1/*
2 * Copyright (c) 1993,94 Winning Strategies, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Winning Strategies, Inc.
16 * 4. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
| 1/*
2 * Copyright (c) 1993,94 Winning Strategies, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Winning Strategies, Inc.
16 * 4. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
29 *
30 * $FreeBSD: head/lib/libc/i386/string/swab.S 50476 1999-08-28 00:22:10Z peter $
| |
31 */
32
33#if defined(LIBC_RCS) && !defined(lint)
34 .text
| 29 */
30
31#if defined(LIBC_RCS) && !defined(lint)
32 .text
|
35 .asciz "$FreeBSD: head/lib/libc/i386/string/swab.S 50476 1999-08-28 00:22:10Z peter $"
| 33 .asciz "$FreeBSD: head/lib/libc/i386/string/swab.S 81586 2001-08-13 14:06:34Z ru $"
|
36#endif
37
38#include "DEFS.h"
39
40/*
41 * void
42 * swab (const void *src, void *dst, size_t len)
43 * copy len bytes from src to dst, swapping adjacent bytes
44 *
45 * On the i486, this code is negligibly faster than the code generated
46 * by gcc at about half the size. If my i386 databook is correct, it
47 * should be considerably faster than the gcc code on a i386.
48 *
49 * Written by:
50 * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
51 */
52
53ENTRY(swab)
54 pushl %esi
55 pushl %edi
56 movl 12(%esp),%esi
57 movl 16(%esp),%edi
58 movl 20(%esp),%ecx
59
60 cld # set direction forward
61
62 shrl $1,%ecx
63 testl $7,%ecx # copy first group of 1 to 7 words
64 jz L2 # while swaping alternate bytes.
65 .align 2,0x90
66L1: lodsw
67 rorw $8,%ax
68 stosw
69 decl %ecx
70 testl $7,%ecx
71 jnz L1
72
73L2: shrl $3,%ecx # copy remainder 8 words at a time
74 jz L4 # while swapping alternate bytes.
75 .align 2,0x90
76L3: lodsw
77 rorw $8,%ax
78 stosw
79 lodsw
80 rorw $8,%ax
81 stosw
82 lodsw
83 rorw $8,%ax
84 stosw
85 lodsw
86 rorw $8,%ax
87 stosw
88 lodsw
89 rorw $8,%ax
90 stosw
91 lodsw
92 rorw $8,%ax
93 stosw
94 lodsw
95 rorw $8,%ax
96 stosw
97 lodsw
98 rorw $8,%ax
99 stosw
100 decl %ecx
101 jnz L3
102
103L4: popl %edi
104 popl %esi
105 ret
| 34#endif
35
36#include "DEFS.h"
37
38/*
39 * void
40 * swab (const void *src, void *dst, size_t len)
41 * copy len bytes from src to dst, swapping adjacent bytes
42 *
43 * On the i486, this code is negligibly faster than the code generated
44 * by gcc at about half the size. If my i386 databook is correct, it
45 * should be considerably faster than the gcc code on a i386.
46 *
47 * Written by:
48 * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
49 */
50
51ENTRY(swab)
52 pushl %esi
53 pushl %edi
54 movl 12(%esp),%esi
55 movl 16(%esp),%edi
56 movl 20(%esp),%ecx
57
58 cld # set direction forward
59
60 shrl $1,%ecx
61 testl $7,%ecx # copy first group of 1 to 7 words
62 jz L2 # while swaping alternate bytes.
63 .align 2,0x90
64L1: lodsw
65 rorw $8,%ax
66 stosw
67 decl %ecx
68 testl $7,%ecx
69 jnz L1
70
71L2: shrl $3,%ecx # copy remainder 8 words at a time
72 jz L4 # while swapping alternate bytes.
73 .align 2,0x90
74L3: lodsw
75 rorw $8,%ax
76 stosw
77 lodsw
78 rorw $8,%ax
79 stosw
80 lodsw
81 rorw $8,%ax
82 stosw
83 lodsw
84 rorw $8,%ax
85 stosw
86 lodsw
87 rorw $8,%ax
88 stosw
89 lodsw
90 rorw $8,%ax
91 stosw
92 lodsw
93 rorw $8,%ax
94 stosw
95 lodsw
96 rorw $8,%ax
97 stosw
98 decl %ecx
99 jnz L3
100
101L4: popl %edi
102 popl %esi
103 ret
|