1 /* Control flow functions for trees.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
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 2, 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 COPYING. If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
25 #include "coretypes.h"
30 #include "hard-reg-set.h"
31 #include "basic-block.h"
37 #include "langhooks.h"
38 #include "diagnostic.h"
39 #include "tree-flow.h"
41 #include "tree-dump.h"
42 #include "tree-pass.h"
46 #include "cfglayout.h"
48 #include "tree-ssa-propagate.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 struct edge_to_cases_elt
73 /* The edge itself. Necessary for hashing and equality tests. */
76 /* The case labels associated with this edge. We link these up via
77 their TREE_CHAIN field, then we wipe out the TREE_CHAIN fields
78 when we destroy the hash table. This prevents problems when copying
83 static htab_t edge_to_cases
;
88 long num_merged_labels
;
91 static struct cfg_stats_d cfg_stats
;
93 /* Nonzero if we found a computed goto while building basic blocks. */
94 static bool found_computed_goto
;
96 /* Basic blocks and flowgraphs. */
97 static basic_block
create_bb (void *, void *, basic_block
);
98 static void make_blocks (tree
);
99 static void factor_computed_gotos (void);
102 static void make_edges (void);
103 static void make_cond_expr_edges (basic_block
);
104 static void make_switch_expr_edges (basic_block
);
105 static void make_goto_expr_edges (basic_block
);
106 static edge
tree_redirect_edge_and_branch (edge
, basic_block
);
107 static edge
tree_try_redirect_by_replacing_jump (edge
, basic_block
);
108 static unsigned int split_critical_edges (void);
110 /* Various helpers. */
111 static inline bool stmt_starts_bb_p (tree
, tree
);
112 static int tree_verify_flow_info (void);
113 static void tree_make_forwarder_block (edge
);
114 static void tree_cfg2vcg (FILE *);
115 static inline void change_bb_for_stmt (tree t
, basic_block bb
);
117 /* Flowgraph optimization and cleanup. */
118 static void tree_merge_blocks (basic_block
, basic_block
);
119 static bool tree_can_merge_blocks_p (basic_block
, basic_block
);
120 static void remove_bb (basic_block
);
121 static edge
find_taken_edge_computed_goto (basic_block
, tree
);
122 static edge
find_taken_edge_cond_expr (basic_block
, tree
);
123 static edge
find_taken_edge_switch_expr (basic_block
, tree
);
124 static tree
find_case_label_for_value (tree
, tree
);
127 init_empty_tree_cfg (void)
129 /* Initialize the basic block array. */
131 profile_status
= PROFILE_ABSENT
;
132 n_basic_blocks
= NUM_FIXED_BLOCKS
;
133 last_basic_block
= NUM_FIXED_BLOCKS
;
134 basic_block_info
= VEC_alloc (basic_block
, gc
, initial_cfg_capacity
);
135 VEC_safe_grow (basic_block
, gc
, basic_block_info
, initial_cfg_capacity
);
136 memset (VEC_address (basic_block
, basic_block_info
), 0,
137 sizeof (basic_block
) * initial_cfg_capacity
);
139 /* Build a mapping of labels to their associated blocks. */
140 label_to_block_map
= VEC_alloc (basic_block
, gc
, initial_cfg_capacity
);
141 VEC_safe_grow (basic_block
, gc
, label_to_block_map
, initial_cfg_capacity
);
142 memset (VEC_address (basic_block
, label_to_block_map
),
143 0, sizeof (basic_block
) * initial_cfg_capacity
);
145 SET_BASIC_BLOCK (ENTRY_BLOCK
, ENTRY_BLOCK_PTR
);
146 SET_BASIC_BLOCK (EXIT_BLOCK
, EXIT_BLOCK_PTR
);
147 ENTRY_BLOCK_PTR
->next_bb
= EXIT_BLOCK_PTR
;
148 EXIT_BLOCK_PTR
->prev_bb
= ENTRY_BLOCK_PTR
;
151 /*---------------------------------------------------------------------------
153 ---------------------------------------------------------------------------*/
155 /* Entry point to the CFG builder for trees. TP points to the list of
156 statements to be added to the flowgraph. */
159 build_tree_cfg (tree
*tp
)
161 /* Register specific tree functions. */
162 tree_register_cfg_hooks ();
164 memset ((void *) &cfg_stats
, 0, sizeof (cfg_stats
));
166 init_empty_tree_cfg ();
168 found_computed_goto
= 0;
171 /* Computed gotos are hell to deal with, especially if there are
172 lots of them with a large number of destinations. So we factor
173 them to a common computed goto location before we build the
174 edge list. After we convert back to normal form, we will un-factor
175 the computed gotos since factoring introduces an unwanted jump. */
176 if (found_computed_goto
)
177 factor_computed_gotos ();
179 /* Make sure there is always at least one block, even if it's empty. */
180 if (n_basic_blocks
== NUM_FIXED_BLOCKS
)
181 create_empty_bb (ENTRY_BLOCK_PTR
);
183 /* Adjust the size of the array. */
184 if (VEC_length (basic_block
, basic_block_info
) < (size_t) n_basic_blocks
)
186 size_t old_size
= VEC_length (basic_block
, basic_block_info
);
188 VEC_safe_grow (basic_block
, gc
, basic_block_info
, n_basic_blocks
);
189 p
= VEC_address (basic_block
, basic_block_info
);
190 memset (&p
[old_size
], 0,
191 sizeof (basic_block
) * (n_basic_blocks
- old_size
));
194 /* To speed up statement iterator walks, we first purge dead labels. */
195 cleanup_dead_labels ();
197 /* Group case nodes to reduce the number of edges.
198 We do this after cleaning up dead labels because otherwise we miss
199 a lot of obvious case merging opportunities. */
200 group_case_labels ();
202 /* Create the edges of the flowgraph. */
205 /* Debugging dumps. */
207 /* Write the flowgraph to a VCG file. */
209 int local_dump_flags
;
210 FILE *vcg_file
= dump_begin (TDI_vcg
, &local_dump_flags
);
213 tree_cfg2vcg (vcg_file
);
214 dump_end (TDI_vcg
, vcg_file
);
218 #ifdef ENABLE_CHECKING
222 /* Dump a textual representation of the flowgraph. */
224 dump_tree_cfg (dump_file
, dump_flags
);
228 execute_build_cfg (void)
230 build_tree_cfg (&DECL_SAVED_TREE (current_function_decl
));
234 struct tree_opt_pass pass_build_cfg
=
238 execute_build_cfg
, /* execute */
241 0, /* static_pass_number */
242 TV_TREE_CFG
, /* tv_id */
243 PROP_gimple_leh
, /* properties_required */
244 PROP_cfg
, /* properties_provided */
245 0, /* properties_destroyed */
246 0, /* todo_flags_start */
247 TODO_verify_stmts
, /* todo_flags_finish */
251 /* Search the CFG for any computed gotos. If found, factor them to a
252 common computed goto site. Also record the location of that site so
253 that we can un-factor the gotos after we have converted back to
257 factor_computed_gotos (void)
260 tree factored_label_decl
= NULL
;
262 tree factored_computed_goto_label
= NULL
;
263 tree factored_computed_goto
= NULL
;
265 /* We know there are one or more computed gotos in this function.
266 Examine the last statement in each basic block to see if the block
267 ends with a computed goto. */
271 block_stmt_iterator bsi
= bsi_last (bb
);
276 last
= bsi_stmt (bsi
);
278 /* Ignore the computed goto we create when we factor the original
280 if (last
== factored_computed_goto
)
283 /* If the last statement is a computed goto, factor it. */
284 if (computed_goto_p (last
))
288 /* The first time we find a computed goto we need to create
289 the factored goto block and the variable each original
290 computed goto will use for their goto destination. */
291 if (! factored_computed_goto
)
293 basic_block new_bb
= create_empty_bb (bb
);
294 block_stmt_iterator new_bsi
= bsi_start (new_bb
);
296 /* Create the destination of the factored goto. Each original
297 computed goto will put its desired destination into this
298 variable and jump to the label we create immediately
300 var
= create_tmp_var (ptr_type_node
, "gotovar");
302 /* Build a label for the new block which will contain the
303 factored computed goto. */
304 factored_label_decl
= create_artificial_label ();
305 factored_computed_goto_label
306 = build1 (LABEL_EXPR
, void_type_node
, factored_label_decl
);
307 bsi_insert_after (&new_bsi
, factored_computed_goto_label
,
310 /* Build our new computed goto. */
311 factored_computed_goto
= build1 (GOTO_EXPR
, void_type_node
, var
);
312 bsi_insert_after (&new_bsi
, factored_computed_goto
,
316 /* Copy the original computed goto's destination into VAR. */
317 assignment
= build2_gimple (GIMPLE_MODIFY_STMT
,
318 var
, GOTO_DESTINATION (last
));
319 bsi_insert_before (&bsi
, assignment
, BSI_SAME_STMT
);
321 /* And re-vector the computed goto to the new destination. */
322 GOTO_DESTINATION (last
) = factored_label_decl
;
328 /* Build a flowgraph for the statement_list STMT_LIST. */
331 make_blocks (tree stmt_list
)
333 tree_stmt_iterator i
= tsi_start (stmt_list
);
335 bool start_new_block
= true;
336 bool first_stmt_of_list
= true;
337 basic_block bb
= ENTRY_BLOCK_PTR
;
339 while (!tsi_end_p (i
))
346 /* If the statement starts a new basic block or if we have determined
347 in a previous pass that we need to create a new block for STMT, do
349 if (start_new_block
|| stmt_starts_bb_p (stmt
, prev_stmt
))
351 if (!first_stmt_of_list
)
352 stmt_list
= tsi_split_statement_list_before (&i
);
353 bb
= create_basic_block (stmt_list
, NULL
, bb
);
354 start_new_block
= false;
357 /* Now add STMT to BB and create the subgraphs for special statement
359 set_bb_for_stmt (stmt
, bb
);
361 if (computed_goto_p (stmt
))
362 found_computed_goto
= true;
364 /* If STMT is a basic block terminator, set START_NEW_BLOCK for the
366 if (stmt_ends_bb_p (stmt
))
367 start_new_block
= true;
370 first_stmt_of_list
= false;
375 /* Create and return a new empty basic block after bb AFTER. */
378 create_bb (void *h
, void *e
, basic_block after
)
384 /* Create and initialize a new basic block. Since alloc_block uses
385 ggc_alloc_cleared to allocate a basic block, we do not have to
386 clear the newly allocated basic block here. */
389 bb
->index
= last_basic_block
;
391 bb
->stmt_list
= h
? (tree
) h
: alloc_stmt_list ();
393 /* Add the new block to the linked list of blocks. */
394 link_block (bb
, after
);
396 /* Grow the basic block array if needed. */
397 if ((size_t) last_basic_block
== VEC_length (basic_block
, basic_block_info
))
399 size_t old_size
= VEC_length (basic_block
, basic_block_info
);
400 size_t new_size
= last_basic_block
+ (last_basic_block
+ 3) / 4;
402 VEC_safe_grow (basic_block
, gc
, basic_block_info
, new_size
);
403 p
= VEC_address (basic_block
, basic_block_info
);
404 memset (&p
[old_size
], 0, sizeof (basic_block
) * (new_size
- old_size
));
407 /* Add the newly created block to the array. */
408 SET_BASIC_BLOCK (last_basic_block
, bb
);
417 /*---------------------------------------------------------------------------
419 ---------------------------------------------------------------------------*/
421 /* Fold COND_EXPR_COND of each COND_EXPR. */
424 fold_cond_expr_cond (void)
430 tree stmt
= last_stmt (bb
);
433 && TREE_CODE (stmt
) == COND_EXPR
)
435 tree cond
= fold (COND_EXPR_COND (stmt
));
436 if (integer_zerop (cond
))
437 COND_EXPR_COND (stmt
) = boolean_false_node
;
438 else if (integer_onep (cond
))
439 COND_EXPR_COND (stmt
) = boolean_true_node
;
444 /* Join all the blocks in the flowgraph. */
450 struct omp_region
*cur_region
= NULL
;
452 /* Create an edge from entry to the first block with executable
454 make_edge (ENTRY_BLOCK_PTR
, BASIC_BLOCK (NUM_FIXED_BLOCKS
), EDGE_FALLTHRU
);
456 /* Traverse the basic block array placing edges. */
459 tree last
= last_stmt (bb
);
464 enum tree_code code
= TREE_CODE (last
);
468 make_goto_expr_edges (bb
);
472 make_edge (bb
, EXIT_BLOCK_PTR
, 0);
476 make_cond_expr_edges (bb
);
480 make_switch_expr_edges (bb
);
484 make_eh_edges (last
);
489 /* If this function receives a nonlocal goto, then we need to
490 make edges from this call site to all the nonlocal goto
492 if (tree_can_make_abnormal_goto (last
))
493 make_abnormal_goto_edges (bb
, true);
495 /* If this statement has reachable exception handlers, then
496 create abnormal edges to them. */
497 make_eh_edges (last
);
499 /* Some calls are known not to return. */
500 fallthru
= !(call_expr_flags (last
) & ECF_NORETURN
);
506 case GIMPLE_MODIFY_STMT
:
507 if (is_ctrl_altering_stmt (last
))
509 /* A GIMPLE_MODIFY_STMT may have a CALL_EXPR on its RHS and
510 the CALL_EXPR may have an abnormal edge. Search the RHS
511 for this case and create any required edges. */
512 if (tree_can_make_abnormal_goto (last
))
513 make_abnormal_goto_edges (bb
, true);
515 make_eh_edges (last
);
527 cur_region
= new_omp_region (bb
, code
, cur_region
);
532 cur_region
= new_omp_region (bb
, code
, cur_region
);
537 /* In the case of an OMP_SECTION, the edge will go somewhere
538 other than the next block. This will be created later. */
539 cur_region
->exit
= bb
;
540 fallthru
= cur_region
->type
!= OMP_SECTION
;
541 cur_region
= cur_region
->outer
;
545 cur_region
->cont
= bb
;
546 switch (cur_region
->type
)
549 /* ??? Technically there should be a some sort of loopback
550 edge here, but it goes to a block that doesn't exist yet,
551 and without it, updating the ssa form would be a real
552 bear. Fortunately, we don't yet do ssa before expanding
557 /* Wire up the edges into and out of the nested sections. */
558 /* ??? Similarly wrt loopback. */
560 struct omp_region
*i
;
561 for (i
= cur_region
->inner
; i
; i
= i
->next
)
563 gcc_assert (i
->type
== OMP_SECTION
);
564 make_edge (cur_region
->entry
, i
->entry
, 0);
565 make_edge (i
->exit
, bb
, EDGE_FALLTHRU
);
577 gcc_assert (!stmt_ends_bb_p (last
));
585 make_edge (bb
, bb
->next_bb
, EDGE_FALLTHRU
);
591 /* Fold COND_EXPR_COND of each COND_EXPR. */
592 fold_cond_expr_cond ();
594 /* Clean up the graph and warn for unreachable code. */
599 /* Create the edges for a COND_EXPR starting at block BB.
600 At this point, both clauses must contain only simple gotos. */
603 make_cond_expr_edges (basic_block bb
)
605 tree entry
= last_stmt (bb
);
606 basic_block then_bb
, else_bb
;
607 tree then_label
, else_label
;
611 gcc_assert (TREE_CODE (entry
) == COND_EXPR
);
613 /* Entry basic blocks for each component. */
614 then_label
= GOTO_DESTINATION (COND_EXPR_THEN (entry
));
615 else_label
= GOTO_DESTINATION (COND_EXPR_ELSE (entry
));
616 then_bb
= label_to_block (then_label
);
617 else_bb
= label_to_block (else_label
);
619 e
= make_edge (bb
, then_bb
, EDGE_TRUE_VALUE
);
620 #ifdef USE_MAPPED_LOCATION
621 e
->goto_locus
= EXPR_LOCATION (COND_EXPR_THEN (entry
));
623 e
->goto_locus
= EXPR_LOCUS (COND_EXPR_THEN (entry
));
625 e
= make_edge (bb
, else_bb
, EDGE_FALSE_VALUE
);
628 #ifdef USE_MAPPED_LOCATION
629 e
->goto_locus
= EXPR_LOCATION (COND_EXPR_ELSE (entry
));
631 e
->goto_locus
= EXPR_LOCUS (COND_EXPR_ELSE (entry
));
636 /* Hashing routine for EDGE_TO_CASES. */
639 edge_to_cases_hash (const void *p
)
641 edge e
= ((struct edge_to_cases_elt
*)p
)->e
;
643 /* Hash on the edge itself (which is a pointer). */
644 return htab_hash_pointer (e
);
647 /* Equality routine for EDGE_TO_CASES, edges are unique, so testing
648 for equality is just a pointer comparison. */
651 edge_to_cases_eq (const void *p1
, const void *p2
)
653 edge e1
= ((struct edge_to_cases_elt
*)p1
)->e
;
654 edge e2
= ((struct edge_to_cases_elt
*)p2
)->e
;
659 /* Called for each element in the hash table (P) as we delete the
660 edge to cases hash table.
662 Clear all the TREE_CHAINs to prevent problems with copying of
663 SWITCH_EXPRs and structure sharing rules, then free the hash table
667 edge_to_cases_cleanup (void *p
)
669 struct edge_to_cases_elt
*elt
= (struct edge_to_cases_elt
*) p
;
672 for (t
= elt
->case_labels
; t
; t
= next
)
674 next
= TREE_CHAIN (t
);
675 TREE_CHAIN (t
) = NULL
;
680 /* Start recording information mapping edges to case labels. */
683 start_recording_case_labels (void)
685 gcc_assert (edge_to_cases
== NULL
);
687 edge_to_cases
= htab_create (37,
690 edge_to_cases_cleanup
);
693 /* Return nonzero if we are recording information for case labels. */
696 recording_case_labels_p (void)
698 return (edge_to_cases
!= NULL
);
701 /* Stop recording information mapping edges to case labels and
702 remove any information we have recorded. */
704 end_recording_case_labels (void)
706 htab_delete (edge_to_cases
);
707 edge_to_cases
= NULL
;
710 /* Record that CASE_LABEL (a CASE_LABEL_EXPR) references edge E. */
713 record_switch_edge (edge e
, tree case_label
)
715 struct edge_to_cases_elt
*elt
;
718 /* Build a hash table element so we can see if E is already
720 elt
= XNEW (struct edge_to_cases_elt
);
722 elt
->case_labels
= case_label
;
724 slot
= htab_find_slot (edge_to_cases
, elt
, INSERT
);
728 /* E was not in the hash table. Install E into the hash table. */
733 /* E was already in the hash table. Free ELT as we do not need it
737 /* Get the entry stored in the hash table. */
738 elt
= (struct edge_to_cases_elt
*) *slot
;
740 /* Add it to the chain of CASE_LABEL_EXPRs referencing E. */
741 TREE_CHAIN (case_label
) = elt
->case_labels
;
742 elt
->case_labels
= case_label
;
746 /* If we are inside a {start,end}_recording_cases block, then return
747 a chain of CASE_LABEL_EXPRs from T which reference E.
749 Otherwise return NULL. */
752 get_cases_for_edge (edge e
, tree t
)
754 struct edge_to_cases_elt elt
, *elt_p
;
759 /* If we are not recording cases, then we do not have CASE_LABEL_EXPR
760 chains available. Return NULL so the caller can detect this case. */
761 if (!recording_case_labels_p ())
766 elt
.case_labels
= NULL
;
767 slot
= htab_find_slot (edge_to_cases
, &elt
, NO_INSERT
);
771 elt_p
= (struct edge_to_cases_elt
*)*slot
;
772 return elt_p
->case_labels
;
775 /* If we did not find E in the hash table, then this must be the first
776 time we have been queried for information about E & T. Add all the
777 elements from T to the hash table then perform the query again. */
779 vec
= SWITCH_LABELS (t
);
780 n
= TREE_VEC_LENGTH (vec
);
781 for (i
= 0; i
< n
; i
++)
783 tree lab
= CASE_LABEL (TREE_VEC_ELT (vec
, i
));
784 basic_block label_bb
= label_to_block (lab
);
785 record_switch_edge (find_edge (e
->src
, label_bb
), TREE_VEC_ELT (vec
, i
));
790 /* Create the edges for a SWITCH_EXPR starting at block BB.
791 At this point, the switch body has been lowered and the
792 SWITCH_LABELS filled in, so this is in effect a multi-way branch. */
795 make_switch_expr_edges (basic_block bb
)
797 tree entry
= last_stmt (bb
);
801 vec
= SWITCH_LABELS (entry
);
802 n
= TREE_VEC_LENGTH (vec
);
804 for (i
= 0; i
< n
; ++i
)
806 tree lab
= CASE_LABEL (TREE_VEC_ELT (vec
, i
));
807 basic_block label_bb
= label_to_block (lab
);
808 make_edge (bb
, label_bb
, 0);
813 /* Return the basic block holding label DEST. */
816 label_to_block_fn (struct function
*ifun
, tree dest
)
818 int uid
= LABEL_DECL_UID (dest
);
820 /* We would die hard when faced by an undefined label. Emit a label to
821 the very first basic block. This will hopefully make even the dataflow
822 and undefined variable warnings quite right. */
823 if ((errorcount
|| sorrycount
) && uid
< 0)
825 block_stmt_iterator bsi
=
826 bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS
));
829 stmt
= build1 (LABEL_EXPR
, void_type_node
, dest
);
830 bsi_insert_before (&bsi
, stmt
, BSI_NEW_STMT
);
831 uid
= LABEL_DECL_UID (dest
);
833 if (VEC_length (basic_block
, ifun
->cfg
->x_label_to_block_map
)
834 <= (unsigned int) uid
)
836 return VEC_index (basic_block
, ifun
->cfg
->x_label_to_block_map
, uid
);
839 /* Create edges for an abnormal goto statement at block BB. If FOR_CALL
840 is true, the source statement is a CALL_EXPR instead of a GOTO_EXPR. */
843 make_abnormal_goto_edges (basic_block bb
, bool for_call
)
845 basic_block target_bb
;
846 block_stmt_iterator bsi
;
848 FOR_EACH_BB (target_bb
)
849 for (bsi
= bsi_start (target_bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
851 tree target
= bsi_stmt (bsi
);
853 if (TREE_CODE (target
) != LABEL_EXPR
)
856 target
= LABEL_EXPR_LABEL (target
);
858 /* Make an edge to every label block that has been marked as a
859 potential target for a computed goto or a non-local goto. */
860 if ((FORCED_LABEL (target
) && !for_call
)
861 || (DECL_NONLOCAL (target
) && for_call
))
863 make_edge (bb
, target_bb
, EDGE_ABNORMAL
);
869 /* Create edges for a goto statement at block BB. */
872 make_goto_expr_edges (basic_block bb
)
874 block_stmt_iterator last
= bsi_last (bb
);
875 tree goto_t
= bsi_stmt (last
);
877 /* A simple GOTO creates normal edges. */
878 if (simple_goto_p (goto_t
))
880 tree dest
= GOTO_DESTINATION (goto_t
);
881 edge e
= make_edge (bb
, label_to_block (dest
), EDGE_FALLTHRU
);
882 #ifdef USE_MAPPED_LOCATION
883 e
->goto_locus
= EXPR_LOCATION (goto_t
);
885 e
->goto_locus
= EXPR_LOCUS (goto_t
);
887 bsi_remove (&last
, true);
891 /* A computed GOTO creates abnormal edges. */
892 make_abnormal_goto_edges (bb
, false);
896 /*---------------------------------------------------------------------------
898 ---------------------------------------------------------------------------*/
900 /* Cleanup useless labels in basic blocks. This is something we wish
901 to do early because it allows us to group case labels before creating
902 the edges for the CFG, and it speeds up block statement iterators in
904 We only run this pass once, running it more than once is probably not
907 /* A map from basic block index to the leading label of that block. */
908 static tree
*label_for_bb
;
910 /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */
912 update_eh_label (struct eh_region
*region
)
914 tree old_label
= get_eh_region_tree_label (region
);
918 basic_block bb
= label_to_block (old_label
);
920 /* ??? After optimizing, there may be EH regions with labels
921 that have already been removed from the function body, so
922 there is no basic block for them. */
926 new_label
= label_for_bb
[bb
->index
];
927 set_eh_region_tree_label (region
, new_label
);
931 /* Given LABEL return the first label in the same basic block. */
933 main_block_label (tree label
)
935 basic_block bb
= label_to_block (label
);
937 /* label_to_block possibly inserted undefined label into the chain. */
938 if (!label_for_bb
[bb
->index
])
939 label_for_bb
[bb
->index
] = label
;
940 return label_for_bb
[bb
->index
];
943 /* Cleanup redundant labels. This is a three-step process:
944 1) Find the leading label for each block.
945 2) Redirect all references to labels to the leading labels.
946 3) Cleanup all useless labels. */
949 cleanup_dead_labels (void)
952 label_for_bb
= XCNEWVEC (tree
, last_basic_block
);
954 /* Find a suitable label for each block. We use the first user-defined
955 label if there is one, or otherwise just the first label we see. */
958 block_stmt_iterator i
;
960 for (i
= bsi_start (bb
); !bsi_end_p (i
); bsi_next (&i
))
962 tree label
, stmt
= bsi_stmt (i
);
964 if (TREE_CODE (stmt
) != LABEL_EXPR
)
967 label
= LABEL_EXPR_LABEL (stmt
);
969 /* If we have not yet seen a label for the current block,
970 remember this one and see if there are more labels. */
971 if (! label_for_bb
[bb
->index
])
973 label_for_bb
[bb
->index
] = label
;
977 /* If we did see a label for the current block already, but it
978 is an artificially created label, replace it if the current
979 label is a user defined label. */
980 if (! DECL_ARTIFICIAL (label
)
981 && DECL_ARTIFICIAL (label_for_bb
[bb
->index
]))
983 label_for_bb
[bb
->index
] = label
;
989 /* Now redirect all jumps/branches to the selected label.
990 First do so for each block ending in a control statement. */
993 tree stmt
= last_stmt (bb
);
997 switch (TREE_CODE (stmt
))
1001 tree true_branch
, false_branch
;
1003 true_branch
= COND_EXPR_THEN (stmt
);
1004 false_branch
= COND_EXPR_ELSE (stmt
);
1006 GOTO_DESTINATION (true_branch
)
1007 = main_block_label (GOTO_DESTINATION (true_branch
));
1008 GOTO_DESTINATION (false_branch
)
1009 = main_block_label (GOTO_DESTINATION (false_branch
));
1017 tree vec
= SWITCH_LABELS (stmt
);
1018 size_t n
= TREE_VEC_LENGTH (vec
);
1020 /* Replace all destination labels. */
1021 for (i
= 0; i
< n
; ++i
)
1023 tree elt
= TREE_VEC_ELT (vec
, i
);
1024 tree label
= main_block_label (CASE_LABEL (elt
));
1025 CASE_LABEL (elt
) = label
;
1030 /* We have to handle GOTO_EXPRs until they're removed, and we don't
1031 remove them until after we've created the CFG edges. */
1033 if (! computed_goto_p (stmt
))
1035 GOTO_DESTINATION (stmt
)
1036 = main_block_label (GOTO_DESTINATION (stmt
));
1045 for_each_eh_region (update_eh_label
);
1047 /* Finally, purge dead labels. All user-defined labels and labels that
1048 can be the target of non-local gotos and labels which have their
1049 address taken are preserved. */
1052 block_stmt_iterator i
;
1053 tree label_for_this_bb
= label_for_bb
[bb
->index
];
1055 if (! label_for_this_bb
)
1058 for (i
= bsi_start (bb
); !bsi_end_p (i
); )
1060 tree label
, stmt
= bsi_stmt (i
);
1062 if (TREE_CODE (stmt
) != LABEL_EXPR
)
1065 label
= LABEL_EXPR_LABEL (stmt
);
1067 if (label
== label_for_this_bb
1068 || ! DECL_ARTIFICIAL (label
)
1069 || DECL_NONLOCAL (label
)
1070 || FORCED_LABEL (label
))
1073 bsi_remove (&i
, true);
1077 free (label_for_bb
);
1080 /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE),
1081 and scan the sorted vector of cases. Combine the ones jumping to the
1083 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
1086 group_case_labels (void)
1092 tree stmt
= last_stmt (bb
);
1093 if (stmt
&& TREE_CODE (stmt
) == SWITCH_EXPR
)
1095 tree labels
= SWITCH_LABELS (stmt
);
1096 int old_size
= TREE_VEC_LENGTH (labels
);
1097 int i
, j
, new_size
= old_size
;
1098 tree default_case
= TREE_VEC_ELT (labels
, old_size
- 1);
1101 /* The default label is always the last case in a switch
1102 statement after gimplification. */
1103 default_label
= CASE_LABEL (default_case
);
1105 /* Look for possible opportunities to merge cases.
1106 Ignore the last element of the label vector because it
1107 must be the default case. */
1109 while (i
< old_size
- 1)
1111 tree base_case
, base_label
, base_high
;
1112 base_case
= TREE_VEC_ELT (labels
, i
);
1114 gcc_assert (base_case
);
1115 base_label
= CASE_LABEL (base_case
);
1117 /* Discard cases that have the same destination as the
1119 if (base_label
== default_label
)
1121 TREE_VEC_ELT (labels
, i
) = NULL_TREE
;
1127 base_high
= CASE_HIGH (base_case
) ?
1128 CASE_HIGH (base_case
) : CASE_LOW (base_case
);
1130 /* Try to merge case labels. Break out when we reach the end
1131 of the label vector or when we cannot merge the next case
1132 label with the current one. */
1133 while (i
< old_size
- 1)
1135 tree merge_case
= TREE_VEC_ELT (labels
, i
);
1136 tree merge_label
= CASE_LABEL (merge_case
);
1137 tree t
= int_const_binop (PLUS_EXPR
, base_high
,
1138 integer_one_node
, 1);
1140 /* Merge the cases if they jump to the same place,
1141 and their ranges are consecutive. */
1142 if (merge_label
== base_label
1143 && tree_int_cst_equal (CASE_LOW (merge_case
), t
))
1145 base_high
= CASE_HIGH (merge_case
) ?
1146 CASE_HIGH (merge_case
) : CASE_LOW (merge_case
);
1147 CASE_HIGH (base_case
) = base_high
;
1148 TREE_VEC_ELT (labels
, i
) = NULL_TREE
;
1157 /* Compress the case labels in the label vector, and adjust the
1158 length of the vector. */
1159 for (i
= 0, j
= 0; i
< new_size
; i
++)
1161 while (! TREE_VEC_ELT (labels
, j
))
1163 TREE_VEC_ELT (labels
, i
) = TREE_VEC_ELT (labels
, j
++);
1165 TREE_VEC_LENGTH (labels
) = new_size
;
1170 /* Checks whether we can merge block B into block A. */
1173 tree_can_merge_blocks_p (basic_block a
, basic_block b
)
1176 block_stmt_iterator bsi
;
1179 if (!single_succ_p (a
))
1182 if (single_succ_edge (a
)->flags
& EDGE_ABNORMAL
)
1185 if (single_succ (a
) != b
)
1188 if (!single_pred_p (b
))
1191 if (b
== EXIT_BLOCK_PTR
)
1194 /* If A ends by a statement causing exceptions or something similar, we
1195 cannot merge the blocks. */
1196 stmt
= last_stmt (a
);
1197 if (stmt
&& stmt_ends_bb_p (stmt
))
1200 /* Do not allow a block with only a non-local label to be merged. */
1201 if (stmt
&& TREE_CODE (stmt
) == LABEL_EXPR
1202 && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
)))
1205 /* It must be possible to eliminate all phi nodes in B. If ssa form
1206 is not up-to-date, we cannot eliminate any phis; however, if only
1207 some symbols as whole are marked for renaming, this is not a problem,
1208 as phi nodes for those symbols are irrelevant in updating anyway. */
1209 phi
= phi_nodes (b
);
1212 if (name_mappings_registered_p ())
1215 for (; phi
; phi
= PHI_CHAIN (phi
))
1216 if (!is_gimple_reg (PHI_RESULT (phi
))
1217 && !may_propagate_copy (PHI_RESULT (phi
), PHI_ARG_DEF (phi
, 0)))
1221 /* Do not remove user labels. */
1222 for (bsi
= bsi_start (b
); !bsi_end_p (bsi
); bsi_next (&bsi
))
1224 stmt
= bsi_stmt (bsi
);
1225 if (TREE_CODE (stmt
) != LABEL_EXPR
)
1227 if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt
)))
1231 /* Protect the loop latches. */
1233 && b
->loop_father
->latch
== b
)
1239 /* Replaces all uses of NAME by VAL. */
1242 replace_uses_by (tree name
, tree val
)
1244 imm_use_iterator imm_iter
;
1249 FOR_EACH_IMM_USE_STMT (stmt
, imm_iter
, name
)
1251 FOR_EACH_IMM_USE_ON_STMT (use
, imm_iter
)
1253 replace_exp (use
, val
);
1255 if (TREE_CODE (stmt
) == PHI_NODE
)
1257 e
= PHI_ARG_EDGE (stmt
, PHI_ARG_INDEX_FROM_USE (use
));
1258 if (e
->flags
& EDGE_ABNORMAL
)
1260 /* This can only occur for virtual operands, since
1261 for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
1262 would prevent replacement. */
1263 gcc_assert (!is_gimple_reg (name
));
1264 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val
) = 1;
1268 if (TREE_CODE (stmt
) != PHI_NODE
)
1272 fold_stmt_inplace (stmt
);
1273 rhs
= get_rhs (stmt
);
1274 if (TREE_CODE (rhs
) == ADDR_EXPR
)
1275 recompute_tree_invariant_for_addr_expr (rhs
);
1277 maybe_clean_or_replace_eh_stmt (stmt
, stmt
);
1278 mark_new_vars_to_rename (stmt
);
1282 gcc_assert (num_imm_uses (name
) == 0);
1284 /* Also update the trees stored in loop structures. */
1290 FOR_EACH_LOOP (li
, loop
, 0)
1292 substitute_in_loop_info (loop
, name
, val
);
1297 /* Merge block B into block A. */
1300 tree_merge_blocks (basic_block a
, basic_block b
)
1302 block_stmt_iterator bsi
;
1303 tree_stmt_iterator last
;
1307 fprintf (dump_file
, "Merging blocks %d and %d\n", a
->index
, b
->index
);
1309 /* Remove all single-valued PHI nodes from block B of the form
1310 V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */
1312 for (phi
= phi_nodes (b
); phi
; phi
= phi_nodes (b
))
1314 tree def
= PHI_RESULT (phi
), use
= PHI_ARG_DEF (phi
, 0);
1316 bool may_replace_uses
= may_propagate_copy (def
, use
);
1318 /* In case we have loops to care about, do not propagate arguments of
1319 loop closed ssa phi nodes. */
1321 && is_gimple_reg (def
)
1322 && TREE_CODE (use
) == SSA_NAME
1323 && a
->loop_father
!= b
->loop_father
)
1324 may_replace_uses
= false;
1326 if (!may_replace_uses
)
1328 gcc_assert (is_gimple_reg (def
));
1330 /* Note that just emitting the copies is fine -- there is no problem
1331 with ordering of phi nodes. This is because A is the single
1332 predecessor of B, therefore results of the phi nodes cannot
1333 appear as arguments of the phi nodes. */
1334 copy
= build2_gimple (GIMPLE_MODIFY_STMT
, def
, use
);
1335 bsi_insert_after (&bsi
, copy
, BSI_NEW_STMT
);
1336 SET_PHI_RESULT (phi
, NULL_TREE
);
1337 SSA_NAME_DEF_STMT (def
) = copy
;
1340 replace_uses_by (def
, use
);
1342 remove_phi_node (phi
, NULL
);
1345 /* Ensure that B follows A. */
1346 move_block_after (b
, a
);
1348 gcc_assert (single_succ_edge (a
)->flags
& EDGE_FALLTHRU
);
1349 gcc_assert (!last_stmt (a
) || !stmt_ends_bb_p (last_stmt (a
)));
1351 /* Remove labels from B and set bb_for_stmt to A for other statements. */
1352 for (bsi
= bsi_start (b
); !bsi_end_p (bsi
);)
1354 if (TREE_CODE (bsi_stmt (bsi
)) == LABEL_EXPR
)
1356 tree label
= bsi_stmt (bsi
);
1358 bsi_remove (&bsi
, false);
1359 /* Now that we can thread computed gotos, we might have
1360 a situation where we have a forced label in block B
1361 However, the label at the start of block B might still be
1362 used in other ways (think about the runtime checking for
1363 Fortran assigned gotos). So we can not just delete the
1364 label. Instead we move the label to the start of block A. */
1365 if (FORCED_LABEL (LABEL_EXPR_LABEL (label
)))
1367 block_stmt_iterator dest_bsi
= bsi_start (a
);
1368 bsi_insert_before (&dest_bsi
, label
, BSI_NEW_STMT
);
1373 change_bb_for_stmt (bsi_stmt (bsi
), a
);
1378 /* Merge the chains. */
1379 last
= tsi_last (a
->stmt_list
);
1380 tsi_link_after (&last
, b
->stmt_list
, TSI_NEW_STMT
);
1381 b
->stmt_list
= NULL
;
1385 /* Return the one of two successors of BB that is not reachable by a
1386 reached by a complex edge, if there is one. Else, return BB. We use
1387 this in optimizations that use post-dominators for their heuristics,
1388 to catch the cases in C++ where function calls are involved. */
1391 single_noncomplex_succ (basic_block bb
)
1394 if (EDGE_COUNT (bb
->succs
) != 2)
1397 e0
= EDGE_SUCC (bb
, 0);
1398 e1
= EDGE_SUCC (bb
, 1);
1399 if (e0
->flags
& EDGE_COMPLEX
)
1401 if (e1
->flags
& EDGE_COMPLEX
)
1408 /* Walk the function tree removing unnecessary statements.
1410 * Empty statement nodes are removed
1412 * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed
1414 * Unnecessary COND_EXPRs are removed
1416 * Some unnecessary BIND_EXPRs are removed
1418 Clearly more work could be done. The trick is doing the analysis
1419 and removal fast enough to be a net improvement in compile times.
1421 Note that when we remove a control structure such as a COND_EXPR
1422 BIND_EXPR, or TRY block, we will need to repeat this optimization pass
1423 to ensure we eliminate all the useless code. */
1434 static void remove_useless_stmts_1 (tree
*, struct rus_data
*);
1437 remove_useless_stmts_warn_notreached (tree stmt
)
1439 if (EXPR_HAS_LOCATION (stmt
))
1441 location_t loc
= EXPR_LOCATION (stmt
);
1442 if (LOCATION_LINE (loc
) > 0)
1444 warning (0, "%Hwill never be executed", &loc
);
1449 switch (TREE_CODE (stmt
))
1451 case STATEMENT_LIST
:
1453 tree_stmt_iterator i
;
1454 for (i
= tsi_start (stmt
); !tsi_end_p (i
); tsi_next (&i
))
1455 if (remove_useless_stmts_warn_notreached (tsi_stmt (i
)))
1461 if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt
)))
1463 if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt
)))
1465 if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt
)))
1469 case TRY_FINALLY_EXPR
:
1470 case TRY_CATCH_EXPR
:
1471 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt
, 0)))
1473 if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt
, 1)))
1478 return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt
));
1479 case EH_FILTER_EXPR
:
1480 return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt
));
1482 return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt
));
1485 /* Not a live container. */
1493 remove_useless_stmts_cond (tree
*stmt_p
, struct rus_data
*data
)
1495 tree then_clause
, else_clause
, cond
;
1496 bool save_has_label
, then_has_label
, else_has_label
;
1498 save_has_label
= data
->has_label
;
1499 data
->has_label
= false;
1500 data
->last_goto
= NULL
;
1502 remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p
), data
);
1504 then_has_label
= data
->has_label
;
1505 data
->has_label
= false;
1506 data
->last_goto
= NULL
;
1508 remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p
), data
);
1510 else_has_label
= data
->has_label
;
1511 data
->has_label
= save_has_label
| then_has_label
| else_has_label
;
1513 then_clause
= COND_EXPR_THEN (*stmt_p
);
1514 else_clause
= COND_EXPR_ELSE (*stmt_p
);
1515 cond
= fold (COND_EXPR_COND (*stmt_p
));
1517 /* If neither arm does anything at all, we can remove the whole IF. */
1518 if (!TREE_SIDE_EFFECTS (then_clause
) && !TREE_SIDE_EFFECTS (else_clause
))
1520 *stmt_p
= build_empty_stmt ();
1521 data
->repeat
= true;
1524 /* If there are no reachable statements in an arm, then we can
1525 zap the entire conditional. */
1526 else if (integer_nonzerop (cond
) && !else_has_label
)
1528 if (warn_notreached
)
1529 remove_useless_stmts_warn_notreached (else_clause
);
1530 *stmt_p
= then_clause
;
1531 data
->repeat
= true;
1533 else if (integer_zerop (cond
) && !then_has_label
)
1535 if (warn_notreached
)
1536 remove_useless_stmts_warn_notreached (then_clause
);
1537 *stmt_p
= else_clause
;
1538 data
->repeat
= true;
1541 /* Check a couple of simple things on then/else with single stmts. */
1544 tree then_stmt
= expr_only (then_clause
);
1545 tree else_stmt
= expr_only (else_clause
);
1547 /* Notice branches to a common destination. */
1548 if (then_stmt
&& else_stmt
1549 && TREE_CODE (then_stmt
) == GOTO_EXPR
1550 && TREE_CODE (else_stmt
) == GOTO_EXPR
1551 && (GOTO_DESTINATION (then_stmt
) == GOTO_DESTINATION (else_stmt
)))
1553 *stmt_p
= then_stmt
;
1554 data
->repeat
= true;
1557 /* If the THEN/ELSE clause merely assigns a value to a variable or
1558 parameter which is already known to contain that value, then
1559 remove the useless THEN/ELSE clause. */
1560 else if (TREE_CODE (cond
) == VAR_DECL
|| TREE_CODE (cond
) == PARM_DECL
)
1563 && TREE_CODE (else_stmt
) == GIMPLE_MODIFY_STMT
1564 && GIMPLE_STMT_OPERAND (else_stmt
, 0) == cond
1565 && integer_zerop (GIMPLE_STMT_OPERAND (else_stmt
, 1)))
1566 COND_EXPR_ELSE (*stmt_p
) = alloc_stmt_list ();
1568 else if ((TREE_CODE (cond
) == EQ_EXPR
|| TREE_CODE (cond
) == NE_EXPR
)
1569 && (TREE_CODE (TREE_OPERAND (cond
, 0)) == VAR_DECL
1570 || TREE_CODE (TREE_OPERAND (cond
, 0)) == PARM_DECL
)
1571 && TREE_CONSTANT (TREE_OPERAND (cond
, 1)))
1573 tree stmt
= (TREE_CODE (cond
) == EQ_EXPR
1574 ? then_stmt
: else_stmt
);
1575 tree
*location
= (TREE_CODE (cond
) == EQ_EXPR
1576 ? &COND_EXPR_THEN (*stmt_p
)
1577 : &COND_EXPR_ELSE (*stmt_p
));
1580 && TREE_CODE (stmt
) == GIMPLE_MODIFY_STMT
1581 && GIMPLE_STMT_OPERAND (stmt
, 0) == TREE_OPERAND (cond
, 0)
1582 && GIMPLE_STMT_OPERAND (stmt
, 1) == TREE_OPERAND (cond
, 1))
1583 *location
= alloc_stmt_list ();
1587 /* Protect GOTOs in the arm of COND_EXPRs from being removed. They
1588 would be re-introduced during lowering. */
1589 data
->last_goto
= NULL
;
1594 remove_useless_stmts_tf (tree
*stmt_p
, struct rus_data
*data
)
1596 bool save_may_branch
, save_may_throw
;
1597 bool this_may_branch
, this_may_throw
;
1599 /* Collect may_branch and may_throw information for the body only. */
1600 save_may_branch
= data
->may_branch
;
1601 save_may_throw
= data
->may_throw
;
1602 data
->may_branch
= false;
1603 data
->may_throw
= false;
1604 data
->last_goto
= NULL
;
1606 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p
, 0), data
);
1608 this_may_branch
= data
->may_branch
;
1609 this_may_throw
= data
->may_throw
;
1610 data
->may_branch
|= save_may_branch
;
1611 data
->may_throw
|= save_may_throw
;
1612 data
->last_goto
= NULL
;
1614 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p
, 1), data
);
1616 /* If the body is empty, then we can emit the FINALLY block without
1617 the enclosing TRY_FINALLY_EXPR. */
1618 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p
, 0)))
1620 *stmt_p
= TREE_OPERAND (*stmt_p
, 1);
1621 data
->repeat
= true;
1624 /* If the handler is empty, then we can emit the TRY block without
1625 the enclosing TRY_FINALLY_EXPR. */
1626 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p
, 1)))
1628 *stmt_p
= TREE_OPERAND (*stmt_p
, 0);
1629 data
->repeat
= true;
1632 /* If the body neither throws, nor branches, then we can safely
1633 string the TRY and FINALLY blocks together. */
1634 else if (!this_may_branch
&& !this_may_throw
)
1636 tree stmt
= *stmt_p
;
1637 *stmt_p
= TREE_OPERAND (stmt
, 0);
1638 append_to_statement_list (TREE_OPERAND (stmt
, 1), stmt_p
);
1639 data
->repeat
= true;
1645 remove_useless_stmts_tc (tree
*stmt_p
, struct rus_data
*data
)
1647 bool save_may_throw
, this_may_throw
;
1648 tree_stmt_iterator i
;
1651 /* Collect may_throw information for the body only. */
1652 save_may_throw
= data
->may_throw
;
1653 data
->may_throw
= false;
1654 data
->last_goto
= NULL
;
1656 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p
, 0), data
);
1658 this_may_throw
= data
->may_throw
;
1659 data
->may_throw
= save_may_throw
;
1661 /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */
1662 if (!this_may_throw
)
1664 if (warn_notreached
)
1665 remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p
, 1));
1666 *stmt_p
= TREE_OPERAND (*stmt_p
, 0);
1667 data
->repeat
= true;
1671 /* Process the catch clause specially. We may be able to tell that
1672 no exceptions propagate past this point. */
1674 this_may_throw
= true;
1675 i
= tsi_start (TREE_OPERAND (*stmt_p
, 1));
1676 stmt
= tsi_stmt (i
);
1677 data
->last_goto
= NULL
;
1679 switch (TREE_CODE (stmt
))
1682 for (; !tsi_end_p (i
); tsi_next (&i
))
1684 stmt
= tsi_stmt (i
);
1685 /* If we catch all exceptions, then the body does not
1686 propagate exceptions past this point. */
1687 if (CATCH_TYPES (stmt
) == NULL
)
1688 this_may_throw
= false;
1689 data
->last_goto
= NULL
;
1690 remove_useless_stmts_1 (&CATCH_BODY (stmt
), data
);
1694 case EH_FILTER_EXPR
:
1695 if (EH_FILTER_MUST_NOT_THROW (stmt
))
1696 this_may_throw
= false;
1697 else if (EH_FILTER_TYPES (stmt
) == NULL
)
1698 this_may_throw
= false;
1699 remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt
), data
);
1703 /* Otherwise this is a cleanup. */
1704 remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p
, 1), data
);
1706 /* If the cleanup is empty, then we can emit the TRY block without
1707 the enclosing TRY_CATCH_EXPR. */
1708 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p
, 1)))
1710 *stmt_p
= TREE_OPERAND (*stmt_p
, 0);
1711 data
->repeat
= true;
1715 data
->may_throw
|= this_may_throw
;
1720 remove_useless_stmts_bind (tree
*stmt_p
, struct rus_data
*data
)
1724 /* First remove anything underneath the BIND_EXPR. */
1725 remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p
), data
);
1727 /* If the BIND_EXPR has no variables, then we can pull everything
1728 up one level and remove the BIND_EXPR, unless this is the toplevel
1729 BIND_EXPR for the current function or an inlined function.
1731 When this situation occurs we will want to apply this
1732 optimization again. */
1733 block
= BIND_EXPR_BLOCK (*stmt_p
);
1734 if (BIND_EXPR_VARS (*stmt_p
) == NULL_TREE
1735 && *stmt_p
!= DECL_SAVED_TREE (current_function_decl
)
1737 || ! BLOCK_ABSTRACT_ORIGIN (block
)
1738 || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block
))
1741 *stmt_p
= BIND_EXPR_BODY (*stmt_p
);
1742 data
->repeat
= true;
1748 remove_useless_stmts_goto (tree
*stmt_p
, struct rus_data
*data
)
1750 tree dest
= GOTO_DESTINATION (*stmt_p
);
1752 data
->may_branch
= true;
1753 data
->last_goto
= NULL
;
1755 /* Record the last goto expr, so that we can delete it if unnecessary. */
1756 if (TREE_CODE (dest
) == LABEL_DECL
)
1757 data
->last_goto
= stmt_p
;
1762 remove_useless_stmts_label (tree
*stmt_p
, struct rus_data
*data
)
1764 tree label
= LABEL_EXPR_LABEL (*stmt_p
);
1766 data
->has_label
= true;
1768 /* We do want to jump across non-local label receiver code. */
1769 if (DECL_NONLOCAL (label
))
1770 data
->last_goto
= NULL
;
1772 else if (data
->last_goto
&& GOTO_DESTINATION (*data
->last_goto
) == label
)
1774 *data
->last_goto
= build_empty_stmt ();
1775 data
->repeat
= true;
1778 /* ??? Add something here to delete unused labels. */
1782 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1783 decl. This allows us to eliminate redundant or useless
1784 calls to "const" functions.
1786 Gimplifier already does the same operation, but we may notice functions
1787 being const and pure once their calls has been gimplified, so we need
1788 to update the flag. */
1791 update_call_expr_flags (tree call
)
1793 tree decl
= get_callee_fndecl (call
);
1796 if (call_expr_flags (call
) & (ECF_CONST
| ECF_PURE
))
1797 TREE_SIDE_EFFECTS (call
) = 0;
1798 if (TREE_NOTHROW (decl
))
1799 TREE_NOTHROW (call
) = 1;
1803 /* T is CALL_EXPR. Set current_function_calls_* flags. */
1806 notice_special_calls (tree t
)
1808 int flags
= call_expr_flags (t
);
1810 if (flags
& ECF_MAY_BE_ALLOCA
)
1811 current_function_calls_alloca
= true;
1812 if (flags
& ECF_RETURNS_TWICE
)
1813 current_function_calls_setjmp
= true;
1817 /* Clear flags set by notice_special_calls. Used by dead code removal
1818 to update the flags. */
1821 clear_special_calls (void)
1823 current_function_calls_alloca
= false;
1824 current_function_calls_setjmp
= false;
1829 remove_useless_stmts_1 (tree
*tp
, struct rus_data
*data
)
1833 switch (TREE_CODE (t
))
1836 remove_useless_stmts_cond (tp
, data
);
1839 case TRY_FINALLY_EXPR
:
1840 remove_useless_stmts_tf (tp
, data
);
1843 case TRY_CATCH_EXPR
:
1844 remove_useless_stmts_tc (tp
, data
);
1848 remove_useless_stmts_bind (tp
, data
);
1852 remove_useless_stmts_goto (tp
, data
);
1856 remove_useless_stmts_label (tp
, data
);
1861 data
->last_goto
= NULL
;
1862 data
->may_branch
= true;
1867 data
->last_goto
= NULL
;
1868 notice_special_calls (t
);
1869 update_call_expr_flags (t
);
1870 if (tree_could_throw_p (t
))
1871 data
->may_throw
= true;
1877 case GIMPLE_MODIFY_STMT
:
1878 data
->last_goto
= NULL
;
1880 op
= get_call_expr_in (t
);
1883 update_call_expr_flags (op
);
1884 notice_special_calls (op
);
1886 if (tree_could_throw_p (t
))
1887 data
->may_throw
= true;
1890 case STATEMENT_LIST
:
1892 tree_stmt_iterator i
= tsi_start (t
);
1893 while (!tsi_end_p (i
))
1896 if (IS_EMPTY_STMT (t
))
1902 remove_useless_stmts_1 (tsi_stmt_ptr (i
), data
);
1905 if (TREE_CODE (t
) == STATEMENT_LIST
)
1907 tsi_link_before (&i
, t
, TSI_SAME_STMT
);
1917 data
->last_goto
= NULL
;
1921 data
->last_goto
= NULL
;
1927 remove_useless_stmts (void)
1929 struct rus_data data
;
1931 clear_special_calls ();
1935 memset (&data
, 0, sizeof (data
));
1936 remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl
), &data
);
1938 while (data
.repeat
);
1943 struct tree_opt_pass pass_remove_useless_stmts
=
1945 "useless", /* name */
1947 remove_useless_stmts
, /* execute */
1950 0, /* static_pass_number */
1952 PROP_gimple_any
, /* properties_required */
1953 0, /* properties_provided */
1954 0, /* properties_destroyed */
1955 0, /* todo_flags_start */
1956 TODO_dump_func
, /* todo_flags_finish */
1960 /* Remove PHI nodes associated with basic block BB and all edges out of BB. */
1963 remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb
)
1967 /* Since this block is no longer reachable, we can just delete all
1968 of its PHI nodes. */
1969 phi
= phi_nodes (bb
);
1972 tree next
= PHI_CHAIN (phi
);
1973 remove_phi_node (phi
, NULL_TREE
);
1977 /* Remove edges to BB's successors. */
1978 while (EDGE_COUNT (bb
->succs
) > 0)
1979 remove_edge (EDGE_SUCC (bb
, 0));
1983 /* Remove statements of basic block BB. */
1986 remove_bb (basic_block bb
)
1988 block_stmt_iterator i
;
1989 #ifdef USE_MAPPED_LOCATION
1990 source_location loc
= UNKNOWN_LOCATION
;
1992 source_locus loc
= 0;
1997 fprintf (dump_file
, "Removing basic block %d\n", bb
->index
);
1998 if (dump_flags
& TDF_DETAILS
)
2000 dump_bb (bb
, dump_file
, 0);
2001 fprintf (dump_file
, "\n");
2007 struct loop
*loop
= bb
->loop_father
;
2009 /* If a loop gets removed, clean up the information associated
2011 if (loop
->latch
== bb
2012 || loop
->header
== bb
)
2013 free_numbers_of_iterations_estimates_loop (loop
);
2016 /* Remove all the instructions in the block. */
2017 for (i
= bsi_start (bb
); !bsi_end_p (i
);)
2019 tree stmt
= bsi_stmt (i
);
2020 if (TREE_CODE (stmt
) == LABEL_EXPR
2021 && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt
))
2022 || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
))))
2025 block_stmt_iterator new_bsi
;
2027 /* A non-reachable non-local label may still be referenced.
2028 But it no longer needs to carry the extra semantics of
2030 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
)))
2032 DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
)) = 0;
2033 FORCED_LABEL (LABEL_EXPR_LABEL (stmt
)) = 1;
2036 new_bb
= bb
->prev_bb
;
2037 new_bsi
= bsi_start (new_bb
);
2038 bsi_remove (&i
, false);
2039 bsi_insert_before (&new_bsi
, stmt
, BSI_NEW_STMT
);
2043 /* Release SSA definitions if we are in SSA. Note that we
2044 may be called when not in SSA. For example,
2045 final_cleanup calls this function via
2046 cleanup_tree_cfg. */
2047 if (gimple_in_ssa_p (cfun
))
2048 release_defs (stmt
);
2050 bsi_remove (&i
, true);
2053 /* Don't warn for removed gotos. Gotos are often removed due to
2054 jump threading, thus resulting in bogus warnings. Not great,
2055 since this way we lose warnings for gotos in the original
2056 program that are indeed unreachable. */
2057 if (TREE_CODE (stmt
) != GOTO_EXPR
&& EXPR_HAS_LOCATION (stmt
) && !loc
)
2059 #ifdef USE_MAPPED_LOCATION
2060 if (EXPR_HAS_LOCATION (stmt
))
2061 loc
= EXPR_LOCATION (stmt
);
2064 t
= EXPR_LOCUS (stmt
);
2065 if (t
&& LOCATION_LINE (*t
) > 0)
2071 /* If requested, give a warning that the first statement in the
2072 block is unreachable. We walk statements backwards in the
2073 loop above, so the last statement we process is the first statement
2075 #ifdef USE_MAPPED_LOCATION
2076 if (loc
> BUILTINS_LOCATION
)
2077 warning (OPT_Wunreachable_code
, "%Hwill never be executed", &loc
);
2080 warning (OPT_Wunreachable_code
, "%Hwill never be executed", loc
);
2083 remove_phi_nodes_and_edges_for_unreachable_block (bb
);
2087 /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a
2088 predicate VAL, return the edge that will be taken out of the block.
2089 If VAL does not match a unique edge, NULL is returned. */
2092 find_taken_edge (basic_block bb
, tree val
)
2096 stmt
= last_stmt (bb
);
2099 gcc_assert (is_ctrl_stmt (stmt
));
2102 if (! is_gimple_min_invariant (val
))
2105 if (TREE_CODE (stmt
) == COND_EXPR
)
2106 return find_taken_edge_cond_expr (bb
, val
);
2108 if (TREE_CODE (stmt
) == SWITCH_EXPR
)
2109 return find_taken_edge_switch_expr (bb
, val
);
2111 if (computed_goto_p (stmt
))
2112 return find_taken_edge_computed_goto (bb
, TREE_OPERAND( val
, 0));
2117 /* Given a constant value VAL and the entry block BB to a GOTO_EXPR
2118 statement, determine which of the outgoing edges will be taken out of the
2119 block. Return NULL if either edge may be taken. */
2122 find_taken_edge_computed_goto (basic_block bb
, tree val
)
2127 dest
= label_to_block (val
);
2130 e
= find_edge (bb
, dest
);
2131 gcc_assert (e
!= NULL
);
2137 /* Given a constant value VAL and the entry block BB to a COND_EXPR
2138 statement, determine which of the two edges will be taken out of the
2139 block. Return NULL if either edge may be taken. */
2142 find_taken_edge_cond_expr (basic_block bb
, tree val
)
2144 edge true_edge
, false_edge
;
2146 extract_true_false_edges_from_block (bb
, &true_edge
, &false_edge
);
2148 gcc_assert (TREE_CODE (val
) == INTEGER_CST
);
2149 return (zero_p (val
) ? false_edge
: true_edge
);
2152 /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR
2153 statement, determine which edge will be taken out of the block. Return
2154 NULL if any edge may be taken. */
2157 find_taken_edge_switch_expr (basic_block bb
, tree val
)
2159 tree switch_expr
, taken_case
;
2160 basic_block dest_bb
;
2163 switch_expr
= last_stmt (bb
);
2164 taken_case
= find_case_label_for_value (switch_expr
, val
);
2165 dest_bb
= label_to_block (CASE_LABEL (taken_case
));
2167 e
= find_edge (bb
, dest_bb
);
2173 /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL.
2174 We can make optimal use here of the fact that the case labels are
2175 sorted: We can do a binary search for a case matching VAL. */
2178 find_case_label_for_value (tree switch_expr
, tree val
)
2180 tree vec
= SWITCH_LABELS (switch_expr
);
2181 size_t low
, high
, n
= TREE_VEC_LENGTH (vec
);
2182 tree default_case
= TREE_VEC_ELT (vec
, n
- 1);
2184 for (low
= -1, high
= n
- 1; high
- low
> 1; )
2186 size_t i
= (high
+ low
) / 2;
2187 tree t
= TREE_VEC_ELT (vec
, i
);
2190 /* Cache the result of comparing CASE_LOW and val. */
2191 cmp
= tree_int_cst_compare (CASE_LOW (t
), val
);
2198 if (CASE_HIGH (t
) == NULL
)
2200 /* A singe-valued case label. */
2206 /* A case range. We can only handle integer ranges. */
2207 if (cmp
<= 0 && tree_int_cst_compare (CASE_HIGH (t
), val
) >= 0)
2212 return default_case
;
2218 /*---------------------------------------------------------------------------
2220 ---------------------------------------------------------------------------*/
2222 /* Dump tree-specific information of block BB to file OUTF. */
2225 tree_dump_bb (basic_block bb
, FILE *outf
, int indent
)
2227 dump_generic_bb (outf
, bb
, indent
, TDF_VOPS
);
2231 /* Dump a basic block on stderr. */
2234 debug_tree_bb (basic_block bb
)
2236 dump_bb (bb
, stderr
, 0);
2240 /* Dump basic block with index N on stderr. */
2243 debug_tree_bb_n (int n
)
2245 debug_tree_bb (BASIC_BLOCK (n
));
2246 return BASIC_BLOCK (n
);
2250 /* Dump the CFG on stderr.
2252 FLAGS are the same used by the tree dumping functions
2253 (see TDF_* in tree-pass.h). */
2256 debug_tree_cfg (int flags
)
2258 dump_tree_cfg (stderr
, flags
);
2262 /* Dump the program showing basic block boundaries on the given FILE.
2264 FLAGS are the same used by the tree dumping functions (see TDF_* in
2268 dump_tree_cfg (FILE *file
, int flags
)
2270 if (flags
& TDF_DETAILS
)
2272 const char *funcname
2273 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
2276 fprintf (file
, ";; Function %s\n\n", funcname
);
2277 fprintf (file
, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n",
2278 n_basic_blocks
, n_edges
, last_basic_block
);
2280 brief_dump_cfg (file
);
2281 fprintf (file
, "\n");
2284 if (flags
& TDF_STATS
)
2285 dump_cfg_stats (file
);
2287 dump_function_to_file (current_function_decl
, file
, flags
| TDF_BLOCKS
);
2291 /* Dump CFG statistics on FILE. */
2294 dump_cfg_stats (FILE *file
)
2296 static long max_num_merged_labels
= 0;
2297 unsigned long size
, total
= 0;
2300 const char * const fmt_str
= "%-30s%-13s%12s\n";
2301 const char * const fmt_str_1
= "%-30s%13d%11lu%c\n";
2302 const char * const fmt_str_2
= "%-30s%13ld%11lu%c\n";
2303 const char * const fmt_str_3
= "%-43s%11lu%c\n";
2304 const char *funcname
2305 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
2308 fprintf (file
, "\nCFG Statistics for %s\n\n", funcname
);
2310 fprintf (file
, "---------------------------------------------------------\n");
2311 fprintf (file
, fmt_str
, "", " Number of ", "Memory");
2312 fprintf (file
, fmt_str
, "", " instances ", "used ");
2313 fprintf (file
, "---------------------------------------------------------\n");
2315 size
= n_basic_blocks
* sizeof (struct basic_block_def
);
2317 fprintf (file
, fmt_str_1
, "Basic blocks", n_basic_blocks
,
2318 SCALE (size
), LABEL (size
));
2322 num_edges
+= EDGE_COUNT (bb
->succs
);
2323 size
= num_edges
* sizeof (struct edge_def
);
2325 fprintf (file
, fmt_str_2
, "Edges", num_edges
, SCALE (size
), LABEL (size
));
2327 fprintf (file
, "---------------------------------------------------------\n");
2328 fprintf (file
, fmt_str_3
, "Total memory used by CFG data", SCALE (total
),
2330 fprintf (file
, "---------------------------------------------------------\n");
2331 fprintf (file
, "\n");
2333 if (cfg_stats
.num_merged_labels
> max_num_merged_labels
)
2334 max_num_merged_labels
= cfg_stats
.num_merged_labels
;
2336 fprintf (file
, "Coalesced label blocks: %ld (Max so far: %ld)\n",
2337 cfg_stats
.num_merged_labels
, max_num_merged_labels
);
2339 fprintf (file
, "\n");
2343 /* Dump CFG statistics on stderr. Keep extern so that it's always
2344 linked in the final executable. */
2347 debug_cfg_stats (void)
2349 dump_cfg_stats (stderr
);
2353 /* Dump the flowgraph to a .vcg FILE. */
2356 tree_cfg2vcg (FILE *file
)
2361 const char *funcname
2362 = lang_hooks
.decl_printable_name (current_function_decl
, 2);
2364 /* Write the file header. */
2365 fprintf (file
, "graph: { title: \"%s\"\n", funcname
);
2366 fprintf (file
, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n");
2367 fprintf (file
, "node: { title: \"EXIT\" label: \"EXIT\" }\n");
2369 /* Write blocks and edges. */
2370 FOR_EACH_EDGE (e
, ei
, ENTRY_BLOCK_PTR
->succs
)
2372 fprintf (file
, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"",
2375 if (e
->flags
& EDGE_FAKE
)
2376 fprintf (file
, " linestyle: dotted priority: 10");
2378 fprintf (file
, " linestyle: solid priority: 100");
2380 fprintf (file
, " }\n");
2386 enum tree_code head_code
, end_code
;
2387 const char *head_name
, *end_name
;
2390 tree first
= first_stmt (bb
);
2391 tree last
= last_stmt (bb
);
2395 head_code
= TREE_CODE (first
);
2396 head_name
= tree_code_name
[head_code
];
2397 head_line
= get_lineno (first
);
2400 head_name
= "no-statement";
2404 end_code
= TREE_CODE (last
);
2405 end_name
= tree_code_name
[end_code
];
2406 end_line
= get_lineno (last
);
2409 end_name
= "no-statement";
2411 fprintf (file
, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n",
2412 bb
->index
, bb
->index
, head_name
, head_line
, end_name
,
2415 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2417 if (e
->dest
== EXIT_BLOCK_PTR
)
2418 fprintf (file
, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb
->index
);
2420 fprintf (file
, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb
->index
, e
->dest
->index
);
2422 if (e
->flags
& EDGE_FAKE
)
2423 fprintf (file
, " priority: 10 linestyle: dotted");
2425 fprintf (file
, " priority: 100 linestyle: solid");
2427 fprintf (file
, " }\n");
2430 if (bb
->next_bb
!= EXIT_BLOCK_PTR
)
2434 fputs ("}\n\n", file
);
2439 /*---------------------------------------------------------------------------
2440 Miscellaneous helpers
2441 ---------------------------------------------------------------------------*/
2443 /* Return true if T represents a stmt that always transfers control. */
2446 is_ctrl_stmt (tree t
)
2448 return (TREE_CODE (t
) == COND_EXPR
2449 || TREE_CODE (t
) == SWITCH_EXPR
2450 || TREE_CODE (t
) == GOTO_EXPR
2451 || TREE_CODE (t
) == RETURN_EXPR
2452 || TREE_CODE (t
) == RESX_EXPR
);
2456 /* Return true if T is a statement that may alter the flow of control
2457 (e.g., a call to a non-returning function). */
2460 is_ctrl_altering_stmt (tree t
)
2465 call
= get_call_expr_in (t
);
2468 /* A non-pure/const CALL_EXPR alters flow control if the current
2469 function has nonlocal labels. */
2470 if (TREE_SIDE_EFFECTS (call
) && current_function_has_nonlocal_label
)
2473 /* A CALL_EXPR also alters control flow if it does not return. */
2474 if (call_expr_flags (call
) & ECF_NORETURN
)
2478 /* OpenMP directives alter control flow. */
2479 if (OMP_DIRECTIVE_P (t
))
2482 /* If a statement can throw, it alters control flow. */
2483 return tree_can_throw_internal (t
);
2487 /* Return true if T is a computed goto. */
2490 computed_goto_p (tree t
)
2492 return (TREE_CODE (t
) == GOTO_EXPR
2493 && TREE_CODE (GOTO_DESTINATION (t
)) != LABEL_DECL
);
2497 /* Return true if T is a simple local goto. */
2500 simple_goto_p (tree t
)
2502 return (TREE_CODE (t
) == GOTO_EXPR
2503 && TREE_CODE (GOTO_DESTINATION (t
)) == LABEL_DECL
);
2507 /* Return true if T can make an abnormal transfer of control flow.
2508 Transfers of control flow associated with EH are excluded. */
2511 tree_can_make_abnormal_goto (tree t
)
2513 if (computed_goto_p (t
))
2515 if (TREE_CODE (t
) == GIMPLE_MODIFY_STMT
)
2516 t
= GIMPLE_STMT_OPERAND (t
, 1);
2517 if (TREE_CODE (t
) == WITH_SIZE_EXPR
)
2518 t
= TREE_OPERAND (t
, 0);
2519 if (TREE_CODE (t
) == CALL_EXPR
)
2520 return TREE_SIDE_EFFECTS (t
) && current_function_has_nonlocal_label
;
2525 /* Return true if T should start a new basic block. PREV_T is the
2526 statement preceding T. It is used when T is a label or a case label.
2527 Labels should only start a new basic block if their previous statement
2528 wasn't a label. Otherwise, sequence of labels would generate
2529 unnecessary basic blocks that only contain a single label. */
2532 stmt_starts_bb_p (tree t
, tree prev_t
)
2537 /* LABEL_EXPRs start a new basic block only if the preceding
2538 statement wasn't a label of the same type. This prevents the
2539 creation of consecutive blocks that have nothing but a single
2541 if (TREE_CODE (t
) == LABEL_EXPR
)
2543 /* Nonlocal and computed GOTO targets always start a new block. */
2544 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t
))
2545 || FORCED_LABEL (LABEL_EXPR_LABEL (t
)))
2548 if (prev_t
&& TREE_CODE (prev_t
) == LABEL_EXPR
)
2550 if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t
)))
2553 cfg_stats
.num_merged_labels
++;
2564 /* Return true if T should end a basic block. */
2567 stmt_ends_bb_p (tree t
)
2569 return is_ctrl_stmt (t
) || is_ctrl_altering_stmt (t
);
2573 /* Add gotos that used to be represented implicitly in the CFG. */
2576 disband_implicit_edges (void)
2579 block_stmt_iterator last
;
2586 last
= bsi_last (bb
);
2587 stmt
= last_stmt (bb
);
2589 if (stmt
&& TREE_CODE (stmt
) == COND_EXPR
)
2591 /* Remove superfluous gotos from COND_EXPR branches. Moved
2592 from cfg_remove_useless_stmts here since it violates the
2593 invariants for tree--cfg correspondence and thus fits better
2594 here where we do it anyway. */
2595 e
= find_edge (bb
, bb
->next_bb
);
2598 if (e
->flags
& EDGE_TRUE_VALUE
)
2599 COND_EXPR_THEN (stmt
) = build_empty_stmt ();
2600 else if (e
->flags
& EDGE_FALSE_VALUE
)
2601 COND_EXPR_ELSE (stmt
) = build_empty_stmt ();
2604 e
->flags
|= EDGE_FALLTHRU
;
2610 if (stmt
&& TREE_CODE (stmt
) == RETURN_EXPR
)
2612 /* Remove the RETURN_EXPR if we may fall though to the exit
2614 gcc_assert (single_succ_p (bb
));
2615 gcc_assert (single_succ (bb
) == EXIT_BLOCK_PTR
);
2617 if (bb
->next_bb
== EXIT_BLOCK_PTR
2618 && !TREE_OPERAND (stmt
, 0))
2620 bsi_remove (&last
, true);
2621 single_succ_edge (bb
)->flags
|= EDGE_FALLTHRU
;
2626 /* There can be no fallthru edge if the last statement is a control
2628 if (stmt
&& is_ctrl_stmt (stmt
))
2631 /* Find a fallthru edge and emit the goto if necessary. */
2632 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2633 if (e
->flags
& EDGE_FALLTHRU
)
2636 if (!e
|| e
->dest
== bb
->next_bb
)
2639 gcc_assert (e
->dest
!= EXIT_BLOCK_PTR
);
2640 label
= tree_block_label (e
->dest
);
2642 stmt
= build1 (GOTO_EXPR
, void_type_node
, label
);
2643 #ifdef USE_MAPPED_LOCATION
2644 SET_EXPR_LOCATION (stmt
, e
->goto_locus
);
2646 SET_EXPR_LOCUS (stmt
, e
->goto_locus
);
2648 bsi_insert_after (&last
, stmt
, BSI_NEW_STMT
);
2649 e
->flags
&= ~EDGE_FALLTHRU
;
2653 /* Remove block annotations and other datastructures. */
2656 delete_tree_cfg_annotations (void)
2658 label_to_block_map
= NULL
;
2662 /* Return the first statement in basic block BB. */
2665 first_stmt (basic_block bb
)
2667 block_stmt_iterator i
= bsi_start (bb
);
2668 return !bsi_end_p (i
) ? bsi_stmt (i
) : NULL_TREE
;
2672 /* Return the last statement in basic block BB. */
2675 last_stmt (basic_block bb
)
2677 block_stmt_iterator b
= bsi_last (bb
);
2678 return !bsi_end_p (b
) ? bsi_stmt (b
) : NULL_TREE
;
2682 /* Return a pointer to the last statement in block BB. */
2685 last_stmt_ptr (basic_block bb
)
2687 block_stmt_iterator last
= bsi_last (bb
);
2688 return !bsi_end_p (last
) ? bsi_stmt_ptr (last
) : NULL
;
2692 /* Return the last statement of an otherwise empty block. Return NULL
2693 if the block is totally empty, or if it contains more than one
2697 last_and_only_stmt (basic_block bb
)
2699 block_stmt_iterator i
= bsi_last (bb
);
2705 last
= bsi_stmt (i
);
2710 /* Empty statements should no longer appear in the instruction stream.
2711 Everything that might have appeared before should be deleted by
2712 remove_useless_stmts, and the optimizers should just bsi_remove
2713 instead of smashing with build_empty_stmt.
2715 Thus the only thing that should appear here in a block containing
2716 one executable statement is a label. */
2717 prev
= bsi_stmt (i
);
2718 if (TREE_CODE (prev
) == LABEL_EXPR
)
2725 /* Mark BB as the basic block holding statement T. */
2728 set_bb_for_stmt (tree t
, basic_block bb
)
2730 if (TREE_CODE (t
) == PHI_NODE
)
2732 else if (TREE_CODE (t
) == STATEMENT_LIST
)
2734 tree_stmt_iterator i
;
2735 for (i
= tsi_start (t
); !tsi_end_p (i
); tsi_next (&i
))
2736 set_bb_for_stmt (tsi_stmt (i
), bb
);
2740 stmt_ann_t ann
= get_stmt_ann (t
);
2743 /* If the statement is a label, add the label to block-to-labels map
2744 so that we can speed up edge creation for GOTO_EXPRs. */
2745 if (TREE_CODE (t
) == LABEL_EXPR
)
2749 t
= LABEL_EXPR_LABEL (t
);
2750 uid
= LABEL_DECL_UID (t
);
2753 unsigned old_len
= VEC_length (basic_block
, label_to_block_map
);
2754 LABEL_DECL_UID (t
) = uid
= cfun
->last_label_uid
++;
2755 if (old_len
<= (unsigned) uid
)
2758 unsigned new_len
= 3 * uid
/ 2;
2760 VEC_safe_grow (basic_block
, gc
, label_to_block_map
,
2762 addr
= VEC_address (basic_block
, label_to_block_map
);
2763 memset (&addr
[old_len
],
2764 0, sizeof (basic_block
) * (new_len
- old_len
));
2768 /* We're moving an existing label. Make sure that we've
2769 removed it from the old block. */
2771 || !VEC_index (basic_block
, label_to_block_map
, uid
));
2772 VEC_replace (basic_block
, label_to_block_map
, uid
, bb
);
2777 /* Faster version of set_bb_for_stmt that assume that statement is being moved
2778 from one basic block to another.
2779 For BB splitting we can run into quadratic case, so performance is quite
2780 important and knowing that the tables are big enough, change_bb_for_stmt
2781 can inline as leaf function. */
2783 change_bb_for_stmt (tree t
, basic_block bb
)
2785 get_stmt_ann (t
)->bb
= bb
;
2786 if (TREE_CODE (t
) == LABEL_EXPR
)
2787 VEC_replace (basic_block
, label_to_block_map
,
2788 LABEL_DECL_UID (LABEL_EXPR_LABEL (t
)), bb
);
2791 /* Finds iterator for STMT. */
2793 extern block_stmt_iterator
2794 bsi_for_stmt (tree stmt
)
2796 block_stmt_iterator bsi
;
2798 for (bsi
= bsi_start (bb_for_stmt (stmt
)); !bsi_end_p (bsi
); bsi_next (&bsi
))
2799 if (bsi_stmt (bsi
) == stmt
)
2805 /* Mark statement T as modified, and update it. */
2807 update_modified_stmts (tree t
)
2809 if (TREE_CODE (t
) == STATEMENT_LIST
)
2811 tree_stmt_iterator i
;
2813 for (i
= tsi_start (t
); !tsi_end_p (i
); tsi_next (&i
))
2815 stmt
= tsi_stmt (i
);
2816 update_stmt_if_modified (stmt
);
2820 update_stmt_if_modified (t
);
2823 /* Insert statement (or statement list) T before the statement
2824 pointed-to by iterator I. M specifies how to update iterator I
2825 after insertion (see enum bsi_iterator_update). */
2828 bsi_insert_before (block_stmt_iterator
*i
, tree t
, enum bsi_iterator_update m
)
2830 set_bb_for_stmt (t
, i
->bb
);
2831 update_modified_stmts (t
);
2832 tsi_link_before (&i
->tsi
, t
, m
);
2836 /* Insert statement (or statement list) T after the statement
2837 pointed-to by iterator I. M specifies how to update iterator I
2838 after insertion (see enum bsi_iterator_update). */
2841 bsi_insert_after (block_stmt_iterator
*i
, tree t
, enum bsi_iterator_update m
)
2843 set_bb_for_stmt (t
, i
->bb
);
2844 update_modified_stmts (t
);
2845 tsi_link_after (&i
->tsi
, t
, m
);
2849 /* Remove the statement pointed to by iterator I. The iterator is updated
2850 to the next statement.
2852 When REMOVE_EH_INFO is true we remove the statement pointed to by
2853 iterator I from the EH tables. Otherwise we do not modify the EH
2856 Generally, REMOVE_EH_INFO should be true when the statement is going to
2857 be removed from the IL and not reinserted elsewhere. */
2860 bsi_remove (block_stmt_iterator
*i
, bool remove_eh_info
)
2862 tree t
= bsi_stmt (*i
);
2863 set_bb_for_stmt (t
, NULL
);
2864 delink_stmt_imm_use (t
);
2865 tsi_delink (&i
->tsi
);
2866 mark_stmt_modified (t
);
2868 remove_stmt_from_eh_region (t
);
2872 /* Move the statement at FROM so it comes right after the statement at TO. */
2875 bsi_move_after (block_stmt_iterator
*from
, block_stmt_iterator
*to
)
2877 tree stmt
= bsi_stmt (*from
);
2878 bsi_remove (from
, false);
2879 bsi_insert_after (to
, stmt
, BSI_SAME_STMT
);
2883 /* Move the statement at FROM so it comes right before the statement at TO. */
2886 bsi_move_before (block_stmt_iterator
*from
, block_stmt_iterator
*to
)
2888 tree stmt
= bsi_stmt (*from
);
2889 bsi_remove (from
, false);
2890 bsi_insert_before (to
, stmt
, BSI_SAME_STMT
);
2894 /* Move the statement at FROM to the end of basic block BB. */
2897 bsi_move_to_bb_end (block_stmt_iterator
*from
, basic_block bb
)
2899 block_stmt_iterator last
= bsi_last (bb
);
2901 /* Have to check bsi_end_p because it could be an empty block. */
2902 if (!bsi_end_p (last
) && is_ctrl_stmt (bsi_stmt (last
)))
2903 bsi_move_before (from
, &last
);
2905 bsi_move_after (from
, &last
);
2909 /* Replace the contents of the statement pointed to by iterator BSI
2910 with STMT. If UPDATE_EH_INFO is true, the exception handling
2911 information of the original statement is moved to the new statement. */
2914 bsi_replace (const block_stmt_iterator
*bsi
, tree stmt
, bool update_eh_info
)
2917 tree orig_stmt
= bsi_stmt (*bsi
);
2919 SET_EXPR_LOCUS (stmt
, EXPR_LOCUS (orig_stmt
));
2920 set_bb_for_stmt (stmt
, bsi
->bb
);
2922 /* Preserve EH region information from the original statement, if
2923 requested by the caller. */
2926 eh_region
= lookup_stmt_eh_region (orig_stmt
);
2929 remove_stmt_from_eh_region (orig_stmt
);
2930 add_stmt_to_eh_region (stmt
, eh_region
);
2934 delink_stmt_imm_use (orig_stmt
);
2935 *bsi_stmt_ptr (*bsi
) = stmt
;
2936 mark_stmt_modified (stmt
);
2937 update_modified_stmts (stmt
);
2941 /* Insert the statement pointed-to by BSI into edge E. Every attempt
2942 is made to place the statement in an existing basic block, but
2943 sometimes that isn't possible. When it isn't possible, the edge is
2944 split and the statement is added to the new block.
2946 In all cases, the returned *BSI points to the correct location. The
2947 return value is true if insertion should be done after the location,
2948 or false if it should be done before the location. If new basic block
2949 has to be created, it is stored in *NEW_BB. */
2952 tree_find_edge_insert_loc (edge e
, block_stmt_iterator
*bsi
,
2953 basic_block
*new_bb
)
2955 basic_block dest
, src
;
2961 /* If the destination has one predecessor which has no PHI nodes,
2962 insert there. Except for the exit block.
2964 The requirement for no PHI nodes could be relaxed. Basically we
2965 would have to examine the PHIs to prove that none of them used
2966 the value set by the statement we want to insert on E. That
2967 hardly seems worth the effort. */
2968 if (single_pred_p (dest
)
2969 && ! phi_nodes (dest
)
2970 && dest
!= EXIT_BLOCK_PTR
)
2972 *bsi
= bsi_start (dest
);
2973 if (bsi_end_p (*bsi
))
2976 /* Make sure we insert after any leading labels. */
2977 tmp
= bsi_stmt (*bsi
);
2978 while (TREE_CODE (tmp
) == LABEL_EXPR
)
2981 if (bsi_end_p (*bsi
))
2983 tmp
= bsi_stmt (*bsi
);
2986 if (bsi_end_p (*bsi
))
2988 *bsi
= bsi_last (dest
);
2995 /* If the source has one successor, the edge is not abnormal and
2996 the last statement does not end a basic block, insert there.
2997 Except for the entry block. */
2999 if ((e
->flags
& EDGE_ABNORMAL
) == 0
3000 && single_succ_p (src
)
3001 && src
!= ENTRY_BLOCK_PTR
)
3003 *bsi
= bsi_last (src
);
3004 if (bsi_end_p (*bsi
))
3007 tmp
= bsi_stmt (*bsi
);
3008 if (!stmt_ends_bb_p (tmp
))
3011 /* Insert code just before returning the value. We may need to decompose
3012 the return in the case it contains non-trivial operand. */
3013 if (TREE_CODE (tmp
) == RETURN_EXPR
)
3015 tree op
= TREE_OPERAND (tmp
, 0);
3016 if (op
&& !is_gimple_val (op
))
3018 gcc_assert (TREE_CODE (op
) == GIMPLE_MODIFY_STMT
);
3019 bsi_insert_before (bsi
, op
, BSI_NEW_STMT
);
3020 TREE_OPERAND (tmp
, 0) = GIMPLE_STMT_OPERAND (op
, 0);
3027 /* Otherwise, create a new basic block, and split this edge. */
3028 dest
= split_edge (e
);
3031 e
= single_pred_edge (dest
);
3036 /* This routine will commit all pending edge insertions, creating any new
3037 basic blocks which are necessary. */
3040 bsi_commit_edge_inserts (void)
3046 bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR
), NULL
);
3049 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
3050 bsi_commit_one_edge_insert (e
, NULL
);
3054 /* Commit insertions pending at edge E. If a new block is created, set NEW_BB
3055 to this block, otherwise set it to NULL. */
3058 bsi_commit_one_edge_insert (edge e
, basic_block
*new_bb
)
3062 if (PENDING_STMT (e
))
3064 block_stmt_iterator bsi
;
3065 tree stmt
= PENDING_STMT (e
);
3067 PENDING_STMT (e
) = NULL_TREE
;
3069 if (tree_find_edge_insert_loc (e
, &bsi
, new_bb
))
3070 bsi_insert_after (&bsi
, stmt
, BSI_NEW_STMT
);
3072 bsi_insert_before (&bsi
, stmt
, BSI_NEW_STMT
);
3077 /* Add STMT to the pending list of edge E. No actual insertion is
3078 made until a call to bsi_commit_edge_inserts () is made. */
3081 bsi_insert_on_edge (edge e
, tree stmt
)
3083 append_to_statement_list (stmt
, &PENDING_STMT (e
));
3086 /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new
3087 block has to be created, it is returned. */
3090 bsi_insert_on_edge_immediate (edge e
, tree stmt
)
3092 block_stmt_iterator bsi
;
3093 basic_block new_bb
= NULL
;
3095 gcc_assert (!PENDING_STMT (e
));
3097 if (tree_find_edge_insert_loc (e
, &bsi
, &new_bb
))
3098 bsi_insert_after (&bsi
, stmt
, BSI_NEW_STMT
);
3100 bsi_insert_before (&bsi
, stmt
, BSI_NEW_STMT
);
3105 /*---------------------------------------------------------------------------
3106 Tree specific functions for CFG manipulation
3107 ---------------------------------------------------------------------------*/
3109 /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
3112 reinstall_phi_args (edge new_edge
, edge old_edge
)
3116 if (!PENDING_STMT (old_edge
))
3119 for (var
= PENDING_STMT (old_edge
), phi
= phi_nodes (new_edge
->dest
);
3121 var
= TREE_CHAIN (var
), phi
= PHI_CHAIN (phi
))
3123 tree result
= TREE_PURPOSE (var
);
3124 tree arg
= TREE_VALUE (var
);
3126 gcc_assert (result
== PHI_RESULT (phi
));
3128 add_phi_arg (phi
, arg
, new_edge
);
3131 PENDING_STMT (old_edge
) = NULL
;
3134 /* Returns the basic block after which the new basic block created
3135 by splitting edge EDGE_IN should be placed. Tries to keep the new block
3136 near its "logical" location. This is of most help to humans looking
3137 at debugging dumps. */
3140 split_edge_bb_loc (edge edge_in
)
3142 basic_block dest
= edge_in
->dest
;
3144 if (dest
->prev_bb
&& find_edge (dest
->prev_bb
, dest
))
3145 return edge_in
->src
;
3147 return dest
->prev_bb
;
3150 /* Split a (typically critical) edge EDGE_IN. Return the new block.
3151 Abort on abnormal edges. */
3154 tree_split_edge (edge edge_in
)
3156 basic_block new_bb
, after_bb
, dest
;
3159 /* Abnormal edges cannot be split. */
3160 gcc_assert (!(edge_in
->flags
& EDGE_ABNORMAL
));
3162 dest
= edge_in
->dest
;
3164 after_bb
= split_edge_bb_loc (edge_in
);
3166 new_bb
= create_empty_bb (after_bb
);
3167 new_bb
->frequency
= EDGE_FREQUENCY (edge_in
);
3168 new_bb
->count
= edge_in
->count
;
3169 new_edge
= make_edge (new_bb
, dest
, EDGE_FALLTHRU
);
3170 new_edge
->probability
= REG_BR_PROB_BASE
;
3171 new_edge
->count
= edge_in
->count
;
3173 e
= redirect_edge_and_branch (edge_in
, new_bb
);
3175 reinstall_phi_args (new_edge
, e
);
3181 /* Return true when BB has label LABEL in it. */
3184 has_label_p (basic_block bb
, tree label
)
3186 block_stmt_iterator bsi
;
3188 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
3190 tree stmt
= bsi_stmt (bsi
);
3192 if (TREE_CODE (stmt
) != LABEL_EXPR
)
3194 if (LABEL_EXPR_LABEL (stmt
) == label
)
3201 /* Callback for walk_tree, check that all elements with address taken are
3202 properly noticed as such. The DATA is an int* that is 1 if TP was seen
3203 inside a PHI node. */
3206 verify_expr (tree
*tp
, int *walk_subtrees
, void *data ATTRIBUTE_UNUSED
)
3209 bool in_phi
= (data
!= NULL
);
3214 /* Check operand N for being valid GIMPLE and give error MSG if not. */
3215 #define CHECK_OP(N, MSG) \
3216 do { if (!is_gimple_val (TREE_OPERAND (t, N))) \
3217 { error (MSG); return TREE_OPERAND (t, N); }} while (0)
3219 switch (TREE_CODE (t
))
3222 if (SSA_NAME_IN_FREE_LIST (t
))
3224 error ("SSA name in freelist but still referenced");
3230 x
= fold (ASSERT_EXPR_COND (t
));
3231 if (x
== boolean_false_node
)
3233 error ("ASSERT_EXPR with an always-false condition");
3241 case GIMPLE_MODIFY_STMT
:
3242 x
= GIMPLE_STMT_OPERAND (t
, 0);
3243 if (TREE_CODE (x
) == BIT_FIELD_REF
3244 && is_gimple_reg (TREE_OPERAND (x
, 0)))
3246 error ("GIMPLE register modified with BIT_FIELD_REF");
3255 bool old_side_effects
;
3258 bool new_side_effects
;
3260 /* ??? tree-ssa-alias.c may have overlooked dead PHI nodes, missing
3261 dead PHIs that take the address of something. But if the PHI
3262 result is dead, the fact that it takes the address of anything
3263 is irrelevant. Because we can not tell from here if a PHI result
3264 is dead, we just skip this check for PHIs altogether. This means
3265 we may be missing "valid" checks, but what can you do?
3266 This was PR19217. */
3270 old_invariant
= TREE_INVARIANT (t
);
3271 old_constant
= TREE_CONSTANT (t
);
3272 old_side_effects
= TREE_SIDE_EFFECTS (t
);
3274 recompute_tree_invariant_for_addr_expr (t
);
3275 new_invariant
= TREE_INVARIANT (t
);
3276 new_side_effects
= TREE_SIDE_EFFECTS (t
);
3277 new_constant
= TREE_CONSTANT (t
);
3279 if (old_invariant
!= new_invariant
)
3281 error ("invariant not recomputed when ADDR_EXPR changed");
3285 if (old_constant
!= new_constant
)
3287 error ("constant not recomputed when ADDR_EXPR changed");
3290 if (old_side_effects
!= new_side_effects
)
3292 error ("side effects not recomputed when ADDR_EXPR changed");
3296 /* Skip any references (they will be checked when we recurse down the
3297 tree) and ensure that any variable used as a prefix is marked
3299 for (x
= TREE_OPERAND (t
, 0);
3300 handled_component_p (x
);
3301 x
= TREE_OPERAND (x
, 0))
3304 if (TREE_CODE (x
) != VAR_DECL
&& TREE_CODE (x
) != PARM_DECL
)
3306 if (!TREE_ADDRESSABLE (x
))
3308 error ("address taken, but ADDRESSABLE bit not set");
3315 x
= COND_EXPR_COND (t
);
3316 if (TREE_CODE (TREE_TYPE (x
)) != BOOLEAN_TYPE
)
3318 error ("non-boolean used in condition");
3321 if (!is_gimple_condexpr (x
))
3323 error ("invalid conditional operand");
3330 case FIX_TRUNC_EXPR
:
3335 case NON_LVALUE_EXPR
:
3336 case TRUTH_NOT_EXPR
:
3337 CHECK_OP (0, "invalid operand to unary operator");
3344 case ARRAY_RANGE_REF
:
3346 case VIEW_CONVERT_EXPR
:
3347 /* We have a nest of references. Verify that each of the operands
3348 that determine where to reference is either a constant or a variable,
3349 verify that the base is valid, and then show we've already checked
3351 while (handled_component_p (t
))
3353 if (TREE_CODE (t
) == COMPONENT_REF
&& TREE_OPERAND (t
, 2))
3354 CHECK_OP (2, "invalid COMPONENT_REF offset operator");
3355 else if (TREE_CODE (t
) == ARRAY_REF
3356 || TREE_CODE (t
) == ARRAY_RANGE_REF
)
3358 CHECK_OP (1, "invalid array index");
3359 if (TREE_OPERAND (t
, 2))
3360 CHECK_OP (2, "invalid array lower bound");
3361 if (TREE_OPERAND (t
, 3))
3362 CHECK_OP (3, "invalid array stride");
3364 else if (TREE_CODE (t
) == BIT_FIELD_REF
)
3366 CHECK_OP (1, "invalid operand to BIT_FIELD_REF");
3367 CHECK_OP (2, "invalid operand to BIT_FIELD_REF");
3370 t
= TREE_OPERAND (t
, 0);
3373 if (!CONSTANT_CLASS_P (t
) && !is_gimple_lvalue (t
))
3375 error ("invalid reference prefix");
3387 case UNORDERED_EXPR
:
3398 case TRUNC_DIV_EXPR
:
3400 case FLOOR_DIV_EXPR
:
3401 case ROUND_DIV_EXPR
:
3402 case TRUNC_MOD_EXPR
:
3404 case FLOOR_MOD_EXPR
:
3405 case ROUND_MOD_EXPR
:
3407 case EXACT_DIV_EXPR
:
3417 CHECK_OP (0, "invalid operand to binary operator");
3418 CHECK_OP (1, "invalid operand to binary operator");
3422 if (TREE_CONSTANT (t
) && TREE_CODE (TREE_TYPE (t
)) == VECTOR_TYPE
)
3435 /* Verify STMT, return true if STMT is not in GIMPLE form.
3436 TODO: Implement type checking. */
3439 verify_stmt (tree stmt
, bool last_in_block
)
3443 if (OMP_DIRECTIVE_P (stmt
))
3445 /* OpenMP directives are validated by the FE and never operated
3446 on by the optimizers. Furthermore, OMP_FOR may contain
3447 non-gimple expressions when the main index variable has had
3448 its address taken. This does not affect the loop itself
3449 because the header of an OMP_FOR is merely used to determine
3450 how to setup the parallel iteration. */
3454 if (!is_gimple_stmt (stmt
))
3456 error ("is not a valid GIMPLE statement");
3460 addr
= walk_tree (&stmt
, verify_expr
, NULL
, NULL
);
3463 debug_generic_stmt (addr
);
3467 /* If the statement is marked as part of an EH region, then it is
3468 expected that the statement could throw. Verify that when we
3469 have optimizations that simplify statements such that we prove
3470 that they cannot throw, that we update other data structures
3472 if (lookup_stmt_eh_region (stmt
) >= 0)
3474 if (!tree_could_throw_p (stmt
))
3476 error ("statement marked for throw, but doesn%'t");
3479 if (!last_in_block
&& tree_can_throw_internal (stmt
))
3481 error ("statement marked for throw in middle of block");
3489 debug_generic_stmt (stmt
);
3494 /* Return true when the T can be shared. */
3497 tree_node_can_be_shared (tree t
)
3499 if (IS_TYPE_OR_DECL_P (t
)
3500 || is_gimple_min_invariant (t
)
3501 || TREE_CODE (t
) == SSA_NAME
3502 || t
== error_mark_node
3503 || TREE_CODE (t
) == IDENTIFIER_NODE
)
3506 if (TREE_CODE (t
) == CASE_LABEL_EXPR
)
3509 while (((TREE_CODE (t
) == ARRAY_REF
|| TREE_CODE (t
) == ARRAY_RANGE_REF
)
3510 && is_gimple_min_invariant (TREE_OPERAND (t
, 1)))
3511 || TREE_CODE (t
) == COMPONENT_REF
3512 || TREE_CODE (t
) == REALPART_EXPR
3513 || TREE_CODE (t
) == IMAGPART_EXPR
)
3514 t
= TREE_OPERAND (t
, 0);
3523 /* Called via walk_trees. Verify tree sharing. */
3526 verify_node_sharing (tree
* tp
, int *walk_subtrees
, void *data
)
3528 htab_t htab
= (htab_t
) data
;
3531 if (tree_node_can_be_shared (*tp
))
3533 *walk_subtrees
= false;
3537 slot
= htab_find_slot (htab
, *tp
, INSERT
);
3539 return (tree
) *slot
;
3546 /* Helper function for verify_gimple_tuples. */
3549 verify_gimple_tuples_1 (tree
*tp
, int *walk_subtrees ATTRIBUTE_UNUSED
,
3550 void *data ATTRIBUTE_UNUSED
)
3552 switch (TREE_CODE (*tp
))
3555 error ("unexpected non-tuple");
3565 /* Verify that there are no trees that should have been converted to
3566 gimple tuples. Return true if T contains a node that should have
3567 been converted to a gimple tuple, but hasn't. */
3570 verify_gimple_tuples (tree t
)
3572 return walk_tree (&t
, verify_gimple_tuples_1
, NULL
, NULL
) != NULL
;
3575 /* Verify the GIMPLE statement chain. */
3581 block_stmt_iterator bsi
;
3586 timevar_push (TV_TREE_STMT_VERIFY
);
3587 htab
= htab_create (37, htab_hash_pointer
, htab_eq_pointer
, NULL
);
3594 for (phi
= phi_nodes (bb
); phi
; phi
= PHI_CHAIN (phi
))
3596 int phi_num_args
= PHI_NUM_ARGS (phi
);
3598 if (bb_for_stmt (phi
) != bb
)
3600 error ("bb_for_stmt (phi) is set to a wrong basic block");
3604 for (i
= 0; i
< phi_num_args
; i
++)
3606 tree t
= PHI_ARG_DEF (phi
, i
);
3609 /* Addressable variables do have SSA_NAMEs but they
3610 are not considered gimple values. */
3611 if (TREE_CODE (t
) != SSA_NAME
3612 && TREE_CODE (t
) != FUNCTION_DECL
3613 && !is_gimple_val (t
))
3615 error ("PHI def is not a GIMPLE value");
3616 debug_generic_stmt (phi
);
3617 debug_generic_stmt (t
);
3621 addr
= walk_tree (&t
, verify_expr
, (void *) 1, NULL
);
3624 debug_generic_stmt (addr
);
3628 addr
= walk_tree (&t
, verify_node_sharing
, htab
, NULL
);
3631 error ("incorrect sharing of tree nodes");
3632 debug_generic_stmt (phi
);
3633 debug_generic_stmt (addr
);
3639 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); )
3641 tree stmt
= bsi_stmt (bsi
);
3643 err
|= verify_gimple_tuples (stmt
);
3645 if (bb_for_stmt (stmt
) != bb
)
3647 error ("bb_for_stmt (stmt) is set to a wrong basic block");
3652 err
|= verify_stmt (stmt
, bsi_end_p (bsi
));
3653 addr
= walk_tree (&stmt
, verify_node_sharing
, htab
, NULL
);
3656 error ("incorrect sharing of tree nodes");
3657 debug_generic_stmt (stmt
);
3658 debug_generic_stmt (addr
);
3665 internal_error ("verify_stmts failed");
3668 timevar_pop (TV_TREE_STMT_VERIFY
);
3672 /* Verifies that the flow information is OK. */
3675 tree_verify_flow_info (void)
3679 block_stmt_iterator bsi
;
3684 if (ENTRY_BLOCK_PTR
->stmt_list
)
3686 error ("ENTRY_BLOCK has a statement list associated with it");
3690 if (EXIT_BLOCK_PTR
->stmt_list
)
3692 error ("EXIT_BLOCK has a statement list associated with it");
3696 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
3697 if (e
->flags
& EDGE_FALLTHRU
)
3699 error ("fallthru to exit from bb %d", e
->src
->index
);
3705 bool found_ctrl_stmt
= false;
3709 /* Skip labels on the start of basic block. */
3710 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
3712 tree prev_stmt
= stmt
;
3714 stmt
= bsi_stmt (bsi
);
3716 if (TREE_CODE (stmt
) != LABEL_EXPR
)
3719 if (prev_stmt
&& DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt
)))
3721 error ("nonlocal label ");
3722 print_generic_expr (stderr
, LABEL_EXPR_LABEL (stmt
), 0);
3723 fprintf (stderr
, " is not first in a sequence of labels in bb %d",
3728 if (label_to_block (LABEL_EXPR_LABEL (stmt
)) != bb
)
3731 print_generic_expr (stderr
, LABEL_EXPR_LABEL (stmt
), 0);
3732 fprintf (stderr
, " to block does not match in bb %d",
3737 if (decl_function_context (LABEL_EXPR_LABEL (stmt
))
3738 != current_function_decl
)
3741 print_generic_expr (stderr
, LABEL_EXPR_LABEL (stmt
), 0);
3742 fprintf (stderr
, " has incorrect context in bb %d",
3748 /* Verify that body of basic block BB is free of control flow. */
3749 for (; !bsi_end_p (bsi
); bsi_next (&bsi
))
3751 tree stmt
= bsi_stmt (bsi
);
3753 if (found_ctrl_stmt
)
3755 error ("control flow in the middle of basic block %d",
3760 if (stmt_ends_bb_p (stmt
))
3761 found_ctrl_stmt
= true;
3763 if (TREE_CODE (stmt
) == LABEL_EXPR
)
3766 print_generic_expr (stderr
, LABEL_EXPR_LABEL (stmt
), 0);
3767 fprintf (stderr
, " in the middle of basic block %d", bb
->index
);
3772 bsi
= bsi_last (bb
);
3773 if (bsi_end_p (bsi
))
3776 stmt
= bsi_stmt (bsi
);
3778 err
|= verify_eh_edges (stmt
);
3780 if (is_ctrl_stmt (stmt
))
3782 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
3783 if (e
->flags
& EDGE_FALLTHRU
)
3785 error ("fallthru edge after a control statement in bb %d",
3791 if (TREE_CODE (stmt
) != COND_EXPR
)
3793 /* Verify that there are no edges with EDGE_TRUE/FALSE_FLAG set
3794 after anything else but if statement. */
3795 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
3796 if (e
->flags
& (EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
))
3798 error ("true/false edge after a non-COND_EXPR in bb %d",
3804 switch (TREE_CODE (stmt
))
3810 if (TREE_CODE (COND_EXPR_THEN (stmt
)) != GOTO_EXPR
3811 || TREE_CODE (COND_EXPR_ELSE (stmt
)) != GOTO_EXPR
)
3813 error ("structured COND_EXPR at the end of bb %d", bb
->index
);
3817 extract_true_false_edges_from_block (bb
, &true_edge
, &false_edge
);
3819 if (!true_edge
|| !false_edge
3820 || !(true_edge
->flags
& EDGE_TRUE_VALUE
)
3821 || !(false_edge
->flags
& EDGE_FALSE_VALUE
)
3822 || (true_edge
->flags
& (EDGE_FALLTHRU
| EDGE_ABNORMAL
))
3823 || (false_edge
->flags
& (EDGE_FALLTHRU
| EDGE_ABNORMAL
))
3824 || EDGE_COUNT (bb
->succs
) >= 3)
3826 error ("wrong outgoing edge flags at end of bb %d",
3831 if (!has_label_p (true_edge
->dest
,
3832 GOTO_DESTINATION (COND_EXPR_THEN (stmt
))))
3834 error ("%<then%> label does not match edge at end of bb %d",
3839 if (!has_label_p (false_edge
->dest
,
3840 GOTO_DESTINATION (COND_EXPR_ELSE (stmt
))))
3842 error ("%<else%> label does not match edge at end of bb %d",
3850 if (simple_goto_p (stmt
))
3852 error ("explicit goto at end of bb %d", bb
->index
);
3857 /* FIXME. We should double check that the labels in the
3858 destination blocks have their address taken. */
3859 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
3860 if ((e
->flags
& (EDGE_FALLTHRU
| EDGE_TRUE_VALUE
3861 | EDGE_FALSE_VALUE
))
3862 || !(e
->flags
& EDGE_ABNORMAL
))
3864 error ("wrong outgoing edge flags at end of bb %d",
3872 if (!single_succ_p (bb
)
3873 || (single_succ_edge (bb
)->flags
3874 & (EDGE_FALLTHRU
| EDGE_ABNORMAL
3875 | EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
)))
3877 error ("wrong outgoing edge flags at end of bb %d", bb
->index
);
3880 if (single_succ (bb
) != EXIT_BLOCK_PTR
)
3882 error ("return edge does not point to exit in bb %d",
3895 vec
= SWITCH_LABELS (stmt
);
3896 n
= TREE_VEC_LENGTH (vec
);
3898 /* Mark all the destination basic blocks. */
3899 for (i
= 0; i
< n
; ++i
)
3901 tree lab
= CASE_LABEL (TREE_VEC_ELT (vec
, i
));
3902 basic_block label_bb
= label_to_block (lab
);
3904 gcc_assert (!label_bb
->aux
|| label_bb
->aux
== (void *)1);
3905 label_bb
->aux
= (void *)1;
3908 /* Verify that the case labels are sorted. */
3909 prev
= TREE_VEC_ELT (vec
, 0);
3910 for (i
= 1; i
< n
- 1; ++i
)
3912 tree c
= TREE_VEC_ELT (vec
, i
);
3915 error ("found default case not at end of case vector");
3919 if (! tree_int_cst_lt (CASE_LOW (prev
), CASE_LOW (c
)))
3921 error ("case labels not sorted: ");
3922 print_generic_expr (stderr
, prev
, 0);
3923 fprintf (stderr
," is greater than ");
3924 print_generic_expr (stderr
, c
, 0);
3925 fprintf (stderr
," but comes before it.\n");
3930 if (CASE_LOW (TREE_VEC_ELT (vec
, n
- 1)))
3932 error ("no default case found at end of case vector");
3936 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
3940 error ("extra outgoing edge %d->%d",
3941 bb
->index
, e
->dest
->index
);
3944 e
->dest
->aux
= (void *)2;
3945 if ((e
->flags
& (EDGE_FALLTHRU
| EDGE_ABNORMAL
3946 | EDGE_TRUE_VALUE
| EDGE_FALSE_VALUE
)))
3948 error ("wrong outgoing edge flags at end of bb %d",
3954 /* Check that we have all of them. */
3955 for (i
= 0; i
< n
; ++i
)
3957 tree lab
= CASE_LABEL (TREE_VEC_ELT (vec
, i
));
3958 basic_block label_bb
= label_to_block (lab
);
3960 if (label_bb
->aux
!= (void *)2)
3962 error ("missing edge %i->%i",
3963 bb
->index
, label_bb
->index
);
3968 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
3969 e
->dest
->aux
= (void *)0;
3976 if (dom_computed
[CDI_DOMINATORS
] >= DOM_NO_FAST_QUERY
)
3977 verify_dominators (CDI_DOMINATORS
);
3983 /* Updates phi nodes after creating a forwarder block joined
3984 by edge FALLTHRU. */
3987 tree_make_forwarder_block (edge fallthru
)
3991 basic_block dummy
, bb
;
3992 tree phi
, new_phi
, var
;
3994 dummy
= fallthru
->src
;
3995 bb
= fallthru
->dest
;
3997 if (single_pred_p (bb
))
4000 /* If we redirected a branch we must create new phi nodes at the
4002 for (phi
= phi_nodes (dummy
); phi
; phi
= PHI_CHAIN (phi
))
4004 var
= PHI_RESULT (phi
);
4005 new_phi
= create_phi_node (var
, bb
);
4006 SSA_NAME_DEF_STMT (var
) = new_phi
;
4007 SET_PHI_RESULT (phi
, make_ssa_name (SSA_NAME_VAR (var
), phi
));
4008 add_phi_arg (new_phi
, PHI_RESULT (phi
), fallthru
);
4011 /* Ensure that the PHI node chain is in the same order. */
4012 set_phi_nodes (bb
, phi_reverse (phi_nodes (bb
)));
4014 /* Add the arguments we have stored on edges. */
4015 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4020 flush_pending_stmts (e
);
4025 /* Return a non-special label in the head of basic block BLOCK.
4026 Create one if it doesn't exist. */
4029 tree_block_label (basic_block bb
)
4031 block_stmt_iterator i
, s
= bsi_start (bb
);
4035 for (i
= s
; !bsi_end_p (i
); first
= false, bsi_next (&i
))
4037 stmt
= bsi_stmt (i
);
4038 if (TREE_CODE (stmt
) != LABEL_EXPR
)
4040 label
= LABEL_EXPR_LABEL (stmt
);
4041 if (!DECL_NONLOCAL (label
))
4044 bsi_move_before (&i
, &s
);
4049 label
= create_artificial_label ();
4050 stmt
= build1 (LABEL_EXPR
, void_type_node
, label
);
4051 bsi_insert_before (&s
, stmt
, BSI_NEW_STMT
);
4056 /* Attempt to perform edge redirection by replacing a possibly complex
4057 jump instruction by a goto or by removing the jump completely.
4058 This can apply only if all edges now point to the same block. The
4059 parameters and return values are equivalent to
4060 redirect_edge_and_branch. */
4063 tree_try_redirect_by_replacing_jump (edge e
, basic_block target
)
4065 basic_block src
= e
->src
;
4066 block_stmt_iterator b
;
4069 /* We can replace or remove a complex jump only when we have exactly
4071 if (EDGE_COUNT (src
->succs
) != 2
4072 /* Verify that all targets will be TARGET. Specifically, the
4073 edge that is not E must also go to TARGET. */
4074 || EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
)->dest
!= target
)
4080 stmt
= bsi_stmt (b
);
4082 if (TREE_CODE (stmt
) == COND_EXPR
4083 || TREE_CODE (stmt
) == SWITCH_EXPR
)
4085 bsi_remove (&b
, true);
4086 e
= ssa_redirect_edge (e
, target
);
4087 e
->flags
= EDGE_FALLTHRU
;
4095 /* Redirect E to DEST. Return NULL on failure. Otherwise, return the
4096 edge representing the redirected branch. */
4099 tree_redirect_edge_and_branch (edge e
, basic_block dest
)
4101 basic_block bb
= e
->src
;
4102 block_stmt_iterator bsi
;
4106 if (e
->flags
& EDGE_ABNORMAL
)
4109 if (e
->src
!= ENTRY_BLOCK_PTR
4110 && (ret
= tree_try_redirect_by_replacing_jump (e
, dest
)))
4113 if (e
->dest
== dest
)
4116 label
= tree_block_label (dest
);
4118 bsi
= bsi_last (bb
);
4119 stmt
= bsi_end_p (bsi
) ? NULL
: bsi_stmt (bsi
);
4121 switch (stmt
? TREE_CODE (stmt
) : ERROR_MARK
)
4124 stmt
= (e
->flags
& EDGE_TRUE_VALUE
4125 ? COND_EXPR_THEN (stmt
)
4126 : COND_EXPR_ELSE (stmt
));
4127 GOTO_DESTINATION (stmt
) = label
;
4131 /* No non-abnormal edges should lead from a non-simple goto, and
4132 simple ones should be represented implicitly. */
4137 tree cases
= get_cases_for_edge (e
, stmt
);
4139 /* If we have a list of cases associated with E, then use it
4140 as it's a lot faster than walking the entire case vector. */
4143 edge e2
= find_edge (e
->src
, dest
);
4150 CASE_LABEL (cases
) = label
;
4151 cases
= TREE_CHAIN (cases
);
4154 /* If there was already an edge in the CFG, then we need
4155 to move all the cases associated with E to E2. */
4158 tree cases2
= get_cases_for_edge (e2
, stmt
);
4160 TREE_CHAIN (last
) = TREE_CHAIN (cases2
);
4161 TREE_CHAIN (cases2
) = first
;
4166 tree vec
= SWITCH_LABELS (stmt
);
4167 size_t i
, n
= TREE_VEC_LENGTH (vec
);
4169 for (i
= 0; i
< n
; i
++)
4171 tree elt
= TREE_VEC_ELT (vec
, i
);
4173 if (label_to_block (CASE_LABEL (elt
)) == e
->dest
)
4174 CASE_LABEL (elt
) = label
;
4182 bsi_remove (&bsi
, true);
4183 e
->flags
|= EDGE_FALLTHRU
;
4187 /* Otherwise it must be a fallthru edge, and we don't need to
4188 do anything besides redirecting it. */
4189 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
4193 /* Update/insert PHI nodes as necessary. */
4195 /* Now update the edges in the CFG. */
4196 e
= ssa_redirect_edge (e
, dest
);
4202 /* Simple wrapper, as we can always redirect fallthru edges. */
4205 tree_redirect_edge_and_branch_force (edge e
, basic_block dest
)
4207 e
= tree_redirect_edge_and_branch (e
, dest
);
4214 /* Splits basic block BB after statement STMT (but at least after the
4215 labels). If STMT is NULL, BB is split just after the labels. */
4218 tree_split_block (basic_block bb
, void *stmt
)
4220 block_stmt_iterator bsi
;
4221 tree_stmt_iterator tsi_tgt
;
4227 new_bb
= create_empty_bb (bb
);
4229 /* Redirect the outgoing edges. */
4230 new_bb
->succs
= bb
->succs
;
4232 FOR_EACH_EDGE (e
, ei
, new_bb
->succs
)
4235 if (stmt
&& TREE_CODE ((tree
) stmt
) == LABEL_EXPR
)
4238 /* Move everything from BSI to the new basic block. */
4239 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
4241 act
= bsi_stmt (bsi
);
4242 if (TREE_CODE (act
) == LABEL_EXPR
)
4255 if (bsi_end_p (bsi
))
4258 /* Split the statement list - avoid re-creating new containers as this
4259 brings ugly quadratic memory consumption in the inliner.
4260 (We are still quadratic since we need to update stmt BB pointers,
4262 new_bb
->stmt_list
= tsi_split_statement_list_before (&bsi
.tsi
);
4263 for (tsi_tgt
= tsi_start (new_bb
->stmt_list
);
4264 !tsi_end_p (tsi_tgt
); tsi_next (&tsi_tgt
))
4265 change_bb_for_stmt (tsi_stmt (tsi_tgt
), new_bb
);
4271 /* Moves basic block BB after block AFTER. */
4274 tree_move_block_after (basic_block bb
, basic_block after
)
4276 if (bb
->prev_bb
== after
)
4280 link_block (bb
, after
);
4286 /* Return true if basic_block can be duplicated. */
4289 tree_can_duplicate_bb_p (basic_block bb ATTRIBUTE_UNUSED
)
4295 /* Create a duplicate of the basic block BB. NOTE: This does not
4296 preserve SSA form. */
4299 tree_duplicate_bb (basic_block bb
)
4302 block_stmt_iterator bsi
, bsi_tgt
;
4305 new_bb
= create_empty_bb (EXIT_BLOCK_PTR
->prev_bb
);
4307 /* Copy the PHI nodes. We ignore PHI node arguments here because
4308 the incoming edges have not been setup yet. */
4309 for (phi
= phi_nodes (bb
); phi
; phi
= PHI_CHAIN (phi
))
4311 tree copy
= create_phi_node (PHI_RESULT (phi
), new_bb
);
4312 create_new_def_for (PHI_RESULT (copy
), copy
, PHI_RESULT_PTR (copy
));
4315 /* Keep the chain of PHI nodes in the same order so that they can be
4316 updated by ssa_redirect_edge. */
4317 set_phi_nodes (new_bb
, phi_reverse (phi_nodes (new_bb
)));
4319 bsi_tgt
= bsi_start (new_bb
);
4320 for (bsi
= bsi_start (bb
); !bsi_end_p (bsi
); bsi_next (&bsi
))
4322 def_operand_p def_p
;
4323 ssa_op_iter op_iter
;
4327 stmt
= bsi_stmt (bsi
);
4328 if (TREE_CODE (stmt
) == LABEL_EXPR
)
4331 /* Create a new copy of STMT and duplicate STMT's virtual
4333 copy
= unshare_expr (stmt
);
4334 bsi_insert_after (&bsi_tgt
, copy
, BSI_NEW_STMT
);
4335 copy_virtual_operands (copy
, stmt
);
4336 region
= lookup_stmt_eh_region (stmt
);
4338 add_stmt_to_eh_region (copy
, region
);
4340 /* Create new names for all the definitions created by COPY and
4341 add replacement mappings for each new name. */
4342 FOR_EACH_SSA_DEF_OPERAND (def_p
, copy
, op_iter
, SSA_OP_ALL_DEFS
)
4343 create_new_def_for (DEF_FROM_PTR (def_p
), copy
, def_p
);
4350 /* Basic block BB_COPY was created by code duplication. Add phi node
4351 arguments for edges going out of BB_COPY. The blocks that were
4352 duplicated have BB_DUPLICATED set. */
4355 add_phi_args_after_copy_bb (basic_block bb_copy
)
4357 basic_block bb
, dest
;
4360 tree phi
, phi_copy
, phi_next
, def
;
4362 bb
= get_bb_original (bb_copy
);
4364 FOR_EACH_EDGE (e_copy
, ei
, bb_copy
->succs
)
4366 if (!phi_nodes (e_copy
->dest
))
4369 if (e_copy
->dest
->flags
& BB_DUPLICATED
)
4370 dest
= get_bb_original (e_copy
->dest
);
4372 dest
= e_copy
->dest
;
4374 e
= find_edge (bb
, dest
);
4377 /* During loop unrolling the target of the latch edge is copied.
4378 In this case we are not looking for edge to dest, but to
4379 duplicated block whose original was dest. */
4380 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4381 if ((e
->dest
->flags
& BB_DUPLICATED
)
4382 && get_bb_original (e
->dest
) == dest
)
4385 gcc_assert (e
!= NULL
);
4388 for (phi
= phi_nodes (e
->dest
), phi_copy
= phi_nodes (e_copy
->dest
);
4390 phi
= phi_next
, phi_copy
= PHI_CHAIN (phi_copy
))
4392 phi_next
= PHI_CHAIN (phi
);
4393 def
= PHI_ARG_DEF_FROM_EDGE (phi
, e
);
4394 add_phi_arg (phi_copy
, def
, e_copy
);
4399 /* Blocks in REGION_COPY array of length N_REGION were created by
4400 duplication of basic blocks. Add phi node arguments for edges
4401 going from these blocks. */
4404 add_phi_args_after_copy (basic_block
*region_copy
, unsigned n_region
)
4408 for (i
= 0; i
< n_region
; i
++)
4409 region_copy
[i
]->flags
|= BB_DUPLICATED
;
4411 for (i
= 0; i
< n_region
; i
++)
4412 add_phi_args_after_copy_bb (region_copy
[i
]);
4414 for (i
= 0; i
< n_region
; i
++)
4415 region_copy
[i
]->flags
&= ~BB_DUPLICATED
;
4418 /* Duplicates a REGION (set of N_REGION basic blocks) with just a single
4419 important exit edge EXIT. By important we mean that no SSA name defined
4420 inside region is live over the other exit edges of the region. All entry
4421 edges to the region must go to ENTRY->dest. The edge ENTRY is redirected
4422 to the duplicate of the region. SSA form, dominance and loop information
4423 is updated. The new basic blocks are stored to REGION_COPY in the same
4424 order as they had in REGION, provided that REGION_COPY is not NULL.
4425 The function returns false if it is unable to copy the region,
4429 tree_duplicate_sese_region (edge entry
, edge exit
,
4430 basic_block
*region
, unsigned n_region
,
4431 basic_block
*region_copy
)
4434 bool free_region_copy
= false, copying_header
= false;
4435 struct loop
*loop
= entry
->dest
->loop_father
;
4439 int total_freq
= 0, entry_freq
= 0;
4440 gcov_type total_count
= 0, entry_count
= 0;
4442 if (!can_copy_bbs_p (region
, n_region
))
4445 /* Some sanity checking. Note that we do not check for all possible
4446 missuses of the functions. I.e. if you ask to copy something weird,
4447 it will work, but the state of structures probably will not be
4449 for (i
= 0; i
< n_region
; i
++)
4451 /* We do not handle subloops, i.e. all the blocks must belong to the
4453 if (region
[i
]->loop_father
!= loop
)
4456 if (region
[i
] != entry
->dest
4457 && region
[i
] == loop
->header
)
4463 /* In case the function is used for loop header copying (which is the primary
4464 use), ensure that EXIT and its copy will be new latch and entry edges. */
4465 if (loop
->header
== entry
->dest
)
4467 copying_header
= true;
4468 loop
->copy
= loop
->outer
;
4470 if (!dominated_by_p (CDI_DOMINATORS
, loop
->latch
, exit
->src
))
4473 for (i
= 0; i
< n_region
; i
++)
4474 if (region
[i
] != exit
->src
4475 && dominated_by_p (CDI_DOMINATORS
, region
[i
], exit
->src
))
4481 region_copy
= XNEWVEC (basic_block
, n_region
);
4482 free_region_copy
= true;
4485 gcc_assert (!need_ssa_update_p ());
4487 /* Record blocks outside the region that are dominated by something
4489 doms
= XNEWVEC (basic_block
, n_basic_blocks
);
4490 initialize_original_copy_tables ();
4492 n_doms
= get_dominated_by_region (CDI_DOMINATORS
, region
, n_region
, doms
);
4494 if (entry
->dest
->count
)
4496 total_count
= entry
->dest
->count
;
4497 entry_count
= entry
->count
;
4498 /* Fix up corner cases, to avoid division by zero or creation of negative
4500 if (entry_count
> total_count
)
4501 entry_count
= total_count
;
4505 total_freq
= entry
->dest
->frequency
;
4506 entry_freq
= EDGE_FREQUENCY (entry
);
4507 /* Fix up corner cases, to avoid division by zero or creation of negative
4509 if (total_freq
== 0)
4511 else if (entry_freq
> total_freq
)
4512 entry_freq
= total_freq
;
4515 copy_bbs (region
, n_region
, region_copy
, &exit
, 1, &exit_copy
, loop
,
4516 split_edge_bb_loc (entry
));
4519 scale_bbs_frequencies_gcov_type (region
, n_region
,
4520 total_count
- entry_count
,
4522 scale_bbs_frequencies_gcov_type (region_copy
, n_region
, entry_count
,
4527 scale_bbs_frequencies_int (region
, n_region
, total_freq
- entry_freq
,
4529 scale_bbs_frequencies_int (region_copy
, n_region
, entry_freq
, total_freq
);
4534 loop
->header
= exit
->dest
;
4535 loop
->latch
= exit
->src
;
4538 /* Redirect the entry and add the phi node arguments. */
4539 redirected
= redirect_edge_and_branch (entry
, get_bb_copy (entry
->dest
));
4540 gcc_assert (redirected
!= NULL
);
4541 flush_pending_stmts (entry
);
4543 /* Concerning updating of dominators: We must recount dominators
4544 for entry block and its copy. Anything that is outside of the
4545 region, but was dominated by something inside needs recounting as
4547 set_immediate_dominator (CDI_DOMINATORS
, entry
->dest
, entry
->src
);
4548 doms
[n_doms
++] = get_bb_original (entry
->dest
);
4549 iterate_fix_dominators (CDI_DOMINATORS
, doms
, n_doms
);
4552 /* Add the other PHI node arguments. */
4553 add_phi_args_after_copy (region_copy
, n_region
);
4555 /* Update the SSA web. */
4556 update_ssa (TODO_update_ssa
);
4558 if (free_region_copy
)
4561 free_original_copy_tables ();
4566 DEF_VEC_P(basic_block);
4567 DEF_VEC_ALLOC_P(basic_block,heap);
4570 /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop
4571 adding blocks when the dominator traversal reaches EXIT. This
4572 function silently assumes that ENTRY strictly dominates EXIT. */
4575 gather_blocks_in_sese_region (basic_block entry
, basic_block exit
,
4576 VEC(basic_block
,heap
) **bbs_p
)
4580 for (son
= first_dom_son (CDI_DOMINATORS
, entry
);
4582 son
= next_dom_son (CDI_DOMINATORS
, son
))
4584 VEC_safe_push (basic_block
, heap
, *bbs_p
, son
);
4586 gather_blocks_in_sese_region (son
, exit
, bbs_p
);
4596 bitmap vars_to_remove
;
4597 htab_t new_label_map
;
4601 /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression
4602 contained in *TP and change the DECL_CONTEXT of every local
4603 variable referenced in *TP. */
4606 move_stmt_r (tree
*tp
, int *walk_subtrees
, void *data
)
4608 struct move_stmt_d
*p
= (struct move_stmt_d
*) data
;
4612 && (EXPR_P (t
) || GIMPLE_STMT_P (t
)))
4613 TREE_BLOCK (t
) = p
->block
;
4615 if (OMP_DIRECTIVE_P (t
)
4616 && TREE_CODE (t
) != OMP_RETURN
4617 && TREE_CODE (t
) != OMP_CONTINUE
)
4619 /* Do not remap variables inside OMP directives. Variables
4620 referenced in clauses and directive header belong to the
4621 parent function and should not be moved into the child
4623 bool save_remap_decls_p
= p
->remap_decls_p
;
4624 p
->remap_decls_p
= false;
4627 walk_tree (&OMP_BODY (t
), move_stmt_r
, p
, NULL
);
4629 p
->remap_decls_p
= save_remap_decls_p
;
4631 else if (DECL_P (t
) && DECL_CONTEXT (t
) == p
->from_context
)
4633 if (TREE_CODE (t
) == LABEL_DECL
)
4635 if (p
->new_label_map
)
4637 struct tree_map in
, *out
;
4639 out
= htab_find_with_hash (p
->new_label_map
, &in
, DECL_UID (t
));
4644 DECL_CONTEXT (t
) = p
->to_context
;
4646 else if (p
->remap_decls_p
)
4648 DECL_CONTEXT (t
) = p
->to_context
;
4650 if (TREE_CODE (t
) == VAR_DECL
)
4652 struct function
*f
= DECL_STRUCT_FUNCTION (p
->to_context
);
4653 f
->unexpanded_var_list
4654 = tree_cons (0, t
, f
->unexpanded_var_list
);
4656 /* Mark T to be removed from the original function,
4657 otherwise it will be given a DECL_RTL when the
4658 original function is expanded. */
4659 bitmap_set_bit (p
->vars_to_remove
, DECL_UID (t
));
4663 else if (TYPE_P (t
))
4670 /* Move basic block BB from function CFUN to function DEST_FN. The
4671 block is moved out of the original linked list and placed after
4672 block AFTER in the new list. Also, the block is removed from the
4673 original array of blocks and placed in DEST_FN's array of blocks.
4674 If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is
4675 updated to reflect the moved edges.
4677 On exit, local variables that need to be removed from
4678 CFUN->UNEXPANDED_VAR_LIST will have been added to VARS_TO_REMOVE. */
4681 move_block_to_fn (struct function
*dest_cfun
, basic_block bb
,
4682 basic_block after
, bool update_edge_count_p
,
4683 bitmap vars_to_remove
, htab_t new_label_map
, int eh_offset
)
4685 struct control_flow_graph
*cfg
;
4688 block_stmt_iterator si
;
4689 struct move_stmt_d d
;
4690 unsigned old_len
, new_len
;
4693 /* Link BB to the new linked list. */
4694 move_block_after (bb
, after
);
4696 /* Update the edge count in the corresponding flowgraphs. */
4697 if (update_edge_count_p
)
4698 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4700 cfun
->cfg
->x_n_edges
--;
4701 dest_cfun
->cfg
->x_n_edges
++;
4704 /* Remove BB from the original basic block array. */
4705 VEC_replace (basic_block
, cfun
->cfg
->x_basic_block_info
, bb
->index
, NULL
);
4706 cfun
->cfg
->x_n_basic_blocks
--;
4708 /* Grow DEST_CFUN's basic block array if needed. */
4709 cfg
= dest_cfun
->cfg
;
4710 cfg
->x_n_basic_blocks
++;
4711 if (bb
->index
> cfg
->x_last_basic_block
)
4712 cfg
->x_last_basic_block
= bb
->index
;
4714 old_len
= VEC_length (basic_block
, cfg
->x_basic_block_info
);
4715 if ((unsigned) cfg
->x_last_basic_block
>= old_len
)
4717 new_len
= cfg
->x_last_basic_block
+ (cfg
->x_last_basic_block
+ 3) / 4;
4718 VEC_safe_grow (basic_block
, gc
, cfg
->x_basic_block_info
, new_len
);
4719 addr
= VEC_address (basic_block
, cfg
->x_basic_block_info
);
4720 memset (&addr
[old_len
], 0, sizeof (basic_block
) * (new_len
- old_len
));
4723 VEC_replace (basic_block
, cfg
->x_basic_block_info
,
4724 cfg
->x_last_basic_block
, bb
);
4726 /* The statements in BB need to be associated with a new TREE_BLOCK.
4727 Labels need to be associated with a new label-to-block map. */
4728 memset (&d
, 0, sizeof (d
));
4729 d
.vars_to_remove
= vars_to_remove
;
4731 for (si
= bsi_start (bb
); !bsi_end_p (si
); bsi_next (&si
))
4733 tree stmt
= bsi_stmt (si
);
4736 d
.from_context
= cfun
->decl
;
4737 d
.to_context
= dest_cfun
->decl
;
4738 d
.remap_decls_p
= true;
4739 d
.new_label_map
= new_label_map
;
4740 if (TREE_BLOCK (stmt
))
4741 d
.block
= DECL_INITIAL (dest_cfun
->decl
);
4743 walk_tree (&stmt
, move_stmt_r
, &d
, NULL
);
4745 if (TREE_CODE (stmt
) == LABEL_EXPR
)
4747 tree label
= LABEL_EXPR_LABEL (stmt
);
4748 int uid
= LABEL_DECL_UID (label
);
4750 gcc_assert (uid
> -1);
4752 old_len
= VEC_length (basic_block
, cfg
->x_label_to_block_map
);
4753 if (old_len
<= (unsigned) uid
)
4755 new_len
= 3 * uid
/ 2;
4756 VEC_safe_grow (basic_block
, gc
, cfg
->x_label_to_block_map
,
4758 addr
= VEC_address (basic_block
, cfg
->x_label_to_block_map
);
4759 memset (&addr
[old_len
], 0,
4760 sizeof (basic_block
) * (new_len
- old_len
));
4763 VEC_replace (basic_block
, cfg
->x_label_to_block_map
, uid
, bb
);
4764 VEC_replace (basic_block
, cfun
->cfg
->x_label_to_block_map
, uid
, NULL
);
4766 gcc_assert (DECL_CONTEXT (label
) == dest_cfun
->decl
);
4768 if (uid
>= dest_cfun
->last_label_uid
)
4769 dest_cfun
->last_label_uid
= uid
+ 1;
4771 else if (TREE_CODE (stmt
) == RESX_EXPR
&& eh_offset
!= 0)
4772 TREE_OPERAND (stmt
, 0) =
4773 build_int_cst (NULL_TREE
,
4774 TREE_INT_CST_LOW (TREE_OPERAND (stmt
, 0))
4777 region
= lookup_stmt_eh_region (stmt
);
4780 add_stmt_to_eh_region_fn (dest_cfun
, stmt
, region
+ eh_offset
);
4781 remove_stmt_from_eh_region (stmt
);
4786 /* Examine the statements in BB (which is in SRC_CFUN); find and return
4787 the outermost EH region. Use REGION as the incoming base EH region. */
4790 find_outermost_region_in_block (struct function
*src_cfun
,
4791 basic_block bb
, int region
)
4793 block_stmt_iterator si
;
4795 for (si
= bsi_start (bb
); !bsi_end_p (si
); bsi_next (&si
))
4797 tree stmt
= bsi_stmt (si
);
4800 if (TREE_CODE (stmt
) == RESX_EXPR
)
4801 stmt_region
= TREE_INT_CST_LOW (TREE_OPERAND (stmt
, 0));
4803 stmt_region
= lookup_stmt_eh_region_fn (src_cfun
, stmt
);
4804 if (stmt_region
> 0)
4807 region
= stmt_region
;
4808 else if (stmt_region
!= region
)
4810 region
= eh_region_outermost (src_cfun
, stmt_region
, region
);
4811 gcc_assert (region
!= -1);
4820 new_label_mapper (tree decl
, void *data
)
4822 htab_t hash
= (htab_t
) data
;
4826 gcc_assert (TREE_CODE (decl
) == LABEL_DECL
);
4828 m
= xmalloc (sizeof (struct tree_map
));
4829 m
->hash
= DECL_UID (decl
);
4831 m
->to
= create_artificial_label ();
4832 LABEL_DECL_UID (m
->to
) = LABEL_DECL_UID (decl
);
4834 slot
= htab_find_slot_with_hash (hash
, m
, m
->hash
, INSERT
);
4835 gcc_assert (*slot
== NULL
);
4842 /* Move a single-entry, single-exit region delimited by ENTRY_BB and
4843 EXIT_BB to function DEST_CFUN. The whole region is replaced by a
4844 single basic block in the original CFG and the new basic block is
4845 returned. DEST_CFUN must not have a CFG yet.
4847 Note that the region need not be a pure SESE region. Blocks inside
4848 the region may contain calls to abort/exit. The only restriction
4849 is that ENTRY_BB should be the only entry point and it must
4852 All local variables referenced in the region are assumed to be in
4853 the corresponding BLOCK_VARS and unexpanded variable lists
4854 associated with DEST_CFUN. */
4857 move_sese_region_to_fn (struct function
*dest_cfun
, basic_block entry_bb
,
4858 basic_block exit_bb
)
4860 VEC(basic_block
,heap
) *bbs
;
4861 basic_block after
, bb
, *entry_pred
, *exit_succ
;
4862 struct function
*saved_cfun
;
4863 int *entry_flag
, *exit_flag
, eh_offset
;
4864 unsigned i
, num_entry_edges
, num_exit_edges
;
4867 bitmap vars_to_remove
;
4868 htab_t new_label_map
;
4872 /* Collect all the blocks in the region. Manually add ENTRY_BB
4873 because it won't be added by dfs_enumerate_from. */
4874 calculate_dominance_info (CDI_DOMINATORS
);
4876 /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE
4878 gcc_assert (entry_bb
!= exit_bb
4880 || dominated_by_p (CDI_DOMINATORS
, exit_bb
, entry_bb
)));
4883 VEC_safe_push (basic_block
, heap
, bbs
, entry_bb
);
4884 gather_blocks_in_sese_region (entry_bb
, exit_bb
, &bbs
);
4886 /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember
4887 the predecessor edges to ENTRY_BB and the successor edges to
4888 EXIT_BB so that we can re-attach them to the new basic block that
4889 will replace the region. */
4890 num_entry_edges
= EDGE_COUNT (entry_bb
->preds
);
4891 entry_pred
= (basic_block
*) xcalloc (num_entry_edges
, sizeof (basic_block
));
4892 entry_flag
= (int *) xcalloc (num_entry_edges
, sizeof (int));
4894 for (ei
= ei_start (entry_bb
->preds
); (e
= ei_safe_edge (ei
)) != NULL
;)
4896 entry_flag
[i
] = e
->flags
;
4897 entry_pred
[i
++] = e
->src
;
4903 num_exit_edges
= EDGE_COUNT (exit_bb
->succs
);
4904 exit_succ
= (basic_block
*) xcalloc (num_exit_edges
,
4905 sizeof (basic_block
));
4906 exit_flag
= (int *) xcalloc (num_exit_edges
, sizeof (int));
4908 for (ei
= ei_start (exit_bb
->succs
); (e
= ei_safe_edge (ei
)) != NULL
;)
4910 exit_flag
[i
] = e
->flags
;
4911 exit_succ
[i
++] = e
->dest
;
4922 /* Switch context to the child function to initialize DEST_FN's CFG. */
4923 gcc_assert (dest_cfun
->cfg
== NULL
);
4926 init_empty_tree_cfg ();
4928 /* Initialize EH information for the new function. */
4930 new_label_map
= NULL
;
4935 for (i
= 0; VEC_iterate (basic_block
, bbs
, i
, bb
); i
++)
4936 region
= find_outermost_region_in_block (saved_cfun
, bb
, region
);
4938 init_eh_for_function ();
4941 new_label_map
= htab_create (17, tree_map_hash
, tree_map_eq
, free
);
4942 eh_offset
= duplicate_eh_regions (saved_cfun
, new_label_mapper
,
4943 new_label_map
, region
, 0);
4949 /* Move blocks from BBS into DEST_CFUN. */
4950 gcc_assert (VEC_length (basic_block
, bbs
) >= 2);
4951 after
= dest_cfun
->cfg
->x_entry_block_ptr
;
4952 vars_to_remove
= BITMAP_ALLOC (NULL
);
4953 for (i
= 0; VEC_iterate (basic_block
, bbs
, i
, bb
); i
++)
4955 /* No need to update edge counts on the last block. It has
4956 already been updated earlier when we detached the region from
4957 the original CFG. */
4958 move_block_to_fn (dest_cfun
, bb
, after
, bb
!= exit_bb
, vars_to_remove
,
4959 new_label_map
, eh_offset
);
4964 htab_delete (new_label_map
);
4966 /* Remove the variables marked in VARS_TO_REMOVE from
4967 CFUN->UNEXPANDED_VAR_LIST. Otherwise, they will be given a
4968 DECL_RTL in the context of CFUN. */
4969 if (!bitmap_empty_p (vars_to_remove
))
4973 for (p
= &cfun
->unexpanded_var_list
; *p
; )
4975 tree var
= TREE_VALUE (*p
);
4976 if (bitmap_bit_p (vars_to_remove
, DECL_UID (var
)))
4978 *p
= TREE_CHAIN (*p
);
4982 p
= &TREE_CHAIN (*p
);
4986 BITMAP_FREE (vars_to_remove
);
4988 /* Rewire the entry and exit blocks. The successor to the entry
4989 block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in
4990 the child function. Similarly, the predecessor of DEST_FN's
4991 EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We
4992 need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the
4993 various CFG manipulation function get to the right CFG.
4995 FIXME, this is silly. The CFG ought to become a parameter to
4998 make_edge (ENTRY_BLOCK_PTR
, entry_bb
, EDGE_FALLTHRU
);
5000 make_edge (exit_bb
, EXIT_BLOCK_PTR
, 0);
5003 /* Back in the original function, the SESE region has disappeared,
5004 create a new basic block in its place. */
5005 bb
= create_empty_bb (entry_pred
[0]);
5006 for (i
= 0; i
< num_entry_edges
; i
++)
5007 make_edge (entry_pred
[i
], bb
, entry_flag
[i
]);
5009 for (i
= 0; i
< num_exit_edges
; i
++)
5010 make_edge (bb
, exit_succ
[i
], exit_flag
[i
]);
5019 free_dominance_info (CDI_DOMINATORS
);
5020 free_dominance_info (CDI_POST_DOMINATORS
);
5021 VEC_free (basic_block
, heap
, bbs
);
5027 /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */
5030 dump_function_to_file (tree fn
, FILE *file
, int flags
)
5032 tree arg
, vars
, var
;
5033 bool ignore_topmost_bind
= false, any_var
= false;
5036 struct function
*saved_cfun
;
5038 fprintf (file
, "%s (", lang_hooks
.decl_printable_name (fn
, 2));
5040 arg
= DECL_ARGUMENTS (fn
);
5043 print_generic_expr (file
, arg
, dump_flags
);
5044 if (TREE_CHAIN (arg
))
5045 fprintf (file
, ", ");
5046 arg
= TREE_CHAIN (arg
);
5048 fprintf (file
, ")\n");
5050 if (flags
& TDF_DETAILS
)
5051 dump_eh_tree (file
, DECL_STRUCT_FUNCTION (fn
));
5052 if (flags
& TDF_RAW
)
5054 dump_node (fn
, TDF_SLIM
| flags
, file
);
5058 /* Switch CFUN to point to FN. */
5060 cfun
= DECL_STRUCT_FUNCTION (fn
);
5062 /* When GIMPLE is lowered, the variables are no longer available in
5063 BIND_EXPRs, so display them separately. */
5064 if (cfun
&& cfun
->decl
== fn
&& cfun
->unexpanded_var_list
)
5066 ignore_topmost_bind
= true;
5068 fprintf (file
, "{\n");
5069 for (vars
= cfun
->unexpanded_var_list
; vars
; vars
= TREE_CHAIN (vars
))
5071 var
= TREE_VALUE (vars
);
5073 print_generic_decl (file
, var
, flags
);
5074 fprintf (file
, "\n");
5080 if (cfun
&& cfun
->decl
== fn
&& cfun
->cfg
&& basic_block_info
)
5082 /* Make a CFG based dump. */
5083 check_bb_profile (ENTRY_BLOCK_PTR
, file
);
5084 if (!ignore_topmost_bind
)
5085 fprintf (file
, "{\n");
5087 if (any_var
&& n_basic_blocks
)
5088 fprintf (file
, "\n");
5091 dump_generic_bb (file
, bb
, 2, flags
);
5093 fprintf (file
, "}\n");
5094 check_bb_profile (EXIT_BLOCK_PTR
, file
);
5100 /* Make a tree based dump. */
5101 chain
= DECL_SAVED_TREE (fn
);
5103 if (chain
&& TREE_CODE (chain
) == BIND_EXPR
)
5105 if (ignore_topmost_bind
)
5107 chain
= BIND_EXPR_BODY (chain
);
5115 if (!ignore_topmost_bind
)
5116 fprintf (file
, "{\n");
5121 fprintf (file
, "\n");
5123 print_generic_stmt_indented (file
, chain
, flags
, indent
);
5124 if (ignore_topmost_bind
)
5125 fprintf (file
, "}\n");
5128 fprintf (file
, "\n\n");
5135 /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */
5138 debug_function (tree fn
, int flags
)
5140 dump_function_to_file (fn
, stderr
, flags
);
5144 /* Pretty print of the loops intermediate representation. */
5145 static void print_loop (FILE *, struct loop
*, int);
5146 static void print_pred_bbs (FILE *, basic_block bb
);
5147 static void print_succ_bbs (FILE *, basic_block bb
);
5150 /* Print on FILE the indexes for the predecessors of basic_block BB. */
5153 print_pred_bbs (FILE *file
, basic_block bb
)
5158 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
5159 fprintf (file
, "bb_%d ", e
->src
->index
);
5163 /* Print on FILE the indexes for the successors of basic_block BB. */
5166 print_succ_bbs (FILE *file
, basic_block bb
)
5171 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5172 fprintf (file
, "bb_%d ", e
->dest
->index
);
5176 /* Pretty print LOOP on FILE, indented INDENT spaces. */
5179 print_loop (FILE *file
, struct loop
*loop
, int indent
)
5187 s_indent
= (char *) alloca ((size_t) indent
+ 1);
5188 memset ((void *) s_indent
, ' ', (size_t) indent
);
5189 s_indent
[indent
] = '\0';
5191 /* Print the loop's header. */
5192 fprintf (file
, "%sloop_%d\n", s_indent
, loop
->num
);
5194 /* Print the loop's body. */
5195 fprintf (file
, "%s{\n", s_indent
);
5197 if (bb
->loop_father
== loop
)
5199 /* Print the basic_block's header. */
5200 fprintf (file
, "%s bb_%d (preds = {", s_indent
, bb
->index
);
5201 print_pred_bbs (file
, bb
);
5202 fprintf (file
, "}, succs = {");
5203 print_succ_bbs (file
, bb
);
5204 fprintf (file
, "})\n");
5206 /* Print the basic_block's body. */
5207 fprintf (file
, "%s {\n", s_indent
);
5208 tree_dump_bb (bb
, file
, indent
+ 4);
5209 fprintf (file
, "%s }\n", s_indent
);
5212 print_loop (file
, loop
->inner
, indent
+ 2);
5213 fprintf (file
, "%s}\n", s_indent
);
5214 print_loop (file
, loop
->next
, indent
);
5218 /* Follow a CFG edge from the entry point of the program, and on entry
5219 of a loop, pretty print the loop structure on FILE. */
5222 print_loop_ir (FILE *file
)
5226 bb
= BASIC_BLOCK (NUM_FIXED_BLOCKS
);
5227 if (bb
&& bb
->loop_father
)
5228 print_loop (file
, bb
->loop_father
, 0);
5232 /* Debugging loops structure at tree level. */
5235 debug_loop_ir (void)
5237 print_loop_ir (stderr
);
5241 /* Return true if BB ends with a call, possibly followed by some
5242 instructions that must stay with the call. Return false,
5246 tree_block_ends_with_call_p (basic_block bb
)
5248 block_stmt_iterator bsi
= bsi_last (bb
);
5249 return get_call_expr_in (bsi_stmt (bsi
)) != NULL
;
5253 /* Return true if BB ends with a conditional branch. Return false,
5257 tree_block_ends_with_condjump_p (basic_block bb
)
5259 tree stmt
= last_stmt (bb
);
5260 return (stmt
&& TREE_CODE (stmt
) == COND_EXPR
);
5264 /* Return true if we need to add fake edge to exit at statement T.
5265 Helper function for tree_flow_call_edges_add. */
5268 need_fake_edge_p (tree t
)
5272 /* NORETURN and LONGJMP calls already have an edge to exit.
5273 CONST and PURE calls do not need one.
5274 We don't currently check for CONST and PURE here, although
5275 it would be a good idea, because those attributes are
5276 figured out from the RTL in mark_constant_function, and
5277 the counter incrementation code from -fprofile-arcs
5278 leads to different results from -fbranch-probabilities. */
5279 call
= get_call_expr_in (t
);
5281 && !(call_expr_flags (call
) & ECF_NORETURN
))
5284 if (TREE_CODE (t
) == ASM_EXPR
5285 && (ASM_VOLATILE_P (t
) || ASM_INPUT_P (t
)))
5292 /* Add fake edges to the function exit for any non constant and non
5293 noreturn calls, volatile inline assembly in the bitmap of blocks
5294 specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return
5295 the number of blocks that were split.
5297 The goal is to expose cases in which entering a basic block does
5298 not imply that all subsequent instructions must be executed. */
5301 tree_flow_call_edges_add (sbitmap blocks
)
5304 int blocks_split
= 0;
5305 int last_bb
= last_basic_block
;
5306 bool check_last_block
= false;
5308 if (n_basic_blocks
== NUM_FIXED_BLOCKS
)
5312 check_last_block
= true;
5314 check_last_block
= TEST_BIT (blocks
, EXIT_BLOCK_PTR
->prev_bb
->index
);
5316 /* In the last basic block, before epilogue generation, there will be
5317 a fallthru edge to EXIT. Special care is required if the last insn
5318 of the last basic block is a call because make_edge folds duplicate
5319 edges, which would result in the fallthru edge also being marked
5320 fake, which would result in the fallthru edge being removed by
5321 remove_fake_edges, which would result in an invalid CFG.
5323 Moreover, we can't elide the outgoing fake edge, since the block
5324 profiler needs to take this into account in order to solve the minimal
5325 spanning tree in the case that the call doesn't return.
5327 Handle this by adding a dummy instruction in a new last basic block. */
5328 if (check_last_block
)
5330 basic_block bb
= EXIT_BLOCK_PTR
->prev_bb
;
5331 block_stmt_iterator bsi
= bsi_last (bb
);
5333 if (!bsi_end_p (bsi
))
5336 if (t
&& need_fake_edge_p (t
))
5340 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
5343 bsi_insert_on_edge (e
, build_empty_stmt ());
5344 bsi_commit_edge_inserts ();
5349 /* Now add fake edges to the function exit for any non constant
5350 calls since there is no way that we can determine if they will
5352 for (i
= 0; i
< last_bb
; i
++)
5354 basic_block bb
= BASIC_BLOCK (i
);
5355 block_stmt_iterator bsi
;
5356 tree stmt
, last_stmt
;
5361 if (blocks
&& !TEST_BIT (blocks
, i
))
5364 bsi
= bsi_last (bb
);
5365 if (!bsi_end_p (bsi
))
5367 last_stmt
= bsi_stmt (bsi
);
5370 stmt
= bsi_stmt (bsi
);
5371 if (need_fake_edge_p (stmt
))
5374 /* The handling above of the final block before the
5375 epilogue should be enough to verify that there is
5376 no edge to the exit block in CFG already.
5377 Calling make_edge in such case would cause us to
5378 mark that edge as fake and remove it later. */
5379 #ifdef ENABLE_CHECKING
5380 if (stmt
== last_stmt
)
5382 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
5383 gcc_assert (e
== NULL
);
5387 /* Note that the following may create a new basic block
5388 and renumber the existing basic blocks. */
5389 if (stmt
!= last_stmt
)
5391 e
= split_block (bb
, stmt
);
5395 make_edge (bb
, EXIT_BLOCK_PTR
, EDGE_FAKE
);
5399 while (!bsi_end_p (bsi
));
5404 verify_flow_info ();
5406 return blocks_split
;
5409 /* Purge dead abnormal call edges from basic block BB. */
5412 tree_purge_dead_abnormal_call_edges (basic_block bb
)
5414 bool changed
= tree_purge_dead_eh_edges (bb
);
5416 if (current_function_has_nonlocal_label
)
5418 tree stmt
= last_stmt (bb
);
5422 if (!(stmt
&& tree_can_make_abnormal_goto (stmt
)))
5423 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
5425 if (e
->flags
& EDGE_ABNORMAL
)
5434 /* See tree_purge_dead_eh_edges below. */
5436 free_dominance_info (CDI_DOMINATORS
);
5442 /* Purge dead EH edges from basic block BB. */
5445 tree_purge_dead_eh_edges (basic_block bb
)
5447 bool changed
= false;
5450 tree stmt
= last_stmt (bb
);
5452 if (stmt
&& tree_can_throw_internal (stmt
))
5455 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
5457 if (e
->flags
& EDGE_EH
)
5466 /* Removal of dead EH edges might change dominators of not
5467 just immediate successors. E.g. when bb1 is changed so that
5468 it no longer can throw and bb1->bb3 and bb1->bb4 are dead
5469 eh edges purged by this function in:
5481 idom(bb5) must be recomputed. For now just free the dominance
5484 free_dominance_info (CDI_DOMINATORS
);
5490 tree_purge_all_dead_eh_edges (bitmap blocks
)
5492 bool changed
= false;
5496 EXECUTE_IF_SET_IN_BITMAP (blocks
, 0, i
, bi
)
5498 changed
|= tree_purge_dead_eh_edges (BASIC_BLOCK (i
));
5504 /* This function is called whenever a new edge is created or
5508 tree_execute_on_growing_pred (edge e
)
5510 basic_block bb
= e
->dest
;
5513 reserve_phi_args_for_new_edge (bb
);
5516 /* This function is called immediately before edge E is removed from
5517 the edge vector E->dest->preds. */
5520 tree_execute_on_shrinking_pred (edge e
)
5522 if (phi_nodes (e
->dest
))
5523 remove_phi_args (e
);
5526 /*---------------------------------------------------------------------------
5527 Helper functions for Loop versioning
5528 ---------------------------------------------------------------------------*/
5530 /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
5531 of 'first'. Both of them are dominated by 'new_head' basic block. When
5532 'new_head' was created by 'second's incoming edge it received phi arguments
5533 on the edge by split_edge(). Later, additional edge 'e' was created to
5534 connect 'new_head' and 'first'. Now this routine adds phi args on this
5535 additional edge 'e' that new_head to second edge received as part of edge
5540 tree_lv_adjust_loop_header_phi (basic_block first
, basic_block second
,
5541 basic_block new_head
, edge e
)
5544 edge e2
= find_edge (new_head
, second
);
5546 /* Because NEW_HEAD has been created by splitting SECOND's incoming
5547 edge, we should always have an edge from NEW_HEAD to SECOND. */
5548 gcc_assert (e2
!= NULL
);
5550 /* Browse all 'second' basic block phi nodes and add phi args to
5551 edge 'e' for 'first' head. PHI args are always in correct order. */
5553 for (phi2
= phi_nodes (second
), phi1
= phi_nodes (first
);
5555 phi2
= PHI_CHAIN (phi2
), phi1
= PHI_CHAIN (phi1
))
5557 tree def
= PHI_ARG_DEF (phi2
, e2
->dest_idx
);
5558 add_phi_arg (phi1
, def
, e
);
5562 /* Adds a if else statement to COND_BB with condition COND_EXPR.
5563 SECOND_HEAD is the destination of the THEN and FIRST_HEAD is
5564 the destination of the ELSE part. */
5566 tree_lv_add_condition_to_bb (basic_block first_head
, basic_block second_head
,
5567 basic_block cond_bb
, void *cond_e
)
5569 block_stmt_iterator bsi
;
5570 tree goto1
= NULL_TREE
;
5571 tree goto2
= NULL_TREE
;
5572 tree new_cond_expr
= NULL_TREE
;
5573 tree cond_expr
= (tree
) cond_e
;
5576 /* Build new conditional expr */
5577 goto1
= build1 (GOTO_EXPR
, void_type_node
, tree_block_label (first_head
));
5578 goto2
= build1 (GOTO_EXPR
, void_type_node
, tree_block_label (second_head
));
5579 new_cond_expr
= build3 (COND_EXPR
, void_type_node
, cond_expr
, goto1
, goto2
);
5581 /* Add new cond in cond_bb. */
5582 bsi
= bsi_start (cond_bb
);
5583 bsi_insert_after (&bsi
, new_cond_expr
, BSI_NEW_STMT
);
5584 /* Adjust edges appropriately to connect new head with first head
5585 as well as second head. */
5586 e0
= single_succ_edge (cond_bb
);
5587 e0
->flags
&= ~EDGE_FALLTHRU
;
5588 e0
->flags
|= EDGE_FALSE_VALUE
;
5591 struct cfg_hooks tree_cfg_hooks
= {
5593 tree_verify_flow_info
,
5594 tree_dump_bb
, /* dump_bb */
5595 create_bb
, /* create_basic_block */
5596 tree_redirect_edge_and_branch
,/* redirect_edge_and_branch */
5597 tree_redirect_edge_and_branch_force
,/* redirect_edge_and_branch_force */
5598 remove_bb
, /* delete_basic_block */
5599 tree_split_block
, /* split_block */
5600 tree_move_block_after
, /* move_block_after */
5601 tree_can_merge_blocks_p
, /* can_merge_blocks_p */
5602 tree_merge_blocks
, /* merge_blocks */
5603 tree_predict_edge
, /* predict_edge */
5604 tree_predicted_by_p
, /* predicted_by_p */
5605 tree_can_duplicate_bb_p
, /* can_duplicate_block_p */
5606 tree_duplicate_bb
, /* duplicate_block */
5607 tree_split_edge
, /* split_edge */
5608 tree_make_forwarder_block
, /* make_forward_block */
5609 NULL
, /* tidy_fallthru_edge */
5610 tree_block_ends_with_call_p
, /* block_ends_with_call_p */
5611 tree_block_ends_with_condjump_p
, /* block_ends_with_condjump_p */
5612 tree_flow_call_edges_add
, /* flow_call_edges_add */
5613 tree_execute_on_growing_pred
, /* execute_on_growing_pred */
5614 tree_execute_on_shrinking_pred
, /* execute_on_shrinking_pred */
5615 tree_duplicate_loop_to_header_edge
, /* duplicate loop for trees */
5616 tree_lv_add_condition_to_bb
, /* lv_add_condition_to_bb */
5617 tree_lv_adjust_loop_header_phi
, /* lv_adjust_loop_header_phi*/
5618 extract_true_false_edges_from_block
, /* extract_cond_bb_edges */
5619 flush_pending_stmts
/* flush_pending_stmts */
5623 /* Split all critical edges. */
5626 split_critical_edges (void)
5632 /* split_edge can redirect edges out of SWITCH_EXPRs, which can get
5633 expensive. So we want to enable recording of edge to CASE_LABEL_EXPR
5634 mappings around the calls to split_edge. */
5635 start_recording_case_labels ();
5638 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
5639 if (EDGE_CRITICAL_P (e
) && !(e
->flags
& EDGE_ABNORMAL
))
5644 end_recording_case_labels ();
5648 struct tree_opt_pass pass_split_crit_edges
=
5650 "crited", /* name */
5652 split_critical_edges
, /* execute */
5655 0, /* static_pass_number */
5656 TV_TREE_SPLIT_EDGES
, /* tv_id */
5657 PROP_cfg
, /* properties required */
5658 PROP_no_crit_edges
, /* properties_provided */
5659 0, /* properties_destroyed */
5660 0, /* todo_flags_start */
5661 TODO_dump_func
, /* todo_flags_finish */
5666 /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into
5667 a temporary, make sure and register it to be renamed if necessary,
5668 and finally return the temporary. Put the statements to compute
5669 EXP before the current statement in BSI. */
5672 gimplify_val (block_stmt_iterator
*bsi
, tree type
, tree exp
)
5674 tree t
, new_stmt
, orig_stmt
;
5676 if (is_gimple_val (exp
))
5679 t
= make_rename_temp (type
, NULL
);
5680 new_stmt
= build2_gimple (GIMPLE_MODIFY_STMT
, t
, exp
);
5682 orig_stmt
= bsi_stmt (*bsi
);
5683 SET_EXPR_LOCUS (new_stmt
, EXPR_LOCUS (orig_stmt
));
5684 TREE_BLOCK (new_stmt
) = TREE_BLOCK (orig_stmt
);
5686 bsi_insert_before (bsi
, new_stmt
, BSI_SAME_STMT
);
5687 if (gimple_in_ssa_p (cfun
))
5688 mark_new_vars_to_rename (new_stmt
);
5693 /* Build a ternary operation and gimplify it. Emit code before BSI.
5694 Return the gimple_val holding the result. */
5697 gimplify_build3 (block_stmt_iterator
*bsi
, enum tree_code code
,
5698 tree type
, tree a
, tree b
, tree c
)
5702 ret
= fold_build3 (code
, type
, a
, b
, c
);
5705 return gimplify_val (bsi
, type
, ret
);
5708 /* Build a binary operation and gimplify it. Emit code before BSI.
5709 Return the gimple_val holding the result. */
5712 gimplify_build2 (block_stmt_iterator
*bsi
, enum tree_code code
,
5713 tree type
, tree a
, tree b
)
5717 ret
= fold_build2 (code
, type
, a
, b
);
5720 return gimplify_val (bsi
, type
, ret
);
5723 /* Build a unary operation and gimplify it. Emit code before BSI.
5724 Return the gimple_val holding the result. */
5727 gimplify_build1 (block_stmt_iterator
*bsi
, enum tree_code code
, tree type
,
5732 ret
= fold_build1 (code
, type
, a
);
5735 return gimplify_val (bsi
, type
, ret
);
5740 /* Emit return warnings. */
5743 execute_warn_function_return (void)
5745 #ifdef USE_MAPPED_LOCATION
5746 source_location location
;
5754 /* If we have a path to EXIT, then we do return. */
5755 if (TREE_THIS_VOLATILE (cfun
->decl
)
5756 && EDGE_COUNT (EXIT_BLOCK_PTR
->preds
) > 0)
5758 #ifdef USE_MAPPED_LOCATION
5759 location
= UNKNOWN_LOCATION
;
5763 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
5765 last
= last_stmt (e
->src
);
5766 if (TREE_CODE (last
) == RETURN_EXPR
5767 #ifdef USE_MAPPED_LOCATION
5768 && (location
= EXPR_LOCATION (last
)) != UNKNOWN_LOCATION
)
5770 && (locus
= EXPR_LOCUS (last
)) != NULL
)
5774 #ifdef USE_MAPPED_LOCATION
5775 if (location
== UNKNOWN_LOCATION
)
5776 location
= cfun
->function_end_locus
;
5777 warning (0, "%H%<noreturn%> function does return", &location
);
5780 locus
= &cfun
->function_end_locus
;
5781 warning (0, "%H%<noreturn%> function does return", locus
);
5785 /* If we see "return;" in some basic block, then we do reach the end
5786 without returning a value. */
5787 else if (warn_return_type
5788 && !TREE_NO_WARNING (cfun
->decl
)
5789 && EDGE_COUNT (EXIT_BLOCK_PTR
->preds
) > 0
5790 && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun
->decl
))))
5792 FOR_EACH_EDGE (e
, ei
, EXIT_BLOCK_PTR
->preds
)
5794 tree last
= last_stmt (e
->src
);
5795 if (TREE_CODE (last
) == RETURN_EXPR
5796 && TREE_OPERAND (last
, 0) == NULL
5797 && !TREE_NO_WARNING (last
))
5799 #ifdef USE_MAPPED_LOCATION
5800 location
= EXPR_LOCATION (last
);
5801 if (location
== UNKNOWN_LOCATION
)
5802 location
= cfun
->function_end_locus
;
5803 warning (0, "%Hcontrol reaches end of non-void function", &location
);
5805 locus
= EXPR_LOCUS (last
);
5807 locus
= &cfun
->function_end_locus
;
5808 warning (0, "%Hcontrol reaches end of non-void function", locus
);
5810 TREE_NO_WARNING (cfun
->decl
) = 1;
5819 /* Given a basic block B which ends with a conditional and has
5820 precisely two successors, determine which of the edges is taken if
5821 the conditional is true and which is taken if the conditional is
5822 false. Set TRUE_EDGE and FALSE_EDGE appropriately. */
5825 extract_true_false_edges_from_block (basic_block b
,
5829 edge e
= EDGE_SUCC (b
, 0);
5831 if (e
->flags
& EDGE_TRUE_VALUE
)
5834 *false_edge
= EDGE_SUCC (b
, 1);
5839 *true_edge
= EDGE_SUCC (b
, 1);
5843 struct tree_opt_pass pass_warn_function_return
=
5847 execute_warn_function_return
, /* execute */
5850 0, /* static_pass_number */
5852 PROP_cfg
, /* properties_required */
5853 0, /* properties_provided */
5854 0, /* properties_destroyed */
5855 0, /* todo_flags_start */
5856 0, /* todo_flags_finish */
5860 /* Emit noreturn warnings. */
5863 execute_warn_function_noreturn (void)
5865 if (warn_missing_noreturn
5866 && !TREE_THIS_VOLATILE (cfun
->decl
)
5867 && EDGE_COUNT (EXIT_BLOCK_PTR
->preds
) == 0
5868 && !lang_hooks
.function
.missing_noreturn_ok_p (cfun
->decl
))
5869 warning (OPT_Wmissing_noreturn
, "%Jfunction might be possible candidate "
5870 "for attribute %<noreturn%>",
5875 struct tree_opt_pass pass_warn_function_noreturn
=
5879 execute_warn_function_noreturn
, /* execute */
5882 0, /* static_pass_number */
5884 PROP_cfg
, /* properties_required */
5885 0, /* properties_provided */
5886 0, /* properties_destroyed */
5887 0, /* todo_flags_start */
5888 0, /* todo_flags_finish */