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bcopy.S revision 1.6.14.2
      1       1.1      cgd /*-
      2       1.1      cgd  * Copyright (c) 1990 The Regents of the University of California.
      3       1.1      cgd  * All rights reserved.
      4       1.1      cgd  *
      5       1.1      cgd  * This code is derived from locore.s.
      6       1.1      cgd  *
      7       1.1      cgd  * Redistribution and use in source and binary forms, with or without
      8       1.1      cgd  * modification, are permitted provided that the following conditions
      9       1.1      cgd  * are met:
     10       1.1      cgd  * 1. Redistributions of source code must retain the above copyright
     11       1.1      cgd  *    notice, this list of conditions and the following disclaimer.
     12       1.1      cgd  * 2. Redistributions in binary form must reproduce the above copyright
     13       1.1      cgd  *    notice, this list of conditions and the following disclaimer in the
     14       1.1      cgd  *    documentation and/or other materials provided with the distribution.
     15       1.1      cgd  * 3. All advertising materials mentioning features or use of this software
     16       1.1      cgd  *    must display the following acknowledgement:
     17       1.1      cgd  *	This product includes software developed by the University of
     18       1.1      cgd  *	California, Berkeley and its contributors.
     19       1.1      cgd  * 4. Neither the name of the University nor the names of its contributors
     20       1.1      cgd  *    may be used to endorse or promote products derived from this software
     21       1.1      cgd  *    without specific prior written permission.
     22       1.1      cgd  *
     23       1.1      cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24       1.1      cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25       1.1      cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26       1.1      cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27       1.1      cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28       1.1      cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29       1.1      cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30       1.1      cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31       1.1      cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32       1.1      cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33       1.1      cgd  * SUCH DAMAGE.
     34       1.1      cgd  */
     35       1.1      cgd 
     36       1.4      jtc #include <machine/asm.h>
     37       1.4      jtc 
     38       1.2      jtc #if defined(LIBC_SCCS)
     39  1.6.14.1  nathanw 	RCSID("$NetBSD: bcopy.S,v 1.6.14.2 2002/11/11 22:21:26 nathanw Exp $")
     40       1.2      jtc #endif
     41       1.1      cgd 
     42       1.1      cgd 	/*
     43       1.1      cgd 	 * (ov)bcopy (src,dst,cnt)
     44       1.1      cgd 	 *  ws (at) tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
     45       1.1      cgd 	 */
     46       1.1      cgd 
     47       1.3  mycroft #ifdef MEMCOPY
     48       1.3  mycroft ENTRY(memcpy)
     49       1.3  mycroft #else
     50       1.3  mycroft #ifdef MEMMOVE
     51       1.3  mycroft ENTRY(memmove)
     52       1.3  mycroft #else
     53       1.1      cgd ENTRY(bcopy)
     54       1.3  mycroft #endif
     55       1.3  mycroft #endif
     56       1.1      cgd 	pushl	%esi
     57       1.1      cgd 	pushl	%edi
     58       1.3  mycroft #if defined(MEMCOPY) || defined(MEMMOVE)
     59       1.3  mycroft 	movl	12(%esp),%edi
     60       1.3  mycroft 	movl	16(%esp),%esi
     61  1.6.14.1  nathanw 	movl	%edi,%eax	/* return value */
     62       1.3  mycroft #else
     63       1.1      cgd 	movl	12(%esp),%esi
     64       1.1      cgd 	movl	16(%esp),%edi
     65       1.3  mycroft #endif
     66       1.1      cgd 	movl	20(%esp),%ecx
     67  1.6.14.2  nathanw #if defined(MEMCOPY)
     68  1.6.14.2  nathanw 	movl	%ecx,%edx
     69  1.6.14.2  nathanw #else
     70  1.6.14.1  nathanw 	movl	%edi,%edx
     71  1.6.14.1  nathanw 	subl	%esi,%edx
     72  1.6.14.1  nathanw 	cmpl	%ecx,%edx	/* overlapping? */
     73  1.6.14.1  nathanw 	movl	%ecx,%edx
     74       1.6      jtc 	jb	1f
     75  1.6.14.2  nathanw #endif
     76       1.1      cgd 	cld			/* nope, copy forwards. */
     77       1.1      cgd 	shrl	$2,%ecx		/* copy by words */
     78       1.1      cgd 	rep
     79       1.1      cgd 	movsl
     80  1.6.14.1  nathanw 	movl	%edx,%ecx
     81       1.1      cgd 	andl	$3,%ecx		/* any bytes left? */
     82       1.1      cgd 	rep
     83       1.1      cgd 	movsb
     84       1.1      cgd 	popl	%edi
     85       1.1      cgd 	popl	%esi
     86       1.1      cgd 	ret
     87       1.1      cgd 1:
     88       1.1      cgd 	addl	%ecx,%edi	/* copy backwards. */
     89       1.1      cgd 	addl	%ecx,%esi
     90       1.1      cgd 	std
     91       1.1      cgd 	andl	$3,%ecx		/* any fractional bytes? */
     92       1.1      cgd 	decl	%edi
     93       1.1      cgd 	decl	%esi
     94       1.1      cgd 	rep
     95       1.1      cgd 	movsb
     96  1.6.14.1  nathanw 	movl	%edx,%ecx	/* copy remainder by words */
     97       1.1      cgd 	shrl	$2,%ecx
     98       1.1      cgd 	subl	$3,%esi
     99       1.1      cgd 	subl	$3,%edi
    100       1.1      cgd 	rep
    101       1.1      cgd 	movsl
    102       1.1      cgd 	popl	%edi
    103       1.1      cgd 	popl	%esi
    104       1.1      cgd 	cld
    105       1.1      cgd 	ret
    106