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| author | Joseph Myers <joseph@codesourcery.com> | 2015-05-15 17:21:08 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2015-05-15 17:21:08 +0000 |
| commit | ff069f024ae8cf15d53429e034d67ddcece0f67a (patch) | |
| tree | d6ad47bf62f47e532cadb862d427eaa2f610c12c /math/s_nan.c | |
| parent | b2fb25240813266e4f62f2dd039573f1a042ea2f (diff) | |
| download | glibc-ff069f024ae8cf15d53429e034d67ddcece0f67a.tar.gz glibc-ff069f024ae8cf15d53429e034d67ddcece0f67a.tar.xz glibc-ff069f024ae8cf15d53429e034d67ddcece0f67a.zip | |
Fix lgammaf spurious underflows (bug 18220).
The flt-32 implementation of lgammaf produces spurious underflow exceptions for some large arguments, because of calculations involving x^-2 multiplied by small constants. This patch fixes this by adjusting the threshold for a simpler computation to 2**26 (the error in the simpler computation is on the order of 0.5 * log (x), for a result on the order of x * log (x)). Tested for x86_64 and x86. [BZ #18220] * sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Use 2**26 not 2**58 as threshold for returning x * (log (x) - 1). * math/auto-libm-test-in: Add another test of lgamma. * math/auto-libm-test-out: Regenerated.
Diffstat (limited to 'math/s_nan.c')
0 files changed, 0 insertions, 0 deletions