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| author | Joseph Myers <joseph@codesourcery.com> | 2015-02-25 11:13:41 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2015-02-25 11:13:41 +0000 |
| commit | 137cef7d433407bd2ded8bcc5bea70e5858df47a (patch) | |
| tree | deb0a6e04c5e7220d1e4eebcf59ab9d792a8eca6 /ChangeLog | |
| parent | cb43bb0d68f001fc3d6e054d712ab8794b5fd1de (diff) | |
| download | glibc-137cef7d433407bd2ded8bcc5bea70e5858df47a.tar.gz glibc-137cef7d433407bd2ded8bcc5bea70e5858df47a.tar.xz glibc-137cef7d433407bd2ded8bcc5bea70e5858df47a.zip | |
Fix ldbl-128ibm asinhl inaccuracy (bug 18020).
The ldbl-128ibm implementation of asinhl uses cut-offs of 0x1p28 and 0x1p-29 to determine when to use simpler formulas that avoid possible overflow / underflow. Both those cut-offs are inappropriate for this format, resulting in large errors. This patch changes the code to use more appropriate cut-offs of 0x1p56 and 0x1p-56, adding tests around the cut-offs for various floating-point formats. Tested for powerpc. Also tested for x86_64 and x86 and updated ulps. [BZ #18020] * sysdeps/ieee754/ldbl-128ibm/s_asinhl.c (__asinhl): Use 2**56 and 2**-56 not 2**28 and 2**-29 as thresholds for simpler formulas. * math/auto-libm-test-in: Add more tests of asinh. * math/auto-libm-test-out: Regenerated. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
Diffstat (limited to 'ChangeLog')
| -rw-r--r-- | ChangeLog | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index e13f9f912b..296f5e8630 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2015-02-25 Joseph Myers <joseph@codesourcery.com> + + [BZ #18020] + * sysdeps/ieee754/ldbl-128ibm/s_asinhl.c (__asinhl): Use 2**56 and + 2**-56 not 2**28 and 2**-29 as thresholds for simpler formulas. + * math/auto-libm-test-in: Add more tests of asinh. + * math/auto-libm-test-out: Regenerated. + * sysdeps/i386/fpu/libm-test-ulps: Update. + * sysdeps/x86_64/fpu/libm-test-ulps: Likewise. + 2015-02-25 Cong Wang <xiyou.wangcong@gmail.com> [BZ #15850] |