On Fri, Mar 31, 2023 at 12:45:10PM +0200, Jakub Jelinek via Gcc-patches wrote:
> - there is a missing case (not handled in this patch) where both operands
> are known to be zeros, but not singleton zeros
This patch adds those cases.
Ok for trunk if it passes bootstrap/regtest?
2023-03-31 Jakub Jelinek <ja...@redhat.com>
* range-op-float.cc (foperator_equal::fold_range): If at least
one of the op ranges is not singleton and neither is NaN and all
4 bounds are zero, return [1, 1].
(foperator_not_equal::fold_range): In the same case return [0, 0].
--- gcc/range-op-float.cc.jj 2023-03-31 11:23:04.817876083 +0200
+++ gcc/range-op-float.cc 2023-03-31 12:51:34.757480162 +0200
@@ -616,6 +616,13 @@ foperator_equal::fold_range (irange &r,
else
r = range_false (type);
}
+ else if (real_iszero (&op1.lower_bound ())
+ && real_iszero (&op1.upper_bound ())
+ && real_iszero (&op2.lower_bound ())
+ && real_iszero (&op2.upper_bound ())
+ && !maybe_isnan (op1, op2))
+ // [-0.0, 0.0] == [-0.0, 0.0] or similar.
+ r = range_true (type);
else
{
// If ranges do not intersect, we know the range is not equal,
@@ -732,6 +739,13 @@ foperator_not_equal::fold_range (irange
else
r = range_true (type);
}
+ else if (real_iszero (&op1.lower_bound ())
+ && real_iszero (&op1.upper_bound ())
+ && real_iszero (&op2.lower_bound ())
+ && real_iszero (&op2.upper_bound ())
+ && !maybe_isnan (op1, op2))
+ // [-0.0, 0.0] != [-0.0, 0.0] or similar.
+ r = range_false (type);
else
{
// If ranges do not intersect, we know the range is not equal,
Jakub
