Joseph Myers <jos...@codesourcery.com> writes:
> The softfloat floatx80 comparisons fail to allow for pseudo-denormals,
> which should compare equal to corresponding values with biased
> exponent 1 rather than 0. Add an adjustment for that case when
> comparing numbers with the same sign.
>
> Note that this fix only changes floatx80_compare_internal, not the
> other more specific comparison operations. That is the only
> comparison function for floatx80 used in the i386 port, which is the
> only supported port with these pseudo-denormal semantics.
Again I can't see anything that triggers this although I noticed
le_quiet has been fixed in the meantime. lt_quiet still fails with:
./fp-test -s -l 2 -r all extF80_lt_quiet
>> Testing extF80_lt_quiet
59535872 tests total.
Errors found in extF80_lt_quiet:
+0000.0000000000000000 +0000.0000000000000000 => 1 ..... expected 0 .....
+0000.0000000000000000 -0000.0000000000000000 => 1 ..... expected 0 .....
+0000.0000000000000001 +0000.0000000000000001 => 1 ..... expected 0 .....
+0000.0000000000000002 +0000.0000000000000002 => 1 ..... expected 0 .....
+0000.0000000000000004 +0000.0000000000000004 => 1 ..... expected 0 .....
+0000.0000000000000008 +0000.0000000000000008 => 1 ..... expected 0 .....
+0000.0000000000000010 +0000.0000000000000010 => 1 ..... expected 0 .....
+0000.0000000000000020 +0000.0000000000000020 => 1 ..... expected 0 .....
+0000.0000000000000040 +0000.0000000000000040 => 1 ..... expected 0 .....
+0000.0000000000000080 +0000.0000000000000080 => 1 ..... expected 0 .....
+0000.0000000000000100 +0000.0000000000000100 => 1 ..... expected 0 .....
+0000.0000000000000200 +0000.0000000000000200 => 1 ..... expected 0 .....
+0000.0000000000000400 +0000.0000000000000400 => 1 ..... expected 0 .....
+0000.0000000000000800 +0000.0000000000000800 => 1 ..... expected 0 .....
+0000.0000000000001000 +0000.0000000000001000 => 1 ..... expected 0 .....
+0000.0000000000002000 +0000.0000000000002000 => 1 ..... expected 0 .....
+0000.0000000000004000 +0000.0000000000004000 => 1 ..... expected 0 .....
+0000.0000000000008000 +0000.0000000000008000 => 1 ..... expected 0 .....
+0000.0000000000010000 +0000.0000000000010000 => 1 ..... expected 0 .....
+0000.0000000000020000 +0000.0000000000020000 => 1 ..... expected 0 .....
>
> Signed-off-by: Joseph Myers <jos...@codesourcery.com>
> ---
> fpu/softfloat.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/fpu/softfloat.c b/fpu/softfloat.c
> index 6094d267b5..8e9c714e6f 100644
> --- a/fpu/softfloat.c
> +++ b/fpu/softfloat.c
> @@ -7966,6 +7966,11 @@ static inline int floatx80_compare_internal(floatx80
> a, floatx80 b,
> return 1 - (2 * aSign);
> }
> } else {
> + /* Normalize pseudo-denormals before comparison. */
> + if ((a.high & 0x7fff) == 0 && a.low & UINT64_C(0x8000000000000000))
> + ++a.high;
> + if ((b.high & 0x7fff) == 0 && b.low & UINT64_C(0x8000000000000000))
> + ++b.high;
> if (a.low == b.low && a.high == b.high) {
> return float_relation_equal;
> } else {
> --
> 2.17.1
--
Alex Bennée
