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
/*-
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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 software contributed to Berkeley by
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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. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. 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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* $Id: bcopy.S,v 1.2 1995/01/23 01:28:49 davidg Exp $
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*/
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#if defined(LIBC_RCS) && !defined(lint)
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.text
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.asciz "$Id: bcopy.S,v 1.2 1995/01/23 01:28:49 davidg Exp $"
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#endif /* LIBC_RCS and not lint */
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#include "DEFS.h"
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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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ENTRY(bcopy)
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pushl %esi
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pushl %edi
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movl 12(%esp),%esi
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movl 16(%esp),%edi
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movl 20(%esp),%ecx
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movl %edi,%eax
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subl %esi,%eax
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cmpl %ecx,%eax /* overlapping? */
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jb 1f
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cld /* nope, copy forwards. */
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shrl $2,%ecx /* copy by words */
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rep
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movsl
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movl 20(%esp),%ecx
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andl $3,%ecx /* any bytes left? */
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rep
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movsb
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popl %edi
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popl %esi
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ret
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1:
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addl %ecx,%edi /* copy backwards. */
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addl %ecx,%esi
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decl %edi
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decl %esi
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andl $3,%ecx /* any fractional bytes? */
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std
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rep
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movsb
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movl 20(%esp),%ecx /* copy remainder by words */
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shrl $2,%ecx
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subl $3,%esi
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subl $3,%edi
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rep
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movsl
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popl %edi
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popl %esi
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cld
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ret
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