1 /* Control flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
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);
224 if (dump_file && (dump_flags & TDF_DETAILS))
226 fprintf (dump_file, "Scope blocks:\n");
227 dump_scope_blocks (dump_file, dump_flags);
232 struct gimple_opt_pass pass_build_cfg =
238 execute_build_cfg, /* execute */
241 0, /* static_pass_number */
242 TV_TREE_CFG, /* tv_id */
243 PROP_gimple_leh, /* properties_required */
244 PROP_cfg, /* properties_provided */
245 0, /* properties_destroyed */
246 0, /* todo_flags_start */
247 TODO_verify_stmts | TODO_cleanup_cfg
248 | TODO_dump_func /* todo_flags_finish */
253 /* Return true if T is a computed goto. */
256 computed_goto_p (gimple t)
258 return (gimple_code (t) == GIMPLE_GOTO
259 && TREE_CODE (gimple_goto_dest (t)) != LABEL_DECL);
263 /* Search the CFG for any computed gotos. If found, factor them to a
264 common computed goto site. Also record the location of that site so
265 that we can un-factor the gotos after we have converted back to
269 factor_computed_gotos (void)
272 tree factored_label_decl = NULL;
274 gimple factored_computed_goto_label = NULL;
275 gimple factored_computed_goto = NULL;
277 /* We know there are one or more computed gotos in this function.
278 Examine the last statement in each basic block to see if the block
279 ends with a computed goto. */
283 gimple_stmt_iterator gsi = gsi_last_bb (bb);
289 last = gsi_stmt (gsi);
291 /* Ignore the computed goto we create when we factor the original
293 if (last == factored_computed_goto)
296 /* If the last statement is a computed goto, factor it. */
297 if (computed_goto_p (last))
301 /* The first time we find a computed goto we need to create
302 the factored goto block and the variable each original
303 computed goto will use for their goto destination. */
304 if (!factored_computed_goto)
306 basic_block new_bb = create_empty_bb (bb);
307 gimple_stmt_iterator new_gsi = gsi_start_bb (new_bb);
309 /* Create the destination of the factored goto. Each original
310 computed goto will put its desired destination into this
311 variable and jump to the label we create immediately
313 var = create_tmp_var (ptr_type_node, "gotovar");
315 /* Build a label for the new block which will contain the
316 factored computed goto. */
317 factored_label_decl = create_artificial_label ();
318 factored_computed_goto_label
319 = gimple_build_label (factored_label_decl);
320 gsi_insert_after (&new_gsi, factored_computed_goto_label,
323 /* Build our new computed goto. */
324 factored_computed_goto = gimple_build_goto (var);
325 gsi_insert_after (&new_gsi, factored_computed_goto, GSI_NEW_STMT);
328 /* Copy the original computed goto's destination into VAR. */
329 assignment = gimple_build_assign (var, gimple_goto_dest (last));
330 gsi_insert_before (&gsi, assignment, GSI_SAME_STMT);
332 /* And re-vector the computed goto to the new destination. */
333 gimple_goto_set_dest (last, factored_label_decl);
339 /* Build a flowgraph for the sequence of stmts SEQ. */
342 make_blocks (gimple_seq seq)
344 gimple_stmt_iterator i = gsi_start (seq);
346 bool start_new_block = true;
347 bool first_stmt_of_seq = true;
348 basic_block bb = ENTRY_BLOCK_PTR;
350 while (!gsi_end_p (i))
357 /* If the statement starts a new basic block or if we have determined
358 in a previous pass that we need to create a new block for STMT, do
360 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
362 if (!first_stmt_of_seq)
363 seq = gsi_split_seq_before (&i);
364 bb = create_basic_block (seq, NULL, bb);
365 start_new_block = false;
368 /* Now add STMT to BB and create the subgraphs for special statement
370 gimple_set_bb (stmt, bb);
372 if (computed_goto_p (stmt))
373 found_computed_goto = true;
375 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
377 if (stmt_ends_bb_p (stmt))
378 start_new_block = true;
381 first_stmt_of_seq = false;
386 /* Create and return a new empty basic block after bb AFTER. */
389 create_bb (void *h, void *e, basic_block after)
395 /* Create and initialize a new basic block. Since alloc_block uses
396 ggc_alloc_cleared to allocate a basic block, we do not have to
397 clear the newly allocated basic block here. */
400 bb->index = last_basic_block;
402 bb->il.gimple = GGC_CNEW (struct gimple_bb_info);
403 set_bb_seq (bb, h ? (gimple_seq) h : gimple_seq_alloc ());
405 /* Add the new block to the linked list of blocks. */
406 link_block (bb, after);
408 /* Grow the basic block array if needed. */
409 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
411 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
412 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
415 /* Add the newly created block to the array. */
416 SET_BASIC_BLOCK (last_basic_block, bb);
425 /*---------------------------------------------------------------------------
427 ---------------------------------------------------------------------------*/
429 /* Fold COND_EXPR_COND of each COND_EXPR. */
432 fold_cond_expr_cond (void)
438 gimple stmt = last_stmt (bb);
440 if (stmt && gimple_code (stmt) == GIMPLE_COND)
445 fold_defer_overflow_warnings ();
446 cond = fold_binary (gimple_cond_code (stmt), boolean_type_node,
447 gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
450 zerop = integer_zerop (cond);
451 onep = integer_onep (cond);
454 zerop = onep = false;
456 fold_undefer_overflow_warnings (zerop || onep,
458 WARN_STRICT_OVERFLOW_CONDITIONAL);
460 gimple_cond_make_false (stmt);
462 gimple_cond_make_true (stmt);
467 /* Join all the blocks in the flowgraph. */
473 struct omp_region *cur_region = NULL;
475 /* Create an edge from entry to the first block with executable
477 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
479 /* Traverse the basic block array placing edges. */
482 gimple last = last_stmt (bb);
487 enum gimple_code code = gimple_code (last);
491 make_goto_expr_edges (bb);
495 make_edge (bb, EXIT_BLOCK_PTR, 0);
499 make_cond_expr_edges (bb);
503 make_gimple_switch_edges (bb);
507 make_eh_edges (last);
512 /* If this function receives a nonlocal goto, then we need to
513 make edges from this call site to all the nonlocal goto
515 if (stmt_can_make_abnormal_goto (last))
516 make_abnormal_goto_edges (bb, true);
518 /* If this statement has reachable exception handlers, then
519 create abnormal edges to them. */
520 make_eh_edges (last);
522 /* Some calls are known not to return. */
523 fallthru = !(gimple_call_flags (last) & ECF_NORETURN);
527 /* A GIMPLE_ASSIGN may throw internally and thus be considered
529 if (is_ctrl_altering_stmt (last))
531 make_eh_edges (last);
536 case GIMPLE_OMP_PARALLEL:
537 case GIMPLE_OMP_TASK:
539 case GIMPLE_OMP_SINGLE:
540 case GIMPLE_OMP_MASTER:
541 case GIMPLE_OMP_ORDERED:
542 case GIMPLE_OMP_CRITICAL:
543 case GIMPLE_OMP_SECTION:
544 cur_region = new_omp_region (bb, code, cur_region);
548 case GIMPLE_OMP_SECTIONS:
549 cur_region = new_omp_region (bb, code, cur_region);
553 case GIMPLE_OMP_SECTIONS_SWITCH:
558 case GIMPLE_OMP_ATOMIC_LOAD:
559 case GIMPLE_OMP_ATOMIC_STORE:
564 case GIMPLE_OMP_RETURN:
565 /* In the case of a GIMPLE_OMP_SECTION, the edge will go
566 somewhere other than the next block. This will be
568 cur_region->exit = bb;
569 fallthru = cur_region->type != GIMPLE_OMP_SECTION;
570 cur_region = cur_region->outer;
573 case GIMPLE_OMP_CONTINUE:
574 cur_region->cont = bb;
575 switch (cur_region->type)
578 /* Mark all GIMPLE_OMP_FOR and GIMPLE_OMP_CONTINUE
579 succs edges as abnormal to prevent splitting
581 single_succ_edge (cur_region->entry)->flags |= EDGE_ABNORMAL;
582 /* Make the loopback edge. */
583 make_edge (bb, single_succ (cur_region->entry),
586 /* Create an edge from GIMPLE_OMP_FOR to exit, which
587 corresponds to the case that the body of the loop
588 is not executed at all. */
589 make_edge (cur_region->entry, bb->next_bb, EDGE_ABNORMAL);
590 make_edge (bb, bb->next_bb, EDGE_FALLTHRU | EDGE_ABNORMAL);
594 case GIMPLE_OMP_SECTIONS:
595 /* Wire up the edges into and out of the nested sections. */
597 basic_block switch_bb = single_succ (cur_region->entry);
599 struct omp_region *i;
600 for (i = cur_region->inner; i ; i = i->next)
602 gcc_assert (i->type == GIMPLE_OMP_SECTION);
603 make_edge (switch_bb, i->entry, 0);
604 make_edge (i->exit, bb, EDGE_FALLTHRU);
607 /* Make the loopback edge to the block with
608 GIMPLE_OMP_SECTIONS_SWITCH. */
609 make_edge (bb, switch_bb, 0);
611 /* Make the edge from the switch to exit. */
612 make_edge (switch_bb, bb->next_bb, 0);
623 gcc_assert (!stmt_ends_bb_p (last));
631 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
637 /* Fold COND_EXPR_COND of each COND_EXPR. */
638 fold_cond_expr_cond ();
642 /* Create the edges for a GIMPLE_COND starting at block BB. */
645 make_cond_expr_edges (basic_block bb)
647 gimple entry = last_stmt (bb);
648 gimple then_stmt, else_stmt;
649 basic_block then_bb, else_bb;
650 tree then_label, else_label;
654 gcc_assert (gimple_code (entry) == GIMPLE_COND);
656 /* Entry basic blocks for each component. */
657 then_label = gimple_cond_true_label (entry);
658 else_label = gimple_cond_false_label (entry);
659 then_bb = label_to_block (then_label);
660 else_bb = label_to_block (else_label);
661 then_stmt = first_stmt (then_bb);
662 else_stmt = first_stmt (else_bb);
664 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
665 e->goto_locus = gimple_location (then_stmt);
667 e->goto_block = gimple_block (then_stmt);
668 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
671 e->goto_locus = gimple_location (else_stmt);
673 e->goto_block = gimple_block (else_stmt);
676 /* We do not need the labels anymore. */
677 gimple_cond_set_true_label (entry, NULL_TREE);
678 gimple_cond_set_false_label (entry, NULL_TREE);
682 /* Called for each element in the hash table (P) as we delete the
683 edge to cases hash table.
685 Clear all the TREE_CHAINs to prevent problems with copying of
686 SWITCH_EXPRs and structure sharing rules, then free the hash table
690 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED, void **value,
691 void *data ATTRIBUTE_UNUSED)
695 for (t = (tree) *value; t; t = next)
697 next = TREE_CHAIN (t);
698 TREE_CHAIN (t) = NULL;
705 /* Start recording information mapping edges to case labels. */
708 start_recording_case_labels (void)
710 gcc_assert (edge_to_cases == NULL);
711 edge_to_cases = pointer_map_create ();
714 /* Return nonzero if we are recording information for case labels. */
717 recording_case_labels_p (void)
719 return (edge_to_cases != NULL);
722 /* Stop recording information mapping edges to case labels and
723 remove any information we have recorded. */
725 end_recording_case_labels (void)
727 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
728 pointer_map_destroy (edge_to_cases);
729 edge_to_cases = NULL;
732 /* If we are inside a {start,end}_recording_cases block, then return
733 a chain of CASE_LABEL_EXPRs from T which reference E.
735 Otherwise return NULL. */
738 get_cases_for_edge (edge e, gimple t)
743 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
744 chains available. Return NULL so the caller can detect this case. */
745 if (!recording_case_labels_p ())
748 slot = pointer_map_contains (edge_to_cases, e);
752 /* If we did not find E in the hash table, then this must be the first
753 time we have been queried for information about E & T. Add all the
754 elements from T to the hash table then perform the query again. */
756 n = gimple_switch_num_labels (t);
757 for (i = 0; i < n; i++)
759 tree elt = gimple_switch_label (t, i);
760 tree lab = CASE_LABEL (elt);
761 basic_block label_bb = label_to_block (lab);
762 edge this_edge = find_edge (e->src, label_bb);
764 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
766 slot = pointer_map_insert (edge_to_cases, this_edge);
767 TREE_CHAIN (elt) = (tree) *slot;
771 return (tree) *pointer_map_contains (edge_to_cases, e);
774 /* Create the edges for a GIMPLE_SWITCH starting at block BB. */
777 make_gimple_switch_edges (basic_block bb)
779 gimple entry = last_stmt (bb);
782 n = gimple_switch_num_labels (entry);
784 for (i = 0; i < n; ++i)
786 tree lab = CASE_LABEL (gimple_switch_label (entry, i));
787 basic_block label_bb = label_to_block (lab);
788 make_edge (bb, label_bb, 0);
793 /* Return the basic block holding label DEST. */
796 label_to_block_fn (struct function *ifun, tree dest)
798 int uid = LABEL_DECL_UID (dest);
800 /* We would die hard when faced by an undefined label. Emit a label to
801 the very first basic block. This will hopefully make even the dataflow
802 and undefined variable warnings quite right. */
803 if ((errorcount || sorrycount) && uid < 0)
805 gimple_stmt_iterator gsi = gsi_start_bb (BASIC_BLOCK (NUM_FIXED_BLOCKS));
808 stmt = gimple_build_label (dest);
809 gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
810 uid = LABEL_DECL_UID (dest);
812 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
813 <= (unsigned int) uid)
815 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
818 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
819 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
822 make_abnormal_goto_edges (basic_block bb, bool for_call)
824 basic_block target_bb;
825 gimple_stmt_iterator gsi;
827 FOR_EACH_BB (target_bb)
828 for (gsi = gsi_start_bb (target_bb); !gsi_end_p (gsi); gsi_next (&gsi))
830 gimple label_stmt = gsi_stmt (gsi);
833 if (gimple_code (label_stmt) != GIMPLE_LABEL)
836 target = gimple_label_label (label_stmt);
838 /* Make an edge to every label block that has been marked as a
839 potential target for a computed goto or a non-local goto. */
840 if ((FORCED_LABEL (target) && !for_call)
841 || (DECL_NONLOCAL (target) && for_call))
843 make_edge (bb, target_bb, EDGE_ABNORMAL);
849 /* Create edges for a goto statement at block BB. */
852 make_goto_expr_edges (basic_block bb)
854 gimple_stmt_iterator last = gsi_last_bb (bb);
855 gimple goto_t = gsi_stmt (last);
857 /* A simple GOTO creates normal edges. */
858 if (simple_goto_p (goto_t))
860 tree dest = gimple_goto_dest (goto_t);
861 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
862 e->goto_locus = gimple_location (goto_t);
864 e->goto_block = gimple_block (goto_t);
865 gsi_remove (&last, true);
869 /* A computed GOTO creates abnormal edges. */
870 make_abnormal_goto_edges (bb, false);
874 /*---------------------------------------------------------------------------
876 ---------------------------------------------------------------------------*/
878 /* Cleanup useless labels in basic blocks. This is something we wish
879 to do early because it allows us to group case labels before creating
880 the edges for the CFG, and it speeds up block statement iterators in
882 We rerun this pass after CFG is created, to get rid of the labels that
883 are no longer referenced. After then we do not run it any more, since
884 (almost) no new labels should be created. */
886 /* A map from basic block index to the leading label of that block. */
887 static struct label_record
892 /* True if the label is referenced from somewhere. */
896 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
898 update_eh_label (struct eh_region *region)
900 tree old_label = get_eh_region_tree_label (region);
904 basic_block bb = label_to_block (old_label);
906 /* ??? After optimizing, there may be EH regions with labels
907 that have already been removed from the function body, so
908 there is no basic block for them. */
912 new_label = label_for_bb[bb->index].label;
913 label_for_bb[bb->index].used = true;
914 set_eh_region_tree_label (region, new_label);
919 /* Given LABEL return the first label in the same basic block. */
922 main_block_label (tree label)
924 basic_block bb = label_to_block (label);
925 tree main_label = label_for_bb[bb->index].label;
927 /* label_to_block possibly inserted undefined label into the chain. */
930 label_for_bb[bb->index].label = label;
934 label_for_bb[bb->index].used = true;
938 /* Cleanup redundant labels. This is a three-step process:
939 1) Find the leading label for each block.
940 2) Redirect all references to labels to the leading labels.
941 3) Cleanup all useless labels. */
944 cleanup_dead_labels (void)
947 label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
949 /* Find a suitable label for each block. We use the first user-defined
950 label if there is one, or otherwise just the first label we see. */
953 gimple_stmt_iterator i;
955 for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
958 gimple stmt = gsi_stmt (i);
960 if (gimple_code (stmt) != GIMPLE_LABEL)
963 label = gimple_label_label (stmt);
965 /* If we have not yet seen a label for the current block,
966 remember this one and see if there are more labels. */
967 if (!label_for_bb[bb->index].label)
969 label_for_bb[bb->index].label = label;
973 /* If we did see a label for the current block already, but it
974 is an artificially created label, replace it if the current
975 label is a user defined label. */
976 if (!DECL_ARTIFICIAL (label)
977 && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
979 label_for_bb[bb->index].label = label;
985 /* Now redirect all jumps/branches to the selected label.
986 First do so for each block ending in a control statement. */
989 gimple stmt = last_stmt (bb);
993 switch (gimple_code (stmt))
997 tree true_label = gimple_cond_true_label (stmt);
998 tree false_label = gimple_cond_false_label (stmt);
1001 gimple_cond_set_true_label (stmt, main_block_label (true_label));
1003 gimple_cond_set_false_label (stmt, main_block_label (false_label));
1009 size_t i, n = gimple_switch_num_labels (stmt);
1011 /* Replace all destination labels. */
1012 for (i = 0; i < n; ++i)
1014 tree case_label = gimple_switch_label (stmt, i);
1015 tree label = main_block_label (CASE_LABEL (case_label));
1016 CASE_LABEL (case_label) = label;
1021 /* We have to handle gotos until they're removed, and we don't
1022 remove them until after we've created the CFG edges. */
1024 if (!computed_goto_p (stmt))
1026 tree new_dest = main_block_label (gimple_goto_dest (stmt));
1027 gimple_goto_set_dest (stmt, new_dest);
1036 for_each_eh_region (update_eh_label);
1038 /* Finally, purge dead labels. All user-defined labels and labels that
1039 can be the target of non-local gotos and labels which have their
1040 address taken are preserved. */
1043 gimple_stmt_iterator i;
1044 tree label_for_this_bb = label_for_bb[bb->index].label;
1046 if (!label_for_this_bb)
1049 /* If the main label of the block is unused, we may still remove it. */
1050 if (!label_for_bb[bb->index].used)
1051 label_for_this_bb = NULL;
1053 for (i = gsi_start_bb (bb); !gsi_end_p (i); )
1056 gimple stmt = gsi_stmt (i);
1058 if (gimple_code (stmt) != GIMPLE_LABEL)
1061 label = gimple_label_label (stmt);
1063 if (label == label_for_this_bb
1064 || !DECL_ARTIFICIAL (label)
1065 || DECL_NONLOCAL (label)
1066 || FORCED_LABEL (label))
1069 gsi_remove (&i, true);
1073 free (label_for_bb);
1076 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1077 and scan the sorted vector of cases. Combine the ones jumping to the
1079 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1082 group_case_labels (void)
1088 gimple stmt = last_stmt (bb);
1089 if (stmt && gimple_code (stmt) == GIMPLE_SWITCH)
1091 int old_size = gimple_switch_num_labels (stmt);
1092 int i, j, new_size = old_size;
1093 tree default_case = NULL_TREE;
1094 tree default_label = NULL_TREE;
1097 /* The default label is always the first case in a switch
1098 statement after gimplification if it was not optimized
1100 if (!CASE_LOW (gimple_switch_default_label (stmt))
1101 && !CASE_HIGH (gimple_switch_default_label (stmt)))
1103 default_case = gimple_switch_default_label (stmt);
1104 default_label = CASE_LABEL (default_case);
1108 has_default = false;
1110 /* Look for possible opportunities to merge cases. */
1115 while (i < old_size)
1117 tree base_case, base_label, base_high;
1118 base_case = gimple_switch_label (stmt, i);
1120 gcc_assert (base_case);
1121 base_label = CASE_LABEL (base_case);
1123 /* Discard cases that have the same destination as the
1125 if (base_label == default_label)
1127 gimple_switch_set_label (stmt, i, NULL_TREE);
1133 base_high = CASE_HIGH (base_case)
1134 ? CASE_HIGH (base_case)
1135 : CASE_LOW (base_case);
1138 /* Try to merge case labels. Break out when we reach the end
1139 of the label vector or when we cannot merge the next case
1140 label with the current one. */
1141 while (i < old_size)
1143 tree merge_case = gimple_switch_label (stmt, i);
1144 tree merge_label = CASE_LABEL (merge_case);
1145 tree t = int_const_binop (PLUS_EXPR, base_high,
1146 integer_one_node, 1);
1148 /* Merge the cases if they jump to the same place,
1149 and their ranges are consecutive. */
1150 if (merge_label == base_label
1151 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1153 base_high = CASE_HIGH (merge_case) ?
1154 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1155 CASE_HIGH (base_case) = base_high;
1156 gimple_switch_set_label (stmt, i, NULL_TREE);
1165 /* Compress the case labels in the label vector, and adjust the
1166 length of the vector. */
1167 for (i = 0, j = 0; i < new_size; i++)
1169 while (! gimple_switch_label (stmt, j))
1171 gimple_switch_set_label (stmt, i,
1172 gimple_switch_label (stmt, j++));
1175 gcc_assert (new_size <= old_size);
1176 gimple_switch_set_num_labels (stmt, new_size);
1181 /* Checks whether we can merge block B into block A. */
1184 gimple_can_merge_blocks_p (basic_block a, basic_block b)
1187 gimple_stmt_iterator gsi;
1190 if (!single_succ_p (a))
1193 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1196 if (single_succ (a) != b)
1199 if (!single_pred_p (b))
1202 if (b == EXIT_BLOCK_PTR)
1205 /* If A ends by a statement causing exceptions or something similar, we
1206 cannot merge the blocks. */
1207 stmt = last_stmt (a);
1208 if (stmt && stmt_ends_bb_p (stmt))
1211 /* Do not allow a block with only a non-local label to be merged. */
1213 && gimple_code (stmt) == GIMPLE_LABEL
1214 && DECL_NONLOCAL (gimple_label_label (stmt)))
1217 /* It must be possible to eliminate all phi nodes in B. If ssa form
1218 is not up-to-date, we cannot eliminate any phis; however, if only
1219 some symbols as whole are marked for renaming, this is not a problem,
1220 as phi nodes for those symbols are irrelevant in updating anyway. */
1221 phis = phi_nodes (b);
1222 if (!gimple_seq_empty_p (phis))
1224 gimple_stmt_iterator i;
1226 if (name_mappings_registered_p ())
1229 for (i = gsi_start (phis); !gsi_end_p (i); gsi_next (&i))
1231 gimple phi = gsi_stmt (i);
1233 if (!is_gimple_reg (gimple_phi_result (phi))
1234 && !may_propagate_copy (gimple_phi_result (phi),
1235 gimple_phi_arg_def (phi, 0)))
1240 /* Do not remove user labels. */
1241 for (gsi = gsi_start_bb (b); !gsi_end_p (gsi); gsi_next (&gsi))
1243 stmt = gsi_stmt (gsi);
1244 if (gimple_code (stmt) != GIMPLE_LABEL)
1246 if (!DECL_ARTIFICIAL (gimple_label_label (stmt)))
1250 /* Protect the loop latches. */
1252 && b->loop_father->latch == b)
1258 /* Replaces all uses of NAME by VAL. */
1261 replace_uses_by (tree name, tree val)
1263 imm_use_iterator imm_iter;
1268 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1270 if (gimple_code (stmt) != GIMPLE_PHI)
1271 push_stmt_changes (&stmt);
1273 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1275 replace_exp (use, val);
1277 if (gimple_code (stmt) == GIMPLE_PHI)
1279 e = gimple_phi_arg_edge (stmt, PHI_ARG_INDEX_FROM_USE (use));
1280 if (e->flags & EDGE_ABNORMAL)
1282 /* This can only occur for virtual operands, since
1283 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1284 would prevent replacement. */
1285 gcc_assert (!is_gimple_reg (name));
1286 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1291 if (gimple_code (stmt) != GIMPLE_PHI)
1295 fold_stmt_inplace (stmt);
1296 if (cfgcleanup_altered_bbs)
1297 bitmap_set_bit (cfgcleanup_altered_bbs, gimple_bb (stmt)->index);
1299 /* FIXME. This should go in pop_stmt_changes. */
1300 for (i = 0; i < gimple_num_ops (stmt); i++)
1302 tree op = gimple_op (stmt, i);
1303 /* Operands may be empty here. For example, the labels
1304 of a GIMPLE_COND are nulled out following the creation
1305 of the corresponding CFG edges. */
1306 if (op && TREE_CODE (op) == ADDR_EXPR)
1307 recompute_tree_invariant_for_addr_expr (op);
1310 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1312 pop_stmt_changes (&stmt);
1316 gcc_assert (has_zero_uses (name));
1318 /* Also update the trees stored in loop structures. */
1324 FOR_EACH_LOOP (li, loop, 0)
1326 substitute_in_loop_info (loop, name, val);
1331 /* Merge block B into block A. */
1334 gimple_merge_blocks (basic_block a, basic_block b)
1336 gimple_stmt_iterator last, gsi, psi;
1337 gimple_seq phis = phi_nodes (b);
1340 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1342 /* Remove all single-valued PHI nodes from block B of the form
1343 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1344 gsi = gsi_last_bb (a);
1345 for (psi = gsi_start (phis); !gsi_end_p (psi); )
1347 gimple phi = gsi_stmt (psi);
1348 tree def = gimple_phi_result (phi), use = gimple_phi_arg_def (phi, 0);
1350 bool may_replace_uses = !is_gimple_reg (def)
1351 || may_propagate_copy (def, use);
1353 /* In case we maintain loop closed ssa form, do not propagate arguments
1354 of loop exit phi nodes. */
1356 && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1357 && is_gimple_reg (def)
1358 && TREE_CODE (use) == SSA_NAME
1359 && a->loop_father != b->loop_father)
1360 may_replace_uses = false;
1362 if (!may_replace_uses)
1364 gcc_assert (is_gimple_reg (def));
1366 /* Note that just emitting the copies is fine -- there is no problem
1367 with ordering of phi nodes. This is because A is the single
1368 predecessor of B, therefore results of the phi nodes cannot
1369 appear as arguments of the phi nodes. */
1370 copy = gimple_build_assign (def, use);
1371 gsi_insert_after (&gsi, copy, GSI_NEW_STMT);
1372 remove_phi_node (&psi, false);
1376 /* If we deal with a PHI for virtual operands, we can simply
1377 propagate these without fussing with folding or updating
1379 if (!is_gimple_reg (def))
1381 imm_use_iterator iter;
1382 use_operand_p use_p;
1385 FOR_EACH_IMM_USE_STMT (stmt, iter, def)
1386 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1387 SET_USE (use_p, use);
1390 replace_uses_by (def, use);
1392 remove_phi_node (&psi, true);
1396 /* Ensure that B follows A. */
1397 move_block_after (b, a);
1399 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1400 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1402 /* Remove labels from B and set gimple_bb to A for other statements. */
1403 for (gsi = gsi_start_bb (b); !gsi_end_p (gsi);)
1405 if (gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL)
1407 gimple label = gsi_stmt (gsi);
1409 gsi_remove (&gsi, false);
1411 /* Now that we can thread computed gotos, we might have
1412 a situation where we have a forced label in block B
1413 However, the label at the start of block B might still be
1414 used in other ways (think about the runtime checking for
1415 Fortran assigned gotos). So we can not just delete the
1416 label. Instead we move the label to the start of block A. */
1417 if (FORCED_LABEL (gimple_label_label (label)))
1419 gimple_stmt_iterator dest_gsi = gsi_start_bb (a);
1420 gsi_insert_before (&dest_gsi, label, GSI_NEW_STMT);
1425 gimple_set_bb (gsi_stmt (gsi), a);
1430 /* Merge the sequences. */
1431 last = gsi_last_bb (a);
1432 gsi_insert_seq_after (&last, bb_seq (b), GSI_NEW_STMT);
1433 set_bb_seq (b, NULL);
1435 if (cfgcleanup_altered_bbs)
1436 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1440 /* Return the one of two successors of BB that is not reachable by a
1441 reached by a complex edge, if there is one. Else, return BB. We use
1442 this in optimizations that use post-dominators for their heuristics,
1443 to catch the cases in C++ where function calls are involved. */
1446 single_noncomplex_succ (basic_block bb)
1449 if (EDGE_COUNT (bb->succs) != 2)
1452 e0 = EDGE_SUCC (bb, 0);
1453 e1 = EDGE_SUCC (bb, 1);
1454 if (e0->flags & EDGE_COMPLEX)
1456 if (e1->flags & EDGE_COMPLEX)
1463 /* Walk the function tree removing unnecessary statements.
1465 * Empty statement nodes are removed
1467 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1469 * Unnecessary COND_EXPRs are removed
1471 * Some unnecessary BIND_EXPRs are removed
1473 * GOTO_EXPRs immediately preceding destination are removed.
1475 Clearly more work could be done. The trick is doing the analysis
1476 and removal fast enough to be a net improvement in compile times.
1478 Note that when we remove a control structure such as a COND_EXPR
1479 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1480 to ensure we eliminate all the useless code. */
1489 gimple_stmt_iterator last_goto_gsi;
1493 static void remove_useless_stmts_1 (gimple_stmt_iterator *gsi, struct rus_data *);
1495 /* Given a statement sequence, find the first executable statement with
1496 location information, and warn that it is unreachable. When searching,
1497 descend into containers in execution order. */
1500 remove_useless_stmts_warn_notreached (gimple_seq stmts)
1502 gimple_stmt_iterator gsi;
1504 for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
1506 gimple stmt = gsi_stmt (gsi);
1508 if (gimple_has_location (stmt))
1510 location_t loc = gimple_location (stmt);
1511 if (LOCATION_LINE (loc) > 0)
1513 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
1518 switch (gimple_code (stmt))
1520 /* Unfortunately, we need the CFG now to detect unreachable
1521 branches in a conditional, so conditionals are not handled here. */
1524 if (remove_useless_stmts_warn_notreached (gimple_try_eval (stmt)))
1526 if (remove_useless_stmts_warn_notreached (gimple_try_cleanup (stmt)))
1531 return remove_useless_stmts_warn_notreached (gimple_catch_handler (stmt));
1533 case GIMPLE_EH_FILTER:
1534 return remove_useless_stmts_warn_notreached (gimple_eh_filter_failure (stmt));
1537 return remove_useless_stmts_warn_notreached (gimple_bind_body (stmt));
1547 /* Helper for remove_useless_stmts_1. Handle GIMPLE_COND statements. */
1550 remove_useless_stmts_cond (gimple_stmt_iterator *gsi, struct rus_data *data)
1552 gimple stmt = gsi_stmt (*gsi);
1554 /* The folded result must still be a conditional statement. */
1555 fold_stmt_inplace (stmt);
1557 data->may_branch = true;
1559 /* Replace trivial conditionals with gotos. */
1560 if (gimple_cond_true_p (stmt))
1562 /* Goto THEN label. */
1563 tree then_label = gimple_cond_true_label (stmt);
1565 gsi_replace (gsi, gimple_build_goto (then_label), false);
1566 data->last_goto_gsi = *gsi;
1567 data->last_was_goto = true;
1568 data->repeat = true;
1570 else if (gimple_cond_false_p (stmt))
1572 /* Goto ELSE label. */
1573 tree else_label = gimple_cond_false_label (stmt);
1575 gsi_replace (gsi, gimple_build_goto (else_label), false);
1576 data->last_goto_gsi = *gsi;
1577 data->last_was_goto = true;
1578 data->repeat = true;
1582 tree then_label = gimple_cond_true_label (stmt);
1583 tree else_label = gimple_cond_false_label (stmt);
1585 if (then_label == else_label)
1587 /* Goto common destination. */
1588 gsi_replace (gsi, gimple_build_goto (then_label), false);
1589 data->last_goto_gsi = *gsi;
1590 data->last_was_goto = true;
1591 data->repeat = true;
1597 data->last_was_goto = false;
1600 /* Helper for remove_useless_stmts_1.
1601 Handle the try-finally case for GIMPLE_TRY statements. */
1604 remove_useless_stmts_tf (gimple_stmt_iterator *gsi, struct rus_data *data)
1606 bool save_may_branch, save_may_throw;
1607 bool this_may_branch, this_may_throw;
1609 gimple_seq eval_seq, cleanup_seq;
1610 gimple_stmt_iterator eval_gsi, cleanup_gsi;
1612 gimple stmt = gsi_stmt (*gsi);
1614 /* Collect may_branch and may_throw information for the body only. */
1615 save_may_branch = data->may_branch;
1616 save_may_throw = data->may_throw;
1617 data->may_branch = false;
1618 data->may_throw = false;
1619 data->last_was_goto = false;
1621 eval_seq = gimple_try_eval (stmt);
1622 eval_gsi = gsi_start (eval_seq);
1623 remove_useless_stmts_1 (&eval_gsi, data);
1625 this_may_branch = data->may_branch;
1626 this_may_throw = data->may_throw;
1627 data->may_branch |= save_may_branch;
1628 data->may_throw |= save_may_throw;
1629 data->last_was_goto = false;
1631 cleanup_seq = gimple_try_cleanup (stmt);
1632 cleanup_gsi = gsi_start (cleanup_seq);
1633 remove_useless_stmts_1 (&cleanup_gsi, data);
1635 /* If the body is empty, then we can emit the FINALLY block without
1636 the enclosing TRY_FINALLY_EXPR. */
1637 if (gimple_seq_empty_p (eval_seq))
1639 gsi_insert_seq_before (gsi, cleanup_seq, GSI_SAME_STMT);
1640 gsi_remove (gsi, false);
1641 data->repeat = true;
1644 /* If the handler is empty, then we can emit the TRY block without
1645 the enclosing TRY_FINALLY_EXPR. */
1646 else if (gimple_seq_empty_p (cleanup_seq))
1648 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1649 gsi_remove (gsi, false);
1650 data->repeat = true;
1653 /* If the body neither throws, nor branches, then we can safely
1654 string the TRY and FINALLY blocks together. */
1655 else if (!this_may_branch && !this_may_throw)
1657 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1658 gsi_insert_seq_before (gsi, cleanup_seq, GSI_SAME_STMT);
1659 gsi_remove (gsi, false);
1660 data->repeat = true;
1666 /* Helper for remove_useless_stmts_1.
1667 Handle the try-catch case for GIMPLE_TRY statements. */
1670 remove_useless_stmts_tc (gimple_stmt_iterator *gsi, struct rus_data *data)
1672 bool save_may_throw, this_may_throw;
1674 gimple_seq eval_seq, cleanup_seq, handler_seq, failure_seq;
1675 gimple_stmt_iterator eval_gsi, cleanup_gsi, handler_gsi, failure_gsi;
1677 gimple stmt = gsi_stmt (*gsi);
1679 /* Collect may_throw information for the body only. */
1680 save_may_throw = data->may_throw;
1681 data->may_throw = false;
1682 data->last_was_goto = false;
1684 eval_seq = gimple_try_eval (stmt);
1685 eval_gsi = gsi_start (eval_seq);
1686 remove_useless_stmts_1 (&eval_gsi, data);
1688 this_may_throw = data->may_throw;
1689 data->may_throw = save_may_throw;
1691 cleanup_seq = gimple_try_cleanup (stmt);
1693 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1694 if (!this_may_throw)
1696 if (warn_notreached)
1698 remove_useless_stmts_warn_notreached (cleanup_seq);
1700 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1701 gsi_remove (gsi, false);
1702 data->repeat = true;
1706 /* Process the catch clause specially. We may be able to tell that
1707 no exceptions propagate past this point. */
1709 this_may_throw = true;
1710 cleanup_gsi = gsi_start (cleanup_seq);
1711 stmt = gsi_stmt (cleanup_gsi);
1712 data->last_was_goto = false;
1714 switch (gimple_code (stmt))
1717 /* If the first element is a catch, they all must be. */
1718 while (!gsi_end_p (cleanup_gsi))
1720 stmt = gsi_stmt (cleanup_gsi);
1721 /* If we catch all exceptions, then the body does not
1722 propagate exceptions past this point. */
1723 if (gimple_catch_types (stmt) == NULL)
1724 this_may_throw = false;
1725 data->last_was_goto = false;
1726 handler_seq = gimple_catch_handler (stmt);
1727 handler_gsi = gsi_start (handler_seq);
1728 remove_useless_stmts_1 (&handler_gsi, data);
1729 gsi_next (&cleanup_gsi);
1734 case GIMPLE_EH_FILTER:
1735 /* If the first element is an eh_filter, it should stand alone. */
1736 if (gimple_eh_filter_must_not_throw (stmt))
1737 this_may_throw = false;
1738 else if (gimple_eh_filter_types (stmt) == NULL)
1739 this_may_throw = false;
1740 failure_seq = gimple_eh_filter_failure (stmt);
1741 failure_gsi = gsi_start (failure_seq);
1742 remove_useless_stmts_1 (&failure_gsi, data);
1747 /* Otherwise this is a list of cleanup statements. */
1748 remove_useless_stmts_1 (&cleanup_gsi, data);
1750 /* If the cleanup is empty, then we can emit the TRY block without
1751 the enclosing TRY_CATCH_EXPR. */
1752 if (gimple_seq_empty_p (cleanup_seq))
1754 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1755 gsi_remove(gsi, false);
1756 data->repeat = true;
1763 data->may_throw |= this_may_throw;
1766 /* Helper for remove_useless_stmts_1. Handle GIMPLE_BIND statements. */
1769 remove_useless_stmts_bind (gimple_stmt_iterator *gsi, struct rus_data *data ATTRIBUTE_UNUSED)
1772 gimple_seq body_seq, fn_body_seq;
1773 gimple_stmt_iterator body_gsi;
1775 gimple stmt = gsi_stmt (*gsi);
1777 /* First remove anything underneath the BIND_EXPR. */
1779 body_seq = gimple_bind_body (stmt);
1780 body_gsi = gsi_start (body_seq);
1781 remove_useless_stmts_1 (&body_gsi, data);
1783 /* If the GIMPLE_BIND has no variables, then we can pull everything
1784 up one level and remove the GIMPLE_BIND, unless this is the toplevel
1785 GIMPLE_BIND for the current function or an inlined function.
1787 When this situation occurs we will want to apply this
1788 optimization again. */
1789 block = gimple_bind_block (stmt);
1790 fn_body_seq = gimple_body (current_function_decl);
1791 if (gimple_bind_vars (stmt) == NULL_TREE
1792 && (gimple_seq_empty_p (fn_body_seq)
1793 || stmt != gimple_seq_first_stmt (fn_body_seq))
1795 || ! BLOCK_ABSTRACT_ORIGIN (block)
1796 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1799 tree var = NULL_TREE;
1800 /* Even if there are no gimple_bind_vars, there might be other
1801 decls in BLOCK_VARS rendering the GIMPLE_BIND not useless. */
1802 if (block && !BLOCK_NUM_NONLOCALIZED_VARS (block))
1803 for (var = BLOCK_VARS (block); var; var = TREE_CHAIN (var))
1804 if (TREE_CODE (var) == IMPORTED_DECL)
1806 if (var || (block && BLOCK_NUM_NONLOCALIZED_VARS (block)))
1810 gsi_insert_seq_before (gsi, body_seq, GSI_SAME_STMT);
1811 gsi_remove (gsi, false);
1812 data->repeat = true;
1819 /* Helper for remove_useless_stmts_1. Handle GIMPLE_GOTO statements. */
1822 remove_useless_stmts_goto (gimple_stmt_iterator *gsi, struct rus_data *data)
1824 gimple stmt = gsi_stmt (*gsi);
1826 tree dest = gimple_goto_dest (stmt);
1828 data->may_branch = true;
1829 data->last_was_goto = false;
1831 /* Record iterator for last goto expr, so that we can delete it if unnecessary. */
1832 if (TREE_CODE (dest) == LABEL_DECL)
1834 data->last_goto_gsi = *gsi;
1835 data->last_was_goto = true;
1841 /* Helper for remove_useless_stmts_1. Handle GIMPLE_LABEL statements. */
1844 remove_useless_stmts_label (gimple_stmt_iterator *gsi, struct rus_data *data)
1846 gimple stmt = gsi_stmt (*gsi);
1848 tree label = gimple_label_label (stmt);
1850 data->has_label = true;
1852 /* We do want to jump across non-local label receiver code. */
1853 if (DECL_NONLOCAL (label))
1854 data->last_was_goto = false;
1856 else if (data->last_was_goto
1857 && gimple_goto_dest (gsi_stmt (data->last_goto_gsi)) == label)
1859 /* Replace the preceding GIMPLE_GOTO statement with
1860 a GIMPLE_NOP, which will be subsequently removed.
1861 In this way, we avoid invalidating other iterators
1862 active on the statement sequence. */
1863 gsi_replace(&data->last_goto_gsi, gimple_build_nop(), false);
1864 data->last_was_goto = false;
1865 data->repeat = true;
1868 /* ??? Add something here to delete unused labels. */
1874 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1877 notice_special_calls (gimple call)
1879 int flags = gimple_call_flags (call);
1881 if (flags & ECF_MAY_BE_ALLOCA)
1882 cfun->calls_alloca = true;
1883 if (flags & ECF_RETURNS_TWICE)
1884 cfun->calls_setjmp = true;
1888 /* Clear flags set by notice_special_calls. Used by dead code removal
1889 to update the flags. */
1892 clear_special_calls (void)
1894 cfun->calls_alloca = false;
1895 cfun->calls_setjmp = false;
1898 /* Remove useless statements from a statement sequence, and perform
1899 some preliminary simplifications. */
1902 remove_useless_stmts_1 (gimple_stmt_iterator *gsi, struct rus_data *data)
1904 while (!gsi_end_p (*gsi))
1906 gimple stmt = gsi_stmt (*gsi);
1908 switch (gimple_code (stmt))
1911 remove_useless_stmts_cond (gsi, data);
1915 remove_useless_stmts_goto (gsi, data);
1919 remove_useless_stmts_label (gsi, data);
1924 stmt = gsi_stmt (*gsi);
1925 data->last_was_goto = false;
1926 if (stmt_could_throw_p (stmt))
1927 data->may_throw = true;
1933 data->last_was_goto = false;
1939 stmt = gsi_stmt (*gsi);
1940 data->last_was_goto = false;
1941 if (is_gimple_call (stmt))
1942 notice_special_calls (stmt);
1944 /* We used to call update_gimple_call_flags here,
1945 which copied side-effects and nothrows status
1946 from the function decl to the call. In the new
1947 tuplified GIMPLE, the accessors for this information
1948 always consult the function decl, so this copying
1949 is no longer necessary. */
1950 if (stmt_could_throw_p (stmt))
1951 data->may_throw = true;
1957 data->last_was_goto = false;
1958 data->may_branch = true;
1963 remove_useless_stmts_bind (gsi, data);
1967 if (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH)
1968 remove_useless_stmts_tc (gsi, data);
1969 else if (gimple_try_kind (stmt) == GIMPLE_TRY_FINALLY)
1970 remove_useless_stmts_tf (gsi, data);
1980 gsi_remove (gsi, false);
1983 case GIMPLE_OMP_FOR:
1985 gimple_seq pre_body_seq = gimple_omp_for_pre_body (stmt);
1986 gimple_stmt_iterator pre_body_gsi = gsi_start (pre_body_seq);
1988 remove_useless_stmts_1 (&pre_body_gsi, data);
1989 data->last_was_goto = false;
1992 case GIMPLE_OMP_CRITICAL:
1993 case GIMPLE_OMP_CONTINUE:
1994 case GIMPLE_OMP_MASTER:
1995 case GIMPLE_OMP_ORDERED:
1996 case GIMPLE_OMP_SECTION:
1997 case GIMPLE_OMP_SECTIONS:
1998 case GIMPLE_OMP_SINGLE:
2000 gimple_seq body_seq = gimple_omp_body (stmt);
2001 gimple_stmt_iterator body_gsi = gsi_start (body_seq);
2003 remove_useless_stmts_1 (&body_gsi, data);
2004 data->last_was_goto = false;
2009 case GIMPLE_OMP_PARALLEL:
2010 case GIMPLE_OMP_TASK:
2012 /* Make sure the outermost GIMPLE_BIND isn't removed
2014 gimple_seq body_seq = gimple_omp_body (stmt);
2015 gimple bind = gimple_seq_first_stmt (body_seq);
2016 gimple_seq bind_seq = gimple_bind_body (bind);
2017 gimple_stmt_iterator bind_gsi = gsi_start (bind_seq);
2019 remove_useless_stmts_1 (&bind_gsi, data);
2020 data->last_was_goto = false;
2025 case GIMPLE_CHANGE_DYNAMIC_TYPE:
2026 /* If we do not optimize remove GIMPLE_CHANGE_DYNAMIC_TYPE as
2027 expansion is confused about them and we only remove them
2028 during alias computation otherwise. */
2031 data->last_was_goto = false;
2032 gsi_remove (gsi, false);
2038 data->last_was_goto = false;
2045 /* Walk the function tree, removing useless statements and performing
2046 some preliminary simplifications. */
2049 remove_useless_stmts (void)
2051 struct rus_data data;
2053 clear_special_calls ();
2057 gimple_stmt_iterator gsi;
2059 gsi = gsi_start (gimple_body (current_function_decl));
2060 memset (&data, 0, sizeof (data));
2061 remove_useless_stmts_1 (&gsi, &data);
2063 while (data.repeat);
2068 struct gimple_opt_pass pass_remove_useless_stmts =
2072 "useless", /* name */
2074 remove_useless_stmts, /* execute */
2077 0, /* static_pass_number */
2079 PROP_gimple_any, /* properties_required */
2080 0, /* properties_provided */
2081 0, /* properties_destroyed */
2082 0, /* todo_flags_start */
2083 TODO_dump_func /* todo_flags_finish */
2087 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
2090 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
2092 /* Since this block is no longer reachable, we can just delete all
2093 of its PHI nodes. */
2094 remove_phi_nodes (bb);
2096 /* Remove edges to BB's successors. */
2097 while (EDGE_COUNT (bb->succs) > 0)
2098 remove_edge (EDGE_SUCC (bb, 0));
2102 /* Remove statements of basic block BB. */
2105 remove_bb (basic_block bb)
2107 gimple_stmt_iterator i;
2108 source_location loc = UNKNOWN_LOCATION;
2112 fprintf (dump_file, "Removing basic block %d\n", bb->index);
2113 if (dump_flags & TDF_DETAILS)
2115 dump_bb (bb, dump_file, 0);
2116 fprintf (dump_file, "\n");
2122 struct loop *loop = bb->loop_father;
2124 /* If a loop gets removed, clean up the information associated
2126 if (loop->latch == bb
2127 || loop->header == bb)
2128 free_numbers_of_iterations_estimates_loop (loop);
2131 /* Remove all the instructions in the block. */
2132 if (bb_seq (bb) != NULL)
2134 for (i = gsi_start_bb (bb); !gsi_end_p (i);)
2136 gimple stmt = gsi_stmt (i);
2137 if (gimple_code (stmt) == GIMPLE_LABEL
2138 && (FORCED_LABEL (gimple_label_label (stmt))
2139 || DECL_NONLOCAL (gimple_label_label (stmt))))
2142 gimple_stmt_iterator new_gsi;
2144 /* A non-reachable non-local label may still be referenced.
2145 But it no longer needs to carry the extra semantics of
2147 if (DECL_NONLOCAL (gimple_label_label (stmt)))
2149 DECL_NONLOCAL (gimple_label_label (stmt)) = 0;
2150 FORCED_LABEL (gimple_label_label (stmt)) = 1;
2153 new_bb = bb->prev_bb;
2154 new_gsi = gsi_start_bb (new_bb);
2155 gsi_remove (&i, false);
2156 gsi_insert_before (&new_gsi, stmt, GSI_NEW_STMT);
2160 /* Release SSA definitions if we are in SSA. Note that we
2161 may be called when not in SSA. For example,
2162 final_cleanup calls this function via
2163 cleanup_tree_cfg. */
2164 if (gimple_in_ssa_p (cfun))
2165 release_defs (stmt);
2167 gsi_remove (&i, true);
2170 /* Don't warn for removed gotos. Gotos are often removed due to
2171 jump threading, thus resulting in bogus warnings. Not great,
2172 since this way we lose warnings for gotos in the original
2173 program that are indeed unreachable. */
2174 if (gimple_code (stmt) != GIMPLE_GOTO
2175 && gimple_has_location (stmt)
2177 loc = gimple_location (stmt);
2181 /* If requested, give a warning that the first statement in the
2182 block is unreachable. We walk statements backwards in the
2183 loop above, so the last statement we process is the first statement
2185 if (loc > BUILTINS_LOCATION && LOCATION_LINE (loc) > 0)
2186 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2188 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2189 bb->il.gimple = NULL;
2193 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2194 predicate VAL, return the edge that will be taken out of the block.
2195 If VAL does not match a unique edge, NULL is returned. */
2198 find_taken_edge (basic_block bb, tree val)
2202 stmt = last_stmt (bb);
2205 gcc_assert (is_ctrl_stmt (stmt));
2210 if (!is_gimple_min_invariant (val))
2213 if (gimple_code (stmt) == GIMPLE_COND)
2214 return find_taken_edge_cond_expr (bb, val);
2216 if (gimple_code (stmt) == GIMPLE_SWITCH)
2217 return find_taken_edge_switch_expr (bb, val);
2219 if (computed_goto_p (stmt))
2221 /* Only optimize if the argument is a label, if the argument is
2222 not a label then we can not construct a proper CFG.
2224 It may be the case that we only need to allow the LABEL_REF to
2225 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2226 appear inside a LABEL_EXPR just to be safe. */
2227 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2228 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2229 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2236 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2237 statement, determine which of the outgoing edges will be taken out of the
2238 block. Return NULL if either edge may be taken. */
2241 find_taken_edge_computed_goto (basic_block bb, tree val)
2246 dest = label_to_block (val);
2249 e = find_edge (bb, dest);
2250 gcc_assert (e != NULL);
2256 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2257 statement, determine which of the two edges will be taken out of the
2258 block. Return NULL if either edge may be taken. */
2261 find_taken_edge_cond_expr (basic_block bb, tree val)
2263 edge true_edge, false_edge;
2265 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2267 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2268 return (integer_zerop (val) ? false_edge : true_edge);
2271 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2272 statement, determine which edge will be taken out of the block. Return
2273 NULL if any edge may be taken. */
2276 find_taken_edge_switch_expr (basic_block bb, tree val)
2278 basic_block dest_bb;
2283 switch_stmt = last_stmt (bb);
2284 taken_case = find_case_label_for_value (switch_stmt, val);
2285 dest_bb = label_to_block (CASE_LABEL (taken_case));
2287 e = find_edge (bb, dest_bb);
2293 /* Return the CASE_LABEL_EXPR that SWITCH_STMT will take for VAL.
2294 We can make optimal use here of the fact that the case labels are
2295 sorted: We can do a binary search for a case matching VAL. */
2298 find_case_label_for_value (gimple switch_stmt, tree val)
2300 size_t low, high, n = gimple_switch_num_labels (switch_stmt);
2301 tree default_case = gimple_switch_default_label (switch_stmt);
2303 for (low = 0, high = n; high - low > 1; )
2305 size_t i = (high + low) / 2;
2306 tree t = gimple_switch_label (switch_stmt, i);
2309 /* Cache the result of comparing CASE_LOW and val. */
2310 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2317 if (CASE_HIGH (t) == NULL)
2319 /* A singe-valued case label. */
2325 /* A case range. We can only handle integer ranges. */
2326 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2331 return default_case;
2335 /* Dump a basic block on stderr. */
2338 gimple_debug_bb (basic_block bb)
2340 gimple_dump_bb (bb, stderr, 0, TDF_VOPS|TDF_MEMSYMS);
2344 /* Dump basic block with index N on stderr. */
2347 gimple_debug_bb_n (int n)
2349 gimple_debug_bb (BASIC_BLOCK (n));
2350 return BASIC_BLOCK (n);
2354 /* Dump the CFG on stderr.
2356 FLAGS are the same used by the tree dumping functions
2357 (see TDF_* in tree-pass.h). */
2360 gimple_debug_cfg (int flags)
2362 gimple_dump_cfg (stderr, flags);
2366 /* Dump the program showing basic block boundaries on the given FILE.
2368 FLAGS are the same used by the tree dumping functions (see TDF_* in
2372 gimple_dump_cfg (FILE *file, int flags)
2374 if (flags & TDF_DETAILS)
2376 const char *funcname
2377 = lang_hooks.decl_printable_name (current_function_decl, 2);
2380 fprintf (file, ";; Function %s\n\n", funcname);
2381 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2382 n_basic_blocks, n_edges, last_basic_block);
2384 brief_dump_cfg (file);
2385 fprintf (file, "\n");
2388 if (flags & TDF_STATS)
2389 dump_cfg_stats (file);
2391 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2395 /* Dump CFG statistics on FILE. */
2398 dump_cfg_stats (FILE *file)
2400 static long max_num_merged_labels = 0;
2401 unsigned long size, total = 0;
2404 const char * const fmt_str = "%-30s%-13s%12s\n";
2405 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2406 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2407 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2408 const char *funcname
2409 = lang_hooks.decl_printable_name (current_function_decl, 2);
2412 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2414 fprintf (file, "---------------------------------------------------------\n");
2415 fprintf (file, fmt_str, "", " Number of ", "Memory");
2416 fprintf (file, fmt_str, "", " instances ", "used ");
2417 fprintf (file, "---------------------------------------------------------\n");
2419 size = n_basic_blocks * sizeof (struct basic_block_def);
2421 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2422 SCALE (size), LABEL (size));
2426 num_edges += EDGE_COUNT (bb->succs);
2427 size = num_edges * sizeof (struct edge_def);
2429 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2431 fprintf (file, "---------------------------------------------------------\n");
2432 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2434 fprintf (file, "---------------------------------------------------------\n");
2435 fprintf (file, "\n");
2437 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2438 max_num_merged_labels = cfg_stats.num_merged_labels;
2440 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2441 cfg_stats.num_merged_labels, max_num_merged_labels);
2443 fprintf (file, "\n");
2447 /* Dump CFG statistics on stderr. Keep extern so that it's always
2448 linked in the final executable. */
2451 debug_cfg_stats (void)
2453 dump_cfg_stats (stderr);
2457 /* Dump the flowgraph to a .vcg FILE. */
2460 gimple_cfg2vcg (FILE *file)
2465 const char *funcname
2466 = lang_hooks.decl_printable_name (current_function_decl, 2);
2468 /* Write the file header. */
2469 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2470 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2471 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2473 /* Write blocks and edges. */
2474 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2476 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2479 if (e->flags & EDGE_FAKE)
2480 fprintf (file, " linestyle: dotted priority: 10");
2482 fprintf (file, " linestyle: solid priority: 100");
2484 fprintf (file, " }\n");
2490 enum gimple_code head_code, end_code;
2491 const char *head_name, *end_name;
2494 gimple first = first_stmt (bb);
2495 gimple last = last_stmt (bb);
2499 head_code = gimple_code (first);
2500 head_name = gimple_code_name[head_code];
2501 head_line = get_lineno (first);
2504 head_name = "no-statement";
2508 end_code = gimple_code (last);
2509 end_name = gimple_code_name[end_code];
2510 end_line = get_lineno (last);
2513 end_name = "no-statement";
2515 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2516 bb->index, bb->index, head_name, head_line, end_name,
2519 FOR_EACH_EDGE (e, ei, bb->succs)
2521 if (e->dest == EXIT_BLOCK_PTR)
2522 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2524 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2526 if (e->flags & EDGE_FAKE)
2527 fprintf (file, " priority: 10 linestyle: dotted");
2529 fprintf (file, " priority: 100 linestyle: solid");
2531 fprintf (file, " }\n");
2534 if (bb->next_bb != EXIT_BLOCK_PTR)
2538 fputs ("}\n\n", file);
2543 /*---------------------------------------------------------------------------
2544 Miscellaneous helpers
2545 ---------------------------------------------------------------------------*/
2547 /* Return true if T represents a stmt that always transfers control. */
2550 is_ctrl_stmt (gimple t)
2552 return gimple_code (t) == GIMPLE_COND
2553 || gimple_code (t) == GIMPLE_SWITCH
2554 || gimple_code (t) == GIMPLE_GOTO
2555 || gimple_code (t) == GIMPLE_RETURN
2556 || gimple_code (t) == GIMPLE_RESX;
2560 /* Return true if T is a statement that may alter the flow of control
2561 (e.g., a call to a non-returning function). */
2564 is_ctrl_altering_stmt (gimple t)
2568 if (is_gimple_call (t))
2570 int flags = gimple_call_flags (t);
2572 /* A non-pure/const call alters flow control if the current
2573 function has nonlocal labels. */
2574 if (!(flags & (ECF_CONST | ECF_PURE))
2575 && cfun->has_nonlocal_label)
2578 /* A call also alters control flow if it does not return. */
2579 if (gimple_call_flags (t) & ECF_NORETURN)
2583 /* OpenMP directives alter control flow. */
2584 if (is_gimple_omp (t))
2587 /* If a statement can throw, it alters control flow. */
2588 return stmt_can_throw_internal (t);
2592 /* Return true if T is a simple local goto. */
2595 simple_goto_p (gimple t)
2597 return (gimple_code (t) == GIMPLE_GOTO
2598 && TREE_CODE (gimple_goto_dest (t)) == LABEL_DECL);
2602 /* Return true if T can make an abnormal transfer of control flow.
2603 Transfers of control flow associated with EH are excluded. */
2606 stmt_can_make_abnormal_goto (gimple t)
2608 if (computed_goto_p (t))
2610 if (is_gimple_call (t))
2611 return gimple_has_side_effects (t) && cfun->has_nonlocal_label;
2616 /* Return true if STMT should start a new basic block. PREV_STMT is
2617 the statement preceding STMT. It is used when STMT is a label or a
2618 case label. Labels should only start a new basic block if their
2619 previous statement wasn't a label. Otherwise, sequence of labels
2620 would generate unnecessary basic blocks that only contain a single
2624 stmt_starts_bb_p (gimple stmt, gimple prev_stmt)
2629 /* Labels start a new basic block only if the preceding statement
2630 wasn't a label of the same type. This prevents the creation of
2631 consecutive blocks that have nothing but a single label. */
2632 if (gimple_code (stmt) == GIMPLE_LABEL)
2634 /* Nonlocal and computed GOTO targets always start a new block. */
2635 if (DECL_NONLOCAL (gimple_label_label (stmt))
2636 || FORCED_LABEL (gimple_label_label (stmt)))
2639 if (prev_stmt && gimple_code (prev_stmt) == GIMPLE_LABEL)
2641 if (DECL_NONLOCAL (gimple_label_label (prev_stmt)))
2644 cfg_stats.num_merged_labels++;
2655 /* Return true if T should end a basic block. */
2658 stmt_ends_bb_p (gimple t)
2660 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2663 /* Remove block annotations and other data structures. */
2666 delete_tree_cfg_annotations (void)
2668 label_to_block_map = NULL;
2672 /* Return the first statement in basic block BB. */
2675 first_stmt (basic_block bb)
2677 gimple_stmt_iterator i = gsi_start_bb (bb);
2678 return !gsi_end_p (i) ? gsi_stmt (i) : NULL;
2681 /* Return the last statement in basic block BB. */
2684 last_stmt (basic_block bb)
2686 gimple_stmt_iterator b = gsi_last_bb (bb);
2687 return !gsi_end_p (b) ? gsi_stmt (b) : NULL;
2690 /* Return the last statement of an otherwise empty block. Return NULL
2691 if the block is totally empty, or if it contains more than one
2695 last_and_only_stmt (basic_block bb)
2697 gimple_stmt_iterator i = gsi_last_bb (bb);
2703 last = gsi_stmt (i);
2708 /* Empty statements should no longer appear in the instruction stream.
2709 Everything that might have appeared before should be deleted by
2710 remove_useless_stmts, and the optimizers should just gsi_remove
2711 instead of smashing with build_empty_stmt.
2713 Thus the only thing that should appear here in a block containing
2714 one executable statement is a label. */
2715 prev = gsi_stmt (i);
2716 if (gimple_code (prev) == GIMPLE_LABEL)
2722 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
2725 reinstall_phi_args (edge new_edge, edge old_edge)
2727 edge_var_map_vector v;
2730 gimple_stmt_iterator phis;
2732 v = redirect_edge_var_map_vector (old_edge);
2736 for (i = 0, phis = gsi_start_phis (new_edge->dest);
2737 VEC_iterate (edge_var_map, v, i, vm) && !gsi_end_p (phis);
2738 i++, gsi_next (&phis))
2740 gimple phi = gsi_stmt (phis);
2741 tree result = redirect_edge_var_map_result (vm);
2742 tree arg = redirect_edge_var_map_def (vm);
2744 gcc_assert (result == gimple_phi_result (phi));
2746 add_phi_arg (phi, arg, new_edge);
2749 redirect_edge_var_map_clear (old_edge);
2752 /* Returns the basic block after which the new basic block created
2753 by splitting edge EDGE_IN should be placed. Tries to keep the new block
2754 near its "logical" location. This is of most help to humans looking
2755 at debugging dumps. */
2758 split_edge_bb_loc (edge edge_in)
2760 basic_block dest = edge_in->dest;
2762 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
2763 return edge_in->src;
2765 return dest->prev_bb;
2768 /* Split a (typically critical) edge EDGE_IN. Return the new block.
2769 Abort on abnormal edges. */
2772 gimple_split_edge (edge edge_in)
2774 basic_block new_bb, after_bb, dest;
2777 /* Abnormal edges cannot be split. */
2778 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
2780 dest = edge_in->dest;
2782 after_bb = split_edge_bb_loc (edge_in);
2784 new_bb = create_empty_bb (after_bb);
2785 new_bb->frequency = EDGE_FREQUENCY (edge_in);
2786 new_bb->count = edge_in->count;
2787 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
2788 new_edge->probability = REG_BR_PROB_BASE;
2789 new_edge->count = edge_in->count;
2791 e = redirect_edge_and_branch (edge_in, new_bb);
2792 gcc_assert (e == edge_in);
2793 reinstall_phi_args (new_edge, e);
2798 /* Callback for walk_tree, check that all elements with address taken are
2799 properly noticed as such. The DATA is an int* that is 1 if TP was seen
2800 inside a PHI node. */
2803 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
2810 /* Check operand N for being valid GIMPLE and give error MSG if not. */
2811 #define CHECK_OP(N, MSG) \
2812 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
2813 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
2815 switch (TREE_CODE (t))
2818 if (SSA_NAME_IN_FREE_LIST (t))
2820 error ("SSA name in freelist but still referenced");
2826 x = TREE_OPERAND (t, 0);
2827 if (!is_gimple_reg (x) && !is_gimple_min_invariant (x))
2829 error ("Indirect reference's operand is not a register or a constant.");
2835 x = fold (ASSERT_EXPR_COND (t));
2836 if (x == boolean_false_node)
2838 error ("ASSERT_EXPR with an always-false condition");
2844 error ("MODIFY_EXPR not expected while having tuples.");
2850 bool old_side_effects;
2852 bool new_side_effects;
2854 gcc_assert (is_gimple_address (t));
2856 old_constant = TREE_CONSTANT (t);
2857 old_side_effects = TREE_SIDE_EFFECTS (t);
2859 recompute_tree_invariant_for_addr_expr (t);
2860 new_side_effects = TREE_SIDE_EFFECTS (t);
2861 new_constant = TREE_CONSTANT (t);
2863 if (old_constant != new_constant)
2865 error ("constant not recomputed when ADDR_EXPR changed");
2868 if (old_side_effects != new_side_effects)
2870 error ("side effects not recomputed when ADDR_EXPR changed");
2874 /* Skip any references (they will be checked when we recurse down the
2875 tree) and ensure that any variable used as a prefix is marked
2877 for (x = TREE_OPERAND (t, 0);
2878 handled_component_p (x);
2879 x = TREE_OPERAND (x, 0))
2882 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
2884 if (!TREE_ADDRESSABLE (x))
2886 error ("address taken, but ADDRESSABLE bit not set");
2894 x = COND_EXPR_COND (t);
2895 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
2897 error ("non-integral used in condition");
2900 if (!is_gimple_condexpr (x))
2902 error ("invalid conditional operand");
2907 case NON_LVALUE_EXPR:
2911 case FIX_TRUNC_EXPR:
2916 case TRUTH_NOT_EXPR:
2917 CHECK_OP (0, "invalid operand to unary operator");
2924 case ARRAY_RANGE_REF:
2926 case VIEW_CONVERT_EXPR:
2927 /* We have a nest of references. Verify that each of the operands
2928 that determine where to reference is either a constant or a variable,
2929 verify that the base is valid, and then show we've already checked
2931 while (handled_component_p (t))
2933 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
2934 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
2935 else if (TREE_CODE (t) == ARRAY_REF
2936 || TREE_CODE (t) == ARRAY_RANGE_REF)
2938 CHECK_OP (1, "invalid array index");
2939 if (TREE_OPERAND (t, 2))
2940 CHECK_OP (2, "invalid array lower bound");
2941 if (TREE_OPERAND (t, 3))
2942 CHECK_OP (3, "invalid array stride");
2944 else if (TREE_CODE (t) == BIT_FIELD_REF)
2946 if (!host_integerp (TREE_OPERAND (t, 1), 1)
2947 || !host_integerp (TREE_OPERAND (t, 2), 1))
2949 error ("invalid position or size operand to BIT_FIELD_REF");
2952 else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
2953 && (TYPE_PRECISION (TREE_TYPE (t))
2954 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2956 error ("integral result type precision does not match "
2957 "field size of BIT_FIELD_REF");
2960 if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
2961 && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
2962 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2964 error ("mode precision of non-integral result does not "
2965 "match field size of BIT_FIELD_REF");
2970 t = TREE_OPERAND (t, 0);
2973 if (!is_gimple_min_invariant (t) && !is_gimple_lvalue (t))
2975 error ("invalid reference prefix");
2982 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
2983 POINTER_PLUS_EXPR. */
2984 if (POINTER_TYPE_P (TREE_TYPE (t)))
2986 error ("invalid operand to plus/minus, type is a pointer");
2989 CHECK_OP (0, "invalid operand to binary operator");
2990 CHECK_OP (1, "invalid operand to binary operator");
2993 case POINTER_PLUS_EXPR:
2994 /* Check to make sure the first operand is a pointer or reference type. */
2995 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
2997 error ("invalid operand to pointer plus, first operand is not a pointer");
3000 /* Check to make sure the second operand is an integer with type of
3002 if (!useless_type_conversion_p (sizetype,
3003 TREE_TYPE (TREE_OPERAND (t, 1))))
3005 error ("invalid operand to pointer plus, second operand is not an "
3006 "integer with type of sizetype.");
3016 case UNORDERED_EXPR:
3025 case TRUNC_DIV_EXPR:
3027 case FLOOR_DIV_EXPR:
3028 case ROUND_DIV_EXPR:
3029 case TRUNC_MOD_EXPR:
3031 case FLOOR_MOD_EXPR:
3032 case ROUND_MOD_EXPR:
3034 case EXACT_DIV_EXPR:
3044 CHECK_OP (0, "invalid operand to binary operator");
3045 CHECK_OP (1, "invalid operand to binary operator");
3049 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3062 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3063 Returns true if there is an error, otherwise false. */
3066 verify_types_in_gimple_min_lval (tree expr)
3070 if (is_gimple_id (expr))
3073 if (!INDIRECT_REF_P (expr)
3074 && TREE_CODE (expr) != TARGET_MEM_REF)
3076 error ("invalid expression for min lvalue");
3080 /* TARGET_MEM_REFs are strange beasts. */
3081 if (TREE_CODE (expr) == TARGET_MEM_REF)
3084 op = TREE_OPERAND (expr, 0);
3085 if (!is_gimple_val (op))
3087 error ("invalid operand in indirect reference");
3088 debug_generic_stmt (op);
3091 if (!useless_type_conversion_p (TREE_TYPE (expr),
3092 TREE_TYPE (TREE_TYPE (op))))
3094 error ("type mismatch in indirect reference");
3095 debug_generic_stmt (TREE_TYPE (expr));
3096 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3103 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3104 if there is an error, otherwise false. */
3107 verify_types_in_gimple_reference (tree expr)
3109 while (handled_component_p (expr))
3111 tree op = TREE_OPERAND (expr, 0);
3113 if (TREE_CODE (expr) == ARRAY_REF
3114 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3116 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3117 || (TREE_OPERAND (expr, 2)
3118 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3119 || (TREE_OPERAND (expr, 3)
3120 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3122 error ("invalid operands to array reference");
3123 debug_generic_stmt (expr);
3128 /* Verify if the reference array element types are compatible. */
3129 if (TREE_CODE (expr) == ARRAY_REF
3130 && !useless_type_conversion_p (TREE_TYPE (expr),
3131 TREE_TYPE (TREE_TYPE (op))))
3133 error ("type mismatch in array reference");
3134 debug_generic_stmt (TREE_TYPE (expr));
3135 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3138 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3139 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3140 TREE_TYPE (TREE_TYPE (op))))
3142 error ("type mismatch in array range reference");
3143 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3144 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3148 if ((TREE_CODE (expr) == REALPART_EXPR
3149 || TREE_CODE (expr) == IMAGPART_EXPR)
3150 && !useless_type_conversion_p (TREE_TYPE (expr),
3151 TREE_TYPE (TREE_TYPE (op))))
3153 error ("type mismatch in real/imagpart reference");
3154 debug_generic_stmt (TREE_TYPE (expr));
3155 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3159 if (TREE_CODE (expr) == COMPONENT_REF
3160 && !useless_type_conversion_p (TREE_TYPE (expr),
3161 TREE_TYPE (TREE_OPERAND (expr, 1))))
3163 error ("type mismatch in component reference");
3164 debug_generic_stmt (TREE_TYPE (expr));
3165 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3169 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3170 is nothing to verify. Gross mismatches at most invoke
3171 undefined behavior. */
3172 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
3173 && !handled_component_p (op))
3179 return verify_types_in_gimple_min_lval (expr);
3182 /* Returns true if there is one pointer type in TYPE_POINTER_TO (SRC_OBJ)
3183 list of pointer-to types that is trivially convertible to DEST. */
3186 one_pointer_to_useless_type_conversion_p (tree dest, tree src_obj)
3190 if (!TYPE_POINTER_TO (src_obj))
3193 for (src = TYPE_POINTER_TO (src_obj); src; src = TYPE_NEXT_PTR_TO (src))
3194 if (useless_type_conversion_p (dest, src))
3200 /* Return true if TYPE1 is a fixed-point type and if conversions to and
3201 from TYPE2 can be handled by FIXED_CONVERT_EXPR. */
3204 valid_fixed_convert_types_p (tree type1, tree type2)
3206 return (FIXED_POINT_TYPE_P (type1)
3207 && (INTEGRAL_TYPE_P (type2)
3208 || SCALAR_FLOAT_TYPE_P (type2)
3209 || FIXED_POINT_TYPE_P (type2)));
3212 /* Verify the contents of a GIMPLE_CALL STMT. Returns true when there
3213 is a problem, otherwise false. */
3216 verify_gimple_call (gimple stmt)
3218 tree fn = gimple_call_fn (stmt);
3221 if (!POINTER_TYPE_P (TREE_TYPE (fn))
3222 || (TREE_CODE (TREE_TYPE (TREE_TYPE (fn))) != FUNCTION_TYPE
3223 && TREE_CODE (TREE_TYPE (TREE_TYPE (fn))) != METHOD_TYPE))
3225 error ("non-function in gimple call");
3229 if (gimple_call_lhs (stmt)
3230 && !is_gimple_lvalue (gimple_call_lhs (stmt)))
3232 error ("invalid LHS in gimple call");
3236 fntype = TREE_TYPE (TREE_TYPE (fn));
3237 if (gimple_call_lhs (stmt)
3238 && !useless_type_conversion_p (TREE_TYPE (gimple_call_lhs (stmt)),
3240 /* ??? At least C++ misses conversions at assignments from
3241 void * call results.
3242 ??? Java is completely off. Especially with functions
3243 returning java.lang.Object.
3244 For now simply allow arbitrary pointer type conversions. */
3245 && !(POINTER_TYPE_P (TREE_TYPE (gimple_call_lhs (stmt)))
3246 && POINTER_TYPE_P (TREE_TYPE (fntype))))
3248 error ("invalid conversion in gimple call");
3249 debug_generic_stmt (TREE_TYPE (gimple_call_lhs (stmt)));
3250 debug_generic_stmt (TREE_TYPE (fntype));
3254 /* ??? The C frontend passes unpromoted arguments in case it
3255 didn't see a function declaration before the call. So for now
3256 leave the call arguments unverified. Once we gimplify
3257 unit-at-a-time we have a chance to fix this. */
3262 /* Verifies the gimple comparison with the result type TYPE and
3263 the operands OP0 and OP1. */
3266 verify_gimple_comparison (tree type, tree op0, tree op1)
3268 tree op0_type = TREE_TYPE (op0);
3269 tree op1_type = TREE_TYPE (op1);
3271 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3273 error ("invalid operands in gimple comparison");
3277 /* For comparisons we do not have the operations type as the
3278 effective type the comparison is carried out in. Instead
3279 we require that either the first operand is trivially
3280 convertible into the second, or the other way around.
3281 The resulting type of a comparison may be any integral type.
3282 Because we special-case pointers to void we allow
3283 comparisons of pointers with the same mode as well. */
3284 if ((!useless_type_conversion_p (op0_type, op1_type)
3285 && !useless_type_conversion_p (op1_type, op0_type)
3286 && (!POINTER_TYPE_P (op0_type)
3287 || !POINTER_TYPE_P (op1_type)
3288 || TYPE_MODE (op0_type) != TYPE_MODE (op1_type)))
3289 || !INTEGRAL_TYPE_P (type))
3291 error ("type mismatch in comparison expression");
3292 debug_generic_expr (type);
3293 debug_generic_expr (op0_type);
3294 debug_generic_expr (op1_type);
3301 /* Verify a gimple assignment statement STMT with an unary rhs.
3302 Returns true if anything is wrong. */
3305 verify_gimple_assign_unary (gimple stmt)
3307 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3308 tree lhs = gimple_assign_lhs (stmt);
3309 tree lhs_type = TREE_TYPE (lhs);
3310 tree rhs1 = gimple_assign_rhs1 (stmt);
3311 tree rhs1_type = TREE_TYPE (rhs1);
3313 if (!is_gimple_reg (lhs)
3315 && TREE_CODE (lhs_type) == COMPLEX_TYPE))
3317 error ("non-register as LHS of unary operation");
3321 if (!is_gimple_val (rhs1))
3323 error ("invalid operand in unary operation");
3327 /* First handle conversions. */
3332 /* Allow conversions between integral types and pointers only if
3333 there is no sign or zero extension involved.
3334 For targets were the precision of sizetype doesn't match that
3335 of pointers we need to allow arbitrary conversions from and
3337 if ((POINTER_TYPE_P (lhs_type)
3338 && INTEGRAL_TYPE_P (rhs1_type)
3339 && (TYPE_PRECISION (lhs_type) >= TYPE_PRECISION (rhs1_type)
3340 || rhs1_type == sizetype))
3341 || (POINTER_TYPE_P (rhs1_type)
3342 && INTEGRAL_TYPE_P (lhs_type)
3343 && (TYPE_PRECISION (rhs1_type) >= TYPE_PRECISION (lhs_type)
3344 || lhs_type == sizetype)))
3347 /* Allow conversion from integer to offset type and vice versa. */
3348 if ((TREE_CODE (lhs_type) == OFFSET_TYPE
3349 && TREE_CODE (rhs1_type) == INTEGER_TYPE)
3350 || (TREE_CODE (lhs_type) == INTEGER_TYPE
3351 && TREE_CODE (rhs1_type) == OFFSET_TYPE))
3354 /* Otherwise assert we are converting between types of the
3356 if (INTEGRAL_TYPE_P (lhs_type) != INTEGRAL_TYPE_P (rhs1_type))
3358 error ("invalid types in nop conversion");
3359 debug_generic_expr (lhs_type);
3360 debug_generic_expr (rhs1_type);
3367 case FIXED_CONVERT_EXPR:
3369 if (!valid_fixed_convert_types_p (lhs_type, rhs1_type)
3370 && !valid_fixed_convert_types_p (rhs1_type, lhs_type))
3372 error ("invalid types in fixed-point conversion");
3373 debug_generic_expr (lhs_type);
3374 debug_generic_expr (rhs1_type);
3383 if (!INTEGRAL_TYPE_P (rhs1_type) || !SCALAR_FLOAT_TYPE_P (lhs_type))
3385 error ("invalid types in conversion to floating point");
3386 debug_generic_expr (lhs_type);
3387 debug_generic_expr (rhs1_type);
3394 case FIX_TRUNC_EXPR:
3396 if (!INTEGRAL_TYPE_P (lhs_type) || !SCALAR_FLOAT_TYPE_P (rhs1_type))
3398 error ("invalid types in conversion to integer");
3399 debug_generic_expr (lhs_type);
3400 debug_generic_expr (rhs1_type);
3407 case TRUTH_NOT_EXPR:
3415 case NON_LVALUE_EXPR:
3417 case REDUC_MAX_EXPR:
3418 case REDUC_MIN_EXPR:
3419 case REDUC_PLUS_EXPR:
3420 case VEC_UNPACK_HI_EXPR:
3421 case VEC_UNPACK_LO_EXPR:
3422 case VEC_UNPACK_FLOAT_HI_EXPR:
3423 case VEC_UNPACK_FLOAT_LO_EXPR:
3430 /* For the remaining codes assert there is no conversion involved. */
3431 if (!useless_type_conversion_p (lhs_type, rhs1_type))
3433 error ("non-trivial conversion in unary operation");
3434 debug_generic_expr (lhs_type);
3435 debug_generic_expr (rhs1_type);
3442 /* Verify a gimple assignment statement STMT with a binary rhs.
3443 Returns true if anything is wrong. */
3446 verify_gimple_assign_binary (gimple stmt)
3448 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3449 tree lhs = gimple_assign_lhs (stmt);
3450 tree lhs_type = TREE_TYPE (lhs);
3451 tree rhs1 = gimple_assign_rhs1 (stmt);
3452 tree rhs1_type = TREE_TYPE (rhs1);
3453 tree rhs2 = gimple_assign_rhs2 (stmt);
3454 tree rhs2_type = TREE_TYPE (rhs2);
3456 if (!is_gimple_reg (lhs)
3458 && TREE_CODE (lhs_type) == COMPLEX_TYPE))
3460 error ("non-register as LHS of binary operation");
3464 if (!is_gimple_val (rhs1)
3465 || !is_gimple_val (rhs2))
3467 error ("invalid operands in binary operation");
3471 /* First handle operations that involve different types. */
3476 if (TREE_CODE (lhs_type) != COMPLEX_TYPE
3477 || !(INTEGRAL_TYPE_P (rhs1_type)
3478 || SCALAR_FLOAT_TYPE_P (rhs1_type))
3479 || !(INTEGRAL_TYPE_P (rhs2_type)
3480 || SCALAR_FLOAT_TYPE_P (rhs2_type)))
3482 error ("type mismatch in complex expression");
3483 debug_generic_expr (lhs_type);
3484 debug_generic_expr (rhs1_type);
3485 debug_generic_expr (rhs2_type);
3494 if (FIXED_POINT_TYPE_P (rhs1_type)
3495 && INTEGRAL_TYPE_P (rhs2_type)
3496 && useless_type_conversion_p (lhs_type, rhs1_type))
3503 if (!INTEGRAL_TYPE_P (rhs1_type)
3504 || !INTEGRAL_TYPE_P (rhs2_type)
3505 || !useless_type_conversion_p (lhs_type, rhs1_type))
3507 error ("type mismatch in shift expression");
3508 debug_generic_expr (lhs_type);
3509 debug_generic_expr (rhs1_type);
3510 debug_generic_expr (rhs2_type);
3517 case VEC_LSHIFT_EXPR:
3518 case VEC_RSHIFT_EXPR:
3520 if (TREE_CODE (rhs1_type) != VECTOR_TYPE
3521 || !(INTEGRAL_TYPE_P (TREE_TYPE (rhs1_type))
3522 || FIXED_POINT_TYPE_P (TREE_TYPE (rhs1_type)))
3523 || (!INTEGRAL_TYPE_P (rhs2_type)
3524 && (TREE_CODE (rhs2_type) != VECTOR_TYPE
3525 || !INTEGRAL_TYPE_P (TREE_TYPE (rhs2_type))))
3526 || !useless_type_conversion_p (lhs_type, rhs1_type))
3528 error ("type mismatch in vector shift expression");
3529 debug_generic_expr (lhs_type);
3530 debug_generic_expr (rhs1_type);
3531 debug_generic_expr (rhs2_type);
3538 case POINTER_PLUS_EXPR:
3540 if (!POINTER_TYPE_P (rhs1_type)
3541 || !useless_type_conversion_p (lhs_type, rhs1_type)
3542 || !useless_type_conversion_p (sizetype, rhs2_type))
3544 error ("type mismatch in pointer plus expression");
3545 debug_generic_stmt (lhs_type);
3546 debug_generic_stmt (rhs1_type);
3547 debug_generic_stmt (rhs2_type);
3554 case TRUTH_ANDIF_EXPR:
3555 case TRUTH_ORIF_EXPR:
3558 case TRUTH_AND_EXPR:
3560 case TRUTH_XOR_EXPR:
3562 /* We allow any kind of integral typed argument and result. */
3563 if (!INTEGRAL_TYPE_P (rhs1_type)
3564 || !INTEGRAL_TYPE_P (rhs2_type)
3565 || !INTEGRAL_TYPE_P (lhs_type))
3567 error ("type mismatch in binary truth expression");
3568 debug_generic_expr (lhs_type);
3569 debug_generic_expr (rhs1_type);
3570 debug_generic_expr (rhs2_type);
3583 case UNORDERED_EXPR:
3591 /* Comparisons are also binary, but the result type is not
3592 connected to the operand types. */
3593 return verify_gimple_comparison (lhs_type, rhs1, rhs2);
3598 if (POINTER_TYPE_P (lhs_type)
3599 || POINTER_TYPE_P (rhs1_type)
3600 || POINTER_TYPE_P (rhs2_type))
3602 error ("invalid (pointer) operands to plus/minus");
3606 /* Continue with generic binary expression handling. */
3611 case TRUNC_DIV_EXPR:
3613 case FLOOR_DIV_EXPR:
3614 case ROUND_DIV_EXPR:
3615 case TRUNC_MOD_EXPR:
3617 case FLOOR_MOD_EXPR:
3618 case ROUND_MOD_EXPR:
3620 case EXACT_DIV_EXPR:
3626 case WIDEN_SUM_EXPR:
3627 case WIDEN_MULT_EXPR:
3628 case VEC_WIDEN_MULT_HI_EXPR:
3629 case VEC_WIDEN_MULT_LO_EXPR:
3630 case VEC_PACK_TRUNC_EXPR:
3631 case VEC_PACK_SAT_EXPR:
3632 case VEC_PACK_FIX_TRUNC_EXPR:
3633 case VEC_EXTRACT_EVEN_EXPR:
3634 case VEC_EXTRACT_ODD_EXPR:
3635 case VEC_INTERLEAVE_HIGH_EXPR:
3636 case VEC_INTERLEAVE_LOW_EXPR:
3637 /* Continue with generic binary expression handling. */
3644 if (!useless_type_conversion_p (lhs_type, rhs1_type)
3645 || !useless_type_conversion_p (lhs_type, rhs2_type))
3647 error ("type mismatch in binary expression");
3648 debug_generic_stmt (lhs_type);
3649 debug_generic_stmt (rhs1_type);
3650 debug_generic_stmt (rhs2_type);
3657 /* Verify a gimple assignment statement STMT with a single rhs.
3658 Returns true if anything is wrong. */
3661 verify_gimple_assign_single (gimple stmt)
3663 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3664 tree lhs = gimple_assign_lhs (stmt);
3665 tree lhs_type = TREE_TYPE (lhs);
3666 tree rhs1 = gimple_assign_rhs1 (stmt);
3667 tree rhs1_type = TREE_TYPE (rhs1);
3670 if (!useless_type_conversion_p (lhs_type, rhs1_type))
3672 error ("non-trivial conversion at assignment");
3673 debug_generic_expr (lhs_type);
3674 debug_generic_expr (rhs1_type);
3678 if (handled_component_p (lhs))
3679 res |= verify_types_in_gimple_reference (lhs);
3681 /* Special codes we cannot handle via their class. */
3686 tree op = TREE_OPERAND (rhs1, 0);
3687 if (!is_gimple_addressable (op))
3689 error ("invalid operand in unary expression");
3693 if (!one_pointer_to_useless_type_conversion_p (lhs_type, TREE_TYPE (op))
3694 /* FIXME: a longstanding wart, &a == &a[0]. */
3695 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3696 || !one_pointer_to_useless_type_conversion_p (lhs_type,
3697 TREE_TYPE (TREE_TYPE (op)))))
3699 error ("type mismatch in address expression");
3700 debug_generic_stmt (lhs_type);
3701 debug_generic_stmt (TYPE_POINTER_TO (TREE_TYPE (op)));
3705 return verify_types_in_gimple_reference (op);
3712 case ALIGN_INDIRECT_REF:
3713 case MISALIGNED_INDIRECT_REF:
3715 case ARRAY_RANGE_REF:
3716 case VIEW_CONVERT_EXPR:
3719 case TARGET_MEM_REF:
3720 if (!is_gimple_reg (lhs)
3721 && is_gimple_reg_type (TREE_TYPE (lhs)))
3723 error ("invalid rhs for gimple memory store");
3724 debug_generic_stmt (lhs);
3725 debug_generic_stmt (rhs1);
3728 return res || verify_types_in_gimple_reference (rhs1);
3740 /* tcc_declaration */
3745 if (!is_gimple_reg (lhs)
3746 && !is_gimple_reg (rhs1)
3747 && is_gimple_reg_type (TREE_TYPE (lhs)))
3749 error ("invalid rhs for gimple memory store");
3750 debug_generic_stmt (lhs);
3751 debug_generic_stmt (rhs1);
3760 case WITH_SIZE_EXPR:
3763 case POLYNOMIAL_CHREC:
3766 case REALIGN_LOAD_EXPR:
3776 /* Verify the contents of a GIMPLE_ASSIGN STMT. Returns true when there
3777 is a problem, otherwise false. */
3780 verify_gimple_assign (gimple stmt)
3782 switch (gimple_assign_rhs_class (stmt))
3784 case GIMPLE_SINGLE_RHS:
3785 return verify_gimple_assign_single (stmt);
3787 case GIMPLE_UNARY_RHS:
3788 return verify_gimple_assign_unary (stmt);
3790 case GIMPLE_BINARY_RHS:
3791 return verify_gimple_assign_binary (stmt);
3798 /* Verify the contents of a GIMPLE_RETURN STMT. Returns true when there
3799 is a problem, otherwise false. */
3802 verify_gimple_return (gimple stmt)
3804 tree op = gimple_return_retval (stmt);
3805 tree restype = TREE_TYPE (TREE_TYPE (cfun->decl));
3807 /* We cannot test for present return values as we do not fix up missing
3808 return values from the original source. */
3812 if (!is_gimple_val (op)
3813 && TREE_CODE (op) != RESULT_DECL)
3815 error ("invalid operand in return statement");
3816 debug_generic_stmt (op);
3820 if (!useless_type_conversion_p (restype, TREE_TYPE (op))
3821 /* ??? With C++ we can have the situation that the result
3822 decl is a reference type while the return type is an aggregate. */
3823 && !(TREE_CODE (op) == RESULT_DECL
3824 && TREE_CODE (TREE_TYPE (op)) == REFERENCE_TYPE
3825 && useless_type_conversion_p (restype, TREE_TYPE (TREE_TYPE (op)))))
3827 error ("invalid conversion in return statement");
3828 debug_generic_stmt (restype);
3829 debug_generic_stmt (TREE_TYPE (op));
3837 /* Verify the contents of a GIMPLE_GOTO STMT. Returns true when there
3838 is a problem, otherwise false. */
3841 verify_gimple_goto (gimple stmt)
3843 tree dest = gimple_goto_dest (stmt);
3845 /* ??? We have two canonical forms of direct goto destinations, a
3846 bare LABEL_DECL and an ADDR_EXPR of a LABEL_DECL. */
3847 if (TREE_CODE (dest) != LABEL_DECL
3848 && (!is_gimple_val (dest)
3849 || !POINTER_TYPE_P (TREE_TYPE (dest))))
3851 error ("goto destination is neither a label nor a pointer");
3858 /* Verify the contents of a GIMPLE_SWITCH STMT. Returns true when there
3859 is a problem, otherwise false. */
3862 verify_gimple_switch (gimple stmt)
3864 if (!is_gimple_val (gimple_switch_index (stmt)))
3866 error ("invalid operand to switch statement");
3867 debug_generic_stmt (gimple_switch_index (stmt));
3875 /* Verify the contents of a GIMPLE_PHI. Returns true if there is a problem,
3876 and false otherwise. */
3879 verify_gimple_phi (gimple stmt)
3881 tree type = TREE_TYPE (gimple_phi_result (stmt));
3884 if (!is_gimple_variable (gimple_phi_result (stmt)))
3886 error ("Invalid PHI result");
3890 for (i = 0; i < gimple_phi_num_args (stmt); i++)
3892 tree arg = gimple_phi_arg_def (stmt, i);
3893 if ((is_gimple_reg (gimple_phi_result (stmt))
3894 && !is_gimple_val (arg))
3895 || (!is_gimple_reg (gimple_phi_result (stmt))
3896 && !is_gimple_addressable (arg)))
3898 error ("Invalid PHI argument");
3899 debug_generic_stmt (arg);
3902 if (!useless_type_conversion_p (type, TREE_TYPE (arg)))
3904 error ("Incompatible types in PHI argument");
3905 debug_generic_stmt (type);
3906 debug_generic_stmt (TREE_TYPE (arg));
3915 /* Verify the GIMPLE statement STMT. Returns true if there is an
3916 error, otherwise false. */
3919 verify_types_in_gimple_stmt (gimple stmt)
3921 if (is_gimple_omp (stmt))
3923 /* OpenMP directives are validated by the FE and never operated
3924 on by the optimizers. Furthermore, GIMPLE_OMP_FOR may contain
3925 non-gimple expressions when the main index variable has had
3926 its address taken. This does not affect the loop itself
3927 because the header of an GIMPLE_OMP_FOR is merely used to determine
3928 how to setup the parallel iteration. */
3932 switch (gimple_code (stmt))
3935 return verify_gimple_assign (stmt);
3938 return TREE_CODE (gimple_label_label (stmt)) != LABEL_DECL;
3941 return verify_gimple_call (stmt);
3944 return verify_gimple_comparison (boolean_type_node,
3945 gimple_cond_lhs (stmt),
3946 gimple_cond_rhs (stmt));
3949 return verify_gimple_goto (stmt);
3952 return verify_gimple_switch (stmt);
3955 return verify_gimple_return (stmt);
3960 case GIMPLE_CHANGE_DYNAMIC_TYPE:
3961 return (!is_gimple_val (gimple_cdt_location (stmt))
3962 || !POINTER_TYPE_P (TREE_TYPE (gimple_cdt_location (stmt))));
3965 return verify_gimple_phi (stmt);
3967 /* Tuples that do not have tree operands. */
3970 case GIMPLE_PREDICT:
3978 /* Verify the GIMPLE statements inside the sequence STMTS. */
3981 verify_types_in_gimple_seq_2 (gimple_seq stmts)
3983 gimple_stmt_iterator ittr;
3986 for (ittr = gsi_start (stmts); !gsi_end_p (ittr); gsi_next (&ittr))
3988 gimple stmt = gsi_stmt (ittr);
3990 switch (gimple_code (stmt))
3993 err |= verify_types_in_gimple_seq_2 (gimple_bind_body (stmt));
3997 err |= verify_types_in_gimple_seq_2 (gimple_try_eval (stmt));
3998 err |= verify_types_in_gimple_seq_2 (gimple_try_cleanup (stmt));
4001 case GIMPLE_EH_FILTER:
4002 err |= verify_types_in_gimple_seq_2 (gimple_eh_filter_failure (stmt));
4006 err |= verify_types_in_gimple_seq_2 (gimple_catch_handler (stmt));
4011 bool err2 = verify_types_in_gimple_stmt (stmt);
4013 debug_gimple_stmt (stmt);
4023 /* Verify the GIMPLE statements inside the statement list STMTS. */
4026 verify_types_in_gimple_seq (gimple_seq stmts)
4028 if (verify_types_in_gimple_seq_2 (stmts))
4029 internal_error ("verify_gimple failed");
4033 /* Verify STMT, return true if STMT is not in GIMPLE form.
4034 TODO: Implement type checking. */
4037 verify_stmt (gimple_stmt_iterator *gsi)
4040 struct walk_stmt_info wi;
4041 bool last_in_block = gsi_one_before_end_p (*gsi);
4042 gimple stmt = gsi_stmt (*gsi);
4044 if (is_gimple_omp (stmt))
4046 /* OpenMP directives are validated by the FE and never operated
4047 on by the optimizers. Furthermore, GIMPLE_OMP_FOR may contain
4048 non-gimple expressions when the main index variable has had
4049 its address taken. This does not affect the loop itself
4050 because the header of an GIMPLE_OMP_FOR is merely used to determine
4051 how to setup the parallel iteration. */
4055 /* FIXME. The C frontend passes unpromoted arguments in case it
4056 didn't see a function declaration before the call. */
4057 if (is_gimple_call (stmt))
4061 if (!is_gimple_call_addr (gimple_call_fn (stmt)))
4063 error ("invalid function in call statement");
4067 decl = gimple_call_fndecl (stmt);
4069 && TREE_CODE (decl) == FUNCTION_DECL
4070 && DECL_LOOPING_CONST_OR_PURE_P (decl)
4071 && (!DECL_PURE_P (decl))
4072 && (!TREE_READONLY (decl)))
4074 error ("invalid pure const state for function");
4079 memset (&wi, 0, sizeof (wi));
4080 addr = walk_gimple_op (gsi_stmt (*gsi), verify_expr, &wi);
4083 debug_generic_expr (addr);
4084 inform (input_location, "in statement");
4085 debug_gimple_stmt (stmt);
4089 /* If the statement is marked as part of an EH region, then it is
4090 expected that the statement could throw. Verify that when we
4091 have optimizations that simplify statements such that we prove
4092 that they cannot throw, that we update other data structures
4094 if (lookup_stmt_eh_region (stmt) >= 0)
4096 if (!stmt_could_throw_p (stmt))
4098 error ("statement marked for throw, but doesn%'t");
4101 if (!last_in_block && stmt_can_throw_internal (stmt))
4103 error ("statement marked for throw in middle of block");
4111 debug_gimple_stmt (stmt);
4116 /* Return true when the T can be shared. */
4119 tree_node_can_be_shared (tree t)
4121 if (IS_TYPE_OR_DECL_P (t)
4122 || is_gimple_min_invariant (t)
4123 || TREE_CODE (t) == SSA_NAME
4124 || t == error_mark_node
4125 || TREE_CODE (t) == IDENTIFIER_NODE)
4128 if (TREE_CODE (t) == CASE_LABEL_EXPR)
4131 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4132 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4133 || TREE_CODE (t) == COMPONENT_REF
4134 || TREE_CODE (t) == REALPART_EXPR
4135 || TREE_CODE (t) == IMAGPART_EXPR)
4136 t = TREE_OPERAND (t, 0);
4145 /* Called via walk_gimple_stmt. Verify tree sharing. */
4148 verify_node_sharing (tree *tp, int *walk_subtrees, void *data)
4150 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
4151 struct pointer_set_t *visited = (struct pointer_set_t *) wi->info;
4153 if (tree_node_can_be_shared (*tp))
4155 *walk_subtrees = false;
4159 if (pointer_set_insert (visited, *tp))
4166 static bool eh_error_found;
4168 verify_eh_throw_stmt_node (void **slot, void *data)
4170 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4171 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4173 if (!pointer_set_contains (visited, node->stmt))
4175 error ("Dead STMT in EH table");
4176 debug_gimple_stmt (node->stmt);
4177 eh_error_found = true;
4183 /* Verify the GIMPLE statements in every basic block. */
4189 gimple_stmt_iterator gsi;
4191 struct pointer_set_t *visited, *visited_stmts;
4193 struct walk_stmt_info wi;
4195 timevar_push (TV_TREE_STMT_VERIFY);
4196 visited = pointer_set_create ();
4197 visited_stmts = pointer_set_create ();
4199 memset (&wi, 0, sizeof (wi));
4200 wi.info = (void *) visited;
4207 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4209 phi = gsi_stmt (gsi);
4210 pointer_set_insert (visited_stmts, phi);
4211 if (gimple_bb (phi) != bb)
4213 error ("gimple_bb (phi) is set to a wrong basic block");
4217 for (i = 0; i < gimple_phi_num_args (phi); i++)
4219 tree t = gimple_phi_arg_def (phi, i);
4224 error ("missing PHI def");
4225 debug_gimple_stmt (phi);
4229 /* Addressable variables do have SSA_NAMEs but they
4230 are not considered gimple values. */
4231 else if (TREE_CODE (t) != SSA_NAME
4232 && TREE_CODE (t) != FUNCTION_DECL
4233 && !is_gimple_min_invariant (t))
4235 error ("PHI argument is not a GIMPLE value");
4236 debug_gimple_stmt (phi);
4237 debug_generic_expr (t);
4241 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4244 error ("incorrect sharing of tree nodes");
4245 debug_gimple_stmt (phi);
4246 debug_generic_expr (addr);
4252 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
4254 gimple stmt = gsi_stmt (gsi);
4256 if (gimple_code (stmt) == GIMPLE_WITH_CLEANUP_EXPR
4257 || gimple_code (stmt) == GIMPLE_BIND)
4259 error ("invalid GIMPLE statement");
4260 debug_gimple_stmt (stmt);
4264 pointer_set_insert (visited_stmts, stmt);
4266 if (gimple_bb (stmt) != bb)
4268 error ("gimple_bb (stmt) is set to a wrong basic block");
4272 if (gimple_code (stmt) == GIMPLE_LABEL)
4274 tree decl = gimple_label_label (stmt);
4275 int uid = LABEL_DECL_UID (decl);
4278 || VEC_index (basic_block, label_to_block_map, uid) != bb)
4280 error ("incorrect entry in label_to_block_map.\n");
4285 err |= verify_stmt (&gsi);
4286 addr = walk_gimple_op (gsi_stmt (gsi), verify_node_sharing, &wi);
4289 error ("incorrect sharing of tree nodes");
4290 debug_gimple_stmt (stmt);
4291 debug_generic_expr (addr);
4298 eh_error_found = false;
4299 if (get_eh_throw_stmt_table (cfun))
4300 htab_traverse (get_eh_throw_stmt_table (cfun),
4301 verify_eh_throw_stmt_node,
4304 if (err | eh_error_found)
4305 internal_error ("verify_stmts failed");
4307 pointer_set_destroy (visited);
4308 pointer_set_destroy (visited_stmts);
4309 verify_histograms ();
4310 timevar_pop (TV_TREE_STMT_VERIFY);
4314 /* Verifies that the flow information is OK. */
4317 gimple_verify_flow_info (void)
4321 gimple_stmt_iterator gsi;
4326 if (ENTRY_BLOCK_PTR->il.gimple)
4328 error ("ENTRY_BLOCK has IL associated with it");
4332 if (EXIT_BLOCK_PTR->il.gimple)
4334 error ("EXIT_BLOCK has IL associated with it");
4338 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4339 if (e->flags & EDGE_FALLTHRU)
4341 error ("fallthru to exit from bb %d", e->src->index);
4347 bool found_ctrl_stmt = false;
4351 /* Skip labels on the start of basic block. */
4352 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4355 gimple prev_stmt = stmt;
4357 stmt = gsi_stmt (gsi);
4359 if (gimple_code (stmt) != GIMPLE_LABEL)
4362 label = gimple_label_label (stmt);
4363 if (prev_stmt && DECL_NONLOCAL (label))
4365 error ("nonlocal label ");
4366 print_generic_expr (stderr, label, 0);
4367 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4372 if (label_to_block (label) != bb)
4375 print_generic_expr (stderr, label, 0);
4376 fprintf (stderr, " to block does not match in bb %d",
4381 if (decl_function_context (label) != current_function_decl)
4384 print_generic_expr (stderr, label, 0);
4385 fprintf (stderr, " has incorrect context in bb %d",
4391 /* Verify that body of basic block BB is free of control flow. */
4392 for (; !gsi_end_p (gsi); gsi_next (&gsi))
4394 gimple stmt = gsi_stmt (gsi);
4396 if (found_ctrl_stmt)
4398 error ("control flow in the middle of basic block %d",
4403 if (stmt_ends_bb_p (stmt))
4404 found_ctrl_stmt = true;
4406 if (gimple_code (stmt) == GIMPLE_LABEL)
4409 print_generic_expr (stderr, gimple_label_label (stmt), 0);
4410 fprintf (stderr, " in the middle of basic block %d", bb->index);
4415 gsi = gsi_last_bb (bb);
4416 if (gsi_end_p (gsi))
4419 stmt = gsi_stmt (gsi);
4421 err |= verify_eh_edges (stmt);
4423 if (is_ctrl_stmt (stmt))
4425 FOR_EACH_EDGE (e, ei, bb->succs)
4426 if (e->flags & EDGE_FALLTHRU)
4428 error ("fallthru edge after a control statement in bb %d",
4434 if (gimple_code (stmt) != GIMPLE_COND)
4436 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4437 after anything else but if statement. */
4438 FOR_EACH_EDGE (e, ei, bb->succs)
4439 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4441 error ("true/false edge after a non-GIMPLE_COND in bb %d",
4447 switch (gimple_code (stmt))
4454 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4458 || !(true_edge->flags & EDGE_TRUE_VALUE)
4459 || !(false_edge->flags & EDGE_FALSE_VALUE)
4460 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4461 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4462 || EDGE_COUNT (bb->succs) >= 3)
4464 error ("wrong outgoing edge flags at end of bb %d",
4472 if (simple_goto_p (stmt))
4474 error ("explicit goto at end of bb %d", bb->index);
4479 /* FIXME. We should double check that the labels in the
4480 destination blocks have their address taken. */
4481 FOR_EACH_EDGE (e, ei, bb->succs)
4482 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4483 | EDGE_FALSE_VALUE))
4484 || !(e->flags & EDGE_ABNORMAL))
4486 error ("wrong outgoing edge flags at end of bb %d",
4494 if (!single_succ_p (bb)
4495 || (single_succ_edge (bb)->flags
4496 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4497 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4499 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4502 if (single_succ (bb) != EXIT_BLOCK_PTR)
4504 error ("return edge does not point to exit in bb %d",
4516 n = gimple_switch_num_labels (stmt);
4518 /* Mark all the destination basic blocks. */
4519 for (i = 0; i < n; ++i)
4521 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4522 basic_block label_bb = label_to_block (lab);
4523 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4524 label_bb->aux = (void *)1;
4527 /* Verify that the case labels are sorted. */
4528 prev = gimple_switch_label (stmt, 0);
4529 for (i = 1; i < n; ++i)
4531 tree c = gimple_switch_label (stmt, i);
4534 error ("found default case not at the start of "
4540 && !tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4542 error ("case labels not sorted: ");
4543 print_generic_expr (stderr, prev, 0);
4544 fprintf (stderr," is greater than ");
4545 print_generic_expr (stderr, c, 0);
4546 fprintf (stderr," but comes before it.\n");
4551 /* VRP will remove the default case if it can prove it will
4552 never be executed. So do not verify there always exists
4553 a default case here. */
4555 FOR_EACH_EDGE (e, ei, bb->succs)
4559 error ("extra outgoing edge %d->%d",
4560 bb->index, e->dest->index);
4564 e->dest->aux = (void *)2;
4565 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4566 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4568 error ("wrong outgoing edge flags at end of bb %d",
4574 /* Check that we have all of them. */
4575 for (i = 0; i < n; ++i)
4577 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4578 basic_block label_bb = label_to_block (lab);
4580 if (label_bb->aux != (void *)2)
4582 error ("missing edge %i->%i", bb->index, label_bb->index);
4587 FOR_EACH_EDGE (e, ei, bb->succs)
4588 e->dest->aux = (void *)0;
4595 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4596 verify_dominators (CDI_DOMINATORS);
4602 /* Updates phi nodes after creating a forwarder block joined
4603 by edge FALLTHRU. */
4606 gimple_make_forwarder_block (edge fallthru)
4610 basic_block dummy, bb;
4612 gimple_stmt_iterator gsi;
4614 dummy = fallthru->src;
4615 bb = fallthru->dest;
4617 if (single_pred_p (bb))
4620 /* If we redirected a branch we must create new PHI nodes at the
4622 for (gsi = gsi_start_phis (dummy); !gsi_end_p (gsi); gsi_next (&gsi))
4624 gimple phi, new_phi;
4626 phi = gsi_stmt (gsi);
4627 var = gimple_phi_result (phi);
4628 new_phi = create_phi_node (var, bb);
4629 SSA_NAME_DEF_STMT (var) = new_phi;
4630 gimple_phi_set_result (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4631 add_phi_arg (new_phi, gimple_phi_result (phi), fallthru);
4634 /* Add the arguments we have stored on edges. */
4635 FOR_EACH_EDGE (e, ei, bb->preds)
4640 flush_pending_stmts (e);
4645 /* Return a non-special label in the head of basic block BLOCK.
4646 Create one if it doesn't exist. */
4649 gimple_block_label (basic_block bb)
4651 gimple_stmt_iterator i, s = gsi_start_bb (bb);
4656 for (i = s; !gsi_end_p (i); first = false, gsi_next (&i))
4658 stmt = gsi_stmt (i);
4659 if (gimple_code (stmt) != GIMPLE_LABEL)
4661 label = gimple_label_label (stmt);
4662 if (!DECL_NONLOCAL (label))
4665 gsi_move_before (&i, &s);
4670 label = create_artificial_label ();
4671 stmt = gimple_build_label (label);
4672 gsi_insert_before (&s, stmt, GSI_NEW_STMT);
4677 /* Attempt to perform edge redirection by replacing a possibly complex
4678 jump instruction by a goto or by removing the jump completely.
4679 This can apply only if all edges now point to the same block. The
4680 parameters and return values are equivalent to
4681 redirect_edge_and_branch. */
4684 gimple_try_redirect_by_replacing_jump (edge e, basic_block target)
4686 basic_block src = e->src;
4687 gimple_stmt_iterator i;
4690 /* We can replace or remove a complex jump only when we have exactly
4692 if (EDGE_COUNT (src->succs) != 2
4693 /* Verify that all targets will be TARGET. Specifically, the
4694 edge that is not E must also go to TARGET. */
4695 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4698 i = gsi_last_bb (src);
4702 stmt = gsi_stmt (i);
4704 if (gimple_code (stmt) == GIMPLE_COND || gimple_code (stmt) == GIMPLE_SWITCH)
4706 gsi_remove (&i, true);
4707 e = ssa_redirect_edge (e, target);
4708 e->flags = EDGE_FALLTHRU;
4716 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4717 edge representing the redirected branch. */
4720 gimple_redirect_edge_and_branch (edge e, basic_block dest)
4722 basic_block bb = e->src;
4723 gimple_stmt_iterator gsi;
4727 if (e->flags & EDGE_ABNORMAL)
4730 if (e->src != ENTRY_BLOCK_PTR
4731 && (ret = gimple_try_redirect_by_replacing_jump (e, dest)))
4734 if (e->dest == dest)
4737 gsi = gsi_last_bb (bb);
4738 stmt = gsi_end_p (gsi) ? NULL : gsi_stmt (gsi);
4740 switch (stmt ? gimple_code (stmt) : ERROR_MARK)
4743 /* For COND_EXPR, we only need to redirect the edge. */
4747 /* No non-abnormal edges should lead from a non-simple goto, and
4748 simple ones should be represented implicitly. */
4753 tree label = gimple_block_label (dest);
4754 tree cases = get_cases_for_edge (e, stmt);
4756 /* If we have a list of cases associated with E, then use it
4757 as it's a lot faster than walking the entire case vector. */
4760 edge e2 = find_edge (e->src, dest);
4767 CASE_LABEL (cases) = label;
4768 cases = TREE_CHAIN (cases);
4771 /* If there was already an edge in the CFG, then we need
4772 to move all the cases associated with E to E2. */
4775 tree cases2 = get_cases_for_edge (e2, stmt);
4777 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4778 TREE_CHAIN (cases2) = first;
4783 size_t i, n = gimple_switch_num_labels (stmt);
4785 for (i = 0; i < n; i++)
4787 tree elt = gimple_switch_label (stmt, i);
4788 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4789 CASE_LABEL (elt) = label;
4797 gsi_remove (&gsi, true);
4798 e->flags |= EDGE_FALLTHRU;
4801 case GIMPLE_OMP_RETURN:
4802 case GIMPLE_OMP_CONTINUE:
4803 case GIMPLE_OMP_SECTIONS_SWITCH:
4804 case GIMPLE_OMP_FOR:
4805 /* The edges from OMP constructs can be simply redirected. */
4809 /* Otherwise it must be a fallthru edge, and we don't need to
4810 do anything besides redirecting it. */
4811 gcc_assert (e->flags & EDGE_FALLTHRU);
4815 /* Update/insert PHI nodes as necessary. */
4817 /* Now update the edges in the CFG. */
4818 e = ssa_redirect_edge (e, dest);
4823 /* Returns true if it is possible to remove edge E by redirecting
4824 it to the destination of the other edge from E->src. */
4827 gimple_can_remove_branch_p (const_edge e)
4829 if (e->flags & EDGE_ABNORMAL)
4835 /* Simple wrapper, as we can always redirect fallthru edges. */
4838 gimple_redirect_edge_and_branch_force (edge e, basic_block dest)
4840 e = gimple_redirect_edge_and_branch (e, dest);
4847 /* Splits basic block BB after statement STMT (but at least after the
4848 labels). If STMT is NULL, BB is split just after the labels. */
4851 gimple_split_block (basic_block bb, void *stmt)
4853 gimple_stmt_iterator gsi;
4854 gimple_stmt_iterator gsi_tgt;
4861 new_bb = create_empty_bb (bb);
4863 /* Redirect the outgoing edges. */
4864 new_bb->succs = bb->succs;
4866 FOR_EACH_EDGE (e, ei, new_bb->succs)
4869 if (stmt && gimple_code ((gimple) stmt) == GIMPLE_LABEL)
4872 /* Move everything from GSI to the new basic block. */
4873 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4875 act = gsi_stmt (gsi);
4876 if (gimple_code (act) == GIMPLE_LABEL)
4889 if (gsi_end_p (gsi))
4892 /* Split the statement list - avoid re-creating new containers as this
4893 brings ugly quadratic memory consumption in the inliner.
4894 (We are still quadratic since we need to update stmt BB pointers,
4896 list = gsi_split_seq_before (&gsi);
4897 set_bb_seq (new_bb, list);
4898 for (gsi_tgt = gsi_start (list);
4899 !gsi_end_p (gsi_tgt); gsi_next (&gsi_tgt))
4900 gimple_set_bb (gsi_stmt (gsi_tgt), new_bb);
4906 /* Moves basic block BB after block AFTER. */
4909 gimple_move_block_after (basic_block bb, basic_block after)
4911 if (bb->prev_bb == after)
4915 link_block (bb, after);
4921 /* Return true if basic_block can be duplicated. */
4924 gimple_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
4926 gimple_seq_node last = gimple_seq_last (bb_seq (bb));
4927 /* We cannot duplicate GIMPLE_RESXs due to expander limitations. */
4928 if (last && gimple_code (last->stmt) == GIMPLE_RESX)
4933 /* Create a duplicate of the basic block BB. NOTE: This does not
4934 preserve SSA form. */
4937 gimple_duplicate_bb (basic_block bb)
4940 gimple_stmt_iterator gsi, gsi_tgt;
4941 gimple_seq phis = phi_nodes (bb);
4942 gimple phi, stmt, copy;
4944 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
4946 /* Copy the PHI nodes. We ignore PHI node arguments here because
4947 the incoming edges have not been setup yet. */
4948 for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi))
4950 phi = gsi_stmt (gsi);
4951 copy = create_phi_node (gimple_phi_result (phi), new_bb);
4952 create_new_def_for (gimple_phi_result (copy), copy,
4953 gimple_phi_result_ptr (copy));
4956 gsi_tgt = gsi_start_bb (new_bb);
4957 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4959 def_operand_p def_p;
4960 ssa_op_iter op_iter;
4963 stmt = gsi_stmt (gsi);
4964 if (gimple_code (stmt) == GIMPLE_LABEL)
4967 /* Create a new copy of STMT and duplicate STMT's virtual
4969 copy = gimple_copy (stmt);
4970 gsi_insert_after (&gsi_tgt, copy, GSI_NEW_STMT);
4971 copy_virtual_operands (copy, stmt);
4972 region = lookup_stmt_eh_region (stmt);
4974 add_stmt_to_eh_region (copy, region);
4975 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
4977 /* Create new names for all the definitions created by COPY and
4978 add replacement mappings for each new name. */
4979 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
4980 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
4986 /* Adds phi node arguments for edge E_COPY after basic block duplication. */
4989 add_phi_args_after_copy_edge (edge e_copy)
4991 basic_block bb, bb_copy = e_copy->src, dest;
4994 gimple phi, phi_copy;
4996 gimple_stmt_iterator psi, psi_copy;
4998 if (gimple_seq_empty_p (phi_nodes (e_copy->dest)))
5001 bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
5003 if (e_copy->dest->flags & BB_DUPLICATED)
5004 dest = get_bb_original (e_copy->dest);
5006 dest = e_copy->dest;
5008 e = find_edge (bb, dest);
5011 /* During loop unrolling the target of the latch edge is copied.
5012 In this case we are not looking for edge to dest, but to
5013 duplicated block whose original was dest. */
5014 FOR_EACH_EDGE (e, ei, bb->succs)
5016 if ((e->dest->flags & BB_DUPLICATED)
5017 && get_bb_original (e->dest) == dest)
5021 gcc_assert (e != NULL);
5024 for (psi = gsi_start_phis (e->dest),
5025 psi_copy = gsi_start_phis (e_copy->dest);
5027 gsi_next (&psi), gsi_next (&psi_copy))
5029 phi = gsi_stmt (psi);
5030 phi_copy = gsi_stmt (psi_copy);
5031 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5032 add_phi_arg (phi_copy, def, e_copy);
5037 /* Basic block BB_COPY was created by code duplication. Add phi node
5038 arguments for edges going out of BB_COPY. The blocks that were
5039 duplicated have BB_DUPLICATED set. */
5042 add_phi_args_after_copy_bb (basic_block bb_copy)
5047 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5049 add_phi_args_after_copy_edge (e_copy);
5053 /* Blocks in REGION_COPY array of length N_REGION were created by
5054 duplication of basic blocks. Add phi node arguments for edges
5055 going from these blocks. If E_COPY is not NULL, also add
5056 phi node arguments for its destination.*/
5059 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
5064 for (i = 0; i < n_region; i++)
5065 region_copy[i]->flags |= BB_DUPLICATED;
5067 for (i = 0; i < n_region; i++)
5068 add_phi_args_after_copy_bb (region_copy[i]);
5070 add_phi_args_after_copy_edge (e_copy);
5072 for (i = 0; i < n_region; i++)
5073 region_copy[i]->flags &= ~BB_DUPLICATED;
5076 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5077 important exit edge EXIT. By important we mean that no SSA name defined
5078 inside region is live over the other exit edges of the region. All entry
5079 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5080 to the duplicate of the region. SSA form, dominance and loop information
5081 is updated. The new basic blocks are stored to REGION_COPY in the same
5082 order as they had in REGION, provided that REGION_COPY is not NULL.
5083 The function returns false if it is unable to copy the region,
5087 gimple_duplicate_sese_region (edge entry, edge exit,
5088 basic_block *region, unsigned n_region,
5089 basic_block *region_copy)
5092 bool free_region_copy = false, copying_header = false;
5093 struct loop *loop = entry->dest->loop_father;
5095 VEC (basic_block, heap) *doms;
5097 int total_freq = 0, entry_freq = 0;
5098 gcov_type total_count = 0, entry_count = 0;
5100 if (!can_copy_bbs_p (region, n_region))
5103 /* Some sanity checking. Note that we do not check for all possible
5104 missuses of the functions. I.e. if you ask to copy something weird,
5105 it will work, but the state of structures probably will not be
5107 for (i = 0; i < n_region; i++)
5109 /* We do not handle subloops, i.e. all the blocks must belong to the
5111 if (region[i]->loop_father != loop)
5114 if (region[i] != entry->dest
5115 && region[i] == loop->header)
5119 set_loop_copy (loop, loop);
5121 /* In case the function is used for loop header copying (which is the primary
5122 use), ensure that EXIT and its copy will be new latch and entry edges. */
5123 if (loop->header == entry->dest)
5125 copying_header = true;
5126 set_loop_copy (loop, loop_outer (loop));
5128 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5131 for (i = 0; i < n_region; i++)
5132 if (region[i] != exit->src
5133 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5139 region_copy = XNEWVEC (basic_block, n_region);
5140 free_region_copy = true;
5143 gcc_assert (!need_ssa_update_p ());
5145 /* Record blocks outside the region that are dominated by something
5148 initialize_original_copy_tables ();
5150 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5152 if (entry->dest->count)
5154 total_count = entry->dest->count;
5155 entry_count = entry->count;
5156 /* Fix up corner cases, to avoid division by zero or creation of negative
5158 if (entry_count > total_count)
5159 entry_count = total_count;
5163 total_freq = entry->dest->frequency;
5164 entry_freq = EDGE_FREQUENCY (entry);
5165 /* Fix up corner cases, to avoid division by zero or creation of negative
5167 if (total_freq == 0)
5169 else if (entry_freq > total_freq)
5170 entry_freq = total_freq;
5173 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5174 split_edge_bb_loc (entry));
5177 scale_bbs_frequencies_gcov_type (region, n_region,
5178 total_count - entry_count,
5180 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5185 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5187 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5192 loop->header = exit->dest;
5193 loop->latch = exit->src;
5196 /* Redirect the entry and add the phi node arguments. */
5197 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5198 gcc_assert (redirected != NULL);
5199 flush_pending_stmts (entry);
5201 /* Concerning updating of dominators: We must recount dominators
5202 for entry block and its copy. Anything that is outside of the
5203 region, but was dominated by something inside needs recounting as
5205 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5206 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5207 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5208 VEC_free (basic_block, heap, doms);
5210 /* Add the other PHI node arguments. */
5211 add_phi_args_after_copy (region_copy, n_region, NULL);
5213 /* Update the SSA web. */
5214 update_ssa (TODO_update_ssa);
5216 if (free_region_copy)
5219 free_original_copy_tables ();
5223 /* Duplicates REGION consisting of N_REGION blocks. The new blocks
5224 are stored to REGION_COPY in the same order in that they appear
5225 in REGION, if REGION_COPY is not NULL. ENTRY is the entry to
5226 the region, EXIT an exit from it. The condition guarding EXIT
5227 is moved to ENTRY. Returns true if duplication succeeds, false
5253 gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNUSED,
5254 basic_block *region ATTRIBUTE_UNUSED, unsigned n_region ATTRIBUTE_UNUSED,
5255 basic_block *region_copy ATTRIBUTE_UNUSED)
5258 bool free_region_copy = false;
5259 struct loop *loop = exit->dest->loop_father;
5260 struct loop *orig_loop = entry->dest->loop_father;
5261 basic_block switch_bb, entry_bb, nentry_bb;
5262 VEC (basic_block, heap) *doms;
5263 int total_freq = 0, exit_freq = 0;
5264 gcov_type total_count = 0, exit_count = 0;
5265 edge exits[2], nexits[2], e;
5266 gimple_stmt_iterator gsi;
5270 gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5272 exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5274 if (!can_copy_bbs_p (region, n_region))
5277 /* Some sanity checking. Note that we do not check for all possible
5278 missuses of the functions. I.e. if you ask to copy something weird
5279 (e.g., in the example, if there is a jump from inside to the middle
5280 of some_code, or come_code defines some of the values used in cond)
5281 it will work, but the resulting code will not be correct. */
5282 for (i = 0; i < n_region; i++)
5284 /* We do not handle subloops, i.e. all the blocks must belong to the
5286 if (region[i]->loop_father != orig_loop)
5289 if (region[i] == orig_loop->latch)
5293 initialize_original_copy_tables ();
5294 set_loop_copy (orig_loop, loop);
5298 region_copy = XNEWVEC (basic_block, n_region);
5299 free_region_copy = true;
5302 gcc_assert (!need_ssa_update_p ());
5304 /* Record blocks outside the region that are dominated by something
5306 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5308 if (exit->src->count)
5310 total_count = exit->src->count;
5311 exit_count = exit->count;
5312 /* Fix up corner cases, to avoid division by zero or creation of negative
5314 if (exit_count > total_count)
5315 exit_count = total_count;
5319 total_freq = exit->src->frequency;
5320 exit_freq = EDGE_FREQUENCY (exit);
5321 /* Fix up corner cases, to avoid division by zero or creation of negative
5323 if (total_freq == 0)
5325 if (exit_freq > total_freq)
5326 exit_freq = total_freq;
5329 copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5330 split_edge_bb_loc (exit));
5333 scale_bbs_frequencies_gcov_type (region, n_region,
5334 total_count - exit_count,
5336 scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5341 scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5343 scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5346 /* Create the switch block, and put the exit condition to it. */
5347 entry_bb = entry->dest;
5348 nentry_bb = get_bb_copy (entry_bb);
5349 if (!last_stmt (entry->src)
5350 || !stmt_ends_bb_p (last_stmt (entry->src)))
5351 switch_bb = entry->src;
5353 switch_bb = split_edge (entry);
5354 set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5356 gsi = gsi_last_bb (switch_bb);
5357 cond_stmt = last_stmt (exit->src);
5358 gcc_assert (gimple_code (cond_stmt) == GIMPLE_COND);
5359 cond_stmt = gimple_copy (cond_stmt);
5360 gimple_cond_set_lhs (cond_stmt, unshare_expr (gimple_cond_lhs (cond_stmt)));
5361 gimple_cond_set_rhs (cond_stmt, unshare_expr (gimple_cond_rhs (cond_stmt)));
5362 gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
5364 sorig = single_succ_edge (switch_bb);
5365 sorig->flags = exits[1]->flags;
5366 snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5368 /* Register the new edge from SWITCH_BB in loop exit lists. */
5369 rescan_loop_exit (snew, true, false);
5371 /* Add the PHI node arguments. */
5372 add_phi_args_after_copy (region_copy, n_region, snew);
5374 /* Get rid of now superfluous conditions and associated edges (and phi node
5376 e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5377 PENDING_STMT (e) = NULL;
5378 e = redirect_edge_and_branch (nexits[1], nexits[0]->dest);
5379 PENDING_STMT (e) = NULL;
5381 /* Anything that is outside of the region, but was dominated by something
5382 inside needs to update dominance info. */
5383 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5384 VEC_free (basic_block, heap, doms);
5386 /* Update the SSA web. */
5387 update_ssa (TODO_update_ssa);
5389 if (free_region_copy)
5392 free_original_copy_tables ();
5396 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5397 adding blocks when the dominator traversal reaches EXIT. This
5398 function silently assumes that ENTRY strictly dominates EXIT. */
5401 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5402 VEC(basic_block,heap) **bbs_p)
5406 for (son = first_dom_son (CDI_DOMINATORS, entry);
5408 son = next_dom_son (CDI_DOMINATORS, son))
5410 VEC_safe_push (basic_block, heap, *bbs_p, son);
5412 gather_blocks_in_sese_region (son, exit, bbs_p);
5416 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5417 The duplicates are recorded in VARS_MAP. */
5420 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5423 tree t = *tp, new_t;
5424 struct function *f = DECL_STRUCT_FUNCTION (to_context);
5427 if (DECL_CONTEXT (t) == to_context)
5430 loc = pointer_map_contains (vars_map, t);
5434 loc = pointer_map_insert (vars_map, t);
5438 new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5439 f->local_decls = tree_cons (NULL_TREE, new_t, f->local_decls);
5443 gcc_assert (TREE_CODE (t) == CONST_DECL);
5444 new_t = copy_node (t);
5446 DECL_CONTEXT (new_t) = to_context;
5451 new_t = (tree) *loc;
5457 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5458 VARS_MAP maps old ssa names and var_decls to the new ones. */
5461 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5465 tree new_name, decl = SSA_NAME_VAR (name);
5467 gcc_assert (is_gimple_reg (name));
5469 loc = pointer_map_contains (vars_map, name);
5473 replace_by_duplicate_decl (&decl, vars_map, to_context);
5475 push_cfun (DECL_STRUCT_FUNCTION (to_context));
5476 if (gimple_in_ssa_p (cfun))
5477 add_referenced_var (decl);
5479 new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5480 if (SSA_NAME_IS_DEFAULT_DEF (name))
5481 set_default_def (decl, new_name);
5484 loc = pointer_map_insert (vars_map, name);
5488 new_name = (tree) *loc;
5499 struct pointer_map_t *vars_map;
5500 htab_t new_label_map;
5504 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5505 contained in *TP if it has been ORIG_BLOCK previously and change the
5506 DECL_CONTEXT of every local variable referenced in *TP. */
5509 move_stmt_op (tree *tp, int *walk_subtrees, void *data)
5511 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
5512 struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5516 /* We should never have TREE_BLOCK set on non-statements. */
5517 gcc_assert (!TREE_BLOCK (t));
5519 else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5521 if (TREE_CODE (t) == SSA_NAME)
5522 *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5523 else if (TREE_CODE (t) == LABEL_DECL)
5525 if (p->new_label_map)
5527 struct tree_map in, *out;
5529 out = (struct tree_map *)
5530 htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5535 DECL_CONTEXT (t) = p->to_context;
5537 else if (p->remap_decls_p)
5539 /* Replace T with its duplicate. T should no longer appear in the
5540 parent function, so this looks wasteful; however, it may appear
5541 in referenced_vars, and more importantly, as virtual operands of
5542 statements, and in alias lists of other variables. It would be
5543 quite difficult to expunge it from all those places. ??? It might
5544 suffice to do this for addressable variables. */
5545 if ((TREE_CODE (t) == VAR_DECL
5546 && !is_global_var (t))
5547 || TREE_CODE (t) == CONST_DECL)
5548 replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5551 && gimple_in_ssa_p (cfun))
5553 push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5554 add_referenced_var (*tp);
5560 else if (TYPE_P (t))
5566 /* Like move_stmt_op, but for gimple statements.
5568 Helper for move_block_to_fn. Set GIMPLE_BLOCK in every expression
5569 contained in the current statement in *GSI_P and change the
5570 DECL_CONTEXT of every local variable referenced in the current
5574 move_stmt_r (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
5575 struct walk_stmt_info *wi)
5577 struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5578 gimple stmt = gsi_stmt (*gsi_p);
5579 tree block = gimple_block (stmt);
5581 if (p->orig_block == NULL_TREE
5582 || block == p->orig_block
5583 || block == NULL_TREE)
5584 gimple_set_block (stmt, p->new_block);
5585 #ifdef ENABLE_CHECKING
5586 else if (block != p->new_block)
5588 while (block && block != p->orig_block)
5589 block = BLOCK_SUPERCONTEXT (block);
5594 if (is_gimple_omp (stmt)
5595 && gimple_code (stmt) != GIMPLE_OMP_RETURN
5596 && gimple_code (stmt) != GIMPLE_OMP_CONTINUE)
5598 /* Do not remap variables inside OMP directives. Variables
5599 referenced in clauses and directive header belong to the
5600 parent function and should not be moved into the child
5602 bool save_remap_decls_p = p->remap_decls_p;
5603 p->remap_decls_p = false;
5604 *handled_ops_p = true;
5606 walk_gimple_seq (gimple_omp_body (stmt), move_stmt_r, move_stmt_op, wi);
5608 p->remap_decls_p = save_remap_decls_p;
5614 /* Marks virtual operands of all statements in basic blocks BBS for
5618 mark_virtual_ops_in_bb (basic_block bb)
5620 gimple_stmt_iterator gsi;
5622 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5623 mark_virtual_ops_for_renaming (gsi_stmt (gsi));
5625 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5626 mark_virtual_ops_for_renaming (gsi_stmt (gsi));
5629 /* Marks virtual operands of all statements in basic blocks BBS for
5633 mark_virtual_ops_in_region (VEC (basic_block,heap) *bbs)
5638 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5639 mark_virtual_ops_in_bb (bb);
5642 /* Move basic block BB from function CFUN to function DEST_FN. The
5643 block is moved out of the original linked list and placed after
5644 block AFTER in the new list. Also, the block is removed from the
5645 original array of blocks and placed in DEST_FN's array of blocks.
5646 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5647 updated to reflect the moved edges.
5649 The local variables are remapped to new instances, VARS_MAP is used
5650 to record the mapping. */
5653 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5654 basic_block after, bool update_edge_count_p,
5655 struct move_stmt_d *d, int eh_offset)
5657 struct control_flow_graph *cfg;
5660 gimple_stmt_iterator si;
5661 unsigned old_len, new_len;
5663 /* Remove BB from dominance structures. */
5664 delete_from_dominance_info (CDI_DOMINATORS, bb);
5666 remove_bb_from_loops (bb);
5668 /* Link BB to the new linked list. */
5669 move_block_after (bb, after);
5671 /* Update the edge count in the corresponding flowgraphs. */
5672 if (update_edge_count_p)
5673 FOR_EACH_EDGE (e, ei, bb->succs)
5675 cfun->cfg->x_n_edges--;
5676 dest_cfun->cfg->x_n_edges++;
5679 /* Remove BB from the original basic block array. */
5680 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5681 cfun->cfg->x_n_basic_blocks--;
5683 /* Grow DEST_CFUN's basic block array if needed. */
5684 cfg = dest_cfun->cfg;
5685 cfg->x_n_basic_blocks++;
5686 if (bb->index >= cfg->x_last_basic_block)
5687 cfg->x_last_basic_block = bb->index + 1;
5689 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5690 if ((unsigned) cfg->x_last_basic_block >= old_len)
5692 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5693 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5697 VEC_replace (basic_block, cfg->x_basic_block_info,
5700 /* Remap the variables in phi nodes. */
5701 for (si = gsi_start_phis (bb); !gsi_end_p (si); )
5703 gimple phi = gsi_stmt (si);
5705 tree op = PHI_RESULT (phi);
5708 if (!is_gimple_reg (op))
5710 /* Remove the phi nodes for virtual operands (alias analysis will be
5711 run for the new function, anyway). */
5712 remove_phi_node (&si, true);
5716 SET_PHI_RESULT (phi,
5717 replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5718 FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5720 op = USE_FROM_PTR (use);
5721 if (TREE_CODE (op) == SSA_NAME)
5722 SET_USE (use, replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5728 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5730 gimple stmt = gsi_stmt (si);
5732 struct walk_stmt_info wi;
5734 memset (&wi, 0, sizeof (wi));
5736 walk_gimple_stmt (&si, move_stmt_r, move_stmt_op, &wi);
5738 if (gimple_code (stmt) == GIMPLE_LABEL)
5740 tree label = gimple_label_label (stmt);
5741 int uid = LABEL_DECL_UID (label);
5743 gcc_assert (uid > -1);
5745 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5746 if (old_len <= (unsigned) uid)
5748 new_len = 3 * uid / 2;
5749 VEC_safe_grow_cleared (basic_block, gc,
5750 cfg->x_label_to_block_map, new_len);
5753 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5754 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5756 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5758 if (uid >= dest_cfun->cfg->last_label_uid)
5759 dest_cfun->cfg->last_label_uid = uid + 1;
5761 else if (gimple_code (stmt) == GIMPLE_RESX && eh_offset != 0)
5762 gimple_resx_set_region (stmt, gimple_resx_region (stmt) + eh_offset);
5764 region = lookup_stmt_eh_region (stmt);
5767 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5768 remove_stmt_from_eh_region (stmt);
5769 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5770 gimple_remove_stmt_histograms (cfun, stmt);
5773 /* We cannot leave any operands allocated from the operand caches of
5774 the current function. */
5775 free_stmt_operands (stmt);
5776 push_cfun (dest_cfun);
5781 FOR_EACH_EDGE (e, ei, bb->succs)
5784 tree block = e->goto_block;
5785 if (d->orig_block == NULL_TREE
5786 || block == d->orig_block)
5787 e->goto_block = d->new_block;
5788 #ifdef ENABLE_CHECKING
5789 else if (block != d->new_block)
5791 while (block && block != d->orig_block)
5792 block = BLOCK_SUPERCONTEXT (block);
5799 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5800 the outermost EH region. Use REGION as the incoming base EH region. */
5803 find_outermost_region_in_block (struct function *src_cfun,
5804 basic_block bb, int region)
5806 gimple_stmt_iterator si;
5808 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5810 gimple stmt = gsi_stmt (si);
5813 if (gimple_code (stmt) == GIMPLE_RESX)
5814 stmt_region = gimple_resx_region (stmt);
5816 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5817 if (stmt_region > 0)
5820 region = stmt_region;
5821 else if (stmt_region != region)
5823 region = eh_region_outermost (src_cfun, stmt_region, region);
5824 gcc_assert (region != -1);
5833 new_label_mapper (tree decl, void *data)
5835 htab_t hash = (htab_t) data;
5839 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5841 m = XNEW (struct tree_map);
5842 m->hash = DECL_UID (decl);
5843 m->base.from = decl;
5844 m->to = create_artificial_label ();
5845 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5846 if (LABEL_DECL_UID (m->to) >= cfun->cfg->last_label_uid)
5847 cfun->cfg->last_label_uid = LABEL_DECL_UID (m->to) + 1;
5849 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5850 gcc_assert (*slot == NULL);
5857 /* Change DECL_CONTEXT of all BLOCK_VARS in block, including
5861 replace_block_vars_by_duplicates (tree block, struct pointer_map_t *vars_map,
5866 for (tp = &BLOCK_VARS (block); *tp; tp = &TREE_CHAIN (*tp))
5869 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != CONST_DECL)
5871 replace_by_duplicate_decl (&t, vars_map, to_context);
5874 if (TREE_CODE (*tp) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (*tp))
5876 SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (*tp));
5877 DECL_HAS_VALUE_EXPR_P (t) = 1;
5879 TREE_CHAIN (t) = TREE_CHAIN (*tp);
5884 for (block = BLOCK_SUBBLOCKS (block); block; block = BLOCK_CHAIN (block))
5885 replace_block_vars_by_duplicates (block, vars_map, to_context);
5888 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5889 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5890 single basic block in the original CFG and the new basic block is
5891 returned. DEST_CFUN must not have a CFG yet.
5893 Note that the region need not be a pure SESE region. Blocks inside
5894 the region may contain calls to abort/exit. The only restriction
5895 is that ENTRY_BB should be the only entry point and it must
5898 Change TREE_BLOCK of all statements in ORIG_BLOCK to the new
5899 functions outermost BLOCK, move all subblocks of ORIG_BLOCK
5900 to the new function.
5902 All local variables referenced in the region are assumed to be in
5903 the corresponding BLOCK_VARS and unexpanded variable lists
5904 associated with DEST_CFUN. */
5907 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5908 basic_block exit_bb, tree orig_block)
5910 VEC(basic_block,heap) *bbs, *dom_bbs;
5911 basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
5912 basic_block after, bb, *entry_pred, *exit_succ, abb;
5913 struct function *saved_cfun = cfun;
5914 int *entry_flag, *exit_flag, eh_offset;
5915 unsigned *entry_prob, *exit_prob;
5916 unsigned i, num_entry_edges, num_exit_edges;
5919 htab_t new_label_map;
5920 struct pointer_map_t *vars_map;
5921 struct loop *loop = entry_bb->loop_father;
5922 struct move_stmt_d d;
5924 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5926 gcc_assert (entry_bb != exit_bb
5928 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
5930 /* Collect all the blocks in the region. Manually add ENTRY_BB
5931 because it won't be added by dfs_enumerate_from. */
5933 VEC_safe_push (basic_block, heap, bbs, entry_bb);
5934 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
5936 /* The blocks that used to be dominated by something in BBS will now be
5937 dominated by the new block. */
5938 dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
5939 VEC_address (basic_block, bbs),
5940 VEC_length (basic_block, bbs));
5942 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5943 the predecessor edges to ENTRY_BB and the successor edges to
5944 EXIT_BB so that we can re-attach them to the new basic block that
5945 will replace the region. */
5946 num_entry_edges = EDGE_COUNT (entry_bb->preds);
5947 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
5948 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
5949 entry_prob = XNEWVEC (unsigned, num_entry_edges);
5951 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
5953 entry_prob[i] = e->probability;
5954 entry_flag[i] = e->flags;
5955 entry_pred[i++] = e->src;
5961 num_exit_edges = EDGE_COUNT (exit_bb->succs);
5962 exit_succ = (basic_block *) xcalloc (num_exit_edges,
5963 sizeof (basic_block));
5964 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
5965 exit_prob = XNEWVEC (unsigned, num_exit_edges);
5967 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
5969 exit_prob[i] = e->probability;
5970 exit_flag[i] = e->flags;
5971 exit_succ[i++] = e->dest;
5983 /* Switch context to the child function to initialize DEST_FN's CFG. */
5984 gcc_assert (dest_cfun->cfg == NULL);
5985 push_cfun (dest_cfun);
5987 init_empty_tree_cfg ();
5989 /* Initialize EH information for the new function. */
5991 new_label_map = NULL;
5996 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5997 region = find_outermost_region_in_block (saved_cfun, bb, region);
5999 init_eh_for_function ();
6002 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
6003 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
6004 new_label_map, region, 0);
6010 /* The ssa form for virtual operands in the source function will have to
6011 be repaired. We do not care for the real operands -- the sese region
6012 must be closed with respect to those. */
6013 mark_virtual_ops_in_region (bbs);
6015 /* Move blocks from BBS into DEST_CFUN. */
6016 gcc_assert (VEC_length (basic_block, bbs) >= 2);
6017 after = dest_cfun->cfg->x_entry_block_ptr;
6018 vars_map = pointer_map_create ();
6020 memset (&d, 0, sizeof (d));
6021 d.vars_map = vars_map;
6022 d.from_context = cfun->decl;
6023 d.to_context = dest_cfun->decl;
6024 d.new_label_map = new_label_map;
6025 d.remap_decls_p = true;
6026 d.orig_block = orig_block;
6027 d.new_block = DECL_INITIAL (dest_cfun->decl);
6029 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6031 /* No need to update edge counts on the last block. It has
6032 already been updated earlier when we detached the region from
6033 the original CFG. */
6034 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, &d, eh_offset);
6038 /* Rewire BLOCK_SUBBLOCKS of orig_block. */
6042 gcc_assert (BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
6044 BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
6045 = BLOCK_SUBBLOCKS (orig_block);
6046 for (block = BLOCK_SUBBLOCKS (orig_block);
6047 block; block = BLOCK_CHAIN (block))
6048 BLOCK_SUPERCONTEXT (block) = DECL_INITIAL (dest_cfun->decl);
6049 BLOCK_SUBBLOCKS (orig_block) = NULL_TREE;
6052 replace_block_vars_by_duplicates (DECL_INITIAL (dest_cfun->decl),
6053 vars_map, dest_cfun->decl);
6056 htab_delete (new_label_map);
6057 pointer_map_destroy (vars_map);
6059 /* Rewire the entry and exit blocks. The successor to the entry
6060 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
6061 the child function. Similarly, the predecessor of DEST_FN's
6062 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
6063 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
6064 various CFG manipulation function get to the right CFG.
6066 FIXME, this is silly. The CFG ought to become a parameter to
6068 push_cfun (dest_cfun);
6069 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
6071 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
6074 /* Back in the original function, the SESE region has disappeared,
6075 create a new basic block in its place. */
6076 bb = create_empty_bb (entry_pred[0]);
6078 add_bb_to_loop (bb, loop);
6079 for (i = 0; i < num_entry_edges; i++)
6081 e = make_edge (entry_pred[i], bb, entry_flag[i]);
6082 e->probability = entry_prob[i];
6085 for (i = 0; i < num_exit_edges; i++)
6087 e = make_edge (bb, exit_succ[i], exit_flag[i]);
6088 e->probability = exit_prob[i];
6091 set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
6092 for (i = 0; VEC_iterate (basic_block, dom_bbs, i, abb); i++)
6093 set_immediate_dominator (CDI_DOMINATORS, abb, bb);
6094 VEC_free (basic_block, heap, dom_bbs);
6105 VEC_free (basic_block, heap, bbs);
6111 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree-pass.h)
6115 dump_function_to_file (tree fn, FILE *file, int flags)
6117 tree arg, vars, var;
6118 struct function *dsf;
6119 bool ignore_topmost_bind = false, any_var = false;
6123 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
6125 arg = DECL_ARGUMENTS (fn);
6128 print_generic_expr (file, TREE_TYPE (arg), dump_flags);
6129 fprintf (file, " ");
6130 print_generic_expr (file, arg, dump_flags);
6131 if (flags & TDF_VERBOSE)
6132 print_node (file, "", arg, 4);
6133 if (TREE_CHAIN (arg))
6134 fprintf (file, ", ");
6135 arg = TREE_CHAIN (arg);
6137 fprintf (file, ")\n");
6139 if (flags & TDF_VERBOSE)
6140 print_node (file, "", fn, 2);
6142 dsf = DECL_STRUCT_FUNCTION (fn);
6143 if (dsf && (flags & TDF_DETAILS))
6144 dump_eh_tree (file, dsf);
6146 if (flags & TDF_RAW && !gimple_has_body_p (fn))
6148 dump_node (fn, TDF_SLIM | flags, file);
6152 /* Switch CFUN to point to FN. */
6153 push_cfun (DECL_STRUCT_FUNCTION (fn));
6155 /* When GIMPLE is lowered, the variables are no longer available in
6156 BIND_EXPRs, so display them separately. */
6157 if (cfun && cfun->decl == fn && cfun->local_decls)
6159 ignore_topmost_bind = true;
6161 fprintf (file, "{\n");
6162 for (vars = cfun->local_decls; vars; vars = TREE_CHAIN (vars))
6164 var = TREE_VALUE (vars);
6166 print_generic_decl (file, var, flags);
6167 if (flags & TDF_VERBOSE)
6168 print_node (file, "", var, 4);
6169 fprintf (file, "\n");
6175 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
6177 /* If the CFG has been built, emit a CFG-based dump. */
6178 check_bb_profile (ENTRY_BLOCK_PTR, file);
6179 if (!ignore_topmost_bind)
6180 fprintf (file, "{\n");
6182 if (any_var && n_basic_blocks)
6183 fprintf (file, "\n");
6186 gimple_dump_bb (bb, file, 2, flags);
6188 fprintf (file, "}\n");
6189 check_bb_profile (EXIT_BLOCK_PTR, file);
6191 else if (DECL_SAVED_TREE (fn) == NULL)
6193 /* The function is now in GIMPLE form but the CFG has not been
6194 built yet. Emit the single sequence of GIMPLE statements
6195 that make up its body. */
6196 gimple_seq body = gimple_body (fn);
6198 if (gimple_seq_first_stmt (body)
6199 && gimple_seq_first_stmt (body) == gimple_seq_last_stmt (body)
6200 && gimple_code (gimple_seq_first_stmt (body)) == GIMPLE_BIND)
6201 print_gimple_seq (file, body, 0, flags);
6204 if (!ignore_topmost_bind)
6205 fprintf (file, "{\n");
6208 fprintf (file, "\n");
6210 print_gimple_seq (file, body, 2, flags);
6211 fprintf (file, "}\n");
6218 /* Make a tree based dump. */
6219 chain = DECL_SAVED_TREE (fn);
6221 if (chain && TREE_CODE (chain) == BIND_EXPR)
6223 if (ignore_topmost_bind)
6225 chain = BIND_EXPR_BODY (chain);
6233 if (!ignore_topmost_bind)
6234 fprintf (file, "{\n");
6239 fprintf (file, "\n");
6241 print_generic_stmt_indented (file, chain, flags, indent);
6242 if (ignore_topmost_bind)
6243 fprintf (file, "}\n");
6246 fprintf (file, "\n\n");
6253 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
6256 debug_function (tree fn, int flags)
6258 dump_function_to_file (fn, stderr, flags);
6262 /* Print on FILE the indexes for the predecessors of basic_block BB. */
6265 print_pred_bbs (FILE *file, basic_block bb)
6270 FOR_EACH_EDGE (e, ei, bb->preds)
6271 fprintf (file, "bb_%d ", e->src->index);
6275 /* Print on FILE the indexes for the successors of basic_block BB. */
6278 print_succ_bbs (FILE *file, basic_block bb)
6283 FOR_EACH_EDGE (e, ei, bb->succs)
6284 fprintf (file, "bb_%d ", e->dest->index);
6287 /* Print to FILE the basic block BB following the VERBOSITY level. */
6290 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6292 char *s_indent = (char *) alloca ((size_t) indent + 1);
6293 memset ((void *) s_indent, ' ', (size_t) indent);
6294 s_indent[indent] = '\0';
6296 /* Print basic_block's header. */
6299 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
6300 print_pred_bbs (file, bb);
6301 fprintf (file, "}, succs = {");
6302 print_succ_bbs (file, bb);
6303 fprintf (file, "})\n");
6306 /* Print basic_block's body. */
6309 fprintf (file, "%s {\n", s_indent);
6310 gimple_dump_bb (bb, file, indent + 4, TDF_VOPS|TDF_MEMSYMS);
6311 fprintf (file, "%s }\n", s_indent);
6315 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6317 /* Pretty print LOOP on FILE, indented INDENT spaces. Following
6318 VERBOSITY level this outputs the contents of the loop, or just its
6322 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6330 s_indent = (char *) alloca ((size_t) indent + 1);
6331 memset ((void *) s_indent, ' ', (size_t) indent);
6332 s_indent[indent] = '\0';
6334 /* Print loop's header. */
6335 fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6336 loop->num, loop->header->index, loop->latch->index);
6337 fprintf (file, ", niter = ");
6338 print_generic_expr (file, loop->nb_iterations, 0);
6340 if (loop->any_upper_bound)
6342 fprintf (file, ", upper_bound = ");
6343 dump_double_int (file, loop->nb_iterations_upper_bound, true);
6346 if (loop->any_estimate)
6348 fprintf (file, ", estimate = ");
6349 dump_double_int (file, loop->nb_iterations_estimate, true);
6351 fprintf (file, ")\n");
6353 /* Print loop's body. */
6356 fprintf (file, "%s{\n", s_indent);
6358 if (bb->loop_father == loop)
6359 print_loops_bb (file, bb, indent, verbosity);
6361 print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6362 fprintf (file, "%s}\n", s_indent);
6366 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6367 spaces. Following VERBOSITY level this outputs the contents of the
6368 loop, or just its structure. */
6371 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6376 print_loop (file, loop, indent, verbosity);
6377 print_loop_and_siblings (file, loop->next, indent, verbosity);
6380 /* Follow a CFG edge from the entry point of the program, and on entry
6381 of a loop, pretty print the loop structure on FILE. */
6384 print_loops (FILE *file, int verbosity)
6388 bb = ENTRY_BLOCK_PTR;
6389 if (bb && bb->loop_father)
6390 print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6394 /* Debugging loops structure at tree level, at some VERBOSITY level. */
6397 debug_loops (int verbosity)
6399 print_loops (stderr, verbosity);
6402 /* Print on stderr the code of LOOP, at some VERBOSITY level. */
6405 debug_loop (struct loop *loop, int verbosity)
6407 print_loop (stderr, loop, 0, verbosity);
6410 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6414 debug_loop_num (unsigned num, int verbosity)
6416 debug_loop (get_loop (num), verbosity);
6419 /* Return true if BB ends with a call, possibly followed by some
6420 instructions that must stay with the call. Return false,
6424 gimple_block_ends_with_call_p (basic_block bb)
6426 gimple_stmt_iterator gsi = gsi_last_bb (bb);
6427 return is_gimple_call (gsi_stmt (gsi));
6431 /* Return true if BB ends with a conditional branch. Return false,
6435 gimple_block_ends_with_condjump_p (const_basic_block bb)
6437 gimple stmt = last_stmt (CONST_CAST_BB (bb));
6438 return (stmt && gimple_code (stmt) == GIMPLE_COND);
6442 /* Return true if we need to add fake edge to exit at statement T.
6443 Helper function for gimple_flow_call_edges_add. */
6446 need_fake_edge_p (gimple t)
6448 tree fndecl = NULL_TREE;
6451 /* NORETURN and LONGJMP calls already have an edge to exit.
6452 CONST and PURE calls do not need one.
6453 We don't currently check for CONST and PURE here, although
6454 it would be a good idea, because those attributes are
6455 figured out from the RTL in mark_constant_function, and
6456 the counter incrementation code from -fprofile-arcs
6457 leads to different results from -fbranch-probabilities. */
6458 if (is_gimple_call (t))
6460 fndecl = gimple_call_fndecl (t);
6461 call_flags = gimple_call_flags (t);
6464 if (is_gimple_call (t)
6466 && DECL_BUILT_IN (fndecl)
6467 && (call_flags & ECF_NOTHROW)
6468 && !(call_flags & ECF_RETURNS_TWICE)
6469 /* fork() doesn't really return twice, but the effect of
6470 wrapping it in __gcov_fork() which calls __gcov_flush()
6471 and clears the counters before forking has the same
6472 effect as returning twice. Force a fake edge. */
6473 && !(DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
6474 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_FORK))
6477 if (is_gimple_call (t)
6478 && !(call_flags & ECF_NORETURN))
6481 if (gimple_code (t) == GIMPLE_ASM
6482 && (gimple_asm_volatile_p (t) || gimple_asm_input_p (t)))
6489 /* Add fake edges to the function exit for any non constant and non
6490 noreturn calls, volatile inline assembly in the bitmap of blocks
6491 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
6492 the number of blocks that were split.
6494 The goal is to expose cases in which entering a basic block does
6495 not imply that all subsequent instructions must be executed. */
6498 gimple_flow_call_edges_add (sbitmap blocks)
6501 int blocks_split = 0;
6502 int last_bb = last_basic_block;
6503 bool check_last_block = false;
6505 if (n_basic_blocks == NUM_FIXED_BLOCKS)
6509 check_last_block = true;
6511 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6513 /* In the last basic block, before epilogue generation, there will be
6514 a fallthru edge to EXIT. Special care is required if the last insn
6515 of the last basic block is a call because make_edge folds duplicate
6516 edges, which would result in the fallthru edge also being marked
6517 fake, which would result in the fallthru edge being removed by
6518 remove_fake_edges, which would result in an invalid CFG.
6520 Moreover, we can't elide the outgoing fake edge, since the block
6521 profiler needs to take this into account in order to solve the minimal
6522 spanning tree in the case that the call doesn't return.
6524 Handle this by adding a dummy instruction in a new last basic block. */
6525 if (check_last_block)
6527 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6528 gimple_stmt_iterator gsi = gsi_last_bb (bb);
6531 if (!gsi_end_p (gsi))
6534 if (t && need_fake_edge_p (t))
6538 e = find_edge (bb, EXIT_BLOCK_PTR);
6541 gsi_insert_on_edge (e, gimple_build_nop ());
6542 gsi_commit_edge_inserts ();
6547 /* Now add fake edges to the function exit for any non constant
6548 calls since there is no way that we can determine if they will
6550 for (i = 0; i < last_bb; i++)
6552 basic_block bb = BASIC_BLOCK (i);
6553 gimple_stmt_iterator gsi;
6554 gimple stmt, last_stmt;
6559 if (blocks && !TEST_BIT (blocks, i))
6562 gsi = gsi_last_bb (bb);
6563 if (!gsi_end_p (gsi))
6565 last_stmt = gsi_stmt (gsi);
6568 stmt = gsi_stmt (gsi);
6569 if (need_fake_edge_p (stmt))
6573 /* The handling above of the final block before the
6574 epilogue should be enough to verify that there is
6575 no edge to the exit block in CFG already.
6576 Calling make_edge in such case would cause us to
6577 mark that edge as fake and remove it later. */
6578 #ifdef ENABLE_CHECKING
6579 if (stmt == last_stmt)
6581 e = find_edge (bb, EXIT_BLOCK_PTR);
6582 gcc_assert (e == NULL);
6586 /* Note that the following may create a new basic block
6587 and renumber the existing basic blocks. */
6588 if (stmt != last_stmt)
6590 e = split_block (bb, stmt);
6594 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6598 while (!gsi_end_p (gsi));
6603 verify_flow_info ();
6605 return blocks_split;
6608 /* Purge dead abnormal call edges from basic block BB. */
6611 gimple_purge_dead_abnormal_call_edges (basic_block bb)
6613 bool changed = gimple_purge_dead_eh_edges (bb);
6615 if (cfun->has_nonlocal_label)
6617 gimple stmt = last_stmt (bb);
6621 if (!(stmt && stmt_can_make_abnormal_goto (stmt)))
6622 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6624 if (e->flags & EDGE_ABNORMAL)
6633 /* See gimple_purge_dead_eh_edges below. */
6635 free_dominance_info (CDI_DOMINATORS);
6641 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6644 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6648 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6649 for (son = first_dom_son (CDI_DOMINATORS, bb);
6651 son = next_dom_son (CDI_DOMINATORS, son))
6652 get_all_dominated_blocks (son, dom_bbs);
6655 /* Removes edge E and all the blocks dominated by it, and updates dominance
6656 information. The IL in E->src needs to be updated separately.
6657 If dominance info is not available, only the edge E is removed.*/
6660 remove_edge_and_dominated_blocks (edge e)
6662 VEC (basic_block, heap) *bbs_to_remove = NULL;
6663 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6667 bool none_removed = false;
6669 basic_block bb, dbb;
6672 if (!dom_info_available_p (CDI_DOMINATORS))
6678 /* No updating is needed for edges to exit. */
6679 if (e->dest == EXIT_BLOCK_PTR)
6681 if (cfgcleanup_altered_bbs)
6682 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6687 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6688 that is not dominated by E->dest, then this set is empty. Otherwise,
6689 all the basic blocks dominated by E->dest are removed.
6691 Also, to DF_IDOM we store the immediate dominators of the blocks in
6692 the dominance frontier of E (i.e., of the successors of the
6693 removed blocks, if there are any, and of E->dest otherwise). */
6694 FOR_EACH_EDGE (f, ei, e->dest->preds)
6699 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6701 none_removed = true;
6706 df = BITMAP_ALLOC (NULL);
6707 df_idom = BITMAP_ALLOC (NULL);
6710 bitmap_set_bit (df_idom,
6711 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6714 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6715 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6717 FOR_EACH_EDGE (f, ei, bb->succs)
6719 if (f->dest != EXIT_BLOCK_PTR)
6720 bitmap_set_bit (df, f->dest->index);
6723 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6724 bitmap_clear_bit (df, bb->index);
6726 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6728 bb = BASIC_BLOCK (i);
6729 bitmap_set_bit (df_idom,
6730 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6734 if (cfgcleanup_altered_bbs)
6736 /* Record the set of the altered basic blocks. */
6737 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6738 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6741 /* Remove E and the cancelled blocks. */
6746 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6747 delete_basic_block (bb);
6750 /* Update the dominance information. The immediate dominator may change only
6751 for blocks whose immediate dominator belongs to DF_IDOM:
6753 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6754 removal. Let Z the arbitrary block such that idom(Z) = Y and
6755 Z dominates X after the removal. Before removal, there exists a path P
6756 from Y to X that avoids Z. Let F be the last edge on P that is
6757 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6758 dominates W, and because of P, Z does not dominate W), and W belongs to
6759 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6760 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6762 bb = BASIC_BLOCK (i);
6763 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6765 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6766 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6769 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6772 BITMAP_FREE (df_idom);
6773 VEC_free (basic_block, heap, bbs_to_remove);
6774 VEC_free (basic_block, heap, bbs_to_fix_dom);
6777 /* Purge dead EH edges from basic block BB. */
6780 gimple_purge_dead_eh_edges (basic_block bb)
6782 bool changed = false;
6785 gimple stmt = last_stmt (bb);
6787 if (stmt && stmt_can_throw_internal (stmt))
6790 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6792 if (e->flags & EDGE_EH)
6794 remove_edge_and_dominated_blocks (e);
6805 gimple_purge_all_dead_eh_edges (const_bitmap blocks)
6807 bool changed = false;
6811 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6813 basic_block bb = BASIC_BLOCK (i);
6815 /* Earlier gimple_purge_dead_eh_edges could have removed
6816 this basic block already. */
6817 gcc_assert (bb || changed);
6819 changed |= gimple_purge_dead_eh_edges (bb);
6825 /* This function is called whenever a new edge is created or
6829 gimple_execute_on_growing_pred (edge e)
6831 basic_block bb = e->dest;
6834 reserve_phi_args_for_new_edge (bb);
6837 /* This function is called immediately before edge E is removed from
6838 the edge vector E->dest->preds. */
6841 gimple_execute_on_shrinking_pred (edge e)
6843 if (phi_nodes (e->dest))
6844 remove_phi_args (e);
6847 /*---------------------------------------------------------------------------
6848 Helper functions for Loop versioning
6849 ---------------------------------------------------------------------------*/
6851 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6852 of 'first'. Both of them are dominated by 'new_head' basic block. When
6853 'new_head' was created by 'second's incoming edge it received phi arguments
6854 on the edge by split_edge(). Later, additional edge 'e' was created to
6855 connect 'new_head' and 'first'. Now this routine adds phi args on this
6856 additional edge 'e' that new_head to second edge received as part of edge
6860 gimple_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6861 basic_block new_head, edge e)
6864 gimple_stmt_iterator psi1, psi2;
6866 edge e2 = find_edge (new_head, second);
6868 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6869 edge, we should always have an edge from NEW_HEAD to SECOND. */
6870 gcc_assert (e2 != NULL);
6872 /* Browse all 'second' basic block phi nodes and add phi args to
6873 edge 'e' for 'first' head. PHI args are always in correct order. */
6875 for (psi2 = gsi_start_phis (second),
6876 psi1 = gsi_start_phis (first);
6877 !gsi_end_p (psi2) && !gsi_end_p (psi1);
6878 gsi_next (&psi2), gsi_next (&psi1))
6880 phi1 = gsi_stmt (psi1);
6881 phi2 = gsi_stmt (psi2);
6882 def = PHI_ARG_DEF (phi2, e2->dest_idx);
6883 add_phi_arg (phi1, def, e);
6888 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6889 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6890 the destination of the ELSE part. */
6893 gimple_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6894 basic_block second_head ATTRIBUTE_UNUSED,
6895 basic_block cond_bb, void *cond_e)
6897 gimple_stmt_iterator gsi;
6898 gimple new_cond_expr;
6899 tree cond_expr = (tree) cond_e;
6902 /* Build new conditional expr */
6903 new_cond_expr = gimple_build_cond_from_tree (cond_expr,
6904 NULL_TREE, NULL_TREE);
6906 /* Add new cond in cond_bb. */
6907 gsi = gsi_last_bb (cond_bb);
6908 gsi_insert_after (&gsi, new_cond_expr, GSI_NEW_STMT);
6910 /* Adjust edges appropriately to connect new head with first head
6911 as well as second head. */
6912 e0 = single_succ_edge (cond_bb);
6913 e0->flags &= ~EDGE_FALLTHRU;
6914 e0->flags |= EDGE_FALSE_VALUE;
6917 struct cfg_hooks gimple_cfg_hooks = {
6919 gimple_verify_flow_info,
6920 gimple_dump_bb, /* dump_bb */
6921 create_bb, /* create_basic_block */
6922 gimple_redirect_edge_and_branch, /* redirect_edge_and_branch */
6923 gimple_redirect_edge_and_branch_force, /* redirect_edge_and_branch_force */
6924 gimple_can_remove_branch_p, /* can_remove_branch_p */
6925 remove_bb, /* delete_basic_block */
6926 gimple_split_block, /* split_block */
6927 gimple_move_block_after, /* move_block_after */
6928 gimple_can_merge_blocks_p, /* can_merge_blocks_p */
6929 gimple_merge_blocks, /* merge_blocks */
6930 gimple_predict_edge, /* predict_edge */
6931 gimple_predicted_by_p, /* predicted_by_p */
6932 gimple_can_duplicate_bb_p, /* can_duplicate_block_p */
6933 gimple_duplicate_bb, /* duplicate_block */
6934 gimple_split_edge, /* split_edge */
6935 gimple_make_forwarder_block, /* make_forward_block */
6936 NULL, /* tidy_fallthru_edge */
6937 gimple_block_ends_with_call_p,/* block_ends_with_call_p */
6938 gimple_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6939 gimple_flow_call_edges_add, /* flow_call_edges_add */
6940 gimple_execute_on_growing_pred, /* execute_on_growing_pred */
6941 gimple_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6942 gimple_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6943 gimple_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6944 gimple_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6945 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6946 flush_pending_stmts /* flush_pending_stmts */
6950 /* Split all critical edges. */
6953 split_critical_edges (void)
6959 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6960 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6961 mappings around the calls to split_edge. */
6962 start_recording_case_labels ();
6965 FOR_EACH_EDGE (e, ei, bb->succs)
6966 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6971 end_recording_case_labels ();
6975 struct gimple_opt_pass pass_split_crit_edges =
6979 "crited", /* name */
6981 split_critical_edges, /* execute */
6984 0, /* static_pass_number */
6985 TV_TREE_SPLIT_EDGES, /* tv_id */
6986 PROP_cfg, /* properties required */
6987 PROP_no_crit_edges, /* properties_provided */
6988 0, /* properties_destroyed */
6989 0, /* todo_flags_start */
6990 TODO_dump_func /* todo_flags_finish */
6995 /* Build a ternary operation and gimplify it. Emit code before GSI.
6996 Return the gimple_val holding the result. */
6999 gimplify_build3 (gimple_stmt_iterator *gsi, enum tree_code code,
7000 tree type, tree a, tree b, tree c)
7004 ret = fold_build3 (code, type, a, b, c);
7007 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7011 /* Build a binary operation and gimplify it. Emit code before GSI.
7012 Return the gimple_val holding the result. */
7015 gimplify_build2 (gimple_stmt_iterator *gsi, enum tree_code code,
7016 tree type, tree a, tree b)
7020 ret = fold_build2 (code, type, a, b);
7023 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7027 /* Build a unary operation and gimplify it. Emit code before GSI.
7028 Return the gimple_val holding the result. */
7031 gimplify_build1 (gimple_stmt_iterator *gsi, enum tree_code code, tree type,
7036 ret = fold_build1 (code, type, a);
7039 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
7045 /* Emit return warnings. */
7048 execute_warn_function_return (void)
7050 source_location location;
7055 /* If we have a path to EXIT, then we do return. */
7056 if (TREE_THIS_VOLATILE (cfun->decl)
7057 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
7059 location = UNKNOWN_LOCATION;
7060 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7062 last = last_stmt (e->src);
7063 if (gimple_code (last) == GIMPLE_RETURN
7064 && (location = gimple_location (last)) != UNKNOWN_LOCATION)
7067 if (location == UNKNOWN_LOCATION)
7068 location = cfun->function_end_locus;
7069 warning (0, "%H%<noreturn%> function does return", &location);
7072 /* If we see "return;" in some basic block, then we do reach the end
7073 without returning a value. */
7074 else if (warn_return_type
7075 && !TREE_NO_WARNING (cfun->decl)
7076 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
7077 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
7079 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7081 gimple last = last_stmt (e->src);
7082 if (gimple_code (last) == GIMPLE_RETURN
7083 && gimple_return_retval (last) == NULL
7084 && !gimple_no_warning_p (last))
7086 location = gimple_location (last);
7087 if (location == UNKNOWN_LOCATION)
7088 location = cfun->function_end_locus;
7089 warning_at (location, OPT_Wreturn_type, "control reaches end of non-void function");
7090 TREE_NO_WARNING (cfun->decl) = 1;
7099 /* Given a basic block B which ends with a conditional and has
7100 precisely two successors, determine which of the edges is taken if
7101 the conditional is true and which is taken if the conditional is
7102 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
7105 extract_true_false_edges_from_block (basic_block b,
7109 edge e = EDGE_SUCC (b, 0);
7111 if (e->flags & EDGE_TRUE_VALUE)
7114 *false_edge = EDGE_SUCC (b, 1);
7119 *true_edge = EDGE_SUCC (b, 1);
7123 struct gimple_opt_pass pass_warn_function_return =
7129 execute_warn_function_return, /* execute */
7132 0, /* static_pass_number */
7134 PROP_cfg, /* properties_required */
7135 0, /* properties_provided */
7136 0, /* properties_destroyed */
7137 0, /* todo_flags_start */
7138 0 /* todo_flags_finish */
7142 /* Emit noreturn warnings. */
7145 execute_warn_function_noreturn (void)
7147 if (warn_missing_noreturn
7148 && !TREE_THIS_VOLATILE (cfun->decl)
7149 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
7150 && !lang_hooks.missing_noreturn_ok_p (cfun->decl))
7151 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
7152 "for attribute %<noreturn%>",
7157 struct gimple_opt_pass pass_warn_function_noreturn =
7163 execute_warn_function_noreturn, /* execute */
7166 0, /* static_pass_number */
7168 PROP_cfg, /* properties_required */
7169 0, /* properties_provided */
7170 0, /* properties_destroyed */
7171 0, /* todo_flags_start */
7172 0 /* todo_flags_finish */