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-rw-r--r--sysdeps/x86_64/strrchr.S81
1 files changed, 81 insertions, 0 deletions
diff --git a/sysdeps/x86_64/strrchr.S b/sysdeps/x86_64/strrchr.S
new file mode 100644
index 0000000000..c75b485ca3
--- /dev/null
+++ b/sysdeps/x86_64/strrchr.S
@@ -0,0 +1,81 @@
+/* strrchr (str, ch) -- Return pointer to last occurrence of CH in STR.
+   For AMD x86-64.
+   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 <sysdep.h>
+
+
+	.text
+ENTRY (strrchr)
+	movd	%esi, %xmm1
+	movq	%rdi, %rcx
+	punpcklbw %xmm1, %xmm1
+	andq	$~15, %rdi
+	pxor	%xmm2, %xmm2
+	punpcklbw %xmm1, %xmm1
+	orl	$0xffffffff, %esi
+	movdqa	(%rdi), %xmm0
+	pshufd	$0, %xmm1, %xmm1
+	subq	%rdi, %rcx
+	movdqa	%xmm0, %xmm3
+	leaq	16(%rdi), %rdi
+	pcmpeqb	%xmm1, %xmm0
+	pcmpeqb	%xmm2, %xmm3
+	shl	%cl, %esi
+	pmovmskb %xmm0, %edx
+	pmovmskb %xmm3, %ecx
+	andl	%esi, %edx
+	andl	%esi, %ecx
+	xorl	%eax, %eax
+	movl	%edx, %esi
+	orl	%ecx, %esi
+	jnz	1f
+
+2:	movdqa	(%rdi), %xmm0
+	leaq	16(%rdi), %rdi
+	movdqa	%xmm0, %xmm3
+	pcmpeqb	%xmm1, %xmm0
+	pcmpeqb	%xmm2, %xmm3
+	pmovmskb %xmm0, %edx
+	pmovmskb %xmm3, %ecx
+	movl	%edx, %esi
+	orl	%ecx, %esi
+	jz	2b
+
+1:	bsfl	%ecx, %r9d
+	movl	$0xffffffff, %r8d
+	movl	$31, %ecx
+	jnz	5f
+
+	bsrl	%edx, %edx
+	jz	2b
+	leaq	-16(%rdi,%rdx), %rax
+	jmp	2b
+
+5:	subl	%r9d, %ecx
+	shrl	%cl, %r8d
+	andl	%r8d, %edx
+	bsrl	%edx, %edx
+	jz	4f
+	leaq	-16(%rdi,%rdx), %rax
+4:	ret
+END (strrchr)
+
+weak_alias (strrchr, rindex)
+libc_hidden_builtin_def (strrchr)