annotate crc32.c @ 0:422835bc1aca

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author Paper <paper@tflc.us>
date Mon, 09 Feb 2026 01:15:00 -0500
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children 6483683ac857
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1 #include "crc32.h"
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2 #include "crc32i.h"
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3 #include <stdio.h>
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4 #include <string.h>
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5 #include <inttypes.h>
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6 #include <assert.h>
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7 #include <stdlib.h>
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8 #include <time.h>
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9
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10 /* Align to a byte offset using the given crc function. */
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11 static void crc32_align(uint32_t *crc, crc32_r_spec crcfunc, size_t align, const unsigned char **message, size_t *sz)
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12 {
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13 size_t sz8, szs;
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14
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15 /* Alignment check */
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16 if (ALIGNED(*message, align))
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17 return;
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18
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19 /* Calculate size needed to align */
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20 sz8 = align - ((uintptr_t)message % align);
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21 szs = MIN(*sz, sz8);
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22
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23 *crc = crcfunc(*crc, *message, sz8);
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24 *message += sz8;
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25 *sz -= sz8;
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26
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27 if (szs == sz8) assert(ALIGNED(*message, align));
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28 }
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29
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30 CRC32_API
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31 uint32_t crc32(const unsigned char *message, size_t sz)
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32 {
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33 uint32_t crc;
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34 size_t i;
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35
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36 if (!sz)
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37 return 0;
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38
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39 crc = 0xFFFFFFFF;
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40 crc32_align(&crc, crc32c_r, ALIGNOF(uint32_t), &message, &sz);
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41 if (!sz) return ~crc;
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42 #ifdef __x86_64__
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43 crc32_align(&crc, crc32qw_r, 16, &message, &sz);
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44 if (!sz) return ~crc;
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45
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46 return ~crc32x86_vpclmulqdq_r(crc, message, sz);
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47 #else
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48 return ~crc32qw_r(crc, message, sz);
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49 #endif
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50 }