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authorJoseph Myers <joseph@codesourcery.com>2014-01-02 16:33:06 +0000
committerJoseph Myers <joseph@codesourcery.com>2014-01-02 16:33:06 +0000
commit396e3ecf3e8f0f05bd7eeaf995a3f0c2327a6cd6 (patch)
treeec6423e6d30d9344e775ce5d6011a60306eb99d2 /sysdeps/ieee754/ldbl-128ibm
parent6c8dbf00f536d78b1937b5af6f57be47fd376344 (diff)
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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/ldbl-128ibm')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/e_acoshl.c4
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 8a4a5bb..b0b33f7 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)