From: "H.J. Lu" <hjl.tools@gmail.com>
To: libc-alpha@sourceware.org
Subject: [PATCH] x86_64: Add expm1 with FMA
Date: Fri, 11 Aug 2023 08:04:08 -0700 [thread overview]
Message-ID: <20230811150408.2832625-1-hjl.tools@gmail.com> (raw)
On Skylake, it improves expm1 bench performance by:
Before After Improvement
max 70.204 68.054 3%
min 20.709 16.2 22%
mean 22.1221 16.7367 24%
NB: Add
extern long double __expm1l (long double);
extern long double __expm1f128 (long double);
for __typeof (__expm1l) and __typeof (__expm1f128) when __expm1 is
defined since __expm1 may be expanded in their declarations which
causes the build failure.
---
sysdeps/ieee754/dbl-64/s_expm1.c | 7 +++++
sysdeps/x86_64/fpu/multiarch/Makefile | 2 ++
sysdeps/x86_64/fpu/multiarch/s_expm1-fma.c | 10 ++++++
sysdeps/x86_64/fpu/multiarch/s_expm1.c | 36 ++++++++++++++++++++++
4 files changed, 55 insertions(+)
create mode 100644 sysdeps/x86_64/fpu/multiarch/s_expm1-fma.c
create mode 100644 sysdeps/x86_64/fpu/multiarch/s_expm1.c
diff --git a/sysdeps/ieee754/dbl-64/s_expm1.c b/sysdeps/ieee754/dbl-64/s_expm1.c
index 8f1c95bd04..1cafeca9c0 100644
--- a/sysdeps/ieee754/dbl-64/s_expm1.c
+++ b/sysdeps/ieee754/dbl-64/s_expm1.c
@@ -130,6 +130,11 @@ static const double
4.00821782732936239552e-06, /* 3ED0CFCA 86E65239 */
-2.01099218183624371326e-07 }; /* BE8AFDB7 6E09C32D */
+#ifndef SECTION
+# define SECTION
+#endif
+
+SECTION
double
__expm1 (double x)
{
@@ -258,4 +263,6 @@ __expm1 (double x)
}
return y;
}
+#ifndef __expm1
libm_alias_double (__expm1, expm1)
+#endif
diff --git a/sysdeps/x86_64/fpu/multiarch/Makefile b/sysdeps/x86_64/fpu/multiarch/Makefile
index f773255721..add339a876 100644
--- a/sysdeps/x86_64/fpu/multiarch/Makefile
+++ b/sysdeps/x86_64/fpu/multiarch/Makefile
@@ -37,6 +37,7 @@ libm-sysdep_routines += \
e_log2-fma \
e_pow-fma \
s_atan-fma \
+ s_expm1-fma \
s_sin-fma \
s_sincos-fma \
s_tan-fma \
@@ -49,6 +50,7 @@ CFLAGS-e_log-fma.c = -mfma -mavx2
CFLAGS-e_log2-fma.c = -mfma -mavx2
CFLAGS-e_pow-fma.c = -mfma -mavx2
CFLAGS-s_atan-fma.c = -mfma -mavx2
+CFLAGS-s_expm1-fma.c = -mfma -mavx2
CFLAGS-s_sin-fma.c = -mfma -mavx2
CFLAGS-s_tan-fma.c = -mfma -mavx2
CFLAGS-s_sincos-fma.c = -mfma -mavx2
diff --git a/sysdeps/x86_64/fpu/multiarch/s_expm1-fma.c b/sysdeps/x86_64/fpu/multiarch/s_expm1-fma.c
new file mode 100644
index 0000000000..3ee2bd804e
--- /dev/null
+++ b/sysdeps/x86_64/fpu/multiarch/s_expm1-fma.c
@@ -0,0 +1,10 @@
+#define __expm1 __expm1_fma
+
+/* NB: __expm1 may be expanded to __expm1_fma in the following
+ prototypes. */
+extern long double __expm1l (long double);
+extern long double __expm1f128 (long double);
+
+#define SECTION __attribute__ ((section (".text.fma")))
+
+#include <sysdeps/ieee754/dbl-64/s_expm1.c>
diff --git a/sysdeps/x86_64/fpu/multiarch/s_expm1.c b/sysdeps/x86_64/fpu/multiarch/s_expm1.c
new file mode 100644
index 0000000000..2cae83fb7f
--- /dev/null
+++ b/sysdeps/x86_64/fpu/multiarch/s_expm1.c
@@ -0,0 +1,36 @@
+/* Multiple versions of expm1.
+ Copyright (C) 2023 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <libm-alias-double.h>
+
+extern double __redirect_expm1 (double);
+
+#define SYMBOL_NAME expm1
+#include "ifunc-fma.h"
+
+libc_ifunc_redirected (__redirect_expm1, __expm1, IFUNC_SELECTOR ());
+libm_alias_double (__expm1, expm1)
+
+#define __expm1 __expm1_sse2
+
+/* NB: __expm1 may be expanded to __expm1_sse2 in the following
+ prototypes. */
+extern long double __expm1l (long double);
+extern long double __expm1f128 (long double);
+
+#include <sysdeps/ieee754/dbl-64/s_expm1.c>
--
2.41.0
next reply other threads:[~2023-08-11 15:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-11 15:04 H.J. Lu [this message]
2023-08-14 4:50 ` Noah Goldstein
2023-08-17 6:46 ` Paul Zimmermann
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