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 2011, 2012 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
33 - CFG fixing after coarse manipulation
36 Functions not supposed for generic use:
37 - Infrastructure to determine quickly basic block for insn
38 compute_bb_for_insn, update_bb_for_insn, set_block_for_insn,
39 - Edge redirection with updating and optimizing of insn chain
40 block_label, tidy_fallthru_edge, force_nonfallthru */
44 #include "coretypes.h"
47 #include "hard-reg-set.h"
48 #include "basic-block.h"
54 #include "rtl-error.h"
57 #include "insn-attr.h"
58 #include "insn-config.h"
59 #include "cfglayout.h"
62 #include "common/common-target.h"
65 #include "tree-pass.h"
68 static int can_delete_note_p (const_rtx
);
69 static int can_delete_label_p (const_rtx
);
70 static basic_block
rtl_split_edge (edge
);
71 static bool rtl_move_block_after (basic_block
, basic_block
);
72 static int rtl_verify_flow_info (void);
73 static basic_block
cfg_layout_split_block (basic_block
, void *);
74 static edge
cfg_layout_redirect_edge_and_branch (edge
, basic_block
);
75 static basic_block
cfg_layout_redirect_edge_and_branch_force (edge
, basic_block
);
76 static void cfg_layout_delete_block (basic_block
);
77 static void rtl_delete_block (basic_block
);
78 static basic_block
rtl_redirect_edge_and_branch_force (edge
, basic_block
);
79 static edge
rtl_redirect_edge_and_branch (edge
, basic_block
);
80 static basic_block
rtl_split_block (basic_block
, void *);
81 static void rtl_dump_bb (basic_block
, FILE *, int, int);
82 static int rtl_verify_flow_info_1 (void);
83 static void rtl_make_forwarder_block (edge
);
85 /* Return true if NOTE is not one of the ones that must be kept paired,
86 so that we may simply delete it. */
89 can_delete_note_p (const_rtx note
)
91 switch (NOTE_KIND (note
))
93 case NOTE_INSN_DELETED
:
94 case NOTE_INSN_BASIC_BLOCK
:
95 case NOTE_INSN_EPILOGUE_BEG
:
103 /* True if a given label can be deleted. */
106 can_delete_label_p (const_rtx label
)
108 return (!LABEL_PRESERVE_P (label
)
109 /* User declared labels must be preserved. */
110 && LABEL_NAME (label
) == 0
111 && !in_expr_list_p (forced_labels
, label
));
114 /* Delete INSN by patching it out. */
117 delete_insn (rtx insn
)
120 bool really_delete
= true;
124 /* Some labels can't be directly removed from the INSN chain, as they
125 might be references via variables, constant pool etc.
126 Convert them to the special NOTE_INSN_DELETED_LABEL note. */
127 if (! can_delete_label_p (insn
))
129 const char *name
= LABEL_NAME (insn
);
130 basic_block bb
= BLOCK_FOR_INSN (insn
);
131 rtx bb_note
= NEXT_INSN (insn
);
133 really_delete
= false;
134 PUT_CODE (insn
, NOTE
);
135 NOTE_KIND (insn
) = NOTE_INSN_DELETED_LABEL
;
136 NOTE_DELETED_LABEL_NAME (insn
) = name
;
138 if (bb_note
!= NULL_RTX
&& NOTE_INSN_BASIC_BLOCK_P (bb_note
)
139 && BLOCK_FOR_INSN (bb_note
) == bb
)
141 reorder_insns_nobb (insn
, insn
, bb_note
);
142 BB_HEAD (bb
) = bb_note
;
143 if (BB_END (bb
) == bb_note
)
148 remove_node_from_expr_list (insn
, &nonlocal_goto_handler_labels
);
153 /* If this insn has already been deleted, something is very wrong. */
154 gcc_assert (!INSN_DELETED_P (insn
));
156 INSN_DELETED_P (insn
) = 1;
159 /* If deleting a jump, decrement the use count of the label. Deleting
160 the label itself should happen in the normal course of block merging. */
163 if (JUMP_LABEL (insn
)
164 && LABEL_P (JUMP_LABEL (insn
)))
165 LABEL_NUSES (JUMP_LABEL (insn
))--;
167 /* If there are more targets, remove them too. */
169 = find_reg_note (insn
, REG_LABEL_TARGET
, NULL_RTX
)) != NULL_RTX
170 && LABEL_P (XEXP (note
, 0)))
172 LABEL_NUSES (XEXP (note
, 0))--;
173 remove_note (insn
, note
);
177 /* Also if deleting any insn that references a label as an operand. */
178 while ((note
= find_reg_note (insn
, REG_LABEL_OPERAND
, NULL_RTX
)) != NULL_RTX
179 && LABEL_P (XEXP (note
, 0)))
181 LABEL_NUSES (XEXP (note
, 0))--;
182 remove_note (insn
, note
);
185 if (JUMP_TABLE_DATA_P (insn
))
187 rtx pat
= PATTERN (insn
);
188 int diff_vec_p
= GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
;
189 int len
= XVECLEN (pat
, diff_vec_p
);
192 for (i
= 0; i
< len
; i
++)
194 rtx label
= XEXP (XVECEXP (pat
, diff_vec_p
, i
), 0);
196 /* When deleting code in bulk (e.g. removing many unreachable
197 blocks) we can delete a label that's a target of the vector
198 before deleting the vector itself. */
200 LABEL_NUSES (label
)--;
205 /* Like delete_insn but also purge dead edges from BB. */
208 delete_insn_and_edges (rtx insn
)
213 && BLOCK_FOR_INSN (insn
)
214 && BB_END (BLOCK_FOR_INSN (insn
)) == insn
)
218 purge_dead_edges (BLOCK_FOR_INSN (insn
));
221 /* Unlink a chain of insns between START and FINISH, leaving notes
222 that must be paired. If CLEAR_BB is true, we set bb field for
223 insns that cannot be removed to NULL. */
226 delete_insn_chain (rtx start
, rtx finish
, bool clear_bb
)
230 /* Unchain the insns one by one. It would be quicker to delete all of these
231 with a single unchaining, rather than one at a time, but we need to keep
236 prev
= PREV_INSN (current
);
237 if (NOTE_P (current
) && !can_delete_note_p (current
))
240 delete_insn (current
);
242 if (clear_bb
&& !INSN_DELETED_P (current
))
243 set_block_for_insn (current
, NULL
);
245 if (current
== start
)
251 /* Create a new basic block consisting of the instructions between HEAD and END
252 inclusive. This function is designed to allow fast BB construction - reuses
253 the note and basic block struct in BB_NOTE, if any and do not grow
254 BASIC_BLOCK chain and should be used directly only by CFG construction code.
255 END can be NULL in to create new empty basic block before HEAD. Both END
256 and HEAD can be NULL to create basic block at the end of INSN chain.
257 AFTER is the basic block we should be put after. */
260 create_basic_block_structure (rtx head
, rtx end
, rtx bb_note
, basic_block after
)
265 && (bb
= NOTE_BASIC_BLOCK (bb_note
)) != NULL
268 /* If we found an existing note, thread it back onto the chain. */
276 after
= PREV_INSN (head
);
280 if (after
!= bb_note
&& NEXT_INSN (after
) != bb_note
)
281 reorder_insns_nobb (bb_note
, bb_note
, after
);
285 /* Otherwise we must create a note and a basic block structure. */
289 init_rtl_bb_info (bb
);
292 = emit_note_after (NOTE_INSN_BASIC_BLOCK
, get_last_insn ());
293 else if (LABEL_P (head
) && end
)
295 bb_note
= emit_note_after (NOTE_INSN_BASIC_BLOCK
, head
);
301 bb_note
= emit_note_before (NOTE_INSN_BASIC_BLOCK
, head
);
307 NOTE_BASIC_BLOCK (bb_note
) = bb
;
310 /* Always include the bb note in the block. */
311 if (NEXT_INSN (end
) == bb_note
)
316 bb
->index
= last_basic_block
++;
317 bb
->flags
= BB_NEW
| BB_RTL
;
318 link_block (bb
, after
);
319 SET_BASIC_BLOCK (bb
->index
, bb
);
320 df_bb_refs_record (bb
->index
, false);
321 update_bb_for_insn (bb
);
322 BB_SET_PARTITION (bb
, BB_UNPARTITIONED
);
324 /* Tag the block so that we know it has been used when considering
325 other basic block notes. */
331 /* Create new basic block consisting of instructions in between HEAD and END
332 and place it to the BB chain after block AFTER. END can be NULL to
333 create a new empty basic block before HEAD. Both END and HEAD can be
334 NULL to create basic block at the end of INSN chain. */
337 rtl_create_basic_block (void *headp
, void *endp
, basic_block after
)
339 rtx head
= (rtx
) headp
, end
= (rtx
) endp
;
342 /* Grow the basic block array if needed. */
343 if ((size_t) last_basic_block
>= VEC_length (basic_block
, basic_block_info
))
345 size_t new_size
= last_basic_block
+ (last_basic_block
+ 3) / 4;
346 VEC_safe_grow_cleared (basic_block
, gc
, basic_block_info
, new_size
);
351 bb
= create_basic_block_structure (head
, end
, NULL
, after
);
357 cfg_layout_create_basic_block (void *head
, void *end
, basic_block after
)
359 basic_block newbb
= rtl_create_basic_block (head
, end
, after
);
364 /* Delete the insns in a (non-live) block. We physically delete every
365 non-deleted-note insn, and update the flow graph appropriately.
367 Return nonzero if we deleted an exception handler. */
369 /* ??? Preserving all such notes strikes me as wrong. It would be nice
370 to post-process the stream to remove empty blocks, loops, ranges, etc. */
373 rtl_delete_block (basic_block b
)
377 /* If the head of this block is a CODE_LABEL, then it might be the
378 label for an exception handler which can't be reached. We need
379 to remove the label from the exception_handler_label list. */
382 end
= get_last_bb_insn (b
);
384 /* Selectively delete the entire chain. */
386 delete_insn_chain (insn
, end
, true);
390 fprintf (dump_file
, "deleting block %d\n", b
->index
);
391 df_bb_delete (b
->index
);
394 /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */
397 compute_bb_for_insn (void)
403 rtx end
= BB_END (bb
);
406 for (insn
= BB_HEAD (bb
); ; insn
= NEXT_INSN (insn
))
408 BLOCK_FOR_INSN (insn
) = bb
;
415 /* Release the basic_block_for_insn array. */
418 free_bb_for_insn (void)
421 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
422 if (!BARRIER_P (insn
))
423 BLOCK_FOR_INSN (insn
) = NULL
;
428 rest_of_pass_free_cfg (void)
431 /* The resource.c machinery uses DF but the CFG isn't guaranteed to be
432 valid at that point so it would be too late to call df_analyze. */
433 if (optimize
> 0 && flag_delayed_branch
)
435 df_note_add_problem ();
444 struct rtl_opt_pass pass_free_cfg
=
448 "*free_cfg", /* name */
450 rest_of_pass_free_cfg
, /* execute */
453 0, /* static_pass_number */
455 0, /* properties_required */
456 0, /* properties_provided */
457 PROP_cfg
, /* properties_destroyed */
458 0, /* todo_flags_start */
459 0, /* todo_flags_finish */
463 /* Return RTX to emit after when we want to emit code on the entry of function. */
465 entry_of_function (void)
467 return (n_basic_blocks
> NUM_FIXED_BLOCKS
?
468 BB_HEAD (ENTRY_BLOCK_PTR
->next_bb
) : get_insns ());
471 /* Emit INSN at the entry point of the function, ensuring that it is only
472 executed once per function. */
474 emit_insn_at_entry (rtx insn
)
476 edge_iterator ei
= ei_start (ENTRY_BLOCK_PTR
->succs
);
477 edge e
= ei_safe_edge (ei
);
478 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
480 insert_insn_on_edge (insn
, e
);
481 commit_edge_insertions ();
484 /* Update BLOCK_FOR_INSN of insns between BEGIN and END
485 (or BARRIER if found) and notify df of the bb change.
486 The insn chain range is inclusive
487 (i.e. both BEGIN and END will be updated. */
490 update_bb_for_insn_chain (rtx begin
, rtx end
, basic_block bb
)
494 end
= NEXT_INSN (end
);
495 for (insn
= begin
; insn
!= end
; insn
= NEXT_INSN (insn
))
496 if (!BARRIER_P (insn
))
497 df_insn_change_bb (insn
, bb
);
500 /* Update BLOCK_FOR_INSN of insns in BB to BB,
501 and notify df of the change. */
504 update_bb_for_insn (basic_block bb
)
506 update_bb_for_insn_chain (BB_HEAD (bb
), BB_END (bb
), bb
);
510 /* Return the NOTE_INSN_BASIC_BLOCK of BB. */
512 bb_note (basic_block bb
)
518 note
= NEXT_INSN (note
);
520 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (note
));
524 /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK
525 note associated with the BLOCK. */
528 first_insn_after_basic_block_note (basic_block block
)
532 /* Get the first instruction in the block. */
533 insn
= BB_HEAD (block
);
535 if (insn
== NULL_RTX
)
538 insn
= NEXT_INSN (insn
);
539 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn
));
541 return NEXT_INSN (insn
);
544 /* Creates a new basic block just after basic block B by splitting
545 everything after specified instruction I. */
548 rtl_split_block (basic_block bb
, void *insnp
)
551 rtx insn
= (rtx
) insnp
;
557 insn
= first_insn_after_basic_block_note (bb
);
563 insn
= PREV_INSN (insn
);
565 /* If the block contains only debug insns, insn would have
566 been NULL in a non-debug compilation, and then we'd end
567 up emitting a DELETED note. For -fcompare-debug
568 stability, emit the note too. */
569 if (insn
!= BB_END (bb
)
570 && DEBUG_INSN_P (next
)
571 && DEBUG_INSN_P (BB_END (bb
)))
573 while (next
!= BB_END (bb
) && DEBUG_INSN_P (next
))
574 next
= NEXT_INSN (next
);
576 if (next
== BB_END (bb
))
577 emit_note_after (NOTE_INSN_DELETED
, next
);
581 insn
= get_last_insn ();
584 /* We probably should check type of the insn so that we do not create
585 inconsistent cfg. It is checked in verify_flow_info anyway, so do not
587 if (insn
== BB_END (bb
))
588 emit_note_after (NOTE_INSN_DELETED
, insn
);
590 /* Create the new basic block. */
591 new_bb
= create_basic_block (NEXT_INSN (insn
), BB_END (bb
), bb
);
592 BB_COPY_PARTITION (new_bb
, bb
);
595 /* Redirect the outgoing edges. */
596 new_bb
->succs
= bb
->succs
;
598 FOR_EACH_EDGE (e
, ei
, new_bb
->succs
)
601 /* The new block starts off being dirty. */
602 df_set_bb_dirty (bb
);
606 /* Return true if the single edge between blocks A and B is the only place
607 in RTL which holds some unique locus. */
610 unique_locus_on_edge_between_p (basic_block a
, basic_block b
)
612 const int goto_locus
= EDGE_SUCC (a
, 0)->goto_locus
;
618 /* First scan block A backward. */
620 end
= PREV_INSN (BB_HEAD (a
));
621 while (insn
!= end
&& (!NONDEBUG_INSN_P (insn
) || INSN_LOCATOR (insn
) == 0))
622 insn
= PREV_INSN (insn
);
624 if (insn
!= end
&& locator_eq (INSN_LOCATOR (insn
), goto_locus
))
627 /* Then scan block B forward. */
631 end
= NEXT_INSN (BB_END (b
));
632 while (insn
!= end
&& !NONDEBUG_INSN_P (insn
))
633 insn
= NEXT_INSN (insn
);
635 if (insn
!= end
&& INSN_LOCATOR (insn
) != 0
636 && locator_eq (INSN_LOCATOR (insn
), goto_locus
))
643 /* If the single edge between blocks A and B is the only place in RTL which
644 holds some unique locus, emit a nop with that locus between the blocks. */
647 emit_nop_for_unique_locus_between (basic_block a
, basic_block b
)
649 if (!unique_locus_on_edge_between_p (a
, b
))
652 BB_END (a
) = emit_insn_after_noloc (gen_nop (), BB_END (a
), a
);
653 INSN_LOCATOR (BB_END (a
)) = EDGE_SUCC (a
, 0)->goto_locus
;
656 /* Blocks A and B are to be merged into a single block A. The insns
657 are already contiguous. */
660 rtl_merge_blocks (basic_block a
, basic_block b
)
662 rtx b_head
= BB_HEAD (b
), b_end
= BB_END (b
), a_end
= BB_END (a
);
663 rtx del_first
= NULL_RTX
, del_last
= NULL_RTX
;
664 rtx b_debug_start
= b_end
, b_debug_end
= b_end
;
665 bool forwarder_p
= (b
->flags
& BB_FORWARDER_BLOCK
) != 0;
669 fprintf (dump_file
, "Merging block %d into block %d...\n", b
->index
,
672 while (DEBUG_INSN_P (b_end
))
673 b_end
= PREV_INSN (b_debug_start
= b_end
);
675 /* If there was a CODE_LABEL beginning B, delete it. */
676 if (LABEL_P (b_head
))
678 /* Detect basic blocks with nothing but a label. This can happen
679 in particular at the end of a function. */
683 del_first
= del_last
= b_head
;
684 b_head
= NEXT_INSN (b_head
);
687 /* Delete the basic block note and handle blocks containing just that
689 if (NOTE_INSN_BASIC_BLOCK_P (b_head
))
697 b_head
= NEXT_INSN (b_head
);
700 /* If there was a jump out of A, delete it. */
705 for (prev
= PREV_INSN (a_end
); ; prev
= PREV_INSN (prev
))
707 || NOTE_INSN_BASIC_BLOCK_P (prev
)
708 || prev
== BB_HEAD (a
))
714 /* If this was a conditional jump, we need to also delete
715 the insn that set cc0. */
716 if (only_sets_cc0_p (prev
))
720 prev
= prev_nonnote_insn (prev
);
727 a_end
= PREV_INSN (del_first
);
729 else if (BARRIER_P (NEXT_INSN (a_end
)))
730 del_first
= NEXT_INSN (a_end
);
732 /* Delete everything marked above as well as crap that might be
733 hanging out between the two blocks. */
735 BB_HEAD (b
) = b_empty
? NULL_RTX
: b_head
;
736 delete_insn_chain (del_first
, del_last
, true);
738 /* When not optimizing CFG and the edge is the only place in RTL which holds
739 some unique locus, emit a nop with that locus in between. */
742 emit_nop_for_unique_locus_between (a
, b
);
746 /* Reassociate the insns of B with A. */
749 update_bb_for_insn_chain (a_end
, b_debug_end
, a
);
751 BB_END (a
) = b_debug_end
;
752 BB_HEAD (b
) = NULL_RTX
;
754 else if (b_end
!= b_debug_end
)
756 /* Move any deleted labels and other notes between the end of A
757 and the debug insns that make up B after the debug insns,
758 bringing the debug insns into A while keeping the notes after
760 if (NEXT_INSN (a_end
) != b_debug_start
)
761 reorder_insns_nobb (NEXT_INSN (a_end
), PREV_INSN (b_debug_start
),
763 update_bb_for_insn_chain (b_debug_start
, b_debug_end
, a
);
764 BB_END (a
) = b_debug_end
;
767 df_bb_delete (b
->index
);
769 /* If B was a forwarder block, propagate the locus on the edge. */
770 if (forwarder_p
&& !EDGE_SUCC (b
, 0)->goto_locus
)
771 EDGE_SUCC (b
, 0)->goto_locus
= EDGE_SUCC (a
, 0)->goto_locus
;
774 fprintf (dump_file
, "Merged blocks %d and %d.\n", a
->index
, b
->index
);
778 /* Return true when block A and B can be merged. */
781 rtl_can_merge_blocks (basic_block a
, basic_block b
)
783 /* If we are partitioning hot/cold basic blocks, we don't want to
784 mess up unconditional or indirect jumps that cross between hot
787 Basic block partitioning may result in some jumps that appear to
788 be optimizable (or blocks that appear to be mergeable), but which really
789 must be left untouched (they are required to make it safely across
790 partition boundaries). See the comments at the top of
791 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
793 if (BB_PARTITION (a
) != BB_PARTITION (b
))
796 /* Protect the loop latches. */
797 if (current_loops
&& b
->loop_father
->latch
== b
)
800 /* There must be exactly one edge in between the blocks. */
801 return (single_succ_p (a
)
802 && single_succ (a
) == b
805 /* Must be simple edge. */
806 && !(single_succ_edge (a
)->flags
& EDGE_COMPLEX
)
808 && a
!= ENTRY_BLOCK_PTR
&& b
!= EXIT_BLOCK_PTR
809 /* If the jump insn has side effects,
810 we can't kill the edge. */
811 && (!JUMP_P (BB_END (a
))
813 ? simplejump_p (BB_END (a
)) : onlyjump_p (BB_END (a
)))));
816 /* Return the label in the head of basic block BLOCK. Create one if it doesn't
820 block_label (basic_block block
)
822 if (block
== EXIT_BLOCK_PTR
)
825 if (!LABEL_P (BB_HEAD (block
)))
827 BB_HEAD (block
) = emit_label_before (gen_label_rtx (), BB_HEAD (block
));
830 return BB_HEAD (block
);
833 /* Attempt to perform edge redirection by replacing possibly complex jump
834 instruction by unconditional jump or removing jump completely. This can
835 apply only if all edges now point to the same block. The parameters and
836 return values are equivalent to redirect_edge_and_branch. */
839 try_redirect_by_replacing_jump (edge e
, basic_block target
, bool in_cfglayout
)
841 basic_block src
= e
->src
;
842 rtx insn
= BB_END (src
), kill_from
;
846 /* If we are partitioning hot/cold basic blocks, we don't want to
847 mess up unconditional or indirect jumps that cross between hot
850 Basic block partitioning may result in some jumps that appear to
851 be optimizable (or blocks that appear to be mergeable), but which really
852 must be left untouched (they are required to make it safely across
853 partition boundaries). See the comments at the top of
854 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
856 if (find_reg_note (insn
, REG_CROSSING_JUMP
, NULL_RTX
)
857 || BB_PARTITION (src
) != BB_PARTITION (target
))
860 /* We can replace or remove a complex jump only when we have exactly
861 two edges. Also, if we have exactly one outgoing edge, we can
863 if (EDGE_COUNT (src
->succs
) >= 3
864 /* Verify that all targets will be TARGET. Specifically, the
865 edge that is not E must also go to TARGET. */
866 || (EDGE_COUNT (src
->succs
) == 2
867 && EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
)->dest
!= target
))
870 if (!onlyjump_p (insn
))
872 if ((!optimize
|| reload_completed
) && tablejump_p (insn
, NULL
, NULL
))
875 /* Avoid removing branch with side effects. */
876 set
= single_set (insn
);
877 if (!set
|| side_effects_p (set
))
880 /* In case we zap a conditional jump, we'll need to kill
881 the cc0 setter too. */
884 if (reg_mentioned_p (cc0_rtx
, PATTERN (insn
))
885 && only_sets_cc0_p (PREV_INSN (insn
)))
886 kill_from
= PREV_INSN (insn
);
889 /* See if we can create the fallthru edge. */
890 if (in_cfglayout
|| can_fallthru (src
, target
))
893 fprintf (dump_file
, "Removing jump %i.\n", INSN_UID (insn
));
896 /* Selectively unlink whole insn chain. */
899 rtx insn
= BB_FOOTER (src
);
901 delete_insn_chain (kill_from
, BB_END (src
), false);
903 /* Remove barriers but keep jumptables. */
906 if (BARRIER_P (insn
))
908 if (PREV_INSN (insn
))
909 NEXT_INSN (PREV_INSN (insn
)) = NEXT_INSN (insn
);
911 BB_FOOTER (src
) = NEXT_INSN (insn
);
912 if (NEXT_INSN (insn
))
913 PREV_INSN (NEXT_INSN (insn
)) = PREV_INSN (insn
);
917 insn
= NEXT_INSN (insn
);
921 delete_insn_chain (kill_from
, PREV_INSN (BB_HEAD (target
)),
925 /* If this already is simplejump, redirect it. */
926 else if (simplejump_p (insn
))
928 if (e
->dest
== target
)
931 fprintf (dump_file
, "Redirecting jump %i from %i to %i.\n",
932 INSN_UID (insn
), e
->dest
->index
, target
->index
);
933 if (!redirect_jump (insn
, block_label (target
), 0))
935 gcc_assert (target
== EXIT_BLOCK_PTR
);
940 /* Cannot do anything for target exit block. */
941 else if (target
== EXIT_BLOCK_PTR
)
944 /* Or replace possibly complicated jump insn by simple jump insn. */
947 rtx target_label
= block_label (target
);
948 rtx barrier
, label
, table
;
950 emit_jump_insn_after_noloc (gen_jump (target_label
), insn
);
951 JUMP_LABEL (BB_END (src
)) = target_label
;
952 LABEL_NUSES (target_label
)++;
954 fprintf (dump_file
, "Replacing insn %i by jump %i\n",
955 INSN_UID (insn
), INSN_UID (BB_END (src
)));
958 delete_insn_chain (kill_from
, insn
, false);
960 /* Recognize a tablejump that we are converting to a
961 simple jump and remove its associated CODE_LABEL
962 and ADDR_VEC or ADDR_DIFF_VEC. */
963 if (tablejump_p (insn
, &label
, &table
))
964 delete_insn_chain (label
, table
, false);
966 barrier
= next_nonnote_insn (BB_END (src
));
967 if (!barrier
|| !BARRIER_P (barrier
))
968 emit_barrier_after (BB_END (src
));
971 if (barrier
!= NEXT_INSN (BB_END (src
)))
973 /* Move the jump before barrier so that the notes
974 which originally were or were created before jump table are
975 inside the basic block. */
976 rtx new_insn
= BB_END (src
);
978 update_bb_for_insn_chain (NEXT_INSN (BB_END (src
)),
979 PREV_INSN (barrier
), src
);
981 NEXT_INSN (PREV_INSN (new_insn
)) = NEXT_INSN (new_insn
);
982 PREV_INSN (NEXT_INSN (new_insn
)) = PREV_INSN (new_insn
);
984 NEXT_INSN (new_insn
) = barrier
;
985 NEXT_INSN (PREV_INSN (barrier
)) = new_insn
;
987 PREV_INSN (new_insn
) = PREV_INSN (barrier
);
988 PREV_INSN (barrier
) = new_insn
;
993 /* Keep only one edge out and set proper flags. */
994 if (!single_succ_p (src
))
996 gcc_assert (single_succ_p (src
));
998 e
= single_succ_edge (src
);
1000 e
->flags
= EDGE_FALLTHRU
;
1004 e
->probability
= REG_BR_PROB_BASE
;
1005 e
->count
= src
->count
;
1007 if (e
->dest
!= target
)
1008 redirect_edge_succ (e
, target
);
1012 /* Subroutine of redirect_branch_edge that tries to patch the jump
1013 instruction INSN so that it reaches block NEW. Do this
1014 only when it originally reached block OLD. Return true if this
1015 worked or the original target wasn't OLD, return false if redirection
1019 patch_jump_insn (rtx insn
, rtx old_label
, basic_block new_bb
)
1022 /* Recognize a tablejump and adjust all matching cases. */
1023 if (tablejump_p (insn
, NULL
, &tmp
))
1027 rtx new_label
= block_label (new_bb
);
1029 if (new_bb
== EXIT_BLOCK_PTR
)
1031 if (GET_CODE (PATTERN (tmp
)) == ADDR_VEC
)
1032 vec
= XVEC (PATTERN (tmp
), 0);
1034 vec
= XVEC (PATTERN (tmp
), 1);
1036 for (j
= GET_NUM_ELEM (vec
) - 1; j
>= 0; --j
)
1037 if (XEXP (RTVEC_ELT (vec
, j
), 0) == old_label
)
1039 RTVEC_ELT (vec
, j
) = gen_rtx_LABEL_REF (Pmode
, new_label
);
1040 --LABEL_NUSES (old_label
);
1041 ++LABEL_NUSES (new_label
);
1044 /* Handle casesi dispatch insns. */
1045 if ((tmp
= single_set (insn
)) != NULL
1046 && SET_DEST (tmp
) == pc_rtx
1047 && GET_CODE (SET_SRC (tmp
)) == IF_THEN_ELSE
1048 && GET_CODE (XEXP (SET_SRC (tmp
), 2)) == LABEL_REF
1049 && XEXP (XEXP (SET_SRC (tmp
), 2), 0) == old_label
)
1051 XEXP (SET_SRC (tmp
), 2) = gen_rtx_LABEL_REF (Pmode
,
1053 --LABEL_NUSES (old_label
);
1054 ++LABEL_NUSES (new_label
);
1057 else if ((tmp
= extract_asm_operands (PATTERN (insn
))) != NULL
)
1059 int i
, n
= ASM_OPERANDS_LABEL_LENGTH (tmp
);
1060 rtx new_label
, note
;
1062 if (new_bb
== EXIT_BLOCK_PTR
)
1064 new_label
= block_label (new_bb
);
1066 for (i
= 0; i
< n
; ++i
)
1068 rtx old_ref
= ASM_OPERANDS_LABEL (tmp
, i
);
1069 gcc_assert (GET_CODE (old_ref
) == LABEL_REF
);
1070 if (XEXP (old_ref
, 0) == old_label
)
1072 ASM_OPERANDS_LABEL (tmp
, i
)
1073 = gen_rtx_LABEL_REF (Pmode
, new_label
);
1074 --LABEL_NUSES (old_label
);
1075 ++LABEL_NUSES (new_label
);
1079 if (JUMP_LABEL (insn
) == old_label
)
1081 JUMP_LABEL (insn
) = new_label
;
1082 note
= find_reg_note (insn
, REG_LABEL_TARGET
, new_label
);
1084 remove_note (insn
, note
);
1088 note
= find_reg_note (insn
, REG_LABEL_TARGET
, old_label
);
1090 remove_note (insn
, note
);
1091 if (JUMP_LABEL (insn
) != new_label
1092 && !find_reg_note (insn
, REG_LABEL_TARGET
, new_label
))
1093 add_reg_note (insn
, REG_LABEL_TARGET
, new_label
);
1095 while ((note
= find_reg_note (insn
, REG_LABEL_OPERAND
, old_label
))
1097 XEXP (note
, 0) = new_label
;
1101 /* ?? We may play the games with moving the named labels from
1102 one basic block to the other in case only one computed_jump is
1104 if (computed_jump_p (insn
)
1105 /* A return instruction can't be redirected. */
1106 || returnjump_p (insn
))
1109 if (!currently_expanding_to_rtl
|| JUMP_LABEL (insn
) == old_label
)
1111 /* If the insn doesn't go where we think, we're confused. */
1112 gcc_assert (JUMP_LABEL (insn
) == old_label
);
1114 /* If the substitution doesn't succeed, die. This can happen
1115 if the back end emitted unrecognizable instructions or if
1116 target is exit block on some arches. */
1117 if (!redirect_jump (insn
, block_label (new_bb
), 0))
1119 gcc_assert (new_bb
== EXIT_BLOCK_PTR
);
1128 /* Redirect edge representing branch of (un)conditional jump or tablejump,
1131 redirect_branch_edge (edge e
, basic_block target
)
1133 rtx old_label
= BB_HEAD (e
->dest
);
1134 basic_block src
= e
->src
;
1135 rtx insn
= BB_END (src
);
1137 /* We can only redirect non-fallthru edges of jump insn. */
1138 if (e
->flags
& EDGE_FALLTHRU
)
1140 else if (!JUMP_P (insn
) && !currently_expanding_to_rtl
)
1143 if (!currently_expanding_to_rtl
)
1145 if (!patch_jump_insn (insn
, old_label
, target
))
1149 /* When expanding this BB might actually contain multiple
1150 jumps (i.e. not yet split by find_many_sub_basic_blocks).
1151 Redirect all of those that match our label. */
1152 FOR_BB_INSNS (src
, insn
)
1153 if (JUMP_P (insn
) && !patch_jump_insn (insn
, old_label
, target
))
1157 fprintf (dump_file
, "Edge %i->%i redirected to %i\n",
1158 e
->src
->index
, e
->dest
->index
, target
->index
);
1160 if (e
->dest
!= target
)
1161 e
= redirect_edge_succ_nodup (e
, target
);
1166 /* Attempt to change code to redirect edge E to TARGET. Don't do that on
1167 expense of adding new instructions or reordering basic blocks.
1169 Function can be also called with edge destination equivalent to the TARGET.
1170 Then it should try the simplifications and do nothing if none is possible.
1172 Return edge representing the branch if transformation succeeded. Return NULL
1174 We still return NULL in case E already destinated TARGET and we didn't
1175 managed to simplify instruction stream. */
1178 rtl_redirect_edge_and_branch (edge e
, basic_block target
)
1181 basic_block src
= e
->src
;
1183 if (e
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
1186 if (e
->dest
== target
)
1189 if ((ret
= try_redirect_by_replacing_jump (e
, target
, false)) != NULL
)
1191 df_set_bb_dirty (src
);
1195 ret
= redirect_branch_edge (e
, target
);
1199 df_set_bb_dirty (src
);
1203 /* Like force_nonfallthru below, but additionally performs redirection
1204 Used by redirect_edge_and_branch_force. JUMP_LABEL is used only
1205 when redirecting to the EXIT_BLOCK, it is either ret_rtx or
1206 simple_return_rtx, indicating which kind of returnjump to create.
1207 It should be NULL otherwise. */
1210 force_nonfallthru_and_redirect (edge e
, basic_block target
, rtx jump_label
)
1212 basic_block jump_block
, new_bb
= NULL
, src
= e
->src
;
1215 int abnormal_edge_flags
= 0;
1216 bool asm_goto_edge
= false;
1219 /* In the case the last instruction is conditional jump to the next
1220 instruction, first redirect the jump itself and then continue
1221 by creating a basic block afterwards to redirect fallthru edge. */
1222 if (e
->src
!= ENTRY_BLOCK_PTR
&& e
->dest
!= EXIT_BLOCK_PTR
1223 && any_condjump_p (BB_END (e
->src
))
1224 && JUMP_LABEL (BB_END (e
->src
)) == BB_HEAD (e
->dest
))
1227 edge b
= unchecked_make_edge (e
->src
, target
, 0);
1230 redirected
= redirect_jump (BB_END (e
->src
), block_label (target
), 0);
1231 gcc_assert (redirected
);
1233 note
= find_reg_note (BB_END (e
->src
), REG_BR_PROB
, NULL_RTX
);
1236 int prob
= INTVAL (XEXP (note
, 0));
1238 b
->probability
= prob
;
1239 b
->count
= e
->count
* prob
/ REG_BR_PROB_BASE
;
1240 e
->probability
-= e
->probability
;
1241 e
->count
-= b
->count
;
1242 if (e
->probability
< 0)
1249 if (e
->flags
& EDGE_ABNORMAL
)
1251 /* Irritating special case - fallthru edge to the same block as abnormal
1253 We can't redirect abnormal edge, but we still can split the fallthru
1254 one and create separate abnormal edge to original destination.
1255 This allows bb-reorder to make such edge non-fallthru. */
1256 gcc_assert (e
->dest
== target
);
1257 abnormal_edge_flags
= e
->flags
& ~(EDGE_FALLTHRU
| EDGE_CAN_FALLTHRU
);
1258 e
->flags
&= EDGE_FALLTHRU
| EDGE_CAN_FALLTHRU
;
1262 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
1263 if (e
->src
== ENTRY_BLOCK_PTR
)
1265 /* We can't redirect the entry block. Create an empty block
1266 at the start of the function which we use to add the new
1272 basic_block bb
= create_basic_block (BB_HEAD (e
->dest
), NULL
, ENTRY_BLOCK_PTR
);
1274 /* Change the existing edge's source to be the new block, and add
1275 a new edge from the entry block to the new block. */
1277 for (ei
= ei_start (ENTRY_BLOCK_PTR
->succs
); (tmp
= ei_safe_edge (ei
)); )
1281 VEC_unordered_remove (edge
, ENTRY_BLOCK_PTR
->succs
, ei
.index
);
1291 VEC_safe_push (edge
, gc
, bb
->succs
, e
);
1292 make_single_succ_edge (ENTRY_BLOCK_PTR
, bb
, EDGE_FALLTHRU
);
1296 /* If e->src ends with asm goto, see if any of the ASM_OPERANDS_LABELs
1297 don't point to target label. */
1298 if (JUMP_P (BB_END (e
->src
))
1299 && target
!= EXIT_BLOCK_PTR
1300 && e
->dest
== target
1301 && (e
->flags
& EDGE_FALLTHRU
)
1302 && (note
= extract_asm_operands (PATTERN (BB_END (e
->src
)))))
1304 int i
, n
= ASM_OPERANDS_LABEL_LENGTH (note
);
1306 for (i
= 0; i
< n
; ++i
)
1307 if (XEXP (ASM_OPERANDS_LABEL (note
, i
), 0) == BB_HEAD (target
))
1309 asm_goto_edge
= true;
1314 if (EDGE_COUNT (e
->src
->succs
) >= 2 || abnormal_edge_flags
|| asm_goto_edge
)
1316 gcov_type count
= e
->count
;
1317 int probability
= e
->probability
;
1318 /* Create the new structures. */
1320 /* If the old block ended with a tablejump, skip its table
1321 by searching forward from there. Otherwise start searching
1322 forward from the last instruction of the old block. */
1323 if (!tablejump_p (BB_END (e
->src
), NULL
, ¬e
))
1324 note
= BB_END (e
->src
);
1325 note
= NEXT_INSN (note
);
1327 jump_block
= create_basic_block (note
, NULL
, e
->src
);
1328 jump_block
->count
= count
;
1329 jump_block
->frequency
= EDGE_FREQUENCY (e
);
1330 jump_block
->loop_depth
= target
->loop_depth
;
1332 /* Make sure new block ends up in correct hot/cold section. */
1334 BB_COPY_PARTITION (jump_block
, e
->src
);
1335 if (flag_reorder_blocks_and_partition
1336 && targetm_common
.have_named_sections
1337 && JUMP_P (BB_END (jump_block
))
1338 && !any_condjump_p (BB_END (jump_block
))
1339 && (EDGE_SUCC (jump_block
, 0)->flags
& EDGE_CROSSING
))
1340 add_reg_note (BB_END (jump_block
), REG_CROSSING_JUMP
, NULL_RTX
);
1343 new_edge
= make_edge (e
->src
, jump_block
, EDGE_FALLTHRU
);
1344 new_edge
->probability
= probability
;
1345 new_edge
->count
= count
;
1347 /* Redirect old edge. */
1348 redirect_edge_pred (e
, jump_block
);
1349 e
->probability
= REG_BR_PROB_BASE
;
1351 /* If asm goto has any label refs to target's label,
1352 add also edge from asm goto bb to target. */
1355 new_edge
->probability
/= 2;
1356 new_edge
->count
/= 2;
1357 jump_block
->count
/= 2;
1358 jump_block
->frequency
/= 2;
1359 new_edge
= make_edge (new_edge
->src
, target
,
1360 e
->flags
& ~EDGE_FALLTHRU
);
1361 new_edge
->probability
= probability
- probability
/ 2;
1362 new_edge
->count
= count
- count
/ 2;
1365 new_bb
= jump_block
;
1368 jump_block
= e
->src
;
1370 if (e
->goto_locus
&& e
->goto_block
== NULL
)
1371 loc
= e
->goto_locus
;
1374 e
->flags
&= ~EDGE_FALLTHRU
;
1375 if (target
== EXIT_BLOCK_PTR
)
1377 if (jump_label
== ret_rtx
)
1380 emit_jump_insn_after_setloc (gen_return (), BB_END (jump_block
), loc
);
1387 gcc_assert (jump_label
== simple_return_rtx
);
1388 #ifdef HAVE_simple_return
1389 emit_jump_insn_after_setloc (gen_simple_return (),
1390 BB_END (jump_block
), loc
);
1395 set_return_jump_label (BB_END (jump_block
));
1399 rtx label
= block_label (target
);
1400 emit_jump_insn_after_setloc (gen_jump (label
), BB_END (jump_block
), loc
);
1401 JUMP_LABEL (BB_END (jump_block
)) = label
;
1402 LABEL_NUSES (label
)++;
1405 emit_barrier_after (BB_END (jump_block
));
1406 redirect_edge_succ_nodup (e
, target
);
1408 if (abnormal_edge_flags
)
1409 make_edge (src
, target
, abnormal_edge_flags
);
1411 df_mark_solutions_dirty ();
1415 /* Edge E is assumed to be fallthru edge. Emit needed jump instruction
1416 (and possibly create new basic block) to make edge non-fallthru.
1417 Return newly created BB or NULL if none. */
1420 rtl_force_nonfallthru (edge e
)
1422 return force_nonfallthru_and_redirect (e
, e
->dest
, NULL_RTX
);
1425 /* Redirect edge even at the expense of creating new jump insn or
1426 basic block. Return new basic block if created, NULL otherwise.
1427 Conversion must be possible. */
1430 rtl_redirect_edge_and_branch_force (edge e
, basic_block target
)
1432 if (redirect_edge_and_branch (e
, target
)
1433 || e
->dest
== target
)
1436 /* In case the edge redirection failed, try to force it to be non-fallthru
1437 and redirect newly created simplejump. */
1438 df_set_bb_dirty (e
->src
);
1439 return force_nonfallthru_and_redirect (e
, target
, NULL_RTX
);
1442 /* The given edge should potentially be a fallthru edge. If that is in
1443 fact true, delete the jump and barriers that are in the way. */
1446 rtl_tidy_fallthru_edge (edge e
)
1449 basic_block b
= e
->src
, c
= b
->next_bb
;
1451 /* ??? In a late-running flow pass, other folks may have deleted basic
1452 blocks by nopping out blocks, leaving multiple BARRIERs between here
1453 and the target label. They ought to be chastised and fixed.
1455 We can also wind up with a sequence of undeletable labels between
1456 one block and the next.
1458 So search through a sequence of barriers, labels, and notes for
1459 the head of block C and assert that we really do fall through. */
1461 for (q
= NEXT_INSN (BB_END (b
)); q
!= BB_HEAD (c
); q
= NEXT_INSN (q
))
1465 /* Remove what will soon cease being the jump insn from the source block.
1466 If block B consisted only of this single jump, turn it into a deleted
1471 && (any_uncondjump_p (q
)
1472 || single_succ_p (b
)))
1475 /* If this was a conditional jump, we need to also delete
1476 the insn that set cc0. */
1477 if (any_condjump_p (q
) && only_sets_cc0_p (PREV_INSN (q
)))
1484 /* Selectively unlink the sequence. */
1485 if (q
!= PREV_INSN (BB_HEAD (c
)))
1486 delete_insn_chain (NEXT_INSN (q
), PREV_INSN (BB_HEAD (c
)), false);
1488 e
->flags
|= EDGE_FALLTHRU
;
1491 /* Should move basic block BB after basic block AFTER. NIY. */
1494 rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED
,
1495 basic_block after ATTRIBUTE_UNUSED
)
1500 /* Split a (typically critical) edge. Return the new block.
1501 The edge must not be abnormal.
1503 ??? The code generally expects to be called on critical edges.
1504 The case of a block ending in an unconditional jump to a
1505 block with multiple predecessors is not handled optimally. */
1508 rtl_split_edge (edge edge_in
)
1513 /* Abnormal edges cannot be split. */
1514 gcc_assert (!(edge_in
->flags
& EDGE_ABNORMAL
));
1516 /* We are going to place the new block in front of edge destination.
1517 Avoid existence of fallthru predecessors. */
1518 if ((edge_in
->flags
& EDGE_FALLTHRU
) == 0)
1520 edge e
= find_fallthru_edge (edge_in
->dest
->preds
);
1523 force_nonfallthru (e
);
1526 /* Create the basic block note. */
1527 if (edge_in
->dest
!= EXIT_BLOCK_PTR
)
1528 before
= BB_HEAD (edge_in
->dest
);
1532 /* If this is a fall through edge to the exit block, the blocks might be
1533 not adjacent, and the right place is after the source. */
1534 if ((edge_in
->flags
& EDGE_FALLTHRU
) && edge_in
->dest
== EXIT_BLOCK_PTR
)
1536 before
= NEXT_INSN (BB_END (edge_in
->src
));
1537 bb
= create_basic_block (before
, NULL
, edge_in
->src
);
1538 BB_COPY_PARTITION (bb
, edge_in
->src
);
1542 bb
= create_basic_block (before
, NULL
, edge_in
->dest
->prev_bb
);
1543 /* ??? Why not edge_in->dest->prev_bb here? */
1544 BB_COPY_PARTITION (bb
, edge_in
->dest
);
1547 make_single_succ_edge (bb
, edge_in
->dest
, EDGE_FALLTHRU
);
1549 /* For non-fallthru edges, we must adjust the predecessor's
1550 jump instruction to target our new block. */
1551 if ((edge_in
->flags
& EDGE_FALLTHRU
) == 0)
1553 edge redirected
= redirect_edge_and_branch (edge_in
, bb
);
1554 gcc_assert (redirected
);
1558 if (edge_in
->src
!= ENTRY_BLOCK_PTR
)
1560 /* For asm goto even splitting of fallthru edge might
1561 need insn patching, as other labels might point to the
1563 rtx last
= BB_END (edge_in
->src
);
1566 && edge_in
->dest
!= EXIT_BLOCK_PTR
1567 && extract_asm_operands (PATTERN (last
)) != NULL_RTX
1568 && patch_jump_insn (last
, before
, bb
))
1569 df_set_bb_dirty (edge_in
->src
);
1571 redirect_edge_succ (edge_in
, bb
);
1577 /* Queue instructions for insertion on an edge between two basic blocks.
1578 The new instructions and basic blocks (if any) will not appear in the
1579 CFG until commit_edge_insertions is called. */
1582 insert_insn_on_edge (rtx pattern
, edge e
)
1584 /* We cannot insert instructions on an abnormal critical edge.
1585 It will be easier to find the culprit if we die now. */
1586 gcc_assert (!((e
->flags
& EDGE_ABNORMAL
) && EDGE_CRITICAL_P (e
)));
1588 if (e
->insns
.r
== NULL_RTX
)
1591 push_to_sequence (e
->insns
.r
);
1593 emit_insn (pattern
);
1595 e
->insns
.r
= get_insns ();
1599 /* Update the CFG for the instructions queued on edge E. */
1602 commit_one_edge_insertion (edge e
)
1604 rtx before
= NULL_RTX
, after
= NULL_RTX
, insns
, tmp
, last
;
1607 /* Pull the insns off the edge now since the edge might go away. */
1609 e
->insns
.r
= NULL_RTX
;
1611 /* Figure out where to put these insns. If the destination has
1612 one predecessor, insert there. Except for the exit block. */
1613 if (single_pred_p (e
->dest
) && e
->dest
!= EXIT_BLOCK_PTR
)
1617 /* Get the location correct wrt a code label, and "nice" wrt
1618 a basic block note, and before everything else. */
1621 tmp
= NEXT_INSN (tmp
);
1622 if (NOTE_INSN_BASIC_BLOCK_P (tmp
))
1623 tmp
= NEXT_INSN (tmp
);
1624 if (tmp
== BB_HEAD (bb
))
1627 after
= PREV_INSN (tmp
);
1629 after
= get_last_insn ();
1632 /* If the source has one successor and the edge is not abnormal,
1633 insert there. Except for the entry block. */
1634 else if ((e
->flags
& EDGE_ABNORMAL
) == 0
1635 && single_succ_p (e
->src
)
1636 && e
->src
!= ENTRY_BLOCK_PTR
)
1640 /* It is possible to have a non-simple jump here. Consider a target
1641 where some forms of unconditional jumps clobber a register. This
1642 happens on the fr30 for example.
1644 We know this block has a single successor, so we can just emit
1645 the queued insns before the jump. */
1646 if (JUMP_P (BB_END (bb
)))
1647 before
= BB_END (bb
);
1650 /* We'd better be fallthru, or we've lost track of what's what. */
1651 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
1653 after
= BB_END (bb
);
1657 /* Otherwise we must split the edge. */
1660 bb
= split_edge (e
);
1661 after
= BB_END (bb
);
1663 if (flag_reorder_blocks_and_partition
1664 && targetm_common
.have_named_sections
1665 && e
->src
!= ENTRY_BLOCK_PTR
1666 && BB_PARTITION (e
->src
) == BB_COLD_PARTITION
1667 && !(e
->flags
& EDGE_CROSSING
)
1669 && !any_condjump_p (after
)
1670 && (single_succ_edge (bb
)->flags
& EDGE_CROSSING
))
1671 add_reg_note (after
, REG_CROSSING_JUMP
, NULL_RTX
);
1674 /* Now that we've found the spot, do the insertion. */
1677 emit_insn_before_noloc (insns
, before
, bb
);
1678 last
= prev_nonnote_insn (before
);
1681 last
= emit_insn_after_noloc (insns
, after
, bb
);
1683 if (returnjump_p (last
))
1685 /* ??? Remove all outgoing edges from BB and add one for EXIT.
1686 This is not currently a problem because this only happens
1687 for the (single) epilogue, which already has a fallthru edge
1690 e
= single_succ_edge (bb
);
1691 gcc_assert (e
->dest
== EXIT_BLOCK_PTR
1692 && single_succ_p (bb
) && (e
->flags
& EDGE_FALLTHRU
));
1694 e
->flags
&= ~EDGE_FALLTHRU
;
1695 emit_barrier_after (last
);
1698 delete_insn (before
);
1701 gcc_assert (!JUMP_P (last
));
1704 /* Update the CFG for all queued instructions. */
1707 commit_edge_insertions (void)
1711 #ifdef ENABLE_CHECKING
1712 verify_flow_info ();
1715 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, EXIT_BLOCK_PTR
, next_bb
)
1720 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
1722 commit_one_edge_insertion (e
);
1727 /* Print out RTL-specific basic block information (live information
1728 at start and end). */
1731 rtl_dump_bb (basic_block bb
, FILE *outf
, int indent
, int flags ATTRIBUTE_UNUSED
)
1737 s_indent
= (char *) alloca ((size_t) indent
+ 1);
1738 memset (s_indent
, ' ', (size_t) indent
);
1739 s_indent
[indent
] = '\0';
1743 df_dump_top (bb
, outf
);
1747 if (bb
->index
!= ENTRY_BLOCK
&& bb
->index
!= EXIT_BLOCK
)
1748 for (insn
= BB_HEAD (bb
), last
= NEXT_INSN (BB_END (bb
)); insn
!= last
;
1749 insn
= NEXT_INSN (insn
))
1750 print_rtl_single (outf
, insn
);
1754 df_dump_bottom (bb
, outf
);
1760 /* Like print_rtl, but also print out live information for the start of each
1764 print_rtl_with_bb (FILE *outf
, const_rtx rtx_first
)
1768 fprintf (outf
, "(nil)\n");
1771 enum bb_state
{ NOT_IN_BB
, IN_ONE_BB
, IN_MULTIPLE_BB
};
1772 int max_uid
= get_max_uid ();
1773 basic_block
*start
= XCNEWVEC (basic_block
, max_uid
);
1774 basic_block
*end
= XCNEWVEC (basic_block
, max_uid
);
1775 enum bb_state
*in_bb_p
= XCNEWVEC (enum bb_state
, max_uid
);
1780 df_dump_start (outf
);
1782 FOR_EACH_BB_REVERSE (bb
)
1786 start
[INSN_UID (BB_HEAD (bb
))] = bb
;
1787 end
[INSN_UID (BB_END (bb
))] = bb
;
1788 for (x
= BB_HEAD (bb
); x
!= NULL_RTX
; x
= NEXT_INSN (x
))
1790 enum bb_state state
= IN_MULTIPLE_BB
;
1792 if (in_bb_p
[INSN_UID (x
)] == NOT_IN_BB
)
1794 in_bb_p
[INSN_UID (x
)] = state
;
1796 if (x
== BB_END (bb
))
1801 for (tmp_rtx
= rtx_first
; NULL
!= tmp_rtx
; tmp_rtx
= NEXT_INSN (tmp_rtx
))
1805 bb
= start
[INSN_UID (tmp_rtx
)];
1807 dump_bb_info (bb
, true, false, dump_flags
, ";; ", outf
);
1809 if (in_bb_p
[INSN_UID (tmp_rtx
)] == NOT_IN_BB
1810 && !NOTE_P (tmp_rtx
)
1811 && !BARRIER_P (tmp_rtx
))
1812 fprintf (outf
, ";; Insn is not within a basic block\n");
1813 else if (in_bb_p
[INSN_UID (tmp_rtx
)] == IN_MULTIPLE_BB
)
1814 fprintf (outf
, ";; Insn is in multiple basic blocks\n");
1816 did_output
= print_rtl_single (outf
, tmp_rtx
);
1818 bb
= end
[INSN_UID (tmp_rtx
)];
1820 dump_bb_info (bb
, false, true, dump_flags
, ";; ", outf
);
1830 if (crtl
->epilogue_delay_list
!= 0)
1832 fprintf (outf
, "\n;; Insns in epilogue delay list:\n\n");
1833 for (tmp_rtx
= crtl
->epilogue_delay_list
; tmp_rtx
!= 0;
1834 tmp_rtx
= XEXP (tmp_rtx
, 1))
1835 print_rtl_single (outf
, XEXP (tmp_rtx
, 0));
1840 update_br_prob_note (basic_block bb
)
1843 if (!JUMP_P (BB_END (bb
)))
1845 note
= find_reg_note (BB_END (bb
), REG_BR_PROB
, NULL_RTX
);
1846 if (!note
|| INTVAL (XEXP (note
, 0)) == BRANCH_EDGE (bb
)->probability
)
1848 XEXP (note
, 0) = GEN_INT (BRANCH_EDGE (bb
)->probability
);
1851 /* Get the last insn associated with block BB (that includes barriers and
1852 tablejumps after BB). */
1854 get_last_bb_insn (basic_block bb
)
1857 rtx end
= BB_END (bb
);
1859 /* Include any jump table following the basic block. */
1860 if (tablejump_p (end
, NULL
, &tmp
))
1863 /* Include any barriers that may follow the basic block. */
1864 tmp
= next_nonnote_insn_bb (end
);
1865 while (tmp
&& BARRIER_P (tmp
))
1868 tmp
= next_nonnote_insn_bb (end
);
1874 /* Verify the CFG and RTL consistency common for both underlying RTL and
1877 Currently it does following checks:
1879 - overlapping of basic blocks
1880 - insns with wrong BLOCK_FOR_INSN pointers
1881 - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note)
1882 - tails of basic blocks (ensure that boundary is necessary)
1883 - scans body of the basic block for JUMP_INSN, CODE_LABEL
1884 and NOTE_INSN_BASIC_BLOCK
1885 - verify that no fall_thru edge crosses hot/cold partition boundaries
1886 - verify that there are no pending RTL branch predictions
1888 In future it can be extended check a lot of other stuff as well
1889 (reachability of basic blocks, life information, etc. etc.). */
1892 rtl_verify_flow_info_1 (void)
1898 /* Check the general integrity of the basic blocks. */
1899 FOR_EACH_BB_REVERSE (bb
)
1903 if (!(bb
->flags
& BB_RTL
))
1905 error ("BB_RTL flag not set for block %d", bb
->index
);
1909 FOR_BB_INSNS (bb
, insn
)
1910 if (BLOCK_FOR_INSN (insn
) != bb
)
1912 error ("insn %d basic block pointer is %d, should be %d",
1914 BLOCK_FOR_INSN (insn
) ? BLOCK_FOR_INSN (insn
)->index
: 0,
1919 for (insn
= BB_HEADER (bb
); insn
; insn
= NEXT_INSN (insn
))
1920 if (!BARRIER_P (insn
)
1921 && BLOCK_FOR_INSN (insn
) != NULL
)
1923 error ("insn %d in header of bb %d has non-NULL basic block",
1924 INSN_UID (insn
), bb
->index
);
1927 for (insn
= BB_FOOTER (bb
); insn
; insn
= NEXT_INSN (insn
))
1928 if (!BARRIER_P (insn
)
1929 && BLOCK_FOR_INSN (insn
) != NULL
)
1931 error ("insn %d in footer of bb %d has non-NULL basic block",
1932 INSN_UID (insn
), bb
->index
);
1937 /* Now check the basic blocks (boundaries etc.) */
1938 FOR_EACH_BB_REVERSE (bb
)
1940 int n_fallthru
= 0, n_eh
= 0, n_call
= 0, n_abnormal
= 0, n_branch
= 0;
1941 edge e
, fallthru
= NULL
;
1945 if (JUMP_P (BB_END (bb
))
1946 && (note
= find_reg_note (BB_END (bb
), REG_BR_PROB
, NULL_RTX
))
1947 && EDGE_COUNT (bb
->succs
) >= 2
1948 && any_condjump_p (BB_END (bb
)))
1950 if (INTVAL (XEXP (note
, 0)) != BRANCH_EDGE (bb
)->probability
1951 && profile_status
!= PROFILE_ABSENT
)
1953 error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i",
1954 INTVAL (XEXP (note
, 0)), BRANCH_EDGE (bb
)->probability
);
1958 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
1962 if (e
->flags
& EDGE_FALLTHRU
)
1963 n_fallthru
++, fallthru
= e
;
1965 is_crossing
= (BB_PARTITION (e
->src
) != BB_PARTITION (e
->dest
)
1966 && e
->src
!= ENTRY_BLOCK_PTR
1967 && e
->dest
!= EXIT_BLOCK_PTR
);
1968 if (e
->flags
& EDGE_CROSSING
)
1972 error ("EDGE_CROSSING incorrectly set across same section");
1975 if (e
->flags
& EDGE_FALLTHRU
)
1977 error ("fallthru edge crosses section boundary (bb %i)",
1981 if (e
->flags
& EDGE_EH
)
1983 error ("EH edge crosses section boundary (bb %i)",
1988 else if (is_crossing
)
1990 error ("EDGE_CROSSING missing across section boundary");
1994 if ((e
->flags
& ~(EDGE_DFS_BACK
1996 | EDGE_IRREDUCIBLE_LOOP
1999 | EDGE_PRESERVE
)) == 0)
2002 if (e
->flags
& EDGE_ABNORMAL_CALL
)
2005 if (e
->flags
& EDGE_EH
)
2007 else if (e
->flags
& EDGE_ABNORMAL
)
2011 if (n_eh
&& !find_reg_note (BB_END (bb
), REG_EH_REGION
, NULL_RTX
))
2013 error ("missing REG_EH_REGION note in the end of bb %i", bb
->index
);
2018 error ("too many eh edges %i", bb
->index
);
2022 && (!JUMP_P (BB_END (bb
))
2023 || (n_branch
> 1 && (any_uncondjump_p (BB_END (bb
))
2024 || any_condjump_p (BB_END (bb
))))))
2026 error ("too many outgoing branch edges from bb %i", bb
->index
);
2029 if (n_fallthru
&& any_uncondjump_p (BB_END (bb
)))
2031 error ("fallthru edge after unconditional jump %i", bb
->index
);
2034 if (n_branch
!= 1 && any_uncondjump_p (BB_END (bb
)))
2036 error ("wrong number of branch edges after unconditional jump %i",
2040 if (n_branch
!= 1 && any_condjump_p (BB_END (bb
))
2041 && JUMP_LABEL (BB_END (bb
)) != BB_HEAD (fallthru
->dest
))
2043 error ("wrong amount of branch edges after conditional jump %i",
2047 if (n_call
&& !CALL_P (BB_END (bb
)))
2049 error ("call edges for non-call insn in bb %i", bb
->index
);
2053 && (!CALL_P (BB_END (bb
)) && n_call
!= n_abnormal
)
2054 && (!JUMP_P (BB_END (bb
))
2055 || any_condjump_p (BB_END (bb
))
2056 || any_uncondjump_p (BB_END (bb
))))
2058 error ("abnormal edges for no purpose in bb %i", bb
->index
);
2062 for (x
= BB_HEAD (bb
); x
!= NEXT_INSN (BB_END (bb
)); x
= NEXT_INSN (x
))
2063 /* We may have a barrier inside a basic block before dead code
2064 elimination. There is no BLOCK_FOR_INSN field in a barrier. */
2065 if (!BARRIER_P (x
) && BLOCK_FOR_INSN (x
) != bb
)
2068 if (! BLOCK_FOR_INSN (x
))
2070 ("insn %d inside basic block %d but block_for_insn is NULL",
2071 INSN_UID (x
), bb
->index
);
2074 ("insn %d inside basic block %d but block_for_insn is %i",
2075 INSN_UID (x
), bb
->index
, BLOCK_FOR_INSN (x
)->index
);
2080 /* OK pointers are correct. Now check the header of basic
2081 block. It ought to contain optional CODE_LABEL followed
2082 by NOTE_BASIC_BLOCK. */
2086 if (BB_END (bb
) == x
)
2088 error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
2096 if (!NOTE_INSN_BASIC_BLOCK_P (x
) || NOTE_BASIC_BLOCK (x
) != bb
)
2098 error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
2103 if (BB_END (bb
) == x
)
2104 /* Do checks for empty blocks here. */
2107 for (x
= NEXT_INSN (x
); x
; x
= NEXT_INSN (x
))
2109 if (NOTE_INSN_BASIC_BLOCK_P (x
))
2111 error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d",
2112 INSN_UID (x
), bb
->index
);
2116 if (x
== BB_END (bb
))
2119 if (control_flow_insn_p (x
))
2121 error ("in basic block %d:", bb
->index
);
2122 fatal_insn ("flow control insn inside a basic block", x
);
2131 /* Verify the CFG and RTL consistency common for both underlying RTL and
2134 Currently it does following checks:
2135 - all checks of rtl_verify_flow_info_1
2136 - test head/end pointers
2137 - check that all insns are in the basic blocks
2138 (except the switch handling code, barriers and notes)
2139 - check that all returns are followed by barriers
2140 - check that all fallthru edge points to the adjacent blocks. */
2143 rtl_verify_flow_info (void)
2146 int err
= rtl_verify_flow_info_1 ();
2148 rtx last_head
= get_last_insn ();
2149 basic_block
*bb_info
;
2151 const rtx rtx_first
= get_insns ();
2152 basic_block last_bb_seen
= ENTRY_BLOCK_PTR
, curr_bb
= NULL
;
2153 const int max_uid
= get_max_uid ();
2155 bb_info
= XCNEWVEC (basic_block
, max_uid
);
2157 FOR_EACH_BB_REVERSE (bb
)
2160 rtx head
= BB_HEAD (bb
);
2161 rtx end
= BB_END (bb
);
2163 for (x
= last_head
; x
!= NULL_RTX
; x
= PREV_INSN (x
))
2165 /* Verify the end of the basic block is in the INSN chain. */
2169 /* And that the code outside of basic blocks has NULL bb field. */
2171 && BLOCK_FOR_INSN (x
) != NULL
)
2173 error ("insn %d outside of basic blocks has non-NULL bb field",
2181 error ("end insn %d for block %d not found in the insn stream",
2182 INSN_UID (end
), bb
->index
);
2186 /* Work backwards from the end to the head of the basic block
2187 to verify the head is in the RTL chain. */
2188 for (; x
!= NULL_RTX
; x
= PREV_INSN (x
))
2190 /* While walking over the insn chain, verify insns appear
2191 in only one basic block. */
2192 if (bb_info
[INSN_UID (x
)] != NULL
)
2194 error ("insn %d is in multiple basic blocks (%d and %d)",
2195 INSN_UID (x
), bb
->index
, bb_info
[INSN_UID (x
)]->index
);
2199 bb_info
[INSN_UID (x
)] = bb
;
2206 error ("head insn %d for block %d not found in the insn stream",
2207 INSN_UID (head
), bb
->index
);
2211 last_head
= PREV_INSN (x
);
2213 e
= find_fallthru_edge (bb
->succs
);
2218 /* Ensure existence of barrier in BB with no fallthru edges. */
2219 for (insn
= NEXT_INSN (BB_END (bb
)); ; insn
= NEXT_INSN (insn
))
2221 if (!insn
|| NOTE_INSN_BASIC_BLOCK_P (insn
))
2223 error ("missing barrier after block %i", bb
->index
);
2227 if (BARRIER_P (insn
))
2231 else if (e
->src
!= ENTRY_BLOCK_PTR
2232 && e
->dest
!= EXIT_BLOCK_PTR
)
2236 if (e
->src
->next_bb
!= e
->dest
)
2239 ("verify_flow_info: Incorrect blocks for fallthru %i->%i",
2240 e
->src
->index
, e
->dest
->index
);
2244 for (insn
= NEXT_INSN (BB_END (e
->src
)); insn
!= BB_HEAD (e
->dest
);
2245 insn
= NEXT_INSN (insn
))
2246 if (BARRIER_P (insn
) || INSN_P (insn
))
2248 error ("verify_flow_info: Incorrect fallthru %i->%i",
2249 e
->src
->index
, e
->dest
->index
);
2250 fatal_insn ("wrong insn in the fallthru edge", insn
);
2256 for (x
= last_head
; x
!= NULL_RTX
; x
= PREV_INSN (x
))
2258 /* Check that the code before the first basic block has NULL
2261 && BLOCK_FOR_INSN (x
) != NULL
)
2263 error ("insn %d outside of basic blocks has non-NULL bb field",
2271 last_bb_seen
= ENTRY_BLOCK_PTR
;
2273 for (x
= rtx_first
; x
; x
= NEXT_INSN (x
))
2275 if (NOTE_INSN_BASIC_BLOCK_P (x
))
2277 bb
= NOTE_BASIC_BLOCK (x
);
2280 if (bb
!= last_bb_seen
->next_bb
)
2281 internal_error ("basic blocks not laid down consecutively");
2283 curr_bb
= last_bb_seen
= bb
;
2288 switch (GET_CODE (x
))
2295 /* An addr_vec is placed outside any basic block. */
2297 && JUMP_TABLE_DATA_P (NEXT_INSN (x
)))
2300 /* But in any case, non-deletable labels can appear anywhere. */
2304 fatal_insn ("insn outside basic block", x
);
2309 && returnjump_p (x
) && ! condjump_p (x
)
2310 && ! (next_nonnote_insn (x
) && BARRIER_P (next_nonnote_insn (x
))))
2311 fatal_insn ("return not followed by barrier", x
);
2312 if (curr_bb
&& x
== BB_END (curr_bb
))
2316 if (num_bb_notes
!= n_basic_blocks
- NUM_FIXED_BLOCKS
)
2318 ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)",
2319 num_bb_notes
, n_basic_blocks
);
2324 /* Assume that the preceding pass has possibly eliminated jump instructions
2325 or converted the unconditional jumps. Eliminate the edges from CFG.
2326 Return true if any edges are eliminated. */
2329 purge_dead_edges (basic_block bb
)
2332 rtx insn
= BB_END (bb
), note
;
2333 bool purged
= false;
2337 if (DEBUG_INSN_P (insn
) && insn
!= BB_HEAD (bb
))
2339 insn
= PREV_INSN (insn
);
2340 while ((DEBUG_INSN_P (insn
) || NOTE_P (insn
)) && insn
!= BB_HEAD (bb
));
2342 /* If this instruction cannot trap, remove REG_EH_REGION notes. */
2343 if (NONJUMP_INSN_P (insn
)
2344 && (note
= find_reg_note (insn
, REG_EH_REGION
, NULL
)))
2348 if (! may_trap_p (PATTERN (insn
))
2349 || ((eqnote
= find_reg_equal_equiv_note (insn
))
2350 && ! may_trap_p (XEXP (eqnote
, 0))))
2351 remove_note (insn
, note
);
2354 /* Cleanup abnormal edges caused by exceptions or non-local gotos. */
2355 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
2357 bool remove
= false;
2359 /* There are three types of edges we need to handle correctly here: EH
2360 edges, abnormal call EH edges, and abnormal call non-EH edges. The
2361 latter can appear when nonlocal gotos are used. */
2362 if (e
->flags
& EDGE_ABNORMAL_CALL
)
2366 else if (can_nonlocal_goto (insn
))
2368 else if ((e
->flags
& EDGE_EH
) && can_throw_internal (insn
))
2370 else if (flag_tm
&& find_reg_note (insn
, REG_TM
, NULL
))
2375 else if (e
->flags
& EDGE_EH
)
2376 remove
= !can_throw_internal (insn
);
2381 df_set_bb_dirty (bb
);
2394 /* We do care only about conditional jumps and simplejumps. */
2395 if (!any_condjump_p (insn
)
2396 && !returnjump_p (insn
)
2397 && !simplejump_p (insn
))
2400 /* Branch probability/prediction notes are defined only for
2401 condjumps. We've possibly turned condjump into simplejump. */
2402 if (simplejump_p (insn
))
2404 note
= find_reg_note (insn
, REG_BR_PROB
, NULL
);
2406 remove_note (insn
, note
);
2407 while ((note
= find_reg_note (insn
, REG_BR_PRED
, NULL
)))
2408 remove_note (insn
, note
);
2411 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
2413 /* Avoid abnormal flags to leak from computed jumps turned
2414 into simplejumps. */
2416 e
->flags
&= ~EDGE_ABNORMAL
;
2418 /* See if this edge is one we should keep. */
2419 if ((e
->flags
& EDGE_FALLTHRU
) && any_condjump_p (insn
))
2420 /* A conditional jump can fall through into the next
2421 block, so we should keep the edge. */
2426 else if (e
->dest
!= EXIT_BLOCK_PTR
2427 && BB_HEAD (e
->dest
) == JUMP_LABEL (insn
))
2428 /* If the destination block is the target of the jump,
2434 else if (e
->dest
== EXIT_BLOCK_PTR
&& returnjump_p (insn
))
2435 /* If the destination block is the exit block, and this
2436 instruction is a return, then keep the edge. */
2441 else if ((e
->flags
& EDGE_EH
) && can_throw_internal (insn
))
2442 /* Keep the edges that correspond to exceptions thrown by
2443 this instruction and rematerialize the EDGE_ABNORMAL
2444 flag we just cleared above. */
2446 e
->flags
|= EDGE_ABNORMAL
;
2451 /* We do not need this edge. */
2452 df_set_bb_dirty (bb
);
2457 if (EDGE_COUNT (bb
->succs
) == 0 || !purged
)
2461 fprintf (dump_file
, "Purged edges from bb %i\n", bb
->index
);
2466 /* Redistribute probabilities. */
2467 if (single_succ_p (bb
))
2469 single_succ_edge (bb
)->probability
= REG_BR_PROB_BASE
;
2470 single_succ_edge (bb
)->count
= bb
->count
;
2474 note
= find_reg_note (insn
, REG_BR_PROB
, NULL
);
2478 b
= BRANCH_EDGE (bb
);
2479 f
= FALLTHRU_EDGE (bb
);
2480 b
->probability
= INTVAL (XEXP (note
, 0));
2481 f
->probability
= REG_BR_PROB_BASE
- b
->probability
;
2482 b
->count
= bb
->count
* b
->probability
/ REG_BR_PROB_BASE
;
2483 f
->count
= bb
->count
* f
->probability
/ REG_BR_PROB_BASE
;
2488 else if (CALL_P (insn
) && SIBLING_CALL_P (insn
))
2490 /* First, there should not be any EH or ABCALL edges resulting
2491 from non-local gotos and the like. If there were, we shouldn't
2492 have created the sibcall in the first place. Second, there
2493 should of course never have been a fallthru edge. */
2494 gcc_assert (single_succ_p (bb
));
2495 gcc_assert (single_succ_edge (bb
)->flags
2496 == (EDGE_SIBCALL
| EDGE_ABNORMAL
));
2501 /* If we don't see a jump insn, we don't know exactly why the block would
2502 have been broken at this point. Look for a simple, non-fallthru edge,
2503 as these are only created by conditional branches. If we find such an
2504 edge we know that there used to be a jump here and can then safely
2505 remove all non-fallthru edges. */
2507 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2508 if (! (e
->flags
& (EDGE_COMPLEX
| EDGE_FALLTHRU
)))
2517 /* Remove all but the fake and fallthru edges. The fake edge may be
2518 the only successor for this block in the case of noreturn
2520 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
2522 if (!(e
->flags
& (EDGE_FALLTHRU
| EDGE_FAKE
)))
2524 df_set_bb_dirty (bb
);
2532 gcc_assert (single_succ_p (bb
));
2534 single_succ_edge (bb
)->probability
= REG_BR_PROB_BASE
;
2535 single_succ_edge (bb
)->count
= bb
->count
;
2538 fprintf (dump_file
, "Purged non-fallthru edges from bb %i\n",
2543 /* Search all basic blocks for potentially dead edges and purge them. Return
2544 true if some edge has been eliminated. */
2547 purge_all_dead_edges (void)
2554 bool purged_here
= purge_dead_edges (bb
);
2556 purged
|= purged_here
;
2562 /* This is used by a few passes that emit some instructions after abnormal
2563 calls, moving the basic block's end, while they in fact do want to emit
2564 them on the fallthru edge. Look for abnormal call edges, find backward
2565 the call in the block and insert the instructions on the edge instead.
2567 Similarly, handle instructions throwing exceptions internally.
2569 Return true when instructions have been found and inserted on edges. */
2572 fixup_abnormal_edges (void)
2574 bool inserted
= false;
2582 /* Look for cases we are interested in - calls or instructions causing
2584 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2585 if ((e
->flags
& EDGE_ABNORMAL_CALL
)
2586 || ((e
->flags
& (EDGE_ABNORMAL
| EDGE_EH
))
2587 == (EDGE_ABNORMAL
| EDGE_EH
)))
2590 if (e
&& !CALL_P (BB_END (bb
)) && !can_throw_internal (BB_END (bb
)))
2594 /* Get past the new insns generated. Allow notes, as the insns
2595 may be already deleted. */
2597 while ((NONJUMP_INSN_P (insn
) || NOTE_P (insn
))
2598 && !can_throw_internal (insn
)
2599 && insn
!= BB_HEAD (bb
))
2600 insn
= PREV_INSN (insn
);
2602 if (CALL_P (insn
) || can_throw_internal (insn
))
2606 e
= find_fallthru_edge (bb
->succs
);
2608 stop
= NEXT_INSN (BB_END (bb
));
2611 for (insn
= NEXT_INSN (insn
); insn
!= stop
; insn
= next
)
2613 next
= NEXT_INSN (insn
);
2618 /* Sometimes there's still the return value USE.
2619 If it's placed after a trapping call (i.e. that
2620 call is the last insn anyway), we have no fallthru
2621 edge. Simply delete this use and don't try to insert
2622 on the non-existent edge. */
2623 if (GET_CODE (PATTERN (insn
)) != USE
)
2625 /* We're not deleting it, we're moving it. */
2626 INSN_DELETED_P (insn
) = 0;
2627 PREV_INSN (insn
) = NULL_RTX
;
2628 NEXT_INSN (insn
) = NULL_RTX
;
2630 insert_insn_on_edge (insn
, e
);
2634 else if (!BARRIER_P (insn
))
2635 set_block_for_insn (insn
, NULL
);
2639 /* It may be that we don't find any trapping insn. In this
2640 case we discovered quite late that the insn that had been
2641 marked as can_throw_internal in fact couldn't trap at all.
2642 So we should in fact delete the EH edges out of the block. */
2644 purge_dead_edges (bb
);
2651 /* Same as split_block but update cfg_layout structures. */
2654 cfg_layout_split_block (basic_block bb
, void *insnp
)
2656 rtx insn
= (rtx
) insnp
;
2657 basic_block new_bb
= rtl_split_block (bb
, insn
);
2659 BB_FOOTER (new_bb
) = BB_FOOTER (bb
);
2660 BB_FOOTER (bb
) = NULL
;
2665 /* Redirect Edge to DEST. */
2667 cfg_layout_redirect_edge_and_branch (edge e
, basic_block dest
)
2669 basic_block src
= e
->src
;
2672 if (e
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
2675 if (e
->dest
== dest
)
2678 if (e
->src
!= ENTRY_BLOCK_PTR
2679 && (ret
= try_redirect_by_replacing_jump (e
, dest
, true)))
2681 df_set_bb_dirty (src
);
2685 if (e
->src
== ENTRY_BLOCK_PTR
2686 && (e
->flags
& EDGE_FALLTHRU
) && !(e
->flags
& EDGE_COMPLEX
))
2689 fprintf (dump_file
, "Redirecting entry edge from bb %i to %i\n",
2690 e
->src
->index
, dest
->index
);
2692 df_set_bb_dirty (e
->src
);
2693 redirect_edge_succ (e
, dest
);
2697 /* Redirect_edge_and_branch may decide to turn branch into fallthru edge
2698 in the case the basic block appears to be in sequence. Avoid this
2701 if (e
->flags
& EDGE_FALLTHRU
)
2703 /* Redirect any branch edges unified with the fallthru one. */
2704 if (JUMP_P (BB_END (src
))
2705 && label_is_jump_target_p (BB_HEAD (e
->dest
),
2711 fprintf (dump_file
, "Fallthru edge unified with branch "
2712 "%i->%i redirected to %i\n",
2713 e
->src
->index
, e
->dest
->index
, dest
->index
);
2714 e
->flags
&= ~EDGE_FALLTHRU
;
2715 redirected
= redirect_branch_edge (e
, dest
);
2716 gcc_assert (redirected
);
2717 redirected
->flags
|= EDGE_FALLTHRU
;
2718 df_set_bb_dirty (redirected
->src
);
2721 /* In case we are redirecting fallthru edge to the branch edge
2722 of conditional jump, remove it. */
2723 if (EDGE_COUNT (src
->succs
) == 2)
2725 /* Find the edge that is different from E. */
2726 edge s
= EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
);
2729 && any_condjump_p (BB_END (src
))
2730 && onlyjump_p (BB_END (src
)))
2731 delete_insn (BB_END (src
));
2734 fprintf (dump_file
, "Redirecting fallthru edge %i->%i to %i\n",
2735 e
->src
->index
, e
->dest
->index
, dest
->index
);
2736 ret
= redirect_edge_succ_nodup (e
, dest
);
2739 ret
= redirect_branch_edge (e
, dest
);
2741 /* We don't want simplejumps in the insn stream during cfglayout. */
2742 gcc_assert (!simplejump_p (BB_END (src
)));
2744 df_set_bb_dirty (src
);
2748 /* Simple wrapper as we always can redirect fallthru edges. */
2750 cfg_layout_redirect_edge_and_branch_force (edge e
, basic_block dest
)
2752 edge redirected
= cfg_layout_redirect_edge_and_branch (e
, dest
);
2754 gcc_assert (redirected
);
2758 /* Same as delete_basic_block but update cfg_layout structures. */
2761 cfg_layout_delete_block (basic_block bb
)
2763 rtx insn
, next
, prev
= PREV_INSN (BB_HEAD (bb
)), *to
, remaints
;
2767 next
= BB_HEAD (bb
);
2769 NEXT_INSN (prev
) = BB_HEADER (bb
);
2771 set_first_insn (BB_HEADER (bb
));
2772 PREV_INSN (BB_HEADER (bb
)) = prev
;
2773 insn
= BB_HEADER (bb
);
2774 while (NEXT_INSN (insn
))
2775 insn
= NEXT_INSN (insn
);
2776 NEXT_INSN (insn
) = next
;
2777 PREV_INSN (next
) = insn
;
2779 next
= NEXT_INSN (BB_END (bb
));
2782 insn
= BB_FOOTER (bb
);
2785 if (BARRIER_P (insn
))
2787 if (PREV_INSN (insn
))
2788 NEXT_INSN (PREV_INSN (insn
)) = NEXT_INSN (insn
);
2790 BB_FOOTER (bb
) = NEXT_INSN (insn
);
2791 if (NEXT_INSN (insn
))
2792 PREV_INSN (NEXT_INSN (insn
)) = PREV_INSN (insn
);
2796 insn
= NEXT_INSN (insn
);
2801 NEXT_INSN (insn
) = BB_FOOTER (bb
);
2802 PREV_INSN (BB_FOOTER (bb
)) = insn
;
2803 while (NEXT_INSN (insn
))
2804 insn
= NEXT_INSN (insn
);
2805 NEXT_INSN (insn
) = next
;
2807 PREV_INSN (next
) = insn
;
2809 set_last_insn (insn
);
2812 if (bb
->next_bb
!= EXIT_BLOCK_PTR
)
2813 to
= &BB_HEADER (bb
->next_bb
);
2815 to
= &cfg_layout_function_footer
;
2817 rtl_delete_block (bb
);
2820 prev
= NEXT_INSN (prev
);
2822 prev
= get_insns ();
2824 next
= PREV_INSN (next
);
2826 next
= get_last_insn ();
2828 if (next
&& NEXT_INSN (next
) != prev
)
2830 remaints
= unlink_insn_chain (prev
, next
);
2832 while (NEXT_INSN (insn
))
2833 insn
= NEXT_INSN (insn
);
2834 NEXT_INSN (insn
) = *to
;
2836 PREV_INSN (*to
) = insn
;
2841 /* Return true when blocks A and B can be safely merged. */
2844 cfg_layout_can_merge_blocks_p (basic_block a
, basic_block b
)
2846 /* If we are partitioning hot/cold basic blocks, we don't want to
2847 mess up unconditional or indirect jumps that cross between hot
2850 Basic block partitioning may result in some jumps that appear to
2851 be optimizable (or blocks that appear to be mergeable), but which really
2852 must be left untouched (they are required to make it safely across
2853 partition boundaries). See the comments at the top of
2854 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
2856 if (BB_PARTITION (a
) != BB_PARTITION (b
))
2859 /* Protect the loop latches. */
2860 if (current_loops
&& b
->loop_father
->latch
== b
)
2863 /* If we would end up moving B's instructions, make sure it doesn't fall
2864 through into the exit block, since we cannot recover from a fallthrough
2865 edge into the exit block occurring in the middle of a function. */
2866 if (NEXT_INSN (BB_END (a
)) != BB_HEAD (b
))
2868 edge e
= find_fallthru_edge (b
->succs
);
2869 if (e
&& e
->dest
== EXIT_BLOCK_PTR
)
2873 /* There must be exactly one edge in between the blocks. */
2874 return (single_succ_p (a
)
2875 && single_succ (a
) == b
2876 && single_pred_p (b
) == 1
2878 /* Must be simple edge. */
2879 && !(single_succ_edge (a
)->flags
& EDGE_COMPLEX
)
2880 && a
!= ENTRY_BLOCK_PTR
&& b
!= EXIT_BLOCK_PTR
2881 /* If the jump insn has side effects, we can't kill the edge.
2882 When not optimizing, try_redirect_by_replacing_jump will
2883 not allow us to redirect an edge by replacing a table jump. */
2884 && (!JUMP_P (BB_END (a
))
2885 || ((!optimize
|| reload_completed
)
2886 ? simplejump_p (BB_END (a
)) : onlyjump_p (BB_END (a
)))));
2889 /* Merge block A and B. The blocks must be mergeable. */
2892 cfg_layout_merge_blocks (basic_block a
, basic_block b
)
2894 bool forwarder_p
= (b
->flags
& BB_FORWARDER_BLOCK
) != 0;
2897 gcc_checking_assert (cfg_layout_can_merge_blocks_p (a
, b
));
2900 fprintf (dump_file
, "Merging block %d into block %d...\n", b
->index
,
2903 /* If there was a CODE_LABEL beginning B, delete it. */
2904 if (LABEL_P (BB_HEAD (b
)))
2906 delete_insn (BB_HEAD (b
));
2909 /* We should have fallthru edge in a, or we can do dummy redirection to get
2911 if (JUMP_P (BB_END (a
)))
2912 try_redirect_by_replacing_jump (EDGE_SUCC (a
, 0), b
, true);
2913 gcc_assert (!JUMP_P (BB_END (a
)));
2915 /* When not optimizing CFG and the edge is the only place in RTL which holds
2916 some unique locus, emit a nop with that locus in between. */
2918 emit_nop_for_unique_locus_between (a
, b
);
2920 /* Possible line number notes should appear in between. */
2923 rtx first
= BB_END (a
), last
;
2925 last
= emit_insn_after_noloc (BB_HEADER (b
), BB_END (a
), a
);
2926 /* The above might add a BARRIER as BB_END, but as barriers
2927 aren't valid parts of a bb, remove_insn doesn't update
2928 BB_END if it is a barrier. So adjust BB_END here. */
2929 while (BB_END (a
) != first
&& BARRIER_P (BB_END (a
)))
2930 BB_END (a
) = PREV_INSN (BB_END (a
));
2931 delete_insn_chain (NEXT_INSN (first
), last
, false);
2932 BB_HEADER (b
) = NULL
;
2935 /* In the case basic blocks are not adjacent, move them around. */
2936 if (NEXT_INSN (BB_END (a
)) != BB_HEAD (b
))
2938 insn
= unlink_insn_chain (BB_HEAD (b
), BB_END (b
));
2940 emit_insn_after_noloc (insn
, BB_END (a
), a
);
2942 /* Otherwise just re-associate the instructions. */
2946 BB_END (a
) = BB_END (b
);
2949 /* emit_insn_after_noloc doesn't call df_insn_change_bb.
2950 We need to explicitly call. */
2951 update_bb_for_insn_chain (insn
, BB_END (b
), a
);
2953 /* Skip possible DELETED_LABEL insn. */
2954 if (!NOTE_INSN_BASIC_BLOCK_P (insn
))
2955 insn
= NEXT_INSN (insn
);
2956 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn
));
2960 df_bb_delete (b
->index
);
2962 /* Possible tablejumps and barriers should appear after the block. */
2966 BB_FOOTER (a
) = BB_FOOTER (b
);
2969 rtx last
= BB_FOOTER (a
);
2971 while (NEXT_INSN (last
))
2972 last
= NEXT_INSN (last
);
2973 NEXT_INSN (last
) = BB_FOOTER (b
);
2974 PREV_INSN (BB_FOOTER (b
)) = last
;
2976 BB_FOOTER (b
) = NULL
;
2979 /* If B was a forwarder block, propagate the locus on the edge. */
2980 if (forwarder_p
&& !EDGE_SUCC (b
, 0)->goto_locus
)
2981 EDGE_SUCC (b
, 0)->goto_locus
= EDGE_SUCC (a
, 0)->goto_locus
;
2984 fprintf (dump_file
, "Merged blocks %d and %d.\n", a
->index
, b
->index
);
2990 cfg_layout_split_edge (edge e
)
2992 basic_block new_bb
=
2993 create_basic_block (e
->src
!= ENTRY_BLOCK_PTR
2994 ? NEXT_INSN (BB_END (e
->src
)) : get_insns (),
2997 if (e
->dest
== EXIT_BLOCK_PTR
)
2998 BB_COPY_PARTITION (new_bb
, e
->src
);
3000 BB_COPY_PARTITION (new_bb
, e
->dest
);
3001 make_edge (new_bb
, e
->dest
, EDGE_FALLTHRU
);
3002 redirect_edge_and_branch_force (e
, new_bb
);
3007 /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */
3010 rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED
)
3014 /* Return 1 if BB ends with a call, possibly followed by some
3015 instructions that must stay with the call, 0 otherwise. */
3018 rtl_block_ends_with_call_p (basic_block bb
)
3020 rtx insn
= BB_END (bb
);
3022 while (!CALL_P (insn
)
3023 && insn
!= BB_HEAD (bb
)
3024 && (keep_with_call_p (insn
)
3026 || DEBUG_INSN_P (insn
)))
3027 insn
= PREV_INSN (insn
);
3028 return (CALL_P (insn
));
3031 /* Return 1 if BB ends with a conditional branch, 0 otherwise. */
3034 rtl_block_ends_with_condjump_p (const_basic_block bb
)
3036 return any_condjump_p (BB_END (bb
));
3039 /* Return true if we need to add fake edge to exit.
3040 Helper function for rtl_flow_call_edges_add. */
3043 need_fake_edge_p (const_rtx insn
)
3049 && !SIBLING_CALL_P (insn
)
3050 && !find_reg_note (insn
, REG_NORETURN
, NULL
)
3051 && !(RTL_CONST_OR_PURE_CALL_P (insn
))))
3054 return ((GET_CODE (PATTERN (insn
)) == ASM_OPERANDS
3055 && MEM_VOLATILE_P (PATTERN (insn
)))
3056 || (GET_CODE (PATTERN (insn
)) == PARALLEL
3057 && asm_noperands (insn
) != -1
3058 && MEM_VOLATILE_P (XVECEXP (PATTERN (insn
), 0, 0)))
3059 || GET_CODE (PATTERN (insn
)) == ASM_INPUT
);
3062 /* Add fake edges to the function exit for any non constant and non noreturn
3063 calls, volatile inline assembly in the bitmap of blocks specified by
3064 BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks
3067 The goal is to expose cases in which entering a basic block does not imply
3068 that all subsequent instructions must be executed. */
3071 rtl_flow_call_edges_add (sbitmap blocks
)
3074 int blocks_split
= 0;
3075 int last_bb
= last_basic_block
;
3076 bool check_last_block
= false;
3078 if (n_basic_blocks
== NUM_FIXED_BLOCKS
)
3082 check_last_block
= true;
3084 check_last_block
= TEST_BIT (blocks
, EXIT_BLOCK_PTR
->prev_bb
->index
);
3086 /* In the last basic block, before epilogue generation, there will be
3087 a fallthru edge to EXIT. Special care is required if the last insn
3088 of the last basic block is a call because make_edge folds duplicate
3089 edges, which would result in the fallthru edge also being marked
3090 fake, which would result in the fallthru edge being removed by
3091 remove_fake_edges, which would result in an invalid CFG.
3093 Moreover, we can't elide the outgoing fake edge, since the block
3094 profiler needs to take this into account in order to solve the minimal
3095 spanning tree in the case that the call doesn't return.
3097 Handle this by adding a dummy instruction in a new last basic block. */
3098 if (check_last_block
)
3100 basic_block bb
= EXIT_BLOCK_PTR
->prev_bb
;
3101 rtx insn
= BB_END (bb
);
3103 /* Back up past insns that must be kept in the same block as a call. */
3104 while (insn
!= BB_HEAD (bb
)
3105 && keep_with_call_p (insn
))
3106 insn
= PREV_INSN (insn
);
3108 if (need_fake_edge_p (insn
))
3112 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
3115 insert_insn_on_edge (gen_use (const0_rtx
), e
);
3116 commit_edge_insertions ();
3121 /* Now add fake edges to the function exit for any non constant
3122 calls since there is no way that we can determine if they will
3125 for (i
= NUM_FIXED_BLOCKS
; i
< last_bb
; i
++)
3127 basic_block bb
= BASIC_BLOCK (i
);
3134 if (blocks
&& !TEST_BIT (blocks
, i
))
3137 for (insn
= BB_END (bb
); ; insn
= prev_insn
)
3139 prev_insn
= PREV_INSN (insn
);
3140 if (need_fake_edge_p (insn
))
3143 rtx split_at_insn
= insn
;
3145 /* Don't split the block between a call and an insn that should
3146 remain in the same block as the call. */
3148 while (split_at_insn
!= BB_END (bb
)
3149 && keep_with_call_p (NEXT_INSN (split_at_insn
)))
3150 split_at_insn
= NEXT_INSN (split_at_insn
);
3152 /* The handling above of the final block before the epilogue
3153 should be enough to verify that there is no edge to the exit
3154 block in CFG already. Calling make_edge in such case would
3155 cause us to mark that edge as fake and remove it later. */
3157 #ifdef ENABLE_CHECKING
3158 if (split_at_insn
== BB_END (bb
))
3160 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
3161 gcc_assert (e
== NULL
);
3165 /* Note that the following may create a new basic block
3166 and renumber the existing basic blocks. */
3167 if (split_at_insn
!= BB_END (bb
))
3169 e
= split_block (bb
, split_at_insn
);
3174 make_edge (bb
, EXIT_BLOCK_PTR
, EDGE_FAKE
);
3177 if (insn
== BB_HEAD (bb
))
3183 verify_flow_info ();
3185 return blocks_split
;
3188 /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is
3189 the conditional branch target, SECOND_HEAD should be the fall-thru
3190 there is no need to handle this here the loop versioning code handles
3191 this. the reason for SECON_HEAD is that it is needed for condition
3192 in trees, and this should be of the same type since it is a hook. */
3194 rtl_lv_add_condition_to_bb (basic_block first_head
,
3195 basic_block second_head ATTRIBUTE_UNUSED
,
3196 basic_block cond_bb
, void *comp_rtx
)
3198 rtx label
, seq
, jump
;
3199 rtx op0
= XEXP ((rtx
)comp_rtx
, 0);
3200 rtx op1
= XEXP ((rtx
)comp_rtx
, 1);
3201 enum rtx_code comp
= GET_CODE ((rtx
)comp_rtx
);
3202 enum machine_mode mode
;
3205 label
= block_label (first_head
);
3206 mode
= GET_MODE (op0
);
3207 if (mode
== VOIDmode
)
3208 mode
= GET_MODE (op1
);
3211 op0
= force_operand (op0
, NULL_RTX
);
3212 op1
= force_operand (op1
, NULL_RTX
);
3213 do_compare_rtx_and_jump (op0
, op1
, comp
, 0,
3214 mode
, NULL_RTX
, NULL_RTX
, label
, -1);
3215 jump
= get_last_insn ();
3216 JUMP_LABEL (jump
) = label
;
3217 LABEL_NUSES (label
)++;
3221 /* Add the new cond , in the new head. */
3222 emit_insn_after(seq
, BB_END(cond_bb
));
3226 /* Given a block B with unconditional branch at its end, get the
3227 store the return the branch edge and the fall-thru edge in
3228 BRANCH_EDGE and FALLTHRU_EDGE respectively. */
3230 rtl_extract_cond_bb_edges (basic_block b
, edge
*branch_edge
,
3231 edge
*fallthru_edge
)
3233 edge e
= EDGE_SUCC (b
, 0);
3235 if (e
->flags
& EDGE_FALLTHRU
)
3238 *branch_edge
= EDGE_SUCC (b
, 1);
3243 *fallthru_edge
= EDGE_SUCC (b
, 1);
3248 init_rtl_bb_info (basic_block bb
)
3250 gcc_assert (!bb
->il
.x
.rtl
);
3251 bb
->il
.x
.head_
= NULL
;
3252 bb
->il
.x
.rtl
= ggc_alloc_cleared_rtl_bb_info ();
3255 /* Returns true if it is possible to remove edge E by redirecting
3256 it to the destination of the other edge from E->src. */
3259 rtl_can_remove_branch_p (const_edge e
)
3261 const_basic_block src
= e
->src
;
3262 const_basic_block target
= EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
)->dest
;
3263 const_rtx insn
= BB_END (src
), set
;
3265 /* The conditions are taken from try_redirect_by_replacing_jump. */
3266 if (target
== EXIT_BLOCK_PTR
)
3269 if (e
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
3272 if (find_reg_note (insn
, REG_CROSSING_JUMP
, NULL_RTX
)
3273 || BB_PARTITION (src
) != BB_PARTITION (target
))
3276 if (!onlyjump_p (insn
)
3277 || tablejump_p (insn
, NULL
, NULL
))
3280 set
= single_set (insn
);
3281 if (!set
|| side_effects_p (set
))
3287 /* We do not want to declare these functions in a header file, since they
3288 should only be used through the cfghooks interface, and we do not want to
3289 move them here since it would require also moving quite a lot of related
3290 code. They are in cfglayout.c. */
3291 extern bool cfg_layout_can_duplicate_bb_p (const_basic_block
);
3292 extern basic_block
cfg_layout_duplicate_bb (basic_block
);
3295 rtl_duplicate_bb (basic_block bb
)
3297 bb
= cfg_layout_duplicate_bb (bb
);
3302 /* Implementation of CFG manipulation for linearized RTL. */
3303 struct cfg_hooks rtl_cfg_hooks
= {
3305 rtl_verify_flow_info
,
3307 rtl_create_basic_block
,
3308 rtl_redirect_edge_and_branch
,
3309 rtl_redirect_edge_and_branch_force
,
3310 rtl_can_remove_branch_p
,
3313 rtl_move_block_after
,
3314 rtl_can_merge_blocks
, /* can_merge_blocks_p */
3318 cfg_layout_can_duplicate_bb_p
,
3321 rtl_make_forwarder_block
,
3322 rtl_tidy_fallthru_edge
,
3323 rtl_force_nonfallthru
,
3324 rtl_block_ends_with_call_p
,
3325 rtl_block_ends_with_condjump_p
,
3326 rtl_flow_call_edges_add
,
3327 NULL
, /* execute_on_growing_pred */
3328 NULL
, /* execute_on_shrinking_pred */
3329 NULL
, /* duplicate loop for trees */
3330 NULL
, /* lv_add_condition_to_bb */
3331 NULL
, /* lv_adjust_loop_header_phi*/
3332 NULL
, /* extract_cond_bb_edges */
3333 NULL
/* flush_pending_stmts */
3336 /* Implementation of CFG manipulation for cfg layout RTL, where
3337 basic block connected via fallthru edges does not have to be adjacent.
3338 This representation will hopefully become the default one in future
3339 version of the compiler. */
3341 struct cfg_hooks cfg_layout_rtl_cfg_hooks
= {
3343 rtl_verify_flow_info_1
,
3345 cfg_layout_create_basic_block
,
3346 cfg_layout_redirect_edge_and_branch
,
3347 cfg_layout_redirect_edge_and_branch_force
,
3348 rtl_can_remove_branch_p
,
3349 cfg_layout_delete_block
,
3350 cfg_layout_split_block
,
3351 rtl_move_block_after
,
3352 cfg_layout_can_merge_blocks_p
,
3353 cfg_layout_merge_blocks
,
3356 cfg_layout_can_duplicate_bb_p
,
3357 cfg_layout_duplicate_bb
,
3358 cfg_layout_split_edge
,
3359 rtl_make_forwarder_block
,
3360 NULL
, /* tidy_fallthru_edge */
3361 rtl_force_nonfallthru
,
3362 rtl_block_ends_with_call_p
,
3363 rtl_block_ends_with_condjump_p
,
3364 rtl_flow_call_edges_add
,
3365 NULL
, /* execute_on_growing_pred */
3366 NULL
, /* execute_on_shrinking_pred */
3367 duplicate_loop_to_header_edge
, /* duplicate loop for trees */
3368 rtl_lv_add_condition_to_bb
, /* lv_add_condition_to_bb */
3369 NULL
, /* lv_adjust_loop_header_phi*/
3370 rtl_extract_cond_bb_edges
, /* extract_cond_bb_edges */
3371 NULL
/* flush_pending_stmts */