(merge_ranges): In (+,-) case, if lower bounds are the same the result

is always false.

From-SVN: r13236

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 2147e2eb5536ec2ace685616882682c14955b4e8..cc27b58a4cf8e88a3cafd99b325a13208294ae89 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -2976,7 +2976,7 @@ merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
       /* If they don't overlap, the result is the first range.  If the
         second range is a subset of the first, we can't describe this as
         a single range unless both ranges end at the same place.  If both
-        ranges also start in the same place, then the result is false.
+        ranges start in the same place, then the result is false.
         Otherwise, we go from the start of the first range to just before
         the start of the second.  */
       if (no_overlap)
@@ -2985,9 +2985,8 @@ merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
               && integer_zerop (range_binop (EQ_EXPR, integer_type_node,
                                              high0, 1, high1, 0)))
        return 0;
-      else if (subset
-              && integer_onep (range_binop (EQ_EXPR, integer_type_node,
-                                            low0, 0, low1, 0)))
+      else if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
+                                         low0, 0, low1, 0)))
        in_p = 0, low = high = 0;
       else
        {