1 /* Control flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "hard-reg-set.h"
30 #include "basic-block.h"
36 #include "langhooks.h"
37 #include "diagnostic.h"
38 #include "tree-flow.h"
40 #include "tree-dump.h"
41 #include "tree-pass.h"
45 #include "cfglayout.h"
46 #include "tree-ssa-propagate.h"
47 #include "value-prof.h"
48 #include "pointer-set.h"
50 /* This file contains functions for building the Control Flow Graph (CFG)
51 for a function tree. */
53 /* Local declarations. */
55 /* Initial capacity for the basic block array. */
56 static const int initial_cfg_capacity = 20;
58 /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs
59 which use a particular edge. The CASE_LABEL_EXPRs are chained together
60 via their TREE_CHAIN field, which we clear after we're done with the
61 hash table to prevent problems with duplication of SWITCH_EXPRs.
63 Access to this list of CASE_LABEL_EXPRs allows us to efficiently
64 update the case vector in response to edge redirections.
66 Right now this table is set up and torn down at key points in the
67 compilation process. It would be nice if we could make the table
68 more persistent. The key is getting notification of changes to
69 the CFG (particularly edge removal, creation and redirection). */
71 static struct pointer_map_t *edge_to_cases;
76 long num_merged_labels;
79 static struct cfg_stats_d cfg_stats;
81 /* Nonzero if we found a computed goto while building basic blocks. */
82 static bool found_computed_goto;
84 /* Basic blocks and flowgraphs. */
85 static basic_block create_bb (void *, void *, basic_block);
86 static void make_blocks (tree);
87 static void factor_computed_gotos (void);
90 static void make_edges (void);
91 static void make_cond_expr_edges (basic_block);
92 static void make_switch_expr_edges (basic_block);
93 static void make_goto_expr_edges (basic_block);
94 static edge tree_redirect_edge_and_branch (edge, basic_block);
95 static edge tree_try_redirect_by_replacing_jump (edge, basic_block);
96 static unsigned int split_critical_edges (void);
98 /* Various helpers. */
99 static inline bool stmt_starts_bb_p (const_tree, const_tree);
100 static int tree_verify_flow_info (void);
101 static void tree_make_forwarder_block (edge);
102 static void tree_cfg2vcg (FILE *);
103 static inline void change_bb_for_stmt (tree t, basic_block bb);
105 /* Flowgraph optimization and cleanup. */
106 static void tree_merge_blocks (basic_block, basic_block);
107 static bool tree_can_merge_blocks_p (basic_block, basic_block);
108 static void remove_bb (basic_block);
109 static edge find_taken_edge_computed_goto (basic_block, tree);
110 static edge find_taken_edge_cond_expr (basic_block, tree);
111 static edge find_taken_edge_switch_expr (basic_block, tree);
112 static tree find_case_label_for_value (tree, tree);
115 init_empty_tree_cfg (void)
117 /* Initialize the basic block array. */
119 profile_status = PROFILE_ABSENT;
120 n_basic_blocks = NUM_FIXED_BLOCKS;
121 last_basic_block = NUM_FIXED_BLOCKS;
122 basic_block_info = VEC_alloc (basic_block, gc, initial_cfg_capacity);
123 VEC_safe_grow_cleared (basic_block, gc, basic_block_info,
124 initial_cfg_capacity);
126 /* Build a mapping of labels to their associated blocks. */
127 label_to_block_map = VEC_alloc (basic_block, gc, initial_cfg_capacity);
128 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
129 initial_cfg_capacity);
131 SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR);
132 SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR);
133 ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR;
134 EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR;
137 /*---------------------------------------------------------------------------
139 ---------------------------------------------------------------------------*/
141 /* Entry point to the CFG builder for trees. TP points to the list of
142 statements to be added to the flowgraph. */
145 build_tree_cfg (tree *tp)
147 /* Register specific tree functions. */
148 tree_register_cfg_hooks ();
150 memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
152 init_empty_tree_cfg ();
154 found_computed_goto = 0;
157 /* Computed gotos are hell to deal with, especially if there are
158 lots of them with a large number of destinations. So we factor
159 them to a common computed goto location before we build the
160 edge list. After we convert back to normal form, we will un-factor
161 the computed gotos since factoring introduces an unwanted jump. */
162 if (found_computed_goto)
163 factor_computed_gotos ();
165 /* Make sure there is always at least one block, even if it's empty. */
166 if (n_basic_blocks == NUM_FIXED_BLOCKS)
167 create_empty_bb (ENTRY_BLOCK_PTR);
169 /* Adjust the size of the array. */
170 if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
171 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
173 /* To speed up statement iterator walks, we first purge dead labels. */
174 cleanup_dead_labels ();
176 /* Group case nodes to reduce the number of edges.
177 We do this after cleaning up dead labels because otherwise we miss
178 a lot of obvious case merging opportunities. */
179 group_case_labels ();
181 /* Create the edges of the flowgraph. */
183 cleanup_dead_labels ();
185 /* Debugging dumps. */
187 /* Write the flowgraph to a VCG file. */
189 int local_dump_flags;
190 FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
193 tree_cfg2vcg (vcg_file);
194 dump_end (TDI_vcg, vcg_file);
198 #ifdef ENABLE_CHECKING
202 /* Dump a textual representation of the flowgraph. */
204 dump_tree_cfg (dump_file, dump_flags);
208 execute_build_cfg (void)
210 build_tree_cfg (&DECL_SAVED_TREE (current_function_decl));
214 struct tree_opt_pass pass_build_cfg =
218 execute_build_cfg, /* execute */
221 0, /* static_pass_number */
222 TV_TREE_CFG, /* tv_id */
223 PROP_gimple_leh, /* properties_required */
224 PROP_cfg, /* properties_provided */
225 0, /* properties_destroyed */
226 0, /* todo_flags_start */
227 TODO_verify_stmts | TODO_cleanup_cfg, /* todo_flags_finish */
231 /* Search the CFG for any computed gotos. If found, factor them to a
232 common computed goto site. Also record the location of that site so
233 that we can un-factor the gotos after we have converted back to
237 factor_computed_gotos (void)
240 tree factored_label_decl = NULL;
242 tree factored_computed_goto_label = NULL;
243 tree factored_computed_goto = NULL;
245 /* We know there are one or more computed gotos in this function.
246 Examine the last statement in each basic block to see if the block
247 ends with a computed goto. */
251 block_stmt_iterator bsi = bsi_last (bb);
256 last = bsi_stmt (bsi);
258 /* Ignore the computed goto we create when we factor the original
260 if (last == factored_computed_goto)
263 /* If the last statement is a computed goto, factor it. */
264 if (computed_goto_p (last))
268 /* The first time we find a computed goto we need to create
269 the factored goto block and the variable each original
270 computed goto will use for their goto destination. */
271 if (! factored_computed_goto)
273 basic_block new_bb = create_empty_bb (bb);
274 block_stmt_iterator new_bsi = bsi_start (new_bb);
276 /* Create the destination of the factored goto. Each original
277 computed goto will put its desired destination into this
278 variable and jump to the label we create immediately
280 var = create_tmp_var (ptr_type_node, "gotovar");
282 /* Build a label for the new block which will contain the
283 factored computed goto. */
284 factored_label_decl = create_artificial_label ();
285 factored_computed_goto_label
286 = build1 (LABEL_EXPR, void_type_node, factored_label_decl);
287 bsi_insert_after (&new_bsi, factored_computed_goto_label,
290 /* Build our new computed goto. */
291 factored_computed_goto = build1 (GOTO_EXPR, void_type_node, var);
292 bsi_insert_after (&new_bsi, factored_computed_goto,
296 /* Copy the original computed goto's destination into VAR. */
297 assignment = build_gimple_modify_stmt (var,
298 GOTO_DESTINATION (last));
299 bsi_insert_before (&bsi, assignment, BSI_SAME_STMT);
301 /* And re-vector the computed goto to the new destination. */
302 GOTO_DESTINATION (last) = factored_label_decl;
308 /* Build a flowgraph for the statement_list STMT_LIST. */
311 make_blocks (tree stmt_list)
313 tree_stmt_iterator i = tsi_start (stmt_list);
315 bool start_new_block = true;
316 bool first_stmt_of_list = true;
317 basic_block bb = ENTRY_BLOCK_PTR;
319 while (!tsi_end_p (i))
326 /* If the statement starts a new basic block or if we have determined
327 in a previous pass that we need to create a new block for STMT, do
329 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
331 if (!first_stmt_of_list)
332 stmt_list = tsi_split_statement_list_before (&i);
333 bb = create_basic_block (stmt_list, NULL, bb);
334 start_new_block = false;
337 /* Now add STMT to BB and create the subgraphs for special statement
339 set_bb_for_stmt (stmt, bb);
341 if (computed_goto_p (stmt))
342 found_computed_goto = true;
344 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
346 if (stmt_ends_bb_p (stmt))
347 start_new_block = true;
350 first_stmt_of_list = false;
355 /* Create and return a new empty basic block after bb AFTER. */
358 create_bb (void *h, void *e, basic_block after)
364 /* Create and initialize a new basic block. Since alloc_block uses
365 ggc_alloc_cleared to allocate a basic block, we do not have to
366 clear the newly allocated basic block here. */
369 bb->index = last_basic_block;
371 bb->il.tree = GGC_CNEW (struct tree_bb_info);
372 set_bb_stmt_list (bb, h ? (tree) h : alloc_stmt_list ());
374 /* Add the new block to the linked list of blocks. */
375 link_block (bb, after);
377 /* Grow the basic block array if needed. */
378 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
380 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
381 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
384 /* Add the newly created block to the array. */
385 SET_BASIC_BLOCK (last_basic_block, bb);
394 /*---------------------------------------------------------------------------
396 ---------------------------------------------------------------------------*/
398 /* Fold COND_EXPR_COND of each COND_EXPR. */
401 fold_cond_expr_cond (void)
407 tree stmt = last_stmt (bb);
410 && TREE_CODE (stmt) == COND_EXPR)
415 fold_defer_overflow_warnings ();
416 cond = fold (COND_EXPR_COND (stmt));
417 zerop = integer_zerop (cond);
418 onep = integer_onep (cond);
419 fold_undefer_overflow_warnings (((zerop || onep)
420 && !TREE_NO_WARNING (stmt)),
422 WARN_STRICT_OVERFLOW_CONDITIONAL);
424 COND_EXPR_COND (stmt) = boolean_false_node;
426 COND_EXPR_COND (stmt) = boolean_true_node;
431 /* Join all the blocks in the flowgraph. */
437 struct omp_region *cur_region = NULL;
439 /* Create an edge from entry to the first block with executable
441 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
443 /* Traverse the basic block array placing edges. */
446 tree last = last_stmt (bb);
451 enum tree_code code = TREE_CODE (last);
455 make_goto_expr_edges (bb);
459 make_edge (bb, EXIT_BLOCK_PTR, 0);
463 make_cond_expr_edges (bb);
467 make_switch_expr_edges (bb);
471 make_eh_edges (last);
476 /* If this function receives a nonlocal goto, then we need to
477 make edges from this call site to all the nonlocal goto
479 if (tree_can_make_abnormal_goto (last))
480 make_abnormal_goto_edges (bb, true);
482 /* If this statement has reachable exception handlers, then
483 create abnormal edges to them. */
484 make_eh_edges (last);
486 /* Some calls are known not to return. */
487 fallthru = !(call_expr_flags (last) & ECF_NORETURN);
493 case GIMPLE_MODIFY_STMT:
494 if (is_ctrl_altering_stmt (last))
496 /* A GIMPLE_MODIFY_STMT may have a CALL_EXPR on its RHS and
497 the CALL_EXPR may have an abnormal edge. Search the RHS
498 for this case and create any required edges. */
499 if (tree_can_make_abnormal_goto (last))
500 make_abnormal_goto_edges (bb, true);
502 make_eh_edges (last);
514 cur_region = new_omp_region (bb, code, cur_region);
519 cur_region = new_omp_region (bb, code, cur_region);
524 /* In the case of an OMP_SECTION, the edge will go somewhere
525 other than the next block. This will be created later. */
526 cur_region->exit = bb;
527 fallthru = cur_region->type != OMP_SECTION;
528 cur_region = cur_region->outer;
532 cur_region->cont = bb;
533 switch (cur_region->type)
536 /* ??? Technically there should be a some sort of loopback
537 edge here, but it goes to a block that doesn't exist yet,
538 and without it, updating the ssa form would be a real
539 bear. Fortunately, we don't yet do ssa before expanding
544 /* Wire up the edges into and out of the nested sections. */
545 /* ??? Similarly wrt loopback. */
547 struct omp_region *i;
548 for (i = cur_region->inner; i ; i = i->next)
550 gcc_assert (i->type == OMP_SECTION);
551 make_edge (cur_region->entry, i->entry, 0);
552 make_edge (i->exit, bb, EDGE_FALLTHRU);
564 gcc_assert (!stmt_ends_bb_p (last));
572 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
578 /* Fold COND_EXPR_COND of each COND_EXPR. */
579 fold_cond_expr_cond ();
583 /* Create the edges for a COND_EXPR starting at block BB.
584 At this point, both clauses must contain only simple gotos. */
587 make_cond_expr_edges (basic_block bb)
589 tree entry = last_stmt (bb);
590 basic_block then_bb, else_bb;
591 tree then_label, else_label;
595 gcc_assert (TREE_CODE (entry) == COND_EXPR);
597 /* Entry basic blocks for each component. */
598 then_label = GOTO_DESTINATION (COND_EXPR_THEN (entry));
599 else_label = GOTO_DESTINATION (COND_EXPR_ELSE (entry));
600 then_bb = label_to_block (then_label);
601 else_bb = label_to_block (else_label);
603 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
604 #ifdef USE_MAPPED_LOCATION
605 e->goto_locus = EXPR_LOCATION (COND_EXPR_THEN (entry));
607 e->goto_locus = EXPR_LOCUS (COND_EXPR_THEN (entry));
609 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
612 #ifdef USE_MAPPED_LOCATION
613 e->goto_locus = EXPR_LOCATION (COND_EXPR_ELSE (entry));
615 e->goto_locus = EXPR_LOCUS (COND_EXPR_ELSE (entry));
619 /* We do not need the gotos anymore. */
620 COND_EXPR_THEN (entry) = NULL_TREE;
621 COND_EXPR_ELSE (entry) = NULL_TREE;
625 /* Called for each element in the hash table (P) as we delete the
626 edge to cases hash table.
628 Clear all the TREE_CHAINs to prevent problems with copying of
629 SWITCH_EXPRs and structure sharing rules, then free the hash table
633 edge_to_cases_cleanup (void *key ATTRIBUTE_UNUSED, void **value,
634 void *data ATTRIBUTE_UNUSED)
638 for (t = (tree) *value; t; t = next)
640 next = TREE_CHAIN (t);
641 TREE_CHAIN (t) = NULL;
648 /* Start recording information mapping edges to case labels. */
651 start_recording_case_labels (void)
653 gcc_assert (edge_to_cases == NULL);
654 edge_to_cases = pointer_map_create ();
657 /* Return nonzero if we are recording information for case labels. */
660 recording_case_labels_p (void)
662 return (edge_to_cases != NULL);
665 /* Stop recording information mapping edges to case labels and
666 remove any information we have recorded. */
668 end_recording_case_labels (void)
670 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
671 pointer_map_destroy (edge_to_cases);
672 edge_to_cases = NULL;
675 /* If we are inside a {start,end}_recording_cases block, then return
676 a chain of CASE_LABEL_EXPRs from T which reference E.
678 Otherwise return NULL. */
681 get_cases_for_edge (edge e, tree t)
687 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
688 chains available. Return NULL so the caller can detect this case. */
689 if (!recording_case_labels_p ())
692 slot = pointer_map_contains (edge_to_cases, e);
696 /* If we did not find E in the hash table, then this must be the first
697 time we have been queried for information about E & T. Add all the
698 elements from T to the hash table then perform the query again. */
700 vec = SWITCH_LABELS (t);
701 n = TREE_VEC_LENGTH (vec);
702 for (i = 0; i < n; i++)
704 tree elt = TREE_VEC_ELT (vec, i);
705 tree lab = CASE_LABEL (elt);
706 basic_block label_bb = label_to_block (lab);
707 edge this_edge = find_edge (e->src, label_bb);
709 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
711 slot = pointer_map_insert (edge_to_cases, this_edge);
712 TREE_CHAIN (elt) = (tree) *slot;
716 return (tree) *pointer_map_contains (edge_to_cases, e);
719 /* Create the edges for a SWITCH_EXPR starting at block BB.
720 At this point, the switch body has been lowered and the
721 SWITCH_LABELS filled in, so this is in effect a multi-way branch. */
724 make_switch_expr_edges (basic_block bb)
726 tree entry = last_stmt (bb);
730 vec = SWITCH_LABELS (entry);
731 n = TREE_VEC_LENGTH (vec);
733 for (i = 0; i < n; ++i)
735 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
736 basic_block label_bb = label_to_block (lab);
737 make_edge (bb, label_bb, 0);
742 /* Return the basic block holding label DEST. */
745 label_to_block_fn (struct function *ifun, tree dest)
747 int uid = LABEL_DECL_UID (dest);
749 /* We would die hard when faced by an undefined label. Emit a label to
750 the very first basic block. This will hopefully make even the dataflow
751 and undefined variable warnings quite right. */
752 if ((errorcount || sorrycount) && uid < 0)
754 block_stmt_iterator bsi =
755 bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS));
758 stmt = build1 (LABEL_EXPR, void_type_node, dest);
759 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
760 uid = LABEL_DECL_UID (dest);
762 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
763 <= (unsigned int) uid)
765 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
768 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
769 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
772 make_abnormal_goto_edges (basic_block bb, bool for_call)
774 basic_block target_bb;
775 block_stmt_iterator bsi;
777 FOR_EACH_BB (target_bb)
778 for (bsi = bsi_start (target_bb); !bsi_end_p (bsi); bsi_next (&bsi))
780 tree target = bsi_stmt (bsi);
782 if (TREE_CODE (target) != LABEL_EXPR)
785 target = LABEL_EXPR_LABEL (target);
787 /* Make an edge to every label block that has been marked as a
788 potential target for a computed goto or a non-local goto. */
789 if ((FORCED_LABEL (target) && !for_call)
790 || (DECL_NONLOCAL (target) && for_call))
792 make_edge (bb, target_bb, EDGE_ABNORMAL);
798 /* Create edges for a goto statement at block BB. */
801 make_goto_expr_edges (basic_block bb)
803 block_stmt_iterator last = bsi_last (bb);
804 tree goto_t = bsi_stmt (last);
806 /* A simple GOTO creates normal edges. */
807 if (simple_goto_p (goto_t))
809 tree dest = GOTO_DESTINATION (goto_t);
810 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
811 #ifdef USE_MAPPED_LOCATION
812 e->goto_locus = EXPR_LOCATION (goto_t);
814 e->goto_locus = EXPR_LOCUS (goto_t);
816 bsi_remove (&last, true);
820 /* A computed GOTO creates abnormal edges. */
821 make_abnormal_goto_edges (bb, false);
825 /*---------------------------------------------------------------------------
827 ---------------------------------------------------------------------------*/
829 /* Cleanup useless labels in basic blocks. This is something we wish
830 to do early because it allows us to group case labels before creating
831 the edges for the CFG, and it speeds up block statement iterators in
833 We rerun this pass after CFG is created, to get rid of the labels that
834 are no longer referenced. After then we do not run it any more, since
835 (almost) no new labels should be created. */
837 /* A map from basic block index to the leading label of that block. */
838 static struct label_record
843 /* True if the label is referenced from somewhere. */
847 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
849 update_eh_label (struct eh_region *region)
851 tree old_label = get_eh_region_tree_label (region);
855 basic_block bb = label_to_block (old_label);
857 /* ??? After optimizing, there may be EH regions with labels
858 that have already been removed from the function body, so
859 there is no basic block for them. */
863 new_label = label_for_bb[bb->index].label;
864 label_for_bb[bb->index].used = true;
865 set_eh_region_tree_label (region, new_label);
869 /* Given LABEL return the first label in the same basic block. */
871 main_block_label (tree label)
873 basic_block bb = label_to_block (label);
874 tree main_label = label_for_bb[bb->index].label;
876 /* label_to_block possibly inserted undefined label into the chain. */
879 label_for_bb[bb->index].label = label;
883 label_for_bb[bb->index].used = true;
887 /* Cleanup redundant labels. This is a three-step process:
888 1) Find the leading label for each block.
889 2) Redirect all references to labels to the leading labels.
890 3) Cleanup all useless labels. */
893 cleanup_dead_labels (void)
896 label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
898 /* Find a suitable label for each block. We use the first user-defined
899 label if there is one, or otherwise just the first label we see. */
902 block_stmt_iterator i;
904 for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i))
906 tree label, stmt = bsi_stmt (i);
908 if (TREE_CODE (stmt) != LABEL_EXPR)
911 label = LABEL_EXPR_LABEL (stmt);
913 /* If we have not yet seen a label for the current block,
914 remember this one and see if there are more labels. */
915 if (!label_for_bb[bb->index].label)
917 label_for_bb[bb->index].label = label;
921 /* If we did see a label for the current block already, but it
922 is an artificially created label, replace it if the current
923 label is a user defined label. */
924 if (!DECL_ARTIFICIAL (label)
925 && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
927 label_for_bb[bb->index].label = label;
933 /* Now redirect all jumps/branches to the selected label.
934 First do so for each block ending in a control statement. */
937 tree stmt = last_stmt (bb);
941 switch (TREE_CODE (stmt))
945 tree true_branch, false_branch;
947 true_branch = COND_EXPR_THEN (stmt);
948 false_branch = COND_EXPR_ELSE (stmt);
951 GOTO_DESTINATION (true_branch)
952 = main_block_label (GOTO_DESTINATION (true_branch));
954 GOTO_DESTINATION (false_branch)
955 = main_block_label (GOTO_DESTINATION (false_branch));
963 tree vec = SWITCH_LABELS (stmt);
964 size_t n = TREE_VEC_LENGTH (vec);
966 /* Replace all destination labels. */
967 for (i = 0; i < n; ++i)
969 tree elt = TREE_VEC_ELT (vec, i);
970 tree label = main_block_label (CASE_LABEL (elt));
971 CASE_LABEL (elt) = label;
976 /* We have to handle GOTO_EXPRs until they're removed, and we don't
977 remove them until after we've created the CFG edges. */
979 if (! computed_goto_p (stmt))
981 GOTO_DESTINATION (stmt)
982 = main_block_label (GOTO_DESTINATION (stmt));
991 for_each_eh_region (update_eh_label);
993 /* Finally, purge dead labels. All user-defined labels and labels that
994 can be the target of non-local gotos and labels which have their
995 address taken are preserved. */
998 block_stmt_iterator i;
999 tree label_for_this_bb = label_for_bb[bb->index].label;
1001 if (!label_for_this_bb)
1004 /* If the main label of the block is unused, we may still remove it. */
1005 if (!label_for_bb[bb->index].used)
1006 label_for_this_bb = NULL;
1008 for (i = bsi_start (bb); !bsi_end_p (i); )
1010 tree label, stmt = bsi_stmt (i);
1012 if (TREE_CODE (stmt) != LABEL_EXPR)
1015 label = LABEL_EXPR_LABEL (stmt);
1017 if (label == label_for_this_bb
1018 || ! DECL_ARTIFICIAL (label)
1019 || DECL_NONLOCAL (label)
1020 || FORCED_LABEL (label))
1023 bsi_remove (&i, true);
1027 free (label_for_bb);
1030 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1031 and scan the sorted vector of cases. Combine the ones jumping to the
1033 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1036 group_case_labels (void)
1042 tree stmt = last_stmt (bb);
1043 if (stmt && TREE_CODE (stmt) == SWITCH_EXPR)
1045 tree labels = SWITCH_LABELS (stmt);
1046 int old_size = TREE_VEC_LENGTH (labels);
1047 int i, j, new_size = old_size;
1048 tree default_case = TREE_VEC_ELT (labels, old_size - 1);
1051 /* The default label is always the last case in a switch
1052 statement after gimplification. */
1053 default_label = CASE_LABEL (default_case);
1055 /* Look for possible opportunities to merge cases.
1056 Ignore the last element of the label vector because it
1057 must be the default case. */
1059 while (i < old_size - 1)
1061 tree base_case, base_label, base_high;
1062 base_case = TREE_VEC_ELT (labels, i);
1064 gcc_assert (base_case);
1065 base_label = CASE_LABEL (base_case);
1067 /* Discard cases that have the same destination as the
1069 if (base_label == default_label)
1071 TREE_VEC_ELT (labels, i) = NULL_TREE;
1077 base_high = CASE_HIGH (base_case) ?
1078 CASE_HIGH (base_case) : CASE_LOW (base_case);
1080 /* Try to merge case labels. Break out when we reach the end
1081 of the label vector or when we cannot merge the next case
1082 label with the current one. */
1083 while (i < old_size - 1)
1085 tree merge_case = TREE_VEC_ELT (labels, i);
1086 tree merge_label = CASE_LABEL (merge_case);
1087 tree t = int_const_binop (PLUS_EXPR, base_high,
1088 integer_one_node, 1);
1090 /* Merge the cases if they jump to the same place,
1091 and their ranges are consecutive. */
1092 if (merge_label == base_label
1093 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1095 base_high = CASE_HIGH (merge_case) ?
1096 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1097 CASE_HIGH (base_case) = base_high;
1098 TREE_VEC_ELT (labels, i) = NULL_TREE;
1107 /* Compress the case labels in the label vector, and adjust the
1108 length of the vector. */
1109 for (i = 0, j = 0; i < new_size; i++)
1111 while (! TREE_VEC_ELT (labels, j))
1113 TREE_VEC_ELT (labels, i) = TREE_VEC_ELT (labels, j++);
1115 TREE_VEC_LENGTH (labels) = new_size;
1120 /* Checks whether we can merge block B into block A. */
1123 tree_can_merge_blocks_p (basic_block a, basic_block b)
1126 block_stmt_iterator bsi;
1129 if (!single_succ_p (a))
1132 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1135 if (single_succ (a) != b)
1138 if (!single_pred_p (b))
1141 if (b == EXIT_BLOCK_PTR)
1144 /* If A ends by a statement causing exceptions or something similar, we
1145 cannot merge the blocks. */
1146 stmt = last_stmt (a);
1147 if (stmt && stmt_ends_bb_p (stmt))
1150 /* Do not allow a block with only a non-local label to be merged. */
1151 if (stmt && TREE_CODE (stmt) == LABEL_EXPR
1152 && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
1155 /* It must be possible to eliminate all phi nodes in B. If ssa form
1156 is not up-to-date, we cannot eliminate any phis; however, if only
1157 some symbols as whole are marked for renaming, this is not a problem,
1158 as phi nodes for those symbols are irrelevant in updating anyway. */
1159 phi = phi_nodes (b);
1162 if (name_mappings_registered_p ())
1165 for (; phi; phi = PHI_CHAIN (phi))
1166 if (!is_gimple_reg (PHI_RESULT (phi))
1167 && !may_propagate_copy (PHI_RESULT (phi), PHI_ARG_DEF (phi, 0)))
1171 /* Do not remove user labels. */
1172 for (bsi = bsi_start (b); !bsi_end_p (bsi); bsi_next (&bsi))
1174 stmt = bsi_stmt (bsi);
1175 if (TREE_CODE (stmt) != LABEL_EXPR)
1177 if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt)))
1181 /* Protect the loop latches. */
1183 && b->loop_father->latch == b)
1189 /* Replaces all uses of NAME by VAL. */
1192 replace_uses_by (tree name, tree val)
1194 imm_use_iterator imm_iter;
1199 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1201 if (TREE_CODE (stmt) != PHI_NODE)
1202 push_stmt_changes (&stmt);
1204 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1206 replace_exp (use, val);
1208 if (TREE_CODE (stmt) == PHI_NODE)
1210 e = PHI_ARG_EDGE (stmt, PHI_ARG_INDEX_FROM_USE (use));
1211 if (e->flags & EDGE_ABNORMAL)
1213 /* This can only occur for virtual operands, since
1214 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1215 would prevent replacement. */
1216 gcc_assert (!is_gimple_reg (name));
1217 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1222 if (TREE_CODE (stmt) != PHI_NODE)
1226 fold_stmt_inplace (stmt);
1227 if (cfgcleanup_altered_bbs)
1228 bitmap_set_bit (cfgcleanup_altered_bbs, bb_for_stmt (stmt)->index);
1230 /* FIXME. This should go in pop_stmt_changes. */
1231 rhs = get_rhs (stmt);
1232 if (TREE_CODE (rhs) == ADDR_EXPR)
1233 recompute_tree_invariant_for_addr_expr (rhs);
1235 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1237 pop_stmt_changes (&stmt);
1241 gcc_assert (has_zero_uses (name));
1243 /* Also update the trees stored in loop structures. */
1249 FOR_EACH_LOOP (li, loop, 0)
1251 substitute_in_loop_info (loop, name, val);
1256 /* Merge block B into block A. */
1259 tree_merge_blocks (basic_block a, basic_block b)
1261 block_stmt_iterator bsi;
1262 tree_stmt_iterator last;
1266 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1268 /* Remove all single-valued PHI nodes from block B of the form
1269 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1271 for (phi = phi_nodes (b); phi; phi = phi_nodes (b))
1273 tree def = PHI_RESULT (phi), use = PHI_ARG_DEF (phi, 0);
1275 bool may_replace_uses = may_propagate_copy (def, use);
1277 /* In case we have loops to care about, do not propagate arguments of
1278 loop closed ssa phi nodes. */
1280 && is_gimple_reg (def)
1281 && TREE_CODE (use) == SSA_NAME
1282 && a->loop_father != b->loop_father)
1283 may_replace_uses = false;
1285 if (!may_replace_uses)
1287 gcc_assert (is_gimple_reg (def));
1289 /* Note that just emitting the copies is fine -- there is no problem
1290 with ordering of phi nodes. This is because A is the single
1291 predecessor of B, therefore results of the phi nodes cannot
1292 appear as arguments of the phi nodes. */
1293 copy = build_gimple_modify_stmt (def, use);
1294 bsi_insert_after (&bsi, copy, BSI_NEW_STMT);
1295 SSA_NAME_DEF_STMT (def) = copy;
1296 remove_phi_node (phi, NULL, false);
1300 replace_uses_by (def, use);
1301 remove_phi_node (phi, NULL, true);
1305 /* Ensure that B follows A. */
1306 move_block_after (b, a);
1308 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1309 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1311 /* Remove labels from B and set bb_for_stmt to A for other statements. */
1312 for (bsi = bsi_start (b); !bsi_end_p (bsi);)
1314 if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR)
1316 tree label = bsi_stmt (bsi);
1318 bsi_remove (&bsi, false);
1319 /* Now that we can thread computed gotos, we might have
1320 a situation where we have a forced label in block B
1321 However, the label at the start of block B might still be
1322 used in other ways (think about the runtime checking for
1323 Fortran assigned gotos). So we can not just delete the
1324 label. Instead we move the label to the start of block A. */
1325 if (FORCED_LABEL (LABEL_EXPR_LABEL (label)))
1327 block_stmt_iterator dest_bsi = bsi_start (a);
1328 bsi_insert_before (&dest_bsi, label, BSI_NEW_STMT);
1333 change_bb_for_stmt (bsi_stmt (bsi), a);
1338 /* Merge the chains. */
1339 last = tsi_last (bb_stmt_list (a));
1340 tsi_link_after (&last, bb_stmt_list (b), TSI_NEW_STMT);
1341 set_bb_stmt_list (b, NULL_TREE);
1343 if (cfgcleanup_altered_bbs)
1344 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1348 /* Return the one of two successors of BB that is not reachable by a
1349 reached by a complex edge, if there is one. Else, return BB. We use
1350 this in optimizations that use post-dominators for their heuristics,
1351 to catch the cases in C++ where function calls are involved. */
1354 single_noncomplex_succ (basic_block bb)
1357 if (EDGE_COUNT (bb->succs) != 2)
1360 e0 = EDGE_SUCC (bb, 0);
1361 e1 = EDGE_SUCC (bb, 1);
1362 if (e0->flags & EDGE_COMPLEX)
1364 if (e1->flags & EDGE_COMPLEX)
1371 /* Walk the function tree removing unnecessary statements.
1373 * Empty statement nodes are removed
1375 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1377 * Unnecessary COND_EXPRs are removed
1379 * Some unnecessary BIND_EXPRs are removed
1381 Clearly more work could be done. The trick is doing the analysis
1382 and removal fast enough to be a net improvement in compile times.
1384 Note that when we remove a control structure such as a COND_EXPR
1385 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1386 to ensure we eliminate all the useless code. */
1397 static void remove_useless_stmts_1 (tree *, struct rus_data *);
1400 remove_useless_stmts_warn_notreached (tree stmt)
1402 if (EXPR_HAS_LOCATION (stmt))
1404 location_t loc = EXPR_LOCATION (stmt);
1405 if (LOCATION_LINE (loc) > 0)
1407 warning (0, "%Hwill never be executed", &loc);
1412 switch (TREE_CODE (stmt))
1414 case STATEMENT_LIST:
1416 tree_stmt_iterator i;
1417 for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i))
1418 if (remove_useless_stmts_warn_notreached (tsi_stmt (i)))
1424 if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt)))
1426 if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt)))
1428 if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt)))
1432 case TRY_FINALLY_EXPR:
1433 case TRY_CATCH_EXPR:
1434 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 0)))
1436 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 1)))
1441 return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt));
1442 case EH_FILTER_EXPR:
1443 return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt));
1445 return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt));
1448 /* Not a live container. */
1456 remove_useless_stmts_cond (tree *stmt_p, struct rus_data *data)
1458 tree then_clause, else_clause, cond;
1459 bool save_has_label, then_has_label, else_has_label;
1461 save_has_label = data->has_label;
1462 data->has_label = false;
1463 data->last_goto = NULL;
1465 remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p), data);
1467 then_has_label = data->has_label;
1468 data->has_label = false;
1469 data->last_goto = NULL;
1471 remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p), data);
1473 else_has_label = data->has_label;
1474 data->has_label = save_has_label | then_has_label | else_has_label;
1476 then_clause = COND_EXPR_THEN (*stmt_p);
1477 else_clause = COND_EXPR_ELSE (*stmt_p);
1478 cond = fold (COND_EXPR_COND (*stmt_p));
1480 /* If neither arm does anything at all, we can remove the whole IF. */
1481 if (!TREE_SIDE_EFFECTS (then_clause) && !TREE_SIDE_EFFECTS (else_clause))
1483 *stmt_p = build_empty_stmt ();
1484 data->repeat = true;
1487 /* If there are no reachable statements in an arm, then we can
1488 zap the entire conditional. */
1489 else if (integer_nonzerop (cond) && !else_has_label)
1491 if (warn_notreached)
1492 remove_useless_stmts_warn_notreached (else_clause);
1493 *stmt_p = then_clause;
1494 data->repeat = true;
1496 else if (integer_zerop (cond) && !then_has_label)
1498 if (warn_notreached)
1499 remove_useless_stmts_warn_notreached (then_clause);
1500 *stmt_p = else_clause;
1501 data->repeat = true;
1504 /* Check a couple of simple things on then/else with single stmts. */
1507 tree then_stmt = expr_only (then_clause);
1508 tree else_stmt = expr_only (else_clause);
1510 /* Notice branches to a common destination. */
1511 if (then_stmt && else_stmt
1512 && TREE_CODE (then_stmt) == GOTO_EXPR
1513 && TREE_CODE (else_stmt) == GOTO_EXPR
1514 && (GOTO_DESTINATION (then_stmt) == GOTO_DESTINATION (else_stmt)))
1516 *stmt_p = then_stmt;
1517 data->repeat = true;
1520 /* If the THEN/ELSE clause merely assigns a value to a variable or
1521 parameter which is already known to contain that value, then
1522 remove the useless THEN/ELSE clause. */
1523 else if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL)
1526 && TREE_CODE (else_stmt) == GIMPLE_MODIFY_STMT
1527 && GIMPLE_STMT_OPERAND (else_stmt, 0) == cond
1528 && integer_zerop (GIMPLE_STMT_OPERAND (else_stmt, 1)))
1529 COND_EXPR_ELSE (*stmt_p) = alloc_stmt_list ();
1531 else if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
1532 && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL
1533 || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL)
1534 && TREE_CONSTANT (TREE_OPERAND (cond, 1)))
1536 tree stmt = (TREE_CODE (cond) == EQ_EXPR
1537 ? then_stmt : else_stmt);
1538 tree *location = (TREE_CODE (cond) == EQ_EXPR
1539 ? &COND_EXPR_THEN (*stmt_p)
1540 : &COND_EXPR_ELSE (*stmt_p));
1543 && TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
1544 && GIMPLE_STMT_OPERAND (stmt, 0) == TREE_OPERAND (cond, 0)
1545 && GIMPLE_STMT_OPERAND (stmt, 1) == TREE_OPERAND (cond, 1))
1546 *location = alloc_stmt_list ();
1550 /* Protect GOTOs in the arm of COND_EXPRs from being removed. They
1551 would be re-introduced during lowering. */
1552 data->last_goto = NULL;
1557 remove_useless_stmts_tf (tree *stmt_p, struct rus_data *data)
1559 bool save_may_branch, save_may_throw;
1560 bool this_may_branch, this_may_throw;
1562 /* Collect may_branch and may_throw information for the body only. */
1563 save_may_branch = data->may_branch;
1564 save_may_throw = data->may_throw;
1565 data->may_branch = false;
1566 data->may_throw = false;
1567 data->last_goto = NULL;
1569 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1571 this_may_branch = data->may_branch;
1572 this_may_throw = data->may_throw;
1573 data->may_branch |= save_may_branch;
1574 data->may_throw |= save_may_throw;
1575 data->last_goto = NULL;
1577 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1579 /* If the body is empty, then we can emit the FINALLY block without
1580 the enclosing TRY_FINALLY_EXPR. */
1581 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 0)))
1583 *stmt_p = TREE_OPERAND (*stmt_p, 1);
1584 data->repeat = true;
1587 /* If the handler is empty, then we can emit the TRY block without
1588 the enclosing TRY_FINALLY_EXPR. */
1589 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1591 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1592 data->repeat = true;
1595 /* If the body neither throws, nor branches, then we can safely
1596 string the TRY and FINALLY blocks together. */
1597 else if (!this_may_branch && !this_may_throw)
1599 tree stmt = *stmt_p;
1600 *stmt_p = TREE_OPERAND (stmt, 0);
1601 append_to_statement_list (TREE_OPERAND (stmt, 1), stmt_p);
1602 data->repeat = true;
1608 remove_useless_stmts_tc (tree *stmt_p, struct rus_data *data)
1610 bool save_may_throw, this_may_throw;
1611 tree_stmt_iterator i;
1614 /* Collect may_throw information for the body only. */
1615 save_may_throw = data->may_throw;
1616 data->may_throw = false;
1617 data->last_goto = NULL;
1619 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1621 this_may_throw = data->may_throw;
1622 data->may_throw = save_may_throw;
1624 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1625 if (!this_may_throw)
1627 if (warn_notreached)
1628 remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p, 1));
1629 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1630 data->repeat = true;
1634 /* Process the catch clause specially. We may be able to tell that
1635 no exceptions propagate past this point. */
1637 this_may_throw = true;
1638 i = tsi_start (TREE_OPERAND (*stmt_p, 1));
1639 stmt = tsi_stmt (i);
1640 data->last_goto = NULL;
1642 switch (TREE_CODE (stmt))
1645 for (; !tsi_end_p (i); tsi_next (&i))
1647 stmt = tsi_stmt (i);
1648 /* If we catch all exceptions, then the body does not
1649 propagate exceptions past this point. */
1650 if (CATCH_TYPES (stmt) == NULL)
1651 this_may_throw = false;
1652 data->last_goto = NULL;
1653 remove_useless_stmts_1 (&CATCH_BODY (stmt), data);
1657 case EH_FILTER_EXPR:
1658 if (EH_FILTER_MUST_NOT_THROW (stmt))
1659 this_may_throw = false;
1660 else if (EH_FILTER_TYPES (stmt) == NULL)
1661 this_may_throw = false;
1662 remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt), data);
1666 /* Otherwise this is a cleanup. */
1667 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1669 /* If the cleanup is empty, then we can emit the TRY block without
1670 the enclosing TRY_CATCH_EXPR. */
1671 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1673 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1674 data->repeat = true;
1678 data->may_throw |= this_may_throw;
1683 remove_useless_stmts_bind (tree *stmt_p, struct rus_data *data)
1687 /* First remove anything underneath the BIND_EXPR. */
1688 remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p), data);
1690 /* If the BIND_EXPR has no variables, then we can pull everything
1691 up one level and remove the BIND_EXPR, unless this is the toplevel
1692 BIND_EXPR for the current function or an inlined function.
1694 When this situation occurs we will want to apply this
1695 optimization again. */
1696 block = BIND_EXPR_BLOCK (*stmt_p);
1697 if (BIND_EXPR_VARS (*stmt_p) == NULL_TREE
1698 && *stmt_p != DECL_SAVED_TREE (current_function_decl)
1700 || ! BLOCK_ABSTRACT_ORIGIN (block)
1701 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1704 *stmt_p = BIND_EXPR_BODY (*stmt_p);
1705 data->repeat = true;
1711 remove_useless_stmts_goto (tree *stmt_p, struct rus_data *data)
1713 tree dest = GOTO_DESTINATION (*stmt_p);
1715 data->may_branch = true;
1716 data->last_goto = NULL;
1718 /* Record the last goto expr, so that we can delete it if unnecessary. */
1719 if (TREE_CODE (dest) == LABEL_DECL)
1720 data->last_goto = stmt_p;
1725 remove_useless_stmts_label (tree *stmt_p, struct rus_data *data)
1727 tree label = LABEL_EXPR_LABEL (*stmt_p);
1729 data->has_label = true;
1731 /* We do want to jump across non-local label receiver code. */
1732 if (DECL_NONLOCAL (label))
1733 data->last_goto = NULL;
1735 else if (data->last_goto && GOTO_DESTINATION (*data->last_goto) == label)
1737 *data->last_goto = build_empty_stmt ();
1738 data->repeat = true;
1741 /* ??? Add something here to delete unused labels. */
1745 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1746 decl. This allows us to eliminate redundant or useless
1747 calls to "const" functions.
1749 Gimplifier already does the same operation, but we may notice functions
1750 being const and pure once their calls has been gimplified, so we need
1751 to update the flag. */
1754 update_call_expr_flags (tree call)
1756 tree decl = get_callee_fndecl (call);
1759 if (call_expr_flags (call) & (ECF_CONST | ECF_PURE))
1760 TREE_SIDE_EFFECTS (call) = 0;
1761 if (TREE_NOTHROW (decl))
1762 TREE_NOTHROW (call) = 1;
1766 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1769 notice_special_calls (tree t)
1771 int flags = call_expr_flags (t);
1773 if (flags & ECF_MAY_BE_ALLOCA)
1774 current_function_calls_alloca = true;
1775 if (flags & ECF_RETURNS_TWICE)
1776 current_function_calls_setjmp = true;
1780 /* Clear flags set by notice_special_calls. Used by dead code removal
1781 to update the flags. */
1784 clear_special_calls (void)
1786 current_function_calls_alloca = false;
1787 current_function_calls_setjmp = false;
1792 remove_useless_stmts_1 (tree *tp, struct rus_data *data)
1796 switch (TREE_CODE (t))
1799 remove_useless_stmts_cond (tp, data);
1802 case TRY_FINALLY_EXPR:
1803 remove_useless_stmts_tf (tp, data);
1806 case TRY_CATCH_EXPR:
1807 remove_useless_stmts_tc (tp, data);
1811 remove_useless_stmts_bind (tp, data);
1815 remove_useless_stmts_goto (tp, data);
1819 remove_useless_stmts_label (tp, data);
1824 data->last_goto = NULL;
1825 data->may_branch = true;
1830 data->last_goto = NULL;
1831 notice_special_calls (t);
1832 update_call_expr_flags (t);
1833 if (tree_could_throw_p (t))
1834 data->may_throw = true;
1840 case GIMPLE_MODIFY_STMT:
1841 data->last_goto = NULL;
1843 op = get_call_expr_in (t);
1846 update_call_expr_flags (op);
1847 notice_special_calls (op);
1849 if (tree_could_throw_p (t))
1850 data->may_throw = true;
1853 case STATEMENT_LIST:
1855 tree_stmt_iterator i = tsi_start (t);
1856 while (!tsi_end_p (i))
1859 if (IS_EMPTY_STMT (t))
1865 remove_useless_stmts_1 (tsi_stmt_ptr (i), data);
1868 if (TREE_CODE (t) == STATEMENT_LIST)
1870 tsi_link_before (&i, t, TSI_SAME_STMT);
1880 data->last_goto = NULL;
1884 data->last_goto = NULL;
1890 remove_useless_stmts (void)
1892 struct rus_data data;
1894 clear_special_calls ();
1898 memset (&data, 0, sizeof (data));
1899 remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl), &data);
1901 while (data.repeat);
1906 struct tree_opt_pass pass_remove_useless_stmts =
1908 "useless", /* name */
1910 remove_useless_stmts, /* execute */
1913 0, /* static_pass_number */
1915 PROP_gimple_any, /* properties_required */
1916 0, /* properties_provided */
1917 0, /* properties_destroyed */
1918 0, /* todo_flags_start */
1919 TODO_dump_func, /* todo_flags_finish */
1923 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
1926 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
1930 /* Since this block is no longer reachable, we can just delete all
1931 of its PHI nodes. */
1932 phi = phi_nodes (bb);
1935 tree next = PHI_CHAIN (phi);
1936 remove_phi_node (phi, NULL_TREE, true);
1940 /* Remove edges to BB's successors. */
1941 while (EDGE_COUNT (bb->succs) > 0)
1942 remove_edge (EDGE_SUCC (bb, 0));
1946 /* Remove statements of basic block BB. */
1949 remove_bb (basic_block bb)
1951 block_stmt_iterator i;
1952 #ifdef USE_MAPPED_LOCATION
1953 source_location loc = UNKNOWN_LOCATION;
1955 source_locus loc = 0;
1960 fprintf (dump_file, "Removing basic block %d\n", bb->index);
1961 if (dump_flags & TDF_DETAILS)
1963 dump_bb (bb, dump_file, 0);
1964 fprintf (dump_file, "\n");
1970 struct loop *loop = bb->loop_father;
1972 /* If a loop gets removed, clean up the information associated
1974 if (loop->latch == bb
1975 || loop->header == bb)
1976 free_numbers_of_iterations_estimates_loop (loop);
1979 /* Remove all the instructions in the block. */
1980 if (bb_stmt_list (bb) != NULL_TREE)
1982 for (i = bsi_start (bb); !bsi_end_p (i);)
1984 tree stmt = bsi_stmt (i);
1985 if (TREE_CODE (stmt) == LABEL_EXPR
1986 && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt))
1987 || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))))
1990 block_stmt_iterator new_bsi;
1992 /* A non-reachable non-local label may still be referenced.
1993 But it no longer needs to carry the extra semantics of
1995 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
1997 DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)) = 0;
1998 FORCED_LABEL (LABEL_EXPR_LABEL (stmt)) = 1;
2001 new_bb = bb->prev_bb;
2002 new_bsi = bsi_start (new_bb);
2003 bsi_remove (&i, false);
2004 bsi_insert_before (&new_bsi, stmt, BSI_NEW_STMT);
2008 /* Release SSA definitions if we are in SSA. Note that we
2009 may be called when not in SSA. For example,
2010 final_cleanup calls this function via
2011 cleanup_tree_cfg. */
2012 if (gimple_in_ssa_p (cfun))
2013 release_defs (stmt);
2015 bsi_remove (&i, true);
2018 /* Don't warn for removed gotos. Gotos are often removed due to
2019 jump threading, thus resulting in bogus warnings. Not great,
2020 since this way we lose warnings for gotos in the original
2021 program that are indeed unreachable. */
2022 if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc)
2024 #ifdef USE_MAPPED_LOCATION
2025 if (EXPR_HAS_LOCATION (stmt))
2026 loc = EXPR_LOCATION (stmt);
2029 t = EXPR_LOCUS (stmt);
2030 if (t && LOCATION_LINE (*t) > 0)
2037 /* If requested, give a warning that the first statement in the
2038 block is unreachable. We walk statements backwards in the
2039 loop above, so the last statement we process is the first statement
2041 #ifdef USE_MAPPED_LOCATION
2042 if (loc > BUILTINS_LOCATION)
2043 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2046 warning (OPT_Wunreachable_code, "%Hwill never be executed", loc);
2049 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2054 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2055 predicate VAL, return the edge that will be taken out of the block.
2056 If VAL does not match a unique edge, NULL is returned. */
2059 find_taken_edge (basic_block bb, tree val)
2063 stmt = last_stmt (bb);
2066 gcc_assert (is_ctrl_stmt (stmt));
2069 if (! is_gimple_min_invariant (val))
2072 if (TREE_CODE (stmt) == COND_EXPR)
2073 return find_taken_edge_cond_expr (bb, val);
2075 if (TREE_CODE (stmt) == SWITCH_EXPR)
2076 return find_taken_edge_switch_expr (bb, val);
2078 if (computed_goto_p (stmt))
2080 /* Only optimize if the argument is a label, if the argument is
2081 not a label then we can not construct a proper CFG.
2083 It may be the case that we only need to allow the LABEL_REF to
2084 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2085 appear inside a LABEL_EXPR just to be safe. */
2086 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2087 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2088 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2095 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2096 statement, determine which of the outgoing edges will be taken out of the
2097 block. Return NULL if either edge may be taken. */
2100 find_taken_edge_computed_goto (basic_block bb, tree val)
2105 dest = label_to_block (val);
2108 e = find_edge (bb, dest);
2109 gcc_assert (e != NULL);
2115 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2116 statement, determine which of the two edges will be taken out of the
2117 block. Return NULL if either edge may be taken. */
2120 find_taken_edge_cond_expr (basic_block bb, tree val)
2122 edge true_edge, false_edge;
2124 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2126 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2127 return (integer_zerop (val) ? false_edge : true_edge);
2130 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2131 statement, determine which edge will be taken out of the block. Return
2132 NULL if any edge may be taken. */
2135 find_taken_edge_switch_expr (basic_block bb, tree val)
2137 tree switch_expr, taken_case;
2138 basic_block dest_bb;
2141 switch_expr = last_stmt (bb);
2142 taken_case = find_case_label_for_value (switch_expr, val);
2143 dest_bb = label_to_block (CASE_LABEL (taken_case));
2145 e = find_edge (bb, dest_bb);
2151 /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL.
2152 We can make optimal use here of the fact that the case labels are
2153 sorted: We can do a binary search for a case matching VAL. */
2156 find_case_label_for_value (tree switch_expr, tree val)
2158 tree vec = SWITCH_LABELS (switch_expr);
2159 size_t low, high, n = TREE_VEC_LENGTH (vec);
2160 tree default_case = TREE_VEC_ELT (vec, n - 1);
2162 for (low = -1, high = n - 1; high - low > 1; )
2164 size_t i = (high + low) / 2;
2165 tree t = TREE_VEC_ELT (vec, i);
2168 /* Cache the result of comparing CASE_LOW and val. */
2169 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2176 if (CASE_HIGH (t) == NULL)
2178 /* A singe-valued case label. */
2184 /* A case range. We can only handle integer ranges. */
2185 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2190 return default_case;
2196 /*---------------------------------------------------------------------------
2198 ---------------------------------------------------------------------------*/
2200 /* Dump tree-specific information of block BB to file OUTF. */
2203 tree_dump_bb (basic_block bb, FILE *outf, int indent)
2205 dump_generic_bb (outf, bb, indent, TDF_VOPS|TDF_MEMSYMS);
2209 /* Dump a basic block on stderr. */
2212 debug_tree_bb (basic_block bb)
2214 dump_bb (bb, stderr, 0);
2218 /* Dump basic block with index N on stderr. */
2221 debug_tree_bb_n (int n)
2223 debug_tree_bb (BASIC_BLOCK (n));
2224 return BASIC_BLOCK (n);
2228 /* Dump the CFG on stderr.
2230 FLAGS are the same used by the tree dumping functions
2231 (see TDF_* in tree-pass.h). */
2234 debug_tree_cfg (int flags)
2236 dump_tree_cfg (stderr, flags);
2240 /* Dump the program showing basic block boundaries on the given FILE.
2242 FLAGS are the same used by the tree dumping functions (see TDF_* in
2246 dump_tree_cfg (FILE *file, int flags)
2248 if (flags & TDF_DETAILS)
2250 const char *funcname
2251 = lang_hooks.decl_printable_name (current_function_decl, 2);
2254 fprintf (file, ";; Function %s\n\n", funcname);
2255 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2256 n_basic_blocks, n_edges, last_basic_block);
2258 brief_dump_cfg (file);
2259 fprintf (file, "\n");
2262 if (flags & TDF_STATS)
2263 dump_cfg_stats (file);
2265 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2269 /* Dump CFG statistics on FILE. */
2272 dump_cfg_stats (FILE *file)
2274 static long max_num_merged_labels = 0;
2275 unsigned long size, total = 0;
2278 const char * const fmt_str = "%-30s%-13s%12s\n";
2279 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2280 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2281 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2282 const char *funcname
2283 = lang_hooks.decl_printable_name (current_function_decl, 2);
2286 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2288 fprintf (file, "---------------------------------------------------------\n");
2289 fprintf (file, fmt_str, "", " Number of ", "Memory");
2290 fprintf (file, fmt_str, "", " instances ", "used ");
2291 fprintf (file, "---------------------------------------------------------\n");
2293 size = n_basic_blocks * sizeof (struct basic_block_def);
2295 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2296 SCALE (size), LABEL (size));
2300 num_edges += EDGE_COUNT (bb->succs);
2301 size = num_edges * sizeof (struct edge_def);
2303 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2305 fprintf (file, "---------------------------------------------------------\n");
2306 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2308 fprintf (file, "---------------------------------------------------------\n");
2309 fprintf (file, "\n");
2311 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2312 max_num_merged_labels = cfg_stats.num_merged_labels;
2314 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2315 cfg_stats.num_merged_labels, max_num_merged_labels);
2317 fprintf (file, "\n");
2321 /* Dump CFG statistics on stderr. Keep extern so that it's always
2322 linked in the final executable. */
2325 debug_cfg_stats (void)
2327 dump_cfg_stats (stderr);
2331 /* Dump the flowgraph to a .vcg FILE. */
2334 tree_cfg2vcg (FILE *file)
2339 const char *funcname
2340 = lang_hooks.decl_printable_name (current_function_decl, 2);
2342 /* Write the file header. */
2343 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2344 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2345 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2347 /* Write blocks and edges. */
2348 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2350 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2353 if (e->flags & EDGE_FAKE)
2354 fprintf (file, " linestyle: dotted priority: 10");
2356 fprintf (file, " linestyle: solid priority: 100");
2358 fprintf (file, " }\n");
2364 enum tree_code head_code, end_code;
2365 const char *head_name, *end_name;
2368 tree first = first_stmt (bb);
2369 tree last = last_stmt (bb);
2373 head_code = TREE_CODE (first);
2374 head_name = tree_code_name[head_code];
2375 head_line = get_lineno (first);
2378 head_name = "no-statement";
2382 end_code = TREE_CODE (last);
2383 end_name = tree_code_name[end_code];
2384 end_line = get_lineno (last);
2387 end_name = "no-statement";
2389 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2390 bb->index, bb->index, head_name, head_line, end_name,
2393 FOR_EACH_EDGE (e, ei, bb->succs)
2395 if (e->dest == EXIT_BLOCK_PTR)
2396 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2398 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2400 if (e->flags & EDGE_FAKE)
2401 fprintf (file, " priority: 10 linestyle: dotted");
2403 fprintf (file, " priority: 100 linestyle: solid");
2405 fprintf (file, " }\n");
2408 if (bb->next_bb != EXIT_BLOCK_PTR)
2412 fputs ("}\n\n", file);
2417 /*---------------------------------------------------------------------------
2418 Miscellaneous helpers
2419 ---------------------------------------------------------------------------*/
2421 /* Return true if T represents a stmt that always transfers control. */
2424 is_ctrl_stmt (const_tree t)
2426 return (TREE_CODE (t) == COND_EXPR
2427 || TREE_CODE (t) == SWITCH_EXPR
2428 || TREE_CODE (t) == GOTO_EXPR
2429 || TREE_CODE (t) == RETURN_EXPR
2430 || TREE_CODE (t) == RESX_EXPR);
2434 /* Return true if T is a statement that may alter the flow of control
2435 (e.g., a call to a non-returning function). */
2438 is_ctrl_altering_stmt (tree t)
2443 call = get_call_expr_in (t);
2446 /* A non-pure/const CALL_EXPR alters flow control if the current
2447 function has nonlocal labels. */
2448 if (TREE_SIDE_EFFECTS (call) && current_function_has_nonlocal_label)
2451 /* A CALL_EXPR also alters control flow if it does not return. */
2452 if (call_expr_flags (call) & ECF_NORETURN)
2456 /* OpenMP directives alter control flow. */
2457 if (OMP_DIRECTIVE_P (t))
2460 /* If a statement can throw, it alters control flow. */
2461 return tree_can_throw_internal (t);
2465 /* Return true if T is a computed goto. */
2468 computed_goto_p (const_tree t)
2470 return (TREE_CODE (t) == GOTO_EXPR
2471 && TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL);
2475 /* Return true if T is a simple local goto. */
2478 simple_goto_p (const_tree t)
2480 return (TREE_CODE (t) == GOTO_EXPR
2481 && TREE_CODE (GOTO_DESTINATION (t)) == LABEL_DECL);
2485 /* Return true if T can make an abnormal transfer of control flow.
2486 Transfers of control flow associated with EH are excluded. */
2489 tree_can_make_abnormal_goto (const_tree t)
2491 if (computed_goto_p (t))
2493 if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
2494 t = GIMPLE_STMT_OPERAND (t, 1);
2495 if (TREE_CODE (t) == WITH_SIZE_EXPR)
2496 t = TREE_OPERAND (t, 0);
2497 if (TREE_CODE (t) == CALL_EXPR)
2498 return TREE_SIDE_EFFECTS (t) && current_function_has_nonlocal_label;
2503 /* Return true if T should start a new basic block. PREV_T is the
2504 statement preceding T. It is used when T is a label or a case label.
2505 Labels should only start a new basic block if their previous statement
2506 wasn't a label. Otherwise, sequence of labels would generate
2507 unnecessary basic blocks that only contain a single label. */
2510 stmt_starts_bb_p (const_tree t, const_tree prev_t)
2515 /* LABEL_EXPRs start a new basic block only if the preceding
2516 statement wasn't a label of the same type. This prevents the
2517 creation of consecutive blocks that have nothing but a single
2519 if (TREE_CODE (t) == LABEL_EXPR)
2521 /* Nonlocal and computed GOTO targets always start a new block. */
2522 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t))
2523 || FORCED_LABEL (LABEL_EXPR_LABEL (t)))
2526 if (prev_t && TREE_CODE (prev_t) == LABEL_EXPR)
2528 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t)))
2531 cfg_stats.num_merged_labels++;
2542 /* Return true if T should end a basic block. */
2545 stmt_ends_bb_p (tree t)
2547 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2550 /* Remove block annotations and other datastructures. */
2553 delete_tree_cfg_annotations (void)
2556 block_stmt_iterator bsi;
2558 /* Remove annotations from every tree in the function. */
2560 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
2562 tree stmt = bsi_stmt (bsi);
2563 ggc_free (stmt->base.ann);
2564 stmt->base.ann = NULL;
2566 label_to_block_map = NULL;
2570 /* Return the first statement in basic block BB. */
2573 first_stmt (basic_block bb)
2575 block_stmt_iterator i = bsi_start (bb);
2576 return !bsi_end_p (i) ? bsi_stmt (i) : NULL_TREE;
2580 /* Return the last statement in basic block BB. */
2583 last_stmt (basic_block bb)
2585 block_stmt_iterator b = bsi_last (bb);
2586 return !bsi_end_p (b) ? bsi_stmt (b) : NULL_TREE;
2590 /* Return the last statement of an otherwise empty block. Return NULL
2591 if the block is totally empty, or if it contains more than one
2595 last_and_only_stmt (basic_block bb)
2597 block_stmt_iterator i = bsi_last (bb);
2603 last = bsi_stmt (i);
2608 /* Empty statements should no longer appear in the instruction stream.
2609 Everything that might have appeared before should be deleted by
2610 remove_useless_stmts, and the optimizers should just bsi_remove
2611 instead of smashing with build_empty_stmt.
2613 Thus the only thing that should appear here in a block containing
2614 one executable statement is a label. */
2615 prev = bsi_stmt (i);
2616 if (TREE_CODE (prev) == LABEL_EXPR)
2623 /* Mark BB as the basic block holding statement T. */
2626 set_bb_for_stmt (tree t, basic_block bb)
2628 if (TREE_CODE (t) == PHI_NODE)
2630 else if (TREE_CODE (t) == STATEMENT_LIST)
2632 tree_stmt_iterator i;
2633 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2634 set_bb_for_stmt (tsi_stmt (i), bb);
2638 stmt_ann_t ann = get_stmt_ann (t);
2641 /* If the statement is a label, add the label to block-to-labels map
2642 so that we can speed up edge creation for GOTO_EXPRs. */
2643 if (TREE_CODE (t) == LABEL_EXPR)
2647 t = LABEL_EXPR_LABEL (t);
2648 uid = LABEL_DECL_UID (t);
2651 unsigned old_len = VEC_length (basic_block, label_to_block_map);
2652 LABEL_DECL_UID (t) = uid = cfun->last_label_uid++;
2653 if (old_len <= (unsigned) uid)
2655 unsigned new_len = 3 * uid / 2;
2657 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
2662 /* We're moving an existing label. Make sure that we've
2663 removed it from the old block. */
2665 || !VEC_index (basic_block, label_to_block_map, uid));
2666 VEC_replace (basic_block, label_to_block_map, uid, bb);
2671 /* Faster version of set_bb_for_stmt that assume that statement is being moved
2672 from one basic block to another.
2673 For BB splitting we can run into quadratic case, so performance is quite
2674 important and knowing that the tables are big enough, change_bb_for_stmt
2675 can inline as leaf function. */
2677 change_bb_for_stmt (tree t, basic_block bb)
2679 get_stmt_ann (t)->bb = bb;
2680 if (TREE_CODE (t) == LABEL_EXPR)
2681 VEC_replace (basic_block, label_to_block_map,
2682 LABEL_DECL_UID (LABEL_EXPR_LABEL (t)), bb);
2685 /* Finds iterator for STMT. */
2687 extern block_stmt_iterator
2688 bsi_for_stmt (tree stmt)
2690 block_stmt_iterator bsi;
2692 for (bsi = bsi_start (bb_for_stmt (stmt)); !bsi_end_p (bsi); bsi_next (&bsi))
2693 if (bsi_stmt (bsi) == stmt)
2699 /* Mark statement T as modified, and update it. */
2701 update_modified_stmts (tree t)
2703 if (!ssa_operands_active ())
2705 if (TREE_CODE (t) == STATEMENT_LIST)
2707 tree_stmt_iterator i;
2709 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2711 stmt = tsi_stmt (i);
2712 update_stmt_if_modified (stmt);
2716 update_stmt_if_modified (t);
2719 /* Insert statement (or statement list) T before the statement
2720 pointed-to by iterator I. M specifies how to update iterator I
2721 after insertion (see enum bsi_iterator_update). */
2724 bsi_insert_before (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2726 set_bb_for_stmt (t, i->bb);
2727 update_modified_stmts (t);
2728 tsi_link_before (&i->tsi, t, m);
2732 /* Insert statement (or statement list) T after the statement
2733 pointed-to by iterator I. M specifies how to update iterator I
2734 after insertion (see enum bsi_iterator_update). */
2737 bsi_insert_after (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2739 set_bb_for_stmt (t, i->bb);
2740 update_modified_stmts (t);
2741 tsi_link_after (&i->tsi, t, m);
2745 /* Remove the statement pointed to by iterator I. The iterator is updated
2746 to the next statement.
2748 When REMOVE_EH_INFO is true we remove the statement pointed to by
2749 iterator I from the EH tables. Otherwise we do not modify the EH
2752 Generally, REMOVE_EH_INFO should be true when the statement is going to
2753 be removed from the IL and not reinserted elsewhere. */
2756 bsi_remove (block_stmt_iterator *i, bool remove_eh_info)
2758 tree t = bsi_stmt (*i);
2759 set_bb_for_stmt (t, NULL);
2760 delink_stmt_imm_use (t);
2761 tsi_delink (&i->tsi);
2762 mark_stmt_modified (t);
2765 remove_stmt_from_eh_region (t);
2766 gimple_remove_stmt_histograms (cfun, t);
2771 /* Move the statement at FROM so it comes right after the statement at TO. */
2774 bsi_move_after (block_stmt_iterator *from, block_stmt_iterator *to)
2776 tree stmt = bsi_stmt (*from);
2777 bsi_remove (from, false);
2778 /* We must have BSI_NEW_STMT here, as bsi_move_after is sometimes used to
2779 move statements to an empty block. */
2780 bsi_insert_after (to, stmt, BSI_NEW_STMT);
2784 /* Move the statement at FROM so it comes right before the statement at TO. */
2787 bsi_move_before (block_stmt_iterator *from, block_stmt_iterator *to)
2789 tree stmt = bsi_stmt (*from);
2790 bsi_remove (from, false);
2791 /* For consistency with bsi_move_after, it might be better to have
2792 BSI_NEW_STMT here; however, that breaks several places that expect
2793 that TO does not change. */
2794 bsi_insert_before (to, stmt, BSI_SAME_STMT);
2798 /* Move the statement at FROM to the end of basic block BB. */
2801 bsi_move_to_bb_end (block_stmt_iterator *from, basic_block bb)
2803 block_stmt_iterator last = bsi_last (bb);
2805 /* Have to check bsi_end_p because it could be an empty block. */
2806 if (!bsi_end_p (last) && is_ctrl_stmt (bsi_stmt (last)))
2807 bsi_move_before (from, &last);
2809 bsi_move_after (from, &last);
2813 /* Replace the contents of the statement pointed to by iterator BSI
2814 with STMT. If UPDATE_EH_INFO is true, the exception handling
2815 information of the original statement is moved to the new statement. */
2818 bsi_replace (const block_stmt_iterator *bsi, tree stmt, bool update_eh_info)
2821 tree orig_stmt = bsi_stmt (*bsi);
2823 if (stmt == orig_stmt)
2825 SET_EXPR_LOCUS (stmt, EXPR_LOCUS (orig_stmt));
2826 set_bb_for_stmt (stmt, bsi->bb);
2828 /* Preserve EH region information from the original statement, if
2829 requested by the caller. */
2832 eh_region = lookup_stmt_eh_region (orig_stmt);
2835 remove_stmt_from_eh_region (orig_stmt);
2836 add_stmt_to_eh_region (stmt, eh_region);
2840 gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
2841 gimple_remove_stmt_histograms (cfun, orig_stmt);
2842 delink_stmt_imm_use (orig_stmt);
2843 *bsi_stmt_ptr (*bsi) = stmt;
2844 mark_stmt_modified (stmt);
2845 update_modified_stmts (stmt);
2849 /* Insert the statement pointed-to by BSI into edge E. Every attempt
2850 is made to place the statement in an existing basic block, but
2851 sometimes that isn't possible. When it isn't possible, the edge is
2852 split and the statement is added to the new block.
2854 In all cases, the returned *BSI points to the correct location. The
2855 return value is true if insertion should be done after the location,
2856 or false if it should be done before the location. If new basic block
2857 has to be created, it is stored in *NEW_BB. */
2860 tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi,
2861 basic_block *new_bb)
2863 basic_block dest, src;
2869 /* If the destination has one predecessor which has no PHI nodes,
2870 insert there. Except for the exit block.
2872 The requirement for no PHI nodes could be relaxed. Basically we
2873 would have to examine the PHIs to prove that none of them used
2874 the value set by the statement we want to insert on E. That
2875 hardly seems worth the effort. */
2876 if (single_pred_p (dest)
2877 && ! phi_nodes (dest)
2878 && dest != EXIT_BLOCK_PTR)
2880 *bsi = bsi_start (dest);
2881 if (bsi_end_p (*bsi))
2884 /* Make sure we insert after any leading labels. */
2885 tmp = bsi_stmt (*bsi);
2886 while (TREE_CODE (tmp) == LABEL_EXPR)
2889 if (bsi_end_p (*bsi))
2891 tmp = bsi_stmt (*bsi);
2894 if (bsi_end_p (*bsi))
2896 *bsi = bsi_last (dest);
2903 /* If the source has one successor, the edge is not abnormal and
2904 the last statement does not end a basic block, insert there.
2905 Except for the entry block. */
2907 if ((e->flags & EDGE_ABNORMAL) == 0
2908 && single_succ_p (src)
2909 && src != ENTRY_BLOCK_PTR)
2911 *bsi = bsi_last (src);
2912 if (bsi_end_p (*bsi))
2915 tmp = bsi_stmt (*bsi);
2916 if (!stmt_ends_bb_p (tmp))
2919 /* Insert code just before returning the value. We may need to decompose
2920 the return in the case it contains non-trivial operand. */
2921 if (TREE_CODE (tmp) == RETURN_EXPR)
2923 tree op = TREE_OPERAND (tmp, 0);
2924 if (op && !is_gimple_val (op))
2926 gcc_assert (TREE_CODE (op) == GIMPLE_MODIFY_STMT);
2927 bsi_insert_before (bsi, op, BSI_NEW_STMT);
2928 TREE_OPERAND (tmp, 0) = GIMPLE_STMT_OPERAND (op, 0);
2935 /* Otherwise, create a new basic block, and split this edge. */
2936 dest = split_edge (e);
2939 e = single_pred_edge (dest);
2944 /* This routine will commit all pending edge insertions, creating any new
2945 basic blocks which are necessary. */
2948 bsi_commit_edge_inserts (void)
2954 bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL);
2957 FOR_EACH_EDGE (e, ei, bb->succs)
2958 bsi_commit_one_edge_insert (e, NULL);
2962 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
2963 to this block, otherwise set it to NULL. */
2966 bsi_commit_one_edge_insert (edge e, basic_block *new_bb)
2970 if (PENDING_STMT (e))
2972 block_stmt_iterator bsi;
2973 tree stmt = PENDING_STMT (e);
2975 PENDING_STMT (e) = NULL_TREE;
2977 if (tree_find_edge_insert_loc (e, &bsi, new_bb))
2978 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
2980 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
2985 /* Add STMT to the pending list of edge E. No actual insertion is
2986 made until a call to bsi_commit_edge_inserts () is made. */
2989 bsi_insert_on_edge (edge e, tree stmt)
2991 append_to_statement_list (stmt, &PENDING_STMT (e));
2994 /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new
2995 block has to be created, it is returned. */
2998 bsi_insert_on_edge_immediate (edge e, tree stmt)
3000 block_stmt_iterator bsi;
3001 basic_block new_bb = NULL;
3003 gcc_assert (!PENDING_STMT (e));
3005 if (tree_find_edge_insert_loc (e, &bsi, &new_bb))
3006 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3008 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3013 /*---------------------------------------------------------------------------
3014 Tree specific functions for CFG manipulation
3015 ---------------------------------------------------------------------------*/
3017 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
3020 reinstall_phi_args (edge new_edge, edge old_edge)
3024 if (!PENDING_STMT (old_edge))
3027 for (var = PENDING_STMT (old_edge), phi = phi_nodes (new_edge->dest);
3029 var = TREE_CHAIN (var), phi = PHI_CHAIN (phi))
3031 tree result = TREE_PURPOSE (var);
3032 tree arg = TREE_VALUE (var);
3034 gcc_assert (result == PHI_RESULT (phi));
3036 add_phi_arg (phi, arg, new_edge);
3039 PENDING_STMT (old_edge) = NULL;
3042 /* Returns the basic block after which the new basic block created
3043 by splitting edge EDGE_IN should be placed. Tries to keep the new block
3044 near its "logical" location. This is of most help to humans looking
3045 at debugging dumps. */
3048 split_edge_bb_loc (edge edge_in)
3050 basic_block dest = edge_in->dest;
3052 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
3053 return edge_in->src;
3055 return dest->prev_bb;
3058 /* Split a (typically critical) edge EDGE_IN. Return the new block.
3059 Abort on abnormal edges. */
3062 tree_split_edge (edge edge_in)
3064 basic_block new_bb, after_bb, dest;
3067 /* Abnormal edges cannot be split. */
3068 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
3070 dest = edge_in->dest;
3072 after_bb = split_edge_bb_loc (edge_in);
3074 new_bb = create_empty_bb (after_bb);
3075 new_bb->frequency = EDGE_FREQUENCY (edge_in);
3076 new_bb->count = edge_in->count;
3077 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
3078 new_edge->probability = REG_BR_PROB_BASE;
3079 new_edge->count = edge_in->count;
3081 e = redirect_edge_and_branch (edge_in, new_bb);
3082 gcc_assert (e == edge_in);
3083 reinstall_phi_args (new_edge, e);
3088 /* Callback for walk_tree, check that all elements with address taken are
3089 properly noticed as such. The DATA is an int* that is 1 if TP was seen
3090 inside a PHI node. */
3093 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
3096 bool in_phi = (data != NULL);
3101 /* Check operand N for being valid GIMPLE and give error MSG if not. */
3102 #define CHECK_OP(N, MSG) \
3103 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
3104 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
3106 switch (TREE_CODE (t))
3109 if (SSA_NAME_IN_FREE_LIST (t))
3111 error ("SSA name in freelist but still referenced");
3117 x = fold (ASSERT_EXPR_COND (t));
3118 if (x == boolean_false_node)
3120 error ("ASSERT_EXPR with an always-false condition");
3128 case GIMPLE_MODIFY_STMT:
3129 x = GIMPLE_STMT_OPERAND (t, 0);
3130 if (TREE_CODE (x) == BIT_FIELD_REF
3131 && is_gimple_reg (TREE_OPERAND (x, 0)))
3133 error ("GIMPLE register modified with BIT_FIELD_REF");
3142 bool old_side_effects;
3145 bool new_side_effects;
3147 /* ??? tree-ssa-alias.c may have overlooked dead PHI nodes, missing
3148 dead PHIs that take the address of something. But if the PHI
3149 result is dead, the fact that it takes the address of anything
3150 is irrelevant. Because we can not tell from here if a PHI result
3151 is dead, we just skip this check for PHIs altogether. This means
3152 we may be missing "valid" checks, but what can you do?
3153 This was PR19217. */
3157 old_invariant = TREE_INVARIANT (t);
3158 old_constant = TREE_CONSTANT (t);
3159 old_side_effects = TREE_SIDE_EFFECTS (t);
3161 recompute_tree_invariant_for_addr_expr (t);
3162 new_invariant = TREE_INVARIANT (t);
3163 new_side_effects = TREE_SIDE_EFFECTS (t);
3164 new_constant = TREE_CONSTANT (t);
3166 if (old_invariant != new_invariant)
3168 error ("invariant not recomputed when ADDR_EXPR changed");
3172 if (old_constant != new_constant)
3174 error ("constant not recomputed when ADDR_EXPR changed");
3177 if (old_side_effects != new_side_effects)
3179 error ("side effects not recomputed when ADDR_EXPR changed");
3183 /* Skip any references (they will be checked when we recurse down the
3184 tree) and ensure that any variable used as a prefix is marked
3186 for (x = TREE_OPERAND (t, 0);
3187 handled_component_p (x);
3188 x = TREE_OPERAND (x, 0))
3191 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
3193 if (!TREE_ADDRESSABLE (x))
3195 error ("address taken, but ADDRESSABLE bit not set");
3202 x = COND_EXPR_COND (t);
3203 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
3205 error ("non-integral used in condition");
3208 if (!is_gimple_condexpr (x))
3210 error ("invalid conditional operand");
3217 case FIX_TRUNC_EXPR:
3222 case NON_LVALUE_EXPR:
3223 case TRUTH_NOT_EXPR:
3224 CHECK_OP (0, "invalid operand to unary operator");
3231 case ARRAY_RANGE_REF:
3233 case VIEW_CONVERT_EXPR:
3234 /* We have a nest of references. Verify that each of the operands
3235 that determine where to reference is either a constant or a variable,
3236 verify that the base is valid, and then show we've already checked
3238 while (handled_component_p (t))
3240 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
3241 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
3242 else if (TREE_CODE (t) == ARRAY_REF
3243 || TREE_CODE (t) == ARRAY_RANGE_REF)
3245 CHECK_OP (1, "invalid array index");
3246 if (TREE_OPERAND (t, 2))
3247 CHECK_OP (2, "invalid array lower bound");
3248 if (TREE_OPERAND (t, 3))
3249 CHECK_OP (3, "invalid array stride");
3251 else if (TREE_CODE (t) == BIT_FIELD_REF)
3253 CHECK_OP (1, "invalid operand to BIT_FIELD_REF");
3254 CHECK_OP (2, "invalid operand to BIT_FIELD_REF");
3257 t = TREE_OPERAND (t, 0);
3260 if (!CONSTANT_CLASS_P (t) && !is_gimple_lvalue (t))
3262 error ("invalid reference prefix");
3269 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
3270 POINTER_PLUS_EXPR. */
3271 if (POINTER_TYPE_P (TREE_TYPE (t)))
3273 error ("invalid operand to plus/minus, type is a pointer");
3276 CHECK_OP (0, "invalid operand to binary operator");
3277 CHECK_OP (1, "invalid operand to binary operator");
3280 case POINTER_PLUS_EXPR:
3281 /* Check to make sure the first operand is a pointer or reference type. */
3282 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
3284 error ("invalid operand to pointer plus, first operand is not a pointer");
3287 /* Check to make sure the second operand is an integer with type of
3289 if (!useless_type_conversion_p (sizetype,
3290 TREE_TYPE (TREE_OPERAND (t, 1))))
3292 error ("invalid operand to pointer plus, second operand is not an "
3293 "integer with type of sizetype.");
3303 case UNORDERED_EXPR:
3312 case TRUNC_DIV_EXPR:
3314 case FLOOR_DIV_EXPR:
3315 case ROUND_DIV_EXPR:
3316 case TRUNC_MOD_EXPR:
3318 case FLOOR_MOD_EXPR:
3319 case ROUND_MOD_EXPR:
3321 case EXACT_DIV_EXPR:
3331 CHECK_OP (0, "invalid operand to binary operator");
3332 CHECK_OP (1, "invalid operand to binary operator");
3336 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3348 /* Verifies if EXPR is a valid GIMPLE unary expression. Returns true
3349 if there is an error, otherwise false. */
3352 verify_gimple_unary_expr (tree expr)
3354 tree op = TREE_OPERAND (expr, 0);
3355 tree type = TREE_TYPE (expr);
3357 if (!is_gimple_val (op))
3359 error ("invalid operand in unary expression");
3363 /* For general unary expressions we have the operations type
3364 as the effective type the operation is carried out on. So all
3365 we need to require is that the operand is trivially convertible
3367 if (!useless_type_conversion_p (type, TREE_TYPE (op)))
3369 error ("type mismatch in unary expression");
3370 debug_generic_expr (type);
3371 debug_generic_expr (TREE_TYPE (op));
3378 /* Verifies if EXPR is a valid GIMPLE binary expression. Returns true
3379 if there is an error, otherwise false. */
3382 verify_gimple_binary_expr (tree expr)
3384 tree op0 = TREE_OPERAND (expr, 0);
3385 tree op1 = TREE_OPERAND (expr, 1);
3386 tree type = TREE_TYPE (expr);
3388 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3390 error ("invalid operands in binary expression");
3394 /* For general binary expressions we have the operations type
3395 as the effective type the operation is carried out on. So all
3396 we need to require is that both operands are trivially convertible
3398 if (!useless_type_conversion_p (type, TREE_TYPE (op0))
3399 || !useless_type_conversion_p (type, TREE_TYPE (op1)))
3401 error ("type mismatch in binary expression");
3402 debug_generic_stmt (type);
3403 debug_generic_stmt (TREE_TYPE (op0));
3404 debug_generic_stmt (TREE_TYPE (op1));
3411 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3412 Returns true if there is an error, otherwise false. */
3415 verify_gimple_min_lval (tree expr)
3419 if (is_gimple_id (expr))
3422 if (TREE_CODE (expr) != INDIRECT_REF
3423 && TREE_CODE (expr) != ALIGN_INDIRECT_REF
3424 && TREE_CODE (expr) != MISALIGNED_INDIRECT_REF)
3426 error ("invalid expression for min lvalue");
3430 op = TREE_OPERAND (expr, 0);
3431 if (!is_gimple_val (op))
3433 error ("invalid operand in indirect reference");
3434 debug_generic_stmt (op);
3437 if (!useless_type_conversion_p (TREE_TYPE (expr),
3438 TREE_TYPE (TREE_TYPE (op))))
3440 error ("type mismatch in indirect reference");
3441 debug_generic_stmt (TREE_TYPE (expr));
3442 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3449 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3450 if there is an error, otherwise false. */
3453 verify_gimple_reference (tree expr)
3455 while (handled_component_p (expr))
3457 tree op = TREE_OPERAND (expr, 0);
3459 if (TREE_CODE (expr) == ARRAY_REF
3460 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3462 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3463 || (TREE_OPERAND (expr, 2)
3464 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3465 || (TREE_OPERAND (expr, 3)
3466 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3468 error ("invalid operands to array reference");
3469 debug_generic_stmt (expr);
3474 /* Verify if the reference array element types are compatible. */
3475 if (TREE_CODE (expr) == ARRAY_REF
3476 && !useless_type_conversion_p (TREE_TYPE (expr),
3477 TREE_TYPE (TREE_TYPE (op))))
3479 error ("type mismatch in array reference");
3480 debug_generic_stmt (TREE_TYPE (expr));
3481 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3484 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3485 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3486 TREE_TYPE (TREE_TYPE (op))))
3488 error ("type mismatch in array range reference");
3489 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3490 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3494 if ((TREE_CODE (expr) == REALPART_EXPR
3495 || TREE_CODE (expr) == IMAGPART_EXPR)
3496 && !useless_type_conversion_p (TREE_TYPE (expr),
3497 TREE_TYPE (TREE_TYPE (op))))
3499 error ("type mismatch in real/imagpart reference");
3500 debug_generic_stmt (TREE_TYPE (expr));
3501 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3505 if (TREE_CODE (expr) == COMPONENT_REF
3506 && !useless_type_conversion_p (TREE_TYPE (expr),
3507 TREE_TYPE (TREE_OPERAND (expr, 1))))
3509 error ("type mismatch in component reference");
3510 debug_generic_stmt (TREE_TYPE (expr));
3511 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3515 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3516 is nothing to verify. Gross mismatches at most invoke
3517 undefined behavior. */
3522 return verify_gimple_min_lval (expr);
3525 /* Verify the GIMPLE expression EXPR. Returns true if there is an
3526 error, otherwise false. */
3529 verify_gimple_expr (tree expr)
3531 tree type = TREE_TYPE (expr);
3533 if (is_gimple_val (expr))
3536 /* Special codes we cannot handle via their class. */
3537 switch (TREE_CODE (expr))
3542 tree op = TREE_OPERAND (expr, 0);
3543 if (!is_gimple_val (op))
3545 error ("invalid operand in conversion");
3549 /* Allow conversions between integral types. */
3550 if (INTEGRAL_TYPE_P (type) == INTEGRAL_TYPE_P (TREE_TYPE (op)))
3553 /* Allow conversions between integral types and pointers only if
3554 there is no sign or zero extension involved. */
3555 if (((POINTER_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3556 || (POINTER_TYPE_P (TREE_TYPE (op)) && INTEGRAL_TYPE_P (type)))
3557 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op)))
3560 /* Allow conversion from integer to offset type and vice versa. */
3561 if ((TREE_CODE (type) == OFFSET_TYPE
3562 && TREE_CODE (TREE_TYPE (op)) == INTEGER_TYPE)
3563 || (TREE_CODE (type) == INTEGER_TYPE
3564 && TREE_CODE (TREE_TYPE (op)) == OFFSET_TYPE))
3567 /* Otherwise assert we are converting between types of the
3569 if (TREE_CODE (type) != TREE_CODE (TREE_TYPE (op)))
3571 error ("invalid types in nop conversion");
3572 debug_generic_expr (type);
3573 debug_generic_expr (TREE_TYPE (op));
3582 tree op = TREE_OPERAND (expr, 0);
3583 if (!is_gimple_val (op))
3585 error ("invalid operand in int to float conversion");
3588 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3589 || !SCALAR_FLOAT_TYPE_P (type))
3591 error ("invalid types in conversion to floating point");
3592 debug_generic_expr (type);
3593 debug_generic_expr (TREE_TYPE (op));
3599 case FIX_TRUNC_EXPR:
3601 tree op = TREE_OPERAND (expr, 0);
3602 if (!is_gimple_val (op))
3604 error ("invalid operand in float to int conversion");
3607 if (!INTEGRAL_TYPE_P (type)
3608 || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (op)))
3610 error ("invalid types in conversion to integer");
3611 debug_generic_expr (type);
3612 debug_generic_expr (TREE_TYPE (op));
3620 tree op0 = TREE_OPERAND (expr, 0);
3621 tree op1 = TREE_OPERAND (expr, 1);
3622 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3624 error ("invalid operands in complex expression");
3627 if (!TREE_CODE (type) == COMPLEX_TYPE
3628 || !(TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
3629 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0)))
3630 || !(TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3631 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op1)))
3632 || !useless_type_conversion_p (TREE_TYPE (type),
3634 || !useless_type_conversion_p (TREE_TYPE (type),
3637 error ("type mismatch in complex expression");
3638 debug_generic_stmt (TREE_TYPE (expr));
3639 debug_generic_stmt (TREE_TYPE (op0));
3640 debug_generic_stmt (TREE_TYPE (op1));
3648 /* This is used like COMPLEX_EXPR but for vectors. */
3649 if (TREE_CODE (type) != VECTOR_TYPE)
3651 error ("constructor not allowed for non-vector types");
3652 debug_generic_stmt (type);
3655 /* FIXME: verify constructor arguments. */
3664 tree op0 = TREE_OPERAND (expr, 0);
3665 tree op1 = TREE_OPERAND (expr, 1);
3666 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3668 error ("invalid operands in shift expression");
3671 if (!TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3672 || !useless_type_conversion_p (type, TREE_TYPE (op0)))
3674 error ("type mismatch in shift expression");
3675 debug_generic_stmt (TREE_TYPE (expr));
3676 debug_generic_stmt (TREE_TYPE (op0));
3677 debug_generic_stmt (TREE_TYPE (op1));
3686 tree op0 = TREE_OPERAND (expr, 0);
3687 tree op1 = TREE_OPERAND (expr, 1);
3688 if (POINTER_TYPE_P (type)
3689 || POINTER_TYPE_P (TREE_TYPE (op0))
3690 || POINTER_TYPE_P (TREE_TYPE (op1)))
3692 error ("invalid (pointer) operands to plus/minus");
3695 /* Continue with generic binary expression handling. */
3699 case POINTER_PLUS_EXPR:
3701 tree op0 = TREE_OPERAND (expr, 0);
3702 tree op1 = TREE_OPERAND (expr, 1);
3703 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3705 error ("invalid operands in pointer plus expression");
3708 if (!POINTER_TYPE_P (TREE_TYPE (op0))
3709 || TREE_CODE (TREE_TYPE (op1)) != INTEGER_TYPE
3710 || !useless_type_conversion_p (type, TREE_TYPE (op0))
3711 || !useless_type_conversion_p (sizetype, TREE_TYPE (op1)))
3713 error ("type mismatch in pointer plus expression");
3714 debug_generic_stmt (type);
3715 debug_generic_stmt (TREE_TYPE (op0));
3716 debug_generic_stmt (TREE_TYPE (op1));
3724 tree op0 = TREE_OPERAND (expr, 0);
3725 tree op1 = TREE_OPERAND (expr, 1);
3726 tree op2 = TREE_OPERAND (expr, 2);
3727 if ((!is_gimple_val (op1)
3728 && TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3729 || (!is_gimple_val (op2)
3730 && TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE))
3732 error ("invalid operands in conditional expression");
3735 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3736 || (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE
3737 && !useless_type_conversion_p (type, TREE_TYPE (op1)))
3738 || (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE
3739 && !useless_type_conversion_p (type, TREE_TYPE (op2))))
3741 error ("type mismatch in conditional expression");
3742 debug_generic_stmt (type);
3743 debug_generic_stmt (TREE_TYPE (op0));
3744 debug_generic_stmt (TREE_TYPE (op1));
3745 debug_generic_stmt (TREE_TYPE (op2));
3748 return verify_gimple_expr (op0);
3753 tree op = TREE_OPERAND (expr, 0);
3755 if (!is_gimple_addressable (op))
3757 error ("invalid operand in unary expression");
3760 ptr_type = build_pointer_type (TREE_TYPE (op));
3761 if (!useless_type_conversion_p (type, ptr_type)
3762 /* FIXME: a longstanding wart, &a == &a[0]. */
3763 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3764 || !useless_type_conversion_p (type,
3765 build_pointer_type (TREE_TYPE (TREE_TYPE (op))))))
3767 error ("type mismatch in address expression");
3768 debug_generic_stmt (TREE_TYPE (expr));
3769 debug_generic_stmt (ptr_type);
3773 return verify_gimple_reference (op);
3776 case TRUTH_ANDIF_EXPR:
3777 case TRUTH_ORIF_EXPR:
3778 case TRUTH_AND_EXPR:
3780 case TRUTH_XOR_EXPR:
3782 tree op0 = TREE_OPERAND (expr, 0);
3783 tree op1 = TREE_OPERAND (expr, 1);
3785 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3787 error ("invalid operands in truth expression");
3791 /* We allow any kind of integral typed argument and result. */
3792 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3793 || !INTEGRAL_TYPE_P (TREE_TYPE (op1))
3794 || !INTEGRAL_TYPE_P (type))
3796 error ("type mismatch in binary truth expression");
3797 debug_generic_stmt (type);
3798 debug_generic_stmt (TREE_TYPE (op0));
3799 debug_generic_stmt (TREE_TYPE (op1));
3806 case TRUTH_NOT_EXPR:
3808 tree op = TREE_OPERAND (expr, 0);
3810 if (!is_gimple_val (op))
3812 error ("invalid operand in unary not");
3816 /* For TRUTH_NOT_EXPR we can have any kind of integral
3817 typed arguments and results. */
3818 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3819 || !INTEGRAL_TYPE_P (type))
3821 error ("type mismatch in not expression");
3822 debug_generic_expr (TREE_TYPE (expr));
3823 debug_generic_expr (TREE_TYPE (op));
3831 /* FIXME. The C frontend passes unpromoted arguments in case it
3832 didn't see a function declaration before the call. */
3838 /* Generic handling via classes. */
3839 switch (TREE_CODE_CLASS (TREE_CODE (expr)))
3842 return verify_gimple_unary_expr (expr);
3845 return verify_gimple_binary_expr (expr);
3848 return verify_gimple_reference (expr);
3850 case tcc_comparison:
3852 tree op0 = TREE_OPERAND (expr, 0);
3853 tree op1 = TREE_OPERAND (expr, 1);
3854 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3856 error ("invalid operands in comparison expression");
3859 /* For comparisons we do not have the operations type as the
3860 effective type the comparison is carried out in. Instead
3861 we require that either the first operand is trivially
3862 convertible into the second, or the other way around.
3863 The resulting type of a comparison may be any integral type.
3864 Because we special-case pointers to void we allow
3865 comparisons of pointers with the same mode as well. */
3866 if ((!useless_type_conversion_p (TREE_TYPE (op0), TREE_TYPE (op1))
3867 && !useless_type_conversion_p (TREE_TYPE (op1), TREE_TYPE (op0))
3868 && (!POINTER_TYPE_P (TREE_TYPE (op0))
3869 || !POINTER_TYPE_P (TREE_TYPE (op1))
3870 || TYPE_MODE (TREE_TYPE (op0)) != TYPE_MODE (TREE_TYPE (op1))))
3871 || !INTEGRAL_TYPE_P (type))
3873 error ("type mismatch in comparison expression");
3874 debug_generic_stmt (TREE_TYPE (expr));
3875 debug_generic_stmt (TREE_TYPE (op0));
3876 debug_generic_stmt (TREE_TYPE (op1));
3889 /* Verify the GIMPLE assignment statement STMT. Returns true if there
3890 is an error, otherwise false. */
3893 verify_gimple_modify_stmt (tree stmt)
3895 tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
3896 tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
3898 gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
3900 if (!useless_type_conversion_p (TREE_TYPE (lhs),
3903 error ("non-trivial conversion at assignment");
3904 debug_generic_expr (TREE_TYPE (lhs));
3905 debug_generic_expr (TREE_TYPE (rhs));
3909 /* Loads/stores from/to a variable are ok. */
3910 if ((is_gimple_val (lhs)
3911 && is_gimple_variable (rhs))
3912 || (is_gimple_val (rhs)
3913 && is_gimple_variable (lhs)))
3916 /* Aggregate copies are ok. */
3917 if (!is_gimple_reg_type (TREE_TYPE (lhs))
3918 && !is_gimple_reg_type (TREE_TYPE (rhs)))
3921 /* We might get 'loads' from a parameter which is not a gimple value. */
3922 if (TREE_CODE (rhs) == PARM_DECL)
3923 return verify_gimple_expr (lhs);
3925 if (!is_gimple_variable (lhs)
3926 && verify_gimple_expr (lhs))
3929 if (!is_gimple_variable (rhs)
3930 && verify_gimple_expr (rhs))
3936 /* Verify the GIMPLE statement STMT. Returns true if there is an
3937 error, otherwise false. */
3940 verify_gimple_stmt (tree stmt)
3942 if (!is_gimple_stmt (stmt))
3944 error ("is not a valid GIMPLE statement");
3948 if (OMP_DIRECTIVE_P (stmt))
3950 /* OpenMP directives are validated by the FE and never operated
3951 on by the optimizers. Furthermore, OMP_FOR may contain
3952 non-gimple expressions when the main index variable has had
3953 its address taken. This does not affect the loop itself
3954 because the header of an OMP_FOR is merely used to determine
3955 how to setup the parallel iteration. */
3959 switch (TREE_CODE (stmt))
3961 case GIMPLE_MODIFY_STMT:
3962 return verify_gimple_modify_stmt (stmt);
3969 if (!is_gimple_val (TREE_OPERAND (stmt, 0)))
3971 error ("invalid operand to switch statement");
3972 debug_generic_expr (TREE_OPERAND (stmt, 0));
3978 tree op = TREE_OPERAND (stmt, 0);
3980 if (TREE_CODE (TREE_TYPE (stmt)) != VOID_TYPE)
3982 error ("type error in return expression");
3987 || TREE_CODE (op) == RESULT_DECL)
3990 return verify_gimple_modify_stmt (op);
3995 return verify_gimple_expr (stmt);
3998 case CHANGE_DYNAMIC_TYPE_EXPR:
4007 /* Verify the GIMPLE statements inside the statement list STMTS. */
4010 verify_gimple_1 (tree stmts)
4012 tree_stmt_iterator tsi;
4014 for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi))
4016 tree stmt = tsi_stmt (tsi);
4018 switch (TREE_CODE (stmt))
4021 verify_gimple_1 (BIND_EXPR_BODY (stmt));
4024 case TRY_CATCH_EXPR:
4025 case TRY_FINALLY_EXPR:
4026 verify_gimple_1 (TREE_OPERAND (stmt, 0));
4027 verify_gimple_1 (TREE_OPERAND (stmt, 1));
4031 verify_gimple_1 (CATCH_BODY (stmt));
4034 case EH_FILTER_EXPR:
4035 verify_gimple_1 (EH_FILTER_FAILURE (stmt));
4039 if (verify_gimple_stmt (stmt))
4040 debug_generic_expr (stmt);
4045 /* Verify the GIMPLE statements inside the current function. */
4048 verify_gimple (void)
4050 verify_gimple_1 (BIND_EXPR_BODY (DECL_SAVED_TREE (cfun->decl)));
4053 /* Verify STMT, return true if STMT is not in GIMPLE form.
4054 TODO: Implement type checking. */
4057 verify_stmt (tree stmt, bool last_in_block)
4061 if (OMP_DIRECTIVE_P (stmt))
4063 /* OpenMP directives are validated by the FE and never operated
4064 on by the optimizers. Furthermore, OMP_FOR may contain
4065 non-gimple expressions when the main index variable has had
4066 its address taken. This does not affect the loop itself
4067 because the header of an OMP_FOR is merely used to determine
4068 how to setup the parallel iteration. */
4072 if (!is_gimple_stmt (stmt))
4074 error ("is not a valid GIMPLE statement");
4078 addr = walk_tree (&stmt, verify_expr, NULL, NULL);
4081 debug_generic_stmt (addr);
4085 /* If the statement is marked as part of an EH region, then it is
4086 expected that the statement could throw. Verify that when we
4087 have optimizations that simplify statements such that we prove
4088 that they cannot throw, that we update other data structures
4090 if (lookup_stmt_eh_region (stmt) >= 0)
4092 if (!tree_could_throw_p (stmt))
4094 error ("statement marked for throw, but doesn%'t");
4097 if (!last_in_block && tree_can_throw_internal (stmt))
4099 error ("statement marked for throw in middle of block");
4107 debug_generic_stmt (stmt);
4112 /* Return true when the T can be shared. */
4115 tree_node_can_be_shared (tree t)
4117 if (IS_TYPE_OR_DECL_P (t)
4118 || is_gimple_min_invariant (t)
4119 || TREE_CODE (t) == SSA_NAME
4120 || t == error_mark_node
4121 || TREE_CODE (t) == IDENTIFIER_NODE)
4124 if (TREE_CODE (t) == CASE_LABEL_EXPR)
4127 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4128 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4129 || TREE_CODE (t) == COMPONENT_REF
4130 || TREE_CODE (t) == REALPART_EXPR
4131 || TREE_CODE (t) == IMAGPART_EXPR)
4132 t = TREE_OPERAND (t, 0);
4141 /* Called via walk_trees. Verify tree sharing. */
4144 verify_node_sharing (tree * tp, int *walk_subtrees, void *data)
4146 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4148 if (tree_node_can_be_shared (*tp))
4150 *walk_subtrees = false;
4154 if (pointer_set_insert (visited, *tp))
4161 /* Helper function for verify_gimple_tuples. */
4164 verify_gimple_tuples_1 (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4165 void *data ATTRIBUTE_UNUSED)
4167 switch (TREE_CODE (*tp))
4170 error ("unexpected non-tuple");
4180 /* Verify that there are no trees that should have been converted to
4181 gimple tuples. Return true if T contains a node that should have
4182 been converted to a gimple tuple, but hasn't. */
4185 verify_gimple_tuples (tree t)
4187 return walk_tree (&t, verify_gimple_tuples_1, NULL, NULL) != NULL;
4190 static bool eh_error_found;
4192 verify_eh_throw_stmt_node (void **slot, void *data)
4194 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4195 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4197 if (!pointer_set_contains (visited, node->stmt))
4199 error ("Dead STMT in EH table");
4200 debug_generic_stmt (node->stmt);
4201 eh_error_found = true;
4206 /* Verify the GIMPLE statement chain. */
4212 block_stmt_iterator bsi;
4214 struct pointer_set_t *visited, *visited_stmts;
4217 timevar_push (TV_TREE_STMT_VERIFY);
4218 visited = pointer_set_create ();
4219 visited_stmts = pointer_set_create ();
4226 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4228 int phi_num_args = PHI_NUM_ARGS (phi);
4230 pointer_set_insert (visited_stmts, phi);
4231 if (bb_for_stmt (phi) != bb)
4233 error ("bb_for_stmt (phi) is set to a wrong basic block");
4237 for (i = 0; i < phi_num_args; i++)
4239 tree t = PHI_ARG_DEF (phi, i);
4242 /* Addressable variables do have SSA_NAMEs but they
4243 are not considered gimple values. */
4244 if (TREE_CODE (t) != SSA_NAME
4245 && TREE_CODE (t) != FUNCTION_DECL
4246 && !is_gimple_val (t))
4248 error ("PHI def is not a GIMPLE value");
4249 debug_generic_stmt (phi);
4250 debug_generic_stmt (t);
4254 addr = walk_tree (&t, verify_expr, (void *) 1, NULL);
4257 debug_generic_stmt (addr);
4261 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4264 error ("incorrect sharing of tree nodes");
4265 debug_generic_stmt (phi);
4266 debug_generic_stmt (addr);
4272 for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
4274 tree stmt = bsi_stmt (bsi);
4276 pointer_set_insert (visited_stmts, stmt);
4277 err |= verify_gimple_tuples (stmt);
4279 if (bb_for_stmt (stmt) != bb)
4281 error ("bb_for_stmt (stmt) is set to a wrong basic block");
4286 err |= verify_stmt (stmt, bsi_end_p (bsi));
4287 addr = walk_tree (&stmt, verify_node_sharing, visited, NULL);
4290 error ("incorrect sharing of tree nodes");
4291 debug_generic_stmt (stmt);
4292 debug_generic_stmt (addr);
4297 eh_error_found = false;
4298 if (get_eh_throw_stmt_table (cfun))
4299 htab_traverse (get_eh_throw_stmt_table (cfun),
4300 verify_eh_throw_stmt_node,
4303 if (err | eh_error_found)
4304 internal_error ("verify_stmts failed");
4306 pointer_set_destroy (visited);
4307 pointer_set_destroy (visited_stmts);
4308 verify_histograms ();
4309 timevar_pop (TV_TREE_STMT_VERIFY);
4313 /* Verifies that the flow information is OK. */
4316 tree_verify_flow_info (void)
4320 block_stmt_iterator bsi;
4325 if (ENTRY_BLOCK_PTR->il.tree)
4327 error ("ENTRY_BLOCK has IL associated with it");
4331 if (EXIT_BLOCK_PTR->il.tree)
4333 error ("EXIT_BLOCK has IL associated with it");
4337 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4338 if (e->flags & EDGE_FALLTHRU)
4340 error ("fallthru to exit from bb %d", e->src->index);
4346 bool found_ctrl_stmt = false;
4350 /* Skip labels on the start of basic block. */
4351 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4353 tree prev_stmt = stmt;
4355 stmt = bsi_stmt (bsi);
4357 if (TREE_CODE (stmt) != LABEL_EXPR)
4360 if (prev_stmt && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
4362 error ("nonlocal label ");
4363 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4364 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4369 if (label_to_block (LABEL_EXPR_LABEL (stmt)) != bb)
4372 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4373 fprintf (stderr, " to block does not match in bb %d",
4378 if (decl_function_context (LABEL_EXPR_LABEL (stmt))
4379 != current_function_decl)
4382 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4383 fprintf (stderr, " has incorrect context in bb %d",
4389 /* Verify that body of basic block BB is free of control flow. */
4390 for (; !bsi_end_p (bsi); bsi_next (&bsi))
4392 tree stmt = bsi_stmt (bsi);
4394 if (found_ctrl_stmt)
4396 error ("control flow in the middle of basic block %d",
4401 if (stmt_ends_bb_p (stmt))
4402 found_ctrl_stmt = true;
4404 if (TREE_CODE (stmt) == LABEL_EXPR)
4407 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4408 fprintf (stderr, " in the middle of basic block %d", bb->index);
4413 bsi = bsi_last (bb);
4414 if (bsi_end_p (bsi))
4417 stmt = bsi_stmt (bsi);
4419 err |= verify_eh_edges (stmt);
4421 if (is_ctrl_stmt (stmt))
4423 FOR_EACH_EDGE (e, ei, bb->succs)
4424 if (e->flags & EDGE_FALLTHRU)
4426 error ("fallthru edge after a control statement in bb %d",
4432 if (TREE_CODE (stmt) != COND_EXPR)
4434 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4435 after anything else but if statement. */
4436 FOR_EACH_EDGE (e, ei, bb->succs)
4437 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4439 error ("true/false edge after a non-COND_EXPR in bb %d",
4445 switch (TREE_CODE (stmt))
4452 if (COND_EXPR_THEN (stmt) != NULL_TREE
4453 || COND_EXPR_ELSE (stmt) != NULL_TREE)
4455 error ("COND_EXPR with code in branches at the end of bb %d",
4460 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4462 if (!true_edge || !false_edge
4463 || !(true_edge->flags & EDGE_TRUE_VALUE)
4464 || !(false_edge->flags & EDGE_FALSE_VALUE)
4465 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4466 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4467 || EDGE_COUNT (bb->succs) >= 3)
4469 error ("wrong outgoing edge flags at end of bb %d",
4477 if (simple_goto_p (stmt))
4479 error ("explicit goto at end of bb %d", bb->index);
4484 /* FIXME. We should double check that the labels in the
4485 destination blocks have their address taken. */
4486 FOR_EACH_EDGE (e, ei, bb->succs)
4487 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4488 | EDGE_FALSE_VALUE))
4489 || !(e->flags & EDGE_ABNORMAL))
4491 error ("wrong outgoing edge flags at end of bb %d",
4499 if (!single_succ_p (bb)
4500 || (single_succ_edge (bb)->flags
4501 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4502 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4504 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4507 if (single_succ (bb) != EXIT_BLOCK_PTR)
4509 error ("return edge does not point to exit in bb %d",
4522 vec = SWITCH_LABELS (stmt);
4523 n = TREE_VEC_LENGTH (vec);
4525 /* Mark all the destination basic blocks. */
4526 for (i = 0; i < n; ++i)
4528 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4529 basic_block label_bb = label_to_block (lab);
4531 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4532 label_bb->aux = (void *)1;
4535 /* Verify that the case labels are sorted. */
4536 prev = TREE_VEC_ELT (vec, 0);
4537 for (i = 1; i < n - 1; ++i)
4539 tree c = TREE_VEC_ELT (vec, i);
4542 error ("found default case not at end of case vector");
4546 if (! tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4548 error ("case labels not sorted: ");
4549 print_generic_expr (stderr, prev, 0);
4550 fprintf (stderr," is greater than ");
4551 print_generic_expr (stderr, c, 0);
4552 fprintf (stderr," but comes before it.\n");
4557 if (CASE_LOW (TREE_VEC_ELT (vec, n - 1)))
4559 error ("no default case found at end of case vector");
4563 FOR_EACH_EDGE (e, ei, bb->succs)
4567 error ("extra outgoing edge %d->%d",
4568 bb->index, e->dest->index);
4571 e->dest->aux = (void *)2;
4572 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4573 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4575 error ("wrong outgoing edge flags at end of bb %d",
4581 /* Check that we have all of them. */
4582 for (i = 0; i < n; ++i)
4584 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4585 basic_block label_bb = label_to_block (lab);
4587 if (label_bb->aux != (void *)2)
4589 error ("missing edge %i->%i",
4590 bb->index, label_bb->index);
4595 FOR_EACH_EDGE (e, ei, bb->succs)
4596 e->dest->aux = (void *)0;
4603 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4604 verify_dominators (CDI_DOMINATORS);
4610 /* Updates phi nodes after creating a forwarder block joined
4611 by edge FALLTHRU. */
4614 tree_make_forwarder_block (edge fallthru)
4618 basic_block dummy, bb;
4619 tree phi, new_phi, var;
4621 dummy = fallthru->src;
4622 bb = fallthru->dest;
4624 if (single_pred_p (bb))
4627 /* If we redirected a branch we must create new PHI nodes at the
4629 for (phi = phi_nodes (dummy); phi; phi = PHI_CHAIN (phi))
4631 var = PHI_RESULT (phi);
4632 new_phi = create_phi_node (var, bb);
4633 SSA_NAME_DEF_STMT (var) = new_phi;
4634 SET_PHI_RESULT (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4635 add_phi_arg (new_phi, PHI_RESULT (phi), fallthru);
4638 /* Ensure that the PHI node chain is in the same order. */
4639 set_phi_nodes (bb, phi_reverse (phi_nodes (bb)));
4641 /* Add the arguments we have stored on edges. */
4642 FOR_EACH_EDGE (e, ei, bb->preds)
4647 flush_pending_stmts (e);
4652 /* Return a non-special label in the head of basic block BLOCK.
4653 Create one if it doesn't exist. */
4656 tree_block_label (basic_block bb)
4658 block_stmt_iterator i, s = bsi_start (bb);
4662 for (i = s; !bsi_end_p (i); first = false, bsi_next (&i))
4664 stmt = bsi_stmt (i);
4665 if (TREE_CODE (stmt) != LABEL_EXPR)
4667 label = LABEL_EXPR_LABEL (stmt);
4668 if (!DECL_NONLOCAL (label))
4671 bsi_move_before (&i, &s);
4676 label = create_artificial_label ();
4677 stmt = build1 (LABEL_EXPR, void_type_node, label);
4678 bsi_insert_before (&s, stmt, BSI_NEW_STMT);
4683 /* Attempt to perform edge redirection by replacing a possibly complex
4684 jump instruction by a goto or by removing the jump completely.
4685 This can apply only if all edges now point to the same block. The
4686 parameters and return values are equivalent to
4687 redirect_edge_and_branch. */
4690 tree_try_redirect_by_replacing_jump (edge e, basic_block target)
4692 basic_block src = e->src;
4693 block_stmt_iterator b;
4696 /* We can replace or remove a complex jump only when we have exactly
4698 if (EDGE_COUNT (src->succs) != 2
4699 /* Verify that all targets will be TARGET. Specifically, the
4700 edge that is not E must also go to TARGET. */
4701 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4707 stmt = bsi_stmt (b);
4709 if (TREE_CODE (stmt) == COND_EXPR
4710 || TREE_CODE (stmt) == SWITCH_EXPR)
4712 bsi_remove (&b, true);
4713 e = ssa_redirect_edge (e, target);
4714 e->flags = EDGE_FALLTHRU;
4722 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4723 edge representing the redirected branch. */
4726 tree_redirect_edge_and_branch (edge e, basic_block dest)
4728 basic_block bb = e->src;
4729 block_stmt_iterator bsi;
4733 if (e->flags & EDGE_ABNORMAL)
4736 if (e->src != ENTRY_BLOCK_PTR
4737 && (ret = tree_try_redirect_by_replacing_jump (e, dest)))
4740 if (e->dest == dest)
4743 bsi = bsi_last (bb);
4744 stmt = bsi_end_p (bsi) ? NULL : bsi_stmt (bsi);
4746 switch (stmt ? TREE_CODE (stmt) : ERROR_MARK)
4749 /* For COND_EXPR, we only need to redirect the edge. */
4753 /* No non-abnormal edges should lead from a non-simple goto, and
4754 simple ones should be represented implicitly. */
4759 tree cases = get_cases_for_edge (e, stmt);
4760 tree label = tree_block_label (dest);
4762 /* If we have a list of cases associated with E, then use it
4763 as it's a lot faster than walking the entire case vector. */
4766 edge e2 = find_edge (e->src, dest);
4773 CASE_LABEL (cases) = label;
4774 cases = TREE_CHAIN (cases);
4777 /* If there was already an edge in the CFG, then we need
4778 to move all the cases associated with E to E2. */
4781 tree cases2 = get_cases_for_edge (e2, stmt);
4783 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4784 TREE_CHAIN (cases2) = first;
4789 tree vec = SWITCH_LABELS (stmt);
4790 size_t i, n = TREE_VEC_LENGTH (vec);
4792 for (i = 0; i < n; i++)
4794 tree elt = TREE_VEC_ELT (vec, i);
4796 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4797 CASE_LABEL (elt) = label;
4805 bsi_remove (&bsi, true);
4806 e->flags |= EDGE_FALLTHRU;
4810 /* Otherwise it must be a fallthru edge, and we don't need to
4811 do anything besides redirecting it. */
4812 gcc_assert (e->flags & EDGE_FALLTHRU);
4816 /* Update/insert PHI nodes as necessary. */
4818 /* Now update the edges in the CFG. */
4819 e = ssa_redirect_edge (e, dest);
4824 /* Returns true if it is possible to remove edge E by redirecting
4825 it to the destination of the other edge from E->src. */
4828 tree_can_remove_branch_p (edge e)
4830 if (e->flags & EDGE_ABNORMAL)
4836 /* Simple wrapper, as we can always redirect fallthru edges. */
4839 tree_redirect_edge_and_branch_force (edge e, basic_block dest)
4841 e = tree_redirect_edge_and_branch (e, dest);
4848 /* Splits basic block BB after statement STMT (but at least after the
4849 labels). If STMT is NULL, BB is split just after the labels. */
4852 tree_split_block (basic_block bb, void *stmt)
4854 block_stmt_iterator bsi;
4855 tree_stmt_iterator tsi_tgt;
4861 new_bb = create_empty_bb (bb);
4863 /* Redirect the outgoing edges. */
4864 new_bb->succs = bb->succs;
4866 FOR_EACH_EDGE (e, ei, new_bb->succs)
4869 if (stmt && TREE_CODE ((tree) stmt) == LABEL_EXPR)
4872 /* Move everything from BSI to the new basic block. */
4873 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4875 act = bsi_stmt (bsi);
4876 if (TREE_CODE (act) == LABEL_EXPR)
4889 if (bsi_end_p (bsi))
4892 /* Split the statement list - avoid re-creating new containers as this
4893 brings ugly quadratic memory consumption in the inliner.
4894 (We are still quadratic since we need to update stmt BB pointers,
4896 list = tsi_split_statement_list_before (&bsi.tsi);
4897 set_bb_stmt_list (new_bb, list);
4898 for (tsi_tgt = tsi_start (list);
4899 !tsi_end_p (tsi_tgt); tsi_next (&tsi_tgt))
4900 change_bb_for_stmt (tsi_stmt (tsi_tgt), new_bb);
4906 /* Moves basic block BB after block AFTER. */
4909 tree_move_block_after (basic_block bb, basic_block after)
4911 if (bb->prev_bb == after)
4915 link_block (bb, after);
4921 /* Return true if basic_block can be duplicated. */
4924 tree_can_duplicate_bb_p (basic_block bb ATTRIBUTE_UNUSED)
4930 /* Create a duplicate of the basic block BB. NOTE: This does not
4931 preserve SSA form. */
4934 tree_duplicate_bb (basic_block bb)
4937 block_stmt_iterator bsi, bsi_tgt;
4940 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
4942 /* Copy the PHI nodes. We ignore PHI node arguments here because
4943 the incoming edges have not been setup yet. */
4944 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4946 tree copy = create_phi_node (PHI_RESULT (phi), new_bb);
4947 create_new_def_for (PHI_RESULT (copy), copy, PHI_RESULT_PTR (copy));
4950 /* Keep the chain of PHI nodes in the same order so that they can be
4951 updated by ssa_redirect_edge. */
4952 set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb)));
4954 bsi_tgt = bsi_start (new_bb);
4955 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4957 def_operand_p def_p;
4958 ssa_op_iter op_iter;
4962 stmt = bsi_stmt (bsi);
4963 if (TREE_CODE (stmt) == LABEL_EXPR)
4966 /* Create a new copy of STMT and duplicate STMT's virtual
4968 copy = unshare_expr (stmt);
4969 bsi_insert_after (&bsi_tgt, copy, BSI_NEW_STMT);
4970 copy_virtual_operands (copy, stmt);
4971 region = lookup_stmt_eh_region (stmt);
4973 add_stmt_to_eh_region (copy, region);
4974 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
4976 /* Create new names for all the definitions created by COPY and
4977 add replacement mappings for each new name. */
4978 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
4979 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
4986 /* Basic block BB_COPY was created by code duplication. Add phi node
4987 arguments for edges going out of BB_COPY. The blocks that were
4988 duplicated have BB_DUPLICATED set. */
4991 add_phi_args_after_copy_bb (basic_block bb_copy)
4993 basic_block bb, dest;
4996 tree phi, phi_copy, phi_next, def;
4998 bb = get_bb_original (bb_copy);
5000 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5002 if (!phi_nodes (e_copy->dest))
5005 if (e_copy->dest->flags & BB_DUPLICATED)
5006 dest = get_bb_original (e_copy->dest);
5008 dest = e_copy->dest;
5010 e = find_edge (bb, dest);
5013 /* During loop unrolling the target of the latch edge is copied.
5014 In this case we are not looking for edge to dest, but to
5015 duplicated block whose original was dest. */
5016 FOR_EACH_EDGE (e, ei, bb->succs)
5017 if ((e->dest->flags & BB_DUPLICATED)
5018 && get_bb_original (e->dest) == dest)
5021 gcc_assert (e != NULL);
5024 for (phi = phi_nodes (e->dest), phi_copy = phi_nodes (e_copy->dest);
5026 phi = phi_next, phi_copy = PHI_CHAIN (phi_copy))
5028 phi_next = PHI_CHAIN (phi);
5029 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5030 add_phi_arg (phi_copy, def, e_copy);
5035 /* Blocks in REGION_COPY array of length N_REGION were created by
5036 duplication of basic blocks. Add phi node arguments for edges
5037 going from these blocks. */
5040 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region)
5044 for (i = 0; i < n_region; i++)
5045 region_copy[i]->flags |= BB_DUPLICATED;
5047 for (i = 0; i < n_region; i++)
5048 add_phi_args_after_copy_bb (region_copy[i]);
5050 for (i = 0; i < n_region; i++)
5051 region_copy[i]->flags &= ~BB_DUPLICATED;
5054 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5055 important exit edge EXIT. By important we mean that no SSA name defined
5056 inside region is live over the other exit edges of the region. All entry
5057 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5058 to the duplicate of the region. SSA form, dominance and loop information
5059 is updated. The new basic blocks are stored to REGION_COPY in the same
5060 order as they had in REGION, provided that REGION_COPY is not NULL.
5061 The function returns false if it is unable to copy the region,
5065 tree_duplicate_sese_region (edge entry, edge exit,
5066 basic_block *region, unsigned n_region,
5067 basic_block *region_copy)
5070 bool free_region_copy = false, copying_header = false;
5071 struct loop *loop = entry->dest->loop_father;
5073 VEC (basic_block, heap) *doms;
5075 int total_freq = 0, entry_freq = 0;
5076 gcov_type total_count = 0, entry_count = 0;
5078 if (!can_copy_bbs_p (region, n_region))
5081 /* Some sanity checking. Note that we do not check for all possible
5082 missuses of the functions. I.e. if you ask to copy something weird,
5083 it will work, but the state of structures probably will not be
5085 for (i = 0; i < n_region; i++)
5087 /* We do not handle subloops, i.e. all the blocks must belong to the
5089 if (region[i]->loop_father != loop)
5092 if (region[i] != entry->dest
5093 && region[i] == loop->header)
5097 set_loop_copy (loop, loop);
5099 /* In case the function is used for loop header copying (which is the primary
5100 use), ensure that EXIT and its copy will be new latch and entry edges. */
5101 if (loop->header == entry->dest)
5103 copying_header = true;
5104 set_loop_copy (loop, loop_outer (loop));
5106 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5109 for (i = 0; i < n_region; i++)
5110 if (region[i] != exit->src
5111 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5117 region_copy = XNEWVEC (basic_block, n_region);
5118 free_region_copy = true;
5121 gcc_assert (!need_ssa_update_p ());
5123 /* Record blocks outside the region that are dominated by something
5126 initialize_original_copy_tables ();
5128 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5130 if (entry->dest->count)
5132 total_count = entry->dest->count;
5133 entry_count = entry->count;
5134 /* Fix up corner cases, to avoid division by zero or creation of negative
5136 if (entry_count > total_count)
5137 entry_count = total_count;
5141 total_freq = entry->dest->frequency;
5142 entry_freq = EDGE_FREQUENCY (entry);
5143 /* Fix up corner cases, to avoid division by zero or creation of negative
5145 if (total_freq == 0)
5147 else if (entry_freq > total_freq)
5148 entry_freq = total_freq;
5151 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5152 split_edge_bb_loc (entry));
5155 scale_bbs_frequencies_gcov_type (region, n_region,
5156 total_count - entry_count,
5158 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5163 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5165 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5170 loop->header = exit->dest;
5171 loop->latch = exit->src;
5174 /* Redirect the entry and add the phi node arguments. */
5175 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5176 gcc_assert (redirected != NULL);
5177 flush_pending_stmts (entry);
5179 /* Concerning updating of dominators: We must recount dominators
5180 for entry block and its copy. Anything that is outside of the
5181 region, but was dominated by something inside needs recounting as
5183 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5184 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5185 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5188 /* Add the other PHI node arguments. */
5189 add_phi_args_after_copy (region_copy, n_region);
5191 /* Update the SSA web. */
5192 update_ssa (TODO_update_ssa);
5194 if (free_region_copy)
5197 free_original_copy_tables ();
5202 DEF_VEC_P(basic_block);
5203 DEF_VEC_ALLOC_P(basic_block,heap);
5206 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5207 adding blocks when the dominator traversal reaches EXIT. This
5208 function silently assumes that ENTRY strictly dominates EXIT. */
5211 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5212 VEC(basic_block,heap) **bbs_p)
5216 for (son = first_dom_son (CDI_DOMINATORS, entry);
5218 son = next_dom_son (CDI_DOMINATORS, son))
5220 VEC_safe_push (basic_block, heap, *bbs_p, son);
5222 gather_blocks_in_sese_region (son, exit, bbs_p);
5232 bitmap vars_to_remove;
5233 htab_t new_label_map;
5237 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5238 contained in *TP and change the DECL_CONTEXT of every local
5239 variable referenced in *TP. */
5242 move_stmt_r (tree *tp, int *walk_subtrees, void *data)
5244 struct move_stmt_d *p = (struct move_stmt_d *) data;
5248 && (EXPR_P (t) || GIMPLE_STMT_P (t)))
5249 TREE_BLOCK (t) = p->block;
5251 if (OMP_DIRECTIVE_P (t)
5252 && TREE_CODE (t) != OMP_RETURN
5253 && TREE_CODE (t) != OMP_CONTINUE)
5255 /* Do not remap variables inside OMP directives. Variables
5256 referenced in clauses and directive header belong to the
5257 parent function and should not be moved into the child
5259 bool save_remap_decls_p = p->remap_decls_p;
5260 p->remap_decls_p = false;
5263 walk_tree (&OMP_BODY (t), move_stmt_r, p, NULL);
5265 p->remap_decls_p = save_remap_decls_p;
5267 else if (DECL_P (t) && DECL_CONTEXT (t) == p->from_context)
5269 if (TREE_CODE (t) == LABEL_DECL)
5271 if (p->new_label_map)
5273 struct tree_map in, *out;
5275 out = htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5280 DECL_CONTEXT (t) = p->to_context;
5282 else if (p->remap_decls_p)
5284 DECL_CONTEXT (t) = p->to_context;
5286 if (TREE_CODE (t) == VAR_DECL)
5288 struct function *f = DECL_STRUCT_FUNCTION (p->to_context);
5289 f->unexpanded_var_list
5290 = tree_cons (0, t, f->unexpanded_var_list);
5292 /* Mark T to be removed from the original function,
5293 otherwise it will be given a DECL_RTL when the
5294 original function is expanded. */
5295 bitmap_set_bit (p->vars_to_remove, DECL_UID (t));
5299 else if (TYPE_P (t))
5306 /* Move basic block BB from function CFUN to function DEST_FN. The
5307 block is moved out of the original linked list and placed after
5308 block AFTER in the new list. Also, the block is removed from the
5309 original array of blocks and placed in DEST_FN's array of blocks.
5310 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5311 updated to reflect the moved edges.
5313 On exit, local variables that need to be removed from
5314 CFUN->UNEXPANDED_VAR_LIST will have been added to VARS_TO_REMOVE. */
5317 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5318 basic_block after, bool update_edge_count_p,
5319 bitmap vars_to_remove, htab_t new_label_map, int eh_offset)
5321 struct control_flow_graph *cfg;
5324 block_stmt_iterator si;
5325 struct move_stmt_d d;
5326 unsigned old_len, new_len;
5328 /* Remove BB from dominance structures. */
5329 delete_from_dominance_info (CDI_DOMINATORS, bb);
5331 /* Link BB to the new linked list. */
5332 move_block_after (bb, after);
5334 /* Update the edge count in the corresponding flowgraphs. */
5335 if (update_edge_count_p)
5336 FOR_EACH_EDGE (e, ei, bb->succs)
5338 cfun->cfg->x_n_edges--;
5339 dest_cfun->cfg->x_n_edges++;
5342 /* Remove BB from the original basic block array. */
5343 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5344 cfun->cfg->x_n_basic_blocks--;
5346 /* Grow DEST_CFUN's basic block array if needed. */
5347 cfg = dest_cfun->cfg;
5348 cfg->x_n_basic_blocks++;
5349 if (bb->index >= cfg->x_last_basic_block)
5350 cfg->x_last_basic_block = bb->index + 1;
5352 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5353 if ((unsigned) cfg->x_last_basic_block >= old_len)
5355 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5356 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5360 VEC_replace (basic_block, cfg->x_basic_block_info,
5363 /* The statements in BB need to be associated with a new TREE_BLOCK.
5364 Labels need to be associated with a new label-to-block map. */
5365 memset (&d, 0, sizeof (d));
5366 d.vars_to_remove = vars_to_remove;
5368 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5370 tree stmt = bsi_stmt (si);
5373 d.from_context = cfun->decl;
5374 d.to_context = dest_cfun->decl;
5375 d.remap_decls_p = true;
5376 d.new_label_map = new_label_map;
5377 if (TREE_BLOCK (stmt))
5378 d.block = DECL_INITIAL (dest_cfun->decl);
5380 walk_tree (&stmt, move_stmt_r, &d, NULL);
5382 if (TREE_CODE (stmt) == LABEL_EXPR)
5384 tree label = LABEL_EXPR_LABEL (stmt);
5385 int uid = LABEL_DECL_UID (label);
5387 gcc_assert (uid > -1);
5389 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5390 if (old_len <= (unsigned) uid)
5392 new_len = 3 * uid / 2;
5393 VEC_safe_grow_cleared (basic_block, gc,
5394 cfg->x_label_to_block_map, new_len);
5397 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5398 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5400 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5402 if (uid >= dest_cfun->last_label_uid)
5403 dest_cfun->last_label_uid = uid + 1;
5405 else if (TREE_CODE (stmt) == RESX_EXPR && eh_offset != 0)
5406 TREE_OPERAND (stmt, 0) =
5407 build_int_cst (NULL_TREE,
5408 TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0))
5411 region = lookup_stmt_eh_region (stmt);
5414 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5415 remove_stmt_from_eh_region (stmt);
5416 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5417 gimple_remove_stmt_histograms (cfun, stmt);
5422 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5423 the outermost EH region. Use REGION as the incoming base EH region. */
5426 find_outermost_region_in_block (struct function *src_cfun,
5427 basic_block bb, int region)
5429 block_stmt_iterator si;
5431 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5433 tree stmt = bsi_stmt (si);
5436 if (TREE_CODE (stmt) == RESX_EXPR)
5437 stmt_region = TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0));
5439 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5440 if (stmt_region > 0)
5443 region = stmt_region;
5444 else if (stmt_region != region)
5446 region = eh_region_outermost (src_cfun, stmt_region, region);
5447 gcc_assert (region != -1);
5456 new_label_mapper (tree decl, void *data)
5458 htab_t hash = (htab_t) data;
5462 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5464 m = xmalloc (sizeof (struct tree_map));
5465 m->hash = DECL_UID (decl);
5466 m->base.from = decl;
5467 m->to = create_artificial_label ();
5468 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5470 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5471 gcc_assert (*slot == NULL);
5478 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5479 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5480 single basic block in the original CFG and the new basic block is
5481 returned. DEST_CFUN must not have a CFG yet.
5483 Note that the region need not be a pure SESE region. Blocks inside
5484 the region may contain calls to abort/exit. The only restriction
5485 is that ENTRY_BB should be the only entry point and it must
5488 All local variables referenced in the region are assumed to be in
5489 the corresponding BLOCK_VARS and unexpanded variable lists
5490 associated with DEST_CFUN. */
5493 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5494 basic_block exit_bb)
5496 VEC(basic_block,heap) *bbs;
5497 basic_block after, bb, *entry_pred, *exit_succ;
5498 struct function *saved_cfun;
5499 int *entry_flag, *exit_flag, eh_offset;
5500 unsigned i, num_entry_edges, num_exit_edges;
5503 bitmap vars_to_remove;
5504 htab_t new_label_map;
5508 /* Collect all the blocks in the region. Manually add ENTRY_BB
5509 because it won't be added by dfs_enumerate_from. */
5510 calculate_dominance_info (CDI_DOMINATORS);
5512 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5514 gcc_assert (entry_bb != exit_bb
5516 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
5519 VEC_safe_push (basic_block, heap, bbs, entry_bb);
5520 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
5522 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5523 the predecessor edges to ENTRY_BB and the successor edges to
5524 EXIT_BB so that we can re-attach them to the new basic block that
5525 will replace the region. */
5526 num_entry_edges = EDGE_COUNT (entry_bb->preds);
5527 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
5528 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
5530 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
5532 entry_flag[i] = e->flags;
5533 entry_pred[i++] = e->src;
5539 num_exit_edges = EDGE_COUNT (exit_bb->succs);
5540 exit_succ = (basic_block *) xcalloc (num_exit_edges,
5541 sizeof (basic_block));
5542 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
5544 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
5546 exit_flag[i] = e->flags;
5547 exit_succ[i++] = e->dest;
5558 /* Switch context to the child function to initialize DEST_FN's CFG. */
5559 gcc_assert (dest_cfun->cfg == NULL);
5562 init_empty_tree_cfg ();
5564 /* Initialize EH information for the new function. */
5566 new_label_map = NULL;
5571 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5572 region = find_outermost_region_in_block (saved_cfun, bb, region);
5574 init_eh_for_function ();
5577 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
5578 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
5579 new_label_map, region, 0);
5585 /* Move blocks from BBS into DEST_CFUN. */
5586 gcc_assert (VEC_length (basic_block, bbs) >= 2);
5587 after = dest_cfun->cfg->x_entry_block_ptr;
5588 vars_to_remove = BITMAP_ALLOC (NULL);
5589 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5591 /* No need to update edge counts on the last block. It has
5592 already been updated earlier when we detached the region from
5593 the original CFG. */
5594 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, vars_to_remove,
5595 new_label_map, eh_offset);
5600 htab_delete (new_label_map);
5602 /* Remove the variables marked in VARS_TO_REMOVE from
5603 CFUN->UNEXPANDED_VAR_LIST. Otherwise, they will be given a
5604 DECL_RTL in the context of CFUN. */
5605 if (!bitmap_empty_p (vars_to_remove))
5609 for (p = &cfun->unexpanded_var_list; *p; )
5611 tree var = TREE_VALUE (*p);
5612 if (bitmap_bit_p (vars_to_remove, DECL_UID (var)))
5614 *p = TREE_CHAIN (*p);
5618 p = &TREE_CHAIN (*p);
5622 BITMAP_FREE (vars_to_remove);
5624 /* Rewire the entry and exit blocks. The successor to the entry
5625 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
5626 the child function. Similarly, the predecessor of DEST_FN's
5627 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
5628 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
5629 various CFG manipulation function get to the right CFG.
5631 FIXME, this is silly. The CFG ought to become a parameter to
5634 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
5636 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
5639 /* Back in the original function, the SESE region has disappeared,
5640 create a new basic block in its place. */
5641 bb = create_empty_bb (entry_pred[0]);
5642 for (i = 0; i < num_entry_edges; i++)
5643 make_edge (entry_pred[i], bb, entry_flag[i]);
5645 for (i = 0; i < num_exit_edges; i++)
5646 make_edge (bb, exit_succ[i], exit_flag[i]);
5655 free_dominance_info (CDI_DOMINATORS);
5656 free_dominance_info (CDI_POST_DOMINATORS);
5657 VEC_free (basic_block, heap, bbs);
5663 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */
5666 dump_function_to_file (tree fn, FILE *file, int flags)
5668 tree arg, vars, var;
5669 struct function *dsf;
5670 bool ignore_topmost_bind = false, any_var = false;
5673 struct function *saved_cfun;
5675 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
5677 arg = DECL_ARGUMENTS (fn);
5680 print_generic_expr (file, arg, dump_flags);
5681 if (TREE_CHAIN (arg))
5682 fprintf (file, ", ");
5683 arg = TREE_CHAIN (arg);
5685 fprintf (file, ")\n");
5687 dsf = DECL_STRUCT_FUNCTION (fn);
5688 if (dsf && (flags & TDF_DETAILS))
5689 dump_eh_tree (file, dsf);
5691 if (flags & TDF_RAW)
5693 dump_node (fn, TDF_SLIM | flags, file);
5697 /* Switch CFUN to point to FN. */
5699 cfun = DECL_STRUCT_FUNCTION (fn);
5701 /* When GIMPLE is lowered, the variables are no longer available in
5702 BIND_EXPRs, so display them separately. */
5703 if (cfun && cfun->decl == fn && cfun->unexpanded_var_list)
5705 ignore_topmost_bind = true;
5707 fprintf (file, "{\n");
5708 for (vars = cfun->unexpanded_var_list; vars; vars = TREE_CHAIN (vars))
5710 var = TREE_VALUE (vars);
5712 print_generic_decl (file, var, flags);
5713 fprintf (file, "\n");
5719 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
5721 /* Make a CFG based dump. */
5722 check_bb_profile (ENTRY_BLOCK_PTR, file);
5723 if (!ignore_topmost_bind)
5724 fprintf (file, "{\n");
5726 if (any_var && n_basic_blocks)
5727 fprintf (file, "\n");
5730 dump_generic_bb (file, bb, 2, flags);
5732 fprintf (file, "}\n");
5733 check_bb_profile (EXIT_BLOCK_PTR, file);
5739 /* Make a tree based dump. */
5740 chain = DECL_SAVED_TREE (fn);
5742 if (chain && TREE_CODE (chain) == BIND_EXPR)
5744 if (ignore_topmost_bind)
5746 chain = BIND_EXPR_BODY (chain);
5754 if (!ignore_topmost_bind)
5755 fprintf (file, "{\n");
5760 fprintf (file, "\n");
5762 print_generic_stmt_indented (file, chain, flags, indent);
5763 if (ignore_topmost_bind)
5764 fprintf (file, "}\n");
5767 fprintf (file, "\n\n");
5774 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
5777 debug_function (tree fn, int flags)
5779 dump_function_to_file (fn, stderr, flags);
5783 /* Pretty print of the loops intermediate representation. */
5784 static void print_loop (FILE *, struct loop *, int);
5785 static void print_pred_bbs (FILE *, basic_block bb);
5786 static void print_succ_bbs (FILE *, basic_block bb);
5789 /* Print on FILE the indexes for the predecessors of basic_block BB. */
5792 print_pred_bbs (FILE *file, basic_block bb)
5797 FOR_EACH_EDGE (e, ei, bb->preds)
5798 fprintf (file, "bb_%d ", e->src->index);
5802 /* Print on FILE the indexes for the successors of basic_block BB. */
5805 print_succ_bbs (FILE *file, basic_block bb)
5810 FOR_EACH_EDGE (e, ei, bb->succs)
5811 fprintf (file, "bb_%d ", e->dest->index);
5815 /* Pretty print LOOP on FILE, indented INDENT spaces. */
5818 print_loop (FILE *file, struct loop *loop, int indent)
5826 s_indent = (char *) alloca ((size_t) indent + 1);
5827 memset ((void *) s_indent, ' ', (size_t) indent);
5828 s_indent[indent] = '\0';
5830 /* Print the loop's header. */
5831 fprintf (file, "%sloop_%d\n", s_indent, loop->num);
5833 /* Print the loop's body. */
5834 fprintf (file, "%s{\n", s_indent);
5836 if (bb->loop_father == loop)
5838 /* Print the basic_block's header. */
5839 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
5840 print_pred_bbs (file, bb);
5841 fprintf (file, "}, succs = {");
5842 print_succ_bbs (file, bb);
5843 fprintf (file, "})\n");
5845 /* Print the basic_block's body. */
5846 fprintf (file, "%s {\n", s_indent);
5847 tree_dump_bb (bb, file, indent + 4);
5848 fprintf (file, "%s }\n", s_indent);
5851 print_loop (file, loop->inner, indent + 2);
5852 fprintf (file, "%s}\n", s_indent);
5853 print_loop (file, loop->next, indent);
5857 /* Follow a CFG edge from the entry point of the program, and on entry
5858 of a loop, pretty print the loop structure on FILE. */
5861 print_loop_ir (FILE *file)
5865 bb = BASIC_BLOCK (NUM_FIXED_BLOCKS);
5866 if (bb && bb->loop_father)
5867 print_loop (file, bb->loop_father, 0);
5871 /* Debugging loops structure at tree level. */
5874 debug_loop_ir (void)
5876 print_loop_ir (stderr);
5880 /* Return true if BB ends with a call, possibly followed by some
5881 instructions that must stay with the call. Return false,
5885 tree_block_ends_with_call_p (basic_block bb)
5887 block_stmt_iterator bsi = bsi_last (bb);
5888 return get_call_expr_in (bsi_stmt (bsi)) != NULL;
5892 /* Return true if BB ends with a conditional branch. Return false,
5896 tree_block_ends_with_condjump_p (basic_block bb)
5898 tree stmt = last_stmt (bb);
5899 return (stmt && TREE_CODE (stmt) == COND_EXPR);
5903 /* Return true if we need to add fake edge to exit at statement T.
5904 Helper function for tree_flow_call_edges_add. */
5907 need_fake_edge_p (tree t)
5911 /* NORETURN and LONGJMP calls already have an edge to exit.
5912 CONST and PURE calls do not need one.
5913 We don't currently check for CONST and PURE here, although
5914 it would be a good idea, because those attributes are
5915 figured out from the RTL in mark_constant_function, and
5916 the counter incrementation code from -fprofile-arcs
5917 leads to different results from -fbranch-probabilities. */
5918 call = get_call_expr_in (t);
5920 && !(call_expr_flags (call) & ECF_NORETURN))
5923 if (TREE_CODE (t) == ASM_EXPR
5924 && (ASM_VOLATILE_P (t) || ASM_INPUT_P (t)))
5931 /* Add fake edges to the function exit for any non constant and non
5932 noreturn calls, volatile inline assembly in the bitmap of blocks
5933 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
5934 the number of blocks that were split.
5936 The goal is to expose cases in which entering a basic block does
5937 not imply that all subsequent instructions must be executed. */
5940 tree_flow_call_edges_add (sbitmap blocks)
5943 int blocks_split = 0;
5944 int last_bb = last_basic_block;
5945 bool check_last_block = false;
5947 if (n_basic_blocks == NUM_FIXED_BLOCKS)
5951 check_last_block = true;
5953 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
5955 /* In the last basic block, before epilogue generation, there will be
5956 a fallthru edge to EXIT. Special care is required if the last insn
5957 of the last basic block is a call because make_edge folds duplicate
5958 edges, which would result in the fallthru edge also being marked
5959 fake, which would result in the fallthru edge being removed by
5960 remove_fake_edges, which would result in an invalid CFG.
5962 Moreover, we can't elide the outgoing fake edge, since the block
5963 profiler needs to take this into account in order to solve the minimal
5964 spanning tree in the case that the call doesn't return.
5966 Handle this by adding a dummy instruction in a new last basic block. */
5967 if (check_last_block)
5969 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
5970 block_stmt_iterator bsi = bsi_last (bb);
5972 if (!bsi_end_p (bsi))
5975 if (t && need_fake_edge_p (t))
5979 e = find_edge (bb, EXIT_BLOCK_PTR);
5982 bsi_insert_on_edge (e, build_empty_stmt ());
5983 bsi_commit_edge_inserts ();
5988 /* Now add fake edges to the function exit for any non constant
5989 calls since there is no way that we can determine if they will
5991 for (i = 0; i < last_bb; i++)
5993 basic_block bb = BASIC_BLOCK (i);
5994 block_stmt_iterator bsi;
5995 tree stmt, last_stmt;
6000 if (blocks && !TEST_BIT (blocks, i))
6003 bsi = bsi_last (bb);
6004 if (!bsi_end_p (bsi))
6006 last_stmt = bsi_stmt (bsi);
6009 stmt = bsi_stmt (bsi);
6010 if (need_fake_edge_p (stmt))
6013 /* The handling above of the final block before the
6014 epilogue should be enough to verify that there is
6015 no edge to the exit block in CFG already.
6016 Calling make_edge in such case would cause us to
6017 mark that edge as fake and remove it later. */
6018 #ifdef ENABLE_CHECKING
6019 if (stmt == last_stmt)
6021 e = find_edge (bb, EXIT_BLOCK_PTR);
6022 gcc_assert (e == NULL);
6026 /* Note that the following may create a new basic block
6027 and renumber the existing basic blocks. */
6028 if (stmt != last_stmt)
6030 e = split_block (bb, stmt);
6034 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6038 while (!bsi_end_p (bsi));
6043 verify_flow_info ();
6045 return blocks_split;
6048 /* Purge dead abnormal call edges from basic block BB. */
6051 tree_purge_dead_abnormal_call_edges (basic_block bb)
6053 bool changed = tree_purge_dead_eh_edges (bb);
6055 if (current_function_has_nonlocal_label)
6057 tree stmt = last_stmt (bb);
6061 if (!(stmt && tree_can_make_abnormal_goto (stmt)))
6062 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6064 if (e->flags & EDGE_ABNORMAL)
6073 /* See tree_purge_dead_eh_edges below. */
6075 free_dominance_info (CDI_DOMINATORS);
6081 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6084 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6088 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6089 for (son = first_dom_son (CDI_DOMINATORS, bb);
6091 son = next_dom_son (CDI_DOMINATORS, son))
6092 get_all_dominated_blocks (son, dom_bbs);
6095 /* Removes edge E and all the blocks dominated by it, and updates dominance
6096 information. The IL in E->src needs to be updated separately.
6097 If dominance info is not available, only the edge E is removed.*/
6100 remove_edge_and_dominated_blocks (edge e)
6102 VEC (basic_block, heap) *bbs_to_remove = NULL;
6103 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6107 bool none_removed = false;
6109 basic_block bb, dbb;
6112 if (!dom_info_available_p (CDI_DOMINATORS))
6118 /* No updating is needed for edges to exit. */
6119 if (e->dest == EXIT_BLOCK_PTR)
6121 if (cfgcleanup_altered_bbs)
6122 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6127 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6128 that is not dominated by E->dest, then this set is empty. Otherwise,
6129 all the basic blocks dominated by E->dest are removed.
6131 Also, to DF_IDOM we store the immediate dominators of the blocks in
6132 the dominance frontier of E (i.e., of the successors of the
6133 removed blocks, if there are any, and of E->dest otherwise). */
6134 FOR_EACH_EDGE (f, ei, e->dest->preds)
6139 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6141 none_removed = true;
6146 df = BITMAP_ALLOC (NULL);
6147 df_idom = BITMAP_ALLOC (NULL);
6150 bitmap_set_bit (df_idom,
6151 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6154 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6155 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6157 FOR_EACH_EDGE (f, ei, bb->succs)
6159 if (f->dest != EXIT_BLOCK_PTR)
6160 bitmap_set_bit (df, f->dest->index);
6163 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6164 bitmap_clear_bit (df, bb->index);
6166 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6168 bb = BASIC_BLOCK (i);
6169 bitmap_set_bit (df_idom,
6170 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6174 if (cfgcleanup_altered_bbs)
6176 /* Record the set of the altered basic blocks. */
6177 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6178 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6181 /* Remove E and the cancelled blocks. */
6186 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6187 delete_basic_block (bb);
6190 /* Update the dominance information. The immediate dominator may change only
6191 for blocks whose immediate dominator belongs to DF_IDOM:
6193 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6194 removal. Let Z the arbitrary block such that idom(Z) = Y and
6195 Z dominates X after the removal. Before removal, there exists a path P
6196 from Y to X that avoids Z. Let F be the last edge on P that is
6197 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6198 dominates W, and because of P, Z does not dominate W), and W belongs to
6199 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6200 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6202 bb = BASIC_BLOCK (i);
6203 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6205 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6206 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6209 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6212 BITMAP_FREE (df_idom);
6213 VEC_free (basic_block, heap, bbs_to_remove);
6214 VEC_free (basic_block, heap, bbs_to_fix_dom);
6217 /* Purge dead EH edges from basic block BB. */
6220 tree_purge_dead_eh_edges (basic_block bb)
6222 bool changed = false;
6225 tree stmt = last_stmt (bb);
6227 if (stmt && tree_can_throw_internal (stmt))
6230 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6232 if (e->flags & EDGE_EH)
6234 remove_edge_and_dominated_blocks (e);
6245 tree_purge_all_dead_eh_edges (const_bitmap blocks)
6247 bool changed = false;
6251 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6253 changed |= tree_purge_dead_eh_edges (BASIC_BLOCK (i));
6259 /* This function is called whenever a new edge is created or
6263 tree_execute_on_growing_pred (edge e)
6265 basic_block bb = e->dest;
6268 reserve_phi_args_for_new_edge (bb);
6271 /* This function is called immediately before edge E is removed from
6272 the edge vector E->dest->preds. */
6275 tree_execute_on_shrinking_pred (edge e)
6277 if (phi_nodes (e->dest))
6278 remove_phi_args (e);
6281 /*---------------------------------------------------------------------------
6282 Helper functions for Loop versioning
6283 ---------------------------------------------------------------------------*/
6285 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6286 of 'first'. Both of them are dominated by 'new_head' basic block. When
6287 'new_head' was created by 'second's incoming edge it received phi arguments
6288 on the edge by split_edge(). Later, additional edge 'e' was created to
6289 connect 'new_head' and 'first'. Now this routine adds phi args on this
6290 additional edge 'e' that new_head to second edge received as part of edge
6295 tree_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6296 basic_block new_head, edge e)
6299 edge e2 = find_edge (new_head, second);
6301 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6302 edge, we should always have an edge from NEW_HEAD to SECOND. */
6303 gcc_assert (e2 != NULL);
6305 /* Browse all 'second' basic block phi nodes and add phi args to
6306 edge 'e' for 'first' head. PHI args are always in correct order. */
6308 for (phi2 = phi_nodes (second), phi1 = phi_nodes (first);
6310 phi2 = PHI_CHAIN (phi2), phi1 = PHI_CHAIN (phi1))
6312 tree def = PHI_ARG_DEF (phi2, e2->dest_idx);
6313 add_phi_arg (phi1, def, e);
6317 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6318 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6319 the destination of the ELSE part. */
6321 tree_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6322 basic_block second_head ATTRIBUTE_UNUSED,
6323 basic_block cond_bb, void *cond_e)
6325 block_stmt_iterator bsi;
6326 tree new_cond_expr = NULL_TREE;
6327 tree cond_expr = (tree) cond_e;
6330 /* Build new conditional expr */
6331 new_cond_expr = build3 (COND_EXPR, void_type_node, cond_expr,
6332 NULL_TREE, NULL_TREE);
6334 /* Add new cond in cond_bb. */
6335 bsi = bsi_start (cond_bb);
6336 bsi_insert_after (&bsi, new_cond_expr, BSI_NEW_STMT);
6337 /* Adjust edges appropriately to connect new head with first head
6338 as well as second head. */
6339 e0 = single_succ_edge (cond_bb);
6340 e0->flags &= ~EDGE_FALLTHRU;
6341 e0->flags |= EDGE_FALSE_VALUE;
6344 struct cfg_hooks tree_cfg_hooks = {
6346 tree_verify_flow_info,
6347 tree_dump_bb, /* dump_bb */
6348 create_bb, /* create_basic_block */
6349 tree_redirect_edge_and_branch,/* redirect_edge_and_branch */
6350 tree_redirect_edge_and_branch_force,/* redirect_edge_and_branch_force */
6351 tree_can_remove_branch_p, /* can_remove_branch_p */
6352 remove_bb, /* delete_basic_block */
6353 tree_split_block, /* split_block */
6354 tree_move_block_after, /* move_block_after */
6355 tree_can_merge_blocks_p, /* can_merge_blocks_p */
6356 tree_merge_blocks, /* merge_blocks */
6357 tree_predict_edge, /* predict_edge */
6358 tree_predicted_by_p, /* predicted_by_p */
6359 tree_can_duplicate_bb_p, /* can_duplicate_block_p */
6360 tree_duplicate_bb, /* duplicate_block */
6361 tree_split_edge, /* split_edge */
6362 tree_make_forwarder_block, /* make_forward_block */
6363 NULL, /* tidy_fallthru_edge */
6364 tree_block_ends_with_call_p, /* block_ends_with_call_p */
6365 tree_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6366 tree_flow_call_edges_add, /* flow_call_edges_add */
6367 tree_execute_on_growing_pred, /* execute_on_growing_pred */
6368 tree_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6369 tree_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6370 tree_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6371 tree_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6372 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6373 flush_pending_stmts /* flush_pending_stmts */
6377 /* Split all critical edges. */
6380 split_critical_edges (void)
6386 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6387 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6388 mappings around the calls to split_edge. */
6389 start_recording_case_labels ();
6392 FOR_EACH_EDGE (e, ei, bb->succs)
6393 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6398 end_recording_case_labels ();
6402 struct tree_opt_pass pass_split_crit_edges =
6404 "crited", /* name */
6406 split_critical_edges, /* execute */
6409 0, /* static_pass_number */
6410 TV_TREE_SPLIT_EDGES, /* tv_id */
6411 PROP_cfg, /* properties required */
6412 PROP_no_crit_edges, /* properties_provided */
6413 0, /* properties_destroyed */
6414 0, /* todo_flags_start */
6415 TODO_dump_func, /* todo_flags_finish */
6420 /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into
6421 a temporary, make sure and register it to be renamed if necessary,
6422 and finally return the temporary. Put the statements to compute
6423 EXP before the current statement in BSI. */
6426 gimplify_val (block_stmt_iterator *bsi, tree type, tree exp)
6428 tree t, new_stmt, orig_stmt;
6430 if (is_gimple_val (exp))
6433 t = make_rename_temp (type, NULL);
6434 new_stmt = build_gimple_modify_stmt (t, exp);
6436 orig_stmt = bsi_stmt (*bsi);
6437 SET_EXPR_LOCUS (new_stmt, EXPR_LOCUS (orig_stmt));
6438 TREE_BLOCK (new_stmt) = TREE_BLOCK (orig_stmt);
6440 bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
6441 if (gimple_in_ssa_p (cfun))
6442 mark_symbols_for_renaming (new_stmt);
6447 /* Build a ternary operation and gimplify it. Emit code before BSI.
6448 Return the gimple_val holding the result. */
6451 gimplify_build3 (block_stmt_iterator *bsi, enum tree_code code,
6452 tree type, tree a, tree b, tree c)
6456 ret = fold_build3 (code, type, a, b, c);
6459 return gimplify_val (bsi, type, ret);
6462 /* Build a binary operation and gimplify it. Emit code before BSI.
6463 Return the gimple_val holding the result. */
6466 gimplify_build2 (block_stmt_iterator *bsi, enum tree_code code,
6467 tree type, tree a, tree b)
6471 ret = fold_build2 (code, type, a, b);
6474 return gimplify_val (bsi, type, ret);
6477 /* Build a unary operation and gimplify it. Emit code before BSI.
6478 Return the gimple_val holding the result. */
6481 gimplify_build1 (block_stmt_iterator *bsi, enum tree_code code, tree type,
6486 ret = fold_build1 (code, type, a);
6489 return gimplify_val (bsi, type, ret);
6494 /* Emit return warnings. */
6497 execute_warn_function_return (void)
6499 #ifdef USE_MAPPED_LOCATION
6500 source_location location;
6508 /* If we have a path to EXIT, then we do return. */
6509 if (TREE_THIS_VOLATILE (cfun->decl)
6510 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
6512 #ifdef USE_MAPPED_LOCATION
6513 location = UNKNOWN_LOCATION;
6517 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6519 last = last_stmt (e->src);
6520 if (TREE_CODE (last) == RETURN_EXPR
6521 #ifdef USE_MAPPED_LOCATION
6522 && (location = EXPR_LOCATION (last)) != UNKNOWN_LOCATION)
6524 && (locus = EXPR_LOCUS (last)) != NULL)
6528 #ifdef USE_MAPPED_LOCATION
6529 if (location == UNKNOWN_LOCATION)
6530 location = cfun->function_end_locus;
6531 warning (0, "%H%<noreturn%> function does return", &location);
6534 locus = &cfun->function_end_locus;
6535 warning (0, "%H%<noreturn%> function does return", locus);
6539 /* If we see "return;" in some basic block, then we do reach the end
6540 without returning a value. */
6541 else if (warn_return_type
6542 && !TREE_NO_WARNING (cfun->decl)
6543 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
6544 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
6546 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6548 tree last = last_stmt (e->src);
6549 if (TREE_CODE (last) == RETURN_EXPR
6550 && TREE_OPERAND (last, 0) == NULL
6551 && !TREE_NO_WARNING (last))
6553 #ifdef USE_MAPPED_LOCATION
6554 location = EXPR_LOCATION (last);
6555 if (location == UNKNOWN_LOCATION)
6556 location = cfun->function_end_locus;
6557 warning (0, "%Hcontrol reaches end of non-void function", &location);
6559 locus = EXPR_LOCUS (last);
6561 locus = &cfun->function_end_locus;
6562 warning (0, "%Hcontrol reaches end of non-void function", locus);
6564 TREE_NO_WARNING (cfun->decl) = 1;
6573 /* Given a basic block B which ends with a conditional and has
6574 precisely two successors, determine which of the edges is taken if
6575 the conditional is true and which is taken if the conditional is
6576 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
6579 extract_true_false_edges_from_block (basic_block b,
6583 edge e = EDGE_SUCC (b, 0);
6585 if (e->flags & EDGE_TRUE_VALUE)
6588 *false_edge = EDGE_SUCC (b, 1);
6593 *true_edge = EDGE_SUCC (b, 1);
6597 struct tree_opt_pass pass_warn_function_return =
6601 execute_warn_function_return, /* execute */
6604 0, /* static_pass_number */
6606 PROP_cfg, /* properties_required */
6607 0, /* properties_provided */
6608 0, /* properties_destroyed */
6609 0, /* todo_flags_start */
6610 0, /* todo_flags_finish */
6614 /* Emit noreturn warnings. */
6617 execute_warn_function_noreturn (void)
6619 if (warn_missing_noreturn
6620 && !TREE_THIS_VOLATILE (cfun->decl)
6621 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
6622 && !lang_hooks.function.missing_noreturn_ok_p (cfun->decl))
6623 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
6624 "for attribute %<noreturn%>",
6629 struct tree_opt_pass pass_warn_function_noreturn =
6633 execute_warn_function_noreturn, /* execute */
6636 0, /* static_pass_number */
6638 PROP_cfg, /* properties_required */
6639 0, /* properties_provided */
6640 0, /* properties_destroyed */
6641 0, /* todo_flags_start */
6642 0, /* todo_flags_finish */