x86-64: Add logf with FMA

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

                           Before            After     Improvement
reciprocal-throughput      16.1534          13.8874       16%
latency                    41.9642          34.3072       22%

	* sysdeps/x86_64/fpu/multiarch/Makefile (libm-sysdep_routines):
	Add e_logf-fma.
	(CFLAGS-e_logf-fma.c): New.
	* sysdeps/x86_64/fpu/multiarch/e_logf-fma.c: New file.
	* sysdeps/x86_64/fpu/multiarch/e_logf.c: Likewise.

3 files changed, 45 insertions, 1 deletions

diff --git a/sysdeps/x86_64/fpu/multiarch/Makefile b/sysdeps/x86_64/fpu/multiarch/Makefile
index 71a3b337ed..97d886aa59 100644
--- a/sysdeps/x86_64/fpu/multiarch/Makefile
+++ b/sysdeps/x86_64/fpu/multiarch/Makefile
@@ -37,10 +37,11 @@ CFLAGS-slowpow-fma.c = -mfma -mavx2
 CFLAGS-s_sin-fma.c = -mfma -mavx2
 CFLAGS-s_tan-fma.c = -mfma -mavx2
 
-libm-sysdep_routines += e_exp2f-fma e_expf-fma
+libm-sysdep_routines += e_exp2f-fma e_expf-fma e_logf-fma
 
 CFLAGS-e_exp2f-fma.c = -mfma -mavx2
 CFLAGS-e_expf-fma.c = -mfma -mavx2
+CFLAGS-e_logf-fma.c = -mfma -mavx2
 
 libm-sysdep_routines += e_exp-fma4 e_log-fma4 e_pow-fma4 s_atan-fma4 \
 			e_asin-fma4 e_atan2-fma4 s_sin-fma4 s_tan-fma4 \
diff --git a/sysdeps/x86_64/fpu/multiarch/e_logf-fma.c b/sysdeps/x86_64/fpu/multiarch/e_logf-fma.c
new file mode 100644
index 0000000000..a47fd8195f
--- /dev/null
+++ b/sysdeps/x86_64/fpu/multiarch/e_logf-fma.c
@@ -0,0 +1,3 @@
+#define __logf __logf_fma
+
+#include <sysdeps/ieee754/flt-32/e_logf.c>
diff --git a/sysdeps/x86_64/fpu/multiarch/e_logf.c b/sysdeps/x86_64/fpu/multiarch/e_logf.c
new file mode 100644
index 0000000000..6b29473f4c
--- /dev/null
+++ b/sysdeps/x86_64/fpu/multiarch/e_logf.c
@@ -0,0 +1,40 @@
+/* Multiple versions of logf.
+   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_logf (float);
+
+#define SYMBOL_NAME logf
+#include "ifunc-fma.h"
+
+libc_ifunc_redirected (__redirect_logf, __logf, IFUNC_SELECTOR ());
+
+#ifdef SHARED
+__hidden_ver1 (__logf, __GI___logf, __redirect_logf)
+  __attribute__ ((visibility ("hidden")));
+
+# include <shlib-compat.h>
+versioned_symbol (libm, __logf, logf, GLIBC_2_27);
+#else
+weak_alias (__logf, logf)
+#endif
+
+strong_alias (__logf, __ieee754_logf)
+strong_alias (__logf, __logf_finite)
+
+#define __logf __logf_sse2
+#include <sysdeps/ieee754/flt-32/e_logf.c>