xref: /netbsd-src/lib/libc/arch/i386/string/bcopy.S (revision 08c81a9c2dc8c7300e893321eb65c0925d60871c)
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#if defined(LIBC_SCCS)
39	RCSID("$NetBSD: bcopy.S,v 1.8 2002/07/10 06:01:51 kent Exp $")
40#endif
41
42	/*
43	 * (ov)bcopy (src,dst,cnt)
44	 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
45	 */
46
47#ifdef MEMCOPY
48ENTRY(memcpy)
49#else
50#ifdef MEMMOVE
51ENTRY(memmove)
52#else
53ENTRY(bcopy)
54#endif
55#endif
56	pushl	%esi
57	pushl	%edi
58#if defined(MEMCOPY) || defined(MEMMOVE)
59	movl	12(%esp),%edi
60	movl	16(%esp),%esi
61	movl	%edi,%eax	/* return value */
62#else
63	movl	12(%esp),%esi
64	movl	16(%esp),%edi
65#endif
66	movl	20(%esp),%ecx
67	movl	%edi,%edx
68	subl	%esi,%edx
69	cmpl	%ecx,%edx	/* overlapping? */
70	movl	%ecx,%edx
71	jb	1f
72	cld			/* nope, copy forwards. */
73	shrl	$2,%ecx		/* copy by words */
74	rep
75	movsl
76	movl	%edx,%ecx
77	andl	$3,%ecx		/* any bytes left? */
78	rep
79	movsb
80	popl	%edi
81	popl	%esi
82	ret
831:
84	addl	%ecx,%edi	/* copy backwards. */
85	addl	%ecx,%esi
86
87#ifdef _DIAGNOSTIC
88				/* check pointer wraparound */
89#if defined(MEMCOPY) || defined(MEMMOVE)
90	cmpl	12(%esp),%edi
91#else
92	cmpl	16(%esp),%edi
93#endif
94	jae	2f
95	pushl	$diagmes1
96	pushl	$func
97	pushl	$__LINE__-4
98	jmp	4f
992:
100#if defined(MEMCOPY) || defined(MEMMOVE)
101	cmpl	16(%esp),%esi
102#else
103	cmpl	12(%esp),%esi
104#endif
105	jae	3f
106	pushl	$diagmes2
107	pushl	$func
108	pushl	$__LINE__-4
1094:
110	pushl	$file
111	call	_C_LABEL(__diagassert13)
112	addl	$16,%esp
113#if defined(MEMCOPY) || defined(MEMMOVE)
114	movl	12(%esp),%eax
115#endif
116	popl	%edi
117	popl	%esi
118	ret
1193:
120#endif	/* _DIAGNOSTIC */
121
122	std
123	andl	$3,%ecx		/* any fractional bytes? */
124	decl	%edi
125	decl	%esi
126	rep
127	movsb
128	movl	%edx,%ecx	/* copy remainder by words */
129	shrl	$2,%ecx
130	subl	$3,%esi
131	subl	$3,%edi
132	rep
133	movsl
134	popl	%edi
135	popl	%esi
136	cld
137	ret
138
139#ifdef _DIAGNOSTIC
140file:
141	.asciz	__FILE__
142func:
143#if defined(MEMCOPY)
144	.asciz	"memcpy"
145#elseif defined(MEMMOVE)
146	.asciz	"memmove"
147#else
148	.asciz	"bcopy"
149#endif
150diagmes1:
151	.asciz	"src + length > src"
152diagmes2:
153	.asciz	"dst + length > dst"
154#endif	/* _DIAGNOSTIC */
155