| Message ID | 87y11wms4v.fsf@oldenburg.str.redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | math: Fix incorrect results of exp10m1f with some GCC versions | expand |
On 06/11/24 10:03, Florian Weimer wrote: > 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. > > Tested on x86-64 with GCC 11 and GCC 14 (on systems with FMA). > > Co-authored-by: Paul Zimmermann <Paul.Zimmermann@inria.fr> LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > > --- > sysdeps/ieee754/flt-32/s_exp10m1f.c | 2 +- > 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 */ > > base-commit: c1560f3f75c0e892b5522c16f91b4e303f677094 >
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 */