xref: /minix3/common/lib/libc/arch/i386/string/memcpy.S (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc/*	$NetBSD: memcpy.S,v 1.4 2014/03/22 19:38:46 jakllsch Exp $	*/
2b6cbf720SGianluca Guida
3b6cbf720SGianluca Guida/*-
4b6cbf720SGianluca Guida * Copyright (c) 1990 The Regents of the University of California.
5b6cbf720SGianluca Guida * All rights reserved.
6b6cbf720SGianluca Guida *
7b6cbf720SGianluca Guida * This code is derived from locore.s.
8b6cbf720SGianluca Guida * Optimised by David Laight 2003
9b6cbf720SGianluca Guida *
10b6cbf720SGianluca Guida * Redistribution and use in source and binary forms, with or without
11b6cbf720SGianluca Guida * modification, are permitted provided that the following conditions
12b6cbf720SGianluca Guida * are met:
13b6cbf720SGianluca Guida * 1. Redistributions of source code must retain the above copyright
14b6cbf720SGianluca Guida *    notice, this list of conditions and the following disclaimer.
15b6cbf720SGianluca Guida * 2. Redistributions in binary form must reproduce the above copyright
16b6cbf720SGianluca Guida *    notice, this list of conditions and the following disclaimer in the
17b6cbf720SGianluca Guida *    documentation and/or other materials provided with the distribution.
18b6cbf720SGianluca Guida * 3. Neither the name of the University nor the names of its contributors
19b6cbf720SGianluca Guida *    may be used to endorse or promote products derived from this software
20b6cbf720SGianluca Guida *    without specific prior written permission.
21b6cbf720SGianluca Guida *
22b6cbf720SGianluca Guida * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23b6cbf720SGianluca Guida * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24b6cbf720SGianluca Guida * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25b6cbf720SGianluca Guida * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26b6cbf720SGianluca Guida * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27b6cbf720SGianluca Guida * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28b6cbf720SGianluca Guida * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29b6cbf720SGianluca Guida * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30b6cbf720SGianluca Guida * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31b6cbf720SGianluca Guida * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32b6cbf720SGianluca Guida * SUCH DAMAGE.
33b6cbf720SGianluca Guida */
34b6cbf720SGianluca Guida
35b6cbf720SGianluca Guida#include <machine/asm.h>
36b6cbf720SGianluca Guida
37b6cbf720SGianluca Guida#if defined(LIBC_SCCS)
38*0a6a1f1dSLionel Sambuc	RCSID("$NetBSD: memcpy.S,v 1.4 2014/03/22 19:38:46 jakllsch Exp $")
39b6cbf720SGianluca Guida#endif
40b6cbf720SGianluca Guida
41b6cbf720SGianluca Guida	/*
42b6cbf720SGianluca Guida	 * (ov)bcopy (src,dst,cnt)
43b6cbf720SGianluca Guida	 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
44b6cbf720SGianluca Guida	 */
45b6cbf720SGianluca Guida
46b6cbf720SGianluca Guida#ifdef BCOPY
47b6cbf720SGianluca GuidaENTRY(bcopy)
48b6cbf720SGianluca Guida#else
49b6cbf720SGianluca Guida#ifdef MEMMOVE
50b6cbf720SGianluca GuidaENTRY(memmove)
51b6cbf720SGianluca Guida#else
52b6cbf720SGianluca Guida#define MEMCPY
53b6cbf720SGianluca Guida#define NO_OVERLAP
54b6cbf720SGianluca GuidaENTRY(memcpy)
55b6cbf720SGianluca Guida#endif
56b6cbf720SGianluca Guida#endif
57b6cbf720SGianluca Guida	push	%esi
58b6cbf720SGianluca Guida	mov	%edi,%edx
59b6cbf720SGianluca Guida#if defined(MEMCPY) || defined(MEMMOVE)
60b6cbf720SGianluca Guida	movl	8(%esp),%edi
61b6cbf720SGianluca Guida	movl	12(%esp),%esi
62b6cbf720SGianluca Guida#else
63b6cbf720SGianluca Guida	movl	8(%esp),%esi
64b6cbf720SGianluca Guida	movl	12(%esp),%edi
65b6cbf720SGianluca Guida#endif
66b6cbf720SGianluca Guida	movl	16(%esp),%ecx
67b6cbf720SGianluca Guida#if defined(NO_OVERLAP)
68b6cbf720SGianluca Guida	movl	%ecx,%eax
69b6cbf720SGianluca Guida#else
70b6cbf720SGianluca Guida	movl	%edi,%eax
71b6cbf720SGianluca Guida	subl	%esi,%eax
72b6cbf720SGianluca Guida	cmpl	%ecx,%eax	/* overlapping? */
73b6cbf720SGianluca Guida	movl	%ecx,%eax
74b6cbf720SGianluca Guida	jb	.Lbackwards
75b6cbf720SGianluca Guida#endif
76b6cbf720SGianluca Guida	/* nope, copy forwards. */
77b6cbf720SGianluca Guida	shrl	$2,%ecx		/* copy by words */
78b6cbf720SGianluca Guida	rep
79b6cbf720SGianluca Guida	movsl
80b6cbf720SGianluca Guida	and	$3,%eax		/* any bytes left? */
81b6cbf720SGianluca Guida	jnz	.Ltrailing
82b6cbf720SGianluca Guida.Ldone:
83b6cbf720SGianluca Guida#if defined(MEMCPY) || defined(MEMMOVE)
84b6cbf720SGianluca Guida	movl	8(%esp),%eax
85b6cbf720SGianluca Guida#endif
86b6cbf720SGianluca Guida	mov	%edx,%edi
87b6cbf720SGianluca Guida	pop	%esi
88b6cbf720SGianluca Guida	ret
89b6cbf720SGianluca Guida
90b6cbf720SGianluca Guida.Ltrailing:
91b6cbf720SGianluca Guida	cmp	$2,%eax
92b6cbf720SGianluca Guida	jb	1f
93b6cbf720SGianluca Guida	movw	(%esi),%ax
94b6cbf720SGianluca Guida	movw	%ax,(%edi)
95b6cbf720SGianluca Guida	je	.Ldone
96b6cbf720SGianluca Guida	movb	2(%esi),%al
97b6cbf720SGianluca Guida	movb	%al,2(%edi)
98b6cbf720SGianluca Guida	jmp	.Ldone
99b6cbf720SGianluca Guida1:	movb	(%esi),%al
100b6cbf720SGianluca Guida	movb	%al,(%edi)
101b6cbf720SGianluca Guida	jmp	.Ldone
102b6cbf720SGianluca Guida
103b6cbf720SGianluca Guida#if !defined(NO_OVERLAP)
104b6cbf720SGianluca Guida.Lbackwards:
105b6cbf720SGianluca Guida	addl	%ecx,%edi	/* copy backwards. */
106b6cbf720SGianluca Guida	addl	%ecx,%esi
107b6cbf720SGianluca Guida	and	$3,%eax		/* any fractional bytes? */
108b6cbf720SGianluca Guida	jnz	.Lback_align
109b6cbf720SGianluca Guida.Lback_aligned:
110b6cbf720SGianluca Guida	shrl	$2,%ecx
111b6cbf720SGianluca Guida	subl	$4,%esi
112b6cbf720SGianluca Guida	subl	$4,%edi
113b6cbf720SGianluca Guida	std
114b6cbf720SGianluca Guida	rep
115b6cbf720SGianluca Guida	movsl
116b6cbf720SGianluca Guida	cld
117b6cbf720SGianluca Guida	jmp	.Ldone
118b6cbf720SGianluca Guida
119b6cbf720SGianluca Guida.Lback_align:
120b6cbf720SGianluca Guida	sub	%eax,%esi
121b6cbf720SGianluca Guida	sub	%eax,%edi
122b6cbf720SGianluca Guida	cmp	$2,%eax
123b6cbf720SGianluca Guida	jb	1f
124b6cbf720SGianluca Guida	je	2f
125b6cbf720SGianluca Guida	movb	2(%esi),%al
126b6cbf720SGianluca Guida	movb	%al,2(%edi)
127b6cbf720SGianluca Guida2:	movw	(%esi),%ax
128b6cbf720SGianluca Guida	movw	%ax,(%edi)
129b6cbf720SGianluca Guida	jmp	.Lback_aligned
130b6cbf720SGianluca Guida1:	movb	(%esi),%al
131b6cbf720SGianluca Guida	movb	%al,(%edi)
132b6cbf720SGianluca Guida	jmp	.Lback_aligned
133b6cbf720SGianluca Guida#endif
134*0a6a1f1dSLionel Sambuc
135*0a6a1f1dSLionel Sambuc#ifdef BCOPY
136*0a6a1f1dSLionel SambucEND(bcopy)
137*0a6a1f1dSLionel Sambuc#else
138*0a6a1f1dSLionel Sambuc#ifdef MEMMOVE
139*0a6a1f1dSLionel SambucEND(memmove)
140*0a6a1f1dSLionel Sambuc#else
141*0a6a1f1dSLionel SambucEND(memcpy)
142*0a6a1f1dSLionel Sambuc#endif
143*0a6a1f1dSLionel Sambuc#endif
144