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-rw-r--r--sysdeps/x86_64/memchr.S67
1 files changed, 67 insertions, 0 deletions
diff --git a/sysdeps/x86_64/memchr.S b/sysdeps/x86_64/memchr.S
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index 0000000000..15484cb9f3
--- /dev/null
+++ b/sysdeps/x86_64/memchr.S
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+/* strlen(str) -- determine the length of the string STR.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+   Contributed by Ulrich Drepper <drepper@redhat.com>.
+   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 (memchr)
+	movd	%esi, %xmm1
+	movq	%rdi, %rcx
+	punpcklbw %xmm1, %xmm1
+	andq	$~15, %rdi
+	punpcklbw %xmm1, %xmm1
+	orl	$0xffffffff, %esi
+	movdqa	(%rdi), %xmm0
+	pshufd	$0, %xmm1, %xmm1
+	subq	%rdi, %rcx
+	pcmpeqb	%xmm1, %xmm0
+	addq	%rcx, %rdx
+	shl	%cl, %esi
+	pmovmskb %xmm0, %ecx
+	andl	%esi, %ecx
+	movl	$0, %esi
+	jnz	1f
+	cmpq	%rsi, %rdx
+	jle	3f
+
+2:	movdqa	16(%rdi,%rsi), %xmm0
+	leaq	16(%rsi), %rsi
+	pcmpeqb	%xmm1, %xmm0
+	pmovmskb %xmm0, %ecx
+	testl	%ecx, %ecx
+	jnz	1f
+	cmpq	%rsi, %rdx
+	jg	2b
+
+3:	xorl	%eax, %eax
+	ret
+
+1:	leaq	(%rdi,%rsi), %rax
+	bsfl	%ecx, %ecx
+	addq	%rcx, %rax
+	addq	%rcx, %rsi
+	cmpq	%rsi, %rdx
+	jle	3b
+	ret
+END (memchr)
+
+strong_alias (memchr, __memchr)
+libc_hidden_builtin_def (memchr)