counts on the last block. It has
6004 already been updated earlier when we detached the region from
6005 the original CFG. */
6006 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, &d, eh_offset);
6010 /* Rewire BLOCK_SUBBLOCKS of orig_block. */
6014 gcc_assert (BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
6016 BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
6017 = BLOCK_SUBBLOCKS (orig_block);
6018 for (block = BLOCK_SUBBLOCKS (orig_block);
6019 block; block = BLOCK_CHAIN (block))
6020 BLOCK_SUPERCONTEXT (block) = DECL_INITIAL (dest_cfun->decl);
6021 BLOCK_SUBBLOCKS (orig_block) = NULL_TREE;
6024 replace_block_vars_by_duplicates (DECL_INITIAL (dest_cfun->decl),
6025 vars_map, dest_cfun->decl);
6028 htab_delete (new_label_map);
6029 pointer_map_destroy (vars_map);
6031 /* Rewire the entry and exit blocks. The successor to the entry
6032 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
6033 the child function. Similarly, the predecessor of DEST_FN's
6034 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
6035 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
6036 various CFG manipulation function get to the right CFG.
6038 FIXME, this is silly. The CFG ought to become a parameter to
6040 push_cfun (dest_cfun);
6041 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
6043 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
6046 /* Back in the original function, the SESE region has disappeared,
6047 create a new basic block in its place. */
6048 bb = create_empty_bb (entry_pred[0]);
6050 add_bb_to_loop (bb, loop);
6051 for (i = 0; i < num_entry_edges; i++)
6053 e = make_edge (entry_pred[i], bb, entry_flag[i]);
6054 e->probability = entry_prob[i];
6057 for (i = 0; i < num_exit_edges; i++)
6059 e = make_edge (bb, exit_succ[i], exit_flag[i]);
6060 e->probability = exit_prob[i];
6063 set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
6064 for (i = 0; VEC_iterate (basic_block, dom_bbs, i, abb); i++)
6065 set_immediate_dominator (CDI_DOMINATORS, abb, bb);
6066 VEC_free (basic_block, heap, dom_bbs);
6077 VEC_free (basic_block, heap, bbs);
6083 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree-pass.h)
6087 dump_function_to_file (tree fn, FILE *file, int flags)
6089 tree arg, vars, var;
6090 struct function *dsf;
6091 bool ignore_topmost_bind = false, any_var = false;
6095 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
6097 arg = DECL_ARGUMENTS (fn);
6100 print_generic_expr (file, TREE_TYPE (arg), dump_flags);
6101 fprintf (file, " ");
6102 print_generic_expr (file, arg, dump_flags);
6103 if (flags & TDF_VERBOSE)
6104 print_node (file, "", arg, 4);
6105 if (TREE_CHAIN (arg))
6106 fprintf (file, ", ");
6107 arg = TREE_CHAIN (arg);
6109 fprintf (file, ")\n");
6111 if (flags & TDF_VERBOSE)
6112 print_node (file, "", fn, 2);
6114 dsf = DECL_STRUCT_FUNCTION (fn);
6115 if (dsf && (flags & TDF_DETAILS))
6116 dump_eh_tree (file, dsf);
6118 if (flags & TDF_RAW && !gimple_has_body_p (fn))
6120 dump_node (fn, TDF_SLIM | flags, file);
6124 /* Switch CFUN to point to FN. */
6125 push_cfun (DECL_STRUCT_FUNCTION (fn));
6127 /* When GIMPLE is lowered, the variables are no longer available in
6128 BIND_EXPRs, so display them separately. */
6129 if (cfun && cfun->decl == fn && cfun->local_decls)
6131 ignore_topmost_bind = true;
6133 fprintf (file, "{\n");
6134 for (vars = cfun->local_decls; vars; vars = TREE_CHAIN (vars))
6136 var = TREE_VALUE (vars);
6138 print_generic_decl (file, var, flags);
6139 if (flags & TDF_VERBOSE)
6140 print_node (file, "", var, 4);
6141 fprintf (file, "\n");
6147 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
6149 /* If the CFG has been built, emit a CFG-based dump. */
6150 check_bb_profile (ENTRY_BLOCK_PTR, file);
6151 if (!ignore_topmost_bind)
6152 fprintf (file, "{\n");
6154 if (any_var && n_basic_blocks)
6155 fprintf (file, "\n");
6158 gimple_dump_bb (bb, file, 2, flags);
6160 fprintf (file, "}\n");
6161 check_bb_profile (EXIT_BLOCK_PTR, file);
6163 else if (DECL_SAVED_TREE (fn) == NULL)
6165 /* The function is now in GIMPLE form but the CFG has not been
6166 built yet. Emit the single sequence of GIMPLE statements
6167 that make up its body. */
6168 gimple_seq body = gimple_body (fn);
6170 if (gimple_seq_first_stmt (body)
6171 && gimple_seq_first_stmt (body) == gimple_seq_last_stmt (body)
6172 && gimple_code (gimple_seq_first_stmt (body)) == GIMPLE_BIND)
6173 print_gimple_seq (file, body, 0, flags);
6176 if (!ignore_topmost_bind)
6177 fprintf (file, "{\n");
6180 fprintf (file, "\n");
6182 print_gimple_seq (file, body, 2, flags);
6183 fprintf (file, "}\n");
6190 /* Make a tree based dump. */
6191 chain = DECL_SAVED_TREE (fn);
6193 if (chain && TREE_CODE (chain) == BIND_EXPR)
6195 if (ignore_topmost_bind)
6197 chain = BIND_EXPR_BODY (chain);
6205 if (!ignore_topmost_bind)
6206 fprintf (file, "{\n");
6211 fprintf (file, "\n");
6213 print_generic_stmt_indented (file, chain, flags, indent);
6214 if (ignore_topmost_bind)
6215 fprintf (file, "}\n");
6218 fprintf (file, "\n\n");
6225 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
6228 debug_function (tree fn, int flags)
6230 dump_function_to_file (fn, stderr, flags);
6234 /* Print on FILE the indexes for the predecessors of basic_block BB. */
6237 print_pred_bbs (FILE *file, basic_block bb)
6242 FOR_EACH_EDGE (e, ei, bb->preds)
6243 fprintf (file, "bb_%d ", e->src->index);
6247 /* Print on FILE the indexes for the successors of basic_block BB. */
6250 print_succ_bbs (FILE *file, basic_block bb)
6255 FOR_EACH_EDGE (e, ei, bb->succs)
6256 fprintf (file, "bb_%d ", e->dest->index);
6259 /* Print to FILE the basic block BB following the VERBOSITY level. */
6262 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6264 char *s_indent = (char *) alloca ((size_t) indent + 1);
6265 memset ((void *) s_indent, ' ', (size_t) indent);
6266 s_indent[indent] = '\0';
6268 /* Print basic_block's header. */
6271 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
6272 print_pred_bbs (file, bb);
6273 fprintf (file, "}, succs = {");
6274 print_succ_bbs (file, bb);
6275 fprintf (file, "})\n");
6278 /* Print basic_block's body. */
6281 fprintf (file, "%s {\n", s_indent);
6282 gimple_dump_bb (bb, file, indent + 4, TDF_VOPS|TDF_MEMSYMS);
6283 fprintf (file, "%s }\n", s_indent);
6287 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6289 /* Pretty print LOOP on FILE, indented INDENT spaces. Following
6290 VERBOSITY level this outputs the contents of the loop, or just its
6294 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6302 s_indent = (char *) alloca ((size_t) indent + 1);
6303 memset ((void *) s_indent, ' ', (size_t) indent);
6304 s_indent[indent] = '\0';
6306 /* Print loop's header. */
6307 fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6308 loop->num, loop->header->index, loop->latch->index);
6309 fprintf (file, ", niter = ");
6310 print_generic_expr (file, loop->nb_iterations, 0);
6312 if (loop->any_upper_bound)
6314 fprintf (file, ", upper_bound = ");
6315 dump_double_int (file, loop->nb_iterations_upper_bound, true);
6318 if (loop->any_estimate)
6320 fprintf (file, ", estimate = ");
6321 dump_double_int (file, loop->nb_iterations_estimate, true);
6323 fprintf (file, ")\n");
6325 /* Print loop's body. */
6328 fprintf (file, "%s{\n", s_indent);
6330 if (bb->loop_father == loop)
6331 print_loops_bb (file, bb, indent, verbosity);
6333 print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6334 fprintf (file, "%s}\n", s_indent);
6338 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6339 spaces. Following VERBOSITY level this outputs the contents of the
6340 loop, or just its structure. */
6343 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6348 print_loop (file, loop, indent, verbosity);
6349 print_loop_and_siblings (file, loop->next, indent, verbosity);
6352 /* Follow a CFG edge from the entry point of the program, and on entry
6353 of a loop, pretty print the loop structure on FILE. */
6356 print_loops (FILE *file, int verbosity)
6360 bb = ENTRY_BLOCK_PTR;
6361 if (bb && bb->loop_father)
6362 print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6366 /* Debugging loops structure at tree level, at some VERBOSITY level. */
6369 debug_loops (int verbosity)
6371 print_loops (stderr, verbosity);
6374 /* Print on stderr the code of LOOP, at some VERBOSITY level. */
6377 debug_loop (struct loop *loop, int verbosity)
6379 print_loop (stderr, loop, 0, verbosity);
6382 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6386 debug_loop_num (unsigned num, int verbosity)
6388 debug_loop (get_loop (num), verbosity);
6391 /* Return true if BB ends with a call, possibly followed by some
6392 instructions that must stay with the call. Return false,
6396 gimple_block_ends_with_call_p (basic_block bb)
6398 gimple_stmt_iterator gsi = gsi_last_bb (bb);
6399 return is_gimple_call (gsi_stmt (gsi));
6403 /* Return true if BB ends with a conditional branch. Return false,
6407 gimple_block_ends_with_condjump_p (const_basic_block bb)
6409 gimple stmt = last_stmt (CONST_CAST_BB (bb));
6410 return (stmt && gimple_code (stmt) == GIMPLE_COND);
6414 /* Return true if we need to add fake edge to exit at statement T.
6415 Helper function for gimple_flow_call_edges_add. */
6418 need_fake_edge_p (gimple t)
6420 tree fndecl = NULL_TREE;
6423 /* NORETURN and LONGJMP calls already have an edge to exit.
6424 CONST and PURE calls do not need one.
6425 We don't currently check for CONST and PURE here, although
6426 it would be a good idea, because those attributes are
6427 figured out from the RTL in mark_constant_function, and
6428 the counter incrementation code from -fprofile-arcs
6429 leads to different results from -fbranch-probabilities. */
6430 if (is_gimple_call (t))
6432 fndecl = gimple_call_fndecl (t);
6433 call_flags = gimple_call_flags (t);
6436 if (is_gimple_call (t)
6438 && DECL_BUILT_IN (fndecl)
6439 && (call_flags & ECF_NOTHROW)
6440 && !(call_flags & ECF_NORETURN)
6441 && !(call_flags & ECF_RETURNS_TWICE))
6444 if (is_gimple_call (t)
6445 && !(call_flags & ECF_NORETURN))
6448 if (gimple_code (t) == GIMPLE_ASM
6449 && (gimple_asm_volatile_p (t) || gimple_asm_input_p (t)))
6456 /* Add fake edges to the function exit for any non constant and non
6457 noreturn calls, volatile inline assembly in the bitmap of blocks
6458 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
6459 the number of blocks that were split.
6461 The goal is to expose cases in which entering a basic block does
6462 not imply that all subsequent instructions must be executed. */
6465 gimple_flow_call_edges_add (sbitmap blocks)
6468 int blocks_split = 0;
6469 int last_bb = last_basic_block;
6470 bool check_last_block = false;
6472 if (n_basic_blocks == NUM_FIXED_BLOCKS)
6476 check_last_block = true;
6478 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6480 /* In the last basic block, before epilogue generation, there will be
6481 a fallthru edge to EXIT. Special care is required if the last insn
6482 of the last basic block is a call because make_edge folds duplicate
6483 edges, which would result in the fallthru edge also being marked
6484 fake, which would result in the fallthru edge being removed by
6485 remove_fake_edges, which would result in an invalid CFG.
6487 Moreover, we can't elide the outgoing fake edge, since the block
6488 profiler needs to take this into account in order to solve the minimal
6489 spanning tree in the case that the call doesn't return.
6491 Handle this by adding a dummy instruction in a new last basic block. */
6492 if (check_last_block)
6494 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6495 gimple_stmt_iterator gsi = gsi_last_bb (bb);
6498 if (!gsi_end_p (gsi))
6501 if (t && need_fake_edge_p (t))
6505 e = find_edge (bb, EXIT_BLOCK_PTR);
6508 gsi_insert_on_edge (e, gimple_build_nop ());
6509 gsi_commit_edge_inserts ();
6514 /* Now add fake edges to the function exit for any non constant
6515 calls since there is no way that we can determine if they will
6517 for (i = 0; i < last_bb; i++)
6519 basic_block bb = BASIC_BLOCK (i);
6520 gimple_stmt_iterator gsi;
6521 gimple stmt, last_stmt;
6526 if (blocks && !TEST_BIT (blocks, i))
6529 gsi = gsi_last_bb (bb);
6530 if (!gsi_end_p (gsi))
6532 last_stmt = gsi_stmt (gsi);
6535 stmt = gsi_stmt (gsi);
6536 if (need_fake_edge_p (stmt))
6540 /* The handling above of the final block before the
6541 epilogue should be enough to verify that there is
6542 no edge to the exit block in CFG already.
6543 Calling make_edge in such case would cause us to
6544 mark that edge as fake and remove it later. */
6545 #ifdef ENABLE_CHECKING
6546 if (stmt == last_stmt)
6548 e = find_edge (bb, EXIT_BLOCK_PTR);
6549 gcc_assert (e == NULL);
6553 /* Note that the following may create a new basic block
6554 and renumber the existing basic blocks. */
6555 if (stmt != last_stmt)
6557 e = split_block (bb, stmt);
6561 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6565 while (!gsi_end_p (gsi));
6570 verify_flow_info ();
6572 return blocks_split;
6575 /* Purge dead abnormal call edges from basic block BB. */
6578 gimple_purge_dead_abnormal_call_edges (basic_block bb)
6580 bool changed = gimple_purge_dead_eh_edges (bb);
6582 if (cfun->has_nonlocal_label)
6584 gimple stmt = last_stmt (bb);
6588 if (!(stmt && stmt_can_make_abnormal_goto (stmt)))
6589 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6591 if (e->flags & EDGE_ABNORMAL)
6600 /* See gimple_purge_dead_eh_edges below. */
6602 free_dominance_info (CDI_DOMINATORS);
6608 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6611 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6615 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6616 for (son = first_dom_son (CDI_DOMINATORS, bb);
6618 son = next_dom_son (CDI_DOMINATORS, son))
6619 get_all_dominated_blocks (son, dom_bbs);
6622 /* Removes edge E and all the blocks dominated by it, and updates dominance
6623 information. The IL in E->src needs to be updated separately.
6624 If dominance info is not available, only the edge E is removed.*/
6627 remove_edge_and_dominated_blocks (edge e)
6629 VEC (basic_block, heap) *bbs_to_remove = NULL;
6630 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6634 bool none_removed = false;
6636 basic_block bb, dbb;
6639 if (!dom_info_available_p (CDI_DOMINATORS))
6645 /* No updating is needed for edges to exit. */
6646 if (e->dest == EXIT_BLOCK_PTR)
6648 if (cfgcleanup_altered_bbs)
6649 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6654 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6655 that is not dominated by E->dest, then this set is empty. Otherwise,
6656 all the basic blocks dominated by E->dest are removed.
6658 Also, to DF_IDOM we store the immediate dominators of the blocks in
6659 the dominance frontier of E (i.e., of the successors of the
6660 removed blocks, if there are any, and of E->dest otherwise). */
6661 FOR_EACH_EDGE (f, ei, e->dest->preds)
6666 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6668 none_removed = true;
6673 df = BITMAP_ALLOC (NULL);
6674 df_idom = BITMAP_ALLOC (NULL);
6677 bitmap_set_bit (df_idom,
6678 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6681 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6682 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6684 FOR_EACH_EDGE (f, ei, bb->succs)
6686 if (f->dest != EXIT_BLOCK_PTR)
6687 bitmap_set_bit (df, f->dest->index);
6690 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6691 bitmap_clear_bit (df, bb->index);
6693 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6695 bb = BASIC_BLOCK (i);
6696 bitmap_set_bit (df_idom,
6697 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6701 if (cfgcleanup_altered_bbs)
6703 /* Record the set of the altered basic blocks. */
6704 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6705 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6708 /* Remove E and the cancelled blocks. */
6713 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6714 delete_basic_block (bb);
6717 /* Update the dominance information. The immediate dominator may change only
6718 for blocks whose immediate dominator belongs to DF_IDOM:
6720 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6721 removal. Let Z the arbitrary block such that idom(Z) = Y and
6722 Z dominates X after the removal. Before removal, there exists a path P
6723 from Y to X that avoids Z. Let F be the last edge on P that is
6724 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6725 dominates W, and because of P, Z does not dominate W), and W belongs to
6726 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6727 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6729 bb = BASIC_BLOCK (i);
6730 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6732 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6733 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6736 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6739 BITMAP_FREE (df_idom);
6740 VEC_free (basic_block, heap, bbs_to_remove);
6741 VEC_free (basic_block, heap, bbs_to_fix_dom);
6744 /* Purge dead EH edges from basic block BB. */
6747 gimple_purge_dead_eh_edges (basic_block bb)
6749 bool changed = false;
6752 gimple stmt = last_stmt (bb);
6754 if (stmt && stmt_can_throw_internal (stmt))
6757 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6759 if (e->flags & EDGE_EH)
6761 remove_edge_and_dominated_blocks (e);
6772 gimple_purge_all_dead_eh_edges (const_bitmap blocks)
6774 bool changed = false;
6778 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6780 basic_block bb = BASIC_BLOCK (i);
6782 /* Earlier gimple_purge_dead_eh_edges could have removed
6783 this basic block already. */
6784 gcc_assert (bb || changed);
6786 changed |= gimple_purge_dead_eh_edges (bb);
6792 /* This function is called whenever a new edge is created or
6796 gimple_execute_on_growing_pred (edge e)
6798 basic_block bb = e->dest;
6801 reserve_phi_args_for_new_edge (bb);
6804 /* This function is called immediately before edge E is removed from
6805 the edge vector E->dest->preds. */
6808 gimple_execute_on_shrinking_pred (edge e)
6810 if (phi_nodes (e->dest))
6811 remove_phi_args (e);
6814 /*---------------------------------------------------------------------------
6815 Helper functions for Loop versioning
6816 ---------------------------------------------------------------------------*/
6818 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6819 of 'first'. Both of them are dominated by 'new_head' basic block. When
6820 'new_head' was created by 'second's incoming edge it received phi arguments
6821 on the edge by split_edge(). Later, additional edge 'e' was created to
6822 connect 'new_head' and 'first'. Now this routine adds phi args on this
6823 additional edge 'e' that new_head to second edge received as part of edge
6827 gimple_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6828 basic_block new_head, edge e)
6831 gimple_stmt_iterator psi1, psi2;
6833 edge e2 = find_edge (new_head, second);
6835 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6836 edge, we should always have an edge from NEW_HEAD to SECOND. */
6837 gcc_assert (e2 != NULL);
6839 /* Browse all 'second' basic block phi nodes and add phi args to
6840 edge 'e' for 'first' head. PHI args are always in correct order. */
6842 for (psi2 = gsi_start_phis (second),
6843 psi1 = gsi_start_phis (first);
6844 !gsi_end_p (psi2) && !gsi_end_p (psi1);
6845 gsi_next (&psi2), gsi_next (&psi1))
6847 phi1 = gsi_stmt (psi1);
6848 phi2 = gsi_stmt (psi2);
6849 def = PHI_ARG_DEF (phi2, e2->dest_idx);
6850 add_phi_arg (phi1, def, e);
6855 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6856 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6857 the destination of the ELSE part. */
6860 gimple_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6861 basic_block second_head ATTRIBUTE_UNUSED,
6862 basic_block cond_bb, void *cond_e)
6864 gimple_stmt_iterator gsi;
6865 gimple new_cond_expr;
6866 tree cond_expr = (tree) cond_e;
6869 /* Build new conditional expr */
6870 new_cond_expr = gimple_build_cond_from_tree (cond_expr,
6871 NULL_TREE, NULL_TREE);
6873 /* Add new cond in cond_bb. */
6874 gsi = gsi_last_bb (cond_bb);
6875 gsi_insert_after (&gsi, new_cond_expr, GSI_NEW_STMT);
6877 /* Adjust edges appropriately to connect new head with first head
6878 as well as second head. */
6879 e0 = single_succ_edge (cond_bb);
6880 e0->flags &= ~EDGE_FALLTHRU;
6881 e0->flags |= EDGE_FALSE_VALUE;
6884 struct cfg_hooks gimple_cfg_hooks = {
6886 gimple_verify_flow_info,
6887 gimple_dump_bb, /* dump_bb */
6888 create_bb, /* create_basic_block */
6889 gimple_redirect_edge_and_branch, /* redirect_edge_and_branch */
6890 gimple_redirect_edge_and_branch_force, /* redirect_edge_and_branch_force */
6891 gimple_can_remove_branch_p, /* can_remove_branch_p */
6892 remove_bb, /* delete_basic_block */
6893 gimple_split_block, /* split_block */
6894 gimple_move_block_after, /* move_block_after */
6895 gimple_can_merge_blocks_p, /* can_merge_blocks_p */
6896 gimple_merge_blocks, /* merge_blocks */
6897 gimple_predict_edge, /* predict_edge */
6898 gimple_predicted_by_p, /* predicted_by_p */
6899 gimple_can_duplicate_bb_p, /* can_duplicate_block_p */
6900 gimple_duplicate_bb, /* duplicate_block */
6901 gimple_split_edge, /* split_edge */
6902 gimple_make_forwarder_block, /* make_forward_block */
6903 NULL, /* tidy_fallthru_edge */
6904 gimple_block_ends_with_call_p,/* block_ends_with_call_p */
6905 gimple_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6906 gimple_flow_call_edges_add, /* flow_call_edges_add */
6907 gimple_execute_on_growing_pred, /* execute_on_growing_pred */
6908 gimple_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6909 gimple_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6910 gimple_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6911 gimple_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6912 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6913 flush_pending_stmts /* flush_pending_stmts */
6917 /* Split all critical edges. */
6920 split_critical_edges (void)
6926 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6927 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6928 mappings around the calls to split_edge. */
6929 start_recording_case_labels ();
6932 FOR_EACH_EDGE (e, ei, bb->succs)
6933 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6938 end_recording_case_labels ();
6942 struct gimple_opt_pass pass_split_crit_edges =
6946 "crited", /* name */
6948 split_critical_edges, /* execute */
6951 0, /* static_pass_number */
6952 TV_TREE_SPLIT_EDGES, /* tv_id */
6953 PROP_cfg, /* properties required */
6954 PROP_no_crit_edges, /* properties_provided */
6955 0, /* properties_destroyed */
6956 0, /* todo_flags_start */
6957 TODO_dump_func /* todo_flags_finish */
6962 /* Build a ternary operation and gimplify it. Emit code before GSI.
6963 Return the gimple_val holding the result. */
6966 gimplify_build3 (gimple_stmt_iterator *gsi, enum tree_code code,
6967 tree type, tree a, tree b, tree c)
6971 ret = fold_build3 (code, type, a, b, c);
6974 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
6978 /* Build a binary operation and gimplify it. Emit code before GSI.
6979 Return the gimple_val holding the result. */
6982 gimplify_build2 (gimple_stmt_iterator *gsi, enum tree_code code,
6983 tree type, tree a, tree b)
6987 ret = fold_build2 (code, type, a, b);
6990 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
6994 /* Build a unary operation and gimplify it. Emit code before GSI.
6995 Return the gimple_val holding the result. */
6998 gimplify_build1 (gimple_stmt_iterator *gsi, enum tree_code code, tree type,
7003 ret = fold_build1 (code, type, a);
7006 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7012 /* Emit return warnings. */
7015 execute_warn_function_return (void)
7017 source_location location;
7022 /* If we have a path to EXIT, then we do return. */
7023 if (TREE_THIS_VOLATILE (cfun->decl)
7024 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
7026 location = UNKNOWN_LOCATION;
7027 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7029 last = last_stmt (e->src);
7030 if (gimple_code (last) == GIMPLE_RETURN
7031 && (location = gimple_location (last)) != UNKNOWN_LOCATION)
7034 if (location == UNKNOWN_LOCATION)
7035 location = cfun->function_end_locus;
7036 warning (0, "%H%<noreturn%> function does return", &location);
7039 /* If we see "return;" in some basic block, then we do reach the end
7040 without returning a value. */
7041 else if (warn_return_type
7042 && !TREE_NO_WARNING (cfun->decl)
7043 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
7044 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
7046 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7048 gimple last = last_stmt (e->src);
7049 if (gimple_code (last) == GIMPLE_RETURN
7050 && gimple_return_retval (last) == NULL
7051 && !gimple_no_warning_p (last))
7053 location = gimple_location (last);
7054 if (location == UNKNOWN_LOCATION)
7055 location = cfun->function_end_locus;
7056 warning_at (location, OPT_Wreturn_type, "control reaches end of non-void function");
7057 TREE_NO_WARNING (cfun->decl) = 1;
7066 /* Given a basic block B which ends with a conditional and has
7067 precisely two successors, determine which of the edges is taken if
7068 the conditional is true and which is taken if the conditional is
7069 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
7072 extract_true_false_edges_from_block (basic_block b,
7076 edge e = EDGE_SUCC (b, 0);
7078 if (e->flags & EDGE_TRUE_VALUE)
7081 *false_edge = EDGE_SUCC (b, 1);
7086 *true_edge = EDGE_SUCC (b, 1);
7090 struct gimple_opt_pass pass_warn_function_return =
7096 execute_warn_function_return, /* execute */
7099 0, /* static_pass_number */
7101 PROP_cfg, /* properties_required */
7102 0, /* properties_provided */
7103 0, /* properties_destroyed */
7104 0, /* todo_flags_start */
7105 0 /* todo_flags_finish */
7109 /* Emit noreturn warnings. */
7112 execute_warn_function_noreturn (void)
7114 if (warn_missing_noreturn
7115 && !TREE_THIS_VOLATILE (cfun->decl)
7116 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
7117 && !lang_hooks.missing_noreturn_ok_p (cfun->decl))
7118 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
7119 "for attribute %<noreturn%>",
7124 struct gimple_opt_pass pass_warn_function_noreturn =
7130 execute_warn_function_noreturn, /* execute */
7133 0, /* static_pass_number */
7135 PROP_cfg, /* properties_required */
7136 0, /* properties_provided */
7137 0, /* properties_destroyed */
7138 0, /* todo_flags_start */
7139 0 /* todo_flags_finish */