https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108540
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
--- gcc/range-op-float.cc.jj 2023-01-16 09:39:36.191929750 +0100
+++ gcc/range-op-float.cc 2023-01-26 13:33:48.712018907 +0100
@@ -607,6 +607,10 @@ foperator_equal::fold_range (irange &r,
{
if (op1 == op2)
r = range_true (type);
+ // If one operand is -0.0 and other 0.0, they are still equal.
+ else if (real_iszero (&op1.lower_bound ())
+ && real_iszero (&op2.lower_bound ()))
+ r = range_true (type);
else
r = range_false (type);
}
@@ -617,7 +621,18 @@ foperator_equal::fold_range (irange &r,
frange tmp = op1;
tmp.intersect (op2);
if (tmp.undefined_p ())
- r = range_false (type);
+ {
+ // If one range is [whatever, -0.0] and another
+ // [0.0, whatever2], we don't know anything either,
+ // because -0.0 == 0.0.
+ if ((real_iszero (&op1.upper_bound ())
+ && real_iszero (&op2.lower_bound ()))
+ || (real_iszero (&op1.lower_bound ())
+ && real_iszero (&op2.upper_bound ())))
+ r = range_true_and_false (type);
+ else
+ r = range_false (type);
+ }
else
r = range_true_and_false (type);
}
fixes both testcases, but I'm afraid I need to look at other relations too with
-0.0 == 0.0 in mind.
