glibc/sysdeps/ieee754
Joseph Myers 2ca725c594 Fix ldbl-96, ldbl-128ibm atanhl inaccuracy (bug 18046, bug 18047).
The threshold in ldbl-96 atanhl for when to return the argument,
0x1p-28, is a bit too big, and that in ldbl-128ibm atanhl is much too
big (the relevant condition being x^3/3 being < 0.5ulp of x),
resulting in errors a bit above the limits of those considered
acceptable in glibc in the ldbl-96 case, and in large errors in the
ldbl-128ibm case.  This patch changes those implementations to use
more appropriate thresholds and adds tests around the thresholds for
various formats.

Tested for x86_64, x86 and powerpc.  x86_64 and x86 ulps updated
accordingly.

	[BZ #18046]
	[BZ #18047]
	* sysdeps/ieee754/ldbl-128ibm/e_atanhl.c (__ieee754_atanhl): Use
	0x1p-56L as threshold for just returning the argument.
	* sysdeps/ieee754/ldbl-96/e_atanhl.c (__ieee754_atanhl): Use
	0x1p-32L as threshold for just returning the argument.
	* math/auto-libm-test-in: Add more tests of atanh.
	* math/auto-libm-test-out: Regenerated.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulp: Likewise.
2015-02-27 17:48:37 +00:00
..
bits Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
dbl-64 Avoid uninitialized warnings in Bessel functions. 2015-02-26 21:49:19 +00:00
flt-32 Avoid uninitialized warnings in Bessel functions. 2015-02-26 21:49:19 +00:00
ldbl-64-128 Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
ldbl-96 Fix ldbl-96, ldbl-128ibm atanhl inaccuracy (bug 18046, bug 18047). 2015-02-27 17:48:37 +00:00
ldbl-128 Fix ldbl-128/ldbl-128ibm acosl inaccuracy (bug 18038, bug 18039). 2015-02-26 21:06:34 +00:00
ldbl-128ibm Fix ldbl-96, ldbl-128ibm atanhl inaccuracy (bug 18046, bug 18047). 2015-02-27 17:48:37 +00:00
ldbl-opt Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
ieee754.h Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
k_standard.c Add comment to CSTR macro in k_standard.c. 2015-02-27 01:12:19 +00:00
k_standardf.c Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
k_standardl.c Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
Makefile Avoid -Wno-write-strings for k_standard.c. 2015-02-26 22:50:54 +00:00
s_lib_version.c Remove trailing whitespace. 2013-06-05 20:44:03 +00:00
s_matherr.c Use <> for math.h and math_private.h everywhere. 2012-03-09 16:09:10 -08:00
s_signgam.c Use <> for math.h and math_private.h everywhere. 2012-03-09 16:09:10 -08:00
support.c Fix leading whitespaces. 2013-06-06 20:36:07 +02:00