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Index: a/gcc/cfgcleanup.c
===================================================================
--- a/gcc/cfgcleanup.c (revision 315947)
+++ b/gcc/cfgcleanup.c (working copy)
@@ -1179,13 +1179,19 @@ flow_find_head_matching_sequence (basic_
while (true)
{
-
- /* Ignore notes. */
+ /* Ignore notes, except NOTE_INSN_EPILOGUE_BEG. */
while (!NONDEBUG_INSN_P (i1) && i1 != BB_END (bb1))
- i1 = NEXT_INSN (i1);
-
+ {
+ if (NOTE_P (i1) && NOTE_KIND (i1) == NOTE_INSN_EPILOGUE_BEG)
+ break;
+ i1 = NEXT_INSN (i1);
+ }
while (!NONDEBUG_INSN_P (i2) && i2 != BB_END (bb2))
- i2 = NEXT_INSN (i2);
+ {
+ if (NOTE_P (i2) && NOTE_KIND (i2) == NOTE_INSN_EPILOGUE_BEG)
+ break;
+ i2 = NEXT_INSN (i2);
+ }
if (NOTE_P (i1) || NOTE_P (i2)
|| JUMP_P (i1) || JUMP_P (i2))
Index: a/gcc/cfglayout.c
===================================================================
--- a/gcc/cfglayout.c (revision 315947)
+++ b/gcc/cfglayout.c (working copy)
@@ -1295,6 +1295,16 @@ cfg_layout_initialize (unsigned int flag
bb->flags |= BB_NON_LOCAL_GOTO_TARGET;
}
+ FOR_EACH_BB (bb)
+ {
+ rtx insn;
+ FOR_BB_INSNS (bb, insn)
+ if (NOTE_P (insn) && NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
+ {
+ bb->flags |= BB_EPILOGUE_BEGIN;
+ break;
+ }
+ }
cleanup_cfg (CLEANUP_CFGLAYOUT | flags);
}
Index: a/gcc/basic-block.h
===================================================================
--- a/gcc/basic-block.h (revision 315947)
+++ b/gcc/basic-block.h (working copy)
@@ -332,7 +332,11 @@ enum bb_flags
/* Set on blocks that cannot be threaded through.
Only used in cfgcleanup.c. */
- BB_NONTHREADABLE_BLOCK = 1 << 11
+ BB_NONTHREADABLE_BLOCK = 1 << 11,
+
+ /* Set on blocks that have a NOTE_INSN_EPILOGUE_BEGIN.
+ Only used in cfglayout mode. */
+ BB_EPILOGUE_BEGIN = 1 << 12
};
/* Dummy flag for convenience in the hot/cold partitioning code. */
Index: a/gcc/cfgrtl.c
===================================================================
--- a/gcc/cfgrtl.c (revision 315947)
+++ b/gcc/cfgrtl.c (working copy)
@@ -2707,7 +2707,10 @@ cfg_layout_can_merge_blocks_p (basic_blo
not allow us to redirect an edge by replacing a table jump. */
&& (!JUMP_P (BB_END (a))
|| ((!optimize || reload_completed)
- ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a)))));
+ ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))
+ /* Don't separate a NOTE_INSN_EPILOGUE_BEG from its returnjump. */
+ && (!(b->flags & BB_EPILOGUE_BEGIN)
+ || returnjump_p (BB_END (b))));
}
/* Merge block A and B. The blocks must be mergeable. */
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