Add support for x86-64 fma instruction.

Use it to implement fma and fmaf, if possible.

ChangeLog

@@ -1,5 +1,19 @@
 2009-07-29  Ulrich Drepper  <drepper@redhat.com>
 
+	* math/s_fma.c: Don't define alias if __fma is a macro.
+	* math/s_fmaf.c: Likewise.
+	* sysdeps/x86_64/multiarch/s_fma.c: New file.
+	* sysdeps/x86_64/multiarch/s_fmaf.c: New file.
+	Partially based on a patch by H.J. Lu <hongjiu.lu@intel.com>.
+
+	* sysdeps/x86_64/multiarch/init-arch.h (__get_cpu_features): Declare.
+	(HAS_POPCOUNT, HAS_SSE4_2): Add variants which work outside libc.
+	New macro HAS_FMA.
+	* sysdeps/x86_64/multiarch/init-arch.c (__get_cpu_features): New
+	function.
+	* include/libc-symbols.h (libm_ifunc): Define.
+	* sysdeps/x86_64/multiarch/Versions: New file.
+
 	* sysdeps/x86_64/dl-trampoline.S (_dl_runtime_profile): Improve CFI.
 
 2009-07-28  H.J. Lu  <hongjiu.lu@intel.com>

math/s_fma.c

@@ -1,5 +1,5 @@
 /* Compute x * y + z as ternary operation.
-   Copyright (C) 1997, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1997, 2001, 2009 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
@@ -25,7 +25,9 @@ __fma (double x, double y, double z)
 {
   return (x * y) + z;
 }
+#ifndef __fma
 weak_alias (__fma, fma)
+#endif
 
 #ifdef NO_LONG_DOUBLE
 strong_alias (__fma, __fmal)

math/s_fmaf.c

@@ -1,5 +1,5 @@
 /* Compute x * y + z as ternary operation.
-   Copyright (C) 1997 Free Software Foundation, Inc.
+   Copyright (C) 1997, 2009 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
@@ -25,4 +25,6 @@ __fmaf (float x, float y, float z)
 {
   return (x * y) + z;
 }
+#ifndef __fmaf
 weak_alias (__fmaf, fmaf)
+#endif

sysdeps/x86_64/multiarch/Versions

@@ -0,0 +1,5 @@
+libc {
+  GLIBC_PRIVATE {
+    __get_cpu_features;
+  }
+}

sysdeps/x86_64/multiarch/s_fma.c

@@ -0,0 +1,43 @@
+/* FMA version of fma.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+   Contributed by Intel Corporation.
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA. */
+
+#include <config.h>
+#include <math.h>
+#include <init-arch.h>
+
+#ifdef HAVE_AVX_SUPPORT
+
+extern double __fma_sse2 (double x, double y, double z);
+
+
+double
+__fma_fma (double x, double y, double z)
+{
+  asm ("vfmadd213sd %3, %2, %0" : "=x" (x) : "0" (x), "x" (y), "xm" (z));
+  return x;
+}
+
+libm_ifunc (__fma, HAS_FMA ? __fma_fma : __fma_sse2);
+weak_alias (__fma, fma)
+
+# define __fma __fma_sse2
+#endif
+
+#include <math/s_fma.c>

sysdeps/x86_64/multiarch/s_fmaf.c

@@ -0,0 +1,42 @@
+/* FMA version of fmaf.
+   Copyright (C) 2009 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA. */
+
+#include <config.h>
+#include <math.h>
+#include <init-arch.h>
+
+#ifdef HAVE_AVX_SUPPORT
+
+extern float __fmaf_sse2 (float x, float y, float z);
+
+
+float
+__fmaf_fma (float x, float y, float z)
+{
+  asm ("vfmadd213ss %3, %2, %0" : "=x" (x) : "0" (x), "x" (y), "xm" (z));
+  return x;
+}
+
+libm_ifunc (__fmaf, HAS_FMA ? __fmaf_fma : __fmaf_sse2);
+weak_alias (__fmaf, fmaf)
+
+# define __fmaf __fmaf_sse2
+#endif
+
+#include <math/s_fmaf.c>