1 /* Control flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "hard-reg-set.h"
30 #include "basic-block.h"
36 #include "langhooks.h"
37 #include "diagnostic.h"
38 #include "tree-flow.h"
40 #include "tree-dump.h"
41 #include "tree-pass.h"
45 #include "cfglayout.h"
46 #include "tree-ssa-propagate.h"
47 #include "value-prof.h"
48 #include "pointer-set.h"
49 #include "tree-inline.h"
51 /* This file contains functions for building the Control Flow Graph (CFG)
52 for a function tree. */
54 /* Local declarations. */
56 /* Initial capacity for the basic block array. */
57 static const int initial_cfg_capacity = 20;
59 /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs
60 which use a particular edge. The CASE_LABEL_EXPRs are chained together
61 via their TREE_CHAIN field, which we clear after we're done with the
62 hash table to prevent problems with duplication of SWITCH_EXPRs.
64 Access to this list of CASE_LABEL_EXPRs allows us to efficiently
65 update the case vector in response to edge redirections.
67 Right now this table is set up and torn down at key points in the
68 compilation process. It would be nice if we could make the table
69 more persistent. The key is getting notification of changes to
70 the CFG (particularly edge removal, creation and redirection). */
72 static struct pointer_map_t *edge_to_cases;
77 long num_merged_labels;
80 static struct cfg_stats_d cfg_stats;
82 /* Nonzero if we found a computed goto while building basic blocks. */
83 static bool found_computed_goto;
85 /* Basic blocks and flowgraphs. */
86 static basic_block create_bb (void *, void *, basic_block);
87 static void make_blocks (tree);
88 static void factor_computed_gotos (void);
91 static void make_edges (void);
92 static void make_cond_expr_edges (basic_block);
93 static void make_switch_expr_edges (basic_block);
94 static void make_goto_expr_edges (basic_block);
95 static edge tree_redirect_edge_and_branch (edge, basic_block);
96 static edge tree_try_redirect_by_replacing_jump (edge, basic_block);
97 static unsigned int split_critical_edges (void);
99 /* Various helpers. */
100 static inline bool stmt_starts_bb_p (const_tree, const_tree);
101 static int tree_verify_flow_info (void);
102 static void tree_make_forwarder_block (edge);
103 static void tree_cfg2vcg (FILE *);
104 static inline void change_bb_for_stmt (tree t, basic_block bb);
105 static bool computed_goto_p (const_tree);
107 /* Flowgraph optimization and cleanup. */
108 static void tree_merge_blocks (basic_block, basic_block);
109 static bool tree_can_merge_blocks_p (basic_block, basic_block);
110 static void remove_bb (basic_block);
111 static edge find_taken_edge_computed_goto (basic_block, tree);
112 static edge find_taken_edge_cond_expr (basic_block, tree);
113 static edge find_taken_edge_switch_expr (basic_block, tree);
114 static tree find_case_label_for_value (tree, tree);
117 init_empty_tree_cfg_for_function (struct function *fn)
119 /* Initialize the basic block array. */
121 profile_status_for_function (fn) = PROFILE_ABSENT;
122 n_basic_blocks_for_function (fn) = NUM_FIXED_BLOCKS;
123 last_basic_block_for_function (fn) = NUM_FIXED_BLOCKS;
124 basic_block_info_for_function (fn)
125 = VEC_alloc (basic_block, gc, initial_cfg_capacity);
126 VEC_safe_grow_cleared (basic_block, gc,
127 basic_block_info_for_function (fn),
128 initial_cfg_capacity);
130 /* Build a mapping of labels to their associated blocks. */
131 label_to_block_map_for_function (fn)
132 = VEC_alloc (basic_block, gc, initial_cfg_capacity);
133 VEC_safe_grow_cleared (basic_block, gc,
134 label_to_block_map_for_function (fn),
135 initial_cfg_capacity);
137 SET_BASIC_BLOCK_FOR_FUNCTION (fn, ENTRY_BLOCK,
138 ENTRY_BLOCK_PTR_FOR_FUNCTION (fn));
139 SET_BASIC_BLOCK_FOR_FUNCTION (fn, EXIT_BLOCK,
140 EXIT_BLOCK_PTR_FOR_FUNCTION (fn));
142 ENTRY_BLOCK_PTR_FOR_FUNCTION (fn)->next_bb
143 = EXIT_BLOCK_PTR_FOR_FUNCTION (fn);
144 EXIT_BLOCK_PTR_FOR_FUNCTION (fn)->prev_bb
145 = ENTRY_BLOCK_PTR_FOR_FUNCTION (fn);
149 init_empty_tree_cfg (void)
151 init_empty_tree_cfg_for_function (cfun);
154 /*---------------------------------------------------------------------------
156 ---------------------------------------------------------------------------*/
158 /* Entry point to the CFG builder for trees. TP points to the list of
159 statements to be added to the flowgraph. */
162 build_tree_cfg (tree *tp)
164 /* Register specific tree functions. */
165 tree_register_cfg_hooks ();
167 memset ((void *) &cfg_stats, 0, sizeof (cfg_stats));
169 init_empty_tree_cfg ();
171 found_computed_goto = 0;
174 /* Computed gotos are hell to deal with, especially if there are
175 lots of them with a large number of destinations. So we factor
176 them to a common computed goto location before we build the
177 edge list. After we convert back to normal form, we will un-factor
178 the computed gotos since factoring introduces an unwanted jump. */
179 if (found_computed_goto)
180 factor_computed_gotos ();
182 /* Make sure there is always at least one block, even if it's empty. */
183 if (n_basic_blocks == NUM_FIXED_BLOCKS)
184 create_empty_bb (ENTRY_BLOCK_PTR);
186 /* Adjust the size of the array. */
187 if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks)
188 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks);
190 /* To speed up statement iterator walks, we first purge dead labels. */
191 cleanup_dead_labels ();
193 /* Group case nodes to reduce the number of edges.
194 We do this after cleaning up dead labels because otherwise we miss
195 a lot of obvious case merging opportunities. */
196 group_case_labels ();
198 /* Create the edges of the flowgraph. */
200 cleanup_dead_labels ();
202 /* Debugging dumps. */
204 /* Write the flowgraph to a VCG file. */
206 int local_dump_flags;
207 FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags);
210 tree_cfg2vcg (vcg_file);
211 dump_end (TDI_vcg, vcg_file);
215 #ifdef ENABLE_CHECKING
219 /* Dump a textual representation of the flowgraph. */
221 dump_tree_cfg (dump_file, dump_flags);
225 execute_build_cfg (void)
227 build_tree_cfg (&DECL_SAVED_TREE (current_function_decl));
231 struct gimple_opt_pass pass_build_cfg =
237 execute_build_cfg, /* execute */
240 0, /* static_pass_number */
241 TV_TREE_CFG, /* tv_id */
242 PROP_gimple_leh, /* properties_required */
243 PROP_cfg, /* properties_provided */
244 0, /* properties_destroyed */
245 0, /* todo_flags_start */
246 TODO_verify_stmts | TODO_cleanup_cfg /* todo_flags_finish */
250 /* Search the CFG for any computed gotos. If found, factor them to a
251 common computed goto site. Also record the location of that site so
252 that we can un-factor the gotos after we have converted back to
256 factor_computed_gotos (void)
259 tree factored_label_decl = NULL;
261 tree factored_computed_goto_label = NULL;
262 tree factored_computed_goto = NULL;
264 /* We know there are one or more computed gotos in this function.
265 Examine the last statement in each basic block to see if the block
266 ends with a computed goto. */
270 block_stmt_iterator bsi = bsi_last (bb);
275 last = bsi_stmt (bsi);
277 /* Ignore the computed goto we create when we factor the original
279 if (last == factored_computed_goto)
282 /* If the last statement is a computed goto, factor it. */
283 if (computed_goto_p (last))
287 /* The first time we find a computed goto we need to create
288 the factored goto block and the variable each original
289 computed goto will use for their goto destination. */
290 if (! factored_computed_goto)
292 basic_block new_bb = create_empty_bb (bb);
293 block_stmt_iterator new_bsi = bsi_start (new_bb);
295 /* Create the destination of the factored goto. Each original
296 computed goto will put its desired destination into this
297 variable and jump to the label we create immediately
299 var = create_tmp_var (ptr_type_node, "gotovar");
301 /* Build a label for the new block which will contain the
302 factored computed goto. */
303 factored_label_decl = create_artificial_label ();
304 factored_computed_goto_label
305 = build1 (LABEL_EXPR, void_type_node, factored_label_decl);
306 bsi_insert_after (&new_bsi, factored_computed_goto_label,
309 /* Build our new computed goto. */
310 factored_computed_goto = build1 (GOTO_EXPR, void_type_node, var);
311 bsi_insert_after (&new_bsi, factored_computed_goto,
315 /* Copy the original computed goto's destination into VAR. */
316 assignment = build_gimple_modify_stmt (var,
317 GOTO_DESTINATION (last));
318 bsi_insert_before (&bsi, assignment, BSI_SAME_STMT);
320 /* And re-vector the computed goto to the new destination. */
321 GOTO_DESTINATION (last) = factored_label_decl;
327 /* Build a flowgraph for the statement_list STMT_LIST. */
330 make_blocks (tree stmt_list)
332 tree_stmt_iterator i = tsi_start (stmt_list);
334 bool start_new_block = true;
335 bool first_stmt_of_list = true;
336 basic_block bb = ENTRY_BLOCK_PTR;
338 while (!tsi_end_p (i))
345 /* If the statement starts a new basic block or if we have determined
346 in a previous pass that we need to create a new block for STMT, do
348 if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt))
350 if (!first_stmt_of_list)
351 stmt_list = tsi_split_statement_list_before (&i);
352 bb = create_basic_block (stmt_list, NULL, bb);
353 start_new_block = false;
356 /* Now add STMT to BB and create the subgraphs for special statement
358 set_bb_for_stmt (stmt, bb);
360 if (computed_goto_p (stmt))
361 found_computed_goto = true;
363 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
365 if (stmt_ends_bb_p (stmt))
366 start_new_block = true;
369 first_stmt_of_list = false;
374 /* Create and return a new empty basic block after bb AFTER. */
377 create_bb (void *h, void *e, basic_block after)
383 /* Create and initialize a new basic block. Since alloc_block uses
384 ggc_alloc_cleared to allocate a basic block, we do not have to
385 clear the newly allocated basic block here. */
388 bb->index = last_basic_block;
390 bb->il.tree = GGC_CNEW (struct tree_bb_info);
391 set_bb_stmt_list (bb, h ? (tree) h : alloc_stmt_list ());
393 /* Add the new block to the linked list of blocks. */
394 link_block (bb, after);
396 /* Grow the basic block array if needed. */
397 if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info))
399 size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
400 VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size);
403 /* Add the newly created block to the array. */
404 SET_BASIC_BLOCK (last_basic_block, bb);
413 /*---------------------------------------------------------------------------
415 ---------------------------------------------------------------------------*/
417 /* Fold COND_EXPR_COND of each COND_EXPR. */
420 fold_cond_expr_cond (void)
426 tree stmt = last_stmt (bb);
429 && TREE_CODE (stmt) == COND_EXPR)
434 fold_defer_overflow_warnings ();
435 cond = fold (COND_EXPR_COND (stmt));
436 zerop = integer_zerop (cond);
437 onep = integer_onep (cond);
438 fold_undefer_overflow_warnings (zerop || onep,
440 WARN_STRICT_OVERFLOW_CONDITIONAL);
442 COND_EXPR_COND (stmt) = boolean_false_node;
444 COND_EXPR_COND (stmt) = boolean_true_node;
449 /* Join all the blocks in the flowgraph. */
455 struct omp_region *cur_region = NULL;
457 /* Create an edge from entry to the first block with executable
459 make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU);
461 /* Traverse the basic block array placing edges. */
464 tree last = last_stmt (bb);
469 enum tree_code code = TREE_CODE (last);
473 make_goto_expr_edges (bb);
477 make_edge (bb, EXIT_BLOCK_PTR, 0);
481 make_cond_expr_edges (bb);
485 make_switch_expr_edges (bb);
489 make_eh_edges (last);
494 /* If this function receives a nonlocal goto, then we need to
495 make edges from this call site to all the nonlocal goto
497 if (tree_can_make_abnormal_goto (last))
498 make_abnormal_goto_edges (bb, true);
500 /* If this statement has reachable exception handlers, then
501 create abnormal edges to them. */
502 make_eh_edges (last);
504 /* Some calls are known not to return. */
505 fallthru = !(call_expr_flags (last) & ECF_NORETURN);
511 case GIMPLE_MODIFY_STMT:
512 if (is_ctrl_altering_stmt (last))
514 /* A GIMPLE_MODIFY_STMT may have a CALL_EXPR on its RHS and
515 the CALL_EXPR may have an abnormal edge. Search the RHS
516 for this case and create any required edges. */
517 if (tree_can_make_abnormal_goto (last))
518 make_abnormal_goto_edges (bb, true);
520 make_eh_edges (last);
532 cur_region = new_omp_region (bb, code, cur_region);
537 cur_region = new_omp_region (bb, code, cur_region);
541 case OMP_SECTIONS_SWITCH:
546 case OMP_ATOMIC_LOAD:
547 case OMP_ATOMIC_STORE:
553 /* In the case of an OMP_SECTION, the edge will go somewhere
554 other than the next block. This will be created later. */
555 cur_region->exit = bb;
556 fallthru = cur_region->type != OMP_SECTION;
557 cur_region = cur_region->outer;
561 cur_region->cont = bb;
562 switch (cur_region->type)
565 /* Mark all OMP_FOR and OMP_CONTINUE succs edges as abnormal
566 to prevent splitting them. */
567 single_succ_edge (cur_region->entry)->flags |= EDGE_ABNORMAL;
568 /* Make the loopback edge. */
569 make_edge (bb, single_succ (cur_region->entry),
572 /* Create an edge from OMP_FOR to exit, which corresponds to
573 the case that the body of the loop is not executed at
575 make_edge (cur_region->entry, bb->next_bb, EDGE_ABNORMAL);
576 make_edge (bb, bb->next_bb, EDGE_FALLTHRU | EDGE_ABNORMAL);
581 /* Wire up the edges into and out of the nested sections. */
583 basic_block switch_bb = single_succ (cur_region->entry);
585 struct omp_region *i;
586 for (i = cur_region->inner; i ; i = i->next)
588 gcc_assert (i->type == OMP_SECTION);
589 make_edge (switch_bb, i->entry, 0);
590 make_edge (i->exit, bb, EDGE_FALLTHRU);
593 /* Make the loopback edge to the block with
594 OMP_SECTIONS_SWITCH. */
595 make_edge (bb, switch_bb, 0);
597 /* Make the edge from the switch to exit. */
598 make_edge (switch_bb, bb->next_bb, 0);
609 gcc_assert (!stmt_ends_bb_p (last));
617 make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
623 /* Fold COND_EXPR_COND of each COND_EXPR. */
624 fold_cond_expr_cond ();
628 /* Create the edges for a COND_EXPR starting at block BB.
629 At this point, both clauses must contain only simple gotos. */
632 make_cond_expr_edges (basic_block bb)
634 tree entry = last_stmt (bb);
635 basic_block then_bb, else_bb;
636 tree then_label, else_label;
640 gcc_assert (TREE_CODE (entry) == COND_EXPR);
642 /* Entry basic blocks for each component. */
643 then_label = GOTO_DESTINATION (COND_EXPR_THEN (entry));
644 else_label = GOTO_DESTINATION (COND_EXPR_ELSE (entry));
645 then_bb = label_to_block (then_label);
646 else_bb = label_to_block (else_label);
648 e = make_edge (bb, then_bb, EDGE_TRUE_VALUE);
649 e->goto_locus = EXPR_LOCATION (COND_EXPR_THEN (entry));
650 e = make_edge (bb, else_bb, EDGE_FALSE_VALUE);
652 e->goto_locus = EXPR_LOCATION (COND_EXPR_ELSE (entry));
654 /* We do not need the gotos anymore. */
655 COND_EXPR_THEN (entry) = NULL_TREE;
656 COND_EXPR_ELSE (entry) = NULL_TREE;
660 /* Called for each element in the hash table (P) as we delete the
661 edge to cases hash table.
663 Clear all the TREE_CHAINs to prevent problems with copying of
664 SWITCH_EXPRs and structure sharing rules, then free the hash table
668 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED, void **value,
669 void *data ATTRIBUTE_UNUSED)
673 for (t = (tree) *value; t; t = next)
675 next = TREE_CHAIN (t);
676 TREE_CHAIN (t) = NULL;
683 /* Start recording information mapping edges to case labels. */
686 start_recording_case_labels (void)
688 gcc_assert (edge_to_cases == NULL);
689 edge_to_cases = pointer_map_create ();
692 /* Return nonzero if we are recording information for case labels. */
695 recording_case_labels_p (void)
697 return (edge_to_cases != NULL);
700 /* Stop recording information mapping edges to case labels and
701 remove any information we have recorded. */
703 end_recording_case_labels (void)
705 pointer_map_traverse (edge_to_cases, edge_to_cases_cleanup, NULL);
706 pointer_map_destroy (edge_to_cases);
707 edge_to_cases = NULL;
710 /* If we are inside a {start,end}_recording_cases block, then return
711 a chain of CASE_LABEL_EXPRs from T which reference E.
713 Otherwise return NULL. */
716 get_cases_for_edge (edge e, tree t)
722 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
723 chains available. Return NULL so the caller can detect this case. */
724 if (!recording_case_labels_p ())
727 slot = pointer_map_contains (edge_to_cases, e);
731 /* If we did not find E in the hash table, then this must be the first
732 time we have been queried for information about E & T. Add all the
733 elements from T to the hash table then perform the query again. */
735 vec = SWITCH_LABELS (t);
736 n = TREE_VEC_LENGTH (vec);
737 for (i = 0; i < n; i++)
739 tree elt = TREE_VEC_ELT (vec, i);
740 tree lab = CASE_LABEL (elt);
741 basic_block label_bb = label_to_block (lab);
742 edge this_edge = find_edge (e->src, label_bb);
744 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
746 slot = pointer_map_insert (edge_to_cases, this_edge);
747 TREE_CHAIN (elt) = (tree) *slot;
751 return (tree) *pointer_map_contains (edge_to_cases, e);
754 /* Create the edges for a SWITCH_EXPR starting at block BB.
755 At this point, the switch body has been lowered and the
756 SWITCH_LABELS filled in, so this is in effect a multi-way branch. */
759 make_switch_expr_edges (basic_block bb)
761 tree entry = last_stmt (bb);
765 vec = SWITCH_LABELS (entry);
766 n = TREE_VEC_LENGTH (vec);
768 for (i = 0; i < n; ++i)
770 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
771 basic_block label_bb = label_to_block (lab);
772 make_edge (bb, label_bb, 0);
777 /* Return the basic block holding label DEST. */
780 label_to_block_fn (struct function *ifun, tree dest)
782 int uid = LABEL_DECL_UID (dest);
784 /* We would die hard when faced by an undefined label. Emit a label to
785 the very first basic block. This will hopefully make even the dataflow
786 and undefined variable warnings quite right. */
787 if ((errorcount || sorrycount) && uid < 0)
789 block_stmt_iterator bsi =
790 bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS));
793 stmt = build1 (LABEL_EXPR, void_type_node, dest);
794 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
795 uid = LABEL_DECL_UID (dest);
797 if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map)
798 <= (unsigned int) uid)
800 return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid);
803 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
804 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
807 make_abnormal_goto_edges (basic_block bb, bool for_call)
809 basic_block target_bb;
810 block_stmt_iterator bsi;
812 FOR_EACH_BB (target_bb)
813 for (bsi = bsi_start (target_bb); !bsi_end_p (bsi); bsi_next (&bsi))
815 tree target = bsi_stmt (bsi);
817 if (TREE_CODE (target) != LABEL_EXPR)
820 target = LABEL_EXPR_LABEL (target);
822 /* Make an edge to every label block that has been marked as a
823 potential target for a computed goto or a non-local goto. */
824 if ((FORCED_LABEL (target) && !for_call)
825 || (DECL_NONLOCAL (target) && for_call))
827 make_edge (bb, target_bb, EDGE_ABNORMAL);
833 /* Create edges for a goto statement at block BB. */
836 make_goto_expr_edges (basic_block bb)
838 block_stmt_iterator last = bsi_last (bb);
839 tree goto_t = bsi_stmt (last);
841 /* A simple GOTO creates normal edges. */
842 if (simple_goto_p (goto_t))
844 tree dest = GOTO_DESTINATION (goto_t);
845 edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU);
846 e->goto_locus = EXPR_LOCATION (goto_t);
847 bsi_remove (&last, true);
851 /* A computed GOTO creates abnormal edges. */
852 make_abnormal_goto_edges (bb, false);
856 /*---------------------------------------------------------------------------
858 ---------------------------------------------------------------------------*/
860 /* Cleanup useless labels in basic blocks. This is something we wish
861 to do early because it allows us to group case labels before creating
862 the edges for the CFG, and it speeds up block statement iterators in
864 We rerun this pass after CFG is created, to get rid of the labels that
865 are no longer referenced. After then we do not run it any more, since
866 (almost) no new labels should be created. */
868 /* A map from basic block index to the leading label of that block. */
869 static struct label_record
874 /* True if the label is referenced from somewhere. */
878 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
880 update_eh_label (struct eh_region *region)
882 tree old_label = get_eh_region_tree_label (region);
886 basic_block bb = label_to_block (old_label);
888 /* ??? After optimizing, there may be EH regions with labels
889 that have already been removed from the function body, so
890 there is no basic block for them. */
894 new_label = label_for_bb[bb->index].label;
895 label_for_bb[bb->index].used = true;
896 set_eh_region_tree_label (region, new_label);
900 /* Given LABEL return the first label in the same basic block. */
902 main_block_label (tree label)
904 basic_block bb = label_to_block (label);
905 tree main_label = label_for_bb[bb->index].label;
907 /* label_to_block possibly inserted undefined label into the chain. */
910 label_for_bb[bb->index].label = label;
914 label_for_bb[bb->index].used = true;
918 /* Cleanup redundant labels. This is a three-step process:
919 1) Find the leading label for each block.
920 2) Redirect all references to labels to the leading labels.
921 3) Cleanup all useless labels. */
924 cleanup_dead_labels (void)
927 label_for_bb = XCNEWVEC (struct label_record, last_basic_block);
929 /* Find a suitable label for each block. We use the first user-defined
930 label if there is one, or otherwise just the first label we see. */
933 block_stmt_iterator i;
935 for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i))
937 tree label, stmt = bsi_stmt (i);
939 if (TREE_CODE (stmt) != LABEL_EXPR)
942 label = LABEL_EXPR_LABEL (stmt);
944 /* If we have not yet seen a label for the current block,
945 remember this one and see if there are more labels. */
946 if (!label_for_bb[bb->index].label)
948 label_for_bb[bb->index].label = label;
952 /* If we did see a label for the current block already, but it
953 is an artificially created label, replace it if the current
954 label is a user defined label. */
955 if (!DECL_ARTIFICIAL (label)
956 && DECL_ARTIFICIAL (label_for_bb[bb->index].label))
958 label_for_bb[bb->index].label = label;
964 /* Now redirect all jumps/branches to the selected label.
965 First do so for each block ending in a control statement. */
968 tree stmt = last_stmt (bb);
972 switch (TREE_CODE (stmt))
976 tree true_branch, false_branch;
978 true_branch = COND_EXPR_THEN (stmt);
979 false_branch = COND_EXPR_ELSE (stmt);
982 GOTO_DESTINATION (true_branch)
983 = main_block_label (GOTO_DESTINATION (true_branch));
985 GOTO_DESTINATION (false_branch)
986 = main_block_label (GOTO_DESTINATION (false_branch));
994 tree vec = SWITCH_LABELS (stmt);
995 size_t n = TREE_VEC_LENGTH (vec);
997 /* Replace all destination labels. */
998 for (i = 0; i < n; ++i)
1000 tree elt = TREE_VEC_ELT (vec, i);
1001 tree label = main_block_label (CASE_LABEL (elt));
1002 CASE_LABEL (elt) = label;
1007 /* We have to handle GOTO_EXPRs until they're removed, and we don't
1008 remove them until after we've created the CFG edges. */
1010 if (! computed_goto_p (stmt))
1012 GOTO_DESTINATION (stmt)
1013 = main_block_label (GOTO_DESTINATION (stmt));
1022 for_each_eh_region (update_eh_label);
1024 /* Finally, purge dead labels. All user-defined labels and labels that
1025 can be the target of non-local gotos and labels which have their
1026 address taken are preserved. */
1029 block_stmt_iterator i;
1030 tree label_for_this_bb = label_for_bb[bb->index].label;
1032 if (!label_for_this_bb)
1035 /* If the main label of the block is unused, we may still remove it. */
1036 if (!label_for_bb[bb->index].used)
1037 label_for_this_bb = NULL;
1039 for (i = bsi_start (bb); !bsi_end_p (i); )
1041 tree label, stmt = bsi_stmt (i);
1043 if (TREE_CODE (stmt) != LABEL_EXPR)
1046 label = LABEL_EXPR_LABEL (stmt);
1048 if (label == label_for_this_bb
1049 || ! DECL_ARTIFICIAL (label)
1050 || DECL_NONLOCAL (label)
1051 || FORCED_LABEL (label))
1054 bsi_remove (&i, true);
1058 free (label_for_bb);
1061 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1062 and scan the sorted vector of cases. Combine the ones jumping to the
1064 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1067 group_case_labels (void)
1073 tree stmt = last_stmt (bb);
1074 if (stmt && TREE_CODE (stmt) == SWITCH_EXPR)
1076 tree labels = SWITCH_LABELS (stmt);
1077 int old_size = TREE_VEC_LENGTH (labels);
1078 int i, j, new_size = old_size;
1079 tree default_case = NULL_TREE;
1080 tree default_label = NULL_TREE;
1082 /* The default label is always the last case in a switch
1083 statement after gimplification if it was not optimized
1085 if (!CASE_LOW (TREE_VEC_ELT (labels, old_size - 1))
1086 && !CASE_HIGH (TREE_VEC_ELT (labels, old_size - 1)))
1088 default_case = TREE_VEC_ELT (labels, old_size - 1);
1089 default_label = CASE_LABEL (default_case);
1093 /* Look for possible opportunities to merge cases. */
1095 while (i < old_size)
1097 tree base_case, base_label, base_high;
1098 base_case = TREE_VEC_ELT (labels, i);
1100 gcc_assert (base_case);
1101 base_label = CASE_LABEL (base_case);
1103 /* Discard cases that have the same destination as the
1105 if (base_label == default_label)
1107 TREE_VEC_ELT (labels, i) = NULL_TREE;
1113 base_high = CASE_HIGH (base_case) ?
1114 CASE_HIGH (base_case) : CASE_LOW (base_case);
1116 /* Try to merge case labels. Break out when we reach the end
1117 of the label vector or when we cannot merge the next case
1118 label with the current one. */
1119 while (i < old_size)
1121 tree merge_case = TREE_VEC_ELT (labels, i);
1122 tree merge_label = CASE_LABEL (merge_case);
1123 tree t = int_const_binop (PLUS_EXPR, base_high,
1124 integer_one_node, 1);
1126 /* Merge the cases if they jump to the same place,
1127 and their ranges are consecutive. */
1128 if (merge_label == base_label
1129 && tree_int_cst_equal (CASE_LOW (merge_case), t))
1131 base_high = CASE_HIGH (merge_case) ?
1132 CASE_HIGH (merge_case) : CASE_LOW (merge_case);
1133 CASE_HIGH (base_case) = base_high;
1134 TREE_VEC_ELT (labels, i) = NULL_TREE;
1143 /* Compress the case labels in the label vector, and adjust the
1144 length of the vector. */
1145 for (i = 0, j = 0; i < new_size; i++)
1147 while (! TREE_VEC_ELT (labels, j))
1149 TREE_VEC_ELT (labels, i) = TREE_VEC_ELT (labels, j++);
1151 TREE_VEC_LENGTH (labels) = new_size;
1156 /* Checks whether we can merge block B into block A. */
1159 tree_can_merge_blocks_p (basic_block a, basic_block b)
1162 block_stmt_iterator bsi;
1165 if (!single_succ_p (a))
1168 if (single_succ_edge (a)->flags & EDGE_ABNORMAL)
1171 if (single_succ (a) != b)
1174 if (!single_pred_p (b))
1177 if (b == EXIT_BLOCK_PTR)
1180 /* If A ends by a statement causing exceptions or something similar, we
1181 cannot merge the blocks. */
1182 /* This CONST_CAST is okay because last_stmt doesn't modify its
1183 argument and the return value is assign to a const_tree. */
1184 stmt = last_stmt (CONST_CAST_BB (a));
1185 if (stmt && stmt_ends_bb_p (stmt))
1188 /* Do not allow a block with only a non-local label to be merged. */
1189 if (stmt && TREE_CODE (stmt) == LABEL_EXPR
1190 && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
1193 /* It must be possible to eliminate all phi nodes in B. If ssa form
1194 is not up-to-date, we cannot eliminate any phis; however, if only
1195 some symbols as whole are marked for renaming, this is not a problem,
1196 as phi nodes for those symbols are irrelevant in updating anyway. */
1197 phi = phi_nodes (b);
1200 if (name_mappings_registered_p ())
1203 for (; phi; phi = PHI_CHAIN (phi))
1204 if (!is_gimple_reg (PHI_RESULT (phi))
1205 && !may_propagate_copy (PHI_RESULT (phi), PHI_ARG_DEF (phi, 0)))
1209 /* Do not remove user labels. */
1210 for (bsi = bsi_start (b); !bsi_end_p (bsi); bsi_next (&bsi))
1212 stmt = bsi_stmt (bsi);
1213 if (TREE_CODE (stmt) != LABEL_EXPR)
1215 if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt)))
1219 /* Protect the loop latches. */
1221 && b->loop_father->latch == b)
1227 /* Replaces all uses of NAME by VAL. */
1230 replace_uses_by (tree name, tree val)
1232 imm_use_iterator imm_iter;
1237 FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
1239 if (TREE_CODE (stmt) != PHI_NODE)
1240 push_stmt_changes (&stmt);
1242 FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
1244 replace_exp (use, val);
1246 if (TREE_CODE (stmt) == PHI_NODE)
1248 e = PHI_ARG_EDGE (stmt, PHI_ARG_INDEX_FROM_USE (use));
1249 if (e->flags & EDGE_ABNORMAL)
1251 /* This can only occur for virtual operands, since
1252 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1253 would prevent replacement. */
1254 gcc_assert (!is_gimple_reg (name));
1255 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1;
1260 if (TREE_CODE (stmt) != PHI_NODE)
1264 fold_stmt_inplace (stmt);
1265 if (cfgcleanup_altered_bbs)
1266 bitmap_set_bit (cfgcleanup_altered_bbs, bb_for_stmt (stmt)->index);
1268 /* FIXME. This should go in pop_stmt_changes. */
1269 rhs = get_rhs (stmt);
1270 if (TREE_CODE (rhs) == ADDR_EXPR)
1271 recompute_tree_invariant_for_addr_expr (rhs);
1273 maybe_clean_or_replace_eh_stmt (stmt, stmt);
1275 pop_stmt_changes (&stmt);
1279 gcc_assert (has_zero_uses (name));
1281 /* Also update the trees stored in loop structures. */
1287 FOR_EACH_LOOP (li, loop, 0)
1289 substitute_in_loop_info (loop, name, val);
1294 /* Merge block B into block A. */
1297 tree_merge_blocks (basic_block a, basic_block b)
1299 block_stmt_iterator bsi;
1300 tree_stmt_iterator last;
1304 fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index);
1306 /* Remove all single-valued PHI nodes from block B of the form
1307 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1309 for (phi = phi_nodes (b); phi; phi = phi_nodes (b))
1311 tree def = PHI_RESULT (phi), use = PHI_ARG_DEF (phi, 0);
1313 bool may_replace_uses = may_propagate_copy (def, use);
1315 /* In case we maintain loop closed ssa form, do not propagate arguments
1316 of loop exit phi nodes. */
1318 && loops_state_satisfies_p (LOOP_CLOSED_SSA)
1319 && is_gimple_reg (def)
1320 && TREE_CODE (use) == SSA_NAME
1321 && a->loop_father != b->loop_father)
1322 may_replace_uses = false;
1324 if (!may_replace_uses)
1326 gcc_assert (is_gimple_reg (def));
1328 /* Note that just emitting the copies is fine -- there is no problem
1329 with ordering of phi nodes. This is because A is the single
1330 predecessor of B, therefore results of the phi nodes cannot
1331 appear as arguments of the phi nodes. */
1332 copy = build_gimple_modify_stmt (def, use);
1333 bsi_insert_after (&bsi, copy, BSI_NEW_STMT);
1334 SSA_NAME_DEF_STMT (def) = copy;
1335 remove_phi_node (phi, NULL, false);
1339 /* If we deal with a PHI for virtual operands, we can simply
1340 propagate these without fussing with folding or updating
1342 if (!is_gimple_reg (def))
1344 imm_use_iterator iter;
1345 use_operand_p use_p;
1348 FOR_EACH_IMM_USE_STMT (stmt, iter, def)
1349 FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
1350 SET_USE (use_p, use);
1353 replace_uses_by (def, use);
1354 remove_phi_node (phi, NULL, true);
1358 /* Ensure that B follows A. */
1359 move_block_after (b, a);
1361 gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU);
1362 gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a)));
1364 /* Remove labels from B and set bb_for_stmt to A for other statements. */
1365 for (bsi = bsi_start (b); !bsi_end_p (bsi);)
1367 if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR)
1369 tree label = bsi_stmt (bsi);
1371 bsi_remove (&bsi, false);
1372 /* Now that we can thread computed gotos, we might have
1373 a situation where we have a forced label in block B
1374 However, the label at the start of block B might still be
1375 used in other ways (think about the runtime checking for
1376 Fortran assigned gotos). So we can not just delete the
1377 label. Instead we move the label to the start of block A. */
1378 if (FORCED_LABEL (LABEL_EXPR_LABEL (label)))
1380 block_stmt_iterator dest_bsi = bsi_start (a);
1381 bsi_insert_before (&dest_bsi, label, BSI_NEW_STMT);
1386 change_bb_for_stmt (bsi_stmt (bsi), a);
1391 /* Merge the chains. */
1392 last = tsi_last (bb_stmt_list (a));
1393 tsi_link_after (&last, bb_stmt_list (b), TSI_NEW_STMT);
1394 set_bb_stmt_list (b, NULL_TREE);
1396 if (cfgcleanup_altered_bbs)
1397 bitmap_set_bit (cfgcleanup_altered_bbs, a->index);
1401 /* Return the one of two successors of BB that is not reachable by a
1402 reached by a complex edge, if there is one. Else, return BB. We use
1403 this in optimizations that use post-dominators for their heuristics,
1404 to catch the cases in C++ where function calls are involved. */
1407 single_noncomplex_succ (basic_block bb)
1410 if (EDGE_COUNT (bb->succs) != 2)
1413 e0 = EDGE_SUCC (bb, 0);
1414 e1 = EDGE_SUCC (bb, 1);
1415 if (e0->flags & EDGE_COMPLEX)
1417 if (e1->flags & EDGE_COMPLEX)
1424 /* Walk the function tree removing unnecessary statements.
1426 * Empty statement nodes are removed
1428 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1430 * Unnecessary COND_EXPRs are removed
1432 * Some unnecessary BIND_EXPRs are removed
1434 Clearly more work could be done. The trick is doing the analysis
1435 and removal fast enough to be a net improvement in compile times.
1437 Note that when we remove a control structure such as a COND_EXPR
1438 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1439 to ensure we eliminate all the useless code. */
1450 static void remove_useless_stmts_1 (tree *, struct rus_data *);
1453 remove_useless_stmts_warn_notreached (tree stmt)
1455 if (EXPR_HAS_LOCATION (stmt))
1457 location_t loc = EXPR_LOCATION (stmt);
1458 if (LOCATION_LINE (loc) > 0)
1460 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
1465 switch (TREE_CODE (stmt))
1467 case STATEMENT_LIST:
1469 tree_stmt_iterator i;
1470 for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i))
1471 if (remove_useless_stmts_warn_notreached (tsi_stmt (i)))
1477 if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt)))
1479 if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt)))
1481 if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt)))
1485 case TRY_FINALLY_EXPR:
1486 case TRY_CATCH_EXPR:
1487 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 0)))
1489 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 1)))
1494 return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt));
1495 case EH_FILTER_EXPR:
1496 return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt));
1498 return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt));
1501 /* Not a live container. */
1509 remove_useless_stmts_cond (tree *stmt_p, struct rus_data *data)
1511 tree then_clause, else_clause, cond;
1512 bool save_has_label, then_has_label, else_has_label;
1514 save_has_label = data->has_label;
1515 data->has_label = false;
1516 data->last_goto = NULL;
1518 remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p), data);
1520 then_has_label = data->has_label;
1521 data->has_label = false;
1522 data->last_goto = NULL;
1524 remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p), data);
1526 else_has_label = data->has_label;
1527 data->has_label = save_has_label | then_has_label | else_has_label;
1529 then_clause = COND_EXPR_THEN (*stmt_p);
1530 else_clause = COND_EXPR_ELSE (*stmt_p);
1531 cond = fold (COND_EXPR_COND (*stmt_p));
1533 /* If neither arm does anything at all, we can remove the whole IF. */
1534 if (!TREE_SIDE_EFFECTS (then_clause) && !TREE_SIDE_EFFECTS (else_clause))
1536 *stmt_p = build_empty_stmt ();
1537 data->repeat = true;
1540 /* If there are no reachable statements in an arm, then we can
1541 zap the entire conditional. */
1542 else if (integer_nonzerop (cond) && !else_has_label)
1544 if (warn_notreached)
1545 remove_useless_stmts_warn_notreached (else_clause);
1546 *stmt_p = then_clause;
1547 data->repeat = true;
1549 else if (integer_zerop (cond) && !then_has_label)
1551 if (warn_notreached)
1552 remove_useless_stmts_warn_notreached (then_clause);
1553 *stmt_p = else_clause;
1554 data->repeat = true;
1557 /* Check a couple of simple things on then/else with single stmts. */
1560 tree then_stmt = expr_only (then_clause);
1561 tree else_stmt = expr_only (else_clause);
1563 /* Notice branches to a common destination. */
1564 if (then_stmt && else_stmt
1565 && TREE_CODE (then_stmt) == GOTO_EXPR
1566 && TREE_CODE (else_stmt) == GOTO_EXPR
1567 && (GOTO_DESTINATION (then_stmt) == GOTO_DESTINATION (else_stmt)))
1569 *stmt_p = then_stmt;
1570 data->repeat = true;
1573 /* If the THEN/ELSE clause merely assigns a value to a variable or
1574 parameter which is already known to contain that value, then
1575 remove the useless THEN/ELSE clause. */
1576 else if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL)
1579 && TREE_CODE (else_stmt) == GIMPLE_MODIFY_STMT
1580 && GIMPLE_STMT_OPERAND (else_stmt, 0) == cond
1581 && integer_zerop (GIMPLE_STMT_OPERAND (else_stmt, 1)))
1582 COND_EXPR_ELSE (*stmt_p) = alloc_stmt_list ();
1584 else if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
1585 && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL
1586 || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL)
1587 && TREE_CONSTANT (TREE_OPERAND (cond, 1)))
1589 tree stmt = (TREE_CODE (cond) == EQ_EXPR
1590 ? then_stmt : else_stmt);
1591 tree *location = (TREE_CODE (cond) == EQ_EXPR
1592 ? &COND_EXPR_THEN (*stmt_p)
1593 : &COND_EXPR_ELSE (*stmt_p));
1596 && TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
1597 && GIMPLE_STMT_OPERAND (stmt, 0) == TREE_OPERAND (cond, 0)
1598 && GIMPLE_STMT_OPERAND (stmt, 1) == TREE_OPERAND (cond, 1))
1599 *location = alloc_stmt_list ();
1603 /* Protect GOTOs in the arm of COND_EXPRs from being removed. They
1604 would be re-introduced during lowering. */
1605 data->last_goto = NULL;
1610 remove_useless_stmts_tf (tree *stmt_p, struct rus_data *data)
1612 bool save_may_branch, save_may_throw;
1613 bool this_may_branch, this_may_throw;
1615 /* Collect may_branch and may_throw information for the body only. */
1616 save_may_branch = data->may_branch;
1617 save_may_throw = data->may_throw;
1618 data->may_branch = false;
1619 data->may_throw = false;
1620 data->last_goto = NULL;
1622 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1624 this_may_branch = data->may_branch;
1625 this_may_throw = data->may_throw;
1626 data->may_branch |= save_may_branch;
1627 data->may_throw |= save_may_throw;
1628 data->last_goto = NULL;
1630 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1632 /* If the body is empty, then we can emit the FINALLY block without
1633 the enclosing TRY_FINALLY_EXPR. */
1634 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 0)))
1636 *stmt_p = TREE_OPERAND (*stmt_p, 1);
1637 data->repeat = true;
1640 /* If the handler is empty, then we can emit the TRY block without
1641 the enclosing TRY_FINALLY_EXPR. */
1642 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1644 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1645 data->repeat = true;
1648 /* If the body neither throws, nor branches, then we can safely
1649 string the TRY and FINALLY blocks together. */
1650 else if (!this_may_branch && !this_may_throw)
1652 tree stmt = *stmt_p;
1653 *stmt_p = TREE_OPERAND (stmt, 0);
1654 append_to_statement_list (TREE_OPERAND (stmt, 1), stmt_p);
1655 data->repeat = true;
1661 remove_useless_stmts_tc (tree *stmt_p, struct rus_data *data)
1663 bool save_may_throw, this_may_throw;
1664 tree_stmt_iterator i;
1667 /* Collect may_throw information for the body only. */
1668 save_may_throw = data->may_throw;
1669 data->may_throw = false;
1670 data->last_goto = NULL;
1672 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data);
1674 this_may_throw = data->may_throw;
1675 data->may_throw = save_may_throw;
1677 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1678 if (!this_may_throw)
1680 if (warn_notreached)
1681 remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p, 1));
1682 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1683 data->repeat = true;
1687 /* Process the catch clause specially. We may be able to tell that
1688 no exceptions propagate past this point. */
1690 this_may_throw = true;
1691 i = tsi_start (TREE_OPERAND (*stmt_p, 1));
1692 stmt = tsi_stmt (i);
1693 data->last_goto = NULL;
1695 switch (TREE_CODE (stmt))
1698 for (; !tsi_end_p (i); tsi_next (&i))
1700 stmt = tsi_stmt (i);
1701 /* If we catch all exceptions, then the body does not
1702 propagate exceptions past this point. */
1703 if (CATCH_TYPES (stmt) == NULL)
1704 this_may_throw = false;
1705 data->last_goto = NULL;
1706 remove_useless_stmts_1 (&CATCH_BODY (stmt), data);
1710 case EH_FILTER_EXPR:
1711 if (EH_FILTER_MUST_NOT_THROW (stmt))
1712 this_may_throw = false;
1713 else if (EH_FILTER_TYPES (stmt) == NULL)
1714 this_may_throw = false;
1715 remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt), data);
1719 /* Otherwise this is a cleanup. */
1720 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data);
1722 /* If the cleanup is empty, then we can emit the TRY block without
1723 the enclosing TRY_CATCH_EXPR. */
1724 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1)))
1726 *stmt_p = TREE_OPERAND (*stmt_p, 0);
1727 data->repeat = true;
1731 data->may_throw |= this_may_throw;
1736 remove_useless_stmts_bind (tree *stmt_p, struct rus_data *data)
1740 /* First remove anything underneath the BIND_EXPR. */
1741 remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p), data);
1743 /* If the BIND_EXPR has no variables, then we can pull everything
1744 up one level and remove the BIND_EXPR, unless this is the toplevel
1745 BIND_EXPR for the current function or an inlined function.
1747 When this situation occurs we will want to apply this
1748 optimization again. */
1749 block = BIND_EXPR_BLOCK (*stmt_p);
1750 if (BIND_EXPR_VARS (*stmt_p) == NULL_TREE
1751 && *stmt_p != DECL_SAVED_TREE (current_function_decl)
1753 || ! BLOCK_ABSTRACT_ORIGIN (block)
1754 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
1757 *stmt_p = BIND_EXPR_BODY (*stmt_p);
1758 data->repeat = true;
1764 remove_useless_stmts_goto (tree *stmt_p, struct rus_data *data)
1766 tree dest = GOTO_DESTINATION (*stmt_p);
1768 data->may_branch = true;
1769 data->last_goto = NULL;
1771 /* Record the last goto expr, so that we can delete it if unnecessary. */
1772 if (TREE_CODE (dest) == LABEL_DECL)
1773 data->last_goto = stmt_p;
1778 remove_useless_stmts_label (tree *stmt_p, struct rus_data *data)
1780 tree label = LABEL_EXPR_LABEL (*stmt_p);
1782 data->has_label = true;
1784 /* We do want to jump across non-local label receiver code. */
1785 if (DECL_NONLOCAL (label))
1786 data->last_goto = NULL;
1788 else if (data->last_goto && GOTO_DESTINATION (*data->last_goto) == label)
1790 *data->last_goto = build_empty_stmt ();
1791 data->repeat = true;
1794 /* ??? Add something here to delete unused labels. */
1798 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1799 decl. This allows us to eliminate redundant or useless
1800 calls to "const" functions.
1802 Gimplifier already does the same operation, but we may notice functions
1803 being const and pure once their calls has been gimplified, so we need
1804 to update the flag. */
1807 update_call_expr_flags (tree call)
1809 tree decl = get_callee_fndecl (call);
1813 flags = call_expr_flags (call);
1814 if (flags & (ECF_CONST | ECF_PURE) && !(flags & ECF_LOOPING_CONST_OR_PURE))
1815 TREE_SIDE_EFFECTS (call) = 0;
1816 if (TREE_NOTHROW (decl))
1817 TREE_NOTHROW (call) = 1;
1821 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1824 notice_special_calls (tree t)
1826 int flags = call_expr_flags (t);
1828 if (flags & ECF_MAY_BE_ALLOCA)
1829 cfun->calls_alloca = true;
1830 if (flags & ECF_RETURNS_TWICE)
1831 cfun->calls_setjmp = true;
1835 /* Clear flags set by notice_special_calls. Used by dead code removal
1836 to update the flags. */
1839 clear_special_calls (void)
1841 cfun->calls_alloca = false;
1842 cfun->calls_setjmp = false;
1847 remove_useless_stmts_1 (tree *tp, struct rus_data *data)
1851 switch (TREE_CODE (t))
1854 remove_useless_stmts_cond (tp, data);
1857 case TRY_FINALLY_EXPR:
1858 remove_useless_stmts_tf (tp, data);
1861 case TRY_CATCH_EXPR:
1862 remove_useless_stmts_tc (tp, data);
1866 remove_useless_stmts_bind (tp, data);
1870 remove_useless_stmts_goto (tp, data);
1874 remove_useless_stmts_label (tp, data);
1879 data->last_goto = NULL;
1880 data->may_branch = true;
1885 data->last_goto = NULL;
1886 notice_special_calls (t);
1887 update_call_expr_flags (t);
1888 if (tree_could_throw_p (t))
1889 data->may_throw = true;
1895 case GIMPLE_MODIFY_STMT:
1896 data->last_goto = NULL;
1898 op = get_call_expr_in (t);
1901 update_call_expr_flags (op);
1902 notice_special_calls (op);
1904 if (tree_could_throw_p (t))
1905 data->may_throw = true;
1908 case STATEMENT_LIST:
1910 tree_stmt_iterator i = tsi_start (t);
1911 while (!tsi_end_p (i))
1914 if (IS_EMPTY_STMT (t))
1920 remove_useless_stmts_1 (tsi_stmt_ptr (i), data);
1923 if (TREE_CODE (t) == STATEMENT_LIST)
1925 tsi_link_before (&i, t, TSI_SAME_STMT);
1935 data->last_goto = NULL;
1939 /* Make sure the outermost BIND_EXPR in OMP_BODY isn't removed
1941 remove_useless_stmts_1 (&BIND_EXPR_BODY (OMP_BODY (*tp)), data);
1942 data->last_goto = NULL;
1951 remove_useless_stmts_1 (&OMP_BODY (*tp), data);
1952 data->last_goto = NULL;
1956 remove_useless_stmts_1 (&OMP_FOR_BODY (*tp), data);
1957 data->last_goto = NULL;
1958 if (OMP_FOR_PRE_BODY (*tp))
1960 remove_useless_stmts_1 (&OMP_FOR_PRE_BODY (*tp), data);
1961 data->last_goto = NULL;
1966 data->last_goto = NULL;
1972 remove_useless_stmts (void)
1974 struct rus_data data;
1976 clear_special_calls ();
1980 memset (&data, 0, sizeof (data));
1981 remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl), &data);
1983 while (data.repeat);
1988 struct gimple_opt_pass pass_remove_useless_stmts =
1992 "useless", /* name */
1994 remove_useless_stmts, /* execute */
1997 0, /* static_pass_number */
1999 PROP_gimple_any, /* properties_required */
2000 0, /* properties_provided */
2001 0, /* properties_destroyed */
2002 0, /* todo_flags_start */
2003 TODO_dump_func /* todo_flags_finish */
2007 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
2010 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb)
2014 /* Since this block is no longer reachable, we can just delete all
2015 of its PHI nodes. */
2016 phi = phi_nodes (bb);
2019 tree next = PHI_CHAIN (phi);
2020 remove_phi_node (phi, NULL_TREE, true);
2024 /* Remove edges to BB's successors. */
2025 while (EDGE_COUNT (bb->succs) > 0)
2026 remove_edge (EDGE_SUCC (bb, 0));
2030 /* Remove statements of basic block BB. */
2033 remove_bb (basic_block bb)
2035 block_stmt_iterator i;
2036 source_location loc = UNKNOWN_LOCATION;
2040 fprintf (dump_file, "Removing basic block %d\n", bb->index);
2041 if (dump_flags & TDF_DETAILS)
2043 dump_bb (bb, dump_file, 0);
2044 fprintf (dump_file, "\n");
2050 struct loop *loop = bb->loop_father;
2052 /* If a loop gets removed, clean up the information associated
2054 if (loop->latch == bb
2055 || loop->header == bb)
2056 free_numbers_of_iterations_estimates_loop (loop);
2059 /* Remove all the instructions in the block. */
2060 if (bb_stmt_list (bb) != NULL_TREE)
2062 for (i = bsi_start (bb); !bsi_end_p (i);)
2064 tree stmt = bsi_stmt (i);
2065 if (TREE_CODE (stmt) == LABEL_EXPR
2066 && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt))
2067 || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))))
2070 block_stmt_iterator new_bsi;
2072 /* A non-reachable non-local label may still be referenced.
2073 But it no longer needs to carry the extra semantics of
2075 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
2077 DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)) = 0;
2078 FORCED_LABEL (LABEL_EXPR_LABEL (stmt)) = 1;
2081 new_bb = bb->prev_bb;
2082 new_bsi = bsi_start (new_bb);
2083 bsi_remove (&i, false);
2084 bsi_insert_before (&new_bsi, stmt, BSI_NEW_STMT);
2088 /* Release SSA definitions if we are in SSA. Note that we
2089 may be called when not in SSA. For example,
2090 final_cleanup calls this function via
2091 cleanup_tree_cfg. */
2092 if (gimple_in_ssa_p (cfun))
2093 release_defs (stmt);
2095 bsi_remove (&i, true);
2098 /* Don't warn for removed gotos. Gotos are often removed due to
2099 jump threading, thus resulting in bogus warnings. Not great,
2100 since this way we lose warnings for gotos in the original
2101 program that are indeed unreachable. */
2102 if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc)
2104 if (EXPR_HAS_LOCATION (stmt))
2105 loc = EXPR_LOCATION (stmt);
2110 /* If requested, give a warning that the first statement in the
2111 block is unreachable. We walk statements backwards in the
2112 loop above, so the last statement we process is the first statement
2114 if (loc > BUILTINS_LOCATION && LOCATION_LINE (loc) > 0)
2115 warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc);
2117 remove_phi_nodes_and_edges_for_unreachable_block (bb);
2122 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2123 predicate VAL, return the edge that will be taken out of the block.
2124 If VAL does not match a unique edge, NULL is returned. */
2127 find_taken_edge (basic_block bb, tree val)
2131 stmt = last_stmt (bb);
2134 gcc_assert (is_ctrl_stmt (stmt));
2137 if (! is_gimple_min_invariant (val))
2140 if (TREE_CODE (stmt) == COND_EXPR)
2141 return find_taken_edge_cond_expr (bb, val);
2143 if (TREE_CODE (stmt) == SWITCH_EXPR)
2144 return find_taken_edge_switch_expr (bb, val);
2146 if (computed_goto_p (stmt))
2148 /* Only optimize if the argument is a label, if the argument is
2149 not a label then we can not construct a proper CFG.
2151 It may be the case that we only need to allow the LABEL_REF to
2152 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2153 appear inside a LABEL_EXPR just to be safe. */
2154 if ((TREE_CODE (val) == ADDR_EXPR || TREE_CODE (val) == LABEL_EXPR)
2155 && TREE_CODE (TREE_OPERAND (val, 0)) == LABEL_DECL)
2156 return find_taken_edge_computed_goto (bb, TREE_OPERAND (val, 0));
2163 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2164 statement, determine which of the outgoing edges will be taken out of the
2165 block. Return NULL if either edge may be taken. */
2168 find_taken_edge_computed_goto (basic_block bb, tree val)
2173 dest = label_to_block (val);
2176 e = find_edge (bb, dest);
2177 gcc_assert (e != NULL);
2183 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2184 statement, determine which of the two edges will be taken out of the
2185 block. Return NULL if either edge may be taken. */
2188 find_taken_edge_cond_expr (basic_block bb, tree val)
2190 edge true_edge, false_edge;
2192 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
2194 gcc_assert (TREE_CODE (val) == INTEGER_CST);
2195 return (integer_zerop (val) ? false_edge : true_edge);
2198 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2199 statement, determine which edge will be taken out of the block. Return
2200 NULL if any edge may be taken. */
2203 find_taken_edge_switch_expr (basic_block bb, tree val)
2205 tree switch_expr, taken_case;
2206 basic_block dest_bb;
2209 switch_expr = last_stmt (bb);
2210 taken_case = find_case_label_for_value (switch_expr, val);
2211 dest_bb = label_to_block (CASE_LABEL (taken_case));
2213 e = find_edge (bb, dest_bb);
2219 /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL.
2220 We can make optimal use here of the fact that the case labels are
2221 sorted: We can do a binary search for a case matching VAL. */
2224 find_case_label_for_value (tree switch_expr, tree val)
2226 tree vec = SWITCH_LABELS (switch_expr);
2227 size_t low, high, n = TREE_VEC_LENGTH (vec);
2228 tree default_case = TREE_VEC_ELT (vec, n - 1);
2230 for (low = -1, high = n - 1; high - low > 1; )
2232 size_t i = (high + low) / 2;
2233 tree t = TREE_VEC_ELT (vec, i);
2236 /* Cache the result of comparing CASE_LOW and val. */
2237 cmp = tree_int_cst_compare (CASE_LOW (t), val);
2244 if (CASE_HIGH (t) == NULL)
2246 /* A singe-valued case label. */
2252 /* A case range. We can only handle integer ranges. */
2253 if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
2258 return default_case;
2264 /*---------------------------------------------------------------------------
2266 ---------------------------------------------------------------------------*/
2268 /* Dump tree-specific information of block BB to file OUTF. */
2271 tree_dump_bb (basic_block bb, FILE *outf, int indent)
2273 dump_generic_bb (outf, bb, indent, TDF_VOPS|TDF_MEMSYMS);
2277 /* Dump a basic block on stderr. */
2280 debug_tree_bb (basic_block bb)
2282 dump_bb (bb, stderr, 0);
2286 /* Dump basic block with index N on stderr. */
2289 debug_tree_bb_n (int n)
2291 debug_tree_bb (BASIC_BLOCK (n));
2292 return BASIC_BLOCK (n);
2296 /* Dump the CFG on stderr.
2298 FLAGS are the same used by the tree dumping functions
2299 (see TDF_* in tree-pass.h). */
2302 debug_tree_cfg (int flags)
2304 dump_tree_cfg (stderr, flags);
2308 /* Dump the program showing basic block boundaries on the given FILE.
2310 FLAGS are the same used by the tree dumping functions (see TDF_* in
2314 dump_tree_cfg (FILE *file, int flags)
2316 if (flags & TDF_DETAILS)
2318 const char *funcname
2319 = lang_hooks.decl_printable_name (current_function_decl, 2);
2322 fprintf (file, ";; Function %s\n\n", funcname);
2323 fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2324 n_basic_blocks, n_edges, last_basic_block);
2326 brief_dump_cfg (file);
2327 fprintf (file, "\n");
2330 if (flags & TDF_STATS)
2331 dump_cfg_stats (file);
2333 dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS);
2337 /* Dump CFG statistics on FILE. */
2340 dump_cfg_stats (FILE *file)
2342 static long max_num_merged_labels = 0;
2343 unsigned long size, total = 0;
2346 const char * const fmt_str = "%-30s%-13s%12s\n";
2347 const char * const fmt_str_1 = "%-30s%13d%11lu%c\n";
2348 const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n";
2349 const char * const fmt_str_3 = "%-43s%11lu%c\n";
2350 const char *funcname
2351 = lang_hooks.decl_printable_name (current_function_decl, 2);
2354 fprintf (file, "\nCFG Statistics for %s\n\n", funcname);
2356 fprintf (file, "---------------------------------------------------------\n");
2357 fprintf (file, fmt_str, "", " Number of ", "Memory");
2358 fprintf (file, fmt_str, "", " instances ", "used ");
2359 fprintf (file, "---------------------------------------------------------\n");
2361 size = n_basic_blocks * sizeof (struct basic_block_def);
2363 fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks,
2364 SCALE (size), LABEL (size));
2368 num_edges += EDGE_COUNT (bb->succs);
2369 size = num_edges * sizeof (struct edge_def);
2371 fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size));
2373 fprintf (file, "---------------------------------------------------------\n");
2374 fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total),
2376 fprintf (file, "---------------------------------------------------------\n");
2377 fprintf (file, "\n");
2379 if (cfg_stats.num_merged_labels > max_num_merged_labels)
2380 max_num_merged_labels = cfg_stats.num_merged_labels;
2382 fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2383 cfg_stats.num_merged_labels, max_num_merged_labels);
2385 fprintf (file, "\n");
2389 /* Dump CFG statistics on stderr. Keep extern so that it's always
2390 linked in the final executable. */
2393 debug_cfg_stats (void)
2395 dump_cfg_stats (stderr);
2399 /* Dump the flowgraph to a .vcg FILE. */
2402 tree_cfg2vcg (FILE *file)
2407 const char *funcname
2408 = lang_hooks.decl_printable_name (current_function_decl, 2);
2410 /* Write the file header. */
2411 fprintf (file, "graph: { title: \"%s\"\n", funcname);
2412 fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2413 fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2415 /* Write blocks and edges. */
2416 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
2418 fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2421 if (e->flags & EDGE_FAKE)
2422 fprintf (file, " linestyle: dotted priority: 10");
2424 fprintf (file, " linestyle: solid priority: 100");
2426 fprintf (file, " }\n");
2432 enum tree_code head_code, end_code;
2433 const char *head_name, *end_name;
2436 tree first = first_stmt (bb);
2437 tree last = last_stmt (bb);
2441 head_code = TREE_CODE (first);
2442 head_name = tree_code_name[head_code];
2443 head_line = get_lineno (first);
2446 head_name = "no-statement";
2450 end_code = TREE_CODE (last);
2451 end_name = tree_code_name[end_code];
2452 end_line = get_lineno (last);
2455 end_name = "no-statement";
2457 fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2458 bb->index, bb->index, head_name, head_line, end_name,
2461 FOR_EACH_EDGE (e, ei, bb->succs)
2463 if (e->dest == EXIT_BLOCK_PTR)
2464 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index);
2466 fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index);
2468 if (e->flags & EDGE_FAKE)
2469 fprintf (file, " priority: 10 linestyle: dotted");
2471 fprintf (file, " priority: 100 linestyle: solid");
2473 fprintf (file, " }\n");
2476 if (bb->next_bb != EXIT_BLOCK_PTR)
2480 fputs ("}\n\n", file);
2485 /*---------------------------------------------------------------------------
2486 Miscellaneous helpers
2487 ---------------------------------------------------------------------------*/
2489 /* Return true if T represents a stmt that always transfers control. */
2492 is_ctrl_stmt (const_tree t)
2494 return (TREE_CODE (t) == COND_EXPR
2495 || TREE_CODE (t) == SWITCH_EXPR
2496 || TREE_CODE (t) == GOTO_EXPR
2497 || TREE_CODE (t) == RETURN_EXPR
2498 || TREE_CODE (t) == RESX_EXPR);
2502 /* Return true if T is a statement that may alter the flow of control
2503 (e.g., a call to a non-returning function). */
2506 is_ctrl_altering_stmt (const_tree t)
2511 call = get_call_expr_in (CONST_CAST_TREE (t));
2514 /* A non-pure/const CALL_EXPR alters flow control if the current
2515 function has nonlocal labels. */
2516 if (TREE_SIDE_EFFECTS (call) && cfun->has_nonlocal_label)
2519 /* A CALL_EXPR also alters control flow if it does not return. */
2520 if (call_expr_flags (call) & ECF_NORETURN)
2524 /* OpenMP directives alter control flow. */
2525 if (OMP_DIRECTIVE_P (t))
2528 /* If a statement can throw, it alters control flow. */
2529 return tree_can_throw_internal (t);
2533 /* Return true if T is a computed goto. */
2536 computed_goto_p (const_tree t)
2538 return (TREE_CODE (t) == GOTO_EXPR
2539 && TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL);
2543 /* Return true if T is a simple local goto. */
2546 simple_goto_p (const_tree t)
2548 return (TREE_CODE (t) == GOTO_EXPR
2549 && TREE_CODE (GOTO_DESTINATION (t)) == LABEL_DECL);
2553 /* Return true if T can make an abnormal transfer of control flow.
2554 Transfers of control flow associated with EH are excluded. */
2557 tree_can_make_abnormal_goto (const_tree t)
2559 if (computed_goto_p (t))
2561 if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
2562 t = GIMPLE_STMT_OPERAND (t, 1);
2563 if (TREE_CODE (t) == WITH_SIZE_EXPR)
2564 t = TREE_OPERAND (t, 0);
2565 if (TREE_CODE (t) == CALL_EXPR)
2566 return TREE_SIDE_EFFECTS (t) && cfun->has_nonlocal_label;
2571 /* Return true if T should start a new basic block. PREV_T is the
2572 statement preceding T. It is used when T is a label or a case label.
2573 Labels should only start a new basic block if their previous statement
2574 wasn't a label. Otherwise, sequence of labels would generate
2575 unnecessary basic blocks that only contain a single label. */
2578 stmt_starts_bb_p (const_tree t, const_tree prev_t)
2583 /* LABEL_EXPRs start a new basic block only if the preceding
2584 statement wasn't a label of the same type. This prevents the
2585 creation of consecutive blocks that have nothing but a single
2587 if (TREE_CODE (t) == LABEL_EXPR)
2589 /* Nonlocal and computed GOTO targets always start a new block. */
2590 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t))
2591 || FORCED_LABEL (LABEL_EXPR_LABEL (t)))
2594 if (prev_t && TREE_CODE (prev_t) == LABEL_EXPR)
2596 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t)))
2599 cfg_stats.num_merged_labels++;
2610 /* Return true if T should end a basic block. */
2613 stmt_ends_bb_p (const_tree t)
2615 return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t);
2618 /* Remove block annotations and other datastructures. */
2621 delete_tree_cfg_annotations (void)
2624 block_stmt_iterator bsi;
2626 /* Remove annotations from every tree in the function. */
2628 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
2630 tree stmt = bsi_stmt (bsi);
2631 ggc_free (stmt->base.ann);
2632 stmt->base.ann = NULL;
2634 label_to_block_map = NULL;
2638 /* Return the first statement in basic block BB. */
2641 first_stmt (basic_block bb)
2643 block_stmt_iterator i = bsi_start (bb);
2644 return !bsi_end_p (i) ? bsi_stmt (i) : NULL_TREE;
2647 /* Return the last statement in basic block BB. */
2650 last_stmt (basic_block bb)
2652 block_stmt_iterator b = bsi_last (bb);
2653 return !bsi_end_p (b) ? bsi_stmt (b) : NULL_TREE;
2656 /* Return the last statement of an otherwise empty block. Return NULL
2657 if the block is totally empty, or if it contains more than one
2661 last_and_only_stmt (basic_block bb)
2663 block_stmt_iterator i = bsi_last (bb);
2669 last = bsi_stmt (i);
2674 /* Empty statements should no longer appear in the instruction stream.
2675 Everything that might have appeared before should be deleted by
2676 remove_useless_stmts, and the optimizers should just bsi_remove
2677 instead of smashing with build_empty_stmt.
2679 Thus the only thing that should appear here in a block containing
2680 one executable statement is a label. */
2681 prev = bsi_stmt (i);
2682 if (TREE_CODE (prev) == LABEL_EXPR)
2689 /* Mark BB as the basic block holding statement T. */
2692 set_bb_for_stmt (tree t, basic_block bb)
2694 if (TREE_CODE (t) == PHI_NODE)
2696 else if (TREE_CODE (t) == STATEMENT_LIST)
2698 tree_stmt_iterator i;
2699 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2700 set_bb_for_stmt (tsi_stmt (i), bb);
2704 stmt_ann_t ann = get_stmt_ann (t);
2707 /* If the statement is a label, add the label to block-to-labels map
2708 so that we can speed up edge creation for GOTO_EXPRs. */
2709 if (TREE_CODE (t) == LABEL_EXPR)
2713 t = LABEL_EXPR_LABEL (t);
2714 uid = LABEL_DECL_UID (t);
2717 unsigned old_len = VEC_length (basic_block, label_to_block_map);
2718 LABEL_DECL_UID (t) = uid = cfun->cfg->last_label_uid++;
2719 if (old_len <= (unsigned) uid)
2721 unsigned new_len = 3 * uid / 2;
2723 VEC_safe_grow_cleared (basic_block, gc, label_to_block_map,
2728 /* We're moving an existing label. Make sure that we've
2729 removed it from the old block. */
2731 || !VEC_index (basic_block, label_to_block_map, uid));
2732 VEC_replace (basic_block, label_to_block_map, uid, bb);
2737 /* Faster version of set_bb_for_stmt that assume that statement is being moved
2738 from one basic block to another.
2739 For BB splitting we can run into quadratic case, so performance is quite
2740 important and knowing that the tables are big enough, change_bb_for_stmt
2741 can inline as leaf function. */
2743 change_bb_for_stmt (tree t, basic_block bb)
2745 get_stmt_ann (t)->bb = bb;
2746 if (TREE_CODE (t) == LABEL_EXPR)
2747 VEC_replace (basic_block, label_to_block_map,
2748 LABEL_DECL_UID (LABEL_EXPR_LABEL (t)), bb);
2751 /* Finds iterator for STMT. */
2753 extern block_stmt_iterator
2754 bsi_for_stmt (tree stmt)
2756 block_stmt_iterator bsi;
2758 for (bsi = bsi_start (bb_for_stmt (stmt)); !bsi_end_p (bsi); bsi_next (&bsi))
2759 if (bsi_stmt (bsi) == stmt)
2765 /* Mark statement T as modified, and update it. */
2767 update_modified_stmts (tree t)
2769 if (!ssa_operands_active ())
2771 if (TREE_CODE (t) == STATEMENT_LIST)
2773 tree_stmt_iterator i;
2775 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
2777 stmt = tsi_stmt (i);
2778 update_stmt_if_modified (stmt);
2782 update_stmt_if_modified (t);
2785 /* Insert statement (or statement list) T before the statement
2786 pointed-to by iterator I. M specifies how to update iterator I
2787 after insertion (see enum bsi_iterator_update). */
2790 bsi_insert_before (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2792 set_bb_for_stmt (t, i->bb);
2793 update_modified_stmts (t);
2794 tsi_link_before (&i->tsi, t, m);
2798 /* Insert statement (or statement list) T after the statement
2799 pointed-to by iterator I. M specifies how to update iterator I
2800 after insertion (see enum bsi_iterator_update). */
2803 bsi_insert_after (block_stmt_iterator *i, tree t, enum bsi_iterator_update m)
2805 set_bb_for_stmt (t, i->bb);
2806 update_modified_stmts (t);
2807 tsi_link_after (&i->tsi, t, m);
2811 /* Remove the statement pointed to by iterator I. The iterator is updated
2812 to the next statement.
2814 When REMOVE_EH_INFO is true we remove the statement pointed to by
2815 iterator I from the EH tables. Otherwise we do not modify the EH
2818 Generally, REMOVE_EH_INFO should be true when the statement is going to
2819 be removed from the IL and not reinserted elsewhere. */
2822 bsi_remove (block_stmt_iterator *i, bool remove_eh_info)
2824 tree t = bsi_stmt (*i);
2825 set_bb_for_stmt (t, NULL);
2826 delink_stmt_imm_use (t);
2827 tsi_delink (&i->tsi);
2828 mark_stmt_modified (t);
2831 remove_stmt_from_eh_region (t);
2832 gimple_remove_stmt_histograms (cfun, t);
2837 /* Move the statement at FROM so it comes right after the statement at TO. */
2840 bsi_move_after (block_stmt_iterator *from, block_stmt_iterator *to)
2842 tree stmt = bsi_stmt (*from);
2843 bsi_remove (from, false);
2844 /* We must have BSI_NEW_STMT here, as bsi_move_after is sometimes used to
2845 move statements to an empty block. */
2846 bsi_insert_after (to, stmt, BSI_NEW_STMT);
2850 /* Move the statement at FROM so it comes right before the statement at TO. */
2853 bsi_move_before (block_stmt_iterator *from, block_stmt_iterator *to)
2855 tree stmt = bsi_stmt (*from);
2856 bsi_remove (from, false);
2857 /* For consistency with bsi_move_after, it might be better to have
2858 BSI_NEW_STMT here; however, that breaks several places that expect
2859 that TO does not change. */
2860 bsi_insert_before (to, stmt, BSI_SAME_STMT);
2864 /* Move the statement at FROM to the end of basic block BB. */
2867 bsi_move_to_bb_end (block_stmt_iterator *from, basic_block bb)
2869 block_stmt_iterator last = bsi_last (bb);
2871 /* Have to check bsi_end_p because it could be an empty block. */
2872 if (!bsi_end_p (last) && is_ctrl_stmt (bsi_stmt (last)))
2873 bsi_move_before (from, &last);
2875 bsi_move_after (from, &last);
2879 /* Replace the contents of the statement pointed to by iterator BSI
2880 with STMT. If UPDATE_EH_INFO is true, the exception handling
2881 information of the original statement is moved to the new statement. */
2884 bsi_replace (const block_stmt_iterator *bsi, tree stmt, bool update_eh_info)
2887 tree orig_stmt = bsi_stmt (*bsi);
2889 if (stmt == orig_stmt)
2891 SET_EXPR_LOCUS (stmt, EXPR_LOCUS (orig_stmt));
2892 set_bb_for_stmt (stmt, bsi->bb);
2894 /* Preserve EH region information from the original statement, if
2895 requested by the caller. */
2898 eh_region = lookup_stmt_eh_region (orig_stmt);
2901 remove_stmt_from_eh_region (orig_stmt);
2902 add_stmt_to_eh_region (stmt, eh_region);
2906 gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
2907 gimple_remove_stmt_histograms (cfun, orig_stmt);
2908 delink_stmt_imm_use (orig_stmt);
2909 *bsi_stmt_ptr (*bsi) = stmt;
2910 mark_stmt_modified (stmt);
2911 update_modified_stmts (stmt);
2915 /* Insert the statement pointed-to by BSI into edge E. Every attempt
2916 is made to place the statement in an existing basic block, but
2917 sometimes that isn't possible. When it isn't possible, the edge is
2918 split and the statement is added to the new block.
2920 In all cases, the returned *BSI points to the correct location. The
2921 return value is true if insertion should be done after the location,
2922 or false if it should be done before the location. If new basic block
2923 has to be created, it is stored in *NEW_BB. */
2926 tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi,
2927 basic_block *new_bb)
2929 basic_block dest, src;
2935 /* If the destination has one predecessor which has no PHI nodes,
2936 insert there. Except for the exit block.
2938 The requirement for no PHI nodes could be relaxed. Basically we
2939 would have to examine the PHIs to prove that none of them used
2940 the value set by the statement we want to insert on E. That
2941 hardly seems worth the effort. */
2942 if (single_pred_p (dest)
2943 && ! phi_nodes (dest)
2944 && dest != EXIT_BLOCK_PTR)
2946 *bsi = bsi_start (dest);
2947 if (bsi_end_p (*bsi))
2950 /* Make sure we insert after any leading labels. */
2951 tmp = bsi_stmt (*bsi);
2952 while (TREE_CODE (tmp) == LABEL_EXPR)
2955 if (bsi_end_p (*bsi))
2957 tmp = bsi_stmt (*bsi);
2960 if (bsi_end_p (*bsi))
2962 *bsi = bsi_last (dest);
2969 /* If the source has one successor, the edge is not abnormal and
2970 the last statement does not end a basic block, insert there.
2971 Except for the entry block. */
2973 if ((e->flags & EDGE_ABNORMAL) == 0
2974 && single_succ_p (src)
2975 && src != ENTRY_BLOCK_PTR)
2977 *bsi = bsi_last (src);
2978 if (bsi_end_p (*bsi))
2981 tmp = bsi_stmt (*bsi);
2982 if (!stmt_ends_bb_p (tmp))
2985 /* Insert code just before returning the value. We may need to decompose
2986 the return in the case it contains non-trivial operand. */
2987 if (TREE_CODE (tmp) == RETURN_EXPR)
2989 tree op = TREE_OPERAND (tmp, 0);
2990 if (op && !is_gimple_val (op))
2992 gcc_assert (TREE_CODE (op) == GIMPLE_MODIFY_STMT);
2993 bsi_insert_before (bsi, op, BSI_NEW_STMT);
2994 TREE_OPERAND (tmp, 0) = GIMPLE_STMT_OPERAND (op, 0);
3001 /* Otherwise, create a new basic block, and split this edge. */
3002 dest = split_edge (e);
3005 e = single_pred_edge (dest);
3010 /* This routine will commit all pending edge insertions, creating any new
3011 basic blocks which are necessary. */
3014 bsi_commit_edge_inserts (void)
3020 bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL);
3023 FOR_EACH_EDGE (e, ei, bb->succs)
3024 bsi_commit_one_edge_insert (e, NULL);
3028 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
3029 to this block, otherwise set it to NULL. */
3032 bsi_commit_one_edge_insert (edge e, basic_block *new_bb)
3036 if (PENDING_STMT (e))
3038 block_stmt_iterator bsi;
3039 tree stmt = PENDING_STMT (e);
3041 PENDING_STMT (e) = NULL_TREE;
3043 if (tree_find_edge_insert_loc (e, &bsi, new_bb))
3044 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3046 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3051 /* Add STMT to the pending list of edge E. No actual insertion is
3052 made until a call to bsi_commit_edge_inserts () is made. */
3055 bsi_insert_on_edge (edge e, tree stmt)
3057 append_to_statement_list (stmt, &PENDING_STMT (e));
3060 /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new
3061 block has to be created, it is returned. */
3064 bsi_insert_on_edge_immediate (edge e, tree stmt)
3066 block_stmt_iterator bsi;
3067 basic_block new_bb = NULL;
3069 gcc_assert (!PENDING_STMT (e));
3071 if (tree_find_edge_insert_loc (e, &bsi, &new_bb))
3072 bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
3074 bsi_insert_before (&bsi, stmt, BSI_NEW_STMT);
3079 /*---------------------------------------------------------------------------
3080 Tree specific functions for CFG manipulation
3081 ---------------------------------------------------------------------------*/
3083 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
3086 reinstall_phi_args (edge new_edge, edge old_edge)
3089 edge_var_map_vector v;
3093 v = redirect_edge_var_map_vector (old_edge);
3097 for (i = 0, phi = phi_nodes (new_edge->dest);
3098 VEC_iterate (edge_var_map, v, i, vm) && phi;
3099 i++, phi = PHI_CHAIN (phi))
3101 tree result = redirect_edge_var_map_result (vm);
3102 tree arg = redirect_edge_var_map_def (vm);
3104 gcc_assert (result == PHI_RESULT (phi));
3106 add_phi_arg (phi, arg, new_edge);
3109 redirect_edge_var_map_clear (old_edge);
3112 /* Returns the basic block after which the new basic block created
3113 by splitting edge EDGE_IN should be placed. Tries to keep the new block
3114 near its "logical" location. This is of most help to humans looking
3115 at debugging dumps. */
3118 split_edge_bb_loc (edge edge_in)
3120 basic_block dest = edge_in->dest;
3122 if (dest->prev_bb && find_edge (dest->prev_bb, dest))
3123 return edge_in->src;
3125 return dest->prev_bb;
3128 /* Split a (typically critical) edge EDGE_IN. Return the new block.
3129 Abort on abnormal edges. */
3132 tree_split_edge (edge edge_in)
3134 basic_block new_bb, after_bb, dest;
3137 /* Abnormal edges cannot be split. */
3138 gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
3140 dest = edge_in->dest;
3142 after_bb = split_edge_bb_loc (edge_in);
3144 new_bb = create_empty_bb (after_bb);
3145 new_bb->frequency = EDGE_FREQUENCY (edge_in);
3146 new_bb->count = edge_in->count;
3147 new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU);
3148 new_edge->probability = REG_BR_PROB_BASE;
3149 new_edge->count = edge_in->count;
3151 e = redirect_edge_and_branch (edge_in, new_bb);
3152 gcc_assert (e == edge_in);
3153 reinstall_phi_args (new_edge, e);
3158 /* Callback for walk_tree, check that all elements with address taken are
3159 properly noticed as such. The DATA is an int* that is 1 if TP was seen
3160 inside a PHI node. */
3163 verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
3170 /* Check operand N for being valid GIMPLE and give error MSG if not. */
3171 #define CHECK_OP(N, MSG) \
3172 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
3173 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
3175 switch (TREE_CODE (t))
3178 if (SSA_NAME_IN_FREE_LIST (t))
3180 error ("SSA name in freelist but still referenced");
3186 x = fold (ASSERT_EXPR_COND (t));
3187 if (x == boolean_false_node)
3189 error ("ASSERT_EXPR with an always-false condition");
3197 case GIMPLE_MODIFY_STMT:
3198 x = GIMPLE_STMT_OPERAND (t, 0);
3199 if (TREE_CODE (x) == BIT_FIELD_REF
3200 && is_gimple_reg (TREE_OPERAND (x, 0)))
3202 error ("GIMPLE register modified with BIT_FIELD_REF");
3210 bool old_side_effects;
3212 bool new_side_effects;
3214 gcc_assert (is_gimple_address (t));
3216 old_constant = TREE_CONSTANT (t);
3217 old_side_effects = TREE_SIDE_EFFECTS (t);
3219 recompute_tree_invariant_for_addr_expr (t);
3220 new_side_effects = TREE_SIDE_EFFECTS (t);
3221 new_constant = TREE_CONSTANT (t);
3223 if (old_constant != new_constant)
3225 error ("constant not recomputed when ADDR_EXPR changed");
3228 if (old_side_effects != new_side_effects)
3230 error ("side effects not recomputed when ADDR_EXPR changed");
3234 /* Skip any references (they will be checked when we recurse down the
3235 tree) and ensure that any variable used as a prefix is marked
3237 for (x = TREE_OPERAND (t, 0);
3238 handled_component_p (x);
3239 x = TREE_OPERAND (x, 0))
3242 if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL)
3244 if (!TREE_ADDRESSABLE (x))
3246 error ("address taken, but ADDRESSABLE bit not set");
3254 x = COND_EXPR_COND (t);
3255 if (!INTEGRAL_TYPE_P (TREE_TYPE (x)))
3257 error ("non-integral used in condition");
3260 if (!is_gimple_condexpr (x))
3262 error ("invalid conditional operand");
3267 case NON_LVALUE_EXPR:
3271 case FIX_TRUNC_EXPR:
3276 case TRUTH_NOT_EXPR:
3277 CHECK_OP (0, "invalid operand to unary operator");
3284 case ARRAY_RANGE_REF:
3286 case VIEW_CONVERT_EXPR:
3287 /* We have a nest of references. Verify that each of the operands
3288 that determine where to reference is either a constant or a variable,
3289 verify that the base is valid, and then show we've already checked
3291 while (handled_component_p (t))
3293 if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2))
3294 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
3295 else if (TREE_CODE (t) == ARRAY_REF
3296 || TREE_CODE (t) == ARRAY_RANGE_REF)
3298 CHECK_OP (1, "invalid array index");
3299 if (TREE_OPERAND (t, 2))
3300 CHECK_OP (2, "invalid array lower bound");
3301 if (TREE_OPERAND (t, 3))
3302 CHECK_OP (3, "invalid array stride");
3304 else if (TREE_CODE (t) == BIT_FIELD_REF)
3306 if (!host_integerp (TREE_OPERAND (t, 1), 1)
3307 || !host_integerp (TREE_OPERAND (t, 2), 1))
3309 error ("invalid position or size operand to BIT_FIELD_REF");
3312 else if (INTEGRAL_TYPE_P (TREE_TYPE (t))
3313 && (TYPE_PRECISION (TREE_TYPE (t))
3314 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
3316 error ("integral result type precision does not match "
3317 "field size of BIT_FIELD_REF");
3320 if (!INTEGRAL_TYPE_P (TREE_TYPE (t))
3321 && (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (t)))
3322 != TREE_INT_CST_LOW (TREE_OPERAND (t, 1))))
3324 error ("mode precision of non-integral result does not "
3325 "match field size of BIT_FIELD_REF");
3330 t = TREE_OPERAND (t, 0);
3333 if (!is_gimple_min_invariant (t) && !is_gimple_lvalue (t))
3335 error ("invalid reference prefix");
3342 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
3343 POINTER_PLUS_EXPR. */
3344 if (POINTER_TYPE_P (TREE_TYPE (t)))
3346 error ("invalid operand to plus/minus, type is a pointer");
3349 CHECK_OP (0, "invalid operand to binary operator");
3350 CHECK_OP (1, "invalid operand to binary operator");
3353 case POINTER_PLUS_EXPR:
3354 /* Check to make sure the first operand is a pointer or reference type. */
3355 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
3357 error ("invalid operand to pointer plus, first operand is not a pointer");
3360 /* Check to make sure the second operand is an integer with type of
3362 if (!useless_type_conversion_p (sizetype,
3363 TREE_TYPE (TREE_OPERAND (t, 1))))
3365 error ("invalid operand to pointer plus, second operand is not an "
3366 "integer with type of sizetype.");
3376 case UNORDERED_EXPR:
3385 case TRUNC_DIV_EXPR:
3387 case FLOOR_DIV_EXPR:
3388 case ROUND_DIV_EXPR:
3389 case TRUNC_MOD_EXPR:
3391 case FLOOR_MOD_EXPR:
3392 case ROUND_MOD_EXPR:
3394 case EXACT_DIV_EXPR:
3404 CHECK_OP (0, "invalid operand to binary operator");
3405 CHECK_OP (1, "invalid operand to binary operator");
3409 if (TREE_CONSTANT (t) && TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
3421 /* Verifies if EXPR is a valid GIMPLE unary expression. Returns true
3422 if there is an error, otherwise false. */
3425 verify_gimple_unary_expr (const_tree expr)
3427 tree op = TREE_OPERAND (expr, 0);
3428 tree type = TREE_TYPE (expr);
3430 if (!is_gimple_val (op))
3432 error ("invalid operand in unary expression");
3436 /* For general unary expressions we have the operations type
3437 as the effective type the operation is carried out on. So all
3438 we need to require is that the operand is trivially convertible
3440 if (!useless_type_conversion_p (type, TREE_TYPE (op)))
3442 error ("type mismatch in unary expression");
3443 debug_generic_expr (type);
3444 debug_generic_expr (TREE_TYPE (op));
3451 /* Verifies if EXPR is a valid GIMPLE binary expression. Returns true
3452 if there is an error, otherwise false. */
3455 verify_gimple_binary_expr (const_tree expr)
3457 tree op0 = TREE_OPERAND (expr, 0);
3458 tree op1 = TREE_OPERAND (expr, 1);
3459 tree type = TREE_TYPE (expr);
3461 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3463 error ("invalid operands in binary expression");
3467 /* For general binary expressions we have the operations type
3468 as the effective type the operation is carried out on. So all
3469 we need to require is that both operands are trivially convertible
3471 if (!useless_type_conversion_p (type, TREE_TYPE (op0))
3472 || !useless_type_conversion_p (type, TREE_TYPE (op1)))
3474 error ("type mismatch in binary expression");
3475 debug_generic_stmt (type);
3476 debug_generic_stmt (TREE_TYPE (op0));
3477 debug_generic_stmt (TREE_TYPE (op1));
3484 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3485 Returns true if there is an error, otherwise false. */
3488 verify_gimple_min_lval (tree expr)
3492 if (is_gimple_id (expr))
3495 if (TREE_CODE (expr) != INDIRECT_REF
3496 && TREE_CODE (expr) != ALIGN_INDIRECT_REF
3497 && TREE_CODE (expr) != MISALIGNED_INDIRECT_REF)
3499 error ("invalid expression for min lvalue");
3503 op = TREE_OPERAND (expr, 0);
3504 if (!is_gimple_val (op))
3506 error ("invalid operand in indirect reference");
3507 debug_generic_stmt (op);
3510 if (!useless_type_conversion_p (TREE_TYPE (expr),
3511 TREE_TYPE (TREE_TYPE (op))))
3513 error ("type mismatch in indirect reference");
3514 debug_generic_stmt (TREE_TYPE (expr));
3515 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3522 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3523 if there is an error, otherwise false. */
3526 verify_gimple_reference (tree expr)
3528 while (handled_component_p (expr))
3530 tree op = TREE_OPERAND (expr, 0);
3532 if (TREE_CODE (expr) == ARRAY_REF
3533 || TREE_CODE (expr) == ARRAY_RANGE_REF)
3535 if (!is_gimple_val (TREE_OPERAND (expr, 1))
3536 || (TREE_OPERAND (expr, 2)
3537 && !is_gimple_val (TREE_OPERAND (expr, 2)))
3538 || (TREE_OPERAND (expr, 3)
3539 && !is_gimple_val (TREE_OPERAND (expr, 3))))
3541 error ("invalid operands to array reference");
3542 debug_generic_stmt (expr);
3547 /* Verify if the reference array element types are compatible. */
3548 if (TREE_CODE (expr) == ARRAY_REF
3549 && !useless_type_conversion_p (TREE_TYPE (expr),
3550 TREE_TYPE (TREE_TYPE (op))))
3552 error ("type mismatch in array reference");
3553 debug_generic_stmt (TREE_TYPE (expr));
3554 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3557 if (TREE_CODE (expr) == ARRAY_RANGE_REF
3558 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr)),
3559 TREE_TYPE (TREE_TYPE (op))))
3561 error ("type mismatch in array range reference");
3562 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr)));
3563 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3567 if ((TREE_CODE (expr) == REALPART_EXPR
3568 || TREE_CODE (expr) == IMAGPART_EXPR)
3569 && !useless_type_conversion_p (TREE_TYPE (expr),
3570 TREE_TYPE (TREE_TYPE (op))))
3572 error ("type mismatch in real/imagpart reference");
3573 debug_generic_stmt (TREE_TYPE (expr));
3574 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op)));
3578 if (TREE_CODE (expr) == COMPONENT_REF
3579 && !useless_type_conversion_p (TREE_TYPE (expr),
3580 TREE_TYPE (TREE_OPERAND (expr, 1))))
3582 error ("type mismatch in component reference");
3583 debug_generic_stmt (TREE_TYPE (expr));
3584 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr, 1)));
3588 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3589 is nothing to verify. Gross mismatches at most invoke
3590 undefined behavior. */
3595 return verify_gimple_min_lval (expr);
3598 /* Returns true if there is one pointer type in TYPE_POINTER_TO (SRC_OBJ)
3599 list of pointer-to types that is trivially convertible to DEST. */
3602 one_pointer_to_useless_type_conversion_p (tree dest, tree src_obj)
3606 if (!TYPE_POINTER_TO (src_obj))
3609 for (src = TYPE_POINTER_TO (src_obj); src; src = TYPE_NEXT_PTR_TO (src))
3610 if (useless_type_conversion_p (dest, src))
3616 /* Return true if TYPE1 is a fixed-point type and if conversions to and
3617 from TYPE2 can be handled by FIXED_CONVERT_EXPR. */
3620 valid_fixed_convert_types_p (tree type1, tree type2)
3622 return (FIXED_POINT_TYPE_P (type1)
3623 && (INTEGRAL_TYPE_P (type2)
3624 || SCALAR_FLOAT_TYPE_P (type2)
3625 || FIXED_POINT_TYPE_P (type2)));
3628 /* Verify the GIMPLE expression EXPR. Returns true if there is an
3629 error, otherwise false. */
3632 verify_gimple_expr (tree expr)
3634 tree type = TREE_TYPE (expr);
3636 if (is_gimple_val (expr))
3639 /* Special codes we cannot handle via their class. */
3640 switch (TREE_CODE (expr))
3644 tree op = TREE_OPERAND (expr, 0);
3645 if (!is_gimple_val (op))
3647 error ("invalid operand in conversion");
3651 /* Allow conversions between integral types and between
3653 if ((INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3654 || (POINTER_TYPE_P (type) && POINTER_TYPE_P (TREE_TYPE (op))))
3657 /* Allow conversions between integral types and pointers only if
3658 there is no sign or zero extension involved. */
3659 if (((POINTER_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
3660 || (POINTER_TYPE_P (TREE_TYPE (op)) && INTEGRAL_TYPE_P (type)))
3661 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op)))
3664 /* Allow conversion from integer to offset type and vice versa. */
3665 if ((TREE_CODE (type) == OFFSET_TYPE
3666 && TREE_CODE (TREE_TYPE (op)) == INTEGER_TYPE)
3667 || (TREE_CODE (type) == INTEGER_TYPE
3668 && TREE_CODE (TREE_TYPE (op)) == OFFSET_TYPE))
3671 /* Otherwise assert we are converting between types of the
3673 if (TREE_CODE (type) != TREE_CODE (TREE_TYPE (op)))
3675 error ("invalid types in nop conversion");
3676 debug_generic_expr (type);
3677 debug_generic_expr (TREE_TYPE (op));
3684 case FIXED_CONVERT_EXPR:
3686 tree op = TREE_OPERAND (expr, 0);
3687 if (!is_gimple_val (op))
3689 error ("invalid operand in conversion");
3693 if (!valid_fixed_convert_types_p (type, TREE_TYPE (op))
3694 && !valid_fixed_convert_types_p (TREE_TYPE (op), type))
3696 error ("invalid types in fixed-point conversion");
3697 debug_generic_expr (type);
3698 debug_generic_expr (TREE_TYPE (op));
3707 tree op = TREE_OPERAND (expr, 0);
3708 if (!is_gimple_val (op))
3710 error ("invalid operand in int to float conversion");
3713 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3714 || !SCALAR_FLOAT_TYPE_P (type))
3716 error ("invalid types in conversion to floating point");
3717 debug_generic_expr (type);
3718 debug_generic_expr (TREE_TYPE (op));
3724 case FIX_TRUNC_EXPR:
3726 tree op = TREE_OPERAND (expr, 0);
3727 if (!is_gimple_val (op))
3729 error ("invalid operand in float to int conversion");
3732 if (!INTEGRAL_TYPE_P (type)
3733 || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (op)))
3735 error ("invalid types in conversion to integer");
3736 debug_generic_expr (type);
3737 debug_generic_expr (TREE_TYPE (op));
3745 tree op0 = TREE_OPERAND (expr, 0);
3746 tree op1 = TREE_OPERAND (expr, 1);
3747 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3749 error ("invalid operands in complex expression");
3752 if (!TREE_CODE (type) == COMPLEX_TYPE
3753 || !(TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
3754 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0)))
3755 || !(TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3756 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op1)))
3757 || !useless_type_conversion_p (TREE_TYPE (type),
3759 || !useless_type_conversion_p (TREE_TYPE (type),
3762 error ("type mismatch in complex expression");
3763 debug_generic_stmt (TREE_TYPE (expr));
3764 debug_generic_stmt (TREE_TYPE (op0));
3765 debug_generic_stmt (TREE_TYPE (op1));
3773 /* This is used like COMPLEX_EXPR but for vectors. */
3774 if (TREE_CODE (type) != VECTOR_TYPE)
3776 error ("constructor not allowed for non-vector types");
3777 debug_generic_stmt (type);
3780 /* FIXME: verify constructor arguments. */
3789 tree op0 = TREE_OPERAND (expr, 0);
3790 tree op1 = TREE_OPERAND (expr, 1);
3791 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3793 error ("invalid operands in shift expression");
3796 if (!TREE_CODE (TREE_TYPE (op1)) == INTEGER_TYPE
3797 || !useless_type_conversion_p (type, TREE_TYPE (op0)))
3799 error ("type mismatch in shift expression");
3800 debug_generic_stmt (TREE_TYPE (expr));
3801 debug_generic_stmt (TREE_TYPE (op0));
3802 debug_generic_stmt (TREE_TYPE (op1));
3811 tree op0 = TREE_OPERAND (expr, 0);
3812 tree op1 = TREE_OPERAND (expr, 1);
3813 if (POINTER_TYPE_P (type)
3814 || POINTER_TYPE_P (TREE_TYPE (op0))
3815 || POINTER_TYPE_P (TREE_TYPE (op1)))
3817 error ("invalid (pointer) operands to plus/minus");
3820 /* Continue with generic binary expression handling. */
3824 case POINTER_PLUS_EXPR:
3826 tree op0 = TREE_OPERAND (expr, 0);
3827 tree op1 = TREE_OPERAND (expr, 1);
3828 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3830 error ("invalid operands in pointer plus expression");
3833 if (!POINTER_TYPE_P (TREE_TYPE (op0))
3834 || !useless_type_conversion_p (type, TREE_TYPE (op0))
3835 || !useless_type_conversion_p (sizetype, TREE_TYPE (op1)))
3837 error ("type mismatch in pointer plus expression");
3838 debug_generic_stmt (type);
3839 debug_generic_stmt (TREE_TYPE (op0));
3840 debug_generic_stmt (TREE_TYPE (op1));
3848 tree op0 = TREE_OPERAND (expr, 0);
3849 tree op1 = TREE_OPERAND (expr, 1);
3850 tree op2 = TREE_OPERAND (expr, 2);
3851 if ((!is_gimple_val (op1)
3852 && TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3853 || (!is_gimple_val (op2)
3854 && TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE))
3856 error ("invalid operands in conditional expression");
3859 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3860 || (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE
3861 && !useless_type_conversion_p (type, TREE_TYPE (op1)))
3862 || (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE
3863 && !useless_type_conversion_p (type, TREE_TYPE (op2))))
3865 error ("type mismatch in conditional expression");
3866 debug_generic_stmt (type);
3867 debug_generic_stmt (TREE_TYPE (op0));
3868 debug_generic_stmt (TREE_TYPE (op1));
3869 debug_generic_stmt (TREE_TYPE (op2));
3872 return verify_gimple_expr (op0);
3877 tree op = TREE_OPERAND (expr, 0);
3878 if (!is_gimple_addressable (op))
3880 error ("invalid operand in unary expression");
3883 if (!one_pointer_to_useless_type_conversion_p (type, TREE_TYPE (op))
3884 /* FIXME: a longstanding wart, &a == &a[0]. */
3885 && (TREE_CODE (TREE_TYPE (op)) != ARRAY_TYPE
3886 || !one_pointer_to_useless_type_conversion_p (type,
3887 TREE_TYPE (TREE_TYPE (op)))))
3889 error ("type mismatch in address expression");
3890 debug_generic_stmt (TREE_TYPE (expr));
3891 debug_generic_stmt (TYPE_POINTER_TO (TREE_TYPE (op)));
3895 return verify_gimple_reference (op);
3898 case TRUTH_ANDIF_EXPR:
3899 case TRUTH_ORIF_EXPR:
3902 case TRUTH_AND_EXPR:
3904 case TRUTH_XOR_EXPR:
3906 tree op0 = TREE_OPERAND (expr, 0);
3907 tree op1 = TREE_OPERAND (expr, 1);
3909 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3911 error ("invalid operands in truth expression");
3915 /* We allow any kind of integral typed argument and result. */
3916 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
3917 || !INTEGRAL_TYPE_P (TREE_TYPE (op1))
3918 || !INTEGRAL_TYPE_P (type))
3920 error ("type mismatch in binary truth expression");
3921 debug_generic_stmt (type);
3922 debug_generic_stmt (TREE_TYPE (op0));
3923 debug_generic_stmt (TREE_TYPE (op1));
3930 case TRUTH_NOT_EXPR:
3932 tree op = TREE_OPERAND (expr, 0);
3934 if (!is_gimple_val (op))
3936 error ("invalid operand in unary not");
3940 /* For TRUTH_NOT_EXPR we can have any kind of integral
3941 typed arguments and results. */
3942 if (!INTEGRAL_TYPE_P (TREE_TYPE (op))
3943 || !INTEGRAL_TYPE_P (type))
3945 error ("type mismatch in not expression");
3946 debug_generic_expr (TREE_TYPE (expr));
3947 debug_generic_expr (TREE_TYPE (op));
3955 /* FIXME. The C frontend passes unpromoted arguments in case it
3956 didn't see a function declaration before the call. */
3958 tree decl = CALL_EXPR_FN (expr);
3960 if (TREE_CODE (decl) == FUNCTION_DECL
3961 && DECL_LOOPING_CONST_OR_PURE_P (decl)
3962 && (!DECL_PURE_P (decl))
3963 && (!TREE_READONLY (decl)))
3965 error ("invalid pure const state for function");
3978 /* Generic handling via classes. */
3979 switch (TREE_CODE_CLASS (TREE_CODE (expr)))
3982 return verify_gimple_unary_expr (expr);
3985 return verify_gimple_binary_expr (expr);
3988 return verify_gimple_reference (expr);
3990 case tcc_comparison:
3992 tree op0 = TREE_OPERAND (expr, 0);
3993 tree op1 = TREE_OPERAND (expr, 1);
3994 if (!is_gimple_val (op0) || !is_gimple_val (op1))
3996 error ("invalid operands in comparison expression");
3999 /* For comparisons we do not have the operations type as the
4000 effective type the comparison is carried out in. Instead
4001 we require that either the first operand is trivially
4002 convertible into the second, or the other way around.
4003 The resulting type of a comparison may be any integral type.
4004 Because we special-case pointers to void we allow
4005 comparisons of pointers with the same mode as well. */
4006 if ((!useless_type_conversion_p (TREE_TYPE (op0), TREE_TYPE (op1))
4007 && !useless_type_conversion_p (TREE_TYPE (op1), TREE_TYPE (op0))
4008 && (!POINTER_TYPE_P (TREE_TYPE (op0))
4009 || !POINTER_TYPE_P (TREE_TYPE (op1))
4010 || TYPE_MODE (TREE_TYPE (op0)) != TYPE_MODE (TREE_TYPE (op1))))
4011 || !INTEGRAL_TYPE_P (type))
4013 error ("type mismatch in comparison expression");
4014 debug_generic_stmt (TREE_TYPE (expr));
4015 debug_generic_stmt (TREE_TYPE (op0));
4016 debug_generic_stmt (TREE_TYPE (op1));
4029 /* Verify the GIMPLE assignment statement STMT. Returns true if there
4030 is an error, otherwise false. */
4033 verify_gimple_modify_stmt (const_tree stmt)
4035 tree lhs = GIMPLE_STMT_OPERAND (stmt, 0);
4036 tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
4038 gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
4040 if (!useless_type_conversion_p (TREE_TYPE (lhs),
4043 error ("non-trivial conversion at assignment");
4044 debug_generic_expr (TREE_TYPE (lhs));
4045 debug_generic_expr (TREE_TYPE (rhs));
4049 /* Loads/stores from/to a variable are ok. */
4050 if ((is_gimple_val (lhs)
4051 && is_gimple_variable (rhs))
4052 || (is_gimple_val (rhs)
4053 && is_gimple_variable (lhs)))
4056 /* Aggregate copies are ok. */
4057 if (!is_gimple_reg_type (TREE_TYPE (lhs))
4058 && !is_gimple_reg_type (TREE_TYPE (rhs)))
4061 /* We might get 'loads' from a parameter which is not a gimple value. */
4062 if (TREE_CODE (rhs) == PARM_DECL)
4063 return verify_gimple_expr (lhs);
4065 if (!is_gimple_variable (lhs)
4066 && verify_gimple_expr (lhs))
4069 if (!is_gimple_variable (rhs)
4070 && verify_gimple_expr (rhs))
4076 /* Verify the GIMPLE statement STMT. Returns true if there is an
4077 error, otherwise false. */
4080 verify_gimple_stmt (tree stmt)
4082 if (!is_gimple_stmt (stmt))
4084 error ("is not a valid GIMPLE statement");
4088 if (OMP_DIRECTIVE_P (stmt))
4090 /* OpenMP directives are validated by the FE and never operated
4091 on by the optimizers. Furthermore, OMP_FOR may contain
4092 non-gimple expressions when the main index variable has had
4093 its address taken. This does not affect the loop itself
4094 because the header of an OMP_FOR is merely used to determine
4095 how to setup the parallel iteration. */
4099 switch (TREE_CODE (stmt))
4101 case GIMPLE_MODIFY_STMT:
4102 return verify_gimple_modify_stmt (stmt);
4109 if (!is_gimple_val (TREE_OPERAND (stmt, 0)))
4111 error ("invalid operand to switch statement");
4112 debug_generic_expr (TREE_OPERAND (stmt, 0));
4118 tree op = TREE_OPERAND (stmt, 0);
4120 if (TREE_CODE (TREE_TYPE (stmt)) != VOID_TYPE)
4122 error ("type error in return expression");
4127 || TREE_CODE (op) == RESULT_DECL)
4130 return verify_gimple_modify_stmt (op);
4135 return verify_gimple_expr (stmt);
4138 case CHANGE_DYNAMIC_TYPE_EXPR:
4148 /* Verify the GIMPLE statements inside the statement list STMTS.
4149 Returns true if there were any errors. */
4152 verify_gimple_2 (tree stmts)
4154 tree_stmt_iterator tsi;
4157 for (tsi = tsi_start (stmts); !tsi_end_p (tsi); tsi_next (&tsi))
4159 tree stmt = tsi_stmt (tsi);
4161 switch (TREE_CODE (stmt))
4164 err |= verify_gimple_2 (BIND_EXPR_BODY (stmt));
4167 case TRY_CATCH_EXPR:
4168 case TRY_FINALLY_EXPR:
4169 err |= verify_gimple_2 (TREE_OPERAND (stmt, 0));
4170 err |= verify_gimple_2 (TREE_OPERAND (stmt, 1));
4174 err |= verify_gimple_2 (CATCH_BODY (stmt));
4177 case EH_FILTER_EXPR:
4178 err |= verify_gimple_2 (EH_FILTER_FAILURE (stmt));
4183 bool err2 = verify_gimple_stmt (stmt);
4185 debug_generic_expr (stmt);
4195 /* Verify the GIMPLE statements inside the statement list STMTS. */
4198 verify_gimple_1 (tree stmts)
4200 if (verify_gimple_2 (stmts))
4201 internal_error ("verify_gimple failed");
4204 /* Verify the GIMPLE statements inside the current function. */
4207 verify_gimple (void)
4209 verify_gimple_1 (BIND_EXPR_BODY (DECL_SAVED_TREE (cfun->decl)));
4212 /* Verify STMT, return true if STMT is not in GIMPLE form.
4213 TODO: Implement type checking. */
4216 verify_stmt (tree stmt, bool last_in_block)
4220 if (OMP_DIRECTIVE_P (stmt))
4222 /* OpenMP directives are validated by the FE and never operated
4223 on by the optimizers. Furthermore, OMP_FOR may contain
4224 non-gimple expressions when the main index variable has had
4225 its address taken. This does not affect the loop itself
4226 because the header of an OMP_FOR is merely used to determine
4227 how to setup the parallel iteration. */
4231 if (!is_gimple_stmt (stmt))
4233 error ("is not a valid GIMPLE statement");
4237 addr = walk_tree (&stmt, verify_expr, NULL, NULL);
4240 debug_generic_stmt (addr);
4243 inform ("in statement");
4244 debug_generic_stmt (stmt);
4249 /* If the statement is marked as part of an EH region, then it is
4250 expected that the statement could throw. Verify that when we
4251 have optimizations that simplify statements such that we prove
4252 that they cannot throw, that we update other data structures
4254 if (lookup_stmt_eh_region (stmt) >= 0)
4256 if (!tree_could_throw_p (stmt))
4258 error ("statement marked for throw, but doesn%'t");
4261 if (!last_in_block && tree_can_throw_internal (stmt))
4263 error ("statement marked for throw in middle of block");
4271 debug_generic_stmt (stmt);
4276 /* Return true when the T can be shared. */
4279 tree_node_can_be_shared (tree t)
4281 if (IS_TYPE_OR_DECL_P (t)
4282 || is_gimple_min_invariant (t)
4283 || TREE_CODE (t) == SSA_NAME
4284 || t == error_mark_node
4285 || TREE_CODE (t) == IDENTIFIER_NODE)
4288 if (TREE_CODE (t) == CASE_LABEL_EXPR)
4291 while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
4292 && is_gimple_min_invariant (TREE_OPERAND (t, 1)))
4293 || TREE_CODE (t) == COMPONENT_REF
4294 || TREE_CODE (t) == REALPART_EXPR
4295 || TREE_CODE (t) == IMAGPART_EXPR)
4296 t = TREE_OPERAND (t, 0);
4305 /* Called via walk_trees. Verify tree sharing. */
4308 verify_node_sharing (tree * tp, int *walk_subtrees, void *data)
4310 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4312 if (tree_node_can_be_shared (*tp))
4314 *walk_subtrees = false;
4318 if (pointer_set_insert (visited, *tp))
4325 /* Helper function for verify_gimple_tuples. */
4328 verify_gimple_tuples_1 (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4329 void *data ATTRIBUTE_UNUSED)
4331 switch (TREE_CODE (*tp))
4334 error ("unexpected non-tuple");
4344 /* Verify that there are no trees that should have been converted to
4345 gimple tuples. Return true if T contains a node that should have
4346 been converted to a gimple tuple, but hasn't. */
4349 verify_gimple_tuples (tree t)
4351 return walk_tree (&t, verify_gimple_tuples_1, NULL, NULL) != NULL;
4354 static bool eh_error_found;
4356 verify_eh_throw_stmt_node (void **slot, void *data)
4358 struct throw_stmt_node *node = (struct throw_stmt_node *)*slot;
4359 struct pointer_set_t *visited = (struct pointer_set_t *) data;
4361 if (!pointer_set_contains (visited, node->stmt))
4363 error ("Dead STMT in EH table");
4364 debug_generic_stmt (node->stmt);
4365 eh_error_found = true;
4370 /* Verify the GIMPLE statement chain. */
4376 block_stmt_iterator bsi;
4378 struct pointer_set_t *visited, *visited_stmts;
4381 timevar_push (TV_TREE_STMT_VERIFY);
4382 visited = pointer_set_create ();
4383 visited_stmts = pointer_set_create ();
4390 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
4392 int phi_num_args = PHI_NUM_ARGS (phi);
4394 pointer_set_insert (visited_stmts, phi);
4395 if (bb_for_stmt (phi) != bb)
4397 error ("bb_for_stmt (phi) is set to a wrong basic block");
4401 for (i = 0; i < phi_num_args; i++)
4403 tree t = PHI_ARG_DEF (phi, i);
4408 error ("missing PHI def");
4409 debug_generic_stmt (phi);
4413 /* Addressable variables do have SSA_NAMEs but they
4414 are not considered gimple values. */
4415 else if (TREE_CODE (t) != SSA_NAME
4416 && TREE_CODE (t) != FUNCTION_DECL
4417 && !is_gimple_min_invariant (t))
4419 error ("PHI def is not a GIMPLE value");
4420 debug_generic_stmt (phi);
4421 debug_generic_stmt (t);
4425 addr = walk_tree (&t, verify_node_sharing, visited, NULL);
4428 error ("incorrect sharing of tree nodes");
4429 debug_generic_stmt (phi);
4430 debug_generic_stmt (addr);
4436 for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
4438 tree stmt = bsi_stmt (bsi);
4440 pointer_set_insert (visited_stmts, stmt);
4441 err |= verify_gimple_tuples (stmt);
4443 if (bb_for_stmt (stmt) != bb)
4445 error ("bb_for_stmt (stmt) is set to a wrong basic block");
4450 err |= verify_stmt (stmt, bsi_end_p (bsi));
4451 addr = walk_tree (&stmt, verify_node_sharing, visited, NULL);
4454 error ("incorrect sharing of tree nodes");
4455 debug_generic_stmt (stmt);
4456 debug_generic_stmt (addr);
4461 eh_error_found = false;
4462 if (get_eh_throw_stmt_table (cfun))
4463 htab_traverse (get_eh_throw_stmt_table (cfun),
4464 verify_eh_throw_stmt_node,
4467 if (err | eh_error_found)
4468 internal_error ("verify_stmts failed");
4470 pointer_set_destroy (visited);
4471 pointer_set_destroy (visited_stmts);
4472 verify_histograms ();
4473 timevar_pop (TV_TREE_STMT_VERIFY);
4477 /* Verifies that the flow information is OK. */
4480 tree_verify_flow_info (void)
4484 block_stmt_iterator bsi;
4489 if (ENTRY_BLOCK_PTR->il.tree)
4491 error ("ENTRY_BLOCK has IL associated with it");
4495 if (EXIT_BLOCK_PTR->il.tree)
4497 error ("EXIT_BLOCK has IL associated with it");
4501 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4502 if (e->flags & EDGE_FALLTHRU)
4504 error ("fallthru to exit from bb %d", e->src->index);
4510 bool found_ctrl_stmt = false;
4514 /* Skip labels on the start of basic block. */
4515 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
4517 tree prev_stmt = stmt;
4519 stmt = bsi_stmt (bsi);
4521 if (TREE_CODE (stmt) != LABEL_EXPR)
4524 if (prev_stmt && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))
4526 error ("nonlocal label ");
4527 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4528 fprintf (stderr, " is not first in a sequence of labels in bb %d",
4533 if (label_to_block (LABEL_EXPR_LABEL (stmt)) != bb)
4536 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4537 fprintf (stderr, " to block does not match in bb %d",
4542 if (decl_function_context (LABEL_EXPR_LABEL (stmt))
4543 != current_function_decl)
4546 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4547 fprintf (stderr, " has incorrect context in bb %d",
4553 /* Verify that body of basic block BB is free of control flow. */
4554 for (; !bsi_end_p (bsi); bsi_next (&bsi))
4556 tree stmt = bsi_stmt (bsi);
4558 if (found_ctrl_stmt)
4560 error ("control flow in the middle of basic block %d",
4565 if (stmt_ends_bb_p (stmt))
4566 found_ctrl_stmt = true;
4568 if (TREE_CODE (stmt) == LABEL_EXPR)
4571 print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0);
4572 fprintf (stderr, " in the middle of basic block %d", bb->index);
4577 bsi = bsi_last (bb);
4578 if (bsi_end_p (bsi))
4581 stmt = bsi_stmt (bsi);
4583 err |= verify_eh_edges (stmt);
4585 if (is_ctrl_stmt (stmt))
4587 FOR_EACH_EDGE (e, ei, bb->succs)
4588 if (e->flags & EDGE_FALLTHRU)
4590 error ("fallthru edge after a control statement in bb %d",
4596 if (TREE_CODE (stmt) != COND_EXPR)
4598 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4599 after anything else but if statement. */
4600 FOR_EACH_EDGE (e, ei, bb->succs)
4601 if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
4603 error ("true/false edge after a non-COND_EXPR in bb %d",
4609 switch (TREE_CODE (stmt))
4616 if (COND_EXPR_THEN (stmt) != NULL_TREE
4617 || COND_EXPR_ELSE (stmt) != NULL_TREE)
4619 error ("COND_EXPR with code in branches at the end of bb %d",
4624 extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
4626 if (!true_edge || !false_edge
4627 || !(true_edge->flags & EDGE_TRUE_VALUE)
4628 || !(false_edge->flags & EDGE_FALSE_VALUE)
4629 || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4630 || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL))
4631 || EDGE_COUNT (bb->succs) >= 3)
4633 error ("wrong outgoing edge flags at end of bb %d",
4641 if (simple_goto_p (stmt))
4643 error ("explicit goto at end of bb %d", bb->index);
4648 /* FIXME. We should double check that the labels in the
4649 destination blocks have their address taken. */
4650 FOR_EACH_EDGE (e, ei, bb->succs)
4651 if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE
4652 | EDGE_FALSE_VALUE))
4653 || !(e->flags & EDGE_ABNORMAL))
4655 error ("wrong outgoing edge flags at end of bb %d",
4663 if (!single_succ_p (bb)
4664 || (single_succ_edge (bb)->flags
4665 & (EDGE_FALLTHRU | EDGE_ABNORMAL
4666 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4668 error ("wrong outgoing edge flags at end of bb %d", bb->index);
4671 if (single_succ (bb) != EXIT_BLOCK_PTR)
4673 error ("return edge does not point to exit in bb %d",
4686 vec = SWITCH_LABELS (stmt);
4687 n = TREE_VEC_LENGTH (vec);
4689 /* Mark all the destination basic blocks. */
4690 for (i = 0; i < n; ++i)
4692 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4693 basic_block label_bb = label_to_block (lab);
4695 gcc_assert (!label_bb->aux || label_bb->aux == (void *)1);
4696 label_bb->aux = (void *)1;
4699 /* Verify that the case labels are sorted. */
4700 prev = TREE_VEC_ELT (vec, 0);
4701 for (i = 1; i < n; ++i)
4703 tree c = TREE_VEC_ELT (vec, i);
4708 error ("found default case not at end of case vector");
4713 if (! tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c)))
4715 error ("case labels not sorted: ");
4716 print_generic_expr (stderr, prev, 0);
4717 fprintf (stderr," is greater than ");
4718 print_generic_expr (stderr, c, 0);
4719 fprintf (stderr," but comes before it.\n");
4724 /* VRP will remove the default case if it can prove it will
4725 never be executed. So do not verify there always exists
4726 a default case here. */
4728 FOR_EACH_EDGE (e, ei, bb->succs)
4732 error ("extra outgoing edge %d->%d",
4733 bb->index, e->dest->index);
4736 e->dest->aux = (void *)2;
4737 if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL
4738 | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
4740 error ("wrong outgoing edge flags at end of bb %d",
4746 /* Check that we have all of them. */
4747 for (i = 0; i < n; ++i)
4749 tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
4750 basic_block label_bb = label_to_block (lab);
4752 if (label_bb->aux != (void *)2)
4754 error ("missing edge %i->%i",
4755 bb->index, label_bb->index);
4760 FOR_EACH_EDGE (e, ei, bb->succs)
4761 e->dest->aux = (void *)0;
4768 if (dom_info_state (CDI_DOMINATORS) >= DOM_NO_FAST_QUERY)
4769 verify_dominators (CDI_DOMINATORS);
4775 /* Updates phi nodes after creating a forwarder block joined
4776 by edge FALLTHRU. */
4779 tree_make_forwarder_block (edge fallthru)
4783 basic_block dummy, bb;
4784 tree phi, new_phi, var;
4786 dummy = fallthru->src;
4787 bb = fallthru->dest;
4789 if (single_pred_p (bb))
4792 /* If we redirected a branch we must create new PHI nodes at the
4794 for (phi = phi_nodes (dummy); phi; phi = PHI_CHAIN (phi))
4796 var = PHI_RESULT (phi);
4797 new_phi = create_phi_node (var, bb);
4798 SSA_NAME_DEF_STMT (var) = new_phi;
4799 SET_PHI_RESULT (phi, make_ssa_name (SSA_NAME_VAR (var), phi));
4800 add_phi_arg (new_phi, PHI_RESULT (phi), fallthru);
4803 /* Ensure that the PHI node chain is in the same order. */
4804 set_phi_nodes (bb, phi_reverse (phi_nodes (bb)));
4806 /* Add the arguments we have stored on edges. */
4807 FOR_EACH_EDGE (e, ei, bb->preds)
4812 flush_pending_stmts (e);
4817 /* Return a non-special label in the head of basic block BLOCK.
4818 Create one if it doesn't exist. */
4821 tree_block_label (basic_block bb)
4823 block_stmt_iterator i, s = bsi_start (bb);
4827 for (i = s; !bsi_end_p (i); first = false, bsi_next (&i))
4829 stmt = bsi_stmt (i);
4830 if (TREE_CODE (stmt) != LABEL_EXPR)
4832 label = LABEL_EXPR_LABEL (stmt);
4833 if (!DECL_NONLOCAL (label))
4836 bsi_move_before (&i, &s);
4841 label = create_artificial_label ();
4842 stmt = build1 (LABEL_EXPR, void_type_node, label);
4843 bsi_insert_before (&s, stmt, BSI_NEW_STMT);
4848 /* Attempt to perform edge redirection by replacing a possibly complex
4849 jump instruction by a goto or by removing the jump completely.
4850 This can apply only if all edges now point to the same block. The
4851 parameters and return values are equivalent to
4852 redirect_edge_and_branch. */
4855 tree_try_redirect_by_replacing_jump (edge e, basic_block target)
4857 basic_block src = e->src;
4858 block_stmt_iterator b;
4861 /* We can replace or remove a complex jump only when we have exactly
4863 if (EDGE_COUNT (src->succs) != 2
4864 /* Verify that all targets will be TARGET. Specifically, the
4865 edge that is not E must also go to TARGET. */
4866 || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)
4872 stmt = bsi_stmt (b);
4874 if (TREE_CODE (stmt) == COND_EXPR
4875 || TREE_CODE (stmt) == SWITCH_EXPR)
4877 bsi_remove (&b, true);
4878 e = ssa_redirect_edge (e, target);
4879 e->flags = EDGE_FALLTHRU;
4887 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4888 edge representing the redirected branch. */
4891 tree_redirect_edge_and_branch (edge e, basic_block dest)
4893 basic_block bb = e->src;
4894 block_stmt_iterator bsi;
4898 if (e->flags & EDGE_ABNORMAL)
4901 if (e->src != ENTRY_BLOCK_PTR
4902 && (ret = tree_try_redirect_by_replacing_jump (e, dest)))
4905 if (e->dest == dest)
4908 bsi = bsi_last (bb);
4909 stmt = bsi_end_p (bsi) ? NULL : bsi_stmt (bsi);
4911 switch (stmt ? TREE_CODE (stmt) : ERROR_MARK)
4914 /* For COND_EXPR, we only need to redirect the edge. */
4918 /* No non-abnormal edges should lead from a non-simple goto, and
4919 simple ones should be represented implicitly. */
4924 tree cases = get_cases_for_edge (e, stmt);
4925 tree label = tree_block_label (dest);
4927 /* If we have a list of cases associated with E, then use it
4928 as it's a lot faster than walking the entire case vector. */
4931 edge e2 = find_edge (e->src, dest);
4938 CASE_LABEL (cases) = label;
4939 cases = TREE_CHAIN (cases);
4942 /* If there was already an edge in the CFG, then we need
4943 to move all the cases associated with E to E2. */
4946 tree cases2 = get_cases_for_edge (e2, stmt);
4948 TREE_CHAIN (last) = TREE_CHAIN (cases2);
4949 TREE_CHAIN (cases2) = first;
4954 tree vec = SWITCH_LABELS (stmt);
4955 size_t i, n = TREE_VEC_LENGTH (vec);
4957 for (i = 0; i < n; i++)
4959 tree elt = TREE_VEC_ELT (vec, i);
4961 if (label_to_block (CASE_LABEL (elt)) == e->dest)
4962 CASE_LABEL (elt) = label;
4970 bsi_remove (&bsi, true);
4971 e->flags |= EDGE_FALLTHRU;
4976 case OMP_SECTIONS_SWITCH:
4978 /* The edges from OMP constructs can be simply redirected. */
4982 /* Otherwise it must be a fallthru edge, and we don't need to
4983 do anything besides redirecting it. */
4984 gcc_assert (e->flags & EDGE_FALLTHRU);
4988 /* Update/insert PHI nodes as necessary. */
4990 /* Now update the edges in the CFG. */
4991 e = ssa_redirect_edge (e, dest);
4996 /* Returns true if it is possible to remove edge E by redirecting
4997 it to the destination of the other edge from E->src. */
5000 tree_can_remove_branch_p (const_edge e)
5002 if (e->flags & EDGE_ABNORMAL)
5008 /* Simple wrapper, as we can always redirect fallthru edges. */
5011 tree_redirect_edge_and_branch_force (edge e, basic_block dest)
5013 e = tree_redirect_edge_and_branch (e, dest);
5020 /* Splits basic block BB after statement STMT (but at least after the
5021 labels). If STMT is NULL, BB is split just after the labels. */
5024 tree_split_block (basic_block bb, void *stmt)
5026 block_stmt_iterator bsi;
5027 tree_stmt_iterator tsi_tgt;
5033 new_bb = create_empty_bb (bb);
5035 /* Redirect the outgoing edges. */
5036 new_bb->succs = bb->succs;
5038 FOR_EACH_EDGE (e, ei, new_bb->succs)
5041 if (stmt && TREE_CODE ((tree) stmt) == LABEL_EXPR)
5044 /* Move everything from BSI to the new basic block. */
5045 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5047 act = bsi_stmt (bsi);
5048 if (TREE_CODE (act) == LABEL_EXPR)
5061 if (bsi_end_p (bsi))
5064 /* Split the statement list - avoid re-creating new containers as this
5065 brings ugly quadratic memory consumption in the inliner.
5066 (We are still quadratic since we need to update stmt BB pointers,
5068 list = tsi_split_statement_list_before (&bsi.tsi);
5069 set_bb_stmt_list (new_bb, list);
5070 for (tsi_tgt = tsi_start (list);
5071 !tsi_end_p (tsi_tgt); tsi_next (&tsi_tgt))
5072 change_bb_for_stmt (tsi_stmt (tsi_tgt), new_bb);
5078 /* Moves basic block BB after block AFTER. */
5081 tree_move_block_after (basic_block bb, basic_block after)
5083 if (bb->prev_bb == after)
5087 link_block (bb, after);
5093 /* Return true if basic_block can be duplicated. */
5096 tree_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
5102 /* Create a duplicate of the basic block BB. NOTE: This does not
5103 preserve SSA form. */
5106 tree_duplicate_bb (basic_block bb)
5109 block_stmt_iterator bsi, bsi_tgt;
5112 new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb);
5114 /* Copy the PHI nodes. We ignore PHI node arguments here because
5115 the incoming edges have not been setup yet. */
5116 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5118 tree copy = create_phi_node (PHI_RESULT (phi), new_bb);
5119 create_new_def_for (PHI_RESULT (copy), copy, PHI_RESULT_PTR (copy));
5122 /* Keep the chain of PHI nodes in the same order so that they can be
5123 updated by ssa_redirect_edge. */
5124 set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb)));
5126 bsi_tgt = bsi_start (new_bb);
5127 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5129 def_operand_p def_p;
5130 ssa_op_iter op_iter;
5134 stmt = bsi_stmt (bsi);
5135 if (TREE_CODE (stmt) == LABEL_EXPR)
5138 /* Create a new copy of STMT and duplicate STMT's virtual
5140 copy = unshare_expr (stmt);
5141 bsi_insert_after (&bsi_tgt, copy, BSI_NEW_STMT);
5142 copy_virtual_operands (copy, stmt);
5143 region = lookup_stmt_eh_region (stmt);
5145 add_stmt_to_eh_region (copy, region);
5146 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
5148 /* Create new names for all the definitions created by COPY and
5149 add replacement mappings for each new name. */
5150 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
5151 create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p);
5157 /* Adds phi node arguments for edge E_COPY after basic block duplication. */
5160 add_phi_args_after_copy_edge (edge e_copy)
5162 basic_block bb, bb_copy = e_copy->src, dest;
5165 tree phi, phi_copy, phi_next, def;
5167 if (!phi_nodes (e_copy->dest))
5170 bb = bb_copy->flags & BB_DUPLICATED ? get_bb_original (bb_copy) : bb_copy;
5172 if (e_copy->dest->flags & BB_DUPLICATED)
5173 dest = get_bb_original (e_copy->dest);
5175 dest = e_copy->dest;
5177 e = find_edge (bb, dest);
5180 /* During loop unrolling the target of the latch edge is copied.
5181 In this case we are not looking for edge to dest, but to
5182 duplicated block whose original was dest. */
5183 FOR_EACH_EDGE (e, ei, bb->succs)
5185 if ((e->dest->flags & BB_DUPLICATED)
5186 && get_bb_original (e->dest) == dest)
5190 gcc_assert (e != NULL);
5193 for (phi = phi_nodes (e->dest), phi_copy = phi_nodes (e_copy->dest);
5195 phi = phi_next, phi_copy = PHI_CHAIN (phi_copy))
5197 phi_next = PHI_CHAIN (phi);
5198 def = PHI_ARG_DEF_FROM_EDGE (phi, e);
5199 add_phi_arg (phi_copy, def, e_copy);
5204 /* Basic block BB_COPY was created by code duplication. Add phi node
5205 arguments for edges going out of BB_COPY. The blocks that were
5206 duplicated have BB_DUPLICATED set. */
5209 add_phi_args_after_copy_bb (basic_block bb_copy)
5214 FOR_EACH_EDGE (e_copy, ei, bb_copy->succs)
5216 add_phi_args_after_copy_edge (e_copy);
5220 /* Blocks in REGION_COPY array of length N_REGION were created by
5221 duplication of basic blocks. Add phi node arguments for edges
5222 going from these blocks. If E_COPY is not NULL, also add
5223 phi node arguments for its destination.*/
5226 add_phi_args_after_copy (basic_block *region_copy, unsigned n_region,
5231 for (i = 0; i < n_region; i++)
5232 region_copy[i]->flags |= BB_DUPLICATED;
5234 for (i = 0; i < n_region; i++)
5235 add_phi_args_after_copy_bb (region_copy[i]);
5237 add_phi_args_after_copy_edge (e_copy);
5239 for (i = 0; i < n_region; i++)
5240 region_copy[i]->flags &= ~BB_DUPLICATED;
5243 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5244 important exit edge EXIT. By important we mean that no SSA name defined
5245 inside region is live over the other exit edges of the region. All entry
5246 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5247 to the duplicate of the region. SSA form, dominance and loop information
5248 is updated. The new basic blocks are stored to REGION_COPY in the same
5249 order as they had in REGION, provided that REGION_COPY is not NULL.
5250 The function returns false if it is unable to copy the region,
5254 tree_duplicate_sese_region (edge entry, edge exit,
5255 basic_block *region, unsigned n_region,
5256 basic_block *region_copy)
5259 bool free_region_copy = false, copying_header = false;
5260 struct loop *loop = entry->dest->loop_father;
5262 VEC (basic_block, heap) *doms;
5264 int total_freq = 0, entry_freq = 0;
5265 gcov_type total_count = 0, entry_count = 0;
5267 if (!can_copy_bbs_p (region, n_region))
5270 /* Some sanity checking. Note that we do not check for all possible
5271 missuses of the functions. I.e. if you ask to copy something weird,
5272 it will work, but the state of structures probably will not be
5274 for (i = 0; i < n_region; i++)
5276 /* We do not handle subloops, i.e. all the blocks must belong to the
5278 if (region[i]->loop_father != loop)
5281 if (region[i] != entry->dest
5282 && region[i] == loop->header)
5286 set_loop_copy (loop, loop);
5288 /* In case the function is used for loop header copying (which is the primary
5289 use), ensure that EXIT and its copy will be new latch and entry edges. */
5290 if (loop->header == entry->dest)
5292 copying_header = true;
5293 set_loop_copy (loop, loop_outer (loop));
5295 if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src))
5298 for (i = 0; i < n_region; i++)
5299 if (region[i] != exit->src
5300 && dominated_by_p (CDI_DOMINATORS, region[i], exit->src))
5306 region_copy = XNEWVEC (basic_block, n_region);
5307 free_region_copy = true;
5310 gcc_assert (!need_ssa_update_p ());
5312 /* Record blocks outside the region that are dominated by something
5315 initialize_original_copy_tables ();
5317 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5319 if (entry->dest->count)
5321 total_count = entry->dest->count;
5322 entry_count = entry->count;
5323 /* Fix up corner cases, to avoid division by zero or creation of negative
5325 if (entry_count > total_count)
5326 entry_count = total_count;
5330 total_freq = entry->dest->frequency;
5331 entry_freq = EDGE_FREQUENCY (entry);
5332 /* Fix up corner cases, to avoid division by zero or creation of negative
5334 if (total_freq == 0)
5336 else if (entry_freq > total_freq)
5337 entry_freq = total_freq;
5340 copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
5341 split_edge_bb_loc (entry));
5344 scale_bbs_frequencies_gcov_type (region, n_region,
5345 total_count - entry_count,
5347 scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count,
5352 scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq,
5354 scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq);
5359 loop->header = exit->dest;
5360 loop->latch = exit->src;
5363 /* Redirect the entry and add the phi node arguments. */
5364 redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest));
5365 gcc_assert (redirected != NULL);
5366 flush_pending_stmts (entry);
5368 /* Concerning updating of dominators: We must recount dominators
5369 for entry block and its copy. Anything that is outside of the
5370 region, but was dominated by something inside needs recounting as
5372 set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src);
5373 VEC_safe_push (basic_block, heap, doms, get_bb_original (entry->dest));
5374 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5375 VEC_free (basic_block, heap, doms);
5377 /* Add the other PHI node arguments. */
5378 add_phi_args_after_copy (region_copy, n_region, NULL);
5380 /* Update the SSA web. */
5381 update_ssa (TODO_update_ssa);
5383 if (free_region_copy)
5386 free_original_copy_tables ();
5390 /* Duplicates REGION consisting of N_REGION blocks. The new blocks
5391 are stored to REGION_COPY in the same order in that they appear
5392 in REGION, if REGION_COPY is not NULL. ENTRY is the entry to
5393 the region, EXIT an exit from it. The condition guarding EXIT
5394 is moved to ENTRY. Returns true if duplication succeeds, false
5420 tree_duplicate_sese_tail (edge entry, edge exit,
5421 basic_block *region, unsigned n_region,
5422 basic_block *region_copy)
5425 bool free_region_copy = false;
5426 struct loop *loop = exit->dest->loop_father;
5427 struct loop *orig_loop = entry->dest->loop_father;
5428 basic_block switch_bb, entry_bb, nentry_bb;
5429 VEC (basic_block, heap) *doms;
5430 int total_freq = 0, exit_freq = 0;
5431 gcov_type total_count = 0, exit_count = 0;
5432 edge exits[2], nexits[2], e;
5433 block_stmt_iterator bsi;
5437 gcc_assert (EDGE_COUNT (exit->src->succs) == 2);
5439 exits[1] = EDGE_SUCC (exit->src, EDGE_SUCC (exit->src, 0) == exit);
5441 if (!can_copy_bbs_p (region, n_region))
5444 /* Some sanity checking. Note that we do not check for all possible
5445 missuses of the functions. I.e. if you ask to copy something weird
5446 (e.g., in the example, if there is a jump from inside to the middle
5447 of some_code, or come_code defines some of the values used in cond)
5448 it will work, but the resulting code will not be correct. */
5449 for (i = 0; i < n_region; i++)
5451 /* We do not handle subloops, i.e. all the blocks must belong to the
5453 if (region[i]->loop_father != orig_loop)
5456 if (region[i] == orig_loop->latch)
5460 initialize_original_copy_tables ();
5461 set_loop_copy (orig_loop, loop);
5465 region_copy = XNEWVEC (basic_block, n_region);
5466 free_region_copy = true;
5469 gcc_assert (!need_ssa_update_p ());
5471 /* Record blocks outside the region that are dominated by something
5473 doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region);
5475 if (exit->src->count)
5477 total_count = exit->src->count;
5478 exit_count = exit->count;
5479 /* Fix up corner cases, to avoid division by zero or creation of negative
5481 if (exit_count > total_count)
5482 exit_count = total_count;
5486 total_freq = exit->src->frequency;
5487 exit_freq = EDGE_FREQUENCY (exit);
5488 /* Fix up corner cases, to avoid division by zero or creation of negative
5490 if (total_freq == 0)
5492 if (exit_freq > total_freq)
5493 exit_freq = total_freq;
5496 copy_bbs (region, n_region, region_copy, exits, 2, nexits, orig_loop,
5497 split_edge_bb_loc (exit));
5500 scale_bbs_frequencies_gcov_type (region, n_region,
5501 total_count - exit_count,
5503 scale_bbs_frequencies_gcov_type (region_copy, n_region, exit_count,
5508 scale_bbs_frequencies_int (region, n_region, total_freq - exit_freq,
5510 scale_bbs_frequencies_int (region_copy, n_region, exit_freq, total_freq);
5513 /* Create the switch block, and put the exit condition to it. */
5514 entry_bb = entry->dest;
5515 nentry_bb = get_bb_copy (entry_bb);
5516 if (!last_stmt (entry->src)
5517 || !stmt_ends_bb_p (last_stmt (entry->src)))
5518 switch_bb = entry->src;
5520 switch_bb = split_edge (entry);
5521 set_immediate_dominator (CDI_DOMINATORS, nentry_bb, switch_bb);
5523 bsi = bsi_last (switch_bb);
5524 cond = last_stmt (exit->src);
5525 gcc_assert (TREE_CODE (cond) == COND_EXPR);
5526 bsi_insert_after (&bsi, unshare_expr (cond), BSI_NEW_STMT);
5528 sorig = single_succ_edge (switch_bb);
5529 sorig->flags = exits[1]->flags;
5530 snew = make_edge (switch_bb, nentry_bb, exits[0]->flags);
5532 /* Register the new edge from SWITCH_BB in loop exit lists. */
5533 rescan_loop_exit (snew, true, false);
5535 /* Add the PHI node arguments. */
5536 add_phi_args_after_copy (region_copy, n_region, snew);
5538 /* Get rid of now superfluous conditions and associated edges (and phi node
5540 e = redirect_edge_and_branch (exits[0], exits[1]->dest);
5541 PENDING_STMT (e) = NULL_TREE;
5542 e = redirect_edge_and_branch (nexits[1], nexits[0]->dest);
5543 PENDING_STMT (e) = NULL_TREE;
5545 /* Anything that is outside of the region, but was dominated by something
5546 inside needs to update dominance info. */
5547 iterate_fix_dominators (CDI_DOMINATORS, doms, false);
5548 VEC_free (basic_block, heap, doms);
5550 /* Update the SSA web. */
5551 update_ssa (TODO_update_ssa);
5553 if (free_region_copy)
5556 free_original_copy_tables ();
5561 DEF_VEC_P(basic_block);
5562 DEF_VEC_ALLOC_P(basic_block,heap);
5565 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5566 adding blocks when the dominator traversal reaches EXIT. This
5567 function silently assumes that ENTRY strictly dominates EXIT. */
5570 gather_blocks_in_sese_region (basic_block entry, basic_block exit,
5571 VEC(basic_block,heap) **bbs_p)
5575 for (son = first_dom_son (CDI_DOMINATORS, entry);
5577 son = next_dom_son (CDI_DOMINATORS, son))
5579 VEC_safe_push (basic_block, heap, *bbs_p, son);
5581 gather_blocks_in_sese_region (son, exit, bbs_p);
5585 /* Replaces *TP with a duplicate (belonging to function TO_CONTEXT).
5586 The duplicates are recorded in VARS_MAP. */
5589 replace_by_duplicate_decl (tree *tp, struct pointer_map_t *vars_map,
5592 tree t = *tp, new_t;
5593 struct function *f = DECL_STRUCT_FUNCTION (to_context);
5596 if (DECL_CONTEXT (t) == to_context)
5599 loc = pointer_map_contains (vars_map, t);
5603 loc = pointer_map_insert (vars_map, t);
5607 new_t = copy_var_decl (t, DECL_NAME (t), TREE_TYPE (t));
5608 f->local_decls = tree_cons (NULL_TREE, new_t, f->local_decls);
5612 gcc_assert (TREE_CODE (t) == CONST_DECL);
5613 new_t = copy_node (t);
5615 DECL_CONTEXT (new_t) = to_context;
5625 /* Creates an ssa name in TO_CONTEXT equivalent to NAME.
5626 VARS_MAP maps old ssa names and var_decls to the new ones. */
5629 replace_ssa_name (tree name, struct pointer_map_t *vars_map,
5633 tree new_name, decl = SSA_NAME_VAR (name);
5635 gcc_assert (is_gimple_reg (name));
5637 loc = pointer_map_contains (vars_map, name);
5641 replace_by_duplicate_decl (&decl, vars_map, to_context);
5643 push_cfun (DECL_STRUCT_FUNCTION (to_context));
5644 if (gimple_in_ssa_p (cfun))
5645 add_referenced_var (decl);
5647 new_name = make_ssa_name (decl, SSA_NAME_DEF_STMT (name));
5648 if (SSA_NAME_IS_DEFAULT_DEF (name))
5649 set_default_def (decl, new_name);
5652 loc = pointer_map_insert (vars_map, name);
5666 struct pointer_map_t *vars_map;
5667 htab_t new_label_map;
5671 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5672 contained in *TP and change the DECL_CONTEXT of every local
5673 variable referenced in *TP. */
5676 move_stmt_r (tree *tp, int *walk_subtrees, void *data)
5678 struct move_stmt_d *p = (struct move_stmt_d *) data;
5682 && (EXPR_P (t) || GIMPLE_STMT_P (t)))
5683 TREE_BLOCK (t) = p->block;
5685 if (OMP_DIRECTIVE_P (t)
5686 && TREE_CODE (t) != OMP_RETURN
5687 && TREE_CODE (t) != OMP_CONTINUE)
5689 /* Do not remap variables inside OMP directives. Variables
5690 referenced in clauses and directive header belong to the
5691 parent function and should not be moved into the child
5693 bool save_remap_decls_p = p->remap_decls_p;
5694 p->remap_decls_p = false;
5697 walk_tree (&OMP_BODY (t), move_stmt_r, p, NULL);
5699 p->remap_decls_p = save_remap_decls_p;
5701 else if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
5703 if (TREE_CODE (t) == SSA_NAME)
5704 *tp = replace_ssa_name (t, p->vars_map, p->to_context);
5705 else if (TREE_CODE (t) == LABEL_DECL)
5707 if (p->new_label_map)
5709 struct tree_map in, *out;
5711 out = htab_find_with_hash (p->new_label_map, &in, DECL_UID (t));
5716 DECL_CONTEXT (t) = p->to_context;
5718 else if (p->remap_decls_p)
5720 /* Replace T with its duplicate. T should no longer appear in the
5721 parent function, so this looks wasteful; however, it may appear
5722 in referenced_vars, and more importantly, as virtual operands of
5723 statements, and in alias lists of other variables. It would be
5724 quite difficult to expunge it from all those places. ??? It might
5725 suffice to do this for addressable variables. */
5726 if ((TREE_CODE (t) == VAR_DECL
5727 && !is_global_var (t))
5728 || TREE_CODE (t) == CONST_DECL)
5729 replace_by_duplicate_decl (tp, p->vars_map, p->to_context);
5732 && gimple_in_ssa_p (cfun))
5734 push_cfun (DECL_STRUCT_FUNCTION (p->to_context));
5735 add_referenced_var (*tp);
5741 else if (TYPE_P (t))
5747 /* Marks virtual operands of all statements in basic blocks BBS for
5751 mark_virtual_ops_in_bb (basic_block bb)
5754 block_stmt_iterator bsi;
5756 for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
5757 mark_virtual_ops_for_renaming (phi);
5759 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
5760 mark_virtual_ops_for_renaming (bsi_stmt (bsi));
5763 /* Marks virtual operands of all statements in basic blocks BBS for
5767 mark_virtual_ops_in_region (VEC (basic_block,heap) *bbs)
5772 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
5773 mark_virtual_ops_in_bb (bb);
5776 /* Move basic block BB from function CFUN to function DEST_FN. The
5777 block is moved out of the original linked list and placed after
5778 block AFTER in the new list. Also, the block is removed from the
5779 original array of blocks and placed in DEST_FN's array of blocks.
5780 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5781 updated to reflect the moved edges.
5783 The local variables are remapped to new instances, VARS_MAP is used
5784 to record the mapping. */
5787 move_block_to_fn (struct function *dest_cfun, basic_block bb,
5788 basic_block after, bool update_edge_count_p,
5789 struct pointer_map_t *vars_map, htab_t new_label_map,
5792 struct control_flow_graph *cfg;
5795 block_stmt_iterator si;
5796 struct move_stmt_d d;
5797 unsigned old_len, new_len;
5800 /* Remove BB from dominance structures. */
5801 delete_from_dominance_info (CDI_DOMINATORS, bb);
5803 remove_bb_from_loops (bb);
5805 /* Link BB to the new linked list. */
5806 move_block_after (bb, after);
5808 /* Update the edge count in the corresponding flowgraphs. */
5809 if (update_edge_count_p)
5810 FOR_EACH_EDGE (e, ei, bb->succs)
5812 cfun->cfg->x_n_edges--;
5813 dest_cfun->cfg->x_n_edges++;
5816 /* Remove BB from the original basic block array. */
5817 VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL);
5818 cfun->cfg->x_n_basic_blocks--;
5820 /* Grow DEST_CFUN's basic block array if needed. */
5821 cfg = dest_cfun->cfg;
5822 cfg->x_n_basic_blocks++;
5823 if (bb->index >= cfg->x_last_basic_block)
5824 cfg->x_last_basic_block = bb->index + 1;
5826 old_len = VEC_length (basic_block, cfg->x_basic_block_info);
5827 if ((unsigned) cfg->x_last_basic_block >= old_len)
5829 new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4;
5830 VEC_safe_grow_cleared (basic_block, gc, cfg->x_basic_block_info,
5834 VEC_replace (basic_block, cfg->x_basic_block_info,
5837 /* Remap the variables in phi nodes. */
5838 for (phi = phi_nodes (bb); phi; phi = next_phi)
5841 tree op = PHI_RESULT (phi);
5844 next_phi = PHI_CHAIN (phi);
5845 if (!is_gimple_reg (op))
5847 /* Remove the phi nodes for virtual operands (alias analysis will be
5848 run for the new function, anyway). */
5849 remove_phi_node (phi, NULL, true);
5853 SET_PHI_RESULT (phi, replace_ssa_name (op, vars_map, dest_cfun->decl));
5854 FOR_EACH_PHI_ARG (use, phi, oi, SSA_OP_USE)
5856 op = USE_FROM_PTR (use);
5857 if (TREE_CODE (op) == SSA_NAME)
5858 SET_USE (use, replace_ssa_name (op, vars_map, dest_cfun->decl));
5862 /* The statements in BB need to be associated with a new TREE_BLOCK.
5863 Labels need to be associated with a new label-to-block map. */
5864 memset (&d, 0, sizeof (d));
5865 d.vars_map = vars_map;
5866 d.from_context = cfun->decl;
5867 d.to_context = dest_cfun->decl;
5868 d.new_label_map = new_label_map;
5870 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5872 tree stmt = bsi_stmt (si);
5875 d.remap_decls_p = true;
5876 if (TREE_BLOCK (stmt))
5877 d.block = DECL_INITIAL (dest_cfun->decl);
5879 walk_tree (&stmt, move_stmt_r, &d, NULL);
5881 if (TREE_CODE (stmt) == LABEL_EXPR)
5883 tree label = LABEL_EXPR_LABEL (stmt);
5884 int uid = LABEL_DECL_UID (label);
5886 gcc_assert (uid > -1);
5888 old_len = VEC_length (basic_block, cfg->x_label_to_block_map);
5889 if (old_len <= (unsigned) uid)
5891 new_len = 3 * uid / 2;
5892 VEC_safe_grow_cleared (basic_block, gc,
5893 cfg->x_label_to_block_map, new_len);
5896 VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb);
5897 VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL);
5899 gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl);
5901 if (uid >= dest_cfun->cfg->last_label_uid)
5902 dest_cfun->cfg->last_label_uid = uid + 1;
5904 else if (TREE_CODE (stmt) == RESX_EXPR && eh_offset != 0)
5905 TREE_OPERAND (stmt, 0) =
5906 build_int_cst (NULL_TREE,
5907 TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0))
5910 region = lookup_stmt_eh_region (stmt);
5913 add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset);
5914 remove_stmt_from_eh_region (stmt);
5915 gimple_duplicate_stmt_histograms (dest_cfun, stmt, cfun, stmt);
5916 gimple_remove_stmt_histograms (cfun, stmt);
5919 /* We cannot leave any operands allocated from the operand caches of
5920 the current function. */
5921 free_stmt_operands (stmt);
5922 push_cfun (dest_cfun);
5928 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5929 the outermost EH region. Use REGION as the incoming base EH region. */
5932 find_outermost_region_in_block (struct function *src_cfun,
5933 basic_block bb, int region)
5935 block_stmt_iterator si;
5937 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
5939 tree stmt = bsi_stmt (si);
5942 if (TREE_CODE (stmt) == RESX_EXPR)
5943 stmt_region = TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0));
5945 stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt);
5946 if (stmt_region > 0)
5949 region = stmt_region;
5950 else if (stmt_region != region)
5952 region = eh_region_outermost (src_cfun, stmt_region, region);
5953 gcc_assert (region != -1);
5962 new_label_mapper (tree decl, void *data)
5964 htab_t hash = (htab_t) data;
5968 gcc_assert (TREE_CODE (decl) == LABEL_DECL);
5970 m = xmalloc (sizeof (struct tree_map));
5971 m->hash = DECL_UID (decl);
5972 m->base.from = decl;
5973 m->to = create_artificial_label ();
5974 LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl);
5975 if (LABEL_DECL_UID (m->to) >= cfun->cfg->last_label_uid)
5976 cfun->cfg->last_label_uid = LABEL_DECL_UID (m->to) + 1;
5978 slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT);
5979 gcc_assert (*slot == NULL);
5986 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5987 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5988 single basic block in the original CFG and the new basic block is
5989 returned. DEST_CFUN must not have a CFG yet.
5991 Note that the region need not be a pure SESE region. Blocks inside
5992 the region may contain calls to abort/exit. The only restriction
5993 is that ENTRY_BB should be the only entry point and it must
5996 All local variables referenced in the region are assumed to be in
5997 the corresponding BLOCK_VARS and unexpanded variable lists
5998 associated with DEST_CFUN. */
6001 move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
6002 basic_block exit_bb)
6004 VEC(basic_block,heap) *bbs, *dom_bbs;
6005 basic_block dom_entry = get_immediate_dominator (CDI_DOMINATORS, entry_bb);
6006 basic_block after, bb, *entry_pred, *exit_succ, abb;
6007 struct function *saved_cfun = cfun;
6008 int *entry_flag, *exit_flag, eh_offset;
6009 unsigned *entry_prob, *exit_prob;
6010 unsigned i, num_entry_edges, num_exit_edges;
6013 htab_t new_label_map;
6014 struct pointer_map_t *vars_map;
6015 struct loop *loop = entry_bb->loop_father;
6017 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
6019 gcc_assert (entry_bb != exit_bb
6021 || dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)));
6023 /* Collect all the blocks in the region. Manually add ENTRY_BB
6024 because it won't be added by dfs_enumerate_from. */
6026 VEC_safe_push (basic_block, heap, bbs, entry_bb);
6027 gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs);
6029 /* The blocks that used to be dominated by something in BBS will now be
6030 dominated by the new block. */
6031 dom_bbs = get_dominated_by_region (CDI_DOMINATORS,
6032 VEC_address (basic_block, bbs),
6033 VEC_length (basic_block, bbs));
6035 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
6036 the predecessor edges to ENTRY_BB and the successor edges to
6037 EXIT_BB so that we can re-attach them to the new basic block that
6038 will replace the region. */
6039 num_entry_edges = EDGE_COUNT (entry_bb->preds);
6040 entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
6041 entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
6042 entry_prob = XNEWVEC (unsigned, num_entry_edges);
6044 for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
6046 entry_prob[i] = e->probability;
6047 entry_flag[i] = e->flags;
6048 entry_pred[i++] = e->src;
6054 num_exit_edges = EDGE_COUNT (exit_bb->succs);
6055 exit_succ = (basic_block *) xcalloc (num_exit_edges,
6056 sizeof (basic_block));
6057 exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
6058 exit_prob = XNEWVEC (unsigned, num_exit_edges);
6060 for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)
6062 exit_prob[i] = e->probability;
6063 exit_flag[i] = e->flags;
6064 exit_succ[i++] = e->dest;
6076 /* Switch context to the child function to initialize DEST_FN's CFG. */
6077 gcc_assert (dest_cfun->cfg == NULL);
6078 push_cfun (dest_cfun);
6080 init_empty_tree_cfg ();
6082 /* Initialize EH information for the new function. */
6084 new_label_map = NULL;
6089 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6090 region = find_outermost_region_in_block (saved_cfun, bb, region);
6092 init_eh_for_function ();
6095 new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free);
6096 eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper,
6097 new_label_map, region, 0);
6103 /* The ssa form for virtual operands in the source function will have to
6104 be repaired. We do not care for the real operands -- the sese region
6105 must be closed with respect to those. */
6106 mark_virtual_ops_in_region (bbs);
6108 /* Move blocks from BBS into DEST_CFUN. */
6109 gcc_assert (VEC_length (basic_block, bbs) >= 2);
6110 after = dest_cfun->cfg->x_entry_block_ptr;
6111 vars_map = pointer_map_create ();
6112 for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++)
6114 /* No need to update edge counts on the last block. It has
6115 already been updated earlier when we detached the region from
6116 the original CFG. */
6117 move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, vars_map,
6118 new_label_map, eh_offset);
6123 htab_delete (new_label_map);
6124 pointer_map_destroy (vars_map);
6126 /* Rewire the entry and exit blocks. The successor to the entry
6127 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
6128 the child function. Similarly, the predecessor of DEST_FN's
6129 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
6130 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
6131 various CFG manipulation function get to the right CFG.
6133 FIXME, this is silly. The CFG ought to become a parameter to
6135 push_cfun (dest_cfun);
6136 make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU);
6138 make_edge (exit_bb, EXIT_BLOCK_PTR, 0);
6141 /* Back in the original function, the SESE region has disappeared,
6142 create a new basic block in its place. */
6143 bb = create_empty_bb (entry_pred[0]);
6145 add_bb_to_loop (bb, loop);
6146 for (i = 0; i < num_entry_edges; i++)
6148 e = make_edge (entry_pred[i], bb, entry_flag[i]);
6149 e->probability = entry_prob[i];
6152 for (i = 0; i < num_exit_edges; i++)
6154 e = make_edge (bb, exit_succ[i], exit_flag[i]);
6155 e->probability = exit_prob[i];
6158 set_immediate_dominator (CDI_DOMINATORS, bb, dom_entry);
6159 for (i = 0; VEC_iterate (basic_block, dom_bbs, i, abb); i++)
6160 set_immediate_dominator (CDI_DOMINATORS, abb, bb);
6161 VEC_free (basic_block, heap, dom_bbs);
6172 VEC_free (basic_block, heap, bbs);
6178 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */
6181 dump_function_to_file (tree fn, FILE *file, int flags)
6183 tree arg, vars, var;
6184 struct function *dsf;
6185 bool ignore_topmost_bind = false, any_var = false;
6189 fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2));
6191 arg = DECL_ARGUMENTS (fn);
6194 print_generic_expr (file, TREE_TYPE (arg), dump_flags);
6195 fprintf (file, " ");
6196 print_generic_expr (file, arg, dump_flags);
6197 if (flags & TDF_VERBOSE)
6198 print_node (file, "", arg, 4);
6199 if (TREE_CHAIN (arg))
6200 fprintf (file, ", ");
6201 arg = TREE_CHAIN (arg);
6203 fprintf (file, ")\n");
6205 if (flags & TDF_VERBOSE)
6206 print_node (file, "", fn, 2);
6208 dsf = DECL_STRUCT_FUNCTION (fn);
6209 if (dsf && (flags & TDF_DETAILS))
6210 dump_eh_tree (file, dsf);
6212 if (flags & TDF_RAW)
6214 dump_node (fn, TDF_SLIM | flags, file);
6218 /* Switch CFUN to point to FN. */
6219 push_cfun (DECL_STRUCT_FUNCTION (fn));
6221 /* When GIMPLE is lowered, the variables are no longer available in
6222 BIND_EXPRs, so display them separately. */
6223 if (cfun && cfun->decl == fn && cfun->local_decls)
6225 ignore_topmost_bind = true;
6227 fprintf (file, "{\n");
6228 for (vars = cfun->local_decls; vars; vars = TREE_CHAIN (vars))
6230 var = TREE_VALUE (vars);
6232 print_generic_decl (file, var, flags);
6233 if (flags & TDF_VERBOSE)
6234 print_node (file, "", var, 4);
6235 fprintf (file, "\n");
6241 if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info)
6243 /* Make a CFG based dump. */
6244 check_bb_profile (ENTRY_BLOCK_PTR, file);
6245 if (!ignore_topmost_bind)
6246 fprintf (file, "{\n");
6248 if (any_var && n_basic_blocks)
6249 fprintf (file, "\n");
6252 dump_generic_bb (file, bb, 2, flags);
6254 fprintf (file, "}\n");
6255 check_bb_profile (EXIT_BLOCK_PTR, file);
6261 /* Make a tree based dump. */
6262 chain = DECL_SAVED_TREE (fn);
6264 if (chain && TREE_CODE (chain) == BIND_EXPR)
6266 if (ignore_topmost_bind)
6268 chain = BIND_EXPR_BODY (chain);
6276 if (!ignore_topmost_bind)
6277 fprintf (file, "{\n");
6282 fprintf (file, "\n");
6284 print_generic_stmt_indented (file, chain, flags, indent);
6285 if (ignore_topmost_bind)
6286 fprintf (file, "}\n");
6289 fprintf (file, "\n\n");
6296 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
6299 debug_function (tree fn, int flags)
6301 dump_function_to_file (fn, stderr, flags);
6305 /* Print on FILE the indexes for the predecessors of basic_block BB. */
6308 print_pred_bbs (FILE *file, basic_block bb)
6313 FOR_EACH_EDGE (e, ei, bb->preds)
6314 fprintf (file, "bb_%d ", e->src->index);
6318 /* Print on FILE the indexes for the successors of basic_block BB. */
6321 print_succ_bbs (FILE *file, basic_block bb)
6326 FOR_EACH_EDGE (e, ei, bb->succs)
6327 fprintf (file, "bb_%d ", e->dest->index);
6330 /* Print to FILE the basic block BB following the VERBOSITY level. */
6333 print_loops_bb (FILE *file, basic_block bb, int indent, int verbosity)
6335 char *s_indent = (char *) alloca ((size_t) indent + 1);
6336 memset ((void *) s_indent, ' ', (size_t) indent);
6337 s_indent[indent] = '\0';
6339 /* Print basic_block's header. */
6342 fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index);
6343 print_pred_bbs (file, bb);
6344 fprintf (file, "}, succs = {");
6345 print_succ_bbs (file, bb);
6346 fprintf (file, "})\n");
6349 /* Print basic_block's body. */
6352 fprintf (file, "%s {\n", s_indent);
6353 tree_dump_bb (bb, file, indent + 4);
6354 fprintf (file, "%s }\n", s_indent);
6358 static void print_loop_and_siblings (FILE *, struct loop *, int, int);
6360 /* Pretty print LOOP on FILE, indented INDENT spaces. Following
6361 VERBOSITY level this outputs the contents of the loop, or just its
6365 print_loop (FILE *file, struct loop *loop, int indent, int verbosity)
6373 s_indent = (char *) alloca ((size_t) indent + 1);
6374 memset ((void *) s_indent, ' ', (size_t) indent);
6375 s_indent[indent] = '\0';
6377 /* Print loop's header. */
6378 fprintf (file, "%sloop_%d (header = %d, latch = %d", s_indent,
6379 loop->num, loop->header->index, loop->latch->index);
6380 fprintf (file, ", niter = ");
6381 print_generic_expr (file, loop->nb_iterations, 0);
6383 if (loop->any_upper_bound)
6385 fprintf (file, ", upper_bound = ");
6386 dump_double_int (file, loop->nb_iterations_upper_bound, true);
6389 if (loop->any_estimate)
6391 fprintf (file, ", estimate = ");
6392 dump_double_int (file, loop->nb_iterations_estimate, true);
6394 fprintf (file, ")\n");
6396 /* Print loop's body. */
6399 fprintf (file, "%s{\n", s_indent);
6401 if (bb->loop_father == loop)
6402 print_loops_bb (file, bb, indent, verbosity);
6404 print_loop_and_siblings (file, loop->inner, indent + 2, verbosity);
6405 fprintf (file, "%s}\n", s_indent);
6409 /* Print the LOOP and its sibling loops on FILE, indented INDENT
6410 spaces. Following VERBOSITY level this outputs the contents of the
6411 loop, or just its structure. */
6414 print_loop_and_siblings (FILE *file, struct loop *loop, int indent, int verbosity)
6419 print_loop (file, loop, indent, verbosity);
6420 print_loop_and_siblings (file, loop->next, indent, verbosity);
6423 /* Follow a CFG edge from the entry point of the program, and on entry
6424 of a loop, pretty print the loop structure on FILE. */
6427 print_loops (FILE *file, int verbosity)
6431 bb = BASIC_BLOCK (NUM_FIXED_BLOCKS);
6432 if (bb && bb->loop_father)
6433 print_loop_and_siblings (file, bb->loop_father, 0, verbosity);
6437 /* Debugging loops structure at tree level, at some VERBOSITY level. */
6440 debug_loops (int verbosity)
6442 print_loops (stderr, verbosity);
6445 /* Print on stderr the code of LOOP, at some VERBOSITY level. */
6448 debug_loop (struct loop *loop, int verbosity)
6450 print_loop (stderr, loop, 0, verbosity);
6453 /* Print on stderr the code of loop number NUM, at some VERBOSITY
6457 debug_loop_num (unsigned num, int verbosity)
6459 debug_loop (get_loop (num), verbosity);
6462 /* Return true if BB ends with a call, possibly followed by some
6463 instructions that must stay with the call. Return false,
6467 tree_block_ends_with_call_p (basic_block bb)
6469 block_stmt_iterator bsi = bsi_last (bb);
6470 return get_call_expr_in (bsi_stmt (bsi)) != NULL;
6474 /* Return true if BB ends with a conditional branch. Return false,
6478 tree_block_ends_with_condjump_p (const_basic_block bb)
6480 /* This CONST_CAST is okay because last_stmt doesn't modify its
6481 argument and the return value is not modified. */
6482 const_tree stmt = last_stmt (CONST_CAST_BB(bb));
6483 return (stmt && TREE_CODE (stmt) == COND_EXPR);
6487 /* Return true if we need to add fake edge to exit at statement T.
6488 Helper function for tree_flow_call_edges_add. */
6491 need_fake_edge_p (tree t)
6493 tree call, fndecl = NULL_TREE;
6496 /* NORETURN and LONGJMP calls already have an edge to exit.
6497 CONST and PURE calls do not need one.
6498 We don't currently check for CONST and PURE here, although
6499 it would be a good idea, because those attributes are
6500 figured out from the RTL in mark_constant_function, and
6501 the counter incrementation code from -fprofile-arcs
6502 leads to different results from -fbranch-probabilities. */
6503 call = get_call_expr_in (t);
6506 fndecl = get_callee_fndecl (call);
6507 call_flags = call_expr_flags (call);
6510 if (call && fndecl && DECL_BUILT_IN (fndecl)
6511 && (call_flags & ECF_NOTHROW)
6512 && !(call_flags & ECF_NORETURN)
6513 && !(call_flags & ECF_RETURNS_TWICE))
6516 if (call && !(call_flags & ECF_NORETURN))
6519 if (TREE_CODE (t) == ASM_EXPR
6520 && (ASM_VOLATILE_P (t) || ASM_INPUT_P (t)))
6527 /* Add fake edges to the function exit for any non constant and non
6528 noreturn calls, volatile inline assembly in the bitmap of blocks
6529 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
6530 the number of blocks that were split.
6532 The goal is to expose cases in which entering a basic block does
6533 not imply that all subsequent instructions must be executed. */
6536 tree_flow_call_edges_add (sbitmap blocks)
6539 int blocks_split = 0;
6540 int last_bb = last_basic_block;
6541 bool check_last_block = false;
6543 if (n_basic_blocks == NUM_FIXED_BLOCKS)
6547 check_last_block = true;
6549 check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
6551 /* In the last basic block, before epilogue generation, there will be
6552 a fallthru edge to EXIT. Special care is required if the last insn
6553 of the last basic block is a call because make_edge folds duplicate
6554 edges, which would result in the fallthru edge also being marked
6555 fake, which would result in the fallthru edge being removed by
6556 remove_fake_edges, which would result in an invalid CFG.
6558 Moreover, we can't elide the outgoing fake edge, since the block
6559 profiler needs to take this into account in order to solve the minimal
6560 spanning tree in the case that the call doesn't return.
6562 Handle this by adding a dummy instruction in a new last basic block. */
6563 if (check_last_block)
6565 basic_block bb = EXIT_BLOCK_PTR->prev_bb;
6566 block_stmt_iterator bsi = bsi_last (bb);
6568 if (!bsi_end_p (bsi))
6571 if (t && need_fake_edge_p (t))
6575 e = find_edge (bb, EXIT_BLOCK_PTR);
6578 bsi_insert_on_edge (e, build_empty_stmt ());
6579 bsi_commit_edge_inserts ();
6584 /* Now add fake edges to the function exit for any non constant
6585 calls since there is no way that we can determine if they will
6587 for (i = 0; i < last_bb; i++)
6589 basic_block bb = BASIC_BLOCK (i);
6590 block_stmt_iterator bsi;
6591 tree stmt, last_stmt;
6596 if (blocks && !TEST_BIT (blocks, i))
6599 bsi = bsi_last (bb);
6600 if (!bsi_end_p (bsi))
6602 last_stmt = bsi_stmt (bsi);
6605 stmt = bsi_stmt (bsi);
6606 if (need_fake_edge_p (stmt))
6609 /* The handling above of the final block before the
6610 epilogue should be enough to verify that there is
6611 no edge to the exit block in CFG already.
6612 Calling make_edge in such case would cause us to
6613 mark that edge as fake and remove it later. */
6614 #ifdef ENABLE_CHECKING
6615 if (stmt == last_stmt)
6617 e = find_edge (bb, EXIT_BLOCK_PTR);
6618 gcc_assert (e == NULL);
6622 /* Note that the following may create a new basic block
6623 and renumber the existing basic blocks. */
6624 if (stmt != last_stmt)
6626 e = split_block (bb, stmt);
6630 make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
6634 while (!bsi_end_p (bsi));
6639 verify_flow_info ();
6641 return blocks_split;
6644 /* Purge dead abnormal call edges from basic block BB. */
6647 tree_purge_dead_abnormal_call_edges (basic_block bb)
6649 bool changed = tree_purge_dead_eh_edges (bb);
6651 if (cfun->has_nonlocal_label)
6653 tree stmt = last_stmt (bb);
6657 if (!(stmt && tree_can_make_abnormal_goto (stmt)))
6658 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6660 if (e->flags & EDGE_ABNORMAL)
6669 /* See tree_purge_dead_eh_edges below. */
6671 free_dominance_info (CDI_DOMINATORS);
6677 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6680 get_all_dominated_blocks (basic_block bb, VEC (basic_block, heap) **dom_bbs)
6684 VEC_safe_push (basic_block, heap, *dom_bbs, bb);
6685 for (son = first_dom_son (CDI_DOMINATORS, bb);
6687 son = next_dom_son (CDI_DOMINATORS, son))
6688 get_all_dominated_blocks (son, dom_bbs);
6691 /* Removes edge E and all the blocks dominated by it, and updates dominance
6692 information. The IL in E->src needs to be updated separately.
6693 If dominance info is not available, only the edge E is removed.*/
6696 remove_edge_and_dominated_blocks (edge e)
6698 VEC (basic_block, heap) *bbs_to_remove = NULL;
6699 VEC (basic_block, heap) *bbs_to_fix_dom = NULL;
6703 bool none_removed = false;
6705 basic_block bb, dbb;
6708 if (!dom_info_available_p (CDI_DOMINATORS))
6714 /* No updating is needed for edges to exit. */
6715 if (e->dest == EXIT_BLOCK_PTR)
6717 if (cfgcleanup_altered_bbs)
6718 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6723 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6724 that is not dominated by E->dest, then this set is empty. Otherwise,
6725 all the basic blocks dominated by E->dest are removed.
6727 Also, to DF_IDOM we store the immediate dominators of the blocks in
6728 the dominance frontier of E (i.e., of the successors of the
6729 removed blocks, if there are any, and of E->dest otherwise). */
6730 FOR_EACH_EDGE (f, ei, e->dest->preds)
6735 if (!dominated_by_p (CDI_DOMINATORS, f->src, e->dest))
6737 none_removed = true;
6742 df = BITMAP_ALLOC (NULL);
6743 df_idom = BITMAP_ALLOC (NULL);
6746 bitmap_set_bit (df_idom,
6747 get_immediate_dominator (CDI_DOMINATORS, e->dest)->index);
6750 get_all_dominated_blocks (e->dest, &bbs_to_remove);
6751 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6753 FOR_EACH_EDGE (f, ei, bb->succs)
6755 if (f->dest != EXIT_BLOCK_PTR)
6756 bitmap_set_bit (df, f->dest->index);
6759 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6760 bitmap_clear_bit (df, bb->index);
6762 EXECUTE_IF_SET_IN_BITMAP (df, 0, i, bi)
6764 bb = BASIC_BLOCK (i);
6765 bitmap_set_bit (df_idom,
6766 get_immediate_dominator (CDI_DOMINATORS, bb)->index);
6770 if (cfgcleanup_altered_bbs)
6772 /* Record the set of the altered basic blocks. */
6773 bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index);
6774 bitmap_ior_into (cfgcleanup_altered_bbs, df);
6777 /* Remove E and the cancelled blocks. */
6782 for (i = 0; VEC_iterate (basic_block, bbs_to_remove, i, bb); i++)
6783 delete_basic_block (bb);
6786 /* Update the dominance information. The immediate dominator may change only
6787 for blocks whose immediate dominator belongs to DF_IDOM:
6789 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6790 removal. Let Z the arbitrary block such that idom(Z) = Y and
6791 Z dominates X after the removal. Before removal, there exists a path P
6792 from Y to X that avoids Z. Let F be the last edge on P that is
6793 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6794 dominates W, and because of P, Z does not dominate W), and W belongs to
6795 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6796 EXECUTE_IF_SET_IN_BITMAP (df_idom, 0, i, bi)
6798 bb = BASIC_BLOCK (i);
6799 for (dbb = first_dom_son (CDI_DOMINATORS, bb);
6801 dbb = next_dom_son (CDI_DOMINATORS, dbb))
6802 VEC_safe_push (basic_block, heap, bbs_to_fix_dom, dbb);
6805 iterate_fix_dominators (CDI_DOMINATORS, bbs_to_fix_dom, true);
6808 BITMAP_FREE (df_idom);
6809 VEC_free (basic_block, heap, bbs_to_remove);
6810 VEC_free (basic_block, heap, bbs_to_fix_dom);
6813 /* Purge dead EH edges from basic block BB. */
6816 tree_purge_dead_eh_edges (basic_block bb)
6818 bool changed = false;
6821 tree stmt = last_stmt (bb);
6823 if (stmt && tree_can_throw_internal (stmt))
6826 for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
6828 if (e->flags & EDGE_EH)
6830 remove_edge_and_dominated_blocks (e);
6841 tree_purge_all_dead_eh_edges (const_bitmap blocks)
6843 bool changed = false;
6847 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi)
6849 changed |= tree_purge_dead_eh_edges (BASIC_BLOCK (i));
6855 /* This function is called whenever a new edge is created or
6859 tree_execute_on_growing_pred (edge e)
6861 basic_block bb = e->dest;
6864 reserve_phi_args_for_new_edge (bb);
6867 /* This function is called immediately before edge E is removed from
6868 the edge vector E->dest->preds. */
6871 tree_execute_on_shrinking_pred (edge e)
6873 if (phi_nodes (e->dest))
6874 remove_phi_args (e);
6877 /*---------------------------------------------------------------------------
6878 Helper functions for Loop versioning
6879 ---------------------------------------------------------------------------*/
6881 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6882 of 'first'. Both of them are dominated by 'new_head' basic block. When
6883 'new_head' was created by 'second's incoming edge it received phi arguments
6884 on the edge by split_edge(). Later, additional edge 'e' was created to
6885 connect 'new_head' and 'first'. Now this routine adds phi args on this
6886 additional edge 'e' that new_head to second edge received as part of edge
6891 tree_lv_adjust_loop_header_phi (basic_block first, basic_block second,
6892 basic_block new_head, edge e)
6895 edge e2 = find_edge (new_head, second);
6897 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6898 edge, we should always have an edge from NEW_HEAD to SECOND. */
6899 gcc_assert (e2 != NULL);
6901 /* Browse all 'second' basic block phi nodes and add phi args to
6902 edge 'e' for 'first' head. PHI args are always in correct order. */
6904 for (phi2 = phi_nodes (second), phi1 = phi_nodes (first);
6906 phi2 = PHI_CHAIN (phi2), phi1 = PHI_CHAIN (phi1))
6908 tree def = PHI_ARG_DEF (phi2, e2->dest_idx);
6909 add_phi_arg (phi1, def, e);
6913 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6914 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6915 the destination of the ELSE part. */
6917 tree_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
6918 basic_block second_head ATTRIBUTE_UNUSED,
6919 basic_block cond_bb, void *cond_e)
6921 block_stmt_iterator bsi;
6922 tree new_cond_expr = NULL_TREE;
6923 tree cond_expr = (tree) cond_e;
6926 /* Build new conditional expr */
6927 new_cond_expr = build3 (COND_EXPR, void_type_node, cond_expr,
6928 NULL_TREE, NULL_TREE);
6930 /* Add new cond in cond_bb. */
6931 bsi = bsi_start (cond_bb);
6932 bsi_insert_after (&bsi, new_cond_expr, BSI_NEW_STMT);
6933 /* Adjust edges appropriately to connect new head with first head
6934 as well as second head. */
6935 e0 = single_succ_edge (cond_bb);
6936 e0->flags &= ~EDGE_FALLTHRU;
6937 e0->flags |= EDGE_FALSE_VALUE;
6940 struct cfg_hooks tree_cfg_hooks = {
6942 tree_verify_flow_info,
6943 tree_dump_bb, /* dump_bb */
6944 create_bb, /* create_basic_block */
6945 tree_redirect_edge_and_branch,/* redirect_edge_and_branch */
6946 tree_redirect_edge_and_branch_force,/* redirect_edge_and_branch_force */
6947 tree_can_remove_branch_p, /* can_remove_branch_p */
6948 remove_bb, /* delete_basic_block */
6949 tree_split_block, /* split_block */
6950 tree_move_block_after, /* move_block_after */
6951 tree_can_merge_blocks_p, /* can_merge_blocks_p */
6952 tree_merge_blocks, /* merge_blocks */
6953 tree_predict_edge, /* predict_edge */
6954 tree_predicted_by_p, /* predicted_by_p */
6955 tree_can_duplicate_bb_p, /* can_duplicate_block_p */
6956 tree_duplicate_bb, /* duplicate_block */
6957 tree_split_edge, /* split_edge */
6958 tree_make_forwarder_block, /* make_forward_block */
6959 NULL, /* tidy_fallthru_edge */
6960 tree_block_ends_with_call_p, /* block_ends_with_call_p */
6961 tree_block_ends_with_condjump_p, /* block_ends_with_condjump_p */
6962 tree_flow_call_edges_add, /* flow_call_edges_add */
6963 tree_execute_on_growing_pred, /* execute_on_growing_pred */
6964 tree_execute_on_shrinking_pred, /* execute_on_shrinking_pred */
6965 tree_duplicate_loop_to_header_edge, /* duplicate loop for trees */
6966 tree_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
6967 tree_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/
6968 extract_true_false_edges_from_block, /* extract_cond_bb_edges */
6969 flush_pending_stmts /* flush_pending_stmts */
6973 /* Split all critical edges. */
6976 split_critical_edges (void)
6982 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6983 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6984 mappings around the calls to split_edge. */
6985 start_recording_case_labels ();
6988 FOR_EACH_EDGE (e, ei, bb->succs)
6989 if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL))
6994 end_recording_case_labels ();
6998 struct gimple_opt_pass pass_split_crit_edges =
7002 "crited", /* name */
7004 split_critical_edges, /* execute */
7007 0, /* static_pass_number */
7008 TV_TREE_SPLIT_EDGES, /* tv_id */
7009 PROP_cfg, /* properties required */
7010 PROP_no_crit_edges, /* properties_provided */
7011 0, /* properties_destroyed */
7012 0, /* todo_flags_start */
7013 TODO_dump_func /* todo_flags_finish */
7018 /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into
7019 a temporary, make sure and register it to be renamed if necessary,
7020 and finally return the temporary. Put the statements to compute
7021 EXP before the current statement in BSI. */
7024 gimplify_val (block_stmt_iterator *bsi, tree type, tree exp)
7026 tree t, new_stmt, orig_stmt;
7028 if (is_gimple_val (exp))
7031 t = make_rename_temp (type, NULL);
7032 new_stmt = build_gimple_modify_stmt (t, exp);
7034 orig_stmt = bsi_stmt (*bsi);
7035 SET_EXPR_LOCUS (new_stmt, EXPR_LOCUS (orig_stmt));
7036 TREE_BLOCK (new_stmt) = TREE_BLOCK (orig_stmt);
7038 bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT);
7039 if (gimple_in_ssa_p (cfun))
7040 mark_symbols_for_renaming (new_stmt);
7045 /* Build a ternary operation and gimplify it. Emit code before BSI.
7046 Return the gimple_val holding the result. */
7049 gimplify_build3 (block_stmt_iterator *bsi, enum tree_code code,
7050 tree type, tree a, tree b, tree c)
7054 ret = fold_build3 (code, type, a, b, c);
7057 return gimplify_val (bsi, type, ret);
7060 /* Build a binary operation and gimplify it. Emit code before BSI.
7061 Return the gimple_val holding the result. */
7064 gimplify_build2 (block_stmt_iterator *bsi, enum tree_code code,
7065 tree type, tree a, tree b)
7069 ret = fold_build2 (code, type, a, b);
7072 return gimplify_val (bsi, type, ret);
7075 /* Build a unary operation and gimplify it. Emit code before BSI.
7076 Return the gimple_val holding the result. */
7079 gimplify_build1 (block_stmt_iterator *bsi, enum tree_code code, tree type,
7084 ret = fold_build1 (code, type, a);
7087 return gimplify_val (bsi, type, ret);
7092 /* Emit return warnings. */
7095 execute_warn_function_return (void)
7097 source_location location;
7102 /* If we have a path to EXIT, then we do return. */
7103 if (TREE_THIS_VOLATILE (cfun->decl)
7104 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
7106 location = UNKNOWN_LOCATION;
7107 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7109 last = last_stmt (e->src);
7110 if (TREE_CODE (last) == RETURN_EXPR
7111 && (location = EXPR_LOCATION (last)) != UNKNOWN_LOCATION)
7114 if (location == UNKNOWN_LOCATION)
7115 location = cfun->function_end_locus;
7116 warning (0, "%H%<noreturn%> function does return", &location);
7119 /* If we see "return;" in some basic block, then we do reach the end
7120 without returning a value. */
7121 else if (warn_return_type
7122 && !TREE_NO_WARNING (cfun->decl)
7123 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0
7124 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl))))
7126 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
7128 tree last = last_stmt (e->src);
7129 if (TREE_CODE (last) == RETURN_EXPR
7130 && TREE_OPERAND (last, 0) == NULL
7131 && !TREE_NO_WARNING (last))
7133 location = EXPR_LOCATION (last);
7134 if (location == UNKNOWN_LOCATION)
7135 location = cfun->function_end_locus;
7136 warning (OPT_Wreturn_type, "%Hcontrol reaches end of non-void function", &location);
7137 TREE_NO_WARNING (cfun->decl) = 1;
7146 /* Given a basic block B which ends with a conditional and has
7147 precisely two successors, determine which of the edges is taken if
7148 the conditional is true and which is taken if the conditional is
7149 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
7152 extract_true_false_edges_from_block (basic_block b,
7156 edge e = EDGE_SUCC (b, 0);
7158 if (e->flags & EDGE_TRUE_VALUE)
7161 *false_edge = EDGE_SUCC (b, 1);
7166 *true_edge = EDGE_SUCC (b, 1);
7170 struct gimple_opt_pass pass_warn_function_return =
7176 execute_warn_function_return, /* execute */
7179 0, /* static_pass_number */
7181 PROP_cfg, /* properties_required */
7182 0, /* properties_provided */
7183 0, /* properties_destroyed */
7184 0, /* todo_flags_start */
7185 0 /* todo_flags_finish */
7189 /* Emit noreturn warnings. */
7192 execute_warn_function_noreturn (void)
7194 if (warn_missing_noreturn
7195 && !TREE_THIS_VOLATILE (cfun->decl)
7196 && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
7197 && !lang_hooks.missing_noreturn_ok_p (cfun->decl))
7198 warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate "
7199 "for attribute %<noreturn%>",
7204 struct gimple_opt_pass pass_warn_function_noreturn =
7210 execute_warn_function_noreturn, /* execute */
7213 0, /* static_pass_number */
7215 PROP_cfg, /* properties_required */
7216 0, /* properties_provided */
7217 0, /* properties_destroyed */
7218 0, /* todo_flags_start */
7219 0 /* todo_flags_finish */