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"
49 #include "tree-inline.h"
51 /* This file contains functions for building the Control Flow Graph (CFG)
52 for a function tree. */
54 /* Local declarations. */
56 /* Initial capacity for the basic block array. */
57 static const int initial_cfg_capacity = 20;
59 /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs
60 which use a particular edge. The CASE_LABEL_EXPRs are chained together
61 via their TREE_CHAIN field, which we clear after we're done with the
62 hash table to prevent problems with duplication of SWITCH_EXPRs.
64 Access to this list of CASE_LABEL_EXPRs allows us to efficiently
65 update the case vector in response to edge redirections.
67 Right now this table is set up and torn down at key points in the
68 compilation process. It would be nice if we could make the table
69 more persistent. The key is getting notification of changes to
70 the CFG (particularly edge removal, creation and redirection). */
72 static struct pointer_map_t *edge_to_cases;
77 long num_merged_labels;
80 static struct cfg_stats_d cfg_stats;
82 /* Nonzero if we found a computed goto while building basic blocks. */
83 static bool found_computed_goto;
85 /* Basic blocks and flowgraphs. */
86 static basic_block create_bb (void *, void *, basic_block);
87 static void make_blocks (tree);
88 static void factor_computed_gotos (void);
91 static void make_edges (void);
92 static void make_cond_expr_edges (basic_block);
93 static void make_switch_expr_edges (basic_block);
94 static void make_goto_expr_edges (basic_block);
95 static edge tree_redirect_edge_and_branch (edge, basic_block);
96 static edge tree_try_redirect_by_replacing_jump (edge, basic_block);
97 static unsigned int split_critical_edges (void);
99 /* Various helpers. */
100 static inline bool stmt_starts_bb_p (const_tree, const_tree);
101 static int tree_verify_flow_info (void);
102 static void tree_make_forwarder_block (edge);
103 static void tree_cfg2vcg (FILE *);
104 static inline void change_bb_for_stmt (tree t, basic_block bb);
106 /* Flowgraph optimization and cleanup. */
107 static void tree_merge_blocks (basic_block, basic_block);
108 static bool tree_can_merge_blocks_p (basic_block, basic_block);
109 static void remove_bb (basic_block);
110 static edge find_taken_edge_computed_goto (basic_block, tree);
111 static edge find_taken_edge_cond_expr (basic_block, tree);
112 static edge find_taken_edge_switch_expr (basic_block, tree);
113 static tree find_case_label_for_value (tree, tree);
116 init_empty_tree_cfg (void)
118 /* Initialize the basic block array. */
120 profile_status = PROFILE_ABSENT;
121 n_basic_blocks = NUM_FIXED_BLOCKS;
122 last_basic_block = NUM_FIXED_BLOCKS;
123 basic_block_info = VEC_alloc (basic_block, gc, initial_cfg_capacity);
124 VEC_safe_grow_cleared (basic_block, gc, basic_block_info,
125 initial_cfg_capacity);
127 /* Build a mapping of labels to their associated blocks. */
128 label_to_block_map = VEC_alloc (basic_block, gc, initial_cfg_capacity);
129 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
130 initial_cfg_capacity);
132 SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR);
133 SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR);
134 ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR;
135 EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR;
138 /*---------------------------------------------------------------------------
140 ---------------------------------------------------------------------------*/
142 /* Entry point to the CFG builder for trees. TP points to the list of
143 statements to be added to the flowgraph. */
146 build_tree_cfg (tree *tp)
148 /* Register specific tree functions. */
149 tree_register_cfg_hooks ();
151 memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
153 init_empty_tree_cfg ();
155 found_computed_goto = 0;
158 /* Computed gotos are hell to deal with, especially if there are
159 lots of them with a large number of destinations. So we factor
160 them to a common computed goto location before we build the
161 edge list. After we convert back to normal form, we will un-factor
162 the computed gotos since factoring introduces an unwanted jump. */
163 if (found_computed_goto)
164 factor_computed_gotos ();
166 /* Make sure there is always at least one block, even if it's empty. */
167 if (n_basic_blocks == NUM_FIXED_BLOCKS)
168 create_empty_bb (ENTRY_BLOCK_PTR);
170 /* Adjust the size of the array. */
171 if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
172 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
174 /* To speed up statement iterator walks, we first purge dead labels. */
175 cleanup_dead_labels ();
177 /* Group case nodes to reduce the number of edges.
178 We do this after cleaning up dead labels because otherwise we miss
179 a lot of obvious case merging opportunities. */
180 group_case_labels ();
182 /* Create the edges of the flowgraph. */
184 cleanup_dead_labels ();
186 /* Debugging dumps. */
188 /* Write the flowgraph to a VCG file. */
190 int local_dump_flags;
191 FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
194 tree_cfg2vcg (vcg_file);
195 dump_end (TDI_vcg, vcg_file);
199 #ifdef ENABLE_CHECKING
203 /* Dump a textual representation of the flowgraph. */
205 dump_tree_cfg (dump_file, dump_flags);
209 execute_build_cfg (void)
211 build_tree_cfg (&DECL_SAVED_TREE (current_function_decl));
215 struct tree_opt_pass pass_build_cfg =
219 execute_build_cfg, /* execute */
222 0, /* static_pass_number */
223 TV_TREE_CFG, /* tv_id */
224 PROP_gimple_leh, /* properties_required */
225 PROP_cfg, /* properties_provided */
226 0, /* properties_destroyed */
227 0, /* todo_flags_start */
228 TODO_verify_stmts | TODO_cleanup_cfg, /* todo_flags_finish */
232 /* Search the CFG for any computed gotos. If found, factor them to a
233 common computed goto site. Also record the location of that site so
234 that we can un-factor the gotos after we have converted back to
238 factor_computed_gotos (void)
241 tree factored_label_decl = NULL;
243 tree factored_computed_goto_label = NULL;
244 tree factored_computed_goto = NULL;
246 /* We know there are one or more computed gotos in this function.
247 Examine the last statement in each basic block to see if the block
248 ends with a computed goto. */
252 block_stmt_iterator bsi = bsi_last (bb);
257 last = bsi_stmt (bsi);
259 /* Ignore the computed goto we create when we factor the original
261 if (last == factored_computed_goto)
264 /* If the last statement is a computed goto, factor it. */
265 if (computed_goto_p (last))
269 /* The first time we find a computed goto we need to create
270 the factored goto block and the variable each original
271 computed goto will use for their goto destination. */
272 if (! factored_computed_goto)
274 basic_block new_bb = create_empty_bb (bb);
275 block_stmt_iterator new_bsi = bsi_start (new_bb);
277 /* Create the destination of the factored goto. Each original
278 computed goto will put its desired destination into this
279 variable and jump to the label we create immediately
281 var = create_tmp_var (ptr_type_node, "gotovar");
283 /* Build a label for the new block which will contain the
284 factored computed goto. */
285 factored_label_decl = create_artificial_label ();
286 factored_computed_goto_label
287 = build1 (LABEL_EXPR, void_type_node, factored_label_decl);
288 bsi_insert_after (&new_bsi, factored_computed_goto_label,
291 /* Build our new computed goto. */
292 factored_computed_goto = build1 (GOTO_EXPR, void_type_node, var);
293 bsi_insert_after (&new_bsi, factored_computed_goto,
297 /* Copy the original computed goto's destination into VAR. */
298 assignment = build_gimple_modify_stmt (var,
299 GOTO_DESTINATION (last));
300 bsi_insert_before (&bsi, assignment, BSI_SAME_STMT);
302 /* And re-vector the computed goto to the new destination. */
303 GOTO_DESTINATION (last) = factored_label_decl;
309 /* Build a flowgraph for the statement_list STMT_LIST. */
312 make_blocks (tree stmt_list)
314 tree_stmt_iterator i = tsi_start (stmt_list);
316 bool start_new_block = true;
317 bool first_stmt_of_list = true;
318 basic_block bb = ENTRY_BLOCK_PTR;
320 while (!tsi_end_p (i))
327 /* If the statement starts a new basic block or if we have determined
328 in a previous pass that we need to create a new block for STMT, do
330 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
332 if (!first_stmt_of_list)
333 stmt_list = tsi_split_statement_list_before (&i);
334 bb = create_basic_block (stmt_list, NULL, bb);
335 start_new_block = false;
338 /* Now add STMT to BB and create the subgraphs for special statement
340 set_bb_for_stmt (stmt, bb);
342 if (computed_goto_p (stmt))
343 found_computed_goto = true;
345 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
347 if (stmt_ends_bb_p (stmt))
348 start_new_block = true;
351 first_stmt_of_list = false;
356 /* Create and return a new empty basic block after bb AFTER. */
359 create_bb (void *h, void *e, basic_block after)
365 /* Create and initialize a new basic block. Since alloc_block uses
366 ggc_alloc_cleared to allocate a basic block, we do not have to
367 clear the newly allocated basic block here. */
370 bb->index = last_basic_block;
372 bb->il.tree = GGC_CNEW (struct tree_bb_info);
373 set_bb_stmt_list (bb, h ? (tree) h : alloc_stmt_list ());
375 /* Add the new block to the linked list of blocks. */
376 link_block (bb, after);
378 /* Grow the basic block array if needed. */
379 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
381 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
382 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
385 /* Add the newly created block to the array. */
386 SET_BASIC_BLOCK (last_basic_block, bb);
395 /*---------------------------------------------------------------------------
397 ---------------------------------------------------------------------------*/
399 /* Fold COND_EXPR_COND of each COND_EXPR. */
402 fold_cond_expr_cond (void)
408 tree stmt = last_stmt (bb);
411 && TREE_CODE (stmt) == COND_EXPR)
416 fold_defer_overflow_warnings ();
417 cond = fold (COND_EXPR_COND (stmt));
418 zerop = integer_zerop (cond);
419 onep = integer_onep (cond);
420 fold_undefer_overflow_warnings (((zerop || onep)
421 && !TREE_NO_WARNING (stmt)),
423 WARN_STRICT_OVERFLOW_CONDITIONAL);
425 COND_EXPR_COND (stmt) = boolean_false_node;
427 COND_EXPR_COND (stmt) = boolean_true_node;
432 /* Join all the blocks in the flowgraph. */
438 struct omp_region *cur_region = NULL;
440 /* Create an edge from entry to the first block with executable
442 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
444 /* Traverse the basic block array placing edges. */
447 tree last = last_stmt (bb);
452 enum tree_code code = TREE_CODE (last);
456 make_goto_expr_edges (bb);
460 make_edge (bb, EXIT_BLOCK_PTR, 0);
464 make_cond_expr_edges (bb);
468 make_switch_expr_edges (bb);
472 make_eh_edges (last);
477 /* If this function receives a nonlocal goto, then we need to
478 make edges from this call site to all the nonlocal goto
480 if (tree_can_make_abnormal_goto (last))
481 make_abnormal_goto_edges (bb, true);
483 /* If this statement has reachable exception handlers, then
484 create abnormal edges to them. */
485 make_eh_edges (last);
487 /* Some calls are known not to return. */
488 fallthru = !(call_expr_flags (last) & ECF_NORETURN);
494 case GIMPLE_MODIFY_STMT:
495 if (is_ctrl_altering_stmt (last))
497 /* A GIMPLE_MODIFY_STMT may have a CALL_EXPR on its RHS and
498 the CALL_EXPR may have an abnormal edge. Search the RHS
499 for this case and create any required edges. */
500 if (tree_can_make_abnormal_goto (last))
501 make_abnormal_goto_edges (bb, true);
503 make_eh_edges (last);
515 cur_region = new_omp_region (bb, code, cur_region);
520 cur_region = new_omp_region (bb, code, cur_region);
524 case OMP_SECTIONS_SWITCH:
529 /* In the case of an OMP_SECTION, the edge will go somewhere
530 other than the next block. This will be created later. */
531 cur_region->exit = bb;
532 fallthru = cur_region->type != OMP_SECTION;
533 cur_region = cur_region->outer;
537 cur_region->cont = bb;
538 switch (cur_region->type)
541 /* Make the loopback edge. */
542 make_edge (bb, single_succ (cur_region->entry), 0);
544 /* Create an edge from OMP_FOR to exit, which corresponds to
545 the case that the body of the loop is not executed at
547 make_edge (cur_region->entry, bb->next_bb, 0);
552 /* Wire up the edges into and out of the nested sections. */
554 basic_block switch_bb = single_succ (cur_region->entry);
556 struct omp_region *i;
557 for (i = cur_region->inner; i ; i = i->next)
559 gcc_assert (i->type == OMP_SECTION);
560 make_edge (switch_bb, i->entry, 0);
561 make_edge (i->exit, bb, EDGE_FALLTHRU);
564 /* Make the loopback edge to the block with
565 OMP_SECTIONS_SWITCH. */
566 make_edge (bb, switch_bb, 0);
568 /* Make the edge from the switch to exit. */
569 make_edge (switch_bb, bb->next_bb, 0);
580 gcc_assert (!stmt_ends_bb_p (last));
588 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
594 /* Fold COND_EXPR_COND of each COND_EXPR. */
595 fold_cond_expr_cond ();
599 /* Create the edges for a COND_EXPR starting at block BB.
600 At this point, both clauses must contain only simple gotos. */
603 make_cond_expr_edges (basic_block bb)
605 tree entry = last_stmt (bb);
606 basic_block then_bb, else_bb;
607 tree then_label, else_label;
611 gcc_assert (TREE_CODE (entry) == COND_EXPR);
613 /* Entry basic blocks for each component. */
614 then_label = GOTO_DESTINATION (COND_EXPR_THEN (entry));
615 else_label = GOTO_DESTINATION (COND_EXPR_ELSE (entry));
616 then_bb = label_to_block (then_label);
617 else_bb = label_to_block (else_label);
619 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
620 #ifdef USE_MAPPED_LOCATION
621 e->goto_locus = EXPR_LOCATION (COND_EXPR_THEN (entry));
623 e->goto_locus = EXPR_LOCUS (COND_EXPR_THEN (entry));
625 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
628 #ifdef USE_MAPPED_LOCATION
629 e->goto_locus = EXPR_LOCATION (COND_EXPR_ELSE (entry));
631 e->goto_locus = EXPR_LOCUS (COND_EXPR_ELSE (entry));
635 /* We do not need the gotos anymore. */
636 COND_EXPR_THEN (entry) = NULL_TREE;
637 COND_EXPR_ELSE (entry) = NULL_TREE;
641 /* Called for each element in the hash table (P) as we delete the
642 edge to cases hash table.
644 Clear all the TREE_CHAINs to prevent problems with copying of
645 SWITCH_EXPRs and structure sharing rules, then free the hash table
649 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED, void **value,
650 void *data ATTRIBUTE_UNUSED)
654 for (t = (tree) *value; t; t = next)
656 next = TREE_CHAIN (t);
657 TREE_CHAIN (t) = NULL;
664 /* Start recording information mapping edges to case labels. */
667 start_recording_case_labels (void)
669 gcc_assert (edge_to_cases == NULL);
670 edge_to_cases = pointer_map_create ();
673 /* Return nonzero if we are recording information for case labels. */
676 recording_case_labels_p (void)
678 return (edge_to_cases != NULL);
681 /* Stop recording information mapping edges to case labels and
682 remove any information we have recorded. */
684 end_recording_case_labels (void)
686 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
687 pointer_map_destroy (edge_to_cases);
688 edge_to_cases = NULL;
691 /* If we are inside a {start,end}_recording_cases block, then return
692 a chain of CASE_LABEL_EXPRs from T which reference E.
694 Otherwise return NULL. */
697 get_cases_for_edge (edge e, tree t)
703 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
704 chains available. Return NULL so the caller can detect this case. */
705 if (!recording_case_labels_p ())
708 slot = pointer_map_contains (edge_to_cases, e);
712 /* If we did not find E in the hash table, then this must be the first
713 time we have been queried for information about E & T. Add all the
714 elements from T to the hash table then perform the query again. */
716 vec = SWITCH_LABELS (t);
717 n = TREE_VEC_LENGTH (vec);
718 for (i = 0; i < n; i++)
720 tree elt = TREE_VEC_ELT (vec, i);
721 tree lab = CASE_LABEL (elt);
722 basic_block label_bb = label_to_block (lab);
723 edge this_edge = find_edge (e->src, label_bb);
725 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
727 slot = pointer_map_insert (edge_to_cases, this_edge);
728 TREE_CHAIN (elt) = (tree) *slot;
732 return (tree) *pointer_map_contains (edge_to_cases, e);
735 /* Create the edges for a SWITCH_EXPR starting at block BB.
736 At this point, the switch body has been lowered and the
737 SWITCH_LABELS filled in, so this is in effect a multi-way branch. */
740 make_switch_expr_edges (basic_block bb)
742 tree entry = last_stmt (bb);
746 vec = SWITCH_LABELS (entry);
747 n = TREE_VEC_LENGTH (vec);
749 for (i = 0; i < n; ++i)
751 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
752 basic_block label_bb = label_to_block (lab);
753 make_edge (bb, label_bb, 0);
758 /* Return the basic block holding label DEST. */
761 label_to_block_fn (struct function *ifun, tree dest)
763 int uid = LABEL_DECL_UID (dest);
765 /* We would die hard when faced by an undefined label. Emit a label to
766 the very first basic block. This will hopefully make even the dataflow
767 and undefined variable warnings quite right. */
768 if ((errorcount || sorrycount) && uid < 0)
770 block_stmt_iterator bsi =
771 bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS));
774 stmt = build1 (LABEL_EXPR, void_type_node, dest);
775 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
776 uid = LABEL_DECL_UID (dest);
778 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
779 <= (unsigned int) uid)
781 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
784 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
785 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
788 make_abnormal_goto_edges (basic_block bb, bool for_call)
790 basic_block target_bb;
791 block_stmt_iterator bsi;
793 FOR_EACH_BB (target_bb)
794 for (bsi = bsi_start (target_bb); !bsi_end_p (bsi); bsi_next (&bsi))
796 tree target = bsi_stmt (bsi);
798 if (TREE_CODE (target) != LABEL_EXPR)
801 target = LABEL_EXPR_LABEL (target);
803 /* Make an edge to every label block that has been marked as a
804 potential target for a computed goto or a non-local goto. */
805 if ((FORCED_LABEL (target) && !for_call)
806 || (DECL_NONLOCAL (target) && for_call))
808 make_edge (bb, target_bb, EDGE_ABNORMAL);
814 /* Create edges for a goto statement at block BB. */
817 make_goto_expr_edges (basic_block bb)
819 block_stmt_iterator last = bsi_last (bb);
820 tree goto_t = bsi_stmt (last);
822 /* A simple GOTO creates normal edges. */
823 if (simple_goto_p (goto_t))
825 tree dest = GOTO_DESTINATION (goto_t);
826 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
827 #ifdef USE_MAPPED_LOCATION
828 e->goto_locus = EXPR_LOCATION (goto_t);
830 e->goto_locus = EXPR_LOCUS (goto_t);
832 bsi_remove (&last, true);
836 /* A computed GOTO creates abnormal edges. */
837 make_abnormal_goto_edges (bb, false);
841 /*---------------------------------------------------------------------------
843 ---------------------------------------------------------------------------*/
845 /* Cleanup useless labels in basic blocks. This is something we wish
846 to do early because it allows us to group case labels before creating
847 the edges for the CFG, and it speeds up block statement iterators in
849 We rerun this pass after CFG is created, to get rid of the labels that
850 are no longer referenced. After then we do not run it any more, since
851 (almost) no new labels should be created. */
853 /* A map from basic block index to the leading label of that block. */
854 static struct label_record
859 /* True if the label is referenced from somewhere. */
863 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
865 update_eh_label (struct eh_region *region)
867 tree old_label = get_eh_region_tree_label (region);
871 basic_block bb = label_to_block (old_label);
873 /* ??? After optimizing, there may be EH regions with labels
874 that have already been removed from the function body, so
875 there is no basic block for them. */
879 new_label = label_for_bb[bb->index].label;
880 label_for_bb[bb->index].used = true;
881 set_eh_region_tree_label (region, new_label);
885 /* Given LABEL return the first label in the same basic block. */
887 main_block_label (tree label)
889 basic_block bb = label_to_block (label);
890 tree main_label = label_for_bb[bb->index].label;
892 /* label_to_block possibly inserted undefined label into the chain. */
895 label_for_bb[bb->index].label = label;
899 label_for_bb[bb->index].used = true;
903 /* Cleanup redundant labels. This is a three-step process:
904 1) Find the leading label for each block.
905 2) Redirect all references to labels to the leading labels.
906 3) Cleanup all useless labels. */
909 cleanup_dead_labels (void)
912 label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
914 /* Find a suitable label for each block. We use the first user-defined
915 label if there is one, or otherwise just the first label we see. */
918 block_stmt_iterator i;
920 for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i))
922 tree label, stmt = bsi_stmt (i);
924 if (TREE_CODE (stmt) != LABEL_EXPR)
927 label = LABEL_EXPR_LABEL (stmt);
929 /* If we have not yet seen a label for the current block,
930 remember this one and see if there are more labels. */
931 if (!label_for_bb[bb->index].label)
933 label_for_bb[bb->index].label = label;
937 /* If we did see a label for the current block already, but it
938 is an artificially created label, replace it if the current
939 label is a user defined label. */
940 if (!DECL_ARTIFICIAL (label)
941 && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
943 label_for_bb[bb->index].label = label;
949 /* Now redirect all jumps/branches to the selected label.
950 First do so for each block ending in a control statement. */
953 tree stmt = last_stmt (bb);
957 switch (TREE_CODE (stmt))
961 tree true_branch, false_branch;
963 true_branch = COND_EXPR_THEN (stmt);
964 false_branch = COND_EXPR_ELSE (stmt);
967 GOTO_DESTINATION (true_branch)
968 = main_block_label (GOTO_DESTINATION (true_branch));
970 GOTO_DESTINATION (false_branch)
971 = main_block_label (GOTO_DESTINATION (false_branch));
979 tree vec = SWITCH_LABELS (stmt);
980 size_t n = TREE_VEC_LENGTH (vec);
982 /* Replace all destination labels. */
983 for (i = 0; i < n; ++i)
985 tree elt = TREE_VEC_ELT (vec, i);
986 tree label = main_block_label (CASE_LABEL (elt));
987 CASE_LABEL (elt) = label;
992 /* We have to handle GOTO_EXPRs until they're removed, and we don't
993 remove them until after we've created the CFG edges. */
995 if (! computed_goto_p (stmt))
997 GOTO_DESTINATION (stmt)
998 = main_block_label (GOTO_DESTINATION (stmt));
1007 for_each_eh_region (update_eh_label);
1009 /* Finally, purge dead labels. All user-defined labels and labels that
1010 can be the target of non-local gotos and labels which have their
1011 address taken are preserved. */
1014 block_stmt_iterator i;
1015 tree label_for_this_bb = label_for_bb[bb->index].label;
1017 if (!label_for_this_bb)
1020 /* If the main label of the block is unused, we may still remove it. */
1021 if (!label_for_bb[bb->index].used)
1022 label_for_this_bb = NULL;
1024 for (i = bsi_start (bb); !bsi_end_p (i); )
1026 tree label, stmt = bsi_stmt (i);
1028 if (TREE_CODE (stmt) != LABEL_EXPR)
1031 label = LABEL_EXPR_LABEL (stmt);
1033 if (label == label_for_this_bb
1034 || ! DECL_ARTIFICIAL (label)
1035 || DECL_NONLOCAL (label)
1036 || FORCED_LABEL (label))
1039 bsi_remove (&i, true);
1043 free (label_for_bb);
1046 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1047 and scan the sorted vector of cases. Combine the ones jumping to the
1049 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1052 group_case_labels (void)
1058 tree stmt = last_stmt (bb);
1059 if (stmt && TREE_CODE (stmt) == SWITCH_EXPR)
1061 tree labels = SWITCH_LABELS (stmt);
1062 int old_size = TREE_VEC_LENGTH (labels);
1063 int i, j, new_size = old_size;
1064 tree default_case = TREE_VEC_ELT (labels, old_size - 1);
1067 /* The default label is always the last case in a switch
1068 statement after gimplification. */
1069 default_label = CASE_LABEL (default_case);
1071 /* Look for possible opportunities to merge cases.
1072 Ignore the last element of the label vector because it
1073 must be the default case. */
1075 while (i < old_size - 1)
1077 tree base_case, base_label, base_high;
1078 base_case = TREE_VEC_ELT (labels, i);
1080 gcc_assert (base_case);
1081 base_label = CASE_LABEL (base_case);
1083 /* Discard cases that have the same destination as the
1085 if (base_label == default_label)
1087 TREE_VEC_ELT (labels, i) = NULL_TREE;
1093 base_high = CASE_HIGH (base_case) ?
1094 CASE_HIGH (base_case) : CASE_LOW (base_case);
1096 /* Try to merge case labels. Break out when we reach the end
1097 of the label vector or when we cannot merge the next case
1098 label with the current one. */
1099 while (i < old_size - 1)
1101 tree merge_case = TREE_VEC_ELT (labels, i);
1102 tree merge_label = CASE_LABEL (merge_case);
1103 tree t = int_const_binop (PLUS_EXPR, base_high,
1104 integer_one_node, 1);
1106 /* Merge the cases if they jump to the same place,
1107 and their ranges are consecutive. */
1108 if (merge_label == base_label
1109 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1111 base_high = CASE_HIGH (merge_case) ?
1112 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1113 CASE_HIGH (base_case) = base_high;
1114 TREE_VEC_ELT (labels, i) = NULL_TREE;
1123 /* Compress the case labels in the label vector, and adjust the
1124 length of the vector. */
1125 for (i = 0, j = 0; i < new_size; i++)
1127 while (! TREE_VEC_ELT (labels, j))
1129 TREE_VEC_ELT (labels, i) = TREE_VEC_ELT (labels, j++);
1131 TREE_VEC_LENGTH (labels) = new_size;
1136 /* Checks whether we can merge block B into block A. */
1139 tree_can_merge_blocks_p (basic_block a, basic_block b)
1142 block_stmt_iterator bsi;
1145 if (!single_succ_p (a))
1148 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1151 if (single_succ (a) != b)
1154 if (!single_pred_p (b))
1157 if (b == EXIT_BLOCK_PTR)
1160 /* If A ends by a statement causing exceptions or something similar, we
1161 cannot merge the blocks. */
1162 /* This CONST_CAST is okay because last_stmt doesn't modify its
1163 argument and the return value is assign to a const_tree. */
1164 stmt = last_stmt (CONST_CAST_BB (a));
1165 if (stmt && stmt_ends_bb_p (stmt))
1168 /* Do not allow a block with only a non-local label to be merged. */
1169 if (stmt && TREE_CODE (stmt) == LABEL_EXPR
1170 && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
1173 /* It must be possible to eliminate all phi nodes in B. If ssa form
1174 is not up-to-date, we cannot eliminate any phis; however, if only
1175 some symbols as whole are marked for renaming, this is not a problem,
1176 as phi nodes for those symbols are irrelevant in updating anyway. */
1177 phi = phi_nodes (b);
1180 if (name_mappings_registered_p ())
1183 for (; phi; phi = PHI_CHAIN (phi))
1184 if (!is_gimple_reg (PHI_RESULT (phi))
1185 && !may_propagate_copy (PHI_RESULT (phi), PHI_ARG_DEF (phi, 0)))
1189 /* Do not remove user labels. */
1190 for (bsi = bsi_start (b); !bsi_end_p (bsi); bsi_next (&bsi))
1192 stmt = bsi_stmt (bsi);
1193 if (TREE_CODE (stmt) != LABEL_EXPR)
1195 if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt)))
1199 /* Protect the loop latches. */
1201 && b->loop_father->latch == b)
1207 /* Replaces all uses of NAME by VAL. */
1210 replace_uses_by (tree name, tree val)
1212 imm_use_iterator imm_iter;
1217 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1219 if (TREE_CODE (stmt) != PHI_NODE)
1220 push_stmt_changes (&stmt);
1222 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1224 replace_exp (use, val);
1226 if (TREE_CODE (stmt) == PHI_NODE)
1228 e = PHI_ARG_EDGE (stmt, PHI_ARG_INDEX_FROM_USE (use));
1229 if (e->flags & EDGE_ABNORMAL)
1231 /* This can only occur for virtual operands, since
1232 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1233 would prevent replacement. */
1234 gcc_assert (!is_gimple_reg (name));
1235 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1240 if (TREE_CODE (stmt) != PHI_NODE)
1244 fold_stmt_inplace (stmt);
1245 if (cfgcleanup_altered_bbs)
1246 bitmap_set_bit (cfgcleanup_altered_bbs, bb_for_stmt (stmt)->index);
1248 /* FIXME. This should go in pop_stmt_changes. */
1249 rhs = get_rhs (stmt);
1250 if (TREE_CODE (rhs) == ADDR_EXPR)
1251 recompute_tree_invariant_for_addr_expr (rhs);
1253 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1255 pop_stmt_changes (&stmt);
1259 gcc_assert (has_zero_uses (name));
1261 /* Also update the trees stored in loop structures. */
1267 FOR_EACH_LOOP (li, loop, 0)
1269 substitute_in_loop_info (loop, name, val);
1274 /* Merge block B into block A. */
1277 tree_merge_blocks (basic_block a, basic_block b)
1279 block_stmt_iterator bsi;
1280 tree_stmt_iterator last;
1284 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1286 /* Remove all single-valued PHI nodes from block B of the form
1287 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1289 for (phi = phi_nodes (b); phi; phi = phi_nodes (b))
1291 tree def = PHI_RESULT (phi), use = PHI_ARG_DEF (phi, 0);
1293 bool may_replace_uses = may_propagate_copy (def, use);
1295 /* In case we maintain loop closed ssa form, do not propagate arguments
1296 of loop exit phi nodes. */
1298 && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1299 && is_gimple_reg (def)
1300 && TREE_CODE (use) == SSA_NAME
1301 && a->loop_father != b->loop_father)
1302 may_replace_uses = false;
1304 if (!may_replace_uses)
1306 gcc_assert (is_gimple_reg (def));
1308 /* Note that just emitting the copies is fine -- there is no problem
1309 with ordering of phi nodes. This is because A is the single
1310 predecessor of B, therefore results of the phi nodes cannot
1311 appear as arguments of the phi nodes. */
1312 copy = build_gimple_modify_stmt (def, use);
1313 bsi_insert_after (&bsi, copy, BSI_NEW_STMT);
1314 SSA_NAME_DEF_STMT (def) = copy;
1315 remove_phi_node (phi, NULL, false);
1319 replace_uses_by (def, use);
1320 remove_phi_node (phi, NULL, true);
1324 /* Ensure that B follows A. */
1325 move_block_after (b, a);
1327 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1328 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1330 /* Remove labels from B and set bb_for_stmt to A for other statements. */
1331 for (bsi = bsi_start (b); !bsi_end_p (bsi);)
1333 if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR)
1335 tree label = bsi_stmt (bsi);
1337 bsi_remove (&bsi, false);
1338 /* Now that we can thread computed gotos, we might have
1339 a situation where we have a forced label in block B
1340 However, the label at the start of block B might still be
1341 used in other ways (think about the runtime checking for
1342 Fortran assigned gotos). So we can not just delete the
1343 label. Instead we move the label to the start of block A. */
1344 if (FORCED_LABEL (LABEL_EXPR_LABEL (label)))
1346 block_stmt_iterator dest_bsi = bsi_start (a);
1347 bsi_insert_before (&dest_bsi, label, BSI_NEW_STMT);
1352 change_bb_for_stmt (bsi_stmt (bsi), a);
1357 /* Merge the chains. */
1358 last = tsi_last (bb_stmt_list (a));
1359 tsi_link_after (&last, bb_stmt_list (b), TSI_NEW_STMT);
1360 set_bb_stmt_list (b, NULL_TREE);
1362 if (cfgcleanup_altered_bbs)
1363 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1367 /* Return the one of two successors of BB that is not reachable by a
1368 reached by a complex edge, if there is one. Else, return BB. We use
1369 this in optimizations that use post-dominators for their heuristics,
1370 to catch the cases in C++ where function calls are involved. */
1373 single_noncomplex_succ (basic_block bb)
1376 if (EDGE_COUNT (bb->succs) != 2)
1379 e0 = EDGE_SUCC (bb, 0);
1380 e1 = EDGE_SUCC (bb, 1);
1381 if (e0->flags & EDGE_COMPLEX)
1383 if (e1->flags & EDGE_COMPLEX)
1390 /* Walk the function tree removing unnecessary statements.
1392 * Empty statement nodes are removed
1394 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1396 * Unnecessary COND_EXPRs are removed
1398 * Some unnecessary BIND_EXPRs are removed
1400 Clearly more work could be done. The trick is doing the analysis
1401 and removal fast enough to be a net improvement in compile times.
1403 Note that when we remove a control structure such as a COND_EXPR
1404 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1405 to ensure we eliminate all the useless code. */
1416 static void remove_useless_stmts_1 (tree *, struct rus_data *);
1419 remove_useless_stmts_warn_notreached (tree stmt)
1421 if (EXPR_HAS_LOCATION (stmt))
1423 location_t loc = EXPR_LOCATION (stmt);
1424 if (LOCATION_LINE (loc) > 0)
1426 warning (0, "%Hwill never be executed", &loc);
1431 switch (TREE_CODE (stmt))
1433 case STATEMENT_LIST:
1435 tree_stmt_iterator i;
1436 for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i))
1437 if (remove_useless_stmts_warn_notreached (tsi_stmt (i)))
1443 if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt)))
1445 if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt)))
1447 if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt)))
1451 case TRY_FINALLY_EXPR:
1452 case TRY_CATCH_EXPR:
1453 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 0)))
1455 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 1)))
1460 return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt));
1461 case EH_FILTER_EXPR:
1462 return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt));
1464 return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt));
1467 /* Not a live container. */
1475 remove_useless_stmts_cond (tree *stmt_p, struct rus_data *data)
1477 tree then_clause, else_clause, cond;
1478 bool save_has_label, then_has_label, else_has_label;
1480 save_has_label = data->has_label;
1481 data->has_label = false;
1482 data->last_goto = NULL;
1484 remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p), data);
1486 then_has_label = data->has_label;
1487 data->has_label = false;
1488 data->last_goto = NULL;
1490 remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p), data);
1492 else_has_label = data->has_label;
1493 data->has_label = save_has_label | then_has_label | else_has_label;
1495 then_clause = COND_EXPR_THEN (*stmt_p);
1496 else_clause = COND_EXPR_ELSE (*stmt_p);
1497 cond = fold (COND_EXPR_COND (*stmt_p));
1499 /* If neither arm does anything at all, we can remove the whole IF. */
1500 if (!TREE_SIDE_EFFECTS (then_clause) && !TREE_SIDE_EFFECTS (else_clause))
1502 *stmt_p = build_empty_stmt ();
1503 data->repeat = true;
1506 /* If there are no reachable statements in an arm, then we can
1507 zap the entire conditional. */
1508 else if (integer_nonzerop (cond) && !else_has_label)
1510 if (warn_notreached)
1511 remove_useless_stmts_warn_notreached (else_clause);
1512 *stmt_p = then_clause;
1513 data->repeat = true;
1515 else if (integer_zerop (cond) && !then_has_label)
1517 if (warn_notreached)
1518 remove_useless_stmts_warn_notreached (then_clause);
1519 *stmt_p = else_clause;
1520 data->repeat = true;
1523 /* Check a couple of simple things on then/else with single stmts. */
1526 tree then_stmt = expr_only (then_clause);
1527 tree else_stmt = expr_only (else_clause);
1529 /* Notice branches to a common destination. */
1530 if (then_stmt && else_stmt
1531 && TREE_CODE (then_stmt) == GOTO_EXPR
1532 && TREE_CODE (else_stmt) == GOTO_EXPR
1533 && (GOTO_DESTINATION (then_stmt) == GOTO_DESTINATION (else_stmt)))
1535 *stmt_p = then_stmt;
1536 data->repeat = true;
1539 /* If the THEN/ELSE clause merely assigns a value to a variable or
1540 parameter which is already known to contain that value, then
1541 remove the useless THEN/ELSE clause. */
1542 else if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL)
1545 && TREE_CODE (else_stmt) == GIMPLE_MODIFY_STMT
1546 && GIMPLE_STMT_OPERAND (else_stmt, 0) == cond
1547 && integer_zerop (GIMPLE_STMT_OPERAND (else_stmt, 1)))
1548 COND_EXPR_ELSE (*stmt_p) = alloc_stmt_list ();
1550 else if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
1551 && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL
1552 || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL)
1553 && TREE_CONSTANT (TREE_OPERAND (cond, 1)))
1555 tree stmt = (TREE_CODE (cond) == EQ_EXPR
1556 ? then_stmt : else_stmt);
1557 tree *location = (TREE_CODE (cond) == EQ_EXPR
1558 ? &COND_EXPR_THEN (*stmt_p)
1559 : &COND_EXPR_ELSE (*stmt_p));
1562 && TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
1563 && GIMPLE_STMT_OPERAND (stmt, 0) == TREE_OPERAND (cond, 0)
1564 && GIMPLE_STMT_OPERAND (stmt, 1) == TREE_OPERAND (cond, 1))
1565 *location = alloc_stmt_list ();
1569 /* Protect GOTOs in the arm of COND_EXPRs from being removed. They
1570 would be re-introduced during lowering. */
1571 data->last_goto = NULL;
1576 remove_useless_stmts_tf (tree *stmt_p, struct rus_data *data)
1578 bool save_may_branch, save_may_throw;
1579 bool this_may_branch, this_may_throw;
1581 /* Collect may_branch and may_throw information for the body only. */
1582 save_may_branch = data->may_branch;
1583 save_may_throw = data->may_throw;
1584 data->may_branch = false;
1585 data->may_throw = false;
1586 data->last_goto = NULL;
1588 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1590 this_may_branch = data->may_branch;
1591 this_may_throw = data->may_throw;
1592 data->may_branch |= save_may_branch;
1593 data->may_throw |= save_may_throw;
1594 data->last_goto = NULL;
1596 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1598 /* If the body is empty, then we can emit the FINALLY block without
1599 the enclosing TRY_FINALLY_EXPR. */
1600 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 0)))
1602 *stmt_p = TREE_OPERAND (*stmt_p, 1);
1603 data->repeat = true;
1606 /* If the handler is empty, then we can emit the TRY block without
1607 the enclosing TRY_FINALLY_EXPR. */
1608 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1610 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1611 data->repeat = true;
1614 /* If the body neither throws, nor branches, then we can safely
1615 string the TRY and FINALLY blocks together. */
1616 else if (!this_may_branch && !this_may_throw)
1618 tree stmt = *stmt_p;
1619 *stmt_p = TREE_OPERAND (stmt, 0);
1620 append_to_statement_list (TREE_OPERAND (stmt, 1), stmt_p);
1621 data->repeat = true;
1627 remove_useless_stmts_tc (tree *stmt_p, struct rus_data *data)
1629 bool save_may_throw, this_may_throw;
1630 tree_stmt_iterator i;
1633 /* Collect may_throw information for the body only. */
1634 save_may_throw = data->may_throw;
1635 data->may_throw = false;
1636 data->last_goto = NULL;
1638 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1640 this_may_throw = data->may_throw;
1641 data->may_throw = save_may_throw;
1643 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1644 if (!this_may_throw)
1646 if (warn_notreached)
1647 remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p, 1));
1648 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1649 data->repeat = true;
1653 /* Process the catch clause specially. We may be able to tell that
1654 no exceptions propagate past this point. */
1656 this_may_throw = true;
1657 i = tsi_start (TREE_OPERAND (*stmt_p, 1));
1658 stmt = tsi_stmt (i);
1659 data->last_goto = NULL;
1661 switch (TREE_CODE (stmt))
1664 for (; !tsi_end_p (i); tsi_next (&i))
1666 stmt = tsi_stmt (i);
1667 /* If we catch all exceptions, then the body does not
1668 propagate exceptions past this point. */
1669 if (CATCH_TYPES (stmt) == NULL)
1670 this_may_throw = false;
1671 data->last_goto = NULL;
1672 remove_useless_stmts_1 (&CATCH_BODY (stmt), data);
1676 case EH_FILTER_EXPR:
1677 if (EH_FILTER_MUST_NOT_THROW (stmt))
1678 this_may_throw = false;
1679 else if (EH_FILTER_TYPES (stmt) == NULL)
1680 this_may_throw = false;
1681 remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt), data);
1685 /* Otherwise this is a cleanup. */
1686 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1688 /* If the cleanup is empty, then we can emit the TRY block without
1689 the enclosing TRY_CATCH_EXPR. */
1690 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1692 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1693 data->repeat = true;
1697 data->may_throw |= this_may_throw;
1702 remove_useless_stmts_bind (tree *stmt_p, struct rus_data *data)
1706 /* First remove anything underneath the BIND_EXPR. */
1707 remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p), data);
1709 /* If the BIND_EXPR has no variables, then we can pull everything
1710 up one level and remove the BIND_EXPR, unless this is the toplevel
1711 BIND_EXPR for the current function or an inlined function.
1713 When this situation occurs we will want to apply this
1714 optimization again. */
1715 block = BIND_EXPR_BLOCK (*stmt_p);
1716 if (BIND_EXPR_VARS (*stmt_p) == NULL_TREE
1717 && *stmt_p != DECL_SAVED_TREE (current_function_decl)
1719 || ! BLOCK_ABSTRACT_ORIGIN (block)
1720 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1723 *stmt_p = BIND_EXPR_BODY (*stmt_p);
1724 data->repeat = true;
1730 remove_useless_stmts_goto (tree *stmt_p, struct rus_data *data)
1732 tree dest = GOTO_DESTINATION (*stmt_p);
1734 data->may_branch = true;
1735 data->last_goto = NULL;
1737 /* Record the last goto expr, so that we can delete it if unnecessary. */
1738 if (TREE_CODE (dest) == LABEL_DECL)
1739 data->last_goto = stmt_p;
1744 remove_useless_stmts_label (tree *stmt_p, struct rus_data *data)
1746 tree label = LABEL_EXPR_LABEL (*stmt_p);
1748 data->has_label = true;
1750 /* We do want to jump across non-local label receiver code. */
1751 if (DECL_NONLOCAL (label))
1752 data->last_goto = NULL;
1754 else if (data->last_goto && GOTO_DESTINATION (*data->last_goto) == label)
1756 *data->last_goto = build_empty_stmt ();
1757 data->repeat = true;
1760 /* ??? Add something here to delete unused labels. */
1764 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1765 decl. This allows us to eliminate redundant or useless
1766 calls to "const" functions.
1768 Gimplifier already does the same operation, but we may notice functions
1769 being const and pure once their calls has been gimplified, so we need
1770 to update the flag. */
1773 update_call_expr_flags (tree call)
1775 tree decl = get_callee_fndecl (call);
1778 if (call_expr_flags (call) & (ECF_CONST | ECF_PURE))
1779 TREE_SIDE_EFFECTS (call) = 0;
1780 if (TREE_NOTHROW (decl))
1781 TREE_NOTHROW (call) = 1;
1785 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1788 notice_special_calls (tree t)
1790 int flags = call_expr_flags (t);
1792 if (flags & ECF_MAY_BE_ALLOCA)
1793 current_function_calls_alloca = true;
1794 if (flags & ECF_RETURNS_TWICE)
1795 current_function_calls_setjmp = true;
1799 /* Clear flags set by notice_special_calls. Used by dead code removal
1800 to update the flags. */
1803 clear_special_calls (void)
1805 current_function_calls_alloca = false;
1806 current_function_calls_setjmp = false;
1811 remove_useless_stmts_1 (tree *tp, struct rus_data *data)
1815 switch (TREE_CODE (t))
1818 remove_useless_stmts_cond (tp, data);
1821 case TRY_FINALLY_EXPR:
1822 remove_useless_stmts_tf (tp, data);
1825 case TRY_CATCH_EXPR:
1826 remove_useless_stmts_tc (tp, data);
1830 remove_useless_stmts_bind (tp, data);
1834 remove_useless_stmts_goto (tp, data);
1838 remove_useless_stmts_label (tp, data);
1843 data->last_goto = NULL;
1844 data->may_branch = true;
1849 data->last_goto = NULL;
1850 notice_special_calls (t);
1851 update_call_expr_flags (t);
1852 if (tree_could_throw_p (t))
1853 data->may_throw = true;
1859 case GIMPLE_MODIFY_STMT:
1860 data->last_goto = NULL;
1862 op = get_call_expr_in (t);
1865 update_call_expr_flags (op);
1866 notice_special_calls (op);
1868 if (tree_could_throw_p (t))
1869 data->may_throw = true;
1872 case STATEMENT_LIST:
1874 tree_stmt_iterator i = tsi_start (t);
1875 while (!tsi_end_p (i))
1878 if (IS_EMPTY_STMT (t))
1884 remove_useless_stmts_1 (tsi_stmt_ptr (i), data);
1887 if (TREE_CODE (t) == STATEMENT_LIST)
1889 tsi_link_before (&i, t, TSI_SAME_STMT);
1899 data->last_goto = NULL;
1903 data->last_goto = NULL;
1909 remove_useless_stmts (void)
1911 struct rus_data data;
1913 clear_special_calls ();
1917 memset (&data, 0, sizeof (data));
1918 remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl), &data);
1920 while (data.repeat);
1925 struct tree_opt_pass pass_remove_useless_stmts =
1927 "useless", /* name */
1929 remove_useless_stmts, /* execute */
1932 0, /* static_pass_number */
1934 PROP_gimple_any, /* properties_required */
1935 0, /* properties_provided */
1936 0, /* properties_destroyed */
1937 0, /* todo_flags_start */
1938 TODO_dump_func, /* todo_flags_finish */
1942 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
1945 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
1949 /* Since this block is no longer reachable, we can just delete all
1950 of its PHI nodes. */
1951 phi = phi_nodes (bb);
1954 tree next = PHI_CHAIN (phi);
1955 remove_phi_node (phi, NULL_TREE, true);
1959 /* Remove edges to BB's successors. */
1960 while (EDGE_COUNT (bb->succs) > 0)
1961 remove_edge (EDGE_SUCC (bb, 0));
1965 /* Remove statements of basic block BB. */
1968 remove_bb (basic_block bb)
1970 block_stmt_iterator i;
1971 #ifdef USE_MAPPED_LOCATION
1972 source_location loc = UNKNOWN_LOCATION;
1974 source_locus loc = 0;
1979 fprintf (dump_file, "Removing basic block %d\n", bb->index);
1980 if (dump_flags & TDF_DETAILS)
1982 dump_bb (bb, dump_file, 0);
1983 fprintf (dump_file, "\n");
1989 struct loop *loop = bb->loop_father;
1991 /* If a loop gets removed, clean up the information associated
1993 if (loop->latch == bb
1994 || loop->header == bb)
1995 free_numbers_of_iterations_estimates_loop (loop);
1998 /* Remove all the instructions in the block. */
1999 if (bb_stmt_list (bb) != NULL_TREE)
2001 for (i = bsi_start (bb); !bsi_end_p (i);)
2003 tree stmt = bsi_stmt (i);
2004 if (TREE_CODE (stmt) == LABEL_EXPR
2005 && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt))
2006 || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))))
2009 block_stmt_iterator new_bsi;
2011 /* A non-reachable non-local label may still be referenced.
2012 But it no longer needs to carry the extra semantics of
2014 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
2016 DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)) = 0;
2017 FORCED_LABEL (LABEL_EXPR_LABEL (stmt)) = 1;
2020 new_bb = bb->prev_bb;
2021 new_bsi = bsi_start (new_bb);
2022 bsi_remove (&i, false);
2023 bsi_insert_before (&new_bsi, stmt, BSI_NEW_STMT);
2027 /* Release SSA definitions if we are in SSA. Note that we
2028 may be called when not in SSA. For example,
2029 final_cleanup calls this function via
2030 cleanup_tree_cfg. */
2031 if (gimple_in_ssa_p (cfun))
2032 release_defs (stmt);
2034 bsi_remove (&i, true);
2037 /* Don't warn for removed gotos. Gotos are often removed due to
2038 jump threading, thus resulting in bogus warnings. Not great,
2039 since this way we lose warnings for gotos in the original
2040 program that are indeed unreachable. */
2041 if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc)
2043 #ifdef USE_MAPPED_LOCATION
2044 if (EXPR_HAS_LOCATION (stmt))
2045 loc = EXPR_LOCATION (stmt);
2048 t = EXPR_LOCUS (stmt);
2049 if (t && LOCATION_LINE (*t) > 0)
2056 /* If requested, give a warning that the first statement in the
2057 block is unreachable. We walk statements backwards in the
2058 loop above, so the last statement we process is the first statement
2060 #ifdef USE_MAPPED_LOCATION
2061 if (loc > BUILTINS_LOCATION && LOCATION_LINE (loc) > 0)
2062 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2065 warning (OPT_Wunreachable_code, "%Hwill never be executed", loc);
2068 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2073 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2074 predicate VAL, return the edge that will be taken out of the block.
2075 If VAL does not match a unique edge, NULL is returned. */
2078 find_taken_edge (basic_block bb, tree val)
2082 stmt = last_stmt (bb);
2085 gcc_assert (is_ctrl_stmt (stmt));
2088 if (! is_gimple_min_invariant (val))
2091 if (TREE_CODE (stmt) == COND_EXPR)
2092 return find_taken_edge_cond_expr (bb, val);
2094 if (TREE_CODE (stmt) == SWITCH_EXPR)
2095 return find_taken_edge_switch_expr (bb, val);
2097 if (computed_goto_p (stmt))
2099 /* Only optimize if the argument is a label, if the argument is
2100 not a label then we can not construct a proper CFG.
2102 It may be the case that we only need to allow the LABEL_REF to
2103 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2104 appear inside a LABEL_EXPR just to be safe. */
2105 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2106 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2107 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2114 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2115 statement, determine which of the outgoing edges will be taken out of the
2116 block. Return NULL if either edge may be taken. */
2119 find_taken_edge_computed_goto (basic_block bb, tree val)
2124 dest = label_to_block (val);
2127 e = find_edge (bb, dest);
2128 gcc_assert (e != NULL);
2134 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2135 statement, determine which of the two edges will be taken out of the
2136 block. Return NULL if either edge may be taken. */
2139 find_taken_edge_cond_expr (basic_block bb, tree val)
2141 edge true_edge, false_edge;
2143 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2145 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2146 return (integer_zerop (val) ? false_edge : true_edge);
2149 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2150 statement, determine which edge will be taken out of the block. Return
2151 NULL if any edge may be taken. */
2154 find_taken_edge_switch_expr (basic_block bb, tree val)
2156 tree switch_expr, taken_case;
2157 basic_block dest_bb;
2160 switch_expr = last_stmt (bb);
2161 taken_case = find_case_label_for_value (switch_expr, val);
2162 dest_bb = label_to_block (CASE_LABEL (taken_case));
2164 e = find_edge (bb, dest_bb);
2170 /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL.
2171 We can make optimal use here of the fact that the case labels are
2172 sorted: We can do a binary search for a case matching VAL. */
2175 find_case_label_for_value (tree switch_expr, tree val)
2177 tree vec = SWITCH_LABELS (switch_expr);
2178 size_t low, high, n = TREE_VEC_LENGTH (vec);
2179 tree default_case = TREE_VEC_ELT (vec, n - 1);
2181 for (low = -1, high = n - 1; high - low > 1; )
2183 size_t i = (high + low) / 2;
2184 tree t = TREE_VEC_ELT (vec, i);
2187 /* Cache the result of comparing CASE_LOW and val. */
2188 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2195 if (CASE_HIGH (t) == NULL)
2197 /* A singe-valued case label. */
2203 /* A case range. We can only handle integer ranges. */
2204 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2209 return default_case;
2215 /*---------------------------------------------------------------------------
2217 ---------------------------------------------------------------------------*/
2219 /* Dump tree-specific information of block BB to file OUTF. */
2222 tree_dump_bb (basic_block bb, FILE *outf, int indent)
2224 dump_generic_bb (outf, bb, indent, TDF_VOPS|TDF_MEMSYMS);
2228 /* Dump a basic block on stderr. */
2231 debug_tree_bb (basic_block bb)
2233 dump_bb (bb, stderr, 0);
2237 /* Dump basic block with index N on stderr. */
2240 debug_tree_bb_n (int n)
2242 debug_tree_bb (BASIC_BLOCK (n));
2243 return BASIC_BLOCK (n);
2247 /* Dump the CFG on stderr.
2249 FLAGS are the same used by the tree dumping functions
2250 (see TDF_* in tree-pass.h). */
2253 debug_tree_cfg (int flags)
2255 dump_tree_cfg (stderr, flags);
2259 /* Dump the program showing basic block boundaries on the given FILE.
2261 FLAGS are the same used by the tree dumping functions (see TDF_* in
2265 dump_tree_cfg (FILE *file, int flags)
2267 if (flags & TDF_DETAILS)
2269 const char *funcname
2270 = lang_hooks.decl_printable_name (current_function_decl, 2);
2273 fprintf (file, ";; Function %s\n\n", funcname);
2274 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2275 n_basic_blocks, n_edges, last_basic_block);
2277 brief_dump_cfg (file);
2278 fprintf (file, "\n");
2281 if (flags & TDF_STATS)
2282 dump_cfg_stats (file);
2284 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2288 /* Dump CFG statistics on FILE. */
2291 dump_cfg_stats (FILE *file)
2293 static long max_num_merged_labels = 0;
2294 unsigned long size, total = 0;
2297 const char * const fmt_str = "%-30s%-13s%12s\n";
2298 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2299 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2300 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2301 const char *funcname
2302 = lang_hooks.decl_printable_name (current_function_decl, 2);
2305 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2307 fprintf (file, "---------------------------------------------------------\n");
2308 fprintf (file, fmt_str, "", " Number of ", "Memory");
2309 fprintf (file, fmt_str, "", " instances ", "used ");
2310 fprintf (file, "---------------------------------------------------------\n");
2312 size = n_basic_blocks * sizeof (struct basic_block_def);
2314 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2315 SCALE (size), LABEL (size));
2319 num_edges += EDGE_COUNT (bb->succs);
2320 size = num_edges * sizeof (struct edge_def);
2322 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2324 fprintf (file, "---------------------------------------------------------\n");
2325 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2327 fprintf (file, "---------------------------------------------------------\n");
2328 fprintf (file, "\n");
2330 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2331 max_num_merged_labels = cfg_stats.num_merged_labels;
2333 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2334 cfg_stats.num_merged_labels, max_num_merged_labels);
2336 fprintf (file, "\n");
2340 /* Dump CFG statistics on stderr. Keep extern so that it's always
2341 linked in the final executable. */
2344 debug_cfg_stats (void)
2346 dump_cfg_stats (stderr);
2350 /* Dump the flowgraph to a .vcg FILE. */
2353 tree_cfg2vcg (FILE *file)
2358 const char *funcname
2359 = lang_hooks.decl_printable_name (current_function_decl, 2);
2361 /* Write the file header. */
2362 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2363 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2364 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2366 /* Write blocks and edges. */
2367 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2369 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2372 if (e->flags & EDGE_FAKE)
2373 fprintf (file, " linestyle: dotted priority: 10");
2375 fprintf (file, " linestyle: solid priority: 100");
2377 fprintf (file, " }\n");
2383 enum tree_code head_code, end_code;
2384 const char *head_name, *end_name;
2387 tree first = first_stmt (bb);
2388 tree last = last_stmt (bb);
2392 head_code = TREE_CODE (first);
2393 head_name = tree_code_name[head_code];
2394 head_line = get_lineno (first);
2397 head_name = "no-statement";
2401 end_code = TREE_CODE (last);
2402 end_name = tree_code_name[end_code];
2403 end_line = get_lineno (last);
2406 end_name = "no-statement";
2408 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2409 bb->index, bb->index, head_name, head_line, end_name,
2412 FOR_EACH_EDGE (e, ei, bb->succs)
2414 if (e->dest == EXIT_BLOCK_PTR)
2415 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2417 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2419 if (e->flags & EDGE_FAKE)
2420 fprintf (file, " priority: 10 linestyle: dotted");
2422 fprintf (file, " priority: 100 linestyle: solid");
2424 fprintf (file, " }\n");
2427 if (bb->next_bb != EXIT_BLOCK_PTR)
2431 fputs ("}\n\n", file);
2436 /*---------------------------------------------------------------------------
2437 Miscellaneous helpers
2438 ---------------------------------------------------------------------------*/
2440 /* Return true if T represents a stmt that always transfers control. */
2443 is_ctrl_stmt (const_tree t)
2445 return (TREE_CODE (t) == COND_EXPR
2446 || TREE_CODE (t) == SWITCH_EXPR
2447 || TREE_CODE (t) == GOTO_EXPR
2448 || TREE_CODE (t) == RETURN_EXPR
2449 || TREE_CODE (t) == RESX_EXPR);
2453 /* Return true if T is a statement that may alter the flow of control
2454 (e.g., a call to a non-returning function). */
2457 is_ctrl_altering_stmt (const_tree t)
2462 call = const_get_call_expr_in (t);
2465 /* A non-pure/const CALL_EXPR alters flow control if the current
2466 function has nonlocal labels. */
2467 if (TREE_SIDE_EFFECTS (call) && current_function_has_nonlocal_label)
2470 /* A CALL_EXPR also alters control flow if it does not return. */
2471 if (call_expr_flags (call) & ECF_NORETURN)
2475 /* OpenMP directives alter control flow. */
2476 if (OMP_DIRECTIVE_P (t))
2479 /* If a statement can throw, it alters control flow. */
2480 return tree_can_throw_internal (t);
2484 /* Return true if T is a computed goto. */
2487 computed_goto_p (const_tree t)
2489 return (TREE_CODE (t) == GOTO_EXPR
2490 && TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL);
2494 /* Return true if T is a simple local goto. */
2497 simple_goto_p (const_tree t)
2499 return (TREE_CODE (t) == GOTO_EXPR
2500 && TREE_CODE (GOTO_DESTINATION (t)) == LABEL_DECL);
2504 /* Return true if T can make an abnormal transfer of control flow.
2505 Transfers of control flow associated with EH are excluded. */
2508 tree_can_make_abnormal_goto (const_tree t)
2510 if (computed_goto_p (t))
2512 if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
2513 t = GIMPLE_STMT_OPERAND (t, 1);
2514 if (TREE_CODE (t) == WITH_SIZE_EXPR)
2515 t = TREE_OPERAND (t, 0);
2516 if (TREE_CODE (t) == CALL_EXPR)
2517 return TREE_SIDE_EFFECTS (t) && current_function_has_nonlocal_label;
2522 /* Return true if T should start a new basic block. PREV_T is the
2523 statement preceding T. It is used when T is a label or a case label.
2524 Labels should only start a new basic block if their previous statement
2525 wasn't a label. Otherwise, sequence of labels would generate
2526 unnecessary basic blocks that only contain a single label. */
2529 stmt_starts_bb_p (const_tree t, const_tree prev_t)
2534 /* LABEL_EXPRs start a new basic block only if the preceding
2535 statement wasn't a label of the same type. This prevents the
2536 creation of consecutive blocks that have nothing but a single
2538 if (TREE_CODE (t) == LABEL_EXPR)
2540 /* Nonlocal and computed GOTO targets always start a new block. */
2541 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t))
2542 || FORCED_LABEL (LABEL_EXPR_LABEL (t)))
2545 if (prev_t && TREE_CODE (prev_t) == LABEL_EXPR)
2547 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t)))
2550 cfg_stats.num_merged_labels++;
2561 /* Return true if T should end a basic block. */
2564 stmt_ends_bb_p (const_tree t)
2566 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2569 /* Remove block annotations and other datastructures. */
2572 delete_tree_cfg_annotations (void)
2575 block_stmt_iterator bsi;
2577 /* Remove annotations from every tree in the function. */
2579 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
2581 tree stmt = bsi_stmt (bsi);
2582 ggc_free (stmt->base.ann);
2583 stmt->base.ann = NULL;
2585 label_to_block_map = NULL;
2589 /* Return the first statement in basic block BB. */
2592 first_stmt (basic_block bb)
2594 block_stmt_iterator i = bsi_start (bb);
2595 return !bsi_end_p (i) ? bsi_stmt (i) : NULL_TREE;
2598 /* Return the last statement in basic block BB. */
2601 last_stmt (basic_block bb)
2603 block_stmt_iterator b = bsi_last (bb);
2604 return !bsi_end_p (b) ? bsi_stmt (b) : NULL_TREE;
2607 /* Return the last statement of an otherwise empty block. Return NULL
2608 if the block is totally empty, or if it contains more than one
2612 last_and_only_stmt (basic_block bb)
2614 block_stmt_iterator i = bsi_last (bb);
2620 last = bsi_stmt (i);
2625 /* Empty statements should no longer appear in the instruction stream.
2626 Everything that might have appeared before should be deleted by
2627 remove_useless_stmts, and the optimizers should just bsi_remove
2628 instead of smashing with build_empty_stmt.
2630 Thus the only thing that should appear here in a block containing
2631 one executable statement is a label. */
2632 prev = bsi_stmt (i);
2633 if (TREE_CODE (prev) == LABEL_EXPR)
2640 /* Mark BB as the basic block holding statement T. */
2643 set_bb_for_stmt (tree t, basic_block bb)
2645 if (TREE_CODE (t) == PHI_NODE)
2647 else if (TREE_CODE (t) == STATEMENT_LIST)
2649 tree_stmt_iterator i;
2650 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2651 set_bb_for_stmt (tsi_stmt (i), bb);
2655 stmt_ann_t ann = get_stmt_ann (t);
2658 /* If the statement is a label, add the label to block-to-labels map
2659 so that we can speed up edge creation for GOTO_EXPRs. */
2660 if (TREE_CODE (t) == LABEL_EXPR)
2664 t = LABEL_EXPR_LABEL (t);
2665 uid = LABEL_DECL_UID (t);
2668 unsigned old_len = VEC_length (basic_block, label_to_block_map);
2669 LABEL_DECL_UID (t) = uid = cfun->last_label_uid++;
2670 if (old_len <= (unsigned) uid)
2672 unsigned new_len = 3 * uid / 2;
2674 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
2679 /* We're moving an existing label. Make sure that we've
2680 removed it from the old block. */
2682 || !VEC_index (basic_block, label_to_block_map, uid));
2683 VEC_replace (basic_block, label_to_block_map, uid, bb);
2688 /* Faster version of set_bb_for_stmt that assume that statement is being moved
2689 from one basic block to another.
2690 For BB splitting we can run into quadratic case, so performance is quite
2691 important and knowing that the tables are big enough, change_bb_for_stmt
2692 can inline as leaf function. */
2694 change_bb_for_stmt (tree t, basic_block bb)
2696 get_stmt_ann (t)->bb = bb;
2697 if (TREE_CODE (t) == LABEL_EXPR)
2698 VEC_replace (basic_block, label_to_block_map,
2699 LABEL_DECL_UID (LABEL_EXPR_LABEL (t)), bb);
2702 /* Finds iterator for STMT. */
2704 extern block_stmt_iterator
2705 bsi_for_stmt (tree stmt)
2707 block_stmt_iterator bsi;
2709 for (bsi = bsi_start (bb_for_stmt (stmt)); !bsi_end_p (bsi); bsi_next (&bsi))
2710 if (bsi_stmt (bsi) == stmt)
2716 /* Mark statement T as modified, and update it. */
2718 update_modified_stmts (tree t)
2720 if (!ssa_operands_active ())
2722 if (TREE_CODE (t) == STATEMENT_LIST)
2724 tree_stmt_iterator i;
2726 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2728 stmt = tsi_stmt (i);
2729 update_stmt_if_modified (stmt);
2733 update_stmt_if_modified (t);
2736 /* Insert statement (or statement list) T before the statement
2737 pointed-to by iterator I. M specifies how to update iterator I
2738 after insertion (see enum bsi_iterator_update). */
2741 bsi_insert_before (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2743 set_bb_for_stmt (t, i->bb);
2744 update_modified_stmts (t);
2745 tsi_link_before (&i->tsi, t, m);
2749 /* Insert statement (or statement list) T after the statement
2750 pointed-to by iterator I. M specifies how to update iterator I
2751 after insertion (see enum bsi_iterator_update). */
2754 bsi_insert_after (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2756 set_bb_for_stmt (t, i->bb);
2757 update_modified_stmts (t);
2758 tsi_link_after (&i->tsi, t, m);
2762 /* Remove the statement pointed to by iterator I. The iterator is updated
2763 to the next statement.
2765 When REMOVE_EH_INFO is true we remove the statement pointed to by
2766 iterator I from the EH tables. Otherwise we do not modify the EH
2769 Generally, REMOVE_EH_INFO should be true when the statement is going to
2770 be removed from the IL and not reinserted elsewhere. */
2773 bsi_remove (block_stmt_iterator *i, bool remove_eh_info)
2775 tree t = bsi_stmt (*i);
2776 set_bb_for_stmt (t, NULL);
2777 delink_stmt_imm_use (t);
2778 tsi_delink (&i->tsi);
2779 mark_stmt_modified (t);
2782 remove_stmt_from_eh_region (t);
2783 gimple_remove_stmt_histograms (cfun, t);
2788 /* Move the statement at FROM so it comes right after the statement at TO. */
2791 bsi_move_after (block_stmt_iterator *from, block_stmt_iterator *to)
2793 tree stmt = bsi_stmt (*from);
2794 bsi_remove (from, false);
2795 /* We must have BSI_NEW_STMT here, as bsi_move_after is sometimes used to
2796 move statements to an empty block. */
2797 bsi_insert_after (to, stmt, BSI_NEW_STMT);
2801 /* Move the statement at FROM so it comes right before the statement at TO. */
2804 bsi_move_before (block_stmt_iterator *from, block_stmt_iterator *to)
2806 tree stmt = bsi_stmt (*from);
2807 bsi_remove (from, false);
2808 /* For consistency with bsi_move_after, it might be better to have
2809 BSI_NEW_STMT here; however, that breaks several places that expect
2810 that TO does not change. */
2811 bsi_insert_before (to, stmt, BSI_SAME_STMT);
2815 /* Move the statement at FROM to the end of basic block BB. */
2818 bsi_move_to_bb_end (block_stmt_iterator *from, basic_block bb)
2820 block_stmt_iterator last = bsi_last (bb);
2822 /* Have to check bsi_end_p because it could be an empty block. */
2823 if (!bsi_end_p (last) && is_ctrl_stmt (bsi_stmt (last)))
2824 bsi_move_before (from, &last);
2826 bsi_move_after (from, &last);
2830 /* Replace the contents of the statement pointed to by iterator BSI
2831 with STMT. If UPDATE_EH_INFO is true, the exception handling
2832 information of the original statement is moved to the new statement. */
2835 bsi_replace (const block_stmt_iterator *bsi, tree stmt, bool update_eh_info)
2838 tree orig_stmt = bsi_stmt (*bsi);
2840 if (stmt == orig_stmt)
2842 SET_EXPR_LOCUS (stmt, EXPR_LOCUS (orig_stmt));
2843 set_bb_for_stmt (stmt, bsi->bb);
2845 /* Preserve EH region information from the original statement, if
2846 requested by the caller. */
2849 eh_region = lookup_stmt_eh_region (orig_stmt);
2852 remove_stmt_from_eh_region (orig_stmt);
2853 add_stmt_to_eh_region (stmt, eh_region);
2857 gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
2858 gimple_remove_stmt_histograms (cfun, orig_stmt);
2859 delink_stmt_imm_use (orig_stmt);
2860 *bsi_stmt_ptr (*bsi) = stmt;
2861 mark_stmt_modified (stmt);
2862 update_modified_stmts (stmt);
2866 /* Insert the statement pointed-to by BSI into edge E. Every attempt
2867 is made to place the statement in an existing basic block, but
2868 sometimes that isn't possible. When it isn't possible, the edge is
2869 split and the statement is added to the new block.
2871 In all cases, the returned *BSI points to the correct location. The
2872 return value is true if insertion should be done after the location,
2873 or false if it should be done before the location. If new basic block
2874 has to be created, it is stored in *NEW_BB. */
2877 tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi,
2878 basic_block *new_bb)
2880 basic_block dest, src;
2886 /* If the destination has one predecessor which has no PHI nodes,
2887 insert there. Except for the exit block.
2889 The requirement for no PHI nodes could be relaxed. Basically we
2890 would have to examine the PHIs to prove that none of them used
2891 the value set by the statement we want to insert on E. That
2892 hardly seems worth the effort. */
2893 if (single_pred_p (dest)
2894 && ! phi_nodes (dest)
2895 && dest != EXIT_BLOCK_PTR)
2897 *bsi = bsi_start (dest);
2898 if (bsi_end_p (*bsi))
2901 /* Make sure we insert after any leading labels. */
2902 tmp = bsi_stmt (*bsi);
2903 while (TREE_CODE (tmp) == LABEL_EXPR)
2906 if (bsi_end_p (*bsi))
2908 tmp = bsi_stmt (*bsi);
2911 if (bsi_end_p (*bsi))
2913 *bsi = bsi_last (dest);
2920 /* If the source has one successor, the edge is not abnormal and
2921 the last statement does not end a basic block, insert there.
2922 Except for the entry block. */
2924 if ((e->flags & EDGE_ABNORMAL) == 0
2925 && single_succ_p (src)
2926 && src != ENTRY_BLOCK_PTR)
2928 *bsi = bsi_last (src);
2929 if (bsi_end_p (*bsi))
2932 tmp = bsi_stmt (*bsi);
2933 if (!stmt_ends_bb_p (tmp))
2936 /* Insert code just before returning the value. We may need to decompose
2937 the return in the case it contains non-trivial operand. */
2938 if (TREE_CODE (tmp) == RETURN_EXPR)
2940 tree op = TREE_OPERAND (tmp, 0);
2941 if (op && !is_gimple_val (op))
2943 gcc_assert (TREE_CODE (op) == GIMPLE_MODIFY_STMT);
2944 bsi_insert_before (bsi, op, BSI_NEW_STMT);
2945 TREE_OPERAND (tmp, 0) = GIMPLE_STMT_OPERAND (op, 0);
2952 /* Otherwise, create a new basic block, and split this edge. */
2953 dest = split_edge (e);
2956 e = single_pred_edge (dest);
2961 /* This routine will commit all pending edge insertions, creating any new
2962 basic blocks which are necessary. */
2965 bsi_commit_edge_inserts (void)
2971 bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL);
2974 FOR_EACH_EDGE (e, ei, bb->succs)
2975 bsi_commit_one_edge_insert (e, NULL);
2979 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
2980 to this block, otherwise set it to NULL. */
2983 bsi_commit_one_edge_insert (edge e, basic_block *new_bb)
2987 if (PENDING_STMT (e))
2989 block_stmt_iterator bsi;
2990 tree stmt = PENDING_STMT (e);
2992 PENDING_STMT (e) = NULL_TREE;
2994 if (tree_find_edge_insert_loc (e, &bsi, new_bb))
2995 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
2997 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3002 /* Add STMT to the pending list of edge E. No actual insertion is
3003 made until a call to bsi_commit_edge_inserts () is made. */
3006 bsi_insert_on_edge (edge e, tree stmt)
3008 append_to_statement_list (stmt, &PENDING_STMT (e));
3011 /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new
3012 block has to be created, it is returned. */
3015 bsi_insert_on_edge_immediate (edge e, tree stmt)
3017 block_stmt_iterator bsi;
3018 basic_block new_bb = NULL;
3020 gcc_assert (!PENDING_STMT (e));
3022 if (tree_find_edge_insert_loc (e, &bsi, &new_bb))
3023 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3025 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3030 /*---------------------------------------------------------------------------
3031 Tree specific functions for CFG manipulation
3032 ---------------------------------------------------------------------------*/
3034 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
3037 reinstall_phi_args (edge new_edge, edge old_edge)
3041 if (!PENDING_STMT (old_edge))
3044 for (var = PENDING_STMT (old_edge), phi = phi_nodes (new_edge->dest);
3046 var = TREE_CHAIN (var), phi = PHI_CHAIN (phi))
3048 tree result = TREE_PURPOSE (var);
3049 tree arg = TREE_VALUE (var);
3051 gcc_assert (result == PHI_RESULT (phi));
3053 add_phi_arg (phi, arg, new_edge);
3056 PENDING_STMT (old_edge) = NULL;
3059 /* Returns the basic block after which the new basic block created
3060 by splitting edge EDGE_IN should be placed. Tries to keep the new block
3061 near its "logical" location. This is of most help to humans looking
3062 at debugging dumps. */
3065 split_edge_bb_loc (edge edge_in)
3067 basic_block dest = edge_in->dest;
3069 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
3070 return edge_in->src;
3072 return dest->prev_bb;
3075 /* Split a (typically critical) edge EDGE_IN. Return the new block.
3076 Abort on abnormal edges. */
3079 tree_split_edge (edge edge_in)
3081 basic_block new_bb, after_bb, dest;
3084 /* Abnormal edges cannot be split. */
3085 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
3087 dest = edge_in->dest;
3089 after_bb = split_edge_bb_loc (edge_in);
3091 new_bb = create_empty_bb (after_bb);
3092 new_bb->frequency = EDGE_FREQUENCY (edge_in);
3093 new_bb->count = edge_in->count;
3094 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
3095 new_edge->probability = REG_BR_PROB_BASE;
3096 new_edge->count = edge_in->count;
3098 e = redirect_edge_and_branch (edge_in, new_bb);
3099 gcc_assert (e == edge_in);
3100 reinstall_phi_args (new_edge, e);
3105 /* Callback for walk_tree, check that all elements with address taken are
3106 properly noticed as such. The DATA is an int* that is 1 if TP was seen
3107 inside a PHI node. */
3110 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
3113 bool in_phi = (data != NULL);
3118 /* Check operand N for being valid GIMPLE and give error MSG if not. */
3119 #define CHECK_OP(N, MSG) \
3120 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
3121 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
3123 switch (TREE_CODE (t))
3126 if (SSA_NAME_IN_FREE_LIST (t))
3128 error ("SSA name in freelist but still referenced");
3134 x = fold (ASSERT_EXPR_COND (t));
3135 if (x == boolean_false_node)
3137 error ("ASSERT_EXPR with an always-false condition");
3145 case GIMPLE_MODIFY_STMT:
3146 x = GIMPLE_STMT_OPERAND (t, 0);
3147 if (TREE_CODE (x) == BIT_FIELD_REF
3148 && is_gimple_reg (TREE_OPERAND (x, 0)))
3150 error ("GIMPLE register modified with BIT_FIELD_REF");
3159 bool old_side_effects;
3162 bool new_side_effects;
3164 /* ??? tree-ssa-alias.c may have overlooked dead PHI nodes, missing
3165 dead PHIs that take the address of something. But if the PHI
3166 result is dead, the fact that it takes the address of anything
3167 is irrelevant. Because we can not tell from here if a PHI result
3168 is dead, we just skip this check for PHIs altogether. This means
3169 we may be missing "valid" checks, but what can you do?
3170 This was PR19217. */
3174 old_invariant = TREE_INVARIANT (t);
3175 old_constant = TREE_CONSTANT (t);
3176 old_side_effects = TREE_SIDE_EFFECTS (t);
3178 recompute_tree_invariant_for_addr_expr (t);
3179 new_invariant = TREE_INVARIANT (t);
3180 new_side_effects = TREE_SIDE_EFFECTS (t);
3181 new_constant = TREE_CONSTANT (t);
3183 if (old_invariant != new_invariant)
3185 error ("invariant not recomputed when ADDR_EXPR changed");
3189 if (old_constant != new_constant)
3191 error ("constant not recomputed when ADDR_EXPR changed");
3194 if (old_side_effects != new_side_effects)
3196 error ("side effects not recomputed when ADDR_EXPR changed");
3200 /* Skip any references (they will be checked when we recurse down the
3201 tree) and ensure that any variable used as a prefix is marked
3203 for (x = TREE_OPERAND (t, 0);
3204 handled_component_p (x);
3205 x = TREE_OPERAND (x, 0))
3208 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
3210 if (!TREE_ADDRESSABLE (x))
3212 error ("address taken, but ADDRESSABLE bit not set");
3219 x = COND_EXPR_COND (t);
3220 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
3222 error ("non-integral used in condition");
3225 if (!is_gimple_condexpr (x))
3227 error ("invalid conditional operand");
3234 case FIX_TRUNC_EXPR:
3239 case NON_LVALUE_EXPR:
3240 case TRUTH_NOT_EXPR:
3241 CHECK_OP (0, "invalid operand to unary operator");
3248 case ARRAY_RANGE_REF:
3250 case VIEW_CONVERT_EXPR:
3251 /* We have a nest of references. Verify that each of the operands
3252 that determine where to reference is either a constant or a variable,
3253 verify that the base is valid, and then show we've already checked
3255 while (handled_component_p (t))
3257 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
3258 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
3259 else if (TREE_CODE (t) == ARRAY_REF
3260 || TREE_CODE (t) == ARRAY_RANGE_REF)
3262 CHECK_OP (1, "invalid array index");
3263 if (TREE_OPERAND (t, 2))
3264 CHECK_OP (2, "invalid array lower bound");
3265 if (TREE_OPERAND (t, 3))
3266 CHECK_OP (3, "invalid array stride");
3268 else if (TREE_CODE (t) == BIT_FIELD_REF)
3270 CHECK_OP (1, "invalid operand to BIT_FIELD_REF");
3271 CHECK_OP (2, "invalid operand to BIT_FIELD_REF");
3274 t = TREE_OPERAND (t, 0);
3277 if (!CONSTANT_CLASS_P (t) && !is_gimple_lvalue (t))
3279 error ("invalid reference prefix");
3286 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
3287 POINTER_PLUS_EXPR. */
3288 if (POINTER_TYPE_P (TREE_TYPE (t)))
3290 error ("invalid operand to plus/minus, type is a pointer");
3293 CHECK_OP (0, "invalid operand to binary operator");
3294 CHECK_OP (1, "invalid operand to binary operator");
3297 case POINTER_PLUS_EXPR:
3298 /* Check to make sure the first operand is a pointer or reference type. */
3299 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
3301 error ("invalid operand to pointer plus, first operand is not a pointer");
3304 /* Check to make sure the second operand is an integer with type of
3306 if (!useless_type_conversion_p (sizetype,
3307 TREE_TYPE (TREE_OPERAND (t, 1))))
3309 error ("invalid operand to pointer plus, second operand is not an "
3310 "integer with type of sizetype.");
3320 case UNORDERED_EXPR:
3329 case TRUNC_DIV_EXPR:
3331 case FLOOR_DIV_EXPR:
3332 case ROUND_DIV_EXPR:
3333 case TRUNC_MOD_EXPR:
3335 case FLOOR_MOD_EXPR:
3336 case ROUND_MOD_EXPR:
3338 case EXACT_DIV_EXPR:
3348 CHECK_OP (0, "invalid operand to binary operator");
3349 CHECK_OP (1, "invalid operand to binary operator");
3353 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3365 /* Verifies if EXPR is a valid GIMPLE unary expression. Returns true
3366 if there is an error, otherwise false. */
3369 verify_gimple_unary_expr (const_tree expr)
3371 tree op = TREE_OPERAND (expr, 0);
3372 tree type = TREE_TYPE (expr);
3374 if (!is_gimple_val (op))
3376 error ("invalid operand in unary expression");
3380 /* For general unary expressions we have the operations type
3381 as the effective type the operation is carried out on. So all
3382 we need to require is that the operand is trivially convertible
3384 if (!useless_type_conversion_p (type, TREE_TYPE (op)))
3386 error ("type mismatch in unary expression");
3387 debug_generic_expr (type);
3388 debug_generic_expr (TREE_TYPE (op));
3395 /* Verifies if EXPR is a valid GIMPLE binary expression. Returns true
3396 if there is an error, otherwise false. */
3399 verify_gimple_binary_expr (const_tree expr)
3401 tree op0 = TREE_OPERAND (expr, 0);
3402 tree op1 = TREE_OPERAND (expr, 1);
3403 tree type = TREE_TYPE (expr);
3405 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3407 error ("invalid operands in binary expression");
3411 /* For general binary expressions we have the operations type
3412 as the effective type the operation is carried out on. So all
3413 we need to require is that both operands are trivially convertible
3415 if (!useless_type_conversion_p (type, TREE_TYPE (op0))
3416 || !useless_type_conversion_p (type, TREE_TYPE (op1)))
3418 error ("type mismatch in binary expression");
3419 debug_generic_stmt (type);
3420 debug_generic_stmt (TREE_TYPE (op0));
3421 debug_generic_stmt (TREE_TYPE (op1));
3428 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3429 Returns true if there is an error, otherwise false. */
3432 verify_gimple_min_lval (tree expr)
3436 if (is_gimple_id (expr))
3439 if (TREE_CODE (expr) != INDIRECT_REF
3440 && TREE_CODE (expr) != ALIGN_INDIRECT_REF
3441 && TREE_CODE (expr) != MISALIGNED_INDIRECT_REF)
3443 error ("invalid expression for min lvalue");
3447 op = TREE_OPERAND (expr, 0);
3448 if (!is_gimple_val (op))
3450 error ("invalid operand in indirect reference");
3451 debug_generic_stmt (op);
3454 if (!useless_type_conversion_p (TREE_TYPE (expr),
3455 TREE_TYPE (TREE_TYPE (op))))
3457 error ("type mismatch in indirect reference");
3458 debug_generic_stmt (TREE_TYPE (expr));
3459 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3466 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3467 if there is an error, otherwise false. */
3470 verify_gimple_reference (tree expr)
3472 while (handled_component_p (expr))
3474 tree op = TREE_OPERAND (expr, 0);
3476 if (TREE_CODE (expr) == ARRAY_REF
3477 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3479 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3480 || (TREE_OPERAND (expr, 2)
3481 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3482 || (TREE_OPERAND (expr, 3)
3483 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3485 error ("invalid operands to array reference");
3486 debug_generic_stmt (expr);
3491 /* Verify if the reference array element types are compatible. */
3492 if (TREE_CODE (expr) == ARRAY_REF
3493 && !useless_type_conversion_p (TREE_TYPE (expr),
3494 TREE_TYPE (TREE_TYPE (op))))
3496 error ("type mismatch in array reference");
3497 debug_generic_stmt (TREE_TYPE (expr));
3498 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3501 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3502 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3503 TREE_TYPE (TREE_TYPE (op))))
3505 error ("type mismatch in array range reference");
3506 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3507 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3511 if ((TREE_CODE (expr) == REALPART_EXPR
3512 || TREE_CODE (expr) == IMAGPART_EXPR)
3513 && !useless_type_conversion_p (TREE_TYPE (expr),
3514 TREE_TYPE (TREE_TYPE (op))))
3516 error ("type mismatch in real/imagpart reference");
3517 debug_generic_stmt (TREE_TYPE (expr));
3518 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3522 if (TREE_CODE (expr) == COMPONENT_REF
3523 && !useless_type_conversion_p (TREE_TYPE (expr),
3524 TREE_TYPE (TREE_OPERAND (expr, 1))))
3526 error ("type mismatch in component reference");
3527 debug_generic_stmt (TREE_TYPE (expr));
3528 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3532 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3533 is nothing to verify. Gross mismatches at most invoke
3534 undefined behavior. */
3539 return verify_gimple_min_lval (expr);
3542 /* Verify the GIMPLE expression EXPR. Returns true if there is an
3543 error, otherwise false. */
3546 verify_gimple_expr (tree expr)
3548 tree type = TREE_TYPE (expr);
3550 if (is_gimple_val (expr))
3553 /* Special codes we cannot handle via their class. */
3554 switch (TREE_CODE (expr))
3559 tree op = TREE_OPERAND (expr, 0);
3560 if (!is_gimple_val (op))
3562 error ("invalid operand in conversion");
3566 /* Allow conversions between integral types and between
3568 if ((INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3569 || (POINTER_TYPE_P (type) && POINTER_TYPE_P (TREE_TYPE (op))))
3572 /* Allow conversions between integral types and pointers only if
3573 there is no sign or zero extension involved. */
3574 if (((POINTER_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3575 || (POINTER_TYPE_P (TREE_TYPE (op)) && INTEGRAL_TYPE_P (type)))
3576 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op)))
3579 /* Allow conversion from integer to offset type and vice versa. */
3580 if ((TREE_CODE (type) == OFFSET_TYPE
3581 && TREE_CODE (TREE_TYPE (op)) == INTEGER_TYPE)
3582 || (TREE_CODE (type) == INTEGER_TYPE
3583 && TREE_CODE (TREE_TYPE (op)) == OFFSET_TYPE))
3586 /* Otherwise assert we are converting between types of the
3588 if (TREE_CODE (type) != TREE_CODE (TREE_TYPE (op)))
3590 error ("invalid types in nop conversion");
3591 debug_generic_expr (type);
3592 debug_generic_expr (TREE_TYPE (op));
3601 tree op = TREE_OPERAND (expr, 0);
3602 if (!is_gimple_val (op))
3604 error ("invalid operand in int to float conversion");
3607 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3608 || !SCALAR_FLOAT_TYPE_P (type))
3610 error ("invalid types in conversion to floating point");
3611 debug_generic_expr (type);
3612 debug_generic_expr (TREE_TYPE (op));
3618 case FIX_TRUNC_EXPR:
3620 tree op = TREE_OPERAND (expr, 0);
3621 if (!is_gimple_val (op))
3623 error ("invalid operand in float to int conversion");
3626 if (!INTEGRAL_TYPE_P (type)
3627 || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (op)))
3629 error ("invalid types in conversion to integer");
3630 debug_generic_expr (type);
3631 debug_generic_expr (TREE_TYPE (op));
3639 tree op0 = TREE_OPERAND (expr, 0);
3640 tree op1 = TREE_OPERAND (expr, 1);
3641 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3643 error ("invalid operands in complex expression");
3646 if (!TREE_CODE (type) == COMPLEX_TYPE
3647 || !(TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
3648 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0)))
3649 || !(TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3650 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op1)))
3651 || !useless_type_conversion_p (TREE_TYPE (type),
3653 || !useless_type_conversion_p (TREE_TYPE (type),
3656 error ("type mismatch in complex expression");
3657 debug_generic_stmt (TREE_TYPE (expr));
3658 debug_generic_stmt (TREE_TYPE (op0));
3659 debug_generic_stmt (TREE_TYPE (op1));
3667 /* This is used like COMPLEX_EXPR but for vectors. */
3668 if (TREE_CODE (type) != VECTOR_TYPE)
3670 error ("constructor not allowed for non-vector types");
3671 debug_generic_stmt (type);
3674 /* FIXME: verify constructor arguments. */
3683 tree op0 = TREE_OPERAND (expr, 0);
3684 tree op1 = TREE_OPERAND (expr, 1);
3685 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3687 error ("invalid operands in shift expression");
3690 if (!TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3691 || !useless_type_conversion_p (type, TREE_TYPE (op0)))
3693 error ("type mismatch in shift expression");
3694 debug_generic_stmt (TREE_TYPE (expr));
3695 debug_generic_stmt (TREE_TYPE (op0));
3696 debug_generic_stmt (TREE_TYPE (op1));
3705 tree op0 = TREE_OPERAND (expr, 0);
3706 tree op1 = TREE_OPERAND (expr, 1);
3707 if (POINTER_TYPE_P (type)
3708 || POINTER_TYPE_P (TREE_TYPE (op0))
3709 || POINTER_TYPE_P (TREE_TYPE (op1)))
3711 error ("invalid (pointer) operands to plus/minus");
3714 /* Continue with generic binary expression handling. */
3718 case POINTER_PLUS_EXPR:
3720 tree op0 = TREE_OPERAND (expr, 0);
3721 tree op1 = TREE_OPERAND (expr, 1);
3722 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3724 error ("invalid operands in pointer plus expression");
3727 if (!POINTER_TYPE_P (TREE_TYPE (op0))
3728 || TREE_CODE (TREE_TYPE (op1)) != INTEGER_TYPE
3729 || !useless_type_conversion_p (type, TREE_TYPE (op0))
3730 || !useless_type_conversion_p (sizetype, TREE_TYPE (op1)))
3732 error ("type mismatch in pointer plus expression");
3733 debug_generic_stmt (type);
3734 debug_generic_stmt (TREE_TYPE (op0));
3735 debug_generic_stmt (TREE_TYPE (op1));
3743 tree op0 = TREE_OPERAND (expr, 0);
3744 tree op1 = TREE_OPERAND (expr, 1);
3745 tree op2 = TREE_OPERAND (expr, 2);
3746 if ((!is_gimple_val (op1)
3747 && TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3748 || (!is_gimple_val (op2)
3749 && TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE))
3751 error ("invalid operands in conditional expression");
3754 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3755 || (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE
3756 && !useless_type_conversion_p (type, TREE_TYPE (op1)))
3757 || (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE
3758 && !useless_type_conversion_p (type, TREE_TYPE (op2))))
3760 error ("type mismatch in conditional expression");
3761 debug_generic_stmt (type);
3762 debug_generic_stmt (TREE_TYPE (op0));
3763 debug_generic_stmt (TREE_TYPE (op1));
3764 debug_generic_stmt (TREE_TYPE (op2));
3767 return verify_gimple_expr (op0);
3772 tree op = TREE_OPERAND (expr, 0);
3774 if (!is_gimple_addressable (op))
3776 error ("invalid operand in unary expression");
3779 ptr_type = build_pointer_type (TREE_TYPE (op));
3780 if (!useless_type_conversion_p (type, ptr_type)
3781 /* FIXME: a longstanding wart, &a == &a[0]. */
3782 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3783 || !useless_type_conversion_p (type,
3784 build_pointer_type (TREE_TYPE (TREE_TYPE (op))))))
3786 error ("type mismatch in address expression");
3787 debug_generic_stmt (TREE_TYPE (expr));
3788 debug_generic_stmt (ptr_type);
3792 return verify_gimple_reference (op);
3795 case TRUTH_ANDIF_EXPR:
3796 case TRUTH_ORIF_EXPR:
3797 case TRUTH_AND_EXPR:
3799 case TRUTH_XOR_EXPR:
3801 tree op0 = TREE_OPERAND (expr, 0);
3802 tree op1 = TREE_OPERAND (expr, 1);
3804 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3806 error ("invalid operands in truth expression");
3810 /* We allow any kind of integral typed argument and result. */
3811 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3812 || !INTEGRAL_TYPE_P (TREE_TYPE (op1))
3813 || !INTEGRAL_TYPE_P (type))
3815 error ("type mismatch in binary truth expression");
3816 debug_generic_stmt (type);
3817 debug_generic_stmt (TREE_TYPE (op0));
3818 debug_generic_stmt (TREE_TYPE (op1));
3825 case TRUTH_NOT_EXPR:
3827 tree op = TREE_OPERAND (expr, 0);
3829 if (!is_gimple_val (op))
3831 error ("invalid operand in unary not");
3835 /* For TRUTH_NOT_EXPR we can have any kind of integral
3836 typed arguments and results. */
3837 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3838 || !INTEGRAL_TYPE_P (type))
3840 error ("type mismatch in not expression");
3841 debug_generic_expr (TREE_TYPE (expr));
3842 debug_generic_expr (TREE_TYPE (op));
3850 /* FIXME. The C frontend passes unpromoted arguments in case it
3851 didn't see a function declaration before the call. */
3857 /* Generic handling via classes. */
3858 switch (TREE_CODE_CLASS (TREE_CODE (expr)))
3861 return verify_gimple_unary_expr (expr);
3864 return verify_gimple_binary_expr (expr);
3867 return verify_gimple_reference (expr);
3869 case tcc_comparison:
3871 tree op0 = TREE_OPERAND (expr, 0);
3872 tree op1 = TREE_OPERAND (expr, 1);
3873 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3875 error ("invalid operands in comparison expression");
3878 /* For comparisons we do not have the operations type as the
3879 effective type the comparison is carried out in. Instead
3880 we require that either the first operand is trivially
3881 convertible into the second, or the other way around.
3882 The resulting type of a comparison may be any integral type.
3883 Because we special-case pointers to void we allow
3884 comparisons of pointers with the same mode as well. */
3885 if ((!useless_type_conversion_p (TREE_TYPE (op0), TREE_TYPE (op1))
3886 && !useless_type_conversion_p (TREE_TYPE (op1), TREE_TYPE (op0))
3887 && (!POINTER_TYPE_P (TREE_TYPE (op0))
3888 || !POINTER_TYPE_P (TREE_TYPE (op1))
3889 || TYPE_MODE (TREE_TYPE (op0)) != TYPE_MODE (TREE_TYPE (op1))))
3890 || !INTEGRAL_TYPE_P (type))
3892 error ("type mismatch in comparison expression");
3893 debug_generic_stmt (TREE_TYPE (expr));
3894 debug_generic_stmt (TREE_TYPE (op0));
3895 debug_generic_stmt (TREE_TYPE (op1));
3908 /* Verify the GIMPLE assignment statement STMT. Returns true if there
3909 is an error, otherwise false. */
3912 verify_gimple_modify_stmt (const_tree stmt)
3914 tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
3915 tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
3917 gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
3919 if (!useless_type_conversion_p (TREE_TYPE (lhs),
3922 error ("non-trivial conversion at assignment");
3923 debug_generic_expr (TREE_TYPE (lhs));
3924 debug_generic_expr (TREE_TYPE (rhs));
3928 /* Loads/stores from/to a variable are ok. */
3929 if ((is_gimple_val (lhs)
3930 && is_gimple_variable (rhs))
3931 || (is_gimple_val (rhs)
3932 && is_gimple_variable (lhs)))
3935 /* Aggregate copies are ok. */
3936 if (!is_gimple_reg_type (TREE_TYPE (lhs))
3937 && !is_gimple_reg_type (TREE_TYPE (rhs)))
3940 /* We might get 'loads' from a parameter which is not a gimple value. */
3941 if (TREE_CODE (rhs) == PARM_DECL)
3942 return verify_gimple_expr (lhs);
3944 if (!is_gimple_variable (lhs)
3945 && verify_gimple_expr (lhs))
3948 if (!is_gimple_variable (rhs)
3949 && verify_gimple_expr (rhs))
3955 /* Verify the GIMPLE statement STMT. Returns true if there is an
3956 error, otherwise false. */
3959 verify_gimple_stmt (tree stmt)
3961 if (!is_gimple_stmt (stmt))
3963 error ("is not a valid GIMPLE statement");
3967 if (OMP_DIRECTIVE_P (stmt))
3969 /* OpenMP directives are validated by the FE and never operated
3970 on by the optimizers. Furthermore, OMP_FOR may contain
3971 non-gimple expressions when the main index variable has had
3972 its address taken. This does not affect the loop itself
3973 because the header of an OMP_FOR is merely used to determine
3974 how to setup the parallel iteration. */
3978 switch (TREE_CODE (stmt))
3980 case GIMPLE_MODIFY_STMT:
3981 return verify_gimple_modify_stmt (stmt);
3988 if (!is_gimple_val (TREE_OPERAND (stmt, 0)))
3990 error ("invalid operand to switch statement");
3991 debug_generic_expr (TREE_OPERAND (stmt, 0));
3997 tree op = TREE_OPERAND (stmt, 0);
3999 if (TREE_CODE (TREE_TYPE (stmt)) != VOID_TYPE)
4001 error ("type error in return expression");
4006 || TREE_CODE (op) == RESULT_DECL)
4009 return verify_gimple_modify_stmt (op);
4014 return verify_gimple_expr (stmt);
4017 case CHANGE_DYNAMIC_TYPE_EXPR:
4026 /* Verify the GIMPLE statements inside the statement list STMTS. */
4029 verify_gimple_1 (tree stmts)
4031 tree_stmt_iterator tsi;
4033 for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi))
4035 tree stmt = tsi_stmt (tsi);
4037 switch (TREE_CODE (stmt))
4040 verify_gimple_1 (BIND_EXPR_BODY (stmt));
4043 case TRY_CATCH_EXPR:
4044 case TRY_FINALLY_EXPR:
4045 verify_gimple_1 (TREE_OPERAND (stmt, 0));
4046 verify_gimple_1 (TREE_OPERAND (stmt, 1));
4050 verify_gimple_1 (CATCH_BODY (stmt));
4053 case EH_FILTER_EXPR:
4054 verify_gimple_1 (EH_FILTER_FAILURE (stmt));
4058 if (verify_gimple_stmt (stmt))
4059 debug_generic_expr (stmt);
4064 /* Verify the GIMPLE statements inside the current function. */
4067 verify_gimple (void)
4069 verify_gimple_1 (BIND_EXPR_BODY (DECL_SAVED_TREE (cfun->decl)));
4072 /* Verify STMT, return true if STMT is not in GIMPLE form.
4073 TODO: Implement type checking. */
4076 verify_stmt (tree stmt, bool last_in_block)
4080 if (OMP_DIRECTIVE_P (stmt))
4082 /* OpenMP directives are validated by the FE and never operated
4083 on by the optimizers. Furthermore, OMP_FOR may contain
4084 non-gimple expressions when the main index variable has had
4085 its address taken. This does not affect the loop itself
4086 because the header of an OMP_FOR is merely used to determine
4087 how to setup the parallel iteration. */
4091 if (!is_gimple_stmt (stmt))
4093 error ("is not a valid GIMPLE statement");
4097 addr = walk_tree (&stmt, verify_expr, NULL, NULL);
4100 debug_generic_stmt (addr);
4104 /* If the statement is marked as part of an EH region, then it is
4105 expected that the statement could throw. Verify that when we
4106 have optimizations that simplify statements such that we prove
4107 that they cannot throw, that we update other data structures
4109 if (lookup_stmt_eh_region (stmt) >= 0)
4111 if (!tree_could_throw_p (stmt))
4113 error ("statement marked for throw, but doesn%'t");
4116 if (!last_in_block && tree_can_throw_internal (stmt))
4118 error ("statement marked for throw in middle of block");
4126 debug_generic_stmt (stmt);
4131 /* Return true when the T can be shared. */
4134 tree_node_can_be_shared (tree t)
4136 if (IS_TYPE_OR_DECL_P (t)
4137 || is_gimple_min_invariant (t)
4138 || TREE_CODE (t) == SSA_NAME
4139 || t == error_mark_node
4140 || TREE_CODE (t) == IDENTIFIER_NODE)
4143 if (TREE_CODE (t) == CASE_LABEL_EXPR)
4146 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4147 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4148 || TREE_CODE (t) == COMPONENT_REF
4149 || TREE_CODE (t) == REALPART_EXPR
4150 || TREE_CODE (t) == IMAGPART_EXPR)
4151 t = TREE_OPERAND (t, 0);
4160 /* Called via walk_trees. Verify tree sharing. */
4163 verify_node_sharing (tree * tp, int *walk_subtrees, void *data)
4165 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4167 if (tree_node_can_be_shared (*tp))
4169 *walk_subtrees = false;
4173 if (pointer_set_insert (visited, *tp))
4180 /* Helper function for verify_gimple_tuples. */
4183 verify_gimple_tuples_1 (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4184 void *data ATTRIBUTE_UNUSED)
4186 switch (TREE_CODE (*tp))
4189 error ("unexpected non-tuple");
4199 /* Verify that there are no trees that should have been converted to
4200 gimple tuples. Return true if T contains a node that should have
4201 been converted to a gimple tuple, but hasn't. */
4204 verify_gimple_tuples (tree t)
4206 return walk_tree (&t, verify_gimple_tuples_1, NULL, NULL) != NULL;
4209 static bool eh_error_found;
4211 verify_eh_throw_stmt_node (void **slot, void *data)
4213 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4214 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4216 if (!pointer_set_contains (visited, node->stmt))
4218 error ("Dead STMT in EH table");
4219 debug_generic_stmt (node->stmt);
4220 eh_error_found = true;
4225 /* Verify the GIMPLE statement chain. */
4231 block_stmt_iterator bsi;
4233 struct pointer_set_t *visited, *visited_stmts;
4236 timevar_push (TV_TREE_STMT_VERIFY);
4237 visited = pointer_set_create ();
4238 visited_stmts = pointer_set_create ();
4245 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4247 int phi_num_args = PHI_NUM_ARGS (phi);
4249 pointer_set_insert (visited_stmts, phi);
4250 if (bb_for_stmt (phi) != bb)
4252 error ("bb_for_stmt (phi) is set to a wrong basic block");
4256 for (i = 0; i < phi_num_args; i++)
4258 tree t = PHI_ARG_DEF (phi, i);
4261 /* Addressable variables do have SSA_NAMEs but they
4262 are not considered gimple values. */
4263 if (TREE_CODE (t) != SSA_NAME
4264 && TREE_CODE (t) != FUNCTION_DECL
4265 && !is_gimple_val (t))
4267 error ("PHI def is not a GIMPLE value");
4268 debug_generic_stmt (phi);
4269 debug_generic_stmt (t);
4273 addr = walk_tree (&t, verify_expr, (void *) 1, NULL);
4276 debug_generic_stmt (addr);
4280 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4283 error ("incorrect sharing of tree nodes");
4284 debug_generic_stmt (phi);
4285 debug_generic_stmt (addr);
4291 for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
4293 tree stmt = bsi_stmt (bsi);
4295 pointer_set_insert (visited_stmts, stmt);
4296 err |= verify_gimple_tuples (stmt);
4298 if (bb_for_stmt (stmt) != bb)
4300 error ("bb_for_stmt (stmt) is set to a wrong basic block");
4305 err |= verify_stmt (stmt, bsi_end_p (bsi));
4306 addr = walk_tree (&stmt, verify_node_sharing, visited, NULL);
4309 error ("incorrect sharing of tree nodes");
4310 debug_generic_stmt (stmt);
4311 debug_generic_stmt (addr);
4316 eh_error_found = false;
4317 if (get_eh_throw_stmt_table (cfun))
4318 htab_traverse (get_eh_throw_stmt_table (cfun),
4319 verify_eh_throw_stmt_node,
4322 if (err | eh_error_found)
4323 internal_error ("verify_stmts failed");
4325 pointer_set_destroy (visited);
4326 pointer_set_destroy (visited_stmts);
4327 verify_histograms ();
4328 timevar_pop (TV_TREE_STMT_VERIFY);
4332 /* Verifies that the flow information is OK. */
4335 tree_verify_flow_info (void)
4339 block_stmt_iterator bsi;
4344 if (ENTRY_BLOCK_PTR->il.tree)
4346 error ("ENTRY_BLOCK has IL associated with it");
4350 if (EXIT_BLOCK_PTR->il.tree)
4352 error ("EXIT_BLOCK has IL associated with it");
4356 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4357 if (e->flags & EDGE_FALLTHRU)
4359 error ("fallthru to exit from bb %d", e->src->index);
4365 bool found_ctrl_stmt = false;
4369 /* Skip labels on the start of basic block. */
4370 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4372 tree prev_stmt = stmt;
4374 stmt = bsi_stmt (bsi);
4376 if (TREE_CODE (stmt) != LABEL_EXPR)
4379 if (prev_stmt && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
4381 error ("nonlocal label ");
4382 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4383 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4388 if (label_to_block (LABEL_EXPR_LABEL (stmt)) != bb)
4391 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4392 fprintf (stderr, " to block does not match in bb %d",
4397 if (decl_function_context (LABEL_EXPR_LABEL (stmt))
4398 != current_function_decl)
4401 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4402 fprintf (stderr, " has incorrect context in bb %d",
4408 /* Verify that body of basic block BB is free of control flow. */
4409 for (; !bsi_end_p (bsi); bsi_next (&bsi))
4411 tree stmt = bsi_stmt (bsi);
4413 if (found_ctrl_stmt)
4415 error ("control flow in the middle of basic block %d",
4420 if (stmt_ends_bb_p (stmt))
4421 found_ctrl_stmt = true;
4423 if (TREE_CODE (stmt) == LABEL_EXPR)
4426 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4427 fprintf (stderr, " in the middle of basic block %d", bb->index);
4432 bsi = bsi_last (bb);
4433 if (bsi_end_p (bsi))
4436 stmt = bsi_stmt (bsi);
4438 err |= verify_eh_edges (stmt);
4440 if (is_ctrl_stmt (stmt))
4442 FOR_EACH_EDGE (e, ei, bb->succs)
4443 if (e->flags & EDGE_FALLTHRU)
4445 error ("fallthru edge after a control statement in bb %d",
4451 if (TREE_CODE (stmt) != COND_EXPR)
4453 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4454 after anything else but if statement. */
4455 FOR_EACH_EDGE (e, ei, bb->succs)
4456 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4458 error ("true/false edge after a non-COND_EXPR in bb %d",
4464 switch (TREE_CODE (stmt))
4471 if (COND_EXPR_THEN (stmt) != NULL_TREE
4472 || COND_EXPR_ELSE (stmt) != NULL_TREE)
4474 error ("COND_EXPR with code in branches at the end of bb %d",
4479 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4481 if (!true_edge || !false_edge
4482 || !(true_edge->flags & EDGE_TRUE_VALUE)
4483 || !(false_edge->flags & EDGE_FALSE_VALUE)
4484 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4485 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4486 || EDGE_COUNT (bb->succs) >= 3)
4488 error ("wrong outgoing edge flags at end of bb %d",
4496 if (simple_goto_p (stmt))
4498 error ("explicit goto at end of bb %d", bb->index);
4503 /* FIXME. We should double check that the labels in the
4504 destination blocks have their address taken. */
4505 FOR_EACH_EDGE (e, ei, bb->succs)
4506 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4507 | EDGE_FALSE_VALUE))
4508 || !(e->flags & EDGE_ABNORMAL))
4510 error ("wrong outgoing edge flags at end of bb %d",
4518 if (!single_succ_p (bb)
4519 || (single_succ_edge (bb)->flags
4520 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4521 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4523 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4526 if (single_succ (bb) != EXIT_BLOCK_PTR)
4528 error ("return edge does not point to exit in bb %d",
4541 vec = SWITCH_LABELS (stmt);
4542 n = TREE_VEC_LENGTH (vec);
4544 /* Mark all the destination basic blocks. */
4545 for (i = 0; i < n; ++i)
4547 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4548 basic_block label_bb = label_to_block (lab);
4550 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4551 label_bb->aux = (void *)1;
4554 /* Verify that the case labels are sorted. */
4555 prev = TREE_VEC_ELT (vec, 0);
4556 for (i = 1; i < n - 1; ++i)
4558 tree c = TREE_VEC_ELT (vec, i);
4561 error ("found default case not at end of case vector");
4565 if (! tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4567 error ("case labels not sorted: ");
4568 print_generic_expr (stderr, prev, 0);
4569 fprintf (stderr," is greater than ");
4570 print_generic_expr (stderr, c, 0);
4571 fprintf (stderr," but comes before it.\n");
4576 if (CASE_LOW (TREE_VEC_ELT (vec, n - 1)))
4578 error ("no default case found at end of case vector");
4582 FOR_EACH_EDGE (e, ei, bb->succs)
4586 error ("extra outgoing edge %d->%d",
4587 bb->index, e->dest->index);
4590 e->dest->aux = (void *)2;
4591 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4592 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4594 error ("wrong outgoing edge flags at end of bb %d",
4600 /* Check that we have all of them. */
4601 for (i = 0; i < n; ++i)
4603 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4604 basic_block label_bb = label_to_block (lab);
4606 if (label_bb->aux != (void *)2)
4608 error ("missing edge %i->%i",
4609 bb->index, label_bb->index);
4614 FOR_EACH_EDGE (e, ei, bb->succs)
4615 e->dest->aux = (void *)0;
4622 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4623 verify_dominators (CDI_DOMINATORS);
4629 /* Updates phi nodes after creating a forwarder block joined
4630 by edge FALLTHRU. */
4633 tree_make_forwarder_block (edge fallthru)
4637 basic_block dummy, bb;
4638 tree phi, new_phi, var;
4640 dummy = fallthru->src;
4641 bb = fallthru->dest;
4643 if (single_pred_p (bb))
4646 /* If we redirected a branch we must create new PHI nodes at the
4648 for (phi = phi_nodes (dummy); phi; phi = PHI_CHAIN (phi))
4650 var = PHI_RESULT (phi);
4651 new_phi = create_phi_node (var, bb);
4652 SSA_NAME_DEF_STMT (var) = new_phi;
4653 SET_PHI_RESULT (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4654 add_phi_arg (new_phi, PHI_RESULT (phi), fallthru);
4657 /* Ensure that the PHI node chain is in the same order. */
4658 set_phi_nodes (bb, phi_reverse (phi_nodes (bb)));
4660 /* Add the arguments we have stored on edges. */
4661 FOR_EACH_EDGE (e, ei, bb->preds)
4666 flush_pending_stmts (e);
4671 /* Return a non-special label in the head of basic block BLOCK.
4672 Create one if it doesn't exist. */
4675 tree_block_label (basic_block bb)
4677 block_stmt_iterator i, s = bsi_start (bb);
4681 for (i = s; !bsi_end_p (i); first = false, bsi_next (&i))
4683 stmt = bsi_stmt (i);
4684 if (TREE_CODE (stmt) != LABEL_EXPR)
4686 label = LABEL_EXPR_LABEL (stmt);
4687 if (!DECL_NONLOCAL (label))
4690 bsi_move_before (&i, &s);
4695 label = create_artificial_label ();
4696 stmt = build1 (LABEL_EXPR, void_type_node, label);
4697 bsi_insert_before (&s, stmt, BSI_NEW_STMT);
4702 /* Attempt to perform edge redirection by replacing a possibly complex
4703 jump instruction by a goto or by removing the jump completely.
4704 This can apply only if all edges now point to the same block. The
4705 parameters and return values are equivalent to
4706 redirect_edge_and_branch. */
4709 tree_try_redirect_by_replacing_jump (edge e, basic_block target)
4711 basic_block src = e->src;
4712 block_stmt_iterator b;
4715 /* We can replace or remove a complex jump only when we have exactly
4717 if (EDGE_COUNT (src->succs) != 2
4718 /* Verify that all targets will be TARGET. Specifically, the
4719 edge that is not E must also go to TARGET. */
4720 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4726 stmt = bsi_stmt (b);
4728 if (TREE_CODE (stmt) == COND_EXPR
4729 || TREE_CODE (stmt) == SWITCH_EXPR)
4731 bsi_remove (&b, true);
4732 e = ssa_redirect_edge (e, target);
4733 e->flags = EDGE_FALLTHRU;
4741 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4742 edge representing the redirected branch. */
4745 tree_redirect_edge_and_branch (edge e, basic_block dest)
4747 basic_block bb = e->src;
4748 block_stmt_iterator bsi;
4752 if (e->flags & EDGE_ABNORMAL)
4755 if (e->src != ENTRY_BLOCK_PTR
4756 && (ret = tree_try_redirect_by_replacing_jump (e, dest)))
4759 if (e->dest == dest)
4762 bsi = bsi_last (bb);
4763 stmt = bsi_end_p (bsi) ? NULL : bsi_stmt (bsi);
4765 switch (stmt ? TREE_CODE (stmt) : ERROR_MARK)
4768 /* For COND_EXPR, we only need to redirect the edge. */
4772 /* No non-abnormal edges should lead from a non-simple goto, and
4773 simple ones should be represented implicitly. */
4778 tree cases = get_cases_for_edge (e, stmt);
4779 tree label = tree_block_label (dest);
4781 /* If we have a list of cases associated with E, then use it
4782 as it's a lot faster than walking the entire case vector. */
4785 edge e2 = find_edge (e->src, dest);
4792 CASE_LABEL (cases) = label;
4793 cases = TREE_CHAIN (cases);
4796 /* If there was already an edge in the CFG, then we need
4797 to move all the cases associated with E to E2. */
4800 tree cases2 = get_cases_for_edge (e2, stmt);
4802 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4803 TREE_CHAIN (cases2) = first;
4808 tree vec = SWITCH_LABELS (stmt);
4809 size_t i, n = TREE_VEC_LENGTH (vec);
4811 for (i = 0; i < n; i++)
4813 tree elt = TREE_VEC_ELT (vec, i);
4815 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4816 CASE_LABEL (elt) = label;
4824 bsi_remove (&bsi, true);
4825 e->flags |= EDGE_FALLTHRU;
4830 case OMP_SECTIONS_SWITCH:
4832 /* The edges from OMP constructs can be simply redirected. */
4836 /* Otherwise it must be a fallthru edge, and we don't need to
4837 do anything besides redirecting it. */
4838 gcc_assert (e->flags & EDGE_FALLTHRU);
4842 /* Update/insert PHI nodes as necessary. */
4844 /* Now update the edges in the CFG. */
4845 e = ssa_redirect_edge (e, dest);
4850 /* Returns true if it is possible to remove edge E by redirecting
4851 it to the destination of the other edge from E->src. */
4854 tree_can_remove_branch_p (const_edge e)
4856 if (e->flags & EDGE_ABNORMAL)
4862 /* Simple wrapper, as we can always redirect fallthru edges. */
4865 tree_redirect_edge_and_branch_force (edge e, basic_block dest)
4867 e = tree_redirect_edge_and_branch (e, dest);
4874 /* Splits basic block BB after statement STMT (but at least after the
4875 labels). If STMT is NULL, BB is split just after the labels. */
4878 tree_split_block (basic_block bb, void *stmt)
4880 block_stmt_iterator bsi;
4881 tree_stmt_iterator tsi_tgt;
4887 new_bb = create_empty_bb (bb);
4889 /* Redirect the outgoing edges. */
4890 new_bb->succs = bb->succs;
4892 FOR_EACH_EDGE (e, ei, new_bb->succs)
4895 if (stmt && TREE_CODE ((tree) stmt) == LABEL_EXPR)
4898 /* Move everything from BSI to the new basic block. */
4899 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4901 act = bsi_stmt (bsi);
4902 if (TREE_CODE (act) == LABEL_EXPR)
4915 if (bsi_end_p (bsi))
4918 /* Split the statement list - avoid re-creating new containers as this
4919 brings ugly quadratic memory consumption in the inliner.
4920 (We are still quadratic since we need to update stmt BB pointers,
4922 list = tsi_split_statement_list_before (&bsi.tsi);
4923 set_bb_stmt_list (new_bb, list);
4924 for (tsi_tgt = tsi_start (list);
4925 !tsi_end_p (tsi_tgt); tsi_next (&tsi_tgt))
4926 change_bb_for_stmt (tsi_stmt (tsi_tgt), new_bb);
4932 /* Moves basic block BB after block AFTER. */
4935 tree_move_block_after (basic_block bb, basic_block after)
4937 if (bb->prev_bb == after)
4941 link_block (bb, after);
4947 /* Return true if basic_block can be duplicated. */
4950 tree_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
4956 /* Create a duplicate of the basic block BB. NOTE: This does not
4957 preserve SSA form. */
4960 tree_duplicate_bb (basic_block bb)
4963 block_stmt_iterator bsi, bsi_tgt;
4966 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
4968 /* Copy the PHI nodes. We ignore PHI node arguments here because
4969 the incoming edges have not been setup yet. */
4970 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4972 tree copy = create_phi_node (PHI_RESULT (phi), new_bb);
4973 create_new_def_for (PHI_RESULT (copy), copy, PHI_RESULT_PTR (copy));
4976 /* Keep the chain of PHI nodes in the same order so that they can be
4977 updated by ssa_redirect_edge. */
4978 set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb)));
4980 bsi_tgt = bsi_start (new_bb);
4981 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4983 def_operand_p def_p;
4984 ssa_op_iter op_iter;
4988 stmt = bsi_stmt (bsi);
4989 if (TREE_CODE (stmt) == LABEL_EXPR)
4992 /* Create a new copy of STMT and duplicate STMT's virtual
4994 copy = unshare_expr (stmt);
4995 bsi_insert_after (&bsi_tgt, copy, BSI_NEW_STMT);
4996 copy_virtual_operands (copy, stmt);
4997 region = lookup_stmt_eh_region (stmt);
4999 add_stmt_to_eh_region (copy, region);
5000 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
5002 /* Create new names for all the definitions created by COPY and
5003 add replacement mappings for each new name. */
5004 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
5005 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
5012 /* Basic block BB_COPY was created by code duplication. Add phi node
5013 arguments for edges going out of BB_COPY. The blocks that were
5014 duplicated have BB_DUPLICATED set. */
5017 add_phi_args_after_copy_bb (basic_block bb_copy)
5019 basic_block bb, dest;
5022 tree phi, phi_copy, phi_next, def;
5024 bb = get_bb_original (bb_copy);
5026 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5028 if (!phi_nodes (e_copy->dest))
5031 if (e_copy->dest->flags & BB_DUPLICATED)
5032 dest = get_bb_original (e_copy->dest);
5034 dest = e_copy->dest;
5036 e = find_edge (bb, dest);
5039 /* During loop unrolling the target of the latch edge is copied.
5040 In this case we are not looking for edge to dest, but to
5041 duplicated block whose original was dest. */
5042 FOR_EACH_EDGE (e, ei, bb->succs)
5043 if ((e->dest->flags & BB_DUPLICATED)
5044 && get_bb_original (e->dest) == dest)
5047 gcc_assert (e != NULL);
5050 for (phi = phi_nodes (e->dest), phi_copy = phi_nodes (e_copy->dest);
5052 phi = phi_next, phi_copy = PHI_CHAIN (phi_copy))
5054 phi_next = PHI_CHAIN (phi);
5055 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5056 add_phi_arg (phi_copy, def, e_copy);
5061 /* Blocks in REGION_COPY array of length N_REGION were created by
5062 duplication of basic blocks. Add phi node arguments for edges
5063 going from these blocks. */
5066 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region)
5070 for (i = 0; i < n_region; i++)
5071 region_copy[i]->flags |= BB_DUPLICATED;
5073 for (i = 0; i < n_region; i++)
5074 add_phi_args_after_copy_bb (region_copy[i]);
5076 for (i = 0; i < n_region; i++)
5077 region_copy[i]->flags &= ~BB_DUPLICATED;
5080 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5081 important exit edge EXIT. By important we mean that no SSA name defined
5082 inside region is live over the other exit edges of the region. All entry
5083 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5084 to the duplicate of the region. SSA form, dominance and loop information
5085 is updated. The new basic blocks are stored to REGION_COPY in the same
5086 order as they had in REGION, provided that REGION_COPY is not NULL.
5087 The function returns false if it is unable to copy the region,
5091 tree_duplicate_sese_region (edge entry, edge exit,
5092 basic_block *region, unsigned n_region,
5093 basic_block *region_copy)
5096 bool free_region_copy = false, copying_header = false;
5097 struct loop *loop = entry->dest->loop_father;
5099 VEC (basic_block, heap) *doms;
5101 int total_freq = 0, entry_freq = 0;
5102 gcov_type total_count = 0, entry_count = 0;
5104 if (!can_copy_bbs_p (region, n_region))
5107 /* Some sanity checking. Note that we do not check for all possible
5108 missuses of the functions. I.e. if you ask to copy something weird,
5109 it will work, but the state of structures probably will not be
5111 for (i = 0; i < n_region; i++)
5113 /* We do not handle subloops, i.e. all the blocks must belong to the
5115 if (region[i]->loop_father != loop)
5118 if (region[i] != entry->dest
5119 && region[i] == loop->header)
5123 set_loop_copy (loop, loop);
5125 /* In case the function is used for loop header copying (which is the primary
5126 use), ensure that EXIT and its copy will be new latch and entry edges. */
5127 if (loop->header == entry->dest)
5129 copying_header = true;
5130 set_loop_copy (loop, loop_outer (loop));
5132 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5135 for (i = 0; i < n_region; i++)
5136 if (region[i] != exit->src
5137 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5143 region_copy = XNEWVEC (basic_block, n_region);
5144 free_region_copy = true;
5147 gcc_assert (!need_ssa_update_p ());
5149 /* Record blocks outside the region that are dominated by something
5152 initialize_original_copy_tables ();
5154 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5156 if (entry->dest->count)
5158 total_count = entry->dest->count;
5159 entry_count = entry->count;
5160 /* Fix up corner cases, to avoid division by zero or creation of negative
5162 if (entry_count > total_count)
5163 entry_count = total_count;
5167 total_freq = entry->dest->frequency;
5168 entry_freq = EDGE_FREQUENCY (entry);
5169 /* Fix up corner cases, to avoid division by zero or creation of negative
5171 if (total_freq == 0)
5173 else if (entry_freq > total_freq)
5174 entry_freq = total_freq;
5177 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5178 split_edge_bb_loc (entry));
5181 scale_bbs_frequencies_gcov_type (region, n_region,
5182 total_count - entry_count,
5184 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5189 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5191 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5196 loop->header = exit->dest;
5197 loop->latch = exit->src;
5200 /* Redirect the entry and add the phi node arguments. */
5201 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5202 gcc_assert (redirected != NULL);
5203 flush_pending_stmts (entry);
5205 /* Concerning updating of dominators: We must recount dominators
5206 for entry block and its copy. Anything that is outside of the
5207 region, but was dominated by something inside needs recounting as
5209 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5210 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5211 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5214 /* Add the other PHI node arguments. */
5215 add_phi_args_after_copy (region_copy, n_region);
5217 /* Update the SSA web. */
5218 update_ssa (TODO_update_ssa);
5220 if (free_region_copy)
5223 free_original_copy_tables ();
5228 DEF_VEC_P(basic_block);
5229 DEF_VEC_ALLOC_P(basic_block,heap);
5232 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5233 adding blocks when the dominator traversal reaches EXIT. This
5234 function silently assumes that ENTRY strictly dominates EXIT. */
5237 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5238 VEC(basic_block,heap) **bbs_p)
5242 for (son = first_dom_son (CDI_DOMINATORS, entry);
5244 son = next_dom_son (CDI_DOMINATORS, son))
5246 VEC_safe_push (basic_block, heap, *bbs_p, son);
5248 gather_blocks_in_sese_region (son, exit, bbs_p);
5252 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5253 The duplicates are recorded in VARS_MAP. */
5256 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5259 tree t = *tp, new_t;
5260 struct function *f = DECL_STRUCT_FUNCTION (to_context);
5263 if (DECL_CONTEXT (t) == to_context)
5266 loc = pointer_map_contains (vars_map, t);
5270 loc = pointer_map_insert (vars_map, t);
5274 new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5275 f->unexpanded_var_list
5276 = tree_cons (NULL_TREE, new_t, f->unexpanded_var_list);
5280 gcc_assert (TREE_CODE (t) == CONST_DECL);
5281 new_t = copy_node (t);
5283 DECL_CONTEXT (new_t) = to_context;
5293 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5294 VARS_MAP maps old ssa names and var_decls to the new ones. */
5297 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5301 tree new_name, decl = SSA_NAME_VAR (name);
5303 gcc_assert (is_gimple_reg (name));
5305 loc = pointer_map_contains (vars_map, name);
5309 replace_by_duplicate_decl (&decl, vars_map, to_context);
5311 push_cfun (DECL_STRUCT_FUNCTION (to_context));
5312 if (gimple_in_ssa_p (cfun))
5313 add_referenced_var (decl);
5315 new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5316 if (SSA_NAME_IS_DEFAULT_DEF (name))
5317 set_default_def (decl, new_name);
5320 loc = pointer_map_insert (vars_map, name);
5334 struct pointer_map_t *vars_map;
5335 htab_t new_label_map;
5339 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5340 contained in *TP and change the DECL_CONTEXT of every local
5341 variable referenced in *TP. */
5344 move_stmt_r (tree *tp, int *walk_subtrees, void *data)
5346 struct move_stmt_d *p = (struct move_stmt_d *) data;
5350 && (EXPR_P (t) || GIMPLE_STMT_P (t)))
5351 TREE_BLOCK (t) = p->block;
5353 if (OMP_DIRECTIVE_P (t)
5354 && TREE_CODE (t) != OMP_RETURN
5355 && TREE_CODE (t) != OMP_CONTINUE)
5357 /* Do not remap variables inside OMP directives. Variables
5358 referenced in clauses and directive header belong to the
5359 parent function and should not be moved into the child
5361 bool save_remap_decls_p = p->remap_decls_p;
5362 p->remap_decls_p = false;
5365 walk_tree (&OMP_BODY (t), move_stmt_r, p, NULL);
5367 p->remap_decls_p = save_remap_decls_p;
5369 else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5371 if (TREE_CODE (t) == SSA_NAME)
5372 *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5373 else if (TREE_CODE (t) == LABEL_DECL)
5375 if (p->new_label_map)
5377 struct tree_map in, *out;
5379 out = htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5384 DECL_CONTEXT (t) = p->to_context;
5386 else if (p->remap_decls_p)
5388 /* Replace T with its duplicate. T should no longer appear in the
5389 parent function, so this looks wasteful; however, it may appear
5390 in referenced_vars, and more importantly, as virtual operands of
5391 statements, and in alias lists of other variables. It would be
5392 quite difficult to expunge it from all those places. ??? It might
5393 suffice to do this for addressable variables. */
5394 if ((TREE_CODE (t) == VAR_DECL
5395 && !is_global_var (t))
5396 || TREE_CODE (t) == CONST_DECL)
5397 replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5400 && gimple_in_ssa_p (cfun))
5402 push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5403 add_referenced_var (*tp);
5409 else if (TYPE_P (t))
5415 /* Marks virtual operands of all statements in basic blocks BBS for
5419 mark_virtual_ops_in_region (VEC (basic_block,heap) *bbs)
5422 block_stmt_iterator bsi;
5426 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5428 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5429 mark_virtual_ops_for_renaming (phi);
5431 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5432 mark_virtual_ops_for_renaming (bsi_stmt (bsi));
5436 /* Move basic block BB from function CFUN to function DEST_FN. The
5437 block is moved out of the original linked list and placed after
5438 block AFTER in the new list. Also, the block is removed from the
5439 original array of blocks and placed in DEST_FN's array of blocks.
5440 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5441 updated to reflect the moved edges.
5443 The local variables are remapped to new instances, VARS_MAP is used
5444 to record the mapping. */
5447 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5448 basic_block after, bool update_edge_count_p,
5449 struct pointer_map_t *vars_map, htab_t new_label_map,
5452 struct control_flow_graph *cfg;
5455 block_stmt_iterator si;
5456 struct move_stmt_d d;
5457 unsigned old_len, new_len;
5460 /* Remove BB from dominance structures. */
5461 delete_from_dominance_info (CDI_DOMINATORS, bb);
5463 /* Link BB to the new linked list. */
5464 move_block_after (bb, after);
5466 /* Update the edge count in the corresponding flowgraphs. */
5467 if (update_edge_count_p)
5468 FOR_EACH_EDGE (e, ei, bb->succs)
5470 cfun->cfg->x_n_edges--;
5471 dest_cfun->cfg->x_n_edges++;
5474 /* Remove BB from the original basic block array. */
5475 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5476 cfun->cfg->x_n_basic_blocks--;
5478 /* Grow DEST_CFUN's basic block array if needed. */
5479 cfg = dest_cfun->cfg;
5480 cfg->x_n_basic_blocks++;
5481 if (bb->index >= cfg->x_last_basic_block)
5482 cfg->x_last_basic_block = bb->index + 1;
5484 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5485 if ((unsigned) cfg->x_last_basic_block >= old_len)
5487 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5488 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5492 VEC_replace (basic_block, cfg->x_basic_block_info,
5495 /* Remap the variables in phi nodes. */
5496 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5499 tree op = PHI_RESULT (phi);
5502 if (!is_gimple_reg (op))
5505 SET_PHI_RESULT (phi, replace_ssa_name (op, vars_map, dest_cfun->decl));
5506 FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5508 op = USE_FROM_PTR (use);
5509 if (TREE_CODE (op) == SSA_NAME)
5510 SET_USE (use, replace_ssa_name (op, vars_map, dest_cfun->decl));
5514 /* The statements in BB need to be associated with a new TREE_BLOCK.
5515 Labels need to be associated with a new label-to-block map. */
5516 memset (&d, 0, sizeof (d));
5517 d.vars_map = vars_map;
5518 d.from_context = cfun->decl;
5519 d.to_context = dest_cfun->decl;
5520 d.new_label_map = new_label_map;
5522 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5524 tree stmt = bsi_stmt (si);
5527 d.remap_decls_p = true;
5528 if (TREE_BLOCK (stmt))
5529 d.block = DECL_INITIAL (dest_cfun->decl);
5531 walk_tree (&stmt, move_stmt_r, &d, NULL);
5533 if (TREE_CODE (stmt) == LABEL_EXPR)
5535 tree label = LABEL_EXPR_LABEL (stmt);
5536 int uid = LABEL_DECL_UID (label);
5538 gcc_assert (uid > -1);
5540 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5541 if (old_len <= (unsigned) uid)
5543 new_len = 3 * uid / 2;
5544 VEC_safe_grow_cleared (basic_block, gc,
5545 cfg->x_label_to_block_map, new_len);
5548 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5549 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5551 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5553 if (uid >= dest_cfun->last_label_uid)
5554 dest_cfun->last_label_uid = uid + 1;
5556 else if (TREE_CODE (stmt) == RESX_EXPR && eh_offset != 0)
5557 TREE_OPERAND (stmt, 0) =
5558 build_int_cst (NULL_TREE,
5559 TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0))
5562 region = lookup_stmt_eh_region (stmt);
5565 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5566 remove_stmt_from_eh_region (stmt);
5567 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5568 gimple_remove_stmt_histograms (cfun, stmt);
5575 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5576 the outermost EH region. Use REGION as the incoming base EH region. */
5579 find_outermost_region_in_block (struct function *src_cfun,
5580 basic_block bb, int region)
5582 block_stmt_iterator si;
5584 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5586 tree stmt = bsi_stmt (si);
5589 if (TREE_CODE (stmt) == RESX_EXPR)
5590 stmt_region = TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0));
5592 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5593 if (stmt_region > 0)
5596 region = stmt_region;
5597 else if (stmt_region != region)
5599 region = eh_region_outermost (src_cfun, stmt_region, region);
5600 gcc_assert (region != -1);
5609 new_label_mapper (tree decl, void *data)
5611 htab_t hash = (htab_t) data;
5615 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5617 m = xmalloc (sizeof (struct tree_map));
5618 m->hash = DECL_UID (decl);
5619 m->base.from = decl;
5620 m->to = create_artificial_label ();
5621 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5623 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5624 gcc_assert (*slot == NULL);
5631 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5632 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5633 single basic block in the original CFG and the new basic block is
5634 returned. DEST_CFUN must not have a CFG yet.
5636 Note that the region need not be a pure SESE region. Blocks inside
5637 the region may contain calls to abort/exit. The only restriction
5638 is that ENTRY_BB should be the only entry point and it must
5641 All local variables referenced in the region are assumed to be in
5642 the corresponding BLOCK_VARS and unexpanded variable lists
5643 associated with DEST_CFUN. */
5646 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5647 basic_block exit_bb)
5649 VEC(basic_block,heap) *bbs, *dom_bbs;
5650 basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
5651 basic_block after, bb, *entry_pred, *exit_succ, abb;
5652 struct function *saved_cfun = cfun;
5653 int *entry_flag, *exit_flag, eh_offset;
5654 unsigned *entry_prob, *exit_prob;
5655 unsigned i, num_entry_edges, num_exit_edges;
5658 htab_t new_label_map;
5659 struct pointer_map_t *vars_map;
5661 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5663 gcc_assert (entry_bb != exit_bb
5665 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
5667 /* Collect all the blocks in the region. Manually add ENTRY_BB
5668 because it won't be added by dfs_enumerate_from. */
5670 VEC_safe_push (basic_block, heap, bbs, entry_bb);
5671 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
5673 /* The blocks that used to be dominated by something in BBS will now be
5674 dominated by the new block. */
5675 dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
5676 VEC_address (basic_block, bbs),
5677 VEC_length (basic_block, bbs));
5679 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5680 the predecessor edges to ENTRY_BB and the successor edges to
5681 EXIT_BB so that we can re-attach them to the new basic block that
5682 will replace the region. */
5683 num_entry_edges = EDGE_COUNT (entry_bb->preds);
5684 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
5685 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
5686 entry_prob = XNEWVEC (unsigned, num_entry_edges);
5688 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
5690 entry_prob[i] = e->probability;
5691 entry_flag[i] = e->flags;
5692 entry_pred[i++] = e->src;
5698 num_exit_edges = EDGE_COUNT (exit_bb->succs);
5699 exit_succ = (basic_block *) xcalloc (num_exit_edges,
5700 sizeof (basic_block));
5701 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
5702 exit_prob = XNEWVEC (unsigned, num_exit_edges);
5704 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
5706 exit_prob[i] = e->probability;
5707 exit_flag[i] = e->flags;
5708 exit_succ[i++] = e->dest;
5720 /* Switch context to the child function to initialize DEST_FN's CFG. */
5721 gcc_assert (dest_cfun->cfg == NULL);
5722 push_cfun (dest_cfun);
5724 init_empty_tree_cfg ();
5726 /* Initialize EH information for the new function. */
5728 new_label_map = NULL;
5733 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5734 region = find_outermost_region_in_block (saved_cfun, bb, region);
5736 init_eh_for_function ();
5739 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
5740 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
5741 new_label_map, region, 0);
5747 /* The ssa form for virtual operands in the source function will have to
5748 be repaired. We do not care for the real operands -- the sese region
5749 must be closed with respect to those. */
5750 mark_virtual_ops_in_region (bbs);
5752 /* Move blocks from BBS into DEST_CFUN. */
5753 gcc_assert (VEC_length (basic_block, bbs) >= 2);
5754 after = dest_cfun->cfg->x_entry_block_ptr;
5755 vars_map = pointer_map_create ();
5756 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5758 /* No need to update edge counts on the last block. It has
5759 already been updated earlier when we detached the region from
5760 the original CFG. */
5761 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, vars_map,
5762 new_label_map, eh_offset);
5767 htab_delete (new_label_map);
5768 pointer_map_destroy (vars_map);
5770 /* Rewire the entry and exit blocks. The successor to the entry
5771 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
5772 the child function. Similarly, the predecessor of DEST_FN's
5773 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
5774 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
5775 various CFG manipulation function get to the right CFG.
5777 FIXME, this is silly. The CFG ought to become a parameter to
5779 push_cfun (dest_cfun);
5780 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
5782 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
5785 /* Back in the original function, the SESE region has disappeared,
5786 create a new basic block in its place. */
5787 bb = create_empty_bb (entry_pred[0]);
5788 for (i = 0; i < num_entry_edges; i++)
5790 e = make_edge (entry_pred[i], bb, entry_flag[i]);
5791 e->probability = entry_prob[i];
5794 for (i = 0; i < num_exit_edges; i++)
5796 e = make_edge (bb, exit_succ[i], exit_flag[i]);
5797 e->probability = exit_prob[i];
5800 set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
5801 for (i = 0; VEC_iterate (basic_block, dom_bbs, i, abb); i++)
5802 set_immediate_dominator (CDI_DOMINATORS, abb, bb);
5803 VEC_free (basic_block, heap, dom_bbs);
5814 VEC_free (basic_block, heap, bbs);
5820 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */
5823 dump_function_to_file (tree fn, FILE *file, int flags)
5825 tree arg, vars, var;
5826 struct function *dsf;
5827 bool ignore_topmost_bind = false, any_var = false;
5831 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
5833 arg = DECL_ARGUMENTS (fn);
5836 print_generic_expr (file, arg, dump_flags);
5837 if (TREE_CHAIN (arg))
5838 fprintf (file, ", ");
5839 arg = TREE_CHAIN (arg);
5841 fprintf (file, ")\n");
5843 dsf = DECL_STRUCT_FUNCTION (fn);
5844 if (dsf && (flags & TDF_DETAILS))
5845 dump_eh_tree (file, dsf);
5847 if (flags & TDF_RAW)
5849 dump_node (fn, TDF_SLIM | flags, file);
5853 /* Switch CFUN to point to FN. */
5854 push_cfun (DECL_STRUCT_FUNCTION (fn));
5856 /* When GIMPLE is lowered, the variables are no longer available in
5857 BIND_EXPRs, so display them separately. */
5858 if (cfun && cfun->decl == fn && cfun->unexpanded_var_list)
5860 ignore_topmost_bind = true;
5862 fprintf (file, "{\n");
5863 for (vars = cfun->unexpanded_var_list; vars; vars = TREE_CHAIN (vars))
5865 var = TREE_VALUE (vars);
5867 print_generic_decl (file, var, flags);
5868 fprintf (file, "\n");
5874 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
5876 /* Make a CFG based dump. */
5877 check_bb_profile (ENTRY_BLOCK_PTR, file);
5878 if (!ignore_topmost_bind)
5879 fprintf (file, "{\n");
5881 if (any_var && n_basic_blocks)
5882 fprintf (file, "\n");
5885 dump_generic_bb (file, bb, 2, flags);
5887 fprintf (file, "}\n");
5888 check_bb_profile (EXIT_BLOCK_PTR, file);
5894 /* Make a tree based dump. */
5895 chain = DECL_SAVED_TREE (fn);
5897 if (chain && TREE_CODE (chain) == BIND_EXPR)
5899 if (ignore_topmost_bind)
5901 chain = BIND_EXPR_BODY (chain);
5909 if (!ignore_topmost_bind)
5910 fprintf (file, "{\n");
5915 fprintf (file, "\n");
5917 print_generic_stmt_indented (file, chain, flags, indent);
5918 if (ignore_topmost_bind)
5919 fprintf (file, "}\n");
5922 fprintf (file, "\n\n");
5929 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
5932 debug_function (tree fn, int flags)
5934 dump_function_to_file (fn, stderr, flags);
5938 /* Pretty print of the loops intermediate representation. */
5939 static void print_loop (FILE *, struct loop *, int);
5940 static void print_pred_bbs (FILE *, basic_block bb);
5941 static void print_succ_bbs (FILE *, basic_block bb);
5944 /* Print on FILE the indexes for the predecessors of basic_block BB. */
5947 print_pred_bbs (FILE *file, basic_block bb)
5952 FOR_EACH_EDGE (e, ei, bb->preds)
5953 fprintf (file, "bb_%d ", e->src->index);
5957 /* Print on FILE the indexes for the successors of basic_block BB. */
5960 print_succ_bbs (FILE *file, basic_block bb)
5965 FOR_EACH_EDGE (e, ei, bb->succs)
5966 fprintf (file, "bb_%d ", e->dest->index);
5970 /* Pretty print LOOP on FILE, indented INDENT spaces. */
5973 print_loop (FILE *file, struct loop *loop, int indent)
5981 s_indent = (char *) alloca ((size_t) indent + 1);
5982 memset ((void *) s_indent, ' ', (size_t) indent);
5983 s_indent[indent] = '\0';
5985 /* Print the loop's header. */
5986 fprintf (file, "%sloop_%d\n", s_indent, loop->num);
5988 /* Print the loop's body. */
5989 fprintf (file, "%s{\n", s_indent);
5991 if (bb->loop_father == loop)
5993 /* Print the basic_block's header. */
5994 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
5995 print_pred_bbs (file, bb);
5996 fprintf (file, "}, succs = {");
5997 print_succ_bbs (file, bb);
5998 fprintf (file, "})\n");
6000 /* Print the basic_block's body. */
6001 fprintf (file, "%s {\n", s_indent);
6002 tree_dump_bb (bb, file, indent + 4);
6003 fprintf (file, "%s }\n", s_indent);
6006 print_loop (file, loop->inner, indent + 2);
6007 fprintf (file, "%s}\n", s_indent);
6008 print_loop (file, loop->next, indent);
6012 /* Follow a CFG edge from the entry point of the program, and on entry
6013 of a loop, pretty print the loop structure on FILE. */
6016 print_loop_ir (FILE *file)
6020 bb = BASIC_BLOCK (NUM_FIXED_BLOCKS);
6021 if (bb && bb->loop_father)
6022 print_loop (file, bb->loop_father, 0);
6026 /* Debugging loops structure at tree level. */
6029 debug_loop_ir (void)
6031 print_loop_ir (stderr);
6035 /* Return true if BB ends with a call, possibly followed by some
6036 instructions that must stay with the call. Return false,
6040 tree_block_ends_with_call_p (basic_block bb)
6042 block_stmt_iterator bsi = bsi_last (bb);
6043 return const_get_call_expr_in (bsi_stmt (bsi)) != NULL;
6047 /* Return true if BB ends with a conditional branch. Return false,
6051 tree_block_ends_with_condjump_p (const_basic_block bb)
6053 /* This CONST_CAST is okay because last_stmt doesn't modify its
6054 argument and the return value is not modified. */
6055 const_tree stmt = last_stmt (CONST_CAST_BB(bb));
6056 return (stmt && TREE_CODE (stmt) == COND_EXPR);
6060 /* Return true if we need to add fake edge to exit at statement T.
6061 Helper function for tree_flow_call_edges_add. */
6064 need_fake_edge_p (tree t)
6068 /* NORETURN and LONGJMP calls already have an edge to exit.
6069 CONST and PURE calls do not need one.
6070 We don't currently check for CONST and PURE here, although
6071 it would be a good idea, because those attributes are
6072 figured out from the RTL in mark_constant_function, and
6073 the counter incrementation code from -fprofile-arcs
6074 leads to different results from -fbranch-probabilities. */
6075 call = get_call_expr_in (t);
6077 && !(call_expr_flags (call) & ECF_NORETURN))
6080 if (TREE_CODE (t) == ASM_EXPR
6081 && (ASM_VOLATILE_P (t) || ASM_INPUT_P (t)))
6088 /* Add fake edges to the function exit for any non constant and non
6089 noreturn calls, volatile inline assembly in the bitmap of blocks
6090 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
6091 the number of blocks that were split.
6093 The goal is to expose cases in which entering a basic block does
6094 not imply that all subsequent instructions must be executed. */
6097 tree_flow_call_edges_add (sbitmap blocks)
6100 int blocks_split = 0;
6101 int last_bb = last_basic_block;
6102 bool check_last_block = false;
6104 if (n_basic_blocks == NUM_FIXED_BLOCKS)
6108 check_last_block = true;
6110 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6112 /* In the last basic block, before epilogue generation, there will be
6113 a fallthru edge to EXIT. Special care is required if the last insn
6114 of the last basic block is a call because make_edge folds duplicate
6115 edges, which would result in the fallthru edge also being marked
6116 fake, which would result in the fallthru edge being removed by
6117 remove_fake_edges, which would result in an invalid CFG.
6119 Moreover, we can't elide the outgoing fake edge, since the block
6120 profiler needs to take this into account in order to solve the minimal
6121 spanning tree in the case that the call doesn't return.
6123 Handle this by adding a dummy instruction in a new last basic block. */
6124 if (check_last_block)
6126 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6127 block_stmt_iterator bsi = bsi_last (bb);
6129 if (!bsi_end_p (bsi))
6132 if (t && need_fake_edge_p (t))
6136 e = find_edge (bb, EXIT_BLOCK_PTR);
6139 bsi_insert_on_edge (e, build_empty_stmt ());
6140 bsi_commit_edge_inserts ();
6145 /* Now add fake edges to the function exit for any non constant
6146 calls since there is no way that we can determine if they will
6148 for (i = 0; i < last_bb; i++)
6150 basic_block bb = BASIC_BLOCK (i);
6151 block_stmt_iterator bsi;
6152 tree stmt, last_stmt;
6157 if (blocks && !TEST_BIT (blocks, i))
6160 bsi = bsi_last (bb);
6161 if (!bsi_end_p (bsi))
6163 last_stmt = bsi_stmt (bsi);
6166 stmt = bsi_stmt (bsi);
6167 if (need_fake_edge_p (stmt))
6170 /* The handling above of the final block before the
6171 epilogue should be enough to verify that there is
6172 no edge to the exit block in CFG already.
6173 Calling make_edge in such case would cause us to
6174 mark that edge as fake and remove it later. */
6175 #ifdef ENABLE_CHECKING
6176 if (stmt == last_stmt)
6178 e = find_edge (bb, EXIT_BLOCK_PTR);
6179 gcc_assert (e == NULL);
6183 /* Note that the following may create a new basic block
6184 and renumber the existing basic blocks. */
6185 if (stmt != last_stmt)
6187 e = split_block (bb, stmt);
6191 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6195 while (!bsi_end_p (bsi));
6200 verify_flow_info ();
6202 return blocks_split;
6205 /* Purge dead abnormal call edges from basic block BB. */
6208 tree_purge_dead_abnormal_call_edges (basic_block bb)
6210 bool changed = tree_purge_dead_eh_edges (bb);
6212 if (current_function_has_nonlocal_label)
6214 tree stmt = last_stmt (bb);
6218 if (!(stmt && tree_can_make_abnormal_goto (stmt)))
6219 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6221 if (e->flags & EDGE_ABNORMAL)
6230 /* See tree_purge_dead_eh_edges below. */
6232 free_dominance_info (CDI_DOMINATORS);
6238 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6241 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6245 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6246 for (son = first_dom_son (CDI_DOMINATORS, bb);
6248 son = next_dom_son (CDI_DOMINATORS, son))
6249 get_all_dominated_blocks (son, dom_bbs);
6252 /* Removes edge E and all the blocks dominated by it, and updates dominance
6253 information. The IL in E->src needs to be updated separately.
6254 If dominance info is not available, only the edge E is removed.*/
6257 remove_edge_and_dominated_blocks (edge e)
6259 VEC (basic_block, heap) *bbs_to_remove = NULL;
6260 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6264 bool none_removed = false;
6266 basic_block bb, dbb;
6269 if (!dom_info_available_p (CDI_DOMINATORS))
6275 /* No updating is needed for edges to exit. */
6276 if (e->dest == EXIT_BLOCK_PTR)
6278 if (cfgcleanup_altered_bbs)
6279 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6284 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6285 that is not dominated by E->dest, then this set is empty. Otherwise,
6286 all the basic blocks dominated by E->dest are removed.
6288 Also, to DF_IDOM we store the immediate dominators of the blocks in
6289 the dominance frontier of E (i.e., of the successors of the
6290 removed blocks, if there are any, and of E->dest otherwise). */
6291 FOR_EACH_EDGE (f, ei, e->dest->preds)
6296 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6298 none_removed = true;
6303 df = BITMAP_ALLOC (NULL);
6304 df_idom = BITMAP_ALLOC (NULL);
6307 bitmap_set_bit (df_idom,
6308 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6311 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6312 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6314 FOR_EACH_EDGE (f, ei, bb->succs)
6316 if (f->dest != EXIT_BLOCK_PTR)
6317 bitmap_set_bit (df, f->dest->index);
6320 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6321 bitmap_clear_bit (df, bb->index);
6323 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6325 bb = BASIC_BLOCK (i);
6326 bitmap_set_bit (df_idom,
6327 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6331 if (cfgcleanup_altered_bbs)
6333 /* Record the set of the altered basic blocks. */
6334 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6335 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6338 /* Remove E and the cancelled blocks. */
6343 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6344 delete_basic_block (bb);
6347 /* Update the dominance information. The immediate dominator may change only
6348 for blocks whose immediate dominator belongs to DF_IDOM:
6350 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6351 removal. Let Z the arbitrary block such that idom(Z) = Y and
6352 Z dominates X after the removal. Before removal, there exists a path P
6353 from Y to X that avoids Z. Let F be the last edge on P that is
6354 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6355 dominates W, and because of P, Z does not dominate W), and W belongs to
6356 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6357 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6359 bb = BASIC_BLOCK (i);
6360 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6362 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6363 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6366 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6369 BITMAP_FREE (df_idom);
6370 VEC_free (basic_block, heap, bbs_to_remove);
6371 VEC_free (basic_block, heap, bbs_to_fix_dom);
6374 /* Purge dead EH edges from basic block BB. */
6377 tree_purge_dead_eh_edges (basic_block bb)
6379 bool changed = false;
6382 tree stmt = last_stmt (bb);
6384 if (stmt && tree_can_throw_internal (stmt))
6387 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6389 if (e->flags & EDGE_EH)
6391 remove_edge_and_dominated_blocks (e);
6402 tree_purge_all_dead_eh_edges (const_bitmap blocks)
6404 bool changed = false;
6408 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6410 changed |= tree_purge_dead_eh_edges (BASIC_BLOCK (i));
6416 /* This function is called whenever a new edge is created or
6420 tree_execute_on_growing_pred (edge e)
6422 basic_block bb = e->dest;
6425 reserve_phi_args_for_new_edge (bb);
6428 /* This function is called immediately before edge E is removed from
6429 the edge vector E->dest->preds. */
6432 tree_execute_on_shrinking_pred (edge e)
6434 if (phi_nodes (e->dest))
6435 remove_phi_args (e);
6438 /*---------------------------------------------------------------------------
6439 Helper functions for Loop versioning
6440 ---------------------------------------------------------------------------*/
6442 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6443 of 'first'. Both of them are dominated by 'new_head' basic block. When
6444 'new_head' was created by 'second's incoming edge it received phi arguments
6445 on the edge by split_edge(). Later, additional edge 'e' was created to
6446 connect 'new_head' and 'first'. Now this routine adds phi args on this
6447 additional edge 'e' that new_head to second edge received as part of edge
6452 tree_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6453 basic_block new_head, edge e)
6456 edge e2 = find_edge (new_head, second);
6458 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6459 edge, we should always have an edge from NEW_HEAD to SECOND. */
6460 gcc_assert (e2 != NULL);
6462 /* Browse all 'second' basic block phi nodes and add phi args to
6463 edge 'e' for 'first' head. PHI args are always in correct order. */
6465 for (phi2 = phi_nodes (second), phi1 = phi_nodes (first);
6467 phi2 = PHI_CHAIN (phi2), phi1 = PHI_CHAIN (phi1))
6469 tree def = PHI_ARG_DEF (phi2, e2->dest_idx);
6470 add_phi_arg (phi1, def, e);
6474 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6475 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6476 the destination of the ELSE part. */
6478 tree_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6479 basic_block second_head ATTRIBUTE_UNUSED,
6480 basic_block cond_bb, void *cond_e)
6482 block_stmt_iterator bsi;
6483 tree new_cond_expr = NULL_TREE;
6484 tree cond_expr = (tree) cond_e;
6487 /* Build new conditional expr */
6488 new_cond_expr = build3 (COND_EXPR, void_type_node, cond_expr,
6489 NULL_TREE, NULL_TREE);
6491 /* Add new cond in cond_bb. */
6492 bsi = bsi_start (cond_bb);
6493 bsi_insert_after (&bsi, new_cond_expr, BSI_NEW_STMT);
6494 /* Adjust edges appropriately to connect new head with first head
6495 as well as second head. */
6496 e0 = single_succ_edge (cond_bb);
6497 e0->flags &= ~EDGE_FALLTHRU;
6498 e0->flags |= EDGE_FALSE_VALUE;
6501 struct cfg_hooks tree_cfg_hooks = {
6503 tree_verify_flow_info,
6504 tree_dump_bb, /* dump_bb */
6505 create_bb, /* create_basic_block */
6506 tree_redirect_edge_and_branch,/* redirect_edge_and_branch */
6507 tree_redirect_edge_and_branch_force,/* redirect_edge_and_branch_force */
6508 tree_can_remove_branch_p, /* can_remove_branch_p */
6509 remove_bb, /* delete_basic_block */
6510 tree_split_block, /* split_block */
6511 tree_move_block_after, /* move_block_after */
6512 tree_can_merge_blocks_p, /* can_merge_blocks_p */
6513 tree_merge_blocks, /* merge_blocks */
6514 tree_predict_edge, /* predict_edge */
6515 tree_predicted_by_p, /* predicted_by_p */
6516 tree_can_duplicate_bb_p, /* can_duplicate_block_p */
6517 tree_duplicate_bb, /* duplicate_block */
6518 tree_split_edge, /* split_edge */
6519 tree_make_forwarder_block, /* make_forward_block */
6520 NULL, /* tidy_fallthru_edge */
6521 tree_block_ends_with_call_p, /* block_ends_with_call_p */
6522 tree_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6523 tree_flow_call_edges_add, /* flow_call_edges_add */
6524 tree_execute_on_growing_pred, /* execute_on_growing_pred */
6525 tree_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6526 tree_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6527 tree_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6528 tree_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6529 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6530 flush_pending_stmts /* flush_pending_stmts */
6534 /* Split all critical edges. */
6537 split_critical_edges (void)
6543 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6544 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6545 mappings around the calls to split_edge. */
6546 start_recording_case_labels ();
6549 FOR_EACH_EDGE (e, ei, bb->succs)
6550 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6555 end_recording_case_labels ();
6559 struct tree_opt_pass pass_split_crit_edges =
6561 "crited", /* name */
6563 split_critical_edges, /* execute */
6566 0, /* static_pass_number */
6567 TV_TREE_SPLIT_EDGES, /* tv_id */
6568 PROP_cfg, /* properties required */
6569 PROP_no_crit_edges, /* properties_provided */
6570 0, /* properties_destroyed */
6571 0, /* todo_flags_start */
6572 TODO_dump_func, /* todo_flags_finish */
6577 /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into
6578 a temporary, make sure and register it to be renamed if necessary,
6579 and finally return the temporary. Put the statements to compute
6580 EXP before the current statement in BSI. */
6583 gimplify_val (block_stmt_iterator *bsi, tree type, tree exp)
6585 tree t, new_stmt, orig_stmt;
6587 if (is_gimple_val (exp))
6590 t = make_rename_temp (type, NULL);
6591 new_stmt = build_gimple_modify_stmt (t, exp);
6593 orig_stmt = bsi_stmt (*bsi);
6594 SET_EXPR_LOCUS (new_stmt, EXPR_LOCUS (orig_stmt));
6595 TREE_BLOCK (new_stmt) = TREE_BLOCK (orig_stmt);
6597 bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
6598 if (gimple_in_ssa_p (cfun))
6599 mark_symbols_for_renaming (new_stmt);
6604 /* Build a ternary operation and gimplify it. Emit code before BSI.
6605 Return the gimple_val holding the result. */
6608 gimplify_build3 (block_stmt_iterator *bsi, enum tree_code code,
6609 tree type, tree a, tree b, tree c)
6613 ret = fold_build3 (code, type, a, b, c);
6616 return gimplify_val (bsi, type, ret);
6619 /* Build a binary operation and gimplify it. Emit code before BSI.
6620 Return the gimple_val holding the result. */
6623 gimplify_build2 (block_stmt_iterator *bsi, enum tree_code code,
6624 tree type, tree a, tree b)
6628 ret = fold_build2 (code, type, a, b);
6631 return gimplify_val (bsi, type, ret);
6634 /* Build a unary operation and gimplify it. Emit code before BSI.
6635 Return the gimple_val holding the result. */
6638 gimplify_build1 (block_stmt_iterator *bsi, enum tree_code code, tree type,
6643 ret = fold_build1 (code, type, a);
6646 return gimplify_val (bsi, type, ret);
6651 /* Emit return warnings. */
6654 execute_warn_function_return (void)
6656 #ifdef USE_MAPPED_LOCATION
6657 source_location location;
6665 /* If we have a path to EXIT, then we do return. */
6666 if (TREE_THIS_VOLATILE (cfun->decl)
6667 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
6669 #ifdef USE_MAPPED_LOCATION
6670 location = UNKNOWN_LOCATION;
6674 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6676 last = last_stmt (e->src);
6677 if (TREE_CODE (last) == RETURN_EXPR
6678 #ifdef USE_MAPPED_LOCATION
6679 && (location = EXPR_LOCATION (last)) != UNKNOWN_LOCATION)
6681 && (locus = EXPR_LOCUS (last)) != NULL)
6685 #ifdef USE_MAPPED_LOCATION
6686 if (location == UNKNOWN_LOCATION)
6687 location = cfun->function_end_locus;
6688 warning (0, "%H%<noreturn%> function does return", &location);
6691 locus = &cfun->function_end_locus;
6692 warning (0, "%H%<noreturn%> function does return", locus);
6696 /* If we see "return;" in some basic block, then we do reach the end
6697 without returning a value. */
6698 else if (warn_return_type
6699 && !TREE_NO_WARNING (cfun->decl)
6700 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
6701 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
6703 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6705 tree last = last_stmt (e->src);
6706 if (TREE_CODE (last) == RETURN_EXPR
6707 && TREE_OPERAND (last, 0) == NULL
6708 && !TREE_NO_WARNING (last))
6710 #ifdef USE_MAPPED_LOCATION
6711 location = EXPR_LOCATION (last);
6712 if (location == UNKNOWN_LOCATION)
6713 location = cfun->function_end_locus;
6714 warning (0, "%Hcontrol reaches end of non-void function", &location);
6716 locus = EXPR_LOCUS (last);
6718 locus = &cfun->function_end_locus;
6719 warning (0, "%Hcontrol reaches end of non-void function", locus);
6721 TREE_NO_WARNING (cfun->decl) = 1;
6730 /* Given a basic block B which ends with a conditional and has
6731 precisely two successors, determine which of the edges is taken if
6732 the conditional is true and which is taken if the conditional is
6733 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
6736 extract_true_false_edges_from_block (basic_block b,
6740 edge e = EDGE_SUCC (b, 0);
6742 if (e->flags & EDGE_TRUE_VALUE)
6745 *false_edge = EDGE_SUCC (b, 1);
6750 *true_edge = EDGE_SUCC (b, 1);
6754 struct tree_opt_pass pass_warn_function_return =
6758 execute_warn_function_return, /* execute */
6761 0, /* static_pass_number */
6763 PROP_cfg, /* properties_required */
6764 0, /* properties_provided */
6765 0, /* properties_destroyed */
6766 0, /* todo_flags_start */
6767 0, /* todo_flags_finish */
6771 /* Emit noreturn warnings. */
6774 execute_warn_function_noreturn (void)
6776 if (warn_missing_noreturn
6777 && !TREE_THIS_VOLATILE (cfun->decl)
6778 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
6779 && !lang_hooks.function.missing_noreturn_ok_p (cfun->decl))
6780 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
6781 "for attribute %<noreturn%>",
6786 struct tree_opt_pass pass_warn_function_noreturn =
6790 execute_warn_function_noreturn, /* execute */
6793 0, /* static_pass_number */
6795 PROP_cfg, /* properties_required */
6796 0, /* properties_provided */
6797 0, /* properties_destroyed */
6798 0, /* todo_flags_start */
6799 0, /* todo_flags_finish */