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/*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright 2019 Joyent, Inc.
*/
/*-
* Copyright (c) 1993 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: src/sys/amd64/amd64/support.S,v 1.102 2003/10/02 05:08:13 alc Exp $
*/
#include <sys/asm_linkage.h>
/*
* Adapted from fbsd bcopy().
*
* bcopy(src, dst, cnt)
* rdi, rsi, rdx
* ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
*/
ENTRY(ovbcopy)
xchgq %rsi,%rdi
movq %rdx,%rcx
movq %rdi,%rax
subq %rsi,%rax
cmpq %rcx,%rax /* overlapping && src < dst? */
jb reverse
shrq $3,%rcx /* copy by 64-bit words */
cld /* nope, copy forwards */
rep
movsq
movq %rdx,%rcx
andq $7,%rcx /* any bytes left? */
rep
movsb
ret
reverse:
addq %rcx,%rdi /* copy backwards */
addq %rcx,%rsi
decq %rdi
decq %rsi
andq $7,%rcx /* any fractional bytes? */
std
rep
movsb
movq %rdx,%rcx /* copy remainder by 32-bit words */
shrq $3,%rcx
subq $7,%rsi
subq $7,%rdi
rep
movsq
cld
ret
SET_SIZE(ovbcopy)
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