diff options
| author | Florian Weimer <fweimer@redhat.com> | 2024-11-06 16:09:05 +0100 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2024-11-06 16:09:05 +0100 |
| commit | ba60be873554ecd141b55ea82647714933c0dbd4 (patch) | |
| tree | c5e684e2e255634d422c0072cd76ba7f7744d9de | |
| parent | ff254cabd64bec6b6810ee1e1f0c901d273efaca (diff) | |
| download | glibc-ba60be873554ecd141b55ea82647714933c0dbd4.tar.xz glibc-ba60be873554ecd141b55ea82647714933c0dbd4.zip | |
math: Fix incorrect results of exp10m1f with some GCC versions
On GCC 11 (x86-64), the previous code produced test failures like
this one:
Failure: Test: exp10m1_towardzero (-0x1.1p+4)
Result:
is: -1.00000000e+00 -0x1.000000p+0
should be: -9.99999940e-01 -0x1.fffffep-1
difference: 5.96046447e-08 0x1.000000p-24
ulp : 1.0000
max.ulp : 0.0000
Apply a similar fix to exp2m1f.
Co-authored-by: Paul Zimmermann <Paul.Zimmermann@inria.fr>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
| -rw-r--r-- | sysdeps/ieee754/flt-32/s_exp10m1f.c | 2 | ||||
| -rw-r--r-- | sysdeps/ieee754/flt-32/s_exp2m1f.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/sysdeps/ieee754/flt-32/s_exp10m1f.c b/sysdeps/ieee754/flt-32/s_exp10m1f.c index 04a068ee32..ea3173a174 100644 --- a/sysdeps/ieee754/flt-32/s_exp10m1f.c +++ b/sysdeps/ieee754/flt-32/s_exp10m1f.c @@ -40,7 +40,7 @@ __exp10m1f (float x) { /* x < -7.52575 */ if (ax > (0xffu << 23)) return x + x; /* nan */ - return (ux == 0xff800000) ? -0x1p+0 : -0x1p+0 + 0x1p-26f; + return (ux == 0xff800000) ? -0x1p+0f : -0x1p+0f + 0x1p-26f; } else if (__glibc_unlikely (ax > 0x421a209au)) { /* x > 38.5318 */ diff --git a/sysdeps/ieee754/flt-32/s_exp2m1f.c b/sysdeps/ieee754/flt-32/s_exp2m1f.c index b3f86409cc..325ffb11b0 100644 --- a/sysdeps/ieee754/flt-32/s_exp2m1f.c +++ b/sysdeps/ieee754/flt-32/s_exp2m1f.c @@ -41,7 +41,7 @@ __exp2m1f (float x) { /* x <= -25 */ if (ax > (0xffu << 23)) return x + x; /* nan */ - return (ux == 0xff800000) ? -0x1p+0 : -0x1p+0 + 0x1p-26f; + return (ux == 0xff800000) ? -0x1p+0f : -0x1p+0f + 0x1p-26f; } else if (__glibc_unlikely (ax >= 0x43000000u)) { /* x >= 128 */ |