89 lines
2.5 KiB
ArmAsm
89 lines
2.5 KiB
ArmAsm
/*-
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from locore.s.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <machine/asm.h>
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__FBSDID("$FreeBSD$");
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#if 0
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RCSID("$NetBSD: bcopy.S,v 1.2 2003/08/07 16:42:36 agc Exp $")
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#endif
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/*
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* (ov)bcopy (src,dst,cnt)
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* ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
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*/
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#ifdef MEMCOPY
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ENTRY(memcpy)
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#else
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#ifdef MEMMOVE
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ENTRY(memmove)
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#else
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ENTRY(bcopy)
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#endif
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#endif
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#if defined(MEMCOPY) || defined(MEMMOVE)
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movq %rdi,%rax /* return dst */
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#else
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xchgq %rdi,%rsi
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#endif
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movq %rdx,%rcx
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movq %rdi,%r8
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subq %rsi,%r8
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cmpq %rcx,%r8 /* overlapping? */
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jb 1f
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cld /* nope, copy forwards. */
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shrq $3,%rcx /* copy by words */
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rep
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movsq
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movq %rdx,%rcx
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andq $7,%rcx /* any bytes left? */
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rep
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movsb
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ret
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1:
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addq %rcx,%rdi /* copy backwards. */
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addq %rcx,%rsi
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std
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andq $7,%rcx /* any fractional bytes? */
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decq %rdi
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decq %rsi
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rep
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movsb
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movq %rdx,%rcx /* copy remainder by words */
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shrq $3,%rcx
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subq $7,%rsi
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subq $7,%rdi
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rep
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movsq
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cld
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ret
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