1 /*
2 * Copyright (c) 2009, 2010
3 * Phillip Lougher <phillip@squashfs.org.uk>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2,
8 * or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 *
19 * swap.c
20 */
21
22 #ifndef linux
23 #define __BYTE_ORDER BYTE_ORDER
24 #define __BIG_ENDIAN BIG_ENDIAN
25 #define __LITTLE_ENDIAN LITTLE_ENDIAN
26 #else
27 #include <endian.h>
28 #endif
29
30 #if __BYTE_ORDER == __BIG_ENDIAN
swap_le16(void * src,void * dest)31 void swap_le16(void *src, void *dest)
32 {
33 unsigned char *s = src;
34 unsigned char *d = dest;
35
36 d[0] = s[1];
37 d[1] = s[0];
38 }
39
40
swap_le32(void * src,void * dest)41 void swap_le32(void *src, void *dest)
42 {
43 unsigned char *s = src;
44 unsigned char *d = dest;
45
46 d[0] = s[3];
47 d[1] = s[2];
48 d[2] = s[1];
49 d[3] = s[0];
50 }
51
52
swap_le64(void * src,void * dest)53 void swap_le64(void *src, void *dest)
54 {
55 unsigned char *s = src;
56 unsigned char *d = dest;
57
58 d[0] = s[7];
59 d[1] = s[6];
60 d[2] = s[5];
61 d[3] = s[4];
62 d[4] = s[3];
63 d[5] = s[2];
64 d[6] = s[1];
65 d[7] = s[0];
66 }
67
68
inswap_le16(unsigned short num)69 unsigned short inswap_le16(unsigned short num)
70 {
71 return (num >> 8) |
72 ((num & 0xff) << 8);
73 }
74
75
inswap_le32(unsigned int num)76 unsigned int inswap_le32(unsigned int num)
77 {
78 return (num >> 24) |
79 ((num & 0xff0000) >> 8) |
80 ((num & 0xff00) << 8) |
81 ((num & 0xff) << 24);
82 }
83
84
inswap_le64(long long n)85 long long inswap_le64(long long n)
86 {
87 unsigned long long num = n;
88
89 return (num >> 56) |
90 ((num & 0xff000000000000LL) >> 40) |
91 ((num & 0xff0000000000LL) >> 24) |
92 ((num & 0xff00000000LL) >> 8) |
93 ((num & 0xff000000) << 8) |
94 ((num & 0xff0000) << 24) |
95 ((num & 0xff00) << 40) |
96 ((num & 0xff) << 56);
97 }
98
99
100 #define SWAP_LE_NUM(BITS) \
101 void swap_le##BITS##_num(void *s, void *d, int n) \
102 {\
103 int i;\
104 for(i = 0; i < n; i++, s += BITS / 8, d += BITS / 8)\
105 swap_le##BITS(s, d);\
106 }
107
108 SWAP_LE_NUM(16)
109 SWAP_LE_NUM(32)
110 SWAP_LE_NUM(64)
111
112 #define INSWAP_LE_NUM(BITS, TYPE) \
113 void inswap_le##BITS##_num(TYPE *s, int n) \
114 {\
115 int i;\
116 for(i = 0; i < n; i++)\
117 s[i] = inswap_le##BITS(s[i]);\
118 }
119
120 INSWAP_LE_NUM(16, unsigned short)
121 INSWAP_LE_NUM(32, unsigned int)
122 INSWAP_LE_NUM(64, long long)
123 #endif
124