1 /* Control flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
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"
50 /* This file contains functions for building the Control Flow Graph (CFG)
51 for a function tree. */
53 /* Local declarations. */
55 /* Initial capacity for the basic block array. */
56 static const int initial_cfg_capacity = 20;
58 /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs
59 which use a particular edge. The CASE_LABEL_EXPRs are chained together
60 via their TREE_CHAIN field, which we clear after we're done with the
61 hash table to prevent problems with duplication of SWITCH_EXPRs.
63 Access to this list of CASE_LABEL_EXPRs allows us to efficiently
64 update the case vector in response to edge redirections.
66 Right now this table is set up and torn down at key points in the
67 compilation process. It would be nice if we could make the table
68 more persistent. The key is getting notification of changes to
69 the CFG (particularly edge removal, creation and redirection). */
71 static struct pointer_map_t *edge_to_cases;
76 long num_merged_labels;
79 static struct cfg_stats_d cfg_stats;
81 /* Nonzero if we found a computed goto while building basic blocks. */
82 static bool found_computed_goto;
84 /* Basic blocks and flowgraphs. */
85 static basic_block create_bb (void *, void *, basic_block);
86 static void make_blocks (tree);
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_switch_expr_edges (basic_block);
93 static void make_goto_expr_edges (basic_block);
94 static edge tree_redirect_edge_and_branch (edge, basic_block);
95 static edge tree_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 (const_tree, const_tree);
100 static int tree_verify_flow_info (void);
101 static void tree_make_forwarder_block (edge);
102 static void tree_cfg2vcg (FILE *);
103 static inline void change_bb_for_stmt (tree t, basic_block bb);
105 /* Flowgraph optimization and cleanup. */
106 static void tree_merge_blocks (basic_block, basic_block);
107 static bool tree_can_merge_blocks_p (basic_block, basic_block);
108 static void remove_bb (basic_block);
109 static edge find_taken_edge_computed_goto (basic_block, tree);
110 static edge find_taken_edge_cond_expr (basic_block, tree);
111 static edge find_taken_edge_switch_expr (basic_block, tree);
112 static tree find_case_label_for_value (tree, tree);
115 init_empty_tree_cfg (void)
117 /* Initialize the basic block array. */
119 profile_status = PROFILE_ABSENT;
120 n_basic_blocks = NUM_FIXED_BLOCKS;
121 last_basic_block = NUM_FIXED_BLOCKS;
122 basic_block_info = VEC_alloc (basic_block, gc, initial_cfg_capacity);
123 VEC_safe_grow_cleared (basic_block, gc, basic_block_info,
124 initial_cfg_capacity);
126 /* Build a mapping of labels to their associated blocks. */
127 label_to_block_map = VEC_alloc (basic_block, gc, initial_cfg_capacity);
128 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
129 initial_cfg_capacity);
131 SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR);
132 SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR);
133 ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR;
134 EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR;
137 /*---------------------------------------------------------------------------
139 ---------------------------------------------------------------------------*/
141 /* Entry point to the CFG builder for trees. TP points to the list of
142 statements to be added to the flowgraph. */
145 build_tree_cfg (tree *tp)
147 /* Register specific tree functions. */
148 tree_register_cfg_hooks ();
150 memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
152 init_empty_tree_cfg ();
154 found_computed_goto = 0;
157 /* Computed gotos are hell to deal with, especially if there are
158 lots of them with a large number of destinations. So we factor
159 them to a common computed goto location before we build the
160 edge list. After we convert back to normal form, we will un-factor
161 the computed gotos since factoring introduces an unwanted jump. */
162 if (found_computed_goto)
163 factor_computed_gotos ();
165 /* Make sure there is always at least one block, even if it's empty. */
166 if (n_basic_blocks == NUM_FIXED_BLOCKS)
167 create_empty_bb (ENTRY_BLOCK_PTR);
169 /* Adjust the size of the array. */
170 if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
171 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
173 /* To speed up statement iterator walks, we first purge dead labels. */
174 cleanup_dead_labels ();
176 /* Group case nodes to reduce the number of edges.
177 We do this after cleaning up dead labels because otherwise we miss
178 a lot of obvious case merging opportunities. */
179 group_case_labels ();
181 /* Create the edges of the flowgraph. */
183 cleanup_dead_labels ();
185 /* Debugging dumps. */
187 /* Write the flowgraph to a VCG file. */
189 int local_dump_flags;
190 FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
193 tree_cfg2vcg (vcg_file);
194 dump_end (TDI_vcg, vcg_file);
198 #ifdef ENABLE_CHECKING
202 /* Dump a textual representation of the flowgraph. */
204 dump_tree_cfg (dump_file, dump_flags);
208 execute_build_cfg (void)
210 build_tree_cfg (&DECL_SAVED_TREE (current_function_decl));
214 struct tree_opt_pass pass_build_cfg =
218 execute_build_cfg, /* execute */
221 0, /* static_pass_number */
222 TV_TREE_CFG, /* tv_id */
223 PROP_gimple_leh, /* properties_required */
224 PROP_cfg, /* properties_provided */
225 0, /* properties_destroyed */
226 0, /* todo_flags_start */
227 TODO_verify_stmts | TODO_cleanup_cfg, /* todo_flags_finish */
231 /* Search the CFG for any computed gotos. If found, factor them to a
232 common computed goto site. Also record the location of that site so
233 that we can un-factor the gotos after we have converted back to
237 factor_computed_gotos (void)
240 tree factored_label_decl = NULL;
242 tree factored_computed_goto_label = NULL;
243 tree factored_computed_goto = NULL;
245 /* We know there are one or more computed gotos in this function.
246 Examine the last statement in each basic block to see if the block
247 ends with a computed goto. */
251 block_stmt_iterator bsi = bsi_last (bb);
256 last = bsi_stmt (bsi);
258 /* Ignore the computed goto we create when we factor the original
260 if (last == factored_computed_goto)
263 /* If the last statement is a computed goto, factor it. */
264 if (computed_goto_p (last))
268 /* The first time we find a computed goto we need to create
269 the factored goto block and the variable each original
270 computed goto will use for their goto destination. */
271 if (! factored_computed_goto)
273 basic_block new_bb = create_empty_bb (bb);
274 block_stmt_iterator new_bsi = bsi_start (new_bb);
276 /* Create the destination of the factored goto. Each original
277 computed goto will put its desired destination into this
278 variable and jump to the label we create immediately
280 var = create_tmp_var (ptr_type_node, "gotovar");
282 /* Build a label for the new block which will contain the
283 factored computed goto. */
284 factored_label_decl = create_artificial_label ();
285 factored_computed_goto_label
286 = build1 (LABEL_EXPR, void_type_node, factored_label_decl);
287 bsi_insert_after (&new_bsi, factored_computed_goto_label,
290 /* Build our new computed goto. */
291 factored_computed_goto = build1 (GOTO_EXPR, void_type_node, var);
292 bsi_insert_after (&new_bsi, factored_computed_goto,
296 /* Copy the original computed goto's destination into VAR. */
297 assignment = build_gimple_modify_stmt (var,
298 GOTO_DESTINATION (last));
299 bsi_insert_before (&bsi, assignment, BSI_SAME_STMT);
301 /* And re-vector the computed goto to the new destination. */
302 GOTO_DESTINATION (last) = factored_label_decl;
308 /* Build a flowgraph for the statement_list STMT_LIST. */
311 make_blocks (tree stmt_list)
313 tree_stmt_iterator i = tsi_start (stmt_list);
315 bool start_new_block = true;
316 bool first_stmt_of_list = true;
317 basic_block bb = ENTRY_BLOCK_PTR;
319 while (!tsi_end_p (i))
326 /* If the statement starts a new basic block or if we have determined
327 in a previous pass that we need to create a new block for STMT, do
329 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
331 if (!first_stmt_of_list)
332 stmt_list = tsi_split_statement_list_before (&i);
333 bb = create_basic_block (stmt_list, NULL, bb);
334 start_new_block = false;
337 /* Now add STMT to BB and create the subgraphs for special statement
339 set_bb_for_stmt (stmt, bb);
341 if (computed_goto_p (stmt))
342 found_computed_goto = true;
344 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
346 if (stmt_ends_bb_p (stmt))
347 start_new_block = true;
350 first_stmt_of_list = false;
355 /* Create and return a new empty basic block after bb AFTER. */
358 create_bb (void *h, void *e, basic_block after)
364 /* Create and initialize a new basic block. Since alloc_block uses
365 ggc_alloc_cleared to allocate a basic block, we do not have to
366 clear the newly allocated basic block here. */
369 bb->index = last_basic_block;
371 bb->il.tree = GGC_CNEW (struct tree_bb_info);
372 set_bb_stmt_list (bb, h ? (tree) h : alloc_stmt_list ());
374 /* Add the new block to the linked list of blocks. */
375 link_block (bb, after);
377 /* Grow the basic block array if needed. */
378 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
380 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
381 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
384 /* Add the newly created block to the array. */
385 SET_BASIC_BLOCK (last_basic_block, bb);
394 /*---------------------------------------------------------------------------
396 ---------------------------------------------------------------------------*/
398 /* Fold COND_EXPR_COND of each COND_EXPR. */
401 fold_cond_expr_cond (void)
407 tree stmt = last_stmt (bb);
410 && TREE_CODE (stmt) == COND_EXPR)
415 fold_defer_overflow_warnings ();
416 cond = fold (COND_EXPR_COND (stmt));
417 zerop = integer_zerop (cond);
418 onep = integer_onep (cond);
419 fold_undefer_overflow_warnings (((zerop || onep)
420 && !TREE_NO_WARNING (stmt)),
422 WARN_STRICT_OVERFLOW_CONDITIONAL);
424 COND_EXPR_COND (stmt) = boolean_false_node;
426 COND_EXPR_COND (stmt) = boolean_true_node;
431 /* Join all the blocks in the flowgraph. */
437 struct omp_region *cur_region = NULL;
439 /* Create an edge from entry to the first block with executable
441 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
443 /* Traverse the basic block array placing edges. */
446 tree last = last_stmt (bb);
451 enum tree_code code = TREE_CODE (last);
455 make_goto_expr_edges (bb);
459 make_edge (bb, EXIT_BLOCK_PTR, 0);
463 make_cond_expr_edges (bb);
467 make_switch_expr_edges (bb);
471 make_eh_edges (last);
476 /* If this function receives a nonlocal goto, then we need to
477 make edges from this call site to all the nonlocal goto
479 if (tree_can_make_abnormal_goto (last))
480 make_abnormal_goto_edges (bb, true);
482 /* If this statement has reachable exception handlers, then
483 create abnormal edges to them. */
484 make_eh_edges (last);
486 /* Some calls are known not to return. */
487 fallthru = !(call_expr_flags (last) & ECF_NORETURN);
493 case GIMPLE_MODIFY_STMT:
494 if (is_ctrl_altering_stmt (last))
496 /* A GIMPLE_MODIFY_STMT may have a CALL_EXPR on its RHS and
497 the CALL_EXPR may have an abnormal edge. Search the RHS
498 for this case and create any required edges. */
499 if (tree_can_make_abnormal_goto (last))
500 make_abnormal_goto_edges (bb, true);
502 make_eh_edges (last);
514 cur_region = new_omp_region (bb, code, cur_region);
519 cur_region = new_omp_region (bb, code, cur_region);
523 case OMP_SECTIONS_SWITCH:
528 /* In the case of an OMP_SECTION, the edge will go somewhere
529 other than the next block. This will be created later. */
530 cur_region->exit = bb;
531 fallthru = cur_region->type != OMP_SECTION;
532 cur_region = cur_region->outer;
536 cur_region->cont = bb;
537 switch (cur_region->type)
540 /* Make the loopback edge. */
541 make_edge (bb, single_succ (cur_region->entry), 0);
543 /* Create an edge from OMP_FOR to exit, which corresponds to
544 the case that the body of the loop is not executed at
546 make_edge (cur_region->entry, bb->next_bb, 0);
551 /* Wire up the edges into and out of the nested sections. */
553 basic_block switch_bb = single_succ (cur_region->entry);
555 struct omp_region *i;
556 for (i = cur_region->inner; i ; i = i->next)
558 gcc_assert (i->type == OMP_SECTION);
559 make_edge (switch_bb, i->entry, 0);
560 make_edge (i->exit, bb, EDGE_FALLTHRU);
563 /* Make the loopback edge to the block with
564 OMP_SECTIONS_SWITCH. */
565 make_edge (bb, switch_bb, 0);
567 /* Make the edge from the switch to exit. */
568 make_edge (switch_bb, bb->next_bb, 0);
579 gcc_assert (!stmt_ends_bb_p (last));
587 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
593 /* Fold COND_EXPR_COND of each COND_EXPR. */
594 fold_cond_expr_cond ();
598 /* Create the edges for a COND_EXPR starting at block BB.
599 At this point, both clauses must contain only simple gotos. */
602 make_cond_expr_edges (basic_block bb)
604 tree entry = last_stmt (bb);
605 basic_block then_bb, else_bb;
606 tree then_label, else_label;
610 gcc_assert (TREE_CODE (entry) == COND_EXPR);
612 /* Entry basic blocks for each component. */
613 then_label = GOTO_DESTINATION (COND_EXPR_THEN (entry));
614 else_label = GOTO_DESTINATION (COND_EXPR_ELSE (entry));
615 then_bb = label_to_block (then_label);
616 else_bb = label_to_block (else_label);
618 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
619 #ifdef USE_MAPPED_LOCATION
620 e->goto_locus = EXPR_LOCATION (COND_EXPR_THEN (entry));
622 e->goto_locus = EXPR_LOCUS (COND_EXPR_THEN (entry));
624 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
627 #ifdef USE_MAPPED_LOCATION
628 e->goto_locus = EXPR_LOCATION (COND_EXPR_ELSE (entry));
630 e->goto_locus = EXPR_LOCUS (COND_EXPR_ELSE (entry));
634 /* We do not need the gotos anymore. */
635 COND_EXPR_THEN (entry) = NULL_TREE;
636 COND_EXPR_ELSE (entry) = NULL_TREE;
640 /* Called for each element in the hash table (P) as we delete the
641 edge to cases hash table.
643 Clear all the TREE_CHAINs to prevent problems with copying of
644 SWITCH_EXPRs and structure sharing rules, then free the hash table
648 edge_to_cases_cleanup (void *key ATTRIBUTE_UNUSED, void **value,
649 void *data ATTRIBUTE_UNUSED)
653 for (t = (tree) *value; t; t = next)
655 next = TREE_CHAIN (t);
656 TREE_CHAIN (t) = NULL;
663 /* Start recording information mapping edges to case labels. */
666 start_recording_case_labels (void)
668 gcc_assert (edge_to_cases == NULL);
669 edge_to_cases = pointer_map_create ();
672 /* Return nonzero if we are recording information for case labels. */
675 recording_case_labels_p (void)
677 return (edge_to_cases != NULL);
680 /* Stop recording information mapping edges to case labels and
681 remove any information we have recorded. */
683 end_recording_case_labels (void)
685 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
686 pointer_map_destroy (edge_to_cases);
687 edge_to_cases = NULL;
690 /* If we are inside a {start,end}_recording_cases block, then return
691 a chain of CASE_LABEL_EXPRs from T which reference E.
693 Otherwise return NULL. */
696 get_cases_for_edge (edge e, tree t)
702 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
703 chains available. Return NULL so the caller can detect this case. */
704 if (!recording_case_labels_p ())
707 slot = pointer_map_contains (edge_to_cases, e);
711 /* If we did not find E in the hash table, then this must be the first
712 time we have been queried for information about E & T. Add all the
713 elements from T to the hash table then perform the query again. */
715 vec = SWITCH_LABELS (t);
716 n = TREE_VEC_LENGTH (vec);
717 for (i = 0; i < n; i++)
719 tree elt = TREE_VEC_ELT (vec, i);
720 tree lab = CASE_LABEL (elt);
721 basic_block label_bb = label_to_block (lab);
722 edge this_edge = find_edge (e->src, label_bb);
724 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
726 slot = pointer_map_insert (edge_to_cases, this_edge);
727 TREE_CHAIN (elt) = (tree) *slot;
731 return (tree) *pointer_map_contains (edge_to_cases, e);
734 /* Create the edges for a SWITCH_EXPR starting at block BB.
735 At this point, the switch body has been lowered and the
736 SWITCH_LABELS filled in, so this is in effect a multi-way branch. */
739 make_switch_expr_edges (basic_block bb)
741 tree entry = last_stmt (bb);
745 vec = SWITCH_LABELS (entry);
746 n = TREE_VEC_LENGTH (vec);
748 for (i = 0; i < n; ++i)
750 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
751 basic_block label_bb = label_to_block (lab);
752 make_edge (bb, label_bb, 0);
757 /* Return the basic block holding label DEST. */
760 label_to_block_fn (struct function *ifun, tree dest)
762 int uid = LABEL_DECL_UID (dest);
764 /* We would die hard when faced by an undefined label. Emit a label to
765 the very first basic block. This will hopefully make even the dataflow
766 and undefined variable warnings quite right. */
767 if ((errorcount || sorrycount) && uid < 0)
769 block_stmt_iterator bsi =
770 bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS));
773 stmt = build1 (LABEL_EXPR, void_type_node, dest);
774 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
775 uid = LABEL_DECL_UID (dest);
777 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
778 <= (unsigned int) uid)
780 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
783 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
784 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
787 make_abnormal_goto_edges (basic_block bb, bool for_call)
789 basic_block target_bb;
790 block_stmt_iterator bsi;
792 FOR_EACH_BB (target_bb)
793 for (bsi = bsi_start (target_bb); !bsi_end_p (bsi); bsi_next (&bsi))
795 tree target = bsi_stmt (bsi);
797 if (TREE_CODE (target) != LABEL_EXPR)
800 target = LABEL_EXPR_LABEL (target);
802 /* Make an edge to every label block that has been marked as a
803 potential target for a computed goto or a non-local goto. */
804 if ((FORCED_LABEL (target) && !for_call)
805 || (DECL_NONLOCAL (target) && for_call))
807 make_edge (bb, target_bb, EDGE_ABNORMAL);
813 /* Create edges for a goto statement at block BB. */
816 make_goto_expr_edges (basic_block bb)
818 block_stmt_iterator last = bsi_last (bb);
819 tree goto_t = bsi_stmt (last);
821 /* A simple GOTO creates normal edges. */
822 if (simple_goto_p (goto_t))
824 tree dest = GOTO_DESTINATION (goto_t);
825 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
826 #ifdef USE_MAPPED_LOCATION
827 e->goto_locus = EXPR_LOCATION (goto_t);
829 e->goto_locus = EXPR_LOCUS (goto_t);
831 bsi_remove (&last, true);
835 /* A computed GOTO creates abnormal edges. */
836 make_abnormal_goto_edges (bb, false);
840 /*---------------------------------------------------------------------------
842 ---------------------------------------------------------------------------*/
844 /* Cleanup useless labels in basic blocks. This is something we wish
845 to do early because it allows us to group case labels before creating
846 the edges for the CFG, and it speeds up block statement iterators in
848 We rerun this pass after CFG is created, to get rid of the labels that
849 are no longer referenced. After then we do not run it any more, since
850 (almost) no new labels should be created. */
852 /* A map from basic block index to the leading label of that block. */
853 static struct label_record
858 /* True if the label is referenced from somewhere. */
862 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
864 update_eh_label (struct eh_region *region)
866 tree old_label = get_eh_region_tree_label (region);
870 basic_block bb = label_to_block (old_label);
872 /* ??? After optimizing, there may be EH regions with labels
873 that have already been removed from the function body, so
874 there is no basic block for them. */
878 new_label = label_for_bb[bb->index].label;
879 label_for_bb[bb->index].used = true;
880 set_eh_region_tree_label (region, new_label);
884 /* Given LABEL return the first label in the same basic block. */
886 main_block_label (tree label)
888 basic_block bb = label_to_block (label);
889 tree main_label = label_for_bb[bb->index].label;
891 /* label_to_block possibly inserted undefined label into the chain. */
894 label_for_bb[bb->index].label = label;
898 label_for_bb[bb->index].used = true;
902 /* Cleanup redundant labels. This is a three-step process:
903 1) Find the leading label for each block.
904 2) Redirect all references to labels to the leading labels.
905 3) Cleanup all useless labels. */
908 cleanup_dead_labels (void)
911 label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
913 /* Find a suitable label for each block. We use the first user-defined
914 label if there is one, or otherwise just the first label we see. */
917 block_stmt_iterator i;
919 for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i))
921 tree label, stmt = bsi_stmt (i);
923 if (TREE_CODE (stmt) != LABEL_EXPR)
926 label = LABEL_EXPR_LABEL (stmt);
928 /* If we have not yet seen a label for the current block,
929 remember this one and see if there are more labels. */
930 if (!label_for_bb[bb->index].label)
932 label_for_bb[bb->index].label = label;
936 /* If we did see a label for the current block already, but it
937 is an artificially created label, replace it if the current
938 label is a user defined label. */
939 if (!DECL_ARTIFICIAL (label)
940 && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
942 label_for_bb[bb->index].label = label;
948 /* Now redirect all jumps/branches to the selected label.
949 First do so for each block ending in a control statement. */
952 tree stmt = last_stmt (bb);
956 switch (TREE_CODE (stmt))
960 tree true_branch, false_branch;
962 true_branch = COND_EXPR_THEN (stmt);
963 false_branch = COND_EXPR_ELSE (stmt);
966 GOTO_DESTINATION (true_branch)
967 = main_block_label (GOTO_DESTINATION (true_branch));
969 GOTO_DESTINATION (false_branch)
970 = main_block_label (GOTO_DESTINATION (false_branch));
978 tree vec = SWITCH_LABELS (stmt);
979 size_t n = TREE_VEC_LENGTH (vec);
981 /* Replace all destination labels. */
982 for (i = 0; i < n; ++i)
984 tree elt = TREE_VEC_ELT (vec, i);
985 tree label = main_block_label (CASE_LABEL (elt));
986 CASE_LABEL (elt) = label;
991 /* We have to handle GOTO_EXPRs until they're removed, and we don't
992 remove them until after we've created the CFG edges. */
994 if (! computed_goto_p (stmt))
996 GOTO_DESTINATION (stmt)
997 = main_block_label (GOTO_DESTINATION (stmt));
1006 for_each_eh_region (update_eh_label);
1008 /* Finally, purge dead labels. All user-defined labels and labels that
1009 can be the target of non-local gotos and labels which have their
1010 address taken are preserved. */
1013 block_stmt_iterator i;
1014 tree label_for_this_bb = label_for_bb[bb->index].label;
1016 if (!label_for_this_bb)
1019 /* If the main label of the block is unused, we may still remove it. */
1020 if (!label_for_bb[bb->index].used)
1021 label_for_this_bb = NULL;
1023 for (i = bsi_start (bb); !bsi_end_p (i); )
1025 tree label, stmt = bsi_stmt (i);
1027 if (TREE_CODE (stmt) != LABEL_EXPR)
1030 label = LABEL_EXPR_LABEL (stmt);
1032 if (label == label_for_this_bb
1033 || ! DECL_ARTIFICIAL (label)
1034 || DECL_NONLOCAL (label)
1035 || FORCED_LABEL (label))
1038 bsi_remove (&i, true);
1042 free (label_for_bb);
1045 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1046 and scan the sorted vector of cases. Combine the ones jumping to the
1048 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1051 group_case_labels (void)
1057 tree stmt = last_stmt (bb);
1058 if (stmt && TREE_CODE (stmt) == SWITCH_EXPR)
1060 tree labels = SWITCH_LABELS (stmt);
1061 int old_size = TREE_VEC_LENGTH (labels);
1062 int i, j, new_size = old_size;
1063 tree default_case = TREE_VEC_ELT (labels, old_size - 1);
1066 /* The default label is always the last case in a switch
1067 statement after gimplification. */
1068 default_label = CASE_LABEL (default_case);
1070 /* Look for possible opportunities to merge cases.
1071 Ignore the last element of the label vector because it
1072 must be the default case. */
1074 while (i < old_size - 1)
1076 tree base_case, base_label, base_high;
1077 base_case = TREE_VEC_ELT (labels, i);
1079 gcc_assert (base_case);
1080 base_label = CASE_LABEL (base_case);
1082 /* Discard cases that have the same destination as the
1084 if (base_label == default_label)
1086 TREE_VEC_ELT (labels, i) = NULL_TREE;
1092 base_high = CASE_HIGH (base_case) ?
1093 CASE_HIGH (base_case) : CASE_LOW (base_case);
1095 /* Try to merge case labels. Break out when we reach the end
1096 of the label vector or when we cannot merge the next case
1097 label with the current one. */
1098 while (i < old_size - 1)
1100 tree merge_case = TREE_VEC_ELT (labels, i);
1101 tree merge_label = CASE_LABEL (merge_case);
1102 tree t = int_const_binop (PLUS_EXPR, base_high,
1103 integer_one_node, 1);
1105 /* Merge the cases if they jump to the same place,
1106 and their ranges are consecutive. */
1107 if (merge_label == base_label
1108 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1110 base_high = CASE_HIGH (merge_case) ?
1111 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1112 CASE_HIGH (base_case) = base_high;
1113 TREE_VEC_ELT (labels, i) = NULL_TREE;
1122 /* Compress the case labels in the label vector, and adjust the
1123 length of the vector. */
1124 for (i = 0, j = 0; i < new_size; i++)
1126 while (! TREE_VEC_ELT (labels, j))
1128 TREE_VEC_ELT (labels, i) = TREE_VEC_ELT (labels, j++);
1130 TREE_VEC_LENGTH (labels) = new_size;
1135 /* Checks whether we can merge block B into block A. */
1138 tree_can_merge_blocks_p (basic_block a, basic_block b)
1141 block_stmt_iterator bsi;
1144 if (!single_succ_p (a))
1147 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1150 if (single_succ (a) != b)
1153 if (!single_pred_p (b))
1156 if (b == EXIT_BLOCK_PTR)
1159 /* If A ends by a statement causing exceptions or something similar, we
1160 cannot merge the blocks. */
1161 stmt = last_stmt (a);
1162 if (stmt && stmt_ends_bb_p (stmt))
1165 /* Do not allow a block with only a non-local label to be merged. */
1166 if (stmt && TREE_CODE (stmt) == LABEL_EXPR
1167 && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
1170 /* It must be possible to eliminate all phi nodes in B. If ssa form
1171 is not up-to-date, we cannot eliminate any phis; however, if only
1172 some symbols as whole are marked for renaming, this is not a problem,
1173 as phi nodes for those symbols are irrelevant in updating anyway. */
1174 phi = phi_nodes (b);
1177 if (name_mappings_registered_p ())
1180 for (; phi; phi = PHI_CHAIN (phi))
1181 if (!is_gimple_reg (PHI_RESULT (phi))
1182 && !may_propagate_copy (PHI_RESULT (phi), PHI_ARG_DEF (phi, 0)))
1186 /* Do not remove user labels. */
1187 for (bsi = bsi_start (b); !bsi_end_p (bsi); bsi_next (&bsi))
1189 stmt = bsi_stmt (bsi);
1190 if (TREE_CODE (stmt) != LABEL_EXPR)
1192 if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt)))
1196 /* Protect the loop latches. */
1198 && b->loop_father->latch == b)
1204 /* Replaces all uses of NAME by VAL. */
1207 replace_uses_by (tree name, tree val)
1209 imm_use_iterator imm_iter;
1214 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1216 if (TREE_CODE (stmt) != PHI_NODE)
1217 push_stmt_changes (&stmt);
1219 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1221 replace_exp (use, val);
1223 if (TREE_CODE (stmt) == PHI_NODE)
1225 e = PHI_ARG_EDGE (stmt, PHI_ARG_INDEX_FROM_USE (use));
1226 if (e->flags & EDGE_ABNORMAL)
1228 /* This can only occur for virtual operands, since
1229 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1230 would prevent replacement. */
1231 gcc_assert (!is_gimple_reg (name));
1232 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1237 if (TREE_CODE (stmt) != PHI_NODE)
1241 fold_stmt_inplace (stmt);
1242 if (cfgcleanup_altered_bbs)
1243 bitmap_set_bit (cfgcleanup_altered_bbs, bb_for_stmt (stmt)->index);
1245 /* FIXME. This should go in pop_stmt_changes. */
1246 rhs = get_rhs (stmt);
1247 if (TREE_CODE (rhs) == ADDR_EXPR)
1248 recompute_tree_invariant_for_addr_expr (rhs);
1250 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1252 pop_stmt_changes (&stmt);
1256 gcc_assert (has_zero_uses (name));
1258 /* Also update the trees stored in loop structures. */
1264 FOR_EACH_LOOP (li, loop, 0)
1266 substitute_in_loop_info (loop, name, val);
1271 /* Merge block B into block A. */
1274 tree_merge_blocks (basic_block a, basic_block b)
1276 block_stmt_iterator bsi;
1277 tree_stmt_iterator last;
1281 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1283 /* Remove all single-valued PHI nodes from block B of the form
1284 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1286 for (phi = phi_nodes (b); phi; phi = phi_nodes (b))
1288 tree def = PHI_RESULT (phi), use = PHI_ARG_DEF (phi, 0);
1290 bool may_replace_uses = may_propagate_copy (def, use);
1292 /* In case we maintain loop closed ssa form, do not propagate arguments
1293 of loop exit phi nodes. */
1295 && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1296 && is_gimple_reg (def)
1297 && TREE_CODE (use) == SSA_NAME
1298 && a->loop_father != b->loop_father)
1299 may_replace_uses = false;
1301 if (!may_replace_uses)
1303 gcc_assert (is_gimple_reg (def));
1305 /* Note that just emitting the copies is fine -- there is no problem
1306 with ordering of phi nodes. This is because A is the single
1307 predecessor of B, therefore results of the phi nodes cannot
1308 appear as arguments of the phi nodes. */
1309 copy = build_gimple_modify_stmt (def, use);
1310 bsi_insert_after (&bsi, copy, BSI_NEW_STMT);
1311 SSA_NAME_DEF_STMT (def) = copy;
1312 remove_phi_node (phi, NULL, false);
1316 replace_uses_by (def, use);
1317 remove_phi_node (phi, NULL, true);
1321 /* Ensure that B follows A. */
1322 move_block_after (b, a);
1324 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1325 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1327 /* Remove labels from B and set bb_for_stmt to A for other statements. */
1328 for (bsi = bsi_start (b); !bsi_end_p (bsi);)
1330 if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR)
1332 tree label = bsi_stmt (bsi);
1334 bsi_remove (&bsi, false);
1335 /* Now that we can thread computed gotos, we might have
1336 a situation where we have a forced label in block B
1337 However, the label at the start of block B might still be
1338 used in other ways (think about the runtime checking for
1339 Fortran assigned gotos). So we can not just delete the
1340 label. Instead we move the label to the start of block A. */
1341 if (FORCED_LABEL (LABEL_EXPR_LABEL (label)))
1343 block_stmt_iterator dest_bsi = bsi_start (a);
1344 bsi_insert_before (&dest_bsi, label, BSI_NEW_STMT);
1349 change_bb_for_stmt (bsi_stmt (bsi), a);
1354 /* Merge the chains. */
1355 last = tsi_last (bb_stmt_list (a));
1356 tsi_link_after (&last, bb_stmt_list (b), TSI_NEW_STMT);
1357 set_bb_stmt_list (b, NULL_TREE);
1359 if (cfgcleanup_altered_bbs)
1360 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1364 /* Return the one of two successors of BB that is not reachable by a
1365 reached by a complex edge, if there is one. Else, return BB. We use
1366 this in optimizations that use post-dominators for their heuristics,
1367 to catch the cases in C++ where function calls are involved. */
1370 single_noncomplex_succ (basic_block bb)
1373 if (EDGE_COUNT (bb->succs) != 2)
1376 e0 = EDGE_SUCC (bb, 0);
1377 e1 = EDGE_SUCC (bb, 1);
1378 if (e0->flags & EDGE_COMPLEX)
1380 if (e1->flags & EDGE_COMPLEX)
1387 /* Walk the function tree removing unnecessary statements.
1389 * Empty statement nodes are removed
1391 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1393 * Unnecessary COND_EXPRs are removed
1395 * Some unnecessary BIND_EXPRs are removed
1397 Clearly more work could be done. The trick is doing the analysis
1398 and removal fast enough to be a net improvement in compile times.
1400 Note that when we remove a control structure such as a COND_EXPR
1401 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1402 to ensure we eliminate all the useless code. */
1413 static void remove_useless_stmts_1 (tree *, struct rus_data *);
1416 remove_useless_stmts_warn_notreached (tree stmt)
1418 if (EXPR_HAS_LOCATION (stmt))
1420 location_t loc = EXPR_LOCATION (stmt);
1421 if (LOCATION_LINE (loc) > 0)
1423 warning (0, "%Hwill never be executed", &loc);
1428 switch (TREE_CODE (stmt))
1430 case STATEMENT_LIST:
1432 tree_stmt_iterator i;
1433 for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i))
1434 if (remove_useless_stmts_warn_notreached (tsi_stmt (i)))
1440 if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt)))
1442 if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt)))
1444 if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt)))
1448 case TRY_FINALLY_EXPR:
1449 case TRY_CATCH_EXPR:
1450 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 0)))
1452 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 1)))
1457 return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt));
1458 case EH_FILTER_EXPR:
1459 return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt));
1461 return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt));
1464 /* Not a live container. */
1472 remove_useless_stmts_cond (tree *stmt_p, struct rus_data *data)
1474 tree then_clause, else_clause, cond;
1475 bool save_has_label, then_has_label, else_has_label;
1477 save_has_label = data->has_label;
1478 data->has_label = false;
1479 data->last_goto = NULL;
1481 remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p), data);
1483 then_has_label = data->has_label;
1484 data->has_label = false;
1485 data->last_goto = NULL;
1487 remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p), data);
1489 else_has_label = data->has_label;
1490 data->has_label = save_has_label | then_has_label | else_has_label;
1492 then_clause = COND_EXPR_THEN (*stmt_p);
1493 else_clause = COND_EXPR_ELSE (*stmt_p);
1494 cond = fold (COND_EXPR_COND (*stmt_p));
1496 /* If neither arm does anything at all, we can remove the whole IF. */
1497 if (!TREE_SIDE_EFFECTS (then_clause) && !TREE_SIDE_EFFECTS (else_clause))
1499 *stmt_p = build_empty_stmt ();
1500 data->repeat = true;
1503 /* If there are no reachable statements in an arm, then we can
1504 zap the entire conditional. */
1505 else if (integer_nonzerop (cond) && !else_has_label)
1507 if (warn_notreached)
1508 remove_useless_stmts_warn_notreached (else_clause);
1509 *stmt_p = then_clause;
1510 data->repeat = true;
1512 else if (integer_zerop (cond) && !then_has_label)
1514 if (warn_notreached)
1515 remove_useless_stmts_warn_notreached (then_clause);
1516 *stmt_p = else_clause;
1517 data->repeat = true;
1520 /* Check a couple of simple things on then/else with single stmts. */
1523 tree then_stmt = expr_only (then_clause);
1524 tree else_stmt = expr_only (else_clause);
1526 /* Notice branches to a common destination. */
1527 if (then_stmt && else_stmt
1528 && TREE_CODE (then_stmt) == GOTO_EXPR
1529 && TREE_CODE (else_stmt) == GOTO_EXPR
1530 && (GOTO_DESTINATION (then_stmt) == GOTO_DESTINATION (else_stmt)))
1532 *stmt_p = then_stmt;
1533 data->repeat = true;
1536 /* If the THEN/ELSE clause merely assigns a value to a variable or
1537 parameter which is already known to contain that value, then
1538 remove the useless THEN/ELSE clause. */
1539 else if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL)
1542 && TREE_CODE (else_stmt) == GIMPLE_MODIFY_STMT
1543 && GIMPLE_STMT_OPERAND (else_stmt, 0) == cond
1544 && integer_zerop (GIMPLE_STMT_OPERAND (else_stmt, 1)))
1545 COND_EXPR_ELSE (*stmt_p) = alloc_stmt_list ();
1547 else if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
1548 && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL
1549 || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL)
1550 && TREE_CONSTANT (TREE_OPERAND (cond, 1)))
1552 tree stmt = (TREE_CODE (cond) == EQ_EXPR
1553 ? then_stmt : else_stmt);
1554 tree *location = (TREE_CODE (cond) == EQ_EXPR
1555 ? &COND_EXPR_THEN (*stmt_p)
1556 : &COND_EXPR_ELSE (*stmt_p));
1559 && TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
1560 && GIMPLE_STMT_OPERAND (stmt, 0) == TREE_OPERAND (cond, 0)
1561 && GIMPLE_STMT_OPERAND (stmt, 1) == TREE_OPERAND (cond, 1))
1562 *location = alloc_stmt_list ();
1566 /* Protect GOTOs in the arm of COND_EXPRs from being removed. They
1567 would be re-introduced during lowering. */
1568 data->last_goto = NULL;
1573 remove_useless_stmts_tf (tree *stmt_p, struct rus_data *data)
1575 bool save_may_branch, save_may_throw;
1576 bool this_may_branch, this_may_throw;
1578 /* Collect may_branch and may_throw information for the body only. */
1579 save_may_branch = data->may_branch;
1580 save_may_throw = data->may_throw;
1581 data->may_branch = false;
1582 data->may_throw = false;
1583 data->last_goto = NULL;
1585 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1587 this_may_branch = data->may_branch;
1588 this_may_throw = data->may_throw;
1589 data->may_branch |= save_may_branch;
1590 data->may_throw |= save_may_throw;
1591 data->last_goto = NULL;
1593 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1595 /* If the body is empty, then we can emit the FINALLY block without
1596 the enclosing TRY_FINALLY_EXPR. */
1597 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 0)))
1599 *stmt_p = TREE_OPERAND (*stmt_p, 1);
1600 data->repeat = true;
1603 /* If the handler is empty, then we can emit the TRY block without
1604 the enclosing TRY_FINALLY_EXPR. */
1605 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1607 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1608 data->repeat = true;
1611 /* If the body neither throws, nor branches, then we can safely
1612 string the TRY and FINALLY blocks together. */
1613 else if (!this_may_branch && !this_may_throw)
1615 tree stmt = *stmt_p;
1616 *stmt_p = TREE_OPERAND (stmt, 0);
1617 append_to_statement_list (TREE_OPERAND (stmt, 1), stmt_p);
1618 data->repeat = true;
1624 remove_useless_stmts_tc (tree *stmt_p, struct rus_data *data)
1626 bool save_may_throw, this_may_throw;
1627 tree_stmt_iterator i;
1630 /* Collect may_throw information for the body only. */
1631 save_may_throw = data->may_throw;
1632 data->may_throw = false;
1633 data->last_goto = NULL;
1635 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1637 this_may_throw = data->may_throw;
1638 data->may_throw = save_may_throw;
1640 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1641 if (!this_may_throw)
1643 if (warn_notreached)
1644 remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p, 1));
1645 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1646 data->repeat = true;
1650 /* Process the catch clause specially. We may be able to tell that
1651 no exceptions propagate past this point. */
1653 this_may_throw = true;
1654 i = tsi_start (TREE_OPERAND (*stmt_p, 1));
1655 stmt = tsi_stmt (i);
1656 data->last_goto = NULL;
1658 switch (TREE_CODE (stmt))
1661 for (; !tsi_end_p (i); tsi_next (&i))
1663 stmt = tsi_stmt (i);
1664 /* If we catch all exceptions, then the body does not
1665 propagate exceptions past this point. */
1666 if (CATCH_TYPES (stmt) == NULL)
1667 this_may_throw = false;
1668 data->last_goto = NULL;
1669 remove_useless_stmts_1 (&CATCH_BODY (stmt), data);
1673 case EH_FILTER_EXPR:
1674 if (EH_FILTER_MUST_NOT_THROW (stmt))
1675 this_may_throw = false;
1676 else if (EH_FILTER_TYPES (stmt) == NULL)
1677 this_may_throw = false;
1678 remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt), data);
1682 /* Otherwise this is a cleanup. */
1683 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1685 /* If the cleanup is empty, then we can emit the TRY block without
1686 the enclosing TRY_CATCH_EXPR. */
1687 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1689 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1690 data->repeat = true;
1694 data->may_throw |= this_may_throw;
1699 remove_useless_stmts_bind (tree *stmt_p, struct rus_data *data)
1703 /* First remove anything underneath the BIND_EXPR. */
1704 remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p), data);
1706 /* If the BIND_EXPR has no variables, then we can pull everything
1707 up one level and remove the BIND_EXPR, unless this is the toplevel
1708 BIND_EXPR for the current function or an inlined function.
1710 When this situation occurs we will want to apply this
1711 optimization again. */
1712 block = BIND_EXPR_BLOCK (*stmt_p);
1713 if (BIND_EXPR_VARS (*stmt_p) == NULL_TREE
1714 && *stmt_p != DECL_SAVED_TREE (current_function_decl)
1716 || ! BLOCK_ABSTRACT_ORIGIN (block)
1717 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1720 *stmt_p = BIND_EXPR_BODY (*stmt_p);
1721 data->repeat = true;
1727 remove_useless_stmts_goto (tree *stmt_p, struct rus_data *data)
1729 tree dest = GOTO_DESTINATION (*stmt_p);
1731 data->may_branch = true;
1732 data->last_goto = NULL;
1734 /* Record the last goto expr, so that we can delete it if unnecessary. */
1735 if (TREE_CODE (dest) == LABEL_DECL)
1736 data->last_goto = stmt_p;
1741 remove_useless_stmts_label (tree *stmt_p, struct rus_data *data)
1743 tree label = LABEL_EXPR_LABEL (*stmt_p);
1745 data->has_label = true;
1747 /* We do want to jump across non-local label receiver code. */
1748 if (DECL_NONLOCAL (label))
1749 data->last_goto = NULL;
1751 else if (data->last_goto && GOTO_DESTINATION (*data->last_goto) == label)
1753 *data->last_goto = build_empty_stmt ();
1754 data->repeat = true;
1757 /* ??? Add something here to delete unused labels. */
1761 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1762 decl. This allows us to eliminate redundant or useless
1763 calls to "const" functions.
1765 Gimplifier already does the same operation, but we may notice functions
1766 being const and pure once their calls has been gimplified, so we need
1767 to update the flag. */
1770 update_call_expr_flags (tree call)
1772 tree decl = get_callee_fndecl (call);
1775 if (call_expr_flags (call) & (ECF_CONST | ECF_PURE))
1776 TREE_SIDE_EFFECTS (call) = 0;
1777 if (TREE_NOTHROW (decl))
1778 TREE_NOTHROW (call) = 1;
1782 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1785 notice_special_calls (tree t)
1787 int flags = call_expr_flags (t);
1789 if (flags & ECF_MAY_BE_ALLOCA)
1790 current_function_calls_alloca = true;
1791 if (flags & ECF_RETURNS_TWICE)
1792 current_function_calls_setjmp = true;
1796 /* Clear flags set by notice_special_calls. Used by dead code removal
1797 to update the flags. */
1800 clear_special_calls (void)
1802 current_function_calls_alloca = false;
1803 current_function_calls_setjmp = false;
1808 remove_useless_stmts_1 (tree *tp, struct rus_data *data)
1812 switch (TREE_CODE (t))
1815 remove_useless_stmts_cond (tp, data);
1818 case TRY_FINALLY_EXPR:
1819 remove_useless_stmts_tf (tp, data);
1822 case TRY_CATCH_EXPR:
1823 remove_useless_stmts_tc (tp, data);
1827 remove_useless_stmts_bind (tp, data);
1831 remove_useless_stmts_goto (tp, data);
1835 remove_useless_stmts_label (tp, data);
1840 data->last_goto = NULL;
1841 data->may_branch = true;
1846 data->last_goto = NULL;
1847 notice_special_calls (t);
1848 update_call_expr_flags (t);
1849 if (tree_could_throw_p (t))
1850 data->may_throw = true;
1856 case GIMPLE_MODIFY_STMT:
1857 data->last_goto = NULL;
1859 op = get_call_expr_in (t);
1862 update_call_expr_flags (op);
1863 notice_special_calls (op);
1865 if (tree_could_throw_p (t))
1866 data->may_throw = true;
1869 case STATEMENT_LIST:
1871 tree_stmt_iterator i = tsi_start (t);
1872 while (!tsi_end_p (i))
1875 if (IS_EMPTY_STMT (t))
1881 remove_useless_stmts_1 (tsi_stmt_ptr (i), data);
1884 if (TREE_CODE (t) == STATEMENT_LIST)
1886 tsi_link_before (&i, t, TSI_SAME_STMT);
1896 data->last_goto = NULL;
1900 data->last_goto = NULL;
1906 remove_useless_stmts (void)
1908 struct rus_data data;
1910 clear_special_calls ();
1914 memset (&data, 0, sizeof (data));
1915 remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl), &data);
1917 while (data.repeat);
1922 struct tree_opt_pass pass_remove_useless_stmts =
1924 "useless", /* name */
1926 remove_useless_stmts, /* execute */
1929 0, /* static_pass_number */
1931 PROP_gimple_any, /* properties_required */
1932 0, /* properties_provided */
1933 0, /* properties_destroyed */
1934 0, /* todo_flags_start */
1935 TODO_dump_func, /* todo_flags_finish */
1939 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
1942 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
1946 /* Since this block is no longer reachable, we can just delete all
1947 of its PHI nodes. */
1948 phi = phi_nodes (bb);
1951 tree next = PHI_CHAIN (phi);
1952 remove_phi_node (phi, NULL_TREE, true);
1956 /* Remove edges to BB's successors. */
1957 while (EDGE_COUNT (bb->succs) > 0)
1958 remove_edge (EDGE_SUCC (bb, 0));
1962 /* Remove statements of basic block BB. */
1965 remove_bb (basic_block bb)
1967 block_stmt_iterator i;
1968 #ifdef USE_MAPPED_LOCATION
1969 source_location loc = UNKNOWN_LOCATION;
1971 source_locus loc = 0;
1976 fprintf (dump_file, "Removing basic block %d\n", bb->index);
1977 if (dump_flags & TDF_DETAILS)
1979 dump_bb (bb, dump_file, 0);
1980 fprintf (dump_file, "\n");
1986 struct loop *loop = bb->loop_father;
1988 /* If a loop gets removed, clean up the information associated
1990 if (loop->latch == bb
1991 || loop->header == bb)
1992 free_numbers_of_iterations_estimates_loop (loop);
1995 /* Remove all the instructions in the block. */
1996 if (bb_stmt_list (bb) != NULL_TREE)
1998 for (i = bsi_start (bb); !bsi_end_p (i);)
2000 tree stmt = bsi_stmt (i);
2001 if (TREE_CODE (stmt) == LABEL_EXPR
2002 && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt))
2003 || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))))
2006 block_stmt_iterator new_bsi;
2008 /* A non-reachable non-local label may still be referenced.
2009 But it no longer needs to carry the extra semantics of
2011 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
2013 DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)) = 0;
2014 FORCED_LABEL (LABEL_EXPR_LABEL (stmt)) = 1;
2017 new_bb = bb->prev_bb;
2018 new_bsi = bsi_start (new_bb);
2019 bsi_remove (&i, false);
2020 bsi_insert_before (&new_bsi, stmt, BSI_NEW_STMT);
2024 /* Release SSA definitions if we are in SSA. Note that we
2025 may be called when not in SSA. For example,
2026 final_cleanup calls this function via
2027 cleanup_tree_cfg. */
2028 if (gimple_in_ssa_p (cfun))
2029 release_defs (stmt);
2031 bsi_remove (&i, true);
2034 /* Don't warn for removed gotos. Gotos are often removed due to
2035 jump threading, thus resulting in bogus warnings. Not great,
2036 since this way we lose warnings for gotos in the original
2037 program that are indeed unreachable. */
2038 if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc)
2040 #ifdef USE_MAPPED_LOCATION
2041 if (EXPR_HAS_LOCATION (stmt))
2042 loc = EXPR_LOCATION (stmt);
2045 t = EXPR_LOCUS (stmt);
2046 if (t && LOCATION_LINE (*t) > 0)
2053 /* If requested, give a warning that the first statement in the
2054 block is unreachable. We walk statements backwards in the
2055 loop above, so the last statement we process is the first statement
2057 #ifdef USE_MAPPED_LOCATION
2058 if (loc > BUILTINS_LOCATION)
2059 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2062 warning (OPT_Wunreachable_code, "%Hwill never be executed", loc);
2065 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2070 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2071 predicate VAL, return the edge that will be taken out of the block.
2072 If VAL does not match a unique edge, NULL is returned. */
2075 find_taken_edge (basic_block bb, tree val)
2079 stmt = last_stmt (bb);
2082 gcc_assert (is_ctrl_stmt (stmt));
2085 if (! is_gimple_min_invariant (val))
2088 if (TREE_CODE (stmt) == COND_EXPR)
2089 return find_taken_edge_cond_expr (bb, val);
2091 if (TREE_CODE (stmt) == SWITCH_EXPR)
2092 return find_taken_edge_switch_expr (bb, val);
2094 if (computed_goto_p (stmt))
2096 /* Only optimize if the argument is a label, if the argument is
2097 not a label then we can not construct a proper CFG.
2099 It may be the case that we only need to allow the LABEL_REF to
2100 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2101 appear inside a LABEL_EXPR just to be safe. */
2102 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2103 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2104 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2111 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2112 statement, determine which of the outgoing edges will be taken out of the
2113 block. Return NULL if either edge may be taken. */
2116 find_taken_edge_computed_goto (basic_block bb, tree val)
2121 dest = label_to_block (val);
2124 e = find_edge (bb, dest);
2125 gcc_assert (e != NULL);
2131 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2132 statement, determine which of the two edges will be taken out of the
2133 block. Return NULL if either edge may be taken. */
2136 find_taken_edge_cond_expr (basic_block bb, tree val)
2138 edge true_edge, false_edge;
2140 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2142 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2143 return (integer_zerop (val) ? false_edge : true_edge);
2146 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2147 statement, determine which edge will be taken out of the block. Return
2148 NULL if any edge may be taken. */
2151 find_taken_edge_switch_expr (basic_block bb, tree val)
2153 tree switch_expr, taken_case;
2154 basic_block dest_bb;
2157 switch_expr = last_stmt (bb);
2158 taken_case = find_case_label_for_value (switch_expr, val);
2159 dest_bb = label_to_block (CASE_LABEL (taken_case));
2161 e = find_edge (bb, dest_bb);
2167 /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL.
2168 We can make optimal use here of the fact that the case labels are
2169 sorted: We can do a binary search for a case matching VAL. */
2172 find_case_label_for_value (tree switch_expr, tree val)
2174 tree vec = SWITCH_LABELS (switch_expr);
2175 size_t low, high, n = TREE_VEC_LENGTH (vec);
2176 tree default_case = TREE_VEC_ELT (vec, n - 1);
2178 for (low = -1, high = n - 1; high - low > 1; )
2180 size_t i = (high + low) / 2;
2181 tree t = TREE_VEC_ELT (vec, i);
2184 /* Cache the result of comparing CASE_LOW and val. */
2185 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2192 if (CASE_HIGH (t) == NULL)
2194 /* A singe-valued case label. */
2200 /* A case range. We can only handle integer ranges. */
2201 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2206 return default_case;
2212 /*---------------------------------------------------------------------------
2214 ---------------------------------------------------------------------------*/
2216 /* Dump tree-specific information of block BB to file OUTF. */
2219 tree_dump_bb (basic_block bb, FILE *outf, int indent)
2221 dump_generic_bb (outf, bb, indent, TDF_VOPS|TDF_MEMSYMS);
2225 /* Dump a basic block on stderr. */
2228 debug_tree_bb (basic_block bb)
2230 dump_bb (bb, stderr, 0);
2234 /* Dump basic block with index N on stderr. */
2237 debug_tree_bb_n (int n)
2239 debug_tree_bb (BASIC_BLOCK (n));
2240 return BASIC_BLOCK (n);
2244 /* Dump the CFG on stderr.
2246 FLAGS are the same used by the tree dumping functions
2247 (see TDF_* in tree-pass.h). */
2250 debug_tree_cfg (int flags)
2252 dump_tree_cfg (stderr, flags);
2256 /* Dump the program showing basic block boundaries on the given FILE.
2258 FLAGS are the same used by the tree dumping functions (see TDF_* in
2262 dump_tree_cfg (FILE *file, int flags)
2264 if (flags & TDF_DETAILS)
2266 const char *funcname
2267 = lang_hooks.decl_printable_name (current_function_decl, 2);
2270 fprintf (file, ";; Function %s\n\n", funcname);
2271 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2272 n_basic_blocks, n_edges, last_basic_block);
2274 brief_dump_cfg (file);
2275 fprintf (file, "\n");
2278 if (flags & TDF_STATS)
2279 dump_cfg_stats (file);
2281 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2285 /* Dump CFG statistics on FILE. */
2288 dump_cfg_stats (FILE *file)
2290 static long max_num_merged_labels = 0;
2291 unsigned long size, total = 0;
2294 const char * const fmt_str = "%-30s%-13s%12s\n";
2295 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2296 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2297 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2298 const char *funcname
2299 = lang_hooks.decl_printable_name (current_function_decl, 2);
2302 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2304 fprintf (file, "---------------------------------------------------------\n");
2305 fprintf (file, fmt_str, "", " Number of ", "Memory");
2306 fprintf (file, fmt_str, "", " instances ", "used ");
2307 fprintf (file, "---------------------------------------------------------\n");
2309 size = n_basic_blocks * sizeof (struct basic_block_def);
2311 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2312 SCALE (size), LABEL (size));
2316 num_edges += EDGE_COUNT (bb->succs);
2317 size = num_edges * sizeof (struct edge_def);
2319 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2321 fprintf (file, "---------------------------------------------------------\n");
2322 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2324 fprintf (file, "---------------------------------------------------------\n");
2325 fprintf (file, "\n");
2327 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2328 max_num_merged_labels = cfg_stats.num_merged_labels;
2330 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2331 cfg_stats.num_merged_labels, max_num_merged_labels);
2333 fprintf (file, "\n");
2337 /* Dump CFG statistics on stderr. Keep extern so that it's always
2338 linked in the final executable. */
2341 debug_cfg_stats (void)
2343 dump_cfg_stats (stderr);
2347 /* Dump the flowgraph to a .vcg FILE. */
2350 tree_cfg2vcg (FILE *file)
2355 const char *funcname
2356 = lang_hooks.decl_printable_name (current_function_decl, 2);
2358 /* Write the file header. */
2359 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2360 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2361 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2363 /* Write blocks and edges. */
2364 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2366 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2369 if (e->flags & EDGE_FAKE)
2370 fprintf (file, " linestyle: dotted priority: 10");
2372 fprintf (file, " linestyle: solid priority: 100");
2374 fprintf (file, " }\n");
2380 enum tree_code head_code, end_code;
2381 const char *head_name, *end_name;
2384 tree first = first_stmt (bb);
2385 tree last = last_stmt (bb);
2389 head_code = TREE_CODE (first);
2390 head_name = tree_code_name[head_code];
2391 head_line = get_lineno (first);
2394 head_name = "no-statement";
2398 end_code = TREE_CODE (last);
2399 end_name = tree_code_name[end_code];
2400 end_line = get_lineno (last);
2403 end_name = "no-statement";
2405 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2406 bb->index, bb->index, head_name, head_line, end_name,
2409 FOR_EACH_EDGE (e, ei, bb->succs)
2411 if (e->dest == EXIT_BLOCK_PTR)
2412 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2414 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2416 if (e->flags & EDGE_FAKE)
2417 fprintf (file, " priority: 10 linestyle: dotted");
2419 fprintf (file, " priority: 100 linestyle: solid");
2421 fprintf (file, " }\n");
2424 if (bb->next_bb != EXIT_BLOCK_PTR)
2428 fputs ("}\n\n", file);
2433 /*---------------------------------------------------------------------------
2434 Miscellaneous helpers
2435 ---------------------------------------------------------------------------*/
2437 /* Return true if T represents a stmt that always transfers control. */
2440 is_ctrl_stmt (const_tree t)
2442 return (TREE_CODE (t) == COND_EXPR
2443 || TREE_CODE (t) == SWITCH_EXPR
2444 || TREE_CODE (t) == GOTO_EXPR
2445 || TREE_CODE (t) == RETURN_EXPR
2446 || TREE_CODE (t) == RESX_EXPR);
2450 /* Return true if T is a statement that may alter the flow of control
2451 (e.g., a call to a non-returning function). */
2454 is_ctrl_altering_stmt (tree t)
2459 call = get_call_expr_in (t);
2462 /* A non-pure/const CALL_EXPR alters flow control if the current
2463 function has nonlocal labels. */
2464 if (TREE_SIDE_EFFECTS (call) && current_function_has_nonlocal_label)
2467 /* A CALL_EXPR also alters control flow if it does not return. */
2468 if (call_expr_flags (call) & ECF_NORETURN)
2472 /* OpenMP directives alter control flow. */
2473 if (OMP_DIRECTIVE_P (t))
2476 /* If a statement can throw, it alters control flow. */
2477 return tree_can_throw_internal (t);
2481 /* Return true if T is a computed goto. */
2484 computed_goto_p (const_tree t)
2486 return (TREE_CODE (t) == GOTO_EXPR
2487 && TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL);
2491 /* Return true if T is a simple local goto. */
2494 simple_goto_p (const_tree t)
2496 return (TREE_CODE (t) == GOTO_EXPR
2497 && TREE_CODE (GOTO_DESTINATION (t)) == LABEL_DECL);
2501 /* Return true if T can make an abnormal transfer of control flow.
2502 Transfers of control flow associated with EH are excluded. */
2505 tree_can_make_abnormal_goto (const_tree t)
2507 if (computed_goto_p (t))
2509 if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
2510 t = GIMPLE_STMT_OPERAND (t, 1);
2511 if (TREE_CODE (t) == WITH_SIZE_EXPR)
2512 t = TREE_OPERAND (t, 0);
2513 if (TREE_CODE (t) == CALL_EXPR)
2514 return TREE_SIDE_EFFECTS (t) && current_function_has_nonlocal_label;
2519 /* Return true if T should start a new basic block. PREV_T is the
2520 statement preceding T. It is used when T is a label or a case label.
2521 Labels should only start a new basic block if their previous statement
2522 wasn't a label. Otherwise, sequence of labels would generate
2523 unnecessary basic blocks that only contain a single label. */
2526 stmt_starts_bb_p (const_tree t, const_tree prev_t)
2531 /* LABEL_EXPRs start a new basic block only if the preceding
2532 statement wasn't a label of the same type. This prevents the
2533 creation of consecutive blocks that have nothing but a single
2535 if (TREE_CODE (t) == LABEL_EXPR)
2537 /* Nonlocal and computed GOTO targets always start a new block. */
2538 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t))
2539 || FORCED_LABEL (LABEL_EXPR_LABEL (t)))
2542 if (prev_t && TREE_CODE (prev_t) == LABEL_EXPR)
2544 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t)))
2547 cfg_stats.num_merged_labels++;
2558 /* Return true if T should end a basic block. */
2561 stmt_ends_bb_p (tree t)
2563 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2566 /* Remove block annotations and other datastructures. */
2569 delete_tree_cfg_annotations (void)
2572 block_stmt_iterator bsi;
2574 /* Remove annotations from every tree in the function. */
2576 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
2578 tree stmt = bsi_stmt (bsi);
2579 ggc_free (stmt->base.ann);
2580 stmt->base.ann = NULL;
2582 label_to_block_map = NULL;
2586 /* Return the first statement in basic block BB. */
2589 first_stmt (basic_block bb)
2591 block_stmt_iterator i = bsi_start (bb);
2592 return !bsi_end_p (i) ? bsi_stmt (i) : NULL_TREE;
2596 /* Return the last statement in basic block BB. */
2599 last_stmt (basic_block bb)
2601 block_stmt_iterator b = bsi_last (bb);
2602 return !bsi_end_p (b) ? bsi_stmt (b) : NULL_TREE;
2606 /* Return the last statement of an otherwise empty block. Return NULL
2607 if the block is totally empty, or if it contains more than one
2611 last_and_only_stmt (basic_block bb)
2613 block_stmt_iterator i = bsi_last (bb);
2619 last = bsi_stmt (i);
2624 /* Empty statements should no longer appear in the instruction stream.
2625 Everything that might have appeared before should be deleted by
2626 remove_useless_stmts, and the optimizers should just bsi_remove
2627 instead of smashing with build_empty_stmt.
2629 Thus the only thing that should appear here in a block containing
2630 one executable statement is a label. */
2631 prev = bsi_stmt (i);
2632 if (TREE_CODE (prev) == LABEL_EXPR)
2639 /* Mark BB as the basic block holding statement T. */
2642 set_bb_for_stmt (tree t, basic_block bb)
2644 if (TREE_CODE (t) == PHI_NODE)
2646 else if (TREE_CODE (t) == STATEMENT_LIST)
2648 tree_stmt_iterator i;
2649 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2650 set_bb_for_stmt (tsi_stmt (i), bb);
2654 stmt_ann_t ann = get_stmt_ann (t);
2657 /* If the statement is a label, add the label to block-to-labels map
2658 so that we can speed up edge creation for GOTO_EXPRs. */
2659 if (TREE_CODE (t) == LABEL_EXPR)
2663 t = LABEL_EXPR_LABEL (t);
2664 uid = LABEL_DECL_UID (t);
2667 unsigned old_len = VEC_length (basic_block, label_to_block_map);
2668 LABEL_DECL_UID (t) = uid = cfun->last_label_uid++;
2669 if (old_len <= (unsigned) uid)
2671 unsigned new_len = 3 * uid / 2;
2673 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
2678 /* We're moving an existing label. Make sure that we've
2679 removed it from the old block. */
2681 || !VEC_index (basic_block, label_to_block_map, uid));
2682 VEC_replace (basic_block, label_to_block_map, uid, bb);
2687 /* Faster version of set_bb_for_stmt that assume that statement is being moved
2688 from one basic block to another.
2689 For BB splitting we can run into quadratic case, so performance is quite
2690 important and knowing that the tables are big enough, change_bb_for_stmt
2691 can inline as leaf function. */
2693 change_bb_for_stmt (tree t, basic_block bb)
2695 get_stmt_ann (t)->bb = bb;
2696 if (TREE_CODE (t) == LABEL_EXPR)
2697 VEC_replace (basic_block, label_to_block_map,
2698 LABEL_DECL_UID (LABEL_EXPR_LABEL (t)), bb);
2701 /* Finds iterator for STMT. */
2703 extern block_stmt_iterator
2704 bsi_for_stmt (tree stmt)
2706 block_stmt_iterator bsi;
2708 for (bsi = bsi_start (bb_for_stmt (stmt)); !bsi_end_p (bsi); bsi_next (&bsi))
2709 if (bsi_stmt (bsi) == stmt)
2715 /* Mark statement T as modified, and update it. */
2717 update_modified_stmts (tree t)
2719 if (!ssa_operands_active ())
2721 if (TREE_CODE (t) == STATEMENT_LIST)
2723 tree_stmt_iterator i;
2725 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2727 stmt = tsi_stmt (i);
2728 update_stmt_if_modified (stmt);
2732 update_stmt_if_modified (t);
2735 /* Insert statement (or statement list) T before the statement
2736 pointed-to by iterator I. M specifies how to update iterator I
2737 after insertion (see enum bsi_iterator_update). */
2740 bsi_insert_before (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2742 set_bb_for_stmt (t, i->bb);
2743 update_modified_stmts (t);
2744 tsi_link_before (&i->tsi, t, m);
2748 /* Insert statement (or statement list) T after the statement
2749 pointed-to by iterator I. M specifies how to update iterator I
2750 after insertion (see enum bsi_iterator_update). */
2753 bsi_insert_after (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2755 set_bb_for_stmt (t, i->bb);
2756 update_modified_stmts (t);
2757 tsi_link_after (&i->tsi, t, m);
2761 /* Remove the statement pointed to by iterator I. The iterator is updated
2762 to the next statement.
2764 When REMOVE_EH_INFO is true we remove the statement pointed to by
2765 iterator I from the EH tables. Otherwise we do not modify the EH
2768 Generally, REMOVE_EH_INFO should be true when the statement is going to
2769 be removed from the IL and not reinserted elsewhere. */
2772 bsi_remove (block_stmt_iterator *i, bool remove_eh_info)
2774 tree t = bsi_stmt (*i);
2775 set_bb_for_stmt (t, NULL);
2776 delink_stmt_imm_use (t);
2777 tsi_delink (&i->tsi);
2778 mark_stmt_modified (t);
2781 remove_stmt_from_eh_region (t);
2782 gimple_remove_stmt_histograms (cfun, t);
2787 /* Move the statement at FROM so it comes right after the statement at TO. */
2790 bsi_move_after (block_stmt_iterator *from, block_stmt_iterator *to)
2792 tree stmt = bsi_stmt (*from);
2793 bsi_remove (from, false);
2794 /* We must have BSI_NEW_STMT here, as bsi_move_after is sometimes used to
2795 move statements to an empty block. */
2796 bsi_insert_after (to, stmt, BSI_NEW_STMT);
2800 /* Move the statement at FROM so it comes right before the statement at TO. */
2803 bsi_move_before (block_stmt_iterator *from, block_stmt_iterator *to)
2805 tree stmt = bsi_stmt (*from);
2806 bsi_remove (from, false);
2807 /* For consistency with bsi_move_after, it might be better to have
2808 BSI_NEW_STMT here; however, that breaks several places that expect
2809 that TO does not change. */
2810 bsi_insert_before (to, stmt, BSI_SAME_STMT);
2814 /* Move the statement at FROM to the end of basic block BB. */
2817 bsi_move_to_bb_end (block_stmt_iterator *from, basic_block bb)
2819 block_stmt_iterator last = bsi_last (bb);
2821 /* Have to check bsi_end_p because it could be an empty block. */
2822 if (!bsi_end_p (last) && is_ctrl_stmt (bsi_stmt (last)))
2823 bsi_move_before (from, &last);
2825 bsi_move_after (from, &last);
2829 /* Replace the contents of the statement pointed to by iterator BSI
2830 with STMT. If UPDATE_EH_INFO is true, the exception handling
2831 information of the original statement is moved to the new statement. */
2834 bsi_replace (const block_stmt_iterator *bsi, tree stmt, bool update_eh_info)
2837 tree orig_stmt = bsi_stmt (*bsi);
2839 if (stmt == orig_stmt)
2841 SET_EXPR_LOCUS (stmt, EXPR_LOCUS (orig_stmt));
2842 set_bb_for_stmt (stmt, bsi->bb);
2844 /* Preserve EH region information from the original statement, if
2845 requested by the caller. */
2848 eh_region = lookup_stmt_eh_region (orig_stmt);
2851 remove_stmt_from_eh_region (orig_stmt);
2852 add_stmt_to_eh_region (stmt, eh_region);
2856 gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
2857 gimple_remove_stmt_histograms (cfun, orig_stmt);
2858 delink_stmt_imm_use (orig_stmt);
2859 *bsi_stmt_ptr (*bsi) = stmt;
2860 mark_stmt_modified (stmt);
2861 update_modified_stmts (stmt);
2865 /* Insert the statement pointed-to by BSI into edge E. Every attempt
2866 is made to place the statement in an existing basic block, but
2867 sometimes that isn't possible. When it isn't possible, the edge is
2868 split and the statement is added to the new block.
2870 In all cases, the returned *BSI points to the correct location. The
2871 return value is true if insertion should be done after the location,
2872 or false if it should be done before the location. If new basic block
2873 has to be created, it is stored in *NEW_BB. */
2876 tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi,
2877 basic_block *new_bb)
2879 basic_block dest, src;
2885 /* If the destination has one predecessor which has no PHI nodes,
2886 insert there. Except for the exit block.
2888 The requirement for no PHI nodes could be relaxed. Basically we
2889 would have to examine the PHIs to prove that none of them used
2890 the value set by the statement we want to insert on E. That
2891 hardly seems worth the effort. */
2892 if (single_pred_p (dest)
2893 && ! phi_nodes (dest)
2894 && dest != EXIT_BLOCK_PTR)
2896 *bsi = bsi_start (dest);
2897 if (bsi_end_p (*bsi))
2900 /* Make sure we insert after any leading labels. */
2901 tmp = bsi_stmt (*bsi);
2902 while (TREE_CODE (tmp) == LABEL_EXPR)
2905 if (bsi_end_p (*bsi))
2907 tmp = bsi_stmt (*bsi);
2910 if (bsi_end_p (*bsi))
2912 *bsi = bsi_last (dest);
2919 /* If the source has one successor, the edge is not abnormal and
2920 the last statement does not end a basic block, insert there.
2921 Except for the entry block. */
2923 if ((e->flags & EDGE_ABNORMAL) == 0
2924 && single_succ_p (src)
2925 && src != ENTRY_BLOCK_PTR)
2927 *bsi = bsi_last (src);
2928 if (bsi_end_p (*bsi))
2931 tmp = bsi_stmt (*bsi);
2932 if (!stmt_ends_bb_p (tmp))
2935 /* Insert code just before returning the value. We may need to decompose
2936 the return in the case it contains non-trivial operand. */
2937 if (TREE_CODE (tmp) == RETURN_EXPR)
2939 tree op = TREE_OPERAND (tmp, 0);
2940 if (op && !is_gimple_val (op))
2942 gcc_assert (TREE_CODE (op) == GIMPLE_MODIFY_STMT);
2943 bsi_insert_before (bsi, op, BSI_NEW_STMT);
2944 TREE_OPERAND (tmp, 0) = GIMPLE_STMT_OPERAND (op, 0);
2951 /* Otherwise, create a new basic block, and split this edge. */
2952 dest = split_edge (e);
2955 e = single_pred_edge (dest);
2960 /* This routine will commit all pending edge insertions, creating any new
2961 basic blocks which are necessary. */
2964 bsi_commit_edge_inserts (void)
2970 bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL);
2973 FOR_EACH_EDGE (e, ei, bb->succs)
2974 bsi_commit_one_edge_insert (e, NULL);
2978 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
2979 to this block, otherwise set it to NULL. */
2982 bsi_commit_one_edge_insert (edge e, basic_block *new_bb)
2986 if (PENDING_STMT (e))
2988 block_stmt_iterator bsi;
2989 tree stmt = PENDING_STMT (e);
2991 PENDING_STMT (e) = NULL_TREE;
2993 if (tree_find_edge_insert_loc (e, &bsi, new_bb))
2994 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
2996 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3001 /* Add STMT to the pending list of edge E. No actual insertion is
3002 made until a call to bsi_commit_edge_inserts () is made. */
3005 bsi_insert_on_edge (edge e, tree stmt)
3007 append_to_statement_list (stmt, &PENDING_STMT (e));
3010 /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new
3011 block has to be created, it is returned. */
3014 bsi_insert_on_edge_immediate (edge e, tree stmt)
3016 block_stmt_iterator bsi;
3017 basic_block new_bb = NULL;
3019 gcc_assert (!PENDING_STMT (e));
3021 if (tree_find_edge_insert_loc (e, &bsi, &new_bb))
3022 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3024 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3029 /*---------------------------------------------------------------------------
3030 Tree specific functions for CFG manipulation
3031 ---------------------------------------------------------------------------*/
3033 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
3036 reinstall_phi_args (edge new_edge, edge old_edge)
3040 if (!PENDING_STMT (old_edge))
3043 for (var = PENDING_STMT (old_edge), phi = phi_nodes (new_edge->dest);
3045 var = TREE_CHAIN (var), phi = PHI_CHAIN (phi))
3047 tree result = TREE_PURPOSE (var);
3048 tree arg = TREE_VALUE (var);
3050 gcc_assert (result == PHI_RESULT (phi));
3052 add_phi_arg (phi, arg, new_edge);
3055 PENDING_STMT (old_edge) = NULL;
3058 /* Returns the basic block after which the new basic block created
3059 by splitting edge EDGE_IN should be placed. Tries to keep the new block
3060 near its "logical" location. This is of most help to humans looking
3061 at debugging dumps. */
3064 split_edge_bb_loc (edge edge_in)
3066 basic_block dest = edge_in->dest;
3068 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
3069 return edge_in->src;
3071 return dest->prev_bb;
3074 /* Split a (typically critical) edge EDGE_IN. Return the new block.
3075 Abort on abnormal edges. */
3078 tree_split_edge (edge edge_in)
3080 basic_block new_bb, after_bb, dest;
3083 /* Abnormal edges cannot be split. */
3084 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
3086 dest = edge_in->dest;
3088 after_bb = split_edge_bb_loc (edge_in);
3090 new_bb = create_empty_bb (after_bb);
3091 new_bb->frequency = EDGE_FREQUENCY (edge_in);
3092 new_bb->count = edge_in->count;
3093 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
3094 new_edge->probability = REG_BR_PROB_BASE;
3095 new_edge->count = edge_in->count;
3097 e = redirect_edge_and_branch (edge_in, new_bb);
3098 gcc_assert (e == edge_in);
3099 reinstall_phi_args (new_edge, e);
3104 /* Callback for walk_tree, check that all elements with address taken are
3105 properly noticed as such. The DATA is an int* that is 1 if TP was seen
3106 inside a PHI node. */
3109 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
3112 bool in_phi = (data != NULL);
3117 /* Check operand N for being valid GIMPLE and give error MSG if not. */
3118 #define CHECK_OP(N, MSG) \
3119 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
3120 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
3122 switch (TREE_CODE (t))
3125 if (SSA_NAME_IN_FREE_LIST (t))
3127 error ("SSA name in freelist but still referenced");
3133 x = fold (ASSERT_EXPR_COND (t));
3134 if (x == boolean_false_node)
3136 error ("ASSERT_EXPR with an always-false condition");
3144 case GIMPLE_MODIFY_STMT:
3145 x = GIMPLE_STMT_OPERAND (t, 0);
3146 if (TREE_CODE (x) == BIT_FIELD_REF
3147 && is_gimple_reg (TREE_OPERAND (x, 0)))
3149 error ("GIMPLE register modified with BIT_FIELD_REF");
3158 bool old_side_effects;
3161 bool new_side_effects;
3163 /* ??? tree-ssa-alias.c may have overlooked dead PHI nodes, missing
3164 dead PHIs that take the address of something. But if the PHI
3165 result is dead, the fact that it takes the address of anything
3166 is irrelevant. Because we can not tell from here if a PHI result
3167 is dead, we just skip this check for PHIs altogether. This means
3168 we may be missing "valid" checks, but what can you do?
3169 This was PR19217. */
3173 old_invariant = TREE_INVARIANT (t);
3174 old_constant = TREE_CONSTANT (t);
3175 old_side_effects = TREE_SIDE_EFFECTS (t);
3177 recompute_tree_invariant_for_addr_expr (t);
3178 new_invariant = TREE_INVARIANT (t);
3179 new_side_effects = TREE_SIDE_EFFECTS (t);
3180 new_constant = TREE_CONSTANT (t);
3182 if (old_invariant != new_invariant)
3184 error ("invariant not recomputed when ADDR_EXPR changed");
3188 if (old_constant != new_constant)
3190 error ("constant not recomputed when ADDR_EXPR changed");
3193 if (old_side_effects != new_side_effects)
3195 error ("side effects not recomputed when ADDR_EXPR changed");
3199 /* Skip any references (they will be checked when we recurse down the
3200 tree) and ensure that any variable used as a prefix is marked
3202 for (x = TREE_OPERAND (t, 0);
3203 handled_component_p (x);
3204 x = TREE_OPERAND (x, 0))
3207 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
3209 if (!TREE_ADDRESSABLE (x))
3211 error ("address taken, but ADDRESSABLE bit not set");
3218 x = COND_EXPR_COND (t);
3219 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
3221 error ("non-integral used in condition");
3224 if (!is_gimple_condexpr (x))
3226 error ("invalid conditional operand");
3233 case FIX_TRUNC_EXPR:
3238 case NON_LVALUE_EXPR:
3239 case TRUTH_NOT_EXPR:
3240 CHECK_OP (0, "invalid operand to unary operator");
3247 case ARRAY_RANGE_REF:
3249 case VIEW_CONVERT_EXPR:
3250 /* We have a nest of references. Verify that each of the operands
3251 that determine where to reference is either a constant or a variable,
3252 verify that the base is valid, and then show we've already checked
3254 while (handled_component_p (t))
3256 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
3257 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
3258 else if (TREE_CODE (t) == ARRAY_REF
3259 || TREE_CODE (t) == ARRAY_RANGE_REF)
3261 CHECK_OP (1, "invalid array index");
3262 if (TREE_OPERAND (t, 2))
3263 CHECK_OP (2, "invalid array lower bound");
3264 if (TREE_OPERAND (t, 3))
3265 CHECK_OP (3, "invalid array stride");
3267 else if (TREE_CODE (t) == BIT_FIELD_REF)
3269 CHECK_OP (1, "invalid operand to BIT_FIELD_REF");
3270 CHECK_OP (2, "invalid operand to BIT_FIELD_REF");
3273 t = TREE_OPERAND (t, 0);
3276 if (!CONSTANT_CLASS_P (t) && !is_gimple_lvalue (t))
3278 error ("invalid reference prefix");
3285 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
3286 POINTER_PLUS_EXPR. */
3287 if (POINTER_TYPE_P (TREE_TYPE (t)))
3289 error ("invalid operand to plus/minus, type is a pointer");
3292 CHECK_OP (0, "invalid operand to binary operator");
3293 CHECK_OP (1, "invalid operand to binary operator");
3296 case POINTER_PLUS_EXPR:
3297 /* Check to make sure the first operand is a pointer or reference type. */
3298 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
3300 error ("invalid operand to pointer plus, first operand is not a pointer");
3303 /* Check to make sure the second operand is an integer with type of
3305 if (!useless_type_conversion_p (sizetype,
3306 TREE_TYPE (TREE_OPERAND (t, 1))))
3308 error ("invalid operand to pointer plus, second operand is not an "
3309 "integer with type of sizetype.");
3319 case UNORDERED_EXPR:
3328 case TRUNC_DIV_EXPR:
3330 case FLOOR_DIV_EXPR:
3331 case ROUND_DIV_EXPR:
3332 case TRUNC_MOD_EXPR:
3334 case FLOOR_MOD_EXPR:
3335 case ROUND_MOD_EXPR:
3337 case EXACT_DIV_EXPR:
3347 CHECK_OP (0, "invalid operand to binary operator");
3348 CHECK_OP (1, "invalid operand to binary operator");
3352 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3364 /* Verifies if EXPR is a valid GIMPLE unary expression. Returns true
3365 if there is an error, otherwise false. */
3368 verify_gimple_unary_expr (tree expr)
3370 tree op = TREE_OPERAND (expr, 0);
3371 tree type = TREE_TYPE (expr);
3373 if (!is_gimple_val (op))
3375 error ("invalid operand in unary expression");
3379 /* For general unary expressions we have the operations type
3380 as the effective type the operation is carried out on. So all
3381 we need to require is that the operand is trivially convertible
3383 if (!useless_type_conversion_p (type, TREE_TYPE (op)))
3385 error ("type mismatch in unary expression");
3386 debug_generic_expr (type);
3387 debug_generic_expr (TREE_TYPE (op));
3394 /* Verifies if EXPR is a valid GIMPLE binary expression. Returns true
3395 if there is an error, otherwise false. */
3398 verify_gimple_binary_expr (tree expr)
3400 tree op0 = TREE_OPERAND (expr, 0);
3401 tree op1 = TREE_OPERAND (expr, 1);
3402 tree type = TREE_TYPE (expr);
3404 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3406 error ("invalid operands in binary expression");
3410 /* For general binary expressions we have the operations type
3411 as the effective type the operation is carried out on. So all
3412 we need to require is that both operands are trivially convertible
3414 if (!useless_type_conversion_p (type, TREE_TYPE (op0))
3415 || !useless_type_conversion_p (type, TREE_TYPE (op1)))
3417 error ("type mismatch in binary expression");
3418 debug_generic_stmt (type);
3419 debug_generic_stmt (TREE_TYPE (op0));
3420 debug_generic_stmt (TREE_TYPE (op1));
3427 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3428 Returns true if there is an error, otherwise false. */
3431 verify_gimple_min_lval (tree expr)
3435 if (is_gimple_id (expr))
3438 if (TREE_CODE (expr) != INDIRECT_REF
3439 && TREE_CODE (expr) != ALIGN_INDIRECT_REF
3440 && TREE_CODE (expr) != MISALIGNED_INDIRECT_REF)
3442 error ("invalid expression for min lvalue");
3446 op = TREE_OPERAND (expr, 0);
3447 if (!is_gimple_val (op))
3449 error ("invalid operand in indirect reference");
3450 debug_generic_stmt (op);
3453 if (!useless_type_conversion_p (TREE_TYPE (expr),
3454 TREE_TYPE (TREE_TYPE (op))))
3456 error ("type mismatch in indirect reference");
3457 debug_generic_stmt (TREE_TYPE (expr));
3458 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3465 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3466 if there is an error, otherwise false. */
3469 verify_gimple_reference (tree expr)
3471 while (handled_component_p (expr))
3473 tree op = TREE_OPERAND (expr, 0);
3475 if (TREE_CODE (expr) == ARRAY_REF
3476 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3478 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3479 || (TREE_OPERAND (expr, 2)
3480 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3481 || (TREE_OPERAND (expr, 3)
3482 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3484 error ("invalid operands to array reference");
3485 debug_generic_stmt (expr);
3490 /* Verify if the reference array element types are compatible. */
3491 if (TREE_CODE (expr) == ARRAY_REF
3492 && !useless_type_conversion_p (TREE_TYPE (expr),
3493 TREE_TYPE (TREE_TYPE (op))))
3495 error ("type mismatch in array reference");
3496 debug_generic_stmt (TREE_TYPE (expr));
3497 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3500 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3501 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3502 TREE_TYPE (TREE_TYPE (op))))
3504 error ("type mismatch in array range reference");
3505 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3506 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3510 if ((TREE_CODE (expr) == REALPART_EXPR
3511 || TREE_CODE (expr) == IMAGPART_EXPR)
3512 && !useless_type_conversion_p (TREE_TYPE (expr),
3513 TREE_TYPE (TREE_TYPE (op))))
3515 error ("type mismatch in real/imagpart reference");
3516 debug_generic_stmt (TREE_TYPE (expr));
3517 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3521 if (TREE_CODE (expr) == COMPONENT_REF
3522 && !useless_type_conversion_p (TREE_TYPE (expr),
3523 TREE_TYPE (TREE_OPERAND (expr, 1))))
3525 error ("type mismatch in component reference");
3526 debug_generic_stmt (TREE_TYPE (expr));
3527 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3531 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3532 is nothing to verify. Gross mismatches at most invoke
3533 undefined behavior. */
3538 return verify_gimple_min_lval (expr);
3541 /* Verify the GIMPLE expression EXPR. Returns true if there is an
3542 error, otherwise false. */
3545 verify_gimple_expr (tree expr)
3547 tree type = TREE_TYPE (expr);
3549 if (is_gimple_val (expr))
3552 /* Special codes we cannot handle via their class. */
3553 switch (TREE_CODE (expr))
3558 tree op = TREE_OPERAND (expr, 0);
3559 if (!is_gimple_val (op))
3561 error ("invalid operand in conversion");
3565 /* Allow conversions between integral types. */
3566 if (INTEGRAL_TYPE_P (type) == INTEGRAL_TYPE_P (TREE_TYPE (op)))
3569 /* Allow conversions between integral types and pointers only if
3570 there is no sign or zero extension involved. */
3571 if (((POINTER_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3572 || (POINTER_TYPE_P (TREE_TYPE (op)) && INTEGRAL_TYPE_P (type)))
3573 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op)))
3576 /* Allow conversion from integer to offset type and vice versa. */
3577 if ((TREE_CODE (type) == OFFSET_TYPE
3578 && TREE_CODE (TREE_TYPE (op)) == INTEGER_TYPE)
3579 || (TREE_CODE (type) == INTEGER_TYPE
3580 && TREE_CODE (TREE_TYPE (op)) == OFFSET_TYPE))
3583 /* Otherwise assert we are converting between types of the
3585 if (TREE_CODE (type) != TREE_CODE (TREE_TYPE (op)))
3587 error ("invalid types in nop conversion");
3588 debug_generic_expr (type);
3589 debug_generic_expr (TREE_TYPE (op));
3598 tree op = TREE_OPERAND (expr, 0);
3599 if (!is_gimple_val (op))
3601 error ("invalid operand in int to float conversion");
3604 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3605 || !SCALAR_FLOAT_TYPE_P (type))
3607 error ("invalid types in conversion to floating point");
3608 debug_generic_expr (type);
3609 debug_generic_expr (TREE_TYPE (op));
3615 case FIX_TRUNC_EXPR:
3617 tree op = TREE_OPERAND (expr, 0);
3618 if (!is_gimple_val (op))
3620 error ("invalid operand in float to int conversion");
3623 if (!INTEGRAL_TYPE_P (type)
3624 || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (op)))
3626 error ("invalid types in conversion to integer");
3627 debug_generic_expr (type);
3628 debug_generic_expr (TREE_TYPE (op));
3636 tree op0 = TREE_OPERAND (expr, 0);
3637 tree op1 = TREE_OPERAND (expr, 1);
3638 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3640 error ("invalid operands in complex expression");
3643 if (!TREE_CODE (type) == COMPLEX_TYPE
3644 || !(TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
3645 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0)))
3646 || !(TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3647 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op1)))
3648 || !useless_type_conversion_p (TREE_TYPE (type),
3650 || !useless_type_conversion_p (TREE_TYPE (type),
3653 error ("type mismatch in complex expression");
3654 debug_generic_stmt (TREE_TYPE (expr));
3655 debug_generic_stmt (TREE_TYPE (op0));
3656 debug_generic_stmt (TREE_TYPE (op1));
3664 /* This is used like COMPLEX_EXPR but for vectors. */
3665 if (TREE_CODE (type) != VECTOR_TYPE)
3667 error ("constructor not allowed for non-vector types");
3668 debug_generic_stmt (type);
3671 /* FIXME: verify constructor arguments. */
3680 tree op0 = TREE_OPERAND (expr, 0);
3681 tree op1 = TREE_OPERAND (expr, 1);
3682 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3684 error ("invalid operands in shift expression");
3687 if (!TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3688 || !useless_type_conversion_p (type, TREE_TYPE (op0)))
3690 error ("type mismatch in shift expression");
3691 debug_generic_stmt (TREE_TYPE (expr));
3692 debug_generic_stmt (TREE_TYPE (op0));
3693 debug_generic_stmt (TREE_TYPE (op1));
3702 tree op0 = TREE_OPERAND (expr, 0);
3703 tree op1 = TREE_OPERAND (expr, 1);
3704 if (POINTER_TYPE_P (type)
3705 || POINTER_TYPE_P (TREE_TYPE (op0))
3706 || POINTER_TYPE_P (TREE_TYPE (op1)))
3708 error ("invalid (pointer) operands to plus/minus");
3711 /* Continue with generic binary expression handling. */
3715 case POINTER_PLUS_EXPR:
3717 tree op0 = TREE_OPERAND (expr, 0);
3718 tree op1 = TREE_OPERAND (expr, 1);
3719 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3721 error ("invalid operands in pointer plus expression");
3724 if (!POINTER_TYPE_P (TREE_TYPE (op0))
3725 || TREE_CODE (TREE_TYPE (op1)) != INTEGER_TYPE
3726 || !useless_type_conversion_p (type, TREE_TYPE (op0))
3727 || !useless_type_conversion_p (sizetype, TREE_TYPE (op1)))
3729 error ("type mismatch in pointer plus expression");
3730 debug_generic_stmt (type);
3731 debug_generic_stmt (TREE_TYPE (op0));
3732 debug_generic_stmt (TREE_TYPE (op1));
3740 tree op0 = TREE_OPERAND (expr, 0);
3741 tree op1 = TREE_OPERAND (expr, 1);
3742 tree op2 = TREE_OPERAND (expr, 2);
3743 if ((!is_gimple_val (op1)
3744 && TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3745 || (!is_gimple_val (op2)
3746 && TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE))
3748 error ("invalid operands in conditional expression");
3751 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3752 || (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE
3753 && !useless_type_conversion_p (type, TREE_TYPE (op1)))
3754 || (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE
3755 && !useless_type_conversion_p (type, TREE_TYPE (op2))))
3757 error ("type mismatch in conditional expression");
3758 debug_generic_stmt (type);
3759 debug_generic_stmt (TREE_TYPE (op0));
3760 debug_generic_stmt (TREE_TYPE (op1));
3761 debug_generic_stmt (TREE_TYPE (op2));
3764 return verify_gimple_expr (op0);
3769 tree op = TREE_OPERAND (expr, 0);
3771 if (!is_gimple_addressable (op))
3773 error ("invalid operand in unary expression");
3776 ptr_type = build_pointer_type (TREE_TYPE (op));
3777 if (!useless_type_conversion_p (type, ptr_type)
3778 /* FIXME: a longstanding wart, &a == &a[0]. */
3779 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3780 || !useless_type_conversion_p (type,
3781 build_pointer_type (TREE_TYPE (TREE_TYPE (op))))))
3783 error ("type mismatch in address expression");
3784 debug_generic_stmt (TREE_TYPE (expr));
3785 debug_generic_stmt (ptr_type);
3789 return verify_gimple_reference (op);
3792 case TRUTH_ANDIF_EXPR:
3793 case TRUTH_ORIF_EXPR:
3794 case TRUTH_AND_EXPR:
3796 case TRUTH_XOR_EXPR:
3798 tree op0 = TREE_OPERAND (expr, 0);
3799 tree op1 = TREE_OPERAND (expr, 1);
3801 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3803 error ("invalid operands in truth expression");
3807 /* We allow any kind of integral typed argument and result. */
3808 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3809 || !INTEGRAL_TYPE_P (TREE_TYPE (op1))
3810 || !INTEGRAL_TYPE_P (type))
3812 error ("type mismatch in binary truth expression");
3813 debug_generic_stmt (type);
3814 debug_generic_stmt (TREE_TYPE (op0));
3815 debug_generic_stmt (TREE_TYPE (op1));
3822 case TRUTH_NOT_EXPR:
3824 tree op = TREE_OPERAND (expr, 0);
3826 if (!is_gimple_val (op))
3828 error ("invalid operand in unary not");
3832 /* For TRUTH_NOT_EXPR we can have any kind of integral
3833 typed arguments and results. */
3834 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3835 || !INTEGRAL_TYPE_P (type))
3837 error ("type mismatch in not expression");
3838 debug_generic_expr (TREE_TYPE (expr));
3839 debug_generic_expr (TREE_TYPE (op));
3847 /* FIXME. The C frontend passes unpromoted arguments in case it
3848 didn't see a function declaration before the call. */
3854 /* Generic handling via classes. */
3855 switch (TREE_CODE_CLASS (TREE_CODE (expr)))
3858 return verify_gimple_unary_expr (expr);
3861 return verify_gimple_binary_expr (expr);
3864 return verify_gimple_reference (expr);
3866 case tcc_comparison:
3868 tree op0 = TREE_OPERAND (expr, 0);
3869 tree op1 = TREE_OPERAND (expr, 1);
3870 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3872 error ("invalid operands in comparison expression");
3875 /* For comparisons we do not have the operations type as the
3876 effective type the comparison is carried out in. Instead
3877 we require that either the first operand is trivially
3878 convertible into the second, or the other way around.
3879 The resulting type of a comparison may be any integral type.
3880 Because we special-case pointers to void we allow
3881 comparisons of pointers with the same mode as well. */
3882 if ((!useless_type_conversion_p (TREE_TYPE (op0), TREE_TYPE (op1))
3883 && !useless_type_conversion_p (TREE_TYPE (op1), TREE_TYPE (op0))
3884 && (!POINTER_TYPE_P (TREE_TYPE (op0))
3885 || !POINTER_TYPE_P (TREE_TYPE (op1))
3886 || TYPE_MODE (TREE_TYPE (op0)) != TYPE_MODE (TREE_TYPE (op1))))
3887 || !INTEGRAL_TYPE_P (type))
3889 error ("type mismatch in comparison expression");
3890 debug_generic_stmt (TREE_TYPE (expr));
3891 debug_generic_stmt (TREE_TYPE (op0));
3892 debug_generic_stmt (TREE_TYPE (op1));
3905 /* Verify the GIMPLE assignment statement STMT. Returns true if there
3906 is an error, otherwise false. */
3909 verify_gimple_modify_stmt (tree stmt)
3911 tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
3912 tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
3914 gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
3916 if (!useless_type_conversion_p (TREE_TYPE (lhs),
3919 error ("non-trivial conversion at assignment");
3920 debug_generic_expr (TREE_TYPE (lhs));
3921 debug_generic_expr (TREE_TYPE (rhs));
3925 /* Loads/stores from/to a variable are ok. */
3926 if ((is_gimple_val (lhs)
3927 && is_gimple_variable (rhs))
3928 || (is_gimple_val (rhs)
3929 && is_gimple_variable (lhs)))
3932 /* Aggregate copies are ok. */
3933 if (!is_gimple_reg_type (TREE_TYPE (lhs))
3934 && !is_gimple_reg_type (TREE_TYPE (rhs)))
3937 /* We might get 'loads' from a parameter which is not a gimple value. */
3938 if (TREE_CODE (rhs) == PARM_DECL)
3939 return verify_gimple_expr (lhs);
3941 if (!is_gimple_variable (lhs)
3942 && verify_gimple_expr (lhs))
3945 if (!is_gimple_variable (rhs)
3946 && verify_gimple_expr (rhs))
3952 /* Verify the GIMPLE statement STMT. Returns true if there is an
3953 error, otherwise false. */
3956 verify_gimple_stmt (tree stmt)
3958 if (!is_gimple_stmt (stmt))
3960 error ("is not a valid GIMPLE statement");
3964 if (OMP_DIRECTIVE_P (stmt))
3966 /* OpenMP directives are validated by the FE and never operated
3967 on by the optimizers. Furthermore, OMP_FOR may contain
3968 non-gimple expressions when the main index variable has had
3969 its address taken. This does not affect the loop itself
3970 because the header of an OMP_FOR is merely used to determine
3971 how to setup the parallel iteration. */
3975 switch (TREE_CODE (stmt))
3977 case GIMPLE_MODIFY_STMT:
3978 return verify_gimple_modify_stmt (stmt);
3985 if (!is_gimple_val (TREE_OPERAND (stmt, 0)))
3987 error ("invalid operand to switch statement");
3988 debug_generic_expr (TREE_OPERAND (stmt, 0));
3994 tree op = TREE_OPERAND (stmt, 0);
3996 if (TREE_CODE (TREE_TYPE (stmt)) != VOID_TYPE)
3998 error ("type error in return expression");
4003 || TREE_CODE (op) == RESULT_DECL)
4006 return verify_gimple_modify_stmt (op);
4011 return verify_gimple_expr (stmt);
4014 case CHANGE_DYNAMIC_TYPE_EXPR:
4023 /* Verify the GIMPLE statements inside the statement list STMTS. */
4026 verify_gimple_1 (tree stmts)
4028 tree_stmt_iterator tsi;
4030 for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi))
4032 tree stmt = tsi_stmt (tsi);
4034 switch (TREE_CODE (stmt))
4037 verify_gimple_1 (BIND_EXPR_BODY (stmt));
4040 case TRY_CATCH_EXPR:
4041 case TRY_FINALLY_EXPR:
4042 verify_gimple_1 (TREE_OPERAND (stmt, 0));
4043 verify_gimple_1 (TREE_OPERAND (stmt, 1));
4047 verify_gimple_1 (CATCH_BODY (stmt));
4050 case EH_FILTER_EXPR:
4051 verify_gimple_1 (EH_FILTER_FAILURE (stmt));
4055 if (verify_gimple_stmt (stmt))
4056 debug_generic_expr (stmt);
4061 /* Verify the GIMPLE statements inside the current function. */
4064 verify_gimple (void)
4066 verify_gimple_1 (BIND_EXPR_BODY (DECL_SAVED_TREE (cfun->decl)));
4069 /* Verify STMT, return true if STMT is not in GIMPLE form.
4070 TODO: Implement type checking. */
4073 verify_stmt (tree stmt, bool last_in_block)
4077 if (OMP_DIRECTIVE_P (stmt))
4079 /* OpenMP directives are validated by the FE and never operated
4080 on by the optimizers. Furthermore, OMP_FOR may contain
4081 non-gimple expressions when the main index variable has had
4082 its address taken. This does not affect the loop itself
4083 because the header of an OMP_FOR is merely used to determine
4084 how to setup the parallel iteration. */
4088 if (!is_gimple_stmt (stmt))
4090 error ("is not a valid GIMPLE statement");
4094 addr = walk_tree (&stmt, verify_expr, NULL, NULL);
4097 debug_generic_stmt (addr);
4101 /* If the statement is marked as part of an EH region, then it is
4102 expected that the statement could throw. Verify that when we
4103 have optimizations that simplify statements such that we prove
4104 that they cannot throw, that we update other data structures
4106 if (lookup_stmt_eh_region (stmt) >= 0)
4108 if (!tree_could_throw_p (stmt))
4110 error ("statement marked for throw, but doesn%'t");
4113 if (!last_in_block && tree_can_throw_internal (stmt))
4115 error ("statement marked for throw in middle of block");
4123 debug_generic_stmt (stmt);
4128 /* Return true when the T can be shared. */
4131 tree_node_can_be_shared (tree t)
4133 if (IS_TYPE_OR_DECL_P (t)
4134 || is_gimple_min_invariant (t)
4135 || TREE_CODE (t) == SSA_NAME
4136 || t == error_mark_node
4137 || TREE_CODE (t) == IDENTIFIER_NODE)
4140 if (TREE_CODE (t) == CASE_LABEL_EXPR)
4143 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4144 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4145 || TREE_CODE (t) == COMPONENT_REF
4146 || TREE_CODE (t) == REALPART_EXPR
4147 || TREE_CODE (t) == IMAGPART_EXPR)
4148 t = TREE_OPERAND (t, 0);
4157 /* Called via walk_trees. Verify tree sharing. */
4160 verify_node_sharing (tree * tp, int *walk_subtrees, void *data)
4162 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4164 if (tree_node_can_be_shared (*tp))
4166 *walk_subtrees = false;
4170 if (pointer_set_insert (visited, *tp))
4177 /* Helper function for verify_gimple_tuples. */
4180 verify_gimple_tuples_1 (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4181 void *data ATTRIBUTE_UNUSED)
4183 switch (TREE_CODE (*tp))
4186 error ("unexpected non-tuple");
4196 /* Verify that there are no trees that should have been converted to
4197 gimple tuples. Return true if T contains a node that should have
4198 been converted to a gimple tuple, but hasn't. */
4201 verify_gimple_tuples (tree t)
4203 return walk_tree (&t, verify_gimple_tuples_1, NULL, NULL) != NULL;
4206 static bool eh_error_found;
4208 verify_eh_throw_stmt_node (void **slot, void *data)
4210 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4211 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4213 if (!pointer_set_contains (visited, node->stmt))
4215 error ("Dead STMT in EH table");
4216 debug_generic_stmt (node->stmt);
4217 eh_error_found = true;
4222 /* Verify the GIMPLE statement chain. */
4228 block_stmt_iterator bsi;
4230 struct pointer_set_t *visited, *visited_stmts;
4233 timevar_push (TV_TREE_STMT_VERIFY);
4234 visited = pointer_set_create ();
4235 visited_stmts = pointer_set_create ();
4242 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4244 int phi_num_args = PHI_NUM_ARGS (phi);
4246 pointer_set_insert (visited_stmts, phi);
4247 if (bb_for_stmt (phi) != bb)
4249 error ("bb_for_stmt (phi) is set to a wrong basic block");
4253 for (i = 0; i < phi_num_args; i++)
4255 tree t = PHI_ARG_DEF (phi, i);
4258 /* Addressable variables do have SSA_NAMEs but they
4259 are not considered gimple values. */
4260 if (TREE_CODE (t) != SSA_NAME
4261 && TREE_CODE (t) != FUNCTION_DECL
4262 && !is_gimple_val (t))
4264 error ("PHI def is not a GIMPLE value");
4265 debug_generic_stmt (phi);
4266 debug_generic_stmt (t);
4270 addr = walk_tree (&t, verify_expr, (void *) 1, NULL);
4273 debug_generic_stmt (addr);
4277 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4280 error ("incorrect sharing of tree nodes");
4281 debug_generic_stmt (phi);
4282 debug_generic_stmt (addr);
4288 for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
4290 tree stmt = bsi_stmt (bsi);
4292 pointer_set_insert (visited_stmts, stmt);
4293 err |= verify_gimple_tuples (stmt);
4295 if (bb_for_stmt (stmt) != bb)
4297 error ("bb_for_stmt (stmt) is set to a wrong basic block");
4302 err |= verify_stmt (stmt, bsi_end_p (bsi));
4303 addr = walk_tree (&stmt, verify_node_sharing, visited, NULL);
4306 error ("incorrect sharing of tree nodes");
4307 debug_generic_stmt (stmt);
4308 debug_generic_stmt (addr);
4313 eh_error_found = false;
4314 if (get_eh_throw_stmt_table (cfun))
4315 htab_traverse (get_eh_throw_stmt_table (cfun),
4316 verify_eh_throw_stmt_node,
4319 if (err | eh_error_found)
4320 internal_error ("verify_stmts failed");
4322 pointer_set_destroy (visited);
4323 pointer_set_destroy (visited_stmts);
4324 verify_histograms ();
4325 timevar_pop (TV_TREE_STMT_VERIFY);
4329 /* Verifies that the flow information is OK. */
4332 tree_verify_flow_info (void)
4336 block_stmt_iterator bsi;
4341 if (ENTRY_BLOCK_PTR->il.tree)
4343 error ("ENTRY_BLOCK has IL associated with it");
4347 if (EXIT_BLOCK_PTR->il.tree)
4349 error ("EXIT_BLOCK has IL associated with it");
4353 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4354 if (e->flags & EDGE_FALLTHRU)
4356 error ("fallthru to exit from bb %d", e->src->index);
4362 bool found_ctrl_stmt = false;
4366 /* Skip labels on the start of basic block. */
4367 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4369 tree prev_stmt = stmt;
4371 stmt = bsi_stmt (bsi);
4373 if (TREE_CODE (stmt) != LABEL_EXPR)
4376 if (prev_stmt && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
4378 error ("nonlocal label ");
4379 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4380 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4385 if (label_to_block (LABEL_EXPR_LABEL (stmt)) != bb)
4388 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4389 fprintf (stderr, " to block does not match in bb %d",
4394 if (decl_function_context (LABEL_EXPR_LABEL (stmt))
4395 != current_function_decl)
4398 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4399 fprintf (stderr, " has incorrect context in bb %d",
4405 /* Verify that body of basic block BB is free of control flow. */
4406 for (; !bsi_end_p (bsi); bsi_next (&bsi))
4408 tree stmt = bsi_stmt (bsi);
4410 if (found_ctrl_stmt)
4412 error ("control flow in the middle of basic block %d",
4417 if (stmt_ends_bb_p (stmt))
4418 found_ctrl_stmt = true;
4420 if (TREE_CODE (stmt) == LABEL_EXPR)
4423 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4424 fprintf (stderr, " in the middle of basic block %d", bb->index);
4429 bsi = bsi_last (bb);
4430 if (bsi_end_p (bsi))
4433 stmt = bsi_stmt (bsi);
4435 err |= verify_eh_edges (stmt);
4437 if (is_ctrl_stmt (stmt))
4439 FOR_EACH_EDGE (e, ei, bb->succs)
4440 if (e->flags & EDGE_FALLTHRU)
4442 error ("fallthru edge after a control statement in bb %d",
4448 if (TREE_CODE (stmt) != COND_EXPR)
4450 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4451 after anything else but if statement. */
4452 FOR_EACH_EDGE (e, ei, bb->succs)
4453 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4455 error ("true/false edge after a non-COND_EXPR in bb %d",
4461 switch (TREE_CODE (stmt))
4468 if (COND_EXPR_THEN (stmt) != NULL_TREE
4469 || COND_EXPR_ELSE (stmt) != NULL_TREE)
4471 error ("COND_EXPR with code in branches at the end of bb %d",
4476 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4478 if (!true_edge || !false_edge
4479 || !(true_edge->flags & EDGE_TRUE_VALUE)
4480 || !(false_edge->flags & EDGE_FALSE_VALUE)
4481 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4482 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4483 || EDGE_COUNT (bb->succs) >= 3)
4485 error ("wrong outgoing edge flags at end of bb %d",
4493 if (simple_goto_p (stmt))
4495 error ("explicit goto at end of bb %d", bb->index);
4500 /* FIXME. We should double check that the labels in the
4501 destination blocks have their address taken. */
4502 FOR_EACH_EDGE (e, ei, bb->succs)
4503 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4504 | EDGE_FALSE_VALUE))
4505 || !(e->flags & EDGE_ABNORMAL))
4507 error ("wrong outgoing edge flags at end of bb %d",
4515 if (!single_succ_p (bb)
4516 || (single_succ_edge (bb)->flags
4517 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4518 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4520 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4523 if (single_succ (bb) != EXIT_BLOCK_PTR)
4525 error ("return edge does not point to exit in bb %d",
4538 vec = SWITCH_LABELS (stmt);
4539 n = TREE_VEC_LENGTH (vec);
4541 /* Mark all the destination basic blocks. */
4542 for (i = 0; i < n; ++i)
4544 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4545 basic_block label_bb = label_to_block (lab);
4547 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4548 label_bb->aux = (void *)1;
4551 /* Verify that the case labels are sorted. */
4552 prev = TREE_VEC_ELT (vec, 0);
4553 for (i = 1; i < n - 1; ++i)
4555 tree c = TREE_VEC_ELT (vec, i);
4558 error ("found default case not at end of case vector");
4562 if (! tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4564 error ("case labels not sorted: ");
4565 print_generic_expr (stderr, prev, 0);
4566 fprintf (stderr," is greater than ");
4567 print_generic_expr (stderr, c, 0);
4568 fprintf (stderr," but comes before it.\n");
4573 if (CASE_LOW (TREE_VEC_ELT (vec, n - 1)))
4575 error ("no default case found at end of case vector");
4579 FOR_EACH_EDGE (e, ei, bb->succs)
4583 error ("extra outgoing edge %d->%d",
4584 bb->index, e->dest->index);
4587 e->dest->aux = (void *)2;
4588 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4589 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4591 error ("wrong outgoing edge flags at end of bb %d",
4597 /* Check that we have all of them. */
4598 for (i = 0; i < n; ++i)
4600 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4601 basic_block label_bb = label_to_block (lab);
4603 if (label_bb->aux != (void *)2)
4605 error ("missing edge %i->%i",
4606 bb->index, label_bb->index);
4611 FOR_EACH_EDGE (e, ei, bb->succs)
4612 e->dest->aux = (void *)0;
4619 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4620 verify_dominators (CDI_DOMINATORS);
4626 /* Updates phi nodes after creating a forwarder block joined
4627 by edge FALLTHRU. */
4630 tree_make_forwarder_block (edge fallthru)
4634 basic_block dummy, bb;
4635 tree phi, new_phi, var;
4637 dummy = fallthru->src;
4638 bb = fallthru->dest;
4640 if (single_pred_p (bb))
4643 /* If we redirected a branch we must create new PHI nodes at the
4645 for (phi = phi_nodes (dummy); phi; phi = PHI_CHAIN (phi))
4647 var = PHI_RESULT (phi);
4648 new_phi = create_phi_node (var, bb);
4649 SSA_NAME_DEF_STMT (var) = new_phi;
4650 SET_PHI_RESULT (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4651 add_phi_arg (new_phi, PHI_RESULT (phi), fallthru);
4654 /* Ensure that the PHI node chain is in the same order. */
4655 set_phi_nodes (bb, phi_reverse (phi_nodes (bb)));
4657 /* Add the arguments we have stored on edges. */
4658 FOR_EACH_EDGE (e, ei, bb->preds)
4663 flush_pending_stmts (e);
4668 /* Return a non-special label in the head of basic block BLOCK.
4669 Create one if it doesn't exist. */
4672 tree_block_label (basic_block bb)
4674 block_stmt_iterator i, s = bsi_start (bb);
4678 for (i = s; !bsi_end_p (i); first = false, bsi_next (&i))
4680 stmt = bsi_stmt (i);
4681 if (TREE_CODE (stmt) != LABEL_EXPR)
4683 label = LABEL_EXPR_LABEL (stmt);
4684 if (!DECL_NONLOCAL (label))
4687 bsi_move_before (&i, &s);
4692 label = create_artificial_label ();
4693 stmt = build1 (LABEL_EXPR, void_type_node, label);
4694 bsi_insert_before (&s, stmt, BSI_NEW_STMT);
4699 /* Attempt to perform edge redirection by replacing a possibly complex
4700 jump instruction by a goto or by removing the jump completely.
4701 This can apply only if all edges now point to the same block. The
4702 parameters and return values are equivalent to
4703 redirect_edge_and_branch. */
4706 tree_try_redirect_by_replacing_jump (edge e, basic_block target)
4708 basic_block src = e->src;
4709 block_stmt_iterator b;
4712 /* We can replace or remove a complex jump only when we have exactly
4714 if (EDGE_COUNT (src->succs) != 2
4715 /* Verify that all targets will be TARGET. Specifically, the
4716 edge that is not E must also go to TARGET. */
4717 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4723 stmt = bsi_stmt (b);
4725 if (TREE_CODE (stmt) == COND_EXPR
4726 || TREE_CODE (stmt) == SWITCH_EXPR)
4728 bsi_remove (&b, true);
4729 e = ssa_redirect_edge (e, target);
4730 e->flags = EDGE_FALLTHRU;
4738 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4739 edge representing the redirected branch. */
4742 tree_redirect_edge_and_branch (edge e, basic_block dest)
4744 basic_block bb = e->src;
4745 block_stmt_iterator bsi;
4749 if (e->flags & EDGE_ABNORMAL)
4752 if (e->src != ENTRY_BLOCK_PTR
4753 && (ret = tree_try_redirect_by_replacing_jump (e, dest)))
4756 if (e->dest == dest)
4759 bsi = bsi_last (bb);
4760 stmt = bsi_end_p (bsi) ? NULL : bsi_stmt (bsi);
4762 switch (stmt ? TREE_CODE (stmt) : ERROR_MARK)
4765 /* For COND_EXPR, we only need to redirect the edge. */
4769 /* No non-abnormal edges should lead from a non-simple goto, and
4770 simple ones should be represented implicitly. */
4775 tree cases = get_cases_for_edge (e, stmt);
4776 tree label = tree_block_label (dest);
4778 /* If we have a list of cases associated with E, then use it
4779 as it's a lot faster than walking the entire case vector. */
4782 edge e2 = find_edge (e->src, dest);
4789 CASE_LABEL (cases) = label;
4790 cases = TREE_CHAIN (cases);
4793 /* If there was already an edge in the CFG, then we need
4794 to move all the cases associated with E to E2. */
4797 tree cases2 = get_cases_for_edge (e2, stmt);
4799 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4800 TREE_CHAIN (cases2) = first;
4805 tree vec = SWITCH_LABELS (stmt);
4806 size_t i, n = TREE_VEC_LENGTH (vec);
4808 for (i = 0; i < n; i++)
4810 tree elt = TREE_VEC_ELT (vec, i);
4812 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4813 CASE_LABEL (elt) = label;
4821 bsi_remove (&bsi, true);
4822 e->flags |= EDGE_FALLTHRU;
4827 case OMP_SECTIONS_SWITCH:
4829 /* The edges from OMP constructs can be simply redirected. */
4833 /* Otherwise it must be a fallthru edge, and we don't need to
4834 do anything besides redirecting it. */
4835 gcc_assert (e->flags & EDGE_FALLTHRU);
4839 /* Update/insert PHI nodes as necessary. */
4841 /* Now update the edges in the CFG. */
4842 e = ssa_redirect_edge (e, dest);
4847 /* Returns true if it is possible to remove edge E by redirecting
4848 it to the destination of the other edge from E->src. */
4851 tree_can_remove_branch_p (edge e)
4853 if (e->flags & EDGE_ABNORMAL)
4859 /* Simple wrapper, as we can always redirect fallthru edges. */
4862 tree_redirect_edge_and_branch_force (edge e, basic_block dest)
4864 e = tree_redirect_edge_and_branch (e, dest);
4871 /* Splits basic block BB after statement STMT (but at least after the
4872 labels). If STMT is NULL, BB is split just after the labels. */
4875 tree_split_block (basic_block bb, void *stmt)
4877 block_stmt_iterator bsi;
4878 tree_stmt_iterator tsi_tgt;
4884 new_bb = create_empty_bb (bb);
4886 /* Redirect the outgoing edges. */
4887 new_bb->succs = bb->succs;
4889 FOR_EACH_EDGE (e, ei, new_bb->succs)
4892 if (stmt && TREE_CODE ((tree) stmt) == LABEL_EXPR)
4895 /* Move everything from BSI to the new basic block. */
4896 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4898 act = bsi_stmt (bsi);
4899 if (TREE_CODE (act) == LABEL_EXPR)
4912 if (bsi_end_p (bsi))
4915 /* Split the statement list - avoid re-creating new containers as this
4916 brings ugly quadratic memory consumption in the inliner.
4917 (We are still quadratic since we need to update stmt BB pointers,
4919 list = tsi_split_statement_list_before (&bsi.tsi);
4920 set_bb_stmt_list (new_bb, list);
4921 for (tsi_tgt = tsi_start (list);
4922 !tsi_end_p (tsi_tgt); tsi_next (&tsi_tgt))
4923 change_bb_for_stmt (tsi_stmt (tsi_tgt), new_bb);
4929 /* Moves basic block BB after block AFTER. */
4932 tree_move_block_after (basic_block bb, basic_block after)
4934 if (bb->prev_bb == after)
4938 link_block (bb, after);
4944 /* Return true if basic_block can be duplicated. */
4947 tree_can_duplicate_bb_p (basic_block bb ATTRIBUTE_UNUSED)
4953 /* Create a duplicate of the basic block BB. NOTE: This does not
4954 preserve SSA form. */
4957 tree_duplicate_bb (basic_block bb)
4960 block_stmt_iterator bsi, bsi_tgt;
4963 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
4965 /* Copy the PHI nodes. We ignore PHI node arguments here because
4966 the incoming edges have not been setup yet. */
4967 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4969 tree copy = create_phi_node (PHI_RESULT (phi), new_bb);
4970 create_new_def_for (PHI_RESULT (copy), copy, PHI_RESULT_PTR (copy));
4973 /* Keep the chain of PHI nodes in the same order so that they can be
4974 updated by ssa_redirect_edge. */
4975 set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb)));
4977 bsi_tgt = bsi_start (new_bb);
4978 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4980 def_operand_p def_p;
4981 ssa_op_iter op_iter;
4985 stmt = bsi_stmt (bsi);
4986 if (TREE_CODE (stmt) == LABEL_EXPR)
4989 /* Create a new copy of STMT and duplicate STMT's virtual
4991 copy = unshare_expr (stmt);
4992 bsi_insert_after (&bsi_tgt, copy, BSI_NEW_STMT);
4993 copy_virtual_operands (copy, stmt);
4994 region = lookup_stmt_eh_region (stmt);
4996 add_stmt_to_eh_region (copy, region);
4997 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
4999 /* Create new names for all the definitions created by COPY and
5000 add replacement mappings for each new name. */
5001 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
5002 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
5009 /* Basic block BB_COPY was created by code duplication. Add phi node
5010 arguments for edges going out of BB_COPY. The blocks that were
5011 duplicated have BB_DUPLICATED set. */
5014 add_phi_args_after_copy_bb (basic_block bb_copy)
5016 basic_block bb, dest;
5019 tree phi, phi_copy, phi_next, def;
5021 bb = get_bb_original (bb_copy);
5023 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5025 if (!phi_nodes (e_copy->dest))
5028 if (e_copy->dest->flags & BB_DUPLICATED)
5029 dest = get_bb_original (e_copy->dest);
5031 dest = e_copy->dest;
5033 e = find_edge (bb, dest);
5036 /* During loop unrolling the target of the latch edge is copied.
5037 In this case we are not looking for edge to dest, but to
5038 duplicated block whose original was dest. */
5039 FOR_EACH_EDGE (e, ei, bb->succs)
5040 if ((e->dest->flags & BB_DUPLICATED)
5041 && get_bb_original (e->dest) == dest)
5044 gcc_assert (e != NULL);
5047 for (phi = phi_nodes (e->dest), phi_copy = phi_nodes (e_copy->dest);
5049 phi = phi_next, phi_copy = PHI_CHAIN (phi_copy))
5051 phi_next = PHI_CHAIN (phi);
5052 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5053 add_phi_arg (phi_copy, def, e_copy);
5058 /* Blocks in REGION_COPY array of length N_REGION were created by
5059 duplication of basic blocks. Add phi node arguments for edges
5060 going from these blocks. */
5063 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region)
5067 for (i = 0; i < n_region; i++)
5068 region_copy[i]->flags |= BB_DUPLICATED;
5070 for (i = 0; i < n_region; i++)
5071 add_phi_args_after_copy_bb (region_copy[i]);
5073 for (i = 0; i < n_region; i++)
5074 region_copy[i]->flags &= ~BB_DUPLICATED;
5077 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5078 important exit edge EXIT. By important we mean that no SSA name defined
5079 inside region is live over the other exit edges of the region. All entry
5080 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5081 to the duplicate of the region. SSA form, dominance and loop information
5082 is updated. The new basic blocks are stored to REGION_COPY in the same
5083 order as they had in REGION, provided that REGION_COPY is not NULL.
5084 The function returns false if it is unable to copy the region,
5088 tree_duplicate_sese_region (edge entry, edge exit,
5089 basic_block *region, unsigned n_region,
5090 basic_block *region_copy)
5093 bool free_region_copy = false, copying_header = false;
5094 struct loop *loop = entry->dest->loop_father;
5096 VEC (basic_block, heap) *doms;
5098 int total_freq = 0, entry_freq = 0;
5099 gcov_type total_count = 0, entry_count = 0;
5101 if (!can_copy_bbs_p (region, n_region))
5104 /* Some sanity checking. Note that we do not check for all possible
5105 missuses of the functions. I.e. if you ask to copy something weird,
5106 it will work, but the state of structures probably will not be
5108 for (i = 0; i < n_region; i++)
5110 /* We do not handle subloops, i.e. all the blocks must belong to the
5112 if (region[i]->loop_father != loop)
5115 if (region[i] != entry->dest
5116 && region[i] == loop->header)
5120 set_loop_copy (loop, loop);
5122 /* In case the function is used for loop header copying (which is the primary
5123 use), ensure that EXIT and its copy will be new latch and entry edges. */
5124 if (loop->header == entry->dest)
5126 copying_header = true;
5127 set_loop_copy (loop, loop_outer (loop));
5129 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5132 for (i = 0; i < n_region; i++)
5133 if (region[i] != exit->src
5134 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5140 region_copy = XNEWVEC (basic_block, n_region);
5141 free_region_copy = true;
5144 gcc_assert (!need_ssa_update_p ());
5146 /* Record blocks outside the region that are dominated by something
5149 initialize_original_copy_tables ();
5151 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5153 if (entry->dest->count)
5155 total_count = entry->dest->count;
5156 entry_count = entry->count;
5157 /* Fix up corner cases, to avoid division by zero or creation of negative
5159 if (entry_count > total_count)
5160 entry_count = total_count;
5164 total_freq = entry->dest->frequency;
5165 entry_freq = EDGE_FREQUENCY (entry);
5166 /* Fix up corner cases, to avoid division by zero or creation of negative
5168 if (total_freq == 0)
5170 else if (entry_freq > total_freq)
5171 entry_freq = total_freq;
5174 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5175 split_edge_bb_loc (entry));
5178 scale_bbs_frequencies_gcov_type (region, n_region,
5179 total_count - entry_count,
5181 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5186 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5188 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5193 loop->header = exit->dest;
5194 loop->latch = exit->src;
5197 /* Redirect the entry and add the phi node arguments. */
5198 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5199 gcc_assert (redirected != NULL);
5200 flush_pending_stmts (entry);
5202 /* Concerning updating of dominators: We must recount dominators
5203 for entry block and its copy. Anything that is outside of the
5204 region, but was dominated by something inside needs recounting as
5206 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5207 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5208 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5211 /* Add the other PHI node arguments. */
5212 add_phi_args_after_copy (region_copy, n_region);
5214 /* Update the SSA web. */
5215 update_ssa (TODO_update_ssa);
5217 if (free_region_copy)
5220 free_original_copy_tables ();
5225 DEF_VEC_P(basic_block);
5226 DEF_VEC_ALLOC_P(basic_block,heap);
5229 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5230 adding blocks when the dominator traversal reaches EXIT. This
5231 function silently assumes that ENTRY strictly dominates EXIT. */
5234 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5235 VEC(basic_block,heap) **bbs_p)
5239 for (son = first_dom_son (CDI_DOMINATORS, entry);
5241 son = next_dom_son (CDI_DOMINATORS, son))
5243 VEC_safe_push (basic_block, heap, *bbs_p, son);
5245 gather_blocks_in_sese_region (son, exit, bbs_p);
5255 bitmap vars_to_remove;
5256 htab_t new_label_map;
5260 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5261 contained in *TP and change the DECL_CONTEXT of every local
5262 variable referenced in *TP. */
5265 move_stmt_r (tree *tp, int *walk_subtrees, void *data)
5267 struct move_stmt_d *p = (struct move_stmt_d *) data;
5271 && (EXPR_P (t) || GIMPLE_STMT_P (t)))
5272 TREE_BLOCK (t) = p->block;
5274 if (OMP_DIRECTIVE_P (t)
5275 && TREE_CODE (t) != OMP_RETURN
5276 && TREE_CODE (t) != OMP_CONTINUE)
5278 /* Do not remap variables inside OMP directives. Variables
5279 referenced in clauses and directive header belong to the
5280 parent function and should not be moved into the child
5282 bool save_remap_decls_p = p->remap_decls_p;
5283 p->remap_decls_p = false;
5286 walk_tree (&OMP_BODY (t), move_stmt_r, p, NULL);
5288 p->remap_decls_p = save_remap_decls_p;
5290 else if (DECL_P (t) && DECL_CONTEXT (t) == p->from_context)
5292 if (TREE_CODE (t) == LABEL_DECL)
5294 if (p->new_label_map)
5296 struct tree_map in, *out;
5298 out = htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5303 DECL_CONTEXT (t) = p->to_context;
5305 else if (p->remap_decls_p)
5307 DECL_CONTEXT (t) = p->to_context;
5309 if (TREE_CODE (t) == VAR_DECL)
5311 struct function *f = DECL_STRUCT_FUNCTION (p->to_context);
5312 f->unexpanded_var_list
5313 = tree_cons (0, t, f->unexpanded_var_list);
5315 /* Mark T to be removed from the original function,
5316 otherwise it will be given a DECL_RTL when the
5317 original function is expanded. */
5318 bitmap_set_bit (p->vars_to_remove, DECL_UID (t));
5322 else if (TYPE_P (t))
5329 /* Move basic block BB from function CFUN to function DEST_FN. The
5330 block is moved out of the original linked list and placed after
5331 block AFTER in the new list. Also, the block is removed from the
5332 original array of blocks and placed in DEST_FN's array of blocks.
5333 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5334 updated to reflect the moved edges.
5336 On exit, local variables that need to be removed from
5337 CFUN->UNEXPANDED_VAR_LIST will have been added to VARS_TO_REMOVE. */
5340 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5341 basic_block after, bool update_edge_count_p,
5342 bitmap vars_to_remove, htab_t new_label_map, int eh_offset)
5344 struct control_flow_graph *cfg;
5347 block_stmt_iterator si;
5348 struct move_stmt_d d;
5349 unsigned old_len, new_len;
5351 /* Remove BB from dominance structures. */
5352 delete_from_dominance_info (CDI_DOMINATORS, bb);
5354 /* Link BB to the new linked list. */
5355 move_block_after (bb, after);
5357 /* Update the edge count in the corresponding flowgraphs. */
5358 if (update_edge_count_p)
5359 FOR_EACH_EDGE (e, ei, bb->succs)
5361 cfun->cfg->x_n_edges--;
5362 dest_cfun->cfg->x_n_edges++;
5365 /* Remove BB from the original basic block array. */
5366 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5367 cfun->cfg->x_n_basic_blocks--;
5369 /* Grow DEST_CFUN's basic block array if needed. */
5370 cfg = dest_cfun->cfg;
5371 cfg->x_n_basic_blocks++;
5372 if (bb->index >= cfg->x_last_basic_block)
5373 cfg->x_last_basic_block = bb->index + 1;
5375 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5376 if ((unsigned) cfg->x_last_basic_block >= old_len)
5378 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5379 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5383 VEC_replace (basic_block, cfg->x_basic_block_info,
5386 /* The statements in BB need to be associated with a new TREE_BLOCK.
5387 Labels need to be associated with a new label-to-block map. */
5388 memset (&d, 0, sizeof (d));
5389 d.vars_to_remove = vars_to_remove;
5391 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5393 tree stmt = bsi_stmt (si);
5396 d.from_context = cfun->decl;
5397 d.to_context = dest_cfun->decl;
5398 d.remap_decls_p = true;
5399 d.new_label_map = new_label_map;
5400 if (TREE_BLOCK (stmt))
5401 d.block = DECL_INITIAL (dest_cfun->decl);
5403 walk_tree (&stmt, move_stmt_r, &d, NULL);
5405 if (TREE_CODE (stmt) == LABEL_EXPR)
5407 tree label = LABEL_EXPR_LABEL (stmt);
5408 int uid = LABEL_DECL_UID (label);
5410 gcc_assert (uid > -1);
5412 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5413 if (old_len <= (unsigned) uid)
5415 new_len = 3 * uid / 2;
5416 VEC_safe_grow_cleared (basic_block, gc,
5417 cfg->x_label_to_block_map, new_len);
5420 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5421 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5423 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5425 if (uid >= dest_cfun->last_label_uid)
5426 dest_cfun->last_label_uid = uid + 1;
5428 else if (TREE_CODE (stmt) == RESX_EXPR && eh_offset != 0)
5429 TREE_OPERAND (stmt, 0) =
5430 build_int_cst (NULL_TREE,
5431 TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0))
5434 region = lookup_stmt_eh_region (stmt);
5437 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5438 remove_stmt_from_eh_region (stmt);
5439 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5440 gimple_remove_stmt_histograms (cfun, stmt);
5445 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5446 the outermost EH region. Use REGION as the incoming base EH region. */
5449 find_outermost_region_in_block (struct function *src_cfun,
5450 basic_block bb, int region)
5452 block_stmt_iterator si;
5454 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5456 tree stmt = bsi_stmt (si);
5459 if (TREE_CODE (stmt) == RESX_EXPR)
5460 stmt_region = TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0));
5462 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5463 if (stmt_region > 0)
5466 region = stmt_region;
5467 else if (stmt_region != region)
5469 region = eh_region_outermost (src_cfun, stmt_region, region);
5470 gcc_assert (region != -1);
5479 new_label_mapper (tree decl, void *data)
5481 htab_t hash = (htab_t) data;
5485 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5487 m = xmalloc (sizeof (struct tree_map));
5488 m->hash = DECL_UID (decl);
5489 m->base.from = decl;
5490 m->to = create_artificial_label ();
5491 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5493 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5494 gcc_assert (*slot == NULL);
5501 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5502 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5503 single basic block in the original CFG and the new basic block is
5504 returned. DEST_CFUN must not have a CFG yet.
5506 Note that the region need not be a pure SESE region. Blocks inside
5507 the region may contain calls to abort/exit. The only restriction
5508 is that ENTRY_BB should be the only entry point and it must
5511 All local variables referenced in the region are assumed to be in
5512 the corresponding BLOCK_VARS and unexpanded variable lists
5513 associated with DEST_CFUN. */
5516 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5517 basic_block exit_bb)
5519 VEC(basic_block,heap) *bbs;
5520 basic_block after, bb, *entry_pred, *exit_succ;
5521 struct function *saved_cfun;
5522 int *entry_flag, *exit_flag, eh_offset;
5523 unsigned i, num_entry_edges, num_exit_edges;
5526 bitmap vars_to_remove;
5527 htab_t new_label_map;
5531 /* Collect all the blocks in the region. Manually add ENTRY_BB
5532 because it won't be added by dfs_enumerate_from. */
5533 calculate_dominance_info (CDI_DOMINATORS);
5535 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5537 gcc_assert (entry_bb != exit_bb
5539 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
5542 VEC_safe_push (basic_block, heap, bbs, entry_bb);
5543 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
5545 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5546 the predecessor edges to ENTRY_BB and the successor edges to
5547 EXIT_BB so that we can re-attach them to the new basic block that
5548 will replace the region. */
5549 num_entry_edges = EDGE_COUNT (entry_bb->preds);
5550 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
5551 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
5553 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
5555 entry_flag[i] = e->flags;
5556 entry_pred[i++] = e->src;
5562 num_exit_edges = EDGE_COUNT (exit_bb->succs);
5563 exit_succ = (basic_block *) xcalloc (num_exit_edges,
5564 sizeof (basic_block));
5565 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
5567 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
5569 exit_flag[i] = e->flags;
5570 exit_succ[i++] = e->dest;
5581 /* Switch context to the child function to initialize DEST_FN's CFG. */
5582 gcc_assert (dest_cfun->cfg == NULL);
5585 init_empty_tree_cfg ();
5587 /* Initialize EH information for the new function. */
5589 new_label_map = NULL;
5594 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5595 region = find_outermost_region_in_block (saved_cfun, bb, region);
5597 init_eh_for_function ();
5600 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
5601 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
5602 new_label_map, region, 0);
5608 /* Move blocks from BBS into DEST_CFUN. */
5609 gcc_assert (VEC_length (basic_block, bbs) >= 2);
5610 after = dest_cfun->cfg->x_entry_block_ptr;
5611 vars_to_remove = BITMAP_ALLOC (NULL);
5612 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5614 /* No need to update edge counts on the last block. It has
5615 already been updated earlier when we detached the region from
5616 the original CFG. */
5617 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, vars_to_remove,
5618 new_label_map, eh_offset);
5623 htab_delete (new_label_map);
5625 /* Remove the variables marked in VARS_TO_REMOVE from
5626 CFUN->UNEXPANDED_VAR_LIST. Otherwise, they will be given a
5627 DECL_RTL in the context of CFUN. */
5628 if (!bitmap_empty_p (vars_to_remove))
5632 for (p = &cfun->unexpanded_var_list; *p; )
5634 tree var = TREE_VALUE (*p);
5635 if (bitmap_bit_p (vars_to_remove, DECL_UID (var)))
5637 *p = TREE_CHAIN (*p);
5641 p = &TREE_CHAIN (*p);
5645 BITMAP_FREE (vars_to_remove);
5647 /* Rewire the entry and exit blocks. The successor to the entry
5648 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
5649 the child function. Similarly, the predecessor of DEST_FN's
5650 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
5651 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
5652 various CFG manipulation function get to the right CFG.
5654 FIXME, this is silly. The CFG ought to become a parameter to
5657 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
5659 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
5662 /* Back in the original function, the SESE region has disappeared,
5663 create a new basic block in its place. */
5664 bb = create_empty_bb (entry_pred[0]);
5665 for (i = 0; i < num_entry_edges; i++)
5666 make_edge (entry_pred[i], bb, entry_flag[i]);
5668 for (i = 0; i < num_exit_edges; i++)
5669 make_edge (bb, exit_succ[i], exit_flag[i]);
5678 free_dominance_info (CDI_DOMINATORS);
5679 free_dominance_info (CDI_POST_DOMINATORS);
5680 VEC_free (basic_block, heap, bbs);
5686 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */
5689 dump_function_to_file (tree fn, FILE *file, int flags)
5691 tree arg, vars, var;
5692 struct function *dsf;
5693 bool ignore_topmost_bind = false, any_var = false;
5696 struct function *saved_cfun;
5698 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
5700 arg = DECL_ARGUMENTS (fn);
5703 print_generic_expr (file, arg, dump_flags);
5704 if (TREE_CHAIN (arg))
5705 fprintf (file, ", ");
5706 arg = TREE_CHAIN (arg);
5708 fprintf (file, ")\n");
5710 dsf = DECL_STRUCT_FUNCTION (fn);
5711 if (dsf && (flags & TDF_DETAILS))
5712 dump_eh_tree (file, dsf);
5714 if (flags & TDF_RAW)
5716 dump_node (fn, TDF_SLIM | flags, file);
5720 /* Switch CFUN to point to FN. */
5722 cfun = DECL_STRUCT_FUNCTION (fn);
5724 /* When GIMPLE is lowered, the variables are no longer available in
5725 BIND_EXPRs, so display them separately. */
5726 if (cfun && cfun->decl == fn && cfun->unexpanded_var_list)
5728 ignore_topmost_bind = true;
5730 fprintf (file, "{\n");
5731 for (vars = cfun->unexpanded_var_list; vars; vars = TREE_CHAIN (vars))
5733 var = TREE_VALUE (vars);
5735 print_generic_decl (file, var, flags);
5736 fprintf (file, "\n");
5742 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
5744 /* Make a CFG based dump. */
5745 check_bb_profile (ENTRY_BLOCK_PTR, file);
5746 if (!ignore_topmost_bind)
5747 fprintf (file, "{\n");
5749 if (any_var && n_basic_blocks)
5750 fprintf (file, "\n");
5753 dump_generic_bb (file, bb, 2, flags);
5755 fprintf (file, "}\n");
5756 check_bb_profile (EXIT_BLOCK_PTR, file);
5762 /* Make a tree based dump. */
5763 chain = DECL_SAVED_TREE (fn);
5765 if (chain && TREE_CODE (chain) == BIND_EXPR)
5767 if (ignore_topmost_bind)
5769 chain = BIND_EXPR_BODY (chain);
5777 if (!ignore_topmost_bind)
5778 fprintf (file, "{\n");
5783 fprintf (file, "\n");
5785 print_generic_stmt_indented (file, chain, flags, indent);
5786 if (ignore_topmost_bind)
5787 fprintf (file, "}\n");
5790 fprintf (file, "\n\n");
5797 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
5800 debug_function (tree fn, int flags)
5802 dump_function_to_file (fn, stderr, flags);
5806 /* Pretty print of the loops intermediate representation. */
5807 static void print_loop (FILE *, struct loop *, int);
5808 static void print_pred_bbs (FILE *, basic_block bb);
5809 static void print_succ_bbs (FILE *, basic_block bb);
5812 /* Print on FILE the indexes for the predecessors of basic_block BB. */
5815 print_pred_bbs (FILE *file, basic_block bb)
5820 FOR_EACH_EDGE (e, ei, bb->preds)
5821 fprintf (file, "bb_%d ", e->src->index);
5825 /* Print on FILE the indexes for the successors of basic_block BB. */
5828 print_succ_bbs (FILE *file, basic_block bb)
5833 FOR_EACH_EDGE (e, ei, bb->succs)
5834 fprintf (file, "bb_%d ", e->dest->index);
5838 /* Pretty print LOOP on FILE, indented INDENT spaces. */
5841 print_loop (FILE *file, struct loop *loop, int indent)
5849 s_indent = (char *) alloca ((size_t) indent + 1);
5850 memset ((void *) s_indent, ' ', (size_t) indent);
5851 s_indent[indent] = '\0';
5853 /* Print the loop's header. */
5854 fprintf (file, "%sloop_%d\n", s_indent, loop->num);
5856 /* Print the loop's body. */
5857 fprintf (file, "%s{\n", s_indent);
5859 if (bb->loop_father == loop)
5861 /* Print the basic_block's header. */
5862 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
5863 print_pred_bbs (file, bb);
5864 fprintf (file, "}, succs = {");
5865 print_succ_bbs (file, bb);
5866 fprintf (file, "})\n");
5868 /* Print the basic_block's body. */
5869 fprintf (file, "%s {\n", s_indent);
5870 tree_dump_bb (bb, file, indent + 4);
5871 fprintf (file, "%s }\n", s_indent);
5874 print_loop (file, loop->inner, indent + 2);
5875 fprintf (file, "%s}\n", s_indent);
5876 print_loop (file, loop->next, indent);
5880 /* Follow a CFG edge from the entry point of the program, and on entry
5881 of a loop, pretty print the loop structure on FILE. */
5884 print_loop_ir (FILE *file)
5888 bb = BASIC_BLOCK (NUM_FIXED_BLOCKS);
5889 if (bb && bb->loop_father)
5890 print_loop (file, bb->loop_father, 0);
5894 /* Debugging loops structure at tree level. */
5897 debug_loop_ir (void)
5899 print_loop_ir (stderr);
5903 /* Return true if BB ends with a call, possibly followed by some
5904 instructions that must stay with the call. Return false,
5908 tree_block_ends_with_call_p (basic_block bb)
5910 block_stmt_iterator bsi = bsi_last (bb);
5911 return get_call_expr_in (bsi_stmt (bsi)) != NULL;
5915 /* Return true if BB ends with a conditional branch. Return false,
5919 tree_block_ends_with_condjump_p (basic_block bb)
5921 tree stmt = last_stmt (bb);
5922 return (stmt && TREE_CODE (stmt) == COND_EXPR);
5926 /* Return true if we need to add fake edge to exit at statement T.
5927 Helper function for tree_flow_call_edges_add. */
5930 need_fake_edge_p (tree t)
5934 /* NORETURN and LONGJMP calls already have an edge to exit.
5935 CONST and PURE calls do not need one.
5936 We don't currently check for CONST and PURE here, although
5937 it would be a good idea, because those attributes are
5938 figured out from the RTL in mark_constant_function, and
5939 the counter incrementation code from -fprofile-arcs
5940 leads to different results from -fbranch-probabilities. */
5941 call = get_call_expr_in (t);
5943 && !(call_expr_flags (call) & ECF_NORETURN))
5946 if (TREE_CODE (t) == ASM_EXPR
5947 && (ASM_VOLATILE_P (t) || ASM_INPUT_P (t)))
5954 /* Add fake edges to the function exit for any non constant and non
5955 noreturn calls, volatile inline assembly in the bitmap of blocks
5956 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
5957 the number of blocks that were split.
5959 The goal is to expose cases in which entering a basic block does
5960 not imply that all subsequent instructions must be executed. */
5963 tree_flow_call_edges_add (sbitmap blocks)
5966 int blocks_split = 0;
5967 int last_bb = last_basic_block;
5968 bool check_last_block = false;
5970 if (n_basic_blocks == NUM_FIXED_BLOCKS)
5974 check_last_block = true;
5976 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
5978 /* In the last basic block, before epilogue generation, there will be
5979 a fallthru edge to EXIT. Special care is required if the last insn
5980 of the last basic block is a call because make_edge folds duplicate
5981 edges, which would result in the fallthru edge also being marked
5982 fake, which would result in the fallthru edge being removed by
5983 remove_fake_edges, which would result in an invalid CFG.
5985 Moreover, we can't elide the outgoing fake edge, since the block
5986 profiler needs to take this into account in order to solve the minimal
5987 spanning tree in the case that the call doesn't return.
5989 Handle this by adding a dummy instruction in a new last basic block. */
5990 if (check_last_block)
5992 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
5993 block_stmt_iterator bsi = bsi_last (bb);
5995 if (!bsi_end_p (bsi))
5998 if (t && need_fake_edge_p (t))
6002 e = find_edge (bb, EXIT_BLOCK_PTR);
6005 bsi_insert_on_edge (e, build_empty_stmt ());
6006 bsi_commit_edge_inserts ();
6011 /* Now add fake edges to the function exit for any non constant
6012 calls since there is no way that we can determine if they will
6014 for (i = 0; i < last_bb; i++)
6016 basic_block bb = BASIC_BLOCK (i);
6017 block_stmt_iterator bsi;
6018 tree stmt, last_stmt;
6023 if (blocks && !TEST_BIT (blocks, i))
6026 bsi = bsi_last (bb);
6027 if (!bsi_end_p (bsi))
6029 last_stmt = bsi_stmt (bsi);
6032 stmt = bsi_stmt (bsi);
6033 if (need_fake_edge_p (stmt))
6036 /* The handling above of the final block before the
6037 epilogue should be enough to verify that there is
6038 no edge to the exit block in CFG already.
6039 Calling make_edge in such case would cause us to
6040 mark that edge as fake and remove it later. */
6041 #ifdef ENABLE_CHECKING
6042 if (stmt == last_stmt)
6044 e = find_edge (bb, EXIT_BLOCK_PTR);
6045 gcc_assert (e == NULL);
6049 /* Note that the following may create a new basic block
6050 and renumber the existing basic blocks. */
6051 if (stmt != last_stmt)
6053 e = split_block (bb, stmt);
6057 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6061 while (!bsi_end_p (bsi));
6066 verify_flow_info ();
6068 return blocks_split;
6071 /* Purge dead abnormal call edges from basic block BB. */
6074 tree_purge_dead_abnormal_call_edges (basic_block bb)
6076 bool changed = tree_purge_dead_eh_edges (bb);
6078 if (current_function_has_nonlocal_label)
6080 tree stmt = last_stmt (bb);
6084 if (!(stmt && tree_can_make_abnormal_goto (stmt)))
6085 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6087 if (e->flags & EDGE_ABNORMAL)
6096 /* See tree_purge_dead_eh_edges below. */
6098 free_dominance_info (CDI_DOMINATORS);
6104 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6107 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6111 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6112 for (son = first_dom_son (CDI_DOMINATORS, bb);
6114 son = next_dom_son (CDI_DOMINATORS, son))
6115 get_all_dominated_blocks (son, dom_bbs);
6118 /* Removes edge E and all the blocks dominated by it, and updates dominance
6119 information. The IL in E->src needs to be updated separately.
6120 If dominance info is not available, only the edge E is removed.*/
6123 remove_edge_and_dominated_blocks (edge e)
6125 VEC (basic_block, heap) *bbs_to_remove = NULL;
6126 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6130 bool none_removed = false;
6132 basic_block bb, dbb;
6135 if (!dom_info_available_p (CDI_DOMINATORS))
6141 /* No updating is needed for edges to exit. */
6142 if (e->dest == EXIT_BLOCK_PTR)
6144 if (cfgcleanup_altered_bbs)
6145 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6150 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6151 that is not dominated by E->dest, then this set is empty. Otherwise,
6152 all the basic blocks dominated by E->dest are removed.
6154 Also, to DF_IDOM we store the immediate dominators of the blocks in
6155 the dominance frontier of E (i.e., of the successors of the
6156 removed blocks, if there are any, and of E->dest otherwise). */
6157 FOR_EACH_EDGE (f, ei, e->dest->preds)
6162 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6164 none_removed = true;
6169 df = BITMAP_ALLOC (NULL);
6170 df_idom = BITMAP_ALLOC (NULL);
6173 bitmap_set_bit (df_idom,
6174 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6177 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6178 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6180 FOR_EACH_EDGE (f, ei, bb->succs)
6182 if (f->dest != EXIT_BLOCK_PTR)
6183 bitmap_set_bit (df, f->dest->index);
6186 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6187 bitmap_clear_bit (df, bb->index);
6189 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6191 bb = BASIC_BLOCK (i);
6192 bitmap_set_bit (df_idom,
6193 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6197 if (cfgcleanup_altered_bbs)
6199 /* Record the set of the altered basic blocks. */
6200 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6201 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6204 /* Remove E and the cancelled blocks. */
6209 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6210 delete_basic_block (bb);
6213 /* Update the dominance information. The immediate dominator may change only
6214 for blocks whose immediate dominator belongs to DF_IDOM:
6216 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6217 removal. Let Z the arbitrary block such that idom(Z) = Y and
6218 Z dominates X after the removal. Before removal, there exists a path P
6219 from Y to X that avoids Z. Let F be the last edge on P that is
6220 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6221 dominates W, and because of P, Z does not dominate W), and W belongs to
6222 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6223 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6225 bb = BASIC_BLOCK (i);
6226 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6228 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6229 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6232 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6235 BITMAP_FREE (df_idom);
6236 VEC_free (basic_block, heap, bbs_to_remove);
6237 VEC_free (basic_block, heap, bbs_to_fix_dom);
6240 /* Purge dead EH edges from basic block BB. */
6243 tree_purge_dead_eh_edges (basic_block bb)
6245 bool changed = false;
6248 tree stmt = last_stmt (bb);
6250 if (stmt && tree_can_throw_internal (stmt))
6253 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6255 if (e->flags & EDGE_EH)
6257 remove_edge_and_dominated_blocks (e);
6268 tree_purge_all_dead_eh_edges (const_bitmap blocks)
6270 bool changed = false;
6274 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6276 changed |= tree_purge_dead_eh_edges (BASIC_BLOCK (i));
6282 /* This function is called whenever a new edge is created or
6286 tree_execute_on_growing_pred (edge e)
6288 basic_block bb = e->dest;
6291 reserve_phi_args_for_new_edge (bb);
6294 /* This function is called immediately before edge E is removed from
6295 the edge vector E->dest->preds. */
6298 tree_execute_on_shrinking_pred (edge e)
6300 if (phi_nodes (e->dest))
6301 remove_phi_args (e);
6304 /*---------------------------------------------------------------------------
6305 Helper functions for Loop versioning
6306 ---------------------------------------------------------------------------*/
6308 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6309 of 'first'. Both of them are dominated by 'new_head' basic block. When
6310 'new_head' was created by 'second's incoming edge it received phi arguments
6311 on the edge by split_edge(). Later, additional edge 'e' was created to
6312 connect 'new_head' and 'first'. Now this routine adds phi args on this
6313 additional edge 'e' that new_head to second edge received as part of edge
6318 tree_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6319 basic_block new_head, edge e)
6322 edge e2 = find_edge (new_head, second);
6324 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6325 edge, we should always have an edge from NEW_HEAD to SECOND. */
6326 gcc_assert (e2 != NULL);
6328 /* Browse all 'second' basic block phi nodes and add phi args to
6329 edge 'e' for 'first' head. PHI args are always in correct order. */
6331 for (phi2 = phi_nodes (second), phi1 = phi_nodes (first);
6333 phi2 = PHI_CHAIN (phi2), phi1 = PHI_CHAIN (phi1))
6335 tree def = PHI_ARG_DEF (phi2, e2->dest_idx);
6336 add_phi_arg (phi1, def, e);
6340 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6341 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6342 the destination of the ELSE part. */
6344 tree_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6345 basic_block second_head ATTRIBUTE_UNUSED,
6346 basic_block cond_bb, void *cond_e)
6348 block_stmt_iterator bsi;
6349 tree new_cond_expr = NULL_TREE;
6350 tree cond_expr = (tree) cond_e;
6353 /* Build new conditional expr */
6354 new_cond_expr = build3 (COND_EXPR, void_type_node, cond_expr,
6355 NULL_TREE, NULL_TREE);
6357 /* Add new cond in cond_bb. */
6358 bsi = bsi_start (cond_bb);
6359 bsi_insert_after (&bsi, new_cond_expr, BSI_NEW_STMT);
6360 /* Adjust edges appropriately to connect new head with first head
6361 as well as second head. */
6362 e0 = single_succ_edge (cond_bb);
6363 e0->flags &= ~EDGE_FALLTHRU;
6364 e0->flags |= EDGE_FALSE_VALUE;
6367 struct cfg_hooks tree_cfg_hooks = {
6369 tree_verify_flow_info,
6370 tree_dump_bb, /* dump_bb */
6371 create_bb, /* create_basic_block */
6372 tree_redirect_edge_and_branch,/* redirect_edge_and_branch */
6373 tree_redirect_edge_and_branch_force,/* redirect_edge_and_branch_force */
6374 tree_can_remove_branch_p, /* can_remove_branch_p */
6375 remove_bb, /* delete_basic_block */
6376 tree_split_block, /* split_block */
6377 tree_move_block_after, /* move_block_after */
6378 tree_can_merge_blocks_p, /* can_merge_blocks_p */
6379 tree_merge_blocks, /* merge_blocks */
6380 tree_predict_edge, /* predict_edge */
6381 tree_predicted_by_p, /* predicted_by_p */
6382 tree_can_duplicate_bb_p, /* can_duplicate_block_p */
6383 tree_duplicate_bb, /* duplicate_block */
6384 tree_split_edge, /* split_edge */
6385 tree_make_forwarder_block, /* make_forward_block */
6386 NULL, /* tidy_fallthru_edge */
6387 tree_block_ends_with_call_p, /* block_ends_with_call_p */
6388 tree_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6389 tree_flow_call_edges_add, /* flow_call_edges_add */
6390 tree_execute_on_growing_pred, /* execute_on_growing_pred */
6391 tree_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6392 tree_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6393 tree_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6394 tree_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6395 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6396 flush_pending_stmts /* flush_pending_stmts */
6400 /* Split all critical edges. */
6403 split_critical_edges (void)
6409 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6410 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6411 mappings around the calls to split_edge. */
6412 start_recording_case_labels ();
6415 FOR_EACH_EDGE (e, ei, bb->succs)
6416 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6421 end_recording_case_labels ();
6425 struct tree_opt_pass pass_split_crit_edges =
6427 "crited", /* name */
6429 split_critical_edges, /* execute */
6432 0, /* static_pass_number */
6433 TV_TREE_SPLIT_EDGES, /* tv_id */
6434 PROP_cfg, /* properties required */
6435 PROP_no_crit_edges, /* properties_provided */
6436 0, /* properties_destroyed */
6437 0, /* todo_flags_start */
6438 TODO_dump_func, /* todo_flags_finish */
6443 /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into
6444 a temporary, make sure and register it to be renamed if necessary,
6445 and finally return the temporary. Put the statements to compute
6446 EXP before the current statement in BSI. */
6449 gimplify_val (block_stmt_iterator *bsi, tree type, tree exp)
6451 tree t, new_stmt, orig_stmt;
6453 if (is_gimple_val (exp))
6456 t = make_rename_temp (type, NULL);
6457 new_stmt = build_gimple_modify_stmt (t, exp);
6459 orig_stmt = bsi_stmt (*bsi);
6460 SET_EXPR_LOCUS (new_stmt, EXPR_LOCUS (orig_stmt));
6461 TREE_BLOCK (new_stmt) = TREE_BLOCK (orig_stmt);
6463 bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
6464 if (gimple_in_ssa_p (cfun))
6465 mark_symbols_for_renaming (new_stmt);
6470 /* Build a ternary operation and gimplify it. Emit code before BSI.
6471 Return the gimple_val holding the result. */
6474 gimplify_build3 (block_stmt_iterator *bsi, enum tree_code code,
6475 tree type, tree a, tree b, tree c)
6479 ret = fold_build3 (code, type, a, b, c);
6482 return gimplify_val (bsi, type, ret);
6485 /* Build a binary operation and gimplify it. Emit code before BSI.
6486 Return the gimple_val holding the result. */
6489 gimplify_build2 (block_stmt_iterator *bsi, enum tree_code code,
6490 tree type, tree a, tree b)
6494 ret = fold_build2 (code, type, a, b);
6497 return gimplify_val (bsi, type, ret);
6500 /* Build a unary operation and gimplify it. Emit code before BSI.
6501 Return the gimple_val holding the result. */
6504 gimplify_build1 (block_stmt_iterator *bsi, enum tree_code code, tree type,
6509 ret = fold_build1 (code, type, a);
6512 return gimplify_val (bsi, type, ret);
6517 /* Emit return warnings. */
6520 execute_warn_function_return (void)
6522 #ifdef USE_MAPPED_LOCATION
6523 source_location location;
6531 /* If we have a path to EXIT, then we do return. */
6532 if (TREE_THIS_VOLATILE (cfun->decl)
6533 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
6535 #ifdef USE_MAPPED_LOCATION
6536 location = UNKNOWN_LOCATION;
6540 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6542 last = last_stmt (e->src);
6543 if (TREE_CODE (last) == RETURN_EXPR
6544 #ifdef USE_MAPPED_LOCATION
6545 && (location = EXPR_LOCATION (last)) != UNKNOWN_LOCATION)
6547 && (locus = EXPR_LOCUS (last)) != NULL)
6551 #ifdef USE_MAPPED_LOCATION
6552 if (location == UNKNOWN_LOCATION)
6553 location = cfun->function_end_locus;
6554 warning (0, "%H%<noreturn%> function does return", &location);
6557 locus = &cfun->function_end_locus;
6558 warning (0, "%H%<noreturn%> function does return", locus);
6562 /* If we see "return;" in some basic block, then we do reach the end
6563 without returning a value. */
6564 else if (warn_return_type
6565 && !TREE_NO_WARNING (cfun->decl)
6566 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
6567 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
6569 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6571 tree last = last_stmt (e->src);
6572 if (TREE_CODE (last) == RETURN_EXPR
6573 && TREE_OPERAND (last, 0) == NULL
6574 && !TREE_NO_WARNING (last))
6576 #ifdef USE_MAPPED_LOCATION
6577 location = EXPR_LOCATION (last);
6578 if (location == UNKNOWN_LOCATION)
6579 location = cfun->function_end_locus;
6580 warning (0, "%Hcontrol reaches end of non-void function", &location);
6582 locus = EXPR_LOCUS (last);
6584 locus = &cfun->function_end_locus;
6585 warning (0, "%Hcontrol reaches end of non-void function", locus);
6587 TREE_NO_WARNING (cfun->decl) = 1;
6596 /* Given a basic block B which ends with a conditional and has
6597 precisely two successors, determine which of the edges is taken if
6598 the conditional is true and which is taken if the conditional is
6599 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
6602 extract_true_false_edges_from_block (basic_block b,
6606 edge e = EDGE_SUCC (b, 0);
6608 if (e->flags & EDGE_TRUE_VALUE)
6611 *false_edge = EDGE_SUCC (b, 1);
6616 *true_edge = EDGE_SUCC (b, 1);
6620 struct tree_opt_pass pass_warn_function_return =
6624 execute_warn_function_return, /* execute */
6627 0, /* static_pass_number */
6629 PROP_cfg, /* properties_required */
6630 0, /* properties_provided */
6631 0, /* properties_destroyed */
6632 0, /* todo_flags_start */
6633 0, /* todo_flags_finish */
6637 /* Emit noreturn warnings. */
6640 execute_warn_function_noreturn (void)
6642 if (warn_missing_noreturn
6643 && !TREE_THIS_VOLATILE (cfun->decl)
6644 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
6645 && !lang_hooks.function.missing_noreturn_ok_p (cfun->decl))
6646 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
6647 "for attribute %<noreturn%>",
6652 struct tree_opt_pass pass_warn_function_noreturn =
6656 execute_warn_function_noreturn, /* execute */
6659 0, /* static_pass_number */
6661 PROP_cfg, /* properties_required */
6662 0, /* properties_provided */
6663 0, /* properties_destroyed */
6664 0, /* todo_flags_start */
6665 0, /* todo_flags_finish */