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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 /NEWS | |
| parent | b2fb25240813266e4f62f2dd039573f1a042ea2f (diff) | |
| download | glibc-ff069f024ae8cf15d53429e034d67ddcece0f67a.zip glibc-ff069f024ae8cf15d53429e034d67ddcece0f67a.tar.gz glibc-ff069f024ae8cf15d53429e034d67ddcece0f67a.tar.bz2 | |
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 'NEWS')
| -rw-r--r-- | NEWS | 2 |
1 files changed, 1 insertions, 1 deletions
@@ -17,7 +17,7 @@ Version 2.22 17999, 18007, 18019, 18020, 18029, 18030, 18032, 18036, 18038, 18039, 18042, 18043, 18046, 18047, 18068, 18080, 18093, 18100, 18104, 18110, 18111, 18125, 18128, 18138, 18185, 18196, 18197, 18206, 18210, 18211, - 18217, 18247, 18287, 18319, 18333, 18346, 18397, 18409. + 18217, 18220, 18247, 18287, 18319, 18333, 18346, 18397, 18409. * Cache information can be queried via sysconf() function on s390 e.g. with _SC_LEVEL1_ICACHE_SIZE as argument. |