xref: /freebsd/lib/libc/i386/string/bcopy.S (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <machine/asm.h>
33#if 0
34	RCSID("$NetBSD: bcopy.S,v 1.6 1996/11/12 00:50:06 jtc Exp $")
35#endif
36
37	/*
38	 * (ov)bcopy (src,dst,cnt)
39	 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
40	 */
41
42#ifdef MEMCOPY
43ENTRY(memcpy)
44#else
45#ifdef MEMMOVE
46ENTRY(memmove)
47#else
48ENTRY(bcopy)
49#endif
50#endif
51	pushl	%esi
52	pushl	%edi
53#if defined(MEMCOPY) || defined(MEMMOVE)
54	movl	12(%esp),%edi
55	movl	16(%esp),%esi
56	movl	%edi,%eax
57#else
58	movl	12(%esp),%esi
59	movl	16(%esp),%edi
60#endif
61	movl	20(%esp),%ecx
62	movl	%edi,%edx
63	subl	%esi,%edx
64	cmpl	%ecx,%edx	/* overlapping? */
65	jb	2f
66	cld			/* nope, copy forwards. */
67	movl	%ecx,%edx
68	shrl	$2,%ecx		/* copy by words */
69	rep
70	movsl
71	movl	%edx,%ecx
72	andl	$3,%ecx		/* any bytes left? */
73	jne	1f
74	popl	%edi
75	popl	%esi
76	ret
771:
78	rep
79	movsb
80	popl	%edi
81	popl	%esi
82	ret
832:
84	addl	%ecx,%edi	/* copy backwards. */
85	addl	%ecx,%esi
86	std
87	movl	%ecx,%edx
88	decl	%edi
89	decl	%esi
90	andl	$3,%ecx		/* any fractional bytes? */
91	je	3f
92	rep
93	movsb
943:
95	movl	%edx,%ecx	/* copy remainder by words */
96	shrl	$2,%ecx
97	subl	$3,%esi
98	subl	$3,%edi
99	rep
100	movsl
101	popl	%edi
102	popl	%esi
103	cld
104	ret
105#ifdef MEMCOPY
106END(memcpy)
107#else
108#ifdef MEMMOVE
109END(memmove)
110#else
111END(bcopy)
112#endif
113#endif
114
115	.section .note.GNU-stack,"",%progbits
116