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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 /sysdeps/x86_64 | |
| parent | ba7d2c543f7d69883ece7eab39bf6c5cd5dc3081 (diff) | |
| download | glibc-440169d681cc9f422e8486f1324079bef0e0c35a.zip glibc-440169d681cc9f422e8486f1324079bef0e0c35a.tar.gz glibc-440169d681cc9f422e8486f1324079bef0e0c35a.tar.bz2 | |
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 'sysdeps/x86_64')
| -rw-r--r-- | sysdeps/x86_64/fpu/libm-test-ulps | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/sysdeps/x86_64/fpu/libm-test-ulps b/sysdeps/x86_64/fpu/libm-test-ulps index 36e1b76..cd9e44f 100644 --- a/sysdeps/x86_64/fpu/libm-test-ulps +++ b/sysdeps/x86_64/fpu/libm-test-ulps @@ -29,20 +29,33 @@ ldouble: 1 Function: "acosh": double: 1 +float: 1 idouble: 1 +ifloat: 1 +ildouble: 1 +ldouble: 1 Function: "acosh_downward": +double: 1 float: 1 -ildouble: 1 +idouble: 1 +ifloat: 1 +ildouble: 2 ldouble: 2 Function: "acosh_towardzero": +double: 1 float: 1 -ildouble: 1 +idouble: 1 +ifloat: 1 +ildouble: 2 ldouble: 2 Function: "acosh_upward": double: 1 +float: 1 +idouble: 1 +ifloat: 1 ildouble: 1 ldouble: 1 |