rtlanal.c (single_set): Reject if the parallel has anything except SET or USE or CLOBBER.

        * rtlanal.c (single_set): Reject if the parallel has anything
        except SET or USE or CLOBBER.

From-SVN: r32614

gcc/ChangeLog

+2000-03-17  Richard Henderson  <rth@cygnus.com>
+
+	* rtlanal.c (single_set): Reject if the parallel has anything
+	except SET or USE or CLOBBER.
+
 2000-03-17  Jeff Law  <law@cygnus.com>
 	    Richard Henderson  <rth@cygnus.com>
 

gcc/rtlanal.c

@@ -703,16 +703,30 @@ single_set (insn)
   else if (GET_CODE (PATTERN (insn)) == PARALLEL)
     {
       for (i = 0, set = 0; i < XVECLEN (PATTERN (insn), 0); i++)
-	if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET
-	    && (! find_reg_note (insn, REG_UNUSED,
-				 SET_DEST (XVECEXP (PATTERN (insn), 0, i)))
-		|| side_effects_p (XVECEXP (PATTERN (insn), 0, i))))
-	  {
-	    if (set)
+	{
+	  rtx sub = XVECEXP (PATTERN (insn), 0, i);
+
+	  switch (GET_CODE (sub))
+	    {
+	    case USE:
+	    case CLOBBER:
+	      break;
+
+	    case SET:
+	      if (! find_reg_note (insn, REG_UNUSED, SET_DEST (sub))
+		  || side_effects_p (sub))
+		{
+		  if (set)
+		    return 0;
+		  else
+		    set = sub;
+		}
+	      break;
+
+	    default:
 	      return 0;
-	    else
-	      set = XVECEXP (PATTERN (insn), 0, i);
-	  }
+	    }
+	}
       return set;
     }