1 /* Control flow graph manipulation code for GNU compiler.
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* This file contains low level functions to manipulate the CFG and analyze it
23 that are aware of the RTL intermediate language.
25 Available functionality:
26 - Basic CFG/RTL manipulation API documented in cfghooks.h
27 - CFG-aware instruction chain manipulation
28 delete_insn, delete_insn_chain
29 - Edge splitting and committing to edges
30 insert_insn_on_edge, commit_edge_insertions
31 - CFG updating after insn simplification
32 purge_dead_edges, purge_all_dead_edges
34 Functions not supposed for generic use:
35 - Infrastructure to determine quickly basic block for insn
36 compute_bb_for_insn, update_bb_for_insn, set_block_for_insn,
37 - Edge redirection with updating and optimizing of insn chain
38 block_label, tidy_fallthru_edge, force_nonfallthru */
42 #include "coretypes.h"
45 #include "hard-reg-set.h"
46 #include "basic-block.h"
52 #include "rtl-error.h"
55 #include "insn-attr.h"
56 #include "insn-config.h"
57 #include "cfglayout.h"
62 #include "tree-pass.h"
65 static int can_delete_note_p (const_rtx
);
66 static int can_delete_label_p (const_rtx
);
67 static basic_block
rtl_split_edge (edge
);
68 static bool rtl_move_block_after (basic_block
, basic_block
);
69 static int rtl_verify_flow_info (void);
70 static basic_block
cfg_layout_split_block (basic_block
, void *);
71 static edge
cfg_layout_redirect_edge_and_branch (edge
, basic_block
);
72 static basic_block
cfg_layout_redirect_edge_and_branch_force (edge
, basic_block
);
73 static void cfg_layout_delete_block (basic_block
);
74 static void rtl_delete_block (basic_block
);
75 static basic_block
rtl_redirect_edge_and_branch_force (edge
, basic_block
);
76 static edge
rtl_redirect_edge_and_branch (edge
, basic_block
);
77 static basic_block
rtl_split_block (basic_block
, void *);
78 static void rtl_dump_bb (basic_block
, FILE *, int, int);
79 static int rtl_verify_flow_info_1 (void);
80 static void rtl_make_forwarder_block (edge
);
82 /* Return true if NOTE is not one of the ones that must be kept paired,
83 so that we may simply delete it. */
86 can_delete_note_p (const_rtx note
)
88 switch (NOTE_KIND (note
))
90 case NOTE_INSN_DELETED
:
91 case NOTE_INSN_BASIC_BLOCK
:
92 case NOTE_INSN_EPILOGUE_BEG
:
100 /* True if a given label can be deleted. */
103 can_delete_label_p (const_rtx label
)
105 return (!LABEL_PRESERVE_P (label
)
106 /* User declared labels must be preserved. */
107 && LABEL_NAME (label
) == 0
108 && !in_expr_list_p (forced_labels
, label
));
111 /* Delete INSN by patching it out. Return the next insn. */
114 delete_insn (rtx insn
)
116 rtx next
= NEXT_INSN (insn
);
118 bool really_delete
= true;
122 /* Some labels can't be directly removed from the INSN chain, as they
123 might be references via variables, constant pool etc.
124 Convert them to the special NOTE_INSN_DELETED_LABEL note. */
125 if (! can_delete_label_p (insn
))
127 const char *name
= LABEL_NAME (insn
);
129 really_delete
= false;
130 PUT_CODE (insn
, NOTE
);
131 NOTE_KIND (insn
) = NOTE_INSN_DELETED_LABEL
;
132 NOTE_DELETED_LABEL_NAME (insn
) = name
;
135 remove_node_from_expr_list (insn
, &nonlocal_goto_handler_labels
);
140 /* If this insn has already been deleted, something is very wrong. */
141 gcc_assert (!INSN_DELETED_P (insn
));
143 INSN_DELETED_P (insn
) = 1;
146 /* If deleting a jump, decrement the use count of the label. Deleting
147 the label itself should happen in the normal course of block merging. */
150 if (JUMP_LABEL (insn
)
151 && LABEL_P (JUMP_LABEL (insn
)))
152 LABEL_NUSES (JUMP_LABEL (insn
))--;
154 /* If there are more targets, remove them too. */
156 = find_reg_note (insn
, REG_LABEL_TARGET
, NULL_RTX
)) != NULL_RTX
157 && LABEL_P (XEXP (note
, 0)))
159 LABEL_NUSES (XEXP (note
, 0))--;
160 remove_note (insn
, note
);
164 /* Also if deleting any insn that references a label as an operand. */
165 while ((note
= find_reg_note (insn
, REG_LABEL_OPERAND
, NULL_RTX
)) != NULL_RTX
166 && LABEL_P (XEXP (note
, 0)))
168 LABEL_NUSES (XEXP (note
, 0))--;
169 remove_note (insn
, note
);
172 if (JUMP_TABLE_DATA_P (insn
))
174 rtx pat
= PATTERN (insn
);
175 int diff_vec_p
= GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
;
176 int len
= XVECLEN (pat
, diff_vec_p
);
179 for (i
= 0; i
< len
; i
++)
181 rtx label
= XEXP (XVECEXP (pat
, diff_vec_p
, i
), 0);
183 /* When deleting code in bulk (e.g. removing many unreachable
184 blocks) we can delete a label that's a target of the vector
185 before deleting the vector itself. */
187 LABEL_NUSES (label
)--;
194 /* Like delete_insn but also purge dead edges from BB. */
197 delete_insn_and_edges (rtx insn
)
203 && BLOCK_FOR_INSN (insn
)
204 && BB_END (BLOCK_FOR_INSN (insn
)) == insn
)
206 x
= delete_insn (insn
);
208 purge_dead_edges (BLOCK_FOR_INSN (insn
));
212 /* Unlink a chain of insns between START and FINISH, leaving notes
213 that must be paired. If CLEAR_BB is true, we set bb field for
214 insns that cannot be removed to NULL. */
217 delete_insn_chain (rtx start
, rtx finish
, bool clear_bb
)
221 /* Unchain the insns one by one. It would be quicker to delete all of these
222 with a single unchaining, rather than one at a time, but we need to keep
226 next
= NEXT_INSN (start
);
227 if (NOTE_P (start
) && !can_delete_note_p (start
))
230 next
= delete_insn (start
);
232 if (clear_bb
&& !INSN_DELETED_P (start
))
233 set_block_for_insn (start
, NULL
);
241 /* Create a new basic block consisting of the instructions between HEAD and END
242 inclusive. This function is designed to allow fast BB construction - reuses
243 the note and basic block struct in BB_NOTE, if any and do not grow
244 BASIC_BLOCK chain and should be used directly only by CFG construction code.
245 END can be NULL in to create new empty basic block before HEAD. Both END
246 and HEAD can be NULL to create basic block at the end of INSN chain.
247 AFTER is the basic block we should be put after. */
250 create_basic_block_structure (rtx head
, rtx end
, rtx bb_note
, basic_block after
)
255 && (bb
= NOTE_BASIC_BLOCK (bb_note
)) != NULL
258 /* If we found an existing note, thread it back onto the chain. */
266 after
= PREV_INSN (head
);
270 if (after
!= bb_note
&& NEXT_INSN (after
) != bb_note
)
271 reorder_insns_nobb (bb_note
, bb_note
, after
);
275 /* Otherwise we must create a note and a basic block structure. */
279 init_rtl_bb_info (bb
);
282 = emit_note_after (NOTE_INSN_BASIC_BLOCK
, get_last_insn ());
283 else if (LABEL_P (head
) && end
)
285 bb_note
= emit_note_after (NOTE_INSN_BASIC_BLOCK
, head
);
291 bb_note
= emit_note_before (NOTE_INSN_BASIC_BLOCK
, head
);
297 NOTE_BASIC_BLOCK (bb_note
) = bb
;
300 /* Always include the bb note in the block. */
301 if (NEXT_INSN (end
) == bb_note
)
306 bb
->index
= last_basic_block
++;
307 bb
->flags
= BB_NEW
| BB_RTL
;
308 link_block (bb
, after
);
309 SET_BASIC_BLOCK (bb
->index
, bb
);
310 df_bb_refs_record (bb
->index
, false);
311 update_bb_for_insn (bb
);
312 BB_SET_PARTITION (bb
, BB_UNPARTITIONED
);
314 /* Tag the block so that we know it has been used when considering
315 other basic block notes. */
321 /* Create new basic block consisting of instructions in between HEAD and END
322 and place it to the BB chain after block AFTER. END can be NULL in to
323 create new empty basic block before HEAD. Both END and HEAD can be NULL to
324 create basic block at the end of INSN chain. */
327 rtl_create_basic_block (void *headp
, void *endp
, basic_block after
)
329 rtx head
= (rtx
) headp
, end
= (rtx
) endp
;
332 /* Grow the basic block array if needed. */
333 if ((size_t) last_basic_block
>= VEC_length (basic_block
, basic_block_info
))
335 size_t new_size
= last_basic_block
+ (last_basic_block
+ 3) / 4;
336 VEC_safe_grow_cleared (basic_block
, gc
, basic_block_info
, new_size
);
341 bb
= create_basic_block_structure (head
, end
, NULL
, after
);
347 cfg_layout_create_basic_block (void *head
, void *end
, basic_block after
)
349 basic_block newbb
= rtl_create_basic_block (head
, end
, after
);
354 /* Delete the insns in a (non-live) block. We physically delete every
355 non-deleted-note insn, and update the flow graph appropriately.
357 Return nonzero if we deleted an exception handler. */
359 /* ??? Preserving all such notes strikes me as wrong. It would be nice
360 to post-process the stream to remove empty blocks, loops, ranges, etc. */
363 rtl_delete_block (basic_block b
)
367 /* If the head of this block is a CODE_LABEL, then it might be the
368 label for an exception handler which can't be reached. We need
369 to remove the label from the exception_handler_label list. */
372 end
= get_last_bb_insn (b
);
374 /* Selectively delete the entire chain. */
376 delete_insn_chain (insn
, end
, true);
380 fprintf (dump_file
, "deleting block %d\n", b
->index
);
381 df_bb_delete (b
->index
);
384 /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */
387 compute_bb_for_insn (void)
393 rtx end
= BB_END (bb
);
396 for (insn
= BB_HEAD (bb
); ; insn
= NEXT_INSN (insn
))
398 BLOCK_FOR_INSN (insn
) = bb
;
405 /* Release the basic_block_for_insn array. */
408 free_bb_for_insn (void)
411 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
412 if (!BARRIER_P (insn
))
413 BLOCK_FOR_INSN (insn
) = NULL
;
418 rest_of_pass_free_cfg (void)
421 /* The resource.c machinery uses DF but the CFG isn't guaranteed to be
422 valid at that point so it would be too late to call df_analyze. */
423 if (optimize
> 0 && flag_delayed_branch
)
425 df_note_add_problem ();
434 struct rtl_opt_pass pass_free_cfg
=
438 "*free_cfg", /* name */
440 rest_of_pass_free_cfg
, /* execute */
443 0, /* static_pass_number */
445 0, /* properties_required */
446 0, /* properties_provided */
447 PROP_cfg
, /* properties_destroyed */
448 0, /* todo_flags_start */
449 0, /* todo_flags_finish */
453 /* Return RTX to emit after when we want to emit code on the entry of function. */
455 entry_of_function (void)
457 return (n_basic_blocks
> NUM_FIXED_BLOCKS
?
458 BB_HEAD (ENTRY_BLOCK_PTR
->next_bb
) : get_insns ());
461 /* Emit INSN at the entry point of the function, ensuring that it is only
462 executed once per function. */
464 emit_insn_at_entry (rtx insn
)
466 edge_iterator ei
= ei_start (ENTRY_BLOCK_PTR
->succs
);
467 edge e
= ei_safe_edge (ei
);
468 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
470 insert_insn_on_edge (insn
, e
);
471 commit_edge_insertions ();
474 /* Update BLOCK_FOR_INSN of insns between BEGIN and END
475 (or BARRIER if found) and notify df of the bb change.
476 The insn chain range is inclusive
477 (i.e. both BEGIN and END will be updated. */
480 update_bb_for_insn_chain (rtx begin
, rtx end
, basic_block bb
)
484 end
= NEXT_INSN (end
);
485 for (insn
= begin
; insn
!= end
; insn
= NEXT_INSN (insn
))
486 if (!BARRIER_P (insn
))
487 df_insn_change_bb (insn
, bb
);
490 /* Update BLOCK_FOR_INSN of insns in BB to BB,
491 and notify df of the change. */
494 update_bb_for_insn (basic_block bb
)
496 update_bb_for_insn_chain (BB_HEAD (bb
), BB_END (bb
), bb
);
500 /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK
501 note associated with the BLOCK. */
504 first_insn_after_basic_block_note (basic_block block
)
508 /* Get the first instruction in the block. */
509 insn
= BB_HEAD (block
);
511 if (insn
== NULL_RTX
)
514 insn
= NEXT_INSN (insn
);
515 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn
));
517 return NEXT_INSN (insn
);
520 /* Creates a new basic block just after basic block B by splitting
521 everything after specified instruction I. */
524 rtl_split_block (basic_block bb
, void *insnp
)
527 rtx insn
= (rtx
) insnp
;
533 insn
= first_insn_after_basic_block_note (bb
);
539 insn
= PREV_INSN (insn
);
541 /* If the block contains only debug insns, insn would have
542 been NULL in a non-debug compilation, and then we'd end
543 up emitting a DELETED note. For -fcompare-debug
544 stability, emit the note too. */
545 if (insn
!= BB_END (bb
)
546 && DEBUG_INSN_P (next
)
547 && DEBUG_INSN_P (BB_END (bb
)))
549 while (next
!= BB_END (bb
) && DEBUG_INSN_P (next
))
550 next
= NEXT_INSN (next
);
552 if (next
== BB_END (bb
))
553 emit_note_after (NOTE_INSN_DELETED
, next
);
557 insn
= get_last_insn ();
560 /* We probably should check type of the insn so that we do not create
561 inconsistent cfg. It is checked in verify_flow_info anyway, so do not
563 if (insn
== BB_END (bb
))
564 emit_note_after (NOTE_INSN_DELETED
, insn
);
566 /* Create the new basic block. */
567 new_bb
= create_basic_block (NEXT_INSN (insn
), BB_END (bb
), bb
);
568 BB_COPY_PARTITION (new_bb
, bb
);
571 /* Redirect the outgoing edges. */
572 new_bb
->succs
= bb
->succs
;
574 FOR_EACH_EDGE (e
, ei
, new_bb
->succs
)
577 /* The new block starts off being dirty. */
578 df_set_bb_dirty (bb
);
582 /* Blocks A and B are to be merged into a single block A. The insns
583 are already contiguous. */
586 rtl_merge_blocks (basic_block a
, basic_block b
)
588 rtx b_head
= BB_HEAD (b
), b_end
= BB_END (b
), a_end
= BB_END (a
);
589 rtx del_first
= NULL_RTX
, del_last
= NULL_RTX
;
590 rtx b_debug_start
= b_end
, b_debug_end
= b_end
;
594 fprintf (dump_file
, "merging block %d into block %d\n", b
->index
, a
->index
);
596 while (DEBUG_INSN_P (b_end
))
597 b_end
= PREV_INSN (b_debug_start
= b_end
);
599 /* If there was a CODE_LABEL beginning B, delete it. */
600 if (LABEL_P (b_head
))
602 /* Detect basic blocks with nothing but a label. This can happen
603 in particular at the end of a function. */
607 del_first
= del_last
= b_head
;
608 b_head
= NEXT_INSN (b_head
);
611 /* Delete the basic block note and handle blocks containing just that
613 if (NOTE_INSN_BASIC_BLOCK_P (b_head
))
621 b_head
= NEXT_INSN (b_head
);
624 /* If there was a jump out of A, delete it. */
629 for (prev
= PREV_INSN (a_end
); ; prev
= PREV_INSN (prev
))
631 || NOTE_INSN_BASIC_BLOCK_P (prev
)
632 || prev
== BB_HEAD (a
))
638 /* If this was a conditional jump, we need to also delete
639 the insn that set cc0. */
640 if (only_sets_cc0_p (prev
))
644 prev
= prev_nonnote_insn (prev
);
651 a_end
= PREV_INSN (del_first
);
653 else if (BARRIER_P (NEXT_INSN (a_end
)))
654 del_first
= NEXT_INSN (a_end
);
656 /* Delete everything marked above as well as crap that might be
657 hanging out between the two blocks. */
659 delete_insn_chain (del_first
, del_last
, true);
661 /* Reassociate the insns of B with A. */
664 update_bb_for_insn_chain (a_end
, b_debug_end
, a
);
668 else if (b_end
!= b_debug_end
)
670 /* Move any deleted labels and other notes between the end of A
671 and the debug insns that make up B after the debug insns,
672 bringing the debug insns into A while keeping the notes after
674 if (NEXT_INSN (a_end
) != b_debug_start
)
675 reorder_insns_nobb (NEXT_INSN (a_end
), PREV_INSN (b_debug_start
),
677 update_bb_for_insn_chain (b_debug_start
, b_debug_end
, a
);
681 df_bb_delete (b
->index
);
686 /* Return true when block A and B can be merged. */
689 rtl_can_merge_blocks (basic_block a
, basic_block b
)
691 /* If we are partitioning hot/cold basic blocks, we don't want to
692 mess up unconditional or indirect jumps that cross between hot
695 Basic block partitioning may result in some jumps that appear to
696 be optimizable (or blocks that appear to be mergeable), but which really
697 must be left untouched (they are required to make it safely across
698 partition boundaries). See the comments at the top of
699 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
701 if (BB_PARTITION (a
) != BB_PARTITION (b
))
704 /* There must be exactly one edge in between the blocks. */
705 return (single_succ_p (a
)
706 && single_succ (a
) == b
709 /* Must be simple edge. */
710 && !(single_succ_edge (a
)->flags
& EDGE_COMPLEX
)
712 && a
!= ENTRY_BLOCK_PTR
&& b
!= EXIT_BLOCK_PTR
713 /* If the jump insn has side effects,
714 we can't kill the edge. */
715 && (!JUMP_P (BB_END (a
))
717 ? simplejump_p (BB_END (a
)) : onlyjump_p (BB_END (a
)))));
720 /* Return the label in the head of basic block BLOCK. Create one if it doesn't
724 block_label (basic_block block
)
726 if (block
== EXIT_BLOCK_PTR
)
729 if (!LABEL_P (BB_HEAD (block
)))
731 BB_HEAD (block
) = emit_label_before (gen_label_rtx (), BB_HEAD (block
));
734 return BB_HEAD (block
);
737 /* Attempt to perform edge redirection by replacing possibly complex jump
738 instruction by unconditional jump or removing jump completely. This can
739 apply only if all edges now point to the same block. The parameters and
740 return values are equivalent to redirect_edge_and_branch. */
743 try_redirect_by_replacing_jump (edge e
, basic_block target
, bool in_cfglayout
)
745 basic_block src
= e
->src
;
746 rtx insn
= BB_END (src
), kill_from
;
750 /* If we are partitioning hot/cold basic blocks, we don't want to
751 mess up unconditional or indirect jumps that cross between hot
754 Basic block partitioning may result in some jumps that appear to
755 be optimizable (or blocks that appear to be mergeable), but which really
756 must be left untouched (they are required to make it safely across
757 partition boundaries). See the comments at the top of
758 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
760 if (find_reg_note (insn
, REG_CROSSING_JUMP
, NULL_RTX
)
761 || BB_PARTITION (src
) != BB_PARTITION (target
))
764 /* We can replace or remove a complex jump only when we have exactly
765 two edges. Also, if we have exactly one outgoing edge, we can
767 if (EDGE_COUNT (src
->succs
) >= 3
768 /* Verify that all targets will be TARGET. Specifically, the
769 edge that is not E must also go to TARGET. */
770 || (EDGE_COUNT (src
->succs
) == 2
771 && EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
)->dest
!= target
))
774 if (!onlyjump_p (insn
))
776 if ((!optimize
|| reload_completed
) && tablejump_p (insn
, NULL
, NULL
))
779 /* Avoid removing branch with side effects. */
780 set
= single_set (insn
);
781 if (!set
|| side_effects_p (set
))
784 /* In case we zap a conditional jump, we'll need to kill
785 the cc0 setter too. */
788 if (reg_mentioned_p (cc0_rtx
, PATTERN (insn
))
789 && only_sets_cc0_p (PREV_INSN (insn
)))
790 kill_from
= PREV_INSN (insn
);
793 /* See if we can create the fallthru edge. */
794 if (in_cfglayout
|| can_fallthru (src
, target
))
797 fprintf (dump_file
, "Removing jump %i.\n", INSN_UID (insn
));
800 /* Selectively unlink whole insn chain. */
803 rtx insn
= src
->il
.rtl
->footer
;
805 delete_insn_chain (kill_from
, BB_END (src
), false);
807 /* Remove barriers but keep jumptables. */
810 if (BARRIER_P (insn
))
812 if (PREV_INSN (insn
))
813 NEXT_INSN (PREV_INSN (insn
)) = NEXT_INSN (insn
);
815 src
->il
.rtl
->footer
= NEXT_INSN (insn
);
816 if (NEXT_INSN (insn
))
817 PREV_INSN (NEXT_INSN (insn
)) = PREV_INSN (insn
);
821 insn
= NEXT_INSN (insn
);
825 delete_insn_chain (kill_from
, PREV_INSN (BB_HEAD (target
)),
829 /* If this already is simplejump, redirect it. */
830 else if (simplejump_p (insn
))
832 if (e
->dest
== target
)
835 fprintf (dump_file
, "Redirecting jump %i from %i to %i.\n",
836 INSN_UID (insn
), e
->dest
->index
, target
->index
);
837 if (!redirect_jump (insn
, block_label (target
), 0))
839 gcc_assert (target
== EXIT_BLOCK_PTR
);
844 /* Cannot do anything for target exit block. */
845 else if (target
== EXIT_BLOCK_PTR
)
848 /* Or replace possibly complicated jump insn by simple jump insn. */
851 rtx target_label
= block_label (target
);
852 rtx barrier
, label
, table
;
854 emit_jump_insn_after_noloc (gen_jump (target_label
), insn
);
855 JUMP_LABEL (BB_END (src
)) = target_label
;
856 LABEL_NUSES (target_label
)++;
858 fprintf (dump_file
, "Replacing insn %i by jump %i\n",
859 INSN_UID (insn
), INSN_UID (BB_END (src
)));
862 delete_insn_chain (kill_from
, insn
, false);
864 /* Recognize a tablejump that we are converting to a
865 simple jump and remove its associated CODE_LABEL
866 and ADDR_VEC or ADDR_DIFF_VEC. */
867 if (tablejump_p (insn
, &label
, &table
))
868 delete_insn_chain (label
, table
, false);
870 barrier
= next_nonnote_insn (BB_END (src
));
871 if (!barrier
|| !BARRIER_P (barrier
))
872 emit_barrier_after (BB_END (src
));
875 if (barrier
!= NEXT_INSN (BB_END (src
)))
877 /* Move the jump before barrier so that the notes
878 which originally were or were created before jump table are
879 inside the basic block. */
880 rtx new_insn
= BB_END (src
);
882 update_bb_for_insn_chain (NEXT_INSN (BB_END (src
)),
883 PREV_INSN (barrier
), src
);
885 NEXT_INSN (PREV_INSN (new_insn
)) = NEXT_INSN (new_insn
);
886 PREV_INSN (NEXT_INSN (new_insn
)) = PREV_INSN (new_insn
);
888 NEXT_INSN (new_insn
) = barrier
;
889 NEXT_INSN (PREV_INSN (barrier
)) = new_insn
;
891 PREV_INSN (new_insn
) = PREV_INSN (barrier
);
892 PREV_INSN (barrier
) = new_insn
;
897 /* Keep only one edge out and set proper flags. */
898 if (!single_succ_p (src
))
900 gcc_assert (single_succ_p (src
));
902 e
= single_succ_edge (src
);
904 e
->flags
= EDGE_FALLTHRU
;
908 e
->probability
= REG_BR_PROB_BASE
;
909 e
->count
= src
->count
;
911 if (e
->dest
!= target
)
912 redirect_edge_succ (e
, target
);
916 /* Subroutine of redirect_branch_edge that tries to patch the jump
917 instruction INSN so that it reaches block NEW. Do this
918 only when it originally reached block OLD. Return true if this
919 worked or the original target wasn't OLD, return false if redirection
923 patch_jump_insn (rtx insn
, rtx old_label
, basic_block new_bb
)
926 /* Recognize a tablejump and adjust all matching cases. */
927 if (tablejump_p (insn
, NULL
, &tmp
))
931 rtx new_label
= block_label (new_bb
);
933 if (new_bb
== EXIT_BLOCK_PTR
)
935 if (GET_CODE (PATTERN (tmp
)) == ADDR_VEC
)
936 vec
= XVEC (PATTERN (tmp
), 0);
938 vec
= XVEC (PATTERN (tmp
), 1);
940 for (j
= GET_NUM_ELEM (vec
) - 1; j
>= 0; --j
)
941 if (XEXP (RTVEC_ELT (vec
, j
), 0) == old_label
)
943 RTVEC_ELT (vec
, j
) = gen_rtx_LABEL_REF (Pmode
, new_label
);
944 --LABEL_NUSES (old_label
);
945 ++LABEL_NUSES (new_label
);
948 /* Handle casesi dispatch insns. */
949 if ((tmp
= single_set (insn
)) != NULL
950 && SET_DEST (tmp
) == pc_rtx
951 && GET_CODE (SET_SRC (tmp
)) == IF_THEN_ELSE
952 && GET_CODE (XEXP (SET_SRC (tmp
), 2)) == LABEL_REF
953 && XEXP (XEXP (SET_SRC (tmp
), 2), 0) == old_label
)
955 XEXP (SET_SRC (tmp
), 2) = gen_rtx_LABEL_REF (Pmode
,
957 --LABEL_NUSES (old_label
);
958 ++LABEL_NUSES (new_label
);
961 else if ((tmp
= extract_asm_operands (PATTERN (insn
))) != NULL
)
963 int i
, n
= ASM_OPERANDS_LABEL_LENGTH (tmp
);
966 if (new_bb
== EXIT_BLOCK_PTR
)
968 new_label
= block_label (new_bb
);
970 for (i
= 0; i
< n
; ++i
)
972 rtx old_ref
= ASM_OPERANDS_LABEL (tmp
, i
);
973 gcc_assert (GET_CODE (old_ref
) == LABEL_REF
);
974 if (XEXP (old_ref
, 0) == old_label
)
976 ASM_OPERANDS_LABEL (tmp
, i
)
977 = gen_rtx_LABEL_REF (Pmode
, new_label
);
978 --LABEL_NUSES (old_label
);
979 ++LABEL_NUSES (new_label
);
983 if (JUMP_LABEL (insn
) == old_label
)
985 JUMP_LABEL (insn
) = new_label
;
986 note
= find_reg_note (insn
, REG_LABEL_TARGET
, new_label
);
988 remove_note (insn
, note
);
992 note
= find_reg_note (insn
, REG_LABEL_TARGET
, old_label
);
994 remove_note (insn
, note
);
995 if (JUMP_LABEL (insn
) != new_label
996 && !find_reg_note (insn
, REG_LABEL_TARGET
, new_label
))
997 add_reg_note (insn
, REG_LABEL_TARGET
, new_label
);
999 while ((note
= find_reg_note (insn
, REG_LABEL_OPERAND
, old_label
))
1001 XEXP (note
, 0) = new_label
;
1005 /* ?? We may play the games with moving the named labels from
1006 one basic block to the other in case only one computed_jump is
1008 if (computed_jump_p (insn
)
1009 /* A return instruction can't be redirected. */
1010 || returnjump_p (insn
))
1013 if (!currently_expanding_to_rtl
|| JUMP_LABEL (insn
) == old_label
)
1015 /* If the insn doesn't go where we think, we're confused. */
1016 gcc_assert (JUMP_LABEL (insn
) == old_label
);
1018 /* If the substitution doesn't succeed, die. This can happen
1019 if the back end emitted unrecognizable instructions or if
1020 target is exit block on some arches. */
1021 if (!redirect_jump (insn
, block_label (new_bb
), 0))
1023 gcc_assert (new_bb
== EXIT_BLOCK_PTR
);
1032 /* Redirect edge representing branch of (un)conditional jump or tablejump,
1035 redirect_branch_edge (edge e
, basic_block target
)
1037 rtx old_label
= BB_HEAD (e
->dest
);
1038 basic_block src
= e
->src
;
1039 rtx insn
= BB_END (src
);
1041 /* We can only redirect non-fallthru edges of jump insn. */
1042 if (e
->flags
& EDGE_FALLTHRU
)
1044 else if (!JUMP_P (insn
) && !currently_expanding_to_rtl
)
1047 if (!currently_expanding_to_rtl
)
1049 if (!patch_jump_insn (insn
, old_label
, target
))
1053 /* When expanding this BB might actually contain multiple
1054 jumps (i.e. not yet split by find_many_sub_basic_blocks).
1055 Redirect all of those that match our label. */
1056 for (insn
= BB_HEAD (src
); insn
!= NEXT_INSN (BB_END (src
));
1057 insn
= NEXT_INSN (insn
))
1058 if (JUMP_P (insn
) && !patch_jump_insn (insn
, old_label
, target
))
1062 fprintf (dump_file
, "Edge %i->%i redirected to %i\n",
1063 e
->src
->index
, e
->dest
->index
, target
->index
);
1065 if (e
->dest
!= target
)
1066 e
= redirect_edge_succ_nodup (e
, target
);
1071 /* Attempt to change code to redirect edge E to TARGET. Don't do that on
1072 expense of adding new instructions or reordering basic blocks.
1074 Function can be also called with edge destination equivalent to the TARGET.
1075 Then it should try the simplifications and do nothing if none is possible.
1077 Return edge representing the branch if transformation succeeded. Return NULL
1079 We still return NULL in case E already destinated TARGET and we didn't
1080 managed to simplify instruction stream. */
1083 rtl_redirect_edge_and_branch (edge e
, basic_block target
)
1086 basic_block src
= e
->src
;
1088 if (e
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
1091 if (e
->dest
== target
)
1094 if ((ret
= try_redirect_by_replacing_jump (e
, target
, false)) != NULL
)
1096 df_set_bb_dirty (src
);
1100 ret
= redirect_branch_edge (e
, target
);
1104 df_set_bb_dirty (src
);
1108 /* Like force_nonfallthru below, but additionally performs redirection
1109 Used by redirect_edge_and_branch_force. */
1112 force_nonfallthru_and_redirect (edge e
, basic_block target
)
1114 basic_block jump_block
, new_bb
= NULL
, src
= e
->src
;
1117 int abnormal_edge_flags
= 0;
1120 /* In the case the last instruction is conditional jump to the next
1121 instruction, first redirect the jump itself and then continue
1122 by creating a basic block afterwards to redirect fallthru edge. */
1123 if (e
->src
!= ENTRY_BLOCK_PTR
&& e
->dest
!= EXIT_BLOCK_PTR
1124 && any_condjump_p (BB_END (e
->src
))
1125 && JUMP_LABEL (BB_END (e
->src
)) == BB_HEAD (e
->dest
))
1128 edge b
= unchecked_make_edge (e
->src
, target
, 0);
1131 redirected
= redirect_jump (BB_END (e
->src
), block_label (target
), 0);
1132 gcc_assert (redirected
);
1134 note
= find_reg_note (BB_END (e
->src
), REG_BR_PROB
, NULL_RTX
);
1137 int prob
= INTVAL (XEXP (note
, 0));
1139 b
->probability
= prob
;
1140 b
->count
= e
->count
* prob
/ REG_BR_PROB_BASE
;
1141 e
->probability
-= e
->probability
;
1142 e
->count
-= b
->count
;
1143 if (e
->probability
< 0)
1150 if (e
->flags
& EDGE_ABNORMAL
)
1152 /* Irritating special case - fallthru edge to the same block as abnormal
1154 We can't redirect abnormal edge, but we still can split the fallthru
1155 one and create separate abnormal edge to original destination.
1156 This allows bb-reorder to make such edge non-fallthru. */
1157 gcc_assert (e
->dest
== target
);
1158 abnormal_edge_flags
= e
->flags
& ~(EDGE_FALLTHRU
| EDGE_CAN_FALLTHRU
);
1159 e
->flags
&= EDGE_FALLTHRU
| EDGE_CAN_FALLTHRU
;
1163 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
1164 if (e
->src
== ENTRY_BLOCK_PTR
)
1166 /* We can't redirect the entry block. Create an empty block
1167 at the start of the function which we use to add the new
1173 basic_block bb
= create_basic_block (BB_HEAD (e
->dest
), NULL
, ENTRY_BLOCK_PTR
);
1175 /* Change the existing edge's source to be the new block, and add
1176 a new edge from the entry block to the new block. */
1178 for (ei
= ei_start (ENTRY_BLOCK_PTR
->succs
); (tmp
= ei_safe_edge (ei
)); )
1182 VEC_unordered_remove (edge
, ENTRY_BLOCK_PTR
->succs
, ei
.index
);
1192 VEC_safe_push (edge
, gc
, bb
->succs
, e
);
1193 make_single_succ_edge (ENTRY_BLOCK_PTR
, bb
, EDGE_FALLTHRU
);
1197 if (EDGE_COUNT (e
->src
->succs
) >= 2 || abnormal_edge_flags
)
1199 /* Create the new structures. */
1201 /* If the old block ended with a tablejump, skip its table
1202 by searching forward from there. Otherwise start searching
1203 forward from the last instruction of the old block. */
1204 if (!tablejump_p (BB_END (e
->src
), NULL
, ¬e
))
1205 note
= BB_END (e
->src
);
1206 note
= NEXT_INSN (note
);
1208 jump_block
= create_basic_block (note
, NULL
, e
->src
);
1209 jump_block
->count
= e
->count
;
1210 jump_block
->frequency
= EDGE_FREQUENCY (e
);
1211 jump_block
->loop_depth
= target
->loop_depth
;
1213 /* Make sure new block ends up in correct hot/cold section. */
1215 BB_COPY_PARTITION (jump_block
, e
->src
);
1216 if (flag_reorder_blocks_and_partition
1217 && targetm
.have_named_sections
1218 && JUMP_P (BB_END (jump_block
))
1219 && !any_condjump_p (BB_END (jump_block
))
1220 && (EDGE_SUCC (jump_block
, 0)->flags
& EDGE_CROSSING
))
1221 add_reg_note (BB_END (jump_block
), REG_CROSSING_JUMP
, NULL_RTX
);
1224 new_edge
= make_edge (e
->src
, jump_block
, EDGE_FALLTHRU
);
1225 new_edge
->probability
= e
->probability
;
1226 new_edge
->count
= e
->count
;
1228 /* Redirect old edge. */
1229 redirect_edge_pred (e
, jump_block
);
1230 e
->probability
= REG_BR_PROB_BASE
;
1232 new_bb
= jump_block
;
1235 jump_block
= e
->src
;
1237 if (e
->goto_locus
&& e
->goto_block
== NULL
)
1238 loc
= e
->goto_locus
;
1241 e
->flags
&= ~EDGE_FALLTHRU
;
1242 if (target
== EXIT_BLOCK_PTR
)
1245 emit_jump_insn_after_setloc (gen_return (), BB_END (jump_block
), loc
);
1252 rtx label
= block_label (target
);
1253 emit_jump_insn_after_setloc (gen_jump (label
), BB_END (jump_block
), loc
);
1254 JUMP_LABEL (BB_END (jump_block
)) = label
;
1255 LABEL_NUSES (label
)++;
1258 emit_barrier_after (BB_END (jump_block
));
1259 redirect_edge_succ_nodup (e
, target
);
1261 if (abnormal_edge_flags
)
1262 make_edge (src
, target
, abnormal_edge_flags
);
1264 df_mark_solutions_dirty ();
1268 /* Edge E is assumed to be fallthru edge. Emit needed jump instruction
1269 (and possibly create new basic block) to make edge non-fallthru.
1270 Return newly created BB or NULL if none. */
1273 force_nonfallthru (edge e
)
1275 return force_nonfallthru_and_redirect (e
, e
->dest
);
1278 /* Redirect edge even at the expense of creating new jump insn or
1279 basic block. Return new basic block if created, NULL otherwise.
1280 Conversion must be possible. */
1283 rtl_redirect_edge_and_branch_force (edge e
, basic_block target
)
1285 if (redirect_edge_and_branch (e
, target
)
1286 || e
->dest
== target
)
1289 /* In case the edge redirection failed, try to force it to be non-fallthru
1290 and redirect newly created simplejump. */
1291 df_set_bb_dirty (e
->src
);
1292 return force_nonfallthru_and_redirect (e
, target
);
1295 /* The given edge should potentially be a fallthru edge. If that is in
1296 fact true, delete the jump and barriers that are in the way. */
1299 rtl_tidy_fallthru_edge (edge e
)
1302 basic_block b
= e
->src
, c
= b
->next_bb
;
1304 /* ??? In a late-running flow pass, other folks may have deleted basic
1305 blocks by nopping out blocks, leaving multiple BARRIERs between here
1306 and the target label. They ought to be chastised and fixed.
1308 We can also wind up with a sequence of undeletable labels between
1309 one block and the next.
1311 So search through a sequence of barriers, labels, and notes for
1312 the head of block C and assert that we really do fall through. */
1314 for (q
= NEXT_INSN (BB_END (b
)); q
!= BB_HEAD (c
); q
= NEXT_INSN (q
))
1318 /* Remove what will soon cease being the jump insn from the source block.
1319 If block B consisted only of this single jump, turn it into a deleted
1324 && (any_uncondjump_p (q
)
1325 || single_succ_p (b
)))
1328 /* If this was a conditional jump, we need to also delete
1329 the insn that set cc0. */
1330 if (any_condjump_p (q
) && only_sets_cc0_p (PREV_INSN (q
)))
1337 /* Selectively unlink the sequence. */
1338 if (q
!= PREV_INSN (BB_HEAD (c
)))
1339 delete_insn_chain (NEXT_INSN (q
), PREV_INSN (BB_HEAD (c
)), false);
1341 e
->flags
|= EDGE_FALLTHRU
;
1344 /* Should move basic block BB after basic block AFTER. NIY. */
1347 rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED
,
1348 basic_block after ATTRIBUTE_UNUSED
)
1353 /* Split a (typically critical) edge. Return the new block.
1354 The edge must not be abnormal.
1356 ??? The code generally expects to be called on critical edges.
1357 The case of a block ending in an unconditional jump to a
1358 block with multiple predecessors is not handled optimally. */
1361 rtl_split_edge (edge edge_in
)
1366 /* Abnormal edges cannot be split. */
1367 gcc_assert (!(edge_in
->flags
& EDGE_ABNORMAL
));
1369 /* We are going to place the new block in front of edge destination.
1370 Avoid existence of fallthru predecessors. */
1371 if ((edge_in
->flags
& EDGE_FALLTHRU
) == 0)
1376 FOR_EACH_EDGE (e
, ei
, edge_in
->dest
->preds
)
1377 if (e
->flags
& EDGE_FALLTHRU
)
1381 force_nonfallthru (e
);
1384 /* Create the basic block note. */
1385 if (edge_in
->dest
!= EXIT_BLOCK_PTR
)
1386 before
= BB_HEAD (edge_in
->dest
);
1390 /* If this is a fall through edge to the exit block, the blocks might be
1391 not adjacent, and the right place is the after the source. */
1392 if (edge_in
->flags
& EDGE_FALLTHRU
&& edge_in
->dest
== EXIT_BLOCK_PTR
)
1394 before
= NEXT_INSN (BB_END (edge_in
->src
));
1395 bb
= create_basic_block (before
, NULL
, edge_in
->src
);
1396 BB_COPY_PARTITION (bb
, edge_in
->src
);
1400 bb
= create_basic_block (before
, NULL
, edge_in
->dest
->prev_bb
);
1401 /* ??? Why not edge_in->dest->prev_bb here? */
1402 BB_COPY_PARTITION (bb
, edge_in
->dest
);
1405 make_single_succ_edge (bb
, edge_in
->dest
, EDGE_FALLTHRU
);
1407 /* For non-fallthru edges, we must adjust the predecessor's
1408 jump instruction to target our new block. */
1409 if ((edge_in
->flags
& EDGE_FALLTHRU
) == 0)
1411 edge redirected
= redirect_edge_and_branch (edge_in
, bb
);
1412 gcc_assert (redirected
);
1416 if (edge_in
->src
!= ENTRY_BLOCK_PTR
)
1418 /* For asm goto even splitting of fallthru edge might
1419 need insn patching, as other labels might point to the
1421 rtx last
= BB_END (edge_in
->src
);
1424 && edge_in
->dest
!= EXIT_BLOCK_PTR
1425 && extract_asm_operands (PATTERN (last
)) != NULL_RTX
1426 && patch_jump_insn (last
, before
, bb
))
1427 df_set_bb_dirty (edge_in
->src
);
1429 redirect_edge_succ (edge_in
, bb
);
1435 /* Queue instructions for insertion on an edge between two basic blocks.
1436 The new instructions and basic blocks (if any) will not appear in the
1437 CFG until commit_edge_insertions is called. */
1440 insert_insn_on_edge (rtx pattern
, edge e
)
1442 /* We cannot insert instructions on an abnormal critical edge.
1443 It will be easier to find the culprit if we die now. */
1444 gcc_assert (!((e
->flags
& EDGE_ABNORMAL
) && EDGE_CRITICAL_P (e
)));
1446 if (e
->insns
.r
== NULL_RTX
)
1449 push_to_sequence (e
->insns
.r
);
1451 emit_insn (pattern
);
1453 e
->insns
.r
= get_insns ();
1457 /* Update the CFG for the instructions queued on edge E. */
1460 commit_one_edge_insertion (edge e
)
1462 rtx before
= NULL_RTX
, after
= NULL_RTX
, insns
, tmp
, last
;
1463 basic_block bb
= NULL
;
1465 /* Pull the insns off the edge now since the edge might go away. */
1467 e
->insns
.r
= NULL_RTX
;
1469 if (!before
&& !after
)
1471 /* Figure out where to put these things. If the destination has
1472 one predecessor, insert there. Except for the exit block. */
1473 if (single_pred_p (e
->dest
) && e
->dest
!= EXIT_BLOCK_PTR
)
1477 /* Get the location correct wrt a code label, and "nice" wrt
1478 a basic block note, and before everything else. */
1481 tmp
= NEXT_INSN (tmp
);
1482 if (NOTE_INSN_BASIC_BLOCK_P (tmp
))
1483 tmp
= NEXT_INSN (tmp
);
1484 if (tmp
== BB_HEAD (bb
))
1487 after
= PREV_INSN (tmp
);
1489 after
= get_last_insn ();
1492 /* If the source has one successor and the edge is not abnormal,
1493 insert there. Except for the entry block. */
1494 else if ((e
->flags
& EDGE_ABNORMAL
) == 0
1495 && single_succ_p (e
->src
)
1496 && e
->src
!= ENTRY_BLOCK_PTR
)
1500 /* It is possible to have a non-simple jump here. Consider a target
1501 where some forms of unconditional jumps clobber a register. This
1502 happens on the fr30 for example.
1504 We know this block has a single successor, so we can just emit
1505 the queued insns before the jump. */
1506 if (JUMP_P (BB_END (bb
)))
1507 before
= BB_END (bb
);
1510 /* We'd better be fallthru, or we've lost track of
1512 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
1514 after
= BB_END (bb
);
1517 /* Otherwise we must split the edge. */
1520 bb
= split_edge (e
);
1521 after
= BB_END (bb
);
1523 if (flag_reorder_blocks_and_partition
1524 && targetm
.have_named_sections
1525 && e
->src
!= ENTRY_BLOCK_PTR
1526 && BB_PARTITION (e
->src
) == BB_COLD_PARTITION
1527 && !(e
->flags
& EDGE_CROSSING
)
1529 && !any_condjump_p (after
)
1530 && (single_succ_edge (bb
)->flags
& EDGE_CROSSING
))
1531 add_reg_note (after
, REG_CROSSING_JUMP
, NULL_RTX
);
1535 /* Now that we've found the spot, do the insertion. */
1539 emit_insn_before_noloc (insns
, before
, bb
);
1540 last
= prev_nonnote_insn (before
);
1543 last
= emit_insn_after_noloc (insns
, after
, bb
);
1545 if (returnjump_p (last
))
1547 /* ??? Remove all outgoing edges from BB and add one for EXIT.
1548 This is not currently a problem because this only happens
1549 for the (single) epilogue, which already has a fallthru edge
1552 e
= single_succ_edge (bb
);
1553 gcc_assert (e
->dest
== EXIT_BLOCK_PTR
1554 && single_succ_p (bb
) && (e
->flags
& EDGE_FALLTHRU
));
1556 e
->flags
&= ~EDGE_FALLTHRU
;
1557 emit_barrier_after (last
);
1560 delete_insn (before
);
1563 gcc_assert (!JUMP_P (last
));
1565 /* Mark the basic block for find_many_sub_basic_blocks. */
1566 if (current_ir_type () != IR_RTL_CFGLAYOUT
)
1570 /* Update the CFG for all queued instructions. */
1573 commit_edge_insertions (void)
1577 bool changed
= false;
1579 #ifdef ENABLE_CHECKING
1580 verify_flow_info ();
1583 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, EXIT_BLOCK_PTR
, next_bb
)
1588 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
1592 commit_one_edge_insertion (e
);
1599 /* In the old rtl CFG API, it was OK to insert control flow on an
1600 edge, apparently? In cfglayout mode, this will *not* work, and
1601 the caller is responsible for making sure that control flow is
1602 valid at all times. */
1603 if (current_ir_type () == IR_RTL_CFGLAYOUT
)
1606 blocks
= sbitmap_alloc (last_basic_block
);
1607 sbitmap_zero (blocks
);
1611 SET_BIT (blocks
, bb
->index
);
1612 /* Check for forgotten bb->aux values before commit_edge_insertions
1614 gcc_assert (bb
->aux
== &bb
->aux
);
1617 find_many_sub_basic_blocks (blocks
);
1618 sbitmap_free (blocks
);
1622 /* Print out RTL-specific basic block information (live information
1623 at start and end). */
1626 rtl_dump_bb (basic_block bb
, FILE *outf
, int indent
, int flags ATTRIBUTE_UNUSED
)
1632 s_indent
= (char *) alloca ((size_t) indent
+ 1);
1633 memset (s_indent
, ' ', (size_t) indent
);
1634 s_indent
[indent
] = '\0';
1638 df_dump_top (bb
, outf
);
1642 for (insn
= BB_HEAD (bb
), last
= NEXT_INSN (BB_END (bb
)); insn
!= last
;
1643 insn
= NEXT_INSN (insn
))
1644 print_rtl_single (outf
, insn
);
1648 df_dump_bottom (bb
, outf
);
1654 /* Like print_rtl, but also print out live information for the start of each
1658 print_rtl_with_bb (FILE *outf
, const_rtx rtx_first
)
1662 fprintf (outf
, "(nil)\n");
1665 enum bb_state
{ NOT_IN_BB
, IN_ONE_BB
, IN_MULTIPLE_BB
};
1666 int max_uid
= get_max_uid ();
1667 basic_block
*start
= XCNEWVEC (basic_block
, max_uid
);
1668 basic_block
*end
= XCNEWVEC (basic_block
, max_uid
);
1669 enum bb_state
*in_bb_p
= XCNEWVEC (enum bb_state
, max_uid
);
1674 df_dump_start (outf
);
1676 FOR_EACH_BB_REVERSE (bb
)
1680 start
[INSN_UID (BB_HEAD (bb
))] = bb
;
1681 end
[INSN_UID (BB_END (bb
))] = bb
;
1682 for (x
= BB_HEAD (bb
); x
!= NULL_RTX
; x
= NEXT_INSN (x
))
1684 enum bb_state state
= IN_MULTIPLE_BB
;
1686 if (in_bb_p
[INSN_UID (x
)] == NOT_IN_BB
)
1688 in_bb_p
[INSN_UID (x
)] = state
;
1690 if (x
== BB_END (bb
))
1695 for (tmp_rtx
= rtx_first
; NULL
!= tmp_rtx
; tmp_rtx
= NEXT_INSN (tmp_rtx
))
1698 if ((bb
= start
[INSN_UID (tmp_rtx
)]) != NULL
)
1703 fprintf (outf
, ";; Start of basic block (");
1704 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
1705 fprintf (outf
, " %d", e
->src
->index
);
1706 fprintf (outf
, ") -> %d\n", bb
->index
);
1710 df_dump_top (bb
, outf
);
1713 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
1715 fputs (";; Pred edge ", outf
);
1716 dump_edge_info (outf
, e
, 0);
1721 if (in_bb_p
[INSN_UID (tmp_rtx
)] == NOT_IN_BB
1722 && !NOTE_P (tmp_rtx
)
1723 && !BARRIER_P (tmp_rtx
))
1724 fprintf (outf
, ";; Insn is not within a basic block\n");
1725 else if (in_bb_p
[INSN_UID (tmp_rtx
)] == IN_MULTIPLE_BB
)
1726 fprintf (outf
, ";; Insn is in multiple basic blocks\n");
1728 did_output
= print_rtl_single (outf
, tmp_rtx
);
1730 if ((bb
= end
[INSN_UID (tmp_rtx
)]) != NULL
)
1735 fprintf (outf
, ";; End of basic block %d -> (", bb
->index
);
1736 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
1737 fprintf (outf
, " %d", e
->dest
->index
);
1738 fprintf (outf
, ")\n");
1742 df_dump_bottom (bb
, outf
);
1746 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
1748 fputs (";; Succ edge ", outf
);
1749 dump_edge_info (outf
, e
, 1);
1762 if (crtl
->epilogue_delay_list
!= 0)
1764 fprintf (outf
, "\n;; Insns in epilogue delay list:\n\n");
1765 for (tmp_rtx
= crtl
->epilogue_delay_list
; tmp_rtx
!= 0;
1766 tmp_rtx
= XEXP (tmp_rtx
, 1))
1767 print_rtl_single (outf
, XEXP (tmp_rtx
, 0));
1772 update_br_prob_note (basic_block bb
)
1775 if (!JUMP_P (BB_END (bb
)))
1777 note
= find_reg_note (BB_END (bb
), REG_BR_PROB
, NULL_RTX
);
1778 if (!note
|| INTVAL (XEXP (note
, 0)) == BRANCH_EDGE (bb
)->probability
)
1780 XEXP (note
, 0) = GEN_INT (BRANCH_EDGE (bb
)->probability
);
1783 /* Get the last insn associated with block BB (that includes barriers and
1784 tablejumps after BB). */
1786 get_last_bb_insn (basic_block bb
)
1789 rtx end
= BB_END (bb
);
1791 /* Include any jump table following the basic block. */
1792 if (tablejump_p (end
, NULL
, &tmp
))
1795 /* Include any barriers that may follow the basic block. */
1796 tmp
= next_nonnote_insn_bb (end
);
1797 while (tmp
&& BARRIER_P (tmp
))
1800 tmp
= next_nonnote_insn_bb (end
);
1806 /* Verify the CFG and RTL consistency common for both underlying RTL and
1809 Currently it does following checks:
1811 - overlapping of basic blocks
1812 - insns with wrong BLOCK_FOR_INSN pointers
1813 - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note)
1814 - tails of basic blocks (ensure that boundary is necessary)
1815 - scans body of the basic block for JUMP_INSN, CODE_LABEL
1816 and NOTE_INSN_BASIC_BLOCK
1817 - verify that no fall_thru edge crosses hot/cold partition boundaries
1818 - verify that there are no pending RTL branch predictions
1820 In future it can be extended check a lot of other stuff as well
1821 (reachability of basic blocks, life information, etc. etc.). */
1824 rtl_verify_flow_info_1 (void)
1830 /* Check the general integrity of the basic blocks. */
1831 FOR_EACH_BB_REVERSE (bb
)
1835 if (!(bb
->flags
& BB_RTL
))
1837 error ("BB_RTL flag not set for block %d", bb
->index
);
1841 FOR_BB_INSNS (bb
, insn
)
1842 if (BLOCK_FOR_INSN (insn
) != bb
)
1844 error ("insn %d basic block pointer is %d, should be %d",
1846 BLOCK_FOR_INSN (insn
) ? BLOCK_FOR_INSN (insn
)->index
: 0,
1851 for (insn
= bb
->il
.rtl
->header
; insn
; insn
= NEXT_INSN (insn
))
1852 if (!BARRIER_P (insn
)
1853 && BLOCK_FOR_INSN (insn
) != NULL
)
1855 error ("insn %d in header of bb %d has non-NULL basic block",
1856 INSN_UID (insn
), bb
->index
);
1859 for (insn
= bb
->il
.rtl
->footer
; insn
; insn
= NEXT_INSN (insn
))
1860 if (!BARRIER_P (insn
)
1861 && BLOCK_FOR_INSN (insn
) != NULL
)
1863 error ("insn %d in footer of bb %d has non-NULL basic block",
1864 INSN_UID (insn
), bb
->index
);
1869 /* Now check the basic blocks (boundaries etc.) */
1870 FOR_EACH_BB_REVERSE (bb
)
1872 int n_fallthru
= 0, n_eh
= 0, n_call
= 0, n_abnormal
= 0, n_branch
= 0;
1873 edge e
, fallthru
= NULL
;
1877 if (JUMP_P (BB_END (bb
))
1878 && (note
= find_reg_note (BB_END (bb
), REG_BR_PROB
, NULL_RTX
))
1879 && EDGE_COUNT (bb
->succs
) >= 2
1880 && any_condjump_p (BB_END (bb
)))
1882 if (INTVAL (XEXP (note
, 0)) != BRANCH_EDGE (bb
)->probability
1883 && profile_status
!= PROFILE_ABSENT
)
1885 error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i",
1886 INTVAL (XEXP (note
, 0)), BRANCH_EDGE (bb
)->probability
);
1890 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
1892 if (e
->flags
& EDGE_FALLTHRU
)
1894 n_fallthru
++, fallthru
= e
;
1895 if ((e
->flags
& EDGE_CROSSING
)
1896 || (BB_PARTITION (e
->src
) != BB_PARTITION (e
->dest
)
1897 && e
->src
!= ENTRY_BLOCK_PTR
1898 && e
->dest
!= EXIT_BLOCK_PTR
))
1900 error ("fallthru edge crosses section boundary (bb %i)",
1906 if ((e
->flags
& ~(EDGE_DFS_BACK
1908 | EDGE_IRREDUCIBLE_LOOP
1910 | EDGE_CROSSING
)) == 0)
1913 if (e
->flags
& EDGE_ABNORMAL_CALL
)
1916 if (e
->flags
& EDGE_EH
)
1918 else if (e
->flags
& EDGE_ABNORMAL
)
1922 if (n_eh
&& !find_reg_note (BB_END (bb
), REG_EH_REGION
, NULL_RTX
))
1924 error ("missing REG_EH_REGION note in the end of bb %i", bb
->index
);
1929 error ("too many eh edges %i", bb
->index
);
1933 && (!JUMP_P (BB_END (bb
))
1934 || (n_branch
> 1 && (any_uncondjump_p (BB_END (bb
))
1935 || any_condjump_p (BB_END (bb
))))))
1937 error ("too many outgoing branch edges from bb %i", bb
->index
);
1940 if (n_fallthru
&& any_uncondjump_p (BB_END (bb
)))
1942 error ("fallthru edge after unconditional jump %i", bb
->index
);
1945 if (n_branch
!= 1 && any_uncondjump_p (BB_END (bb
)))
1947 error ("wrong number of branch edges after unconditional jump %i",
1951 if (n_branch
!= 1 && any_condjump_p (BB_END (bb
))
1952 && JUMP_LABEL (BB_END (bb
)) != BB_HEAD (fallthru
->dest
))
1954 error ("wrong amount of branch edges after conditional jump %i",
1958 if (n_call
&& !CALL_P (BB_END (bb
)))
1960 error ("call edges for non-call insn in bb %i", bb
->index
);
1964 && (!CALL_P (BB_END (bb
)) && n_call
!= n_abnormal
)
1965 && (!JUMP_P (BB_END (bb
))
1966 || any_condjump_p (BB_END (bb
))
1967 || any_uncondjump_p (BB_END (bb
))))
1969 error ("abnormal edges for no purpose in bb %i", bb
->index
);
1973 for (x
= BB_HEAD (bb
); x
!= NEXT_INSN (BB_END (bb
)); x
= NEXT_INSN (x
))
1974 /* We may have a barrier inside a basic block before dead code
1975 elimination. There is no BLOCK_FOR_INSN field in a barrier. */
1976 if (!BARRIER_P (x
) && BLOCK_FOR_INSN (x
) != bb
)
1979 if (! BLOCK_FOR_INSN (x
))
1981 ("insn %d inside basic block %d but block_for_insn is NULL",
1982 INSN_UID (x
), bb
->index
);
1985 ("insn %d inside basic block %d but block_for_insn is %i",
1986 INSN_UID (x
), bb
->index
, BLOCK_FOR_INSN (x
)->index
);
1991 /* OK pointers are correct. Now check the header of basic
1992 block. It ought to contain optional CODE_LABEL followed
1993 by NOTE_BASIC_BLOCK. */
1997 if (BB_END (bb
) == x
)
1999 error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
2007 if (!NOTE_INSN_BASIC_BLOCK_P (x
) || NOTE_BASIC_BLOCK (x
) != bb
)
2009 error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
2014 if (BB_END (bb
) == x
)
2015 /* Do checks for empty blocks here. */
2018 for (x
= NEXT_INSN (x
); x
; x
= NEXT_INSN (x
))
2020 if (NOTE_INSN_BASIC_BLOCK_P (x
))
2022 error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d",
2023 INSN_UID (x
), bb
->index
);
2027 if (x
== BB_END (bb
))
2030 if (control_flow_insn_p (x
))
2032 error ("in basic block %d:", bb
->index
);
2033 fatal_insn ("flow control insn inside a basic block", x
);
2042 /* Verify the CFG and RTL consistency common for both underlying RTL and
2045 Currently it does following checks:
2046 - all checks of rtl_verify_flow_info_1
2047 - test head/end pointers
2048 - check that all insns are in the basic blocks
2049 (except the switch handling code, barriers and notes)
2050 - check that all returns are followed by barriers
2051 - check that all fallthru edge points to the adjacent blocks. */
2054 rtl_verify_flow_info (void)
2057 int err
= rtl_verify_flow_info_1 ();
2059 rtx last_head
= get_last_insn ();
2060 basic_block
*bb_info
;
2062 const rtx rtx_first
= get_insns ();
2063 basic_block last_bb_seen
= ENTRY_BLOCK_PTR
, curr_bb
= NULL
;
2064 const int max_uid
= get_max_uid ();
2066 bb_info
= XCNEWVEC (basic_block
, max_uid
);
2068 FOR_EACH_BB_REVERSE (bb
)
2072 rtx head
= BB_HEAD (bb
);
2073 rtx end
= BB_END (bb
);
2075 for (x
= last_head
; x
!= NULL_RTX
; x
= PREV_INSN (x
))
2077 /* Verify the end of the basic block is in the INSN chain. */
2081 /* And that the code outside of basic blocks has NULL bb field. */
2083 && BLOCK_FOR_INSN (x
) != NULL
)
2085 error ("insn %d outside of basic blocks has non-NULL bb field",
2093 error ("end insn %d for block %d not found in the insn stream",
2094 INSN_UID (end
), bb
->index
);
2098 /* Work backwards from the end to the head of the basic block
2099 to verify the head is in the RTL chain. */
2100 for (; x
!= NULL_RTX
; x
= PREV_INSN (x
))
2102 /* While walking over the insn chain, verify insns appear
2103 in only one basic block. */
2104 if (bb_info
[INSN_UID (x
)] != NULL
)
2106 error ("insn %d is in multiple basic blocks (%d and %d)",
2107 INSN_UID (x
), bb
->index
, bb_info
[INSN_UID (x
)]->index
);
2111 bb_info
[INSN_UID (x
)] = bb
;
2118 error ("head insn %d for block %d not found in the insn stream",
2119 INSN_UID (head
), bb
->index
);
2123 last_head
= PREV_INSN (x
);
2125 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2126 if (e
->flags
& EDGE_FALLTHRU
)
2132 /* Ensure existence of barrier in BB with no fallthru edges. */
2133 for (insn
= NEXT_INSN (BB_END (bb
)); ; insn
= NEXT_INSN (insn
))
2135 if (!insn
|| NOTE_INSN_BASIC_BLOCK_P (insn
))
2137 error ("missing barrier after block %i", bb
->index
);
2141 if (BARRIER_P (insn
))
2145 else if (e
->src
!= ENTRY_BLOCK_PTR
2146 && e
->dest
!= EXIT_BLOCK_PTR
)
2150 if (e
->src
->next_bb
!= e
->dest
)
2153 ("verify_flow_info: Incorrect blocks for fallthru %i->%i",
2154 e
->src
->index
, e
->dest
->index
);
2158 for (insn
= NEXT_INSN (BB_END (e
->src
)); insn
!= BB_HEAD (e
->dest
);
2159 insn
= NEXT_INSN (insn
))
2160 if (BARRIER_P (insn
) || INSN_P (insn
))
2162 error ("verify_flow_info: Incorrect fallthru %i->%i",
2163 e
->src
->index
, e
->dest
->index
);
2164 fatal_insn ("wrong insn in the fallthru edge", insn
);
2170 for (x
= last_head
; x
!= NULL_RTX
; x
= PREV_INSN (x
))
2172 /* Check that the code before the first basic block has NULL
2175 && BLOCK_FOR_INSN (x
) != NULL
)
2177 error ("insn %d outside of basic blocks has non-NULL bb field",
2185 last_bb_seen
= ENTRY_BLOCK_PTR
;
2187 for (x
= rtx_first
; x
; x
= NEXT_INSN (x
))
2189 if (NOTE_INSN_BASIC_BLOCK_P (x
))
2191 bb
= NOTE_BASIC_BLOCK (x
);
2194 if (bb
!= last_bb_seen
->next_bb
)
2195 internal_error ("basic blocks not laid down consecutively");
2197 curr_bb
= last_bb_seen
= bb
;
2202 switch (GET_CODE (x
))
2209 /* An addr_vec is placed outside any basic block. */
2211 && JUMP_TABLE_DATA_P (NEXT_INSN (x
)))
2214 /* But in any case, non-deletable labels can appear anywhere. */
2218 fatal_insn ("insn outside basic block", x
);
2223 && returnjump_p (x
) && ! condjump_p (x
)
2224 && ! (next_nonnote_insn (x
) && BARRIER_P (next_nonnote_insn (x
))))
2225 fatal_insn ("return not followed by barrier", x
);
2226 if (curr_bb
&& x
== BB_END (curr_bb
))
2230 if (num_bb_notes
!= n_basic_blocks
- NUM_FIXED_BLOCKS
)
2232 ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)",
2233 num_bb_notes
, n_basic_blocks
);
2238 /* Assume that the preceding pass has possibly eliminated jump instructions
2239 or converted the unconditional jumps. Eliminate the edges from CFG.
2240 Return true if any edges are eliminated. */
2243 purge_dead_edges (basic_block bb
)
2246 rtx insn
= BB_END (bb
), note
;
2247 bool purged
= false;
2251 if (DEBUG_INSN_P (insn
) && insn
!= BB_HEAD (bb
))
2253 insn
= PREV_INSN (insn
);
2254 while ((DEBUG_INSN_P (insn
) || NOTE_P (insn
)) && insn
!= BB_HEAD (bb
));
2256 /* If this instruction cannot trap, remove REG_EH_REGION notes. */
2257 if (NONJUMP_INSN_P (insn
)
2258 && (note
= find_reg_note (insn
, REG_EH_REGION
, NULL
)))
2262 if (! may_trap_p (PATTERN (insn
))
2263 || ((eqnote
= find_reg_equal_equiv_note (insn
))
2264 && ! may_trap_p (XEXP (eqnote
, 0))))
2265 remove_note (insn
, note
);
2268 /* Cleanup abnormal edges caused by exceptions or non-local gotos. */
2269 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
2271 bool remove
= false;
2273 /* There are three types of edges we need to handle correctly here: EH
2274 edges, abnormal call EH edges, and abnormal call non-EH edges. The
2275 latter can appear when nonlocal gotos are used. */
2276 if (e
->flags
& EDGE_ABNORMAL_CALL
)
2280 else if (can_nonlocal_goto (insn
))
2282 else if ((e
->flags
& EDGE_EH
) && can_throw_internal (insn
))
2287 else if (e
->flags
& EDGE_EH
)
2288 remove
= !can_throw_internal (insn
);
2293 df_set_bb_dirty (bb
);
2306 /* We do care only about conditional jumps and simplejumps. */
2307 if (!any_condjump_p (insn
)
2308 && !returnjump_p (insn
)
2309 && !simplejump_p (insn
))
2312 /* Branch probability/prediction notes are defined only for
2313 condjumps. We've possibly turned condjump into simplejump. */
2314 if (simplejump_p (insn
))
2316 note
= find_reg_note (insn
, REG_BR_PROB
, NULL
);
2318 remove_note (insn
, note
);
2319 while ((note
= find_reg_note (insn
, REG_BR_PRED
, NULL
)))
2320 remove_note (insn
, note
);
2323 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
2325 /* Avoid abnormal flags to leak from computed jumps turned
2326 into simplejumps. */
2328 e
->flags
&= ~EDGE_ABNORMAL
;
2330 /* See if this edge is one we should keep. */
2331 if ((e
->flags
& EDGE_FALLTHRU
) && any_condjump_p (insn
))
2332 /* A conditional jump can fall through into the next
2333 block, so we should keep the edge. */
2338 else if (e
->dest
!= EXIT_BLOCK_PTR
2339 && BB_HEAD (e
->dest
) == JUMP_LABEL (insn
))
2340 /* If the destination block is the target of the jump,
2346 else if (e
->dest
== EXIT_BLOCK_PTR
&& returnjump_p (insn
))
2347 /* If the destination block is the exit block, and this
2348 instruction is a return, then keep the edge. */
2353 else if ((e
->flags
& EDGE_EH
) && can_throw_internal (insn
))
2354 /* Keep the edges that correspond to exceptions thrown by
2355 this instruction and rematerialize the EDGE_ABNORMAL
2356 flag we just cleared above. */
2358 e
->flags
|= EDGE_ABNORMAL
;
2363 /* We do not need this edge. */
2364 df_set_bb_dirty (bb
);
2369 if (EDGE_COUNT (bb
->succs
) == 0 || !purged
)
2373 fprintf (dump_file
, "Purged edges from bb %i\n", bb
->index
);
2378 /* Redistribute probabilities. */
2379 if (single_succ_p (bb
))
2381 single_succ_edge (bb
)->probability
= REG_BR_PROB_BASE
;
2382 single_succ_edge (bb
)->count
= bb
->count
;
2386 note
= find_reg_note (insn
, REG_BR_PROB
, NULL
);
2390 b
= BRANCH_EDGE (bb
);
2391 f
= FALLTHRU_EDGE (bb
);
2392 b
->probability
= INTVAL (XEXP (note
, 0));
2393 f
->probability
= REG_BR_PROB_BASE
- b
->probability
;
2394 b
->count
= bb
->count
* b
->probability
/ REG_BR_PROB_BASE
;
2395 f
->count
= bb
->count
* f
->probability
/ REG_BR_PROB_BASE
;
2400 else if (CALL_P (insn
) && SIBLING_CALL_P (insn
))
2402 /* First, there should not be any EH or ABCALL edges resulting
2403 from non-local gotos and the like. If there were, we shouldn't
2404 have created the sibcall in the first place. Second, there
2405 should of course never have been a fallthru edge. */
2406 gcc_assert (single_succ_p (bb
));
2407 gcc_assert (single_succ_edge (bb
)->flags
2408 == (EDGE_SIBCALL
| EDGE_ABNORMAL
));
2413 /* If we don't see a jump insn, we don't know exactly why the block would
2414 have been broken at this point. Look for a simple, non-fallthru edge,
2415 as these are only created by conditional branches. If we find such an
2416 edge we know that there used to be a jump here and can then safely
2417 remove all non-fallthru edges. */
2419 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2420 if (! (e
->flags
& (EDGE_COMPLEX
| EDGE_FALLTHRU
)))
2429 /* Remove all but the fake and fallthru edges. The fake edge may be
2430 the only successor for this block in the case of noreturn
2432 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
2434 if (!(e
->flags
& (EDGE_FALLTHRU
| EDGE_FAKE
)))
2436 df_set_bb_dirty (bb
);
2444 gcc_assert (single_succ_p (bb
));
2446 single_succ_edge (bb
)->probability
= REG_BR_PROB_BASE
;
2447 single_succ_edge (bb
)->count
= bb
->count
;
2450 fprintf (dump_file
, "Purged non-fallthru edges from bb %i\n",
2455 /* Search all basic blocks for potentially dead edges and purge them. Return
2456 true if some edge has been eliminated. */
2459 purge_all_dead_edges (void)
2466 bool purged_here
= purge_dead_edges (bb
);
2468 purged
|= purged_here
;
2474 /* Same as split_block but update cfg_layout structures. */
2477 cfg_layout_split_block (basic_block bb
, void *insnp
)
2479 rtx insn
= (rtx
) insnp
;
2480 basic_block new_bb
= rtl_split_block (bb
, insn
);
2482 new_bb
->il
.rtl
->footer
= bb
->il
.rtl
->footer
;
2483 bb
->il
.rtl
->footer
= NULL
;
2488 /* Redirect Edge to DEST. */
2490 cfg_layout_redirect_edge_and_branch (edge e
, basic_block dest
)
2492 basic_block src
= e
->src
;
2495 if (e
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
2498 if (e
->dest
== dest
)
2501 if (e
->src
!= ENTRY_BLOCK_PTR
2502 && (ret
= try_redirect_by_replacing_jump (e
, dest
, true)))
2504 df_set_bb_dirty (src
);
2508 if (e
->src
== ENTRY_BLOCK_PTR
2509 && (e
->flags
& EDGE_FALLTHRU
) && !(e
->flags
& EDGE_COMPLEX
))
2512 fprintf (dump_file
, "Redirecting entry edge from bb %i to %i\n",
2513 e
->src
->index
, dest
->index
);
2515 df_set_bb_dirty (e
->src
);
2516 redirect_edge_succ (e
, dest
);
2520 /* Redirect_edge_and_branch may decide to turn branch into fallthru edge
2521 in the case the basic block appears to be in sequence. Avoid this
2524 if (e
->flags
& EDGE_FALLTHRU
)
2526 /* Redirect any branch edges unified with the fallthru one. */
2527 if (JUMP_P (BB_END (src
))
2528 && label_is_jump_target_p (BB_HEAD (e
->dest
),
2534 fprintf (dump_file
, "Fallthru edge unified with branch "
2535 "%i->%i redirected to %i\n",
2536 e
->src
->index
, e
->dest
->index
, dest
->index
);
2537 e
->flags
&= ~EDGE_FALLTHRU
;
2538 redirected
= redirect_branch_edge (e
, dest
);
2539 gcc_assert (redirected
);
2540 e
->flags
|= EDGE_FALLTHRU
;
2541 df_set_bb_dirty (e
->src
);
2544 /* In case we are redirecting fallthru edge to the branch edge
2545 of conditional jump, remove it. */
2546 if (EDGE_COUNT (src
->succs
) == 2)
2548 /* Find the edge that is different from E. */
2549 edge s
= EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
);
2552 && any_condjump_p (BB_END (src
))
2553 && onlyjump_p (BB_END (src
)))
2554 delete_insn (BB_END (src
));
2556 ret
= redirect_edge_succ_nodup (e
, dest
);
2558 fprintf (dump_file
, "Fallthru edge %i->%i redirected to %i\n",
2559 e
->src
->index
, e
->dest
->index
, dest
->index
);
2562 ret
= redirect_branch_edge (e
, dest
);
2564 /* We don't want simplejumps in the insn stream during cfglayout. */
2565 gcc_assert (!simplejump_p (BB_END (src
)));
2567 df_set_bb_dirty (src
);
2571 /* Simple wrapper as we always can redirect fallthru edges. */
2573 cfg_layout_redirect_edge_and_branch_force (edge e
, basic_block dest
)
2575 edge redirected
= cfg_layout_redirect_edge_and_branch (e
, dest
);
2577 gcc_assert (redirected
);
2581 /* Same as delete_basic_block but update cfg_layout structures. */
2584 cfg_layout_delete_block (basic_block bb
)
2586 rtx insn
, next
, prev
= PREV_INSN (BB_HEAD (bb
)), *to
, remaints
;
2588 if (bb
->il
.rtl
->header
)
2590 next
= BB_HEAD (bb
);
2592 NEXT_INSN (prev
) = bb
->il
.rtl
->header
;
2594 set_first_insn (bb
->il
.rtl
->header
);
2595 PREV_INSN (bb
->il
.rtl
->header
) = prev
;
2596 insn
= bb
->il
.rtl
->header
;
2597 while (NEXT_INSN (insn
))
2598 insn
= NEXT_INSN (insn
);
2599 NEXT_INSN (insn
) = next
;
2600 PREV_INSN (next
) = insn
;
2602 next
= NEXT_INSN (BB_END (bb
));
2603 if (bb
->il
.rtl
->footer
)
2605 insn
= bb
->il
.rtl
->footer
;
2608 if (BARRIER_P (insn
))
2610 if (PREV_INSN (insn
))
2611 NEXT_INSN (PREV_INSN (insn
)) = NEXT_INSN (insn
);
2613 bb
->il
.rtl
->footer
= NEXT_INSN (insn
);
2614 if (NEXT_INSN (insn
))
2615 PREV_INSN (NEXT_INSN (insn
)) = PREV_INSN (insn
);
2619 insn
= NEXT_INSN (insn
);
2621 if (bb
->il
.rtl
->footer
)
2624 NEXT_INSN (insn
) = bb
->il
.rtl
->footer
;
2625 PREV_INSN (bb
->il
.rtl
->footer
) = insn
;
2626 while (NEXT_INSN (insn
))
2627 insn
= NEXT_INSN (insn
);
2628 NEXT_INSN (insn
) = next
;
2630 PREV_INSN (next
) = insn
;
2632 set_last_insn (insn
);
2635 if (bb
->next_bb
!= EXIT_BLOCK_PTR
)
2636 to
= &bb
->next_bb
->il
.rtl
->header
;
2638 to
= &cfg_layout_function_footer
;
2640 rtl_delete_block (bb
);
2643 prev
= NEXT_INSN (prev
);
2645 prev
= get_insns ();
2647 next
= PREV_INSN (next
);
2649 next
= get_last_insn ();
2651 if (next
&& NEXT_INSN (next
) != prev
)
2653 remaints
= unlink_insn_chain (prev
, next
);
2655 while (NEXT_INSN (insn
))
2656 insn
= NEXT_INSN (insn
);
2657 NEXT_INSN (insn
) = *to
;
2659 PREV_INSN (*to
) = insn
;
2664 /* Return true when blocks A and B can be safely merged. */
2667 cfg_layout_can_merge_blocks_p (basic_block a
, basic_block b
)
2669 /* If we are partitioning hot/cold basic blocks, we don't want to
2670 mess up unconditional or indirect jumps that cross between hot
2673 Basic block partitioning may result in some jumps that appear to
2674 be optimizable (or blocks that appear to be mergeable), but which really
2675 must be left untouched (they are required to make it safely across
2676 partition boundaries). See the comments at the top of
2677 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
2679 if (BB_PARTITION (a
) != BB_PARTITION (b
))
2682 /* There must be exactly one edge in between the blocks. */
2683 return (single_succ_p (a
)
2684 && single_succ (a
) == b
2685 && single_pred_p (b
) == 1
2687 /* Must be simple edge. */
2688 && !(single_succ_edge (a
)->flags
& EDGE_COMPLEX
)
2689 && a
!= ENTRY_BLOCK_PTR
&& b
!= EXIT_BLOCK_PTR
2690 /* If the jump insn has side effects, we can't kill the edge.
2691 When not optimizing, try_redirect_by_replacing_jump will
2692 not allow us to redirect an edge by replacing a table jump. */
2693 && (!JUMP_P (BB_END (a
))
2694 || ((!optimize
|| reload_completed
)
2695 ? simplejump_p (BB_END (a
)) : onlyjump_p (BB_END (a
)))));
2698 /* Merge block A and B. The blocks must be mergeable. */
2701 cfg_layout_merge_blocks (basic_block a
, basic_block b
)
2703 #ifdef ENABLE_CHECKING
2704 gcc_assert (cfg_layout_can_merge_blocks_p (a
, b
));
2708 fprintf (dump_file
, "merging block %d into block %d\n", b
->index
, a
->index
);
2710 /* If there was a CODE_LABEL beginning B, delete it. */
2711 if (LABEL_P (BB_HEAD (b
)))
2713 delete_insn (BB_HEAD (b
));
2716 /* We should have fallthru edge in a, or we can do dummy redirection to get
2718 if (JUMP_P (BB_END (a
)))
2719 try_redirect_by_replacing_jump (EDGE_SUCC (a
, 0), b
, true);
2720 gcc_assert (!JUMP_P (BB_END (a
)));
2722 /* When not optimizing and the edge is the only place in RTL which holds
2723 some unique locus, emit a nop with that locus in between. */
2724 if (!optimize
&& EDGE_SUCC (a
, 0)->goto_locus
)
2726 rtx insn
= BB_END (a
), end
= PREV_INSN (BB_HEAD (a
));
2727 int goto_locus
= EDGE_SUCC (a
, 0)->goto_locus
;
2729 while (insn
!= end
&& (!INSN_P (insn
) || INSN_LOCATOR (insn
) == 0))
2730 insn
= PREV_INSN (insn
);
2731 if (insn
!= end
&& locator_eq (INSN_LOCATOR (insn
), goto_locus
))
2736 end
= NEXT_INSN (BB_END (b
));
2737 while (insn
!= end
&& !INSN_P (insn
))
2738 insn
= NEXT_INSN (insn
);
2739 if (insn
!= end
&& INSN_LOCATOR (insn
) != 0
2740 && locator_eq (INSN_LOCATOR (insn
), goto_locus
))
2745 BB_END (a
) = emit_insn_after_noloc (gen_nop (), BB_END (a
), a
);
2746 INSN_LOCATOR (BB_END (a
)) = goto_locus
;
2750 /* Possible line number notes should appear in between. */
2751 if (b
->il
.rtl
->header
)
2753 rtx first
= BB_END (a
), last
;
2755 last
= emit_insn_after_noloc (b
->il
.rtl
->header
, BB_END (a
), a
);
2756 delete_insn_chain (NEXT_INSN (first
), last
, false);
2757 b
->il
.rtl
->header
= NULL
;
2760 /* In the case basic blocks are not adjacent, move them around. */
2761 if (NEXT_INSN (BB_END (a
)) != BB_HEAD (b
))
2763 rtx first
= unlink_insn_chain (BB_HEAD (b
), BB_END (b
));
2765 emit_insn_after_noloc (first
, BB_END (a
), a
);
2766 /* Skip possible DELETED_LABEL insn. */
2767 if (!NOTE_INSN_BASIC_BLOCK_P (first
))
2768 first
= NEXT_INSN (first
);
2769 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first
));
2772 /* emit_insn_after_noloc doesn't call df_insn_change_bb.
2773 We need to explicitly call. */
2774 update_bb_for_insn_chain (NEXT_INSN (first
),
2778 delete_insn (first
);
2780 /* Otherwise just re-associate the instructions. */
2785 update_bb_for_insn_chain (BB_HEAD (b
), BB_END (b
), a
);
2788 /* Skip possible DELETED_LABEL insn. */
2789 if (!NOTE_INSN_BASIC_BLOCK_P (insn
))
2790 insn
= NEXT_INSN (insn
);
2791 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn
));
2793 BB_END (a
) = BB_END (b
);
2797 df_bb_delete (b
->index
);
2799 /* Possible tablejumps and barriers should appear after the block. */
2800 if (b
->il
.rtl
->footer
)
2802 if (!a
->il
.rtl
->footer
)
2803 a
->il
.rtl
->footer
= b
->il
.rtl
->footer
;
2806 rtx last
= a
->il
.rtl
->footer
;
2808 while (NEXT_INSN (last
))
2809 last
= NEXT_INSN (last
);
2810 NEXT_INSN (last
) = b
->il
.rtl
->footer
;
2811 PREV_INSN (b
->il
.rtl
->footer
) = last
;
2813 b
->il
.rtl
->footer
= NULL
;
2817 fprintf (dump_file
, "Merged blocks %d and %d.\n",
2818 a
->index
, b
->index
);
2824 cfg_layout_split_edge (edge e
)
2826 basic_block new_bb
=
2827 create_basic_block (e
->src
!= ENTRY_BLOCK_PTR
2828 ? NEXT_INSN (BB_END (e
->src
)) : get_insns (),
2831 if (e
->dest
== EXIT_BLOCK_PTR
)
2832 BB_COPY_PARTITION (new_bb
, e
->src
);
2834 BB_COPY_PARTITION (new_bb
, e
->dest
);
2835 make_edge (new_bb
, e
->dest
, EDGE_FALLTHRU
);
2836 redirect_edge_and_branch_force (e
, new_bb
);
2841 /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */
2844 rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED
)
2848 /* Return 1 if BB ends with a call, possibly followed by some
2849 instructions that must stay with the call, 0 otherwise. */
2852 rtl_block_ends_with_call_p (basic_block bb
)
2854 rtx insn
= BB_END (bb
);
2856 while (!CALL_P (insn
)
2857 && insn
!= BB_HEAD (bb
)
2858 && (keep_with_call_p (insn
)
2860 || DEBUG_INSN_P (insn
)))
2861 insn
= PREV_INSN (insn
);
2862 return (CALL_P (insn
));
2865 /* Return 1 if BB ends with a conditional branch, 0 otherwise. */
2868 rtl_block_ends_with_condjump_p (const_basic_block bb
)
2870 return any_condjump_p (BB_END (bb
));
2873 /* Return true if we need to add fake edge to exit.
2874 Helper function for rtl_flow_call_edges_add. */
2877 need_fake_edge_p (const_rtx insn
)
2883 && !SIBLING_CALL_P (insn
)
2884 && !find_reg_note (insn
, REG_NORETURN
, NULL
)
2885 && !(RTL_CONST_OR_PURE_CALL_P (insn
))))
2888 return ((GET_CODE (PATTERN (insn
)) == ASM_OPERANDS
2889 && MEM_VOLATILE_P (PATTERN (insn
)))
2890 || (GET_CODE (PATTERN (insn
)) == PARALLEL
2891 && asm_noperands (insn
) != -1
2892 && MEM_VOLATILE_P (XVECEXP (PATTERN (insn
), 0, 0)))
2893 || GET_CODE (PATTERN (insn
)) == ASM_INPUT
);
2896 /* Add fake edges to the function exit for any non constant and non noreturn
2897 calls, volatile inline assembly in the bitmap of blocks specified by
2898 BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks
2901 The goal is to expose cases in which entering a basic block does not imply
2902 that all subsequent instructions must be executed. */
2905 rtl_flow_call_edges_add (sbitmap blocks
)
2908 int blocks_split
= 0;
2909 int last_bb
= last_basic_block
;
2910 bool check_last_block
= false;
2912 if (n_basic_blocks
== NUM_FIXED_BLOCKS
)
2916 check_last_block
= true;
2918 check_last_block
= TEST_BIT (blocks
, EXIT_BLOCK_PTR
->prev_bb
->index
);
2920 /* In the last basic block, before epilogue generation, there will be
2921 a fallthru edge to EXIT. Special care is required if the last insn
2922 of the last basic block is a call because make_edge folds duplicate
2923 edges, which would result in the fallthru edge also being marked
2924 fake, which would result in the fallthru edge being removed by
2925 remove_fake_edges, which would result in an invalid CFG.
2927 Moreover, we can't elide the outgoing fake edge, since the block
2928 profiler needs to take this into account in order to solve the minimal
2929 spanning tree in the case that the call doesn't return.
2931 Handle this by adding a dummy instruction in a new last basic block. */
2932 if (check_last_block
)
2934 basic_block bb
= EXIT_BLOCK_PTR
->prev_bb
;
2935 rtx insn
= BB_END (bb
);
2937 /* Back up past insns that must be kept in the same block as a call. */
2938 while (insn
!= BB_HEAD (bb
)
2939 && keep_with_call_p (insn
))
2940 insn
= PREV_INSN (insn
);
2942 if (need_fake_edge_p (insn
))
2946 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
2949 insert_insn_on_edge (gen_use (const0_rtx
), e
);
2950 commit_edge_insertions ();
2955 /* Now add fake edges to the function exit for any non constant
2956 calls since there is no way that we can determine if they will
2959 for (i
= NUM_FIXED_BLOCKS
; i
< last_bb
; i
++)
2961 basic_block bb
= BASIC_BLOCK (i
);
2968 if (blocks
&& !TEST_BIT (blocks
, i
))
2971 for (insn
= BB_END (bb
); ; insn
= prev_insn
)
2973 prev_insn
= PREV_INSN (insn
);
2974 if (need_fake_edge_p (insn
))
2977 rtx split_at_insn
= insn
;
2979 /* Don't split the block between a call and an insn that should
2980 remain in the same block as the call. */
2982 while (split_at_insn
!= BB_END (bb
)
2983 && keep_with_call_p (NEXT_INSN (split_at_insn
)))
2984 split_at_insn
= NEXT_INSN (split_at_insn
);
2986 /* The handling above of the final block before the epilogue
2987 should be enough to verify that there is no edge to the exit
2988 block in CFG already. Calling make_edge in such case would
2989 cause us to mark that edge as fake and remove it later. */
2991 #ifdef ENABLE_CHECKING
2992 if (split_at_insn
== BB_END (bb
))
2994 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
2995 gcc_assert (e
== NULL
);
2999 /* Note that the following may create a new basic block
3000 and renumber the existing basic blocks. */
3001 if (split_at_insn
!= BB_END (bb
))
3003 e
= split_block (bb
, split_at_insn
);
3008 make_edge (bb
, EXIT_BLOCK_PTR
, EDGE_FAKE
);
3011 if (insn
== BB_HEAD (bb
))
3017 verify_flow_info ();
3019 return blocks_split
;
3022 /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is
3023 the conditional branch target, SECOND_HEAD should be the fall-thru
3024 there is no need to handle this here the loop versioning code handles
3025 this. the reason for SECON_HEAD is that it is needed for condition
3026 in trees, and this should be of the same type since it is a hook. */
3028 rtl_lv_add_condition_to_bb (basic_block first_head
,
3029 basic_block second_head ATTRIBUTE_UNUSED
,
3030 basic_block cond_bb
, void *comp_rtx
)
3032 rtx label
, seq
, jump
;
3033 rtx op0
= XEXP ((rtx
)comp_rtx
, 0);
3034 rtx op1
= XEXP ((rtx
)comp_rtx
, 1);
3035 enum rtx_code comp
= GET_CODE ((rtx
)comp_rtx
);
3036 enum machine_mode mode
;
3039 label
= block_label (first_head
);
3040 mode
= GET_MODE (op0
);
3041 if (mode
== VOIDmode
)
3042 mode
= GET_MODE (op1
);
3045 op0
= force_operand (op0
, NULL_RTX
);
3046 op1
= force_operand (op1
, NULL_RTX
);
3047 do_compare_rtx_and_jump (op0
, op1
, comp
, 0,
3048 mode
, NULL_RTX
, NULL_RTX
, label
, -1);
3049 jump
= get_last_insn ();
3050 JUMP_LABEL (jump
) = label
;
3051 LABEL_NUSES (label
)++;
3055 /* Add the new cond , in the new head. */
3056 emit_insn_after(seq
, BB_END(cond_bb
));
3060 /* Given a block B with unconditional branch at its end, get the
3061 store the return the branch edge and the fall-thru edge in
3062 BRANCH_EDGE and FALLTHRU_EDGE respectively. */
3064 rtl_extract_cond_bb_edges (basic_block b
, edge
*branch_edge
,
3065 edge
*fallthru_edge
)
3067 edge e
= EDGE_SUCC (b
, 0);
3069 if (e
->flags
& EDGE_FALLTHRU
)
3072 *branch_edge
= EDGE_SUCC (b
, 1);
3077 *fallthru_edge
= EDGE_SUCC (b
, 1);
3082 init_rtl_bb_info (basic_block bb
)
3084 gcc_assert (!bb
->il
.rtl
);
3085 bb
->il
.rtl
= ggc_alloc_cleared_rtl_bb_info ();
3089 /* Add EXPR to the end of basic block BB. */
3092 insert_insn_end_bb_new (rtx pat
, basic_block bb
)
3094 rtx insn
= BB_END (bb
);
3098 while (NEXT_INSN (pat_end
) != NULL_RTX
)
3099 pat_end
= NEXT_INSN (pat_end
);
3101 /* If the last insn is a jump, insert EXPR in front [taking care to
3102 handle cc0, etc. properly]. Similarly we need to care trapping
3103 instructions in presence of non-call exceptions. */
3106 || (NONJUMP_INSN_P (insn
)
3107 && (!single_succ_p (bb
)
3108 || single_succ_edge (bb
)->flags
& EDGE_ABNORMAL
)))
3113 /* If this is a jump table, then we can't insert stuff here. Since
3114 we know the previous real insn must be the tablejump, we insert
3115 the new instruction just before the tablejump. */
3116 if (GET_CODE (PATTERN (insn
)) == ADDR_VEC
3117 || GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
)
3118 insn
= prev_real_insn (insn
);
3121 /* FIXME: 'twould be nice to call prev_cc0_setter here but it aborts
3122 if cc0 isn't set. */
3123 note
= find_reg_note (insn
, REG_CC_SETTER
, NULL_RTX
);
3125 insn
= XEXP (note
, 0);
3128 rtx maybe_cc0_setter
= prev_nonnote_insn (insn
);
3129 if (maybe_cc0_setter
3130 && INSN_P (maybe_cc0_setter
)
3131 && sets_cc0_p (PATTERN (maybe_cc0_setter
)))
3132 insn
= maybe_cc0_setter
;
3135 /* FIXME: What if something in cc0/jump uses value set in new
3137 new_insn
= emit_insn_before_noloc (pat
, insn
, bb
);
3140 /* Likewise if the last insn is a call, as will happen in the presence
3141 of exception handling. */
3142 else if (CALL_P (insn
)
3143 && (!single_succ_p (bb
)
3144 || single_succ_edge (bb
)->flags
& EDGE_ABNORMAL
))
3146 /* Keeping in mind targets with small register classes and parameters
3147 in registers, we search backward and place the instructions before
3148 the first parameter is loaded. Do this for everyone for consistency
3149 and a presumption that we'll get better code elsewhere as well. */
3151 /* Since different machines initialize their parameter registers
3152 in different orders, assume nothing. Collect the set of all
3153 parameter registers. */
3154 insn
= find_first_parameter_load (insn
, BB_HEAD (bb
));
3156 /* If we found all the parameter loads, then we want to insert
3157 before the first parameter load.
3159 If we did not find all the parameter loads, then we might have
3160 stopped on the head of the block, which could be a CODE_LABEL.
3161 If we inserted before the CODE_LABEL, then we would be putting
3162 the insn in the wrong basic block. In that case, put the insn
3163 after the CODE_LABEL. Also, respect NOTE_INSN_BASIC_BLOCK. */
3164 while (LABEL_P (insn
)
3165 || NOTE_INSN_BASIC_BLOCK_P (insn
))
3166 insn
= NEXT_INSN (insn
);
3168 new_insn
= emit_insn_before_noloc (pat
, insn
, bb
);
3171 new_insn
= emit_insn_after_noloc (pat
, insn
, bb
);
3176 /* Returns true if it is possible to remove edge E by redirecting
3177 it to the destination of the other edge from E->src. */
3180 rtl_can_remove_branch_p (const_edge e
)
3182 const_basic_block src
= e
->src
;
3183 const_basic_block target
= EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
)->dest
;
3184 const_rtx insn
= BB_END (src
), set
;
3186 /* The conditions are taken from try_redirect_by_replacing_jump. */
3187 if (target
== EXIT_BLOCK_PTR
)
3190 if (e
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
3193 if (find_reg_note (insn
, REG_CROSSING_JUMP
, NULL_RTX
)
3194 || BB_PARTITION (src
) != BB_PARTITION (target
))
3197 if (!onlyjump_p (insn
)
3198 || tablejump_p (insn
, NULL
, NULL
))
3201 set
= single_set (insn
);
3202 if (!set
|| side_effects_p (set
))
3208 /* Implementation of CFG manipulation for linearized RTL. */
3209 struct cfg_hooks rtl_cfg_hooks
= {
3211 rtl_verify_flow_info
,
3213 rtl_create_basic_block
,
3214 rtl_redirect_edge_and_branch
,
3215 rtl_redirect_edge_and_branch_force
,
3216 rtl_can_remove_branch_p
,
3219 rtl_move_block_after
,
3220 rtl_can_merge_blocks
, /* can_merge_blocks_p */
3224 NULL
, /* can_duplicate_block_p */
3225 NULL
, /* duplicate_block */
3227 rtl_make_forwarder_block
,
3228 rtl_tidy_fallthru_edge
,
3229 rtl_block_ends_with_call_p
,
3230 rtl_block_ends_with_condjump_p
,
3231 rtl_flow_call_edges_add
,
3232 NULL
, /* execute_on_growing_pred */
3233 NULL
, /* execute_on_shrinking_pred */
3234 NULL
, /* duplicate loop for trees */
3235 NULL
, /* lv_add_condition_to_bb */
3236 NULL
, /* lv_adjust_loop_header_phi*/
3237 NULL
, /* extract_cond_bb_edges */
3238 NULL
/* flush_pending_stmts */
3241 /* Implementation of CFG manipulation for cfg layout RTL, where
3242 basic block connected via fallthru edges does not have to be adjacent.
3243 This representation will hopefully become the default one in future
3244 version of the compiler. */
3246 /* We do not want to declare these functions in a header file, since they
3247 should only be used through the cfghooks interface, and we do not want to
3248 move them here since it would require also moving quite a lot of related
3249 code. They are in cfglayout.c. */
3250 extern bool cfg_layout_can_duplicate_bb_p (const_basic_block
);
3251 extern basic_block
cfg_layout_duplicate_bb (basic_block
);
3253 struct cfg_hooks cfg_layout_rtl_cfg_hooks
= {
3255 rtl_verify_flow_info_1
,
3257 cfg_layout_create_basic_block
,
3258 cfg_layout_redirect_edge_and_branch
,
3259 cfg_layout_redirect_edge_and_branch_force
,
3260 rtl_can_remove_branch_p
,
3261 cfg_layout_delete_block
,
3262 cfg_layout_split_block
,
3263 rtl_move_block_after
,
3264 cfg_layout_can_merge_blocks_p
,
3265 cfg_layout_merge_blocks
,
3268 cfg_layout_can_duplicate_bb_p
,
3269 cfg_layout_duplicate_bb
,
3270 cfg_layout_split_edge
,
3271 rtl_make_forwarder_block
,
3273 rtl_block_ends_with_call_p
,
3274 rtl_block_ends_with_condjump_p
,
3275 rtl_flow_call_edges_add
,
3276 NULL
, /* execute_on_growing_pred */
3277 NULL
, /* execute_on_shrinking_pred */
3278 duplicate_loop_to_header_edge
, /* duplicate loop for trees */
3279 rtl_lv_add_condition_to_bb
, /* lv_add_condition_to_bb */
3280 NULL
, /* lv_adjust_loop_header_phi*/
3281 rtl_extract_cond_bb_edges
, /* extract_cond_bb_edges */
3282 NULL
/* flush_pending_stmts */