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author | Joseph Myers <joseph@codesourcery.com> | 2015-02-25 11:13:41 +0000 |
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committer | Joseph Myers <joseph@codesourcery.com> | 2015-02-25 11:13:41 +0000 |
commit | 137cef7d433407bd2ded8bcc5bea70e5858df47a (patch) | |
tree | deb0a6e04c5e7220d1e4eebcf59ab9d792a8eca6 /sysdeps/i386/fpu | |
parent | cb43bb0d68f001fc3d6e054d712ab8794b5fd1de (diff) | |
download | glibc-137cef7d433407bd2ded8bcc5bea70e5858df47a.tar.gz glibc-137cef7d433407bd2ded8bcc5bea70e5858df47a.tar.xz glibc-137cef7d433407bd2ded8bcc5bea70e5858df47a.zip |
Fix ldbl-128ibm asinhl inaccuracy (bug 18020).
The ldbl-128ibm implementation of asinhl uses cut-offs of 0x1p28 and 0x1p-29 to determine when to use simpler formulas that avoid possible overflow / underflow. Both those cut-offs are inappropriate for this format, resulting in large errors. This patch changes the code to use more appropriate cut-offs of 0x1p56 and 0x1p-56, 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 #18020] * sysdeps/ieee754/ldbl-128ibm/s_asinhl.c (__asinhl): Use 2**56 and 2**-56 not 2**28 and 2**-29 as thresholds for simpler formulas. * math/auto-libm-test-in: Add more tests of asinh. * 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/i386/fpu')
-rw-r--r-- | sysdeps/i386/fpu/libm-test-ulps | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/sysdeps/i386/fpu/libm-test-ulps b/sysdeps/i386/fpu/libm-test-ulps index 0977557f02..3ba23a4fc5 100644 --- a/sysdeps/i386/fpu/libm-test-ulps +++ b/sysdeps/i386/fpu/libm-test-ulps @@ -68,14 +68,14 @@ ldouble: 1 Function: "asinh_downward": double: 1 float: 1 -ildouble: 1 +ildouble: 3 ldouble: 3 Function: "asinh_towardzero": double: 1 float: 1 -ildouble: 1 -ldouble: 2 +ildouble: 3 +ldouble: 3 Function: "asinh_upward": double: 1 @@ -83,7 +83,7 @@ float: 1 idouble: 1 ifloat: 1 ildouble: 5 -ldouble: 2 +ldouble: 3 Function: "atan2": ildouble: 1 |