glibc/sysdeps/ieee754/dbl-64/s_cbrt.c
Joseph Myers 1e2bffd05c Use libm_alias_double for some dbl-64 functions.
Continuing the move of libm aliases to common macros that can create
_FloatN / _FloatNx aliases in future, this patch converts some dbl-64
functions to using libm_alias_double, thereby eliminating the need for
some ldbl-opt wrappers.

This patch deliberately limits what functions are converted so that it
can be verified by comparison of stipped binaries.  Specifically, atan
and tan are excluded because they first need converting to being weak
aliases; fma is omitted as it has additional complications with
versions in other directories (removing the ldbl-opt version can
e.g. cause the ldbl-128 version to be used instead of dbl-64); and
functions that have both dbl-64/wordsize-64 and ldbl-opt versions are
excluded because ldbl-opt currently always wraps dbl-64 function
versions, so changing those will result in platforms using both
ldbl-opt and dbl-64/wordsize-64 (i.e. alpha) starting to use the
dbl-64/wordsize-64 versions of those functions (which is good, as an
optimization, but still best separated from the present patch to get
better validation).

Tested for x86_64, and tested with build-many-glibcs.py that installed
stripped shared libraries are unchanged by the patch.

	* sysdeps/ieee754/dbl-64/s_asinh.c: Include <libm-alias-double.h>.
	(asinh): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_cbrt.c: Include <libm-alias-double.h>.
	(cbrt): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_copysign.c: Include
	<libm-alias-double.h>.
	(copysign): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_erf.c: Include <libm-alias-double.h>.
	(erf): Define using libm_alias_double.
	(erfc): Likewise.
	* sysdeps/ieee754/dbl-64/s_expm1.c: Include <libm-alias-double.h>.
	(expm1): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_fabs.c: Include <libm-alias-double.h>.
	(fabs): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_fromfp.c (fromfp): Define using
	libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_fromfp_main.c: Include
	<libm-alias-double.h>.
	* sysdeps/ieee754/dbl-64/s_fromfpx.c (fromfpx): Define using
	libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_getpayload.c: Include
	<libm-alias-double.h>.
	(getpayload): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_llrint.c: Include
	<libm-alias-double.h>.
	(llrint): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_lrint.c: Include <libm-alias-double.h>.
	(lrint): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_nextup.c: Include
	<libm-alias-double.h>.
	(nextup): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_roundeven.c: Include
	<libm-alias-double.h>.
	(roundeven): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_setpayload.c (setpayload): Define using
	libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_setpayload_main.c: Include
	<libm-alias-double.h>.
	* sysdeps/ieee754/dbl-64/s_setpayloadsig.c (setpayloadsig): Define
	using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_sin.c: Include <libm-alias-double.h>.
	(cos): Define using libm_alias_double.
	(sin): Likewise.
	* sysdeps/ieee754/dbl-64/s_sincos.c: Include
	<libm-alias-double.h>.
	(sincos): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_tanh.c: Include <libm-alias-double.h>.
	(tanh): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_totalorder.c: Include
	<libm-alias-double.h>.
	(totalorder): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_totalordermag.c: Include
	<libm-alias-double.h>.
	(totalordermag): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_ufromfp.c (ufromfp): Define using
	libm_alias_double.
	* sysdeps/ieee754/dbl-64/s_ufromfpx.c (ufromfpx): Define using
	libm_alias_double.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_getpayload.c: Include
	<libm-alias-double.h>.
	(getpayload): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_roundeven.c: Include
	<libm-alias-double.h>.
	(roundeven): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_setpayload_main.c: Include
	<libm-alias-double.h>.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_totalorder.c: Include
	<libm-alias-double.h>.
	(totalorder): Define using libm_alias_double.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_totalordermag.c: Include
	<libm-alias-double.h>.
	(totalordermag): Define using libm_alias_double.
	* sysdeps/ieee754/ldbl-opt/s_copysign.c (copysignl): Only define
	libc compat symbol here.
	* sysdeps/ieee754/ldbl-opt/s_asinh.c: Remove file.
	* sysdeps/ieee754/ldbl-opt/s_cbrt.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_erf.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_expm1.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_fabs.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_llrint.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_lrint.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_sin.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_sincos.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/s_tanh.c: Likewise.
2017-09-29 23:54:33 +00:00

74 lines
2.1 KiB
C

/* Compute cubic root of double value.
Copyright (C) 1997-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Dirk Alboth <dirka@uni-paderborn.de> and
Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
#include <libm-alias-double.h>
#define CBRT2 1.2599210498948731648 /* 2^(1/3) */
#define SQR_CBRT2 1.5874010519681994748 /* 2^(2/3) */
static const double factor[5] =
{
1.0 / SQR_CBRT2,
1.0 / CBRT2,
1.0,
CBRT2,
SQR_CBRT2
};
double
__cbrt (double x)
{
double xm, ym, u, t2;
int xe;
/* Reduce X. XM now is an range 1.0 to 0.5. */
xm = __frexp (fabs (x), &xe);
/* If X is not finite or is null return it (with raising exceptions
if necessary.
Note: *Our* version of `frexp' sets XE to zero if the argument is
Inf or NaN. This is not portable but faster. */
if (xe == 0 && fpclassify (x) <= FP_ZERO)
return x + x;
u = (0.354895765043919860
+ ((1.50819193781584896
+ ((-2.11499494167371287
+ ((2.44693122563534430
+ ((-1.83469277483613086
+ (0.784932344976639262 - 0.145263899385486377 * xm)
* xm)
* xm))
* xm))
* xm))
* xm));
t2 = u * u * u;
ym = u * (t2 + 2.0 * xm) / (2.0 * t2 + xm) * factor[2 + xe % 3];
return __ldexp (x > 0.0 ? ym : -ym, xe / 3);
}
libm_alias_double (__cbrt, cbrt)