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"
53 #include "rtl-error.h"
56 #include "insn-attr.h"
57 #include "insn-config.h"
58 #include "cfglayout.h"
61 #include "common/common-target.h"
64 #include "tree-pass.h"
67 static int can_delete_note_p (const_rtx
);
68 static int can_delete_label_p (const_rtx
);
69 static basic_block
rtl_split_edge (edge
);
70 static bool rtl_move_block_after (basic_block
, basic_block
);
71 static int rtl_verify_flow_info (void);
72 static basic_block
cfg_layout_split_block (basic_block
, void *);
73 static edge
cfg_layout_redirect_edge_and_branch (edge
, basic_block
);
74 static basic_block
cfg_layout_redirect_edge_and_branch_force (edge
, basic_block
);
75 static void cfg_layout_delete_block (basic_block
);
76 static void rtl_delete_block (basic_block
);
77 static basic_block
rtl_redirect_edge_and_branch_force (edge
, basic_block
);
78 static edge
rtl_redirect_edge_and_branch (edge
, basic_block
);
79 static basic_block
rtl_split_block (basic_block
, void *);
80 static void rtl_dump_bb (basic_block
, FILE *, int, int);
81 static int rtl_verify_flow_info_1 (void);
82 static void rtl_make_forwarder_block (edge
);
84 /* Return true if NOTE is not one of the ones that must be kept paired,
85 so that we may simply delete it. */
88 can_delete_note_p (const_rtx note
)
90 switch (NOTE_KIND (note
))
92 case NOTE_INSN_DELETED
:
93 case NOTE_INSN_BASIC_BLOCK
:
94 case NOTE_INSN_EPILOGUE_BEG
:
102 /* True if a given label can be deleted. */
105 can_delete_label_p (const_rtx label
)
107 return (!LABEL_PRESERVE_P (label
)
108 /* User declared labels must be preserved. */
109 && LABEL_NAME (label
) == 0
110 && !in_expr_list_p (forced_labels
, label
));
113 /* Delete INSN by patching it out. */
116 delete_insn (rtx insn
)
119 bool really_delete
= true;
123 /* Some labels can't be directly removed from the INSN chain, as they
124 might be references via variables, constant pool etc.
125 Convert them to the special NOTE_INSN_DELETED_LABEL note. */
126 if (! can_delete_label_p (insn
))
128 const char *name
= LABEL_NAME (insn
);
129 basic_block bb
= BLOCK_FOR_INSN (insn
);
130 rtx bb_note
= NEXT_INSN (insn
);
132 really_delete
= false;
133 PUT_CODE (insn
, NOTE
);
134 NOTE_KIND (insn
) = NOTE_INSN_DELETED_LABEL
;
135 NOTE_DELETED_LABEL_NAME (insn
) = name
;
137 if (bb_note
!= NULL_RTX
&& NOTE_INSN_BASIC_BLOCK_P (bb_note
)
138 && BLOCK_FOR_INSN (bb_note
) == bb
)
140 reorder_insns_nobb (insn
, insn
, bb_note
);
141 BB_HEAD (bb
) = bb_note
;
142 if (BB_END (bb
) == bb_note
)
147 remove_node_from_expr_list (insn
, &nonlocal_goto_handler_labels
);
152 /* If this insn has already been deleted, something is very wrong. */
153 gcc_assert (!INSN_DELETED_P (insn
));
155 INSN_DELETED_P (insn
) = 1;
158 /* If deleting a jump, decrement the use count of the label. Deleting
159 the label itself should happen in the normal course of block merging. */
162 if (JUMP_LABEL (insn
)
163 && LABEL_P (JUMP_LABEL (insn
)))
164 LABEL_NUSES (JUMP_LABEL (insn
))--;
166 /* If there are more targets, remove them too. */
168 = find_reg_note (insn
, REG_LABEL_TARGET
, NULL_RTX
)) != NULL_RTX
169 && LABEL_P (XEXP (note
, 0)))
171 LABEL_NUSES (XEXP (note
, 0))--;
172 remove_note (insn
, note
);
176 /* Also if deleting any insn that references a label as an operand. */
177 while ((note
= find_reg_note (insn
, REG_LABEL_OPERAND
, NULL_RTX
)) != NULL_RTX
178 && LABEL_P (XEXP (note
, 0)))
180 LABEL_NUSES (XEXP (note
, 0))--;
181 remove_note (insn
, note
);
184 if (JUMP_TABLE_DATA_P (insn
))
186 rtx pat
= PATTERN (insn
);
187 int diff_vec_p
= GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
;
188 int len
= XVECLEN (pat
, diff_vec_p
);
191 for (i
= 0; i
< len
; i
++)
193 rtx label
= XEXP (XVECEXP (pat
, diff_vec_p
, i
), 0);
195 /* When deleting code in bulk (e.g. removing many unreachable
196 blocks) we can delete a label that's a target of the vector
197 before deleting the vector itself. */
199 LABEL_NUSES (label
)--;
204 /* Like delete_insn but also purge dead edges from BB. */
207 delete_insn_and_edges (rtx insn
)
212 && BLOCK_FOR_INSN (insn
)
213 && BB_END (BLOCK_FOR_INSN (insn
)) == insn
)
217 purge_dead_edges (BLOCK_FOR_INSN (insn
));
220 /* Unlink a chain of insns between START and FINISH, leaving notes
221 that must be paired. If CLEAR_BB is true, we set bb field for
222 insns that cannot be removed to NULL. */
225 delete_insn_chain (rtx start
, rtx finish
, bool clear_bb
)
229 /* Unchain the insns one by one. It would be quicker to delete all of these
230 with a single unchaining, rather than one at a time, but we need to keep
235 prev
= PREV_INSN (current
);
236 if (NOTE_P (current
) && !can_delete_note_p (current
))
239 delete_insn (current
);
241 if (clear_bb
&& !INSN_DELETED_P (current
))
242 set_block_for_insn (current
, NULL
);
244 if (current
== start
)
250 /* Create a new basic block consisting of the instructions between HEAD and END
251 inclusive. This function is designed to allow fast BB construction - reuses
252 the note and basic block struct in BB_NOTE, if any and do not grow
253 BASIC_BLOCK chain and should be used directly only by CFG construction code.
254 END can be NULL in to create new empty basic block before HEAD. Both END
255 and HEAD can be NULL to create basic block at the end of INSN chain.
256 AFTER is the basic block we should be put after. */
259 create_basic_block_structure (rtx head
, rtx end
, rtx bb_note
, basic_block after
)
264 && (bb
= NOTE_BASIC_BLOCK (bb_note
)) != NULL
267 /* If we found an existing note, thread it back onto the chain. */
275 after
= PREV_INSN (head
);
279 if (after
!= bb_note
&& NEXT_INSN (after
) != bb_note
)
280 reorder_insns_nobb (bb_note
, bb_note
, after
);
284 /* Otherwise we must create a note and a basic block structure. */
288 init_rtl_bb_info (bb
);
291 = emit_note_after (NOTE_INSN_BASIC_BLOCK
, get_last_insn ());
292 else if (LABEL_P (head
) && end
)
294 bb_note
= emit_note_after (NOTE_INSN_BASIC_BLOCK
, head
);
300 bb_note
= emit_note_before (NOTE_INSN_BASIC_BLOCK
, head
);
306 NOTE_BASIC_BLOCK (bb_note
) = bb
;
309 /* Always include the bb note in the block. */
310 if (NEXT_INSN (end
) == bb_note
)
315 bb
->index
= last_basic_block
++;
316 bb
->flags
= BB_NEW
| BB_RTL
;
317 link_block (bb
, after
);
318 SET_BASIC_BLOCK (bb
->index
, bb
);
319 df_bb_refs_record (bb
->index
, false);
320 update_bb_for_insn (bb
);
321 BB_SET_PARTITION (bb
, BB_UNPARTITIONED
);
323 /* Tag the block so that we know it has been used when considering
324 other basic block notes. */
330 /* Create new basic block consisting of instructions in between HEAD and END
331 and place it to the BB chain after block AFTER. END can be NULL to
332 create a new empty basic block before HEAD. Both END and HEAD can be
333 NULL to create basic block at the end of INSN chain. */
336 rtl_create_basic_block (void *headp
, void *endp
, basic_block after
)
338 rtx head
= (rtx
) headp
, end
= (rtx
) endp
;
341 /* Grow the basic block array if needed. */
342 if ((size_t) last_basic_block
>= VEC_length (basic_block
, basic_block_info
))
344 size_t new_size
= last_basic_block
+ (last_basic_block
+ 3) / 4;
345 VEC_safe_grow_cleared (basic_block
, gc
, basic_block_info
, new_size
);
350 bb
= create_basic_block_structure (head
, end
, NULL
, after
);
356 cfg_layout_create_basic_block (void *head
, void *end
, basic_block after
)
358 basic_block newbb
= rtl_create_basic_block (head
, end
, after
);
363 /* Delete the insns in a (non-live) block. We physically delete every
364 non-deleted-note insn, and update the flow graph appropriately.
366 Return nonzero if we deleted an exception handler. */
368 /* ??? Preserving all such notes strikes me as wrong. It would be nice
369 to post-process the stream to remove empty blocks, loops, ranges, etc. */
372 rtl_delete_block (basic_block b
)
376 /* If the head of this block is a CODE_LABEL, then it might be the
377 label for an exception handler which can't be reached. We need
378 to remove the label from the exception_handler_label list. */
381 end
= get_last_bb_insn (b
);
383 /* Selectively delete the entire chain. */
385 delete_insn_chain (insn
, end
, true);
389 fprintf (dump_file
, "deleting block %d\n", b
->index
);
390 df_bb_delete (b
->index
);
393 /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */
396 compute_bb_for_insn (void)
402 rtx end
= BB_END (bb
);
405 for (insn
= BB_HEAD (bb
); ; insn
= NEXT_INSN (insn
))
407 BLOCK_FOR_INSN (insn
) = bb
;
414 /* Release the basic_block_for_insn array. */
417 free_bb_for_insn (void)
420 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
421 if (!BARRIER_P (insn
))
422 BLOCK_FOR_INSN (insn
) = NULL
;
427 rest_of_pass_free_cfg (void)
430 /* The resource.c machinery uses DF but the CFG isn't guaranteed to be
431 valid at that point so it would be too late to call df_analyze. */
432 if (optimize
> 0 && flag_delayed_branch
)
434 df_note_add_problem ();
443 struct rtl_opt_pass pass_free_cfg
=
447 "*free_cfg", /* name */
449 rest_of_pass_free_cfg
, /* execute */
452 0, /* static_pass_number */
454 0, /* properties_required */
455 0, /* properties_provided */
456 PROP_cfg
, /* properties_destroyed */
457 0, /* todo_flags_start */
458 0, /* todo_flags_finish */
462 /* Return RTX to emit after when we want to emit code on the entry of function. */
464 entry_of_function (void)
466 return (n_basic_blocks
> NUM_FIXED_BLOCKS
?
467 BB_HEAD (ENTRY_BLOCK_PTR
->next_bb
) : get_insns ());
470 /* Emit INSN at the entry point of the function, ensuring that it is only
471 executed once per function. */
473 emit_insn_at_entry (rtx insn
)
475 edge_iterator ei
= ei_start (ENTRY_BLOCK_PTR
->succs
);
476 edge e
= ei_safe_edge (ei
);
477 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
479 insert_insn_on_edge (insn
, e
);
480 commit_edge_insertions ();
483 /* Update BLOCK_FOR_INSN of insns between BEGIN and END
484 (or BARRIER if found) and notify df of the bb change.
485 The insn chain range is inclusive
486 (i.e. both BEGIN and END will be updated. */
489 update_bb_for_insn_chain (rtx begin
, rtx end
, basic_block bb
)
493 end
= NEXT_INSN (end
);
494 for (insn
= begin
; insn
!= end
; insn
= NEXT_INSN (insn
))
495 if (!BARRIER_P (insn
))
496 df_insn_change_bb (insn
, bb
);
499 /* Update BLOCK_FOR_INSN of insns in BB to BB,
500 and notify df of the change. */
503 update_bb_for_insn (basic_block bb
)
505 update_bb_for_insn_chain (BB_HEAD (bb
), BB_END (bb
), bb
);
509 /* Return the NOTE_INSN_BASIC_BLOCK of BB. */
511 bb_note (basic_block bb
)
517 note
= NEXT_INSN (note
);
519 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (note
));
523 /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK
524 note associated with the BLOCK. */
527 first_insn_after_basic_block_note (basic_block block
)
531 /* Get the first instruction in the block. */
532 insn
= BB_HEAD (block
);
534 if (insn
== NULL_RTX
)
537 insn
= NEXT_INSN (insn
);
538 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn
));
540 return NEXT_INSN (insn
);
543 /* Creates a new basic block just after basic block B by splitting
544 everything after specified instruction I. */
547 rtl_split_block (basic_block bb
, void *insnp
)
550 rtx insn
= (rtx
) insnp
;
556 insn
= first_insn_after_basic_block_note (bb
);
562 insn
= PREV_INSN (insn
);
564 /* If the block contains only debug insns, insn would have
565 been NULL in a non-debug compilation, and then we'd end
566 up emitting a DELETED note. For -fcompare-debug
567 stability, emit the note too. */
568 if (insn
!= BB_END (bb
)
569 && DEBUG_INSN_P (next
)
570 && DEBUG_INSN_P (BB_END (bb
)))
572 while (next
!= BB_END (bb
) && DEBUG_INSN_P (next
))
573 next
= NEXT_INSN (next
);
575 if (next
== BB_END (bb
))
576 emit_note_after (NOTE_INSN_DELETED
, next
);
580 insn
= get_last_insn ();
583 /* We probably should check type of the insn so that we do not create
584 inconsistent cfg. It is checked in verify_flow_info anyway, so do not
586 if (insn
== BB_END (bb
))
587 emit_note_after (NOTE_INSN_DELETED
, insn
);
589 /* Create the new basic block. */
590 new_bb
= create_basic_block (NEXT_INSN (insn
), BB_END (bb
), bb
);
591 BB_COPY_PARTITION (new_bb
, bb
);
594 /* Redirect the outgoing edges. */
595 new_bb
->succs
= bb
->succs
;
597 FOR_EACH_EDGE (e
, ei
, new_bb
->succs
)
600 /* The new block starts off being dirty. */
601 df_set_bb_dirty (bb
);
605 /* Return true if the single edge between blocks A and B is the only place
606 in RTL which holds some unique locus. */
609 unique_locus_on_edge_between_p (basic_block a
, basic_block b
)
611 const int goto_locus
= EDGE_SUCC (a
, 0)->goto_locus
;
617 /* First scan block A backward. */
619 end
= PREV_INSN (BB_HEAD (a
));
620 while (insn
!= end
&& (!NONDEBUG_INSN_P (insn
) || INSN_LOCATOR (insn
) == 0))
621 insn
= PREV_INSN (insn
);
623 if (insn
!= end
&& locator_eq (INSN_LOCATOR (insn
), goto_locus
))
626 /* Then scan block B forward. */
630 end
= NEXT_INSN (BB_END (b
));
631 while (insn
!= end
&& !NONDEBUG_INSN_P (insn
))
632 insn
= NEXT_INSN (insn
);
634 if (insn
!= end
&& INSN_LOCATOR (insn
) != 0
635 && locator_eq (INSN_LOCATOR (insn
), goto_locus
))
642 /* If the single edge between blocks A and B is the only place in RTL which
643 holds some unique locus, emit a nop with that locus between the blocks. */
646 emit_nop_for_unique_locus_between (basic_block a
, basic_block b
)
648 if (!unique_locus_on_edge_between_p (a
, b
))
651 BB_END (a
) = emit_insn_after_noloc (gen_nop (), BB_END (a
), a
);
652 INSN_LOCATOR (BB_END (a
)) = EDGE_SUCC (a
, 0)->goto_locus
;
655 /* Blocks A and B are to be merged into a single block A. The insns
656 are already contiguous. */
659 rtl_merge_blocks (basic_block a
, basic_block b
)
661 rtx b_head
= BB_HEAD (b
), b_end
= BB_END (b
), a_end
= BB_END (a
);
662 rtx del_first
= NULL_RTX
, del_last
= NULL_RTX
;
663 rtx b_debug_start
= b_end
, b_debug_end
= b_end
;
664 bool forwarder_p
= (b
->flags
& BB_FORWARDER_BLOCK
) != 0;
668 fprintf (dump_file
, "Merging block %d into block %d...\n", b
->index
,
671 while (DEBUG_INSN_P (b_end
))
672 b_end
= PREV_INSN (b_debug_start
= b_end
);
674 /* If there was a CODE_LABEL beginning B, delete it. */
675 if (LABEL_P (b_head
))
677 /* Detect basic blocks with nothing but a label. This can happen
678 in particular at the end of a function. */
682 del_first
= del_last
= b_head
;
683 b_head
= NEXT_INSN (b_head
);
686 /* Delete the basic block note and handle blocks containing just that
688 if (NOTE_INSN_BASIC_BLOCK_P (b_head
))
696 b_head
= NEXT_INSN (b_head
);
699 /* If there was a jump out of A, delete it. */
704 for (prev
= PREV_INSN (a_end
); ; prev
= PREV_INSN (prev
))
706 || NOTE_INSN_BASIC_BLOCK_P (prev
)
707 || prev
== BB_HEAD (a
))
713 /* If this was a conditional jump, we need to also delete
714 the insn that set cc0. */
715 if (only_sets_cc0_p (prev
))
719 prev
= prev_nonnote_insn (prev
);
726 a_end
= PREV_INSN (del_first
);
728 else if (BARRIER_P (NEXT_INSN (a_end
)))
729 del_first
= NEXT_INSN (a_end
);
731 /* Delete everything marked above as well as crap that might be
732 hanging out between the two blocks. */
734 BB_HEAD (b
) = b_empty
? NULL_RTX
: b_head
;
735 delete_insn_chain (del_first
, del_last
, true);
737 /* When not optimizing CFG and the edge is the only place in RTL which holds
738 some unique locus, emit a nop with that locus in between. */
741 emit_nop_for_unique_locus_between (a
, b
);
745 /* Reassociate the insns of B with A. */
748 update_bb_for_insn_chain (a_end
, b_debug_end
, a
);
750 BB_END (a
) = b_debug_end
;
751 BB_HEAD (b
) = NULL_RTX
;
753 else if (b_end
!= b_debug_end
)
755 /* Move any deleted labels and other notes between the end of A
756 and the debug insns that make up B after the debug insns,
757 bringing the debug insns into A while keeping the notes after
759 if (NEXT_INSN (a_end
) != b_debug_start
)
760 reorder_insns_nobb (NEXT_INSN (a_end
), PREV_INSN (b_debug_start
),
762 update_bb_for_insn_chain (b_debug_start
, b_debug_end
, a
);
763 BB_END (a
) = b_debug_end
;
766 df_bb_delete (b
->index
);
768 /* If B was a forwarder block, propagate the locus on the edge. */
769 if (forwarder_p
&& !EDGE_SUCC (b
, 0)->goto_locus
)
770 EDGE_SUCC (b
, 0)->goto_locus
= EDGE_SUCC (a
, 0)->goto_locus
;
773 fprintf (dump_file
, "Merged blocks %d and %d.\n", a
->index
, b
->index
);
777 /* Return true when block A and B can be merged. */
780 rtl_can_merge_blocks (basic_block a
, basic_block b
)
782 /* If we are partitioning hot/cold basic blocks, we don't want to
783 mess up unconditional or indirect jumps that cross between hot
786 Basic block partitioning may result in some jumps that appear to
787 be optimizable (or blocks that appear to be mergeable), but which really
788 must be left untouched (they are required to make it safely across
789 partition boundaries). See the comments at the top of
790 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
792 if (BB_PARTITION (a
) != BB_PARTITION (b
))
795 /* Protect the loop latches. */
796 if (current_loops
&& b
->loop_father
->latch
== b
)
799 /* There must be exactly one edge in between the blocks. */
800 return (single_succ_p (a
)
801 && single_succ (a
) == b
804 /* Must be simple edge. */
805 && !(single_succ_edge (a
)->flags
& EDGE_COMPLEX
)
807 && a
!= ENTRY_BLOCK_PTR
&& b
!= EXIT_BLOCK_PTR
808 /* If the jump insn has side effects,
809 we can't kill the edge. */
810 && (!JUMP_P (BB_END (a
))
812 ? simplejump_p (BB_END (a
)) : onlyjump_p (BB_END (a
)))));
815 /* Return the label in the head of basic block BLOCK. Create one if it doesn't
819 block_label (basic_block block
)
821 if (block
== EXIT_BLOCK_PTR
)
824 if (!LABEL_P (BB_HEAD (block
)))
826 BB_HEAD (block
) = emit_label_before (gen_label_rtx (), BB_HEAD (block
));
829 return BB_HEAD (block
);
832 /* Attempt to perform edge redirection by replacing possibly complex jump
833 instruction by unconditional jump or removing jump completely. This can
834 apply only if all edges now point to the same block. The parameters and
835 return values are equivalent to redirect_edge_and_branch. */
838 try_redirect_by_replacing_jump (edge e
, basic_block target
, bool in_cfglayout
)
840 basic_block src
= e
->src
;
841 rtx insn
= BB_END (src
), kill_from
;
845 /* If we are partitioning hot/cold basic blocks, we don't want to
846 mess up unconditional or indirect jumps that cross between hot
849 Basic block partitioning may result in some jumps that appear to
850 be optimizable (or blocks that appear to be mergeable), but which really
851 must be left untouched (they are required to make it safely across
852 partition boundaries). See the comments at the top of
853 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
855 if (find_reg_note (insn
, REG_CROSSING_JUMP
, NULL_RTX
)
856 || BB_PARTITION (src
) != BB_PARTITION (target
))
859 /* We can replace or remove a complex jump only when we have exactly
860 two edges. Also, if we have exactly one outgoing edge, we can
862 if (EDGE_COUNT (src
->succs
) >= 3
863 /* Verify that all targets will be TARGET. Specifically, the
864 edge that is not E must also go to TARGET. */
865 || (EDGE_COUNT (src
->succs
) == 2
866 && EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
)->dest
!= target
))
869 if (!onlyjump_p (insn
))
871 if ((!optimize
|| reload_completed
) && tablejump_p (insn
, NULL
, NULL
))
874 /* Avoid removing branch with side effects. */
875 set
= single_set (insn
);
876 if (!set
|| side_effects_p (set
))
879 /* In case we zap a conditional jump, we'll need to kill
880 the cc0 setter too. */
883 if (reg_mentioned_p (cc0_rtx
, PATTERN (insn
))
884 && only_sets_cc0_p (PREV_INSN (insn
)))
885 kill_from
= PREV_INSN (insn
);
888 /* See if we can create the fallthru edge. */
889 if (in_cfglayout
|| can_fallthru (src
, target
))
892 fprintf (dump_file
, "Removing jump %i.\n", INSN_UID (insn
));
895 /* Selectively unlink whole insn chain. */
898 rtx insn
= BB_FOOTER (src
);
900 delete_insn_chain (kill_from
, BB_END (src
), false);
902 /* Remove barriers but keep jumptables. */
905 if (BARRIER_P (insn
))
907 if (PREV_INSN (insn
))
908 NEXT_INSN (PREV_INSN (insn
)) = NEXT_INSN (insn
);
910 BB_FOOTER (src
) = NEXT_INSN (insn
);
911 if (NEXT_INSN (insn
))
912 PREV_INSN (NEXT_INSN (insn
)) = PREV_INSN (insn
);
916 insn
= NEXT_INSN (insn
);
920 delete_insn_chain (kill_from
, PREV_INSN (BB_HEAD (target
)),
924 /* If this already is simplejump, redirect it. */
925 else if (simplejump_p (insn
))
927 if (e
->dest
== target
)
930 fprintf (dump_file
, "Redirecting jump %i from %i to %i.\n",
931 INSN_UID (insn
), e
->dest
->index
, target
->index
);
932 if (!redirect_jump (insn
, block_label (target
), 0))
934 gcc_assert (target
== EXIT_BLOCK_PTR
);
939 /* Cannot do anything for target exit block. */
940 else if (target
== EXIT_BLOCK_PTR
)
943 /* Or replace possibly complicated jump insn by simple jump insn. */
946 rtx target_label
= block_label (target
);
947 rtx barrier
, label
, table
;
949 emit_jump_insn_after_noloc (gen_jump (target_label
), insn
);
950 JUMP_LABEL (BB_END (src
)) = target_label
;
951 LABEL_NUSES (target_label
)++;
953 fprintf (dump_file
, "Replacing insn %i by jump %i\n",
954 INSN_UID (insn
), INSN_UID (BB_END (src
)));
957 delete_insn_chain (kill_from
, insn
, false);
959 /* Recognize a tablejump that we are converting to a
960 simple jump and remove its associated CODE_LABEL
961 and ADDR_VEC or ADDR_DIFF_VEC. */
962 if (tablejump_p (insn
, &label
, &table
))
963 delete_insn_chain (label
, table
, false);
965 barrier
= next_nonnote_insn (BB_END (src
));
966 if (!barrier
|| !BARRIER_P (barrier
))
967 emit_barrier_after (BB_END (src
));
970 if (barrier
!= NEXT_INSN (BB_END (src
)))
972 /* Move the jump before barrier so that the notes
973 which originally were or were created before jump table are
974 inside the basic block. */
975 rtx new_insn
= BB_END (src
);
977 update_bb_for_insn_chain (NEXT_INSN (BB_END (src
)),
978 PREV_INSN (barrier
), src
);
980 NEXT_INSN (PREV_INSN (new_insn
)) = NEXT_INSN (new_insn
);
981 PREV_INSN (NEXT_INSN (new_insn
)) = PREV_INSN (new_insn
);
983 NEXT_INSN (new_insn
) = barrier
;
984 NEXT_INSN (PREV_INSN (barrier
)) = new_insn
;
986 PREV_INSN (new_insn
) = PREV_INSN (barrier
);
987 PREV_INSN (barrier
) = new_insn
;
992 /* Keep only one edge out and set proper flags. */
993 if (!single_succ_p (src
))
995 gcc_assert (single_succ_p (src
));
997 e
= single_succ_edge (src
);
999 e
->flags
= EDGE_FALLTHRU
;
1003 e
->probability
= REG_BR_PROB_BASE
;
1004 e
->count
= src
->count
;
1006 if (e
->dest
!= target
)
1007 redirect_edge_succ (e
, target
);
1011 /* Subroutine of redirect_branch_edge that tries to patch the jump
1012 instruction INSN so that it reaches block NEW. Do this
1013 only when it originally reached block OLD. Return true if this
1014 worked or the original target wasn't OLD, return false if redirection
1018 patch_jump_insn (rtx insn
, rtx old_label
, basic_block new_bb
)
1021 /* Recognize a tablejump and adjust all matching cases. */
1022 if (tablejump_p (insn
, NULL
, &tmp
))
1026 rtx new_label
= block_label (new_bb
);
1028 if (new_bb
== EXIT_BLOCK_PTR
)
1030 if (GET_CODE (PATTERN (tmp
)) == ADDR_VEC
)
1031 vec
= XVEC (PATTERN (tmp
), 0);
1033 vec
= XVEC (PATTERN (tmp
), 1);
1035 for (j
= GET_NUM_ELEM (vec
) - 1; j
>= 0; --j
)
1036 if (XEXP (RTVEC_ELT (vec
, j
), 0) == old_label
)
1038 RTVEC_ELT (vec
, j
) = gen_rtx_LABEL_REF (Pmode
, new_label
);
1039 --LABEL_NUSES (old_label
);
1040 ++LABEL_NUSES (new_label
);
1043 /* Handle casesi dispatch insns. */
1044 if ((tmp
= single_set (insn
)) != NULL
1045 && SET_DEST (tmp
) == pc_rtx
1046 && GET_CODE (SET_SRC (tmp
)) == IF_THEN_ELSE
1047 && GET_CODE (XEXP (SET_SRC (tmp
), 2)) == LABEL_REF
1048 && XEXP (XEXP (SET_SRC (tmp
), 2), 0) == old_label
)
1050 XEXP (SET_SRC (tmp
), 2) = gen_rtx_LABEL_REF (Pmode
,
1052 --LABEL_NUSES (old_label
);
1053 ++LABEL_NUSES (new_label
);
1056 else if ((tmp
= extract_asm_operands (PATTERN (insn
))) != NULL
)
1058 int i
, n
= ASM_OPERANDS_LABEL_LENGTH (tmp
);
1059 rtx new_label
, note
;
1061 if (new_bb
== EXIT_BLOCK_PTR
)
1063 new_label
= block_label (new_bb
);
1065 for (i
= 0; i
< n
; ++i
)
1067 rtx old_ref
= ASM_OPERANDS_LABEL (tmp
, i
);
1068 gcc_assert (GET_CODE (old_ref
) == LABEL_REF
);
1069 if (XEXP (old_ref
, 0) == old_label
)
1071 ASM_OPERANDS_LABEL (tmp
, i
)
1072 = gen_rtx_LABEL_REF (Pmode
, new_label
);
1073 --LABEL_NUSES (old_label
);
1074 ++LABEL_NUSES (new_label
);
1078 if (JUMP_LABEL (insn
) == old_label
)
1080 JUMP_LABEL (insn
) = new_label
;
1081 note
= find_reg_note (insn
, REG_LABEL_TARGET
, new_label
);
1083 remove_note (insn
, note
);
1087 note
= find_reg_note (insn
, REG_LABEL_TARGET
, old_label
);
1089 remove_note (insn
, note
);
1090 if (JUMP_LABEL (insn
) != new_label
1091 && !find_reg_note (insn
, REG_LABEL_TARGET
, new_label
))
1092 add_reg_note (insn
, REG_LABEL_TARGET
, new_label
);
1094 while ((note
= find_reg_note (insn
, REG_LABEL_OPERAND
, old_label
))
1096 XEXP (note
, 0) = new_label
;
1100 /* ?? We may play the games with moving the named labels from
1101 one basic block to the other in case only one computed_jump is
1103 if (computed_jump_p (insn
)
1104 /* A return instruction can't be redirected. */
1105 || returnjump_p (insn
))
1108 if (!currently_expanding_to_rtl
|| JUMP_LABEL (insn
) == old_label
)
1110 /* If the insn doesn't go where we think, we're confused. */
1111 gcc_assert (JUMP_LABEL (insn
) == old_label
);
1113 /* If the substitution doesn't succeed, die. This can happen
1114 if the back end emitted unrecognizable instructions or if
1115 target is exit block on some arches. */
1116 if (!redirect_jump (insn
, block_label (new_bb
), 0))
1118 gcc_assert (new_bb
== EXIT_BLOCK_PTR
);
1127 /* Redirect edge representing branch of (un)conditional jump or tablejump,
1130 redirect_branch_edge (edge e
, basic_block target
)
1132 rtx old_label
= BB_HEAD (e
->dest
);
1133 basic_block src
= e
->src
;
1134 rtx insn
= BB_END (src
);
1136 /* We can only redirect non-fallthru edges of jump insn. */
1137 if (e
->flags
& EDGE_FALLTHRU
)
1139 else if (!JUMP_P (insn
) && !currently_expanding_to_rtl
)
1142 if (!currently_expanding_to_rtl
)
1144 if (!patch_jump_insn (insn
, old_label
, target
))
1148 /* When expanding this BB might actually contain multiple
1149 jumps (i.e. not yet split by find_many_sub_basic_blocks).
1150 Redirect all of those that match our label. */
1151 FOR_BB_INSNS (src
, insn
)
1152 if (JUMP_P (insn
) && !patch_jump_insn (insn
, old_label
, target
))
1156 fprintf (dump_file
, "Edge %i->%i redirected to %i\n",
1157 e
->src
->index
, e
->dest
->index
, target
->index
);
1159 if (e
->dest
!= target
)
1160 e
= redirect_edge_succ_nodup (e
, target
);
1165 /* Attempt to change code to redirect edge E to TARGET. Don't do that on
1166 expense of adding new instructions or reordering basic blocks.
1168 Function can be also called with edge destination equivalent to the TARGET.
1169 Then it should try the simplifications and do nothing if none is possible.
1171 Return edge representing the branch if transformation succeeded. Return NULL
1173 We still return NULL in case E already destinated TARGET and we didn't
1174 managed to simplify instruction stream. */
1177 rtl_redirect_edge_and_branch (edge e
, basic_block target
)
1180 basic_block src
= e
->src
;
1182 if (e
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
1185 if (e
->dest
== target
)
1188 if ((ret
= try_redirect_by_replacing_jump (e
, target
, false)) != NULL
)
1190 df_set_bb_dirty (src
);
1194 ret
= redirect_branch_edge (e
, target
);
1198 df_set_bb_dirty (src
);
1202 /* Like force_nonfallthru below, but additionally performs redirection
1203 Used by redirect_edge_and_branch_force. JUMP_LABEL is used only
1204 when redirecting to the EXIT_BLOCK, it is either ret_rtx or
1205 simple_return_rtx, indicating which kind of returnjump to create.
1206 It should be NULL otherwise. */
1209 force_nonfallthru_and_redirect (edge e
, basic_block target
, rtx jump_label
)
1211 basic_block jump_block
, new_bb
= NULL
, src
= e
->src
;
1214 int abnormal_edge_flags
= 0;
1215 bool asm_goto_edge
= false;
1218 /* In the case the last instruction is conditional jump to the next
1219 instruction, first redirect the jump itself and then continue
1220 by creating a basic block afterwards to redirect fallthru edge. */
1221 if (e
->src
!= ENTRY_BLOCK_PTR
&& e
->dest
!= EXIT_BLOCK_PTR
1222 && any_condjump_p (BB_END (e
->src
))
1223 && JUMP_LABEL (BB_END (e
->src
)) == BB_HEAD (e
->dest
))
1226 edge b
= unchecked_make_edge (e
->src
, target
, 0);
1229 redirected
= redirect_jump (BB_END (e
->src
), block_label (target
), 0);
1230 gcc_assert (redirected
);
1232 note
= find_reg_note (BB_END (e
->src
), REG_BR_PROB
, NULL_RTX
);
1235 int prob
= INTVAL (XEXP (note
, 0));
1237 b
->probability
= prob
;
1238 b
->count
= e
->count
* prob
/ REG_BR_PROB_BASE
;
1239 e
->probability
-= e
->probability
;
1240 e
->count
-= b
->count
;
1241 if (e
->probability
< 0)
1248 if (e
->flags
& EDGE_ABNORMAL
)
1250 /* Irritating special case - fallthru edge to the same block as abnormal
1252 We can't redirect abnormal edge, but we still can split the fallthru
1253 one and create separate abnormal edge to original destination.
1254 This allows bb-reorder to make such edge non-fallthru. */
1255 gcc_assert (e
->dest
== target
);
1256 abnormal_edge_flags
= e
->flags
& ~(EDGE_FALLTHRU
| EDGE_CAN_FALLTHRU
);
1257 e
->flags
&= EDGE_FALLTHRU
| EDGE_CAN_FALLTHRU
;
1261 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
1262 if (e
->src
== ENTRY_BLOCK_PTR
)
1264 /* We can't redirect the entry block. Create an empty block
1265 at the start of the function which we use to add the new
1271 basic_block bb
= create_basic_block (BB_HEAD (e
->dest
), NULL
, ENTRY_BLOCK_PTR
);
1273 /* Change the existing edge's source to be the new block, and add
1274 a new edge from the entry block to the new block. */
1276 for (ei
= ei_start (ENTRY_BLOCK_PTR
->succs
); (tmp
= ei_safe_edge (ei
)); )
1280 VEC_unordered_remove (edge
, ENTRY_BLOCK_PTR
->succs
, ei
.index
);
1290 VEC_safe_push (edge
, gc
, bb
->succs
, e
);
1291 make_single_succ_edge (ENTRY_BLOCK_PTR
, bb
, EDGE_FALLTHRU
);
1295 /* If e->src ends with asm goto, see if any of the ASM_OPERANDS_LABELs
1296 don't point to target label. */
1297 if (JUMP_P (BB_END (e
->src
))
1298 && target
!= EXIT_BLOCK_PTR
1299 && e
->dest
== target
1300 && (e
->flags
& EDGE_FALLTHRU
)
1301 && (note
= extract_asm_operands (PATTERN (BB_END (e
->src
)))))
1303 int i
, n
= ASM_OPERANDS_LABEL_LENGTH (note
);
1305 for (i
= 0; i
< n
; ++i
)
1306 if (XEXP (ASM_OPERANDS_LABEL (note
, i
), 0) == BB_HEAD (target
))
1308 asm_goto_edge
= true;
1313 if (EDGE_COUNT (e
->src
->succs
) >= 2 || abnormal_edge_flags
|| asm_goto_edge
)
1315 gcov_type count
= e
->count
;
1316 int probability
= e
->probability
;
1317 /* Create the new structures. */
1319 /* If the old block ended with a tablejump, skip its table
1320 by searching forward from there. Otherwise start searching
1321 forward from the last instruction of the old block. */
1322 if (!tablejump_p (BB_END (e
->src
), NULL
, ¬e
))
1323 note
= BB_END (e
->src
);
1324 note
= NEXT_INSN (note
);
1326 jump_block
= create_basic_block (note
, NULL
, e
->src
);
1327 jump_block
->count
= count
;
1328 jump_block
->frequency
= EDGE_FREQUENCY (e
);
1329 jump_block
->loop_depth
= target
->loop_depth
;
1331 /* Make sure new block ends up in correct hot/cold section. */
1333 BB_COPY_PARTITION (jump_block
, e
->src
);
1334 if (flag_reorder_blocks_and_partition
1335 && targetm_common
.have_named_sections
1336 && JUMP_P (BB_END (jump_block
))
1337 && !any_condjump_p (BB_END (jump_block
))
1338 && (EDGE_SUCC (jump_block
, 0)->flags
& EDGE_CROSSING
))
1339 add_reg_note (BB_END (jump_block
), REG_CROSSING_JUMP
, NULL_RTX
);
1342 new_edge
= make_edge (e
->src
, jump_block
, EDGE_FALLTHRU
);
1343 new_edge
->probability
= probability
;
1344 new_edge
->count
= count
;
1346 /* Redirect old edge. */
1347 redirect_edge_pred (e
, jump_block
);
1348 e
->probability
= REG_BR_PROB_BASE
;
1350 /* If asm goto has any label refs to target's label,
1351 add also edge from asm goto bb to target. */
1354 new_edge
->probability
/= 2;
1355 new_edge
->count
/= 2;
1356 jump_block
->count
/= 2;
1357 jump_block
->frequency
/= 2;
1358 new_edge
= make_edge (new_edge
->src
, target
,
1359 e
->flags
& ~EDGE_FALLTHRU
);
1360 new_edge
->probability
= probability
- probability
/ 2;
1361 new_edge
->count
= count
- count
/ 2;
1364 new_bb
= jump_block
;
1367 jump_block
= e
->src
;
1369 if (e
->goto_locus
&& e
->goto_block
== NULL
)
1370 loc
= e
->goto_locus
;
1373 e
->flags
&= ~EDGE_FALLTHRU
;
1374 if (target
== EXIT_BLOCK_PTR
)
1376 if (jump_label
== ret_rtx
)
1379 emit_jump_insn_after_setloc (gen_return (), BB_END (jump_block
), loc
);
1386 gcc_assert (jump_label
== simple_return_rtx
);
1387 #ifdef HAVE_simple_return
1388 emit_jump_insn_after_setloc (gen_simple_return (),
1389 BB_END (jump_block
), loc
);
1394 set_return_jump_label (BB_END (jump_block
));
1398 rtx label
= block_label (target
);
1399 emit_jump_insn_after_setloc (gen_jump (label
), BB_END (jump_block
), loc
);
1400 JUMP_LABEL (BB_END (jump_block
)) = label
;
1401 LABEL_NUSES (label
)++;
1404 emit_barrier_after (BB_END (jump_block
));
1405 redirect_edge_succ_nodup (e
, target
);
1407 if (abnormal_edge_flags
)
1408 make_edge (src
, target
, abnormal_edge_flags
);
1410 df_mark_solutions_dirty ();
1414 /* Edge E is assumed to be fallthru edge. Emit needed jump instruction
1415 (and possibly create new basic block) to make edge non-fallthru.
1416 Return newly created BB or NULL if none. */
1419 rtl_force_nonfallthru (edge e
)
1421 return force_nonfallthru_and_redirect (e
, e
->dest
, NULL_RTX
);
1424 /* Redirect edge even at the expense of creating new jump insn or
1425 basic block. Return new basic block if created, NULL otherwise.
1426 Conversion must be possible. */
1429 rtl_redirect_edge_and_branch_force (edge e
, basic_block target
)
1431 if (redirect_edge_and_branch (e
, target
)
1432 || e
->dest
== target
)
1435 /* In case the edge redirection failed, try to force it to be non-fallthru
1436 and redirect newly created simplejump. */
1437 df_set_bb_dirty (e
->src
);
1438 return force_nonfallthru_and_redirect (e
, target
, NULL_RTX
);
1441 /* The given edge should potentially be a fallthru edge. If that is in
1442 fact true, delete the jump and barriers that are in the way. */
1445 rtl_tidy_fallthru_edge (edge e
)
1448 basic_block b
= e
->src
, c
= b
->next_bb
;
1450 /* ??? In a late-running flow pass, other folks may have deleted basic
1451 blocks by nopping out blocks, leaving multiple BARRIERs between here
1452 and the target label. They ought to be chastised and fixed.
1454 We can also wind up with a sequence of undeletable labels between
1455 one block and the next.
1457 So search through a sequence of barriers, labels, and notes for
1458 the head of block C and assert that we really do fall through. */
1460 for (q
= NEXT_INSN (BB_END (b
)); q
!= BB_HEAD (c
); q
= NEXT_INSN (q
))
1464 /* Remove what will soon cease being the jump insn from the source block.
1465 If block B consisted only of this single jump, turn it into a deleted
1470 && (any_uncondjump_p (q
)
1471 || single_succ_p (b
)))
1474 /* If this was a conditional jump, we need to also delete
1475 the insn that set cc0. */
1476 if (any_condjump_p (q
) && only_sets_cc0_p (PREV_INSN (q
)))
1483 /* Selectively unlink the sequence. */
1484 if (q
!= PREV_INSN (BB_HEAD (c
)))
1485 delete_insn_chain (NEXT_INSN (q
), PREV_INSN (BB_HEAD (c
)), false);
1487 e
->flags
|= EDGE_FALLTHRU
;
1490 /* Should move basic block BB after basic block AFTER. NIY. */
1493 rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED
,
1494 basic_block after ATTRIBUTE_UNUSED
)
1499 /* Split a (typically critical) edge. Return the new block.
1500 The edge must not be abnormal.
1502 ??? The code generally expects to be called on critical edges.
1503 The case of a block ending in an unconditional jump to a
1504 block with multiple predecessors is not handled optimally. */
1507 rtl_split_edge (edge edge_in
)
1512 /* Abnormal edges cannot be split. */
1513 gcc_assert (!(edge_in
->flags
& EDGE_ABNORMAL
));
1515 /* We are going to place the new block in front of edge destination.
1516 Avoid existence of fallthru predecessors. */
1517 if ((edge_in
->flags
& EDGE_FALLTHRU
) == 0)
1519 edge e
= find_fallthru_edge (edge_in
->dest
->preds
);
1522 force_nonfallthru (e
);
1525 /* Create the basic block note. */
1526 if (edge_in
->dest
!= EXIT_BLOCK_PTR
)
1527 before
= BB_HEAD (edge_in
->dest
);
1531 /* If this is a fall through edge to the exit block, the blocks might be
1532 not adjacent, and the right place is after the source. */
1533 if ((edge_in
->flags
& EDGE_FALLTHRU
) && edge_in
->dest
== EXIT_BLOCK_PTR
)
1535 before
= NEXT_INSN (BB_END (edge_in
->src
));
1536 bb
= create_basic_block (before
, NULL
, edge_in
->src
);
1537 BB_COPY_PARTITION (bb
, edge_in
->src
);
1541 bb
= create_basic_block (before
, NULL
, edge_in
->dest
->prev_bb
);
1542 /* ??? Why not edge_in->dest->prev_bb here? */
1543 BB_COPY_PARTITION (bb
, edge_in
->dest
);
1546 make_single_succ_edge (bb
, edge_in
->dest
, EDGE_FALLTHRU
);
1548 /* For non-fallthru edges, we must adjust the predecessor's
1549 jump instruction to target our new block. */
1550 if ((edge_in
->flags
& EDGE_FALLTHRU
) == 0)
1552 edge redirected
= redirect_edge_and_branch (edge_in
, bb
);
1553 gcc_assert (redirected
);
1557 if (edge_in
->src
!= ENTRY_BLOCK_PTR
)
1559 /* For asm goto even splitting of fallthru edge might
1560 need insn patching, as other labels might point to the
1562 rtx last
= BB_END (edge_in
->src
);
1565 && edge_in
->dest
!= EXIT_BLOCK_PTR
1566 && extract_asm_operands (PATTERN (last
)) != NULL_RTX
1567 && patch_jump_insn (last
, before
, bb
))
1568 df_set_bb_dirty (edge_in
->src
);
1570 redirect_edge_succ (edge_in
, bb
);
1576 /* Queue instructions for insertion on an edge between two basic blocks.
1577 The new instructions and basic blocks (if any) will not appear in the
1578 CFG until commit_edge_insertions is called. */
1581 insert_insn_on_edge (rtx pattern
, edge e
)
1583 /* We cannot insert instructions on an abnormal critical edge.
1584 It will be easier to find the culprit if we die now. */
1585 gcc_assert (!((e
->flags
& EDGE_ABNORMAL
) && EDGE_CRITICAL_P (e
)));
1587 if (e
->insns
.r
== NULL_RTX
)
1590 push_to_sequence (e
->insns
.r
);
1592 emit_insn (pattern
);
1594 e
->insns
.r
= get_insns ();
1598 /* Update the CFG for the instructions queued on edge E. */
1601 commit_one_edge_insertion (edge e
)
1603 rtx before
= NULL_RTX
, after
= NULL_RTX
, insns
, tmp
, last
;
1606 /* Pull the insns off the edge now since the edge might go away. */
1608 e
->insns
.r
= NULL_RTX
;
1610 /* Figure out where to put these insns. If the destination has
1611 one predecessor, insert there. Except for the exit block. */
1612 if (single_pred_p (e
->dest
) && e
->dest
!= EXIT_BLOCK_PTR
)
1616 /* Get the location correct wrt a code label, and "nice" wrt
1617 a basic block note, and before everything else. */
1620 tmp
= NEXT_INSN (tmp
);
1621 if (NOTE_INSN_BASIC_BLOCK_P (tmp
))
1622 tmp
= NEXT_INSN (tmp
);
1623 if (tmp
== BB_HEAD (bb
))
1626 after
= PREV_INSN (tmp
);
1628 after
= get_last_insn ();
1631 /* If the source has one successor and the edge is not abnormal,
1632 insert there. Except for the entry block. */
1633 else if ((e
->flags
& EDGE_ABNORMAL
) == 0
1634 && single_succ_p (e
->src
)
1635 && e
->src
!= ENTRY_BLOCK_PTR
)
1639 /* It is possible to have a non-simple jump here. Consider a target
1640 where some forms of unconditional jumps clobber a register. This
1641 happens on the fr30 for example.
1643 We know this block has a single successor, so we can just emit
1644 the queued insns before the jump. */
1645 if (JUMP_P (BB_END (bb
)))
1646 before
= BB_END (bb
);
1649 /* We'd better be fallthru, or we've lost track of what's what. */
1650 gcc_assert (e
->flags
& EDGE_FALLTHRU
);
1652 after
= BB_END (bb
);
1656 /* Otherwise we must split the edge. */
1659 bb
= split_edge (e
);
1660 after
= BB_END (bb
);
1662 if (flag_reorder_blocks_and_partition
1663 && targetm_common
.have_named_sections
1664 && e
->src
!= ENTRY_BLOCK_PTR
1665 && BB_PARTITION (e
->src
) == BB_COLD_PARTITION
1666 && !(e
->flags
& EDGE_CROSSING
)
1668 && !any_condjump_p (after
)
1669 && (single_succ_edge (bb
)->flags
& EDGE_CROSSING
))
1670 add_reg_note (after
, REG_CROSSING_JUMP
, NULL_RTX
);
1673 /* Now that we've found the spot, do the insertion. */
1676 emit_insn_before_noloc (insns
, before
, bb
);
1677 last
= prev_nonnote_insn (before
);
1680 last
= emit_insn_after_noloc (insns
, after
, bb
);
1682 if (returnjump_p (last
))
1684 /* ??? Remove all outgoing edges from BB and add one for EXIT.
1685 This is not currently a problem because this only happens
1686 for the (single) epilogue, which already has a fallthru edge
1689 e
= single_succ_edge (bb
);
1690 gcc_assert (e
->dest
== EXIT_BLOCK_PTR
1691 && single_succ_p (bb
) && (e
->flags
& EDGE_FALLTHRU
));
1693 e
->flags
&= ~EDGE_FALLTHRU
;
1694 emit_barrier_after (last
);
1697 delete_insn (before
);
1700 gcc_assert (!JUMP_P (last
));
1703 /* Update the CFG for all queued instructions. */
1706 commit_edge_insertions (void)
1710 #ifdef ENABLE_CHECKING
1711 verify_flow_info ();
1714 FOR_BB_BETWEEN (bb
, ENTRY_BLOCK_PTR
, EXIT_BLOCK_PTR
, next_bb
)
1719 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
1721 commit_one_edge_insertion (e
);
1726 /* Print out RTL-specific basic block information (live information
1727 at start and end). */
1730 rtl_dump_bb (basic_block bb
, FILE *outf
, int indent
, int flags ATTRIBUTE_UNUSED
)
1736 s_indent
= (char *) alloca ((size_t) indent
+ 1);
1737 memset (s_indent
, ' ', (size_t) indent
);
1738 s_indent
[indent
] = '\0';
1742 df_dump_top (bb
, outf
);
1746 if (bb
->index
!= ENTRY_BLOCK
&& bb
->index
!= EXIT_BLOCK
)
1747 for (insn
= BB_HEAD (bb
), last
= NEXT_INSN (BB_END (bb
)); insn
!= last
;
1748 insn
= NEXT_INSN (insn
))
1749 print_rtl_single (outf
, insn
);
1753 df_dump_bottom (bb
, outf
);
1759 /* Like print_rtl, but also print out live information for the start of each
1763 print_rtl_with_bb (FILE *outf
, const_rtx rtx_first
)
1767 fprintf (outf
, "(nil)\n");
1770 enum bb_state
{ NOT_IN_BB
, IN_ONE_BB
, IN_MULTIPLE_BB
};
1771 int max_uid
= get_max_uid ();
1772 basic_block
*start
= XCNEWVEC (basic_block
, max_uid
);
1773 basic_block
*end
= XCNEWVEC (basic_block
, max_uid
);
1774 enum bb_state
*in_bb_p
= XCNEWVEC (enum bb_state
, max_uid
);
1779 df_dump_start (outf
);
1781 FOR_EACH_BB_REVERSE (bb
)
1785 start
[INSN_UID (BB_HEAD (bb
))] = bb
;
1786 end
[INSN_UID (BB_END (bb
))] = bb
;
1787 for (x
= BB_HEAD (bb
); x
!= NULL_RTX
; x
= NEXT_INSN (x
))
1789 enum bb_state state
= IN_MULTIPLE_BB
;
1791 if (in_bb_p
[INSN_UID (x
)] == NOT_IN_BB
)
1793 in_bb_p
[INSN_UID (x
)] = state
;
1795 if (x
== BB_END (bb
))
1800 for (tmp_rtx
= rtx_first
; NULL
!= tmp_rtx
; tmp_rtx
= NEXT_INSN (tmp_rtx
))
1804 bb
= start
[INSN_UID (tmp_rtx
)];
1806 dump_bb_info (bb
, true, false, dump_flags
, ";; ", outf
);
1808 if (in_bb_p
[INSN_UID (tmp_rtx
)] == NOT_IN_BB
1809 && !NOTE_P (tmp_rtx
)
1810 && !BARRIER_P (tmp_rtx
))
1811 fprintf (outf
, ";; Insn is not within a basic block\n");
1812 else if (in_bb_p
[INSN_UID (tmp_rtx
)] == IN_MULTIPLE_BB
)
1813 fprintf (outf
, ";; Insn is in multiple basic blocks\n");
1815 did_output
= print_rtl_single (outf
, tmp_rtx
);
1817 bb
= end
[INSN_UID (tmp_rtx
)];
1819 dump_bb_info (bb
, false, true, dump_flags
, ";; ", outf
);
1829 if (crtl
->epilogue_delay_list
!= 0)
1831 fprintf (outf
, "\n;; Insns in epilogue delay list:\n\n");
1832 for (tmp_rtx
= crtl
->epilogue_delay_list
; tmp_rtx
!= 0;
1833 tmp_rtx
= XEXP (tmp_rtx
, 1))
1834 print_rtl_single (outf
, XEXP (tmp_rtx
, 0));
1839 update_br_prob_note (basic_block bb
)
1842 if (!JUMP_P (BB_END (bb
)))
1844 note
= find_reg_note (BB_END (bb
), REG_BR_PROB
, NULL_RTX
);
1845 if (!note
|| INTVAL (XEXP (note
, 0)) == BRANCH_EDGE (bb
)->probability
)
1847 XEXP (note
, 0) = GEN_INT (BRANCH_EDGE (bb
)->probability
);
1850 /* Get the last insn associated with block BB (that includes barriers and
1851 tablejumps after BB). */
1853 get_last_bb_insn (basic_block bb
)
1856 rtx end
= BB_END (bb
);
1858 /* Include any jump table following the basic block. */
1859 if (tablejump_p (end
, NULL
, &tmp
))
1862 /* Include any barriers that may follow the basic block. */
1863 tmp
= next_nonnote_insn_bb (end
);
1864 while (tmp
&& BARRIER_P (tmp
))
1867 tmp
= next_nonnote_insn_bb (end
);
1873 /* Verify the CFG and RTL consistency common for both underlying RTL and
1876 Currently it does following checks:
1878 - overlapping of basic blocks
1879 - insns with wrong BLOCK_FOR_INSN pointers
1880 - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note)
1881 - tails of basic blocks (ensure that boundary is necessary)
1882 - scans body of the basic block for JUMP_INSN, CODE_LABEL
1883 and NOTE_INSN_BASIC_BLOCK
1884 - verify that no fall_thru edge crosses hot/cold partition boundaries
1885 - verify that there are no pending RTL branch predictions
1887 In future it can be extended check a lot of other stuff as well
1888 (reachability of basic blocks, life information, etc. etc.). */
1891 rtl_verify_flow_info_1 (void)
1897 /* Check the general integrity of the basic blocks. */
1898 FOR_EACH_BB_REVERSE (bb
)
1902 if (!(bb
->flags
& BB_RTL
))
1904 error ("BB_RTL flag not set for block %d", bb
->index
);
1908 FOR_BB_INSNS (bb
, insn
)
1909 if (BLOCK_FOR_INSN (insn
) != bb
)
1911 error ("insn %d basic block pointer is %d, should be %d",
1913 BLOCK_FOR_INSN (insn
) ? BLOCK_FOR_INSN (insn
)->index
: 0,
1918 for (insn
= BB_HEADER (bb
); insn
; insn
= NEXT_INSN (insn
))
1919 if (!BARRIER_P (insn
)
1920 && BLOCK_FOR_INSN (insn
) != NULL
)
1922 error ("insn %d in header of bb %d has non-NULL basic block",
1923 INSN_UID (insn
), bb
->index
);
1926 for (insn
= BB_FOOTER (bb
); insn
; insn
= NEXT_INSN (insn
))
1927 if (!BARRIER_P (insn
)
1928 && BLOCK_FOR_INSN (insn
) != NULL
)
1930 error ("insn %d in footer of bb %d has non-NULL basic block",
1931 INSN_UID (insn
), bb
->index
);
1936 /* Now check the basic blocks (boundaries etc.) */
1937 FOR_EACH_BB_REVERSE (bb
)
1939 int n_fallthru
= 0, n_eh
= 0, n_call
= 0, n_abnormal
= 0, n_branch
= 0;
1940 edge e
, fallthru
= NULL
;
1944 if (JUMP_P (BB_END (bb
))
1945 && (note
= find_reg_note (BB_END (bb
), REG_BR_PROB
, NULL_RTX
))
1946 && EDGE_COUNT (bb
->succs
) >= 2
1947 && any_condjump_p (BB_END (bb
)))
1949 if (INTVAL (XEXP (note
, 0)) != BRANCH_EDGE (bb
)->probability
1950 && profile_status
!= PROFILE_ABSENT
)
1952 error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i",
1953 INTVAL (XEXP (note
, 0)), BRANCH_EDGE (bb
)->probability
);
1957 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
1961 if (e
->flags
& EDGE_FALLTHRU
)
1962 n_fallthru
++, fallthru
= e
;
1964 is_crossing
= (BB_PARTITION (e
->src
) != BB_PARTITION (e
->dest
)
1965 && e
->src
!= ENTRY_BLOCK_PTR
1966 && e
->dest
!= EXIT_BLOCK_PTR
);
1967 if (e
->flags
& EDGE_CROSSING
)
1971 error ("EDGE_CROSSING incorrectly set across same section");
1974 if (e
->flags
& EDGE_FALLTHRU
)
1976 error ("fallthru edge crosses section boundary (bb %i)",
1980 if (e
->flags
& EDGE_EH
)
1982 error ("EH edge crosses section boundary (bb %i)",
1987 else if (is_crossing
)
1989 error ("EDGE_CROSSING missing across section boundary");
1993 if ((e
->flags
& ~(EDGE_DFS_BACK
1995 | EDGE_IRREDUCIBLE_LOOP
1998 | EDGE_PRESERVE
)) == 0)
2001 if (e
->flags
& EDGE_ABNORMAL_CALL
)
2004 if (e
->flags
& EDGE_EH
)
2006 else if (e
->flags
& EDGE_ABNORMAL
)
2010 if (n_eh
&& !find_reg_note (BB_END (bb
), REG_EH_REGION
, NULL_RTX
))
2012 error ("missing REG_EH_REGION note in the end of bb %i", bb
->index
);
2017 error ("too many eh edges %i", bb
->index
);
2021 && (!JUMP_P (BB_END (bb
))
2022 || (n_branch
> 1 && (any_uncondjump_p (BB_END (bb
))
2023 || any_condjump_p (BB_END (bb
))))))
2025 error ("too many outgoing branch edges from bb %i", bb
->index
);
2028 if (n_fallthru
&& any_uncondjump_p (BB_END (bb
)))
2030 error ("fallthru edge after unconditional jump %i", bb
->index
);
2033 if (n_branch
!= 1 && any_uncondjump_p (BB_END (bb
)))
2035 error ("wrong number of branch edges after unconditional jump %i",
2039 if (n_branch
!= 1 && any_condjump_p (BB_END (bb
))
2040 && JUMP_LABEL (BB_END (bb
)) != BB_HEAD (fallthru
->dest
))
2042 error ("wrong amount of branch edges after conditional jump %i",
2046 if (n_call
&& !CALL_P (BB_END (bb
)))
2048 error ("call edges for non-call insn in bb %i", bb
->index
);
2052 && (!CALL_P (BB_END (bb
)) && n_call
!= n_abnormal
)
2053 && (!JUMP_P (BB_END (bb
))
2054 || any_condjump_p (BB_END (bb
))
2055 || any_uncondjump_p (BB_END (bb
))))
2057 error ("abnormal edges for no purpose in bb %i", bb
->index
);
2061 for (x
= BB_HEAD (bb
); x
!= NEXT_INSN (BB_END (bb
)); x
= NEXT_INSN (x
))
2062 /* We may have a barrier inside a basic block before dead code
2063 elimination. There is no BLOCK_FOR_INSN field in a barrier. */
2064 if (!BARRIER_P (x
) && BLOCK_FOR_INSN (x
) != bb
)
2067 if (! BLOCK_FOR_INSN (x
))
2069 ("insn %d inside basic block %d but block_for_insn is NULL",
2070 INSN_UID (x
), bb
->index
);
2073 ("insn %d inside basic block %d but block_for_insn is %i",
2074 INSN_UID (x
), bb
->index
, BLOCK_FOR_INSN (x
)->index
);
2079 /* OK pointers are correct. Now check the header of basic
2080 block. It ought to contain optional CODE_LABEL followed
2081 by NOTE_BASIC_BLOCK. */
2085 if (BB_END (bb
) == x
)
2087 error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
2095 if (!NOTE_INSN_BASIC_BLOCK_P (x
) || NOTE_BASIC_BLOCK (x
) != bb
)
2097 error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
2102 if (BB_END (bb
) == x
)
2103 /* Do checks for empty blocks here. */
2106 for (x
= NEXT_INSN (x
); x
; x
= NEXT_INSN (x
))
2108 if (NOTE_INSN_BASIC_BLOCK_P (x
))
2110 error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d",
2111 INSN_UID (x
), bb
->index
);
2115 if (x
== BB_END (bb
))
2118 if (control_flow_insn_p (x
))
2120 error ("in basic block %d:", bb
->index
);
2121 fatal_insn ("flow control insn inside a basic block", x
);
2130 /* Verify the CFG and RTL consistency common for both underlying RTL and
2133 Currently it does following checks:
2134 - all checks of rtl_verify_flow_info_1
2135 - test head/end pointers
2136 - check that all insns are in the basic blocks
2137 (except the switch handling code, barriers and notes)
2138 - check that all returns are followed by barriers
2139 - check that all fallthru edge points to the adjacent blocks. */
2142 rtl_verify_flow_info (void)
2145 int err
= rtl_verify_flow_info_1 ();
2147 rtx last_head
= get_last_insn ();
2148 basic_block
*bb_info
;
2150 const rtx rtx_first
= get_insns ();
2151 basic_block last_bb_seen
= ENTRY_BLOCK_PTR
, curr_bb
= NULL
;
2152 const int max_uid
= get_max_uid ();
2154 bb_info
= XCNEWVEC (basic_block
, max_uid
);
2156 FOR_EACH_BB_REVERSE (bb
)
2159 rtx head
= BB_HEAD (bb
);
2160 rtx end
= BB_END (bb
);
2162 for (x
= last_head
; x
!= NULL_RTX
; x
= PREV_INSN (x
))
2164 /* Verify the end of the basic block is in the INSN chain. */
2168 /* And that the code outside of basic blocks has NULL bb field. */
2170 && BLOCK_FOR_INSN (x
) != NULL
)
2172 error ("insn %d outside of basic blocks has non-NULL bb field",
2180 error ("end insn %d for block %d not found in the insn stream",
2181 INSN_UID (end
), bb
->index
);
2185 /* Work backwards from the end to the head of the basic block
2186 to verify the head is in the RTL chain. */
2187 for (; x
!= NULL_RTX
; x
= PREV_INSN (x
))
2189 /* While walking over the insn chain, verify insns appear
2190 in only one basic block. */
2191 if (bb_info
[INSN_UID (x
)] != NULL
)
2193 error ("insn %d is in multiple basic blocks (%d and %d)",
2194 INSN_UID (x
), bb
->index
, bb_info
[INSN_UID (x
)]->index
);
2198 bb_info
[INSN_UID (x
)] = bb
;
2205 error ("head insn %d for block %d not found in the insn stream",
2206 INSN_UID (head
), bb
->index
);
2210 last_head
= PREV_INSN (x
);
2212 e
= find_fallthru_edge (bb
->succs
);
2217 /* Ensure existence of barrier in BB with no fallthru edges. */
2218 for (insn
= NEXT_INSN (BB_END (bb
)); ; insn
= NEXT_INSN (insn
))
2220 if (!insn
|| NOTE_INSN_BASIC_BLOCK_P (insn
))
2222 error ("missing barrier after block %i", bb
->index
);
2226 if (BARRIER_P (insn
))
2230 else if (e
->src
!= ENTRY_BLOCK_PTR
2231 && e
->dest
!= EXIT_BLOCK_PTR
)
2235 if (e
->src
->next_bb
!= e
->dest
)
2238 ("verify_flow_info: Incorrect blocks for fallthru %i->%i",
2239 e
->src
->index
, e
->dest
->index
);
2243 for (insn
= NEXT_INSN (BB_END (e
->src
)); insn
!= BB_HEAD (e
->dest
);
2244 insn
= NEXT_INSN (insn
))
2245 if (BARRIER_P (insn
) || INSN_P (insn
))
2247 error ("verify_flow_info: Incorrect fallthru %i->%i",
2248 e
->src
->index
, e
->dest
->index
);
2249 fatal_insn ("wrong insn in the fallthru edge", insn
);
2255 for (x
= last_head
; x
!= NULL_RTX
; x
= PREV_INSN (x
))
2257 /* Check that the code before the first basic block has NULL
2260 && BLOCK_FOR_INSN (x
) != NULL
)
2262 error ("insn %d outside of basic blocks has non-NULL bb field",
2270 last_bb_seen
= ENTRY_BLOCK_PTR
;
2272 for (x
= rtx_first
; x
; x
= NEXT_INSN (x
))
2274 if (NOTE_INSN_BASIC_BLOCK_P (x
))
2276 bb
= NOTE_BASIC_BLOCK (x
);
2279 if (bb
!= last_bb_seen
->next_bb
)
2280 internal_error ("basic blocks not laid down consecutively");
2282 curr_bb
= last_bb_seen
= bb
;
2287 switch (GET_CODE (x
))
2294 /* An addr_vec is placed outside any basic block. */
2296 && JUMP_TABLE_DATA_P (NEXT_INSN (x
)))
2299 /* But in any case, non-deletable labels can appear anywhere. */
2303 fatal_insn ("insn outside basic block", x
);
2308 && returnjump_p (x
) && ! condjump_p (x
)
2309 && ! (next_nonnote_insn (x
) && BARRIER_P (next_nonnote_insn (x
))))
2310 fatal_insn ("return not followed by barrier", x
);
2311 if (curr_bb
&& x
== BB_END (curr_bb
))
2315 if (num_bb_notes
!= n_basic_blocks
- NUM_FIXED_BLOCKS
)
2317 ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)",
2318 num_bb_notes
, n_basic_blocks
);
2323 /* Assume that the preceding pass has possibly eliminated jump instructions
2324 or converted the unconditional jumps. Eliminate the edges from CFG.
2325 Return true if any edges are eliminated. */
2328 purge_dead_edges (basic_block bb
)
2331 rtx insn
= BB_END (bb
), note
;
2332 bool purged
= false;
2336 if (DEBUG_INSN_P (insn
) && insn
!= BB_HEAD (bb
))
2338 insn
= PREV_INSN (insn
);
2339 while ((DEBUG_INSN_P (insn
) || NOTE_P (insn
)) && insn
!= BB_HEAD (bb
));
2341 /* If this instruction cannot trap, remove REG_EH_REGION notes. */
2342 if (NONJUMP_INSN_P (insn
)
2343 && (note
= find_reg_note (insn
, REG_EH_REGION
, NULL
)))
2347 if (! may_trap_p (PATTERN (insn
))
2348 || ((eqnote
= find_reg_equal_equiv_note (insn
))
2349 && ! may_trap_p (XEXP (eqnote
, 0))))
2350 remove_note (insn
, note
);
2353 /* Cleanup abnormal edges caused by exceptions or non-local gotos. */
2354 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
2356 bool remove
= false;
2358 /* There are three types of edges we need to handle correctly here: EH
2359 edges, abnormal call EH edges, and abnormal call non-EH edges. The
2360 latter can appear when nonlocal gotos are used. */
2361 if (e
->flags
& EDGE_ABNORMAL_CALL
)
2365 else if (can_nonlocal_goto (insn
))
2367 else if ((e
->flags
& EDGE_EH
) && can_throw_internal (insn
))
2369 else if (flag_tm
&& find_reg_note (insn
, REG_TM
, NULL
))
2374 else if (e
->flags
& EDGE_EH
)
2375 remove
= !can_throw_internal (insn
);
2380 df_set_bb_dirty (bb
);
2393 /* We do care only about conditional jumps and simplejumps. */
2394 if (!any_condjump_p (insn
)
2395 && !returnjump_p (insn
)
2396 && !simplejump_p (insn
))
2399 /* Branch probability/prediction notes are defined only for
2400 condjumps. We've possibly turned condjump into simplejump. */
2401 if (simplejump_p (insn
))
2403 note
= find_reg_note (insn
, REG_BR_PROB
, NULL
);
2405 remove_note (insn
, note
);
2406 while ((note
= find_reg_note (insn
, REG_BR_PRED
, NULL
)))
2407 remove_note (insn
, note
);
2410 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
2412 /* Avoid abnormal flags to leak from computed jumps turned
2413 into simplejumps. */
2415 e
->flags
&= ~EDGE_ABNORMAL
;
2417 /* See if this edge is one we should keep. */
2418 if ((e
->flags
& EDGE_FALLTHRU
) && any_condjump_p (insn
))
2419 /* A conditional jump can fall through into the next
2420 block, so we should keep the edge. */
2425 else if (e
->dest
!= EXIT_BLOCK_PTR
2426 && BB_HEAD (e
->dest
) == JUMP_LABEL (insn
))
2427 /* If the destination block is the target of the jump,
2433 else if (e
->dest
== EXIT_BLOCK_PTR
&& returnjump_p (insn
))
2434 /* If the destination block is the exit block, and this
2435 instruction is a return, then keep the edge. */
2440 else if ((e
->flags
& EDGE_EH
) && can_throw_internal (insn
))
2441 /* Keep the edges that correspond to exceptions thrown by
2442 this instruction and rematerialize the EDGE_ABNORMAL
2443 flag we just cleared above. */
2445 e
->flags
|= EDGE_ABNORMAL
;
2450 /* We do not need this edge. */
2451 df_set_bb_dirty (bb
);
2456 if (EDGE_COUNT (bb
->succs
) == 0 || !purged
)
2460 fprintf (dump_file
, "Purged edges from bb %i\n", bb
->index
);
2465 /* Redistribute probabilities. */
2466 if (single_succ_p (bb
))
2468 single_succ_edge (bb
)->probability
= REG_BR_PROB_BASE
;
2469 single_succ_edge (bb
)->count
= bb
->count
;
2473 note
= find_reg_note (insn
, REG_BR_PROB
, NULL
);
2477 b
= BRANCH_EDGE (bb
);
2478 f
= FALLTHRU_EDGE (bb
);
2479 b
->probability
= INTVAL (XEXP (note
, 0));
2480 f
->probability
= REG_BR_PROB_BASE
- b
->probability
;
2481 b
->count
= bb
->count
* b
->probability
/ REG_BR_PROB_BASE
;
2482 f
->count
= bb
->count
* f
->probability
/ REG_BR_PROB_BASE
;
2487 else if (CALL_P (insn
) && SIBLING_CALL_P (insn
))
2489 /* First, there should not be any EH or ABCALL edges resulting
2490 from non-local gotos and the like. If there were, we shouldn't
2491 have created the sibcall in the first place. Second, there
2492 should of course never have been a fallthru edge. */
2493 gcc_assert (single_succ_p (bb
));
2494 gcc_assert (single_succ_edge (bb
)->flags
2495 == (EDGE_SIBCALL
| EDGE_ABNORMAL
));
2500 /* If we don't see a jump insn, we don't know exactly why the block would
2501 have been broken at this point. Look for a simple, non-fallthru edge,
2502 as these are only created by conditional branches. If we find such an
2503 edge we know that there used to be a jump here and can then safely
2504 remove all non-fallthru edges. */
2506 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2507 if (! (e
->flags
& (EDGE_COMPLEX
| EDGE_FALLTHRU
)))
2516 /* Remove all but the fake and fallthru edges. The fake edge may be
2517 the only successor for this block in the case of noreturn
2519 for (ei
= ei_start (bb
->succs
); (e
= ei_safe_edge (ei
)); )
2521 if (!(e
->flags
& (EDGE_FALLTHRU
| EDGE_FAKE
)))
2523 df_set_bb_dirty (bb
);
2531 gcc_assert (single_succ_p (bb
));
2533 single_succ_edge (bb
)->probability
= REG_BR_PROB_BASE
;
2534 single_succ_edge (bb
)->count
= bb
->count
;
2537 fprintf (dump_file
, "Purged non-fallthru edges from bb %i\n",
2542 /* Search all basic blocks for potentially dead edges and purge them. Return
2543 true if some edge has been eliminated. */
2546 purge_all_dead_edges (void)
2553 bool purged_here
= purge_dead_edges (bb
);
2555 purged
|= purged_here
;
2561 /* This is used by a few passes that emit some instructions after abnormal
2562 calls, moving the basic block's end, while they in fact do want to emit
2563 them on the fallthru edge. Look for abnormal call edges, find backward
2564 the call in the block and insert the instructions on the edge instead.
2566 Similarly, handle instructions throwing exceptions internally.
2568 Return true when instructions have been found and inserted on edges. */
2571 fixup_abnormal_edges (void)
2573 bool inserted
= false;
2581 /* Look for cases we are interested in - calls or instructions causing
2583 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
2584 if ((e
->flags
& EDGE_ABNORMAL_CALL
)
2585 || ((e
->flags
& (EDGE_ABNORMAL
| EDGE_EH
))
2586 == (EDGE_ABNORMAL
| EDGE_EH
)))
2589 if (e
&& !CALL_P (BB_END (bb
)) && !can_throw_internal (BB_END (bb
)))
2593 /* Get past the new insns generated. Allow notes, as the insns
2594 may be already deleted. */
2596 while ((NONJUMP_INSN_P (insn
) || NOTE_P (insn
))
2597 && !can_throw_internal (insn
)
2598 && insn
!= BB_HEAD (bb
))
2599 insn
= PREV_INSN (insn
);
2601 if (CALL_P (insn
) || can_throw_internal (insn
))
2605 e
= find_fallthru_edge (bb
->succs
);
2607 stop
= NEXT_INSN (BB_END (bb
));
2610 for (insn
= NEXT_INSN (insn
); insn
!= stop
; insn
= next
)
2612 next
= NEXT_INSN (insn
);
2617 /* Sometimes there's still the return value USE.
2618 If it's placed after a trapping call (i.e. that
2619 call is the last insn anyway), we have no fallthru
2620 edge. Simply delete this use and don't try to insert
2621 on the non-existent edge. */
2622 if (GET_CODE (PATTERN (insn
)) != USE
)
2624 /* We're not deleting it, we're moving it. */
2625 INSN_DELETED_P (insn
) = 0;
2626 PREV_INSN (insn
) = NULL_RTX
;
2627 NEXT_INSN (insn
) = NULL_RTX
;
2629 insert_insn_on_edge (insn
, e
);
2633 else if (!BARRIER_P (insn
))
2634 set_block_for_insn (insn
, NULL
);
2638 /* It may be that we don't find any trapping insn. In this
2639 case we discovered quite late that the insn that had been
2640 marked as can_throw_internal in fact couldn't trap at all.
2641 So we should in fact delete the EH edges out of the block. */
2643 purge_dead_edges (bb
);
2650 /* Same as split_block but update cfg_layout structures. */
2653 cfg_layout_split_block (basic_block bb
, void *insnp
)
2655 rtx insn
= (rtx
) insnp
;
2656 basic_block new_bb
= rtl_split_block (bb
, insn
);
2658 BB_FOOTER (new_bb
) = BB_FOOTER (bb
);
2659 BB_FOOTER (bb
) = NULL
;
2664 /* Redirect Edge to DEST. */
2666 cfg_layout_redirect_edge_and_branch (edge e
, basic_block dest
)
2668 basic_block src
= e
->src
;
2671 if (e
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
2674 if (e
->dest
== dest
)
2677 if (e
->src
!= ENTRY_BLOCK_PTR
2678 && (ret
= try_redirect_by_replacing_jump (e
, dest
, true)))
2680 df_set_bb_dirty (src
);
2684 if (e
->src
== ENTRY_BLOCK_PTR
2685 && (e
->flags
& EDGE_FALLTHRU
) && !(e
->flags
& EDGE_COMPLEX
))
2688 fprintf (dump_file
, "Redirecting entry edge from bb %i to %i\n",
2689 e
->src
->index
, dest
->index
);
2691 df_set_bb_dirty (e
->src
);
2692 redirect_edge_succ (e
, dest
);
2696 /* Redirect_edge_and_branch may decide to turn branch into fallthru edge
2697 in the case the basic block appears to be in sequence. Avoid this
2700 if (e
->flags
& EDGE_FALLTHRU
)
2702 /* Redirect any branch edges unified with the fallthru one. */
2703 if (JUMP_P (BB_END (src
))
2704 && label_is_jump_target_p (BB_HEAD (e
->dest
),
2710 fprintf (dump_file
, "Fallthru edge unified with branch "
2711 "%i->%i redirected to %i\n",
2712 e
->src
->index
, e
->dest
->index
, dest
->index
);
2713 e
->flags
&= ~EDGE_FALLTHRU
;
2714 redirected
= redirect_branch_edge (e
, dest
);
2715 gcc_assert (redirected
);
2716 redirected
->flags
|= EDGE_FALLTHRU
;
2717 df_set_bb_dirty (redirected
->src
);
2720 /* In case we are redirecting fallthru edge to the branch edge
2721 of conditional jump, remove it. */
2722 if (EDGE_COUNT (src
->succs
) == 2)
2724 /* Find the edge that is different from E. */
2725 edge s
= EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
);
2728 && any_condjump_p (BB_END (src
))
2729 && onlyjump_p (BB_END (src
)))
2730 delete_insn (BB_END (src
));
2733 fprintf (dump_file
, "Redirecting fallthru edge %i->%i to %i\n",
2734 e
->src
->index
, e
->dest
->index
, dest
->index
);
2735 ret
= redirect_edge_succ_nodup (e
, dest
);
2738 ret
= redirect_branch_edge (e
, dest
);
2740 /* We don't want simplejumps in the insn stream during cfglayout. */
2741 gcc_assert (!simplejump_p (BB_END (src
)));
2743 df_set_bb_dirty (src
);
2747 /* Simple wrapper as we always can redirect fallthru edges. */
2749 cfg_layout_redirect_edge_and_branch_force (edge e
, basic_block dest
)
2751 edge redirected
= cfg_layout_redirect_edge_and_branch (e
, dest
);
2753 gcc_assert (redirected
);
2757 /* Same as delete_basic_block but update cfg_layout structures. */
2760 cfg_layout_delete_block (basic_block bb
)
2762 rtx insn
, next
, prev
= PREV_INSN (BB_HEAD (bb
)), *to
, remaints
;
2766 next
= BB_HEAD (bb
);
2768 NEXT_INSN (prev
) = BB_HEADER (bb
);
2770 set_first_insn (BB_HEADER (bb
));
2771 PREV_INSN (BB_HEADER (bb
)) = prev
;
2772 insn
= BB_HEADER (bb
);
2773 while (NEXT_INSN (insn
))
2774 insn
= NEXT_INSN (insn
);
2775 NEXT_INSN (insn
) = next
;
2776 PREV_INSN (next
) = insn
;
2778 next
= NEXT_INSN (BB_END (bb
));
2781 insn
= BB_FOOTER (bb
);
2784 if (BARRIER_P (insn
))
2786 if (PREV_INSN (insn
))
2787 NEXT_INSN (PREV_INSN (insn
)) = NEXT_INSN (insn
);
2789 BB_FOOTER (bb
) = NEXT_INSN (insn
);
2790 if (NEXT_INSN (insn
))
2791 PREV_INSN (NEXT_INSN (insn
)) = PREV_INSN (insn
);
2795 insn
= NEXT_INSN (insn
);
2800 NEXT_INSN (insn
) = BB_FOOTER (bb
);
2801 PREV_INSN (BB_FOOTER (bb
)) = insn
;
2802 while (NEXT_INSN (insn
))
2803 insn
= NEXT_INSN (insn
);
2804 NEXT_INSN (insn
) = next
;
2806 PREV_INSN (next
) = insn
;
2808 set_last_insn (insn
);
2811 if (bb
->next_bb
!= EXIT_BLOCK_PTR
)
2812 to
= &BB_HEADER (bb
->next_bb
);
2814 to
= &cfg_layout_function_footer
;
2816 rtl_delete_block (bb
);
2819 prev
= NEXT_INSN (prev
);
2821 prev
= get_insns ();
2823 next
= PREV_INSN (next
);
2825 next
= get_last_insn ();
2827 if (next
&& NEXT_INSN (next
) != prev
)
2829 remaints
= unlink_insn_chain (prev
, next
);
2831 while (NEXT_INSN (insn
))
2832 insn
= NEXT_INSN (insn
);
2833 NEXT_INSN (insn
) = *to
;
2835 PREV_INSN (*to
) = insn
;
2840 /* Return true when blocks A and B can be safely merged. */
2843 cfg_layout_can_merge_blocks_p (basic_block a
, basic_block b
)
2845 /* If we are partitioning hot/cold basic blocks, we don't want to
2846 mess up unconditional or indirect jumps that cross between hot
2849 Basic block partitioning may result in some jumps that appear to
2850 be optimizable (or blocks that appear to be mergeable), but which really
2851 must be left untouched (they are required to make it safely across
2852 partition boundaries). See the comments at the top of
2853 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
2855 if (BB_PARTITION (a
) != BB_PARTITION (b
))
2858 /* Protect the loop latches. */
2859 if (current_loops
&& b
->loop_father
->latch
== b
)
2862 /* If we would end up moving B's instructions, make sure it doesn't fall
2863 through into the exit block, since we cannot recover from a fallthrough
2864 edge into the exit block occurring in the middle of a function. */
2865 if (NEXT_INSN (BB_END (a
)) != BB_HEAD (b
))
2867 edge e
= find_fallthru_edge (b
->succs
);
2868 if (e
&& e
->dest
== EXIT_BLOCK_PTR
)
2872 /* There must be exactly one edge in between the blocks. */
2873 return (single_succ_p (a
)
2874 && single_succ (a
) == b
2875 && single_pred_p (b
) == 1
2877 /* Must be simple edge. */
2878 && !(single_succ_edge (a
)->flags
& EDGE_COMPLEX
)
2879 && a
!= ENTRY_BLOCK_PTR
&& b
!= EXIT_BLOCK_PTR
2880 /* If the jump insn has side effects, we can't kill the edge.
2881 When not optimizing, try_redirect_by_replacing_jump will
2882 not allow us to redirect an edge by replacing a table jump. */
2883 && (!JUMP_P (BB_END (a
))
2884 || ((!optimize
|| reload_completed
)
2885 ? simplejump_p (BB_END (a
)) : onlyjump_p (BB_END (a
)))));
2888 /* Merge block A and B. The blocks must be mergeable. */
2891 cfg_layout_merge_blocks (basic_block a
, basic_block b
)
2893 bool forwarder_p
= (b
->flags
& BB_FORWARDER_BLOCK
) != 0;
2896 gcc_checking_assert (cfg_layout_can_merge_blocks_p (a
, b
));
2899 fprintf (dump_file
, "Merging block %d into block %d...\n", b
->index
,
2902 /* If there was a CODE_LABEL beginning B, delete it. */
2903 if (LABEL_P (BB_HEAD (b
)))
2905 delete_insn (BB_HEAD (b
));
2908 /* We should have fallthru edge in a, or we can do dummy redirection to get
2910 if (JUMP_P (BB_END (a
)))
2911 try_redirect_by_replacing_jump (EDGE_SUCC (a
, 0), b
, true);
2912 gcc_assert (!JUMP_P (BB_END (a
)));
2914 /* When not optimizing CFG and the edge is the only place in RTL which holds
2915 some unique locus, emit a nop with that locus in between. */
2917 emit_nop_for_unique_locus_between (a
, b
);
2919 /* Possible line number notes should appear in between. */
2922 rtx first
= BB_END (a
), last
;
2924 last
= emit_insn_after_noloc (BB_HEADER (b
), BB_END (a
), a
);
2925 /* The above might add a BARRIER as BB_END, but as barriers
2926 aren't valid parts of a bb, remove_insn doesn't update
2927 BB_END if it is a barrier. So adjust BB_END here. */
2928 while (BB_END (a
) != first
&& BARRIER_P (BB_END (a
)))
2929 BB_END (a
) = PREV_INSN (BB_END (a
));
2930 delete_insn_chain (NEXT_INSN (first
), last
, false);
2931 BB_HEADER (b
) = NULL
;
2934 /* In the case basic blocks are not adjacent, move them around. */
2935 if (NEXT_INSN (BB_END (a
)) != BB_HEAD (b
))
2937 insn
= unlink_insn_chain (BB_HEAD (b
), BB_END (b
));
2939 emit_insn_after_noloc (insn
, BB_END (a
), a
);
2941 /* Otherwise just re-associate the instructions. */
2945 BB_END (a
) = BB_END (b
);
2948 /* emit_insn_after_noloc doesn't call df_insn_change_bb.
2949 We need to explicitly call. */
2950 update_bb_for_insn_chain (insn
, BB_END (b
), a
);
2952 /* Skip possible DELETED_LABEL insn. */
2953 if (!NOTE_INSN_BASIC_BLOCK_P (insn
))
2954 insn
= NEXT_INSN (insn
);
2955 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn
));
2959 df_bb_delete (b
->index
);
2961 /* Possible tablejumps and barriers should appear after the block. */
2965 BB_FOOTER (a
) = BB_FOOTER (b
);
2968 rtx last
= BB_FOOTER (a
);
2970 while (NEXT_INSN (last
))
2971 last
= NEXT_INSN (last
);
2972 NEXT_INSN (last
) = BB_FOOTER (b
);
2973 PREV_INSN (BB_FOOTER (b
)) = last
;
2975 BB_FOOTER (b
) = NULL
;
2978 /* If B was a forwarder block, propagate the locus on the edge. */
2979 if (forwarder_p
&& !EDGE_SUCC (b
, 0)->goto_locus
)
2980 EDGE_SUCC (b
, 0)->goto_locus
= EDGE_SUCC (a
, 0)->goto_locus
;
2983 fprintf (dump_file
, "Merged blocks %d and %d.\n", a
->index
, b
->index
);
2989 cfg_layout_split_edge (edge e
)
2991 basic_block new_bb
=
2992 create_basic_block (e
->src
!= ENTRY_BLOCK_PTR
2993 ? NEXT_INSN (BB_END (e
->src
)) : get_insns (),
2996 if (e
->dest
== EXIT_BLOCK_PTR
)
2997 BB_COPY_PARTITION (new_bb
, e
->src
);
2999 BB_COPY_PARTITION (new_bb
, e
->dest
);
3000 make_edge (new_bb
, e
->dest
, EDGE_FALLTHRU
);
3001 redirect_edge_and_branch_force (e
, new_bb
);
3006 /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */
3009 rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED
)
3013 /* Return 1 if BB ends with a call, possibly followed by some
3014 instructions that must stay with the call, 0 otherwise. */
3017 rtl_block_ends_with_call_p (basic_block bb
)
3019 rtx insn
= BB_END (bb
);
3021 while (!CALL_P (insn
)
3022 && insn
!= BB_HEAD (bb
)
3023 && (keep_with_call_p (insn
)
3025 || DEBUG_INSN_P (insn
)))
3026 insn
= PREV_INSN (insn
);
3027 return (CALL_P (insn
));
3030 /* Return 1 if BB ends with a conditional branch, 0 otherwise. */
3033 rtl_block_ends_with_condjump_p (const_basic_block bb
)
3035 return any_condjump_p (BB_END (bb
));
3038 /* Return true if we need to add fake edge to exit.
3039 Helper function for rtl_flow_call_edges_add. */
3042 need_fake_edge_p (const_rtx insn
)
3048 && !SIBLING_CALL_P (insn
)
3049 && !find_reg_note (insn
, REG_NORETURN
, NULL
)
3050 && !(RTL_CONST_OR_PURE_CALL_P (insn
))))
3053 return ((GET_CODE (PATTERN (insn
)) == ASM_OPERANDS
3054 && MEM_VOLATILE_P (PATTERN (insn
)))
3055 || (GET_CODE (PATTERN (insn
)) == PARALLEL
3056 && asm_noperands (insn
) != -1
3057 && MEM_VOLATILE_P (XVECEXP (PATTERN (insn
), 0, 0)))
3058 || GET_CODE (PATTERN (insn
)) == ASM_INPUT
);
3061 /* Add fake edges to the function exit for any non constant and non noreturn
3062 calls, volatile inline assembly in the bitmap of blocks specified by
3063 BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks
3066 The goal is to expose cases in which entering a basic block does not imply
3067 that all subsequent instructions must be executed. */
3070 rtl_flow_call_edges_add (sbitmap blocks
)
3073 int blocks_split
= 0;
3074 int last_bb
= last_basic_block
;
3075 bool check_last_block
= false;
3077 if (n_basic_blocks
== NUM_FIXED_BLOCKS
)
3081 check_last_block
= true;
3083 check_last_block
= TEST_BIT (blocks
, EXIT_BLOCK_PTR
->prev_bb
->index
);
3085 /* In the last basic block, before epilogue generation, there will be
3086 a fallthru edge to EXIT. Special care is required if the last insn
3087 of the last basic block is a call because make_edge folds duplicate
3088 edges, which would result in the fallthru edge also being marked
3089 fake, which would result in the fallthru edge being removed by
3090 remove_fake_edges, which would result in an invalid CFG.
3092 Moreover, we can't elide the outgoing fake edge, since the block
3093 profiler needs to take this into account in order to solve the minimal
3094 spanning tree in the case that the call doesn't return.
3096 Handle this by adding a dummy instruction in a new last basic block. */
3097 if (check_last_block
)
3099 basic_block bb
= EXIT_BLOCK_PTR
->prev_bb
;
3100 rtx insn
= BB_END (bb
);
3102 /* Back up past insns that must be kept in the same block as a call. */
3103 while (insn
!= BB_HEAD (bb
)
3104 && keep_with_call_p (insn
))
3105 insn
= PREV_INSN (insn
);
3107 if (need_fake_edge_p (insn
))
3111 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
3114 insert_insn_on_edge (gen_use (const0_rtx
), e
);
3115 commit_edge_insertions ();
3120 /* Now add fake edges to the function exit for any non constant
3121 calls since there is no way that we can determine if they will
3124 for (i
= NUM_FIXED_BLOCKS
; i
< last_bb
; i
++)
3126 basic_block bb
= BASIC_BLOCK (i
);
3133 if (blocks
&& !TEST_BIT (blocks
, i
))
3136 for (insn
= BB_END (bb
); ; insn
= prev_insn
)
3138 prev_insn
= PREV_INSN (insn
);
3139 if (need_fake_edge_p (insn
))
3142 rtx split_at_insn
= insn
;
3144 /* Don't split the block between a call and an insn that should
3145 remain in the same block as the call. */
3147 while (split_at_insn
!= BB_END (bb
)
3148 && keep_with_call_p (NEXT_INSN (split_at_insn
)))
3149 split_at_insn
= NEXT_INSN (split_at_insn
);
3151 /* The handling above of the final block before the epilogue
3152 should be enough to verify that there is no edge to the exit
3153 block in CFG already. Calling make_edge in such case would
3154 cause us to mark that edge as fake and remove it later. */
3156 #ifdef ENABLE_CHECKING
3157 if (split_at_insn
== BB_END (bb
))
3159 e
= find_edge (bb
, EXIT_BLOCK_PTR
);
3160 gcc_assert (e
== NULL
);
3164 /* Note that the following may create a new basic block
3165 and renumber the existing basic blocks. */
3166 if (split_at_insn
!= BB_END (bb
))
3168 e
= split_block (bb
, split_at_insn
);
3173 make_edge (bb
, EXIT_BLOCK_PTR
, EDGE_FAKE
);
3176 if (insn
== BB_HEAD (bb
))
3182 verify_flow_info ();
3184 return blocks_split
;
3187 /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is
3188 the conditional branch target, SECOND_HEAD should be the fall-thru
3189 there is no need to handle this here the loop versioning code handles
3190 this. the reason for SECON_HEAD is that it is needed for condition
3191 in trees, and this should be of the same type since it is a hook. */
3193 rtl_lv_add_condition_to_bb (basic_block first_head
,
3194 basic_block second_head ATTRIBUTE_UNUSED
,
3195 basic_block cond_bb
, void *comp_rtx
)
3197 rtx label
, seq
, jump
;
3198 rtx op0
= XEXP ((rtx
)comp_rtx
, 0);
3199 rtx op1
= XEXP ((rtx
)comp_rtx
, 1);
3200 enum rtx_code comp
= GET_CODE ((rtx
)comp_rtx
);
3201 enum machine_mode mode
;
3204 label
= block_label (first_head
);
3205 mode
= GET_MODE (op0
);
3206 if (mode
== VOIDmode
)
3207 mode
= GET_MODE (op1
);
3210 op0
= force_operand (op0
, NULL_RTX
);
3211 op1
= force_operand (op1
, NULL_RTX
);
3212 do_compare_rtx_and_jump (op0
, op1
, comp
, 0,
3213 mode
, NULL_RTX
, NULL_RTX
, label
, -1);
3214 jump
= get_last_insn ();
3215 JUMP_LABEL (jump
) = label
;
3216 LABEL_NUSES (label
)++;
3220 /* Add the new cond , in the new head. */
3221 emit_insn_after(seq
, BB_END(cond_bb
));
3225 /* Given a block B with unconditional branch at its end, get the
3226 store the return the branch edge and the fall-thru edge in
3227 BRANCH_EDGE and FALLTHRU_EDGE respectively. */
3229 rtl_extract_cond_bb_edges (basic_block b
, edge
*branch_edge
,
3230 edge
*fallthru_edge
)
3232 edge e
= EDGE_SUCC (b
, 0);
3234 if (e
->flags
& EDGE_FALLTHRU
)
3237 *branch_edge
= EDGE_SUCC (b
, 1);
3242 *fallthru_edge
= EDGE_SUCC (b
, 1);
3247 init_rtl_bb_info (basic_block bb
)
3249 gcc_assert (!bb
->il
.x
.rtl
);
3250 bb
->il
.x
.head_
= NULL
;
3251 bb
->il
.x
.rtl
= ggc_alloc_cleared_rtl_bb_info ();
3254 /* Returns true if it is possible to remove edge E by redirecting
3255 it to the destination of the other edge from E->src. */
3258 rtl_can_remove_branch_p (const_edge e
)
3260 const_basic_block src
= e
->src
;
3261 const_basic_block target
= EDGE_SUCC (src
, EDGE_SUCC (src
, 0) == e
)->dest
;
3262 const_rtx insn
= BB_END (src
), set
;
3264 /* The conditions are taken from try_redirect_by_replacing_jump. */
3265 if (target
== EXIT_BLOCK_PTR
)
3268 if (e
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
3271 if (find_reg_note (insn
, REG_CROSSING_JUMP
, NULL_RTX
)
3272 || BB_PARTITION (src
) != BB_PARTITION (target
))
3275 if (!onlyjump_p (insn
)
3276 || tablejump_p (insn
, NULL
, NULL
))
3279 set
= single_set (insn
);
3280 if (!set
|| side_effects_p (set
))
3286 /* We do not want to declare these functions in a header file, since they
3287 should only be used through the cfghooks interface, and we do not want to
3288 move them here since it would require also moving quite a lot of related
3289 code. They are in cfglayout.c. */
3290 extern bool cfg_layout_can_duplicate_bb_p (const_basic_block
);
3291 extern basic_block
cfg_layout_duplicate_bb (basic_block
);
3294 rtl_duplicate_bb (basic_block bb
)
3296 bb
= cfg_layout_duplicate_bb (bb
);
3301 /* Implementation of CFG manipulation for linearized RTL. */
3302 struct cfg_hooks rtl_cfg_hooks
= {
3304 rtl_verify_flow_info
,
3306 rtl_create_basic_block
,
3307 rtl_redirect_edge_and_branch
,
3308 rtl_redirect_edge_and_branch_force
,
3309 rtl_can_remove_branch_p
,
3312 rtl_move_block_after
,
3313 rtl_can_merge_blocks
, /* can_merge_blocks_p */
3317 cfg_layout_can_duplicate_bb_p
,
3320 rtl_make_forwarder_block
,
3321 rtl_tidy_fallthru_edge
,
3322 rtl_force_nonfallthru
,
3323 rtl_block_ends_with_call_p
,
3324 rtl_block_ends_with_condjump_p
,
3325 rtl_flow_call_edges_add
,
3326 NULL
, /* execute_on_growing_pred */
3327 NULL
, /* execute_on_shrinking_pred */
3328 NULL
, /* duplicate loop for trees */
3329 NULL
, /* lv_add_condition_to_bb */
3330 NULL
, /* lv_adjust_loop_header_phi*/
3331 NULL
, /* extract_cond_bb_edges */
3332 NULL
/* flush_pending_stmts */
3335 /* Implementation of CFG manipulation for cfg layout RTL, where
3336 basic block connected via fallthru edges does not have to be adjacent.
3337 This representation will hopefully become the default one in future
3338 version of the compiler. */
3340 struct cfg_hooks cfg_layout_rtl_cfg_hooks
= {
3342 rtl_verify_flow_info_1
,
3344 cfg_layout_create_basic_block
,
3345 cfg_layout_redirect_edge_and_branch
,
3346 cfg_layout_redirect_edge_and_branch_force
,
3347 rtl_can_remove_branch_p
,
3348 cfg_layout_delete_block
,
3349 cfg_layout_split_block
,
3350 rtl_move_block_after
,
3351 cfg_layout_can_merge_blocks_p
,
3352 cfg_layout_merge_blocks
,
3355 cfg_layout_can_duplicate_bb_p
,
3356 cfg_layout_duplicate_bb
,
3357 cfg_layout_split_edge
,
3358 rtl_make_forwarder_block
,
3359 NULL
, /* tidy_fallthru_edge */
3360 rtl_force_nonfallthru
,
3361 rtl_block_ends_with_call_p
,
3362 rtl_block_ends_with_condjump_p
,
3363 rtl_flow_call_edges_add
,
3364 NULL
, /* execute_on_growing_pred */
3365 NULL
, /* execute_on_shrinking_pred */
3366 duplicate_loop_to_header_edge
, /* duplicate loop for trees */
3367 rtl_lv_add_condition_to_bb
, /* lv_add_condition_to_bb */
3368 NULL
, /* lv_adjust_loop_header_phi*/
3369 rtl_extract_cond_bb_edges
, /* extract_cond_bb_edges */
3370 NULL
/* flush_pending_stmts */