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author | Joseph Myers <joseph@codesourcery.com> | 2015-05-14 23:51:09 +0000 |
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committer | Joseph Myers <joseph@codesourcery.com> | 2015-05-14 23:51:09 +0000 |
commit | 9a71f1fcf53615c00b5f9e5da4bba92bccb0efb4 (patch) | |
tree | 803585f46a9049a90164009e560b8f25e262faa0 /ChangeLog | |
parent | 0b7a5f920163d03806d7c5d9d1c83b16942c9496 (diff) | |
download | glibc-9a71f1fcf53615c00b5f9e5da4bba92bccb0efb4.tar.gz glibc-9a71f1fcf53615c00b5f9e5da4bba92bccb0efb4.tar.xz glibc-9a71f1fcf53615c00b5f9e5da4bba92bccb0efb4.zip |
Fix atanf spurious underflows (bug 18196).
The sysdeps/ieee754/flt-32 version of atanf produces spurious underflow exceptions for some large arguments, because of computations that compute x^-4. This patch fixes this by adjusting the threshold for large arguments (for which +/- pi/2 can just be returned, the correct result being roughly +/- pi/2 - 1/x) from 2^34 to 2^25. Tested for x86_64 and x86. [BZ #18196] * sysdeps/ieee754/flt-32/s_atanf.c (__atanf): Use 2^25 not 2^34 as threshold for large arguments. * math/auto-libm-test-in: Add another test of atan. * math/auto-libm-test-out: Regenerated.
Diffstat (limited to 'ChangeLog')
-rw-r--r-- | ChangeLog | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index f6bf877b16..1179142c92 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,11 @@ 2015-05-14 Joseph Myers <joseph@codesourcery.com> + [BZ #18196] + * sysdeps/ieee754/flt-32/s_atanf.c (__atanf): Use 2^25 not 2^34 as + threshold for large arguments. + * math/auto-libm-test-in: Add another test of atan. + * math/auto-libm-test-out: Regenerated. + [BZ #16339] * sysdeps/i386/fpu/s_log1p.S (dbl_min): New object. (__log1p): Force underflow exception for results with small |