xref: /freebsd/lib/libc/i386/string/bcopy.S (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from locore.s.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <machine/asm.h>
37
38	RCSID("$NetBSD: bcopy.S,v 1.6 1996/11/12 00:50:06 jtc Exp $")
39
40	/*
41	 * (ov)bcopy (src,dst,cnt)
42	 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
43	 */
44
45#ifdef MEMCOPY
46ENTRY(memcpy)
47#else
48#ifdef MEMMOVE
49ENTRY(memmove)
50#else
51ENTRY(bcopy)
52#endif
53#endif
54	pushl	%esi
55	pushl	%edi
56#if defined(MEMCOPY) || defined(MEMMOVE)
57	movl	12(%esp),%edi
58	movl	16(%esp),%esi
59#else
60	movl	12(%esp),%esi
61	movl	16(%esp),%edi
62#endif
63	movl	20(%esp),%ecx
64	movl	%edi,%eax
65	subl	%esi,%eax
66	cmpl	%ecx,%eax	/* overlapping? */
67	jb	1f
68	cld			/* nope, copy forwards. */
69	shrl	$2,%ecx		/* copy by words */
70	rep
71	movsl
72	movl	20(%esp),%ecx
73	andl	$3,%ecx		/* any bytes left? */
74	rep
75	movsb
76#if defined(MEMCOPY) || defined(MEMMOVE)
77	movl	12(%esp),%eax
78#endif
79	popl	%edi
80	popl	%esi
81	ret
821:
83	addl	%ecx,%edi	/* copy backwards. */
84	addl	%ecx,%esi
85	std
86	andl	$3,%ecx		/* any fractional bytes? */
87	decl	%edi
88	decl	%esi
89	rep
90	movsb
91	movl	20(%esp),%ecx	/* copy remainder by words */
92	shrl	$2,%ecx
93	subl	$3,%esi
94	subl	$3,%edi
95	rep
96	movsl
97#if defined(MEMCOPY) || defined(MEMMOVE)
98	movl	12(%esp),%eax
99#endif
100	popl	%edi
101	popl	%esi
102	cld
103	ret
104