From e6e02211d2073eb013365b4d51b30fd0b76d1850 Mon Sep 17 00:00:00 2001
From: Harsha Jagasia <hjagasia@gccpike4.amd.com>
Date: Tue, 31 May 2011 16:27:11 -0500
Subject: [PATCH] Use IFUNC on x86-64 memset.

2010-11-07  H.J. Lu  <hongjiu.lu@intel.com>

	* sysdeps/x86_64/memset.S: Check USE_MULTIARCH and USE_SSE2 for
	IFUNC support.
	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
	memset-x86-64.
	* sysdeps/x86_64/multiarch/bzero.S: New file.
	* sysdeps/x86_64/multiarch/cacheinfo.c: New file.
	* sysdeps/x86_64/multiarch/memset-x86-64.S: New file.
	* sysdeps/x86_64/multiarch/memset.S: New file.
	* sysdeps/x86_64/multiarch/memset_chk.S: New file.
	* sysdeps/x86_64/multiarch/init-arch.c (__init_cpu_features):
	Set bit_Prefer_SSE_for_memop for Intel processors.
	* sysdeps/x86_64/multiarch/init-arch.h (bit_Prefer_SSE_for_memop):
	Define.
	(index_Prefer_SSE_for_memop): Define.
	(HAS_PREFER_SSE_FOR_MEMOP): Define.
---
 sysdeps/x86_64/memset.S                  |  311 +++++++++++++++---------------
 sysdeps/x86_64/multiarch/Makefile        |    2 +-
 sysdeps/x86_64/multiarch/bzero.S         |   56 ++++++
 sysdeps/x86_64/multiarch/cacheinfo.c     |    2 +
 sysdeps/x86_64/multiarch/init-arch.c     |    5 +
 sysdeps/x86_64/multiarch/init-arch.h     |    9 +
 sysdeps/x86_64/multiarch/memset-x86-64.S |   18 ++
 sysdeps/x86_64/multiarch/memset.S        |   74 +++++++
 sysdeps/x86_64/multiarch/memset_chk.S    |   44 +++++
 9 files changed, 368 insertions(+), 153 deletions(-)
 create mode 100644 sysdeps/x86_64/multiarch/bzero.S
 create mode 100644 sysdeps/x86_64/multiarch/cacheinfo.c
 create mode 100644 sysdeps/x86_64/multiarch/memset-x86-64.S
 create mode 100644 sysdeps/x86_64/multiarch/memset.S
 create mode 100644 sysdeps/x86_64/multiarch/memset_chk.S

diff --git a/sysdeps/x86_64/memset.S b/sysdeps/x86_64/memset.S
index 681ab87..f6eb71f 100644
--- a/sysdeps/x86_64/memset.S
+++ b/sysdeps/x86_64/memset.S
@@ -24,7 +24,7 @@
 #define __STOS_UPPER_BOUNDARY	$65536
 
         .text
-#ifndef NOT_IN_libc
+#if !defined NOT_IN_libc && !defined USE_MULTIARCH
 ENTRY(__bzero)
 	mov	%rsi,%rdx	/* Adjust parameter.  */
 	xorl	%esi,%esi	/* Fill with 0s.  */
@@ -34,10 +34,10 @@ weak_alias (__bzero, bzero)
 #endif
 
 #if defined PIC && !defined NOT_IN_libc
-ENTRY (__memset_chk)
+ENTRY_CHK (__memset_chk)
 	cmpq	%rdx, %rcx
 	jb	HIDDEN_JUMPTARGET (__chk_fail)
-END (__memset_chk)
+END_CHK (__memset_chk)
 #endif
 ENTRY (memset)
 L(memset_entry):
@@ -591,157 +591,13 @@ L(A6Q1):    mov    %dx,-0xe(%rdi)
 L(A7Q0):    mov    %dl,-0x7(%rdi)
 L(A6Q0):    mov    %dx,-0x6(%rdi)
 	mov    %edx,-0x4(%rdi)
-	jmp    L(aligned_now)
-
-	.balign     16
-L(aligned_now):
-
-	 cmpl   $0x1,__x86_64_preferred_memory_instruction(%rip)
-	 jg     L(SSE_pre)
-
-L(8byte_move_try):
-	cmpq	__STOS_LOWER_BOUNDARY,%r8
-	jae	L(8byte_stos_try)
-
-	.balign     16
-L(8byte_move):
-	movq	%r8,%rcx
-	shrq	$7,%rcx
-	jz	L(8byte_move_skip)
-
-	.p2align 4
-
-L(8byte_move_loop):
-	decq	%rcx
-
-	movq	%rdx,    (%rdi)
-	movq	%rdx,  8 (%rdi)
-	movq	%rdx, 16 (%rdi)
-	movq	%rdx, 24 (%rdi)
-	movq	%rdx, 32 (%rdi)
-	movq	%rdx, 40 (%rdi)
-	movq	%rdx, 48 (%rdi)
-	movq	%rdx, 56 (%rdi)
-	movq	%rdx, 64 (%rdi)
-	movq	%rdx, 72 (%rdi)
-	movq	%rdx, 80 (%rdi)
-	movq	%rdx, 88 (%rdi)
-	movq	%rdx, 96 (%rdi)
-	movq	%rdx, 104 (%rdi)
-	movq	%rdx, 112 (%rdi)
-	movq	%rdx, 120 (%rdi)
-
-	leaq	128 (%rdi),%rdi
-
-	jnz     L(8byte_move_loop)
-
-L(8byte_move_skip):
-	andl	$127,%r8d
-	lea    	(%rdi,%r8,1),%rdi
-
-#ifndef PIC
-	lea    	L(setPxQx)(%rip),%r11
-	jmpq   	*(%r11,%r8,8) # old scheme remained for nonPIC
-#else
-	lea    	L(Got0)(%rip),%r11
-	lea	L(setPxQx)(%rip),%rcx
-	movswq	(%rcx,%r8,2),%rcx
-	lea    	(%rcx,%r11,1),%r11
-	jmpq   	*%r11
-#endif
-
-	.balign     16
-L(8byte_stos_try):
-	mov    __x86_64_shared_cache_size(%rip),%r9d // ck largest cache size
-	cmpq	%r8,%r9		// calculate the lesser of remaining
-	cmovaq	%r8,%r9		// bytes and largest cache size
-	jbe	L(8byte_stos)
-
-L(8byte_move_reuse_try):
-	cmp	__STOS_UPPER_BOUNDARY,%r8
-	jae	L(8byte_move)
-
-	.balign     16
-L(8byte_stos):
-	movq	%r9,%rcx
-	andq	$-8,%r9
-
-	shrq	$3,%rcx
-	jz	L(8byte_stos_skip)
-
-	xchgq	%rax,%rdx
-
-	rep
-	stosq
-
-	xchgq	%rax,%rdx
-
-L(8byte_stos_skip):
-	subq	%r9,%r8
-	ja	L(8byte_nt_move)
-
-	andl	$7,%r8d
-	lea    	(%rdi,%r8,1),%rdi
-#ifndef PIC
-	lea    	L(setPxQx)(%rip),%r11
-	jmpq   	*(%r11,%r8,8) # old scheme remained for nonPIC
-#else
-	lea    	L(Got0)(%rip),%r11
-	lea     L(setPxQx)(%rip),%rcx
-	movswq	(%rcx,%r8,2),%rcx
-	lea	(%rcx,%r11,1),%r11
-	jmpq   	*%r11
-#endif
 
-	.balign     16
-L(8byte_nt_move):
-	movq	%r8,%rcx
-	shrq	$7,%rcx
-	jz      L(8byte_nt_move_skip)
-
-	.balign     16
-L(8byte_nt_move_loop):
-	decq	%rcx
-
-	movntiq	%rdx,     (%rdi)
-	movntiq	%rdx,   8 (%rdi)
-	movntiq	%rdx,  16 (%rdi)
-	movntiq	%rdx,  24 (%rdi)
-	movntiq	%rdx,  32 (%rdi)
-	movntiq	%rdx,  40 (%rdi)
-	movntiq	%rdx,  48 (%rdi)
-	movntiq	%rdx,  56 (%rdi)
-	movntiq	%rdx,  64 (%rdi)
-	movntiq	%rdx,  72 (%rdi)
-	movntiq	%rdx,  80 (%rdi)
-	movntiq	%rdx,  88 (%rdi)
-	movntiq	%rdx,  96 (%rdi)
-	movntiq	%rdx, 104 (%rdi)
-	movntiq	%rdx, 112 (%rdi)
-	movntiq	%rdx, 120 (%rdi)
-
-	leaq	128 (%rdi),%rdi
-
-	jnz     L(8byte_nt_move_loop)
-
-	sfence
-
-L(8byte_nt_move_skip):
-	andl	$127,%r8d
-
-	lea    	(%rdi,%r8,1),%rdi
-#ifndef PIC
-	lea    	L(setPxQx)(%rip),%r11
-	jmpq   	*(%r11,%r8,8) # old scheme remained for nonPIC
-#else
-	lea    	L(Got0)(%rip),%r11
-	lea     L(setPxQx)(%rip),%rcx
-	movswq	(%rcx,%r8,2),%rcx
-	lea    	(%rcx,%r11,1),%r11
-	jmpq   	*%r11
-#endif
+#ifndef USE_MULTIARCH
+	jmp    L(aligned_now)
 
 L(SSE_pre):
+#endif
+#if !defined USE_MULTIARCH || defined USE_SSE2
 	 # fill RegXMM0 with the pattern
 	 movd   %rdx,%xmm0
 	 punpcklqdq %xmm0,%xmm0
@@ -1342,11 +1198,162 @@ L(SSExDx):
 	.short     L(SSE15QB)-L(SSE0Q0)
 #endif
 	.popsection
+#endif /* !defined USE_MULTIARCH || defined USE_SSE2  */
+
+	.balign     16
+L(aligned_now):
+
+#ifndef USE_MULTIARCH
+	 cmpl   $0x1,__x86_64_preferred_memory_instruction(%rip)
+	 jg     L(SSE_pre)
+#endif /* USE_MULTIARCH */
+
+L(8byte_move_try):
+	cmpq	__STOS_LOWER_BOUNDARY,%r8
+	jae	L(8byte_stos_try)
+
+	.balign     16
+L(8byte_move):
+	movq	%r8,%rcx
+	shrq	$7,%rcx
+	jz	L(8byte_move_skip)
+
+	.p2align 4
+
+L(8byte_move_loop):
+	decq	%rcx
+
+	movq	%rdx,    (%rdi)
+	movq	%rdx,  8 (%rdi)
+	movq	%rdx, 16 (%rdi)
+	movq	%rdx, 24 (%rdi)
+	movq	%rdx, 32 (%rdi)
+	movq	%rdx, 40 (%rdi)
+	movq	%rdx, 48 (%rdi)
+	movq	%rdx, 56 (%rdi)
+	movq	%rdx, 64 (%rdi)
+	movq	%rdx, 72 (%rdi)
+	movq	%rdx, 80 (%rdi)
+	movq	%rdx, 88 (%rdi)
+	movq	%rdx, 96 (%rdi)
+	movq	%rdx, 104 (%rdi)
+	movq	%rdx, 112 (%rdi)
+	movq	%rdx, 120 (%rdi)
+
+	leaq	128 (%rdi),%rdi
+
+	jnz     L(8byte_move_loop)
+
+L(8byte_move_skip):
+	andl	$127,%r8d
+	lea    	(%rdi,%r8,1),%rdi
+
+#ifndef PIC
+	lea    	L(setPxQx)(%rip),%r11
+	jmpq   	*(%r11,%r8,8) # old scheme remained for nonPIC
+#else
+	lea    	L(Got0)(%rip),%r11
+	lea	L(setPxQx)(%rip),%rcx
+	movswq	(%rcx,%r8,2),%rcx
+	lea    	(%rcx,%r11,1),%r11
+	jmpq   	*%r11
+#endif
+
+	.balign     16
+L(8byte_stos_try):
+	mov    __x86_64_shared_cache_size(%rip),%r9d // ck largest cache size
+	cmpq	%r8,%r9		// calculate the lesser of remaining
+	cmovaq	%r8,%r9		// bytes and largest cache size
+	jbe	L(8byte_stos)
+
+L(8byte_move_reuse_try):
+	cmp	__STOS_UPPER_BOUNDARY,%r8
+	jae	L(8byte_move)
+
+	.balign     16
+L(8byte_stos):
+	movq	%r9,%rcx
+	andq	$-8,%r9
+
+	shrq	$3,%rcx
+	jz	L(8byte_stos_skip)
+
+	xchgq	%rax,%rdx
+
+	rep
+	stosq
+
+	xchgq	%rax,%rdx
+
+L(8byte_stos_skip):
+	subq	%r9,%r8
+	ja	L(8byte_nt_move)
+
+	andl	$7,%r8d
+	lea    	(%rdi,%r8,1),%rdi
+#ifndef PIC
+	lea    	L(setPxQx)(%rip),%r11
+	jmpq   	*(%r11,%r8,8) # old scheme remained for nonPIC
+#else
+	lea    	L(Got0)(%rip),%r11
+	lea     L(setPxQx)(%rip),%rcx
+	movswq	(%rcx,%r8,2),%rcx
+	lea	(%rcx,%r11,1),%r11
+	jmpq   	*%r11
+#endif
+
+	.balign     16
+L(8byte_nt_move):
+	movq	%r8,%rcx
+	shrq	$7,%rcx
+	jz      L(8byte_nt_move_skip)
+
+	.balign     16
+L(8byte_nt_move_loop):
+	decq	%rcx
+
+	movntiq	%rdx,     (%rdi)
+	movntiq	%rdx,   8 (%rdi)
+	movntiq	%rdx,  16 (%rdi)
+	movntiq	%rdx,  24 (%rdi)
+	movntiq	%rdx,  32 (%rdi)
+	movntiq	%rdx,  40 (%rdi)
+	movntiq	%rdx,  48 (%rdi)
+	movntiq	%rdx,  56 (%rdi)
+	movntiq	%rdx,  64 (%rdi)
+	movntiq	%rdx,  72 (%rdi)
+	movntiq	%rdx,  80 (%rdi)
+	movntiq	%rdx,  88 (%rdi)
+	movntiq	%rdx,  96 (%rdi)
+	movntiq	%rdx, 104 (%rdi)
+	movntiq	%rdx, 112 (%rdi)
+	movntiq	%rdx, 120 (%rdi)
+
+	leaq	128 (%rdi),%rdi
+
+	jnz     L(8byte_nt_move_loop)
+
+	sfence
+
+L(8byte_nt_move_skip):
+	andl	$127,%r8d
+
+	lea    	(%rdi,%r8,1),%rdi
+#ifndef PIC
+	lea    	L(setPxQx)(%rip),%r11
+	jmpq   	*(%r11,%r8,8) # old scheme remained for nonPIC
+#else
+	lea    	L(Got0)(%rip),%r11
+	lea     L(setPxQx)(%rip),%rcx
+	movswq	(%rcx,%r8,2),%rcx
+	lea    	(%rcx,%r11,1),%r11
+	jmpq   	*%r11
+#endif
 
 END (memset)
 libc_hidden_builtin_def (memset)
 
-#if defined PIC && !defined NOT_IN_libc
+#if defined PIC && !defined NOT_IN_libc && !defined USE_MULTIARCH
 strong_alias (__memset_chk, __memset_zero_constant_len_parameter)
 	.section .gnu.warning.__memset_zero_constant_len_parameter
 	.string "memset used with constant zero length parameter; this could be due to transposed parameters"
diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile
index b905db1..4fcb22c 100644
--- a/sysdeps/x86_64/multiarch/Makefile
+++ b/sysdeps/x86_64/multiarch/Makefile
@@ -6,7 +6,7 @@ endif
 ifeq ($(subdir),string)
 sysdep_routines += stpncpy-c strncpy-c strcmp-ssse3 strncmp-ssse3 \
 		   strend-sse4 memcpy-ssse3 mempcpy-ssse3 \
-		   memmove-ssse3
+		   memmove-ssse3 memset-x86-64
 ifeq (yes,$(config-cflags-sse4))
 sysdep_routines += strcspn-c strpbrk-c strspn-c strstr-c strcasestr-c
 CFLAGS-strcspn-c.c += -msse4
diff --git a/sysdeps/x86_64/multiarch/bzero.S b/sysdeps/x86_64/multiarch/bzero.S
new file mode 100644
index 0000000..9c9eebd
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/bzero.S
@@ -0,0 +1,56 @@
+/* Multiple versions of bzero
+   Copyright (C) 2010 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 <sysdep.h>
+#include <init-arch.h>
+
+	.text
+ENTRY(__bzero)
+	.type	__bzero, @gnu_indirect_function
+	cmpl	$0, __cpu_features+KIND_OFFSET(%rip)
+	jne	1f
+	call	__init_cpu_features
+1:	leaq	__bzero_x86_64(%rip), %rax
+	testl	$bit_Prefer_SSE_for_memop, __cpu_features+FEATURE_OFFSET+index_Prefer_SSE_for_memop(%rip)
+	jz	2f
+	leaq	__bzero_sse2(%rip), %rax
+2:	ret
+END(__bzero)
+
+	.type	__bzero_sse2, @function
+__bzero_sse2:
+	cfi_startproc
+	CALL_MCOUNT
+	mov	%rsi,%rdx	/* Adjust parameter.  */
+	xorl	%esi,%esi	/* Fill with 0s.  */
+	jmp	__memset_sse2
+	cfi_endproc
+	.size __bzero_sse2, .-__bzero_sse2
+
+	.type	__bzero_x86_64, @function
+__bzero_x86_64:
+	cfi_startproc
+	CALL_MCOUNT
+	mov	%rsi,%rdx	/* Adjust parameter.  */
+	xorl	%esi,%esi	/* Fill with 0s.  */
+	jmp	__memset_x86_64
+	cfi_endproc
+	.size __bzero_x86_64, .-__bzero_x86_64
+
+weak_alias (__bzero, bzero)
diff --git a/sysdeps/x86_64/multiarch/cacheinfo.c b/sysdeps/x86_64/multiarch/cacheinfo.c
new file mode 100644
index 0000000..f87b8dc
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/cacheinfo.c
@@ -0,0 +1,2 @@
+#define DISABLE_PREFERRED_MEMORY_INSTRUCTION
+#include "../cacheinfo.c"
diff --git a/sysdeps/x86_64/multiarch/init-arch.c b/sysdeps/x86_64/multiarch/init-arch.c
index 198fcaa..17888fd 100644
--- a/sysdeps/x86_64/multiarch/init-arch.c
+++ b/sysdeps/x86_64/multiarch/init-arch.c
@@ -59,6 +59,11 @@ __init_cpu_features (void)
 
       get_common_indeces (&family, &model);
 
+      /* Intel processors prefer SSE instruction for memory/string
+	 routines if they are avaiable.  */
+      __cpu_features.feature[index_Prefer_SSE_for_memop]
+	|= bit_Prefer_SSE_for_memop;
+
       unsigned int eax = __cpu_features.cpuid[COMMON_CPUID_INDEX_1].eax;
       unsigned int extended_family = (eax >> 20) & 0xff;
       unsigned int extended_model = (eax >> 12) & 0xf0;
diff --git a/sysdeps/x86_64/multiarch/init-arch.h b/sysdeps/x86_64/multiarch/init-arch.h
index a2228b6..9b84beb 100644
--- a/sysdeps/x86_64/multiarch/init-arch.h
+++ b/sysdeps/x86_64/multiarch/init-arch.h
@@ -16,6 +16,8 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
+#define bit_Prefer_SSE_for_memop	(1 << 3)
+
 #ifdef	__ASSEMBLER__
 
 # include <ifunc-defines.h>
@@ -30,6 +32,8 @@
 # define index_SSE4_1	COMMON_CPUID_INDEX_1*CPUID_SIZE+CPUID_ECX_OFFSET
 # define index_SSE4_2	COMMON_CPUID_INDEX_1*CPUID_SIZE+CPUID_ECX_OFFSET
 
+# define index_Prefer_SSE_for_memop	FEATURE_INDEX_1*FEATURE_SIZE
+
 #else	/* __ASSEMBLER__ */
 
 # include <sys/param.h>
@@ -98,7 +102,12 @@ extern const struct cpu_features *__get_cpu_features (void)
 # define HAS_SSE4_2	HAS_CPU_FEATURE (COMMON_CPUID_INDEX_1, ecx, 20)
 # define HAS_FMA	HAS_CPU_FEATURE (COMMON_CPUID_INDEX_1, ecx, 12)
 
+# define index_Prefer_SSE_for_memop	FEATURE_INDEX_1
+
 #define HAS_ARCH_FEATURE(idx, bit) \
   ((__get_cpu_features ()->feature[idx] & (bit)) != 0)
 
+#define HAS_PREFER_SSE_FOR_MEMOP \
+  HAS_ARCH_FEATURE (index_Prefer_SSE_for_memop, bit_Prefer_SSE_for_memop)
+
 #endif	/* __ASSEMBLER__ */
diff --git a/sysdeps/x86_64/multiarch/memset-x86-64.S b/sysdeps/x86_64/multiarch/memset-x86-64.S
new file mode 100644
index 0000000..5e8cfb3
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/memset-x86-64.S
@@ -0,0 +1,18 @@
+#include <sysdep.h>
+
+#ifndef NOT_IN_libc
+# undef ENTRY_CHK
+# define ENTRY_CHK(name) \
+	.type __memset_chk_x86_64, @function; \
+	.globl __memset_chk_x86_64; \
+	.p2align 4; \
+	__memset_chk_x86_64: cfi_startproc; \
+	CALL_MCOUNT
+# undef END_CHK
+# define END_CHK(name) \
+	cfi_endproc; .size __memset_chk_x86_64, .-__memset_chk_x86_64
+
+# define libc_hidden_builtin_def(name)
+# define memset __memset_x86_64
+# include "../memset.S"
+#endif
diff --git a/sysdeps/x86_64/multiarch/memset.S b/sysdeps/x86_64/multiarch/memset.S
new file mode 100644
index 0000000..a8d0e9e
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/memset.S
@@ -0,0 +1,74 @@
+/* Multiple versions of memset
+   Copyright (C) 2010 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 <sysdep.h>
+#include <init-arch.h>
+
+/* Define multiple versions only for the definition in lib.  */
+#ifndef NOT_IN_libc
+ENTRY(memset)
+	.type	memset, @gnu_indirect_function
+	cmpl	$0, __cpu_features+KIND_OFFSET(%rip)
+	jne	1f
+	call	__init_cpu_features
+1:	leaq	__memset_x86_64(%rip), %rax
+	testl	$bit_Prefer_SSE_for_memop, __cpu_features+FEATURE_OFFSET+index_Prefer_SSE_for_memop(%rip)
+	jz	2f
+	leaq	__memset_sse2(%rip), %rax
+2:	ret
+END(memset)
+
+# define USE_SSE2 1
+
+# undef ENTRY
+# define ENTRY(name) \
+	.type __memset_sse2, @function; \
+	.globl __memset_sse2; \
+	.p2align 4; \
+	__memset_sse2: cfi_startproc; \
+	CALL_MCOUNT
+# undef END
+# define END(name) \
+	cfi_endproc; .size __memset_sse2, .-__memset_sse2
+
+# undef ENTRY_CHK
+# define ENTRY_CHK(name) \
+	.type __memset_chk_sse2, @function; \
+	.globl __memset_chk_sse2; \
+	.p2align 4; \
+	__memset_chk_sse2: cfi_startproc; \
+	CALL_MCOUNT
+# undef END_CHK
+# define END_CHK(name) \
+	cfi_endproc; .size __memset_chk_sse2, .-__memset_chk_sse2
+
+# ifdef SHARED
+#  undef libc_hidden_builtin_def
+/* It doesn't make sense to send libc-internal memset calls through a PLT.
+   The speedup we get from using GPR instruction is likely eaten away
+   by the indirect call in the PLT.  */
+#  define libc_hidden_builtin_def(name) \
+	.globl __GI_memset; __GI_memset = __memset_sse2
+# endif
+
+# undef strong_alias
+# define strong_alias(original, alias)
+#endif
+
+#include "../memset.S"
diff --git a/sysdeps/x86_64/multiarch/memset_chk.S b/sysdeps/x86_64/multiarch/memset_chk.S
new file mode 100644
index 0000000..16afe60
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/memset_chk.S
@@ -0,0 +1,44 @@
+/* Multiple versions of __memset_chk
+   Copyright (C) 2010 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 <sysdep.h>
+#include <init-arch.h>
+
+/* Define multiple versions only for the definition in lib.  */
+#ifndef NOT_IN_libc
+# ifdef SHARED
+ENTRY(__memset_chk)
+	.type	__memset_chk, @gnu_indirect_function
+	cmpl	$0, __cpu_features+KIND_OFFSET(%rip)
+	jne	1f
+	call	__init_cpu_features
+1:	leaq	__memset_chk_x86_64(%rip), %rax
+	testl	$bit_Prefer_SSE_for_memop, __cpu_features+FEATURE_OFFSET+index_Prefer_SSE_for_memop(%rip)
+	jz	2f
+	leaq	__memset_chk_sse2(%rip), %rax
+2:	ret
+END(__memset_chk)
+
+strong_alias (__memset_chk, __memset_zero_constant_len_parameter)
+	.section .gnu.warning.__memset_zero_constant_len_parameter
+	.string "memset used with constant zero length parameter; this could be due to transposed parameters"
+# else
+#  include "../memset_chk.S"
+# endif
+#endif
-- 
1.6.0.2

