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| author | Joseph Myers <joseph@codesourcery.com> | 2015-02-25 00:01:15 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2015-02-25 00:01:15 +0000 |
| commit | 440169d681cc9f422e8486f1324079bef0e0c35a (patch) | |
| tree | 9b732f618ba081518cf0cca84ef33328526a4633 /ChangeLog | |
| parent | ba7d2c543f7d69883ece7eab39bf6c5cd5dc3081 (diff) | |
| download | glibc-440169d681cc9f422e8486f1324079bef0e0c35a.tar.gz glibc-440169d681cc9f422e8486f1324079bef0e0c35a.tar.xz glibc-440169d681cc9f422e8486f1324079bef0e0c35a.zip | |
Fix ldbl-128ibm acoshl inaccuracy (bug 18019).
The ldbl-128ibm implementation of acoshl uses a cut-off of 0x1p28 to determine when to use log(x) + log(2) as a formula. That cut-off is too small for this format, resulting in large errors. This patch changes it to a more appropriate cut-off of 0x1p56, 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 #18019] * sysdeps/ieee754/ldbl-128ibm/e_acoshl.c (__ieee754_acoshl): Use 2**56 not 2**28 as threshold for log (2x) formula. * math/auto-libm-test-in: Add more tests of acosh. * 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 b8da862dc2..5ea4c4f9f9 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2015-02-24 Joseph Myers <joseph@codesourcery.com> + + [BZ #18019] + * sysdeps/ieee754/ldbl-128ibm/e_acoshl.c (__ieee754_acoshl): Use + 2**56 not 2**28 as threshold for log (2x) formula. + * math/auto-libm-test-in: Add more tests of acosh. + * math/auto-libm-test-out: Regenerated. + * sysdeps/i386/fpu/libm-test-ulps: Update. + * sysdeps/x86_64/fpu/libm-test-ulps: Likewise. + 2015-02-24 Mike Frysinger <vapier@gentoo.org> * include/alloca.h [_STACK_GROWS_DOWN] (extend_alloca): Add |