[PATCH 03/10] x86-64: Add exp2f with FMA

["H.J. Lu" <hjl dot tools at gmail dot com>]

For workload-spec2017.wrf, on Skylake, it improves performance by:

                           Before            After     Improvement
reciprocal-throughput      13.0291          11.2225       16%
latency                    44.5154          37.5766       18%

	* sysdeps/x86_64/fpu/multiarch/Makefile (libm-sysdep_routines):
	Add e_exp2f-fma.
	(CFLAGS-e_exp2f-fma.c): New.
	* sysdeps/x86_64/fpu/multiarch/e_exp2f-fma.c: New file.
	* sysdeps/x86_64/fpu/multiarch/e_exp2f.c: Likewise.
---
 sysdeps/x86_64/fpu/multiarch/Makefile      |  3 ++-
 sysdeps/x86_64/fpu/multiarch/e_exp2f-fma.c |  3 +++
 sysdeps/x86_64/fpu/multiarch/e_exp2f.c     | 37 ++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/x86_64/fpu/multiarch/e_exp2f-fma.c
 create mode 100644 sysdeps/x86_64/fpu/multiarch/e_exp2f.c

diff --git a/sysdeps/x86_64/fpu/multiarch/Makefile b/sysdeps/x86_64/fpu/multiarch/Makefile
index 92e91d79af..71a3b337ed 100644
--- a/sysdeps/x86_64/fpu/multiarch/Makefile
+++ b/sysdeps/x86_64/fpu/multiarch/Makefile
@@ -37,8 +37,9 @@ CFLAGS-slowpow-fma.c = -mfma -mavx2
 CFLAGS-s_sin-fma.c = -mfma -mavx2
 CFLAGS-s_tan-fma.c = -mfma -mavx2
 
-libm-sysdep_routines += e_expf-fma
+libm-sysdep_routines += e_exp2f-fma e_expf-fma
 
+CFLAGS-e_exp2f-fma.c = -mfma -mavx2
 CFLAGS-e_expf-fma.c = -mfma -mavx2
 
 libm-sysdep_routines += e_exp-fma4 e_log-fma4 e_pow-fma4 s_atan-fma4 \
diff --git a/sysdeps/x86_64/fpu/multiarch/e_exp2f-fma.c b/sysdeps/x86_64/fpu/multiarch/e_exp2f-fma.c
new file mode 100644
index 0000000000..c915a50794
--- /dev/null
+++ b/sysdeps/x86_64/fpu/multiarch/e_exp2f-fma.c
@@ -0,0 +1,3 @@
+#define __exp2f __exp2f_fma
+
+#include <sysdeps/ieee754/flt-32/e_exp2f.c>
diff --git a/sysdeps/x86_64/fpu/multiarch/e_exp2f.c b/sysdeps/x86_64/fpu/multiarch/e_exp2f.c
new file mode 100644
index 0000000000..13cfcf9b8c
--- /dev/null
+++ b/sysdeps/x86_64/fpu/multiarch/e_exp2f.c
@@ -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-fma.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_sse2
+#include <sysdeps/ieee754/flt-32/e_exp2f.c>
-- 
2.13.6