1 /*
2 * Copyright (c) 2022, Alliance for Open Media. All rights reserved
3 *
4 * This source code is subject to the terms of the BSD 2 Clause License and
5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6 * was not distributed with this source code in the LICENSE file, you can
7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8 * Media Patent License 1.0 was not distributed with this source code in the
9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10 */
11
12 #include <stdint.h>
13 #include <stddef.h>
14 #include <arm_acle.h>
15
16 #define CRC_LOOP(op, crc, type, buf, len) \
17 while ((len) >= sizeof(type)) { \
18 (crc) = op((crc), *(type *)(buf)); \
19 (len) -= sizeof(type); \
20 buf += sizeof(type); \
21 }
22
23 #define CRC_SINGLE(op, crc, type, buf, len) \
24 if ((len) >= sizeof(type)) { \
25 (crc) = op((crc), *(type *)(buf)); \
26 (len) -= sizeof(type); \
27 buf += sizeof(type); \
28 }
29
30 /* Return 32-bit CRC for the input buffer.
31 * Polynomial is 0x1EDC6F41.
32 */
33
av1_get_crc32c_value_arm_crc32(void * crc_calculator,uint8_t * p,size_t len)34 uint32_t av1_get_crc32c_value_arm_crc32(void *crc_calculator, uint8_t *p,
35 size_t len) {
36 (void)crc_calculator;
37 const uint8_t *buf = p;
38 uint32_t crc = 0xFFFFFFFF;
39
40 #if !defined(__aarch64__)
41 // Align input to 8-byte boundary (only necessary for 32-bit builds.)
42 while (len && ((uintptr_t)buf & 7)) {
43 crc = __crc32cb(crc, *buf++);
44 len--;
45 }
46 #endif
47
48 CRC_LOOP(__crc32cd, crc, uint64_t, buf, len)
49 CRC_SINGLE(__crc32cw, crc, uint32_t, buf, len)
50 CRC_SINGLE(__crc32ch, crc, uint16_t, buf, len)
51 CRC_SINGLE(__crc32cb, crc, uint8_t, buf, len)
52
53 return ~crc;
54 }
55