1 /* Control flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "hard-reg-set.h"
30 #include "basic-block.h"
36 #include "langhooks.h"
37 #include "diagnostic.h"
38 #include "tree-flow.h"
40 #include "tree-dump.h"
41 #include "tree-pass.h"
45 #include "cfglayout.h"
46 #include "tree-ssa-propagate.h"
47 #include "value-prof.h"
48 #include "pointer-set.h"
49 #include "tree-inline.h"
51 /* This file contains functions for building the Control Flow Graph (CFG)
52 for a function tree. */
54 /* Local declarations. */
56 /* Initial capacity for the basic block array. */
57 static const int initial_cfg_capacity = 20;
59 /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs
60 which use a particular edge. The CASE_LABEL_EXPRs are chained together
61 via their TREE_CHAIN field, which we clear after we're done with the
62 hash table to prevent problems with duplication of SWITCH_EXPRs.
64 Access to this list of CASE_LABEL_EXPRs allows us to efficiently
65 update the case vector in response to edge redirections.
67 Right now this table is set up and torn down at key points in the
68 compilation process. It would be nice if we could make the table
69 more persistent. The key is getting notification of changes to
70 the CFG (particularly edge removal, creation and redirection). */
72 static struct pointer_map_t *edge_to_cases;
77 long num_merged_labels;
80 static struct cfg_stats_d cfg_stats;
82 /* Nonzero if we found a computed goto while building basic blocks. */
83 static bool found_computed_goto;
85 /* Basic blocks and flowgraphs. */
86 static basic_block create_bb (void *, void *, basic_block);
87 static void make_blocks (tree);
88 static void factor_computed_gotos (void);
91 static void make_edges (void);
92 static void make_cond_expr_edges (basic_block);
93 static void make_switch_expr_edges (basic_block);
94 static void make_goto_expr_edges (basic_block);
95 static edge tree_redirect_edge_and_branch (edge, basic_block);
96 static edge tree_try_redirect_by_replacing_jump (edge, basic_block);
97 static unsigned int split_critical_edges (void);
99 /* Various helpers. */
100 static inline bool stmt_starts_bb_p (const_tree, const_tree);
101 static int tree_verify_flow_info (void);
102 static void tree_make_forwarder_block (edge);
103 static void tree_cfg2vcg (FILE *);
104 static inline void change_bb_for_stmt (tree t, basic_block bb);
105 static bool computed_goto_p (const_tree);
107 /* Flowgraph optimization and cleanup. */
108 static void tree_merge_blocks (basic_block, basic_block);
109 static bool tree_can_merge_blocks_p (basic_block, basic_block);
110 static void remove_bb (basic_block);
111 static edge find_taken_edge_computed_goto (basic_block, tree);
112 static edge find_taken_edge_cond_expr (basic_block, tree);
113 static edge find_taken_edge_switch_expr (basic_block, tree);
114 static tree find_case_label_for_value (tree, tree);
117 init_empty_tree_cfg (void)
119 /* Initialize the basic block array. */
121 profile_status = PROFILE_ABSENT;
122 n_basic_blocks = NUM_FIXED_BLOCKS;
123 last_basic_block = NUM_FIXED_BLOCKS;
124 basic_block_info = VEC_alloc (basic_block, gc, initial_cfg_capacity);
125 VEC_safe_grow_cleared (basic_block, gc, basic_block_info,
126 initial_cfg_capacity);
128 /* Build a mapping of labels to their associated blocks. */
129 label_to_block_map = VEC_alloc (basic_block, gc, initial_cfg_capacity);
130 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
131 initial_cfg_capacity);
133 SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR);
134 SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR);
135 ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR;
136 EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR;
139 /*---------------------------------------------------------------------------
141 ---------------------------------------------------------------------------*/
143 /* Entry point to the CFG builder for trees. TP points to the list of
144 statements to be added to the flowgraph. */
147 build_tree_cfg (tree *tp)
149 /* Register specific tree functions. */
150 tree_register_cfg_hooks ();
152 memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
154 init_empty_tree_cfg ();
156 found_computed_goto = 0;
159 /* Computed gotos are hell to deal with, especially if there are
160 lots of them with a large number of destinations. So we factor
161 them to a common computed goto location before we build the
162 edge list. After we convert back to normal form, we will un-factor
163 the computed gotos since factoring introduces an unwanted jump. */
164 if (found_computed_goto)
165 factor_computed_gotos ();
167 /* Make sure there is always at least one block, even if it's empty. */
168 if (n_basic_blocks == NUM_FIXED_BLOCKS)
169 create_empty_bb (ENTRY_BLOCK_PTR);
171 /* Adjust the size of the array. */
172 if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
173 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
175 /* To speed up statement iterator walks, we first purge dead labels. */
176 cleanup_dead_labels ();
178 /* Group case nodes to reduce the number of edges.
179 We do this after cleaning up dead labels because otherwise we miss
180 a lot of obvious case merging opportunities. */
181 group_case_labels ();
183 /* Create the edges of the flowgraph. */
185 cleanup_dead_labels ();
187 /* Debugging dumps. */
189 /* Write the flowgraph to a VCG file. */
191 int local_dump_flags;
192 FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
195 tree_cfg2vcg (vcg_file);
196 dump_end (TDI_vcg, vcg_file);
200 #ifdef ENABLE_CHECKING
204 /* Dump a textual representation of the flowgraph. */
206 dump_tree_cfg (dump_file, dump_flags);
210 execute_build_cfg (void)
212 build_tree_cfg (&DECL_SAVED_TREE (current_function_decl));
216 struct gimple_opt_pass pass_build_cfg =
222 execute_build_cfg, /* execute */
225 0, /* static_pass_number */
226 TV_TREE_CFG, /* tv_id */
227 PROP_gimple_leh, /* properties_required */
228 PROP_cfg, /* properties_provided */
229 0, /* properties_destroyed */
230 0, /* todo_flags_start */
231 TODO_verify_stmts | TODO_cleanup_cfg /* todo_flags_finish */
235 /* Search the CFG for any computed gotos. If found, factor them to a
236 common computed goto site. Also record the location of that site so
237 that we can un-factor the gotos after we have converted back to
241 factor_computed_gotos (void)
244 tree factored_label_decl = NULL;
246 tree factored_computed_goto_label = NULL;
247 tree factored_computed_goto = NULL;
249 /* We know there are one or more computed gotos in this function.
250 Examine the last statement in each basic block to see if the block
251 ends with a computed goto. */
255 block_stmt_iterator bsi = bsi_last (bb);
260 last = bsi_stmt (bsi);
262 /* Ignore the computed goto we create when we factor the original
264 if (last == factored_computed_goto)
267 /* If the last statement is a computed goto, factor it. */
268 if (computed_goto_p (last))
272 /* The first time we find a computed goto we need to create
273 the factored goto block and the variable each original
274 computed goto will use for their goto destination. */
275 if (! factored_computed_goto)
277 basic_block new_bb = create_empty_bb (bb);
278 block_stmt_iterator new_bsi = bsi_start (new_bb);
280 /* Create the destination of the factored goto. Each original
281 computed goto will put its desired destination into this
282 variable and jump to the label we create immediately
284 var = create_tmp_var (ptr_type_node, "gotovar");
286 /* Build a label for the new block which will contain the
287 factored computed goto. */
288 factored_label_decl = create_artificial_label ();
289 factored_computed_goto_label
290 = build1 (LABEL_EXPR, void_type_node, factored_label_decl);
291 bsi_insert_after (&new_bsi, factored_computed_goto_label,
294 /* Build our new computed goto. */
295 factored_computed_goto = build1 (GOTO_EXPR, void_type_node, var);
296 bsi_insert_after (&new_bsi, factored_computed_goto,
300 /* Copy the original computed goto's destination into VAR. */
301 assignment = build_gimple_modify_stmt (var,
302 GOTO_DESTINATION (last));
303 bsi_insert_before (&bsi, assignment, BSI_SAME_STMT);
305 /* And re-vector the computed goto to the new destination. */
306 GOTO_DESTINATION (last) = factored_label_decl;
312 /* Build a flowgraph for the statement_list STMT_LIST. */
315 make_blocks (tree stmt_list)
317 tree_stmt_iterator i = tsi_start (stmt_list);
319 bool start_new_block = true;
320 bool first_stmt_of_list = true;
321 basic_block bb = ENTRY_BLOCK_PTR;
323 while (!tsi_end_p (i))
330 /* If the statement starts a new basic block or if we have determined
331 in a previous pass that we need to create a new block for STMT, do
333 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
335 if (!first_stmt_of_list)
336 stmt_list = tsi_split_statement_list_before (&i);
337 bb = create_basic_block (stmt_list, NULL, bb);
338 start_new_block = false;
341 /* Now add STMT to BB and create the subgraphs for special statement
343 set_bb_for_stmt (stmt, bb);
345 if (computed_goto_p (stmt))
346 found_computed_goto = true;
348 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
350 if (stmt_ends_bb_p (stmt))
351 start_new_block = true;
354 first_stmt_of_list = false;
359 /* Create and return a new empty basic block after bb AFTER. */
362 create_bb (void *h, void *e, basic_block after)
368 /* Create and initialize a new basic block. Since alloc_block uses
369 ggc_alloc_cleared to allocate a basic block, we do not have to
370 clear the newly allocated basic block here. */
373 bb->index = last_basic_block;
375 bb->il.tree = GGC_CNEW (struct tree_bb_info);
376 set_bb_stmt_list (bb, h ? (tree) h : alloc_stmt_list ());
378 /* Add the new block to the linked list of blocks. */
379 link_block (bb, after);
381 /* Grow the basic block array if needed. */
382 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
384 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
385 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
388 /* Add the newly created block to the array. */
389 SET_BASIC_BLOCK (last_basic_block, bb);
398 /*---------------------------------------------------------------------------
400 ---------------------------------------------------------------------------*/
402 /* Fold COND_EXPR_COND of each COND_EXPR. */
405 fold_cond_expr_cond (void)
411 tree stmt = last_stmt (bb);
414 && TREE_CODE (stmt) == COND_EXPR)
419 fold_defer_overflow_warnings ();
420 cond = fold (COND_EXPR_COND (stmt));
421 zerop = integer_zerop (cond);
422 onep = integer_onep (cond);
423 fold_undefer_overflow_warnings (zerop || onep,
425 WARN_STRICT_OVERFLOW_CONDITIONAL);
427 COND_EXPR_COND (stmt) = boolean_false_node;
429 COND_EXPR_COND (stmt) = boolean_true_node;
434 /* Join all the blocks in the flowgraph. */
440 struct omp_region *cur_region = NULL;
442 /* Create an edge from entry to the first block with executable
444 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
446 /* Traverse the basic block array placing edges. */
449 tree last = last_stmt (bb);
454 enum tree_code code = TREE_CODE (last);
458 make_goto_expr_edges (bb);
462 make_edge (bb, EXIT_BLOCK_PTR, 0);
466 make_cond_expr_edges (bb);
470 make_switch_expr_edges (bb);
474 make_eh_edges (last);
479 /* If this function receives a nonlocal goto, then we need to
480 make edges from this call site to all the nonlocal goto
482 if (tree_can_make_abnormal_goto (last))
483 make_abnormal_goto_edges (bb, true);
485 /* If this statement has reachable exception handlers, then
486 create abnormal edges to them. */
487 make_eh_edges (last);
489 /* Some calls are known not to return. */
490 fallthru = !(call_expr_flags (last) & ECF_NORETURN);
496 case GIMPLE_MODIFY_STMT:
497 if (is_ctrl_altering_stmt (last))
499 /* A GIMPLE_MODIFY_STMT may have a CALL_EXPR on its RHS and
500 the CALL_EXPR may have an abnormal edge. Search the RHS
501 for this case and create any required edges. */
502 if (tree_can_make_abnormal_goto (last))
503 make_abnormal_goto_edges (bb, true);
505 make_eh_edges (last);
517 cur_region = new_omp_region (bb, code, cur_region);
522 cur_region = new_omp_region (bb, code, cur_region);
526 case OMP_SECTIONS_SWITCH:
531 case OMP_ATOMIC_LOAD:
532 case OMP_ATOMIC_STORE:
538 /* In the case of an OMP_SECTION, the edge will go somewhere
539 other than the next block. This will be created later. */
540 cur_region->exit = bb;
541 fallthru = cur_region->type != OMP_SECTION;
542 cur_region = cur_region->outer;
546 cur_region->cont = bb;
547 switch (cur_region->type)
550 /* Mark all OMP_FOR and OMP_CONTINUE succs edges as abnormal
551 to prevent splitting them. */
552 single_succ_edge (cur_region->entry)->flags |= EDGE_ABNORMAL;
553 /* Make the loopback edge. */
554 make_edge (bb, single_succ (cur_region->entry),
557 /* Create an edge from OMP_FOR to exit, which corresponds to
558 the case that the body of the loop is not executed at
560 make_edge (cur_region->entry, bb->next_bb, EDGE_ABNORMAL);
561 make_edge (bb, bb->next_bb, EDGE_FALLTHRU | EDGE_ABNORMAL);
566 /* Wire up the edges into and out of the nested sections. */
568 basic_block switch_bb = single_succ (cur_region->entry);
570 struct omp_region *i;
571 for (i = cur_region->inner; i ; i = i->next)
573 gcc_assert (i->type == OMP_SECTION);
574 make_edge (switch_bb, i->entry, 0);
575 make_edge (i->exit, bb, EDGE_FALLTHRU);
578 /* Make the loopback edge to the block with
579 OMP_SECTIONS_SWITCH. */
580 make_edge (bb, switch_bb, 0);
582 /* Make the edge from the switch to exit. */
583 make_edge (switch_bb, bb->next_bb, 0);
594 gcc_assert (!stmt_ends_bb_p (last));
602 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
608 /* Fold COND_EXPR_COND of each COND_EXPR. */
609 fold_cond_expr_cond ();
613 /* Create the edges for a COND_EXPR starting at block BB.
614 At this point, both clauses must contain only simple gotos. */
617 make_cond_expr_edges (basic_block bb)
619 tree entry = last_stmt (bb);
620 basic_block then_bb, else_bb;
621 tree then_label, else_label;
625 gcc_assert (TREE_CODE (entry) == COND_EXPR);
627 /* Entry basic blocks for each component. */
628 then_label = GOTO_DESTINATION (COND_EXPR_THEN (entry));
629 else_label = GOTO_DESTINATION (COND_EXPR_ELSE (entry));
630 then_bb = label_to_block (then_label);
631 else_bb = label_to_block (else_label);
633 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
634 e->goto_locus = EXPR_LOCATION (COND_EXPR_THEN (entry));
635 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
637 e->goto_locus = EXPR_LOCATION (COND_EXPR_ELSE (entry));
639 /* We do not need the gotos anymore. */
640 COND_EXPR_THEN (entry) = NULL_TREE;
641 COND_EXPR_ELSE (entry) = NULL_TREE;
645 /* Called for each element in the hash table (P) as we delete the
646 edge to cases hash table.
648 Clear all the TREE_CHAINs to prevent problems with copying of
649 SWITCH_EXPRs and structure sharing rules, then free the hash table
653 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED, void **value,
654 void *data ATTRIBUTE_UNUSED)
658 for (t = (tree) *value; t; t = next)
660 next = TREE_CHAIN (t);
661 TREE_CHAIN (t) = NULL;
668 /* Start recording information mapping edges to case labels. */
671 start_recording_case_labels (void)
673 gcc_assert (edge_to_cases == NULL);
674 edge_to_cases = pointer_map_create ();
677 /* Return nonzero if we are recording information for case labels. */
680 recording_case_labels_p (void)
682 return (edge_to_cases != NULL);
685 /* Stop recording information mapping edges to case labels and
686 remove any information we have recorded. */
688 end_recording_case_labels (void)
690 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
691 pointer_map_destroy (edge_to_cases);
692 edge_to_cases = NULL;
695 /* If we are inside a {start,end}_recording_cases block, then return
696 a chain of CASE_LABEL_EXPRs from T which reference E.
698 Otherwise return NULL. */
701 get_cases_for_edge (edge e, tree t)
707 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
708 chains available. Return NULL so the caller can detect this case. */
709 if (!recording_case_labels_p ())
712 slot = pointer_map_contains (edge_to_cases, e);
716 /* If we did not find E in the hash table, then this must be the first
717 time we have been queried for information about E & T. Add all the
718 elements from T to the hash table then perform the query again. */
720 vec = SWITCH_LABELS (t);
721 n = TREE_VEC_LENGTH (vec);
722 for (i = 0; i < n; i++)
724 tree elt = TREE_VEC_ELT (vec, i);
725 tree lab = CASE_LABEL (elt);
726 basic_block label_bb = label_to_block (lab);
727 edge this_edge = find_edge (e->src, label_bb);
729 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
731 slot = pointer_map_insert (edge_to_cases, this_edge);
732 TREE_CHAIN (elt) = (tree) *slot;
736 return (tree) *pointer_map_contains (edge_to_cases, e);
739 /* Create the edges for a SWITCH_EXPR starting at block BB.
740 At this point, the switch body has been lowered and the
741 SWITCH_LABELS filled in, so this is in effect a multi-way branch. */
744 make_switch_expr_edges (basic_block bb)
746 tree entry = last_stmt (bb);
750 vec = SWITCH_LABELS (entry);
751 n = TREE_VEC_LENGTH (vec);
753 for (i = 0; i < n; ++i)
755 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
756 basic_block label_bb = label_to_block (lab);
757 make_edge (bb, label_bb, 0);
762 /* Return the basic block holding label DEST. */
765 label_to_block_fn (struct function *ifun, tree dest)
767 int uid = LABEL_DECL_UID (dest);
769 /* We would die hard when faced by an undefined label. Emit a label to
770 the very first basic block. This will hopefully make even the dataflow
771 and undefined variable warnings quite right. */
772 if ((errorcount || sorrycount) && uid < 0)
774 block_stmt_iterator bsi =
775 bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS));
778 stmt = build1 (LABEL_EXPR, void_type_node, dest);
779 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
780 uid = LABEL_DECL_UID (dest);
782 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
783 <= (unsigned int) uid)
785 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
788 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
789 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
792 make_abnormal_goto_edges (basic_block bb, bool for_call)
794 basic_block target_bb;
795 block_stmt_iterator bsi;
797 FOR_EACH_BB (target_bb)
798 for (bsi = bsi_start (target_bb); !bsi_end_p (bsi); bsi_next (&bsi))
800 tree target = bsi_stmt (bsi);
802 if (TREE_CODE (target) != LABEL_EXPR)
805 target = LABEL_EXPR_LABEL (target);
807 /* Make an edge to every label block that has been marked as a
808 potential target for a computed goto or a non-local goto. */
809 if ((FORCED_LABEL (target) && !for_call)
810 || (DECL_NONLOCAL (target) && for_call))
812 make_edge (bb, target_bb, EDGE_ABNORMAL);
818 /* Create edges for a goto statement at block BB. */
821 make_goto_expr_edges (basic_block bb)
823 block_stmt_iterator last = bsi_last (bb);
824 tree goto_t = bsi_stmt (last);
826 /* A simple GOTO creates normal edges. */
827 if (simple_goto_p (goto_t))
829 tree dest = GOTO_DESTINATION (goto_t);
830 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
831 e->goto_locus = EXPR_LOCATION (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 = NULL_TREE;
1065 tree default_label = NULL_TREE;
1067 /* The default label is always the last case in a switch
1068 statement after gimplification if it was not optimized
1070 if (!CASE_LOW (TREE_VEC_ELT (labels, old_size - 1))
1071 && !CASE_HIGH (TREE_VEC_ELT (labels, old_size - 1)))
1073 default_case = TREE_VEC_ELT (labels, old_size - 1);
1074 default_label = CASE_LABEL (default_case);
1078 /* Look for possible opportunities to merge cases. */
1080 while (i < old_size)
1082 tree base_case, base_label, base_high;
1083 base_case = TREE_VEC_ELT (labels, i);
1085 gcc_assert (base_case);
1086 base_label = CASE_LABEL (base_case);
1088 /* Discard cases that have the same destination as the
1090 if (base_label == default_label)
1092 TREE_VEC_ELT (labels, i) = NULL_TREE;
1098 base_high = CASE_HIGH (base_case) ?
1099 CASE_HIGH (base_case) : CASE_LOW (base_case);
1101 /* Try to merge case labels. Break out when we reach the end
1102 of the label vector or when we cannot merge the next case
1103 label with the current one. */
1104 while (i < old_size)
1106 tree merge_case = TREE_VEC_ELT (labels, i);
1107 tree merge_label = CASE_LABEL (merge_case);
1108 tree t = int_const_binop (PLUS_EXPR, base_high,
1109 integer_one_node, 1);
1111 /* Merge the cases if they jump to the same place,
1112 and their ranges are consecutive. */
1113 if (merge_label == base_label
1114 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1116 base_high = CASE_HIGH (merge_case) ?
1117 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1118 CASE_HIGH (base_case) = base_high;
1119 TREE_VEC_ELT (labels, i) = NULL_TREE;
1128 /* Compress the case labels in the label vector, and adjust the
1129 length of the vector. */
1130 for (i = 0, j = 0; i < new_size; i++)
1132 while (! TREE_VEC_ELT (labels, j))
1134 TREE_VEC_ELT (labels, i) = TREE_VEC_ELT (labels, j++);
1136 TREE_VEC_LENGTH (labels) = new_size;
1141 /* Checks whether we can merge block B into block A. */
1144 tree_can_merge_blocks_p (basic_block a, basic_block b)
1147 block_stmt_iterator bsi;
1150 if (!single_succ_p (a))
1153 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1156 if (single_succ (a) != b)
1159 if (!single_pred_p (b))
1162 if (b == EXIT_BLOCK_PTR)
1165 /* If A ends by a statement causing exceptions or something similar, we
1166 cannot merge the blocks. */
1167 /* This CONST_CAST is okay because last_stmt doesn't modify its
1168 argument and the return value is assign to a const_tree. */
1169 stmt = last_stmt (CONST_CAST_BB (a));
1170 if (stmt && stmt_ends_bb_p (stmt))
1173 /* Do not allow a block with only a non-local label to be merged. */
1174 if (stmt && TREE_CODE (stmt) == LABEL_EXPR
1175 && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
1178 /* It must be possible to eliminate all phi nodes in B. If ssa form
1179 is not up-to-date, we cannot eliminate any phis; however, if only
1180 some symbols as whole are marked for renaming, this is not a problem,
1181 as phi nodes for those symbols are irrelevant in updating anyway. */
1182 phi = phi_nodes (b);
1185 if (name_mappings_registered_p ())
1188 for (; phi; phi = PHI_CHAIN (phi))
1189 if (!is_gimple_reg (PHI_RESULT (phi))
1190 && !may_propagate_copy (PHI_RESULT (phi), PHI_ARG_DEF (phi, 0)))
1194 /* Do not remove user labels. */
1195 for (bsi = bsi_start (b); !bsi_end_p (bsi); bsi_next (&bsi))
1197 stmt = bsi_stmt (bsi);
1198 if (TREE_CODE (stmt) != LABEL_EXPR)
1200 if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt)))
1204 /* Protect the loop latches. */
1206 && b->loop_father->latch == b)
1212 /* Replaces all uses of NAME by VAL. */
1215 replace_uses_by (tree name, tree val)
1217 imm_use_iterator imm_iter;
1222 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1224 if (TREE_CODE (stmt) != PHI_NODE)
1225 push_stmt_changes (&stmt);
1227 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1229 replace_exp (use, val);
1231 if (TREE_CODE (stmt) == PHI_NODE)
1233 e = PHI_ARG_EDGE (stmt, PHI_ARG_INDEX_FROM_USE (use));
1234 if (e->flags & EDGE_ABNORMAL)
1236 /* This can only occur for virtual operands, since
1237 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1238 would prevent replacement. */
1239 gcc_assert (!is_gimple_reg (name));
1240 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1245 if (TREE_CODE (stmt) != PHI_NODE)
1249 fold_stmt_inplace (stmt);
1250 if (cfgcleanup_altered_bbs)
1251 bitmap_set_bit (cfgcleanup_altered_bbs, bb_for_stmt (stmt)->index);
1253 /* FIXME. This should go in pop_stmt_changes. */
1254 rhs = get_rhs (stmt);
1255 if (TREE_CODE (rhs) == ADDR_EXPR)
1256 recompute_tree_invariant_for_addr_expr (rhs);
1258 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1260 pop_stmt_changes (&stmt);
1264 gcc_assert (has_zero_uses (name));
1266 /* Also update the trees stored in loop structures. */
1272 FOR_EACH_LOOP (li, loop, 0)
1274 substitute_in_loop_info (loop, name, val);
1279 /* Merge block B into block A. */
1282 tree_merge_blocks (basic_block a, basic_block b)
1284 block_stmt_iterator bsi;
1285 tree_stmt_iterator last;
1289 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1291 /* Remove all single-valued PHI nodes from block B of the form
1292 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1294 for (phi = phi_nodes (b); phi; phi = phi_nodes (b))
1296 tree def = PHI_RESULT (phi), use = PHI_ARG_DEF (phi, 0);
1298 bool may_replace_uses = may_propagate_copy (def, use);
1300 /* In case we maintain loop closed ssa form, do not propagate arguments
1301 of loop exit phi nodes. */
1303 && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1304 && is_gimple_reg (def)
1305 && TREE_CODE (use) == SSA_NAME
1306 && a->loop_father != b->loop_father)
1307 may_replace_uses = false;
1309 if (!may_replace_uses)
1311 gcc_assert (is_gimple_reg (def));
1313 /* Note that just emitting the copies is fine -- there is no problem
1314 with ordering of phi nodes. This is because A is the single
1315 predecessor of B, therefore results of the phi nodes cannot
1316 appear as arguments of the phi nodes. */
1317 copy = build_gimple_modify_stmt (def, use);
1318 bsi_insert_after (&bsi, copy, BSI_NEW_STMT);
1319 SSA_NAME_DEF_STMT (def) = copy;
1320 remove_phi_node (phi, NULL, false);
1324 /* If we deal with a PHI for virtual operands, we can simply
1325 propagate these without fussing with folding or updating
1327 if (!is_gimple_reg (def))
1329 imm_use_iterator iter;
1330 use_operand_p use_p;
1333 FOR_EACH_IMM_USE_STMT (stmt, iter, def)
1334 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1335 SET_USE (use_p, use);
1338 replace_uses_by (def, use);
1339 remove_phi_node (phi, NULL, true);
1343 /* Ensure that B follows A. */
1344 move_block_after (b, a);
1346 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1347 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1349 /* Remove labels from B and set bb_for_stmt to A for other statements. */
1350 for (bsi = bsi_start (b); !bsi_end_p (bsi);)
1352 if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR)
1354 tree label = bsi_stmt (bsi);
1356 bsi_remove (&bsi, false);
1357 /* Now that we can thread computed gotos, we might have
1358 a situation where we have a forced label in block B
1359 However, the label at the start of block B might still be
1360 used in other ways (think about the runtime checking for
1361 Fortran assigned gotos). So we can not just delete the
1362 label. Instead we move the label to the start of block A. */
1363 if (FORCED_LABEL (LABEL_EXPR_LABEL (label)))
1365 block_stmt_iterator dest_bsi = bsi_start (a);
1366 bsi_insert_before (&dest_bsi, label, BSI_NEW_STMT);
1371 change_bb_for_stmt (bsi_stmt (bsi), a);
1376 /* Merge the chains. */
1377 last = tsi_last (bb_stmt_list (a));
1378 tsi_link_after (&last, bb_stmt_list (b), TSI_NEW_STMT);
1379 set_bb_stmt_list (b, NULL_TREE);
1381 if (cfgcleanup_altered_bbs)
1382 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1386 /* Return the one of two successors of BB that is not reachable by a
1387 reached by a complex edge, if there is one. Else, return BB. We use
1388 this in optimizations that use post-dominators for their heuristics,
1389 to catch the cases in C++ where function calls are involved. */
1392 single_noncomplex_succ (basic_block bb)
1395 if (EDGE_COUNT (bb->succs) != 2)
1398 e0 = EDGE_SUCC (bb, 0);
1399 e1 = EDGE_SUCC (bb, 1);
1400 if (e0->flags & EDGE_COMPLEX)
1402 if (e1->flags & EDGE_COMPLEX)
1409 /* Walk the function tree removing unnecessary statements.
1411 * Empty statement nodes are removed
1413 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1415 * Unnecessary COND_EXPRs are removed
1417 * Some unnecessary BIND_EXPRs are removed
1419 Clearly more work could be done. The trick is doing the analysis
1420 and removal fast enough to be a net improvement in compile times.
1422 Note that when we remove a control structure such as a COND_EXPR
1423 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1424 to ensure we eliminate all the useless code. */
1435 static void remove_useless_stmts_1 (tree *, struct rus_data *);
1438 remove_useless_stmts_warn_notreached (tree stmt)
1440 if (EXPR_HAS_LOCATION (stmt))
1442 location_t loc = EXPR_LOCATION (stmt);
1443 if (LOCATION_LINE (loc) > 0)
1445 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
1450 switch (TREE_CODE (stmt))
1452 case STATEMENT_LIST:
1454 tree_stmt_iterator i;
1455 for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i))
1456 if (remove_useless_stmts_warn_notreached (tsi_stmt (i)))
1462 if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt)))
1464 if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt)))
1466 if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt)))
1470 case TRY_FINALLY_EXPR:
1471 case TRY_CATCH_EXPR:
1472 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 0)))
1474 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 1)))
1479 return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt));
1480 case EH_FILTER_EXPR:
1481 return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt));
1483 return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt));
1486 /* Not a live container. */
1494 remove_useless_stmts_cond (tree *stmt_p, struct rus_data *data)
1496 tree then_clause, else_clause, cond;
1497 bool save_has_label, then_has_label, else_has_label;
1499 save_has_label = data->has_label;
1500 data->has_label = false;
1501 data->last_goto = NULL;
1503 remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p), data);
1505 then_has_label = data->has_label;
1506 data->has_label = false;
1507 data->last_goto = NULL;
1509 remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p), data);
1511 else_has_label = data->has_label;
1512 data->has_label = save_has_label | then_has_label | else_has_label;
1514 then_clause = COND_EXPR_THEN (*stmt_p);
1515 else_clause = COND_EXPR_ELSE (*stmt_p);
1516 cond = fold (COND_EXPR_COND (*stmt_p));
1518 /* If neither arm does anything at all, we can remove the whole IF. */
1519 if (!TREE_SIDE_EFFECTS (then_clause) && !TREE_SIDE_EFFECTS (else_clause))
1521 *stmt_p = build_empty_stmt ();
1522 data->repeat = true;
1525 /* If there are no reachable statements in an arm, then we can
1526 zap the entire conditional. */
1527 else if (integer_nonzerop (cond) && !else_has_label)
1529 if (warn_notreached)
1530 remove_useless_stmts_warn_notreached (else_clause);
1531 *stmt_p = then_clause;
1532 data->repeat = true;
1534 else if (integer_zerop (cond) && !then_has_label)
1536 if (warn_notreached)
1537 remove_useless_stmts_warn_notreached (then_clause);
1538 *stmt_p = else_clause;
1539 data->repeat = true;
1542 /* Check a couple of simple things on then/else with single stmts. */
1545 tree then_stmt = expr_only (then_clause);
1546 tree else_stmt = expr_only (else_clause);
1548 /* Notice branches to a common destination. */
1549 if (then_stmt && else_stmt
1550 && TREE_CODE (then_stmt) == GOTO_EXPR
1551 && TREE_CODE (else_stmt) == GOTO_EXPR
1552 && (GOTO_DESTINATION (then_stmt) == GOTO_DESTINATION (else_stmt)))
1554 *stmt_p = then_stmt;
1555 data->repeat = true;
1558 /* If the THEN/ELSE clause merely assigns a value to a variable or
1559 parameter which is already known to contain that value, then
1560 remove the useless THEN/ELSE clause. */
1561 else if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL)
1564 && TREE_CODE (else_stmt) == GIMPLE_MODIFY_STMT
1565 && GIMPLE_STMT_OPERAND (else_stmt, 0) == cond
1566 && integer_zerop (GIMPLE_STMT_OPERAND (else_stmt, 1)))
1567 COND_EXPR_ELSE (*stmt_p) = alloc_stmt_list ();
1569 else if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
1570 && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL
1571 || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL)
1572 && TREE_CONSTANT (TREE_OPERAND (cond, 1)))
1574 tree stmt = (TREE_CODE (cond) == EQ_EXPR
1575 ? then_stmt : else_stmt);
1576 tree *location = (TREE_CODE (cond) == EQ_EXPR
1577 ? &COND_EXPR_THEN (*stmt_p)
1578 : &COND_EXPR_ELSE (*stmt_p));
1581 && TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
1582 && GIMPLE_STMT_OPERAND (stmt, 0) == TREE_OPERAND (cond, 0)
1583 && GIMPLE_STMT_OPERAND (stmt, 1) == TREE_OPERAND (cond, 1))
1584 *location = alloc_stmt_list ();
1588 /* Protect GOTOs in the arm of COND_EXPRs from being removed. They
1589 would be re-introduced during lowering. */
1590 data->last_goto = NULL;
1595 remove_useless_stmts_tf (tree *stmt_p, struct rus_data *data)
1597 bool save_may_branch, save_may_throw;
1598 bool this_may_branch, this_may_throw;
1600 /* Collect may_branch and may_throw information for the body only. */
1601 save_may_branch = data->may_branch;
1602 save_may_throw = data->may_throw;
1603 data->may_branch = false;
1604 data->may_throw = false;
1605 data->last_goto = NULL;
1607 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1609 this_may_branch = data->may_branch;
1610 this_may_throw = data->may_throw;
1611 data->may_branch |= save_may_branch;
1612 data->may_throw |= save_may_throw;
1613 data->last_goto = NULL;
1615 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1617 /* If the body is empty, then we can emit the FINALLY block without
1618 the enclosing TRY_FINALLY_EXPR. */
1619 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 0)))
1621 *stmt_p = TREE_OPERAND (*stmt_p, 1);
1622 data->repeat = true;
1625 /* If the handler is empty, then we can emit the TRY block without
1626 the enclosing TRY_FINALLY_EXPR. */
1627 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1629 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1630 data->repeat = true;
1633 /* If the body neither throws, nor branches, then we can safely
1634 string the TRY and FINALLY blocks together. */
1635 else if (!this_may_branch && !this_may_throw)
1637 tree stmt = *stmt_p;
1638 *stmt_p = TREE_OPERAND (stmt, 0);
1639 append_to_statement_list (TREE_OPERAND (stmt, 1), stmt_p);
1640 data->repeat = true;
1646 remove_useless_stmts_tc (tree *stmt_p, struct rus_data *data)
1648 bool save_may_throw, this_may_throw;
1649 tree_stmt_iterator i;
1652 /* Collect may_throw information for the body only. */
1653 save_may_throw = data->may_throw;
1654 data->may_throw = false;
1655 data->last_goto = NULL;
1657 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1659 this_may_throw = data->may_throw;
1660 data->may_throw = save_may_throw;
1662 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1663 if (!this_may_throw)
1665 if (warn_notreached)
1666 remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p, 1));
1667 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1668 data->repeat = true;
1672 /* Process the catch clause specially. We may be able to tell that
1673 no exceptions propagate past this point. */
1675 this_may_throw = true;
1676 i = tsi_start (TREE_OPERAND (*stmt_p, 1));
1677 stmt = tsi_stmt (i);
1678 data->last_goto = NULL;
1680 switch (TREE_CODE (stmt))
1683 for (; !tsi_end_p (i); tsi_next (&i))
1685 stmt = tsi_stmt (i);
1686 /* If we catch all exceptions, then the body does not
1687 propagate exceptions past this point. */
1688 if (CATCH_TYPES (stmt) == NULL)
1689 this_may_throw = false;
1690 data->last_goto = NULL;
1691 remove_useless_stmts_1 (&CATCH_BODY (stmt), data);
1695 case EH_FILTER_EXPR:
1696 if (EH_FILTER_MUST_NOT_THROW (stmt))
1697 this_may_throw = false;
1698 else if (EH_FILTER_TYPES (stmt) == NULL)
1699 this_may_throw = false;
1700 remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt), data);
1704 /* Otherwise this is a cleanup. */
1705 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1707 /* If the cleanup is empty, then we can emit the TRY block without
1708 the enclosing TRY_CATCH_EXPR. */
1709 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1711 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1712 data->repeat = true;
1716 data->may_throw |= this_may_throw;
1721 remove_useless_stmts_bind (tree *stmt_p, struct rus_data *data)
1725 /* First remove anything underneath the BIND_EXPR. */
1726 remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p), data);
1728 /* If the BIND_EXPR has no variables, then we can pull everything
1729 up one level and remove the BIND_EXPR, unless this is the toplevel
1730 BIND_EXPR for the current function or an inlined function.
1732 When this situation occurs we will want to apply this
1733 optimization again. */
1734 block = BIND_EXPR_BLOCK (*stmt_p);
1735 if (BIND_EXPR_VARS (*stmt_p) == NULL_TREE
1736 && *stmt_p != DECL_SAVED_TREE (current_function_decl)
1738 || ! BLOCK_ABSTRACT_ORIGIN (block)
1739 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1742 *stmt_p = BIND_EXPR_BODY (*stmt_p);
1743 data->repeat = true;
1749 remove_useless_stmts_goto (tree *stmt_p, struct rus_data *data)
1751 tree dest = GOTO_DESTINATION (*stmt_p);
1753 data->may_branch = true;
1754 data->last_goto = NULL;
1756 /* Record the last goto expr, so that we can delete it if unnecessary. */
1757 if (TREE_CODE (dest) == LABEL_DECL)
1758 data->last_goto = stmt_p;
1763 remove_useless_stmts_label (tree *stmt_p, struct rus_data *data)
1765 tree label = LABEL_EXPR_LABEL (*stmt_p);
1767 data->has_label = true;
1769 /* We do want to jump across non-local label receiver code. */
1770 if (DECL_NONLOCAL (label))
1771 data->last_goto = NULL;
1773 else if (data->last_goto && GOTO_DESTINATION (*data->last_goto) == label)
1775 *data->last_goto = build_empty_stmt ();
1776 data->repeat = true;
1779 /* ??? Add something here to delete unused labels. */
1783 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1784 decl. This allows us to eliminate redundant or useless
1785 calls to "const" functions.
1787 Gimplifier already does the same operation, but we may notice functions
1788 being const and pure once their calls has been gimplified, so we need
1789 to update the flag. */
1792 update_call_expr_flags (tree call)
1794 tree decl = get_callee_fndecl (call);
1798 flags = call_expr_flags (call);
1799 if (flags & (ECF_CONST | ECF_PURE) && !(flags & ECF_LOOPING_CONST_OR_PURE))
1800 TREE_SIDE_EFFECTS (call) = 0;
1801 if (TREE_NOTHROW (decl))
1802 TREE_NOTHROW (call) = 1;
1806 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1809 notice_special_calls (tree t)
1811 int flags = call_expr_flags (t);
1813 if (flags & ECF_MAY_BE_ALLOCA)
1814 cfun->calls_alloca = true;
1815 if (flags & ECF_RETURNS_TWICE)
1816 cfun->calls_setjmp = true;
1820 /* Clear flags set by notice_special_calls. Used by dead code removal
1821 to update the flags. */
1824 clear_special_calls (void)
1826 cfun->calls_alloca = false;
1827 cfun->calls_setjmp = false;
1832 remove_useless_stmts_1 (tree *tp, struct rus_data *data)
1836 switch (TREE_CODE (t))
1839 remove_useless_stmts_cond (tp, data);
1842 case TRY_FINALLY_EXPR:
1843 remove_useless_stmts_tf (tp, data);
1846 case TRY_CATCH_EXPR:
1847 remove_useless_stmts_tc (tp, data);
1851 remove_useless_stmts_bind (tp, data);
1855 remove_useless_stmts_goto (tp, data);
1859 remove_useless_stmts_label (tp, data);
1864 data->last_goto = NULL;
1865 data->may_branch = true;
1870 data->last_goto = NULL;
1871 notice_special_calls (t);
1872 update_call_expr_flags (t);
1873 if (tree_could_throw_p (t))
1874 data->may_throw = true;
1880 case GIMPLE_MODIFY_STMT:
1881 data->last_goto = NULL;
1883 op = get_call_expr_in (t);
1886 update_call_expr_flags (op);
1887 notice_special_calls (op);
1889 if (tree_could_throw_p (t))
1890 data->may_throw = true;
1893 case STATEMENT_LIST:
1895 tree_stmt_iterator i = tsi_start (t);
1896 while (!tsi_end_p (i))
1899 if (IS_EMPTY_STMT (t))
1905 remove_useless_stmts_1 (tsi_stmt_ptr (i), data);
1908 if (TREE_CODE (t) == STATEMENT_LIST)
1910 tsi_link_before (&i, t, TSI_SAME_STMT);
1920 data->last_goto = NULL;
1924 /* Make sure the outermost BIND_EXPR in OMP_BODY isn't removed
1926 remove_useless_stmts_1 (&BIND_EXPR_BODY (OMP_BODY (*tp)), data);
1927 data->last_goto = NULL;
1936 remove_useless_stmts_1 (&OMP_BODY (*tp), data);
1937 data->last_goto = NULL;
1941 remove_useless_stmts_1 (&OMP_FOR_BODY (*tp), data);
1942 data->last_goto = NULL;
1943 if (OMP_FOR_PRE_BODY (*tp))
1945 remove_useless_stmts_1 (&OMP_FOR_PRE_BODY (*tp), data);
1946 data->last_goto = NULL;
1951 data->last_goto = NULL;
1957 remove_useless_stmts (void)
1959 struct rus_data data;
1961 clear_special_calls ();
1965 memset (&data, 0, sizeof (data));
1966 remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl), &data);
1968 while (data.repeat);
1973 struct gimple_opt_pass pass_remove_useless_stmts =
1977 "useless", /* name */
1979 remove_useless_stmts, /* execute */
1982 0, /* static_pass_number */
1984 PROP_gimple_any, /* properties_required */
1985 0, /* properties_provided */
1986 0, /* properties_destroyed */
1987 0, /* todo_flags_start */
1988 TODO_dump_func /* todo_flags_finish */
1992 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
1995 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
1999 /* Since this block is no longer reachable, we can just delete all
2000 of its PHI nodes. */
2001 phi = phi_nodes (bb);
2004 tree next = PHI_CHAIN (phi);
2005 remove_phi_node (phi, NULL_TREE, true);
2009 /* Remove edges to BB's successors. */
2010 while (EDGE_COUNT (bb->succs) > 0)
2011 remove_edge (EDGE_SUCC (bb, 0));
2015 /* Remove statements of basic block BB. */
2018 remove_bb (basic_block bb)
2020 block_stmt_iterator i;
2021 source_location loc = UNKNOWN_LOCATION;
2025 fprintf (dump_file, "Removing basic block %d\n", bb->index);
2026 if (dump_flags & TDF_DETAILS)
2028 dump_bb (bb, dump_file, 0);
2029 fprintf (dump_file, "\n");
2035 struct loop *loop = bb->loop_father;
2037 /* If a loop gets removed, clean up the information associated
2039 if (loop->latch == bb
2040 || loop->header == bb)
2041 free_numbers_of_iterations_estimates_loop (loop);
2044 /* Remove all the instructions in the block. */
2045 if (bb_stmt_list (bb) != NULL_TREE)
2047 for (i = bsi_start (bb); !bsi_end_p (i);)
2049 tree stmt = bsi_stmt (i);
2050 if (TREE_CODE (stmt) == LABEL_EXPR
2051 && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt))
2052 || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))))
2055 block_stmt_iterator new_bsi;
2057 /* A non-reachable non-local label may still be referenced.
2058 But it no longer needs to carry the extra semantics of
2060 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
2062 DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)) = 0;
2063 FORCED_LABEL (LABEL_EXPR_LABEL (stmt)) = 1;
2066 new_bb = bb->prev_bb;
2067 new_bsi = bsi_start (new_bb);
2068 bsi_remove (&i, false);
2069 bsi_insert_before (&new_bsi, stmt, BSI_NEW_STMT);
2073 /* Release SSA definitions if we are in SSA. Note that we
2074 may be called when not in SSA. For example,
2075 final_cleanup calls this function via
2076 cleanup_tree_cfg. */
2077 if (gimple_in_ssa_p (cfun))
2078 release_defs (stmt);
2080 bsi_remove (&i, true);
2083 /* Don't warn for removed gotos. Gotos are often removed due to
2084 jump threading, thus resulting in bogus warnings. Not great,
2085 since this way we lose warnings for gotos in the original
2086 program that are indeed unreachable. */
2087 if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc)
2089 if (EXPR_HAS_LOCATION (stmt))
2090 loc = EXPR_LOCATION (stmt);
2095 /* If requested, give a warning that the first statement in the
2096 block is unreachable. We walk statements backwards in the
2097 loop above, so the last statement we process is the first statement
2099 if (loc > BUILTINS_LOCATION && LOCATION_LINE (loc) > 0)
2100 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2102 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2107 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2108 predicate VAL, return the edge that will be taken out of the block.
2109 If VAL does not match a unique edge, NULL is returned. */
2112 find_taken_edge (basic_block bb, tree val)
2116 stmt = last_stmt (bb);
2119 gcc_assert (is_ctrl_stmt (stmt));
2122 if (! is_gimple_min_invariant (val))
2125 if (TREE_CODE (stmt) == COND_EXPR)
2126 return find_taken_edge_cond_expr (bb, val);
2128 if (TREE_CODE (stmt) == SWITCH_EXPR)
2129 return find_taken_edge_switch_expr (bb, val);
2131 if (computed_goto_p (stmt))
2133 /* Only optimize if the argument is a label, if the argument is
2134 not a label then we can not construct a proper CFG.
2136 It may be the case that we only need to allow the LABEL_REF to
2137 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2138 appear inside a LABEL_EXPR just to be safe. */
2139 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2140 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2141 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2148 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2149 statement, determine which of the outgoing edges will be taken out of the
2150 block. Return NULL if either edge may be taken. */
2153 find_taken_edge_computed_goto (basic_block bb, tree val)
2158 dest = label_to_block (val);
2161 e = find_edge (bb, dest);
2162 gcc_assert (e != NULL);
2168 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2169 statement, determine which of the two edges will be taken out of the
2170 block. Return NULL if either edge may be taken. */
2173 find_taken_edge_cond_expr (basic_block bb, tree val)
2175 edge true_edge, false_edge;
2177 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2179 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2180 return (integer_zerop (val) ? false_edge : true_edge);
2183 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2184 statement, determine which edge will be taken out of the block. Return
2185 NULL if any edge may be taken. */
2188 find_taken_edge_switch_expr (basic_block bb, tree val)
2190 tree switch_expr, taken_case;
2191 basic_block dest_bb;
2194 switch_expr = last_stmt (bb);
2195 taken_case = find_case_label_for_value (switch_expr, val);
2196 dest_bb = label_to_block (CASE_LABEL (taken_case));
2198 e = find_edge (bb, dest_bb);
2204 /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL.
2205 We can make optimal use here of the fact that the case labels are
2206 sorted: We can do a binary search for a case matching VAL. */
2209 find_case_label_for_value (tree switch_expr, tree val)
2211 tree vec = SWITCH_LABELS (switch_expr);
2212 size_t low, high, n = TREE_VEC_LENGTH (vec);
2213 tree default_case = TREE_VEC_ELT (vec, n - 1);
2215 for (low = -1, high = n - 1; high - low > 1; )
2217 size_t i = (high + low) / 2;
2218 tree t = TREE_VEC_ELT (vec, i);
2221 /* Cache the result of comparing CASE_LOW and val. */
2222 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2229 if (CASE_HIGH (t) == NULL)
2231 /* A singe-valued case label. */
2237 /* A case range. We can only handle integer ranges. */
2238 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2243 return default_case;
2249 /*---------------------------------------------------------------------------
2251 ---------------------------------------------------------------------------*/
2253 /* Dump tree-specific information of block BB to file OUTF. */
2256 tree_dump_bb (basic_block bb, FILE *outf, int indent)
2258 dump_generic_bb (outf, bb, indent, TDF_VOPS|TDF_MEMSYMS);
2262 /* Dump a basic block on stderr. */
2265 debug_tree_bb (basic_block bb)
2267 dump_bb (bb, stderr, 0);
2271 /* Dump basic block with index N on stderr. */
2274 debug_tree_bb_n (int n)
2276 debug_tree_bb (BASIC_BLOCK (n));
2277 return BASIC_BLOCK (n);
2281 /* Dump the CFG on stderr.
2283 FLAGS are the same used by the tree dumping functions
2284 (see TDF_* in tree-pass.h). */
2287 debug_tree_cfg (int flags)
2289 dump_tree_cfg (stderr, flags);
2293 /* Dump the program showing basic block boundaries on the given FILE.
2295 FLAGS are the same used by the tree dumping functions (see TDF_* in
2299 dump_tree_cfg (FILE *file, int flags)
2301 if (flags & TDF_DETAILS)
2303 const char *funcname
2304 = lang_hooks.decl_printable_name (current_function_decl, 2);
2307 fprintf (file, ";; Function %s\n\n", funcname);
2308 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2309 n_basic_blocks, n_edges, last_basic_block);
2311 brief_dump_cfg (file);
2312 fprintf (file, "\n");
2315 if (flags & TDF_STATS)
2316 dump_cfg_stats (file);
2318 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2322 /* Dump CFG statistics on FILE. */
2325 dump_cfg_stats (FILE *file)
2327 static long max_num_merged_labels = 0;
2328 unsigned long size, total = 0;
2331 const char * const fmt_str = "%-30s%-13s%12s\n";
2332 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2333 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2334 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2335 const char *funcname
2336 = lang_hooks.decl_printable_name (current_function_decl, 2);
2339 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2341 fprintf (file, "---------------------------------------------------------\n");
2342 fprintf (file, fmt_str, "", " Number of ", "Memory");
2343 fprintf (file, fmt_str, "", " instances ", "used ");
2344 fprintf (file, "---------------------------------------------------------\n");
2346 size = n_basic_blocks * sizeof (struct basic_block_def);
2348 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2349 SCALE (size), LABEL (size));
2353 num_edges += EDGE_COUNT (bb->succs);
2354 size = num_edges * sizeof (struct edge_def);
2356 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2358 fprintf (file, "---------------------------------------------------------\n");
2359 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2361 fprintf (file, "---------------------------------------------------------\n");
2362 fprintf (file, "\n");
2364 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2365 max_num_merged_labels = cfg_stats.num_merged_labels;
2367 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2368 cfg_stats.num_merged_labels, max_num_merged_labels);
2370 fprintf (file, "\n");
2374 /* Dump CFG statistics on stderr. Keep extern so that it's always
2375 linked in the final executable. */
2378 debug_cfg_stats (void)
2380 dump_cfg_stats (stderr);
2384 /* Dump the flowgraph to a .vcg FILE. */
2387 tree_cfg2vcg (FILE *file)
2392 const char *funcname
2393 = lang_hooks.decl_printable_name (current_function_decl, 2);
2395 /* Write the file header. */
2396 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2397 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2398 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2400 /* Write blocks and edges. */
2401 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2403 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2406 if (e->flags & EDGE_FAKE)
2407 fprintf (file, " linestyle: dotted priority: 10");
2409 fprintf (file, " linestyle: solid priority: 100");
2411 fprintf (file, " }\n");
2417 enum tree_code head_code, end_code;
2418 const char *head_name, *end_name;
2421 tree first = first_stmt (bb);
2422 tree last = last_stmt (bb);
2426 head_code = TREE_CODE (first);
2427 head_name = tree_code_name[head_code];
2428 head_line = get_lineno (first);
2431 head_name = "no-statement";
2435 end_code = TREE_CODE (last);
2436 end_name = tree_code_name[end_code];
2437 end_line = get_lineno (last);
2440 end_name = "no-statement";
2442 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2443 bb->index, bb->index, head_name, head_line, end_name,
2446 FOR_EACH_EDGE (e, ei, bb->succs)
2448 if (e->dest == EXIT_BLOCK_PTR)
2449 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2451 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2453 if (e->flags & EDGE_FAKE)
2454 fprintf (file, " priority: 10 linestyle: dotted");
2456 fprintf (file, " priority: 100 linestyle: solid");
2458 fprintf (file, " }\n");
2461 if (bb->next_bb != EXIT_BLOCK_PTR)
2465 fputs ("}\n\n", file);
2470 /*---------------------------------------------------------------------------
2471 Miscellaneous helpers
2472 ---------------------------------------------------------------------------*/
2474 /* Return true if T represents a stmt that always transfers control. */
2477 is_ctrl_stmt (const_tree t)
2479 return (TREE_CODE (t) == COND_EXPR
2480 || TREE_CODE (t) == SWITCH_EXPR
2481 || TREE_CODE (t) == GOTO_EXPR
2482 || TREE_CODE (t) == RETURN_EXPR
2483 || TREE_CODE (t) == RESX_EXPR);
2487 /* Return true if T is a statement that may alter the flow of control
2488 (e.g., a call to a non-returning function). */
2491 is_ctrl_altering_stmt (const_tree t)
2496 call = get_call_expr_in (CONST_CAST_TREE (t));
2499 /* A non-pure/const CALL_EXPR alters flow control if the current
2500 function has nonlocal labels. */
2501 if (TREE_SIDE_EFFECTS (call) && cfun->has_nonlocal_label)
2504 /* A CALL_EXPR also alters control flow if it does not return. */
2505 if (call_expr_flags (call) & ECF_NORETURN)
2509 /* OpenMP directives alter control flow. */
2510 if (OMP_DIRECTIVE_P (t))
2513 /* If a statement can throw, it alters control flow. */
2514 return tree_can_throw_internal (t);
2518 /* Return true if T is a computed goto. */
2521 computed_goto_p (const_tree t)
2523 return (TREE_CODE (t) == GOTO_EXPR
2524 && TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL);
2528 /* Return true if T is a simple local goto. */
2531 simple_goto_p (const_tree t)
2533 return (TREE_CODE (t) == GOTO_EXPR
2534 && TREE_CODE (GOTO_DESTINATION (t)) == LABEL_DECL);
2538 /* Return true if T can make an abnormal transfer of control flow.
2539 Transfers of control flow associated with EH are excluded. */
2542 tree_can_make_abnormal_goto (const_tree t)
2544 if (computed_goto_p (t))
2546 if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
2547 t = GIMPLE_STMT_OPERAND (t, 1);
2548 if (TREE_CODE (t) == WITH_SIZE_EXPR)
2549 t = TREE_OPERAND (t, 0);
2550 if (TREE_CODE (t) == CALL_EXPR)
2551 return TREE_SIDE_EFFECTS (t) && cfun->has_nonlocal_label;
2556 /* Return true if T should start a new basic block. PREV_T is the
2557 statement preceding T. It is used when T is a label or a case label.
2558 Labels should only start a new basic block if their previous statement
2559 wasn't a label. Otherwise, sequence of labels would generate
2560 unnecessary basic blocks that only contain a single label. */
2563 stmt_starts_bb_p (const_tree t, const_tree prev_t)
2568 /* LABEL_EXPRs start a new basic block only if the preceding
2569 statement wasn't a label of the same type. This prevents the
2570 creation of consecutive blocks that have nothing but a single
2572 if (TREE_CODE (t) == LABEL_EXPR)
2574 /* Nonlocal and computed GOTO targets always start a new block. */
2575 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t))
2576 || FORCED_LABEL (LABEL_EXPR_LABEL (t)))
2579 if (prev_t && TREE_CODE (prev_t) == LABEL_EXPR)
2581 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t)))
2584 cfg_stats.num_merged_labels++;
2595 /* Return true if T should end a basic block. */
2598 stmt_ends_bb_p (const_tree t)
2600 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2603 /* Remove block annotations and other datastructures. */
2606 delete_tree_cfg_annotations (void)
2609 block_stmt_iterator bsi;
2611 /* Remove annotations from every tree in the function. */
2613 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
2615 tree stmt = bsi_stmt (bsi);
2616 ggc_free (stmt->base.ann);
2617 stmt->base.ann = NULL;
2619 label_to_block_map = NULL;
2623 /* Return the first statement in basic block BB. */
2626 first_stmt (basic_block bb)
2628 block_stmt_iterator i = bsi_start (bb);
2629 return !bsi_end_p (i) ? bsi_stmt (i) : NULL_TREE;
2632 /* Return the last statement in basic block BB. */
2635 last_stmt (basic_block bb)
2637 block_stmt_iterator b = bsi_last (bb);
2638 return !bsi_end_p (b) ? bsi_stmt (b) : NULL_TREE;
2641 /* Return the last statement of an otherwise empty block. Return NULL
2642 if the block is totally empty, or if it contains more than one
2646 last_and_only_stmt (basic_block bb)
2648 block_stmt_iterator i = bsi_last (bb);
2654 last = bsi_stmt (i);
2659 /* Empty statements should no longer appear in the instruction stream.
2660 Everything that might have appeared before should be deleted by
2661 remove_useless_stmts, and the optimizers should just bsi_remove
2662 instead of smashing with build_empty_stmt.
2664 Thus the only thing that should appear here in a block containing
2665 one executable statement is a label. */
2666 prev = bsi_stmt (i);
2667 if (TREE_CODE (prev) == LABEL_EXPR)
2674 /* Mark BB as the basic block holding statement T. */
2677 set_bb_for_stmt (tree t, basic_block bb)
2679 if (TREE_CODE (t) == PHI_NODE)
2681 else if (TREE_CODE (t) == STATEMENT_LIST)
2683 tree_stmt_iterator i;
2684 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2685 set_bb_for_stmt (tsi_stmt (i), bb);
2689 stmt_ann_t ann = get_stmt_ann (t);
2692 /* If the statement is a label, add the label to block-to-labels map
2693 so that we can speed up edge creation for GOTO_EXPRs. */
2694 if (TREE_CODE (t) == LABEL_EXPR)
2698 t = LABEL_EXPR_LABEL (t);
2699 uid = LABEL_DECL_UID (t);
2702 unsigned old_len = VEC_length (basic_block, label_to_block_map);
2703 LABEL_DECL_UID (t) = uid = cfun->cfg->last_label_uid++;
2704 if (old_len <= (unsigned) uid)
2706 unsigned new_len = 3 * uid / 2;
2708 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
2713 /* We're moving an existing label. Make sure that we've
2714 removed it from the old block. */
2716 || !VEC_index (basic_block, label_to_block_map, uid));
2717 VEC_replace (basic_block, label_to_block_map, uid, bb);
2722 /* Faster version of set_bb_for_stmt that assume that statement is being moved
2723 from one basic block to another.
2724 For BB splitting we can run into quadratic case, so performance is quite
2725 important and knowing that the tables are big enough, change_bb_for_stmt
2726 can inline as leaf function. */
2728 change_bb_for_stmt (tree t, basic_block bb)
2730 get_stmt_ann (t)->bb = bb;
2731 if (TREE_CODE (t) == LABEL_EXPR)
2732 VEC_replace (basic_block, label_to_block_map,
2733 LABEL_DECL_UID (LABEL_EXPR_LABEL (t)), bb);
2736 /* Finds iterator for STMT. */
2738 extern block_stmt_iterator
2739 bsi_for_stmt (tree stmt)
2741 block_stmt_iterator bsi;
2743 for (bsi = bsi_start (bb_for_stmt (stmt)); !bsi_end_p (bsi); bsi_next (&bsi))
2744 if (bsi_stmt (bsi) == stmt)
2750 /* Mark statement T as modified, and update it. */
2752 update_modified_stmts (tree t)
2754 if (!ssa_operands_active ())
2756 if (TREE_CODE (t) == STATEMENT_LIST)
2758 tree_stmt_iterator i;
2760 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2762 stmt = tsi_stmt (i);
2763 update_stmt_if_modified (stmt);
2767 update_stmt_if_modified (t);
2770 /* Insert statement (or statement list) T before the statement
2771 pointed-to by iterator I. M specifies how to update iterator I
2772 after insertion (see enum bsi_iterator_update). */
2775 bsi_insert_before (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2777 set_bb_for_stmt (t, i->bb);
2778 update_modified_stmts (t);
2779 tsi_link_before (&i->tsi, t, m);
2783 /* Insert statement (or statement list) T after the statement
2784 pointed-to by iterator I. M specifies how to update iterator I
2785 after insertion (see enum bsi_iterator_update). */
2788 bsi_insert_after (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2790 set_bb_for_stmt (t, i->bb);
2791 update_modified_stmts (t);
2792 tsi_link_after (&i->tsi, t, m);
2796 /* Remove the statement pointed to by iterator I. The iterator is updated
2797 to the next statement.
2799 When REMOVE_EH_INFO is true we remove the statement pointed to by
2800 iterator I from the EH tables. Otherwise we do not modify the EH
2803 Generally, REMOVE_EH_INFO should be true when the statement is going to
2804 be removed from the IL and not reinserted elsewhere. */
2807 bsi_remove (block_stmt_iterator *i, bool remove_eh_info)
2809 tree t = bsi_stmt (*i);
2810 set_bb_for_stmt (t, NULL);
2811 delink_stmt_imm_use (t);
2812 tsi_delink (&i->tsi);
2813 mark_stmt_modified (t);
2816 remove_stmt_from_eh_region (t);
2817 gimple_remove_stmt_histograms (cfun, t);
2822 /* Move the statement at FROM so it comes right after the statement at TO. */
2825 bsi_move_after (block_stmt_iterator *from, block_stmt_iterator *to)
2827 tree stmt = bsi_stmt (*from);
2828 bsi_remove (from, false);
2829 /* We must have BSI_NEW_STMT here, as bsi_move_after is sometimes used to
2830 move statements to an empty block. */
2831 bsi_insert_after (to, stmt, BSI_NEW_STMT);
2835 /* Move the statement at FROM so it comes right before the statement at TO. */
2838 bsi_move_before (block_stmt_iterator *from, block_stmt_iterator *to)
2840 tree stmt = bsi_stmt (*from);
2841 bsi_remove (from, false);
2842 /* For consistency with bsi_move_after, it might be better to have
2843 BSI_NEW_STMT here; however, that breaks several places that expect
2844 that TO does not change. */
2845 bsi_insert_before (to, stmt, BSI_SAME_STMT);
2849 /* Move the statement at FROM to the end of basic block BB. */
2852 bsi_move_to_bb_end (block_stmt_iterator *from, basic_block bb)
2854 block_stmt_iterator last = bsi_last (bb);
2856 /* Have to check bsi_end_p because it could be an empty block. */
2857 if (!bsi_end_p (last) && is_ctrl_stmt (bsi_stmt (last)))
2858 bsi_move_before (from, &last);
2860 bsi_move_after (from, &last);
2864 /* Replace the contents of the statement pointed to by iterator BSI
2865 with STMT. If UPDATE_EH_INFO is true, the exception handling
2866 information of the original statement is moved to the new statement. */
2869 bsi_replace (const block_stmt_iterator *bsi, tree stmt, bool update_eh_info)
2872 tree orig_stmt = bsi_stmt (*bsi);
2874 if (stmt == orig_stmt)
2876 SET_EXPR_LOCUS (stmt, EXPR_LOCUS (orig_stmt));
2877 set_bb_for_stmt (stmt, bsi->bb);
2879 /* Preserve EH region information from the original statement, if
2880 requested by the caller. */
2883 eh_region = lookup_stmt_eh_region (orig_stmt);
2886 remove_stmt_from_eh_region (orig_stmt);
2887 add_stmt_to_eh_region (stmt, eh_region);
2891 gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
2892 gimple_remove_stmt_histograms (cfun, orig_stmt);
2893 delink_stmt_imm_use (orig_stmt);
2894 *bsi_stmt_ptr (*bsi) = stmt;
2895 mark_stmt_modified (stmt);
2896 update_modified_stmts (stmt);
2900 /* Insert the statement pointed-to by BSI into edge E. Every attempt
2901 is made to place the statement in an existing basic block, but
2902 sometimes that isn't possible. When it isn't possible, the edge is
2903 split and the statement is added to the new block.
2905 In all cases, the returned *BSI points to the correct location. The
2906 return value is true if insertion should be done after the location,
2907 or false if it should be done before the location. If new basic block
2908 has to be created, it is stored in *NEW_BB. */
2911 tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi,
2912 basic_block *new_bb)
2914 basic_block dest, src;
2920 /* If the destination has one predecessor which has no PHI nodes,
2921 insert there. Except for the exit block.
2923 The requirement for no PHI nodes could be relaxed. Basically we
2924 would have to examine the PHIs to prove that none of them used
2925 the value set by the statement we want to insert on E. That
2926 hardly seems worth the effort. */
2927 if (single_pred_p (dest)
2928 && ! phi_nodes (dest)
2929 && dest != EXIT_BLOCK_PTR)
2931 *bsi = bsi_start (dest);
2932 if (bsi_end_p (*bsi))
2935 /* Make sure we insert after any leading labels. */
2936 tmp = bsi_stmt (*bsi);
2937 while (TREE_CODE (tmp) == LABEL_EXPR)
2940 if (bsi_end_p (*bsi))
2942 tmp = bsi_stmt (*bsi);
2945 if (bsi_end_p (*bsi))
2947 *bsi = bsi_last (dest);
2954 /* If the source has one successor, the edge is not abnormal and
2955 the last statement does not end a basic block, insert there.
2956 Except for the entry block. */
2958 if ((e->flags & EDGE_ABNORMAL) == 0
2959 && single_succ_p (src)
2960 && src != ENTRY_BLOCK_PTR)
2962 *bsi = bsi_last (src);
2963 if (bsi_end_p (*bsi))
2966 tmp = bsi_stmt (*bsi);
2967 if (!stmt_ends_bb_p (tmp))
2970 /* Insert code just before returning the value. We may need to decompose
2971 the return in the case it contains non-trivial operand. */
2972 if (TREE_CODE (tmp) == RETURN_EXPR)
2974 tree op = TREE_OPERAND (tmp, 0);
2975 if (op && !is_gimple_val (op))
2977 gcc_assert (TREE_CODE (op) == GIMPLE_MODIFY_STMT);
2978 bsi_insert_before (bsi, op, BSI_NEW_STMT);
2979 TREE_OPERAND (tmp, 0) = GIMPLE_STMT_OPERAND (op, 0);
2986 /* Otherwise, create a new basic block, and split this edge. */
2987 dest = split_edge (e);
2990 e = single_pred_edge (dest);
2995 /* This routine will commit all pending edge insertions, creating any new
2996 basic blocks which are necessary. */
2999 bsi_commit_edge_inserts (void)
3005 bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL);
3008 FOR_EACH_EDGE (e, ei, bb->succs)
3009 bsi_commit_one_edge_insert (e, NULL);
3013 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
3014 to this block, otherwise set it to NULL. */
3017 bsi_commit_one_edge_insert (edge e, basic_block *new_bb)
3021 if (PENDING_STMT (e))
3023 block_stmt_iterator bsi;
3024 tree stmt = PENDING_STMT (e);
3026 PENDING_STMT (e) = NULL_TREE;
3028 if (tree_find_edge_insert_loc (e, &bsi, new_bb))
3029 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3031 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3036 /* Add STMT to the pending list of edge E. No actual insertion is
3037 made until a call to bsi_commit_edge_inserts () is made. */
3040 bsi_insert_on_edge (edge e, tree stmt)
3042 append_to_statement_list (stmt, &PENDING_STMT (e));
3045 /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new
3046 block has to be created, it is returned. */
3049 bsi_insert_on_edge_immediate (edge e, tree stmt)
3051 block_stmt_iterator bsi;
3052 basic_block new_bb = NULL;
3054 gcc_assert (!PENDING_STMT (e));
3056 if (tree_find_edge_insert_loc (e, &bsi, &new_bb))
3057 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3059 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3064 /*---------------------------------------------------------------------------
3065 Tree specific functions for CFG manipulation
3066 ---------------------------------------------------------------------------*/
3068 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
3071 reinstall_phi_args (edge new_edge, edge old_edge)
3074 edge_var_map_vector v;
3078 v = redirect_edge_var_map_vector (old_edge);
3082 for (i = 0, phi = phi_nodes (new_edge->dest);
3083 VEC_iterate (edge_var_map, v, i, vm) && phi;
3084 i++, phi = PHI_CHAIN (phi))
3086 tree result = redirect_edge_var_map_result (vm);
3087 tree arg = redirect_edge_var_map_def (vm);
3089 gcc_assert (result == PHI_RESULT (phi));
3091 add_phi_arg (phi, arg, new_edge);
3094 redirect_edge_var_map_clear (old_edge);
3097 /* Returns the basic block after which the new basic block created
3098 by splitting edge EDGE_IN should be placed. Tries to keep the new block
3099 near its "logical" location. This is of most help to humans looking
3100 at debugging dumps. */
3103 split_edge_bb_loc (edge edge_in)
3105 basic_block dest = edge_in->dest;
3107 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
3108 return edge_in->src;
3110 return dest->prev_bb;
3113 /* Split a (typically critical) edge EDGE_IN. Return the new block.
3114 Abort on abnormal edges. */
3117 tree_split_edge (edge edge_in)
3119 basic_block new_bb, after_bb, dest;
3122 /* Abnormal edges cannot be split. */
3123 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
3125 dest = edge_in->dest;
3127 after_bb = split_edge_bb_loc (edge_in);
3129 new_bb = create_empty_bb (after_bb);
3130 new_bb->frequency = EDGE_FREQUENCY (edge_in);
3131 new_bb->count = edge_in->count;
3132 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
3133 new_edge->probability = REG_BR_PROB_BASE;
3134 new_edge->count = edge_in->count;
3136 e = redirect_edge_and_branch (edge_in, new_bb);
3137 gcc_assert (e == edge_in);
3138 reinstall_phi_args (new_edge, e);
3143 /* Callback for walk_tree, check that all elements with address taken are
3144 properly noticed as such. The DATA is an int* that is 1 if TP was seen
3145 inside a PHI node. */
3148 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
3155 /* Check operand N for being valid GIMPLE and give error MSG if not. */
3156 #define CHECK_OP(N, MSG) \
3157 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
3158 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
3160 switch (TREE_CODE (t))
3163 if (SSA_NAME_IN_FREE_LIST (t))
3165 error ("SSA name in freelist but still referenced");
3171 x = fold (ASSERT_EXPR_COND (t));
3172 if (x == boolean_false_node)
3174 error ("ASSERT_EXPR with an always-false condition");
3182 case GIMPLE_MODIFY_STMT:
3183 x = GIMPLE_STMT_OPERAND (t, 0);
3184 if (TREE_CODE (x) == BIT_FIELD_REF
3185 && is_gimple_reg (TREE_OPERAND (x, 0)))
3187 error ("GIMPLE register modified with BIT_FIELD_REF");
3195 bool old_side_effects;
3197 bool new_side_effects;
3199 gcc_assert (is_gimple_address (t));
3201 old_constant = TREE_CONSTANT (t);
3202 old_side_effects = TREE_SIDE_EFFECTS (t);
3204 recompute_tree_invariant_for_addr_expr (t);
3205 new_side_effects = TREE_SIDE_EFFECTS (t);
3206 new_constant = TREE_CONSTANT (t);
3208 if (old_constant != new_constant)
3210 error ("constant not recomputed when ADDR_EXPR changed");
3213 if (old_side_effects != new_side_effects)
3215 error ("side effects not recomputed when ADDR_EXPR changed");
3219 /* Skip any references (they will be checked when we recurse down the
3220 tree) and ensure that any variable used as a prefix is marked
3222 for (x = TREE_OPERAND (t, 0);
3223 handled_component_p (x);
3224 x = TREE_OPERAND (x, 0))
3227 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
3229 if (!TREE_ADDRESSABLE (x))
3231 error ("address taken, but ADDRESSABLE bit not set");
3239 x = COND_EXPR_COND (t);
3240 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
3242 error ("non-integral used in condition");
3245 if (!is_gimple_condexpr (x))
3247 error ("invalid conditional operand");
3252 case NON_LVALUE_EXPR:
3256 case FIX_TRUNC_EXPR:
3261 case TRUTH_NOT_EXPR:
3262 CHECK_OP (0, "invalid operand to unary operator");
3269 case ARRAY_RANGE_REF:
3271 case VIEW_CONVERT_EXPR:
3272 /* We have a nest of references. Verify that each of the operands
3273 that determine where to reference is either a constant or a variable,
3274 verify that the base is valid, and then show we've already checked
3276 while (handled_component_p (t))
3278 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
3279 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
3280 else if (TREE_CODE (t) == ARRAY_REF
3281 || TREE_CODE (t) == ARRAY_RANGE_REF)
3283 CHECK_OP (1, "invalid array index");
3284 if (TREE_OPERAND (t, 2))
3285 CHECK_OP (2, "invalid array lower bound");
3286 if (TREE_OPERAND (t, 3))
3287 CHECK_OP (3, "invalid array stride");
3289 else if (TREE_CODE (t) == BIT_FIELD_REF)
3291 if (!host_integerp (TREE_OPERAND (t, 1), 1)
3292 || !host_integerp (TREE_OPERAND (t, 2), 1))
3294 error ("invalid position or size operand to BIT_FIELD_REF");
3297 else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
3298 && (TYPE_PRECISION (TREE_TYPE (t))
3299 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
3301 error ("integral result type precision does not match "
3302 "field size of BIT_FIELD_REF");
3305 if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
3306 && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
3307 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
3309 error ("mode precision of non-integral result does not "
3310 "match field size of BIT_FIELD_REF");
3315 t = TREE_OPERAND (t, 0);
3318 if (!is_gimple_min_invariant (t) && !is_gimple_lvalue (t))
3320 error ("invalid reference prefix");
3327 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
3328 POINTER_PLUS_EXPR. */
3329 if (POINTER_TYPE_P (TREE_TYPE (t)))
3331 error ("invalid operand to plus/minus, type is a pointer");
3334 CHECK_OP (0, "invalid operand to binary operator");
3335 CHECK_OP (1, "invalid operand to binary operator");
3338 case POINTER_PLUS_EXPR:
3339 /* Check to make sure the first operand is a pointer or reference type. */
3340 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
3342 error ("invalid operand to pointer plus, first operand is not a pointer");
3345 /* Check to make sure the second operand is an integer with type of
3347 if (!useless_type_conversion_p (sizetype,
3348 TREE_TYPE (TREE_OPERAND (t, 1))))
3350 error ("invalid operand to pointer plus, second operand is not an "
3351 "integer with type of sizetype.");
3361 case UNORDERED_EXPR:
3370 case TRUNC_DIV_EXPR:
3372 case FLOOR_DIV_EXPR:
3373 case ROUND_DIV_EXPR:
3374 case TRUNC_MOD_EXPR:
3376 case FLOOR_MOD_EXPR:
3377 case ROUND_MOD_EXPR:
3379 case EXACT_DIV_EXPR:
3389 CHECK_OP (0, "invalid operand to binary operator");
3390 CHECK_OP (1, "invalid operand to binary operator");
3394 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3406 /* Verifies if EXPR is a valid GIMPLE unary expression. Returns true
3407 if there is an error, otherwise false. */
3410 verify_gimple_unary_expr (const_tree expr)
3412 tree op = TREE_OPERAND (expr, 0);
3413 tree type = TREE_TYPE (expr);
3415 if (!is_gimple_val (op))
3417 error ("invalid operand in unary expression");
3421 /* For general unary expressions we have the operations type
3422 as the effective type the operation is carried out on. So all
3423 we need to require is that the operand is trivially convertible
3425 if (!useless_type_conversion_p (type, TREE_TYPE (op)))
3427 error ("type mismatch in unary expression");
3428 debug_generic_expr (type);
3429 debug_generic_expr (TREE_TYPE (op));
3436 /* Verifies if EXPR is a valid GIMPLE binary expression. Returns true
3437 if there is an error, otherwise false. */
3440 verify_gimple_binary_expr (const_tree expr)
3442 tree op0 = TREE_OPERAND (expr, 0);
3443 tree op1 = TREE_OPERAND (expr, 1);
3444 tree type = TREE_TYPE (expr);
3446 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3448 error ("invalid operands in binary expression");
3452 /* For general binary expressions we have the operations type
3453 as the effective type the operation is carried out on. So all
3454 we need to require is that both operands are trivially convertible
3456 if (!useless_type_conversion_p (type, TREE_TYPE (op0))
3457 || !useless_type_conversion_p (type, TREE_TYPE (op1)))
3459 error ("type mismatch in binary expression");
3460 debug_generic_stmt (type);
3461 debug_generic_stmt (TREE_TYPE (op0));
3462 debug_generic_stmt (TREE_TYPE (op1));
3469 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3470 Returns true if there is an error, otherwise false. */
3473 verify_gimple_min_lval (tree expr)
3477 if (is_gimple_id (expr))
3480 if (TREE_CODE (expr) != INDIRECT_REF
3481 && TREE_CODE (expr) != ALIGN_INDIRECT_REF
3482 && TREE_CODE (expr) != MISALIGNED_INDIRECT_REF)
3484 error ("invalid expression for min lvalue");
3488 op = TREE_OPERAND (expr, 0);
3489 if (!is_gimple_val (op))
3491 error ("invalid operand in indirect reference");
3492 debug_generic_stmt (op);
3495 if (!useless_type_conversion_p (TREE_TYPE (expr),
3496 TREE_TYPE (TREE_TYPE (op))))
3498 error ("type mismatch in indirect reference");
3499 debug_generic_stmt (TREE_TYPE (expr));
3500 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3507 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3508 if there is an error, otherwise false. */
3511 verify_gimple_reference (tree expr)
3513 while (handled_component_p (expr))
3515 tree op = TREE_OPERAND (expr, 0);
3517 if (TREE_CODE (expr) == ARRAY_REF
3518 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3520 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3521 || (TREE_OPERAND (expr, 2)
3522 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3523 || (TREE_OPERAND (expr, 3)
3524 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3526 error ("invalid operands to array reference");
3527 debug_generic_stmt (expr);
3532 /* Verify if the reference array element types are compatible. */
3533 if (TREE_CODE (expr) == ARRAY_REF
3534 && !useless_type_conversion_p (TREE_TYPE (expr),
3535 TREE_TYPE (TREE_TYPE (op))))
3537 error ("type mismatch in array reference");
3538 debug_generic_stmt (TREE_TYPE (expr));
3539 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3542 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3543 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3544 TREE_TYPE (TREE_TYPE (op))))
3546 error ("type mismatch in array range reference");
3547 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3548 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3552 if ((TREE_CODE (expr) == REALPART_EXPR
3553 || TREE_CODE (expr) == IMAGPART_EXPR)
3554 && !useless_type_conversion_p (TREE_TYPE (expr),
3555 TREE_TYPE (TREE_TYPE (op))))
3557 error ("type mismatch in real/imagpart reference");
3558 debug_generic_stmt (TREE_TYPE (expr));
3559 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3563 if (TREE_CODE (expr) == COMPONENT_REF
3564 && !useless_type_conversion_p (TREE_TYPE (expr),
3565 TREE_TYPE (TREE_OPERAND (expr, 1))))
3567 error ("type mismatch in component reference");
3568 debug_generic_stmt (TREE_TYPE (expr));
3569 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3573 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3574 is nothing to verify. Gross mismatches at most invoke
3575 undefined behavior. */
3580 return verify_gimple_min_lval (expr);
3583 /* Returns true if there is one pointer type in TYPE_POINTER_TO (SRC_OBJ)
3584 list of pointer-to types that is trivially convertible to DEST. */
3587 one_pointer_to_useless_type_conversion_p (tree dest, tree src_obj)
3591 if (!TYPE_POINTER_TO (src_obj))
3594 for (src = TYPE_POINTER_TO (src_obj); src; src = TYPE_NEXT_PTR_TO (src))
3595 if (useless_type_conversion_p (dest, src))
3601 /* Return true if TYPE1 is a fixed-point type and if conversions to and
3602 from TYPE2 can be handled by FIXED_CONVERT_EXPR. */
3605 valid_fixed_convert_types_p (tree type1, tree type2)
3607 return (FIXED_POINT_TYPE_P (type1)
3608 && (INTEGRAL_TYPE_P (type2)
3609 || SCALAR_FLOAT_TYPE_P (type2)
3610 || FIXED_POINT_TYPE_P (type2)));
3613 /* Verify the GIMPLE expression EXPR. Returns true if there is an
3614 error, otherwise false. */
3617 verify_gimple_expr (tree expr)
3619 tree type = TREE_TYPE (expr);
3621 if (is_gimple_val (expr))
3624 /* Special codes we cannot handle via their class. */
3625 switch (TREE_CODE (expr))
3629 tree op = TREE_OPERAND (expr, 0);
3630 if (!is_gimple_val (op))
3632 error ("invalid operand in conversion");
3636 /* Allow conversions between integral types and between
3638 if ((INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3639 || (POINTER_TYPE_P (type) && POINTER_TYPE_P (TREE_TYPE (op))))
3642 /* Allow conversions between integral types and pointers only if
3643 there is no sign or zero extension involved. */
3644 if (((POINTER_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3645 || (POINTER_TYPE_P (TREE_TYPE (op)) && INTEGRAL_TYPE_P (type)))
3646 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op)))
3649 /* Allow conversion from integer to offset type and vice versa. */
3650 if ((TREE_CODE (type) == OFFSET_TYPE
3651 && TREE_CODE (TREE_TYPE (op)) == INTEGER_TYPE)
3652 || (TREE_CODE (type) == INTEGER_TYPE
3653 && TREE_CODE (TREE_TYPE (op)) == OFFSET_TYPE))
3656 /* Otherwise assert we are converting between types of the
3658 if (TREE_CODE (type) != TREE_CODE (TREE_TYPE (op)))
3660 error ("invalid types in nop conversion");
3661 debug_generic_expr (type);
3662 debug_generic_expr (TREE_TYPE (op));
3669 case FIXED_CONVERT_EXPR:
3671 tree op = TREE_OPERAND (expr, 0);
3672 if (!is_gimple_val (op))
3674 error ("invalid operand in conversion");
3678 if (!valid_fixed_convert_types_p (type, TREE_TYPE (op))
3679 && !valid_fixed_convert_types_p (TREE_TYPE (op), type))
3681 error ("invalid types in fixed-point conversion");
3682 debug_generic_expr (type);
3683 debug_generic_expr (TREE_TYPE (op));
3692 tree op = TREE_OPERAND (expr, 0);
3693 if (!is_gimple_val (op))
3695 error ("invalid operand in int to float conversion");
3698 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3699 || !SCALAR_FLOAT_TYPE_P (type))
3701 error ("invalid types in conversion to floating point");
3702 debug_generic_expr (type);
3703 debug_generic_expr (TREE_TYPE (op));
3709 case FIX_TRUNC_EXPR:
3711 tree op = TREE_OPERAND (expr, 0);
3712 if (!is_gimple_val (op))
3714 error ("invalid operand in float to int conversion");
3717 if (!INTEGRAL_TYPE_P (type)
3718 || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (op)))
3720 error ("invalid types in conversion to integer");
3721 debug_generic_expr (type);
3722 debug_generic_expr (TREE_TYPE (op));
3730 tree op0 = TREE_OPERAND (expr, 0);
3731 tree op1 = TREE_OPERAND (expr, 1);
3732 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3734 error ("invalid operands in complex expression");
3737 if (!TREE_CODE (type) == COMPLEX_TYPE
3738 || !(TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
3739 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0)))
3740 || !(TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3741 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op1)))
3742 || !useless_type_conversion_p (TREE_TYPE (type),
3744 || !useless_type_conversion_p (TREE_TYPE (type),
3747 error ("type mismatch in complex expression");
3748 debug_generic_stmt (TREE_TYPE (expr));
3749 debug_generic_stmt (TREE_TYPE (op0));
3750 debug_generic_stmt (TREE_TYPE (op1));
3758 /* This is used like COMPLEX_EXPR but for vectors. */
3759 if (TREE_CODE (type) != VECTOR_TYPE)
3761 error ("constructor not allowed for non-vector types");
3762 debug_generic_stmt (type);
3765 /* FIXME: verify constructor arguments. */
3774 tree op0 = TREE_OPERAND (expr, 0);
3775 tree op1 = TREE_OPERAND (expr, 1);
3776 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3778 error ("invalid operands in shift expression");
3781 if (!TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3782 || !useless_type_conversion_p (type, TREE_TYPE (op0)))
3784 error ("type mismatch in shift expression");
3785 debug_generic_stmt (TREE_TYPE (expr));
3786 debug_generic_stmt (TREE_TYPE (op0));
3787 debug_generic_stmt (TREE_TYPE (op1));
3796 tree op0 = TREE_OPERAND (expr, 0);
3797 tree op1 = TREE_OPERAND (expr, 1);
3798 if (POINTER_TYPE_P (type)
3799 || POINTER_TYPE_P (TREE_TYPE (op0))
3800 || POINTER_TYPE_P (TREE_TYPE (op1)))
3802 error ("invalid (pointer) operands to plus/minus");
3805 /* Continue with generic binary expression handling. */
3809 case POINTER_PLUS_EXPR:
3811 tree op0 = TREE_OPERAND (expr, 0);
3812 tree op1 = TREE_OPERAND (expr, 1);
3813 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3815 error ("invalid operands in pointer plus expression");
3818 if (!POINTER_TYPE_P (TREE_TYPE (op0))
3819 || !useless_type_conversion_p (type, TREE_TYPE (op0))
3820 || !useless_type_conversion_p (sizetype, TREE_TYPE (op1)))
3822 error ("type mismatch in pointer plus expression");
3823 debug_generic_stmt (type);
3824 debug_generic_stmt (TREE_TYPE (op0));
3825 debug_generic_stmt (TREE_TYPE (op1));
3833 tree op0 = TREE_OPERAND (expr, 0);
3834 tree op1 = TREE_OPERAND (expr, 1);
3835 tree op2 = TREE_OPERAND (expr, 2);
3836 if ((!is_gimple_val (op1)
3837 && TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3838 || (!is_gimple_val (op2)
3839 && TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE))
3841 error ("invalid operands in conditional expression");
3844 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3845 || (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE
3846 && !useless_type_conversion_p (type, TREE_TYPE (op1)))
3847 || (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE
3848 && !useless_type_conversion_p (type, TREE_TYPE (op2))))
3850 error ("type mismatch in conditional expression");
3851 debug_generic_stmt (type);
3852 debug_generic_stmt (TREE_TYPE (op0));
3853 debug_generic_stmt (TREE_TYPE (op1));
3854 debug_generic_stmt (TREE_TYPE (op2));
3857 return verify_gimple_expr (op0);
3862 tree op = TREE_OPERAND (expr, 0);
3863 if (!is_gimple_addressable (op))
3865 error ("invalid operand in unary expression");
3868 if (!one_pointer_to_useless_type_conversion_p (type, TREE_TYPE (op))
3869 /* FIXME: a longstanding wart, &a == &a[0]. */
3870 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3871 || !one_pointer_to_useless_type_conversion_p (type,
3872 TREE_TYPE (TREE_TYPE (op)))))
3874 error ("type mismatch in address expression");
3875 debug_generic_stmt (TREE_TYPE (expr));
3876 debug_generic_stmt (TYPE_POINTER_TO (TREE_TYPE (op)));
3880 return verify_gimple_reference (op);
3883 case TRUTH_ANDIF_EXPR:
3884 case TRUTH_ORIF_EXPR:
3887 case TRUTH_AND_EXPR:
3889 case TRUTH_XOR_EXPR:
3891 tree op0 = TREE_OPERAND (expr, 0);
3892 tree op1 = TREE_OPERAND (expr, 1);
3894 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3896 error ("invalid operands in truth expression");
3900 /* We allow any kind of integral typed argument and result. */
3901 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3902 || !INTEGRAL_TYPE_P (TREE_TYPE (op1))
3903 || !INTEGRAL_TYPE_P (type))
3905 error ("type mismatch in binary truth expression");
3906 debug_generic_stmt (type);
3907 debug_generic_stmt (TREE_TYPE (op0));
3908 debug_generic_stmt (TREE_TYPE (op1));
3915 case TRUTH_NOT_EXPR:
3917 tree op = TREE_OPERAND (expr, 0);
3919 if (!is_gimple_val (op))
3921 error ("invalid operand in unary not");
3925 /* For TRUTH_NOT_EXPR we can have any kind of integral
3926 typed arguments and results. */
3927 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3928 || !INTEGRAL_TYPE_P (type))
3930 error ("type mismatch in not expression");
3931 debug_generic_expr (TREE_TYPE (expr));
3932 debug_generic_expr (TREE_TYPE (op));
3940 /* FIXME. The C frontend passes unpromoted arguments in case it
3941 didn't see a function declaration before the call. */
3943 tree decl = CALL_EXPR_FN (expr);
3945 if (TREE_CODE (decl) == FUNCTION_DECL
3946 && DECL_LOOPING_CONST_OR_PURE_P (decl)
3947 && (!DECL_PURE_P (decl))
3948 && (!TREE_READONLY (decl)))
3950 error ("invalid pure const state for function");
3963 /* Generic handling via classes. */
3964 switch (TREE_CODE_CLASS (TREE_CODE (expr)))
3967 return verify_gimple_unary_expr (expr);
3970 return verify_gimple_binary_expr (expr);
3973 return verify_gimple_reference (expr);
3975 case tcc_comparison:
3977 tree op0 = TREE_OPERAND (expr, 0);
3978 tree op1 = TREE_OPERAND (expr, 1);
3979 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3981 error ("invalid operands in comparison expression");
3984 /* For comparisons we do not have the operations type as the
3985 effective type the comparison is carried out in. Instead
3986 we require that either the first operand is trivially
3987 convertible into the second, or the other way around.
3988 The resulting type of a comparison may be any integral type.
3989 Because we special-case pointers to void we allow
3990 comparisons of pointers with the same mode as well. */
3991 if ((!useless_type_conversion_p (TREE_TYPE (op0), TREE_TYPE (op1))
3992 && !useless_type_conversion_p (TREE_TYPE (op1), TREE_TYPE (op0))
3993 && (!POINTER_TYPE_P (TREE_TYPE (op0))
3994 || !POINTER_TYPE_P (TREE_TYPE (op1))
3995 || TYPE_MODE (TREE_TYPE (op0)) != TYPE_MODE (TREE_TYPE (op1))))
3996 || !INTEGRAL_TYPE_P (type))
3998 error ("type mismatch in comparison expression");
3999 debug_generic_stmt (TREE_TYPE (expr));
4000 debug_generic_stmt (TREE_TYPE (op0));
4001 debug_generic_stmt (TREE_TYPE (op1));
4014 /* Verify the GIMPLE assignment statement STMT. Returns true if there
4015 is an error, otherwise false. */
4018 verify_gimple_modify_stmt (const_tree stmt)
4020 tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
4021 tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
4023 gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
4025 if (!useless_type_conversion_p (TREE_TYPE (lhs),
4028 error ("non-trivial conversion at assignment");
4029 debug_generic_expr (TREE_TYPE (lhs));
4030 debug_generic_expr (TREE_TYPE (rhs));
4034 /* Loads/stores from/to a variable are ok. */
4035 if ((is_gimple_val (lhs)
4036 && is_gimple_variable (rhs))
4037 || (is_gimple_val (rhs)
4038 && is_gimple_variable (lhs)))
4041 /* Aggregate copies are ok. */
4042 if (!is_gimple_reg_type (TREE_TYPE (lhs))
4043 && !is_gimple_reg_type (TREE_TYPE (rhs)))
4046 /* We might get 'loads' from a parameter which is not a gimple value. */
4047 if (TREE_CODE (rhs) == PARM_DECL)
4048 return verify_gimple_expr (lhs);
4050 if (!is_gimple_variable (lhs)
4051 && verify_gimple_expr (lhs))
4054 if (!is_gimple_variable (rhs)
4055 && verify_gimple_expr (rhs))
4061 /* Verify the GIMPLE statement STMT. Returns true if there is an
4062 error, otherwise false. */
4065 verify_gimple_stmt (tree stmt)
4067 if (!is_gimple_stmt (stmt))
4069 error ("is not a valid GIMPLE statement");
4073 if (OMP_DIRECTIVE_P (stmt))
4075 /* OpenMP directives are validated by the FE and never operated
4076 on by the optimizers. Furthermore, OMP_FOR may contain
4077 non-gimple expressions when the main index variable has had
4078 its address taken. This does not affect the loop itself
4079 because the header of an OMP_FOR is merely used to determine
4080 how to setup the parallel iteration. */
4084 switch (TREE_CODE (stmt))
4086 case GIMPLE_MODIFY_STMT:
4087 return verify_gimple_modify_stmt (stmt);
4094 if (!is_gimple_val (TREE_OPERAND (stmt, 0)))
4096 error ("invalid operand to switch statement");
4097 debug_generic_expr (TREE_OPERAND (stmt, 0));
4103 tree op = TREE_OPERAND (stmt, 0);
4105 if (TREE_CODE (TREE_TYPE (stmt)) != VOID_TYPE)
4107 error ("type error in return expression");
4112 || TREE_CODE (op) == RESULT_DECL)
4115 return verify_gimple_modify_stmt (op);
4120 return verify_gimple_expr (stmt);
4123 case CHANGE_DYNAMIC_TYPE_EXPR:
4133 /* Verify the GIMPLE statements inside the statement list STMTS.
4134 Returns true if there were any errors. */
4137 verify_gimple_2 (tree stmts)
4139 tree_stmt_iterator tsi;
4142 for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi))
4144 tree stmt = tsi_stmt (tsi);
4146 switch (TREE_CODE (stmt))
4149 err |= verify_gimple_2 (BIND_EXPR_BODY (stmt));
4152 case TRY_CATCH_EXPR:
4153 case TRY_FINALLY_EXPR:
4154 err |= verify_gimple_2 (TREE_OPERAND (stmt, 0));
4155 err |= verify_gimple_2 (TREE_OPERAND (stmt, 1));
4159 err |= verify_gimple_2 (CATCH_BODY (stmt));
4162 case EH_FILTER_EXPR:
4163 err |= verify_gimple_2 (EH_FILTER_FAILURE (stmt));
4168 bool err2 = verify_gimple_stmt (stmt);
4170 debug_generic_expr (stmt);
4180 /* Verify the GIMPLE statements inside the statement list STMTS. */
4183 verify_gimple_1 (tree stmts)
4185 if (verify_gimple_2 (stmts))
4186 internal_error ("verify_gimple failed");
4189 /* Verify the GIMPLE statements inside the current function. */
4192 verify_gimple (void)
4194 verify_gimple_1 (BIND_EXPR_BODY (DECL_SAVED_TREE (cfun->decl)));
4197 /* Verify STMT, return true if STMT is not in GIMPLE form.
4198 TODO: Implement type checking. */
4201 verify_stmt (tree stmt, bool last_in_block)
4205 if (OMP_DIRECTIVE_P (stmt))
4207 /* OpenMP directives are validated by the FE and never operated
4208 on by the optimizers. Furthermore, OMP_FOR may contain
4209 non-gimple expressions when the main index variable has had
4210 its address taken. This does not affect the loop itself
4211 because the header of an OMP_FOR is merely used to determine
4212 how to setup the parallel iteration. */
4216 if (!is_gimple_stmt (stmt))
4218 error ("is not a valid GIMPLE statement");
4222 addr = walk_tree (&stmt, verify_expr, NULL, NULL);
4225 debug_generic_stmt (addr);
4228 inform ("in statement");
4229 debug_generic_stmt (stmt);
4234 /* If the statement is marked as part of an EH region, then it is
4235 expected that the statement could throw. Verify that when we
4236 have optimizations that simplify statements such that we prove
4237 that they cannot throw, that we update other data structures
4239 if (lookup_stmt_eh_region (stmt) >= 0)
4241 if (!tree_could_throw_p (stmt))
4243 error ("statement marked for throw, but doesn%'t");
4246 if (!last_in_block && tree_can_throw_internal (stmt))
4248 error ("statement marked for throw in middle of block");
4256 debug_generic_stmt (stmt);
4261 /* Return true when the T can be shared. */
4264 tree_node_can_be_shared (tree t)
4266 if (IS_TYPE_OR_DECL_P (t)
4267 || is_gimple_min_invariant (t)
4268 || TREE_CODE (t) == SSA_NAME
4269 || t == error_mark_node
4270 || TREE_CODE (t) == IDENTIFIER_NODE)
4273 if (TREE_CODE (t) == CASE_LABEL_EXPR)
4276 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4277 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4278 || TREE_CODE (t) == COMPONENT_REF
4279 || TREE_CODE (t) == REALPART_EXPR
4280 || TREE_CODE (t) == IMAGPART_EXPR)
4281 t = TREE_OPERAND (t, 0);
4290 /* Called via walk_trees. Verify tree sharing. */
4293 verify_node_sharing (tree * tp, int *walk_subtrees, void *data)
4295 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4297 if (tree_node_can_be_shared (*tp))
4299 *walk_subtrees = false;
4303 if (pointer_set_insert (visited, *tp))
4310 /* Helper function for verify_gimple_tuples. */
4313 verify_gimple_tuples_1 (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4314 void *data ATTRIBUTE_UNUSED)
4316 switch (TREE_CODE (*tp))
4319 error ("unexpected non-tuple");
4329 /* Verify that there are no trees that should have been converted to
4330 gimple tuples. Return true if T contains a node that should have
4331 been converted to a gimple tuple, but hasn't. */
4334 verify_gimple_tuples (tree t)
4336 return walk_tree (&t, verify_gimple_tuples_1, NULL, NULL) != NULL;
4339 static bool eh_error_found;
4341 verify_eh_throw_stmt_node (void **slot, void *data)
4343 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4344 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4346 if (!pointer_set_contains (visited, node->stmt))
4348 error ("Dead STMT in EH table");
4349 debug_generic_stmt (node->stmt);
4350 eh_error_found = true;
4355 /* Verify the GIMPLE statement chain. */
4361 block_stmt_iterator bsi;
4363 struct pointer_set_t *visited, *visited_stmts;
4366 timevar_push (TV_TREE_STMT_VERIFY);
4367 visited = pointer_set_create ();
4368 visited_stmts = pointer_set_create ();
4375 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4377 int phi_num_args = PHI_NUM_ARGS (phi);
4379 pointer_set_insert (visited_stmts, phi);
4380 if (bb_for_stmt (phi) != bb)
4382 error ("bb_for_stmt (phi) is set to a wrong basic block");
4386 for (i = 0; i < phi_num_args; i++)
4388 tree t = PHI_ARG_DEF (phi, i);
4393 error ("missing PHI def");
4394 debug_generic_stmt (phi);
4398 /* Addressable variables do have SSA_NAMEs but they
4399 are not considered gimple values. */
4400 else if (TREE_CODE (t) != SSA_NAME
4401 && TREE_CODE (t) != FUNCTION_DECL
4402 && !is_gimple_min_invariant (t))
4404 error ("PHI def is not a GIMPLE value");
4405 debug_generic_stmt (phi);
4406 debug_generic_stmt (t);
4410 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4413 error ("incorrect sharing of tree nodes");
4414 debug_generic_stmt (phi);
4415 debug_generic_stmt (addr);
4421 for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
4423 tree stmt = bsi_stmt (bsi);
4425 pointer_set_insert (visited_stmts, stmt);
4426 err |= verify_gimple_tuples (stmt);
4428 if (bb_for_stmt (stmt) != bb)
4430 error ("bb_for_stmt (stmt) is set to a wrong basic block");
4435 err |= verify_stmt (stmt, bsi_end_p (bsi));
4436 addr = walk_tree (&stmt, verify_node_sharing, visited, NULL);
4439 error ("incorrect sharing of tree nodes");
4440 debug_generic_stmt (stmt);
4441 debug_generic_stmt (addr);
4446 eh_error_found = false;
4447 if (get_eh_throw_stmt_table (cfun))
4448 htab_traverse (get_eh_throw_stmt_table (cfun),
4449 verify_eh_throw_stmt_node,
4452 if (err | eh_error_found)
4453 internal_error ("verify_stmts failed");
4455 pointer_set_destroy (visited);
4456 pointer_set_destroy (visited_stmts);
4457 verify_histograms ();
4458 timevar_pop (TV_TREE_STMT_VERIFY);
4462 /* Verifies that the flow information is OK. */
4465 tree_verify_flow_info (void)
4469 block_stmt_iterator bsi;
4474 if (ENTRY_BLOCK_PTR->il.tree)
4476 error ("ENTRY_BLOCK has IL associated with it");
4480 if (EXIT_BLOCK_PTR->il.tree)
4482 error ("EXIT_BLOCK has IL associated with it");
4486 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4487 if (e->flags & EDGE_FALLTHRU)
4489 error ("fallthru to exit from bb %d", e->src->index);
4495 bool found_ctrl_stmt = false;
4499 /* Skip labels on the start of basic block. */
4500 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4502 tree prev_stmt = stmt;
4504 stmt = bsi_stmt (bsi);
4506 if (TREE_CODE (stmt) != LABEL_EXPR)
4509 if (prev_stmt && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
4511 error ("nonlocal label ");
4512 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4513 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4518 if (label_to_block (LABEL_EXPR_LABEL (stmt)) != bb)
4521 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4522 fprintf (stderr, " to block does not match in bb %d",
4527 if (decl_function_context (LABEL_EXPR_LABEL (stmt))
4528 != current_function_decl)
4531 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4532 fprintf (stderr, " has incorrect context in bb %d",
4538 /* Verify that body of basic block BB is free of control flow. */
4539 for (; !bsi_end_p (bsi); bsi_next (&bsi))
4541 tree stmt = bsi_stmt (bsi);
4543 if (found_ctrl_stmt)
4545 error ("control flow in the middle of basic block %d",
4550 if (stmt_ends_bb_p (stmt))
4551 found_ctrl_stmt = true;
4553 if (TREE_CODE (stmt) == LABEL_EXPR)
4556 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4557 fprintf (stderr, " in the middle of basic block %d", bb->index);
4562 bsi = bsi_last (bb);
4563 if (bsi_end_p (bsi))
4566 stmt = bsi_stmt (bsi);
4568 err |= verify_eh_edges (stmt);
4570 if (is_ctrl_stmt (stmt))
4572 FOR_EACH_EDGE (e, ei, bb->succs)
4573 if (e->flags & EDGE_FALLTHRU)
4575 error ("fallthru edge after a control statement in bb %d",
4581 if (TREE_CODE (stmt) != COND_EXPR)
4583 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4584 after anything else but if statement. */
4585 FOR_EACH_EDGE (e, ei, bb->succs)
4586 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4588 error ("true/false edge after a non-COND_EXPR in bb %d",
4594 switch (TREE_CODE (stmt))
4601 if (COND_EXPR_THEN (stmt) != NULL_TREE
4602 || COND_EXPR_ELSE (stmt) != NULL_TREE)
4604 error ("COND_EXPR with code in branches at the end of bb %d",
4609 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4611 if (!true_edge || !false_edge
4612 || !(true_edge->flags & EDGE_TRUE_VALUE)
4613 || !(false_edge->flags & EDGE_FALSE_VALUE)
4614 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4615 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4616 || EDGE_COUNT (bb->succs) >= 3)
4618 error ("wrong outgoing edge flags at end of bb %d",
4626 if (simple_goto_p (stmt))
4628 error ("explicit goto at end of bb %d", bb->index);
4633 /* FIXME. We should double check that the labels in the
4634 destination blocks have their address taken. */
4635 FOR_EACH_EDGE (e, ei, bb->succs)
4636 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4637 | EDGE_FALSE_VALUE))
4638 || !(e->flags & EDGE_ABNORMAL))
4640 error ("wrong outgoing edge flags at end of bb %d",
4648 if (!single_succ_p (bb)
4649 || (single_succ_edge (bb)->flags
4650 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4651 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4653 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4656 if (single_succ (bb) != EXIT_BLOCK_PTR)
4658 error ("return edge does not point to exit in bb %d",
4671 vec = SWITCH_LABELS (stmt);
4672 n = TREE_VEC_LENGTH (vec);
4674 /* Mark all the destination basic blocks. */
4675 for (i = 0; i < n; ++i)
4677 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4678 basic_block label_bb = label_to_block (lab);
4680 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4681 label_bb->aux = (void *)1;
4684 /* Verify that the case labels are sorted. */
4685 prev = TREE_VEC_ELT (vec, 0);
4686 for (i = 1; i < n; ++i)
4688 tree c = TREE_VEC_ELT (vec, i);
4693 error ("found default case not at end of case vector");
4698 if (! tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4700 error ("case labels not sorted: ");
4701 print_generic_expr (stderr, prev, 0);
4702 fprintf (stderr," is greater than ");
4703 print_generic_expr (stderr, c, 0);
4704 fprintf (stderr," but comes before it.\n");
4709 /* VRP will remove the default case if it can prove it will
4710 never be executed. So do not verify there always exists
4711 a default case here. */
4713 FOR_EACH_EDGE (e, ei, bb->succs)
4717 error ("extra outgoing edge %d->%d",
4718 bb->index, e->dest->index);
4721 e->dest->aux = (void *)2;
4722 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4723 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4725 error ("wrong outgoing edge flags at end of bb %d",
4731 /* Check that we have all of them. */
4732 for (i = 0; i < n; ++i)
4734 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4735 basic_block label_bb = label_to_block (lab);
4737 if (label_bb->aux != (void *)2)
4739 error ("missing edge %i->%i",
4740 bb->index, label_bb->index);
4745 FOR_EACH_EDGE (e, ei, bb->succs)
4746 e->dest->aux = (void *)0;
4753 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4754 verify_dominators (CDI_DOMINATORS);
4760 /* Updates phi nodes after creating a forwarder block joined
4761 by edge FALLTHRU. */
4764 tree_make_forwarder_block (edge fallthru)
4768 basic_block dummy, bb;
4769 tree phi, new_phi, var;
4771 dummy = fallthru->src;
4772 bb = fallthru->dest;
4774 if (single_pred_p (bb))
4777 /* If we redirected a branch we must create new PHI nodes at the
4779 for (phi = phi_nodes (dummy); phi; phi = PHI_CHAIN (phi))
4781 var = PHI_RESULT (phi);
4782 new_phi = create_phi_node (var, bb);
4783 SSA_NAME_DEF_STMT (var) = new_phi;
4784 SET_PHI_RESULT (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4785 add_phi_arg (new_phi, PHI_RESULT (phi), fallthru);
4788 /* Ensure that the PHI node chain is in the same order. */
4789 set_phi_nodes (bb, phi_reverse (phi_nodes (bb)));
4791 /* Add the arguments we have stored on edges. */
4792 FOR_EACH_EDGE (e, ei, bb->preds)
4797 flush_pending_stmts (e);
4802 /* Return a non-special label in the head of basic block BLOCK.
4803 Create one if it doesn't exist. */
4806 tree_block_label (basic_block bb)
4808 block_stmt_iterator i, s = bsi_start (bb);
4812 for (i = s; !bsi_end_p (i); first = false, bsi_next (&i))
4814 stmt = bsi_stmt (i);
4815 if (TREE_CODE (stmt) != LABEL_EXPR)
4817 label = LABEL_EXPR_LABEL (stmt);
4818 if (!DECL_NONLOCAL (label))
4821 bsi_move_before (&i, &s);
4826 label = create_artificial_label ();
4827 stmt = build1 (LABEL_EXPR, void_type_node, label);
4828 bsi_insert_before (&s, stmt, BSI_NEW_STMT);
4833 /* Attempt to perform edge redirection by replacing a possibly complex
4834 jump instruction by a goto or by removing the jump completely.
4835 This can apply only if all edges now point to the same block. The
4836 parameters and return values are equivalent to
4837 redirect_edge_and_branch. */
4840 tree_try_redirect_by_replacing_jump (edge e, basic_block target)
4842 basic_block src = e->src;
4843 block_stmt_iterator b;
4846 /* We can replace or remove a complex jump only when we have exactly
4848 if (EDGE_COUNT (src->succs) != 2
4849 /* Verify that all targets will be TARGET. Specifically, the
4850 edge that is not E must also go to TARGET. */
4851 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4857 stmt = bsi_stmt (b);
4859 if (TREE_CODE (stmt) == COND_EXPR
4860 || TREE_CODE (stmt) == SWITCH_EXPR)
4862 bsi_remove (&b, true);
4863 e = ssa_redirect_edge (e, target);
4864 e->flags = EDGE_FALLTHRU;
4872 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4873 edge representing the redirected branch. */
4876 tree_redirect_edge_and_branch (edge e, basic_block dest)
4878 basic_block bb = e->src;
4879 block_stmt_iterator bsi;
4883 if (e->flags & EDGE_ABNORMAL)
4886 if (e->src != ENTRY_BLOCK_PTR
4887 && (ret = tree_try_redirect_by_replacing_jump (e, dest)))
4890 if (e->dest == dest)
4893 bsi = bsi_last (bb);
4894 stmt = bsi_end_p (bsi) ? NULL : bsi_stmt (bsi);
4896 switch (stmt ? TREE_CODE (stmt) : ERROR_MARK)
4899 /* For COND_EXPR, we only need to redirect the edge. */
4903 /* No non-abnormal edges should lead from a non-simple goto, and
4904 simple ones should be represented implicitly. */
4909 tree cases = get_cases_for_edge (e, stmt);
4910 tree label = tree_block_label (dest);
4912 /* If we have a list of cases associated with E, then use it
4913 as it's a lot faster than walking the entire case vector. */
4916 edge e2 = find_edge (e->src, dest);
4923 CASE_LABEL (cases) = label;
4924 cases = TREE_CHAIN (cases);
4927 /* If there was already an edge in the CFG, then we need
4928 to move all the cases associated with E to E2. */
4931 tree cases2 = get_cases_for_edge (e2, stmt);
4933 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4934 TREE_CHAIN (cases2) = first;
4939 tree vec = SWITCH_LABELS (stmt);
4940 size_t i, n = TREE_VEC_LENGTH (vec);
4942 for (i = 0; i < n; i++)
4944 tree elt = TREE_VEC_ELT (vec, i);
4946 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4947 CASE_LABEL (elt) = label;
4955 bsi_remove (&bsi, true);
4956 e->flags |= EDGE_FALLTHRU;
4961 case OMP_SECTIONS_SWITCH:
4963 /* The edges from OMP constructs can be simply redirected. */
4967 /* Otherwise it must be a fallthru edge, and we don't need to
4968 do anything besides redirecting it. */
4969 gcc_assert (e->flags & EDGE_FALLTHRU);
4973 /* Update/insert PHI nodes as necessary. */
4975 /* Now update the edges in the CFG. */
4976 e = ssa_redirect_edge (e, dest);
4981 /* Returns true if it is possible to remove edge E by redirecting
4982 it to the destination of the other edge from E->src. */
4985 tree_can_remove_branch_p (const_edge e)
4987 if (e->flags & EDGE_ABNORMAL)
4993 /* Simple wrapper, as we can always redirect fallthru edges. */
4996 tree_redirect_edge_and_branch_force (edge e, basic_block dest)
4998 e = tree_redirect_edge_and_branch (e, dest);
5005 /* Splits basic block BB after statement STMT (but at least after the
5006 labels). If STMT is NULL, BB is split just after the labels. */
5009 tree_split_block (basic_block bb, void *stmt)
5011 block_stmt_iterator bsi;
5012 tree_stmt_iterator tsi_tgt;
5018 new_bb = create_empty_bb (bb);
5020 /* Redirect the outgoing edges. */
5021 new_bb->succs = bb->succs;
5023 FOR_EACH_EDGE (e, ei, new_bb->succs)
5026 if (stmt && TREE_CODE ((tree) stmt) == LABEL_EXPR)
5029 /* Move everything from BSI to the new basic block. */
5030 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5032 act = bsi_stmt (bsi);
5033 if (TREE_CODE (act) == LABEL_EXPR)
5046 if (bsi_end_p (bsi))
5049 /* Split the statement list - avoid re-creating new containers as this
5050 brings ugly quadratic memory consumption in the inliner.
5051 (We are still quadratic since we need to update stmt BB pointers,
5053 list = tsi_split_statement_list_before (&bsi.tsi);
5054 set_bb_stmt_list (new_bb, list);
5055 for (tsi_tgt = tsi_start (list);
5056 !tsi_end_p (tsi_tgt); tsi_next (&tsi_tgt))
5057 change_bb_for_stmt (tsi_stmt (tsi_tgt), new_bb);
5063 /* Moves basic block BB after block AFTER. */
5066 tree_move_block_after (basic_block bb, basic_block after)
5068 if (bb->prev_bb == after)
5072 link_block (bb, after);
5078 /* Return true if basic_block can be duplicated. */
5081 tree_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
5087 /* Create a duplicate of the basic block BB. NOTE: This does not
5088 preserve SSA form. */
5091 tree_duplicate_bb (basic_block bb)
5094 block_stmt_iterator bsi, bsi_tgt;
5097 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
5099 /* Copy the PHI nodes. We ignore PHI node arguments here because
5100 the incoming edges have not been setup yet. */
5101 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5103 tree copy = create_phi_node (PHI_RESULT (phi), new_bb);
5104 create_new_def_for (PHI_RESULT (copy), copy, PHI_RESULT_PTR (copy));
5107 /* Keep the chain of PHI nodes in the same order so that they can be
5108 updated by ssa_redirect_edge. */
5109 set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb)));
5111 bsi_tgt = bsi_start (new_bb);
5112 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5114 def_operand_p def_p;
5115 ssa_op_iter op_iter;
5119 stmt = bsi_stmt (bsi);
5120 if (TREE_CODE (stmt) == LABEL_EXPR)
5123 /* Create a new copy of STMT and duplicate STMT's virtual
5125 copy = unshare_expr (stmt);
5126 bsi_insert_after (&bsi_tgt, copy, BSI_NEW_STMT);
5127 copy_virtual_operands (copy, stmt);
5128 region = lookup_stmt_eh_region (stmt);
5130 add_stmt_to_eh_region (copy, region);
5131 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
5133 /* Create new names for all the definitions created by COPY and
5134 add replacement mappings for each new name. */
5135 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
5136 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
5142 /* Adds phi node arguments for edge E_COPY after basic block duplication. */
5145 add_phi_args_after_copy_edge (edge e_copy)
5147 basic_block bb, bb_copy = e_copy->src, dest;
5150 tree phi, phi_copy, phi_next, def;
5152 if (!phi_nodes (e_copy->dest))
5155 bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
5157 if (e_copy->dest->flags & BB_DUPLICATED)
5158 dest = get_bb_original (e_copy->dest);
5160 dest = e_copy->dest;
5162 e = find_edge (bb, dest);
5165 /* During loop unrolling the target of the latch edge is copied.
5166 In this case we are not looking for edge to dest, but to
5167 duplicated block whose original was dest. */
5168 FOR_EACH_EDGE (e, ei, bb->succs)
5170 if ((e->dest->flags & BB_DUPLICATED)
5171 && get_bb_original (e->dest) == dest)
5175 gcc_assert (e != NULL);
5178 for (phi = phi_nodes (e->dest), phi_copy = phi_nodes (e_copy->dest);
5180 phi = phi_next, phi_copy = PHI_CHAIN (phi_copy))
5182 phi_next = PHI_CHAIN (phi);
5183 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5184 add_phi_arg (phi_copy, def, e_copy);
5189 /* Basic block BB_COPY was created by code duplication. Add phi node
5190 arguments for edges going out of BB_COPY. The blocks that were
5191 duplicated have BB_DUPLICATED set. */
5194 add_phi_args_after_copy_bb (basic_block bb_copy)
5199 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5201 add_phi_args_after_copy_edge (e_copy);
5205 /* Blocks in REGION_COPY array of length N_REGION were created by
5206 duplication of basic blocks. Add phi node arguments for edges
5207 going from these blocks. If E_COPY is not NULL, also add
5208 phi node arguments for its destination.*/
5211 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
5216 for (i = 0; i < n_region; i++)
5217 region_copy[i]->flags |= BB_DUPLICATED;
5219 for (i = 0; i < n_region; i++)
5220 add_phi_args_after_copy_bb (region_copy[i]);
5222 add_phi_args_after_copy_edge (e_copy);
5224 for (i = 0; i < n_region; i++)
5225 region_copy[i]->flags &= ~BB_DUPLICATED;
5228 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5229 important exit edge EXIT. By important we mean that no SSA name defined
5230 inside region is live over the other exit edges of the region. All entry
5231 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5232 to the duplicate of the region. SSA form, dominance and loop information
5233 is updated. The new basic blocks are stored to REGION_COPY in the same
5234 order as they had in REGION, provided that REGION_COPY is not NULL.
5235 The function returns false if it is unable to copy the region,
5239 tree_duplicate_sese_region (edge entry, edge exit,
5240 basic_block *region, unsigned n_region,
5241 basic_block *region_copy)
5244 bool free_region_copy = false, copying_header = false;
5245 struct loop *loop = entry->dest->loop_father;
5247 VEC (basic_block, heap) *doms;
5249 int total_freq = 0, entry_freq = 0;
5250 gcov_type total_count = 0, entry_count = 0;
5252 if (!can_copy_bbs_p (region, n_region))
5255 /* Some sanity checking. Note that we do not check for all possible
5256 missuses of the functions. I.e. if you ask to copy something weird,
5257 it will work, but the state of structures probably will not be
5259 for (i = 0; i < n_region; i++)
5261 /* We do not handle subloops, i.e. all the blocks must belong to the
5263 if (region[i]->loop_father != loop)
5266 if (region[i] != entry->dest
5267 && region[i] == loop->header)
5271 set_loop_copy (loop, loop);
5273 /* In case the function is used for loop header copying (which is the primary
5274 use), ensure that EXIT and its copy will be new latch and entry edges. */
5275 if (loop->header == entry->dest)
5277 copying_header = true;
5278 set_loop_copy (loop, loop_outer (loop));
5280 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5283 for (i = 0; i < n_region; i++)
5284 if (region[i] != exit->src
5285 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5291 region_copy = XNEWVEC (basic_block, n_region);
5292 free_region_copy = true;
5295 gcc_assert (!need_ssa_update_p ());
5297 /* Record blocks outside the region that are dominated by something
5300 initialize_original_copy_tables ();
5302 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5304 if (entry->dest->count)
5306 total_count = entry->dest->count;
5307 entry_count = entry->count;
5308 /* Fix up corner cases, to avoid division by zero or creation of negative
5310 if (entry_count > total_count)
5311 entry_count = total_count;
5315 total_freq = entry->dest->frequency;
5316 entry_freq = EDGE_FREQUENCY (entry);
5317 /* Fix up corner cases, to avoid division by zero or creation of negative
5319 if (total_freq == 0)
5321 else if (entry_freq > total_freq)
5322 entry_freq = total_freq;
5325 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5326 split_edge_bb_loc (entry));
5329 scale_bbs_frequencies_gcov_type (region, n_region,
5330 total_count - entry_count,
5332 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5337 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5339 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5344 loop->header = exit->dest;
5345 loop->latch = exit->src;
5348 /* Redirect the entry and add the phi node arguments. */
5349 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5350 gcc_assert (redirected != NULL);
5351 flush_pending_stmts (entry);
5353 /* Concerning updating of dominators: We must recount dominators
5354 for entry block and its copy. Anything that is outside of the
5355 region, but was dominated by something inside needs recounting as
5357 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5358 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5359 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5360 VEC_free (basic_block, heap, doms);
5362 /* Add the other PHI node arguments. */
5363 add_phi_args_after_copy (region_copy, n_region, NULL);
5365 /* Update the SSA web. */
5366 update_ssa (TODO_update_ssa);
5368 if (free_region_copy)
5371 free_original_copy_tables ();
5375 /* Duplicates REGION consisting of N_REGION blocks. The new blocks
5376 are stored to REGION_COPY in the same order in that they appear
5377 in REGION, if REGION_COPY is not NULL. ENTRY is the entry to
5378 the region, EXIT an exit from it. The condition guarding EXIT
5379 is moved to ENTRY. Returns true if duplication succeeds, false
5405 tree_duplicate_sese_tail (edge entry, edge exit,
5406 basic_block *region, unsigned n_region,
5407 basic_block *region_copy)
5410 bool free_region_copy = false;
5411 struct loop *loop = exit->dest->loop_father;
5412 struct loop *orig_loop = entry->dest->loop_father;
5413 basic_block switch_bb, entry_bb, nentry_bb;
5414 VEC (basic_block, heap) *doms;
5415 int total_freq = 0, exit_freq = 0;
5416 gcov_type total_count = 0, exit_count = 0;
5417 edge exits[2], nexits[2], e;
5418 block_stmt_iterator bsi;
5422 gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5424 exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5426 if (!can_copy_bbs_p (region, n_region))
5429 /* Some sanity checking. Note that we do not check for all possible
5430 missuses of the functions. I.e. if you ask to copy something weird
5431 (e.g., in the example, if there is a jump from inside to the middle
5432 of some_code, or come_code defines some of the values used in cond)
5433 it will work, but the resulting code will not be correct. */
5434 for (i = 0; i < n_region; i++)
5436 /* We do not handle subloops, i.e. all the blocks must belong to the
5438 if (region[i]->loop_father != orig_loop)
5441 if (region[i] == orig_loop->latch)
5445 initialize_original_copy_tables ();
5446 set_loop_copy (orig_loop, loop);
5450 region_copy = XNEWVEC (basic_block, n_region);
5451 free_region_copy = true;
5454 gcc_assert (!need_ssa_update_p ());
5456 /* Record blocks outside the region that are dominated by something
5458 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5460 if (exit->src->count)
5462 total_count = exit->src->count;
5463 exit_count = exit->count;
5464 /* Fix up corner cases, to avoid division by zero or creation of negative
5466 if (exit_count > total_count)
5467 exit_count = total_count;
5471 total_freq = exit->src->frequency;
5472 exit_freq = EDGE_FREQUENCY (exit);
5473 /* Fix up corner cases, to avoid division by zero or creation of negative
5475 if (total_freq == 0)
5477 if (exit_freq > total_freq)
5478 exit_freq = total_freq;
5481 copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5482 split_edge_bb_loc (exit));
5485 scale_bbs_frequencies_gcov_type (region, n_region,
5486 total_count - exit_count,
5488 scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5493 scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5495 scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5498 /* Create the switch block, and put the exit condition to it. */
5499 entry_bb = entry->dest;
5500 nentry_bb = get_bb_copy (entry_bb);
5501 if (!last_stmt (entry->src)
5502 || !stmt_ends_bb_p (last_stmt (entry->src)))
5503 switch_bb = entry->src;
5505 switch_bb = split_edge (entry);
5506 set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5508 bsi = bsi_last (switch_bb);
5509 cond = last_stmt (exit->src);
5510 gcc_assert (TREE_CODE (cond) == COND_EXPR);
5511 bsi_insert_after (&bsi, unshare_expr (cond), BSI_NEW_STMT);
5513 sorig = single_succ_edge (switch_bb);
5514 sorig->flags = exits[1]->flags;
5515 snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5517 /* Register the new edge from SWITCH_BB in loop exit lists. */
5518 rescan_loop_exit (snew, true, false);
5520 /* Add the PHI node arguments. */
5521 add_phi_args_after_copy (region_copy, n_region, snew);
5523 /* Get rid of now superfluous conditions and associated edges (and phi node
5525 e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5526 PENDING_STMT (e) = NULL_TREE;
5527 e = redirect_edge_and_branch (nexits[1], nexits[0]->dest);
5528 PENDING_STMT (e) = NULL_TREE;
5530 /* Anything that is outside of the region, but was dominated by something
5531 inside needs to update dominance info. */
5532 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5533 VEC_free (basic_block, heap, doms);
5535 /* Update the SSA web. */
5536 update_ssa (TODO_update_ssa);
5538 if (free_region_copy)
5541 free_original_copy_tables ();
5546 DEF_VEC_P(basic_block);
5547 DEF_VEC_ALLOC_P(basic_block,heap);
5550 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5551 adding blocks when the dominator traversal reaches EXIT. This
5552 function silently assumes that ENTRY strictly dominates EXIT. */
5555 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5556 VEC(basic_block,heap) **bbs_p)
5560 for (son = first_dom_son (CDI_DOMINATORS, entry);
5562 son = next_dom_son (CDI_DOMINATORS, son))
5564 VEC_safe_push (basic_block, heap, *bbs_p, son);
5566 gather_blocks_in_sese_region (son, exit, bbs_p);
5570 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5571 The duplicates are recorded in VARS_MAP. */
5574 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5577 tree t = *tp, new_t;
5578 struct function *f = DECL_STRUCT_FUNCTION (to_context);
5581 if (DECL_CONTEXT (t) == to_context)
5584 loc = pointer_map_contains (vars_map, t);
5588 loc = pointer_map_insert (vars_map, t);
5592 new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5593 f->local_decls = tree_cons (NULL_TREE, new_t, f->local_decls);
5597 gcc_assert (TREE_CODE (t) == CONST_DECL);
5598 new_t = copy_node (t);
5600 DECL_CONTEXT (new_t) = to_context;
5610 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5611 VARS_MAP maps old ssa names and var_decls to the new ones. */
5614 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5618 tree new_name, decl = SSA_NAME_VAR (name);
5620 gcc_assert (is_gimple_reg (name));
5622 loc = pointer_map_contains (vars_map, name);
5626 replace_by_duplicate_decl (&decl, vars_map, to_context);
5628 push_cfun (DECL_STRUCT_FUNCTION (to_context));
5629 if (gimple_in_ssa_p (cfun))
5630 add_referenced_var (decl);
5632 new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5633 if (SSA_NAME_IS_DEFAULT_DEF (name))
5634 set_default_def (decl, new_name);
5637 loc = pointer_map_insert (vars_map, name);
5651 struct pointer_map_t *vars_map;
5652 htab_t new_label_map;
5656 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5657 contained in *TP and change the DECL_CONTEXT of every local
5658 variable referenced in *TP. */
5661 move_stmt_r (tree *tp, int *walk_subtrees, void *data)
5663 struct move_stmt_d *p = (struct move_stmt_d *) data;
5667 && (EXPR_P (t) || GIMPLE_STMT_P (t)))
5668 TREE_BLOCK (t) = p->block;
5670 if (OMP_DIRECTIVE_P (t)
5671 && TREE_CODE (t) != OMP_RETURN
5672 && TREE_CODE (t) != OMP_CONTINUE)
5674 /* Do not remap variables inside OMP directives. Variables
5675 referenced in clauses and directive header belong to the
5676 parent function and should not be moved into the child
5678 bool save_remap_decls_p = p->remap_decls_p;
5679 p->remap_decls_p = false;
5682 walk_tree (&OMP_BODY (t), move_stmt_r, p, NULL);
5684 p->remap_decls_p = save_remap_decls_p;
5686 else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5688 if (TREE_CODE (t) == SSA_NAME)
5689 *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5690 else if (TREE_CODE (t) == LABEL_DECL)
5692 if (p->new_label_map)
5694 struct tree_map in, *out;
5696 out = htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5701 DECL_CONTEXT (t) = p->to_context;
5703 else if (p->remap_decls_p)
5705 /* Replace T with its duplicate. T should no longer appear in the
5706 parent function, so this looks wasteful; however, it may appear
5707 in referenced_vars, and more importantly, as virtual operands of
5708 statements, and in alias lists of other variables. It would be
5709 quite difficult to expunge it from all those places. ??? It might
5710 suffice to do this for addressable variables. */
5711 if ((TREE_CODE (t) == VAR_DECL
5712 && !is_global_var (t))
5713 || TREE_CODE (t) == CONST_DECL)
5714 replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5717 && gimple_in_ssa_p (cfun))
5719 push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5720 add_referenced_var (*tp);
5726 else if (TYPE_P (t))
5732 /* Marks virtual operands of all statements in basic blocks BBS for
5736 mark_virtual_ops_in_bb (basic_block bb)
5739 block_stmt_iterator bsi;
5741 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5742 mark_virtual_ops_for_renaming (phi);
5744 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5745 mark_virtual_ops_for_renaming (bsi_stmt (bsi));
5748 /* Marks virtual operands of all statements in basic blocks BBS for
5752 mark_virtual_ops_in_region (VEC (basic_block,heap) *bbs)
5757 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5758 mark_virtual_ops_in_bb (bb);
5761 /* Move basic block BB from function CFUN to function DEST_FN. The
5762 block is moved out of the original linked list and placed after
5763 block AFTER in the new list. Also, the block is removed from the
5764 original array of blocks and placed in DEST_FN's array of blocks.
5765 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5766 updated to reflect the moved edges.
5768 The local variables are remapped to new instances, VARS_MAP is used
5769 to record the mapping. */
5772 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5773 basic_block after, bool update_edge_count_p,
5774 struct pointer_map_t *vars_map, htab_t new_label_map,
5777 struct control_flow_graph *cfg;
5780 block_stmt_iterator si;
5781 struct move_stmt_d d;
5782 unsigned old_len, new_len;
5785 /* Remove BB from dominance structures. */
5786 delete_from_dominance_info (CDI_DOMINATORS, bb);
5788 remove_bb_from_loops (bb);
5790 /* Link BB to the new linked list. */
5791 move_block_after (bb, after);
5793 /* Update the edge count in the corresponding flowgraphs. */
5794 if (update_edge_count_p)
5795 FOR_EACH_EDGE (e, ei, bb->succs)
5797 cfun->cfg->x_n_edges--;
5798 dest_cfun->cfg->x_n_edges++;
5801 /* Remove BB from the original basic block array. */
5802 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5803 cfun->cfg->x_n_basic_blocks--;
5805 /* Grow DEST_CFUN's basic block array if needed. */
5806 cfg = dest_cfun->cfg;
5807 cfg->x_n_basic_blocks++;
5808 if (bb->index >= cfg->x_last_basic_block)
5809 cfg->x_last_basic_block = bb->index + 1;
5811 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5812 if ((unsigned) cfg->x_last_basic_block >= old_len)
5814 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5815 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5819 VEC_replace (basic_block, cfg->x_basic_block_info,
5822 /* Remap the variables in phi nodes. */
5823 for (phi = phi_nodes (bb); phi; phi = next_phi)
5826 tree op = PHI_RESULT (phi);
5829 next_phi = PHI_CHAIN (phi);
5830 if (!is_gimple_reg (op))
5832 /* Remove the phi nodes for virtual operands (alias analysis will be
5833 run for the new function, anyway). */
5834 remove_phi_node (phi, NULL, true);
5838 SET_PHI_RESULT (phi, replace_ssa_name (op, vars_map, dest_cfun->decl));
5839 FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5841 op = USE_FROM_PTR (use);
5842 if (TREE_CODE (op) == SSA_NAME)
5843 SET_USE (use, replace_ssa_name (op, vars_map, dest_cfun->decl));
5847 /* The statements in BB need to be associated with a new TREE_BLOCK.
5848 Labels need to be associated with a new label-to-block map. */
5849 memset (&d, 0, sizeof (d));
5850 d.vars_map = vars_map;
5851 d.from_context = cfun->decl;
5852 d.to_context = dest_cfun->decl;
5853 d.new_label_map = new_label_map;
5855 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5857 tree stmt = bsi_stmt (si);
5860 d.remap_decls_p = true;
5861 if (TREE_BLOCK (stmt))
5862 d.block = DECL_INITIAL (dest_cfun->decl);
5864 walk_tree (&stmt, move_stmt_r, &d, NULL);
5866 if (TREE_CODE (stmt) == LABEL_EXPR)
5868 tree label = LABEL_EXPR_LABEL (stmt);
5869 int uid = LABEL_DECL_UID (label);
5871 gcc_assert (uid > -1);
5873 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5874 if (old_len <= (unsigned) uid)
5876 new_len = 3 * uid / 2;
5877 VEC_safe_grow_cleared (basic_block, gc,
5878 cfg->x_label_to_block_map, new_len);
5881 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5882 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5884 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5886 if (uid >= dest_cfun->cfg->last_label_uid)
5887 dest_cfun->cfg->last_label_uid = uid + 1;
5889 else if (TREE_CODE (stmt) == RESX_EXPR && eh_offset != 0)
5890 TREE_OPERAND (stmt, 0) =
5891 build_int_cst (NULL_TREE,
5892 TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0))
5895 region = lookup_stmt_eh_region (stmt);
5898 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5899 remove_stmt_from_eh_region (stmt);
5900 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5901 gimple_remove_stmt_histograms (cfun, stmt);
5904 /* We cannot leave any operands allocated from the operand caches of
5905 the current function. */
5906 free_stmt_operands (stmt);
5907 push_cfun (dest_cfun);
5913 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5914 the outermost EH region. Use REGION as the incoming base EH region. */
5917 find_outermost_region_in_block (struct function *src_cfun,
5918 basic_block bb, int region)
5920 block_stmt_iterator si;
5922 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5924 tree stmt = bsi_stmt (si);
5927 if (TREE_CODE (stmt) == RESX_EXPR)
5928 stmt_region = TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0));
5930 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5931 if (stmt_region > 0)
5934 region = stmt_region;
5935 else if (stmt_region != region)
5937 region = eh_region_outermost (src_cfun, stmt_region, region);
5938 gcc_assert (region != -1);
5947 new_label_mapper (tree decl, void *data)
5949 htab_t hash = (htab_t) data;
5953 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5955 m = xmalloc (sizeof (struct tree_map));
5956 m->hash = DECL_UID (decl);
5957 m->base.from = decl;
5958 m->to = create_artificial_label ();
5959 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5960 if (LABEL_DECL_UID (m->to) >= cfun->cfg->last_label_uid)
5961 cfun->cfg->last_label_uid = LABEL_DECL_UID (m->to) + 1;
5963 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5964 gcc_assert (*slot == NULL);
5971 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5972 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5973 single basic block in the original CFG and the new basic block is
5974 returned. DEST_CFUN must not have a CFG yet.
5976 Note that the region need not be a pure SESE region. Blocks inside
5977 the region may contain calls to abort/exit. The only restriction
5978 is that ENTRY_BB should be the only entry point and it must
5981 All local variables referenced in the region are assumed to be in
5982 the corresponding BLOCK_VARS and unexpanded variable lists
5983 associated with DEST_CFUN. */
5986 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5987 basic_block exit_bb)
5989 VEC(basic_block,heap) *bbs, *dom_bbs;
5990 basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
5991 basic_block after, bb, *entry_pred, *exit_succ, abb;
5992 struct function *saved_cfun = cfun;
5993 int *entry_flag, *exit_flag, eh_offset;
5994 unsigned *entry_prob, *exit_prob;
5995 unsigned i, num_entry_edges, num_exit_edges;
5998 htab_t new_label_map;
5999 struct pointer_map_t *vars_map;
6000 struct loop *loop = entry_bb->loop_father;
6002 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
6004 gcc_assert (entry_bb != exit_bb
6006 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
6008 /* Collect all the blocks in the region. Manually add ENTRY_BB
6009 because it won't be added by dfs_enumerate_from. */
6011 VEC_safe_push (basic_block, heap, bbs, entry_bb);
6012 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
6014 /* The blocks that used to be dominated by something in BBS will now be
6015 dominated by the new block. */
6016 dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
6017 VEC_address (basic_block, bbs),
6018 VEC_length (basic_block, bbs));
6020 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
6021 the predecessor edges to ENTRY_BB and the successor edges to
6022 EXIT_BB so that we can re-attach them to the new basic block that
6023 will replace the region. */
6024 num_entry_edges = EDGE_COUNT (entry_bb->preds);
6025 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
6026 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
6027 entry_prob = XNEWVEC (unsigned, num_entry_edges);
6029 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
6031 entry_prob[i] = e->probability;
6032 entry_flag[i] = e->flags;
6033 entry_pred[i++] = e->src;
6039 num_exit_edges = EDGE_COUNT (exit_bb->succs);
6040 exit_succ = (basic_block *) xcalloc (num_exit_edges,
6041 sizeof (basic_block));
6042 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
6043 exit_prob = XNEWVEC (unsigned, num_exit_edges);
6045 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
6047 exit_prob[i] = e->probability;
6048 exit_flag[i] = e->flags;
6049 exit_succ[i++] = e->dest;
6061 /* Switch context to the child function to initialize DEST_FN's CFG. */
6062 gcc_assert (dest_cfun->cfg == NULL);
6063 push_cfun (dest_cfun);
6065 init_empty_tree_cfg ();
6067 /* Initialize EH information for the new function. */
6069 new_label_map = NULL;
6074 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6075 region = find_outermost_region_in_block (saved_cfun, bb, region);
6077 init_eh_for_function ();
6080 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
6081 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
6082 new_label_map, region, 0);
6088 /* The ssa form for virtual operands in the source function will have to
6089 be repaired. We do not care for the real operands -- the sese region
6090 must be closed with respect to those. */
6091 mark_virtual_ops_in_region (bbs);
6093 /* Move blocks from BBS into DEST_CFUN. */
6094 gcc_assert (VEC_length (basic_block, bbs) >= 2);
6095 after = dest_cfun->cfg->x_entry_block_ptr;
6096 vars_map = pointer_map_create ();
6097 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6099 /* No need to update edge counts on the last block. It has
6100 already been updated earlier when we detached the region from
6101 the original CFG. */
6102 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, vars_map,
6103 new_label_map, eh_offset);
6108 htab_delete (new_label_map);
6109 pointer_map_destroy (vars_map);
6111 /* Rewire the entry and exit blocks. The successor to the entry
6112 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
6113 the child function. Similarly, the predecessor of DEST_FN's
6114 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
6115 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
6116 various CFG manipulation function get to the right CFG.
6118 FIXME, this is silly. The CFG ought to become a parameter to
6120 push_cfun (dest_cfun);
6121 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
6123 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
6126 /* Back in the original function, the SESE region has disappeared,
6127 create a new basic block in its place. */
6128 bb = create_empty_bb (entry_pred[0]);
6130 add_bb_to_loop (bb, loop);
6131 for (i = 0; i < num_entry_edges; i++)
6133 e = make_edge (entry_pred[i], bb, entry_flag[i]);
6134 e->probability = entry_prob[i];
6137 for (i = 0; i < num_exit_edges; i++)
6139 e = make_edge (bb, exit_succ[i], exit_flag[i]);
6140 e->probability = exit_prob[i];
6143 set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
6144 for (i = 0; VEC_iterate (basic_block, dom_bbs, i, abb); i++)
6145 set_immediate_dominator (CDI_DOMINATORS, abb, bb);
6146 VEC_free (basic_block, heap, dom_bbs);
6157 VEC_free (basic_block, heap, bbs);
6163 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */
6166 dump_function_to_file (tree fn, FILE *file, int flags)
6168 tree arg, vars, var;
6169 struct function *dsf;
6170 bool ignore_topmost_bind = false, any_var = false;
6174 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
6176 arg = DECL_ARGUMENTS (fn);
6179 print_generic_expr (file, TREE_TYPE (arg), dump_flags);
6180 fprintf (file, " ");
6181 print_generic_expr (file, arg, dump_flags);
6182 if (flags & TDF_VERBOSE)
6183 print_node (file, "", arg, 4);
6184 if (TREE_CHAIN (arg))
6185 fprintf (file, ", ");
6186 arg = TREE_CHAIN (arg);
6188 fprintf (file, ")\n");
6190 if (flags & TDF_VERBOSE)
6191 print_node (file, "", fn, 2);
6193 dsf = DECL_STRUCT_FUNCTION (fn);
6194 if (dsf && (flags & TDF_DETAILS))
6195 dump_eh_tree (file, dsf);
6197 if (flags & TDF_RAW)
6199 dump_node (fn, TDF_SLIM | flags, file);
6203 /* Switch CFUN to point to FN. */
6204 push_cfun (DECL_STRUCT_FUNCTION (fn));
6206 /* When GIMPLE is lowered, the variables are no longer available in
6207 BIND_EXPRs, so display them separately. */
6208 if (cfun && cfun->decl == fn && cfun->local_decls)
6210 ignore_topmost_bind = true;
6212 fprintf (file, "{\n");
6213 for (vars = cfun->local_decls; vars; vars = TREE_CHAIN (vars))
6215 var = TREE_VALUE (vars);
6217 print_generic_decl (file, var, flags);
6218 if (flags & TDF_VERBOSE)
6219 print_node (file, "", var, 4);
6220 fprintf (file, "\n");
6226 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
6228 /* Make a CFG based dump. */
6229 check_bb_profile (ENTRY_BLOCK_PTR, file);
6230 if (!ignore_topmost_bind)
6231 fprintf (file, "{\n");
6233 if (any_var && n_basic_blocks)
6234 fprintf (file, "\n");
6237 dump_generic_bb (file, bb, 2, flags);
6239 fprintf (file, "}\n");
6240 check_bb_profile (EXIT_BLOCK_PTR, file);
6246 /* Make a tree based dump. */
6247 chain = DECL_SAVED_TREE (fn);
6249 if (chain && TREE_CODE (chain) == BIND_EXPR)
6251 if (ignore_topmost_bind)
6253 chain = BIND_EXPR_BODY (chain);
6261 if (!ignore_topmost_bind)
6262 fprintf (file, "{\n");
6267 fprintf (file, "\n");
6269 print_generic_stmt_indented (file, chain, flags, indent);
6270 if (ignore_topmost_bind)
6271 fprintf (file, "}\n");
6274 fprintf (file, "\n\n");
6281 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
6284 debug_function (tree fn, int flags)
6286 dump_function_to_file (fn, stderr, flags);
6290 /* Print on FILE the indexes for the predecessors of basic_block BB. */
6293 print_pred_bbs (FILE *file, basic_block bb)
6298 FOR_EACH_EDGE (e, ei, bb->preds)
6299 fprintf (file, "bb_%d ", e->src->index);
6303 /* Print on FILE the indexes for the successors of basic_block BB. */
6306 print_succ_bbs (FILE *file, basic_block bb)
6311 FOR_EACH_EDGE (e, ei, bb->succs)
6312 fprintf (file, "bb_%d ", e->dest->index);
6315 /* Print to FILE the basic block BB following the VERBOSITY level. */
6318 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6320 char *s_indent = (char *) alloca ((size_t) indent + 1);
6321 memset ((void *) s_indent, ' ', (size_t) indent);
6322 s_indent[indent] = '\0';
6324 /* Print basic_block's header. */
6327 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
6328 print_pred_bbs (file, bb);
6329 fprintf (file, "}, succs = {");
6330 print_succ_bbs (file, bb);
6331 fprintf (file, "})\n");
6334 /* Print basic_block's body. */
6337 fprintf (file, "%s {\n", s_indent);
6338 tree_dump_bb (bb, file, indent + 4);
6339 fprintf (file, "%s }\n", s_indent);
6343 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6345 /* Pretty print LOOP on FILE, indented INDENT spaces. Following
6346 VERBOSITY level this outputs the contents of the loop, or just its
6350 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6358 s_indent = (char *) alloca ((size_t) indent + 1);
6359 memset ((void *) s_indent, ' ', (size_t) indent);
6360 s_indent[indent] = '\0';
6362 /* Print loop's header. */
6363 fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6364 loop->num, loop->header->index, loop->latch->index);
6365 fprintf (file, ", niter = ");
6366 print_generic_expr (file, loop->nb_iterations, 0);
6368 if (loop->any_upper_bound)
6370 fprintf (file, ", upper_bound = ");
6371 dump_double_int (file, loop->nb_iterations_upper_bound, true);
6374 if (loop->any_estimate)
6376 fprintf (file, ", estimate = ");
6377 dump_double_int (file, loop->nb_iterations_estimate, true);
6379 fprintf (file, ")\n");
6381 /* Print loop's body. */
6384 fprintf (file, "%s{\n", s_indent);
6386 if (bb->loop_father == loop)
6387 print_loops_bb (file, bb, indent, verbosity);
6389 print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6390 fprintf (file, "%s}\n", s_indent);
6394 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6395 spaces. Following VERBOSITY level this outputs the contents of the
6396 loop, or just its structure. */
6399 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6404 print_loop (file, loop, indent, verbosity);
6405 print_loop_and_siblings (file, loop->next, indent, verbosity);
6408 /* Follow a CFG edge from the entry point of the program, and on entry
6409 of a loop, pretty print the loop structure on FILE. */
6412 print_loops (FILE *file, int verbosity)
6416 bb = BASIC_BLOCK (NUM_FIXED_BLOCKS);
6417 if (bb && bb->loop_father)
6418 print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6422 /* Debugging loops structure at tree level, at some VERBOSITY level. */
6425 debug_loops (int verbosity)
6427 print_loops (stderr, verbosity);
6430 /* Print on stderr the code of LOOP, at some VERBOSITY level. */
6433 debug_loop (struct loop *loop, int verbosity)
6435 print_loop (stderr, loop, 0, verbosity);
6438 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6442 debug_loop_num (unsigned num, int verbosity)
6444 debug_loop (get_loop (num), verbosity);
6447 /* Return true if BB ends with a call, possibly followed by some
6448 instructions that must stay with the call. Return false,
6452 tree_block_ends_with_call_p (basic_block bb)
6454 block_stmt_iterator bsi = bsi_last (bb);
6455 return get_call_expr_in (bsi_stmt (bsi)) != NULL;
6459 /* Return true if BB ends with a conditional branch. Return false,
6463 tree_block_ends_with_condjump_p (const_basic_block bb)
6465 /* This CONST_CAST is okay because last_stmt doesn't modify its
6466 argument and the return value is not modified. */
6467 const_tree stmt = last_stmt (CONST_CAST_BB(bb));
6468 return (stmt && TREE_CODE (stmt) == COND_EXPR);
6472 /* Return true if we need to add fake edge to exit at statement T.
6473 Helper function for tree_flow_call_edges_add. */
6476 need_fake_edge_p (tree t)
6478 tree call, fndecl = NULL_TREE;
6481 /* NORETURN and LONGJMP calls already have an edge to exit.
6482 CONST and PURE calls do not need one.
6483 We don't currently check for CONST and PURE here, although
6484 it would be a good idea, because those attributes are
6485 figured out from the RTL in mark_constant_function, and
6486 the counter incrementation code from -fprofile-arcs
6487 leads to different results from -fbranch-probabilities. */
6488 call = get_call_expr_in (t);
6491 fndecl = get_callee_fndecl (call);
6492 call_flags = call_expr_flags (call);
6495 if (call && fndecl && DECL_BUILT_IN (fndecl)
6496 && (call_flags & ECF_NOTHROW)
6497 && !(call_flags & ECF_NORETURN)
6498 && !(call_flags & ECF_RETURNS_TWICE))
6501 if (call && !(call_flags & ECF_NORETURN))
6504 if (TREE_CODE (t) == ASM_EXPR
6505 && (ASM_VOLATILE_P (t) || ASM_INPUT_P (t)))
6512 /* Add fake edges to the function exit for any non constant and non
6513 noreturn calls, volatile inline assembly in the bitmap of blocks
6514 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
6515 the number of blocks that were split.
6517 The goal is to expose cases in which entering a basic block does
6518 not imply that all subsequent instructions must be executed. */
6521 tree_flow_call_edges_add (sbitmap blocks)
6524 int blocks_split = 0;
6525 int last_bb = last_basic_block;
6526 bool check_last_block = false;
6528 if (n_basic_blocks == NUM_FIXED_BLOCKS)
6532 check_last_block = true;
6534 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6536 /* In the last basic block, before epilogue generation, there will be
6537 a fallthru edge to EXIT. Special care is required if the last insn
6538 of the last basic block is a call because make_edge folds duplicate
6539 edges, which would result in the fallthru edge also being marked
6540 fake, which would result in the fallthru edge being removed by
6541 remove_fake_edges, which would result in an invalid CFG.
6543 Moreover, we can't elide the outgoing fake edge, since the block
6544 profiler needs to take this into account in order to solve the minimal
6545 spanning tree in the case that the call doesn't return.
6547 Handle this by adding a dummy instruction in a new last basic block. */
6548 if (check_last_block)
6550 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6551 block_stmt_iterator bsi = bsi_last (bb);
6553 if (!bsi_end_p (bsi))
6556 if (t && need_fake_edge_p (t))
6560 e = find_edge (bb, EXIT_BLOCK_PTR);
6563 bsi_insert_on_edge (e, build_empty_stmt ());
6564 bsi_commit_edge_inserts ();
6569 /* Now add fake edges to the function exit for any non constant
6570 calls since there is no way that we can determine if they will
6572 for (i = 0; i < last_bb; i++)
6574 basic_block bb = BASIC_BLOCK (i);
6575 block_stmt_iterator bsi;
6576 tree stmt, last_stmt;
6581 if (blocks && !TEST_BIT (blocks, i))
6584 bsi = bsi_last (bb);
6585 if (!bsi_end_p (bsi))
6587 last_stmt = bsi_stmt (bsi);
6590 stmt = bsi_stmt (bsi);
6591 if (need_fake_edge_p (stmt))
6594 /* The handling above of the final block before the
6595 epilogue should be enough to verify that there is
6596 no edge to the exit block in CFG already.
6597 Calling make_edge in such case would cause us to
6598 mark that edge as fake and remove it later. */
6599 #ifdef ENABLE_CHECKING
6600 if (stmt == last_stmt)
6602 e = find_edge (bb, EXIT_BLOCK_PTR);
6603 gcc_assert (e == NULL);
6607 /* Note that the following may create a new basic block
6608 and renumber the existing basic blocks. */
6609 if (stmt != last_stmt)
6611 e = split_block (bb, stmt);
6615 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6619 while (!bsi_end_p (bsi));
6624 verify_flow_info ();
6626 return blocks_split;
6629 /* Purge dead abnormal call edges from basic block BB. */
6632 tree_purge_dead_abnormal_call_edges (basic_block bb)
6634 bool changed = tree_purge_dead_eh_edges (bb);
6636 if (cfun->has_nonlocal_label)
6638 tree stmt = last_stmt (bb);
6642 if (!(stmt && tree_can_make_abnormal_goto (stmt)))
6643 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6645 if (e->flags & EDGE_ABNORMAL)
6654 /* See tree_purge_dead_eh_edges below. */
6656 free_dominance_info (CDI_DOMINATORS);
6662 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6665 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6669 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6670 for (son = first_dom_son (CDI_DOMINATORS, bb);
6672 son = next_dom_son (CDI_DOMINATORS, son))
6673 get_all_dominated_blocks (son, dom_bbs);
6676 /* Removes edge E and all the blocks dominated by it, and updates dominance
6677 information. The IL in E->src needs to be updated separately.
6678 If dominance info is not available, only the edge E is removed.*/
6681 remove_edge_and_dominated_blocks (edge e)
6683 VEC (basic_block, heap) *bbs_to_remove = NULL;
6684 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6688 bool none_removed = false;
6690 basic_block bb, dbb;
6693 if (!dom_info_available_p (CDI_DOMINATORS))
6699 /* No updating is needed for edges to exit. */
6700 if (e->dest == EXIT_BLOCK_PTR)
6702 if (cfgcleanup_altered_bbs)
6703 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6708 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6709 that is not dominated by E->dest, then this set is empty. Otherwise,
6710 all the basic blocks dominated by E->dest are removed.
6712 Also, to DF_IDOM we store the immediate dominators of the blocks in
6713 the dominance frontier of E (i.e., of the successors of the
6714 removed blocks, if there are any, and of E->dest otherwise). */
6715 FOR_EACH_EDGE (f, ei, e->dest->preds)
6720 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6722 none_removed = true;
6727 df = BITMAP_ALLOC (NULL);
6728 df_idom = BITMAP_ALLOC (NULL);
6731 bitmap_set_bit (df_idom,
6732 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6735 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6736 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6738 FOR_EACH_EDGE (f, ei, bb->succs)
6740 if (f->dest != EXIT_BLOCK_PTR)
6741 bitmap_set_bit (df, f->dest->index);
6744 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6745 bitmap_clear_bit (df, bb->index);
6747 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6749 bb = BASIC_BLOCK (i);
6750 bitmap_set_bit (df_idom,
6751 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6755 if (cfgcleanup_altered_bbs)
6757 /* Record the set of the altered basic blocks. */
6758 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6759 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6762 /* Remove E and the cancelled blocks. */
6767 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6768 delete_basic_block (bb);
6771 /* Update the dominance information. The immediate dominator may change only
6772 for blocks whose immediate dominator belongs to DF_IDOM:
6774 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6775 removal. Let Z the arbitrary block such that idom(Z) = Y and
6776 Z dominates X after the removal. Before removal, there exists a path P
6777 from Y to X that avoids Z. Let F be the last edge on P that is
6778 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6779 dominates W, and because of P, Z does not dominate W), and W belongs to
6780 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6781 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6783 bb = BASIC_BLOCK (i);
6784 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6786 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6787 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6790 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6793 BITMAP_FREE (df_idom);
6794 VEC_free (basic_block, heap, bbs_to_remove);
6795 VEC_free (basic_block, heap, bbs_to_fix_dom);
6798 /* Purge dead EH edges from basic block BB. */
6801 tree_purge_dead_eh_edges (basic_block bb)
6803 bool changed = false;
6806 tree stmt = last_stmt (bb);
6808 if (stmt && tree_can_throw_internal (stmt))
6811 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6813 if (e->flags & EDGE_EH)
6815 remove_edge_and_dominated_blocks (e);
6826 tree_purge_all_dead_eh_edges (const_bitmap blocks)
6828 bool changed = false;
6832 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6834 changed |= tree_purge_dead_eh_edges (BASIC_BLOCK (i));
6840 /* This function is called whenever a new edge is created or
6844 tree_execute_on_growing_pred (edge e)
6846 basic_block bb = e->dest;
6849 reserve_phi_args_for_new_edge (bb);
6852 /* This function is called immediately before edge E is removed from
6853 the edge vector E->dest->preds. */
6856 tree_execute_on_shrinking_pred (edge e)
6858 if (phi_nodes (e->dest))
6859 remove_phi_args (e);
6862 /*---------------------------------------------------------------------------
6863 Helper functions for Loop versioning
6864 ---------------------------------------------------------------------------*/
6866 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6867 of 'first'. Both of them are dominated by 'new_head' basic block. When
6868 'new_head' was created by 'second's incoming edge it received phi arguments
6869 on the edge by split_edge(). Later, additional edge 'e' was created to
6870 connect 'new_head' and 'first'. Now this routine adds phi args on this
6871 additional edge 'e' that new_head to second edge received as part of edge
6876 tree_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6877 basic_block new_head, edge e)
6880 edge e2 = find_edge (new_head, second);
6882 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6883 edge, we should always have an edge from NEW_HEAD to SECOND. */
6884 gcc_assert (e2 != NULL);
6886 /* Browse all 'second' basic block phi nodes and add phi args to
6887 edge 'e' for 'first' head. PHI args are always in correct order. */
6889 for (phi2 = phi_nodes (second), phi1 = phi_nodes (first);
6891 phi2 = PHI_CHAIN (phi2), phi1 = PHI_CHAIN (phi1))
6893 tree def = PHI_ARG_DEF (phi2, e2->dest_idx);
6894 add_phi_arg (phi1, def, e);
6898 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6899 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6900 the destination of the ELSE part. */
6902 tree_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6903 basic_block second_head ATTRIBUTE_UNUSED,
6904 basic_block cond_bb, void *cond_e)
6906 block_stmt_iterator bsi;
6907 tree new_cond_expr = NULL_TREE;
6908 tree cond_expr = (tree) cond_e;
6911 /* Build new conditional expr */
6912 new_cond_expr = build3 (COND_EXPR, void_type_node, cond_expr,
6913 NULL_TREE, NULL_TREE);
6915 /* Add new cond in cond_bb. */
6916 bsi = bsi_start (cond_bb);
6917 bsi_insert_after (&bsi, new_cond_expr, BSI_NEW_STMT);
6918 /* Adjust edges appropriately to connect new head with first head
6919 as well as second head. */
6920 e0 = single_succ_edge (cond_bb);
6921 e0->flags &= ~EDGE_FALLTHRU;
6922 e0->flags |= EDGE_FALSE_VALUE;
6925 struct cfg_hooks tree_cfg_hooks = {
6927 tree_verify_flow_info,
6928 tree_dump_bb, /* dump_bb */
6929 create_bb, /* create_basic_block */
6930 tree_redirect_edge_and_branch,/* redirect_edge_and_branch */
6931 tree_redirect_edge_and_branch_force,/* redirect_edge_and_branch_force */
6932 tree_can_remove_branch_p, /* can_remove_branch_p */
6933 remove_bb, /* delete_basic_block */
6934 tree_split_block, /* split_block */
6935 tree_move_block_after, /* move_block_after */
6936 tree_can_merge_blocks_p, /* can_merge_blocks_p */
6937 tree_merge_blocks, /* merge_blocks */
6938 tree_predict_edge, /* predict_edge */
6939 tree_predicted_by_p, /* predicted_by_p */
6940 tree_can_duplicate_bb_p, /* can_duplicate_block_p */
6941 tree_duplicate_bb, /* duplicate_block */
6942 tree_split_edge, /* split_edge */
6943 tree_make_forwarder_block, /* make_forward_block */
6944 NULL, /* tidy_fallthru_edge */
6945 tree_block_ends_with_call_p, /* block_ends_with_call_p */
6946 tree_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6947 tree_flow_call_edges_add, /* flow_call_edges_add */
6948 tree_execute_on_growing_pred, /* execute_on_growing_pred */
6949 tree_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6950 tree_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6951 tree_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6952 tree_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6953 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6954 flush_pending_stmts /* flush_pending_stmts */
6958 /* Split all critical edges. */
6961 split_critical_edges (void)
6967 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6968 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6969 mappings around the calls to split_edge. */
6970 start_recording_case_labels ();
6973 FOR_EACH_EDGE (e, ei, bb->succs)
6974 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6979 end_recording_case_labels ();
6983 struct gimple_opt_pass pass_split_crit_edges =
6987 "crited", /* name */
6989 split_critical_edges, /* execute */
6992 0, /* static_pass_number */
6993 TV_TREE_SPLIT_EDGES, /* tv_id */
6994 PROP_cfg, /* properties required */
6995 PROP_no_crit_edges, /* properties_provided */
6996 0, /* properties_destroyed */
6997 0, /* todo_flags_start */
6998 TODO_dump_func /* todo_flags_finish */
7003 /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into
7004 a temporary, make sure and register it to be renamed if necessary,
7005 and finally return the temporary. Put the statements to compute
7006 EXP before the current statement in BSI. */
7009 gimplify_val (block_stmt_iterator *bsi, tree type, tree exp)
7011 tree t, new_stmt, orig_stmt;
7013 if (is_gimple_val (exp))
7016 t = make_rename_temp (type, NULL);
7017 new_stmt = build_gimple_modify_stmt (t, exp);
7019 orig_stmt = bsi_stmt (*bsi);
7020 SET_EXPR_LOCUS (new_stmt, EXPR_LOCUS (orig_stmt));
7021 TREE_BLOCK (new_stmt) = TREE_BLOCK (orig_stmt);
7023 bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
7024 if (gimple_in_ssa_p (cfun))
7025 mark_symbols_for_renaming (new_stmt);
7030 /* Build a ternary operation and gimplify it. Emit code before BSI.
7031 Return the gimple_val holding the result. */
7034 gimplify_build3 (block_stmt_iterator *bsi, enum tree_code code,
7035 tree type, tree a, tree b, tree c)
7039 ret = fold_build3 (code, type, a, b, c);
7042 return gimplify_val (bsi, type, ret);
7045 /* Build a binary operation and gimplify it. Emit code before BSI.
7046 Return the gimple_val holding the result. */
7049 gimplify_build2 (block_stmt_iterator *bsi, enum tree_code code,
7050 tree type, tree a, tree b)
7054 ret = fold_build2 (code, type, a, b);
7057 return gimplify_val (bsi, type, ret);
7060 /* Build a unary operation and gimplify it. Emit code before BSI.
7061 Return the gimple_val holding the result. */
7064 gimplify_build1 (block_stmt_iterator *bsi, enum tree_code code, tree type,
7069 ret = fold_build1 (code, type, a);
7072 return gimplify_val (bsi, type, ret);
7077 /* Emit return warnings. */
7080 execute_warn_function_return (void)
7082 source_location location;
7087 /* If we have a path to EXIT, then we do return. */
7088 if (TREE_THIS_VOLATILE (cfun->decl)
7089 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
7091 location = UNKNOWN_LOCATION;
7092 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7094 last = last_stmt (e->src);
7095 if (TREE_CODE (last) == RETURN_EXPR
7096 && (location = EXPR_LOCATION (last)) != UNKNOWN_LOCATION)
7099 if (location == UNKNOWN_LOCATION)
7100 location = cfun->function_end_locus;
7101 warning (0, "%H%<noreturn%> function does return", &location);
7104 /* If we see "return;" in some basic block, then we do reach the end
7105 without returning a value. */
7106 else if (warn_return_type
7107 && !TREE_NO_WARNING (cfun->decl)
7108 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
7109 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
7111 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7113 tree last = last_stmt (e->src);
7114 if (TREE_CODE (last) == RETURN_EXPR
7115 && TREE_OPERAND (last, 0) == NULL
7116 && !TREE_NO_WARNING (last))
7118 location = EXPR_LOCATION (last);
7119 if (location == UNKNOWN_LOCATION)
7120 location = cfun->function_end_locus;
7121 warning (OPT_Wreturn_type, "%Hcontrol reaches end of non-void function", &location);
7122 TREE_NO_WARNING (cfun->decl) = 1;
7131 /* Given a basic block B which ends with a conditional and has
7132 precisely two successors, determine which of the edges is taken if
7133 the conditional is true and which is taken if the conditional is
7134 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
7137 extract_true_false_edges_from_block (basic_block b,
7141 edge e = EDGE_SUCC (b, 0);
7143 if (e->flags & EDGE_TRUE_VALUE)
7146 *false_edge = EDGE_SUCC (b, 1);
7151 *true_edge = EDGE_SUCC (b, 1);
7155 struct gimple_opt_pass pass_warn_function_return =
7161 execute_warn_function_return, /* execute */
7164 0, /* static_pass_number */
7166 PROP_cfg, /* properties_required */
7167 0, /* properties_provided */
7168 0, /* properties_destroyed */
7169 0, /* todo_flags_start */
7170 0 /* todo_flags_finish */
7174 /* Emit noreturn warnings. */
7177 execute_warn_function_noreturn (void)
7179 if (warn_missing_noreturn
7180 && !TREE_THIS_VOLATILE (cfun->decl)
7181 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
7182 && !lang_hooks.missing_noreturn_ok_p (cfun->decl))
7183 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
7184 "for attribute %<noreturn%>",
7189 struct gimple_opt_pass pass_warn_function_noreturn =
7195 execute_warn_function_noreturn, /* execute */
7198 0, /* static_pass_number */
7200 PROP_cfg, /* properties_required */
7201 0, /* properties_provided */
7202 0, /* properties_destroyed */
7203 0, /* todo_flags_start */
7204 0 /* todo_flags_finish */