* rtlanal.c (label_is_jump_target_p): Return true for a matching

	REG_LABEL_TARGET.
	* reorg.c (fill_slots_from_thread): Correct last change to use
	NULL_RTX, not NULL.  Outside of REG_NOTES loop, increase and
	decrease LABEL_NUSES for JUMP_LABEL (trial), not XEXP (note, 0).
	* jump.c (mark_jump_label_1): Add comment for last change
	regarding JUMP_LABEL setting.
	* gcse.c (add_label_notes): Remove conditional that the label is
	mentioned in insn before adding regnote.
	* sched-rgn.c (is_cfg_nonregular): Don't return 1 for a
	single_set insn only feeding a label to a jump through a
	register that dies there.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@130398 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 29 insertions, 5 deletions

diff --git a/gcc/sched-rgn.c b/gcc/sched-rgn.c
index 12f2e66832b..b340bd532e4 100644
--- a/gcc/sched-rgn.c
+++ b/gcc/sched-rgn.c
@@ -320,16 +320,40 @@ is_cfg_nonregular (void)
   FOR_EACH_BB (b)
     FOR_BB_INSNS (b, insn)
       {
-	/* Check for labels referred to but (at least not directly) as
-	   jump targets.  */
-	if (INSN_P (insn)
-	    && find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX))
-	  return 1;
+	rtx note, next, set, dest;
 
 	/* If this function has a computed jump, then we consider the cfg
 	   not well structured.  */
 	if (JUMP_P (insn) && computed_jump_p (insn))
 	  return 1;
+
+	if (!INSN_P (insn))
+	  continue;
+
+	note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX);
+	if (note == NULL_RTX)
+	  continue;
+
+	/* For that label not to be seen as a referred-to label, this
+	   must be a single-set which is feeding a jump *only*.  This
+	   could be a conditional jump with the label split off for
+	   machine-specific reasons or a casesi/tablejump.  */
+	next = next_nonnote_insn (insn);
+	if (next == NULL_RTX
+	    || !JUMP_P (next)
+	    || (JUMP_LABEL (next) != XEXP (note, 0)
+		&& find_reg_note (next, REG_LABEL_TARGET,
+				  XEXP (note, 0)) == NULL_RTX)
+	    || BLOCK_FOR_INSN (insn) != BLOCK_FOR_INSN (next))
+	  return 1;
+
+	set = single_set (insn);
+	if (set == NULL_RTX)
+	  return 1;
+
+	dest = SET_DEST (set);
+	if (!REG_P (dest) || !dead_or_set_p (next, dest))
+	  return 1;
       }
 
   /* Unreachable loops with more than one basic block are detected