Improve 64 bit memchr, memrchr, rawmemchr with SSE2

6 files changed, 857 insertions, 59 deletions

diff --git a/ChangeLog b/ChangeLog
index c369539..a5b5a53 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2011-08-31  Liubov Dmitrieva  <liubov.dmitrieva@gmail.com>
+
+	* sysdeps/x86_64/multiarch/rawmemchr.S: Update.
+	Use new sse2 version for core i3 - i7 as it's faster
+	than sse42 version.
+	(bit_Prefer_PMINUB_for_stringop): New.
+	* sysdeps/x86_64/rawmemchr.S: Update.
+	Replace with faster SSE2 version.
+	* sysdeps/x86_64/memrchr.S: New file.
+	* sysdeps/x86_64/memchr.S: Update.
+	Replace with faster SSE2 version.
+
 2011-09-12  Marek Polacek  <mpolacek@redhat.com>
 
 	* elf/dl-load.c (lose): Add cast to avoid warning.
diff --git a/NEWS b/NEWS
index 1af566f..73552e6 100644
--- a/NEWS
+++ b/NEWS
@@ -33,6 +33,9 @@ Version 2.15
 * Optimized strchr and strrchr for SSE on x86-32.
   Contributed by Liubov Dmitrieva.
 
+* Optimized memchr, memrchr, rawmemchr for x86-64.
+  Contributed by Liubov Dmitrieva.
+
 * New interfaces: scandirat, scandirat64
   Implemented by Ulrich Drepper.
 
diff --git a/sysdeps/x86_64/memchr.S b/sysdeps/x86_64/memchr.S
index 6082aa7..895a014 100644
--- a/sysdeps/x86_64/memchr.S
+++ b/sysdeps/x86_64/memchr.S
@@ -1,5 +1,5 @@
-/* Copyright (C) 2009 Free Software Foundation, Inc.
-   Contributed by Ulrich Drepper <drepper@redhat.com>.
+/* Copyright (C)  2011 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
@@ -19,50 +19,294 @@
 
 #include <sysdep.h>
 
+/* fast SSE2 version with using pmaxub and 64 byte loop */
 
 	.text
-ENTRY (memchr)
-	movd	%esi, %xmm1
-	movq	%rdi, %rcx
+ENTRY(memchr)
+	movd	%rsi, %xmm1
+	mov	%rdi, %rcx
+
 	punpcklbw %xmm1, %xmm1
-	andq	$~15, %rdi
-	testq	%rdx, %rdx
+	test	%rdx, %rdx
+	jz	L(return_null)
 	punpcklbw %xmm1, %xmm1
-	jz	3f
-	orl	$0xffffffff, %esi
-	movdqa	(%rdi), %xmm0
+
+	and	$63, %rcx
 	pshufd	$0, %xmm1, %xmm1
-	subq	%rdi, %rcx
+
+	cmp	$48, %rcx
+	ja	L(crosscache)
+
+	movdqu	(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+
+	jnz	L(matches_1)
+	sub	$16, %rdx
+	jbe	L(return_null)
+	add	$16, %rdi
+	and	$15, %rcx
+	and	$-16, %rdi
+	add	%rcx, %rdx
+	sub	$64, %rdx
+	jbe	L(exit_loop)
+	jmp	L(loop_prolog)
+
+	.p2align 4
+L(crosscache):
+	and	$15, %rcx
+	and	$-16, %rdi
+	movdqa	(%rdi), %xmm0
+
+	pcmpeqb	%xmm1, %xmm0
+/* Check if there is a match.  */
+	pmovmskb %xmm0, %eax
+/* Remove the leading bytes.  */
+	sar	%cl, %eax
+	test	%eax, %eax
+	je	L(unaligned_no_match)
+/* Check which byte is a match.  */
+	bsf	%eax, %eax
+
+	sub	%rax, %rdx
+	jbe	L(return_null)
+	add	%rdi, %rax
+	add	%rcx, %rax
+	ret
+
+	.p2align 4
+L(unaligned_no_match):
+	add	%rcx, %rdx
+	sub	$16, %rdx
+	jbe	L(return_null)
+	add	$16, %rdi
+	sub	$64, %rdx
+	jbe	L(exit_loop)
+
+	.p2align 4
+L(loop_prolog):
+	movdqa	(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches)
+
+	movdqa	16(%rdi), %xmm2
+	pcmpeqb	%xmm1, %xmm2
+	pmovmskb %xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	movdqa	32(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb %xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	movdqa	48(%rdi), %xmm4
+	pcmpeqb	%xmm1, %xmm4
+	add	$64, %rdi
+	pmovmskb %xmm4, %eax
+	test	%eax, %eax
+	jnz	L(matches0)
+
+	test	$0x3f, %rdi
+	jz	L(align64_loop)
+
+	sub	$64, %rdx
+	jbe	L(exit_loop)
+
+	movdqa	(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches)
+
+	movdqa	16(%rdi), %xmm2
+	pcmpeqb	%xmm1, %xmm2
+	pmovmskb %xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	movdqa	32(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb %xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	movdqa	48(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb %xmm3, %eax
+
+	add	$64, %rdi
+	test	%eax, %eax
+	jnz	L(matches0)
+
+	mov	%rdi, %rcx
+	and	$-64, %rdi
+	and	$63, %rcx
+	add	%rcx, %rdx
+
+	.p2align 4
+L(align64_loop):
+	sub	$64, %rdx
+	jbe	L(exit_loop)
+	movdqa	(%rdi), %xmm0
+	movdqa	16(%rdi), %xmm2
+	movdqa	32(%rdi), %xmm3
+	movdqa	48(%rdi), %xmm4
+
+	pcmpeqb	%xmm1, %xmm0
+	pcmpeqb	%xmm1, %xmm2
+	pcmpeqb	%xmm1, %xmm3
+	pcmpeqb	%xmm1, %xmm4
+
+	pmaxub	%xmm0, %xmm3
+	pmaxub	%xmm2, %xmm4
+	pmaxub	%xmm3, %xmm4
+	pmovmskb %xmm4, %eax
+
+	add	$64, %rdi
+
+	test	%eax, %eax
+	jz	L(align64_loop)
+
+	sub	$64, %rdi
+
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches)
+
+	pmovmskb %xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	movdqa	32(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+
+	pcmpeqb	48(%rdi), %xmm1
+	pmovmskb %xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	pmovmskb %xmm1, %eax
+	bsf	%eax, %eax
+	lea	48(%rdi, %rax), %rax
+	ret
+
+	.p2align 4
+L(exit_loop):
+	add	$32, %rdx
+	jle	L(exit_loop_32)
+
+	movdqa	(%rdi), %xmm0
 	pcmpeqb	%xmm1, %xmm0
-	addq	%rcx, %rdx
-	shl	%cl, %esi
-	pmovmskb %xmm0, %ecx
-	andl	%esi, %ecx
-	movl	$16, %esi
-	jnz	1f
-	cmpq	%rsi, %rdx
-	jbe	3f
-
-2:	movdqa	(%rdi,%rsi), %xmm0
-	leaq	16(%rsi), %rsi
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches)
+
+	movdqa	16(%rdi), %xmm2
+	pcmpeqb	%xmm1, %xmm2
+	pmovmskb %xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	movdqa	32(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb %xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches32_1)
+	sub	$16, %rdx
+	jle	L(return_null)
+
+	pcmpeqb	48(%rdi), %xmm1
+	pmovmskb %xmm1, %eax
+	test	%eax, %eax
+	jnz	L(matches48_1)
+	xor	%rax, %rax
+	ret
+
+	.p2align 4
+L(exit_loop_32):
+	add	$32, %rdx
+	movdqa	(%rdi), %xmm0
 	pcmpeqb	%xmm1, %xmm0
-	pmovmskb %xmm0, %ecx
-	testl	%ecx, %ecx
-	jnz	1f
-	cmpq	%rsi, %rdx
-	ja	2b
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches_1)
+	sub	$16, %rdx
+	jbe	L(return_null)
 
-3:	xorl	%eax, %eax
+	pcmpeqb	16(%rdi), %xmm1
+	pmovmskb %xmm1, %eax
+	test	%eax, %eax
+	jnz	L(matches16_1)
+	xor	%rax, %rax
 	ret
 
-1:	leaq	-16(%rdi,%rsi), %rax
-	bsfl	%ecx, %ecx
-	addq	%rcx, %rax
-	leaq	-16(%rsi,%rcx), %rsi
-	cmpq	%rsi, %rdx
-	jbe	3b
+	.p2align 4
+L(matches0):
+	bsf	%eax, %eax
+	lea	-16(%rax, %rdi), %rax
 	ret
-END (memchr)
+
+	.p2align 4
+L(matches):
+	bsf	%eax, %eax
+	add	%rdi, %rax
+	ret
+
+	.p2align 4
+L(matches16):
+	bsf	%eax, %eax
+	lea	16(%rax, %rdi), %rax
+	ret
+
+	.p2align 4
+L(matches32):
+	bsf	%eax, %eax
+	lea	32(%rax, %rdi), %rax
+	ret
+
+	.p2align 4
+L(matches_1):
+	bsf	%eax, %eax
+	sub	%rax, %rdx
+	jbe	L(return_null)
+	add	%rdi, %rax
+	ret
+
+	.p2align 4
+L(matches16_1):
+	bsf	%eax, %eax
+	sub	%rax, %rdx
+	jbe	L(return_null)
+	lea	16(%rdi, %rax), %rax
+	ret
+
+	.p2align 4
+L(matches32_1):
+	bsf	%eax, %eax
+	sub	%rax, %rdx
+	jbe	L(return_null)
+	lea	32(%rdi, %rax), %rax
+	ret
+
+	.p2align 4
+L(matches48_1):
+	bsf	%eax, %eax
+	sub	%rax, %rdx
+	jbe	L(return_null)
+	lea	48(%rdi, %rax), %rax
+	ret
+
+	.p2align 4
+L(return_null):
+	xor	%rax, %rax
+	ret
+END(memchr)
 
 strong_alias (memchr, __memchr)
-libc_hidden_builtin_def (memchr)
+
+libc_hidden_builtin_def(memchr)
diff --git a/sysdeps/x86_64/memrchr.S b/sysdeps/x86_64/memrchr.S
new file mode 100644
index 0000000..a85dc6b
--- /dev/null
+++ b/sysdeps/x86_64/memrchr.S
@@ -0,0 +1,380 @@
+/* fast SSE2 memrchr with 64 byte loop and pmaxub instruction using
+
+   Copyright (C) 2011 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 <sysdep.h>
+
+	.text
+ENTRY (memrchr)
+	movd	%rsi, %xmm1
+
+	sub	$16, %rdx
+	jbe	L(length_less16)
+
+	punpcklbw	%xmm1, %xmm1
+	punpcklbw	%xmm1, %xmm1
+
+	add	%rdx, %rdi
+	pshufd	$0, %xmm1, %xmm1
+
+	movdqu	(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+
+/* Check if there is a match.  */
+	pmovmskb	%xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches0)
+
+	sub	$64, %rdi
+	mov	%rdi, %rcx
+	and	$15, %rcx
+	jz	L(loop_prolog)
+
+	add	$16, %rdi
+	add	$16, %rdx
+	and	$-16, %rdi
+	sub	%rcx, %rdx
+
+	.p2align 4
+L(loop_prolog):
+	sub	$64, %rdx
+	jbe	L(exit_loop)
+
+	movdqa	48(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb	%xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches48)
+
+	movdqa	32(%rdi), %xmm2
+	pcmpeqb	%xmm1, %xmm2
+	pmovmskb	%xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	movdqa	16(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb	%xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	movdqa	(%rdi), %xmm4
+	pcmpeqb	%xmm1, %xmm4
+	pmovmskb	%xmm4, %eax
+	test	%eax, %eax
+	jnz	L(matches0)
+
+	sub	$64, %rdi
+	sub	$64, %rdx
+	jbe	L(exit_loop)
+
+	movdqa	48(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb	%xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches48)
+
+	movdqa	32(%rdi), %xmm2
+	pcmpeqb	%xmm1, %xmm2
+	pmovmskb	%xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	movdqa	16(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb	%xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	movdqa	(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb	%xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches0)
+
+	mov	%rdi, %rcx
+	and	$63, %rcx
+	jz	L(align64_loop)    
+
+	add	$64, %rdi
+	add	$64, %rdx
+	and	$-64, %rdi
+	sub	%rcx, %rdx
+
+	.p2align 4
+L(align64_loop):
+	sub	$64, %rdi
+	sub	$64, %rdx
+	jbe	L(exit_loop)
+
+	movdqa	(%rdi), %xmm0
+	movdqa	16(%rdi), %xmm2
+	movdqa	32(%rdi), %xmm3
+	movdqa	48(%rdi), %xmm4
+
+	pcmpeqb	%xmm1, %xmm0
+	pcmpeqb	%xmm1, %xmm2
+	pcmpeqb	%xmm1, %xmm3
+	pcmpeqb	%xmm1, %xmm4
+
+	pmaxub	%xmm3, %xmm0
+	pmaxub	%xmm4, %xmm2
+	pmaxub	%xmm0, %xmm2
+	pmovmskb	%xmm2, %eax
+
+	test	%eax, %eax
+	jz	L(align64_loop)
+
+	pmovmskb	%xmm4, %eax
+	test	%eax, %eax
+	jnz	L(matches48)
+
+	pmovmskb	%xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	movdqa	16(%rdi), %xmm2
+
+	pcmpeqb	%xmm1, %xmm2
+	pcmpeqb	(%rdi), %xmm1
+
+	pmovmskb	%xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	pmovmskb	%xmm1, %eax
+	bsr	%eax, %eax
+
+	add	%rdi, %rax
+	ret
+
+	.p2align 4
+L(exit_loop):
+	add	$64, %rdx
+	cmp	$32, %rdx
+	jbe	L(exit_loop_32)
+
+	movdqa	48(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb	%xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches48)
+
+	movdqa	32(%rdi), %xmm2
+	pcmpeqb	%xmm1, %xmm2
+	pmovmskb	%xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	movdqa	16(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb	%xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches16_1)
+	cmp	$48, %rdx
+	jbe	L(return_null)
+
+	pcmpeqb	(%rdi), %xmm1
+	pmovmskb	%xmm1, %eax
+	test	%eax, %eax
+	jnz	L(matches0_1)
+	xor	%eax, %eax
+	ret
+
+	.p2align 4
+L(exit_loop_32):
+	movdqa	48(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb	%xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches48_1)
+	cmp	$16, %rdx
+	jbe	L(return_null)
+
+	pcmpeqb	32(%rdi), %xmm1
+	pmovmskb	%xmm1, %eax
+	test	%eax, %eax
+	jnz	L(matches32_1)
+	xor	%eax, %eax
+	ret
+
+	.p2align 4
+L(matches0):
+	bsr	%eax, %eax
+	add	%rdi, %rax
+	ret
+
+	.p2align 4
+L(matches16):
+	bsr	%eax, %eax
+	lea	16(%rax, %rdi), %rax
+	ret
+
+	.p2align 4
+L(matches32):
+	bsr	%eax, %eax
+	lea	32(%rax, %rdi), %rax
+	ret
+
+	.p2align 4
+L(matches48):
+	bsr	%eax, %eax
+	lea	48(%rax, %rdi), %rax
+	ret
+
+	.p2align 4
+L(matches0_1):
+	bsr	%eax, %eax
+	sub	$64, %rdx
+	add	%rax, %rdx
+	jl	L(return_null)
+	add	%rdi, %rax
+	ret
+
+	.p2align 4
+L(matches16_1):
+	bsr	%eax, %eax
+	sub	$48, %rdx
+	add	%rax, %rdx
+	jl	L(return_null)
+	lea	16(%rdi, %rax), %rax
+	ret
+
+	.p2align 4
+L(matches32_1):
+	bsr	%eax, %eax
+	sub	$32, %rdx
+	add	%rax, %rdx
+	jl	L(return_null)
+	lea	32(%rdi, %rax), %rax
+	ret
+
+	.p2align 4
+L(matches48_1):
+	bsr	%eax, %eax
+	sub	$16, %rdx
+	add	%rax, %rdx
+	jl	L(return_null)
+	lea	48(%rdi, %rax), %rax
+	ret
+
+	.p2align 4
+L(return_null):
+	xor	%rax, %rax
+	ret
+
+	.p2align 4
+L(length_less16_offset0):
+	mov	%dl, %cl
+	pcmpeqb	(%rdi), %xmm1
+
+	mov	$1, %edx
+	sal	%cl, %edx
+	sub	$1, %edx
+
+	pmovmskb	%xmm1, %eax
+
+	and	%edx, %eax
+	test	%eax, %eax
+	jz	L(return_null)
+
+	bsr	%eax, %eax
+	add	%rdi, %rax
+	ret
+
+	.p2align 4
+L(length_less16):
+	punpcklbw	%xmm1, %xmm1
+	punpcklbw	%xmm1, %xmm1
+
+	add	$16, %rdx
+
+	pshufd	$0, %xmm1, %xmm1
+
+	mov	%rdi, %rcx
+	and	$15, %rcx
+	jz	L(length_less16_offset0)
+
+	mov	%rdi, %rcx
+	and	$15, %rcx
+	mov	%cl, %dh
+	mov	%rcx, %r8
+	add	%dl, %dh
+	and	$-16, %rdi
+
+	sub	$16, %dh
+	ja	L(length_less16_part2)
+
+	pcmpeqb	(%rdi), %xmm1
+	pmovmskb	%xmm1, %eax
+
+	sar	%cl, %eax
+	mov	%dl, %cl
+
+	mov	$1, %edx
+	sal	%cl, %edx
+	sub	$1, %edx
+
+	and	%edx, %eax
+	test	%eax, %eax
+	jz	L(return_null)
+
+	bsr	%eax, %eax
+	add	%rdi, %rax
+	add	%r8, %rax
+	ret
+
+	.p2align 4
+L(length_less16_part2):
+	movdqa	16(%rdi), %xmm2
+	pcmpeqb	%xmm1, %xmm2
+	pmovmskb	%xmm2, %eax
+
+	mov	%dh, %cl
+	mov	$1, %edx
+	sal	%cl, %edx
+	sub	$1, %edx
+
+	and	%edx, %eax
+
+	test	%eax, %eax
+	jnz	L(length_less16_part2_return)
+
+	pcmpeqb	(%rdi), %xmm1
+	pmovmskb	%xmm1, %eax
+
+	mov	%r8, %rcx
+	sar	%cl, %eax
+	test	%eax, %eax
+	jz	L(return_null)
+
+	bsr	%eax, %eax
+	add	%rdi, %rax
+	add	%r8, %rax
+	ret
+
+	.p2align 4
+L(length_less16_part2_return):
+	bsr	%eax, %eax
+	lea	16(%rax, %rdi), %rax
+	ret
+
+END (memrchr)
+strong_alias (memrchr, __memrchr)
diff --git a/sysdeps/x86_64/multiarch/rawmemchr.S b/sysdeps/x86_64/multiarch/rawmemchr.S
index 2a8a690..a8933fb 100644
--- a/sysdeps/x86_64/multiarch/rawmemchr.S
+++ b/sysdeps/x86_64/multiarch/rawmemchr.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2009 Free Software Foundation, Inc.
+/* Copyright (C) 2009, 2011 Free Software Foundation, Inc.
    Contributed by Ulrich Drepper <drepper@redhat.com>.
    This file is part of the GNU C Library.
 
@@ -29,11 +29,15 @@ ENTRY(rawmemchr)
 	cmpl	$0, __cpu_features+KIND_OFFSET(%rip)
 	jne	1f
 	call	__init_cpu_features
-1:	leaq	__rawmemchr_sse2(%rip), %rax
+1:	testl	$bit_Prefer_PMINUB_for_stringop, __cpu_features+FEATURE_OFFSET+index_Prefer_PMINUB_for_stringop(%rip)
+	jnz	2f
 	testl	$bit_SSE4_2, __cpu_features+CPUID_OFFSET+index_SSE4_2(%rip)
 	jz	2f
 	leaq	__rawmemchr_sse42(%rip), %rax
-2:	ret
+	ret
+2:	leaq	__rawmemchr_sse2(%rip), %rax
+	ret
+
 END(rawmemchr)
 strong_alias (rawmemchr, __rawmemchr)
 
diff --git a/sysdeps/x86_64/rawmemchr.S b/sysdeps/x86_64/rawmemchr.S
index cfb4ceb..a68b52c 100644
--- a/sysdeps/x86_64/rawmemchr.S
+++ b/sysdeps/x86_64/rawmemchr.S
@@ -1,5 +1,7 @@
-/* Copyright (C) 2009 Free Software Foundation, Inc.
-   Contributed by Ulrich Drepper <drepper@redhat.com>.
+/* fast SSE2 memchr with 64 byte loop and pmaxub instruction using
+
+   Copyright (C) 2011 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
@@ -19,34 +21,187 @@
 
 #include <sysdep.h>
 
-
 	.text
 ENTRY (rawmemchr)
-	movd	%esi, %xmm1
-	movq	%rdi, %rcx
+	movd	%rsi, %xmm1
+	mov	%rdi, %rcx
+
 	punpcklbw %xmm1, %xmm1
-	andq	$~15, %rdi
 	punpcklbw %xmm1, %xmm1
-	orl	$0xffffffff, %esi
-	movdqa	(%rdi), %xmm0
+
+	and	$63, %rcx
 	pshufd	$0, %xmm1, %xmm1
-	subq	%rdi, %rcx
+
+	cmp	$48, %rcx
+	ja	L(crosscache)
+
+	movdqu	(%rdi), %xmm0
 	pcmpeqb	%xmm1, %xmm0
-	shl	%cl, %esi
-	pmovmskb %xmm0, %ecx
-	andl	%esi, %ecx
-	jnz	1f
+/* Check if there is a match.  */
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+
+	jnz	L(matches)
+	add	$16, %rdi
+	and	$-16, %rdi
+	jmp	L(loop_prolog)
+
+	.p2align 4
+L(crosscache):
+	and	$15, %rcx
+	and	$-16, %rdi
+	movdqa	(%rdi), %xmm0
 
-2:	movdqa	16(%rdi), %xmm0
-	leaq	16(%rdi), %rdi
 	pcmpeqb	%xmm1, %xmm0
-	pmovmskb %xmm0, %ecx
-	testl	%ecx, %ecx
-	jz	2b
+/* Check if there is a match.  */
+	pmovmskb %xmm0, %eax
+/* Remove the leading bytes.  */
+	sar	%cl, %eax
+	test	%eax, %eax
+	je	L(unaligned_no_match)
+/* Check which byte is a match.  */
+	bsf	%eax, %eax
 
-1:	bsfl	%ecx, %eax
-	addq	%rdi, %rax
+	add	%rdi, %rax
+	add	%rcx, %rax
 	ret
+
+	.p2align 4
+L(unaligned_no_match):
+	add	$16, %rdi
+
+	.p2align 4
+L(loop_prolog):
+	movdqa	(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches)
+
+	movdqa	16(%rdi), %xmm2
+	pcmpeqb	%xmm1, %xmm2
+	pmovmskb %xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	movdqa	32(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb %xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	movdqa	48(%rdi), %xmm4
+	pcmpeqb	%xmm1, %xmm4
+	add	$64, %rdi
+	pmovmskb %xmm4, %eax
+	test	%eax, %eax
+	jnz	L(matches0)
+
+	test	$0x3f, %rdi
+	jz	L(align64_loop)
+
+	movdqa	(%rdi), %xmm0
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches)
+
+	movdqa	16(%rdi), %xmm2
+	pcmpeqb	%xmm1, %xmm2
+	pmovmskb %xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	movdqa	32(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb %xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	movdqa	48(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+	pmovmskb %xmm3, %eax
+
+	add	$64, %rdi
+	test	%eax, %eax
+	jnz	L(matches0)
+
+	and	$-64, %rdi
+
+	.p2align 4
+L(align64_loop):
+	movdqa	(%rdi), %xmm0
+	movdqa	16(%rdi), %xmm2
+	movdqa	32(%rdi), %xmm3
+	movdqa	48(%rdi), %xmm4
+
+	pcmpeqb	%xmm1, %xmm0
+	pcmpeqb	%xmm1, %xmm2
+	pcmpeqb	%xmm1, %xmm3
+	pcmpeqb	%xmm1, %xmm4
+
+	pmaxub	%xmm0, %xmm3
+	pmaxub	%xmm2, %xmm4
+	pmaxub	%xmm3, %xmm4
+	pmovmskb %xmm4, %eax
+
+	add	$64, %rdi
+
+	test	%eax, %eax
+	jz	L(align64_loop)
+
+	sub	$64, %rdi
+
+	pmovmskb %xmm0, %eax
+	test	%eax, %eax
+	jnz	L(matches)
+
+	pmovmskb %xmm2, %eax
+	test	%eax, %eax
+	jnz	L(matches16)
+
+	movdqa	32(%rdi), %xmm3
+	pcmpeqb	%xmm1, %xmm3
+
+	pcmpeqb	48(%rdi), %xmm1
+	pmovmskb %xmm3, %eax
+	test	%eax, %eax
+	jnz	L(matches32)
+
+	pmovmskb %xmm1, %eax
+	bsf	%eax, %eax
+	lea	48(%rdi, %rax), %rax
+	ret
+
+	.p2align 4
+L(matches0):
+	bsf	%eax, %eax
+	lea	-16(%rax, %rdi), %rax
+	ret
+
+	.p2align 4
+L(matches):
+	bsf	%eax, %eax
+	add	%rdi, %rax
+	ret
+
+	.p2align 4
+L(matches16):
+	bsf	%eax, %eax
+	lea	16(%rax, %rdi), %rax
+	ret
+
+	.p2align 4
+L(matches32):
+	bsf	%eax, %eax
+	lea	32(%rax, %rdi), %rax
+	ret
+
+	.p2align 4
+L(return_null):
+	xor	%rax, %rax
+	ret
+
 END (rawmemchr)
 
 strong_alias (rawmemchr, __rawmemchr)