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comparison crc32.c @ 0:422835bc1aca

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*: checkin
author Paper <paper@tflc.us>
date Mon, 09 Feb 2026 01:15:00 -0500
parents
children 6483683ac857
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-1:000000000000 0:422835bc1aca
1 #include "crc32.h"
2 #include "crc32i.h"
3 #include <stdio.h>
4 #include <string.h>
5 #include <inttypes.h>
6 #include <assert.h>
7 #include <stdlib.h>
8 #include <time.h>
9
10 /* Align to a byte offset using the given crc function. */
11 static void crc32_align(uint32_t *crc, crc32_r_spec crcfunc, size_t align, const unsigned char **message, size_t *sz)
12 {
13 size_t sz8, szs;
14
15 /* Alignment check */
16 if (ALIGNED(*message, align))
17 return;
18
19 /* Calculate size needed to align */
20 sz8 = align - ((uintptr_t)message % align);
21 szs = MIN(*sz, sz8);
22
23 *crc = crcfunc(*crc, *message, sz8);
24 *message += sz8;
25 *sz -= sz8;
26
27 if (szs == sz8) assert(ALIGNED(*message, align));
28 }
29
30 CRC32_API
31 uint32_t crc32(const unsigned char *message, size_t sz)
32 {
33 uint32_t crc;
34 size_t i;
35
36 if (!sz)
37 return 0;
38
39 crc = 0xFFFFFFFF;
40 crc32_align(&crc, crc32c_r, ALIGNOF(uint32_t), &message, &sz);
41 if (!sz) return ~crc;
42 #ifdef __x86_64__
43 crc32_align(&crc, crc32qw_r, 16, &message, &sz);
44 if (!sz) return ~crc;
45
46 return ~crc32x86_vpclmulqdq_r(crc, message, sz);
47 #else
48 return ~crc32qw_r(crc, message, sz);
49 #endif
50 }