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| author | Joseph Myers <joseph@codesourcery.com> | 2014-01-06 18:20:20 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2014-01-06 18:20:20 +0000 |
| commit | eb3fc44b56e5e780be5e2830c72d20b9e74fef8a (patch) | |
| tree | 77225ddae4384596a6c9e46ae8340ee9e2698032 | |
| parent | 5fd3eccbea76216091e147ebd84ed64a839f76eb (diff) | |
| download | glibc-eb3fc44b56e5e780be5e2830c72d20b9e74fef8a.tar.gz glibc-eb3fc44b56e5e780be5e2830c72d20b9e74fef8a.tar.xz glibc-eb3fc44b56e5e780be5e2830c72d20b9e74fef8a.zip | |
Fix ldbl-128 / ldbl-128ibm lgammal spurious underflow (bug 16400).
This patch fixes bug 16400, spurious underflow exceptions for ldbl-128 / ldbl-128ibm lgammal with small positive arguments, by just using -__logl (x) as the result in the problem cases (similar to the previous fix for problems with small negative arguments). Tested powerpc32, and also tested on mips64 that this does not require ulps regeneration for the ldbl-128 case. * sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r): Return -__logl (x) for small positive arguments without evaluating a polynomial.
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | NEWS | 2 | ||||
| -rw-r--r-- | sysdeps/ieee754/ldbl-128/e_lgammal_r.c | 4 |
3 files changed, 11 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog index 1984691a78..8bdea17179 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2014-01-06 Joseph Myers <joseph@codesourcery.com> + + [BZ #16400] + * sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r): + Return -__logl (x) for small positive arguments without evaluating + a polynomial. + 2014-01-06 Mike Frysinger <vapier@gentoo.org> * sysdeps/unix/sysv/linux/sys/ptrace.h (ptrace_peeksiginfo_args): diff --git a/NEWS b/NEWS index e6c5020a07..ab3b882631 100644 --- a/NEWS +++ b/NEWS @@ -24,7 +24,7 @@ Version 2.19 16112, 16143, 16144, 16146, 16150, 16151, 16153, 16167, 16172, 16195, 16214, 16245, 16271, 16274, 16283, 16289, 16293, 16314, 16316, 16330, 16337, 16338, 16356, 16365, 16366, 16369, 16372, 16375, 16379, 16384, - 16385, 16386, 16390. + 16385, 16386, 16390, 16400. * Slovenian translations for glibc messages have been contributed by the Translation Project's Slovenian team of translators. diff --git a/sysdeps/ieee754/ldbl-128/e_lgammal_r.c b/sysdeps/ieee754/ldbl-128/e_lgammal_r.c index 23ab9b9a43..1961355a73 100644 --- a/sysdeps/ieee754/ldbl-128/e_lgammal_r.c +++ b/sysdeps/ieee754/ldbl-128/e_lgammal_r.c @@ -805,7 +805,9 @@ __ieee754_lgammal_r (long double x, int *signgamp) { case 0: /* log gamma (x + 1) = log(x) + log gamma(x) */ - if (x <= 0.125) + if (x < 0x1p-120L) + return -__logl (x); + else if (x <= 0.125) { p = x * neval (x, RN1, NRN1) / deval (x, RD1, NRD1); } |