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| author | Joseph Myers <joseph@codesourcery.com> | 2014-01-02 16:35:46 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2014-01-02 16:35:46 +0000 |
| commit | 819e5d50dd4d10dc359037eba74c70e74cb42739 (patch) | |
| tree | fe51e811c4c6bb9e91bf2ab3730d34aa8c03452c | |
| parent | 90b6a1e55fdbb3e6a3132742c26eb19666ad9e33 (diff) | |
| download | glibc-819e5d50dd4d10dc359037eba74c70e74cb42739.tar.gz glibc-819e5d50dd4d10dc359037eba74c70e74cb42739.tar.xz glibc-819e5d50dd4d10dc359037eba74c70e74cb42739.zip | |
Fix ldbl-128ibm logl inaccuracy (bug 16386).
This patch fixes bug 16386, ldbl-128ibm logl inaccuracy (with consequent inaccuracy for lgammal) for arguments where the high double is subnormal, which showed up while attempting to regenerate ulps for powerpc-nofpu for 2.19. The problem here is logic failing to allow for subnormals when calculating the exponent of the argument. Tested for powerpc-nofpu. * sysdeps/ieee754/ldbl-128ibm/e_logl.c (__ieee754_logl): Adjust numbers with subnormal high part when calculating exponent.
| -rw-r--r-- | ChangeLog | 4 | ||||
| -rw-r--r-- | NEWS | 3 | ||||
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/e_logl.c | 8 |
3 files changed, 14 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog index 8200122be7..7f4d564d0c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 2014-01-02 Joseph Myers <joseph@codesourcery.com> + [BZ #16386] + * sysdeps/ieee754/ldbl-128ibm/e_logl.c (__ieee754_logl): Adjust + numbers with subnormal high part when calculating exponent. + [BZ #16385] * sysdeps/ieee754/ldbl-128ibm/s_asinhl.c (__asinhl): Use fabsl not fabs. diff --git a/NEWS b/NEWS index c96c0e3cd9..e0ea97aa0e 100644 --- a/NEWS +++ b/NEWS @@ -23,7 +23,8 @@ Version 2.19 16038, 16041, 16055, 16071, 16072, 16074, 16077, 16078, 16103, 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. + 16338, 16356, 16365, 16366, 16369, 16372, 16375, 16379, 16384, 16385, + 16386. * Slovenian translations for glibc messages have been contributed by the Translation Project's Slovenian team of translators. diff --git a/sysdeps/ieee754/ldbl-128ibm/e_logl.c b/sysdeps/ieee754/ldbl-128ibm/e_logl.c index b7db2b9784..58d6bc6972 100644 --- a/sysdeps/ieee754/ldbl-128ibm/e_logl.c +++ b/sysdeps/ieee754/ldbl-128ibm/e_logl.c @@ -229,6 +229,14 @@ __ieee754_logl(long double x) /* Extract exponent and reduce domain to 0.703125 <= u < 1.40625 */ unsigned int w0; e = (int) (m >> 20) - (int) 0x3fe; + if (e == -1022) + { + x *= 0x1p106L; + xhi = ldbl_high (x); + EXTRACT_WORDS (hx, lx, xhi); + m = hx; + e = (int) (m >> 20) - (int) 0x3fe - 106; + } m &= 0xfffff; w0 = m | 0x3fe00000; m |= 0x100000; |