Fix bug in frange::contains_p() for signed zeros.

The contains_p() code wasn't returning true for non-singleton ranges
containing signed zeros.  With this patch we now handle:

	-0.0 exists in [-3, +5.0]
	+0.0 exists in [-3, +5.0]

gcc/ChangeLog:

	* value-range.cc (frange::contains_p): Fix signed zero handling.
	(range_tests_signed_zeros): New test.

diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index 3743ec714b31fdc744c0c4e27284ffe4c1b5fb24..a855aaf626c7ee0948f1d58bdd8f07b46586f072 100644 (file)
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -661,7 +661,7 @@ frange::contains_p (tree cst) const
     {
       // Make sure the signs are equal for signed zeros.
       if (HONOR_SIGNED_ZEROS (m_type) && real_iszero (rv))
-       return m_min.sign == m_max.sign && m_min.sign == rv->sign;
+       return rv->sign == m_min.sign || rv->sign == m_max.sign;
       return true;
     }
   return false;
@@ -3859,6 +3859,14 @@ range_tests_signed_zeros ()
   ASSERT_TRUE (r0.contains_p (neg_zero));
   ASSERT_FALSE (r0.contains_p (zero));
 
+  r0 = frange (neg_zero, zero);
+  ASSERT_TRUE (r0.contains_p (neg_zero));
+  ASSERT_TRUE (r0.contains_p (zero));
+
+  r0 = frange_float ("-3", "5");
+  ASSERT_TRUE (r0.contains_p (neg_zero));
+  ASSERT_TRUE (r0.contains_p (zero));
+
   // The intersection of zeros that differ in sign is a NAN (or
   // undefined if not honoring NANs).
   r0 = frange (neg_zero, neg_zero);