1 /* Control flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "hard-reg-set.h"
30 #include "basic-block.h"
36 #include "langhooks.h"
37 #include "diagnostic.h"
38 #include "tree-flow.h"
40 #include "tree-dump.h"
41 #include "tree-pass.h"
45 #include "cfglayout.h"
46 #include "tree-ssa-propagate.h"
47 #include "value-prof.h"
48 #include "pointer-set.h"
49 #include "tree-inline.h"
51 /* This file contains functions for building the Control Flow Graph (CFG)
52 for a function tree. */
54 /* Local declarations. */
56 /* Initial capacity for the basic block array. */
57 static const int initial_cfg_capacity = 20;
59 /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs
60 which use a particular edge. The CASE_LABEL_EXPRs are chained together
61 via their TREE_CHAIN field, which we clear after we're done with the
62 hash table to prevent problems with duplication of GIMPLE_SWITCHes.
64 Access to this list of CASE_LABEL_EXPRs allows us to efficiently
65 update the case vector in response to edge redirections.
67 Right now this table is set up and torn down at key points in the
68 compilation process. It would be nice if we could make the table
69 more persistent. The key is getting notification of changes to
70 the CFG (particularly edge removal, creation and redirection). */
72 static struct pointer_map_t *edge_to_cases;
77 long num_merged_labels;
80 static struct cfg_stats_d cfg_stats;
82 /* Nonzero if we found a computed goto while building basic blocks. */
83 static bool found_computed_goto;
85 /* Basic blocks and flowgraphs. */
86 static void make_blocks (gimple_seq);
87 static void factor_computed_gotos (void);
90 static void make_edges (void);
91 static void make_cond_expr_edges (basic_block);
92 static void make_gimple_switch_edges (basic_block);
93 static void make_goto_expr_edges (basic_block);
94 static edge gimple_redirect_edge_and_branch (edge, basic_block);
95 static edge gimple_try_redirect_by_replacing_jump (edge, basic_block);
96 static unsigned int split_critical_edges (void);
98 /* Various helpers. */
99 static inline bool stmt_starts_bb_p (gimple, gimple);
100 static int gimple_verify_flow_info (void);
101 static void gimple_make_forwarder_block (edge);
102 static void gimple_cfg2vcg (FILE *);
104 /* Flowgraph optimization and cleanup. */
105 static void gimple_merge_blocks (basic_block, basic_block);
106 static bool gimple_can_merge_blocks_p (basic_block, basic_block);
107 static void remove_bb (basic_block);
108 static edge find_taken_edge_computed_goto (basic_block, tree);
109 static edge find_taken_edge_cond_expr (basic_block, tree);
110 static edge find_taken_edge_switch_expr (basic_block, tree);
111 static tree find_case_label_for_value (gimple, tree);
114 init_empty_tree_cfg_for_function (struct function *fn)
116 /* Initialize the basic block array. */
118 profile_status_for_function (fn) = PROFILE_ABSENT;
119 n_basic_blocks_for_function (fn) = NUM_FIXED_BLOCKS;
120 last_basic_block_for_function (fn) = NUM_FIXED_BLOCKS;
121 basic_block_info_for_function (fn)
122 = VEC_alloc (basic_block, gc, initial_cfg_capacity);
123 VEC_safe_grow_cleared (basic_block, gc,
124 basic_block_info_for_function (fn),
125 initial_cfg_capacity);
127 /* Build a mapping of labels to their associated blocks. */
128 label_to_block_map_for_function (fn)
129 = VEC_alloc (basic_block, gc, initial_cfg_capacity);
130 VEC_safe_grow_cleared (basic_block, gc,
131 label_to_block_map_for_function (fn),
132 initial_cfg_capacity);
134 SET_BASIC_BLOCK_FOR_FUNCTION (fn, ENTRY_BLOCK,
135 ENTRY_BLOCK_PTR_FOR_FUNCTION (fn));
136 SET_BASIC_BLOCK_FOR_FUNCTION (fn, EXIT_BLOCK,
137 EXIT_BLOCK_PTR_FOR_FUNCTION (fn));
139 ENTRY_BLOCK_PTR_FOR_FUNCTION (fn)->next_bb
140 = EXIT_BLOCK_PTR_FOR_FUNCTION (fn);
141 EXIT_BLOCK_PTR_FOR_FUNCTION (fn)->prev_bb
142 = ENTRY_BLOCK_PTR_FOR_FUNCTION (fn);
146 init_empty_tree_cfg (void)
148 init_empty_tree_cfg_for_function (cfun);
151 /*---------------------------------------------------------------------------
153 ---------------------------------------------------------------------------*/
155 /* Entry point to the CFG builder for trees. SEQ is the sequence of
156 statements to be added to the flowgraph. */
159 build_gimple_cfg (gimple_seq seq)
161 /* Register specific gimple functions. */
162 gimple_register_cfg_hooks ();
164 memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
166 init_empty_tree_cfg ();
168 found_computed_goto = 0;
171 /* Computed gotos are hell to deal with, especially if there are
172 lots of them with a large number of destinations. So we factor
173 them to a common computed goto location before we build the
174 edge list. After we convert back to normal form, we will un-factor
175 the computed gotos since factoring introduces an unwanted jump. */
176 if (found_computed_goto)
177 factor_computed_gotos ();
179 /* Make sure there is always at least one block, even if it's empty. */
180 if (n_basic_blocks == NUM_FIXED_BLOCKS)
181 create_empty_bb (ENTRY_BLOCK_PTR);
183 /* Adjust the size of the array. */
184 if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
185 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
187 /* To speed up statement iterator walks, we first purge dead labels. */
188 cleanup_dead_labels ();
190 /* Group case nodes to reduce the number of edges.
191 We do this after cleaning up dead labels because otherwise we miss
192 a lot of obvious case merging opportunities. */
193 group_case_labels ();
195 /* Create the edges of the flowgraph. */
197 cleanup_dead_labels ();
199 /* Debugging dumps. */
201 /* Write the flowgraph to a VCG file. */
203 int local_dump_flags;
204 FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
207 gimple_cfg2vcg (vcg_file);
208 dump_end (TDI_vcg, vcg_file);
212 #ifdef ENABLE_CHECKING
216 /* Dump a textual representation of the flowgraph. */
218 gimple_dump_cfg (dump_file, dump_flags);
222 execute_build_cfg (void)
224 build_gimple_cfg (gimple_body (current_function_decl));
228 struct gimple_opt_pass pass_build_cfg =
234 execute_build_cfg, /* execute */
237 0, /* static_pass_number */
238 TV_TREE_CFG, /* tv_id */
239 PROP_gimple_leh, /* properties_required */
240 PROP_cfg, /* properties_provided */
241 0, /* properties_destroyed */
242 0, /* todo_flags_start */
243 TODO_verify_stmts | TODO_cleanup_cfg /* todo_flags_finish */
248 /* Return true if T is a computed goto. */
251 computed_goto_p (gimple t)
253 return (gimple_code (t) == GIMPLE_GOTO
254 && TREE_CODE (gimple_goto_dest (t)) != LABEL_DECL);
258 /* Search the CFG for any computed gotos. If found, factor them to a
259 common computed goto site. Also record the location of that site so
260 that we can un-factor the gotos after we have converted back to
264 factor_computed_gotos (void)
267 tree factored_label_decl = NULL;
269 gimple factored_computed_goto_label = NULL;
270 gimple factored_computed_goto = NULL;
272 /* We know there are one or more computed gotos in this function.
273 Examine the last statement in each basic block to see if the block
274 ends with a computed goto. */
278 gimple_stmt_iterator gsi = gsi_last_bb (bb);
284 last = gsi_stmt (gsi);
286 /* Ignore the computed goto we create when we factor the original
288 if (last == factored_computed_goto)
291 /* If the last statement is a computed goto, factor it. */
292 if (computed_goto_p (last))
296 /* The first time we find a computed goto we need to create
297 the factored goto block and the variable each original
298 computed goto will use for their goto destination. */
299 if (!factored_computed_goto)
301 basic_block new_bb = create_empty_bb (bb);
302 gimple_stmt_iterator new_gsi = gsi_start_bb (new_bb);
304 /* Create the destination of the factored goto. Each original
305 computed goto will put its desired destination into this
306 variable and jump to the label we create immediately
308 var = create_tmp_var (ptr_type_node, "gotovar");
310 /* Build a label for the new block which will contain the
311 factored computed goto. */
312 factored_label_decl = create_artificial_label ();
313 factored_computed_goto_label
314 = gimple_build_label (factored_label_decl);
315 gsi_insert_after (&new_gsi, factored_computed_goto_label,
318 /* Build our new computed goto. */
319 factored_computed_goto = gimple_build_goto (var);
320 gsi_insert_after (&new_gsi, factored_computed_goto, GSI_NEW_STMT);
323 /* Copy the original computed goto's destination into VAR. */
324 assignment = gimple_build_assign (var, gimple_goto_dest (last));
325 gsi_insert_before (&gsi, assignment, GSI_SAME_STMT);
327 /* And re-vector the computed goto to the new destination. */
328 gimple_goto_set_dest (last, factored_label_decl);
334 /* Build a flowgraph for the sequence of stmts SEQ. */
337 make_blocks (gimple_seq seq)
339 gimple_stmt_iterator i = gsi_start (seq);
341 bool start_new_block = true;
342 bool first_stmt_of_seq = true;
343 basic_block bb = ENTRY_BLOCK_PTR;
345 while (!gsi_end_p (i))
352 /* If the statement starts a new basic block or if we have determined
353 in a previous pass that we need to create a new block for STMT, do
355 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
357 if (!first_stmt_of_seq)
358 seq = gsi_split_seq_before (&i);
359 bb = create_basic_block (seq, NULL, bb);
360 start_new_block = false;
363 /* Now add STMT to BB and create the subgraphs for special statement
365 gimple_set_bb (stmt, bb);
367 if (computed_goto_p (stmt))
368 found_computed_goto = true;
370 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
372 if (stmt_ends_bb_p (stmt))
373 start_new_block = true;
376 first_stmt_of_seq = false;
381 /* Create and return a new empty basic block after bb AFTER. */
384 create_bb (void *h, void *e, basic_block after)
390 /* Create and initialize a new basic block. Since alloc_block uses
391 ggc_alloc_cleared to allocate a basic block, we do not have to
392 clear the newly allocated basic block here. */
395 bb->index = last_basic_block;
397 bb->il.gimple = GGC_CNEW (struct gimple_bb_info);
398 set_bb_seq (bb, h ? (gimple_seq) h : gimple_seq_alloc ());
400 /* Add the new block to the linked list of blocks. */
401 link_block (bb, after);
403 /* Grow the basic block array if needed. */
404 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
406 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
407 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
410 /* Add the newly created block to the array. */
411 SET_BASIC_BLOCK (last_basic_block, bb);
420 /*---------------------------------------------------------------------------
422 ---------------------------------------------------------------------------*/
424 /* Fold COND_EXPR_COND of each COND_EXPR. */
427 fold_cond_expr_cond (void)
433 gimple stmt = last_stmt (bb);
435 if (stmt && gimple_code (stmt) == GIMPLE_COND)
440 fold_defer_overflow_warnings ();
441 cond = fold_binary (gimple_cond_code (stmt), boolean_type_node,
442 gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
445 zerop = integer_zerop (cond);
446 onep = integer_onep (cond);
449 zerop = onep = false;
451 fold_undefer_overflow_warnings (zerop || onep,
453 WARN_STRICT_OVERFLOW_CONDITIONAL);
455 gimple_cond_make_false (stmt);
457 gimple_cond_make_true (stmt);
462 /* Join all the blocks in the flowgraph. */
468 struct omp_region *cur_region = NULL;
470 /* Create an edge from entry to the first block with executable
472 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
474 /* Traverse the basic block array placing edges. */
477 gimple last = last_stmt (bb);
482 enum gimple_code code = gimple_code (last);
486 make_goto_expr_edges (bb);
490 make_edge (bb, EXIT_BLOCK_PTR, 0);
494 make_cond_expr_edges (bb);
498 make_gimple_switch_edges (bb);
502 make_eh_edges (last);
507 /* If this function receives a nonlocal goto, then we need to
508 make edges from this call site to all the nonlocal goto
510 if (stmt_can_make_abnormal_goto (last))
511 make_abnormal_goto_edges (bb, true);
513 /* If this statement has reachable exception handlers, then
514 create abnormal edges to them. */
515 make_eh_edges (last);
517 /* Some calls are known not to return. */
518 fallthru = !(gimple_call_flags (last) & ECF_NORETURN);
522 /* A GIMPLE_ASSIGN may throw internally and thus be considered
524 if (is_ctrl_altering_stmt (last))
526 make_eh_edges (last);
531 case GIMPLE_OMP_PARALLEL:
532 case GIMPLE_OMP_TASK:
534 case GIMPLE_OMP_SINGLE:
535 case GIMPLE_OMP_MASTER:
536 case GIMPLE_OMP_ORDERED:
537 case GIMPLE_OMP_CRITICAL:
538 case GIMPLE_OMP_SECTION:
539 cur_region = new_omp_region (bb, code, cur_region);
543 case GIMPLE_OMP_SECTIONS:
544 cur_region = new_omp_region (bb, code, cur_region);
548 case GIMPLE_OMP_SECTIONS_SWITCH:
553 case GIMPLE_OMP_ATOMIC_LOAD:
554 case GIMPLE_OMP_ATOMIC_STORE:
559 case GIMPLE_OMP_RETURN:
560 /* In the case of a GIMPLE_OMP_SECTION, the edge will go
561 somewhere other than the next block. This will be
563 cur_region->exit = bb;
564 fallthru = cur_region->type != GIMPLE_OMP_SECTION;
565 cur_region = cur_region->outer;
568 case GIMPLE_OMP_CONTINUE:
569 cur_region->cont = bb;
570 switch (cur_region->type)
573 /* Mark all GIMPLE_OMP_FOR and GIMPLE_OMP_CONTINUE
574 succs edges as abnormal to prevent splitting
576 single_succ_edge (cur_region->entry)->flags |= EDGE_ABNORMAL;
577 /* Make the loopback edge. */
578 make_edge (bb, single_succ (cur_region->entry),
581 /* Create an edge from GIMPLE_OMP_FOR to exit, which
582 corresponds to the case that the body of the loop
583 is not executed at all. */
584 make_edge (cur_region->entry, bb->next_bb, EDGE_ABNORMAL);
585 make_edge (bb, bb->next_bb, EDGE_FALLTHRU | EDGE_ABNORMAL);
589 case GIMPLE_OMP_SECTIONS:
590 /* Wire up the edges into and out of the nested sections. */
592 basic_block switch_bb = single_succ (cur_region->entry);
594 struct omp_region *i;
595 for (i = cur_region->inner; i ; i = i->next)
597 gcc_assert (i->type == GIMPLE_OMP_SECTION);
598 make_edge (switch_bb, i->entry, 0);
599 make_edge (i->exit, bb, EDGE_FALLTHRU);
602 /* Make the loopback edge to the block with
603 GIMPLE_OMP_SECTIONS_SWITCH. */
604 make_edge (bb, switch_bb, 0);
606 /* Make the edge from the switch to exit. */
607 make_edge (switch_bb, bb->next_bb, 0);
618 gcc_assert (!stmt_ends_bb_p (last));
626 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
632 /* Fold COND_EXPR_COND of each COND_EXPR. */
633 fold_cond_expr_cond ();
637 /* Create the edges for a GIMPLE_COND starting at block BB. */
640 make_cond_expr_edges (basic_block bb)
642 gimple entry = last_stmt (bb);
643 gimple then_stmt, else_stmt;
644 basic_block then_bb, else_bb;
645 tree then_label, else_label;
649 gcc_assert (gimple_code (entry) == GIMPLE_COND);
651 /* Entry basic blocks for each component. */
652 then_label = gimple_cond_true_label (entry);
653 else_label = gimple_cond_false_label (entry);
654 then_bb = label_to_block (then_label);
655 else_bb = label_to_block (else_label);
656 then_stmt = first_stmt (then_bb);
657 else_stmt = first_stmt (else_bb);
659 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
660 e->goto_locus = gimple_location (then_stmt);
661 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
663 e->goto_locus = gimple_location (else_stmt);
665 /* We do not need the labels anymore. */
666 gimple_cond_set_true_label (entry, NULL_TREE);
667 gimple_cond_set_false_label (entry, NULL_TREE);
671 /* Called for each element in the hash table (P) as we delete the
672 edge to cases hash table.
674 Clear all the TREE_CHAINs to prevent problems with copying of
675 SWITCH_EXPRs and structure sharing rules, then free the hash table
679 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED, void **value,
680 void *data ATTRIBUTE_UNUSED)
684 for (t = (tree) *value; t; t = next)
686 next = TREE_CHAIN (t);
687 TREE_CHAIN (t) = NULL;
694 /* Start recording information mapping edges to case labels. */
697 start_recording_case_labels (void)
699 gcc_assert (edge_to_cases == NULL);
700 edge_to_cases = pointer_map_create ();
703 /* Return nonzero if we are recording information for case labels. */
706 recording_case_labels_p (void)
708 return (edge_to_cases != NULL);
711 /* Stop recording information mapping edges to case labels and
712 remove any information we have recorded. */
714 end_recording_case_labels (void)
716 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
717 pointer_map_destroy (edge_to_cases);
718 edge_to_cases = NULL;
721 /* If we are inside a {start,end}_recording_cases block, then return
722 a chain of CASE_LABEL_EXPRs from T which reference E.
724 Otherwise return NULL. */
727 get_cases_for_edge (edge e, gimple t)
732 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
733 chains available. Return NULL so the caller can detect this case. */
734 if (!recording_case_labels_p ())
737 slot = pointer_map_contains (edge_to_cases, e);
741 /* If we did not find E in the hash table, then this must be the first
742 time we have been queried for information about E & T. Add all the
743 elements from T to the hash table then perform the query again. */
745 n = gimple_switch_num_labels (t);
746 for (i = 0; i < n; i++)
748 tree elt = gimple_switch_label (t, i);
749 tree lab = CASE_LABEL (elt);
750 basic_block label_bb = label_to_block (lab);
751 edge this_edge = find_edge (e->src, label_bb);
753 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
755 slot = pointer_map_insert (edge_to_cases, this_edge);
756 TREE_CHAIN (elt) = (tree) *slot;
760 return (tree) *pointer_map_contains (edge_to_cases, e);
763 /* Create the edges for a GIMPLE_SWITCH starting at block BB. */
766 make_gimple_switch_edges (basic_block bb)
768 gimple entry = last_stmt (bb);
771 n = gimple_switch_num_labels (entry);
773 for (i = 0; i < n; ++i)
775 tree lab = CASE_LABEL (gimple_switch_label (entry, i));
776 basic_block label_bb = label_to_block (lab);
777 make_edge (bb, label_bb, 0);
782 /* Return the basic block holding label DEST. */
785 label_to_block_fn (struct function *ifun, tree dest)
787 int uid = LABEL_DECL_UID (dest);
789 /* We would die hard when faced by an undefined label. Emit a label to
790 the very first basic block. This will hopefully make even the dataflow
791 and undefined variable warnings quite right. */
792 if ((errorcount || sorrycount) && uid < 0)
794 gimple_stmt_iterator gsi = gsi_start_bb (BASIC_BLOCK (NUM_FIXED_BLOCKS));
797 stmt = gimple_build_label (dest);
798 gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
799 uid = LABEL_DECL_UID (dest);
801 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
802 <= (unsigned int) uid)
804 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
807 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
808 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
811 make_abnormal_goto_edges (basic_block bb, bool for_call)
813 basic_block target_bb;
814 gimple_stmt_iterator gsi;
816 FOR_EACH_BB (target_bb)
817 for (gsi = gsi_start_bb (target_bb); !gsi_end_p (gsi); gsi_next (&gsi))
819 gimple label_stmt = gsi_stmt (gsi);
822 if (gimple_code (label_stmt) != GIMPLE_LABEL)
825 target = gimple_label_label (label_stmt);
827 /* Make an edge to every label block that has been marked as a
828 potential target for a computed goto or a non-local goto. */
829 if ((FORCED_LABEL (target) && !for_call)
830 || (DECL_NONLOCAL (target) && for_call))
832 make_edge (bb, target_bb, EDGE_ABNORMAL);
838 /* Create edges for a goto statement at block BB. */
841 make_goto_expr_edges (basic_block bb)
843 gimple_stmt_iterator last = gsi_last_bb (bb);
844 gimple goto_t = gsi_stmt (last);
846 /* A simple GOTO creates normal edges. */
847 if (simple_goto_p (goto_t))
849 tree dest = gimple_goto_dest (goto_t);
850 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
851 e->goto_locus = gimple_location (goto_t);
852 gsi_remove (&last, true);
856 /* A computed GOTO creates abnormal edges. */
857 make_abnormal_goto_edges (bb, false);
861 /*---------------------------------------------------------------------------
863 ---------------------------------------------------------------------------*/
865 /* Cleanup useless labels in basic blocks. This is something we wish
866 to do early because it allows us to group case labels before creating
867 the edges for the CFG, and it speeds up block statement iterators in
869 We rerun this pass after CFG is created, to get rid of the labels that
870 are no longer referenced. After then we do not run it any more, since
871 (almost) no new labels should be created. */
873 /* A map from basic block index to the leading label of that block. */
874 static struct label_record
879 /* True if the label is referenced from somewhere. */
883 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
885 update_eh_label (struct eh_region *region)
887 tree old_label = get_eh_region_tree_label (region);
891 basic_block bb = label_to_block (old_label);
893 /* ??? After optimizing, there may be EH regions with labels
894 that have already been removed from the function body, so
895 there is no basic block for them. */
899 new_label = label_for_bb[bb->index].label;
900 label_for_bb[bb->index].used = true;
901 set_eh_region_tree_label (region, new_label);
906 /* Given LABEL return the first label in the same basic block. */
909 main_block_label (tree label)
911 basic_block bb = label_to_block (label);
912 tree main_label = label_for_bb[bb->index].label;
914 /* label_to_block possibly inserted undefined label into the chain. */
917 label_for_bb[bb->index].label = label;
921 label_for_bb[bb->index].used = true;
925 /* Cleanup redundant labels. This is a three-step process:
926 1) Find the leading label for each block.
927 2) Redirect all references to labels to the leading labels.
928 3) Cleanup all useless labels. */
931 cleanup_dead_labels (void)
934 label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
936 /* Find a suitable label for each block. We use the first user-defined
937 label if there is one, or otherwise just the first label we see. */
940 gimple_stmt_iterator i;
942 for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
945 gimple stmt = gsi_stmt (i);
947 if (gimple_code (stmt) != GIMPLE_LABEL)
950 label = gimple_label_label (stmt);
952 /* If we have not yet seen a label for the current block,
953 remember this one and see if there are more labels. */
954 if (!label_for_bb[bb->index].label)
956 label_for_bb[bb->index].label = label;
960 /* If we did see a label for the current block already, but it
961 is an artificially created label, replace it if the current
962 label is a user defined label. */
963 if (!DECL_ARTIFICIAL (label)
964 && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
966 label_for_bb[bb->index].label = label;
972 /* Now redirect all jumps/branches to the selected label.
973 First do so for each block ending in a control statement. */
976 gimple stmt = last_stmt (bb);
980 switch (gimple_code (stmt))
984 tree true_label = gimple_cond_true_label (stmt);
985 tree false_label = gimple_cond_false_label (stmt);
988 gimple_cond_set_true_label (stmt, main_block_label (true_label));
990 gimple_cond_set_false_label (stmt, main_block_label (false_label));
996 size_t i, n = gimple_switch_num_labels (stmt);
998 /* Replace all destination labels. */
999 for (i = 0; i < n; ++i)
1001 tree case_label = gimple_switch_label (stmt, i);
1002 tree label = main_block_label (CASE_LABEL (case_label));
1003 CASE_LABEL (case_label) = label;
1008 /* We have to handle gotos until they're removed, and we don't
1009 remove them until after we've created the CFG edges. */
1011 if (!computed_goto_p (stmt))
1013 tree new_dest = main_block_label (gimple_goto_dest (stmt));
1014 gimple_goto_set_dest (stmt, new_dest);
1023 for_each_eh_region (update_eh_label);
1025 /* Finally, purge dead labels. All user-defined labels and labels that
1026 can be the target of non-local gotos and labels which have their
1027 address taken are preserved. */
1030 gimple_stmt_iterator i;
1031 tree label_for_this_bb = label_for_bb[bb->index].label;
1033 if (!label_for_this_bb)
1036 /* If the main label of the block is unused, we may still remove it. */
1037 if (!label_for_bb[bb->index].used)
1038 label_for_this_bb = NULL;
1040 for (i = gsi_start_bb (bb); !gsi_end_p (i); )
1043 gimple stmt = gsi_stmt (i);
1045 if (gimple_code (stmt) != GIMPLE_LABEL)
1048 label = gimple_label_label (stmt);
1050 if (label == label_for_this_bb
1051 || !DECL_ARTIFICIAL (label)
1052 || DECL_NONLOCAL (label)
1053 || FORCED_LABEL (label))
1056 gsi_remove (&i, true);
1060 free (label_for_bb);
1063 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1064 and scan the sorted vector of cases. Combine the ones jumping to the
1066 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1069 group_case_labels (void)
1075 gimple stmt = last_stmt (bb);
1076 if (stmt && gimple_code (stmt) == GIMPLE_SWITCH)
1078 int old_size = gimple_switch_num_labels (stmt);
1079 int i, j, new_size = old_size;
1080 tree default_case = NULL_TREE;
1081 tree default_label = NULL_TREE;
1084 /* The default label is always the first case in a switch
1085 statement after gimplification if it was not optimized
1087 if (!CASE_LOW (gimple_switch_default_label (stmt))
1088 && !CASE_HIGH (gimple_switch_default_label (stmt)))
1090 default_case = gimple_switch_default_label (stmt);
1091 default_label = CASE_LABEL (default_case);
1095 has_default = false;
1097 /* Look for possible opportunities to merge cases. */
1102 while (i < old_size)
1104 tree base_case, base_label, base_high;
1105 base_case = gimple_switch_label (stmt, i);
1107 gcc_assert (base_case);
1108 base_label = CASE_LABEL (base_case);
1110 /* Discard cases that have the same destination as the
1112 if (base_label == default_label)
1114 gimple_switch_set_label (stmt, i, NULL_TREE);
1120 base_high = CASE_HIGH (base_case)
1121 ? CASE_HIGH (base_case)
1122 : CASE_LOW (base_case);
1125 /* Try to merge case labels. Break out when we reach the end
1126 of the label vector or when we cannot merge the next case
1127 label with the current one. */
1128 while (i < old_size)
1130 tree merge_case = gimple_switch_label (stmt, i);
1131 tree merge_label = CASE_LABEL (merge_case);
1132 tree t = int_const_binop (PLUS_EXPR, base_high,
1133 integer_one_node, 1);
1135 /* Merge the cases if they jump to the same place,
1136 and their ranges are consecutive. */
1137 if (merge_label == base_label
1138 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1140 base_high = CASE_HIGH (merge_case) ?
1141 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1142 CASE_HIGH (base_case) = base_high;
1143 gimple_switch_set_label (stmt, i, NULL_TREE);
1152 /* Compress the case labels in the label vector, and adjust the
1153 length of the vector. */
1154 for (i = 0, j = 0; i < new_size; i++)
1156 while (! gimple_switch_label (stmt, j))
1158 gimple_switch_set_label (stmt, i,
1159 gimple_switch_label (stmt, j++));
1162 gcc_assert (new_size <= old_size);
1163 gimple_switch_set_num_labels (stmt, new_size);
1168 /* Checks whether we can merge block B into block A. */
1171 gimple_can_merge_blocks_p (basic_block a, basic_block b)
1174 gimple_stmt_iterator gsi;
1177 if (!single_succ_p (a))
1180 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1183 if (single_succ (a) != b)
1186 if (!single_pred_p (b))
1189 if (b == EXIT_BLOCK_PTR)
1192 /* If A ends by a statement causing exceptions or something similar, we
1193 cannot merge the blocks. */
1194 stmt = last_stmt (a);
1195 if (stmt && stmt_ends_bb_p (stmt))
1198 /* Do not allow a block with only a non-local label to be merged. */
1200 && gimple_code (stmt) == GIMPLE_LABEL
1201 && DECL_NONLOCAL (gimple_label_label (stmt)))
1204 /* It must be possible to eliminate all phi nodes in B. If ssa form
1205 is not up-to-date, we cannot eliminate any phis; however, if only
1206 some symbols as whole are marked for renaming, this is not a problem,
1207 as phi nodes for those symbols are irrelevant in updating anyway. */
1208 phis = phi_nodes (b);
1209 if (!gimple_seq_empty_p (phis))
1211 gimple_stmt_iterator i;
1213 if (name_mappings_registered_p ())
1216 for (i = gsi_start (phis); !gsi_end_p (i); gsi_next (&i))
1218 gimple phi = gsi_stmt (i);
1220 if (!is_gimple_reg (gimple_phi_result (phi))
1221 && !may_propagate_copy (gimple_phi_result (phi),
1222 gimple_phi_arg_def (phi, 0)))
1227 /* Do not remove user labels. */
1228 for (gsi = gsi_start_bb (b); !gsi_end_p (gsi); gsi_next (&gsi))
1230 stmt = gsi_stmt (gsi);
1231 if (gimple_code (stmt) != GIMPLE_LABEL)
1233 if (!DECL_ARTIFICIAL (gimple_label_label (stmt)))
1237 /* Protect the loop latches. */
1239 && b->loop_father->latch == b)
1245 /* Replaces all uses of NAME by VAL. */
1248 replace_uses_by (tree name, tree val)
1250 imm_use_iterator imm_iter;
1255 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1257 if (gimple_code (stmt) != GIMPLE_PHI)
1258 push_stmt_changes (&stmt);
1260 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1262 replace_exp (use, val);
1264 if (gimple_code (stmt) == GIMPLE_PHI)
1266 e = gimple_phi_arg_edge (stmt, PHI_ARG_INDEX_FROM_USE (use));
1267 if (e->flags & EDGE_ABNORMAL)
1269 /* This can only occur for virtual operands, since
1270 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1271 would prevent replacement. */
1272 gcc_assert (!is_gimple_reg (name));
1273 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1278 if (gimple_code (stmt) != GIMPLE_PHI)
1282 fold_stmt_inplace (stmt);
1283 if (cfgcleanup_altered_bbs)
1284 bitmap_set_bit (cfgcleanup_altered_bbs, gimple_bb (stmt)->index);
1286 /* FIXME. This should go in pop_stmt_changes. */
1287 for (i = 0; i < gimple_num_ops (stmt); i++)
1289 tree op = gimple_op (stmt, i);
1290 /* Operands may be empty here. For example, the labels
1291 of a GIMPLE_COND are nulled out following the creation
1292 of the corresponding CFG edges. */
1293 if (op && TREE_CODE (op) == ADDR_EXPR)
1294 recompute_tree_invariant_for_addr_expr (op);
1297 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1299 pop_stmt_changes (&stmt);
1303 gcc_assert (has_zero_uses (name));
1305 /* Also update the trees stored in loop structures. */
1311 FOR_EACH_LOOP (li, loop, 0)
1313 substitute_in_loop_info (loop, name, val);
1318 /* Merge block B into block A. */
1321 gimple_merge_blocks (basic_block a, basic_block b)
1323 gimple_stmt_iterator last, gsi, psi;
1324 gimple_seq phis = phi_nodes (b);
1327 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1329 /* Remove all single-valued PHI nodes from block B of the form
1330 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1331 gsi = gsi_last_bb (a);
1332 for (psi = gsi_start (phis); !gsi_end_p (psi); )
1334 gimple phi = gsi_stmt (psi);
1335 tree def = gimple_phi_result (phi), use = gimple_phi_arg_def (phi, 0);
1337 bool may_replace_uses = !is_gimple_reg (def)
1338 || may_propagate_copy (def, use);
1340 /* In case we maintain loop closed ssa form, do not propagate arguments
1341 of loop exit phi nodes. */
1343 && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1344 && is_gimple_reg (def)
1345 && TREE_CODE (use) == SSA_NAME
1346 && a->loop_father != b->loop_father)
1347 may_replace_uses = false;
1349 if (!may_replace_uses)
1351 gcc_assert (is_gimple_reg (def));
1353 /* Note that just emitting the copies is fine -- there is no problem
1354 with ordering of phi nodes. This is because A is the single
1355 predecessor of B, therefore results of the phi nodes cannot
1356 appear as arguments of the phi nodes. */
1357 copy = gimple_build_assign (def, use);
1358 gsi_insert_after (&gsi, copy, GSI_NEW_STMT);
1359 remove_phi_node (&psi, false);
1363 /* If we deal with a PHI for virtual operands, we can simply
1364 propagate these without fussing with folding or updating
1366 if (!is_gimple_reg (def))
1368 imm_use_iterator iter;
1369 use_operand_p use_p;
1372 FOR_EACH_IMM_USE_STMT (stmt, iter, def)
1373 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1374 SET_USE (use_p, use);
1377 replace_uses_by (def, use);
1379 remove_phi_node (&psi, true);
1383 /* Ensure that B follows A. */
1384 move_block_after (b, a);
1386 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1387 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1389 /* Remove labels from B and set gimple_bb to A for other statements. */
1390 for (gsi = gsi_start_bb (b); !gsi_end_p (gsi);)
1392 if (gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL)
1394 gimple label = gsi_stmt (gsi);
1396 gsi_remove (&gsi, false);
1398 /* Now that we can thread computed gotos, we might have
1399 a situation where we have a forced label in block B
1400 However, the label at the start of block B might still be
1401 used in other ways (think about the runtime checking for
1402 Fortran assigned gotos). So we can not just delete the
1403 label. Instead we move the label to the start of block A. */
1404 if (FORCED_LABEL (gimple_label_label (label)))
1406 gimple_stmt_iterator dest_gsi = gsi_start_bb (a);
1407 gsi_insert_before (&dest_gsi, label, GSI_NEW_STMT);
1412 gimple_set_bb (gsi_stmt (gsi), a);
1417 /* Merge the sequences. */
1418 last = gsi_last_bb (a);
1419 gsi_insert_seq_after (&last, bb_seq (b), GSI_NEW_STMT);
1420 set_bb_seq (b, NULL);
1422 if (cfgcleanup_altered_bbs)
1423 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1427 /* Return the one of two successors of BB that is not reachable by a
1428 reached by a complex edge, if there is one. Else, return BB. We use
1429 this in optimizations that use post-dominators for their heuristics,
1430 to catch the cases in C++ where function calls are involved. */
1433 single_noncomplex_succ (basic_block bb)
1436 if (EDGE_COUNT (bb->succs) != 2)
1439 e0 = EDGE_SUCC (bb, 0);
1440 e1 = EDGE_SUCC (bb, 1);
1441 if (e0->flags & EDGE_COMPLEX)
1443 if (e1->flags & EDGE_COMPLEX)
1450 /* Walk the function tree removing unnecessary statements.
1452 * Empty statement nodes are removed
1454 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1456 * Unnecessary COND_EXPRs are removed
1458 * Some unnecessary BIND_EXPRs are removed
1460 * GOTO_EXPRs immediately preceding destination are removed.
1462 Clearly more work could be done. The trick is doing the analysis
1463 and removal fast enough to be a net improvement in compile times.
1465 Note that when we remove a control structure such as a COND_EXPR
1466 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1467 to ensure we eliminate all the useless code. */
1476 gimple_stmt_iterator last_goto_gsi;
1480 static void remove_useless_stmts_1 (gimple_stmt_iterator *gsi, struct rus_data *);
1482 /* Given a statement sequence, find the first executable statement with
1483 location information, and warn that it is unreachable. When searching,
1484 descend into containers in execution order. */
1487 remove_useless_stmts_warn_notreached (gimple_seq stmts)
1489 gimple_stmt_iterator gsi;
1491 for (gsi = gsi_start (stmts); !gsi_end_p (gsi); gsi_next (&gsi))
1493 gimple stmt = gsi_stmt (gsi);
1495 if (gimple_has_location (stmt))
1497 location_t loc = gimple_location (stmt);
1498 if (LOCATION_LINE (loc) > 0)
1500 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
1505 switch (gimple_code (stmt))
1507 /* Unfortunately, we need the CFG now to detect unreachable
1508 branches in a conditional, so conditionals are not handled here. */
1511 if (remove_useless_stmts_warn_notreached (gimple_try_eval (stmt)))
1513 if (remove_useless_stmts_warn_notreached (gimple_try_cleanup (stmt)))
1518 return remove_useless_stmts_warn_notreached (gimple_catch_handler (stmt));
1520 case GIMPLE_EH_FILTER:
1521 return remove_useless_stmts_warn_notreached (gimple_eh_filter_failure (stmt));
1524 return remove_useless_stmts_warn_notreached (gimple_bind_body (stmt));
1534 /* Helper for remove_useless_stmts_1. Handle GIMPLE_COND statements. */
1537 remove_useless_stmts_cond (gimple_stmt_iterator *gsi, struct rus_data *data)
1539 gimple stmt = gsi_stmt (*gsi);
1541 /* The folded result must still be a conditional statement. */
1542 fold_stmt_inplace (stmt);
1544 data->may_branch = true;
1546 /* Replace trivial conditionals with gotos. */
1547 if (gimple_cond_true_p (stmt))
1549 /* Goto THEN label. */
1550 tree then_label = gimple_cond_true_label (stmt);
1552 gsi_replace (gsi, gimple_build_goto (then_label), false);
1553 data->last_goto_gsi = *gsi;
1554 data->last_was_goto = true;
1555 data->repeat = true;
1557 else if (gimple_cond_false_p (stmt))
1559 /* Goto ELSE label. */
1560 tree else_label = gimple_cond_false_label (stmt);
1562 gsi_replace (gsi, gimple_build_goto (else_label), false);
1563 data->last_goto_gsi = *gsi;
1564 data->last_was_goto = true;
1565 data->repeat = true;
1569 tree then_label = gimple_cond_true_label (stmt);
1570 tree else_label = gimple_cond_false_label (stmt);
1572 if (then_label == else_label)
1574 /* Goto common destination. */
1575 gsi_replace (gsi, gimple_build_goto (then_label), false);
1576 data->last_goto_gsi = *gsi;
1577 data->last_was_goto = true;
1578 data->repeat = true;
1584 data->last_was_goto = false;
1587 /* Helper for remove_useless_stmts_1.
1588 Handle the try-finally case for GIMPLE_TRY statements. */
1591 remove_useless_stmts_tf (gimple_stmt_iterator *gsi, struct rus_data *data)
1593 bool save_may_branch, save_may_throw;
1594 bool this_may_branch, this_may_throw;
1596 gimple_seq eval_seq, cleanup_seq;
1597 gimple_stmt_iterator eval_gsi, cleanup_gsi;
1599 gimple stmt = gsi_stmt (*gsi);
1601 /* Collect may_branch and may_throw information for the body only. */
1602 save_may_branch = data->may_branch;
1603 save_may_throw = data->may_throw;
1604 data->may_branch = false;
1605 data->may_throw = false;
1606 data->last_was_goto = false;
1608 eval_seq = gimple_try_eval (stmt);
1609 eval_gsi = gsi_start (eval_seq);
1610 remove_useless_stmts_1 (&eval_gsi, data);
1612 this_may_branch = data->may_branch;
1613 this_may_throw = data->may_throw;
1614 data->may_branch |= save_may_branch;
1615 data->may_throw |= save_may_throw;
1616 data->last_was_goto = false;
1618 cleanup_seq = gimple_try_cleanup (stmt);
1619 cleanup_gsi = gsi_start (cleanup_seq);
1620 remove_useless_stmts_1 (&cleanup_gsi, data);
1622 /* If the body is empty, then we can emit the FINALLY block without
1623 the enclosing TRY_FINALLY_EXPR. */
1624 if (gimple_seq_empty_p (eval_seq))
1626 gsi_insert_seq_before (gsi, cleanup_seq, GSI_SAME_STMT);
1627 gsi_remove (gsi, false);
1628 data->repeat = true;
1631 /* If the handler is empty, then we can emit the TRY block without
1632 the enclosing TRY_FINALLY_EXPR. */
1633 else if (gimple_seq_empty_p (cleanup_seq))
1635 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1636 gsi_remove (gsi, false);
1637 data->repeat = true;
1640 /* If the body neither throws, nor branches, then we can safely
1641 string the TRY and FINALLY blocks together. */
1642 else if (!this_may_branch && !this_may_throw)
1644 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1645 gsi_insert_seq_before (gsi, cleanup_seq, GSI_SAME_STMT);
1646 gsi_remove (gsi, false);
1647 data->repeat = true;
1653 /* Helper for remove_useless_stmts_1.
1654 Handle the try-catch case for GIMPLE_TRY statements. */
1657 remove_useless_stmts_tc (gimple_stmt_iterator *gsi, struct rus_data *data)
1659 bool save_may_throw, this_may_throw;
1661 gimple_seq eval_seq, cleanup_seq, handler_seq, failure_seq;
1662 gimple_stmt_iterator eval_gsi, cleanup_gsi, handler_gsi, failure_gsi;
1664 gimple stmt = gsi_stmt (*gsi);
1666 /* Collect may_throw information for the body only. */
1667 save_may_throw = data->may_throw;
1668 data->may_throw = false;
1669 data->last_was_goto = false;
1671 eval_seq = gimple_try_eval (stmt);
1672 eval_gsi = gsi_start (eval_seq);
1673 remove_useless_stmts_1 (&eval_gsi, data);
1675 this_may_throw = data->may_throw;
1676 data->may_throw = save_may_throw;
1678 cleanup_seq = gimple_try_cleanup (stmt);
1680 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1681 if (!this_may_throw)
1683 if (warn_notreached)
1685 remove_useless_stmts_warn_notreached (cleanup_seq);
1687 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1688 gsi_remove (gsi, false);
1689 data->repeat = true;
1693 /* Process the catch clause specially. We may be able to tell that
1694 no exceptions propagate past this point. */
1696 this_may_throw = true;
1697 cleanup_gsi = gsi_start (cleanup_seq);
1698 stmt = gsi_stmt (cleanup_gsi);
1699 data->last_was_goto = false;
1701 switch (gimple_code (stmt))
1704 /* If the first element is a catch, they all must be. */
1705 while (!gsi_end_p (cleanup_gsi))
1707 stmt = gsi_stmt (cleanup_gsi);
1708 /* If we catch all exceptions, then the body does not
1709 propagate exceptions past this point. */
1710 if (gimple_catch_types (stmt) == NULL)
1711 this_may_throw = false;
1712 data->last_was_goto = false;
1713 handler_seq = gimple_catch_handler (stmt);
1714 handler_gsi = gsi_start (handler_seq);
1715 remove_useless_stmts_1 (&handler_gsi, data);
1716 gsi_next (&cleanup_gsi);
1721 case GIMPLE_EH_FILTER:
1722 /* If the first element is an eh_filter, it should stand alone. */
1723 if (gimple_eh_filter_must_not_throw (stmt))
1724 this_may_throw = false;
1725 else if (gimple_eh_filter_types (stmt) == NULL)
1726 this_may_throw = false;
1727 failure_seq = gimple_eh_filter_failure (stmt);
1728 failure_gsi = gsi_start (failure_seq);
1729 remove_useless_stmts_1 (&failure_gsi, data);
1734 /* Otherwise this is a list of cleanup statements. */
1735 remove_useless_stmts_1 (&cleanup_gsi, data);
1737 /* If the cleanup is empty, then we can emit the TRY block without
1738 the enclosing TRY_CATCH_EXPR. */
1739 if (gimple_seq_empty_p (cleanup_seq))
1741 gsi_insert_seq_before (gsi, eval_seq, GSI_SAME_STMT);
1742 gsi_remove(gsi, false);
1743 data->repeat = true;
1750 data->may_throw |= this_may_throw;
1753 /* Helper for remove_useless_stmts_1. Handle GIMPLE_BIND statements. */
1756 remove_useless_stmts_bind (gimple_stmt_iterator *gsi, struct rus_data *data ATTRIBUTE_UNUSED)
1759 gimple_seq body_seq, fn_body_seq;
1760 gimple_stmt_iterator body_gsi;
1762 gimple stmt = gsi_stmt (*gsi);
1764 /* First remove anything underneath the BIND_EXPR. */
1766 body_seq = gimple_bind_body (stmt);
1767 body_gsi = gsi_start (body_seq);
1768 remove_useless_stmts_1 (&body_gsi, data);
1770 /* If the GIMPLE_BIND has no variables, then we can pull everything
1771 up one level and remove the GIMPLE_BIND, unless this is the toplevel
1772 GIMPLE_BIND for the current function or an inlined function.
1774 When this situation occurs we will want to apply this
1775 optimization again. */
1776 block = gimple_bind_block (stmt);
1777 fn_body_seq = gimple_body (current_function_decl);
1778 if (gimple_bind_vars (stmt) == NULL_TREE
1779 && (gimple_seq_empty_p (fn_body_seq)
1780 || stmt != gimple_seq_first_stmt (fn_body_seq))
1782 || ! BLOCK_ABSTRACT_ORIGIN (block)
1783 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1786 gsi_insert_seq_before (gsi, body_seq, GSI_SAME_STMT);
1787 gsi_remove (gsi, false);
1788 data->repeat = true;
1794 /* Helper for remove_useless_stmts_1. Handle GIMPLE_GOTO statements. */
1797 remove_useless_stmts_goto (gimple_stmt_iterator *gsi, struct rus_data *data)
1799 gimple stmt = gsi_stmt (*gsi);
1801 tree dest = gimple_goto_dest (stmt);
1803 data->may_branch = true;
1804 data->last_was_goto = false;
1806 /* Record iterator for last goto expr, so that we can delete it if unnecessary. */
1807 if (TREE_CODE (dest) == LABEL_DECL)
1809 data->last_goto_gsi = *gsi;
1810 data->last_was_goto = true;
1816 /* Helper for remove_useless_stmts_1. Handle GIMPLE_LABEL statements. */
1819 remove_useless_stmts_label (gimple_stmt_iterator *gsi, struct rus_data *data)
1821 gimple stmt = gsi_stmt (*gsi);
1823 tree label = gimple_label_label (stmt);
1825 data->has_label = true;
1827 /* We do want to jump across non-local label receiver code. */
1828 if (DECL_NONLOCAL (label))
1829 data->last_was_goto = false;
1831 else if (data->last_was_goto
1832 && gimple_goto_dest (gsi_stmt (data->last_goto_gsi)) == label)
1834 /* Replace the preceding GIMPLE_GOTO statement with
1835 a GIMPLE_NOP, which will be subsequently removed.
1836 In this way, we avoid invalidating other iterators
1837 active on the statement sequence. */
1838 gsi_replace(&data->last_goto_gsi, gimple_build_nop(), false);
1839 data->last_was_goto = false;
1840 data->repeat = true;
1843 /* ??? Add something here to delete unused labels. */
1849 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1852 notice_special_calls (gimple call)
1854 int flags = gimple_call_flags (call);
1856 if (flags & ECF_MAY_BE_ALLOCA)
1857 cfun->calls_alloca = true;
1858 if (flags & ECF_RETURNS_TWICE)
1859 cfun->calls_setjmp = true;
1863 /* Clear flags set by notice_special_calls. Used by dead code removal
1864 to update the flags. */
1867 clear_special_calls (void)
1869 cfun->calls_alloca = false;
1870 cfun->calls_setjmp = false;
1873 /* Remove useless statements from a statement sequence, and perform
1874 some preliminary simplifications. */
1877 remove_useless_stmts_1 (gimple_stmt_iterator *gsi, struct rus_data *data)
1879 while (!gsi_end_p (*gsi))
1881 gimple stmt = gsi_stmt (*gsi);
1883 switch (gimple_code (stmt))
1886 remove_useless_stmts_cond (gsi, data);
1890 remove_useless_stmts_goto (gsi, data);
1894 remove_useless_stmts_label (gsi, data);
1899 stmt = gsi_stmt (*gsi);
1900 data->last_was_goto = false;
1901 if (stmt_could_throw_p (stmt))
1902 data->may_throw = true;
1908 data->last_was_goto = false;
1914 stmt = gsi_stmt (*gsi);
1915 data->last_was_goto = false;
1916 if (is_gimple_call (stmt))
1917 notice_special_calls (stmt);
1919 /* We used to call update_gimple_call_flags here,
1920 which copied side-effects and nothrows status
1921 from the function decl to the call. In the new
1922 tuplified GIMPLE, the accessors for this information
1923 always consult the function decl, so this copying
1924 is no longer necessary. */
1925 if (stmt_could_throw_p (stmt))
1926 data->may_throw = true;
1932 data->last_was_goto = false;
1933 data->may_branch = true;
1938 remove_useless_stmts_bind (gsi, data);
1942 if (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH)
1943 remove_useless_stmts_tc (gsi, data);
1944 else if (gimple_try_kind (stmt) == GIMPLE_TRY_FINALLY)
1945 remove_useless_stmts_tf (gsi, data);
1955 gsi_remove (gsi, false);
1958 case GIMPLE_OMP_FOR:
1960 gimple_seq pre_body_seq = gimple_omp_for_pre_body (stmt);
1961 gimple_stmt_iterator pre_body_gsi = gsi_start (pre_body_seq);
1963 remove_useless_stmts_1 (&pre_body_gsi, data);
1964 data->last_was_goto = false;
1967 case GIMPLE_OMP_CRITICAL:
1968 case GIMPLE_OMP_CONTINUE:
1969 case GIMPLE_OMP_MASTER:
1970 case GIMPLE_OMP_ORDERED:
1971 case GIMPLE_OMP_SECTION:
1972 case GIMPLE_OMP_SECTIONS:
1973 case GIMPLE_OMP_SINGLE:
1975 gimple_seq body_seq = gimple_omp_body (stmt);
1976 gimple_stmt_iterator body_gsi = gsi_start (body_seq);
1978 remove_useless_stmts_1 (&body_gsi, data);
1979 data->last_was_goto = false;
1984 case GIMPLE_OMP_PARALLEL:
1985 case GIMPLE_OMP_TASK:
1987 /* Make sure the outermost GIMPLE_BIND isn't removed
1989 gimple_seq body_seq = gimple_omp_body (stmt);
1990 gimple bind = gimple_seq_first_stmt (body_seq);
1991 gimple_seq bind_seq = gimple_bind_body (bind);
1992 gimple_stmt_iterator bind_gsi = gsi_start (bind_seq);
1994 remove_useless_stmts_1 (&bind_gsi, data);
1995 data->last_was_goto = false;
2001 data->last_was_goto = false;
2008 /* Walk the function tree, removing useless statements and performing
2009 some preliminary simplifications. */
2012 remove_useless_stmts (void)
2014 struct rus_data data;
2016 clear_special_calls ();
2020 gimple_stmt_iterator gsi;
2022 gsi = gsi_start (gimple_body (current_function_decl));
2023 memset (&data, 0, sizeof (data));
2024 remove_useless_stmts_1 (&gsi, &data);
2026 while (data.repeat);
2031 struct gimple_opt_pass pass_remove_useless_stmts =
2035 "useless", /* name */
2037 remove_useless_stmts, /* execute */
2040 0, /* static_pass_number */
2042 PROP_gimple_any, /* properties_required */
2043 0, /* properties_provided */
2044 0, /* properties_destroyed */
2045 0, /* todo_flags_start */
2046 TODO_dump_func /* todo_flags_finish */
2050 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
2053 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
2055 gimple_stmt_iterator gsi;
2057 /* Since this block is no longer reachable, we can just delete all
2058 of its PHI nodes. */
2059 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
2060 remove_phi_node (&gsi, true);
2062 set_phi_nodes (bb, NULL);
2064 /* Remove edges to BB's successors. */
2065 while (EDGE_COUNT (bb->succs) > 0)
2066 remove_edge (EDGE_SUCC (bb, 0));
2070 /* Remove statements of basic block BB. */
2073 remove_bb (basic_block bb)
2075 gimple_stmt_iterator i;
2076 source_location loc = UNKNOWN_LOCATION;
2080 fprintf (dump_file, "Removing basic block %d\n", bb->index);
2081 if (dump_flags & TDF_DETAILS)
2083 dump_bb (bb, dump_file, 0);
2084 fprintf (dump_file, "\n");
2090 struct loop *loop = bb->loop_father;
2092 /* If a loop gets removed, clean up the information associated
2094 if (loop->latch == bb
2095 || loop->header == bb)
2096 free_numbers_of_iterations_estimates_loop (loop);
2099 /* Remove all the instructions in the block. */
2100 if (bb_seq (bb) != NULL)
2102 for (i = gsi_start_bb (bb); !gsi_end_p (i);)
2104 gimple stmt = gsi_stmt (i);
2105 if (gimple_code (stmt) == GIMPLE_LABEL
2106 && (FORCED_LABEL (gimple_label_label (stmt))
2107 || DECL_NONLOCAL (gimple_label_label (stmt))))
2110 gimple_stmt_iterator new_gsi;
2112 /* A non-reachable non-local label may still be referenced.
2113 But it no longer needs to carry the extra semantics of
2115 if (DECL_NONLOCAL (gimple_label_label (stmt)))
2117 DECL_NONLOCAL (gimple_label_label (stmt)) = 0;
2118 FORCED_LABEL (gimple_label_label (stmt)) = 1;
2121 new_bb = bb->prev_bb;
2122 new_gsi = gsi_start_bb (new_bb);
2123 gsi_remove (&i, false);
2124 gsi_insert_before (&new_gsi, stmt, GSI_NEW_STMT);
2128 /* Release SSA definitions if we are in SSA. Note that we
2129 may be called when not in SSA. For example,
2130 final_cleanup calls this function via
2131 cleanup_tree_cfg. */
2132 if (gimple_in_ssa_p (cfun))
2133 release_defs (stmt);
2135 gsi_remove (&i, true);
2138 /* Don't warn for removed gotos. Gotos are often removed due to
2139 jump threading, thus resulting in bogus warnings. Not great,
2140 since this way we lose warnings for gotos in the original
2141 program that are indeed unreachable. */
2142 if (gimple_code (stmt) != GIMPLE_GOTO
2143 && gimple_has_location (stmt)
2145 loc = gimple_location (stmt);
2149 /* If requested, give a warning that the first statement in the
2150 block is unreachable. We walk statements backwards in the
2151 loop above, so the last statement we process is the first statement
2153 if (loc > BUILTINS_LOCATION && LOCATION_LINE (loc) > 0)
2154 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2156 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2157 bb->il.gimple = NULL;
2161 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2162 predicate VAL, return the edge that will be taken out of the block.
2163 If VAL does not match a unique edge, NULL is returned. */
2166 find_taken_edge (basic_block bb, tree val)
2170 stmt = last_stmt (bb);
2173 gcc_assert (is_ctrl_stmt (stmt));
2178 if (!is_gimple_min_invariant (val))
2181 if (gimple_code (stmt) == GIMPLE_COND)
2182 return find_taken_edge_cond_expr (bb, val);
2184 if (gimple_code (stmt) == GIMPLE_SWITCH)
2185 return find_taken_edge_switch_expr (bb, val);
2187 if (computed_goto_p (stmt))
2189 /* Only optimize if the argument is a label, if the argument is
2190 not a label then we can not construct a proper CFG.
2192 It may be the case that we only need to allow the LABEL_REF to
2193 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2194 appear inside a LABEL_EXPR just to be safe. */
2195 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2196 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2197 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2204 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2205 statement, determine which of the outgoing edges will be taken out of the
2206 block. Return NULL if either edge may be taken. */
2209 find_taken_edge_computed_goto (basic_block bb, tree val)
2214 dest = label_to_block (val);
2217 e = find_edge (bb, dest);
2218 gcc_assert (e != NULL);
2224 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2225 statement, determine which of the two edges will be taken out of the
2226 block. Return NULL if either edge may be taken. */
2229 find_taken_edge_cond_expr (basic_block bb, tree val)
2231 edge true_edge, false_edge;
2233 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2235 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2236 return (integer_zerop (val) ? false_edge : true_edge);
2239 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2240 statement, determine which edge will be taken out of the block. Return
2241 NULL if any edge may be taken. */
2244 find_taken_edge_switch_expr (basic_block bb, tree val)
2246 basic_block dest_bb;
2251 switch_stmt = last_stmt (bb);
2252 taken_case = find_case_label_for_value (switch_stmt, val);
2253 dest_bb = label_to_block (CASE_LABEL (taken_case));
2255 e = find_edge (bb, dest_bb);
2261 /* Return the CASE_LABEL_EXPR that SWITCH_STMT will take for VAL.
2262 We can make optimal use here of the fact that the case labels are
2263 sorted: We can do a binary search for a case matching VAL. */
2266 find_case_label_for_value (gimple switch_stmt, tree val)
2268 size_t low, high, n = gimple_switch_num_labels (switch_stmt);
2269 tree default_case = gimple_switch_default_label (switch_stmt);
2271 for (low = 0, high = n; high - low > 1; )
2273 size_t i = (high + low) / 2;
2274 tree t = gimple_switch_label (switch_stmt, i);
2277 /* Cache the result of comparing CASE_LOW and val. */
2278 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2285 if (CASE_HIGH (t) == NULL)
2287 /* A singe-valued case label. */
2293 /* A case range. We can only handle integer ranges. */
2294 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2299 return default_case;
2303 /* Dump a basic block on stderr. */
2306 gimple_debug_bb (basic_block bb)
2308 gimple_dump_bb (bb, stderr, 0, TDF_VOPS|TDF_MEMSYMS);
2312 /* Dump basic block with index N on stderr. */
2315 gimple_debug_bb_n (int n)
2317 gimple_debug_bb (BASIC_BLOCK (n));
2318 return BASIC_BLOCK (n);
2322 /* Dump the CFG on stderr.
2324 FLAGS are the same used by the tree dumping functions
2325 (see TDF_* in tree-pass.h). */
2328 gimple_debug_cfg (int flags)
2330 gimple_dump_cfg (stderr, flags);
2334 /* Dump the program showing basic block boundaries on the given FILE.
2336 FLAGS are the same used by the tree dumping functions (see TDF_* in
2340 gimple_dump_cfg (FILE *file, int flags)
2342 if (flags & TDF_DETAILS)
2344 const char *funcname
2345 = lang_hooks.decl_printable_name (current_function_decl, 2);
2348 fprintf (file, ";; Function %s\n\n", funcname);
2349 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2350 n_basic_blocks, n_edges, last_basic_block);
2352 brief_dump_cfg (file);
2353 fprintf (file, "\n");
2356 if (flags & TDF_STATS)
2357 dump_cfg_stats (file);
2359 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2363 /* Dump CFG statistics on FILE. */
2366 dump_cfg_stats (FILE *file)
2368 static long max_num_merged_labels = 0;
2369 unsigned long size, total = 0;
2372 const char * const fmt_str = "%-30s%-13s%12s\n";
2373 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2374 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2375 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2376 const char *funcname
2377 = lang_hooks.decl_printable_name (current_function_decl, 2);
2380 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2382 fprintf (file, "---------------------------------------------------------\n");
2383 fprintf (file, fmt_str, "", " Number of ", "Memory");
2384 fprintf (file, fmt_str, "", " instances ", "used ");
2385 fprintf (file, "---------------------------------------------------------\n");
2387 size = n_basic_blocks * sizeof (struct basic_block_def);
2389 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2390 SCALE (size), LABEL (size));
2394 num_edges += EDGE_COUNT (bb->succs);
2395 size = num_edges * sizeof (struct edge_def);
2397 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2399 fprintf (file, "---------------------------------------------------------\n");
2400 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2402 fprintf (file, "---------------------------------------------------------\n");
2403 fprintf (file, "\n");
2405 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2406 max_num_merged_labels = cfg_stats.num_merged_labels;
2408 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2409 cfg_stats.num_merged_labels, max_num_merged_labels);
2411 fprintf (file, "\n");
2415 /* Dump CFG statistics on stderr. Keep extern so that it's always
2416 linked in the final executable. */
2419 debug_cfg_stats (void)
2421 dump_cfg_stats (stderr);
2425 /* Dump the flowgraph to a .vcg FILE. */
2428 gimple_cfg2vcg (FILE *file)
2433 const char *funcname
2434 = lang_hooks.decl_printable_name (current_function_decl, 2);
2436 /* Write the file header. */
2437 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2438 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2439 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2441 /* Write blocks and edges. */
2442 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2444 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2447 if (e->flags & EDGE_FAKE)
2448 fprintf (file, " linestyle: dotted priority: 10");
2450 fprintf (file, " linestyle: solid priority: 100");
2452 fprintf (file, " }\n");
2458 enum gimple_code head_code, end_code;
2459 const char *head_name, *end_name;
2462 gimple first = first_stmt (bb);
2463 gimple last = last_stmt (bb);
2467 head_code = gimple_code (first);
2468 head_name = gimple_code_name[head_code];
2469 head_line = get_lineno (first);
2472 head_name = "no-statement";
2476 end_code = gimple_code (last);
2477 end_name = gimple_code_name[end_code];
2478 end_line = get_lineno (last);
2481 end_name = "no-statement";
2483 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2484 bb->index, bb->index, head_name, head_line, end_name,
2487 FOR_EACH_EDGE (e, ei, bb->succs)
2489 if (e->dest == EXIT_BLOCK_PTR)
2490 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2492 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2494 if (e->flags & EDGE_FAKE)
2495 fprintf (file, " priority: 10 linestyle: dotted");
2497 fprintf (file, " priority: 100 linestyle: solid");
2499 fprintf (file, " }\n");
2502 if (bb->next_bb != EXIT_BLOCK_PTR)
2506 fputs ("}\n\n", file);
2511 /*---------------------------------------------------------------------------
2512 Miscellaneous helpers
2513 ---------------------------------------------------------------------------*/
2515 /* Return true if T represents a stmt that always transfers control. */
2518 is_ctrl_stmt (gimple t)
2520 return gimple_code (t) == GIMPLE_COND
2521 || gimple_code (t) == GIMPLE_SWITCH
2522 || gimple_code (t) == GIMPLE_GOTO
2523 || gimple_code (t) == GIMPLE_RETURN
2524 || gimple_code (t) == GIMPLE_RESX;
2528 /* Return true if T is a statement that may alter the flow of control
2529 (e.g., a call to a non-returning function). */
2532 is_ctrl_altering_stmt (gimple t)
2536 if (is_gimple_call (t))
2538 int flags = gimple_call_flags (t);
2540 /* A non-pure/const call alters flow control if the current
2541 function has nonlocal labels. */
2542 if (!(flags & (ECF_CONST | ECF_PURE))
2543 && cfun->has_nonlocal_label)
2546 /* A call also alters control flow if it does not return. */
2547 if (gimple_call_flags (t) & ECF_NORETURN)
2551 /* OpenMP directives alter control flow. */
2552 if (is_gimple_omp (t))
2555 /* If a statement can throw, it alters control flow. */
2556 return stmt_can_throw_internal (t);
2560 /* Return true if T is a simple local goto. */
2563 simple_goto_p (gimple t)
2565 return (gimple_code (t) == GIMPLE_GOTO
2566 && TREE_CODE (gimple_goto_dest (t)) == LABEL_DECL);
2570 /* Return true if T can make an abnormal transfer of control flow.
2571 Transfers of control flow associated with EH are excluded. */
2574 stmt_can_make_abnormal_goto (gimple t)
2576 if (computed_goto_p (t))
2578 if (is_gimple_call (t))
2579 return gimple_has_side_effects (t) && cfun->has_nonlocal_label;
2584 /* Return true if STMT should start a new basic block. PREV_STMT is
2585 the statement preceding STMT. It is used when STMT is a label or a
2586 case label. Labels should only start a new basic block if their
2587 previous statement wasn't a label. Otherwise, sequence of labels
2588 would generate unnecessary basic blocks that only contain a single
2592 stmt_starts_bb_p (gimple stmt, gimple prev_stmt)
2597 /* Labels start a new basic block only if the preceding statement
2598 wasn't a label of the same type. This prevents the creation of
2599 consecutive blocks that have nothing but a single label. */
2600 if (gimple_code (stmt) == GIMPLE_LABEL)
2602 /* Nonlocal and computed GOTO targets always start a new block. */
2603 if (DECL_NONLOCAL (gimple_label_label (stmt))
2604 || FORCED_LABEL (gimple_label_label (stmt)))
2607 if (prev_stmt && gimple_code (prev_stmt) == GIMPLE_LABEL)
2609 if (DECL_NONLOCAL (gimple_label_label (prev_stmt)))
2612 cfg_stats.num_merged_labels++;
2623 /* Return true if T should end a basic block. */
2626 stmt_ends_bb_p (gimple t)
2628 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2631 /* Remove block annotations and other data structures. */
2634 delete_tree_cfg_annotations (void)
2636 label_to_block_map = NULL;
2640 /* Return the first statement in basic block BB. */
2643 first_stmt (basic_block bb)
2645 gimple_stmt_iterator i = gsi_start_bb (bb);
2646 return !gsi_end_p (i) ? gsi_stmt (i) : NULL;
2649 /* Return the last statement in basic block BB. */
2652 last_stmt (basic_block bb)
2654 gimple_stmt_iterator b = gsi_last_bb (bb);
2655 return !gsi_end_p (b) ? gsi_stmt (b) : NULL;
2658 /* Return the last statement of an otherwise empty block. Return NULL
2659 if the block is totally empty, or if it contains more than one
2663 last_and_only_stmt (basic_block bb)
2665 gimple_stmt_iterator i = gsi_last_bb (bb);
2671 last = gsi_stmt (i);
2676 /* Empty statements should no longer appear in the instruction stream.
2677 Everything that might have appeared before should be deleted by
2678 remove_useless_stmts, and the optimizers should just gsi_remove
2679 instead of smashing with build_empty_stmt.
2681 Thus the only thing that should appear here in a block containing
2682 one executable statement is a label. */
2683 prev = gsi_stmt (i);
2684 if (gimple_code (prev) == GIMPLE_LABEL)
2690 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
2693 reinstall_phi_args (edge new_edge, edge old_edge)
2695 edge_var_map_vector v;
2698 gimple_stmt_iterator phis;
2700 v = redirect_edge_var_map_vector (old_edge);
2704 for (i = 0, phis = gsi_start_phis (new_edge->dest);
2705 VEC_iterate (edge_var_map, v, i, vm) && !gsi_end_p (phis);
2706 i++, gsi_next (&phis))
2708 gimple phi = gsi_stmt (phis);
2709 tree result = redirect_edge_var_map_result (vm);
2710 tree arg = redirect_edge_var_map_def (vm);
2712 gcc_assert (result == gimple_phi_result (phi));
2714 add_phi_arg (phi, arg, new_edge);
2717 redirect_edge_var_map_clear (old_edge);
2720 /* Returns the basic block after which the new basic block created
2721 by splitting edge EDGE_IN should be placed. Tries to keep the new block
2722 near its "logical" location. This is of most help to humans looking
2723 at debugging dumps. */
2726 split_edge_bb_loc (edge edge_in)
2728 basic_block dest = edge_in->dest;
2730 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
2731 return edge_in->src;
2733 return dest->prev_bb;
2736 /* Split a (typically critical) edge EDGE_IN. Return the new block.
2737 Abort on abnormal edges. */
2740 gimple_split_edge (edge edge_in)
2742 basic_block new_bb, after_bb, dest;
2745 /* Abnormal edges cannot be split. */
2746 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
2748 dest = edge_in->dest;
2750 after_bb = split_edge_bb_loc (edge_in);
2752 new_bb = create_empty_bb (after_bb);
2753 new_bb->frequency = EDGE_FREQUENCY (edge_in);
2754 new_bb->count = edge_in->count;
2755 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
2756 new_edge->probability = REG_BR_PROB_BASE;
2757 new_edge->count = edge_in->count;
2759 e = redirect_edge_and_branch (edge_in, new_bb);
2760 gcc_assert (e == edge_in);
2761 reinstall_phi_args (new_edge, e);
2766 /* Callback for walk_tree, check that all elements with address taken are
2767 properly noticed as such. The DATA is an int* that is 1 if TP was seen
2768 inside a PHI node. */
2771 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
2778 /* Check operand N for being valid GIMPLE and give error MSG if not. */
2779 #define CHECK_OP(N, MSG) \
2780 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
2781 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
2783 switch (TREE_CODE (t))
2786 if (SSA_NAME_IN_FREE_LIST (t))
2788 error ("SSA name in freelist but still referenced");
2794 x = fold (ASSERT_EXPR_COND (t));
2795 if (x == boolean_false_node)
2797 error ("ASSERT_EXPR with an always-false condition");
2803 x = TREE_OPERAND (t, 0);
2804 if (TREE_CODE (x) == BIT_FIELD_REF
2805 && is_gimple_reg (TREE_OPERAND (x, 0)))
2807 error ("GIMPLE register modified with BIT_FIELD_REF");
2815 bool old_side_effects;
2817 bool new_side_effects;
2819 gcc_assert (is_gimple_address (t));
2821 old_constant = TREE_CONSTANT (t);
2822 old_side_effects = TREE_SIDE_EFFECTS (t);
2824 recompute_tree_invariant_for_addr_expr (t);
2825 new_side_effects = TREE_SIDE_EFFECTS (t);
2826 new_constant = TREE_CONSTANT (t);
2828 if (old_constant != new_constant)
2830 error ("constant not recomputed when ADDR_EXPR changed");
2833 if (old_side_effects != new_side_effects)
2835 error ("side effects not recomputed when ADDR_EXPR changed");
2839 /* Skip any references (they will be checked when we recurse down the
2840 tree) and ensure that any variable used as a prefix is marked
2842 for (x = TREE_OPERAND (t, 0);
2843 handled_component_p (x);
2844 x = TREE_OPERAND (x, 0))
2847 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
2849 if (!TREE_ADDRESSABLE (x))
2851 error ("address taken, but ADDRESSABLE bit not set");
2859 x = COND_EXPR_COND (t);
2860 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
2862 error ("non-integral used in condition");
2865 if (!is_gimple_condexpr (x))
2867 error ("invalid conditional operand");
2872 case NON_LVALUE_EXPR:
2876 case FIX_TRUNC_EXPR:
2881 case TRUTH_NOT_EXPR:
2882 CHECK_OP (0, "invalid operand to unary operator");
2889 case ARRAY_RANGE_REF:
2891 case VIEW_CONVERT_EXPR:
2892 /* We have a nest of references. Verify that each of the operands
2893 that determine where to reference is either a constant or a variable,
2894 verify that the base is valid, and then show we've already checked
2896 while (handled_component_p (t))
2898 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
2899 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
2900 else if (TREE_CODE (t) == ARRAY_REF
2901 || TREE_CODE (t) == ARRAY_RANGE_REF)
2903 CHECK_OP (1, "invalid array index");
2904 if (TREE_OPERAND (t, 2))
2905 CHECK_OP (2, "invalid array lower bound");
2906 if (TREE_OPERAND (t, 3))
2907 CHECK_OP (3, "invalid array stride");
2909 else if (TREE_CODE (t) == BIT_FIELD_REF)
2911 if (!host_integerp (TREE_OPERAND (t, 1), 1)
2912 || !host_integerp (TREE_OPERAND (t, 2), 1))
2914 error ("invalid position or size operand to BIT_FIELD_REF");
2917 else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
2918 && (TYPE_PRECISION (TREE_TYPE (t))
2919 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2921 error ("integral result type precision does not match "
2922 "field size of BIT_FIELD_REF");
2925 if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
2926 && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
2927 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
2929 error ("mode precision of non-integral result does not "
2930 "match field size of BIT_FIELD_REF");
2935 t = TREE_OPERAND (t, 0);
2938 if (!is_gimple_min_invariant (t) && !is_gimple_lvalue (t))
2940 error ("invalid reference prefix");
2947 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
2948 POINTER_PLUS_EXPR. */
2949 if (POINTER_TYPE_P (TREE_TYPE (t)))
2951 error ("invalid operand to plus/minus, type is a pointer");
2954 CHECK_OP (0, "invalid operand to binary operator");
2955 CHECK_OP (1, "invalid operand to binary operator");
2958 case POINTER_PLUS_EXPR:
2959 /* Check to make sure the first operand is a pointer or reference type. */
2960 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
2962 error ("invalid operand to pointer plus, first operand is not a pointer");
2965 /* Check to make sure the second operand is an integer with type of
2967 if (!useless_type_conversion_p (sizetype,
2968 TREE_TYPE (TREE_OPERAND (t, 1))))
2970 error ("invalid operand to pointer plus, second operand is not an "
2971 "integer with type of sizetype.");
2981 case UNORDERED_EXPR:
2990 case TRUNC_DIV_EXPR:
2992 case FLOOR_DIV_EXPR:
2993 case ROUND_DIV_EXPR:
2994 case TRUNC_MOD_EXPR:
2996 case FLOOR_MOD_EXPR:
2997 case ROUND_MOD_EXPR:
2999 case EXACT_DIV_EXPR:
3009 CHECK_OP (0, "invalid operand to binary operator");
3010 CHECK_OP (1, "invalid operand to binary operator");
3014 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3027 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3028 Returns true if there is an error, otherwise false. */
3031 verify_types_in_gimple_min_lval (tree expr)
3035 if (is_gimple_id (expr))
3038 if (TREE_CODE (expr) != INDIRECT_REF
3039 && TREE_CODE (expr) != ALIGN_INDIRECT_REF
3040 && TREE_CODE (expr) != MISALIGNED_INDIRECT_REF)
3042 error ("invalid expression for min lvalue");
3046 op = TREE_OPERAND (expr, 0);
3047 if (!is_gimple_val (op))
3049 error ("invalid operand in indirect reference");
3050 debug_generic_stmt (op);
3053 if (!useless_type_conversion_p (TREE_TYPE (expr),
3054 TREE_TYPE (TREE_TYPE (op))))
3056 error ("type mismatch in indirect reference");
3057 debug_generic_stmt (TREE_TYPE (expr));
3058 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3065 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3066 if there is an error, otherwise false. */
3069 verify_types_in_gimple_reference (tree expr)
3071 while (handled_component_p (expr))
3073 tree op = TREE_OPERAND (expr, 0);
3075 if (TREE_CODE (expr) == ARRAY_REF
3076 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3078 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3079 || (TREE_OPERAND (expr, 2)
3080 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3081 || (TREE_OPERAND (expr, 3)
3082 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3084 error ("invalid operands to array reference");
3085 debug_generic_stmt (expr);
3090 /* Verify if the reference array element types are compatible. */
3091 if (TREE_CODE (expr) == ARRAY_REF
3092 && !useless_type_conversion_p (TREE_TYPE (expr),
3093 TREE_TYPE (TREE_TYPE (op))))
3095 error ("type mismatch in array reference");
3096 debug_generic_stmt (TREE_TYPE (expr));
3097 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3100 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3101 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3102 TREE_TYPE (TREE_TYPE (op))))
3104 error ("type mismatch in array range reference");
3105 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3106 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3110 if ((TREE_CODE (expr) == REALPART_EXPR
3111 || TREE_CODE (expr) == IMAGPART_EXPR)
3112 && !useless_type_conversion_p (TREE_TYPE (expr),
3113 TREE_TYPE (TREE_TYPE (op))))
3115 error ("type mismatch in real/imagpart reference");
3116 debug_generic_stmt (TREE_TYPE (expr));
3117 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3121 if (TREE_CODE (expr) == COMPONENT_REF
3122 && !useless_type_conversion_p (TREE_TYPE (expr),
3123 TREE_TYPE (TREE_OPERAND (expr, 1))))
3125 error ("type mismatch in component reference");
3126 debug_generic_stmt (TREE_TYPE (expr));
3127 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3131 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3132 is nothing to verify. Gross mismatches at most invoke
3133 undefined behavior. */
3138 return verify_types_in_gimple_min_lval (expr);
3141 /* Returns true if there is one pointer type in TYPE_POINTER_TO (SRC_OBJ)
3142 list of pointer-to types that is trivially convertible to DEST. */
3145 one_pointer_to_useless_type_conversion_p (tree dest, tree src_obj)
3149 if (!TYPE_POINTER_TO (src_obj))
3152 for (src = TYPE_POINTER_TO (src_obj); src; src = TYPE_NEXT_PTR_TO (src))
3153 if (useless_type_conversion_p (dest, src))
3159 /* Return true if TYPE1 is a fixed-point type and if conversions to and
3160 from TYPE2 can be handled by FIXED_CONVERT_EXPR. */
3163 valid_fixed_convert_types_p (tree type1, tree type2)
3165 return (FIXED_POINT_TYPE_P (type1)
3166 && (INTEGRAL_TYPE_P (type2)
3167 || SCALAR_FLOAT_TYPE_P (type2)
3168 || FIXED_POINT_TYPE_P (type2)));
3171 /* Verify that OP is a valid GIMPLE operand. Return true if there is
3172 an error, false otherwise. */
3175 verify_types_in_gimple_op (tree op)
3177 if (!is_gimple_val (op) && !is_gimple_lvalue (op))
3179 error ("Invalid GIMPLE operand");
3180 debug_generic_expr (op);
3188 /* Verify the contents of a GIMPLE_CALL STMT. Returns true when there
3189 is a problem, otherwise false. */
3192 verify_types_in_gimple_call (gimple stmt)
3194 bool failed = false;
3198 if (gimple_call_lhs (stmt))
3199 failed |= verify_types_in_gimple_op (gimple_call_lhs (stmt));
3201 fn = gimple_call_fn (stmt);
3202 if (TREE_CODE (fn) != OBJ_TYPE_REF
3203 && verify_types_in_gimple_op (fn))
3206 if (gimple_call_chain (stmt))
3207 failed |= verify_types_in_gimple_op (gimple_call_chain (stmt));
3209 for (i = 0; i < gimple_call_num_args (stmt); i++)
3210 failed |= verify_types_in_gimple_op (gimple_call_arg (stmt,i));
3216 /* Verify the contents of a GIMPLE_COND STMT. Returns true when there
3217 is a problem, otherwise false. */
3220 verify_types_in_gimple_cond (gimple stmt)
3222 bool failed = false;
3224 failed |= verify_types_in_gimple_op (gimple_cond_lhs (stmt));
3225 failed |= verify_types_in_gimple_op (gimple_cond_rhs (stmt));
3226 failed |= verify_types_in_gimple_op (gimple_cond_true_label (stmt));
3227 failed |= verify_types_in_gimple_op (gimple_cond_false_label (stmt));
3233 /* Verify the contents of a GIMPLE_ASSIGN STMT. Returns true when there
3234 is a problem, otherwise false.
3236 Verify that the types of the LHS and the RHS operands are
3237 compatible. This verification largely depends on what kind of
3238 operation is done on the RHS of the assignment. It is not always
3239 the case that all the types of the operands must match (e.g., 'a =
3240 (unsigned long) b' or 'ptr = ptr + 1'). */
3243 verify_types_in_gimple_assign (gimple stmt)
3245 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3246 tree lhs = gimple_assign_lhs (stmt);
3247 tree rhs1 = gimple_assign_rhs1 (stmt);
3248 tree rhs2 = (gimple_num_ops (stmt) == 3) ? gimple_assign_rhs2 (stmt) : NULL;
3249 tree lhs_type = TREE_TYPE (lhs);
3250 tree rhs1_type = TREE_TYPE (rhs1);
3251 tree rhs2_type = (rhs2) ? TREE_TYPE (rhs2) : NULL;
3253 /* Special codes we cannot handle via their class. */
3258 if (!is_gimple_val (rhs1))
3260 error ("invalid operand in conversion");
3264 /* Allow conversions between integral types and pointers only if
3265 there is no sign or zero extension involved. */
3266 if (((POINTER_TYPE_P (lhs_type) && INTEGRAL_TYPE_P (rhs1_type))
3267 || (POINTER_TYPE_P (rhs1_type) && INTEGRAL_TYPE_P (lhs_type)))
3268 && (TYPE_PRECISION (lhs_type) == TYPE_PRECISION (rhs1_type)
3269 /* For targets were the precision of sizetype doesn't
3270 match that of pointers we need the following. */
3271 || lhs_type == sizetype || rhs1_type == sizetype))
3274 /* Allow conversion from integer to offset type and vice versa. */
3275 if ((TREE_CODE (lhs_type) == OFFSET_TYPE
3276 && TREE_CODE (rhs1_type) == INTEGER_TYPE)
3277 || (TREE_CODE (lhs_type) == INTEGER_TYPE
3278 && TREE_CODE (rhs1_type) == OFFSET_TYPE))
3281 /* Otherwise assert we are converting between types of the
3283 if (INTEGRAL_TYPE_P (lhs_type) != INTEGRAL_TYPE_P (rhs1_type))
3285 error ("invalid types in nop conversion");
3286 debug_generic_expr (lhs_type);
3287 debug_generic_expr (rhs1_type);
3294 case FIXED_CONVERT_EXPR:
3296 if (!is_gimple_val (rhs1))
3298 error ("invalid operand in conversion");
3302 if (!valid_fixed_convert_types_p (lhs_type, rhs1_type)
3303 && !valid_fixed_convert_types_p (rhs1_type, lhs_type))
3305 error ("invalid types in fixed-point conversion");
3306 debug_generic_expr (lhs_type);
3307 debug_generic_expr (rhs1_type);
3316 if (!is_gimple_val (rhs1))
3318 error ("invalid operand in int to float conversion");
3322 if (!INTEGRAL_TYPE_P (rhs1_type) || !SCALAR_FLOAT_TYPE_P (lhs_type))
3324 error ("invalid types in conversion to floating point");
3325 debug_generic_expr (lhs_type);
3326 debug_generic_expr (rhs1_type);
3333 case FIX_TRUNC_EXPR:
3335 if (!is_gimple_val (rhs1))
3337 error ("invalid operand in float to int conversion");
3341 if (!INTEGRAL_TYPE_P (lhs_type) || !SCALAR_FLOAT_TYPE_P (rhs1_type))
3343 error ("invalid types in conversion to integer");
3344 debug_generic_expr (lhs_type);
3345 debug_generic_expr (rhs1_type);
3354 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3356 error ("invalid operands in complex expression");
3360 if (!TREE_CODE (lhs_type) == COMPLEX_TYPE
3361 || !(TREE_CODE (rhs1_type) == INTEGER_TYPE
3362 || SCALAR_FLOAT_TYPE_P (rhs1_type))
3363 || !(TREE_CODE (rhs2_type) == INTEGER_TYPE
3364 || SCALAR_FLOAT_TYPE_P (rhs2_type)))
3366 error ("type mismatch in complex expression");
3367 debug_generic_expr (lhs_type);
3368 debug_generic_expr (rhs1_type);
3369 debug_generic_expr (rhs2_type);
3378 /* In this context we know that we are on the RHS of an
3379 assignment, so CONSTRUCTOR operands are OK. */
3380 /* FIXME: verify constructor arguments. */
3389 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3391 error ("invalid operands in shift expression");
3395 if (!TREE_CODE (rhs1_type) == INTEGER_TYPE
3396 || !useless_type_conversion_p (lhs_type, rhs1_type))
3398 error ("type mismatch in shift expression");
3399 debug_generic_expr (lhs_type);
3400 debug_generic_expr (rhs1_type);
3401 debug_generic_expr (rhs2_type);
3411 if (POINTER_TYPE_P (lhs_type)
3412 || POINTER_TYPE_P (rhs1_type)
3413 || POINTER_TYPE_P (rhs2_type))
3415 error ("invalid (pointer) operands to plus/minus");
3419 /* Continue with generic binary expression handling. */
3423 case POINTER_PLUS_EXPR:
3425 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3427 error ("invalid operands in pointer plus expression");
3430 if (!POINTER_TYPE_P (rhs1_type)
3431 || !useless_type_conversion_p (lhs_type, rhs1_type)
3432 || !useless_type_conversion_p (sizetype, rhs2_type))
3434 error ("type mismatch in pointer plus expression");
3435 debug_generic_stmt (lhs_type);
3436 debug_generic_stmt (rhs1_type);
3437 debug_generic_stmt (rhs2_type);
3446 tree op = TREE_OPERAND (rhs1, 0);
3447 if (!is_gimple_addressable (op))
3449 error ("invalid operand in unary expression");
3453 if (!one_pointer_to_useless_type_conversion_p (lhs_type, TREE_TYPE (op))
3454 /* FIXME: a longstanding wart, &a == &a[0]. */
3455 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3456 || !one_pointer_to_useless_type_conversion_p (lhs_type,
3457 TREE_TYPE (TREE_TYPE (op)))))
3459 error ("type mismatch in address expression");
3460 debug_generic_stmt (lhs_type);
3461 debug_generic_stmt (TYPE_POINTER_TO (TREE_TYPE (op)));
3465 return verify_types_in_gimple_reference (TREE_OPERAND (rhs1, 0));
3468 case TRUTH_ANDIF_EXPR:
3469 case TRUTH_ORIF_EXPR:
3472 case TRUTH_AND_EXPR:
3474 case TRUTH_XOR_EXPR:
3476 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3478 error ("invalid operands in truth expression");
3482 /* We allow any kind of integral typed argument and result. */
3483 if (!INTEGRAL_TYPE_P (rhs1_type)
3484 || !INTEGRAL_TYPE_P (rhs2_type)
3485 || !INTEGRAL_TYPE_P (lhs_type))
3487 error ("type mismatch in binary truth expression");
3488 debug_generic_expr (lhs_type);
3489 debug_generic_expr (rhs1_type);
3490 debug_generic_expr (rhs2_type);
3497 case TRUTH_NOT_EXPR:
3499 if (!is_gimple_val (rhs1))
3501 error ("invalid operand in unary not");
3505 /* For TRUTH_NOT_EXPR we can have any kind of integral
3506 typed arguments and results. */
3507 if (!INTEGRAL_TYPE_P (rhs1_type)
3508 || !INTEGRAL_TYPE_P (lhs_type))
3510 error ("type mismatch in not expression");
3511 debug_generic_expr (lhs_type);
3512 debug_generic_expr (rhs1_type);
3519 /* After gimplification we should not have any of these. */
3531 case TRY_FINALLY_EXPR:
3532 case TRY_CATCH_EXPR:
3533 case EH_FILTER_EXPR:
3534 case STATEMENT_LIST:
3536 error ("tree node that should already be gimple.");
3547 /* Generic handling via classes. */
3548 switch (TREE_CODE_CLASS (rhs_code))
3551 if (!useless_type_conversion_p (lhs_type, rhs1_type))
3553 error ("non-trivial conversion at assignment");
3554 debug_generic_expr (lhs);
3555 debug_generic_expr (rhs1);
3561 return verify_types_in_gimple_reference (rhs1);
3563 case tcc_comparison:
3565 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3567 error ("invalid operands in comparison expression");
3571 /* For comparisons we do not have the operations type as the
3572 effective type the comparison is carried out in. Instead
3573 we require that either the first operand is trivially
3574 convertible into the second, or the other way around.
3575 The resulting type of a comparison may be any integral type.
3576 Because we special-case pointers to void we allow
3577 comparisons of pointers with the same mode as well. */
3578 if ((!useless_type_conversion_p (rhs1_type, rhs2_type)
3579 && !useless_type_conversion_p (rhs2_type, rhs1_type)
3580 && (!POINTER_TYPE_P (rhs1_type)
3581 || !POINTER_TYPE_P (rhs2_type)
3582 || TYPE_MODE (rhs1_type) != TYPE_MODE (rhs2_type)))
3583 || !INTEGRAL_TYPE_P (lhs_type))
3585 error ("type mismatch in comparison expression");
3586 debug_generic_expr (lhs_type);
3587 debug_generic_expr (rhs1_type);
3588 debug_generic_expr (rhs2_type);
3601 /* Verify the contents of a GIMPLE_RETURN STMT. Returns true when there
3602 is a problem, otherwise false. */
3605 verify_types_in_gimple_return (gimple stmt)
3607 tree op = gimple_return_retval (stmt);
3612 return verify_types_in_gimple_op (op);
3616 /* Verify the contents of a GIMPLE_SWITCH STMT. Returns true when there
3617 is a problem, otherwise false. */
3620 verify_types_in_gimple_switch (gimple stmt)
3622 if (!is_gimple_val (gimple_switch_index (stmt)))
3624 error ("invalid operand to switch statement");
3625 debug_generic_expr (gimple_switch_index (stmt));
3633 /* Verify the contents of a GIMPLE_PHI. Returns true if there is a problem,
3634 and false otherwise. */
3637 verify_types_in_gimple_phi (gimple stmt)
3641 if (verify_types_in_gimple_op (gimple_phi_result (stmt)))
3644 for (i = 0; i < gimple_phi_num_args (stmt); i++)
3645 if (verify_types_in_gimple_op (gimple_phi_arg_def (stmt, i)))
3652 /* Verify the GIMPLE statement STMT. Returns true if there is an
3653 error, otherwise false. */
3656 verify_types_in_gimple_stmt (gimple stmt)
3658 if (is_gimple_omp (stmt))
3660 /* OpenMP directives are validated by the FE and never operated
3661 on by the optimizers. Furthermore, GIMPLE_OMP_FOR may contain
3662 non-gimple expressions when the main index variable has had
3663 its address taken. This does not affect the loop itself
3664 because the header of an GIMPLE_OMP_FOR is merely used to determine
3665 how to setup the parallel iteration. */
3669 switch (gimple_code (stmt))
3672 return verify_types_in_gimple_assign (stmt);
3675 return TREE_CODE (gimple_label_label (stmt)) != LABEL_DECL;
3678 return verify_types_in_gimple_call (stmt);
3681 return verify_types_in_gimple_cond (stmt);
3684 return verify_types_in_gimple_op (gimple_goto_dest (stmt));
3687 case GIMPLE_PREDICT:
3691 return verify_types_in_gimple_switch (stmt);
3694 return verify_types_in_gimple_return (stmt);
3699 case GIMPLE_CHANGE_DYNAMIC_TYPE:
3700 return verify_types_in_gimple_op (gimple_cdt_location (stmt));
3703 return verify_types_in_gimple_phi (stmt);
3710 /* Verify the GIMPLE statements inside the sequence STMTS. */
3713 verify_types_in_gimple_seq_2 (gimple_seq stmts)
3715 gimple_stmt_iterator ittr;
3718 for (ittr = gsi_start (stmts); !gsi_end_p (ittr); gsi_next (&ittr))
3720 gimple stmt = gsi_stmt (ittr);
3722 switch (gimple_code (stmt))
3725 err |= verify_types_in_gimple_seq_2 (gimple_bind_body (stmt));
3729 err |= verify_types_in_gimple_seq_2 (gimple_try_eval (stmt));
3730 err |= verify_types_in_gimple_seq_2 (gimple_try_cleanup (stmt));
3733 case GIMPLE_EH_FILTER:
3734 err |= verify_types_in_gimple_seq_2
3735 (gimple_eh_filter_failure (stmt));
3739 err |= verify_types_in_gimple_seq_2 (gimple_catch_handler (stmt));
3742 case GIMPLE_OMP_CRITICAL:
3743 case GIMPLE_OMP_CONTINUE:
3744 case GIMPLE_OMP_MASTER:
3745 case GIMPLE_OMP_ORDERED:
3746 case GIMPLE_OMP_SECTION:
3747 case GIMPLE_OMP_FOR:
3748 case GIMPLE_OMP_PARALLEL:
3749 case GIMPLE_OMP_TASK:
3750 case GIMPLE_OMP_SECTIONS:
3751 case GIMPLE_OMP_SINGLE:
3752 case GIMPLE_OMP_ATOMIC_STORE:
3753 case GIMPLE_OMP_ATOMIC_LOAD:
3756 /* Tuples that do not have trees. */
3759 case GIMPLE_OMP_RETURN:
3760 case GIMPLE_PREDICT:
3765 bool err2 = verify_types_in_gimple_stmt (stmt);
3767 debug_gimple_stmt (stmt);
3777 /* Verify the GIMPLE statements inside the statement list STMTS. */
3780 verify_types_in_gimple_seq (gimple_seq stmts)
3782 if (verify_types_in_gimple_seq_2 (stmts))
3783 internal_error ("verify_gimple failed");
3787 /* Verify STMT, return true if STMT is not in GIMPLE form.
3788 TODO: Implement type checking. */
3791 verify_stmt (gimple_stmt_iterator *gsi)
3794 struct walk_stmt_info wi;
3795 bool last_in_block = gsi_one_before_end_p (*gsi);
3796 gimple stmt = gsi_stmt (*gsi);
3798 if (is_gimple_omp (stmt))
3800 /* OpenMP directives are validated by the FE and never operated
3801 on by the optimizers. Furthermore, GIMPLE_OMP_FOR may contain
3802 non-gimple expressions when the main index variable has had
3803 its address taken. This does not affect the loop itself
3804 because the header of an GIMPLE_OMP_FOR is merely used to determine
3805 how to setup the parallel iteration. */
3809 /* FIXME. The C frontend passes unpromoted arguments in case it
3810 didn't see a function declaration before the call. */
3811 if (is_gimple_call (stmt))
3813 tree decl = gimple_call_fn (stmt);
3815 if (TREE_CODE (decl) == FUNCTION_DECL
3816 && DECL_LOOPING_CONST_OR_PURE_P (decl)
3817 && (!DECL_PURE_P (decl))
3818 && (!TREE_READONLY (decl)))
3820 error ("invalid pure const state for function");
3825 memset (&wi, 0, sizeof (wi));
3826 addr = walk_gimple_op (gsi_stmt (*gsi), verify_expr, &wi);
3829 debug_generic_expr (addr);
3830 inform ("in statement");
3831 debug_gimple_stmt (stmt);
3835 /* If the statement is marked as part of an EH region, then it is
3836 expected that the statement could throw. Verify that when we
3837 have optimizations that simplify statements such that we prove
3838 that they cannot throw, that we update other data structures
3840 if (lookup_stmt_eh_region (stmt) >= 0)
3842 if (!stmt_could_throw_p (stmt))
3844 error ("statement marked for throw, but doesn%'t");
3847 if (!last_in_block && stmt_can_throw_internal (stmt))
3849 error ("statement marked for throw in middle of block");
3857 debug_gimple_stmt (stmt);
3862 /* Return true when the T can be shared. */
3865 tree_node_can_be_shared (tree t)
3867 if (IS_TYPE_OR_DECL_P (t)
3868 || is_gimple_min_invariant (t)
3869 || TREE_CODE (t) == SSA_NAME
3870 || t == error_mark_node
3871 || TREE_CODE (t) == IDENTIFIER_NODE)
3874 if (TREE_CODE (t) == CASE_LABEL_EXPR)
3877 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
3878 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
3879 || TREE_CODE (t) == COMPONENT_REF
3880 || TREE_CODE (t) == REALPART_EXPR
3881 || TREE_CODE (t) == IMAGPART_EXPR)
3882 t = TREE_OPERAND (t, 0);
3891 /* Called via walk_gimple_stmt. Verify tree sharing. */
3894 verify_node_sharing (tree *tp, int *walk_subtrees, void *data)
3896 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
3897 struct pointer_set_t *visited = (struct pointer_set_t *) wi->info;
3899 if (tree_node_can_be_shared (*tp))
3901 *walk_subtrees = false;
3905 if (pointer_set_insert (visited, *tp))
3912 static bool eh_error_found;
3914 verify_eh_throw_stmt_node (void **slot, void *data)
3916 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
3917 struct pointer_set_t *visited = (struct pointer_set_t *) data;
3919 if (!pointer_set_contains (visited, node->stmt))
3921 error ("Dead STMT in EH table");
3922 debug_gimple_stmt (node->stmt);
3923 eh_error_found = true;
3929 /* Verify the GIMPLE statements in every basic block. */
3935 gimple_stmt_iterator gsi;
3937 struct pointer_set_t *visited, *visited_stmts;
3939 struct walk_stmt_info wi;
3941 timevar_push (TV_TREE_STMT_VERIFY);
3942 visited = pointer_set_create ();
3943 visited_stmts = pointer_set_create ();
3945 memset (&wi, 0, sizeof (wi));
3946 wi.info = (void *) visited;
3953 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
3955 phi = gsi_stmt (gsi);
3956 pointer_set_insert (visited_stmts, phi);
3957 if (gimple_bb (phi) != bb)
3959 error ("gimple_bb (phi) is set to a wrong basic block");
3963 for (i = 0; i < gimple_phi_num_args (phi); i++)
3965 tree t = gimple_phi_arg_def (phi, i);
3970 error ("missing PHI def");
3971 debug_gimple_stmt (phi);
3975 /* Addressable variables do have SSA_NAMEs but they
3976 are not considered gimple values. */
3977 else if (TREE_CODE (t) != SSA_NAME
3978 && TREE_CODE (t) != FUNCTION_DECL
3979 && !is_gimple_min_invariant (t))
3981 error ("PHI argument is not a GIMPLE value");
3982 debug_gimple_stmt (phi);
3983 debug_generic_expr (t);
3987 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
3990 error ("incorrect sharing of tree nodes");
3991 debug_gimple_stmt (phi);
3992 debug_generic_expr (addr);
3998 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
4000 gimple stmt = gsi_stmt (gsi);
4002 if (gimple_code (stmt) == GIMPLE_WITH_CLEANUP_EXPR
4003 || gimple_code (stmt) == GIMPLE_BIND)
4005 error ("invalid GIMPLE statement");
4006 debug_gimple_stmt (stmt);
4010 pointer_set_insert (visited_stmts, stmt);
4012 if (gimple_bb (stmt) != bb)
4014 error ("gimple_bb (stmt) is set to a wrong basic block");
4018 if (gimple_code (stmt) == GIMPLE_LABEL)
4020 tree decl = gimple_label_label (stmt);
4021 int uid = LABEL_DECL_UID (decl);
4024 || VEC_index (basic_block, label_to_block_map, uid) != bb)
4026 error ("incorrect entry in label_to_block_map.\n");
4031 err |= verify_stmt (&gsi);
4032 addr = walk_gimple_op (gsi_stmt (gsi), verify_node_sharing, &wi);
4035 error ("incorrect sharing of tree nodes");
4036 debug_gimple_stmt (stmt);
4037 debug_generic_expr (addr);
4044 eh_error_found = false;
4045 if (get_eh_throw_stmt_table (cfun))
4046 htab_traverse (get_eh_throw_stmt_table (cfun),
4047 verify_eh_throw_stmt_node,
4050 if (err | eh_error_found)
4051 internal_error ("verify_stmts failed");
4053 pointer_set_destroy (visited);
4054 pointer_set_destroy (visited_stmts);
4055 verify_histograms ();
4056 timevar_pop (TV_TREE_STMT_VERIFY);
4060 /* Verifies that the flow information is OK. */
4063 gimple_verify_flow_info (void)
4067 gimple_stmt_iterator gsi;
4072 if (ENTRY_BLOCK_PTR->il.gimple)
4074 error ("ENTRY_BLOCK has IL associated with it");
4078 if (EXIT_BLOCK_PTR->il.gimple)
4080 error ("EXIT_BLOCK has IL associated with it");
4084 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4085 if (e->flags & EDGE_FALLTHRU)
4087 error ("fallthru to exit from bb %d", e->src->index);
4093 bool found_ctrl_stmt = false;
4097 /* Skip labels on the start of basic block. */
4098 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4101 gimple prev_stmt = stmt;
4103 stmt = gsi_stmt (gsi);
4105 if (gimple_code (stmt) != GIMPLE_LABEL)
4108 label = gimple_label_label (stmt);
4109 if (prev_stmt && DECL_NONLOCAL (label))
4111 error ("nonlocal label ");
4112 print_generic_expr (stderr, label, 0);
4113 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4118 if (label_to_block (label) != bb)
4121 print_generic_expr (stderr, label, 0);
4122 fprintf (stderr, " to block does not match in bb %d",
4127 if (decl_function_context (label) != current_function_decl)
4130 print_generic_expr (stderr, label, 0);
4131 fprintf (stderr, " has incorrect context in bb %d",
4137 /* Verify that body of basic block BB is free of control flow. */
4138 for (; !gsi_end_p (gsi); gsi_next (&gsi))
4140 gimple stmt = gsi_stmt (gsi);
4142 if (found_ctrl_stmt)
4144 error ("control flow in the middle of basic block %d",
4149 if (stmt_ends_bb_p (stmt))
4150 found_ctrl_stmt = true;
4152 if (gimple_code (stmt) == GIMPLE_LABEL)
4155 print_generic_expr (stderr, gimple_label_label (stmt), 0);
4156 fprintf (stderr, " in the middle of basic block %d", bb->index);
4161 gsi = gsi_last_bb (bb);
4162 if (gsi_end_p (gsi))
4165 stmt = gsi_stmt (gsi);
4167 err |= verify_eh_edges (stmt);
4169 if (is_ctrl_stmt (stmt))
4171 FOR_EACH_EDGE (e, ei, bb->succs)
4172 if (e->flags & EDGE_FALLTHRU)
4174 error ("fallthru edge after a control statement in bb %d",
4180 if (gimple_code (stmt) != GIMPLE_COND)
4182 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4183 after anything else but if statement. */
4184 FOR_EACH_EDGE (e, ei, bb->succs)
4185 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4187 error ("true/false edge after a non-GIMPLE_COND in bb %d",
4193 switch (gimple_code (stmt))
4200 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4204 || !(true_edge->flags & EDGE_TRUE_VALUE)
4205 || !(false_edge->flags & EDGE_FALSE_VALUE)
4206 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4207 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4208 || EDGE_COUNT (bb->succs) >= 3)
4210 error ("wrong outgoing edge flags at end of bb %d",
4218 if (simple_goto_p (stmt))
4220 error ("explicit goto at end of bb %d", bb->index);
4225 /* FIXME. We should double check that the labels in the
4226 destination blocks have their address taken. */
4227 FOR_EACH_EDGE (e, ei, bb->succs)
4228 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4229 | EDGE_FALSE_VALUE))
4230 || !(e->flags & EDGE_ABNORMAL))
4232 error ("wrong outgoing edge flags at end of bb %d",
4240 if (!single_succ_p (bb)
4241 || (single_succ_edge (bb)->flags
4242 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4243 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4245 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4248 if (single_succ (bb) != EXIT_BLOCK_PTR)
4250 error ("return edge does not point to exit in bb %d",
4262 n = gimple_switch_num_labels (stmt);
4264 /* Mark all the destination basic blocks. */
4265 for (i = 0; i < n; ++i)
4267 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4268 basic_block label_bb = label_to_block (lab);
4269 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4270 label_bb->aux = (void *)1;
4273 /* Verify that the case labels are sorted. */
4274 prev = gimple_switch_label (stmt, 0);
4275 for (i = 1; i < n; ++i)
4277 tree c = gimple_switch_label (stmt, i);
4280 error ("found default case not at the start of "
4286 && !tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4288 error ("case labels not sorted: ");
4289 print_generic_expr (stderr, prev, 0);
4290 fprintf (stderr," is greater than ");
4291 print_generic_expr (stderr, c, 0);
4292 fprintf (stderr," but comes before it.\n");
4297 /* VRP will remove the default case if it can prove it will
4298 never be executed. So do not verify there always exists
4299 a default case here. */
4301 FOR_EACH_EDGE (e, ei, bb->succs)
4305 error ("extra outgoing edge %d->%d",
4306 bb->index, e->dest->index);
4310 e->dest->aux = (void *)2;
4311 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4312 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4314 error ("wrong outgoing edge flags at end of bb %d",
4320 /* Check that we have all of them. */
4321 for (i = 0; i < n; ++i)
4323 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4324 basic_block label_bb = label_to_block (lab);
4326 if (label_bb->aux != (void *)2)
4328 error ("missing edge %i->%i", bb->index, label_bb->index);
4333 FOR_EACH_EDGE (e, ei, bb->succs)
4334 e->dest->aux = (void *)0;
4341 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4342 verify_dominators (CDI_DOMINATORS);
4348 /* Updates phi nodes after creating a forwarder block joined
4349 by edge FALLTHRU. */
4352 gimple_make_forwarder_block (edge fallthru)
4356 basic_block dummy, bb;
4358 gimple_stmt_iterator gsi;
4360 dummy = fallthru->src;
4361 bb = fallthru->dest;
4363 if (single_pred_p (bb))
4366 /* If we redirected a branch we must create new PHI nodes at the
4368 for (gsi = gsi_start_phis (dummy); !gsi_end_p (gsi); gsi_next (&gsi))
4370 gimple phi, new_phi;
4372 phi = gsi_stmt (gsi);
4373 var = gimple_phi_result (phi);
4374 new_phi = create_phi_node (var, bb);
4375 SSA_NAME_DEF_STMT (var) = new_phi;
4376 gimple_phi_set_result (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4377 add_phi_arg (new_phi, gimple_phi_result (phi), fallthru);
4380 /* Add the arguments we have stored on edges. */
4381 FOR_EACH_EDGE (e, ei, bb->preds)
4386 flush_pending_stmts (e);
4391 /* Return a non-special label in the head of basic block BLOCK.
4392 Create one if it doesn't exist. */
4395 gimple_block_label (basic_block bb)
4397 gimple_stmt_iterator i, s = gsi_start_bb (bb);
4402 for (i = s; !gsi_end_p (i); first = false, gsi_next (&i))
4404 stmt = gsi_stmt (i);
4405 if (gimple_code (stmt) != GIMPLE_LABEL)
4407 label = gimple_label_label (stmt);
4408 if (!DECL_NONLOCAL (label))
4411 gsi_move_before (&i, &s);
4416 label = create_artificial_label ();
4417 stmt = gimple_build_label (label);
4418 gsi_insert_before (&s, stmt, GSI_NEW_STMT);
4423 /* Attempt to perform edge redirection by replacing a possibly complex
4424 jump instruction by a goto or by removing the jump completely.
4425 This can apply only if all edges now point to the same block. The
4426 parameters and return values are equivalent to
4427 redirect_edge_and_branch. */
4430 gimple_try_redirect_by_replacing_jump (edge e, basic_block target)
4432 basic_block src = e->src;
4433 gimple_stmt_iterator i;
4436 /* We can replace or remove a complex jump only when we have exactly
4438 if (EDGE_COUNT (src->succs) != 2
4439 /* Verify that all targets will be TARGET. Specifically, the
4440 edge that is not E must also go to TARGET. */
4441 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4444 i = gsi_last_bb (src);
4448 stmt = gsi_stmt (i);
4450 if (gimple_code (stmt) == GIMPLE_COND || gimple_code (stmt) == GIMPLE_SWITCH)
4452 gsi_remove (&i, true);
4453 e = ssa_redirect_edge (e, target);
4454 e->flags = EDGE_FALLTHRU;
4462 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4463 edge representing the redirected branch. */
4466 gimple_redirect_edge_and_branch (edge e, basic_block dest)
4468 basic_block bb = e->src;
4469 gimple_stmt_iterator gsi;
4473 if (e->flags & EDGE_ABNORMAL)
4476 if (e->src != ENTRY_BLOCK_PTR
4477 && (ret = gimple_try_redirect_by_replacing_jump (e, dest)))
4480 if (e->dest == dest)
4483 gsi = gsi_last_bb (bb);
4484 stmt = gsi_end_p (gsi) ? NULL : gsi_stmt (gsi);
4486 switch (stmt ? gimple_code (stmt) : ERROR_MARK)
4489 /* For COND_EXPR, we only need to redirect the edge. */
4493 /* No non-abnormal edges should lead from a non-simple goto, and
4494 simple ones should be represented implicitly. */
4499 tree label = gimple_block_label (dest);
4500 tree cases = get_cases_for_edge (e, stmt);
4502 /* If we have a list of cases associated with E, then use it
4503 as it's a lot faster than walking the entire case vector. */
4506 edge e2 = find_edge (e->src, dest);
4513 CASE_LABEL (cases) = label;
4514 cases = TREE_CHAIN (cases);
4517 /* If there was already an edge in the CFG, then we need
4518 to move all the cases associated with E to E2. */
4521 tree cases2 = get_cases_for_edge (e2, stmt);
4523 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4524 TREE_CHAIN (cases2) = first;
4529 size_t i, n = gimple_switch_num_labels (stmt);
4531 for (i = 0; i < n; i++)
4533 tree elt = gimple_switch_label (stmt, i);
4534 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4535 CASE_LABEL (elt) = label;
4543 gsi_remove (&gsi, true);
4544 e->flags |= EDGE_FALLTHRU;
4547 case GIMPLE_OMP_RETURN:
4548 case GIMPLE_OMP_CONTINUE:
4549 case GIMPLE_OMP_SECTIONS_SWITCH:
4550 case GIMPLE_OMP_FOR:
4551 /* The edges from OMP constructs can be simply redirected. */
4555 /* Otherwise it must be a fallthru edge, and we don't need to
4556 do anything besides redirecting it. */
4557 gcc_assert (e->flags & EDGE_FALLTHRU);
4561 /* Update/insert PHI nodes as necessary. */
4563 /* Now update the edges in the CFG. */
4564 e = ssa_redirect_edge (e, dest);
4569 /* Returns true if it is possible to remove edge E by redirecting
4570 it to the destination of the other edge from E->src. */
4573 gimple_can_remove_branch_p (const_edge e)
4575 if (e->flags & EDGE_ABNORMAL)
4581 /* Simple wrapper, as we can always redirect fallthru edges. */
4584 gimple_redirect_edge_and_branch_force (edge e, basic_block dest)
4586 e = gimple_redirect_edge_and_branch (e, dest);
4593 /* Splits basic block BB after statement STMT (but at least after the
4594 labels). If STMT is NULL, BB is split just after the labels. */
4597 gimple_split_block (basic_block bb, void *stmt)
4599 gimple_stmt_iterator gsi;
4600 gimple_stmt_iterator gsi_tgt;
4607 new_bb = create_empty_bb (bb);
4609 /* Redirect the outgoing edges. */
4610 new_bb->succs = bb->succs;
4612 FOR_EACH_EDGE (e, ei, new_bb->succs)
4615 if (stmt && gimple_code ((gimple) stmt) == GIMPLE_LABEL)
4618 /* Move everything from GSI to the new basic block. */
4619 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4621 act = gsi_stmt (gsi);
4622 if (gimple_code (act) == GIMPLE_LABEL)
4635 if (gsi_end_p (gsi))
4638 /* Split the statement list - avoid re-creating new containers as this
4639 brings ugly quadratic memory consumption in the inliner.
4640 (We are still quadratic since we need to update stmt BB pointers,
4642 list = gsi_split_seq_before (&gsi);
4643 set_bb_seq (new_bb, list);
4644 for (gsi_tgt = gsi_start (list);
4645 !gsi_end_p (gsi_tgt); gsi_next (&gsi_tgt))
4646 gimple_set_bb (gsi_stmt (gsi_tgt), new_bb);
4652 /* Moves basic block BB after block AFTER. */
4655 gimple_move_block_after (basic_block bb, basic_block after)
4657 if (bb->prev_bb == after)
4661 link_block (bb, after);
4667 /* Return true if basic_block can be duplicated. */
4670 gimple_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
4675 /* Create a duplicate of the basic block BB. NOTE: This does not
4676 preserve SSA form. */
4679 gimple_duplicate_bb (basic_block bb)
4682 gimple_stmt_iterator gsi, gsi_tgt;
4683 gimple_seq phis = phi_nodes (bb);
4684 gimple phi, stmt, copy;
4686 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
4688 /* Copy the PHI nodes. We ignore PHI node arguments here because
4689 the incoming edges have not been setup yet. */
4690 for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi))
4692 phi = gsi_stmt (gsi);
4693 copy = create_phi_node (gimple_phi_result (phi), new_bb);
4694 create_new_def_for (gimple_phi_result (copy), copy,
4695 gimple_phi_result_ptr (copy));
4698 gsi_tgt = gsi_start_bb (new_bb);
4699 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4701 def_operand_p def_p;
4702 ssa_op_iter op_iter;
4705 stmt = gsi_stmt (gsi);
4706 if (gimple_code (stmt) == GIMPLE_LABEL)
4709 /* Create a new copy of STMT and duplicate STMT's virtual
4711 copy = gimple_copy (stmt);
4712 gsi_insert_after (&gsi_tgt, copy, GSI_NEW_STMT);
4713 copy_virtual_operands (copy, stmt);
4714 region = lookup_stmt_eh_region (stmt);
4716 add_stmt_to_eh_region (copy, region);
4717 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
4719 /* Create new names for all the definitions created by COPY and
4720 add replacement mappings for each new name. */
4721 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
4722 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
4728 /* Adds phi node arguments for edge E_COPY after basic block duplication. */
4731 add_phi_args_after_copy_edge (edge e_copy)
4733 basic_block bb, bb_copy = e_copy->src, dest;
4736 gimple phi, phi_copy;
4738 gimple_stmt_iterator psi, psi_copy;
4740 if (gimple_seq_empty_p (phi_nodes (e_copy->dest)))
4743 bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
4745 if (e_copy->dest->flags & BB_DUPLICATED)
4746 dest = get_bb_original (e_copy->dest);
4748 dest = e_copy->dest;
4750 e = find_edge (bb, dest);
4753 /* During loop unrolling the target of the latch edge is copied.
4754 In this case we are not looking for edge to dest, but to
4755 duplicated block whose original was dest. */
4756 FOR_EACH_EDGE (e, ei, bb->succs)
4758 if ((e->dest->flags & BB_DUPLICATED)
4759 && get_bb_original (e->dest) == dest)
4763 gcc_assert (e != NULL);
4766 for (psi = gsi_start_phis (e->dest),
4767 psi_copy = gsi_start_phis (e_copy->dest);
4769 gsi_next (&psi), gsi_next (&psi_copy))
4771 phi = gsi_stmt (psi);
4772 phi_copy = gsi_stmt (psi_copy);
4773 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
4774 add_phi_arg (phi_copy, def, e_copy);
4779 /* Basic block BB_COPY was created by code duplication. Add phi node
4780 arguments for edges going out of BB_COPY. The blocks that were
4781 duplicated have BB_DUPLICATED set. */
4784 add_phi_args_after_copy_bb (basic_block bb_copy)
4789 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
4791 add_phi_args_after_copy_edge (e_copy);
4795 /* Blocks in REGION_COPY array of length N_REGION were created by
4796 duplication of basic blocks. Add phi node arguments for edges
4797 going from these blocks. If E_COPY is not NULL, also add
4798 phi node arguments for its destination.*/
4801 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
4806 for (i = 0; i < n_region; i++)
4807 region_copy[i]->flags |= BB_DUPLICATED;
4809 for (i = 0; i < n_region; i++)
4810 add_phi_args_after_copy_bb (region_copy[i]);
4812 add_phi_args_after_copy_edge (e_copy);
4814 for (i = 0; i < n_region; i++)
4815 region_copy[i]->flags &= ~BB_DUPLICATED;
4818 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
4819 important exit edge EXIT. By important we mean that no SSA name defined
4820 inside region is live over the other exit edges of the region. All entry
4821 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
4822 to the duplicate of the region. SSA form, dominance and loop information
4823 is updated. The new basic blocks are stored to REGION_COPY in the same
4824 order as they had in REGION, provided that REGION_COPY is not NULL.
4825 The function returns false if it is unable to copy the region,
4829 gimple_duplicate_sese_region (edge entry, edge exit,
4830 basic_block *region, unsigned n_region,
4831 basic_block *region_copy)
4834 bool free_region_copy = false, copying_header = false;
4835 struct loop *loop = entry->dest->loop_father;
4837 VEC (basic_block, heap) *doms;
4839 int total_freq = 0, entry_freq = 0;
4840 gcov_type total_count = 0, entry_count = 0;
4842 if (!can_copy_bbs_p (region, n_region))
4845 /* Some sanity checking. Note that we do not check for all possible
4846 missuses of the functions. I.e. if you ask to copy something weird,
4847 it will work, but the state of structures probably will not be
4849 for (i = 0; i < n_region; i++)
4851 /* We do not handle subloops, i.e. all the blocks must belong to the
4853 if (region[i]->loop_father != loop)
4856 if (region[i] != entry->dest
4857 && region[i] == loop->header)
4861 set_loop_copy (loop, loop);
4863 /* In case the function is used for loop header copying (which is the primary
4864 use), ensure that EXIT and its copy will be new latch and entry edges. */
4865 if (loop->header == entry->dest)
4867 copying_header = true;
4868 set_loop_copy (loop, loop_outer (loop));
4870 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
4873 for (i = 0; i < n_region; i++)
4874 if (region[i] != exit->src
4875 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
4881 region_copy = XNEWVEC (basic_block, n_region);
4882 free_region_copy = true;
4885 gcc_assert (!need_ssa_update_p ());
4887 /* Record blocks outside the region that are dominated by something
4890 initialize_original_copy_tables ();
4892 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
4894 if (entry->dest->count)
4896 total_count = entry->dest->count;
4897 entry_count = entry->count;
4898 /* Fix up corner cases, to avoid division by zero or creation of negative
4900 if (entry_count > total_count)
4901 entry_count = total_count;
4905 total_freq = entry->dest->frequency;
4906 entry_freq = EDGE_FREQUENCY (entry);
4907 /* Fix up corner cases, to avoid division by zero or creation of negative
4909 if (total_freq == 0)
4911 else if (entry_freq > total_freq)
4912 entry_freq = total_freq;
4915 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
4916 split_edge_bb_loc (entry));
4919 scale_bbs_frequencies_gcov_type (region, n_region,
4920 total_count - entry_count,
4922 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
4927 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
4929 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
4934 loop->header = exit->dest;
4935 loop->latch = exit->src;
4938 /* Redirect the entry and add the phi node arguments. */
4939 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
4940 gcc_assert (redirected != NULL);
4941 flush_pending_stmts (entry);
4943 /* Concerning updating of dominators: We must recount dominators
4944 for entry block and its copy. Anything that is outside of the
4945 region, but was dominated by something inside needs recounting as
4947 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
4948 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
4949 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
4950 VEC_free (basic_block, heap, doms);
4952 /* Add the other PHI node arguments. */
4953 add_phi_args_after_copy (region_copy, n_region, NULL);
4955 /* Update the SSA web. */
4956 update_ssa (TODO_update_ssa);
4958 if (free_region_copy)
4961 free_original_copy_tables ();
4965 /* Duplicates REGION consisting of N_REGION blocks. The new blocks
4966 are stored to REGION_COPY in the same order in that they appear
4967 in REGION, if REGION_COPY is not NULL. ENTRY is the entry to
4968 the region, EXIT an exit from it. The condition guarding EXIT
4969 is moved to ENTRY. Returns true if duplication succeeds, false
4995 gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNUSED,
4996 basic_block *region ATTRIBUTE_UNUSED, unsigned n_region ATTRIBUTE_UNUSED,
4997 basic_block *region_copy ATTRIBUTE_UNUSED)
5000 bool free_region_copy = false;
5001 struct loop *loop = exit->dest->loop_father;
5002 struct loop *orig_loop = entry->dest->loop_father;
5003 basic_block switch_bb, entry_bb, nentry_bb;
5004 VEC (basic_block, heap) *doms;
5005 int total_freq = 0, exit_freq = 0;
5006 gcov_type total_count = 0, exit_count = 0;
5007 edge exits[2], nexits[2], e;
5008 gimple_stmt_iterator gsi;
5012 gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5014 exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5016 if (!can_copy_bbs_p (region, n_region))
5019 /* Some sanity checking. Note that we do not check for all possible
5020 missuses of the functions. I.e. if you ask to copy something weird
5021 (e.g., in the example, if there is a jump from inside to the middle
5022 of some_code, or come_code defines some of the values used in cond)
5023 it will work, but the resulting code will not be correct. */
5024 for (i = 0; i < n_region; i++)
5026 /* We do not handle subloops, i.e. all the blocks must belong to the
5028 if (region[i]->loop_father != orig_loop)
5031 if (region[i] == orig_loop->latch)
5035 initialize_original_copy_tables ();
5036 set_loop_copy (orig_loop, loop);
5040 region_copy = XNEWVEC (basic_block, n_region);
5041 free_region_copy = true;
5044 gcc_assert (!need_ssa_update_p ());
5046 /* Record blocks outside the region that are dominated by something
5048 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5050 if (exit->src->count)
5052 total_count = exit->src->count;
5053 exit_count = exit->count;
5054 /* Fix up corner cases, to avoid division by zero or creation of negative
5056 if (exit_count > total_count)
5057 exit_count = total_count;
5061 total_freq = exit->src->frequency;
5062 exit_freq = EDGE_FREQUENCY (exit);
5063 /* Fix up corner cases, to avoid division by zero or creation of negative
5065 if (total_freq == 0)
5067 if (exit_freq > total_freq)
5068 exit_freq = total_freq;
5071 copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5072 split_edge_bb_loc (exit));
5075 scale_bbs_frequencies_gcov_type (region, n_region,
5076 total_count - exit_count,
5078 scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5083 scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5085 scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5088 /* Create the switch block, and put the exit condition to it. */
5089 entry_bb = entry->dest;
5090 nentry_bb = get_bb_copy (entry_bb);
5091 if (!last_stmt (entry->src)
5092 || !stmt_ends_bb_p (last_stmt (entry->src)))
5093 switch_bb = entry->src;
5095 switch_bb = split_edge (entry);
5096 set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5098 gsi = gsi_last_bb (switch_bb);
5099 cond_stmt = last_stmt (exit->src);
5100 gcc_assert (gimple_code (cond_stmt) == GIMPLE_COND);
5101 cond_stmt = gimple_copy (cond_stmt);
5102 gimple_cond_set_lhs (cond_stmt, unshare_expr (gimple_cond_lhs (cond_stmt)));
5103 gimple_cond_set_rhs (cond_stmt, unshare_expr (gimple_cond_rhs (cond_stmt)));
5104 gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
5106 sorig = single_succ_edge (switch_bb);
5107 sorig->flags = exits[1]->flags;
5108 snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5110 /* Register the new edge from SWITCH_BB in loop exit lists. */
5111 rescan_loop_exit (snew, true, false);
5113 /* Add the PHI node arguments. */
5114 add_phi_args_after_copy (region_copy, n_region, snew);
5116 /* Get rid of now superfluous conditions and associated edges (and phi node
5118 e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5119 PENDING_STMT (e) = NULL;
5120 e = redirect_edge_and_branch (nexits[1], nexits[0]->dest);
5121 PENDING_STMT (e) = NULL;
5123 /* Anything that is outside of the region, but was dominated by something
5124 inside needs to update dominance info. */
5125 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5126 VEC_free (basic_block, heap, doms);
5128 /* Update the SSA web. */
5129 update_ssa (TODO_update_ssa);
5131 if (free_region_copy)
5134 free_original_copy_tables ();
5138 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5139 adding blocks when the dominator traversal reaches EXIT. This
5140 function silently assumes that ENTRY strictly dominates EXIT. */
5143 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5144 VEC(basic_block,heap) **bbs_p)
5148 for (son = first_dom_son (CDI_DOMINATORS, entry);
5150 son = next_dom_son (CDI_DOMINATORS, son))
5152 VEC_safe_push (basic_block, heap, *bbs_p, son);
5154 gather_blocks_in_sese_region (son, exit, bbs_p);
5158 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5159 The duplicates are recorded in VARS_MAP. */
5162 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5165 tree t = *tp, new_t;
5166 struct function *f = DECL_STRUCT_FUNCTION (to_context);
5169 if (DECL_CONTEXT (t) == to_context)
5172 loc = pointer_map_contains (vars_map, t);
5176 loc = pointer_map_insert (vars_map, t);
5180 new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5181 f->local_decls = tree_cons (NULL_TREE, new_t, f->local_decls);
5185 gcc_assert (TREE_CODE (t) == CONST_DECL);
5186 new_t = copy_node (t);
5188 DECL_CONTEXT (new_t) = to_context;
5193 new_t = (tree) *loc;
5199 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5200 VARS_MAP maps old ssa names and var_decls to the new ones. */
5203 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5207 tree new_name, decl = SSA_NAME_VAR (name);
5209 gcc_assert (is_gimple_reg (name));
5211 loc = pointer_map_contains (vars_map, name);
5215 replace_by_duplicate_decl (&decl, vars_map, to_context);
5217 push_cfun (DECL_STRUCT_FUNCTION (to_context));
5218 if (gimple_in_ssa_p (cfun))
5219 add_referenced_var (decl);
5221 new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5222 if (SSA_NAME_IS_DEFAULT_DEF (name))
5223 set_default_def (decl, new_name);
5226 loc = pointer_map_insert (vars_map, name);
5230 new_name = (tree) *loc;
5241 struct pointer_map_t *vars_map;
5242 htab_t new_label_map;
5246 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5247 contained in *TP if it has been ORIG_BLOCK previously and change the
5248 DECL_CONTEXT of every local variable referenced in *TP. */
5251 move_stmt_op (tree *tp, int *walk_subtrees, void *data)
5253 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
5254 struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5258 /* We should never have TREE_BLOCK set on non-statements. */
5259 gcc_assert (!TREE_BLOCK (t));
5261 else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5263 if (TREE_CODE (t) == SSA_NAME)
5264 *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5265 else if (TREE_CODE (t) == LABEL_DECL)
5267 if (p->new_label_map)
5269 struct tree_map in, *out;
5271 out = (struct tree_map *)
5272 htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5277 DECL_CONTEXT (t) = p->to_context;
5279 else if (p->remap_decls_p)
5281 /* Replace T with its duplicate. T should no longer appear in the
5282 parent function, so this looks wasteful; however, it may appear
5283 in referenced_vars, and more importantly, as virtual operands of
5284 statements, and in alias lists of other variables. It would be
5285 quite difficult to expunge it from all those places. ??? It might
5286 suffice to do this for addressable variables. */
5287 if ((TREE_CODE (t) == VAR_DECL
5288 && !is_global_var (t))
5289 || TREE_CODE (t) == CONST_DECL)
5290 replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5293 && gimple_in_ssa_p (cfun))
5295 push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5296 add_referenced_var (*tp);
5302 else if (TYPE_P (t))
5308 /* Like move_stmt_op, but for gimple statements.
5310 Helper for move_block_to_fn. Set GIMPLE_BLOCK in every expression
5311 contained in the current statement in *GSI_P and change the
5312 DECL_CONTEXT of every local variable referenced in the current
5316 move_stmt_r (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
5317 struct walk_stmt_info *wi)
5319 struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5320 gimple stmt = gsi_stmt (*gsi_p);
5321 tree block = gimple_block (stmt);
5323 if (p->orig_block == NULL_TREE
5324 || block == p->orig_block
5325 || block == NULL_TREE)
5326 gimple_set_block (stmt, p->new_block);
5327 #ifdef ENABLE_CHECKING
5328 else if (block != p->new_block)
5330 while (block && block != p->orig_block)
5331 block = BLOCK_SUPERCONTEXT (block);
5336 if (is_gimple_omp (stmt)
5337 && gimple_code (stmt) != GIMPLE_OMP_RETURN
5338 && gimple_code (stmt) != GIMPLE_OMP_CONTINUE)
5340 /* Do not remap variables inside OMP directives. Variables
5341 referenced in clauses and directive header belong to the
5342 parent function and should not be moved into the child
5344 bool save_remap_decls_p = p->remap_decls_p;
5345 p->remap_decls_p = false;
5346 *handled_ops_p = true;
5348 walk_gimple_seq (gimple_omp_body (stmt), move_stmt_r, move_stmt_op, wi);
5350 p->remap_decls_p = save_remap_decls_p;
5356 /* Marks virtual operands of all statements in basic blocks BBS for
5360 mark_virtual_ops_in_bb (basic_block bb)
5362 gimple_stmt_iterator gsi;
5364 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5365 mark_virtual_ops_for_renaming (gsi_stmt (gsi));
5367 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5368 mark_virtual_ops_for_renaming (gsi_stmt (gsi));
5371 /* Marks virtual operands of all statements in basic blocks BBS for
5375 mark_virtual_ops_in_region (VEC (basic_block,heap) *bbs)
5380 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5381 mark_virtual_ops_in_bb (bb);
5384 /* Move basic block BB from function CFUN to function DEST_FN. The
5385 block is moved out of the original linked list and placed after
5386 block AFTER in the new list. Also, the block is removed from the
5387 original array of blocks and placed in DEST_FN's array of blocks.
5388 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5389 updated to reflect the moved edges.
5391 The local variables are remapped to new instances, VARS_MAP is used
5392 to record the mapping. */
5395 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5396 basic_block after, bool update_edge_count_p,
5397 struct move_stmt_d *d, int eh_offset)
5399 struct control_flow_graph *cfg;
5402 gimple_stmt_iterator si;
5403 unsigned old_len, new_len;
5405 /* Remove BB from dominance structures. */
5406 delete_from_dominance_info (CDI_DOMINATORS, bb);
5408 remove_bb_from_loops (bb);
5410 /* Link BB to the new linked list. */
5411 move_block_after (bb, after);
5413 /* Update the edge count in the corresponding flowgraphs. */
5414 if (update_edge_count_p)
5415 FOR_EACH_EDGE (e, ei, bb->succs)
5417 cfun->cfg->x_n_edges--;
5418 dest_cfun->cfg->x_n_edges++;
5421 /* Remove BB from the original basic block array. */
5422 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5423 cfun->cfg->x_n_basic_blocks--;
5425 /* Grow DEST_CFUN's basic block array if needed. */
5426 cfg = dest_cfun->cfg;
5427 cfg->x_n_basic_blocks++;
5428 if (bb->index >= cfg->x_last_basic_block)
5429 cfg->x_last_basic_block = bb->index + 1;
5431 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5432 if ((unsigned) cfg->x_last_basic_block >= old_len)
5434 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5435 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5439 VEC_replace (basic_block, cfg->x_basic_block_info,
5442 /* Remap the variables in phi nodes. */
5443 for (si = gsi_start_phis (bb); !gsi_end_p (si); )
5445 gimple phi = gsi_stmt (si);
5447 tree op = PHI_RESULT (phi);
5450 if (!is_gimple_reg (op))
5452 /* Remove the phi nodes for virtual operands (alias analysis will be
5453 run for the new function, anyway). */
5454 remove_phi_node (&si, true);
5458 SET_PHI_RESULT (phi,
5459 replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5460 FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5462 op = USE_FROM_PTR (use);
5463 if (TREE_CODE (op) == SSA_NAME)
5464 SET_USE (use, replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5470 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5472 gimple stmt = gsi_stmt (si);
5474 struct walk_stmt_info wi;
5476 memset (&wi, 0, sizeof (wi));
5478 walk_gimple_stmt (&si, move_stmt_r, move_stmt_op, &wi);
5480 if (gimple_code (stmt) == GIMPLE_LABEL)
5482 tree label = gimple_label_label (stmt);
5483 int uid = LABEL_DECL_UID (label);
5485 gcc_assert (uid > -1);
5487 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5488 if (old_len <= (unsigned) uid)
5490 new_len = 3 * uid / 2;
5491 VEC_safe_grow_cleared (basic_block, gc,
5492 cfg->x_label_to_block_map, new_len);
5495 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5496 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5498 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5500 if (uid >= dest_cfun->cfg->last_label_uid)
5501 dest_cfun->cfg->last_label_uid = uid + 1;
5503 else if (gimple_code (stmt) == GIMPLE_RESX && eh_offset != 0)
5504 gimple_resx_set_region (stmt, gimple_resx_region (stmt) + eh_offset);
5506 region = lookup_stmt_eh_region (stmt);
5509 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5510 remove_stmt_from_eh_region (stmt);
5511 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5512 gimple_remove_stmt_histograms (cfun, stmt);
5515 /* We cannot leave any operands allocated from the operand caches of
5516 the current function. */
5517 free_stmt_operands (stmt);
5518 push_cfun (dest_cfun);
5524 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5525 the outermost EH region. Use REGION as the incoming base EH region. */
5528 find_outermost_region_in_block (struct function *src_cfun,
5529 basic_block bb, int region)
5531 gimple_stmt_iterator si;
5533 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5535 gimple stmt = gsi_stmt (si);
5538 if (gimple_code (stmt) == GIMPLE_RESX)
5539 stmt_region = gimple_resx_region (stmt);
5541 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5542 if (stmt_region > 0)
5545 region = stmt_region;
5546 else if (stmt_region != region)
5548 region = eh_region_outermost (src_cfun, stmt_region, region);
5549 gcc_assert (region != -1);
5558 new_label_mapper (tree decl, void *data)
5560 htab_t hash = (htab_t) data;
5564 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5566 m = XNEW (struct tree_map);
5567 m->hash = DECL_UID (decl);
5568 m->base.from = decl;
5569 m->to = create_artificial_label ();
5570 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5571 if (LABEL_DECL_UID (m->to) >= cfun->cfg->last_label_uid)
5572 cfun->cfg->last_label_uid = LABEL_DECL_UID (m->to) + 1;
5574 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5575 gcc_assert (*slot == NULL);
5582 /* Change DECL_CONTEXT of all BLOCK_VARS in block, including
5586 replace_block_vars_by_duplicates (tree block, struct pointer_map_t *vars_map,
5591 for (tp = &BLOCK_VARS (block); *tp; tp = &TREE_CHAIN (*tp))
5594 replace_by_duplicate_decl (&t, vars_map, to_context);
5597 if (TREE_CODE (*tp) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (*tp))
5599 SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (*tp));
5600 DECL_HAS_VALUE_EXPR_P (t) = 1;
5602 TREE_CHAIN (t) = TREE_CHAIN (*tp);
5607 for (block = BLOCK_SUBBLOCKS (block); block; block = BLOCK_CHAIN (block))
5608 replace_block_vars_by_duplicates (block, vars_map, to_context);
5611 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5612 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5613 single basic block in the original CFG and the new basic block is
5614 returned. DEST_CFUN must not have a CFG yet.
5616 Note that the region need not be a pure SESE region. Blocks inside
5617 the region may contain calls to abort/exit. The only restriction
5618 is that ENTRY_BB should be the only entry point and it must
5621 Change TREE_BLOCK of all statements in ORIG_BLOCK to the new
5622 functions outermost BLOCK, move all subblocks of ORIG_BLOCK
5623 to the new function.
5625 All local variables referenced in the region are assumed to be in
5626 the corresponding BLOCK_VARS and unexpanded variable lists
5627 associated with DEST_CFUN. */
5630 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5631 basic_block exit_bb, tree orig_block)
5633 VEC(basic_block,heap) *bbs, *dom_bbs;
5634 basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
5635 basic_block after, bb, *entry_pred, *exit_succ, abb;
5636 struct function *saved_cfun = cfun;
5637 int *entry_flag, *exit_flag, eh_offset;
5638 unsigned *entry_prob, *exit_prob;
5639 unsigned i, num_entry_edges, num_exit_edges;
5642 htab_t new_label_map;
5643 struct pointer_map_t *vars_map;
5644 struct loop *loop = entry_bb->loop_father;
5645 struct move_stmt_d d;
5647 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5649 gcc_assert (entry_bb != exit_bb
5651 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
5653 /* Collect all the blocks in the region. Manually add ENTRY_BB
5654 because it won't be added by dfs_enumerate_from. */
5656 VEC_safe_push (basic_block, heap, bbs, entry_bb);
5657 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
5659 /* The blocks that used to be dominated by something in BBS will now be
5660 dominated by the new block. */
5661 dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
5662 VEC_address (basic_block, bbs),
5663 VEC_length (basic_block, bbs));
5665 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5666 the predecessor edges to ENTRY_BB and the successor edges to
5667 EXIT_BB so that we can re-attach them to the new basic block that
5668 will replace the region. */
5669 num_entry_edges = EDGE_COUNT (entry_bb->preds);
5670 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
5671 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
5672 entry_prob = XNEWVEC (unsigned, num_entry_edges);
5674 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
5676 entry_prob[i] = e->probability;
5677 entry_flag[i] = e->flags;
5678 entry_pred[i++] = e->src;
5684 num_exit_edges = EDGE_COUNT (exit_bb->succs);
5685 exit_succ = (basic_block *) xcalloc (num_exit_edges,
5686 sizeof (basic_block));
5687 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
5688 exit_prob = XNEWVEC (unsigned, num_exit_edges);
5690 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
5692 exit_prob[i] = e->probability;
5693 exit_flag[i] = e->flags;
5694 exit_succ[i++] = e->dest;
5706 /* Switch context to the child function to initialize DEST_FN's CFG. */
5707 gcc_assert (dest_cfun->cfg == NULL);
5708 push_cfun (dest_cfun);
5710 init_empty_tree_cfg ();
5712 /* Initialize EH information for the new function. */
5714 new_label_map = NULL;
5719 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5720 region = find_outermost_region_in_block (saved_cfun, bb, region);
5722 init_eh_for_function ();
5725 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
5726 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
5727 new_label_map, region, 0);
5733 /* The ssa form for virtual operands in the source function will have to
5734 be repaired. We do not care for the real operands -- the sese region
5735 must be closed with respect to those. */
5736 mark_virtual_ops_in_region (bbs);
5738 /* Move blocks from BBS into DEST_CFUN. */
5739 gcc_assert (VEC_length (basic_block, bbs) >= 2);
5740 after = dest_cfun->cfg->x_entry_block_ptr;
5741 vars_map = pointer_map_create ();
5743 memset (&d, 0, sizeof (d));
5744 d.vars_map = vars_map;
5745 d.from_context = cfun->decl;
5746 d.to_context = dest_cfun->decl;
5747 d.new_label_map = new_label_map;
5748 d.remap_decls_p = true;
5749 d.orig_block = orig_block;
5750 d.new_block = DECL_INITIAL (dest_cfun->decl);
5752 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5754 /* No need to update edge counts on the last block. It has
5755 already been updated earlier when we detached the region from
5756 the original CFG. */
5757 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, &d, eh_offset);
5761 /* Rewire BLOCK_SUBBLOCKS of orig_block. */
5765 gcc_assert (BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
5767 BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
5768 = BLOCK_SUBBLOCKS (orig_block);
5769 for (block = BLOCK_SUBBLOCKS (orig_block);
5770 block; block = BLOCK_CHAIN (block))
5771 BLOCK_SUPERCONTEXT (block) = DECL_INITIAL (dest_cfun->decl);
5772 BLOCK_SUBBLOCKS (orig_block) = NULL_TREE;
5775 replace_block_vars_by_duplicates (DECL_INITIAL (dest_cfun->decl),
5776 vars_map, dest_cfun->decl);
5779 htab_delete (new_label_map);
5780 pointer_map_destroy (vars_map);
5782 /* Rewire the entry and exit blocks. The successor to the entry
5783 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
5784 the child function. Similarly, the predecessor of DEST_FN's
5785 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
5786 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
5787 various CFG manipulation function get to the right CFG.
5789 FIXME, this is silly. The CFG ought to become a parameter to
5791 push_cfun (dest_cfun);
5792 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
5794 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
5797 /* Back in the original function, the SESE region has disappeared,
5798 create a new basic block in its place. */
5799 bb = create_empty_bb (entry_pred[0]);
5801 add_bb_to_loop (bb, loop);
5802 for (i = 0; i < num_entry_edges; i++)
5804 e = make_edge (entry_pred[i], bb, entry_flag[i]);
5805 e->probability = entry_prob[i];
5808 for (i = 0; i < num_exit_edges; i++)
5810 e = make_edge (bb, exit_succ[i], exit_flag[i]);
5811 e->probability = exit_prob[i];
5814 set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
5815 for (i = 0; VEC_iterate (basic_block, dom_bbs, i, abb); i++)
5816 set_immediate_dominator (CDI_DOMINATORS, abb, bb);
5817 VEC_free (basic_block, heap, dom_bbs);
5828 VEC_free (basic_block, heap, bbs);
5834 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree-pass.h)
5838 dump_function_to_file (tree fn, FILE *file, int flags)
5840 tree arg, vars, var;
5841 struct function *dsf;
5842 bool ignore_topmost_bind = false, any_var = false;
5846 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
5848 arg = DECL_ARGUMENTS (fn);
5851 print_generic_expr (file, TREE_TYPE (arg), dump_flags);
5852 fprintf (file, " ");
5853 print_generic_expr (file, arg, dump_flags);
5854 if (flags & TDF_VERBOSE)
5855 print_node (file, "", arg, 4);
5856 if (TREE_CHAIN (arg))
5857 fprintf (file, ", ");
5858 arg = TREE_CHAIN (arg);
5860 fprintf (file, ")\n");
5862 if (flags & TDF_VERBOSE)
5863 print_node (file, "", fn, 2);
5865 dsf = DECL_STRUCT_FUNCTION (fn);
5866 if (dsf && (flags & TDF_DETAILS))
5867 dump_eh_tree (file, dsf);
5869 if (flags & TDF_RAW && !gimple_body (fn))
5871 dump_node (fn, TDF_SLIM | flags, file);
5875 /* Switch CFUN to point to FN. */
5876 push_cfun (DECL_STRUCT_FUNCTION (fn));
5878 /* When GIMPLE is lowered, the variables are no longer available in
5879 BIND_EXPRs, so display them separately. */
5880 if (cfun && cfun->decl == fn && cfun->local_decls)
5882 ignore_topmost_bind = true;
5884 fprintf (file, "{\n");
5885 for (vars = cfun->local_decls; vars; vars = TREE_CHAIN (vars))
5887 var = TREE_VALUE (vars);
5889 print_generic_decl (file, var, flags);
5890 if (flags & TDF_VERBOSE)
5891 print_node (file, "", var, 4);
5892 fprintf (file, "\n");
5898 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
5900 /* If the CFG has been built, emit a CFG-based dump. */
5901 check_bb_profile (ENTRY_BLOCK_PTR, file);
5902 if (!ignore_topmost_bind)
5903 fprintf (file, "{\n");
5905 if (any_var && n_basic_blocks)
5906 fprintf (file, "\n");
5909 gimple_dump_bb (bb, file, 2, flags);
5911 fprintf (file, "}\n");
5912 check_bb_profile (EXIT_BLOCK_PTR, file);
5914 else if (DECL_SAVED_TREE (fn) == NULL)
5916 /* The function is now in GIMPLE form but the CFG has not been
5917 built yet. Emit the single sequence of GIMPLE statements
5918 that make up its body. */
5919 gimple_seq body = gimple_body (fn);
5921 if (gimple_seq_first_stmt (body)
5922 && gimple_seq_first_stmt (body) == gimple_seq_last_stmt (body)
5923 && gimple_code (gimple_seq_first_stmt (body)) == GIMPLE_BIND)
5924 print_gimple_seq (file, body, 0, flags);
5927 if (!ignore_topmost_bind)
5928 fprintf (file, "{\n");
5931 fprintf (file, "\n");
5933 print_gimple_seq (file, body, 2, flags);
5934 fprintf (file, "}\n");
5941 /* Make a tree based dump. */
5942 chain = DECL_SAVED_TREE (fn);
5944 if (chain && TREE_CODE (chain) == BIND_EXPR)
5946 if (ignore_topmost_bind)
5948 chain = BIND_EXPR_BODY (chain);
5956 if (!ignore_topmost_bind)
5957 fprintf (file, "{\n");
5962 fprintf (file, "\n");
5964 print_generic_stmt_indented (file, chain, flags, indent);
5965 if (ignore_topmost_bind)
5966 fprintf (file, "}\n");
5969 fprintf (file, "\n\n");
5976 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
5979 debug_function (tree fn, int flags)
5981 dump_function_to_file (fn, stderr, flags);
5985 /* Print on FILE the indexes for the predecessors of basic_block BB. */
5988 print_pred_bbs (FILE *file, basic_block bb)
5993 FOR_EACH_EDGE (e, ei, bb->preds)
5994 fprintf (file, "bb_%d ", e->src->index);
5998 /* Print on FILE the indexes for the successors of basic_block BB. */
6001 print_succ_bbs (FILE *file, basic_block bb)
6006 FOR_EACH_EDGE (e, ei, bb->succs)
6007 fprintf (file, "bb_%d ", e->dest->index);
6010 /* Print to FILE the basic block BB following the VERBOSITY level. */
6013 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6015 char *s_indent = (char *) alloca ((size_t) indent + 1);
6016 memset ((void *) s_indent, ' ', (size_t) indent);
6017 s_indent[indent] = '\0';
6019 /* Print basic_block's header. */
6022 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
6023 print_pred_bbs (file, bb);
6024 fprintf (file, "}, succs = {");
6025 print_succ_bbs (file, bb);
6026 fprintf (file, "})\n");
6029 /* Print basic_block's body. */
6032 fprintf (file, "%s {\n", s_indent);
6033 gimple_dump_bb (bb, file, indent + 4, TDF_VOPS|TDF_MEMSYMS);
6034 fprintf (file, "%s }\n", s_indent);
6038 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6040 /* Pretty print LOOP on FILE, indented INDENT spaces. Following
6041 VERBOSITY level this outputs the contents of the loop, or just its
6045 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6053 s_indent = (char *) alloca ((size_t) indent + 1);
6054 memset ((void *) s_indent, ' ', (size_t) indent);
6055 s_indent[indent] = '\0';
6057 /* Print loop's header. */
6058 fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6059 loop->num, loop->header->index, loop->latch->index);
6060 fprintf (file, ", niter = ");
6061 print_generic_expr (file, loop->nb_iterations, 0);
6063 if (loop->any_upper_bound)
6065 fprintf (file, ", upper_bound = ");
6066 dump_double_int (file, loop->nb_iterations_upper_bound, true);
6069 if (loop->any_estimate)
6071 fprintf (file, ", estimate = ");
6072 dump_double_int (file, loop->nb_iterations_estimate, true);
6074 fprintf (file, ")\n");
6076 /* Print loop's body. */
6079 fprintf (file, "%s{\n", s_indent);
6081 if (bb->loop_father == loop)
6082 print_loops_bb (file, bb, indent, verbosity);
6084 print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6085 fprintf (file, "%s}\n", s_indent);
6089 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6090 spaces. Following VERBOSITY level this outputs the contents of the
6091 loop, or just its structure. */
6094 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6099 print_loop (file, loop, indent, verbosity);
6100 print_loop_and_siblings (file, loop->next, indent, verbosity);
6103 /* Follow a CFG edge from the entry point of the program, and on entry
6104 of a loop, pretty print the loop structure on FILE. */
6107 print_loops (FILE *file, int verbosity)
6111 bb = BASIC_BLOCK (NUM_FIXED_BLOCKS);
6112 if (bb && bb->loop_father)
6113 print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6117 /* Debugging loops structure at tree level, at some VERBOSITY level. */
6120 debug_loops (int verbosity)
6122 print_loops (stderr, verbosity);
6125 /* Print on stderr the code of LOOP, at some VERBOSITY level. */
6128 debug_loop (struct loop *loop, int verbosity)
6130 print_loop (stderr, loop, 0, verbosity);
6133 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6137 debug_loop_num (unsigned num, int verbosity)
6139 debug_loop (get_loop (num), verbosity);
6142 /* Return true if BB ends with a call, possibly followed by some
6143 instructions that must stay with the call. Return false,
6147 gimple_block_ends_with_call_p (basic_block bb)
6149 gimple_stmt_iterator gsi = gsi_last_bb (bb);
6150 return is_gimple_call (gsi_stmt (gsi));
6154 /* Return true if BB ends with a conditional branch. Return false,
6158 gimple_block_ends_with_condjump_p (const_basic_block bb)
6160 gimple stmt = last_stmt (CONST_CAST_BB (bb));
6161 return (stmt && gimple_code (stmt) == GIMPLE_COND);
6165 /* Return true if we need to add fake edge to exit at statement T.
6166 Helper function for gimple_flow_call_edges_add. */
6169 need_fake_edge_p (gimple t)
6171 tree fndecl = NULL_TREE;
6174 /* NORETURN and LONGJMP calls already have an edge to exit.
6175 CONST and PURE calls do not need one.
6176 We don't currently check for CONST and PURE here, although
6177 it would be a good idea, because those attributes are
6178 figured out from the RTL in mark_constant_function, and
6179 the counter incrementation code from -fprofile-arcs
6180 leads to different results from -fbranch-probabilities. */
6181 if (is_gimple_call (t))
6183 fndecl = gimple_call_fndecl (t);
6184 call_flags = gimple_call_flags (t);
6187 if (is_gimple_call (t)
6189 && DECL_BUILT_IN (fndecl)
6190 && (call_flags & ECF_NOTHROW)
6191 && !(call_flags & ECF_NORETURN)
6192 && !(call_flags & ECF_RETURNS_TWICE))
6195 if (is_gimple_call (t)
6196 && !(call_flags & ECF_NORETURN))
6199 if (gimple_code (t) == ASM_EXPR
6200 && (gimple_asm_volatile_p (t) || gimple_asm_input_p (t)))
6207 /* Add fake edges to the function exit for any non constant and non
6208 noreturn calls, volatile inline assembly in the bitmap of blocks
6209 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
6210 the number of blocks that were split.
6212 The goal is to expose cases in which entering a basic block does
6213 not imply that all subsequent instructions must be executed. */
6216 gimple_flow_call_edges_add (sbitmap blocks)
6219 int blocks_split = 0;
6220 int last_bb = last_basic_block;
6221 bool check_last_block = false;
6223 if (n_basic_blocks == NUM_FIXED_BLOCKS)
6227 check_last_block = true;
6229 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6231 /* In the last basic block, before epilogue generation, there will be
6232 a fallthru edge to EXIT. Special care is required if the last insn
6233 of the last basic block is a call because make_edge folds duplicate
6234 edges, which would result in the fallthru edge also being marked
6235 fake, which would result in the fallthru edge being removed by
6236 remove_fake_edges, which would result in an invalid CFG.
6238 Moreover, we can't elide the outgoing fake edge, since the block
6239 profiler needs to take this into account in order to solve the minimal
6240 spanning tree in the case that the call doesn't return.
6242 Handle this by adding a dummy instruction in a new last basic block. */
6243 if (check_last_block)
6245 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6246 gimple_stmt_iterator gsi = gsi_last_bb (bb);
6249 if (!gsi_end_p (gsi))
6252 if (t && need_fake_edge_p (t))
6256 e = find_edge (bb, EXIT_BLOCK_PTR);
6259 gsi_insert_on_edge (e, gimple_build_nop ());
6260 gsi_commit_edge_inserts ();
6265 /* Now add fake edges to the function exit for any non constant
6266 calls since there is no way that we can determine if they will
6268 for (i = 0; i < last_bb; i++)
6270 basic_block bb = BASIC_BLOCK (i);
6271 gimple_stmt_iterator gsi;
6272 gimple stmt, last_stmt;
6277 if (blocks && !TEST_BIT (blocks, i))
6280 gsi = gsi_last_bb (bb);
6281 if (!gsi_end_p (gsi))
6283 last_stmt = gsi_stmt (gsi);
6286 stmt = gsi_stmt (gsi);
6287 if (need_fake_edge_p (stmt))
6291 /* The handling above of the final block before the
6292 epilogue should be enough to verify that there is
6293 no edge to the exit block in CFG already.
6294 Calling make_edge in such case would cause us to
6295 mark that edge as fake and remove it later. */
6296 #ifdef ENABLE_CHECKING
6297 if (stmt == last_stmt)
6299 e = find_edge (bb, EXIT_BLOCK_PTR);
6300 gcc_assert (e == NULL);
6304 /* Note that the following may create a new basic block
6305 and renumber the existing basic blocks. */
6306 if (stmt != last_stmt)
6308 e = split_block (bb, stmt);
6312 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6316 while (!gsi_end_p (gsi));
6321 verify_flow_info ();
6323 return blocks_split;
6326 /* Purge dead abnormal call edges from basic block BB. */
6329 gimple_purge_dead_abnormal_call_edges (basic_block bb)
6331 bool changed = gimple_purge_dead_eh_edges (bb);
6333 if (cfun->has_nonlocal_label)
6335 gimple stmt = last_stmt (bb);
6339 if (!(stmt && stmt_can_make_abnormal_goto (stmt)))
6340 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6342 if (e->flags & EDGE_ABNORMAL)
6351 /* See gimple_purge_dead_eh_edges below. */
6353 free_dominance_info (CDI_DOMINATORS);
6359 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6362 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6366 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6367 for (son = first_dom_son (CDI_DOMINATORS, bb);
6369 son = next_dom_son (CDI_DOMINATORS, son))
6370 get_all_dominated_blocks (son, dom_bbs);
6373 /* Removes edge E and all the blocks dominated by it, and updates dominance
6374 information. The IL in E->src needs to be updated separately.
6375 If dominance info is not available, only the edge E is removed.*/
6378 remove_edge_and_dominated_blocks (edge e)
6380 VEC (basic_block, heap) *bbs_to_remove = NULL;
6381 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6385 bool none_removed = false;
6387 basic_block bb, dbb;
6390 if (!dom_info_available_p (CDI_DOMINATORS))
6396 /* No updating is needed for edges to exit. */
6397 if (e->dest == EXIT_BLOCK_PTR)
6399 if (cfgcleanup_altered_bbs)
6400 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6405 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6406 that is not dominated by E->dest, then this set is empty. Otherwise,
6407 all the basic blocks dominated by E->dest are removed.
6409 Also, to DF_IDOM we store the immediate dominators of the blocks in
6410 the dominance frontier of E (i.e., of the successors of the
6411 removed blocks, if there are any, and of E->dest otherwise). */
6412 FOR_EACH_EDGE (f, ei, e->dest->preds)
6417 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6419 none_removed = true;
6424 df = BITMAP_ALLOC (NULL);
6425 df_idom = BITMAP_ALLOC (NULL);
6428 bitmap_set_bit (df_idom,
6429 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6432 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6433 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6435 FOR_EACH_EDGE (f, ei, bb->succs)
6437 if (f->dest != EXIT_BLOCK_PTR)
6438 bitmap_set_bit (df, f->dest->index);
6441 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6442 bitmap_clear_bit (df, bb->index);
6444 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6446 bb = BASIC_BLOCK (i);
6447 bitmap_set_bit (df_idom,
6448 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6452 if (cfgcleanup_altered_bbs)
6454 /* Record the set of the altered basic blocks. */
6455 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6456 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6459 /* Remove E and the cancelled blocks. */
6464 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6465 delete_basic_block (bb);
6468 /* Update the dominance information. The immediate dominator may change only
6469 for blocks whose immediate dominator belongs to DF_IDOM:
6471 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6472 removal. Let Z the arbitrary block such that idom(Z) = Y and
6473 Z dominates X after the removal. Before removal, there exists a path P
6474 from Y to X that avoids Z. Let F be the last edge on P that is
6475 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6476 dominates W, and because of P, Z does not dominate W), and W belongs to
6477 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6478 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6480 bb = BASIC_BLOCK (i);
6481 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6483 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6484 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6487 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6490 BITMAP_FREE (df_idom);
6491 VEC_free (basic_block, heap, bbs_to_remove);
6492 VEC_free (basic_block, heap, bbs_to_fix_dom);
6495 /* Purge dead EH edges from basic block BB. */
6498 gimple_purge_dead_eh_edges (basic_block bb)
6500 bool changed = false;
6503 gimple stmt = last_stmt (bb);
6505 if (stmt && stmt_can_throw_internal (stmt))
6508 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6510 if (e->flags & EDGE_EH)
6512 remove_edge_and_dominated_blocks (e);
6523 gimple_purge_all_dead_eh_edges (const_bitmap blocks)
6525 bool changed = false;
6529 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6531 changed |= gimple_purge_dead_eh_edges (BASIC_BLOCK (i));
6537 /* This function is called whenever a new edge is created or
6541 gimple_execute_on_growing_pred (edge e)
6543 basic_block bb = e->dest;
6546 reserve_phi_args_for_new_edge (bb);
6549 /* This function is called immediately before edge E is removed from
6550 the edge vector E->dest->preds. */
6553 gimple_execute_on_shrinking_pred (edge e)
6555 if (phi_nodes (e->dest))
6556 remove_phi_args (e);
6559 /*---------------------------------------------------------------------------
6560 Helper functions for Loop versioning
6561 ---------------------------------------------------------------------------*/
6563 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6564 of 'first'. Both of them are dominated by 'new_head' basic block. When
6565 'new_head' was created by 'second's incoming edge it received phi arguments
6566 on the edge by split_edge(). Later, additional edge 'e' was created to
6567 connect 'new_head' and 'first'. Now this routine adds phi args on this
6568 additional edge 'e' that new_head to second edge received as part of edge
6572 gimple_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6573 basic_block new_head, edge e)
6576 gimple_stmt_iterator psi1, psi2;
6578 edge e2 = find_edge (new_head, second);
6580 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6581 edge, we should always have an edge from NEW_HEAD to SECOND. */
6582 gcc_assert (e2 != NULL);
6584 /* Browse all 'second' basic block phi nodes and add phi args to
6585 edge 'e' for 'first' head. PHI args are always in correct order. */
6587 for (psi2 = gsi_start_phis (second),
6588 psi1 = gsi_start_phis (first);
6589 !gsi_end_p (psi2) && !gsi_end_p (psi1);
6590 gsi_next (&psi2), gsi_next (&psi1))
6592 phi1 = gsi_stmt (psi1);
6593 phi2 = gsi_stmt (psi2);
6594 def = PHI_ARG_DEF (phi2, e2->dest_idx);
6595 add_phi_arg (phi1, def, e);
6600 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6601 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6602 the destination of the ELSE part. */
6605 gimple_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6606 basic_block second_head ATTRIBUTE_UNUSED,
6607 basic_block cond_bb, void *cond_e)
6609 gimple_stmt_iterator gsi;
6610 gimple new_cond_expr;
6611 tree cond_expr = (tree) cond_e;
6614 /* Build new conditional expr */
6615 new_cond_expr = gimple_build_cond_from_tree (cond_expr,
6616 NULL_TREE, NULL_TREE);
6618 /* Add new cond in cond_bb. */
6619 gsi = gsi_last_bb (cond_bb);
6620 gsi_insert_after (&gsi, new_cond_expr, GSI_NEW_STMT);
6622 /* Adjust edges appropriately to connect new head with first head
6623 as well as second head. */
6624 e0 = single_succ_edge (cond_bb);
6625 e0->flags &= ~EDGE_FALLTHRU;
6626 e0->flags |= EDGE_FALSE_VALUE;
6629 struct cfg_hooks gimple_cfg_hooks = {
6631 gimple_verify_flow_info,
6632 gimple_dump_bb, /* dump_bb */
6633 create_bb, /* create_basic_block */
6634 gimple_redirect_edge_and_branch, /* redirect_edge_and_branch */
6635 gimple_redirect_edge_and_branch_force, /* redirect_edge_and_branch_force */
6636 gimple_can_remove_branch_p, /* can_remove_branch_p */
6637 remove_bb, /* delete_basic_block */
6638 gimple_split_block, /* split_block */
6639 gimple_move_block_after, /* move_block_after */
6640 gimple_can_merge_blocks_p, /* can_merge_blocks_p */
6641 gimple_merge_blocks, /* merge_blocks */
6642 gimple_predict_edge, /* predict_edge */
6643 gimple_predicted_by_p, /* predicted_by_p */
6644 gimple_can_duplicate_bb_p, /* can_duplicate_block_p */
6645 gimple_duplicate_bb, /* duplicate_block */
6646 gimple_split_edge, /* split_edge */
6647 gimple_make_forwarder_block, /* make_forward_block */
6648 NULL, /* tidy_fallthru_edge */
6649 gimple_block_ends_with_call_p,/* block_ends_with_call_p */
6650 gimple_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6651 gimple_flow_call_edges_add, /* flow_call_edges_add */
6652 gimple_execute_on_growing_pred, /* execute_on_growing_pred */
6653 gimple_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6654 gimple_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6655 gimple_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6656 gimple_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6657 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6658 flush_pending_stmts /* flush_pending_stmts */
6662 /* Split all critical edges. */
6665 split_critical_edges (void)
6671 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6672 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6673 mappings around the calls to split_edge. */
6674 start_recording_case_labels ();
6677 FOR_EACH_EDGE (e, ei, bb->succs)
6678 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6683 end_recording_case_labels ();
6687 struct gimple_opt_pass pass_split_crit_edges =
6691 "crited", /* name */
6693 split_critical_edges, /* execute */
6696 0, /* static_pass_number */
6697 TV_TREE_SPLIT_EDGES, /* tv_id */
6698 PROP_cfg, /* properties required */
6699 PROP_no_crit_edges, /* properties_provided */
6700 0, /* properties_destroyed */
6701 0, /* todo_flags_start */
6702 TODO_dump_func /* todo_flags_finish */
6707 /* Build a ternary operation and gimplify it. Emit code before GSI.
6708 Return the gimple_val holding the result. */
6711 gimplify_build3 (gimple_stmt_iterator *gsi, enum tree_code code,
6712 tree type, tree a, tree b, tree c)
6716 ret = fold_build3 (code, type, a, b, c);
6719 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
6723 /* Build a binary operation and gimplify it. Emit code before GSI.
6724 Return the gimple_val holding the result. */
6727 gimplify_build2 (gimple_stmt_iterator *gsi, enum tree_code code,
6728 tree type, tree a, tree b)
6732 ret = fold_build2 (code, type, a, b);
6735 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
6739 /* Build a unary operation and gimplify it. Emit code before GSI.
6740 Return the gimple_val holding the result. */
6743 gimplify_build1 (gimple_stmt_iterator *gsi, enum tree_code code, tree type,
6748 ret = fold_build1 (code, type, a);
6751 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
6757 /* Emit return warnings. */
6760 execute_warn_function_return (void)
6762 source_location location;
6767 /* If we have a path to EXIT, then we do return. */
6768 if (TREE_THIS_VOLATILE (cfun->decl)
6769 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
6771 location = UNKNOWN_LOCATION;
6772 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6774 last = last_stmt (e->src);
6775 if (gimple_code (last) == GIMPLE_RETURN
6776 && (location = gimple_location (last)) != UNKNOWN_LOCATION)
6779 if (location == UNKNOWN_LOCATION)
6780 location = cfun->function_end_locus;
6781 warning (0, "%H%<noreturn%> function does return", &location);
6784 /* If we see "return;" in some basic block, then we do reach the end
6785 without returning a value. */
6786 else if (warn_return_type
6787 && !TREE_NO_WARNING (cfun->decl)
6788 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
6789 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
6791 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6793 gimple last = last_stmt (e->src);
6794 if (gimple_code (last) == GIMPLE_RETURN
6795 && gimple_return_retval (last) == NULL
6796 && !gimple_no_warning_p (last))
6798 location = gimple_location (last);
6799 if (location == UNKNOWN_LOCATION)
6800 location = cfun->function_end_locus;
6801 warning_at (location, OPT_Wreturn_type, "control reaches end of non-void function");
6802 TREE_NO_WARNING (cfun->decl) = 1;
6811 /* Given a basic block B which ends with a conditional and has
6812 precisely two successors, determine which of the edges is taken if
6813 the conditional is true and which is taken if the conditional is
6814 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
6817 extract_true_false_edges_from_block (basic_block b,
6821 edge e = EDGE_SUCC (b, 0);
6823 if (e->flags & EDGE_TRUE_VALUE)
6826 *false_edge = EDGE_SUCC (b, 1);
6831 *true_edge = EDGE_SUCC (b, 1);
6835 struct gimple_opt_pass pass_warn_function_return =
6841 execute_warn_function_return, /* execute */
6844 0, /* static_pass_number */
6846 PROP_cfg, /* properties_required */
6847 0, /* properties_provided */
6848 0, /* properties_destroyed */
6849 0, /* todo_flags_start */
6850 0 /* todo_flags_finish */
6854 /* Emit noreturn warnings. */
6857 execute_warn_function_noreturn (void)
6859 if (warn_missing_noreturn
6860 && !TREE_THIS_VOLATILE (cfun->decl)
6861 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
6862 && !lang_hooks.missing_noreturn_ok_p (cfun->decl))
6863 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
6864 "for attribute %<noreturn%>",
6869 struct gimple_opt_pass pass_warn_function_noreturn =
6875 execute_warn_function_noreturn, /* execute */
6878 0, /* static_pass_number */
6880 PROP_cfg, /* properties_required */
6881 0, /* properties_provided */
6882 0, /* properties_destroyed */
6883 0, /* todo_flags_start */
6884 0 /* todo_flags_finish */