xref: /freebsd/lib/libc/i386/string/bcopy.S (revision dc60165b73e4c4d829a2cb9fed5cce585e93d9a9)
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 * 4. 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__FBSDID("$FreeBSD$");
34
35#if 0
36	RCSID("$NetBSD: bcopy.S,v 1.6 1996/11/12 00:50:06 jtc Exp $")
37#endif
38
39	/*
40	 * (ov)bcopy (src,dst,cnt)
41	 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
42	 */
43
44#ifdef MEMCOPY
45ENTRY(memcpy)
46#else
47#ifdef MEMMOVE
48ENTRY(memmove)
49#else
50ENTRY(bcopy)
51#endif
52#endif
53	pushl	%esi
54	pushl	%edi
55#if defined(MEMCOPY) || defined(MEMMOVE)
56	movl	12(%esp),%edi
57	movl	16(%esp),%esi
58	movl	%edi,%eax
59#else
60	movl	12(%esp),%esi
61	movl	16(%esp),%edi
62#endif
63	movl	20(%esp),%ecx
64	movl	%edi,%edx
65	subl	%esi,%edx
66	cmpl	%ecx,%edx	/* overlapping? */
67	jb	1f
68	cld			/* nope, copy forwards. */
69	movl	%ecx,%edx
70	shrl	$2,%ecx		/* copy by words */
71	rep
72	movsl
73	movl	%edx,%ecx
74	andl	$3,%ecx		/* any bytes left? */
75	rep
76	movsb
77	popl	%edi
78	popl	%esi
79	ret
801:
81	addl	%ecx,%edi	/* copy backwards. */
82	addl	%ecx,%esi
83	std
84	movl	%ecx,%edx
85	andl	$3,%ecx		/* any fractional bytes? */
86	decl	%edi
87	decl	%esi
88	rep
89	movsb
90	movl	%edx,%ecx	/* copy remainder by words */
91	shrl	$2,%ecx
92	subl	$3,%esi
93	subl	$3,%edi
94	rep
95	movsl
96	popl	%edi
97	popl	%esi
98	cld
99	ret
100#ifdef MEMCOPY
101END(memcpy)
102#else
103#ifdef MEMMOVE
104END(memmove)
105#else
106END(bcopy)
107#endif
108#endif
109