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| author | Paul Zimmermann <Paul.Zimmermann@inria.fr> | 2021-04-01 08:14:10 +0200 |
|---|---|---|
| committer | Paul Zimmermann <Paul.Zimmermann@inria.fr> | 2021-04-02 06:15:48 +0200 |
| commit | 9acda61d94acc5348c2330f2519a14d1a4a37e73 (patch) | |
| tree | dcad90e95870279c37b5be7c646b3a3f6edc15cb /sysdeps/x86_64 | |
| parent | 595c22ecd8e87a27fd19270ed30fdbae9ad25426 (diff) | |
| download | glibc-9acda61d94acc5348c2330f2519a14d1a4a37e73.tar.gz glibc-9acda61d94acc5348c2330f2519a14d1a4a37e73.tar.xz glibc-9acda61d94acc5348c2330f2519a14d1a4a37e73.zip | |
Fix the inaccuracy of j0f/j1f/y0f/y1f [BZ #14469, #14470, #14471, #14472]
For j0f/j1f/y0f/y1f, the largest error for all binary32
inputs is reduced to at most 9 ulps for all rounding modes.
The new code is enabled only when there is a cancellation at the very end of
the j0f/j1f/y0f/y1f computation, or for very large inputs, thus should not
give any visible slowdown on average. Two different algorithms are used:
* around the first 64 zeros of j0/j1/y0/y1, approximation polynomials of
degree 3 are used, computed using the Sollya tool (https://www.sollya.org/)
* for large inputs, an asymptotic formula from [1] is used
[1] Fast and Accurate Bessel Function Computation,
John Harrison, Proceedings of Arith 19, 2009.
Inputs yielding the new largest errors are added to auto-libm-test-in,
and ulps are regenerated for various targets (thanks Adhemerval Zanella).
Tested on x86_64 with --disable-multi-arch and on powerpc64le-linux-gnu.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'sysdeps/x86_64')
| -rw-r--r-- | sysdeps/x86_64/fpu/libm-test-ulps | 76 |
1 files changed, 38 insertions, 38 deletions
diff --git a/sysdeps/x86_64/fpu/libm-test-ulps b/sysdeps/x86_64/fpu/libm-test-ulps index bd1fa63702..0edb95e14c 100644 --- a/sysdeps/x86_64/fpu/libm-test-ulps +++ b/sysdeps/x86_64/fpu/libm-test-ulps @@ -1317,50 +1317,50 @@ ldouble: 1 Function: "j0": double: 2 -float: 8 +float: 9 float128: 2 -ldouble: 2 +ldouble: 8 Function: "j0_downward": -double: 2 -float: 4 -float128: 4 +double: 5 +float: 9 +float128: 9 ldouble: 6 Function: "j0_towardzero": -double: 5 -float: 6 -float128: 4 +double: 6 +float: 9 +float128: 9 ldouble: 6 Function: "j0_upward": -double: 4 -float: 5 -float128: 5 +double: 9 +float: 9 +float128: 7 ldouble: 6 Function: "j1": -double: 2 +double: 4 float: 9 float128: 4 -ldouble: 5 +ldouble: 9 Function: "j1_downward": -double: 3 -float: 5 -float128: 4 -ldouble: 4 +double: 6 +float: 8 +float128: 6 +ldouble: 8 Function: "j1_towardzero": -double: 3 -float: 2 -float128: 4 +double: 4 +float: 9 +float128: 9 ldouble: 4 Function: "j1_upward": -double: 3 -float: 5 -float128: 3 +double: 9 +float: 9 +float128: 9 ldouble: 3 Function: "jn": @@ -1753,27 +1753,27 @@ ldouble: 5 Function: "y0": double: 3 -float: 8 +float: 9 float128: 3 -ldouble: 1 +ldouble: 2 Function: "y0_downward": -double: 3 -float: 6 -float128: 4 -ldouble: 5 +double: 4 +float: 9 +float128: 7 +ldouble: 7 Function: "y0_towardzero": -double: 3 -float: 3 +double: 4 +float: 9 float128: 3 -ldouble: 6 +ldouble: 8 Function: "y0_upward": double: 3 -float: 6 -float128: 3 -ldouble: 5 +float: 9 +float128: 4 +ldouble: 7 Function: "y1": double: 6 @@ -1782,14 +1782,14 @@ float128: 5 ldouble: 3 Function: "y1_downward": -double: 3 -float: 2 +double: 6 +float: 9 float128: 5 ldouble: 7 Function: "y1_towardzero": double: 4 -float: 5 +float: 9 float128: 6 ldouble: 5 |