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/*
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/*
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 * Copyright (c) 2005 Martin Decky
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 * Copyright (c) 2005 Martin Decky
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 * Copyright (c) 2008 Jiri Svoboda
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 * Copyright (c) 2008 Jiri Svoboda
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 * All rights reserved.
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 * All rights reserved.
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 *
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * are met:
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 *
9
 *
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 * - Redistributions of source code must retain the above copyright
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
15
 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *   derived from this software without specific prior written permission.
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 *
17
 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
28
 */
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29
 
30
/** @addtogroup libc
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/** @addtogroup libc
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 * @{
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 * @{
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 */
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 */
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/** @file
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/** @file
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 */
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 */
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35
 
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#include <mem.h>
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#include <mem.h>
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#include <stdlib.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/types.h>
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39
 
40
/** Fill memory block with a constant value. */
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/** Fill memory block with a constant value. */
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void *memset(void *dest, int b, size_t n)
41
void *memset(void *dest, int b, size_t n)
42
{
42
{
43
    char *pb;
43
    char *pb;
44
    unsigned long *pw;
44
    unsigned long *pw;
45
    size_t word_size;
45
    size_t word_size;
46
    size_t n_words;
46
    size_t n_words;
47
 
47
 
48
    unsigned long pattern;
48
    unsigned long pattern;
49
    size_t i;
49
    size_t i;
50
    size_t fill;
50
    size_t fill;
51
 
51
 
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    /* Fill initial segment. */
52
    /* Fill initial segment. */
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    word_size = sizeof(unsigned long);
53
    word_size = sizeof(unsigned long);
54
    fill = word_size - ((uintptr_t) dest & (word_size - 1));
54
    fill = word_size - ((uintptr_t) dest & (word_size - 1));
55
    if (fill > n) fill = n;
55
    if (fill > n) fill = n;
56
 
56
 
57
    pb = dest;
57
    pb = dest;
58
 
58
 
59
    i = fill;
59
    i = fill;
60
    while (i-- != 0)
60
    while (i-- != 0)
61
        *pb++ = b;
61
        *pb++ = b;
62
 
62
 
63
    /* Compute remaining size. */
63
    /* Compute remaining size. */
64
    n -= fill;
64
    n -= fill;
65
    if (n == 0) return dest;
65
    if (n == 0) return dest;
66
 
66
 
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    n_words = n / word_size;
67
    n_words = n / word_size;
68
    n = n % word_size;
68
    n = n % word_size;
69
    pw = (unsigned long *) pb;
69
    pw = (unsigned long *) pb;
70
 
70
 
71
    /* Create word-sized pattern for aligned segment. */
71
    /* Create word-sized pattern for aligned segment. */
72
    pattern = 0;
72
    pattern = 0;
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    i = word_size;
73
    i = word_size;
74
    while (i-- != 0)
74
    while (i-- != 0)
75
        pattern = (pattern << 8) | (uint8_t) b;
75
        pattern = (pattern << 8) | (uint8_t) b;
76
 
76
 
77
    /* Fill aligned segment. */
77
    /* Fill aligned segment. */
78
    i = n_words;
78
    i = n_words;
79
    while (i-- != 0)
79
    while (i-- != 0)
80
        *pw++ = pattern;
80
        *pw++ = pattern;
81
 
81
 
82
    pb = (char *) pw;
82
    pb = (char *) pw;
83
 
83
 
84
    /* Fill final segment. */
84
    /* Fill final segment. */
85
    i = n;
85
    i = n;
86
    while (i-- != 0)
86
    while (i-- != 0)
87
        *pb++ = b;
87
        *pb++ = b;
88
 
88
 
89
    return dest;
89
    return dest;
90
}
90
}
91
 
91
 
92
struct along {
92
struct along {
93
    unsigned long n;
93
    unsigned long n;
94
} __attribute__ ((packed));
94
} __attribute__ ((packed));
95
 
95
 
96
static void *unaligned_memcpy(void *dst, const void *src, size_t n)
96
static void *unaligned_memcpy(void *dst, const void *src, size_t n)
97
{
97
{
98
    int i, j;
98
    size_t i, j;
99
    struct along *adst = dst;
99
    struct along *adst = dst;
100
    const struct along *asrc = src;
100
    const struct along *asrc = src;
101
 
101
 
102
    for (i = 0; i < n / sizeof(unsigned long); i++)
102
    for (i = 0; i < n / sizeof(unsigned long); i++)
103
        adst[i].n = asrc[i].n;
103
        adst[i].n = asrc[i].n;
104
       
104
       
105
    for (j = 0; j < n % sizeof(unsigned long); j++)
105
    for (j = 0; j < n % sizeof(unsigned long); j++)
106
        ((unsigned char *) (((unsigned long *) dst) + i))[j] =
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        ((unsigned char *) (((unsigned long *) dst) + i))[j] =
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            ((unsigned char *) (((unsigned long *) src) + i))[j];
107
            ((unsigned char *) (((unsigned long *) src) + i))[j];
108
       
108
       
109
    return (char *) dst;
109
    return (char *) dst;
110
}
110
}
111
 
111
 
112
/** Copy memory block. */
112
/** Copy memory block. */
113
void *memcpy(void *dst, const void *src, size_t n)
113
void *memcpy(void *dst, const void *src, size_t n)
114
{
114
{
115
    size_t i;
115
    size_t i;
116
    size_t mod, fill;
116
    size_t mod, fill;
117
    size_t word_size;
117
    size_t word_size;
118
    size_t n_words;
118
    size_t n_words;
119
 
119
 
120
    const unsigned long *srcw;
120
    const unsigned long *srcw;
121
    unsigned long *dstw;
121
    unsigned long *dstw;
122
    const uint8_t *srcb;
122
    const uint8_t *srcb;
123
    uint8_t *dstb;
123
    uint8_t *dstb;
124
 
124
 
125
    word_size = sizeof(unsigned long);
125
    word_size = sizeof(unsigned long);
126
 
126
 
127
    /*
127
    /*
128
     * Are source and destination addresses congruent modulo word_size?
128
     * Are source and destination addresses congruent modulo word_size?
129
     * If not, use unaligned_memcpy().
129
     * If not, use unaligned_memcpy().
130
     */
130
     */
131
 
131
 
132
    if (((uintptr_t) dst & (word_size - 1)) !=
132
    if (((uintptr_t) dst & (word_size - 1)) !=
133
        ((uintptr_t) src & (word_size - 1)))
133
        ((uintptr_t) src & (word_size - 1)))
134
        return unaligned_memcpy(dst, src, n);
134
        return unaligned_memcpy(dst, src, n);
135
 
135
 
136
    /*
136
    /*
137
     * mod is the address modulo word size. fill is the length of the
137
     * mod is the address modulo word size. fill is the length of the
138
     * initial buffer segment before the first word boundary.
138
     * initial buffer segment before the first word boundary.
139
     * If the buffer is very short, use unaligned_memcpy(), too.
139
     * If the buffer is very short, use unaligned_memcpy(), too.
140
     */
140
     */
141
 
141
 
142
    mod = (uintptr_t) dst & (word_size - 1);
142
    mod = (uintptr_t) dst & (word_size - 1);
143
    fill = word_size - mod;
143
    fill = word_size - mod;
144
    if (fill > n) fill = n;
144
    if (fill > n) fill = n;
145
 
145
 
146
    /* Copy the initial segment. */
146
    /* Copy the initial segment. */
147
 
147
 
148
    srcb = src;
148
    srcb = src;
149
    dstb = dst;
149
    dstb = dst;
150
 
150
 
151
    i = fill;
151
    i = fill;
152
    while (i-- != 0)
152
    while (i-- != 0)
153
        *dstb++ = *srcb++;
153
        *dstb++ = *srcb++;
154
 
154
 
155
    /* Compute remaining length. */
155
    /* Compute remaining length. */
156
 
156
 
157
    n -= fill;
157
    n -= fill;
158
    if (n == 0) return dst;
158
    if (n == 0) return dst;
159
 
159
 
160
    /* Pointers to aligned segment. */
160
    /* Pointers to aligned segment. */
161
 
161
 
162
    dstw = (unsigned long *) dstb;
162
    dstw = (unsigned long *) dstb;
163
    srcw = (const unsigned long *) srcb;
163
    srcw = (const unsigned long *) srcb;
164
 
164
 
165
    n_words = n / word_size;    /* Number of whole words to copy. */
165
    n_words = n / word_size;    /* Number of whole words to copy. */
166
    n -= n_words * word_size;   /* Remaining bytes at the end. */
166
    n -= n_words * word_size;   /* Remaining bytes at the end. */
167
 
167
 
168
    /* "Fast" copy. */
168
    /* "Fast" copy. */
169
    i = n_words;
169
    i = n_words;
170
    while (i-- != 0)
170
    while (i-- != 0)
171
        *dstw++ = *srcw++;
171
        *dstw++ = *srcw++;
172
 
172
 
173
    /*
173
    /*
174
     * Copy the rest.
174
     * Copy the rest.
175
     */
175
     */
176
 
176
 
177
    srcb = (const uint8_t *) srcw;
177
    srcb = (const uint8_t *) srcw;
178
    dstb = (uint8_t *) dstw;
178
    dstb = (uint8_t *) dstw;
179
 
179
 
180
    i = n;
180
    i = n;
181
    while (i-- != 0)
181
    while (i-- != 0)
182
        *dstb++ = *srcb++;
182
        *dstb++ = *srcb++;
183
 
183
 
184
    return dst;
184
    return dst;
185
}
185
}
186
 
186
 
187
/** Move memory block with possible overlapping. */
187
/** Move memory block with possible overlapping. */
188
void *memmove(void *dst, const void *src, size_t n)
188
void *memmove(void *dst, const void *src, size_t n)
189
{
189
{
190
    const uint8_t *sp;
190
    const uint8_t *sp;
191
    uint8_t *dp;
191
    uint8_t *dp;
192
 
192
 
193
    /* Nothing to do? */
193
    /* Nothing to do? */
194
    if (src == dst)
194
    if (src == dst)
195
        return dst;
195
        return dst;
196
 
196
 
197
    /* Non-overlapping? */
197
    /* Non-overlapping? */
198
    if (dst >= src + n || src >= dst + n) {
198
    if (dst >= src + n || src >= dst + n) {
199
        return memcpy(dst, src, n);
199
        return memcpy(dst, src, n);
200
    }
200
    }
201
 
201
 
202
    /* Which direction? */
202
    /* Which direction? */
203
    if (src > dst) {
203
    if (src > dst) {
204
        /* Forwards. */
204
        /* Forwards. */
205
        sp = src;
205
        sp = src;
206
        dp = dst;
206
        dp = dst;
207
 
207
 
208
        while (n-- != 0)
208
        while (n-- != 0)
209
            *dp++ = *sp++;
209
            *dp++ = *sp++;
210
    } else {
210
    } else {
211
        /* Backwards. */
211
        /* Backwards. */
212
        sp = src + (n - 1);
212
        sp = src + (n - 1);
213
        dp = dst + (n - 1);
213
        dp = dst + (n - 1);
214
 
214
 
215
        while (n-- != 0)
215
        while (n-- != 0)
216
            *dp-- = *sp--;
216
            *dp-- = *sp--;
217
    }
217
    }
218
 
218
 
219
    return dst;
219
    return dst;
220
}
220
}
221
 
221
 
222
/** Compare two memory areas.
222
/** Compare two memory areas.
223
 *
223
 *
224
 * @param s1        Pointer to the first area to compare.
224
 * @param s1        Pointer to the first area to compare.
225
 * @param s2        Pointer to the second area to compare.
225
 * @param s2        Pointer to the second area to compare.
226
 * @param len       Size of the first area in bytes. Both areas must have
226
 * @param len       Size of the first area in bytes. Both areas must have
227
 *          the same length.
227
 *          the same length.
228
 * @return      If len is 0, return zero. If the areas match, return
228
 * @return      If len is 0, return zero. If the areas match, return
229
 *          zero. Otherwise return non-zero.
229
 *          zero. Otherwise return non-zero.
230
 */
230
 */
231
int bcmp(const char *s1, const char *s2, size_t len)
231
int bcmp(const char *s1, const char *s2, size_t len)
232
{
232
{
233
    for (; len && *s1++ == *s2++; len--)
233
    for (; len && *s1++ == *s2++; len--)
234
        ;
234
        ;
235
    return len;
235
    return len;
236
}
236
}
237
 
237
 
238
/** @}
238
/** @}
239
 */
239
 */
240
 
240