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
218 execute_build_cfg (void)
220 gimple_seq body = gimple_body (current_function_decl);
222 build_gimple_cfg (body);
223 gimple_set_body (current_function_decl, NULL);
227 struct gimple_opt_pass pass_build_cfg =
233 execute_build_cfg, /* execute */
236 0, /* static_pass_number */
237 TV_TREE_CFG, /* tv_id */
238 PROP_gimple_leh, /* properties_required */
239 PROP_cfg, /* properties_provided */
240 0, /* properties_destroyed */
241 0, /* todo_flags_start */
242 TODO_verify_stmts | TODO_cleanup_cfg
243 | TODO_dump_func /* 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 the contents of a GIMPLE_CALL STMT. Returns true when there
3172 is a problem, otherwise false. */
3175 verify_gimple_call (gimple stmt)
3177 tree fn = gimple_call_fn (stmt);
3180 if (!POINTER_TYPE_P (TREE_TYPE (fn))
3181 || (TREE_CODE (TREE_TYPE (TREE_TYPE (fn))) != FUNCTION_TYPE
3182 && TREE_CODE (TREE_TYPE (TREE_TYPE (fn))) != METHOD_TYPE))
3184 error ("non-function in gimple call");
3188 if (gimple_call_lhs (stmt)
3189 && !is_gimple_lvalue (gimple_call_lhs (stmt)))
3191 error ("invalid LHS in gimple call");
3195 fntype = TREE_TYPE (TREE_TYPE (fn));
3196 if (gimple_call_lhs (stmt)
3197 && !useless_type_conversion_p (TREE_TYPE (gimple_call_lhs (stmt)),
3199 /* ??? At least C++ misses conversions at assignments from
3200 void * call results.
3201 ??? Java is completely off. Especially with functions
3202 returning java.lang.Object.
3203 For now simply allow arbitrary pointer type conversions. */
3204 && !(POINTER_TYPE_P (TREE_TYPE (gimple_call_lhs (stmt)))
3205 && POINTER_TYPE_P (TREE_TYPE (fntype))))
3207 error ("invalid conversion in gimple call");
3208 debug_generic_stmt (TREE_TYPE (gimple_call_lhs (stmt)));
3209 debug_generic_stmt (TREE_TYPE (fntype));
3213 /* ??? The C frontend passes unpromoted arguments in case it
3214 didn't see a function declaration before the call. So for now
3215 leave the call arguments unverified. Once we gimplify
3216 unit-at-a-time we have a chance to fix this. */
3221 /* Verifies the gimple comparison with the result type TYPE and
3222 the operands OP0 and OP1. */
3225 verify_gimple_comparison (tree type, tree op0, tree op1)
3227 tree op0_type = TREE_TYPE (op0);
3228 tree op1_type = TREE_TYPE (op1);
3230 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3232 error ("invalid operands in gimple comparison");
3236 /* For comparisons we do not have the operations type as the
3237 effective type the comparison is carried out in. Instead
3238 we require that either the first operand is trivially
3239 convertible into the second, or the other way around.
3240 The resulting type of a comparison may be any integral type.
3241 Because we special-case pointers to void we allow
3242 comparisons of pointers with the same mode as well. */
3243 if ((!useless_type_conversion_p (op0_type, op1_type)
3244 && !useless_type_conversion_p (op1_type, op0_type)
3245 && (!POINTER_TYPE_P (op0_type)
3246 || !POINTER_TYPE_P (op1_type)
3247 || TYPE_MODE (op0_type) != TYPE_MODE (op1_type)))
3248 || !INTEGRAL_TYPE_P (type))
3250 error ("type mismatch in comparison expression");
3251 debug_generic_expr (type);
3252 debug_generic_expr (op0_type);
3253 debug_generic_expr (op1_type);
3260 /* Verify the contents of a GIMPLE_ASSIGN STMT. Returns true when there
3261 is a problem, otherwise false.
3263 Verify that the types of the LHS and the RHS operands are
3264 compatible. This verification largely depends on what kind of
3265 operation is done on the RHS of the assignment. It is not always
3266 the case that all the types of the operands must match (e.g., 'a =
3267 (unsigned long) b' or 'ptr = ptr + 1'). */
3270 verify_types_in_gimple_assign (gimple stmt)
3272 enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
3273 tree lhs = gimple_assign_lhs (stmt);
3274 tree rhs1 = gimple_assign_rhs1 (stmt);
3275 tree rhs2 = (gimple_num_ops (stmt) == 3) ? gimple_assign_rhs2 (stmt) : NULL;
3276 tree lhs_type = TREE_TYPE (lhs);
3277 tree rhs1_type = TREE_TYPE (rhs1);
3278 tree rhs2_type = (rhs2) ? TREE_TYPE (rhs2) : NULL;
3280 /* Special codes we cannot handle via their class. */
3285 if (!is_gimple_val (rhs1))
3287 error ("invalid operand in conversion");
3291 /* Allow conversions between integral types and pointers only if
3292 there is no sign or zero extension involved. */
3293 if (((POINTER_TYPE_P (lhs_type) && INTEGRAL_TYPE_P (rhs1_type))
3294 || (POINTER_TYPE_P (rhs1_type) && INTEGRAL_TYPE_P (lhs_type)))
3295 && (TYPE_PRECISION (lhs_type) == TYPE_PRECISION (rhs1_type)
3296 /* For targets were the precision of sizetype doesn't
3297 match that of pointers we need the following. */
3298 || lhs_type == sizetype || rhs1_type == sizetype))
3301 /* Allow conversion from integer to offset type and vice versa. */
3302 if ((TREE_CODE (lhs_type) == OFFSET_TYPE
3303 && TREE_CODE (rhs1_type) == INTEGER_TYPE)
3304 || (TREE_CODE (lhs_type) == INTEGER_TYPE
3305 && TREE_CODE (rhs1_type) == OFFSET_TYPE))
3308 /* Otherwise assert we are converting between types of the
3310 if (INTEGRAL_TYPE_P (lhs_type) != INTEGRAL_TYPE_P (rhs1_type))
3312 error ("invalid types in nop conversion");
3313 debug_generic_expr (lhs_type);
3314 debug_generic_expr (rhs1_type);
3321 case FIXED_CONVERT_EXPR:
3323 if (!is_gimple_val (rhs1))
3325 error ("invalid operand in conversion");
3329 if (!valid_fixed_convert_types_p (lhs_type, rhs1_type)
3330 && !valid_fixed_convert_types_p (rhs1_type, lhs_type))
3332 error ("invalid types in fixed-point conversion");
3333 debug_generic_expr (lhs_type);
3334 debug_generic_expr (rhs1_type);
3343 if (!is_gimple_val (rhs1))
3345 error ("invalid operand in int to float conversion");
3349 if (!INTEGRAL_TYPE_P (rhs1_type) || !SCALAR_FLOAT_TYPE_P (lhs_type))
3351 error ("invalid types in conversion to floating point");
3352 debug_generic_expr (lhs_type);
3353 debug_generic_expr (rhs1_type);
3360 case FIX_TRUNC_EXPR:
3362 if (!is_gimple_val (rhs1))
3364 error ("invalid operand in float to int conversion");
3368 if (!INTEGRAL_TYPE_P (lhs_type) || !SCALAR_FLOAT_TYPE_P (rhs1_type))
3370 error ("invalid types in conversion to integer");
3371 debug_generic_expr (lhs_type);
3372 debug_generic_expr (rhs1_type);
3381 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3383 error ("invalid operands in complex expression");
3387 if (!TREE_CODE (lhs_type) == COMPLEX_TYPE
3388 || !(TREE_CODE (rhs1_type) == INTEGER_TYPE
3389 || SCALAR_FLOAT_TYPE_P (rhs1_type))
3390 || !(TREE_CODE (rhs2_type) == INTEGER_TYPE
3391 || SCALAR_FLOAT_TYPE_P (rhs2_type)))
3393 error ("type mismatch in complex expression");
3394 debug_generic_expr (lhs_type);
3395 debug_generic_expr (rhs1_type);
3396 debug_generic_expr (rhs2_type);
3405 /* In this context we know that we are on the RHS of an
3406 assignment, so CONSTRUCTOR operands are OK. */
3407 /* FIXME: verify constructor arguments. */
3416 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3418 error ("invalid operands in shift expression");
3422 if (!TREE_CODE (rhs1_type) == INTEGER_TYPE
3423 || !useless_type_conversion_p (lhs_type, rhs1_type))
3425 error ("type mismatch in shift expression");
3426 debug_generic_expr (lhs_type);
3427 debug_generic_expr (rhs1_type);
3428 debug_generic_expr (rhs2_type);
3438 if (POINTER_TYPE_P (lhs_type)
3439 || POINTER_TYPE_P (rhs1_type)
3440 || POINTER_TYPE_P (rhs2_type))
3442 error ("invalid (pointer) operands to plus/minus");
3446 /* Continue with generic binary expression handling. */
3450 case POINTER_PLUS_EXPR:
3452 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3454 error ("invalid operands in pointer plus expression");
3457 if (!POINTER_TYPE_P (rhs1_type)
3458 || !useless_type_conversion_p (lhs_type, rhs1_type)
3459 || !useless_type_conversion_p (sizetype, rhs2_type))
3461 error ("type mismatch in pointer plus expression");
3462 debug_generic_stmt (lhs_type);
3463 debug_generic_stmt (rhs1_type);
3464 debug_generic_stmt (rhs2_type);
3473 tree op = TREE_OPERAND (rhs1, 0);
3474 if (!is_gimple_addressable (op))
3476 error ("invalid operand in unary expression");
3480 if (!one_pointer_to_useless_type_conversion_p (lhs_type, TREE_TYPE (op))
3481 /* FIXME: a longstanding wart, &a == &a[0]. */
3482 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3483 || !one_pointer_to_useless_type_conversion_p (lhs_type,
3484 TREE_TYPE (TREE_TYPE (op)))))
3486 error ("type mismatch in address expression");
3487 debug_generic_stmt (lhs_type);
3488 debug_generic_stmt (TYPE_POINTER_TO (TREE_TYPE (op)));
3492 return verify_types_in_gimple_reference (TREE_OPERAND (rhs1, 0));
3495 case TRUTH_ANDIF_EXPR:
3496 case TRUTH_ORIF_EXPR:
3499 case TRUTH_AND_EXPR:
3501 case TRUTH_XOR_EXPR:
3503 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3505 error ("invalid operands in truth expression");
3509 /* We allow any kind of integral typed argument and result. */
3510 if (!INTEGRAL_TYPE_P (rhs1_type)
3511 || !INTEGRAL_TYPE_P (rhs2_type)
3512 || !INTEGRAL_TYPE_P (lhs_type))
3514 error ("type mismatch in binary truth expression");
3515 debug_generic_expr (lhs_type);
3516 debug_generic_expr (rhs1_type);
3517 debug_generic_expr (rhs2_type);
3524 case TRUTH_NOT_EXPR:
3526 if (!is_gimple_val (rhs1))
3528 error ("invalid operand in unary not");
3532 /* For TRUTH_NOT_EXPR we can have any kind of integral
3533 typed arguments and results. */
3534 if (!INTEGRAL_TYPE_P (rhs1_type)
3535 || !INTEGRAL_TYPE_P (lhs_type))
3537 error ("type mismatch in not expression");
3538 debug_generic_expr (lhs_type);
3539 debug_generic_expr (rhs1_type);
3546 /* After gimplification we should not have any of these. */
3558 case TRY_FINALLY_EXPR:
3559 case TRY_CATCH_EXPR:
3560 case EH_FILTER_EXPR:
3561 case STATEMENT_LIST:
3563 error ("tree node that should already be gimple.");
3574 /* Generic handling via classes. */
3575 switch (TREE_CODE_CLASS (rhs_code))
3577 case tcc_exceptional: /* for SSA_NAME */
3579 if (!useless_type_conversion_p (lhs_type, rhs1_type))
3581 error ("non-trivial conversion at assignment");
3582 debug_generic_expr (lhs_type);
3583 debug_generic_expr (rhs1_type);
3589 if (!is_gimple_val (rhs1) || !is_gimple_val (rhs2))
3591 error ("invalid operands in binary expression");
3594 if (!useless_type_conversion_p (lhs_type, rhs1_type)
3595 || !useless_type_conversion_p (lhs_type, rhs2_type))
3597 error ("type mismatch in binary expression");
3598 debug_generic_stmt (lhs_type);
3599 debug_generic_stmt (rhs1_type);
3600 debug_generic_stmt (rhs2_type);
3606 /* All tcc_reference trees are GIMPLE_SINGLE_RHS. Verify that
3607 no implicit type change happens here. */
3608 if (!useless_type_conversion_p (lhs_type, rhs1_type))
3610 error ("non-trivial conversion at assignment");
3611 debug_generic_expr (lhs_type);
3612 debug_generic_expr (rhs1_type);
3615 return verify_types_in_gimple_reference (rhs1);
3617 case tcc_comparison:
3618 return verify_gimple_comparison (lhs_type, rhs1, rhs2);
3627 /* Verify the contents of a GIMPLE_RETURN STMT. Returns true when there
3628 is a problem, otherwise false. */
3631 verify_gimple_return (gimple stmt)
3633 tree op = gimple_return_retval (stmt);
3634 tree restype = TREE_TYPE (TREE_TYPE (cfun->decl));
3636 /* We cannot test for present return values as we do not fix up missing
3637 return values from the original source. */
3641 if (!is_gimple_val (op)
3642 && TREE_CODE (op) != RESULT_DECL)
3644 error ("invalid operand in return statement");
3645 debug_generic_stmt (op);
3649 if (!useless_type_conversion_p (restype, TREE_TYPE (op))
3650 /* ??? With C++ we can have the situation that the result
3651 decl is a reference type while the return type is an aggregate. */
3652 && !(TREE_CODE (op) == RESULT_DECL
3653 && TREE_CODE (TREE_TYPE (op)) == REFERENCE_TYPE
3654 && useless_type_conversion_p (restype, TREE_TYPE (TREE_TYPE (op)))))
3656 error ("invalid conversion in return statement");
3657 debug_generic_stmt (restype);
3658 debug_generic_stmt (TREE_TYPE (op));
3666 /* Verify the contents of a GIMPLE_GOTO STMT. Returns true when there
3667 is a problem, otherwise false. */
3670 verify_gimple_goto (gimple stmt)
3672 tree dest = gimple_goto_dest (stmt);
3674 /* ??? We have two canonical forms of direct goto destinations, a
3675 bare LABEL_DECL and an ADDR_EXPR of a LABEL_DECL. */
3676 if (TREE_CODE (dest) != LABEL_DECL
3677 && (!is_gimple_val (dest)
3678 || !POINTER_TYPE_P (TREE_TYPE (dest))))
3680 error ("goto destination is neither a label nor a pointer");
3687 /* Verify the contents of a GIMPLE_SWITCH STMT. Returns true when there
3688 is a problem, otherwise false. */
3691 verify_gimple_switch (gimple stmt)
3693 if (!is_gimple_val (gimple_switch_index (stmt)))
3695 error ("invalid operand to switch statement");
3696 debug_generic_stmt (gimple_switch_index (stmt));
3704 /* Verify the contents of a GIMPLE_PHI. Returns true if there is a problem,
3705 and false otherwise. */
3708 verify_gimple_phi (gimple stmt)
3710 tree type = TREE_TYPE (gimple_phi_result (stmt));
3713 if (!is_gimple_variable (gimple_phi_result (stmt)))
3715 error ("Invalid PHI result");
3719 for (i = 0; i < gimple_phi_num_args (stmt); i++)
3721 tree arg = gimple_phi_arg_def (stmt, i);
3722 if (!is_gimple_val (arg))
3724 error ("Invalid PHI argument");
3725 debug_generic_stmt (arg);
3728 if (!useless_type_conversion_p (type, TREE_TYPE (arg)))
3730 error ("Incompatible types in PHI argument");
3731 debug_generic_stmt (type);
3732 debug_generic_stmt (TREE_TYPE (arg));
3741 /* Verify the GIMPLE statement STMT. Returns true if there is an
3742 error, otherwise false. */
3745 verify_types_in_gimple_stmt (gimple stmt)
3747 if (is_gimple_omp (stmt))
3749 /* OpenMP directives are validated by the FE and never operated
3750 on by the optimizers. Furthermore, GIMPLE_OMP_FOR may contain
3751 non-gimple expressions when the main index variable has had
3752 its address taken. This does not affect the loop itself
3753 because the header of an GIMPLE_OMP_FOR is merely used to determine
3754 how to setup the parallel iteration. */
3758 switch (gimple_code (stmt))
3761 return verify_types_in_gimple_assign (stmt);
3764 return TREE_CODE (gimple_label_label (stmt)) != LABEL_DECL;
3767 return verify_gimple_call (stmt);
3770 return verify_gimple_comparison (boolean_type_node,
3771 gimple_cond_lhs (stmt),
3772 gimple_cond_rhs (stmt));
3775 return verify_gimple_goto (stmt);
3778 return verify_gimple_switch (stmt);
3781 return verify_gimple_return (stmt);
3786 case GIMPLE_CHANGE_DYNAMIC_TYPE:
3787 return (!is_gimple_reg (gimple_cdt_location (stmt))
3788 || !POINTER_TYPE_P (TREE_TYPE (gimple_cdt_location (stmt))));
3791 return verify_gimple_phi (stmt);
3793 /* Tuples that do not have tree operands. */
3796 case GIMPLE_PREDICT:
3804 /* Verify the GIMPLE statements inside the sequence STMTS. */
3807 verify_types_in_gimple_seq_2 (gimple_seq stmts)
3809 gimple_stmt_iterator ittr;
3812 for (ittr = gsi_start (stmts); !gsi_end_p (ittr); gsi_next (&ittr))
3814 gimple stmt = gsi_stmt (ittr);
3816 switch (gimple_code (stmt))
3819 err |= verify_types_in_gimple_seq_2 (gimple_bind_body (stmt));
3823 err |= verify_types_in_gimple_seq_2 (gimple_try_eval (stmt));
3824 err |= verify_types_in_gimple_seq_2 (gimple_try_cleanup (stmt));
3827 case GIMPLE_EH_FILTER:
3828 err |= verify_types_in_gimple_seq_2 (gimple_eh_filter_failure (stmt));
3832 err |= verify_types_in_gimple_seq_2 (gimple_catch_handler (stmt));
3837 bool err2 = verify_types_in_gimple_stmt (stmt);
3839 debug_gimple_stmt (stmt);
3849 /* Verify the GIMPLE statements inside the statement list STMTS. */
3852 verify_types_in_gimple_seq (gimple_seq stmts)
3854 if (verify_types_in_gimple_seq_2 (stmts))
3855 internal_error ("verify_gimple failed");
3859 /* Verify STMT, return true if STMT is not in GIMPLE form.
3860 TODO: Implement type checking. */
3863 verify_stmt (gimple_stmt_iterator *gsi)
3866 struct walk_stmt_info wi;
3867 bool last_in_block = gsi_one_before_end_p (*gsi);
3868 gimple stmt = gsi_stmt (*gsi);
3870 if (is_gimple_omp (stmt))
3872 /* OpenMP directives are validated by the FE and never operated
3873 on by the optimizers. Furthermore, GIMPLE_OMP_FOR may contain
3874 non-gimple expressions when the main index variable has had
3875 its address taken. This does not affect the loop itself
3876 because the header of an GIMPLE_OMP_FOR is merely used to determine
3877 how to setup the parallel iteration. */
3881 /* FIXME. The C frontend passes unpromoted arguments in case it
3882 didn't see a function declaration before the call. */
3883 if (is_gimple_call (stmt))
3887 if (!is_gimple_call_addr (gimple_call_fn (stmt)))
3889 error ("invalid function in call statement");
3893 decl = gimple_call_fndecl (stmt);
3895 && TREE_CODE (decl) == FUNCTION_DECL
3896 && DECL_LOOPING_CONST_OR_PURE_P (decl)
3897 && (!DECL_PURE_P (decl))
3898 && (!TREE_READONLY (decl)))
3900 error ("invalid pure const state for function");
3905 memset (&wi, 0, sizeof (wi));
3906 addr = walk_gimple_op (gsi_stmt (*gsi), verify_expr, &wi);
3909 debug_generic_expr (addr);
3910 inform (input_location, "in statement");
3911 debug_gimple_stmt (stmt);
3915 /* If the statement is marked as part of an EH region, then it is
3916 expected that the statement could throw. Verify that when we
3917 have optimizations that simplify statements such that we prove
3918 that they cannot throw, that we update other data structures
3920 if (lookup_stmt_eh_region (stmt) >= 0)
3922 if (!stmt_could_throw_p (stmt))
3924 error ("statement marked for throw, but doesn%'t");
3927 if (!last_in_block && stmt_can_throw_internal (stmt))
3929 error ("statement marked for throw in middle of block");
3937 debug_gimple_stmt (stmt);
3942 /* Return true when the T can be shared. */
3945 tree_node_can_be_shared (tree t)
3947 if (IS_TYPE_OR_DECL_P (t)
3948 || is_gimple_min_invariant (t)
3949 || TREE_CODE (t) == SSA_NAME
3950 || t == error_mark_node
3951 || TREE_CODE (t) == IDENTIFIER_NODE)
3954 if (TREE_CODE (t) == CASE_LABEL_EXPR)
3957 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
3958 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
3959 || TREE_CODE (t) == COMPONENT_REF
3960 || TREE_CODE (t) == REALPART_EXPR
3961 || TREE_CODE (t) == IMAGPART_EXPR)
3962 t = TREE_OPERAND (t, 0);
3971 /* Called via walk_gimple_stmt. Verify tree sharing. */
3974 verify_node_sharing (tree *tp, int *walk_subtrees, void *data)
3976 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
3977 struct pointer_set_t *visited = (struct pointer_set_t *) wi->info;
3979 if (tree_node_can_be_shared (*tp))
3981 *walk_subtrees = false;
3985 if (pointer_set_insert (visited, *tp))
3992 static bool eh_error_found;
3994 verify_eh_throw_stmt_node (void **slot, void *data)
3996 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
3997 struct pointer_set_t *visited = (struct pointer_set_t *) data;
3999 if (!pointer_set_contains (visited, node->stmt))
4001 error ("Dead STMT in EH table");
4002 debug_gimple_stmt (node->stmt);
4003 eh_error_found = true;
4009 /* Verify the GIMPLE statements in every basic block. */
4015 gimple_stmt_iterator gsi;
4017 struct pointer_set_t *visited, *visited_stmts;
4019 struct walk_stmt_info wi;
4021 timevar_push (TV_TREE_STMT_VERIFY);
4022 visited = pointer_set_create ();
4023 visited_stmts = pointer_set_create ();
4025 memset (&wi, 0, sizeof (wi));
4026 wi.info = (void *) visited;
4033 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4035 phi = gsi_stmt (gsi);
4036 pointer_set_insert (visited_stmts, phi);
4037 if (gimple_bb (phi) != bb)
4039 error ("gimple_bb (phi) is set to a wrong basic block");
4043 for (i = 0; i < gimple_phi_num_args (phi); i++)
4045 tree t = gimple_phi_arg_def (phi, i);
4050 error ("missing PHI def");
4051 debug_gimple_stmt (phi);
4055 /* Addressable variables do have SSA_NAMEs but they
4056 are not considered gimple values. */
4057 else if (TREE_CODE (t) != SSA_NAME
4058 && TREE_CODE (t) != FUNCTION_DECL
4059 && !is_gimple_min_invariant (t))
4061 error ("PHI argument is not a GIMPLE value");
4062 debug_gimple_stmt (phi);
4063 debug_generic_expr (t);
4067 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4070 error ("incorrect sharing of tree nodes");
4071 debug_gimple_stmt (phi);
4072 debug_generic_expr (addr);
4078 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
4080 gimple stmt = gsi_stmt (gsi);
4082 if (gimple_code (stmt) == GIMPLE_WITH_CLEANUP_EXPR
4083 || gimple_code (stmt) == GIMPLE_BIND)
4085 error ("invalid GIMPLE statement");
4086 debug_gimple_stmt (stmt);
4090 pointer_set_insert (visited_stmts, stmt);
4092 if (gimple_bb (stmt) != bb)
4094 error ("gimple_bb (stmt) is set to a wrong basic block");
4098 if (gimple_code (stmt) == GIMPLE_LABEL)
4100 tree decl = gimple_label_label (stmt);
4101 int uid = LABEL_DECL_UID (decl);
4104 || VEC_index (basic_block, label_to_block_map, uid) != bb)
4106 error ("incorrect entry in label_to_block_map.\n");
4111 err |= verify_stmt (&gsi);
4112 addr = walk_gimple_op (gsi_stmt (gsi), verify_node_sharing, &wi);
4115 error ("incorrect sharing of tree nodes");
4116 debug_gimple_stmt (stmt);
4117 debug_generic_expr (addr);
4124 eh_error_found = false;
4125 if (get_eh_throw_stmt_table (cfun))
4126 htab_traverse (get_eh_throw_stmt_table (cfun),
4127 verify_eh_throw_stmt_node,
4130 if (err | eh_error_found)
4131 internal_error ("verify_stmts failed");
4133 pointer_set_destroy (visited);
4134 pointer_set_destroy (visited_stmts);
4135 verify_histograms ();
4136 timevar_pop (TV_TREE_STMT_VERIFY);
4140 /* Verifies that the flow information is OK. */
4143 gimple_verify_flow_info (void)
4147 gimple_stmt_iterator gsi;
4152 if (ENTRY_BLOCK_PTR->il.gimple)
4154 error ("ENTRY_BLOCK has IL associated with it");
4158 if (EXIT_BLOCK_PTR->il.gimple)
4160 error ("EXIT_BLOCK has IL associated with it");
4164 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4165 if (e->flags & EDGE_FALLTHRU)
4167 error ("fallthru to exit from bb %d", e->src->index);
4173 bool found_ctrl_stmt = false;
4177 /* Skip labels on the start of basic block. */
4178 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4181 gimple prev_stmt = stmt;
4183 stmt = gsi_stmt (gsi);
4185 if (gimple_code (stmt) != GIMPLE_LABEL)
4188 label = gimple_label_label (stmt);
4189 if (prev_stmt && DECL_NONLOCAL (label))
4191 error ("nonlocal label ");
4192 print_generic_expr (stderr, label, 0);
4193 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4198 if (label_to_block (label) != bb)
4201 print_generic_expr (stderr, label, 0);
4202 fprintf (stderr, " to block does not match in bb %d",
4207 if (decl_function_context (label) != current_function_decl)
4210 print_generic_expr (stderr, label, 0);
4211 fprintf (stderr, " has incorrect context in bb %d",
4217 /* Verify that body of basic block BB is free of control flow. */
4218 for (; !gsi_end_p (gsi); gsi_next (&gsi))
4220 gimple stmt = gsi_stmt (gsi);
4222 if (found_ctrl_stmt)
4224 error ("control flow in the middle of basic block %d",
4229 if (stmt_ends_bb_p (stmt))
4230 found_ctrl_stmt = true;
4232 if (gimple_code (stmt) == GIMPLE_LABEL)
4235 print_generic_expr (stderr, gimple_label_label (stmt), 0);
4236 fprintf (stderr, " in the middle of basic block %d", bb->index);
4241 gsi = gsi_last_bb (bb);
4242 if (gsi_end_p (gsi))
4245 stmt = gsi_stmt (gsi);
4247 err |= verify_eh_edges (stmt);
4249 if (is_ctrl_stmt (stmt))
4251 FOR_EACH_EDGE (e, ei, bb->succs)
4252 if (e->flags & EDGE_FALLTHRU)
4254 error ("fallthru edge after a control statement in bb %d",
4260 if (gimple_code (stmt) != GIMPLE_COND)
4262 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4263 after anything else but if statement. */
4264 FOR_EACH_EDGE (e, ei, bb->succs)
4265 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4267 error ("true/false edge after a non-GIMPLE_COND in bb %d",
4273 switch (gimple_code (stmt))
4280 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4284 || !(true_edge->flags & EDGE_TRUE_VALUE)
4285 || !(false_edge->flags & EDGE_FALSE_VALUE)
4286 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4287 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4288 || EDGE_COUNT (bb->succs) >= 3)
4290 error ("wrong outgoing edge flags at end of bb %d",
4298 if (simple_goto_p (stmt))
4300 error ("explicit goto at end of bb %d", bb->index);
4305 /* FIXME. We should double check that the labels in the
4306 destination blocks have their address taken. */
4307 FOR_EACH_EDGE (e, ei, bb->succs)
4308 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4309 | EDGE_FALSE_VALUE))
4310 || !(e->flags & EDGE_ABNORMAL))
4312 error ("wrong outgoing edge flags at end of bb %d",
4320 if (!single_succ_p (bb)
4321 || (single_succ_edge (bb)->flags
4322 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4323 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4325 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4328 if (single_succ (bb) != EXIT_BLOCK_PTR)
4330 error ("return edge does not point to exit in bb %d",
4342 n = gimple_switch_num_labels (stmt);
4344 /* Mark all the destination basic blocks. */
4345 for (i = 0; i < n; ++i)
4347 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4348 basic_block label_bb = label_to_block (lab);
4349 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4350 label_bb->aux = (void *)1;
4353 /* Verify that the case labels are sorted. */
4354 prev = gimple_switch_label (stmt, 0);
4355 for (i = 1; i < n; ++i)
4357 tree c = gimple_switch_label (stmt, i);
4360 error ("found default case not at the start of "
4366 && !tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4368 error ("case labels not sorted: ");
4369 print_generic_expr (stderr, prev, 0);
4370 fprintf (stderr," is greater than ");
4371 print_generic_expr (stderr, c, 0);
4372 fprintf (stderr," but comes before it.\n");
4377 /* VRP will remove the default case if it can prove it will
4378 never be executed. So do not verify there always exists
4379 a default case here. */
4381 FOR_EACH_EDGE (e, ei, bb->succs)
4385 error ("extra outgoing edge %d->%d",
4386 bb->index, e->dest->index);
4390 e->dest->aux = (void *)2;
4391 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4392 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4394 error ("wrong outgoing edge flags at end of bb %d",
4400 /* Check that we have all of them. */
4401 for (i = 0; i < n; ++i)
4403 tree lab = CASE_LABEL (gimple_switch_label (stmt, i));
4404 basic_block label_bb = label_to_block (lab);
4406 if (label_bb->aux != (void *)2)
4408 error ("missing edge %i->%i", bb->index, label_bb->index);
4413 FOR_EACH_EDGE (e, ei, bb->succs)
4414 e->dest->aux = (void *)0;
4421 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4422 verify_dominators (CDI_DOMINATORS);
4428 /* Updates phi nodes after creating a forwarder block joined
4429 by edge FALLTHRU. */
4432 gimple_make_forwarder_block (edge fallthru)
4436 basic_block dummy, bb;
4438 gimple_stmt_iterator gsi;
4440 dummy = fallthru->src;
4441 bb = fallthru->dest;
4443 if (single_pred_p (bb))
4446 /* If we redirected a branch we must create new PHI nodes at the
4448 for (gsi = gsi_start_phis (dummy); !gsi_end_p (gsi); gsi_next (&gsi))
4450 gimple phi, new_phi;
4452 phi = gsi_stmt (gsi);
4453 var = gimple_phi_result (phi);
4454 new_phi = create_phi_node (var, bb);
4455 SSA_NAME_DEF_STMT (var) = new_phi;
4456 gimple_phi_set_result (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4457 add_phi_arg (new_phi, gimple_phi_result (phi), fallthru);
4460 /* Add the arguments we have stored on edges. */
4461 FOR_EACH_EDGE (e, ei, bb->preds)
4466 flush_pending_stmts (e);
4471 /* Return a non-special label in the head of basic block BLOCK.
4472 Create one if it doesn't exist. */
4475 gimple_block_label (basic_block bb)
4477 gimple_stmt_iterator i, s = gsi_start_bb (bb);
4482 for (i = s; !gsi_end_p (i); first = false, gsi_next (&i))
4484 stmt = gsi_stmt (i);
4485 if (gimple_code (stmt) != GIMPLE_LABEL)
4487 label = gimple_label_label (stmt);
4488 if (!DECL_NONLOCAL (label))
4491 gsi_move_before (&i, &s);
4496 label = create_artificial_label ();
4497 stmt = gimple_build_label (label);
4498 gsi_insert_before (&s, stmt, GSI_NEW_STMT);
4503 /* Attempt to perform edge redirection by replacing a possibly complex
4504 jump instruction by a goto or by removing the jump completely.
4505 This can apply only if all edges now point to the same block. The
4506 parameters and return values are equivalent to
4507 redirect_edge_and_branch. */
4510 gimple_try_redirect_by_replacing_jump (edge e, basic_block target)
4512 basic_block src = e->src;
4513 gimple_stmt_iterator i;
4516 /* We can replace or remove a complex jump only when we have exactly
4518 if (EDGE_COUNT (src->succs) != 2
4519 /* Verify that all targets will be TARGET. Specifically, the
4520 edge that is not E must also go to TARGET. */
4521 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4524 i = gsi_last_bb (src);
4528 stmt = gsi_stmt (i);
4530 if (gimple_code (stmt) == GIMPLE_COND || gimple_code (stmt) == GIMPLE_SWITCH)
4532 gsi_remove (&i, true);
4533 e = ssa_redirect_edge (e, target);
4534 e->flags = EDGE_FALLTHRU;
4542 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4543 edge representing the redirected branch. */
4546 gimple_redirect_edge_and_branch (edge e, basic_block dest)
4548 basic_block bb = e->src;
4549 gimple_stmt_iterator gsi;
4553 if (e->flags & EDGE_ABNORMAL)
4556 if (e->src != ENTRY_BLOCK_PTR
4557 && (ret = gimple_try_redirect_by_replacing_jump (e, dest)))
4560 if (e->dest == dest)
4563 gsi = gsi_last_bb (bb);
4564 stmt = gsi_end_p (gsi) ? NULL : gsi_stmt (gsi);
4566 switch (stmt ? gimple_code (stmt) : ERROR_MARK)
4569 /* For COND_EXPR, we only need to redirect the edge. */
4573 /* No non-abnormal edges should lead from a non-simple goto, and
4574 simple ones should be represented implicitly. */
4579 tree label = gimple_block_label (dest);
4580 tree cases = get_cases_for_edge (e, stmt);
4582 /* If we have a list of cases associated with E, then use it
4583 as it's a lot faster than walking the entire case vector. */
4586 edge e2 = find_edge (e->src, dest);
4593 CASE_LABEL (cases) = label;
4594 cases = TREE_CHAIN (cases);
4597 /* If there was already an edge in the CFG, then we need
4598 to move all the cases associated with E to E2. */
4601 tree cases2 = get_cases_for_edge (e2, stmt);
4603 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4604 TREE_CHAIN (cases2) = first;
4609 size_t i, n = gimple_switch_num_labels (stmt);
4611 for (i = 0; i < n; i++)
4613 tree elt = gimple_switch_label (stmt, i);
4614 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4615 CASE_LABEL (elt) = label;
4623 gsi_remove (&gsi, true);
4624 e->flags |= EDGE_FALLTHRU;
4627 case GIMPLE_OMP_RETURN:
4628 case GIMPLE_OMP_CONTINUE:
4629 case GIMPLE_OMP_SECTIONS_SWITCH:
4630 case GIMPLE_OMP_FOR:
4631 /* The edges from OMP constructs can be simply redirected. */
4635 /* Otherwise it must be a fallthru edge, and we don't need to
4636 do anything besides redirecting it. */
4637 gcc_assert (e->flags & EDGE_FALLTHRU);
4641 /* Update/insert PHI nodes as necessary. */
4643 /* Now update the edges in the CFG. */
4644 e = ssa_redirect_edge (e, dest);
4649 /* Returns true if it is possible to remove edge E by redirecting
4650 it to the destination of the other edge from E->src. */
4653 gimple_can_remove_branch_p (const_edge e)
4655 if (e->flags & EDGE_ABNORMAL)
4661 /* Simple wrapper, as we can always redirect fallthru edges. */
4664 gimple_redirect_edge_and_branch_force (edge e, basic_block dest)
4666 e = gimple_redirect_edge_and_branch (e, dest);
4673 /* Splits basic block BB after statement STMT (but at least after the
4674 labels). If STMT is NULL, BB is split just after the labels. */
4677 gimple_split_block (basic_block bb, void *stmt)
4679 gimple_stmt_iterator gsi;
4680 gimple_stmt_iterator gsi_tgt;
4687 new_bb = create_empty_bb (bb);
4689 /* Redirect the outgoing edges. */
4690 new_bb->succs = bb->succs;
4692 FOR_EACH_EDGE (e, ei, new_bb->succs)
4695 if (stmt && gimple_code ((gimple) stmt) == GIMPLE_LABEL)
4698 /* Move everything from GSI to the new basic block. */
4699 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4701 act = gsi_stmt (gsi);
4702 if (gimple_code (act) == GIMPLE_LABEL)
4715 if (gsi_end_p (gsi))
4718 /* Split the statement list - avoid re-creating new containers as this
4719 brings ugly quadratic memory consumption in the inliner.
4720 (We are still quadratic since we need to update stmt BB pointers,
4722 list = gsi_split_seq_before (&gsi);
4723 set_bb_seq (new_bb, list);
4724 for (gsi_tgt = gsi_start (list);
4725 !gsi_end_p (gsi_tgt); gsi_next (&gsi_tgt))
4726 gimple_set_bb (gsi_stmt (gsi_tgt), new_bb);
4732 /* Moves basic block BB after block AFTER. */
4735 gimple_move_block_after (basic_block bb, basic_block after)
4737 if (bb->prev_bb == after)
4741 link_block (bb, after);
4747 /* Return true if basic_block can be duplicated. */
4750 gimple_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
4755 /* Create a duplicate of the basic block BB. NOTE: This does not
4756 preserve SSA form. */
4759 gimple_duplicate_bb (basic_block bb)
4762 gimple_stmt_iterator gsi, gsi_tgt;
4763 gimple_seq phis = phi_nodes (bb);
4764 gimple phi, stmt, copy;
4766 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
4768 /* Copy the PHI nodes. We ignore PHI node arguments here because
4769 the incoming edges have not been setup yet. */
4770 for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi))
4772 phi = gsi_stmt (gsi);
4773 copy = create_phi_node (gimple_phi_result (phi), new_bb);
4774 create_new_def_for (gimple_phi_result (copy), copy,
4775 gimple_phi_result_ptr (copy));
4778 gsi_tgt = gsi_start_bb (new_bb);
4779 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
4781 def_operand_p def_p;
4782 ssa_op_iter op_iter;
4785 stmt = gsi_stmt (gsi);
4786 if (gimple_code (stmt) == GIMPLE_LABEL)
4789 /* Create a new copy of STMT and duplicate STMT's virtual
4791 copy = gimple_copy (stmt);
4792 gsi_insert_after (&gsi_tgt, copy, GSI_NEW_STMT);
4793 copy_virtual_operands (copy, stmt);
4794 region = lookup_stmt_eh_region (stmt);
4796 add_stmt_to_eh_region (copy, region);
4797 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
4799 /* Create new names for all the definitions created by COPY and
4800 add replacement mappings for each new name. */
4801 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
4802 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
4808 /* Adds phi node arguments for edge E_COPY after basic block duplication. */
4811 add_phi_args_after_copy_edge (edge e_copy)
4813 basic_block bb, bb_copy = e_copy->src, dest;
4816 gimple phi, phi_copy;
4818 gimple_stmt_iterator psi, psi_copy;
4820 if (gimple_seq_empty_p (phi_nodes (e_copy->dest)))
4823 bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
4825 if (e_copy->dest->flags & BB_DUPLICATED)
4826 dest = get_bb_original (e_copy->dest);
4828 dest = e_copy->dest;
4830 e = find_edge (bb, dest);
4833 /* During loop unrolling the target of the latch edge is copied.
4834 In this case we are not looking for edge to dest, but to
4835 duplicated block whose original was dest. */
4836 FOR_EACH_EDGE (e, ei, bb->succs)
4838 if ((e->dest->flags & BB_DUPLICATED)
4839 && get_bb_original (e->dest) == dest)
4843 gcc_assert (e != NULL);
4846 for (psi = gsi_start_phis (e->dest),
4847 psi_copy = gsi_start_phis (e_copy->dest);
4849 gsi_next (&psi), gsi_next (&psi_copy))
4851 phi = gsi_stmt (psi);
4852 phi_copy = gsi_stmt (psi_copy);
4853 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
4854 add_phi_arg (phi_copy, def, e_copy);
4859 /* Basic block BB_COPY was created by code duplication. Add phi node
4860 arguments for edges going out of BB_COPY. The blocks that were
4861 duplicated have BB_DUPLICATED set. */
4864 add_phi_args_after_copy_bb (basic_block bb_copy)
4869 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
4871 add_phi_args_after_copy_edge (e_copy);
4875 /* Blocks in REGION_COPY array of length N_REGION were created by
4876 duplication of basic blocks. Add phi node arguments for edges
4877 going from these blocks. If E_COPY is not NULL, also add
4878 phi node arguments for its destination.*/
4881 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
4886 for (i = 0; i < n_region; i++)
4887 region_copy[i]->flags |= BB_DUPLICATED;
4889 for (i = 0; i < n_region; i++)
4890 add_phi_args_after_copy_bb (region_copy[i]);
4892 add_phi_args_after_copy_edge (e_copy);
4894 for (i = 0; i < n_region; i++)
4895 region_copy[i]->flags &= ~BB_DUPLICATED;
4898 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
4899 important exit edge EXIT. By important we mean that no SSA name defined
4900 inside region is live over the other exit edges of the region. All entry
4901 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
4902 to the duplicate of the region. SSA form, dominance and loop information
4903 is updated. The new basic blocks are stored to REGION_COPY in the same
4904 order as they had in REGION, provided that REGION_COPY is not NULL.
4905 The function returns false if it is unable to copy the region,
4909 gimple_duplicate_sese_region (edge entry, edge exit,
4910 basic_block *region, unsigned n_region,
4911 basic_block *region_copy)
4914 bool free_region_copy = false, copying_header = false;
4915 struct loop *loop = entry->dest->loop_father;
4917 VEC (basic_block, heap) *doms;
4919 int total_freq = 0, entry_freq = 0;
4920 gcov_type total_count = 0, entry_count = 0;
4922 if (!can_copy_bbs_p (region, n_region))
4925 /* Some sanity checking. Note that we do not check for all possible
4926 missuses of the functions. I.e. if you ask to copy something weird,
4927 it will work, but the state of structures probably will not be
4929 for (i = 0; i < n_region; i++)
4931 /* We do not handle subloops, i.e. all the blocks must belong to the
4933 if (region[i]->loop_father != loop)
4936 if (region[i] != entry->dest
4937 && region[i] == loop->header)
4941 set_loop_copy (loop, loop);
4943 /* In case the function is used for loop header copying (which is the primary
4944 use), ensure that EXIT and its copy will be new latch and entry edges. */
4945 if (loop->header == entry->dest)
4947 copying_header = true;
4948 set_loop_copy (loop, loop_outer (loop));
4950 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
4953 for (i = 0; i < n_region; i++)
4954 if (region[i] != exit->src
4955 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
4961 region_copy = XNEWVEC (basic_block, n_region);
4962 free_region_copy = true;
4965 gcc_assert (!need_ssa_update_p ());
4967 /* Record blocks outside the region that are dominated by something
4970 initialize_original_copy_tables ();
4972 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
4974 if (entry->dest->count)
4976 total_count = entry->dest->count;
4977 entry_count = entry->count;
4978 /* Fix up corner cases, to avoid division by zero or creation of negative
4980 if (entry_count > total_count)
4981 entry_count = total_count;
4985 total_freq = entry->dest->frequency;
4986 entry_freq = EDGE_FREQUENCY (entry);
4987 /* Fix up corner cases, to avoid division by zero or creation of negative
4989 if (total_freq == 0)
4991 else if (entry_freq > total_freq)
4992 entry_freq = total_freq;
4995 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
4996 split_edge_bb_loc (entry));
4999 scale_bbs_frequencies_gcov_type (region, n_region,
5000 total_count - entry_count,
5002 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5007 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5009 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5014 loop->header = exit->dest;
5015 loop->latch = exit->src;
5018 /* Redirect the entry and add the phi node arguments. */
5019 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5020 gcc_assert (redirected != NULL);
5021 flush_pending_stmts (entry);
5023 /* Concerning updating of dominators: We must recount dominators
5024 for entry block and its copy. Anything that is outside of the
5025 region, but was dominated by something inside needs recounting as
5027 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5028 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5029 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5030 VEC_free (basic_block, heap, doms);
5032 /* Add the other PHI node arguments. */
5033 add_phi_args_after_copy (region_copy, n_region, NULL);
5035 /* Update the SSA web. */
5036 update_ssa (TODO_update_ssa);
5038 if (free_region_copy)
5041 free_original_copy_tables ();
5045 /* Duplicates REGION consisting of N_REGION blocks. The new blocks
5046 are stored to REGION_COPY in the same order in that they appear
5047 in REGION, if REGION_COPY is not NULL. ENTRY is the entry to
5048 the region, EXIT an exit from it. The condition guarding EXIT
5049 is moved to ENTRY. Returns true if duplication succeeds, false
5075 gimple_duplicate_sese_tail (edge entry ATTRIBUTE_UNUSED, edge exit ATTRIBUTE_UNUSED,
5076 basic_block *region ATTRIBUTE_UNUSED, unsigned n_region ATTRIBUTE_UNUSED,
5077 basic_block *region_copy ATTRIBUTE_UNUSED)
5080 bool free_region_copy = false;
5081 struct loop *loop = exit->dest->loop_father;
5082 struct loop *orig_loop = entry->dest->loop_father;
5083 basic_block switch_bb, entry_bb, nentry_bb;
5084 VEC (basic_block, heap) *doms;
5085 int total_freq = 0, exit_freq = 0;
5086 gcov_type total_count = 0, exit_count = 0;
5087 edge exits[2], nexits[2], e;
5088 gimple_stmt_iterator gsi;
5092 gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5094 exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5096 if (!can_copy_bbs_p (region, n_region))
5099 /* Some sanity checking. Note that we do not check for all possible
5100 missuses of the functions. I.e. if you ask to copy something weird
5101 (e.g., in the example, if there is a jump from inside to the middle
5102 of some_code, or come_code defines some of the values used in cond)
5103 it will work, but the resulting code will not be correct. */
5104 for (i = 0; i < n_region; i++)
5106 /* We do not handle subloops, i.e. all the blocks must belong to the
5108 if (region[i]->loop_father != orig_loop)
5111 if (region[i] == orig_loop->latch)
5115 initialize_original_copy_tables ();
5116 set_loop_copy (orig_loop, loop);
5120 region_copy = XNEWVEC (basic_block, n_region);
5121 free_region_copy = true;
5124 gcc_assert (!need_ssa_update_p ());
5126 /* Record blocks outside the region that are dominated by something
5128 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5130 if (exit->src->count)
5132 total_count = exit->src->count;
5133 exit_count = exit->count;
5134 /* Fix up corner cases, to avoid division by zero or creation of negative
5136 if (exit_count > total_count)
5137 exit_count = total_count;
5141 total_freq = exit->src->frequency;
5142 exit_freq = EDGE_FREQUENCY (exit);
5143 /* Fix up corner cases, to avoid division by zero or creation of negative
5145 if (total_freq == 0)
5147 if (exit_freq > total_freq)
5148 exit_freq = total_freq;
5151 copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5152 split_edge_bb_loc (exit));
5155 scale_bbs_frequencies_gcov_type (region, n_region,
5156 total_count - exit_count,
5158 scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5163 scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5165 scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5168 /* Create the switch block, and put the exit condition to it. */
5169 entry_bb = entry->dest;
5170 nentry_bb = get_bb_copy (entry_bb);
5171 if (!last_stmt (entry->src)
5172 || !stmt_ends_bb_p (last_stmt (entry->src)))
5173 switch_bb = entry->src;
5175 switch_bb = split_edge (entry);
5176 set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5178 gsi = gsi_last_bb (switch_bb);
5179 cond_stmt = last_stmt (exit->src);
5180 gcc_assert (gimple_code (cond_stmt) == GIMPLE_COND);
5181 cond_stmt = gimple_copy (cond_stmt);
5182 gimple_cond_set_lhs (cond_stmt, unshare_expr (gimple_cond_lhs (cond_stmt)));
5183 gimple_cond_set_rhs (cond_stmt, unshare_expr (gimple_cond_rhs (cond_stmt)));
5184 gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
5186 sorig = single_succ_edge (switch_bb);
5187 sorig->flags = exits[1]->flags;
5188 snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5190 /* Register the new edge from SWITCH_BB in loop exit lists. */
5191 rescan_loop_exit (snew, true, false);
5193 /* Add the PHI node arguments. */
5194 add_phi_args_after_copy (region_copy, n_region, snew);
5196 /* Get rid of now superfluous conditions and associated edges (and phi node
5198 e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5199 PENDING_STMT (e) = NULL;
5200 e = redirect_edge_and_branch (nexits[1], nexits[0]->dest);
5201 PENDING_STMT (e) = NULL;
5203 /* Anything that is outside of the region, but was dominated by something
5204 inside needs to update dominance info. */
5205 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5206 VEC_free (basic_block, heap, doms);
5208 /* Update the SSA web. */
5209 update_ssa (TODO_update_ssa);
5211 if (free_region_copy)
5214 free_original_copy_tables ();
5218 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5219 adding blocks when the dominator traversal reaches EXIT. This
5220 function silently assumes that ENTRY strictly dominates EXIT. */
5223 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5224 VEC(basic_block,heap) **bbs_p)
5228 for (son = first_dom_son (CDI_DOMINATORS, entry);
5230 son = next_dom_son (CDI_DOMINATORS, son))
5232 VEC_safe_push (basic_block, heap, *bbs_p, son);
5234 gather_blocks_in_sese_region (son, exit, bbs_p);
5238 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5239 The duplicates are recorded in VARS_MAP. */
5242 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5245 tree t = *tp, new_t;
5246 struct function *f = DECL_STRUCT_FUNCTION (to_context);
5249 if (DECL_CONTEXT (t) == to_context)
5252 loc = pointer_map_contains (vars_map, t);
5256 loc = pointer_map_insert (vars_map, t);
5260 new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5261 f->local_decls = tree_cons (NULL_TREE, new_t, f->local_decls);
5265 gcc_assert (TREE_CODE (t) == CONST_DECL);
5266 new_t = copy_node (t);
5268 DECL_CONTEXT (new_t) = to_context;
5273 new_t = (tree) *loc;
5279 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5280 VARS_MAP maps old ssa names and var_decls to the new ones. */
5283 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5287 tree new_name, decl = SSA_NAME_VAR (name);
5289 gcc_assert (is_gimple_reg (name));
5291 loc = pointer_map_contains (vars_map, name);
5295 replace_by_duplicate_decl (&decl, vars_map, to_context);
5297 push_cfun (DECL_STRUCT_FUNCTION (to_context));
5298 if (gimple_in_ssa_p (cfun))
5299 add_referenced_var (decl);
5301 new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5302 if (SSA_NAME_IS_DEFAULT_DEF (name))
5303 set_default_def (decl, new_name);
5306 loc = pointer_map_insert (vars_map, name);
5310 new_name = (tree) *loc;
5321 struct pointer_map_t *vars_map;
5322 htab_t new_label_map;
5326 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5327 contained in *TP if it has been ORIG_BLOCK previously and change the
5328 DECL_CONTEXT of every local variable referenced in *TP. */
5331 move_stmt_op (tree *tp, int *walk_subtrees, void *data)
5333 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
5334 struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5338 /* We should never have TREE_BLOCK set on non-statements. */
5339 gcc_assert (!TREE_BLOCK (t));
5341 else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5343 if (TREE_CODE (t) == SSA_NAME)
5344 *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5345 else if (TREE_CODE (t) == LABEL_DECL)
5347 if (p->new_label_map)
5349 struct tree_map in, *out;
5351 out = (struct tree_map *)
5352 htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5357 DECL_CONTEXT (t) = p->to_context;
5359 else if (p->remap_decls_p)
5361 /* Replace T with its duplicate. T should no longer appear in the
5362 parent function, so this looks wasteful; however, it may appear
5363 in referenced_vars, and more importantly, as virtual operands of
5364 statements, and in alias lists of other variables. It would be
5365 quite difficult to expunge it from all those places. ??? It might
5366 suffice to do this for addressable variables. */
5367 if ((TREE_CODE (t) == VAR_DECL
5368 && !is_global_var (t))
5369 || TREE_CODE (t) == CONST_DECL)
5370 replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5373 && gimple_in_ssa_p (cfun))
5375 push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5376 add_referenced_var (*tp);
5382 else if (TYPE_P (t))
5388 /* Like move_stmt_op, but for gimple statements.
5390 Helper for move_block_to_fn. Set GIMPLE_BLOCK in every expression
5391 contained in the current statement in *GSI_P and change the
5392 DECL_CONTEXT of every local variable referenced in the current
5396 move_stmt_r (gimple_stmt_iterator *gsi_p, bool *handled_ops_p,
5397 struct walk_stmt_info *wi)
5399 struct move_stmt_d *p = (struct move_stmt_d *) wi->info;
5400 gimple stmt = gsi_stmt (*gsi_p);
5401 tree block = gimple_block (stmt);
5403 if (p->orig_block == NULL_TREE
5404 || block == p->orig_block
5405 || block == NULL_TREE)
5406 gimple_set_block (stmt, p->new_block);
5407 #ifdef ENABLE_CHECKING
5408 else if (block != p->new_block)
5410 while (block && block != p->orig_block)
5411 block = BLOCK_SUPERCONTEXT (block);
5416 if (is_gimple_omp (stmt)
5417 && gimple_code (stmt) != GIMPLE_OMP_RETURN
5418 && gimple_code (stmt) != GIMPLE_OMP_CONTINUE)
5420 /* Do not remap variables inside OMP directives. Variables
5421 referenced in clauses and directive header belong to the
5422 parent function and should not be moved into the child
5424 bool save_remap_decls_p = p->remap_decls_p;
5425 p->remap_decls_p = false;
5426 *handled_ops_p = true;
5428 walk_gimple_seq (gimple_omp_body (stmt), move_stmt_r, move_stmt_op, wi);
5430 p->remap_decls_p = save_remap_decls_p;
5436 /* Marks virtual operands of all statements in basic blocks BBS for
5440 mark_virtual_ops_in_bb (basic_block bb)
5442 gimple_stmt_iterator gsi;
5444 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5445 mark_virtual_ops_for_renaming (gsi_stmt (gsi));
5447 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
5448 mark_virtual_ops_for_renaming (gsi_stmt (gsi));
5451 /* Marks virtual operands of all statements in basic blocks BBS for
5455 mark_virtual_ops_in_region (VEC (basic_block,heap) *bbs)
5460 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5461 mark_virtual_ops_in_bb (bb);
5464 /* Move basic block BB from function CFUN to function DEST_FN. The
5465 block is moved out of the original linked list and placed after
5466 block AFTER in the new list. Also, the block is removed from the
5467 original array of blocks and placed in DEST_FN's array of blocks.
5468 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5469 updated to reflect the moved edges.
5471 The local variables are remapped to new instances, VARS_MAP is used
5472 to record the mapping. */
5475 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5476 basic_block after, bool update_edge_count_p,
5477 struct move_stmt_d *d, int eh_offset)
5479 struct control_flow_graph *cfg;
5482 gimple_stmt_iterator si;
5483 unsigned old_len, new_len;
5485 /* Remove BB from dominance structures. */
5486 delete_from_dominance_info (CDI_DOMINATORS, bb);
5488 remove_bb_from_loops (bb);
5490 /* Link BB to the new linked list. */
5491 move_block_after (bb, after);
5493 /* Update the edge count in the corresponding flowgraphs. */
5494 if (update_edge_count_p)
5495 FOR_EACH_EDGE (e, ei, bb->succs)
5497 cfun->cfg->x_n_edges--;
5498 dest_cfun->cfg->x_n_edges++;
5501 /* Remove BB from the original basic block array. */
5502 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5503 cfun->cfg->x_n_basic_blocks--;
5505 /* Grow DEST_CFUN's basic block array if needed. */
5506 cfg = dest_cfun->cfg;
5507 cfg->x_n_basic_blocks++;
5508 if (bb->index >= cfg->x_last_basic_block)
5509 cfg->x_last_basic_block = bb->index + 1;
5511 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5512 if ((unsigned) cfg->x_last_basic_block >= old_len)
5514 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5515 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5519 VEC_replace (basic_block, cfg->x_basic_block_info,
5522 /* Remap the variables in phi nodes. */
5523 for (si = gsi_start_phis (bb); !gsi_end_p (si); )
5525 gimple phi = gsi_stmt (si);
5527 tree op = PHI_RESULT (phi);
5530 if (!is_gimple_reg (op))
5532 /* Remove the phi nodes for virtual operands (alias analysis will be
5533 run for the new function, anyway). */
5534 remove_phi_node (&si, true);
5538 SET_PHI_RESULT (phi,
5539 replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5540 FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5542 op = USE_FROM_PTR (use);
5543 if (TREE_CODE (op) == SSA_NAME)
5544 SET_USE (use, replace_ssa_name (op, d->vars_map, dest_cfun->decl));
5550 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5552 gimple stmt = gsi_stmt (si);
5554 struct walk_stmt_info wi;
5556 memset (&wi, 0, sizeof (wi));
5558 walk_gimple_stmt (&si, move_stmt_r, move_stmt_op, &wi);
5560 if (gimple_code (stmt) == GIMPLE_LABEL)
5562 tree label = gimple_label_label (stmt);
5563 int uid = LABEL_DECL_UID (label);
5565 gcc_assert (uid > -1);
5567 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5568 if (old_len <= (unsigned) uid)
5570 new_len = 3 * uid / 2;
5571 VEC_safe_grow_cleared (basic_block, gc,
5572 cfg->x_label_to_block_map, new_len);
5575 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5576 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5578 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5580 if (uid >= dest_cfun->cfg->last_label_uid)
5581 dest_cfun->cfg->last_label_uid = uid + 1;
5583 else if (gimple_code (stmt) == GIMPLE_RESX && eh_offset != 0)
5584 gimple_resx_set_region (stmt, gimple_resx_region (stmt) + eh_offset);
5586 region = lookup_stmt_eh_region (stmt);
5589 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5590 remove_stmt_from_eh_region (stmt);
5591 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5592 gimple_remove_stmt_histograms (cfun, stmt);
5595 /* We cannot leave any operands allocated from the operand caches of
5596 the current function. */
5597 free_stmt_operands (stmt);
5598 push_cfun (dest_cfun);
5604 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5605 the outermost EH region. Use REGION as the incoming base EH region. */
5608 find_outermost_region_in_block (struct function *src_cfun,
5609 basic_block bb, int region)
5611 gimple_stmt_iterator si;
5613 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
5615 gimple stmt = gsi_stmt (si);
5618 if (gimple_code (stmt) == GIMPLE_RESX)
5619 stmt_region = gimple_resx_region (stmt);
5621 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5622 if (stmt_region > 0)
5625 region = stmt_region;
5626 else if (stmt_region != region)
5628 region = eh_region_outermost (src_cfun, stmt_region, region);
5629 gcc_assert (region != -1);
5638 new_label_mapper (tree decl, void *data)
5640 htab_t hash = (htab_t) data;
5644 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5646 m = XNEW (struct tree_map);
5647 m->hash = DECL_UID (decl);
5648 m->base.from = decl;
5649 m->to = create_artificial_label ();
5650 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5651 if (LABEL_DECL_UID (m->to) >= cfun->cfg->last_label_uid)
5652 cfun->cfg->last_label_uid = LABEL_DECL_UID (m->to) + 1;
5654 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5655 gcc_assert (*slot == NULL);
5662 /* Change DECL_CONTEXT of all BLOCK_VARS in block, including
5666 replace_block_vars_by_duplicates (tree block, struct pointer_map_t *vars_map,
5671 for (tp = &BLOCK_VARS (block); *tp; tp = &TREE_CHAIN (*tp))
5674 replace_by_duplicate_decl (&t, vars_map, to_context);
5677 if (TREE_CODE (*tp) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (*tp))
5679 SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (*tp));
5680 DECL_HAS_VALUE_EXPR_P (t) = 1;
5682 TREE_CHAIN (t) = TREE_CHAIN (*tp);
5687 for (block = BLOCK_SUBBLOCKS (block); block; block = BLOCK_CHAIN (block))
5688 replace_block_vars_by_duplicates (block, vars_map, to_context);
5691 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5692 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5693 single basic block in the original CFG and the new basic block is
5694 returned. DEST_CFUN must not have a CFG yet.
5696 Note that the region need not be a pure SESE region. Blocks inside
5697 the region may contain calls to abort/exit. The only restriction
5698 is that ENTRY_BB should be the only entry point and it must
5701 Change TREE_BLOCK of all statements in ORIG_BLOCK to the new
5702 functions outermost BLOCK, move all subblocks of ORIG_BLOCK
5703 to the new function.
5705 All local variables referenced in the region are assumed to be in
5706 the corresponding BLOCK_VARS and unexpanded variable lists
5707 associated with DEST_CFUN. */
5710 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
5711 basic_block exit_bb, tree orig_block)
5713 VEC(basic_block,heap) *bbs, *dom_bbs;
5714 basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
5715 basic_block after, bb, *entry_pred, *exit_succ, abb;
5716 struct function *saved_cfun = cfun;
5717 int *entry_flag, *exit_flag, eh_offset;
5718 unsigned *entry_prob, *exit_prob;
5719 unsigned i, num_entry_edges, num_exit_edges;
5722 htab_t new_label_map;
5723 struct pointer_map_t *vars_map;
5724 struct loop *loop = entry_bb->loop_father;
5725 struct move_stmt_d d;
5727 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5729 gcc_assert (entry_bb != exit_bb
5731 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
5733 /* Collect all the blocks in the region. Manually add ENTRY_BB
5734 because it won't be added by dfs_enumerate_from. */
5736 VEC_safe_push (basic_block, heap, bbs, entry_bb);
5737 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
5739 /* The blocks that used to be dominated by something in BBS will now be
5740 dominated by the new block. */
5741 dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
5742 VEC_address (basic_block, bbs),
5743 VEC_length (basic_block, bbs));
5745 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5746 the predecessor edges to ENTRY_BB and the successor edges to
5747 EXIT_BB so that we can re-attach them to the new basic block that
5748 will replace the region. */
5749 num_entry_edges = EDGE_COUNT (entry_bb->preds);
5750 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
5751 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
5752 entry_prob = XNEWVEC (unsigned, num_entry_edges);
5754 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
5756 entry_prob[i] = e->probability;
5757 entry_flag[i] = e->flags;
5758 entry_pred[i++] = e->src;
5764 num_exit_edges = EDGE_COUNT (exit_bb->succs);
5765 exit_succ = (basic_block *) xcalloc (num_exit_edges,
5766 sizeof (basic_block));
5767 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
5768 exit_prob = XNEWVEC (unsigned, num_exit_edges);
5770 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
5772 exit_prob[i] = e->probability;
5773 exit_flag[i] = e->flags;
5774 exit_succ[i++] = e->dest;
5786 /* Switch context to the child function to initialize DEST_FN's CFG. */
5787 gcc_assert (dest_cfun->cfg == NULL);
5788 push_cfun (dest_cfun);
5790 init_empty_tree_cfg ();
5792 /* Initialize EH information for the new function. */
5794 new_label_map = NULL;
5799 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5800 region = find_outermost_region_in_block (saved_cfun, bb, region);
5802 init_eh_for_function ();
5805 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
5806 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
5807 new_label_map, region, 0);
5813 /* The ssa form for virtual operands in the source function will have to
5814 be repaired. We do not care for the real operands -- the sese region
5815 must be closed with respect to those. */
5816 mark_virtual_ops_in_region (bbs);
5818 /* Move blocks from BBS into DEST_CFUN. */
5819 gcc_assert (VEC_length (basic_block, bbs) >= 2);
5820 after = dest_cfun->cfg->x_entry_block_ptr;
5821 vars_map = pointer_map_create ();
5823 memset (&d, 0, sizeof (d));
5824 d.vars_map = vars_map;
5825 d.from_context = cfun->decl;
5826 d.to_context = dest_cfun->decl;
5827 d.new_label_map = new_label_map;
5828 d.remap_decls_p = true;
5829 d.orig_block = orig_block;
5830 d.new_block = DECL_INITIAL (dest_cfun->decl);
5832 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5834 /* No need to update edge counts on the last block. It has
5835 already been updated earlier when we detached the region from
5836 the original CFG. */
5837 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, &d, eh_offset);
5841 /* Rewire BLOCK_SUBBLOCKS of orig_block. */
5845 gcc_assert (BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
5847 BLOCK_SUBBLOCKS (DECL_INITIAL (dest_cfun->decl))
5848 = BLOCK_SUBBLOCKS (orig_block);
5849 for (block = BLOCK_SUBBLOCKS (orig_block);
5850 block; block = BLOCK_CHAIN (block))
5851 BLOCK_SUPERCONTEXT (block) = DECL_INITIAL (dest_cfun->decl);
5852 BLOCK_SUBBLOCKS (orig_block) = NULL_TREE;
5855 replace_block_vars_by_duplicates (DECL_INITIAL (dest_cfun->decl),
5856 vars_map, dest_cfun->decl);
5859 htab_delete (new_label_map);
5860 pointer_map_destroy (vars_map);
5862 /* Rewire the entry and exit blocks. The successor to the entry
5863 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
5864 the child function. Similarly, the predecessor of DEST_FN's
5865 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
5866 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
5867 various CFG manipulation function get to the right CFG.
5869 FIXME, this is silly. The CFG ought to become a parameter to
5871 push_cfun (dest_cfun);
5872 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
5874 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
5877 /* Back in the original function, the SESE region has disappeared,
5878 create a new basic block in its place. */
5879 bb = create_empty_bb (entry_pred[0]);
5881 add_bb_to_loop (bb, loop);
5882 for (i = 0; i < num_entry_edges; i++)
5884 e = make_edge (entry_pred[i], bb, entry_flag[i]);
5885 e->probability = entry_prob[i];
5888 for (i = 0; i < num_exit_edges; i++)
5890 e = make_edge (bb, exit_succ[i], exit_flag[i]);
5891 e->probability = exit_prob[i];
5894 set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
5895 for (i = 0; VEC_iterate (basic_block, dom_bbs, i, abb); i++)
5896 set_immediate_dominator (CDI_DOMINATORS, abb, bb);
5897 VEC_free (basic_block, heap, dom_bbs);
5908 VEC_free (basic_block, heap, bbs);
5914 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree-pass.h)
5918 dump_function_to_file (tree fn, FILE *file, int flags)
5920 tree arg, vars, var;
5921 struct function *dsf;
5922 bool ignore_topmost_bind = false, any_var = false;
5926 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
5928 arg = DECL_ARGUMENTS (fn);
5931 print_generic_expr (file, TREE_TYPE (arg), dump_flags);
5932 fprintf (file, " ");
5933 print_generic_expr (file, arg, dump_flags);
5934 if (flags & TDF_VERBOSE)
5935 print_node (file, "", arg, 4);
5936 if (TREE_CHAIN (arg))
5937 fprintf (file, ", ");
5938 arg = TREE_CHAIN (arg);
5940 fprintf (file, ")\n");
5942 if (flags & TDF_VERBOSE)
5943 print_node (file, "", fn, 2);
5945 dsf = DECL_STRUCT_FUNCTION (fn);
5946 if (dsf && (flags & TDF_DETAILS))
5947 dump_eh_tree (file, dsf);
5949 if (flags & TDF_RAW && !gimple_has_body_p (fn))
5951 dump_node (fn, TDF_SLIM | flags, file);
5955 /* Switch CFUN to point to FN. */
5956 push_cfun (DECL_STRUCT_FUNCTION (fn));
5958 /* When GIMPLE is lowered, the variables are no longer available in
5959 BIND_EXPRs, so display them separately. */
5960 if (cfun && cfun->decl == fn && cfun->local_decls)
5962 ignore_topmost_bind = true;
5964 fprintf (file, "{\n");
5965 for (vars = cfun->local_decls; vars; vars = TREE_CHAIN (vars))
5967 var = TREE_VALUE (vars);
5969 print_generic_decl (file, var, flags);
5970 if (flags & TDF_VERBOSE)
5971 print_node (file, "", var, 4);
5972 fprintf (file, "\n");
5978 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
5980 /* If the CFG has been built, emit a CFG-based dump. */
5981 check_bb_profile (ENTRY_BLOCK_PTR, file);
5982 if (!ignore_topmost_bind)
5983 fprintf (file, "{\n");
5985 if (any_var && n_basic_blocks)
5986 fprintf (file, "\n");
5989 gimple_dump_bb (bb, file, 2, flags);
5991 fprintf (file, "}\n");
5992 check_bb_profile (EXIT_BLOCK_PTR, file);
5994 else if (DECL_SAVED_TREE (fn) == NULL)
5996 /* The function is now in GIMPLE form but the CFG has not been
5997 built yet. Emit the single sequence of GIMPLE statements
5998 that make up its body. */
5999 gimple_seq body = gimple_body (fn);
6001 if (gimple_seq_first_stmt (body)
6002 && gimple_seq_first_stmt (body) == gimple_seq_last_stmt (body)
6003 && gimple_code (gimple_seq_first_stmt (body)) == GIMPLE_BIND)
6004 print_gimple_seq (file, body, 0, flags);
6007 if (!ignore_topmost_bind)
6008 fprintf (file, "{\n");
6011 fprintf (file, "\n");
6013 print_gimple_seq (file, body, 2, flags);
6014 fprintf (file, "}\n");
6021 /* Make a tree based dump. */
6022 chain = DECL_SAVED_TREE (fn);
6024 if (chain && TREE_CODE (chain) == BIND_EXPR)
6026 if (ignore_topmost_bind)
6028 chain = BIND_EXPR_BODY (chain);
6036 if (!ignore_topmost_bind)
6037 fprintf (file, "{\n");
6042 fprintf (file, "\n");
6044 print_generic_stmt_indented (file, chain, flags, indent);
6045 if (ignore_topmost_bind)
6046 fprintf (file, "}\n");
6049 fprintf (file, "\n\n");
6056 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
6059 debug_function (tree fn, int flags)
6061 dump_function_to_file (fn, stderr, flags);
6065 /* Print on FILE the indexes for the predecessors of basic_block BB. */
6068 print_pred_bbs (FILE *file, basic_block bb)
6073 FOR_EACH_EDGE (e, ei, bb->preds)
6074 fprintf (file, "bb_%d ", e->src->index);
6078 /* Print on FILE the indexes for the successors of basic_block BB. */
6081 print_succ_bbs (FILE *file, basic_block bb)
6086 FOR_EACH_EDGE (e, ei, bb->succs)
6087 fprintf (file, "bb_%d ", e->dest->index);
6090 /* Print to FILE the basic block BB following the VERBOSITY level. */
6093 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6095 char *s_indent = (char *) alloca ((size_t) indent + 1);
6096 memset ((void *) s_indent, ' ', (size_t) indent);
6097 s_indent[indent] = '\0';
6099 /* Print basic_block's header. */
6102 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
6103 print_pred_bbs (file, bb);
6104 fprintf (file, "}, succs = {");
6105 print_succ_bbs (file, bb);
6106 fprintf (file, "})\n");
6109 /* Print basic_block's body. */
6112 fprintf (file, "%s {\n", s_indent);
6113 gimple_dump_bb (bb, file, indent + 4, TDF_VOPS|TDF_MEMSYMS);
6114 fprintf (file, "%s }\n", s_indent);
6118 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6120 /* Pretty print LOOP on FILE, indented INDENT spaces. Following
6121 VERBOSITY level this outputs the contents of the loop, or just its
6125 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6133 s_indent = (char *) alloca ((size_t) indent + 1);
6134 memset ((void *) s_indent, ' ', (size_t) indent);
6135 s_indent[indent] = '\0';
6137 /* Print loop's header. */
6138 fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6139 loop->num, loop->header->index, loop->latch->index);
6140 fprintf (file, ", niter = ");
6141 print_generic_expr (file, loop->nb_iterations, 0);
6143 if (loop->any_upper_bound)
6145 fprintf (file, ", upper_bound = ");
6146 dump_double_int (file, loop->nb_iterations_upper_bound, true);
6149 if (loop->any_estimate)
6151 fprintf (file, ", estimate = ");
6152 dump_double_int (file, loop->nb_iterations_estimate, true);
6154 fprintf (file, ")\n");
6156 /* Print loop's body. */
6159 fprintf (file, "%s{\n", s_indent);
6161 if (bb->loop_father == loop)
6162 print_loops_bb (file, bb, indent, verbosity);
6164 print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6165 fprintf (file, "%s}\n", s_indent);
6169 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6170 spaces. Following VERBOSITY level this outputs the contents of the
6171 loop, or just its structure. */
6174 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6179 print_loop (file, loop, indent, verbosity);
6180 print_loop_and_siblings (file, loop->next, indent, verbosity);
6183 /* Follow a CFG edge from the entry point of the program, and on entry
6184 of a loop, pretty print the loop structure on FILE. */
6187 print_loops (FILE *file, int verbosity)
6191 bb = ENTRY_BLOCK_PTR;
6192 if (bb && bb->loop_father)
6193 print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6197 /* Debugging loops structure at tree level, at some VERBOSITY level. */
6200 debug_loops (int verbosity)
6202 print_loops (stderr, verbosity);
6205 /* Print on stderr the code of LOOP, at some VERBOSITY level. */
6208 debug_loop (struct loop *loop, int verbosity)
6210 print_loop (stderr, loop, 0, verbosity);
6213 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6217 debug_loop_num (unsigned num, int verbosity)
6219 debug_loop (get_loop (num), verbosity);
6222 /* Return true if BB ends with a call, possibly followed by some
6223 instructions that must stay with the call. Return false,
6227 gimple_block_ends_with_call_p (basic_block bb)
6229 gimple_stmt_iterator gsi = gsi_last_bb (bb);
6230 return is_gimple_call (gsi_stmt (gsi));
6234 /* Return true if BB ends with a conditional branch. Return false,
6238 gimple_block_ends_with_condjump_p (const_basic_block bb)
6240 gimple stmt = last_stmt (CONST_CAST_BB (bb));
6241 return (stmt && gimple_code (stmt) == GIMPLE_COND);
6245 /* Return true if we need to add fake edge to exit at statement T.
6246 Helper function for gimple_flow_call_edges_add. */
6249 need_fake_edge_p (gimple t)
6251 tree fndecl = NULL_TREE;
6254 /* NORETURN and LONGJMP calls already have an edge to exit.
6255 CONST and PURE calls do not need one.
6256 We don't currently check for CONST and PURE here, although
6257 it would be a good idea, because those attributes are
6258 figured out from the RTL in mark_constant_function, and
6259 the counter incrementation code from -fprofile-arcs
6260 leads to different results from -fbranch-probabilities. */
6261 if (is_gimple_call (t))
6263 fndecl = gimple_call_fndecl (t);
6264 call_flags = gimple_call_flags (t);
6267 if (is_gimple_call (t)
6269 && DECL_BUILT_IN (fndecl)
6270 && (call_flags & ECF_NOTHROW)
6271 && !(call_flags & ECF_NORETURN)
6272 && !(call_flags & ECF_RETURNS_TWICE))
6275 if (is_gimple_call (t)
6276 && !(call_flags & ECF_NORETURN))
6279 if (gimple_code (t) == GIMPLE_ASM
6280 && (gimple_asm_volatile_p (t) || gimple_asm_input_p (t)))
6287 /* Add fake edges to the function exit for any non constant and non
6288 noreturn calls, volatile inline assembly in the bitmap of blocks
6289 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
6290 the number of blocks that were split.
6292 The goal is to expose cases in which entering a basic block does
6293 not imply that all subsequent instructions must be executed. */
6296 gimple_flow_call_edges_add (sbitmap blocks)
6299 int blocks_split = 0;
6300 int last_bb = last_basic_block;
6301 bool check_last_block = false;
6303 if (n_basic_blocks == NUM_FIXED_BLOCKS)
6307 check_last_block = true;
6309 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6311 /* In the last basic block, before epilogue generation, there will be
6312 a fallthru edge to EXIT. Special care is required if the last insn
6313 of the last basic block is a call because make_edge folds duplicate
6314 edges, which would result in the fallthru edge also being marked
6315 fake, which would result in the fallthru edge being removed by
6316 remove_fake_edges, which would result in an invalid CFG.
6318 Moreover, we can't elide the outgoing fake edge, since the block
6319 profiler needs to take this into account in order to solve the minimal
6320 spanning tree in the case that the call doesn't return.
6322 Handle this by adding a dummy instruction in a new last basic block. */
6323 if (check_last_block)
6325 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6326 gimple_stmt_iterator gsi = gsi_last_bb (bb);
6329 if (!gsi_end_p (gsi))
6332 if (t && need_fake_edge_p (t))
6336 e = find_edge (bb, EXIT_BLOCK_PTR);
6339 gsi_insert_on_edge (e, gimple_build_nop ());
6340 gsi_commit_edge_inserts ();
6345 /* Now add fake edges to the function exit for any non constant
6346 calls since there is no way that we can determine if they will
6348 for (i = 0; i < last_bb; i++)
6350 basic_block bb = BASIC_BLOCK (i);
6351 gimple_stmt_iterator gsi;
6352 gimple stmt, last_stmt;
6357 if (blocks && !TEST_BIT (blocks, i))
6360 gsi = gsi_last_bb (bb);
6361 if (!gsi_end_p (gsi))
6363 last_stmt = gsi_stmt (gsi);
6366 stmt = gsi_stmt (gsi);
6367 if (need_fake_edge_p (stmt))
6371 /* The handling above of the final block before the
6372 epilogue should be enough to verify that there is
6373 no edge to the exit block in CFG already.
6374 Calling make_edge in such case would cause us to
6375 mark that edge as fake and remove it later. */
6376 #ifdef ENABLE_CHECKING
6377 if (stmt == last_stmt)
6379 e = find_edge (bb, EXIT_BLOCK_PTR);
6380 gcc_assert (e == NULL);
6384 /* Note that the following may create a new basic block
6385 and renumber the existing basic blocks. */
6386 if (stmt != last_stmt)
6388 e = split_block (bb, stmt);
6392 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6396 while (!gsi_end_p (gsi));
6401 verify_flow_info ();
6403 return blocks_split;
6406 /* Purge dead abnormal call edges from basic block BB. */
6409 gimple_purge_dead_abnormal_call_edges (basic_block bb)
6411 bool changed = gimple_purge_dead_eh_edges (bb);
6413 if (cfun->has_nonlocal_label)
6415 gimple stmt = last_stmt (bb);
6419 if (!(stmt && stmt_can_make_abnormal_goto (stmt)))
6420 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6422 if (e->flags & EDGE_ABNORMAL)
6431 /* See gimple_purge_dead_eh_edges below. */
6433 free_dominance_info (CDI_DOMINATORS);
6439 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6442 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6446 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6447 for (son = first_dom_son (CDI_DOMINATORS, bb);
6449 son = next_dom_son (CDI_DOMINATORS, son))
6450 get_all_dominated_blocks (son, dom_bbs);
6453 /* Removes edge E and all the blocks dominated by it, and updates dominance
6454 information. The IL in E->src needs to be updated separately.
6455 If dominance info is not available, only the edge E is removed.*/
6458 remove_edge_and_dominated_blocks (edge e)
6460 VEC (basic_block, heap) *bbs_to_remove = NULL;
6461 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6465 bool none_removed = false;
6467 basic_block bb, dbb;
6470 if (!dom_info_available_p (CDI_DOMINATORS))
6476 /* No updating is needed for edges to exit. */
6477 if (e->dest == EXIT_BLOCK_PTR)
6479 if (cfgcleanup_altered_bbs)
6480 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6485 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6486 that is not dominated by E->dest, then this set is empty. Otherwise,
6487 all the basic blocks dominated by E->dest are removed.
6489 Also, to DF_IDOM we store the immediate dominators of the blocks in
6490 the dominance frontier of E (i.e., of the successors of the
6491 removed blocks, if there are any, and of E->dest otherwise). */
6492 FOR_EACH_EDGE (f, ei, e->dest->preds)
6497 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6499 none_removed = true;
6504 df = BITMAP_ALLOC (NULL);
6505 df_idom = BITMAP_ALLOC (NULL);
6508 bitmap_set_bit (df_idom,
6509 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6512 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6513 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6515 FOR_EACH_EDGE (f, ei, bb->succs)
6517 if (f->dest != EXIT_BLOCK_PTR)
6518 bitmap_set_bit (df, f->dest->index);
6521 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6522 bitmap_clear_bit (df, bb->index);
6524 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6526 bb = BASIC_BLOCK (i);
6527 bitmap_set_bit (df_idom,
6528 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6532 if (cfgcleanup_altered_bbs)
6534 /* Record the set of the altered basic blocks. */
6535 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6536 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6539 /* Remove E and the cancelled blocks. */
6544 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6545 delete_basic_block (bb);
6548 /* Update the dominance information. The immediate dominator may change only
6549 for blocks whose immediate dominator belongs to DF_IDOM:
6551 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6552 removal. Let Z the arbitrary block such that idom(Z) = Y and
6553 Z dominates X after the removal. Before removal, there exists a path P
6554 from Y to X that avoids Z. Let F be the last edge on P that is
6555 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6556 dominates W, and because of P, Z does not dominate W), and W belongs to
6557 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6558 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6560 bb = BASIC_BLOCK (i);
6561 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6563 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6564 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6567 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6570 BITMAP_FREE (df_idom);
6571 VEC_free (basic_block, heap, bbs_to_remove);
6572 VEC_free (basic_block, heap, bbs_to_fix_dom);
6575 /* Purge dead EH edges from basic block BB. */
6578 gimple_purge_dead_eh_edges (basic_block bb)
6580 bool changed = false;
6583 gimple stmt = last_stmt (bb);
6585 if (stmt && stmt_can_throw_internal (stmt))
6588 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6590 if (e->flags & EDGE_EH)
6592 remove_edge_and_dominated_blocks (e);
6603 gimple_purge_all_dead_eh_edges (const_bitmap blocks)
6605 bool changed = false;
6609 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6611 basic_block bb = BASIC_BLOCK (i);
6613 /* Earlier gimple_purge_dead_eh_edges could have removed
6614 this basic block already. */
6615 gcc_assert (bb || changed);
6617 changed |= gimple_purge_dead_eh_edges (bb);
6623 /* This function is called whenever a new edge is created or
6627 gimple_execute_on_growing_pred (edge e)
6629 basic_block bb = e->dest;
6632 reserve_phi_args_for_new_edge (bb);
6635 /* This function is called immediately before edge E is removed from
6636 the edge vector E->dest->preds. */
6639 gimple_execute_on_shrinking_pred (edge e)
6641 if (phi_nodes (e->dest))
6642 remove_phi_args (e);
6645 /*---------------------------------------------------------------------------
6646 Helper functions for Loop versioning
6647 ---------------------------------------------------------------------------*/
6649 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6650 of 'first'. Both of them are dominated by 'new_head' basic block. When
6651 'new_head' was created by 'second's incoming edge it received phi arguments
6652 on the edge by split_edge(). Later, additional edge 'e' was created to
6653 connect 'new_head' and 'first'. Now this routine adds phi args on this
6654 additional edge 'e' that new_head to second edge received as part of edge
6658 gimple_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6659 basic_block new_head, edge e)
6662 gimple_stmt_iterator psi1, psi2;
6664 edge e2 = find_edge (new_head, second);
6666 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6667 edge, we should always have an edge from NEW_HEAD to SECOND. */
6668 gcc_assert (e2 != NULL);
6670 /* Browse all 'second' basic block phi nodes and add phi args to
6671 edge 'e' for 'first' head. PHI args are always in correct order. */
6673 for (psi2 = gsi_start_phis (second),
6674 psi1 = gsi_start_phis (first);
6675 !gsi_end_p (psi2) && !gsi_end_p (psi1);
6676 gsi_next (&psi2), gsi_next (&psi1))
6678 phi1 = gsi_stmt (psi1);
6679 phi2 = gsi_stmt (psi2);
6680 def = PHI_ARG_DEF (phi2, e2->dest_idx);
6681 add_phi_arg (phi1, def, e);
6686 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6687 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6688 the destination of the ELSE part. */
6691 gimple_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6692 basic_block second_head ATTRIBUTE_UNUSED,
6693 basic_block cond_bb, void *cond_e)
6695 gimple_stmt_iterator gsi;
6696 gimple new_cond_expr;
6697 tree cond_expr = (tree) cond_e;
6700 /* Build new conditional expr */
6701 new_cond_expr = gimple_build_cond_from_tree (cond_expr,
6702 NULL_TREE, NULL_TREE);
6704 /* Add new cond in cond_bb. */
6705 gsi = gsi_last_bb (cond_bb);
6706 gsi_insert_after (&gsi, new_cond_expr, GSI_NEW_STMT);
6708 /* Adjust edges appropriately to connect new head with first head
6709 as well as second head. */
6710 e0 = single_succ_edge (cond_bb);
6711 e0->flags &= ~EDGE_FALLTHRU;
6712 e0->flags |= EDGE_FALSE_VALUE;
6715 struct cfg_hooks gimple_cfg_hooks = {
6717 gimple_verify_flow_info,
6718 gimple_dump_bb, /* dump_bb */
6719 create_bb, /* create_basic_block */
6720 gimple_redirect_edge_and_branch, /* redirect_edge_and_branch */
6721 gimple_redirect_edge_and_branch_force, /* redirect_edge_and_branch_force */
6722 gimple_can_remove_branch_p, /* can_remove_branch_p */
6723 remove_bb, /* delete_basic_block */
6724 gimple_split_block, /* split_block */
6725 gimple_move_block_after, /* move_block_after */
6726 gimple_can_merge_blocks_p, /* can_merge_blocks_p */
6727 gimple_merge_blocks, /* merge_blocks */
6728 gimple_predict_edge, /* predict_edge */
6729 gimple_predicted_by_p, /* predicted_by_p */
6730 gimple_can_duplicate_bb_p, /* can_duplicate_block_p */
6731 gimple_duplicate_bb, /* duplicate_block */
6732 gimple_split_edge, /* split_edge */
6733 gimple_make_forwarder_block, /* make_forward_block */
6734 NULL, /* tidy_fallthru_edge */
6735 gimple_block_ends_with_call_p,/* block_ends_with_call_p */
6736 gimple_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6737 gimple_flow_call_edges_add, /* flow_call_edges_add */
6738 gimple_execute_on_growing_pred, /* execute_on_growing_pred */
6739 gimple_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6740 gimple_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6741 gimple_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6742 gimple_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6743 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6744 flush_pending_stmts /* flush_pending_stmts */
6748 /* Split all critical edges. */
6751 split_critical_edges (void)
6757 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6758 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6759 mappings around the calls to split_edge. */
6760 start_recording_case_labels ();
6763 FOR_EACH_EDGE (e, ei, bb->succs)
6764 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6769 end_recording_case_labels ();
6773 struct gimple_opt_pass pass_split_crit_edges =
6777 "crited", /* name */
6779 split_critical_edges, /* execute */
6782 0, /* static_pass_number */
6783 TV_TREE_SPLIT_EDGES, /* tv_id */
6784 PROP_cfg, /* properties required */
6785 PROP_no_crit_edges, /* properties_provided */
6786 0, /* properties_destroyed */
6787 0, /* todo_flags_start */
6788 TODO_dump_func /* todo_flags_finish */
6793 /* Build a ternary operation and gimplify it. Emit code before GSI.
6794 Return the gimple_val holding the result. */
6797 gimplify_build3 (gimple_stmt_iterator *gsi, enum tree_code code,
6798 tree type, tree a, tree b, tree c)
6802 ret = fold_build3 (code, type, a, b, c);
6805 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
6809 /* Build a binary operation and gimplify it. Emit code before GSI.
6810 Return the gimple_val holding the result. */
6813 gimplify_build2 (gimple_stmt_iterator *gsi, enum tree_code code,
6814 tree type, tree a, tree b)
6818 ret = fold_build2 (code, type, a, b);
6821 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
6825 /* Build a unary operation and gimplify it. Emit code before GSI.
6826 Return the gimple_val holding the result. */
6829 gimplify_build1 (gimple_stmt_iterator *gsi, enum tree_code code, tree type,
6834 ret = fold_build1 (code, type, a);
6837 return force_gimple_operand_gsi (gsi, ret, true, NULL, true,
6843 /* Emit return warnings. */
6846 execute_warn_function_return (void)
6848 source_location location;
6853 /* If we have a path to EXIT, then we do return. */
6854 if (TREE_THIS_VOLATILE (cfun->decl)
6855 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
6857 location = UNKNOWN_LOCATION;
6858 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6860 last = last_stmt (e->src);
6861 if (gimple_code (last) == GIMPLE_RETURN
6862 && (location = gimple_location (last)) != UNKNOWN_LOCATION)
6865 if (location == UNKNOWN_LOCATION)
6866 location = cfun->function_end_locus;
6867 warning (0, "%H%<noreturn%> function does return", &location);
6870 /* If we see "return;" in some basic block, then we do reach the end
6871 without returning a value. */
6872 else if (warn_return_type
6873 && !TREE_NO_WARNING (cfun->decl)
6874 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
6875 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
6877 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
6879 gimple last = last_stmt (e->src);
6880 if (gimple_code (last) == GIMPLE_RETURN
6881 && gimple_return_retval (last) == NULL
6882 && !gimple_no_warning_p (last))
6884 location = gimple_location (last);
6885 if (location == UNKNOWN_LOCATION)
6886 location = cfun->function_end_locus;
6887 warning_at (location, OPT_Wreturn_type, "control reaches end of non-void function");
6888 TREE_NO_WARNING (cfun->decl) = 1;
6897 /* Given a basic block B which ends with a conditional and has
6898 precisely two successors, determine which of the edges is taken if
6899 the conditional is true and which is taken if the conditional is
6900 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
6903 extract_true_false_edges_from_block (basic_block b,
6907 edge e = EDGE_SUCC (b, 0);
6909 if (e->flags & EDGE_TRUE_VALUE)
6912 *false_edge = EDGE_SUCC (b, 1);
6917 *true_edge = EDGE_SUCC (b, 1);
6921 struct gimple_opt_pass pass_warn_function_return =
6927 execute_warn_function_return, /* execute */
6930 0, /* static_pass_number */
6932 PROP_cfg, /* properties_required */
6933 0, /* properties_provided */
6934 0, /* properties_destroyed */
6935 0, /* todo_flags_start */
6936 0 /* todo_flags_finish */
6940 /* Emit noreturn warnings. */
6943 execute_warn_function_noreturn (void)
6945 if (warn_missing_noreturn
6946 && !TREE_THIS_VOLATILE (cfun->decl)
6947 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
6948 && !lang_hooks.missing_noreturn_ok_p (cfun->decl))
6949 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
6950 "for attribute %<noreturn%>",
6955 struct gimple_opt_pass pass_warn_function_noreturn =
6961 execute_warn_function_noreturn, /* execute */
6964 0, /* static_pass_number */
6966 PROP_cfg, /* properties_required */
6967 0, /* properties_provided */
6968 0, /* properties_destroyed */
6969 0, /* todo_flags_start */
6970 0 /* todo_flags_finish */