diff options
| author | Joseph Myers <joseph@codesourcery.com> | 2014-01-02 16:33:06 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2014-01-02 16:33:06 +0000 |
| commit | 396e3ecf3e8f0f05bd7eeaf995a3f0c2327a6cd6 (patch) | |
| tree | ec6423e6d30d9344e775ce5d6011a60306eb99d2 /sysdeps/ieee754 | |
| parent | 6c8dbf00f536d78b1937b5af6f57be47fd376344 (diff) | |
Fix ldbl-128ibm acoshl inaccuracy (bug 16384).
This patch fixes bug 16384, ldbl-128ibm acoshl inaccuracy, which
showed up while attempting to regenerate ulps for powerpc-nofpu for
2.19. There were two separate problems, use of __log1p instead of
__log1pl and an insufficiently accurate constant value for log 2
(which this patch replaces by use of M_LN2l), each of which could
cause substantial inaccuracy in affected cases.
Tested for powerpc-nofpu.
* sysdeps/ieee754/ldbl-128ibm/e_acoshl.c (ln2): Initialize with
M_LN2l.
(__ieee754_acoshl): Use __log1pl not __log1p.
Diffstat (limited to 'sysdeps/ieee754')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/e_acoshl.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_acoshl.c b/sysdeps/ieee754/ldbl-128ibm/e_acoshl.c index 8a4a5bb7b9..b0b33f7520 100644 --- a/sysdeps/ieee754/ldbl-128ibm/e_acoshl.c +++ b/sysdeps/ieee754/ldbl-128ibm/e_acoshl.c @@ -29,7 +29,7 @@ static const long double one = 1.0L, -ln2 = 6.93147180559945286227e-01L; /* 0x3FE62E42, 0xFEFA39EF */ +ln2 = M_LN2l; long double __ieee754_acoshl(long double x) @@ -56,7 +56,7 @@ __ieee754_acoshl(long double x) return __ieee754_logl(2.0*x-one/(x+__ieee754_sqrtl(t-one))); } else { /* 1<x<2 */ t = x-one; - return __log1p(t+__ieee754_sqrtl(2.0*t+t*t)); + return __log1pl(t+__ieee754_sqrtl(2.0*t+t*t)); } } strong_alias (__ieee754_acoshl, __acoshl_finite) |