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i386: Replace assembly versions of e_exp2f with generic e_exp2f.c 

This patch replaces i386 assembly versions of e_exp2f with generic
e_exp2f.c.  For workload-spec2017.wrf, on Nehalem, it improves
performance by:

                           Before            After     Improvement
reciprocal-throughput      112.996          40.0454       182%
latency                    126.581          54.4479       132%

On Skylake, it improves performance by:

                           Before            After     Improvement
reciprocal-throughput      113.14           39.447        186%
latency                    136.068          55.684        144%

On IvyBridge with --disable-multi-arch, it improves performance by:

                           Before            After     Improvement
reciprocal-throughput      132.521          40.3759       228%
latency                    145.791          58.4587       149%

	* sysdeps/i386/fpu/e_exp2f.S: Removed.
	* sysdeps/i386/fpu/w_exp2f.c: Likewise.
	* sysdeps/i386/fpu/libm-test-ulps: Updated for generic e_exp2f.c.
	* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
	* sysdeps/i386/i686/fpu/multiarch/Makefile (libm-sysdep_routines):
	Add e_exp2f-sse2.
	(CFLAGS-e_exp2f-sse2.c): New.
	* sysdeps/i386/i686/fpu/multiarch/e_exp2f-sse2.c: New file.
	* sysdeps/i386/i686/fpu/multiarch/e_exp2f.c: Likewise.
This commit is contained in:
H.J. Lu 2017-10-22 07:58:54 -07:00
parent 5d15c96975
commit 7eda65f69e
8 changed files with 58 additions and 54 deletions
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12
ChangeLog
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@ -1,3 +1,15 @@
2017-10-22 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/i386/fpu/e_exp2f.S: Removed.
* sysdeps/i386/fpu/w_exp2f.c: Likewise.
* sysdeps/i386/fpu/libm-test-ulps: Updated for generic e_exp2f.c.
* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
* sysdeps/i386/i686/fpu/multiarch/Makefile (libm-sysdep_routines):
Add e_exp2f-sse2.
(CFLAGS-e_exp2f-sse2.c): New.
* sysdeps/i386/i686/fpu/multiarch/e_exp2f-sse2.c: New file.
* sysdeps/i386/i686/fpu/multiarch/e_exp2f.c: Likewise.
2017-10-22 H.J. Lu <hongjiu.lu@intel.com> 2017-10-22 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/x86_64/fpu/multiarch/Makefile (libm-sysdep_routines): * sysdeps/x86_64/fpu/multiarch/Makefile (libm-sysdep_routines):

52
sysdeps/i386/fpu/e_exp2f.S
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@ -1,52 +0,0 @@
/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Adapted for exp2 by Ulrich Drepper <drepper@cygnus.com>.
* Public domain.
*/
#include <machine/asm.h>
#include <i386-math-asm.h>
DEFINE_FLT_MIN
#ifdef PIC
# define MO(op) op##@GOTOFF(%ecx)
#else
# define MO(op) op
#endif
.text
ENTRY(__ieee754_exp2f)
#ifdef PIC
LOAD_PIC_REG (cx)
#endif
flds 4(%esp)
/* I added the following ugly construct because exp(+-Inf) resulted
in NaN. The ugliness results from the bright minds at Intel.
For the i686 the code can be written better.
-- drepper@cygnus.com. */
fxam /* Is NaN or +-Inf? */
fstsw %ax
movb $0x45, %dh
andb %ah, %dh
cmpb $0x05, %dh
je 1f /* Is +-Inf, jump. */
fld %st
frndint /* int(x) */
fsubr %st,%st(1) /* fract(x) */
fxch
f2xm1 /* 2^(fract(x)) - 1 */
fld1
faddp /* 2^(fract(x)) */
fscale /* e^x */
fstp %st(1)
FLT_NARROW_EVAL_UFLOW_NONNEG_NAN
ret
1: testl $0x200, %eax /* Test sign. */
jz 2f /* If positive, jump. */
fstp %st
fldz /* Set result to 0. */
2: ret
END (__ieee754_exp2f)
strong_alias (__ieee754_exp2f, __exp2f_finite)

2
sysdeps/i386/fpu/libm-test-ulps
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@ -1921,7 +1921,9 @@ ildouble: 1
ldouble: 1 ldouble: 1
Function: "exp2_upward": Function: "exp2_upward":
float: 1
float128: 2 float128: 2
ifloat: 1
ifloat128: 2 ifloat128: 2
ildouble: 1 ildouble: 1
ldouble: 1 ldouble: 1

1
sysdeps/i386/fpu/w_exp2f.c
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@ -1 +0,0 @@
#include <sysdeps/../math/w_exp2f.c>

3
sysdeps/i386/i686/fpu/multiarch/Makefile
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@ -1,6 +1,7 @@
ifeq ($(subdir),math) ifeq ($(subdir),math)
libm-sysdep_routines += e_expf-sse2 s_sinf-sse2 s_cosf-sse2 \ libm-sysdep_routines += e_exp2f-sse2 e_expf-sse2 s_sinf-sse2 s_cosf-sse2 \
s_sincosf-sse2 s_sincosf-sse2
CFLAGS-e_exp2f-sse2.c = -msse2 -mfpmath=sse
CFLAGS-e_expf-sse2.c = -msse2 -mfpmath=sse CFLAGS-e_expf-sse2.c = -msse2 -mfpmath=sse
endif endif

3
sysdeps/i386/i686/fpu/multiarch/e_exp2f-sse2.c Normal file
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@ -0,0 +1,3 @@
#define __exp2f __exp2f_sse2
#include <sysdeps/ieee754/flt-32/e_exp2f.c>

37
sysdeps/i386/i686/fpu/multiarch/e_exp2f.c Normal file
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@ -0,0 +1,37 @@
/* Multiple versions of exp2f.
Copyright (C) 2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
extern float __redirect_exp2f (float);
#define SYMBOL_NAME exp2f
#include "ifunc-sse2.h"
libc_ifunc_redirected (__redirect_exp2f, __exp2f, IFUNC_SELECTOR ());
#ifdef SHARED
# include <shlib-compat.h>
versioned_symbol (libm, __exp2f, exp2f, GLIBC_2_27);
#else
weak_alias (__exp2f, exp2f)
#endif
strong_alias (__exp2f, __ieee754_exp2f)
strong_alias (__exp2f, __exp2f_finite)
#define __exp2f __exp2f_ia32
#include <sysdeps/ieee754/flt-32/e_exp2f.c>

2
sysdeps/i386/i686/fpu/multiarch/libm-test-ulps
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@ -1921,7 +1921,9 @@ ildouble: 1
ldouble: 1 ldouble: 1
Function: "exp2_upward": Function: "exp2_upward":
float: 1
float128: 2 float128: 2
ifloat: 1
ifloat128: 2 ifloat128: 2
ildouble: 1 ildouble: 1
ldouble: 1 ldouble: 1