mirror of
https://github.com/freebsd/freebsd-src.git
synced 2024-12-02 04:13:39 +00:00
aacd7f348e
is really necessary. Going backwards on a P6 is much slower than forwards and it's a little slower on a P5. Also moved the count mask and 'std' down a few lines - it's a couple percent faster this way on a P5.
90 lines
2.8 KiB
ArmAsm
90 lines
2.8 KiB
ArmAsm
/*-
|
|
* Copyright (c) 1990 The Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
*
|
|
* 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.
|
|
*
|
|
* $Id: bcopy.S,v 1.2 1995/01/23 01:28:49 davidg Exp $
|
|
*/
|
|
|
|
#if defined(LIBC_RCS) && !defined(lint)
|
|
.text
|
|
.asciz "$Id: bcopy.S,v 1.2 1995/01/23 01:28:49 davidg Exp $"
|
|
#endif /* LIBC_RCS and not lint */
|
|
|
|
#include "DEFS.h"
|
|
|
|
/*
|
|
* (ov)bcopy (src,dst,cnt)
|
|
* ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
|
|
*/
|
|
|
|
ENTRY(bcopy)
|
|
pushl %esi
|
|
pushl %edi
|
|
movl 12(%esp),%esi
|
|
movl 16(%esp),%edi
|
|
movl 20(%esp),%ecx
|
|
movl %edi,%eax
|
|
subl %esi,%eax
|
|
cmpl %ecx,%eax /* overlapping? */
|
|
jb 1f
|
|
cld /* nope, copy forwards. */
|
|
shrl $2,%ecx /* copy by words */
|
|
rep
|
|
movsl
|
|
movl 20(%esp),%ecx
|
|
andl $3,%ecx /* any bytes left? */
|
|
rep
|
|
movsb
|
|
popl %edi
|
|
popl %esi
|
|
ret
|
|
1:
|
|
addl %ecx,%edi /* copy backwards. */
|
|
addl %ecx,%esi
|
|
decl %edi
|
|
decl %esi
|
|
andl $3,%ecx /* any fractional bytes? */
|
|
std
|
|
rep
|
|
movsb
|
|
movl 20(%esp),%ecx /* copy remainder by words */
|
|
shrl $2,%ecx
|
|
subl $3,%esi
|
|
subl $3,%edi
|
|
rep
|
|
movsl
|
|
popl %edi
|
|
popl %esi
|
|
cld
|
|
ret
|