1 /* Control flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
3 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@redhat.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "hard-reg-set.h"
30 #include "basic-block.h"
36 #include "langhooks.h"
37 #include "diagnostic.h"
38 #include "tree-flow.h"
40 #include "tree-dump.h"
41 #include "tree-pass.h"
45 #include "cfglayout.h"
46 #include "tree-ssa-propagate.h"
47 #include "value-prof.h"
48 #include "pointer-set.h"
50 /* This file contains functions for building the Control Flow Graph (CFG)
51 for a function tree. */
53 /* Local declarations. */
55 /* Initial capacity for the basic block array. */
56 static const int initial_cfg_capacity
= 20;
58 /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs
59 which use a particular edge. The CASE_LABEL_EXPRs are chained together
60 via their TREE_CHAIN field, which we clear after we're done with the
61 hash table to prevent problems with duplication of SWITCH_EXPRs.
63 Access to this list of CASE_LABEL_EXPRs allows us to efficiently
64 update the case vector in response to edge redirections.
66 Right now this table is set up and torn down at key points in the
67 compilation process. It would be nice if we could make the table
68 more persistent. The key is getting notification of changes to
69 the CFG (particularly edge removal, creation and redirection). */
71 static struct pointer_map_t
*edge_to_cases
;
76 long num_merged_labels
;
79 static struct cfg_stats_d cfg_stats
;
81 /* Nonzero if we found a computed goto while building basic blocks. */
82 static bool found_computed_goto
;
84 /* Basic blocks and flowgraphs. */
85 static basic_block
create_bb (void *, void *, basic_block
);
86 static void make_blocks (tree
);
87 static void factor_computed_gotos (void);
90 static void make_edges (void);
91 static void make_cond_expr_edges (basic_block
);
92 static void make_switch_expr_edges (basic_block
);
93 static void make_goto_expr_edges (basic_block
);
94 static edge
tree_redirect_edge_and_branch (edge
, basic_block
);
95 static edge
tree_try_redirect_by_replacing_jump (edge
, basic_block
);
96 static unsigned int split_critical_edges (void);
98 /* Various helpers. */
99 static inline bool stmt_starts_bb_p (const_tree
, const_tree
);
100 static int tree_verify_flow_info (void);
101 static void tree_make_forwarder_block (edge
);
102 static void tree_cfg2vcg (FILE *);
103 static inline void change_bb_for_stmt (tree t
, basic_block bb
);
105 /* Flowgraph optimization and cleanup. */
106 static void tree_merge_blocks (basic_block
, basic_block
);
107 static bool tree_can_merge_blocks_p (const_basic_block
, const_basic_block
);
108 static void remove_bb (basic_block
);
109 static edge
find_taken_edge_computed_goto (basic_block
, tree
);
110 static edge
find_taken_edge_cond_expr (basic_block
, tree
);
111 static edge
find_taken_edge_switch_expr (basic_block
, tree
);
112 static tree
find_case_label_for_value (tree
, tree
);
115 init_empty_tree_cfg (void)
117 /* Initialize the basic block array. */
119 profile_status
= PROFILE_ABSENT
;
120 n_basic_blocks
= NUM_FIXED_BLOCKS
;
121 last_basic_block
= NUM_FIXED_BLOCKS
;
122 basic_block_info
= VEC_alloc (basic_block
, gc
, initial_cfg_capacity
);
123 VEC_safe_grow_cleared (basic_block
, gc
, basic_block_info
,
124 initial_cfg_capacity
);
126 /* Build a mapping of labels to their associated blocks. */
127 label_to_block_map
= VEC_alloc (basic_block
, gc
, initial_cfg_capacity
);
128 VEC_safe_grow_cleared (basic_block
, gc
, label_to_block_map
,
129 initial_cfg_capacity
);
131 SET_BASIC_BLOCK (ENTRY_BLOCK
, ENTRY_BLOCK_PTR
);
132 SET_BASIC_BLOCK (EXIT_BLOCK
, EXIT_BLOCK_PTR
);
133 ENTRY_BLOCK_PTR
->next_bb
= EXIT_BLOCK_PTR
;
134 EXIT_BLOCK_PTR
->prev_bb
= ENTRY_BLOCK_PTR
;
137 /*---------------------------------------------------------------------------
139 ---------------------------------------------------------------------------*/
141 /* Entry point to the CFG builder for trees. TP points to the list of
142 statements to be added to the flowgraph. */
145 build_tree_cfg (tree
*tp
)
147 /* Register specific tree functions. */
148 tree_register_cfg_hooks ();
150 memset ((void *) &cfg_stats
, 0, sizeof (cfg_stats
));
152 init_empty_tree_cfg ();
154 found_computed_goto
= 0;
157 /* Computed gotos are hell to deal with, especially if there are
158 lots of them with a large number of destinations. So we factor
159 them to a common computed goto location before we build the
160 edge list. After we convert back to normal form, we will un-factor
161 the computed gotos since factoring introduces an unwanted jump. */
162 if (found_computed_goto
)
163 factor_computed_gotos ();
165 /* Make sure there is always at least one block, even if it's empty. */
166 if (n_basic_blocks
== NUM_FIXED_BLOCKS
)
167 create_empty_bb (ENTRY_BLOCK_PTR
);
169 /* Adjust the size of the array. */
170 if (VEC_length (basic_block
, basic_block_info
) < (size_t) n_basic_blocks
)
171 VEC_safe_grow_cleared (basic_block
, gc
, basic_block_info
, n_basic_blocks
);
173 /* To speed up statement iterator walks, we first purge dead labels. */
174 cleanup_dead_labels ();
176 /* Group case nodes to reduce the number of edges.
177 We do this after cleaning up dead labels because otherwise we miss
178 a lot of obvious case merging opportunities. */
179 group_case_labels ();
181 /* Create the edges of the flowgraph. */
183 cleanup_dead_labels ();
185 /* Debugging dumps. */
187 /* Write the flowgraph to a VCG file. */
189 int local_dump_flags
;
190 FILE *vcg_file
= dump_begin (TDI_vcg
, &local_dump_flags
);
193 tree_cfg2vcg (vcg_file
);
194 dump_end (TDI_vcg
, vcg_file
);
198 #ifdef ENABLE_CHECKING
202 /* Dump a textual representation of the flowgraph. */
204 dump_tree_cfg (dump_file
, dump_flags
);
208 execute_build_cfg (void)
210 build_tree_cfg (&DECL_SAVED_TREE (current_function_decl
));
214 struct tree_opt_pass pass_build_cfg
=
218 execute_build_cfg
, /* execute */
221 0, /* static_pass_number */
222 TV_TREE_CFG
, /* tv_id */
223 PROP_gimple_leh
, /* properties_required */
224 PROP_cfg
, /* properties_provided */
225 0, /* properties_destroyed */
226 0, /* todo_flags_start */
227 TODO_verify_stmts
| TODO_cleanup_cfg
, /* todo_flags_finish */
231 /* Search the CFG for any computed gotos. If found, factor them to a
232 common computed goto site. Also record the location of that site so
233 that we can un-factor the gotos after we have converted back to
237 factor_computed_gotos (void)
240 tree factored_label_decl
= NULL
;
242 tree factored_computed_goto_label
= NULL
;
243 tree factored_computed_goto
= NULL
;
245 /* We know there are one or more computed gotos in this function.
246 Examine the last statement in each basic block to see if the block
247 ends with a computed goto. */
251 block_stmt_iterator bsi
= bsi_last (bb
);
256 last
= bsi_stmt (bsi
);
258 /* Ignore the computed goto we create when we factor the original
260 if (last
== factored_computed_goto
)
263 /* If the last statement is a computed goto, factor it. */
264 if (computed_goto_p (last
))
268 /* The first time we find a computed goto we need to create
269 the factored goto block and the variable each original
270 computed goto will use for their goto destination. */
271 if (! factored_computed_goto
)
273 basic_block new_bb
= create_empty_bb (bb
);
274 block_stmt_iterator new_bsi
= bsi_start (new_bb
);
276 /* Create the destination of the factored goto. Each original
277 computed goto will put its desired destination into this
278 variable and jump to the label we create immediately
280 var
= create_tmp_var (ptr_type_node
, "gotovar");
282 /* Build a label for the new block which will contain the
283 factored computed goto. */
284 factored_label_decl
= create_artificial_label ();
285 factored_computed_goto_label
286 = build1 (LABEL_EXPR
, void_type_node
, factored_label_decl
);
287 bsi_insert_after (&new_bsi
, factored_computed_goto_label
,
290 /* Build our new computed goto. */
291 factored_computed_goto
= build1 (GOTO_EXPR
, void_type_node
, var
);
292 bsi_insert_after (&new_bsi
, factored_computed_goto
,
296 /* Copy the original computed goto's destination into VAR. */
297 assignment
= build_gimple_modify_stmt (var
,
298 GOTO_DESTINATION (last
));
299 bsi_insert_before (&bsi
, assignment
, BSI_SAME_STMT
);
301 /* And re-vector the computed goto to the new destination. */
302 GOTO_DESTINATION (last
) = factored_label_decl
;
308 /* Build a flowgraph for the statement_list STMT_LIST. */
311 make_blocks (tree stmt_list
)
313 tree_stmt_iterator i
= tsi_start (stmt_list
);
315 bool start_new_block
= true;
316 bool first_stmt_of_list
= true;
317 basic_block bb
= ENTRY_BLOCK_PTR
;
319 while (!tsi_end_p (i
))
326 /* If the statement starts a new basic block or if we have determined
327 in a previous pass that we need to create a new block for STMT, do
329 if (start_new_block
|| stmt_starts_bb_p (stmt
, prev_stmt
))
331 if (!first_stmt_of_list
)
332 stmt_list
= tsi_split_statement_list_before (&i
);
333 bb
= create_basic_block (stmt_list
, NULL
, bb
);
334 start_new_block
= false;
337 /* Now add STMT to BB and create the subgraphs for special statement
339 set_bb_for_stmt (stmt
, bb
);
341 if (computed_goto_p (stmt
))
342 found_computed_goto
= true;
344 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
346 if (stmt_ends_bb_p (stmt
))
347 start_new_block
= true;
350 first_stmt_of_list
= false;
355 /* Create and return a new empty basic block after bb AFTER. */
358 create_bb (void *h
, void *e
, basic_block after
)
364 /* Create and initialize a new basic block. Since alloc_block uses
365 ggc_alloc_cleared to allocate a basic block, we do not have to
366 clear the newly allocated basic block here. */
369 bb
->index
= last_basic_block
;
371 bb
->il
.tree
= GGC_CNEW (struct tree_bb_info
);
372 set_bb_stmt_list (bb
, h
? (tree
) h
: alloc_stmt_list ());
374 /* Add the new block to the linked list of blocks. */
375 link_block (bb
, after
);
377 /* Grow the basic block array if needed. */
378 if ((size_t) last_basic_block
== VEC_length (basic_block
, basic_block_info
))
380 size_t new_size
= last_basic_block
+ (last_basic_block
+ 3) / 4;
381 VEC_safe_grow_cleared (basic_block
, gc
, basic_block_info
, new_size
);
384 /* Add the newly created block to the array. */
385 SET_BASIC_BLOCK (last_basic_block
, bb
);
394 /*---------------------------------------------------------------------------
396 ---------------------------------------------------------------------------*/
398 /* Fold COND_EXPR_COND of each COND_EXPR. */
401 fold_cond_expr_cond (void)
407 tree stmt
= last_stmt (bb
);
410 && TREE_CODE (stmt
) == COND_EXPR
)
415 fold_defer_overflow_warnings ();
416 cond
= fold (COND_EXPR_COND (stmt
));
417 zerop
= integer_zerop (cond
);
418 onep
= integer_onep (cond
);
419 fold_undefer_overflow_warnings (((zerop
|| onep
)
420 && !TREE_NO_WARNING (stmt
)),
422 WARN_STRICT_OVERFLOW_CONDITIONAL
);
424 COND_EXPR_COND (stmt
) = boolean_false_node
;
426 COND_EXPR_COND (stmt
) = boolean_true_node
;
431 /* Join all the blocks in the flowgraph. */
437 struct omp_region
*cur_region
= NULL
;
439 /* Create an edge from entry to the first block with executable
441 make_edge (ENTRY_BLOCK_PTR
, BASIC_BLOCK (NUM_FIXED_BLOCKS
), EDGE_FALLTHRU
);
443 /* Traverse the basic block array placing edges. */
446 tree last
= last_stmt (bb
);
451 enum tree_code code
= TREE_CODE (last
);
455 make_goto_expr_edges (bb
);
459 make_edge (bb
, EXIT_BLOCK_PTR
, 0);
463 make_cond_expr_edges (bb
);
467 make_switch_expr_edges (bb
);
471 make_eh_edges (last
);
476 /* If this function receives a nonlocal goto, then we need to
477 make edges from this call site to all the nonlocal goto
479 if (tree_can_make_abnormal_goto (last
))
480 make_abnormal_goto_edges (bb
, true);
482 /* If this statement has reachable exception handlers, then
483 create abnormal edges to them. */
484 make_eh_edges (last
);
486 /* Some calls are known not to return. */
487 fallthru
= !(call_expr_flags (last
) & ECF_NORETURN
);
493 case GIMPLE_MODIFY_STMT
:
494 if (is_ctrl_altering_stmt (last
))
496 /* A GIMPLE_MODIFY_STMT may have a CALL_EXPR on its RHS and
497 the CALL_EXPR may have an abnormal edge. Search the RHS
498 for this case and create any required edges. */
499 if (tree_can_make_abnormal_goto (last
))
500 make_abnormal_goto_edges (bb
, true);
502 make_eh_edges (last
);
514 cur_region
= new_omp_region (bb
, code
, cur_region
);
519 cur_region
= new_omp_region (bb
, code
, cur_region
);
523 case OMP_SECTIONS_SWITCH
:
528 /* In the case of an OMP_SECTION, the edge will go somewhere
529 other than the next block. This will be created later. */
530 cur_region
->exit
= bb
;
531 fallthru
= cur_region
->type
!= OMP_SECTION
;
532 cur_region
= cur_region
->outer
;
536 cur_region
->cont
= bb
;
537 switch (cur_region
->type
)
540 /* Make the loopback edge. */
541 make_edge (bb
, single_succ (cur_region
->entry
), 0);
543 /* Create an edge from OMP_FOR to exit, which corresponds to
544 the case that the body of the loop is not executed at
546 make_edge (cur_region
->entry
, bb
->next_bb
, 0);
551 /* Wire up the edges into and out of the nested sections. */
553 basic_block switch_bb
= single_succ (cur_region
->entry
);
555 struct omp_region
*i
;
556 for (i
= cur_region
->inner
; i
; i
= i
->next
)
558 gcc_assert (i
->type
== OMP_SECTION
);
559 make_edge (switch_bb
, i
->entry
, 0);
560 make_edge (i
->exit
, bb
, EDGE_FALLTHRU
);
563 /* Make the loopback edge to the block with
564 OMP_SECTIONS_SWITCH. */
565 make_edge (bb
, switch_bb
, 0);
567 /* Make the edge from the switch to exit. */
568 make_edge (switch_bb
, bb
->next_bb
, 0);
579 gcc_assert (!stmt_ends_bb_p (last
));
587 make_edge (bb
, bb
->next_bb
, EDGE_FALLTHRU
);
593 /* Fold COND_EXPR_COND of each COND_EXPR. */
594 fold_cond_expr_cond ();
598 /* Create the edges for a COND_EXPR starting at block BB.
599 At this point, both clauses must contain only simple gotos. */
602 make_cond_expr_edges (basic_block bb
)
604 tree entry
= last_stmt (bb
);
605 basic_block then_bb
, else_bb
;
606 tree then_label
, else_label
;
610 gcc_assert (TREE_CODE (entry
) == COND_EXPR
);
612 /* Entry basic blocks for each component. */
613 then_label
= GOTO_DESTINATION (COND_EXPR_THEN (entry
));
614 else_label
= GOTO_DESTINATION (COND_EXPR_ELSE (entry
));
615 then_bb
= label_to_block (then_label
);
616 else_bb
= label_to_block (else_label
);
618 e
= make_edge (bb
, then_bb
, EDGE_TRUE_VALUE
);
619 #ifdef USE_MAPPED_LOCATION
620 e
->goto_locus
= EXPR_LOCATION (COND_EXPR_THEN (entry
));
622 e
->goto_locus
= EXPR_LOCUS (COND_EXPR_THEN (entry
));
624 e
= make_edge (bb
, else_bb
, EDGE_FALSE_VALUE
);
627 #ifdef USE_MAPPED_LOCATION
628 e
->goto_locus
= EXPR_LOCATION (COND_EXPR_ELSE (entry
));
630 e
->goto_locus
= EXPR_LOCUS (COND_EXPR_ELSE (entry
));
634 /* We do not need the gotos anymore. */
635 COND_EXPR_THEN (entry
) = NULL_TREE
;
636 COND_EXPR_ELSE (entry
) = NULL_TREE
;
640 /* Called for each element in the hash table (P) as we delete the
641 edge to cases hash table.
643 Clear all the TREE_CHAINs to prevent problems with copying of
644 SWITCH_EXPRs and structure sharing rules, then free the hash table
648 edge_to_cases_cleanup (const void *key ATTRIBUTE_UNUSED
, void **value
,
649 void *data ATTRIBUTE_UNUSED
)
653 for (t
= (tree
) *value
; t
; t
= next
)
655 next
= TREE_CHAIN (t
);
656 TREE_CHAIN (t
) = NULL
;
663 /* Start recording information mapping edges to case labels. */
666 start_recording_case_labels (void)
668 gcc_assert (edge_to_cases
== NULL
);
669 edge_to_cases
= pointer_map_create ();
672 /* Return nonzero if we are recording information for case labels. */
675 recording_case_labels_p (void)
677 return (edge_to_cases
!= NULL
);
680 /* Stop recording information mapping edges to case labels and
681 remove any information we have recorded. */
683 end_recording_case_labels (void)
685 pointer_map_traverse (edge_to_cases
, edge_to_cases_cleanup
, NULL
);
686 pointer_map_destroy (edge_to_cases
);
687 edge_to_cases
= NULL
;
690 /* If we are inside a {start,end}_recording_cases block, then return
691 a chain of CASE_LABEL_EXPRs from T which reference E.
693 Otherwise return NULL. */
696 get_cases_for_edge (edge e
, tree t
)
702 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
703 chains available. Return NULL so the caller can detect this case. */
704 if (!recording_case_labels_p ())
707 slot
= pointer_map_contains (edge_to_cases
, e
);
711 /* If we did not find E in the hash table, then this must be the first
712 time we have been queried for information about E & T. Add all the
713 elements from T to the hash table then perform the query again. */
715 vec
= SWITCH_LABELS (t
);
716 n
= TREE_VEC_LENGTH (vec
);
717 for (i
= 0; i
< n
; i
++)
719 tree elt
= TREE_VEC_ELT (vec
, i
);
720 tree lab
= CASE_LABEL (elt
);
721 basic_block label_bb
= label_to_block (lab
);
722 edge this_edge
= find_edge (e
->src
, label_bb
);
724 /* Add it to the chain of CASE_LABEL_EXPRs referencing E, or create
726 slot
= pointer_map_insert (edge_to_cases
, this_edge
);
727 TREE_CHAIN (elt
) = (tree
) *slot
;
731 return (tree
) *pointer_map_contains (edge_to_cases
, e
);
734 /* Create the edges for a SWITCH_EXPR starting at block BB.
735 At this point, the switch body has been lowered and the
736 SWITCH_LABELS filled in, so this is in effect a multi-way branch. */
739 make_switch_expr_edges (basic_block bb
)
741 tree entry
= last_stmt (bb
);
745 vec
= SWITCH_LABELS (entry
);
746 n
= TREE_VEC_LENGTH (vec
);
748 for (i
= 0; i
< n
; ++i
)
750 tree lab
= CASE_LABEL (TREE_VEC_ELT (vec
, i
));
751 basic_block label_bb
= label_to_block (lab
);
752 make_edge (bb
, label_bb
, 0);
757 /* Return the basic block holding label DEST. */
760 label_to_block_fn (struct function
*ifun
, tree dest
)
762 int uid
= LABEL_DECL_UID (dest
);
764 /* We would die hard when faced by an undefined label. Emit a label to
765 the very first basic block. This will hopefully make even the dataflow
766 and undefined variable warnings quite right. */
767 if ((errorcount
|| sorrycount
) && uid
< 0)
769 block_stmt_iterator bsi
=
770 bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS
));
773 stmt
= build1 (LABEL_EXPR
, void_type_node
, dest
);
774 bsi_insert_before (&bsi
, stmt
, BSI_NEW_STMT
);
775 uid
= LABEL_DECL_UID (dest
);
777 if (VEC_length (basic_block
, ifun
->cfg
->x_label_to_block_map
)
778 <= (unsigned int) uid
)
780 return VEC_index (basic_block
, ifun
->cfg
->x_label_to_block_map
, uid
);
783 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
784 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
787 make_abnormal_goto_edges (basic_block bb
, bool for_call
)
789 basic_block target_bb
;
790 block_stmt_iterator bsi
;
792 FOR_EACH_BB (target_bb
)
793 for (bsi
= bsi_start (target_bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
795 tree target
= bsi_stmt (bsi
);
797 if (TREE_CODE (target
) != LABEL_EXPR
)
800 target
= LABEL_EXPR_LABEL (target
);
802 /* Make an edge to every label block that has been marked as a
803 potential target for a computed goto or a non-local goto. */
804 if ((FORCED_LABEL (target
) && !for_call
)
805 || (DECL_NONLOCAL (target
) && for_call
))
807 make_edge (bb
, target_bb
, EDGE_ABNORMAL
);
813 /* Create edges for a goto statement at block BB. */
816 make_goto_expr_edges (basic_block bb
)
818 block_stmt_iterator last
= bsi_last (bb
);
819 tree goto_t
= bsi_stmt (last
);
821 /* A simple GOTO creates normal edges. */
822 if (simple_goto_p (goto_t
))
824 tree dest
= GOTO_DESTINATION (goto_t
);
825 edge e
= make_edge (bb
, label_to_block (dest
), EDGE_FALLTHRU
);
826 #ifdef USE_MAPPED_LOCATION
827 e
->goto_locus
= EXPR_LOCATION (goto_t
);
829 e
->goto_locus
= EXPR_LOCUS (goto_t
);
831 bsi_remove (&last
, true);
835 /* A computed GOTO creates abnormal edges. */
836 make_abnormal_goto_edges (bb
, false);
840 /*---------------------------------------------------------------------------
842 ---------------------------------------------------------------------------*/
844 /* Cleanup useless labels in basic blocks. This is something we wish
845 to do early because it allows us to group case labels before creating
846 the edges for the CFG, and it speeds up block statement iterators in
848 We rerun this pass after CFG is created, to get rid of the labels that
849 are no longer referenced. After then we do not run it any more, since
850 (almost) no new labels should be created. */
852 /* A map from basic block index to the leading label of that block. */
853 static struct label_record
858 /* True if the label is referenced from somewhere. */
862 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
864 update_eh_label (struct eh_region
*region
)
866 tree old_label
= get_eh_region_tree_label (region
);
870 basic_block bb
= label_to_block (old_label
);
872 /* ??? After optimizing, there may be EH regions with labels
873 that have already been removed from the function body, so
874 there is no basic block for them. */
878 new_label
= label_for_bb
[bb
->index
].label
;
879 label_for_bb
[bb
->index
].used
= true;
880 set_eh_region_tree_label (region
, new_label
);
884 /* Given LABEL return the first label in the same basic block. */
886 main_block_label (tree label
)
888 basic_block bb
= label_to_block (label
);
889 tree main_label
= label_for_bb
[bb
->index
].label
;
891 /* label_to_block possibly inserted undefined label into the chain. */
894 label_for_bb
[bb
->index
].label
= label
;
898 label_for_bb
[bb
->index
].used
= true;
902 /* Cleanup redundant labels. This is a three-step process:
903 1) Find the leading label for each block.
904 2) Redirect all references to labels to the leading labels.
905 3) Cleanup all useless labels. */
908 cleanup_dead_labels (void)
911 label_for_bb
= XCNEWVEC (struct label_record
, last_basic_block
);
913 /* Find a suitable label for each block. We use the first user-defined
914 label if there is one, or otherwise just the first label we see. */
917 block_stmt_iterator i
;
919 for (i
= bsi_start (bb
); !bsi_end_p (i
); bsi_next (&i
))
921 tree label
, stmt
= bsi_stmt (i
);
923 if (TREE_CODE (stmt
) != LABEL_EXPR
)
926 label
= LABEL_EXPR_LABEL (stmt
);
928 /* If we have not yet seen a label for the current block,
929 remember this one and see if there are more labels. */
930 if (!label_for_bb
[bb
->index
].label
)
932 label_for_bb
[bb
->index
].label
= label
;
936 /* If we did see a label for the current block already, but it
937 is an artificially created label, replace it if the current
938 label is a user defined label. */
939 if (!DECL_ARTIFICIAL (label
)
940 && DECL_ARTIFICIAL (label_for_bb
[bb
->index
].label
))
942 label_for_bb
[bb
->index
].label
= label
;
948 /* Now redirect all jumps/branches to the selected label.
949 First do so for each block ending in a control statement. */
952 tree stmt
= last_stmt (bb
);
956 switch (TREE_CODE (stmt
))
960 tree true_branch
, false_branch
;
962 true_branch
= COND_EXPR_THEN (stmt
);
963 false_branch
= COND_EXPR_ELSE (stmt
);
966 GOTO_DESTINATION (true_branch
)
967 = main_block_label (GOTO_DESTINATION (true_branch
));
969 GOTO_DESTINATION (false_branch
)
970 = main_block_label (GOTO_DESTINATION (false_branch
));
978 tree vec
= SWITCH_LABELS (stmt
);
979 size_t n
= TREE_VEC_LENGTH (vec
);
981 /* Replace all destination labels. */
982 for (i
= 0; i
< n
; ++i
)
984 tree elt
= TREE_VEC_ELT (vec
, i
);
985 tree label
= main_block_label (CASE_LABEL (elt
));
986 CASE_LABEL (elt
) = label
;
991 /* We have to handle GOTO_EXPRs until they're removed, and we don't
992 remove them until after we've created the CFG edges. */
994 if (! computed_goto_p (stmt
))
996 GOTO_DESTINATION (stmt
)
997 = main_block_label (GOTO_DESTINATION (stmt
));
1006 for_each_eh_region (update_eh_label
);
1008 /* Finally, purge dead labels. All user-defined labels and labels that
1009 can be the target of non-local gotos and labels which have their
1010 address taken are preserved. */
1013 block_stmt_iterator i
;
1014 tree label_for_this_bb
= label_for_bb
[bb
->index
].label
;
1016 if (!label_for_this_bb
)
1019 /* If the main label of the block is unused, we may still remove it. */
1020 if (!label_for_bb
[bb
->index
].used
)
1021 label_for_this_bb
= NULL
;
1023 for (i
= bsi_start (bb
); !bsi_end_p (i
); )
1025 tree label
, stmt
= bsi_stmt (i
);
1027 if (TREE_CODE (stmt
) != LABEL_EXPR
)
1030 label
= LABEL_EXPR_LABEL (stmt
);
1032 if (label
== label_for_this_bb
1033 || ! DECL_ARTIFICIAL (label
)
1034 || DECL_NONLOCAL (label
)
1035 || FORCED_LABEL (label
))
1038 bsi_remove (&i
, true);
1042 free (label_for_bb
);
1045 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1046 and scan the sorted vector of cases. Combine the ones jumping to the
1048 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1051 group_case_labels (void)
1057 tree stmt
= last_stmt (bb
);
1058 if (stmt
&& TREE_CODE (stmt
) == SWITCH_EXPR
)
1060 tree labels
= SWITCH_LABELS (stmt
);
1061 int old_size
= TREE_VEC_LENGTH (labels
);
1062 int i
, j
, new_size
= old_size
;
1063 tree default_case
= TREE_VEC_ELT (labels
, old_size
- 1);
1066 /* The default label is always the last case in a switch
1067 statement after gimplification. */
1068 default_label
= CASE_LABEL (default_case
);
1070 /* Look for possible opportunities to merge cases.
1071 Ignore the last element of the label vector because it
1072 must be the default case. */
1074 while (i
< old_size
- 1)
1076 tree base_case
, base_label
, base_high
;
1077 base_case
= TREE_VEC_ELT (labels
, i
);
1079 gcc_assert (base_case
);
1080 base_label
= CASE_LABEL (base_case
);
1082 /* Discard cases that have the same destination as the
1084 if (base_label
== default_label
)
1086 TREE_VEC_ELT (labels
, i
) = NULL_TREE
;
1092 base_high
= CASE_HIGH (base_case
) ?
1093 CASE_HIGH (base_case
) : CASE_LOW (base_case
);
1095 /* Try to merge case labels. Break out when we reach the end
1096 of the label vector or when we cannot merge the next case
1097 label with the current one. */
1098 while (i
< old_size
- 1)
1100 tree merge_case
= TREE_VEC_ELT (labels
, i
);
1101 tree merge_label
= CASE_LABEL (merge_case
);
1102 tree t
= int_const_binop (PLUS_EXPR
, base_high
,
1103 integer_one_node
, 1);
1105 /* Merge the cases if they jump to the same place,
1106 and their ranges are consecutive. */
1107 if (merge_label
== base_label
1108 && tree_int_cst_equal (CASE_LOW (merge_case
), t
))
1110 base_high
= CASE_HIGH (merge_case
) ?
1111 CASE_HIGH (merge_case
) : CASE_LOW (merge_case
);
1112 CASE_HIGH (base_case
) = base_high
;
1113 TREE_VEC_ELT (labels
, i
) = NULL_TREE
;
1122 /* Compress the case labels in the label vector, and adjust the
1123 length of the vector. */
1124 for (i
= 0, j
= 0; i
< new_size
; i
++)
1126 while (! TREE_VEC_ELT (labels
, j
))
1128 TREE_VEC_ELT (labels
, i
) = TREE_VEC_ELT (labels
, j
++);
1130 TREE_VEC_LENGTH (labels
) = new_size
;
1135 /* Checks whether we can merge block B into block A. */
1138 tree_can_merge_blocks_p (const_basic_block a
, const_basic_block b
)
1141 const_block_stmt_iterator bsi
;
1144 if (!single_succ_p (a
))
1147 if (single_succ_edge (a
)->flags
& EDGE_ABNORMAL
)
1150 if (single_succ (a
) != b
)
1153 if (!single_pred_p (b
))
1156 if (b
== EXIT_BLOCK_PTR
)
1159 /* If A ends by a statement causing exceptions or something similar, we
1160 cannot merge the blocks. */
1161 /* This CONST_CAST is okay because last_stmt doesn't modify its
1162 argument and the return value is assign to a const_tree. */
1163 stmt
= last_stmt (CONST_CAST_BB(a
));
1164 if (stmt
&& stmt_ends_bb_p (stmt
))
1167 /* Do not allow a block with only a non-local label to be merged. */
1168 if (stmt
&& TREE_CODE (stmt
) == LABEL_EXPR
1169 && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
)))
1172 /* It must be possible to eliminate all phi nodes in B. If ssa form
1173 is not up-to-date, we cannot eliminate any phis; however, if only
1174 some symbols as whole are marked for renaming, this is not a problem,
1175 as phi nodes for those symbols are irrelevant in updating anyway. */
1176 phi
= phi_nodes (b
);
1179 if (name_mappings_registered_p ())
1182 for (; phi
; phi
= PHI_CHAIN (phi
))
1183 if (!is_gimple_reg (PHI_RESULT (phi
))
1184 && !may_propagate_copy (PHI_RESULT (phi
), PHI_ARG_DEF (phi
, 0)))
1188 /* Do not remove user labels. */
1189 for (bsi
= cbsi_start (b
); !cbsi_end_p (bsi
); cbsi_next (&bsi
))
1191 stmt
= cbsi_stmt (bsi
);
1192 if (TREE_CODE (stmt
) != LABEL_EXPR
)
1194 if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt
)))
1198 /* Protect the loop latches. */
1200 && b
->loop_father
->latch
== b
)
1206 /* Replaces all uses of NAME by VAL. */
1209 replace_uses_by (tree name
, tree val
)
1211 imm_use_iterator imm_iter
;
1216 FOR_EACH_IMM_USE_STMT (stmt
, imm_iter
, name
)
1218 if (TREE_CODE (stmt
) != PHI_NODE
)
1219 push_stmt_changes (&stmt
);
1221 FOR_EACH_IMM_USE_ON_STMT (use
, imm_iter
)
1223 replace_exp (use
, val
);
1225 if (TREE_CODE (stmt
) == PHI_NODE
)
1227 e
= PHI_ARG_EDGE (stmt
, PHI_ARG_INDEX_FROM_USE (use
));
1228 if (e
->flags
& EDGE_ABNORMAL
)
1230 /* This can only occur for virtual operands, since
1231 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1232 would prevent replacement. */
1233 gcc_assert (!is_gimple_reg (name
));
1234 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val
) = 1;
1239 if (TREE_CODE (stmt
) != PHI_NODE
)
1243 fold_stmt_inplace (stmt
);
1244 if (cfgcleanup_altered_bbs
)
1245 bitmap_set_bit (cfgcleanup_altered_bbs
, bb_for_stmt (stmt
)->index
);
1247 /* FIXME. This should go in pop_stmt_changes. */
1248 rhs
= get_rhs (stmt
);
1249 if (TREE_CODE (rhs
) == ADDR_EXPR
)
1250 recompute_tree_invariant_for_addr_expr (rhs
);
1252 maybe_clean_or_replace_eh_stmt (stmt
, stmt
);
1254 pop_stmt_changes (&stmt
);
1258 gcc_assert (has_zero_uses (name
));
1260 /* Also update the trees stored in loop structures. */
1266 FOR_EACH_LOOP (li
, loop
, 0)
1268 substitute_in_loop_info (loop
, name
, val
);
1273 /* Merge block B into block A. */
1276 tree_merge_blocks (basic_block a
, basic_block b
)
1278 block_stmt_iterator bsi
;
1279 tree_stmt_iterator last
;
1283 fprintf (dump_file
, "Merging blocks %d and %d\n", a
->index
, b
->index
);
1285 /* Remove all single-valued PHI nodes from block B of the form
1286 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1288 for (phi
= phi_nodes (b
); phi
; phi
= phi_nodes (b
))
1290 tree def
= PHI_RESULT (phi
), use
= PHI_ARG_DEF (phi
, 0);
1292 bool may_replace_uses
= may_propagate_copy (def
, use
);
1294 /* In case we maintain loop closed ssa form, do not propagate arguments
1295 of loop exit phi nodes. */
1297 && loops_state_satisfies_p (LOOP_CLOSED_SSA
)
1298 && is_gimple_reg (def
)
1299 && TREE_CODE (use
) == SSA_NAME
1300 && a
->loop_father
!= b
->loop_father
)
1301 may_replace_uses
= false;
1303 if (!may_replace_uses
)
1305 gcc_assert (is_gimple_reg (def
));
1307 /* Note that just emitting the copies is fine -- there is no problem
1308 with ordering of phi nodes. This is because A is the single
1309 predecessor of B, therefore results of the phi nodes cannot
1310 appear as arguments of the phi nodes. */
1311 copy
= build_gimple_modify_stmt (def
, use
);
1312 bsi_insert_after (&bsi
, copy
, BSI_NEW_STMT
);
1313 SSA_NAME_DEF_STMT (def
) = copy
;
1314 remove_phi_node (phi
, NULL
, false);
1318 replace_uses_by (def
, use
);
1319 remove_phi_node (phi
, NULL
, true);
1323 /* Ensure that B follows A. */
1324 move_block_after (b
, a
);
1326 gcc_assert (single_succ_edge (a
)->flags
& EDGE_FALLTHRU
);
1327 gcc_assert (!last_stmt (a
) || !stmt_ends_bb_p (last_stmt (a
)));
1329 /* Remove labels from B and set bb_for_stmt to A for other statements. */
1330 for (bsi
= bsi_start (b
); !bsi_end_p (bsi
);)
1332 if (TREE_CODE (bsi_stmt (bsi
)) == LABEL_EXPR
)
1334 tree label
= bsi_stmt (bsi
);
1336 bsi_remove (&bsi
, false);
1337 /* Now that we can thread computed gotos, we might have
1338 a situation where we have a forced label in block B
1339 However, the label at the start of block B might still be
1340 used in other ways (think about the runtime checking for
1341 Fortran assigned gotos). So we can not just delete the
1342 label. Instead we move the label to the start of block A. */
1343 if (FORCED_LABEL (LABEL_EXPR_LABEL (label
)))
1345 block_stmt_iterator dest_bsi
= bsi_start (a
);
1346 bsi_insert_before (&dest_bsi
, label
, BSI_NEW_STMT
);
1351 change_bb_for_stmt (bsi_stmt (bsi
), a
);
1356 /* Merge the chains. */
1357 last
= tsi_last (bb_stmt_list (a
));
1358 tsi_link_after (&last
, bb_stmt_list (b
), TSI_NEW_STMT
);
1359 set_bb_stmt_list (b
, NULL_TREE
);
1361 if (cfgcleanup_altered_bbs
)
1362 bitmap_set_bit (cfgcleanup_altered_bbs
, a
->index
);
1366 /* Return the one of two successors of BB that is not reachable by a
1367 reached by a complex edge, if there is one. Else, return BB. We use
1368 this in optimizations that use post-dominators for their heuristics,
1369 to catch the cases in C++ where function calls are involved. */
1372 single_noncomplex_succ (basic_block bb
)
1375 if (EDGE_COUNT (bb
->succs
) != 2)
1378 e0
= EDGE_SUCC (bb
, 0);
1379 e1
= EDGE_SUCC (bb
, 1);
1380 if (e0
->flags
& EDGE_COMPLEX
)
1382 if (e1
->flags
& EDGE_COMPLEX
)
1389 /* Walk the function tree removing unnecessary statements.
1391 * Empty statement nodes are removed
1393 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1395 * Unnecessary COND_EXPRs are removed
1397 * Some unnecessary BIND_EXPRs are removed
1399 Clearly more work could be done. The trick is doing the analysis
1400 and removal fast enough to be a net improvement in compile times.
1402 Note that when we remove a control structure such as a COND_EXPR
1403 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1404 to ensure we eliminate all the useless code. */
1415 static void remove_useless_stmts_1 (tree
*, struct rus_data
*);
1418 remove_useless_stmts_warn_notreached (tree stmt
)
1420 if (EXPR_HAS_LOCATION (stmt
))
1422 location_t loc
= EXPR_LOCATION (stmt
);
1423 if (LOCATION_LINE (loc
) > 0)
1425 warning (0, "%Hwill never be executed", &loc
);
1430 switch (TREE_CODE (stmt
))
1432 case STATEMENT_LIST
:
1434 tree_stmt_iterator i
;
1435 for (i
= tsi_start (stmt
); !tsi_end_p (i
); tsi_next (&i
))
1436 if (remove_useless_stmts_warn_notreached (tsi_stmt (i
)))
1442 if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt
)))
1444 if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt
)))
1446 if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt
)))
1450 case TRY_FINALLY_EXPR
:
1451 case TRY_CATCH_EXPR
:
1452 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt
, 0)))
1454 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt
, 1)))
1459 return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt
));
1460 case EH_FILTER_EXPR
:
1461 return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt
));
1463 return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt
));
1466 /* Not a live container. */
1474 remove_useless_stmts_cond (tree
*stmt_p
, struct rus_data
*data
)
1476 tree then_clause
, else_clause
, cond
;
1477 bool save_has_label
, then_has_label
, else_has_label
;
1479 save_has_label
= data
->has_label
;
1480 data
->has_label
= false;
1481 data
->last_goto
= NULL
;
1483 remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p
), data
);
1485 then_has_label
= data
->has_label
;
1486 data
->has_label
= false;
1487 data
->last_goto
= NULL
;
1489 remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p
), data
);
1491 else_has_label
= data
->has_label
;
1492 data
->has_label
= save_has_label
| then_has_label
| else_has_label
;
1494 then_clause
= COND_EXPR_THEN (*stmt_p
);
1495 else_clause
= COND_EXPR_ELSE (*stmt_p
);
1496 cond
= fold (COND_EXPR_COND (*stmt_p
));
1498 /* If neither arm does anything at all, we can remove the whole IF. */
1499 if (!TREE_SIDE_EFFECTS (then_clause
) && !TREE_SIDE_EFFECTS (else_clause
))
1501 *stmt_p
= build_empty_stmt ();
1502 data
->repeat
= true;
1505 /* If there are no reachable statements in an arm, then we can
1506 zap the entire conditional. */
1507 else if (integer_nonzerop (cond
) && !else_has_label
)
1509 if (warn_notreached
)
1510 remove_useless_stmts_warn_notreached (else_clause
);
1511 *stmt_p
= then_clause
;
1512 data
->repeat
= true;
1514 else if (integer_zerop (cond
) && !then_has_label
)
1516 if (warn_notreached
)
1517 remove_useless_stmts_warn_notreached (then_clause
);
1518 *stmt_p
= else_clause
;
1519 data
->repeat
= true;
1522 /* Check a couple of simple things on then/else with single stmts. */
1525 tree then_stmt
= expr_only (then_clause
);
1526 tree else_stmt
= expr_only (else_clause
);
1528 /* Notice branches to a common destination. */
1529 if (then_stmt
&& else_stmt
1530 && TREE_CODE (then_stmt
) == GOTO_EXPR
1531 && TREE_CODE (else_stmt
) == GOTO_EXPR
1532 && (GOTO_DESTINATION (then_stmt
) == GOTO_DESTINATION (else_stmt
)))
1534 *stmt_p
= then_stmt
;
1535 data
->repeat
= true;
1538 /* If the THEN/ELSE clause merely assigns a value to a variable or
1539 parameter which is already known to contain that value, then
1540 remove the useless THEN/ELSE clause. */
1541 else if (TREE_CODE (cond
) == VAR_DECL
|| TREE_CODE (cond
) == PARM_DECL
)
1544 && TREE_CODE (else_stmt
) == GIMPLE_MODIFY_STMT
1545 && GIMPLE_STMT_OPERAND (else_stmt
, 0) == cond
1546 && integer_zerop (GIMPLE_STMT_OPERAND (else_stmt
, 1)))
1547 COND_EXPR_ELSE (*stmt_p
) = alloc_stmt_list ();
1549 else if ((TREE_CODE (cond
) == EQ_EXPR
|| TREE_CODE (cond
) == NE_EXPR
)
1550 && (TREE_CODE (TREE_OPERAND (cond
, 0)) == VAR_DECL
1551 || TREE_CODE (TREE_OPERAND (cond
, 0)) == PARM_DECL
)
1552 && TREE_CONSTANT (TREE_OPERAND (cond
, 1)))
1554 tree stmt
= (TREE_CODE (cond
) == EQ_EXPR
1555 ? then_stmt
: else_stmt
);
1556 tree
*location
= (TREE_CODE (cond
) == EQ_EXPR
1557 ? &COND_EXPR_THEN (*stmt_p
)
1558 : &COND_EXPR_ELSE (*stmt_p
));
1561 && TREE_CODE (stmt
) == GIMPLE_MODIFY_STMT
1562 && GIMPLE_STMT_OPERAND (stmt
, 0) == TREE_OPERAND (cond
, 0)
1563 && GIMPLE_STMT_OPERAND (stmt
, 1) == TREE_OPERAND (cond
, 1))
1564 *location
= alloc_stmt_list ();
1568 /* Protect GOTOs in the arm of COND_EXPRs from being removed. They
1569 would be re-introduced during lowering. */
1570 data
->last_goto
= NULL
;
1575 remove_useless_stmts_tf (tree
*stmt_p
, struct rus_data
*data
)
1577 bool save_may_branch
, save_may_throw
;
1578 bool this_may_branch
, this_may_throw
;
1580 /* Collect may_branch and may_throw information for the body only. */
1581 save_may_branch
= data
->may_branch
;
1582 save_may_throw
= data
->may_throw
;
1583 data
->may_branch
= false;
1584 data
->may_throw
= false;
1585 data
->last_goto
= NULL
;
1587 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p
, 0), data
);
1589 this_may_branch
= data
->may_branch
;
1590 this_may_throw
= data
->may_throw
;
1591 data
->may_branch
|= save_may_branch
;
1592 data
->may_throw
|= save_may_throw
;
1593 data
->last_goto
= NULL
;
1595 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p
, 1), data
);
1597 /* If the body is empty, then we can emit the FINALLY block without
1598 the enclosing TRY_FINALLY_EXPR. */
1599 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p
, 0)))
1601 *stmt_p
= TREE_OPERAND (*stmt_p
, 1);
1602 data
->repeat
= true;
1605 /* If the handler is empty, then we can emit the TRY block without
1606 the enclosing TRY_FINALLY_EXPR. */
1607 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p
, 1)))
1609 *stmt_p
= TREE_OPERAND (*stmt_p
, 0);
1610 data
->repeat
= true;
1613 /* If the body neither throws, nor branches, then we can safely
1614 string the TRY and FINALLY blocks together. */
1615 else if (!this_may_branch
&& !this_may_throw
)
1617 tree stmt
= *stmt_p
;
1618 *stmt_p
= TREE_OPERAND (stmt
, 0);
1619 append_to_statement_list (TREE_OPERAND (stmt
, 1), stmt_p
);
1620 data
->repeat
= true;
1626 remove_useless_stmts_tc (tree
*stmt_p
, struct rus_data
*data
)
1628 bool save_may_throw
, this_may_throw
;
1629 tree_stmt_iterator i
;
1632 /* Collect may_throw information for the body only. */
1633 save_may_throw
= data
->may_throw
;
1634 data
->may_throw
= false;
1635 data
->last_goto
= NULL
;
1637 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p
, 0), data
);
1639 this_may_throw
= data
->may_throw
;
1640 data
->may_throw
= save_may_throw
;
1642 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1643 if (!this_may_throw
)
1645 if (warn_notreached
)
1646 remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p
, 1));
1647 *stmt_p
= TREE_OPERAND (*stmt_p
, 0);
1648 data
->repeat
= true;
1652 /* Process the catch clause specially. We may be able to tell that
1653 no exceptions propagate past this point. */
1655 this_may_throw
= true;
1656 i
= tsi_start (TREE_OPERAND (*stmt_p
, 1));
1657 stmt
= tsi_stmt (i
);
1658 data
->last_goto
= NULL
;
1660 switch (TREE_CODE (stmt
))
1663 for (; !tsi_end_p (i
); tsi_next (&i
))
1665 stmt
= tsi_stmt (i
);
1666 /* If we catch all exceptions, then the body does not
1667 propagate exceptions past this point. */
1668 if (CATCH_TYPES (stmt
) == NULL
)
1669 this_may_throw
= false;
1670 data
->last_goto
= NULL
;
1671 remove_useless_stmts_1 (&CATCH_BODY (stmt
), data
);
1675 case EH_FILTER_EXPR
:
1676 if (EH_FILTER_MUST_NOT_THROW (stmt
))
1677 this_may_throw
= false;
1678 else if (EH_FILTER_TYPES (stmt
) == NULL
)
1679 this_may_throw
= false;
1680 remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt
), data
);
1684 /* Otherwise this is a cleanup. */
1685 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p
, 1), data
);
1687 /* If the cleanup is empty, then we can emit the TRY block without
1688 the enclosing TRY_CATCH_EXPR. */
1689 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p
, 1)))
1691 *stmt_p
= TREE_OPERAND (*stmt_p
, 0);
1692 data
->repeat
= true;
1696 data
->may_throw
|= this_may_throw
;
1701 remove_useless_stmts_bind (tree
*stmt_p
, struct rus_data
*data
)
1705 /* First remove anything underneath the BIND_EXPR. */
1706 remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p
), data
);
1708 /* If the BIND_EXPR has no variables, then we can pull everything
1709 up one level and remove the BIND_EXPR, unless this is the toplevel
1710 BIND_EXPR for the current function or an inlined function.
1712 When this situation occurs we will want to apply this
1713 optimization again. */
1714 block
= BIND_EXPR_BLOCK (*stmt_p
);
1715 if (BIND_EXPR_VARS (*stmt_p
) == NULL_TREE
1716 && *stmt_p
!= DECL_SAVED_TREE (current_function_decl
)
1718 || ! BLOCK_ABSTRACT_ORIGIN (block
)
1719 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block
))
1722 *stmt_p
= BIND_EXPR_BODY (*stmt_p
);
1723 data
->repeat
= true;
1729 remove_useless_stmts_goto (tree
*stmt_p
, struct rus_data
*data
)
1731 tree dest
= GOTO_DESTINATION (*stmt_p
);
1733 data
->may_branch
= true;
1734 data
->last_goto
= NULL
;
1736 /* Record the last goto expr, so that we can delete it if unnecessary. */
1737 if (TREE_CODE (dest
) == LABEL_DECL
)
1738 data
->last_goto
= stmt_p
;
1743 remove_useless_stmts_label (tree
*stmt_p
, struct rus_data
*data
)
1745 tree label
= LABEL_EXPR_LABEL (*stmt_p
);
1747 data
->has_label
= true;
1749 /* We do want to jump across non-local label receiver code. */
1750 if (DECL_NONLOCAL (label
))
1751 data
->last_goto
= NULL
;
1753 else if (data
->last_goto
&& GOTO_DESTINATION (*data
->last_goto
) == label
)
1755 *data
->last_goto
= build_empty_stmt ();
1756 data
->repeat
= true;
1759 /* ??? Add something here to delete unused labels. */
1763 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1764 decl. This allows us to eliminate redundant or useless
1765 calls to "const" functions.
1767 Gimplifier already does the same operation, but we may notice functions
1768 being const and pure once their calls has been gimplified, so we need
1769 to update the flag. */
1772 update_call_expr_flags (tree call
)
1774 tree decl
= get_callee_fndecl (call
);
1777 if (call_expr_flags (call
) & (ECF_CONST
| ECF_PURE
))
1778 TREE_SIDE_EFFECTS (call
) = 0;
1779 if (TREE_NOTHROW (decl
))
1780 TREE_NOTHROW (call
) = 1;
1784 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1787 notice_special_calls (tree t
)
1789 int flags
= call_expr_flags (t
);
1791 if (flags
& ECF_MAY_BE_ALLOCA
)
1792 current_function_calls_alloca
= true;
1793 if (flags
& ECF_RETURNS_TWICE
)
1794 current_function_calls_setjmp
= true;
1798 /* Clear flags set by notice_special_calls. Used by dead code removal
1799 to update the flags. */
1802 clear_special_calls (void)
1804 current_function_calls_alloca
= false;
1805 current_function_calls_setjmp
= false;
1810 remove_useless_stmts_1 (tree
*tp
, struct rus_data
*data
)
1814 switch (TREE_CODE (t
))
1817 remove_useless_stmts_cond (tp
, data
);
1820 case TRY_FINALLY_EXPR
:
1821 remove_useless_stmts_tf (tp
, data
);
1824 case TRY_CATCH_EXPR
:
1825 remove_useless_stmts_tc (tp
, data
);
1829 remove_useless_stmts_bind (tp
, data
);
1833 remove_useless_stmts_goto (tp
, data
);
1837 remove_useless_stmts_label (tp
, data
);
1842 data
->last_goto
= NULL
;
1843 data
->may_branch
= true;
1848 data
->last_goto
= NULL
;
1849 notice_special_calls (t
);
1850 update_call_expr_flags (t
);
1851 if (tree_could_throw_p (t
))
1852 data
->may_throw
= true;
1858 case GIMPLE_MODIFY_STMT
:
1859 data
->last_goto
= NULL
;
1861 op
= get_call_expr_in (t
);
1864 update_call_expr_flags (op
);
1865 notice_special_calls (op
);
1867 if (tree_could_throw_p (t
))
1868 data
->may_throw
= true;
1871 case STATEMENT_LIST
:
1873 tree_stmt_iterator i
= tsi_start (t
);
1874 while (!tsi_end_p (i
))
1877 if (IS_EMPTY_STMT (t
))
1883 remove_useless_stmts_1 (tsi_stmt_ptr (i
), data
);
1886 if (TREE_CODE (t
) == STATEMENT_LIST
)
1888 tsi_link_before (&i
, t
, TSI_SAME_STMT
);
1898 data
->last_goto
= NULL
;
1902 data
->last_goto
= NULL
;
1908 remove_useless_stmts (void)
1910 struct rus_data data
;
1912 clear_special_calls ();
1916 memset (&data
, 0, sizeof (data
));
1917 remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl
), &data
);
1919 while (data
.repeat
);
1924 struct tree_opt_pass pass_remove_useless_stmts
=
1926 "useless", /* name */
1928 remove_useless_stmts
, /* execute */
1931 0, /* static_pass_number */
1933 PROP_gimple_any
, /* properties_required */
1934 0, /* properties_provided */
1935 0, /* properties_destroyed */
1936 0, /* todo_flags_start */
1937 TODO_dump_func
, /* todo_flags_finish */
1941 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
1944 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb
)
1948 /* Since this block is no longer reachable, we can just delete all
1949 of its PHI nodes. */
1950 phi
= phi_nodes (bb
);
1953 tree next
= PHI_CHAIN (phi
);
1954 remove_phi_node (phi
, NULL_TREE
, true);
1958 /* Remove edges to BB's successors. */
1959 while (EDGE_COUNT (bb
->succs
) > 0)
1960 remove_edge (EDGE_SUCC (bb
, 0));
1964 /* Remove statements of basic block BB. */
1967 remove_bb (basic_block bb
)
1969 block_stmt_iterator i
;
1970 #ifdef USE_MAPPED_LOCATION
1971 source_location loc
= UNKNOWN_LOCATION
;
1973 source_locus loc
= 0;
1978 fprintf (dump_file
, "Removing basic block %d\n", bb
->index
);
1979 if (dump_flags
& TDF_DETAILS
)
1981 dump_bb (bb
, dump_file
, 0);
1982 fprintf (dump_file
, "\n");
1988 struct loop
*loop
= bb
->loop_father
;
1990 /* If a loop gets removed, clean up the information associated
1992 if (loop
->latch
== bb
1993 || loop
->header
== bb
)
1994 free_numbers_of_iterations_estimates_loop (loop
);
1997 /* Remove all the instructions in the block. */
1998 if (bb_stmt_list (bb
) != NULL_TREE
)
2000 for (i
= bsi_start (bb
); !bsi_end_p (i
);)
2002 tree stmt
= bsi_stmt (i
);
2003 if (TREE_CODE (stmt
) == LABEL_EXPR
2004 && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt
))
2005 || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
))))
2008 block_stmt_iterator new_bsi
;
2010 /* A non-reachable non-local label may still be referenced.
2011 But it no longer needs to carry the extra semantics of
2013 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
)))
2015 DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
)) = 0;
2016 FORCED_LABEL (LABEL_EXPR_LABEL (stmt
)) = 1;
2019 new_bb
= bb
->prev_bb
;
2020 new_bsi
= bsi_start (new_bb
);
2021 bsi_remove (&i
, false);
2022 bsi_insert_before (&new_bsi
, stmt
, BSI_NEW_STMT
);
2026 /* Release SSA definitions if we are in SSA. Note that we
2027 may be called when not in SSA. For example,
2028 final_cleanup calls this function via
2029 cleanup_tree_cfg. */
2030 if (gimple_in_ssa_p (cfun
))
2031 release_defs (stmt
);
2033 bsi_remove (&i
, true);
2036 /* Don't warn for removed gotos. Gotos are often removed due to
2037 jump threading, thus resulting in bogus warnings. Not great,
2038 since this way we lose warnings for gotos in the original
2039 program that are indeed unreachable. */
2040 if (TREE_CODE (stmt
) != GOTO_EXPR
&& EXPR_HAS_LOCATION (stmt
) && !loc
)
2042 #ifdef USE_MAPPED_LOCATION
2043 if (EXPR_HAS_LOCATION (stmt
))
2044 loc
= EXPR_LOCATION (stmt
);
2047 t
= EXPR_LOCUS (stmt
);
2048 if (t
&& LOCATION_LINE (*t
) > 0)
2055 /* If requested, give a warning that the first statement in the
2056 block is unreachable. We walk statements backwards in the
2057 loop above, so the last statement we process is the first statement
2059 #ifdef USE_MAPPED_LOCATION
2060 if (loc
> BUILTINS_LOCATION
&& LOCATION_LINE (loc
) > 0)
2061 warning (OPT_Wunreachable_code
, "%Hwill never be executed", &loc
);
2064 warning (OPT_Wunreachable_code
, "%Hwill never be executed", loc
);
2067 remove_phi_nodes_and_edges_for_unreachable_block (bb
);
2072 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2073 predicate VAL, return the edge that will be taken out of the block.
2074 If VAL does not match a unique edge, NULL is returned. */
2077 find_taken_edge (basic_block bb
, tree val
)
2081 stmt
= last_stmt (bb
);
2084 gcc_assert (is_ctrl_stmt (stmt
));
2087 if (! is_gimple_min_invariant (val
))
2090 if (TREE_CODE (stmt
) == COND_EXPR
)
2091 return find_taken_edge_cond_expr (bb
, val
);
2093 if (TREE_CODE (stmt
) == SWITCH_EXPR
)
2094 return find_taken_edge_switch_expr (bb
, val
);
2096 if (computed_goto_p (stmt
))
2098 /* Only optimize if the argument is a label, if the argument is
2099 not a label then we can not construct a proper CFG.
2101 It may be the case that we only need to allow the LABEL_REF to
2102 appear inside an ADDR_EXPR, but we also allow the LABEL_REF to
2103 appear inside a LABEL_EXPR just to be safe. */
2104 if ((TREE_CODE (val
) == ADDR_EXPR
|| TREE_CODE (val
) == LABEL_EXPR
)
2105 && TREE_CODE (TREE_OPERAND (val
, 0)) == LABEL_DECL
)
2106 return find_taken_edge_computed_goto (bb
, TREE_OPERAND (val
, 0));
2113 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2114 statement, determine which of the outgoing edges will be taken out of the
2115 block. Return NULL if either edge may be taken. */
2118 find_taken_edge_computed_goto (basic_block bb
, tree val
)
2123 dest
= label_to_block (val
);
2126 e
= find_edge (bb
, dest
);
2127 gcc_assert (e
!= NULL
);
2133 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2134 statement, determine which of the two edges will be taken out of the
2135 block. Return NULL if either edge may be taken. */
2138 find_taken_edge_cond_expr (basic_block bb
, tree val
)
2140 edge true_edge
, false_edge
;
2142 extract_true_false_edges_from_block (bb
, &true_edge
, &false_edge
);
2144 gcc_assert (TREE_CODE (val
) == INTEGER_CST
);
2145 return (integer_zerop (val
) ? false_edge
: true_edge
);
2148 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2149 statement, determine which edge will be taken out of the block. Return
2150 NULL if any edge may be taken. */
2153 find_taken_edge_switch_expr (basic_block bb
, tree val
)
2155 tree switch_expr
, taken_case
;
2156 basic_block dest_bb
;
2159 switch_expr
= last_stmt (bb
);
2160 taken_case
= find_case_label_for_value (switch_expr
, val
);
2161 dest_bb
= label_to_block (CASE_LABEL (taken_case
));
2163 e
= find_edge (bb
, dest_bb
);
2169 /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL.
2170 We can make optimal use here of the fact that the case labels are
2171 sorted: We can do a binary search for a case matching VAL. */
2174 find_case_label_for_value (tree switch_expr
, tree val
)
2176 tree vec
= SWITCH_LABELS (switch_expr
);
2177 size_t low
, high
, n
= TREE_VEC_LENGTH (vec
);
2178 tree default_case
= TREE_VEC_ELT (vec
, n
- 1);
2180 for (low
= -1, high
= n
- 1; high
- low
> 1; )
2182 size_t i
= (high
+ low
) / 2;
2183 tree t
= TREE_VEC_ELT (vec
, i
);
2186 /* Cache the result of comparing CASE_LOW and val. */
2187 cmp
= tree_int_cst_compare (CASE_LOW (t
), val
);
2194 if (CASE_HIGH (t
) == NULL
)
2196 /* A singe-valued case label. */
2202 /* A case range. We can only handle integer ranges. */
2203 if (cmp
<= 0 && tree_int_cst_compare (CASE_HIGH (t
), val
) >= 0)
2208 return default_case
;
2214 /*---------------------------------------------------------------------------
2216 ---------------------------------------------------------------------------*/
2218 /* Dump tree-specific information of block BB to file OUTF. */
2221 tree_dump_bb (basic_block bb
, FILE *outf
, int indent
)
2223 dump_generic_bb (outf
, bb
, indent
, TDF_VOPS
|TDF_MEMSYMS
);
2227 /* Dump a basic block on stderr. */
2230 debug_tree_bb (basic_block bb
)
2232 dump_bb (bb
, stderr
, 0);
2236 /* Dump basic block with index N on stderr. */
2239 debug_tree_bb_n (int n
)
2241 debug_tree_bb (BASIC_BLOCK (n
));
2242 return BASIC_BLOCK (n
);
2246 /* Dump the CFG on stderr.
2248 FLAGS are the same used by the tree dumping functions
2249 (see TDF_* in tree-pass.h). */
2252 debug_tree_cfg (int flags
)
2254 dump_tree_cfg (stderr
, flags
);
2258 /* Dump the program showing basic block boundaries on the given FILE.
2260 FLAGS are the same used by the tree dumping functions (see TDF_* in
2264 dump_tree_cfg (FILE *file
, int flags
)
2266 if (flags
& TDF_DETAILS
)
2268 const char *funcname
2269 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
2272 fprintf (file
, ";; Function %s\n\n", funcname
);
2273 fprintf (file
, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2274 n_basic_blocks
, n_edges
, last_basic_block
);
2276 brief_dump_cfg (file
);
2277 fprintf (file
, "\n");
2280 if (flags
& TDF_STATS
)
2281 dump_cfg_stats (file
);
2283 dump_function_to_file (current_function_decl
, file
, flags
| TDF_BLOCKS
);
2287 /* Dump CFG statistics on FILE. */
2290 dump_cfg_stats (FILE *file
)
2292 static long max_num_merged_labels
= 0;
2293 unsigned long size
, total
= 0;
2296 const char * const fmt_str
= "%-30s%-13s%12s\n";
2297 const char * const fmt_str_1
= "%-30s%13d%11lu%c\n";
2298 const char * const fmt_str_2
= "%-30s%13ld%11lu%c\n";
2299 const char * const fmt_str_3
= "%-43s%11lu%c\n";
2300 const char *funcname
2301 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
2304 fprintf (file
, "\nCFG Statistics for %s\n\n", funcname
);
2306 fprintf (file
, "---------------------------------------------------------\n");
2307 fprintf (file
, fmt_str
, "", " Number of ", "Memory");
2308 fprintf (file
, fmt_str
, "", " instances ", "used ");
2309 fprintf (file
, "---------------------------------------------------------\n");
2311 size
= n_basic_blocks
* sizeof (struct basic_block_def
);
2313 fprintf (file
, fmt_str_1
, "Basic blocks", n_basic_blocks
,
2314 SCALE (size
), LABEL (size
));
2318 num_edges
+= EDGE_COUNT (bb
->succs
);
2319 size
= num_edges
* sizeof (struct edge_def
);
2321 fprintf (file
, fmt_str_2
, "Edges", num_edges
, SCALE (size
), LABEL (size
));
2323 fprintf (file
, "---------------------------------------------------------\n");
2324 fprintf (file
, fmt_str_3
, "Total memory used by CFG data", SCALE (total
),
2326 fprintf (file
, "---------------------------------------------------------\n");
2327 fprintf (file
, "\n");
2329 if (cfg_stats
.num_merged_labels
> max_num_merged_labels
)
2330 max_num_merged_labels
= cfg_stats
.num_merged_labels
;
2332 fprintf (file
, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2333 cfg_stats
.num_merged_labels
, max_num_merged_labels
);
2335 fprintf (file
, "\n");
2339 /* Dump CFG statistics on stderr. Keep extern so that it's always
2340 linked in the final executable. */
2343 debug_cfg_stats (void)
2345 dump_cfg_stats (stderr
);
2349 /* Dump the flowgraph to a .vcg FILE. */
2352 tree_cfg2vcg (FILE *file
)
2357 const char *funcname
2358 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
2360 /* Write the file header. */
2361 fprintf (file
, "graph: { title: \"%s\"\n", funcname
);
2362 fprintf (file
, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2363 fprintf (file
, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2365 /* Write blocks and edges. */
2366 FOR_EACH_EDGE (e
, ei
, ENTRY_BLOCK_PTR
->succs
)
2368 fprintf (file
, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2371 if (e
->flags
& EDGE_FAKE
)
2372 fprintf (file
, " linestyle: dotted priority: 10");
2374 fprintf (file
, " linestyle: solid priority: 100");
2376 fprintf (file
, " }\n");
2382 enum tree_code head_code
, end_code
;
2383 const char *head_name
, *end_name
;
2386 tree first
= first_stmt (bb
);
2387 tree last
= last_stmt (bb
);
2391 head_code
= TREE_CODE (first
);
2392 head_name
= tree_code_name
[head_code
];
2393 head_line
= get_lineno (first
);
2396 head_name
= "no-statement";
2400 end_code
= TREE_CODE (last
);
2401 end_name
= tree_code_name
[end_code
];
2402 end_line
= get_lineno (last
);
2405 end_name
= "no-statement";
2407 fprintf (file
, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2408 bb
->index
, bb
->index
, head_name
, head_line
, end_name
,
2411 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2413 if (e
->dest
== EXIT_BLOCK_PTR
)
2414 fprintf (file
, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb
->index
);
2416 fprintf (file
, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb
->index
, e
->dest
->index
);
2418 if (e
->flags
& EDGE_FAKE
)
2419 fprintf (file
, " priority: 10 linestyle: dotted");
2421 fprintf (file
, " priority: 100 linestyle: solid");
2423 fprintf (file
, " }\n");
2426 if (bb
->next_bb
!= EXIT_BLOCK_PTR
)
2430 fputs ("}\n\n", file
);
2435 /*---------------------------------------------------------------------------
2436 Miscellaneous helpers
2437 ---------------------------------------------------------------------------*/
2439 /* Return true if T represents a stmt that always transfers control. */
2442 is_ctrl_stmt (const_tree t
)
2444 return (TREE_CODE (t
) == COND_EXPR
2445 || TREE_CODE (t
) == SWITCH_EXPR
2446 || TREE_CODE (t
) == GOTO_EXPR
2447 || TREE_CODE (t
) == RETURN_EXPR
2448 || TREE_CODE (t
) == RESX_EXPR
);
2452 /* Return true if T is a statement that may alter the flow of control
2453 (e.g., a call to a non-returning function). */
2456 is_ctrl_altering_stmt (const_tree t
)
2461 call
= const_get_call_expr_in (t
);
2464 /* A non-pure/const CALL_EXPR alters flow control if the current
2465 function has nonlocal labels. */
2466 if (TREE_SIDE_EFFECTS (call
) && current_function_has_nonlocal_label
)
2469 /* A CALL_EXPR also alters control flow if it does not return. */
2470 if (call_expr_flags (call
) & ECF_NORETURN
)
2474 /* OpenMP directives alter control flow. */
2475 if (OMP_DIRECTIVE_P (t
))
2478 /* If a statement can throw, it alters control flow. */
2479 return tree_can_throw_internal (t
);
2483 /* Return true if T is a computed goto. */
2486 computed_goto_p (const_tree t
)
2488 return (TREE_CODE (t
) == GOTO_EXPR
2489 && TREE_CODE (GOTO_DESTINATION (t
)) != LABEL_DECL
);
2493 /* Return true if T is a simple local goto. */
2496 simple_goto_p (const_tree t
)
2498 return (TREE_CODE (t
) == GOTO_EXPR
2499 && TREE_CODE (GOTO_DESTINATION (t
)) == LABEL_DECL
);
2503 /* Return true if T can make an abnormal transfer of control flow.
2504 Transfers of control flow associated with EH are excluded. */
2507 tree_can_make_abnormal_goto (const_tree t
)
2509 if (computed_goto_p (t
))
2511 if (TREE_CODE (t
) == GIMPLE_MODIFY_STMT
)
2512 t
= GIMPLE_STMT_OPERAND (t
, 1);
2513 if (TREE_CODE (t
) == WITH_SIZE_EXPR
)
2514 t
= TREE_OPERAND (t
, 0);
2515 if (TREE_CODE (t
) == CALL_EXPR
)
2516 return TREE_SIDE_EFFECTS (t
) && current_function_has_nonlocal_label
;
2521 /* Return true if T should start a new basic block. PREV_T is the
2522 statement preceding T. It is used when T is a label or a case label.
2523 Labels should only start a new basic block if their previous statement
2524 wasn't a label. Otherwise, sequence of labels would generate
2525 unnecessary basic blocks that only contain a single label. */
2528 stmt_starts_bb_p (const_tree t
, const_tree prev_t
)
2533 /* LABEL_EXPRs start a new basic block only if the preceding
2534 statement wasn't a label of the same type. This prevents the
2535 creation of consecutive blocks that have nothing but a single
2537 if (TREE_CODE (t
) == LABEL_EXPR
)
2539 /* Nonlocal and computed GOTO targets always start a new block. */
2540 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t
))
2541 || FORCED_LABEL (LABEL_EXPR_LABEL (t
)))
2544 if (prev_t
&& TREE_CODE (prev_t
) == LABEL_EXPR
)
2546 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t
)))
2549 cfg_stats
.num_merged_labels
++;
2560 /* Return true if T should end a basic block. */
2563 stmt_ends_bb_p (const_tree t
)
2565 return is_ctrl_stmt (t
) || is_ctrl_altering_stmt (t
);
2568 /* Remove block annotations and other datastructures. */
2571 delete_tree_cfg_annotations (void)
2574 block_stmt_iterator bsi
;
2576 /* Remove annotations from every tree in the function. */
2578 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
2580 tree stmt
= bsi_stmt (bsi
);
2581 ggc_free (stmt
->base
.ann
);
2582 stmt
->base
.ann
= NULL
;
2584 label_to_block_map
= NULL
;
2588 /* Return the first statement in basic block BB. */
2591 first_stmt (basic_block bb
)
2593 block_stmt_iterator i
= bsi_start (bb
);
2594 return !bsi_end_p (i
) ? bsi_stmt (i
) : NULL_TREE
;
2597 /* Return the last statement in basic block BB. */
2600 last_stmt (basic_block bb
)
2602 block_stmt_iterator b
= bsi_last (bb
);
2603 return !bsi_end_p (b
) ? bsi_stmt (b
) : NULL_TREE
;
2606 /* Return the last statement of an otherwise empty block. Return NULL
2607 if the block is totally empty, or if it contains more than one
2611 last_and_only_stmt (basic_block bb
)
2613 block_stmt_iterator i
= bsi_last (bb
);
2619 last
= bsi_stmt (i
);
2624 /* Empty statements should no longer appear in the instruction stream.
2625 Everything that might have appeared before should be deleted by
2626 remove_useless_stmts, and the optimizers should just bsi_remove
2627 instead of smashing with build_empty_stmt.
2629 Thus the only thing that should appear here in a block containing
2630 one executable statement is a label. */
2631 prev
= bsi_stmt (i
);
2632 if (TREE_CODE (prev
) == LABEL_EXPR
)
2639 /* Mark BB as the basic block holding statement T. */
2642 set_bb_for_stmt (tree t
, basic_block bb
)
2644 if (TREE_CODE (t
) == PHI_NODE
)
2646 else if (TREE_CODE (t
) == STATEMENT_LIST
)
2648 tree_stmt_iterator i
;
2649 for (i
= tsi_start (t
); !tsi_end_p (i
); tsi_next (&i
))
2650 set_bb_for_stmt (tsi_stmt (i
), bb
);
2654 stmt_ann_t ann
= get_stmt_ann (t
);
2657 /* If the statement is a label, add the label to block-to-labels map
2658 so that we can speed up edge creation for GOTO_EXPRs. */
2659 if (TREE_CODE (t
) == LABEL_EXPR
)
2663 t
= LABEL_EXPR_LABEL (t
);
2664 uid
= LABEL_DECL_UID (t
);
2667 unsigned old_len
= VEC_length (basic_block
, label_to_block_map
);
2668 LABEL_DECL_UID (t
) = uid
= cfun
->last_label_uid
++;
2669 if (old_len
<= (unsigned) uid
)
2671 unsigned new_len
= 3 * uid
/ 2;
2673 VEC_safe_grow_cleared (basic_block
, gc
, label_to_block_map
,
2678 /* We're moving an existing label. Make sure that we've
2679 removed it from the old block. */
2681 || !VEC_index (basic_block
, label_to_block_map
, uid
));
2682 VEC_replace (basic_block
, label_to_block_map
, uid
, bb
);
2687 /* Faster version of set_bb_for_stmt that assume that statement is being moved
2688 from one basic block to another.
2689 For BB splitting we can run into quadratic case, so performance is quite
2690 important and knowing that the tables are big enough, change_bb_for_stmt
2691 can inline as leaf function. */
2693 change_bb_for_stmt (tree t
, basic_block bb
)
2695 get_stmt_ann (t
)->bb
= bb
;
2696 if (TREE_CODE (t
) == LABEL_EXPR
)
2697 VEC_replace (basic_block
, label_to_block_map
,
2698 LABEL_DECL_UID (LABEL_EXPR_LABEL (t
)), bb
);
2701 /* Finds iterator for STMT. */
2703 extern block_stmt_iterator
2704 bsi_for_stmt (tree stmt
)
2706 block_stmt_iterator bsi
;
2708 for (bsi
= bsi_start (bb_for_stmt (stmt
)); !bsi_end_p (bsi
); bsi_next (&bsi
))
2709 if (bsi_stmt (bsi
) == stmt
)
2715 /* Mark statement T as modified, and update it. */
2717 update_modified_stmts (tree t
)
2719 if (!ssa_operands_active ())
2721 if (TREE_CODE (t
) == STATEMENT_LIST
)
2723 tree_stmt_iterator i
;
2725 for (i
= tsi_start (t
); !tsi_end_p (i
); tsi_next (&i
))
2727 stmt
= tsi_stmt (i
);
2728 update_stmt_if_modified (stmt
);
2732 update_stmt_if_modified (t
);
2735 /* Insert statement (or statement list) T before the statement
2736 pointed-to by iterator I. M specifies how to update iterator I
2737 after insertion (see enum bsi_iterator_update). */
2740 bsi_insert_before (block_stmt_iterator
*i
, tree t
, enum bsi_iterator_update m
)
2742 set_bb_for_stmt (t
, i
->bb
);
2743 update_modified_stmts (t
);
2744 tsi_link_before (&i
->tsi
, t
, m
);
2748 /* Insert statement (or statement list) T after the statement
2749 pointed-to by iterator I. M specifies how to update iterator I
2750 after insertion (see enum bsi_iterator_update). */
2753 bsi_insert_after (block_stmt_iterator
*i
, tree t
, enum bsi_iterator_update m
)
2755 set_bb_for_stmt (t
, i
->bb
);
2756 update_modified_stmts (t
);
2757 tsi_link_after (&i
->tsi
, t
, m
);
2761 /* Remove the statement pointed to by iterator I. The iterator is updated
2762 to the next statement.
2764 When REMOVE_EH_INFO is true we remove the statement pointed to by
2765 iterator I from the EH tables. Otherwise we do not modify the EH
2768 Generally, REMOVE_EH_INFO should be true when the statement is going to
2769 be removed from the IL and not reinserted elsewhere. */
2772 bsi_remove (block_stmt_iterator
*i
, bool remove_eh_info
)
2774 tree t
= bsi_stmt (*i
);
2775 set_bb_for_stmt (t
, NULL
);
2776 delink_stmt_imm_use (t
);
2777 tsi_delink (&i
->tsi
);
2778 mark_stmt_modified (t
);
2781 remove_stmt_from_eh_region (t
);
2782 gimple_remove_stmt_histograms (cfun
, t
);
2787 /* Move the statement at FROM so it comes right after the statement at TO. */
2790 bsi_move_after (block_stmt_iterator
*from
, block_stmt_iterator
*to
)
2792 tree stmt
= bsi_stmt (*from
);
2793 bsi_remove (from
, false);
2794 /* We must have BSI_NEW_STMT here, as bsi_move_after is sometimes used to
2795 move statements to an empty block. */
2796 bsi_insert_after (to
, stmt
, BSI_NEW_STMT
);
2800 /* Move the statement at FROM so it comes right before the statement at TO. */
2803 bsi_move_before (block_stmt_iterator
*from
, block_stmt_iterator
*to
)
2805 tree stmt
= bsi_stmt (*from
);
2806 bsi_remove (from
, false);
2807 /* For consistency with bsi_move_after, it might be better to have
2808 BSI_NEW_STMT here; however, that breaks several places that expect
2809 that TO does not change. */
2810 bsi_insert_before (to
, stmt
, BSI_SAME_STMT
);
2814 /* Move the statement at FROM to the end of basic block BB. */
2817 bsi_move_to_bb_end (block_stmt_iterator
*from
, basic_block bb
)
2819 block_stmt_iterator last
= bsi_last (bb
);
2821 /* Have to check bsi_end_p because it could be an empty block. */
2822 if (!bsi_end_p (last
) && is_ctrl_stmt (bsi_stmt (last
)))
2823 bsi_move_before (from
, &last
);
2825 bsi_move_after (from
, &last
);
2829 /* Replace the contents of the statement pointed to by iterator BSI
2830 with STMT. If UPDATE_EH_INFO is true, the exception handling
2831 information of the original statement is moved to the new statement. */
2834 bsi_replace (const block_stmt_iterator
*bsi
, tree stmt
, bool update_eh_info
)
2837 tree orig_stmt
= bsi_stmt (*bsi
);
2839 if (stmt
== orig_stmt
)
2841 SET_EXPR_LOCUS (stmt
, EXPR_LOCUS (orig_stmt
));
2842 set_bb_for_stmt (stmt
, bsi
->bb
);
2844 /* Preserve EH region information from the original statement, if
2845 requested by the caller. */
2848 eh_region
= lookup_stmt_eh_region (orig_stmt
);
2851 remove_stmt_from_eh_region (orig_stmt
);
2852 add_stmt_to_eh_region (stmt
, eh_region
);
2856 gimple_duplicate_stmt_histograms (cfun
, stmt
, cfun
, orig_stmt
);
2857 gimple_remove_stmt_histograms (cfun
, orig_stmt
);
2858 delink_stmt_imm_use (orig_stmt
);
2859 *bsi_stmt_ptr (*bsi
) = stmt
;
2860 mark_stmt_modified (stmt
);
2861 update_modified_stmts (stmt
);
2865 /* Insert the statement pointed-to by BSI into edge E. Every attempt
2866 is made to place the statement in an existing basic block, but
2867 sometimes that isn't possible. When it isn't possible, the edge is
2868 split and the statement is added to the new block.
2870 In all cases, the returned *BSI points to the correct location. The
2871 return value is true if insertion should be done after the location,
2872 or false if it should be done before the location. If new basic block
2873 has to be created, it is stored in *NEW_BB. */
2876 tree_find_edge_insert_loc (edge e
, block_stmt_iterator
*bsi
,
2877 basic_block
*new_bb
)
2879 basic_block dest
, src
;
2885 /* If the destination has one predecessor which has no PHI nodes,
2886 insert there. Except for the exit block.
2888 The requirement for no PHI nodes could be relaxed. Basically we
2889 would have to examine the PHIs to prove that none of them used
2890 the value set by the statement we want to insert on E. That
2891 hardly seems worth the effort. */
2892 if (single_pred_p (dest
)
2893 && ! phi_nodes (dest
)
2894 && dest
!= EXIT_BLOCK_PTR
)
2896 *bsi
= bsi_start (dest
);
2897 if (bsi_end_p (*bsi
))
2900 /* Make sure we insert after any leading labels. */
2901 tmp
= bsi_stmt (*bsi
);
2902 while (TREE_CODE (tmp
) == LABEL_EXPR
)
2905 if (bsi_end_p (*bsi
))
2907 tmp
= bsi_stmt (*bsi
);
2910 if (bsi_end_p (*bsi
))
2912 *bsi
= bsi_last (dest
);
2919 /* If the source has one successor, the edge is not abnormal and
2920 the last statement does not end a basic block, insert there.
2921 Except for the entry block. */
2923 if ((e
->flags
& EDGE_ABNORMAL
) == 0
2924 && single_succ_p (src
)
2925 && src
!= ENTRY_BLOCK_PTR
)
2927 *bsi
= bsi_last (src
);
2928 if (bsi_end_p (*bsi
))
2931 tmp
= bsi_stmt (*bsi
);
2932 if (!stmt_ends_bb_p (tmp
))
2935 /* Insert code just before returning the value. We may need to decompose
2936 the return in the case it contains non-trivial operand. */
2937 if (TREE_CODE (tmp
) == RETURN_EXPR
)
2939 tree op
= TREE_OPERAND (tmp
, 0);
2940 if (op
&& !is_gimple_val (op
))
2942 gcc_assert (TREE_CODE (op
) == GIMPLE_MODIFY_STMT
);
2943 bsi_insert_before (bsi
, op
, BSI_NEW_STMT
);
2944 TREE_OPERAND (tmp
, 0) = GIMPLE_STMT_OPERAND (op
, 0);
2951 /* Otherwise, create a new basic block, and split this edge. */
2952 dest
= split_edge (e
);
2955 e
= single_pred_edge (dest
);
2960 /* This routine will commit all pending edge insertions, creating any new
2961 basic blocks which are necessary. */
2964 bsi_commit_edge_inserts (void)
2970 bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR
), NULL
);
2973 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2974 bsi_commit_one_edge_insert (e
, NULL
);
2978 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
2979 to this block, otherwise set it to NULL. */
2982 bsi_commit_one_edge_insert (edge e
, basic_block
*new_bb
)
2986 if (PENDING_STMT (e
))
2988 block_stmt_iterator bsi
;
2989 tree stmt
= PENDING_STMT (e
);
2991 PENDING_STMT (e
) = NULL_TREE
;
2993 if (tree_find_edge_insert_loc (e
, &bsi
, new_bb
))
2994 bsi_insert_after (&bsi
, stmt
, BSI_NEW_STMT
);
2996 bsi_insert_before (&bsi
, stmt
, BSI_NEW_STMT
);
3001 /* Add STMT to the pending list of edge E. No actual insertion is
3002 made until a call to bsi_commit_edge_inserts () is made. */
3005 bsi_insert_on_edge (edge e
, tree stmt
)
3007 append_to_statement_list (stmt
, &PENDING_STMT (e
));
3010 /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new
3011 block has to be created, it is returned. */
3014 bsi_insert_on_edge_immediate (edge e
, tree stmt
)
3016 block_stmt_iterator bsi
;
3017 basic_block new_bb
= NULL
;
3019 gcc_assert (!PENDING_STMT (e
));
3021 if (tree_find_edge_insert_loc (e
, &bsi
, &new_bb
))
3022 bsi_insert_after (&bsi
, stmt
, BSI_NEW_STMT
);
3024 bsi_insert_before (&bsi
, stmt
, BSI_NEW_STMT
);
3029 /*---------------------------------------------------------------------------
3030 Tree specific functions for CFG manipulation
3031 ---------------------------------------------------------------------------*/
3033 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
3036 reinstall_phi_args (edge new_edge
, edge old_edge
)
3040 if (!PENDING_STMT (old_edge
))
3043 for (var
= PENDING_STMT (old_edge
), phi
= phi_nodes (new_edge
->dest
);
3045 var
= TREE_CHAIN (var
), phi
= PHI_CHAIN (phi
))
3047 tree result
= TREE_PURPOSE (var
);
3048 tree arg
= TREE_VALUE (var
);
3050 gcc_assert (result
== PHI_RESULT (phi
));
3052 add_phi_arg (phi
, arg
, new_edge
);
3055 PENDING_STMT (old_edge
) = NULL
;
3058 /* Returns the basic block after which the new basic block created
3059 by splitting edge EDGE_IN should be placed. Tries to keep the new block
3060 near its "logical" location. This is of most help to humans looking
3061 at debugging dumps. */
3064 split_edge_bb_loc (edge edge_in
)
3066 basic_block dest
= edge_in
->dest
;
3068 if (dest
->prev_bb
&& find_edge (dest
->prev_bb
, dest
))
3069 return edge_in
->src
;
3071 return dest
->prev_bb
;
3074 /* Split a (typically critical) edge EDGE_IN. Return the new block.
3075 Abort on abnormal edges. */
3078 tree_split_edge (edge edge_in
)
3080 basic_block new_bb
, after_bb
, dest
;
3083 /* Abnormal edges cannot be split. */
3084 gcc_assert (!(edge_in
->flags
& EDGE_ABNORMAL
));
3086 dest
= edge_in
->dest
;
3088 after_bb
= split_edge_bb_loc (edge_in
);
3090 new_bb
= create_empty_bb (after_bb
);
3091 new_bb
->frequency
= EDGE_FREQUENCY (edge_in
);
3092 new_bb
->count
= edge_in
->count
;
3093 new_edge
= make_edge (new_bb
, dest
, EDGE_FALLTHRU
);
3094 new_edge
->probability
= REG_BR_PROB_BASE
;
3095 new_edge
->count
= edge_in
->count
;
3097 e
= redirect_edge_and_branch (edge_in
, new_bb
);
3098 gcc_assert (e
== edge_in
);
3099 reinstall_phi_args (new_edge
, e
);
3104 /* Callback for walk_tree, check that all elements with address taken are
3105 properly noticed as such. The DATA is an int* that is 1 if TP was seen
3106 inside a PHI node. */
3109 verify_expr (tree
*tp
, int *walk_subtrees
, void *data ATTRIBUTE_UNUSED
)
3112 bool in_phi
= (data
!= NULL
);
3117 /* Check operand N for being valid GIMPLE and give error MSG if not. */
3118 #define CHECK_OP(N, MSG) \
3119 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
3120 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
3122 switch (TREE_CODE (t
))
3125 if (SSA_NAME_IN_FREE_LIST (t
))
3127 error ("SSA name in freelist but still referenced");
3133 x
= fold (ASSERT_EXPR_COND (t
));
3134 if (x
== boolean_false_node
)
3136 error ("ASSERT_EXPR with an always-false condition");
3144 case GIMPLE_MODIFY_STMT
:
3145 x
= GIMPLE_STMT_OPERAND (t
, 0);
3146 if (TREE_CODE (x
) == BIT_FIELD_REF
3147 && is_gimple_reg (TREE_OPERAND (x
, 0)))
3149 error ("GIMPLE register modified with BIT_FIELD_REF");
3158 bool old_side_effects
;
3161 bool new_side_effects
;
3163 /* ??? tree-ssa-alias.c may have overlooked dead PHI nodes, missing
3164 dead PHIs that take the address of something. But if the PHI
3165 result is dead, the fact that it takes the address of anything
3166 is irrelevant. Because we can not tell from here if a PHI result
3167 is dead, we just skip this check for PHIs altogether. This means
3168 we may be missing "valid" checks, but what can you do?
3169 This was PR19217. */
3173 old_invariant
= TREE_INVARIANT (t
);
3174 old_constant
= TREE_CONSTANT (t
);
3175 old_side_effects
= TREE_SIDE_EFFECTS (t
);
3177 recompute_tree_invariant_for_addr_expr (t
);
3178 new_invariant
= TREE_INVARIANT (t
);
3179 new_side_effects
= TREE_SIDE_EFFECTS (t
);
3180 new_constant
= TREE_CONSTANT (t
);
3182 if (old_invariant
!= new_invariant
)
3184 error ("invariant not recomputed when ADDR_EXPR changed");
3188 if (old_constant
!= new_constant
)
3190 error ("constant not recomputed when ADDR_EXPR changed");
3193 if (old_side_effects
!= new_side_effects
)
3195 error ("side effects not recomputed when ADDR_EXPR changed");
3199 /* Skip any references (they will be checked when we recurse down the
3200 tree) and ensure that any variable used as a prefix is marked
3202 for (x
= TREE_OPERAND (t
, 0);
3203 handled_component_p (x
);
3204 x
= TREE_OPERAND (x
, 0))
3207 if (TREE_CODE (x
) != VAR_DECL
&& TREE_CODE (x
) != PARM_DECL
)
3209 if (!TREE_ADDRESSABLE (x
))
3211 error ("address taken, but ADDRESSABLE bit not set");
3218 x
= COND_EXPR_COND (t
);
3219 if (!INTEGRAL_TYPE_P (TREE_TYPE (x
)))
3221 error ("non-integral used in condition");
3224 if (!is_gimple_condexpr (x
))
3226 error ("invalid conditional operand");
3233 case FIX_TRUNC_EXPR
:
3238 case NON_LVALUE_EXPR
:
3239 case TRUTH_NOT_EXPR
:
3240 CHECK_OP (0, "invalid operand to unary operator");
3247 case ARRAY_RANGE_REF
:
3249 case VIEW_CONVERT_EXPR
:
3250 /* We have a nest of references. Verify that each of the operands
3251 that determine where to reference is either a constant or a variable,
3252 verify that the base is valid, and then show we've already checked
3254 while (handled_component_p (t
))
3256 if (TREE_CODE (t
) == COMPONENT_REF
&& TREE_OPERAND (t
, 2))
3257 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
3258 else if (TREE_CODE (t
) == ARRAY_REF
3259 || TREE_CODE (t
) == ARRAY_RANGE_REF
)
3261 CHECK_OP (1, "invalid array index");
3262 if (TREE_OPERAND (t
, 2))
3263 CHECK_OP (2, "invalid array lower bound");
3264 if (TREE_OPERAND (t
, 3))
3265 CHECK_OP (3, "invalid array stride");
3267 else if (TREE_CODE (t
) == BIT_FIELD_REF
)
3269 CHECK_OP (1, "invalid operand to BIT_FIELD_REF");
3270 CHECK_OP (2, "invalid operand to BIT_FIELD_REF");
3273 t
= TREE_OPERAND (t
, 0);
3276 if (!CONSTANT_CLASS_P (t
) && !is_gimple_lvalue (t
))
3278 error ("invalid reference prefix");
3285 /* PLUS_EXPR and MINUS_EXPR don't work on pointers, they should be done using
3286 POINTER_PLUS_EXPR. */
3287 if (POINTER_TYPE_P (TREE_TYPE (t
)))
3289 error ("invalid operand to plus/minus, type is a pointer");
3292 CHECK_OP (0, "invalid operand to binary operator");
3293 CHECK_OP (1, "invalid operand to binary operator");
3296 case POINTER_PLUS_EXPR
:
3297 /* Check to make sure the first operand is a pointer or reference type. */
3298 if (!POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t
, 0))))
3300 error ("invalid operand to pointer plus, first operand is not a pointer");
3303 /* Check to make sure the second operand is an integer with type of
3305 if (!useless_type_conversion_p (sizetype
,
3306 TREE_TYPE (TREE_OPERAND (t
, 1))))
3308 error ("invalid operand to pointer plus, second operand is not an "
3309 "integer with type of sizetype.");
3319 case UNORDERED_EXPR
:
3328 case TRUNC_DIV_EXPR
:
3330 case FLOOR_DIV_EXPR
:
3331 case ROUND_DIV_EXPR
:
3332 case TRUNC_MOD_EXPR
:
3334 case FLOOR_MOD_EXPR
:
3335 case ROUND_MOD_EXPR
:
3337 case EXACT_DIV_EXPR
:
3347 CHECK_OP (0, "invalid operand to binary operator");
3348 CHECK_OP (1, "invalid operand to binary operator");
3352 if (TREE_CONSTANT (t
) && TREE_CODE (TREE_TYPE (t
)) == VECTOR_TYPE
)
3364 /* Verifies if EXPR is a valid GIMPLE unary expression. Returns true
3365 if there is an error, otherwise false. */
3368 verify_gimple_unary_expr (const_tree expr
)
3370 tree op
= TREE_OPERAND (expr
, 0);
3371 tree type
= TREE_TYPE (expr
);
3373 if (!is_gimple_val (op
))
3375 error ("invalid operand in unary expression");
3379 /* For general unary expressions we have the operations type
3380 as the effective type the operation is carried out on. So all
3381 we need to require is that the operand is trivially convertible
3383 if (!useless_type_conversion_p (type
, TREE_TYPE (op
)))
3385 error ("type mismatch in unary expression");
3386 debug_generic_expr (type
);
3387 debug_generic_expr (TREE_TYPE (op
));
3394 /* Verifies if EXPR is a valid GIMPLE binary expression. Returns true
3395 if there is an error, otherwise false. */
3398 verify_gimple_binary_expr (const_tree expr
)
3400 tree op0
= TREE_OPERAND (expr
, 0);
3401 tree op1
= TREE_OPERAND (expr
, 1);
3402 tree type
= TREE_TYPE (expr
);
3404 if (!is_gimple_val (op0
) || !is_gimple_val (op1
))
3406 error ("invalid operands in binary expression");
3410 /* For general binary expressions we have the operations type
3411 as the effective type the operation is carried out on. So all
3412 we need to require is that both operands are trivially convertible
3414 if (!useless_type_conversion_p (type
, TREE_TYPE (op0
))
3415 || !useless_type_conversion_p (type
, TREE_TYPE (op1
)))
3417 error ("type mismatch in binary expression");
3418 debug_generic_stmt (type
);
3419 debug_generic_stmt (TREE_TYPE (op0
));
3420 debug_generic_stmt (TREE_TYPE (op1
));
3427 /* Verify if EXPR is either a GIMPLE ID or a GIMPLE indirect reference.
3428 Returns true if there is an error, otherwise false. */
3431 verify_gimple_min_lval (tree expr
)
3435 if (is_gimple_id (expr
))
3438 if (TREE_CODE (expr
) != INDIRECT_REF
3439 && TREE_CODE (expr
) != ALIGN_INDIRECT_REF
3440 && TREE_CODE (expr
) != MISALIGNED_INDIRECT_REF
)
3442 error ("invalid expression for min lvalue");
3446 op
= TREE_OPERAND (expr
, 0);
3447 if (!is_gimple_val (op
))
3449 error ("invalid operand in indirect reference");
3450 debug_generic_stmt (op
);
3453 if (!useless_type_conversion_p (TREE_TYPE (expr
),
3454 TREE_TYPE (TREE_TYPE (op
))))
3456 error ("type mismatch in indirect reference");
3457 debug_generic_stmt (TREE_TYPE (expr
));
3458 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op
)));
3465 /* Verify if EXPR is a valid GIMPLE reference expression. Returns true
3466 if there is an error, otherwise false. */
3469 verify_gimple_reference (tree expr
)
3471 while (handled_component_p (expr
))
3473 tree op
= TREE_OPERAND (expr
, 0);
3475 if (TREE_CODE (expr
) == ARRAY_REF
3476 || TREE_CODE (expr
) == ARRAY_RANGE_REF
)
3478 if (!is_gimple_val (TREE_OPERAND (expr
, 1))
3479 || (TREE_OPERAND (expr
, 2)
3480 && !is_gimple_val (TREE_OPERAND (expr
, 2)))
3481 || (TREE_OPERAND (expr
, 3)
3482 && !is_gimple_val (TREE_OPERAND (expr
, 3))))
3484 error ("invalid operands to array reference");
3485 debug_generic_stmt (expr
);
3490 /* Verify if the reference array element types are compatible. */
3491 if (TREE_CODE (expr
) == ARRAY_REF
3492 && !useless_type_conversion_p (TREE_TYPE (expr
),
3493 TREE_TYPE (TREE_TYPE (op
))))
3495 error ("type mismatch in array reference");
3496 debug_generic_stmt (TREE_TYPE (expr
));
3497 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op
)));
3500 if (TREE_CODE (expr
) == ARRAY_RANGE_REF
3501 && !useless_type_conversion_p (TREE_TYPE (TREE_TYPE (expr
)),
3502 TREE_TYPE (TREE_TYPE (op
))))
3504 error ("type mismatch in array range reference");
3505 debug_generic_stmt (TREE_TYPE (TREE_TYPE (expr
)));
3506 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op
)));
3510 if ((TREE_CODE (expr
) == REALPART_EXPR
3511 || TREE_CODE (expr
) == IMAGPART_EXPR
)
3512 && !useless_type_conversion_p (TREE_TYPE (expr
),
3513 TREE_TYPE (TREE_TYPE (op
))))
3515 error ("type mismatch in real/imagpart reference");
3516 debug_generic_stmt (TREE_TYPE (expr
));
3517 debug_generic_stmt (TREE_TYPE (TREE_TYPE (op
)));
3521 if (TREE_CODE (expr
) == COMPONENT_REF
3522 && !useless_type_conversion_p (TREE_TYPE (expr
),
3523 TREE_TYPE (TREE_OPERAND (expr
, 1))))
3525 error ("type mismatch in component reference");
3526 debug_generic_stmt (TREE_TYPE (expr
));
3527 debug_generic_stmt (TREE_TYPE (TREE_OPERAND (expr
, 1)));
3531 /* For VIEW_CONVERT_EXPRs which are allowed here, too, there
3532 is nothing to verify. Gross mismatches at most invoke
3533 undefined behavior. */
3538 return verify_gimple_min_lval (expr
);
3541 /* Verify the GIMPLE expression EXPR. Returns true if there is an
3542 error, otherwise false. */
3545 verify_gimple_expr (tree expr
)
3547 tree type
= TREE_TYPE (expr
);
3549 if (is_gimple_val (expr
))
3552 /* Special codes we cannot handle via their class. */
3553 switch (TREE_CODE (expr
))
3558 tree op
= TREE_OPERAND (expr
, 0);
3559 if (!is_gimple_val (op
))
3561 error ("invalid operand in conversion");
3565 /* Allow conversions between integral types and between
3567 if ((INTEGRAL_TYPE_P (type
) && INTEGRAL_TYPE_P (TREE_TYPE (op
)))
3568 || (POINTER_TYPE_P (type
) && POINTER_TYPE_P (TREE_TYPE (op
))))
3571 /* Allow conversions between integral types and pointers only if
3572 there is no sign or zero extension involved. */
3573 if (((POINTER_TYPE_P (type
) && INTEGRAL_TYPE_P (TREE_TYPE (op
)))
3574 || (POINTER_TYPE_P (TREE_TYPE (op
)) && INTEGRAL_TYPE_P (type
)))
3575 && TYPE_PRECISION (type
) == TYPE_PRECISION (TREE_TYPE (op
)))
3578 /* Allow conversion from integer to offset type and vice versa. */
3579 if ((TREE_CODE (type
) == OFFSET_TYPE
3580 && TREE_CODE (TREE_TYPE (op
)) == INTEGER_TYPE
)
3581 || (TREE_CODE (type
) == INTEGER_TYPE
3582 && TREE_CODE (TREE_TYPE (op
)) == OFFSET_TYPE
))
3585 /* Otherwise assert we are converting between types of the
3587 if (TREE_CODE (type
) != TREE_CODE (TREE_TYPE (op
)))
3589 error ("invalid types in nop conversion");
3590 debug_generic_expr (type
);
3591 debug_generic_expr (TREE_TYPE (op
));
3600 tree op
= TREE_OPERAND (expr
, 0);
3601 if (!is_gimple_val (op
))
3603 error ("invalid operand in int to float conversion");
3606 if (!INTEGRAL_TYPE_P (TREE_TYPE (op
))
3607 || !SCALAR_FLOAT_TYPE_P (type
))
3609 error ("invalid types in conversion to floating point");
3610 debug_generic_expr (type
);
3611 debug_generic_expr (TREE_TYPE (op
));
3617 case FIX_TRUNC_EXPR
:
3619 tree op
= TREE_OPERAND (expr
, 0);
3620 if (!is_gimple_val (op
))
3622 error ("invalid operand in float to int conversion");
3625 if (!INTEGRAL_TYPE_P (type
)
3626 || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (op
)))
3628 error ("invalid types in conversion to integer");
3629 debug_generic_expr (type
);
3630 debug_generic_expr (TREE_TYPE (op
));
3638 tree op0
= TREE_OPERAND (expr
, 0);
3639 tree op1
= TREE_OPERAND (expr
, 1);
3640 if (!is_gimple_val (op0
) || !is_gimple_val (op1
))
3642 error ("invalid operands in complex expression");
3645 if (!TREE_CODE (type
) == COMPLEX_TYPE
3646 || !(TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
3647 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0
)))
3648 || !(TREE_CODE (TREE_TYPE (op1
)) == INTEGER_TYPE
3649 || SCALAR_FLOAT_TYPE_P (TREE_TYPE (op1
)))
3650 || !useless_type_conversion_p (TREE_TYPE (type
),
3652 || !useless_type_conversion_p (TREE_TYPE (type
),
3655 error ("type mismatch in complex expression");
3656 debug_generic_stmt (TREE_TYPE (expr
));
3657 debug_generic_stmt (TREE_TYPE (op0
));
3658 debug_generic_stmt (TREE_TYPE (op1
));
3666 /* This is used like COMPLEX_EXPR but for vectors. */
3667 if (TREE_CODE (type
) != VECTOR_TYPE
)
3669 error ("constructor not allowed for non-vector types");
3670 debug_generic_stmt (type
);
3673 /* FIXME: verify constructor arguments. */
3682 tree op0
= TREE_OPERAND (expr
, 0);
3683 tree op1
= TREE_OPERAND (expr
, 1);
3684 if (!is_gimple_val (op0
) || !is_gimple_val (op1
))
3686 error ("invalid operands in shift expression");
3689 if (!TREE_CODE (TREE_TYPE (op1
)) == INTEGER_TYPE
3690 || !useless_type_conversion_p (type
, TREE_TYPE (op0
)))
3692 error ("type mismatch in shift expression");
3693 debug_generic_stmt (TREE_TYPE (expr
));
3694 debug_generic_stmt (TREE_TYPE (op0
));
3695 debug_generic_stmt (TREE_TYPE (op1
));
3704 tree op0
= TREE_OPERAND (expr
, 0);
3705 tree op1
= TREE_OPERAND (expr
, 1);
3706 if (POINTER_TYPE_P (type
)
3707 || POINTER_TYPE_P (TREE_TYPE (op0
))
3708 || POINTER_TYPE_P (TREE_TYPE (op1
)))
3710 error ("invalid (pointer) operands to plus/minus");
3713 /* Continue with generic binary expression handling. */
3717 case POINTER_PLUS_EXPR
:
3719 tree op0
= TREE_OPERAND (expr
, 0);
3720 tree op1
= TREE_OPERAND (expr
, 1);
3721 if (!is_gimple_val (op0
) || !is_gimple_val (op1
))
3723 error ("invalid operands in pointer plus expression");
3726 if (!POINTER_TYPE_P (TREE_TYPE (op0
))
3727 || TREE_CODE (TREE_TYPE (op1
)) != INTEGER_TYPE
3728 || !useless_type_conversion_p (type
, TREE_TYPE (op0
))
3729 || !useless_type_conversion_p (sizetype
, TREE_TYPE (op1
)))
3731 error ("type mismatch in pointer plus expression");
3732 debug_generic_stmt (type
);
3733 debug_generic_stmt (TREE_TYPE (op0
));
3734 debug_generic_stmt (TREE_TYPE (op1
));
3742 tree op0
= TREE_OPERAND (expr
, 0);
3743 tree op1
= TREE_OPERAND (expr
, 1);
3744 tree op2
= TREE_OPERAND (expr
, 2);
3745 if ((!is_gimple_val (op1
)
3746 && TREE_CODE (TREE_TYPE (op1
)) != VOID_TYPE
)
3747 || (!is_gimple_val (op2
)
3748 && TREE_CODE (TREE_TYPE (op2
)) != VOID_TYPE
))
3750 error ("invalid operands in conditional expression");
3753 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0
))
3754 || (TREE_CODE (TREE_TYPE (op1
)) != VOID_TYPE
3755 && !useless_type_conversion_p (type
, TREE_TYPE (op1
)))
3756 || (TREE_CODE (TREE_TYPE (op2
)) != VOID_TYPE
3757 && !useless_type_conversion_p (type
, TREE_TYPE (op2
))))
3759 error ("type mismatch in conditional expression");
3760 debug_generic_stmt (type
);
3761 debug_generic_stmt (TREE_TYPE (op0
));
3762 debug_generic_stmt (TREE_TYPE (op1
));
3763 debug_generic_stmt (TREE_TYPE (op2
));
3766 return verify_gimple_expr (op0
);
3771 tree op
= TREE_OPERAND (expr
, 0);
3773 if (!is_gimple_addressable (op
))
3775 error ("invalid operand in unary expression");
3778 ptr_type
= build_pointer_type (TREE_TYPE (op
));
3779 if (!useless_type_conversion_p (type
, ptr_type
)
3780 /* FIXME: a longstanding wart, &a == &a[0]. */
3781 && (TREE_CODE (TREE_TYPE (op
)) != ARRAY_TYPE
3782 || !useless_type_conversion_p (type
,
3783 build_pointer_type (TREE_TYPE (TREE_TYPE (op
))))))
3785 error ("type mismatch in address expression");
3786 debug_generic_stmt (TREE_TYPE (expr
));
3787 debug_generic_stmt (ptr_type
);
3791 return verify_gimple_reference (op
);
3794 case TRUTH_ANDIF_EXPR
:
3795 case TRUTH_ORIF_EXPR
:
3796 case TRUTH_AND_EXPR
:
3798 case TRUTH_XOR_EXPR
:
3800 tree op0
= TREE_OPERAND (expr
, 0);
3801 tree op1
= TREE_OPERAND (expr
, 1);
3803 if (!is_gimple_val (op0
) || !is_gimple_val (op1
))
3805 error ("invalid operands in truth expression");
3809 /* We allow any kind of integral typed argument and result. */
3810 if (!INTEGRAL_TYPE_P (TREE_TYPE (op0
))
3811 || !INTEGRAL_TYPE_P (TREE_TYPE (op1
))
3812 || !INTEGRAL_TYPE_P (type
))
3814 error ("type mismatch in binary truth expression");
3815 debug_generic_stmt (type
);
3816 debug_generic_stmt (TREE_TYPE (op0
));
3817 debug_generic_stmt (TREE_TYPE (op1
));
3824 case TRUTH_NOT_EXPR
:
3826 tree op
= TREE_OPERAND (expr
, 0);
3828 if (!is_gimple_val (op
))
3830 error ("invalid operand in unary not");
3834 /* For TRUTH_NOT_EXPR we can have any kind of integral
3835 typed arguments and results. */
3836 if (!INTEGRAL_TYPE_P (TREE_TYPE (op
))
3837 || !INTEGRAL_TYPE_P (type
))
3839 error ("type mismatch in not expression");
3840 debug_generic_expr (TREE_TYPE (expr
));
3841 debug_generic_expr (TREE_TYPE (op
));
3849 /* FIXME. The C frontend passes unpromoted arguments in case it
3850 didn't see a function declaration before the call. */
3856 /* Generic handling via classes. */
3857 switch (TREE_CODE_CLASS (TREE_CODE (expr
)))
3860 return verify_gimple_unary_expr (expr
);
3863 return verify_gimple_binary_expr (expr
);
3866 return verify_gimple_reference (expr
);
3868 case tcc_comparison
:
3870 tree op0
= TREE_OPERAND (expr
, 0);
3871 tree op1
= TREE_OPERAND (expr
, 1);
3872 if (!is_gimple_val (op0
) || !is_gimple_val (op1
))
3874 error ("invalid operands in comparison expression");
3877 /* For comparisons we do not have the operations type as the
3878 effective type the comparison is carried out in. Instead
3879 we require that either the first operand is trivially
3880 convertible into the second, or the other way around.
3881 The resulting type of a comparison may be any integral type.
3882 Because we special-case pointers to void we allow
3883 comparisons of pointers with the same mode as well. */
3884 if ((!useless_type_conversion_p (TREE_TYPE (op0
), TREE_TYPE (op1
))
3885 && !useless_type_conversion_p (TREE_TYPE (op1
), TREE_TYPE (op0
))
3886 && (!POINTER_TYPE_P (TREE_TYPE (op0
))
3887 || !POINTER_TYPE_P (TREE_TYPE (op1
))
3888 || TYPE_MODE (TREE_TYPE (op0
)) != TYPE_MODE (TREE_TYPE (op1
))))
3889 || !INTEGRAL_TYPE_P (type
))
3891 error ("type mismatch in comparison expression");
3892 debug_generic_stmt (TREE_TYPE (expr
));
3893 debug_generic_stmt (TREE_TYPE (op0
));
3894 debug_generic_stmt (TREE_TYPE (op1
));
3907 /* Verify the GIMPLE assignment statement STMT. Returns true if there
3908 is an error, otherwise false. */
3911 verify_gimple_modify_stmt (const_tree stmt
)
3913 tree lhs
= GIMPLE_STMT_OPERAND (stmt
, 0);
3914 tree rhs
= GIMPLE_STMT_OPERAND (stmt
, 1);
3916 gcc_assert (TREE_CODE (stmt
) == GIMPLE_MODIFY_STMT
);
3918 if (!useless_type_conversion_p (TREE_TYPE (lhs
),
3921 error ("non-trivial conversion at assignment");
3922 debug_generic_expr (TREE_TYPE (lhs
));
3923 debug_generic_expr (TREE_TYPE (rhs
));
3927 /* Loads/stores from/to a variable are ok. */
3928 if ((is_gimple_val (lhs
)
3929 && is_gimple_variable (rhs
))
3930 || (is_gimple_val (rhs
)
3931 && is_gimple_variable (lhs
)))
3934 /* Aggregate copies are ok. */
3935 if (!is_gimple_reg_type (TREE_TYPE (lhs
))
3936 && !is_gimple_reg_type (TREE_TYPE (rhs
)))
3939 /* We might get 'loads' from a parameter which is not a gimple value. */
3940 if (TREE_CODE (rhs
) == PARM_DECL
)
3941 return verify_gimple_expr (lhs
);
3943 if (!is_gimple_variable (lhs
)
3944 && verify_gimple_expr (lhs
))
3947 if (!is_gimple_variable (rhs
)
3948 && verify_gimple_expr (rhs
))
3954 /* Verify the GIMPLE statement STMT. Returns true if there is an
3955 error, otherwise false. */
3958 verify_gimple_stmt (tree stmt
)
3960 if (!is_gimple_stmt (stmt
))
3962 error ("is not a valid GIMPLE statement");
3966 if (OMP_DIRECTIVE_P (stmt
))
3968 /* OpenMP directives are validated by the FE and never operated
3969 on by the optimizers. Furthermore, OMP_FOR may contain
3970 non-gimple expressions when the main index variable has had
3971 its address taken. This does not affect the loop itself
3972 because the header of an OMP_FOR is merely used to determine
3973 how to setup the parallel iteration. */
3977 switch (TREE_CODE (stmt
))
3979 case GIMPLE_MODIFY_STMT
:
3980 return verify_gimple_modify_stmt (stmt
);
3987 if (!is_gimple_val (TREE_OPERAND (stmt
, 0)))
3989 error ("invalid operand to switch statement");
3990 debug_generic_expr (TREE_OPERAND (stmt
, 0));
3996 tree op
= TREE_OPERAND (stmt
, 0);
3998 if (TREE_CODE (TREE_TYPE (stmt
)) != VOID_TYPE
)
4000 error ("type error in return expression");
4005 || TREE_CODE (op
) == RESULT_DECL
)
4008 return verify_gimple_modify_stmt (op
);
4013 return verify_gimple_expr (stmt
);
4016 case CHANGE_DYNAMIC_TYPE_EXPR
:
4025 /* Verify the GIMPLE statements inside the statement list STMTS. */
4028 verify_gimple_1 (tree stmts
)
4030 tree_stmt_iterator tsi
;
4032 for (tsi
= tsi_start (stmts
); !tsi_end_p (tsi
); tsi_next (&tsi
))
4034 tree stmt
= tsi_stmt (tsi
);
4036 switch (TREE_CODE (stmt
))
4039 verify_gimple_1 (BIND_EXPR_BODY (stmt
));
4042 case TRY_CATCH_EXPR
:
4043 case TRY_FINALLY_EXPR
:
4044 verify_gimple_1 (TREE_OPERAND (stmt
, 0));
4045 verify_gimple_1 (TREE_OPERAND (stmt
, 1));
4049 verify_gimple_1 (CATCH_BODY (stmt
));
4052 case EH_FILTER_EXPR
:
4053 verify_gimple_1 (EH_FILTER_FAILURE (stmt
));
4057 if (verify_gimple_stmt (stmt
))
4058 debug_generic_expr (stmt
);
4063 /* Verify the GIMPLE statements inside the current function. */
4066 verify_gimple (void)
4068 verify_gimple_1 (BIND_EXPR_BODY (DECL_SAVED_TREE (cfun
->decl
)));
4071 /* Verify STMT, return true if STMT is not in GIMPLE form.
4072 TODO: Implement type checking. */
4075 verify_stmt (tree stmt
, bool last_in_block
)
4079 if (OMP_DIRECTIVE_P (stmt
))
4081 /* OpenMP directives are validated by the FE and never operated
4082 on by the optimizers. Furthermore, OMP_FOR may contain
4083 non-gimple expressions when the main index variable has had
4084 its address taken. This does not affect the loop itself
4085 because the header of an OMP_FOR is merely used to determine
4086 how to setup the parallel iteration. */
4090 if (!is_gimple_stmt (stmt
))
4092 error ("is not a valid GIMPLE statement");
4096 addr
= walk_tree (&stmt
, verify_expr
, NULL
, NULL
);
4099 debug_generic_stmt (addr
);
4103 /* If the statement is marked as part of an EH region, then it is
4104 expected that the statement could throw. Verify that when we
4105 have optimizations that simplify statements such that we prove
4106 that they cannot throw, that we update other data structures
4108 if (lookup_stmt_eh_region (stmt
) >= 0)
4110 if (!tree_could_throw_p (stmt
))
4112 error ("statement marked for throw, but doesn%'t");
4115 if (!last_in_block
&& tree_can_throw_internal (stmt
))
4117 error ("statement marked for throw in middle of block");
4125 debug_generic_stmt (stmt
);
4130 /* Return true when the T can be shared. */
4133 tree_node_can_be_shared (tree t
)
4135 if (IS_TYPE_OR_DECL_P (t
)
4136 || is_gimple_min_invariant (t
)
4137 || TREE_CODE (t
) == SSA_NAME
4138 || t
== error_mark_node
4139 || TREE_CODE (t
) == IDENTIFIER_NODE
)
4142 if (TREE_CODE (t
) == CASE_LABEL_EXPR
)
4145 while (((TREE_CODE (t
) == ARRAY_REF
|| TREE_CODE (t
) == ARRAY_RANGE_REF
)
4146 && is_gimple_min_invariant (TREE_OPERAND (t
, 1)))
4147 || TREE_CODE (t
) == COMPONENT_REF
4148 || TREE_CODE (t
) == REALPART_EXPR
4149 || TREE_CODE (t
) == IMAGPART_EXPR
)
4150 t
= TREE_OPERAND (t
, 0);
4159 /* Called via walk_trees. Verify tree sharing. */
4162 verify_node_sharing (tree
* tp
, int *walk_subtrees
, void *data
)
4164 struct pointer_set_t
*visited
= (struct pointer_set_t
*) data
;
4166 if (tree_node_can_be_shared (*tp
))
4168 *walk_subtrees
= false;
4172 if (pointer_set_insert (visited
, *tp
))
4179 /* Helper function for verify_gimple_tuples. */
4182 verify_gimple_tuples_1 (tree
*tp
, int *walk_subtrees ATTRIBUTE_UNUSED
,
4183 void *data ATTRIBUTE_UNUSED
)
4185 switch (TREE_CODE (*tp
))
4188 error ("unexpected non-tuple");
4198 /* Verify that there are no trees that should have been converted to
4199 gimple tuples. Return true if T contains a node that should have
4200 been converted to a gimple tuple, but hasn't. */
4203 verify_gimple_tuples (tree t
)
4205 return walk_tree (&t
, verify_gimple_tuples_1
, NULL
, NULL
) != NULL
;
4208 static bool eh_error_found
;
4210 verify_eh_throw_stmt_node (void **slot
, void *data
)
4212 struct throw_stmt_node
*node
= (struct throw_stmt_node
*)*slot
;
4213 struct pointer_set_t
*visited
= (struct pointer_set_t
*) data
;
4215 if (!pointer_set_contains (visited
, node
->stmt
))
4217 error ("Dead STMT in EH table");
4218 debug_generic_stmt (node
->stmt
);
4219 eh_error_found
= true;
4224 /* Verify the GIMPLE statement chain. */
4230 block_stmt_iterator bsi
;
4232 struct pointer_set_t
*visited
, *visited_stmts
;
4235 timevar_push (TV_TREE_STMT_VERIFY
);
4236 visited
= pointer_set_create ();
4237 visited_stmts
= pointer_set_create ();
4244 for (phi
= phi_nodes (bb
); phi
; phi
= PHI_CHAIN (phi
))
4246 int phi_num_args
= PHI_NUM_ARGS (phi
);
4248 pointer_set_insert (visited_stmts
, phi
);
4249 if (bb_for_stmt (phi
) != bb
)
4251 error ("bb_for_stmt (phi) is set to a wrong basic block");
4255 for (i
= 0; i
< phi_num_args
; i
++)
4257 tree t
= PHI_ARG_DEF (phi
, i
);
4260 /* Addressable variables do have SSA_NAMEs but they
4261 are not considered gimple values. */
4262 if (TREE_CODE (t
) != SSA_NAME
4263 && TREE_CODE (t
) != FUNCTION_DECL
4264 && !is_gimple_val (t
))
4266 error ("PHI def is not a GIMPLE value");
4267 debug_generic_stmt (phi
);
4268 debug_generic_stmt (t
);
4272 addr
= walk_tree (&t
, verify_expr
, (void *) 1, NULL
);
4275 debug_generic_stmt (addr
);
4279 addr
= walk_tree (&t
, verify_node_sharing
, visited
, NULL
);
4282 error ("incorrect sharing of tree nodes");
4283 debug_generic_stmt (phi
);
4284 debug_generic_stmt (addr
);
4290 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); )
4292 tree stmt
= bsi_stmt (bsi
);
4294 pointer_set_insert (visited_stmts
, stmt
);
4295 err
|= verify_gimple_tuples (stmt
);
4297 if (bb_for_stmt (stmt
) != bb
)
4299 error ("bb_for_stmt (stmt) is set to a wrong basic block");
4304 err
|= verify_stmt (stmt
, bsi_end_p (bsi
));
4305 addr
= walk_tree (&stmt
, verify_node_sharing
, visited
, NULL
);
4308 error ("incorrect sharing of tree nodes");
4309 debug_generic_stmt (stmt
);
4310 debug_generic_stmt (addr
);
4315 eh_error_found
= false;
4316 if (get_eh_throw_stmt_table (cfun
))
4317 htab_traverse (get_eh_throw_stmt_table (cfun
),
4318 verify_eh_throw_stmt_node
,
4321 if (err
| eh_error_found
)
4322 internal_error ("verify_stmts failed");
4324 pointer_set_destroy (visited
);
4325 pointer_set_destroy (visited_stmts
);
4326 verify_histograms ();
4327 timevar_pop (TV_TREE_STMT_VERIFY
);
4331 /* Verifies that the flow information is OK. */
4334 tree_verify_flow_info (void)
4338 block_stmt_iterator bsi
;
4343 if (ENTRY_BLOCK_PTR
->il
.tree
)
4345 error ("ENTRY_BLOCK has IL associated with it");
4349 if (EXIT_BLOCK_PTR
->il
.tree
)
4351 error ("EXIT_BLOCK has IL associated with it");
4355 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
4356 if (e
->flags
& EDGE_FALLTHRU
)
4358 error ("fallthru to exit from bb %d", e
->src
->index
);
4364 bool found_ctrl_stmt
= false;
4368 /* Skip labels on the start of basic block. */
4369 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
4371 tree prev_stmt
= stmt
;
4373 stmt
= bsi_stmt (bsi
);
4375 if (TREE_CODE (stmt
) != LABEL_EXPR
)
4378 if (prev_stmt
&& DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
)))
4380 error ("nonlocal label ");
4381 print_generic_expr (stderr
, LABEL_EXPR_LABEL (stmt
), 0);
4382 fprintf (stderr
, " is not first in a sequence of labels in bb %d",
4387 if (label_to_block (LABEL_EXPR_LABEL (stmt
)) != bb
)
4390 print_generic_expr (stderr
, LABEL_EXPR_LABEL (stmt
), 0);
4391 fprintf (stderr
, " to block does not match in bb %d",
4396 if (decl_function_context (LABEL_EXPR_LABEL (stmt
))
4397 != current_function_decl
)
4400 print_generic_expr (stderr
, LABEL_EXPR_LABEL (stmt
), 0);
4401 fprintf (stderr
, " has incorrect context in bb %d",
4407 /* Verify that body of basic block BB is free of control flow. */
4408 for (; !bsi_end_p (bsi
); bsi_next (&bsi
))
4410 tree stmt
= bsi_stmt (bsi
);
4412 if (found_ctrl_stmt
)
4414 error ("control flow in the middle of basic block %d",
4419 if (stmt_ends_bb_p (stmt
))
4420 found_ctrl_stmt
= true;
4422 if (TREE_CODE (stmt
) == LABEL_EXPR
)
4425 print_generic_expr (stderr
, LABEL_EXPR_LABEL (stmt
), 0);
4426 fprintf (stderr
, " in the middle of basic block %d", bb
->index
);
4431 bsi
= bsi_last (bb
);
4432 if (bsi_end_p (bsi
))
4435 stmt
= bsi_stmt (bsi
);
4437 err
|= verify_eh_edges (stmt
);
4439 if (is_ctrl_stmt (stmt
))
4441 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4442 if (e
->flags
& EDGE_FALLTHRU
)
4444 error ("fallthru edge after a control statement in bb %d",
4450 if (TREE_CODE (stmt
) != COND_EXPR
)
4452 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
4453 after anything else but if statement. */
4454 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4455 if (e
->flags
& (EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
))
4457 error ("true/false edge after a non-COND_EXPR in bb %d",
4463 switch (TREE_CODE (stmt
))
4470 if (COND_EXPR_THEN (stmt
) != NULL_TREE
4471 || COND_EXPR_ELSE (stmt
) != NULL_TREE
)
4473 error ("COND_EXPR with code in branches at the end of bb %d",
4478 extract_true_false_edges_from_block (bb
, &true_edge
, &false_edge
);
4480 if (!true_edge
|| !false_edge
4481 || !(true_edge
->flags
& EDGE_TRUE_VALUE
)
4482 || !(false_edge
->flags
& EDGE_FALSE_VALUE
)
4483 || (true_edge
->flags
& (EDGE_FALLTHRU
| EDGE_ABNORMAL
))
4484 || (false_edge
->flags
& (EDGE_FALLTHRU
| EDGE_ABNORMAL
))
4485 || EDGE_COUNT (bb
->succs
) >= 3)
4487 error ("wrong outgoing edge flags at end of bb %d",
4495 if (simple_goto_p (stmt
))
4497 error ("explicit goto at end of bb %d", bb
->index
);
4502 /* FIXME. We should double check that the labels in the
4503 destination blocks have their address taken. */
4504 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4505 if ((e
->flags
& (EDGE_FALLTHRU
| EDGE_TRUE_VALUE
4506 | EDGE_FALSE_VALUE
))
4507 || !(e
->flags
& EDGE_ABNORMAL
))
4509 error ("wrong outgoing edge flags at end of bb %d",
4517 if (!single_succ_p (bb
)
4518 || (single_succ_edge (bb
)->flags
4519 & (EDGE_FALLTHRU
| EDGE_ABNORMAL
4520 | EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
)))
4522 error ("wrong outgoing edge flags at end of bb %d", bb
->index
);
4525 if (single_succ (bb
) != EXIT_BLOCK_PTR
)
4527 error ("return edge does not point to exit in bb %d",
4540 vec
= SWITCH_LABELS (stmt
);
4541 n
= TREE_VEC_LENGTH (vec
);
4543 /* Mark all the destination basic blocks. */
4544 for (i
= 0; i
< n
; ++i
)
4546 tree lab
= CASE_LABEL (TREE_VEC_ELT (vec
, i
));
4547 basic_block label_bb
= label_to_block (lab
);
4549 gcc_assert (!label_bb
->aux
|| label_bb
->aux
== (void *)1);
4550 label_bb
->aux
= (void *)1;
4553 /* Verify that the case labels are sorted. */
4554 prev
= TREE_VEC_ELT (vec
, 0);
4555 for (i
= 1; i
< n
- 1; ++i
)
4557 tree c
= TREE_VEC_ELT (vec
, i
);
4560 error ("found default case not at end of case vector");
4564 if (! tree_int_cst_lt (CASE_LOW (prev
), CASE_LOW (c
)))
4566 error ("case labels not sorted: ");
4567 print_generic_expr (stderr
, prev
, 0);
4568 fprintf (stderr
," is greater than ");
4569 print_generic_expr (stderr
, c
, 0);
4570 fprintf (stderr
," but comes before it.\n");
4575 if (CASE_LOW (TREE_VEC_ELT (vec
, n
- 1)))
4577 error ("no default case found at end of case vector");
4581 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4585 error ("extra outgoing edge %d->%d",
4586 bb
->index
, e
->dest
->index
);
4589 e
->dest
->aux
= (void *)2;
4590 if ((e
->flags
& (EDGE_FALLTHRU
| EDGE_ABNORMAL
4591 | EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
)))
4593 error ("wrong outgoing edge flags at end of bb %d",
4599 /* Check that we have all of them. */
4600 for (i
= 0; i
< n
; ++i
)
4602 tree lab
= CASE_LABEL (TREE_VEC_ELT (vec
, i
));
4603 basic_block label_bb
= label_to_block (lab
);
4605 if (label_bb
->aux
!= (void *)2)
4607 error ("missing edge %i->%i",
4608 bb
->index
, label_bb
->index
);
4613 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4614 e
->dest
->aux
= (void *)0;
4621 if (dom_info_state (CDI_DOMINATORS
) >= DOM_NO_FAST_QUERY
)
4622 verify_dominators (CDI_DOMINATORS
);
4628 /* Updates phi nodes after creating a forwarder block joined
4629 by edge FALLTHRU. */
4632 tree_make_forwarder_block (edge fallthru
)
4636 basic_block dummy
, bb
;
4637 tree phi
, new_phi
, var
;
4639 dummy
= fallthru
->src
;
4640 bb
= fallthru
->dest
;
4642 if (single_pred_p (bb
))
4645 /* If we redirected a branch we must create new PHI nodes at the
4647 for (phi
= phi_nodes (dummy
); phi
; phi
= PHI_CHAIN (phi
))
4649 var
= PHI_RESULT (phi
);
4650 new_phi
= create_phi_node (var
, bb
);
4651 SSA_NAME_DEF_STMT (var
) = new_phi
;
4652 SET_PHI_RESULT (phi
, make_ssa_name (SSA_NAME_VAR (var
), phi
));
4653 add_phi_arg (new_phi
, PHI_RESULT (phi
), fallthru
);
4656 /* Ensure that the PHI node chain is in the same order. */
4657 set_phi_nodes (bb
, phi_reverse (phi_nodes (bb
)));
4659 /* Add the arguments we have stored on edges. */
4660 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4665 flush_pending_stmts (e
);
4670 /* Return a non-special label in the head of basic block BLOCK.
4671 Create one if it doesn't exist. */
4674 tree_block_label (basic_block bb
)
4676 block_stmt_iterator i
, s
= bsi_start (bb
);
4680 for (i
= s
; !bsi_end_p (i
); first
= false, bsi_next (&i
))
4682 stmt
= bsi_stmt (i
);
4683 if (TREE_CODE (stmt
) != LABEL_EXPR
)
4685 label
= LABEL_EXPR_LABEL (stmt
);
4686 if (!DECL_NONLOCAL (label
))
4689 bsi_move_before (&i
, &s
);
4694 label
= create_artificial_label ();
4695 stmt
= build1 (LABEL_EXPR
, void_type_node
, label
);
4696 bsi_insert_before (&s
, stmt
, BSI_NEW_STMT
);
4701 /* Attempt to perform edge redirection by replacing a possibly complex
4702 jump instruction by a goto or by removing the jump completely.
4703 This can apply only if all edges now point to the same block. The
4704 parameters and return values are equivalent to
4705 redirect_edge_and_branch. */
4708 tree_try_redirect_by_replacing_jump (edge e
, basic_block target
)
4710 basic_block src
= e
->src
;
4711 block_stmt_iterator b
;
4714 /* We can replace or remove a complex jump only when we have exactly
4716 if (EDGE_COUNT (src
->succs
) != 2
4717 /* Verify that all targets will be TARGET. Specifically, the
4718 edge that is not E must also go to TARGET. */
4719 || EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
)->dest
!= target
)
4725 stmt
= bsi_stmt (b
);
4727 if (TREE_CODE (stmt
) == COND_EXPR
4728 || TREE_CODE (stmt
) == SWITCH_EXPR
)
4730 bsi_remove (&b
, true);
4731 e
= ssa_redirect_edge (e
, target
);
4732 e
->flags
= EDGE_FALLTHRU
;
4740 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4741 edge representing the redirected branch. */
4744 tree_redirect_edge_and_branch (edge e
, basic_block dest
)
4746 basic_block bb
= e
->src
;
4747 block_stmt_iterator bsi
;
4751 if (e
->flags
& EDGE_ABNORMAL
)
4754 if (e
->src
!= ENTRY_BLOCK_PTR
4755 && (ret
= tree_try_redirect_by_replacing_jump (e
, dest
)))
4758 if (e
->dest
== dest
)
4761 bsi
= bsi_last (bb
);
4762 stmt
= bsi_end_p (bsi
) ? NULL
: bsi_stmt (bsi
);
4764 switch (stmt
? TREE_CODE (stmt
) : ERROR_MARK
)
4767 /* For COND_EXPR, we only need to redirect the edge. */
4771 /* No non-abnormal edges should lead from a non-simple goto, and
4772 simple ones should be represented implicitly. */
4777 tree cases
= get_cases_for_edge (e
, stmt
);
4778 tree label
= tree_block_label (dest
);
4780 /* If we have a list of cases associated with E, then use it
4781 as it's a lot faster than walking the entire case vector. */
4784 edge e2
= find_edge (e
->src
, dest
);
4791 CASE_LABEL (cases
) = label
;
4792 cases
= TREE_CHAIN (cases
);
4795 /* If there was already an edge in the CFG, then we need
4796 to move all the cases associated with E to E2. */
4799 tree cases2
= get_cases_for_edge (e2
, stmt
);
4801 TREE_CHAIN (last
) = TREE_CHAIN (cases2
);
4802 TREE_CHAIN (cases2
) = first
;
4807 tree vec
= SWITCH_LABELS (stmt
);
4808 size_t i
, n
= TREE_VEC_LENGTH (vec
);
4810 for (i
= 0; i
< n
; i
++)
4812 tree elt
= TREE_VEC_ELT (vec
, i
);
4814 if (label_to_block (CASE_LABEL (elt
)) == e
->dest
)
4815 CASE_LABEL (elt
) = label
;
4823 bsi_remove (&bsi
, true);
4824 e
->flags
|= EDGE_FALLTHRU
;
4829 case OMP_SECTIONS_SWITCH
:
4831 /* The edges from OMP constructs can be simply redirected. */
4835 /* Otherwise it must be a fallthru edge, and we don't need to
4836 do anything besides redirecting it. */
4837 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
4841 /* Update/insert PHI nodes as necessary. */
4843 /* Now update the edges in the CFG. */
4844 e
= ssa_redirect_edge (e
, dest
);
4849 /* Returns true if it is possible to remove edge E by redirecting
4850 it to the destination of the other edge from E->src. */
4853 tree_can_remove_branch_p (const_edge e
)
4855 if (e
->flags
& EDGE_ABNORMAL
)
4861 /* Simple wrapper, as we can always redirect fallthru edges. */
4864 tree_redirect_edge_and_branch_force (edge e
, basic_block dest
)
4866 e
= tree_redirect_edge_and_branch (e
, dest
);
4873 /* Splits basic block BB after statement STMT (but at least after the
4874 labels). If STMT is NULL, BB is split just after the labels. */
4877 tree_split_block (basic_block bb
, void *stmt
)
4879 block_stmt_iterator bsi
;
4880 tree_stmt_iterator tsi_tgt
;
4886 new_bb
= create_empty_bb (bb
);
4888 /* Redirect the outgoing edges. */
4889 new_bb
->succs
= bb
->succs
;
4891 FOR_EACH_EDGE (e
, ei
, new_bb
->succs
)
4894 if (stmt
&& TREE_CODE ((tree
) stmt
) == LABEL_EXPR
)
4897 /* Move everything from BSI to the new basic block. */
4898 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
4900 act
= bsi_stmt (bsi
);
4901 if (TREE_CODE (act
) == LABEL_EXPR
)
4914 if (bsi_end_p (bsi
))
4917 /* Split the statement list - avoid re-creating new containers as this
4918 brings ugly quadratic memory consumption in the inliner.
4919 (We are still quadratic since we need to update stmt BB pointers,
4921 list
= tsi_split_statement_list_before (&bsi
.tsi
);
4922 set_bb_stmt_list (new_bb
, list
);
4923 for (tsi_tgt
= tsi_start (list
);
4924 !tsi_end_p (tsi_tgt
); tsi_next (&tsi_tgt
))
4925 change_bb_for_stmt (tsi_stmt (tsi_tgt
), new_bb
);
4931 /* Moves basic block BB after block AFTER. */
4934 tree_move_block_after (basic_block bb
, basic_block after
)
4936 if (bb
->prev_bb
== after
)
4940 link_block (bb
, after
);
4946 /* Return true if basic_block can be duplicated. */
4949 tree_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED
)
4955 /* Create a duplicate of the basic block BB. NOTE: This does not
4956 preserve SSA form. */
4959 tree_duplicate_bb (basic_block bb
)
4962 block_stmt_iterator bsi
, bsi_tgt
;
4965 new_bb
= create_empty_bb (EXIT_BLOCK_PTR
->prev_bb
);
4967 /* Copy the PHI nodes. We ignore PHI node arguments here because
4968 the incoming edges have not been setup yet. */
4969 for (phi
= phi_nodes (bb
); phi
; phi
= PHI_CHAIN (phi
))
4971 tree copy
= create_phi_node (PHI_RESULT (phi
), new_bb
);
4972 create_new_def_for (PHI_RESULT (copy
), copy
, PHI_RESULT_PTR (copy
));
4975 /* Keep the chain of PHI nodes in the same order so that they can be
4976 updated by ssa_redirect_edge. */
4977 set_phi_nodes (new_bb
, phi_reverse (phi_nodes (new_bb
)));
4979 bsi_tgt
= bsi_start (new_bb
);
4980 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
4982 def_operand_p def_p
;
4983 ssa_op_iter op_iter
;
4987 stmt
= bsi_stmt (bsi
);
4988 if (TREE_CODE (stmt
) == LABEL_EXPR
)
4991 /* Create a new copy of STMT and duplicate STMT's virtual
4993 copy
= unshare_expr (stmt
);
4994 bsi_insert_after (&bsi_tgt
, copy
, BSI_NEW_STMT
);
4995 copy_virtual_operands (copy
, stmt
);
4996 region
= lookup_stmt_eh_region (stmt
);
4998 add_stmt_to_eh_region (copy
, region
);
4999 gimple_duplicate_stmt_histograms (cfun
, copy
, cfun
, stmt
);
5001 /* Create new names for all the definitions created by COPY and
5002 add replacement mappings for each new name. */
5003 FOR_EACH_SSA_DEF_OPERAND (def_p
, copy
, op_iter
, SSA_OP_ALL_DEFS
)
5004 create_new_def_for (DEF_FROM_PTR (def_p
), copy
, def_p
);
5011 /* Basic block BB_COPY was created by code duplication. Add phi node
5012 arguments for edges going out of BB_COPY. The blocks that were
5013 duplicated have BB_DUPLICATED set. */
5016 add_phi_args_after_copy_bb (basic_block bb_copy
)
5018 basic_block bb
, dest
;
5021 tree phi
, phi_copy
, phi_next
, def
;
5023 bb
= get_bb_original (bb_copy
);
5025 FOR_EACH_EDGE (e_copy
, ei
, bb_copy
->succs
)
5027 if (!phi_nodes (e_copy
->dest
))
5030 if (e_copy
->dest
->flags
& BB_DUPLICATED
)
5031 dest
= get_bb_original (e_copy
->dest
);
5033 dest
= e_copy
->dest
;
5035 e
= find_edge (bb
, dest
);
5038 /* During loop unrolling the target of the latch edge is copied.
5039 In this case we are not looking for edge to dest, but to
5040 duplicated block whose original was dest. */
5041 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5042 if ((e
->dest
->flags
& BB_DUPLICATED
)
5043 && get_bb_original (e
->dest
) == dest
)
5046 gcc_assert (e
!= NULL
);
5049 for (phi
= phi_nodes (e
->dest
), phi_copy
= phi_nodes (e_copy
->dest
);
5051 phi
= phi_next
, phi_copy
= PHI_CHAIN (phi_copy
))
5053 phi_next
= PHI_CHAIN (phi
);
5054 def
= PHI_ARG_DEF_FROM_EDGE (phi
, e
);
5055 add_phi_arg (phi_copy
, def
, e_copy
);
5060 /* Blocks in REGION_COPY array of length N_REGION were created by
5061 duplication of basic blocks. Add phi node arguments for edges
5062 going from these blocks. */
5065 add_phi_args_after_copy (basic_block
*region_copy
, unsigned n_region
)
5069 for (i
= 0; i
< n_region
; i
++)
5070 region_copy
[i
]->flags
|= BB_DUPLICATED
;
5072 for (i
= 0; i
< n_region
; i
++)
5073 add_phi_args_after_copy_bb (region_copy
[i
]);
5075 for (i
= 0; i
< n_region
; i
++)
5076 region_copy
[i
]->flags
&= ~BB_DUPLICATED
;
5079 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
5080 important exit edge EXIT. By important we mean that no SSA name defined
5081 inside region is live over the other exit edges of the region. All entry
5082 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
5083 to the duplicate of the region. SSA form, dominance and loop information
5084 is updated. The new basic blocks are stored to REGION_COPY in the same
5085 order as they had in REGION, provided that REGION_COPY is not NULL.
5086 The function returns false if it is unable to copy the region,
5090 tree_duplicate_sese_region (edge entry
, edge exit
,
5091 basic_block
*region
, unsigned n_region
,
5092 basic_block
*region_copy
)
5095 bool free_region_copy
= false, copying_header
= false;
5096 struct loop
*loop
= entry
->dest
->loop_father
;
5098 VEC (basic_block
, heap
) *doms
;
5100 int total_freq
= 0, entry_freq
= 0;
5101 gcov_type total_count
= 0, entry_count
= 0;
5103 if (!can_copy_bbs_p (region
, n_region
))
5106 /* Some sanity checking. Note that we do not check for all possible
5107 missuses of the functions. I.e. if you ask to copy something weird,
5108 it will work, but the state of structures probably will not be
5110 for (i
= 0; i
< n_region
; i
++)
5112 /* We do not handle subloops, i.e. all the blocks must belong to the
5114 if (region
[i
]->loop_father
!= loop
)
5117 if (region
[i
] != entry
->dest
5118 && region
[i
] == loop
->header
)
5122 set_loop_copy (loop
, loop
);
5124 /* In case the function is used for loop header copying (which is the primary
5125 use), ensure that EXIT and its copy will be new latch and entry edges. */
5126 if (loop
->header
== entry
->dest
)
5128 copying_header
= true;
5129 set_loop_copy (loop
, loop_outer (loop
));
5131 if (!dominated_by_p (CDI_DOMINATORS
, loop
->latch
, exit
->src
))
5134 for (i
= 0; i
< n_region
; i
++)
5135 if (region
[i
] != exit
->src
5136 && dominated_by_p (CDI_DOMINATORS
, region
[i
], exit
->src
))
5142 region_copy
= XNEWVEC (basic_block
, n_region
);
5143 free_region_copy
= true;
5146 gcc_assert (!need_ssa_update_p ());
5148 /* Record blocks outside the region that are dominated by something
5151 initialize_original_copy_tables ();
5153 doms
= get_dominated_by_region (CDI_DOMINATORS
, region
, n_region
);
5155 if (entry
->dest
->count
)
5157 total_count
= entry
->dest
->count
;
5158 entry_count
= entry
->count
;
5159 /* Fix up corner cases, to avoid division by zero or creation of negative
5161 if (entry_count
> total_count
)
5162 entry_count
= total_count
;
5166 total_freq
= entry
->dest
->frequency
;
5167 entry_freq
= EDGE_FREQUENCY (entry
);
5168 /* Fix up corner cases, to avoid division by zero or creation of negative
5170 if (total_freq
== 0)
5172 else if (entry_freq
> total_freq
)
5173 entry_freq
= total_freq
;
5176 copy_bbs (region
, n_region
, region_copy
, &exit
, 1, &exit_copy
, loop
,
5177 split_edge_bb_loc (entry
));
5180 scale_bbs_frequencies_gcov_type (region
, n_region
,
5181 total_count
- entry_count
,
5183 scale_bbs_frequencies_gcov_type (region_copy
, n_region
, entry_count
,
5188 scale_bbs_frequencies_int (region
, n_region
, total_freq
- entry_freq
,
5190 scale_bbs_frequencies_int (region_copy
, n_region
, entry_freq
, total_freq
);
5195 loop
->header
= exit
->dest
;
5196 loop
->latch
= exit
->src
;
5199 /* Redirect the entry and add the phi node arguments. */
5200 redirected
= redirect_edge_and_branch (entry
, get_bb_copy (entry
->dest
));
5201 gcc_assert (redirected
!= NULL
);
5202 flush_pending_stmts (entry
);
5204 /* Concerning updating of dominators: We must recount dominators
5205 for entry block and its copy. Anything that is outside of the
5206 region, but was dominated by something inside needs recounting as
5208 set_immediate_dominator (CDI_DOMINATORS
, entry
->dest
, entry
->src
);
5209 VEC_safe_push (basic_block
, heap
, doms
, get_bb_original (entry
->dest
));
5210 iterate_fix_dominators (CDI_DOMINATORS
, doms
, false);
5213 /* Add the other PHI node arguments. */
5214 add_phi_args_after_copy (region_copy
, n_region
);
5216 /* Update the SSA web. */
5217 update_ssa (TODO_update_ssa
);
5219 if (free_region_copy
)
5222 free_original_copy_tables ();
5227 DEF_VEC_P(basic_block);
5228 DEF_VEC_ALLOC_P(basic_block,heap);
5231 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
5232 adding blocks when the dominator traversal reaches EXIT. This
5233 function silently assumes that ENTRY strictly dominates EXIT. */
5236 gather_blocks_in_sese_region (basic_block entry
, basic_block exit
,
5237 VEC(basic_block
,heap
) **bbs_p
)
5241 for (son
= first_dom_son (CDI_DOMINATORS
, entry
);
5243 son
= next_dom_son (CDI_DOMINATORS
, son
))
5245 VEC_safe_push (basic_block
, heap
, *bbs_p
, son
);
5247 gather_blocks_in_sese_region (son
, exit
, bbs_p
);
5257 bitmap vars_to_remove
;
5258 htab_t new_label_map
;
5262 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
5263 contained in *TP and change the DECL_CONTEXT of every local
5264 variable referenced in *TP. */
5267 move_stmt_r (tree
*tp
, int *walk_subtrees
, void *data
)
5269 struct move_stmt_d
*p
= (struct move_stmt_d
*) data
;
5273 && (EXPR_P (t
) || GIMPLE_STMT_P (t
)))
5274 TREE_BLOCK (t
) = p
->block
;
5276 if (OMP_DIRECTIVE_P (t
)
5277 && TREE_CODE (t
) != OMP_RETURN
5278 && TREE_CODE (t
) != OMP_CONTINUE
)
5280 /* Do not remap variables inside OMP directives. Variables
5281 referenced in clauses and directive header belong to the
5282 parent function and should not be moved into the child
5284 bool save_remap_decls_p
= p
->remap_decls_p
;
5285 p
->remap_decls_p
= false;
5288 walk_tree (&OMP_BODY (t
), move_stmt_r
, p
, NULL
);
5290 p
->remap_decls_p
= save_remap_decls_p
;
5292 else if (DECL_P (t
) && DECL_CONTEXT (t
) == p
->from_context
)
5294 if (TREE_CODE (t
) == LABEL_DECL
)
5296 if (p
->new_label_map
)
5298 struct tree_map in
, *out
;
5300 out
= htab_find_with_hash (p
->new_label_map
, &in
, DECL_UID (t
));
5305 DECL_CONTEXT (t
) = p
->to_context
;
5307 else if (p
->remap_decls_p
)
5309 DECL_CONTEXT (t
) = p
->to_context
;
5311 if (TREE_CODE (t
) == VAR_DECL
)
5313 struct function
*f
= DECL_STRUCT_FUNCTION (p
->to_context
);
5314 f
->unexpanded_var_list
5315 = tree_cons (0, t
, f
->unexpanded_var_list
);
5317 /* Mark T to be removed from the original function,
5318 otherwise it will be given a DECL_RTL when the
5319 original function is expanded. */
5320 bitmap_set_bit (p
->vars_to_remove
, DECL_UID (t
));
5324 else if (TYPE_P (t
))
5331 /* Move basic block BB from function CFUN to function DEST_FN. The
5332 block is moved out of the original linked list and placed after
5333 block AFTER in the new list. Also, the block is removed from the
5334 original array of blocks and placed in DEST_FN's array of blocks.
5335 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
5336 updated to reflect the moved edges.
5338 On exit, local variables that need to be removed from
5339 CFUN->UNEXPANDED_VAR_LIST will have been added to VARS_TO_REMOVE. */
5342 move_block_to_fn (struct function
*dest_cfun
, basic_block bb
,
5343 basic_block after
, bool update_edge_count_p
,
5344 bitmap vars_to_remove
, htab_t new_label_map
, int eh_offset
)
5346 struct control_flow_graph
*cfg
;
5349 block_stmt_iterator si
;
5350 struct move_stmt_d d
;
5351 unsigned old_len
, new_len
;
5353 /* Remove BB from dominance structures. */
5354 delete_from_dominance_info (CDI_DOMINATORS
, bb
);
5356 /* Link BB to the new linked list. */
5357 move_block_after (bb
, after
);
5359 /* Update the edge count in the corresponding flowgraphs. */
5360 if (update_edge_count_p
)
5361 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5363 cfun
->cfg
->x_n_edges
--;
5364 dest_cfun
->cfg
->x_n_edges
++;
5367 /* Remove BB from the original basic block array. */
5368 VEC_replace (basic_block
, cfun
->cfg
->x_basic_block_info
, bb
->index
, NULL
);
5369 cfun
->cfg
->x_n_basic_blocks
--;
5371 /* Grow DEST_CFUN's basic block array if needed. */
5372 cfg
= dest_cfun
->cfg
;
5373 cfg
->x_n_basic_blocks
++;
5374 if (bb
->index
>= cfg
->x_last_basic_block
)
5375 cfg
->x_last_basic_block
= bb
->index
+ 1;
5377 old_len
= VEC_length (basic_block
, cfg
->x_basic_block_info
);
5378 if ((unsigned) cfg
->x_last_basic_block
>= old_len
)
5380 new_len
= cfg
->x_last_basic_block
+ (cfg
->x_last_basic_block
+ 3) / 4;
5381 VEC_safe_grow_cleared (basic_block
, gc
, cfg
->x_basic_block_info
,
5385 VEC_replace (basic_block
, cfg
->x_basic_block_info
,
5388 /* The statements in BB need to be associated with a new TREE_BLOCK.
5389 Labels need to be associated with a new label-to-block map. */
5390 memset (&d
, 0, sizeof (d
));
5391 d
.vars_to_remove
= vars_to_remove
;
5393 for (si
= bsi_start (bb
); !bsi_end_p (si
); bsi_next (&si
))
5395 tree stmt
= bsi_stmt (si
);
5398 d
.from_context
= cfun
->decl
;
5399 d
.to_context
= dest_cfun
->decl
;
5400 d
.remap_decls_p
= true;
5401 d
.new_label_map
= new_label_map
;
5402 if (TREE_BLOCK (stmt
))
5403 d
.block
= DECL_INITIAL (dest_cfun
->decl
);
5405 walk_tree (&stmt
, move_stmt_r
, &d
, NULL
);
5407 if (TREE_CODE (stmt
) == LABEL_EXPR
)
5409 tree label
= LABEL_EXPR_LABEL (stmt
);
5410 int uid
= LABEL_DECL_UID (label
);
5412 gcc_assert (uid
> -1);
5414 old_len
= VEC_length (basic_block
, cfg
->x_label_to_block_map
);
5415 if (old_len
<= (unsigned) uid
)
5417 new_len
= 3 * uid
/ 2;
5418 VEC_safe_grow_cleared (basic_block
, gc
,
5419 cfg
->x_label_to_block_map
, new_len
);
5422 VEC_replace (basic_block
, cfg
->x_label_to_block_map
, uid
, bb
);
5423 VEC_replace (basic_block
, cfun
->cfg
->x_label_to_block_map
, uid
, NULL
);
5425 gcc_assert (DECL_CONTEXT (label
) == dest_cfun
->decl
);
5427 if (uid
>= dest_cfun
->last_label_uid
)
5428 dest_cfun
->last_label_uid
= uid
+ 1;
5430 else if (TREE_CODE (stmt
) == RESX_EXPR
&& eh_offset
!= 0)
5431 TREE_OPERAND (stmt
, 0) =
5432 build_int_cst (NULL_TREE
,
5433 TREE_INT_CST_LOW (TREE_OPERAND (stmt
, 0))
5436 region
= lookup_stmt_eh_region (stmt
);
5439 add_stmt_to_eh_region_fn (dest_cfun
, stmt
, region
+ eh_offset
);
5440 remove_stmt_from_eh_region (stmt
);
5441 gimple_duplicate_stmt_histograms (dest_cfun
, stmt
, cfun
, stmt
);
5442 gimple_remove_stmt_histograms (cfun
, stmt
);
5447 /* Examine the statements in BB (which is in SRC_CFUN); find and return
5448 the outermost EH region. Use REGION as the incoming base EH region. */
5451 find_outermost_region_in_block (struct function
*src_cfun
,
5452 basic_block bb
, int region
)
5454 block_stmt_iterator si
;
5456 for (si
= bsi_start (bb
); !bsi_end_p (si
); bsi_next (&si
))
5458 tree stmt
= bsi_stmt (si
);
5461 if (TREE_CODE (stmt
) == RESX_EXPR
)
5462 stmt_region
= TREE_INT_CST_LOW (TREE_OPERAND (stmt
, 0));
5464 stmt_region
= lookup_stmt_eh_region_fn (src_cfun
, stmt
);
5465 if (stmt_region
> 0)
5468 region
= stmt_region
;
5469 else if (stmt_region
!= region
)
5471 region
= eh_region_outermost (src_cfun
, stmt_region
, region
);
5472 gcc_assert (region
!= -1);
5481 new_label_mapper (tree decl
, void *data
)
5483 htab_t hash
= (htab_t
) data
;
5487 gcc_assert (TREE_CODE (decl
) == LABEL_DECL
);
5489 m
= xmalloc (sizeof (struct tree_map
));
5490 m
->hash
= DECL_UID (decl
);
5491 m
->base
.from
= decl
;
5492 m
->to
= create_artificial_label ();
5493 LABEL_DECL_UID (m
->to
) = LABEL_DECL_UID (decl
);
5495 slot
= htab_find_slot_with_hash (hash
, m
, m
->hash
, INSERT
);
5496 gcc_assert (*slot
== NULL
);
5503 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
5504 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
5505 single basic block in the original CFG and the new basic block is
5506 returned. DEST_CFUN must not have a CFG yet.
5508 Note that the region need not be a pure SESE region. Blocks inside
5509 the region may contain calls to abort/exit. The only restriction
5510 is that ENTRY_BB should be the only entry point and it must
5513 All local variables referenced in the region are assumed to be in
5514 the corresponding BLOCK_VARS and unexpanded variable lists
5515 associated with DEST_CFUN. */
5518 move_sese_region_to_fn (struct function
*dest_cfun
, basic_block entry_bb
,
5519 basic_block exit_bb
)
5521 VEC(basic_block
,heap
) *bbs
;
5522 basic_block after
, bb
, *entry_pred
, *exit_succ
;
5523 struct function
*saved_cfun
;
5524 int *entry_flag
, *exit_flag
, eh_offset
;
5525 unsigned i
, num_entry_edges
, num_exit_edges
;
5528 bitmap vars_to_remove
;
5529 htab_t new_label_map
;
5533 /* Collect all the blocks in the region. Manually add ENTRY_BB
5534 because it won't be added by dfs_enumerate_from. */
5535 calculate_dominance_info (CDI_DOMINATORS
);
5537 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
5539 gcc_assert (entry_bb
!= exit_bb
5541 || dominated_by_p (CDI_DOMINATORS
, exit_bb
, entry_bb
)));
5544 VEC_safe_push (basic_block
, heap
, bbs
, entry_bb
);
5545 gather_blocks_in_sese_region (entry_bb
, exit_bb
, &bbs
);
5547 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
5548 the predecessor edges to ENTRY_BB and the successor edges to
5549 EXIT_BB so that we can re-attach them to the new basic block that
5550 will replace the region. */
5551 num_entry_edges
= EDGE_COUNT (entry_bb
->preds
);
5552 entry_pred
= (basic_block
*) xcalloc (num_entry_edges
, sizeof (basic_block
));
5553 entry_flag
= (int *) xcalloc (num_entry_edges
, sizeof (int));
5555 for (ei
= ei_start (entry_bb
->preds
); (e
= ei_safe_edge (ei
)) != NULL
;)
5557 entry_flag
[i
] = e
->flags
;
5558 entry_pred
[i
++] = e
->src
;
5564 num_exit_edges
= EDGE_COUNT (exit_bb
->succs
);
5565 exit_succ
= (basic_block
*) xcalloc (num_exit_edges
,
5566 sizeof (basic_block
));
5567 exit_flag
= (int *) xcalloc (num_exit_edges
, sizeof (int));
5569 for (ei
= ei_start (exit_bb
->succs
); (e
= ei_safe_edge (ei
)) != NULL
;)
5571 exit_flag
[i
] = e
->flags
;
5572 exit_succ
[i
++] = e
->dest
;
5583 /* Switch context to the child function to initialize DEST_FN's CFG. */
5584 gcc_assert (dest_cfun
->cfg
== NULL
);
5585 set_cfun (dest_cfun
);
5587 init_empty_tree_cfg ();
5589 /* Initialize EH information for the new function. */
5591 new_label_map
= NULL
;
5596 for (i
= 0; VEC_iterate (basic_block
, bbs
, i
, bb
); i
++)
5597 region
= find_outermost_region_in_block (saved_cfun
, bb
, region
);
5599 init_eh_for_function ();
5602 new_label_map
= htab_create (17, tree_map_hash
, tree_map_eq
, free
);
5603 eh_offset
= duplicate_eh_regions (saved_cfun
, new_label_mapper
,
5604 new_label_map
, region
, 0);
5608 set_cfun (saved_cfun
);
5610 /* Move blocks from BBS into DEST_CFUN. */
5611 gcc_assert (VEC_length (basic_block
, bbs
) >= 2);
5612 after
= dest_cfun
->cfg
->x_entry_block_ptr
;
5613 vars_to_remove
= BITMAP_ALLOC (NULL
);
5614 for (i
= 0; VEC_iterate (basic_block
, bbs
, i
, bb
); i
++)
5616 /* No need to update edge counts on the last block. It has
5617 already been updated earlier when we detached the region from
5618 the original CFG. */
5619 move_block_to_fn (dest_cfun
, bb
, after
, bb
!= exit_bb
, vars_to_remove
,
5620 new_label_map
, eh_offset
);
5625 htab_delete (new_label_map
);
5627 /* Remove the variables marked in VARS_TO_REMOVE from
5628 CFUN->UNEXPANDED_VAR_LIST. Otherwise, they will be given a
5629 DECL_RTL in the context of CFUN. */
5630 if (!bitmap_empty_p (vars_to_remove
))
5634 for (p
= &cfun
->unexpanded_var_list
; *p
; )
5636 tree var
= TREE_VALUE (*p
);
5637 if (bitmap_bit_p (vars_to_remove
, DECL_UID (var
)))
5639 *p
= TREE_CHAIN (*p
);
5643 p
= &TREE_CHAIN (*p
);
5647 BITMAP_FREE (vars_to_remove
);
5649 /* Rewire the entry and exit blocks. The successor to the entry
5650 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
5651 the child function. Similarly, the predecessor of DEST_FN's
5652 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
5653 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
5654 various CFG manipulation function get to the right CFG.
5656 FIXME, this is silly. The CFG ought to become a parameter to
5658 set_cfun (dest_cfun
);
5659 make_edge (ENTRY_BLOCK_PTR
, entry_bb
, EDGE_FALLTHRU
);
5661 make_edge (exit_bb
, EXIT_BLOCK_PTR
, 0);
5662 set_cfun (saved_cfun
);
5664 /* Back in the original function, the SESE region has disappeared,
5665 create a new basic block in its place. */
5666 bb
= create_empty_bb (entry_pred
[0]);
5667 for (i
= 0; i
< num_entry_edges
; i
++)
5668 make_edge (entry_pred
[i
], bb
, entry_flag
[i
]);
5670 for (i
= 0; i
< num_exit_edges
; i
++)
5671 make_edge (bb
, exit_succ
[i
], exit_flag
[i
]);
5680 free_dominance_info (CDI_DOMINATORS
);
5681 free_dominance_info (CDI_POST_DOMINATORS
);
5682 VEC_free (basic_block
, heap
, bbs
);
5688 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */
5691 dump_function_to_file (tree fn
, FILE *file
, int flags
)
5693 tree arg
, vars
, var
;
5694 struct function
*dsf
;
5695 bool ignore_topmost_bind
= false, any_var
= false;
5699 fprintf (file
, "%s (", lang_hooks
.decl_printable_name (fn
, 2));
5701 arg
= DECL_ARGUMENTS (fn
);
5704 print_generic_expr (file
, arg
, dump_flags
);
5705 if (TREE_CHAIN (arg
))
5706 fprintf (file
, ", ");
5707 arg
= TREE_CHAIN (arg
);
5709 fprintf (file
, ")\n");
5711 dsf
= DECL_STRUCT_FUNCTION (fn
);
5712 if (dsf
&& (flags
& TDF_DETAILS
))
5713 dump_eh_tree (file
, dsf
);
5715 if (flags
& TDF_RAW
)
5717 dump_node (fn
, TDF_SLIM
| flags
, file
);
5721 /* Switch CFUN to point to FN. */
5722 push_cfun (DECL_STRUCT_FUNCTION (fn
));
5724 /* When GIMPLE is lowered, the variables are no longer available in
5725 BIND_EXPRs, so display them separately. */
5726 if (cfun
&& cfun
->decl
== fn
&& cfun
->unexpanded_var_list
)
5728 ignore_topmost_bind
= true;
5730 fprintf (file
, "{\n");
5731 for (vars
= cfun
->unexpanded_var_list
; vars
; vars
= TREE_CHAIN (vars
))
5733 var
= TREE_VALUE (vars
);
5735 print_generic_decl (file
, var
, flags
);
5736 fprintf (file
, "\n");
5742 if (cfun
&& cfun
->decl
== fn
&& cfun
->cfg
&& basic_block_info
)
5744 /* Make a CFG based dump. */
5745 check_bb_profile (ENTRY_BLOCK_PTR
, file
);
5746 if (!ignore_topmost_bind
)
5747 fprintf (file
, "{\n");
5749 if (any_var
&& n_basic_blocks
)
5750 fprintf (file
, "\n");
5753 dump_generic_bb (file
, bb
, 2, flags
);
5755 fprintf (file
, "}\n");
5756 check_bb_profile (EXIT_BLOCK_PTR
, file
);
5762 /* Make a tree based dump. */
5763 chain
= DECL_SAVED_TREE (fn
);
5765 if (chain
&& TREE_CODE (chain
) == BIND_EXPR
)
5767 if (ignore_topmost_bind
)
5769 chain
= BIND_EXPR_BODY (chain
);
5777 if (!ignore_topmost_bind
)
5778 fprintf (file
, "{\n");
5783 fprintf (file
, "\n");
5785 print_generic_stmt_indented (file
, chain
, flags
, indent
);
5786 if (ignore_topmost_bind
)
5787 fprintf (file
, "}\n");
5790 fprintf (file
, "\n\n");
5797 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
5800 debug_function (tree fn
, int flags
)
5802 dump_function_to_file (fn
, stderr
, flags
);
5806 /* Pretty print of the loops intermediate representation. */
5807 static void print_loop (FILE *, struct loop
*, int);
5808 static void print_pred_bbs (FILE *, basic_block bb
);
5809 static void print_succ_bbs (FILE *, basic_block bb
);
5812 /* Print on FILE the indexes for the predecessors of basic_block BB. */
5815 print_pred_bbs (FILE *file
, basic_block bb
)
5820 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
5821 fprintf (file
, "bb_%d ", e
->src
->index
);
5825 /* Print on FILE the indexes for the successors of basic_block BB. */
5828 print_succ_bbs (FILE *file
, basic_block bb
)
5833 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5834 fprintf (file
, "bb_%d ", e
->dest
->index
);
5838 /* Pretty print LOOP on FILE, indented INDENT spaces. */
5841 print_loop (FILE *file
, struct loop
*loop
, int indent
)
5849 s_indent
= (char *) alloca ((size_t) indent
+ 1);
5850 memset ((void *) s_indent
, ' ', (size_t) indent
);
5851 s_indent
[indent
] = '\0';
5853 /* Print the loop's header. */
5854 fprintf (file
, "%sloop_%d\n", s_indent
, loop
->num
);
5856 /* Print the loop's body. */
5857 fprintf (file
, "%s{\n", s_indent
);
5859 if (bb
->loop_father
== loop
)
5861 /* Print the basic_block's header. */
5862 fprintf (file
, "%s bb_%d (preds = {", s_indent
, bb
->index
);
5863 print_pred_bbs (file
, bb
);
5864 fprintf (file
, "}, succs = {");
5865 print_succ_bbs (file
, bb
);
5866 fprintf (file
, "})\n");
5868 /* Print the basic_block's body. */
5869 fprintf (file
, "%s {\n", s_indent
);
5870 tree_dump_bb (bb
, file
, indent
+ 4);
5871 fprintf (file
, "%s }\n", s_indent
);
5874 print_loop (file
, loop
->inner
, indent
+ 2);
5875 fprintf (file
, "%s}\n", s_indent
);
5876 print_loop (file
, loop
->next
, indent
);
5880 /* Follow a CFG edge from the entry point of the program, and on entry
5881 of a loop, pretty print the loop structure on FILE. */
5884 print_loop_ir (FILE *file
)
5888 bb
= BASIC_BLOCK (NUM_FIXED_BLOCKS
);
5889 if (bb
&& bb
->loop_father
)
5890 print_loop (file
, bb
->loop_father
, 0);
5894 /* Debugging loops structure at tree level. */
5897 debug_loop_ir (void)
5899 print_loop_ir (stderr
);
5903 /* Return true if BB ends with a call, possibly followed by some
5904 instructions that must stay with the call. Return false,
5908 tree_block_ends_with_call_p (const_basic_block bb
)
5910 const_block_stmt_iterator bsi
= cbsi_last (bb
);
5911 return const_get_call_expr_in (cbsi_stmt (bsi
)) != NULL
;
5915 /* Return true if BB ends with a conditional branch. Return false,
5919 tree_block_ends_with_condjump_p (const_basic_block bb
)
5921 /* This CONST_CAST is okay because last_stmt doesn't modify its
5922 argument and the return value is not modified. */
5923 const_tree stmt
= last_stmt (CONST_CAST_BB(bb
));
5924 return (stmt
&& TREE_CODE (stmt
) == COND_EXPR
);
5928 /* Return true if we need to add fake edge to exit at statement T.
5929 Helper function for tree_flow_call_edges_add. */
5932 need_fake_edge_p (tree t
)
5936 /* NORETURN and LONGJMP calls already have an edge to exit.
5937 CONST and PURE calls do not need one.
5938 We don't currently check for CONST and PURE here, although
5939 it would be a good idea, because those attributes are
5940 figured out from the RTL in mark_constant_function, and
5941 the counter incrementation code from -fprofile-arcs
5942 leads to different results from -fbranch-probabilities. */
5943 call
= get_call_expr_in (t
);
5945 && !(call_expr_flags (call
) & ECF_NORETURN
))
5948 if (TREE_CODE (t
) == ASM_EXPR
5949 && (ASM_VOLATILE_P (t
) || ASM_INPUT_P (t
)))
5956 /* Add fake edges to the function exit for any non constant and non
5957 noreturn calls, volatile inline assembly in the bitmap of blocks
5958 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
5959 the number of blocks that were split.
5961 The goal is to expose cases in which entering a basic block does
5962 not imply that all subsequent instructions must be executed. */
5965 tree_flow_call_edges_add (sbitmap blocks
)
5968 int blocks_split
= 0;
5969 int last_bb
= last_basic_block
;
5970 bool check_last_block
= false;
5972 if (n_basic_blocks
== NUM_FIXED_BLOCKS
)
5976 check_last_block
= true;
5978 check_last_block
= TEST_BIT (blocks
, EXIT_BLOCK_PTR
->prev_bb
->index
);
5980 /* In the last basic block, before epilogue generation, there will be
5981 a fallthru edge to EXIT. Special care is required if the last insn
5982 of the last basic block is a call because make_edge folds duplicate
5983 edges, which would result in the fallthru edge also being marked
5984 fake, which would result in the fallthru edge being removed by
5985 remove_fake_edges, which would result in an invalid CFG.
5987 Moreover, we can't elide the outgoing fake edge, since the block
5988 profiler needs to take this into account in order to solve the minimal
5989 spanning tree in the case that the call doesn't return.
5991 Handle this by adding a dummy instruction in a new last basic block. */
5992 if (check_last_block
)
5994 basic_block bb
= EXIT_BLOCK_PTR
->prev_bb
;
5995 block_stmt_iterator bsi
= bsi_last (bb
);
5997 if (!bsi_end_p (bsi
))
6000 if (t
&& need_fake_edge_p (t
))
6004 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
6007 bsi_insert_on_edge (e
, build_empty_stmt ());
6008 bsi_commit_edge_inserts ();
6013 /* Now add fake edges to the function exit for any non constant
6014 calls since there is no way that we can determine if they will
6016 for (i
= 0; i
< last_bb
; i
++)
6018 basic_block bb
= BASIC_BLOCK (i
);
6019 block_stmt_iterator bsi
;
6020 tree stmt
, last_stmt
;
6025 if (blocks
&& !TEST_BIT (blocks
, i
))
6028 bsi
= bsi_last (bb
);
6029 if (!bsi_end_p (bsi
))
6031 last_stmt
= bsi_stmt (bsi
);
6034 stmt
= bsi_stmt (bsi
);
6035 if (need_fake_edge_p (stmt
))
6038 /* The handling above of the final block before the
6039 epilogue should be enough to verify that there is
6040 no edge to the exit block in CFG already.
6041 Calling make_edge in such case would cause us to
6042 mark that edge as fake and remove it later. */
6043 #ifdef ENABLE_CHECKING
6044 if (stmt
== last_stmt
)
6046 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
6047 gcc_assert (e
== NULL
);
6051 /* Note that the following may create a new basic block
6052 and renumber the existing basic blocks. */
6053 if (stmt
!= last_stmt
)
6055 e
= split_block (bb
, stmt
);
6059 make_edge (bb
, EXIT_BLOCK_PTR
, EDGE_FAKE
);
6063 while (!bsi_end_p (bsi
));
6068 verify_flow_info ();
6070 return blocks_split
;
6073 /* Purge dead abnormal call edges from basic block BB. */
6076 tree_purge_dead_abnormal_call_edges (basic_block bb
)
6078 bool changed
= tree_purge_dead_eh_edges (bb
);
6080 if (current_function_has_nonlocal_label
)
6082 tree stmt
= last_stmt (bb
);
6086 if (!(stmt
&& tree_can_make_abnormal_goto (stmt
)))
6087 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
6089 if (e
->flags
& EDGE_ABNORMAL
)
6098 /* See tree_purge_dead_eh_edges below. */
6100 free_dominance_info (CDI_DOMINATORS
);
6106 /* Stores all basic blocks dominated by BB to DOM_BBS. */
6109 get_all_dominated_blocks (basic_block bb
, VEC (basic_block
, heap
) **dom_bbs
)
6113 VEC_safe_push (basic_block
, heap
, *dom_bbs
, bb
);
6114 for (son
= first_dom_son (CDI_DOMINATORS
, bb
);
6116 son
= next_dom_son (CDI_DOMINATORS
, son
))
6117 get_all_dominated_blocks (son
, dom_bbs
);
6120 /* Removes edge E and all the blocks dominated by it, and updates dominance
6121 information. The IL in E->src needs to be updated separately.
6122 If dominance info is not available, only the edge E is removed.*/
6125 remove_edge_and_dominated_blocks (edge e
)
6127 VEC (basic_block
, heap
) *bbs_to_remove
= NULL
;
6128 VEC (basic_block
, heap
) *bbs_to_fix_dom
= NULL
;
6132 bool none_removed
= false;
6134 basic_block bb
, dbb
;
6137 if (!dom_info_available_p (CDI_DOMINATORS
))
6143 /* No updating is needed for edges to exit. */
6144 if (e
->dest
== EXIT_BLOCK_PTR
)
6146 if (cfgcleanup_altered_bbs
)
6147 bitmap_set_bit (cfgcleanup_altered_bbs
, e
->src
->index
);
6152 /* First, we find the basic blocks to remove. If E->dest has a predecessor
6153 that is not dominated by E->dest, then this set is empty. Otherwise,
6154 all the basic blocks dominated by E->dest are removed.
6156 Also, to DF_IDOM we store the immediate dominators of the blocks in
6157 the dominance frontier of E (i.e., of the successors of the
6158 removed blocks, if there are any, and of E->dest otherwise). */
6159 FOR_EACH_EDGE (f
, ei
, e
->dest
->preds
)
6164 if (!dominated_by_p (CDI_DOMINATORS
, f
->src
, e
->dest
))
6166 none_removed
= true;
6171 df
= BITMAP_ALLOC (NULL
);
6172 df_idom
= BITMAP_ALLOC (NULL
);
6175 bitmap_set_bit (df_idom
,
6176 get_immediate_dominator (CDI_DOMINATORS
, e
->dest
)->index
);
6179 get_all_dominated_blocks (e
->dest
, &bbs_to_remove
);
6180 for (i
= 0; VEC_iterate (basic_block
, bbs_to_remove
, i
, bb
); i
++)
6182 FOR_EACH_EDGE (f
, ei
, bb
->succs
)
6184 if (f
->dest
!= EXIT_BLOCK_PTR
)
6185 bitmap_set_bit (df
, f
->dest
->index
);
6188 for (i
= 0; VEC_iterate (basic_block
, bbs_to_remove
, i
, bb
); i
++)
6189 bitmap_clear_bit (df
, bb
->index
);
6191 EXECUTE_IF_SET_IN_BITMAP (df
, 0, i
, bi
)
6193 bb
= BASIC_BLOCK (i
);
6194 bitmap_set_bit (df_idom
,
6195 get_immediate_dominator (CDI_DOMINATORS
, bb
)->index
);
6199 if (cfgcleanup_altered_bbs
)
6201 /* Record the set of the altered basic blocks. */
6202 bitmap_set_bit (cfgcleanup_altered_bbs
, e
->src
->index
);
6203 bitmap_ior_into (cfgcleanup_altered_bbs
, df
);
6206 /* Remove E and the cancelled blocks. */
6211 for (i
= 0; VEC_iterate (basic_block
, bbs_to_remove
, i
, bb
); i
++)
6212 delete_basic_block (bb
);
6215 /* Update the dominance information. The immediate dominator may change only
6216 for blocks whose immediate dominator belongs to DF_IDOM:
6218 Suppose that idom(X) = Y before removal of E and idom(X) != Y after the
6219 removal. Let Z the arbitrary block such that idom(Z) = Y and
6220 Z dominates X after the removal. Before removal, there exists a path P
6221 from Y to X that avoids Z. Let F be the last edge on P that is
6222 removed, and let W = F->dest. Before removal, idom(W) = Y (since Y
6223 dominates W, and because of P, Z does not dominate W), and W belongs to
6224 the dominance frontier of E. Therefore, Y belongs to DF_IDOM. */
6225 EXECUTE_IF_SET_IN_BITMAP (df_idom
, 0, i
, bi
)
6227 bb
= BASIC_BLOCK (i
);
6228 for (dbb
= first_dom_son (CDI_DOMINATORS
, bb
);
6230 dbb
= next_dom_son (CDI_DOMINATORS
, dbb
))
6231 VEC_safe_push (basic_block
, heap
, bbs_to_fix_dom
, dbb
);
6234 iterate_fix_dominators (CDI_DOMINATORS
, bbs_to_fix_dom
, true);
6237 BITMAP_FREE (df_idom
);
6238 VEC_free (basic_block
, heap
, bbs_to_remove
);
6239 VEC_free (basic_block
, heap
, bbs_to_fix_dom
);
6242 /* Purge dead EH edges from basic block BB. */
6245 tree_purge_dead_eh_edges (basic_block bb
)
6247 bool changed
= false;
6250 tree stmt
= last_stmt (bb
);
6252 if (stmt
&& tree_can_throw_internal (stmt
))
6255 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
6257 if (e
->flags
& EDGE_EH
)
6259 remove_edge_and_dominated_blocks (e
);
6270 tree_purge_all_dead_eh_edges (const_bitmap blocks
)
6272 bool changed
= false;
6276 EXECUTE_IF_SET_IN_BITMAP (blocks
, 0, i
, bi
)
6278 changed
|= tree_purge_dead_eh_edges (BASIC_BLOCK (i
));
6284 /* This function is called whenever a new edge is created or
6288 tree_execute_on_growing_pred (edge e
)
6290 basic_block bb
= e
->dest
;
6293 reserve_phi_args_for_new_edge (bb
);
6296 /* This function is called immediately before edge E is removed from
6297 the edge vector E->dest->preds. */
6300 tree_execute_on_shrinking_pred (edge e
)
6302 if (phi_nodes (e
->dest
))
6303 remove_phi_args (e
);
6306 /*---------------------------------------------------------------------------
6307 Helper functions for Loop versioning
6308 ---------------------------------------------------------------------------*/
6310 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
6311 of 'first'. Both of them are dominated by 'new_head' basic block. When
6312 'new_head' was created by 'second's incoming edge it received phi arguments
6313 on the edge by split_edge(). Later, additional edge 'e' was created to
6314 connect 'new_head' and 'first'. Now this routine adds phi args on this
6315 additional edge 'e' that new_head to second edge received as part of edge
6320 tree_lv_adjust_loop_header_phi (basic_block first
, basic_block second
,
6321 basic_block new_head
, edge e
)
6324 edge e2
= find_edge (new_head
, second
);
6326 /* Because NEW_HEAD has been created by splitting SECOND's incoming
6327 edge, we should always have an edge from NEW_HEAD to SECOND. */
6328 gcc_assert (e2
!= NULL
);
6330 /* Browse all 'second' basic block phi nodes and add phi args to
6331 edge 'e' for 'first' head. PHI args are always in correct order. */
6333 for (phi2
= phi_nodes (second
), phi1
= phi_nodes (first
);
6335 phi2
= PHI_CHAIN (phi2
), phi1
= PHI_CHAIN (phi1
))
6337 tree def
= PHI_ARG_DEF (phi2
, e2
->dest_idx
);
6338 add_phi_arg (phi1
, def
, e
);
6342 /* Adds a if else statement to COND_BB with condition COND_EXPR.
6343 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
6344 the destination of the ELSE part. */
6346 tree_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED
,
6347 basic_block second_head ATTRIBUTE_UNUSED
,
6348 basic_block cond_bb
, void *cond_e
)
6350 block_stmt_iterator bsi
;
6351 tree new_cond_expr
= NULL_TREE
;
6352 tree cond_expr
= (tree
) cond_e
;
6355 /* Build new conditional expr */
6356 new_cond_expr
= build3 (COND_EXPR
, void_type_node
, cond_expr
,
6357 NULL_TREE
, NULL_TREE
);
6359 /* Add new cond in cond_bb. */
6360 bsi
= bsi_start (cond_bb
);
6361 bsi_insert_after (&bsi
, new_cond_expr
, BSI_NEW_STMT
);
6362 /* Adjust edges appropriately to connect new head with first head
6363 as well as second head. */
6364 e0
= single_succ_edge (cond_bb
);
6365 e0
->flags
&= ~EDGE_FALLTHRU
;
6366 e0
->flags
|= EDGE_FALSE_VALUE
;
6369 struct cfg_hooks tree_cfg_hooks
= {
6371 tree_verify_flow_info
,
6372 tree_dump_bb
, /* dump_bb */
6373 create_bb
, /* create_basic_block */
6374 tree_redirect_edge_and_branch
,/* redirect_edge_and_branch */
6375 tree_redirect_edge_and_branch_force
,/* redirect_edge_and_branch_force */
6376 tree_can_remove_branch_p
, /* can_remove_branch_p */
6377 remove_bb
, /* delete_basic_block */
6378 tree_split_block
, /* split_block */
6379 tree_move_block_after
, /* move_block_after */
6380 tree_can_merge_blocks_p
, /* can_merge_blocks_p */
6381 tree_merge_blocks
, /* merge_blocks */
6382 tree_predict_edge
, /* predict_edge */
6383 tree_predicted_by_p
, /* predicted_by_p */
6384 tree_can_duplicate_bb_p
, /* can_duplicate_block_p */
6385 tree_duplicate_bb
, /* duplicate_block */
6386 tree_split_edge
, /* split_edge */
6387 tree_make_forwarder_block
, /* make_forward_block */
6388 NULL
, /* tidy_fallthru_edge */
6389 tree_block_ends_with_call_p
, /* block_ends_with_call_p */
6390 tree_block_ends_with_condjump_p
, /* block_ends_with_condjump_p */
6391 tree_flow_call_edges_add
, /* flow_call_edges_add */
6392 tree_execute_on_growing_pred
, /* execute_on_growing_pred */
6393 tree_execute_on_shrinking_pred
, /* execute_on_shrinking_pred */
6394 tree_duplicate_loop_to_header_edge
, /* duplicate loop for trees */
6395 tree_lv_add_condition_to_bb
, /* lv_add_condition_to_bb */
6396 tree_lv_adjust_loop_header_phi
, /* lv_adjust_loop_header_phi*/
6397 extract_true_false_edges_from_block
, /* extract_cond_bb_edges */
6398 flush_pending_stmts
/* flush_pending_stmts */
6402 /* Split all critical edges. */
6405 split_critical_edges (void)
6411 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
6412 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
6413 mappings around the calls to split_edge. */
6414 start_recording_case_labels ();
6417 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
6418 if (EDGE_CRITICAL_P (e
) && !(e
->flags
& EDGE_ABNORMAL
))
6423 end_recording_case_labels ();
6427 struct tree_opt_pass pass_split_crit_edges
=
6429 "crited", /* name */
6431 split_critical_edges
, /* execute */
6434 0, /* static_pass_number */
6435 TV_TREE_SPLIT_EDGES
, /* tv_id */
6436 PROP_cfg
, /* properties required */
6437 PROP_no_crit_edges
, /* properties_provided */
6438 0, /* properties_destroyed */
6439 0, /* todo_flags_start */
6440 TODO_dump_func
, /* todo_flags_finish */
6445 /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into
6446 a temporary, make sure and register it to be renamed if necessary,
6447 and finally return the temporary. Put the statements to compute
6448 EXP before the current statement in BSI. */
6451 gimplify_val (block_stmt_iterator
*bsi
, tree type
, tree exp
)
6453 tree t
, new_stmt
, orig_stmt
;
6455 if (is_gimple_val (exp
))
6458 t
= make_rename_temp (type
, NULL
);
6459 new_stmt
= build_gimple_modify_stmt (t
, exp
);
6461 orig_stmt
= bsi_stmt (*bsi
);
6462 SET_EXPR_LOCUS (new_stmt
, EXPR_LOCUS (orig_stmt
));
6463 TREE_BLOCK (new_stmt
) = TREE_BLOCK (orig_stmt
);
6465 bsi_insert_before (bsi
, new_stmt
, BSI_SAME_STMT
);
6466 if (gimple_in_ssa_p (cfun
))
6467 mark_symbols_for_renaming (new_stmt
);
6472 /* Build a ternary operation and gimplify it. Emit code before BSI.
6473 Return the gimple_val holding the result. */
6476 gimplify_build3 (block_stmt_iterator
*bsi
, enum tree_code code
,
6477 tree type
, tree a
, tree b
, tree c
)
6481 ret
= fold_build3 (code
, type
, a
, b
, c
);
6484 return gimplify_val (bsi
, type
, ret
);
6487 /* Build a binary operation and gimplify it. Emit code before BSI.
6488 Return the gimple_val holding the result. */
6491 gimplify_build2 (block_stmt_iterator
*bsi
, enum tree_code code
,
6492 tree type
, tree a
, tree b
)
6496 ret
= fold_build2 (code
, type
, a
, b
);
6499 return gimplify_val (bsi
, type
, ret
);
6502 /* Build a unary operation and gimplify it. Emit code before BSI.
6503 Return the gimple_val holding the result. */
6506 gimplify_build1 (block_stmt_iterator
*bsi
, enum tree_code code
, tree type
,
6511 ret
= fold_build1 (code
, type
, a
);
6514 return gimplify_val (bsi
, type
, ret
);
6519 /* Emit return warnings. */
6522 execute_warn_function_return (void)
6524 #ifdef USE_MAPPED_LOCATION
6525 source_location location
;
6533 /* If we have a path to EXIT, then we do return. */
6534 if (TREE_THIS_VOLATILE (cfun
->decl
)
6535 && EDGE_COUNT (EXIT_BLOCK_PTR
->preds
) > 0)
6537 #ifdef USE_MAPPED_LOCATION
6538 location
= UNKNOWN_LOCATION
;
6542 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6544 last
= last_stmt (e
->src
);
6545 if (TREE_CODE (last
) == RETURN_EXPR
6546 #ifdef USE_MAPPED_LOCATION
6547 && (location
= EXPR_LOCATION (last
)) != UNKNOWN_LOCATION
)
6549 && (locus
= EXPR_LOCUS (last
)) != NULL
)
6553 #ifdef USE_MAPPED_LOCATION
6554 if (location
== UNKNOWN_LOCATION
)
6555 location
= cfun
->function_end_locus
;
6556 warning (0, "%H%<noreturn%> function does return", &location
);
6559 locus
= &cfun
->function_end_locus
;
6560 warning (0, "%H%<noreturn%> function does return", locus
);
6564 /* If we see "return;" in some basic block, then we do reach the end
6565 without returning a value. */
6566 else if (warn_return_type
6567 && !TREE_NO_WARNING (cfun
->decl
)
6568 && EDGE_COUNT (EXIT_BLOCK_PTR
->preds
) > 0
6569 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun
->decl
))))
6571 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
6573 tree last
= last_stmt (e
->src
);
6574 if (TREE_CODE (last
) == RETURN_EXPR
6575 && TREE_OPERAND (last
, 0) == NULL
6576 && !TREE_NO_WARNING (last
))
6578 #ifdef USE_MAPPED_LOCATION
6579 location
= EXPR_LOCATION (last
);
6580 if (location
== UNKNOWN_LOCATION
)
6581 location
= cfun
->function_end_locus
;
6582 warning (0, "%Hcontrol reaches end of non-void function", &location
);
6584 locus
= EXPR_LOCUS (last
);
6586 locus
= &cfun
->function_end_locus
;
6587 warning (0, "%Hcontrol reaches end of non-void function", locus
);
6589 TREE_NO_WARNING (cfun
->decl
) = 1;
6598 /* Given a basic block B which ends with a conditional and has
6599 precisely two successors, determine which of the edges is taken if
6600 the conditional is true and which is taken if the conditional is
6601 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
6604 extract_true_false_edges_from_block (basic_block b
,
6608 edge e
= EDGE_SUCC (b
, 0);
6610 if (e
->flags
& EDGE_TRUE_VALUE
)
6613 *false_edge
= EDGE_SUCC (b
, 1);
6618 *true_edge
= EDGE_SUCC (b
, 1);
6622 struct tree_opt_pass pass_warn_function_return
=
6626 execute_warn_function_return
, /* execute */
6629 0, /* static_pass_number */
6631 PROP_cfg
, /* properties_required */
6632 0, /* properties_provided */
6633 0, /* properties_destroyed */
6634 0, /* todo_flags_start */
6635 0, /* todo_flags_finish */
6639 /* Emit noreturn warnings. */
6642 execute_warn_function_noreturn (void)
6644 if (warn_missing_noreturn
6645 && !TREE_THIS_VOLATILE (cfun
->decl
)
6646 && EDGE_COUNT (EXIT_BLOCK_PTR
->preds
) == 0
6647 && !lang_hooks
.function
.missing_noreturn_ok_p (cfun
->decl
))
6648 warning (OPT_Wmissing_noreturn
, "%Jfunction might be possible candidate "
6649 "for attribute %<noreturn%>",
6654 struct tree_opt_pass pass_warn_function_noreturn
=
6658 execute_warn_function_noreturn
, /* execute */
6661 0, /* static_pass_number */
6663 PROP_cfg
, /* properties_required */
6664 0, /* properties_provided */
6665 0, /* properties_destroyed */
6666 0, /* todo_flags_start */
6667 0, /* todo_flags_finish */