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 #if defined(_MSC_VER) && !defined(__clang__)
13 #include <intrin.h>
14 #else
15 #include <arm_acle.h>
16 #endif
17
18 #include <stddef.h>
19 #include <stdint.h>
20
21 #include "config/aom_config.h"
22
23 #define CRC_LOOP(op, crc, type, buf, len) \
24 while ((len) >= sizeof(type)) { \
25 (crc) = op((crc), *(type *)(buf)); \
26 (len) -= sizeof(type); \
27 buf += sizeof(type); \
28 }
29
30 #define CRC_SINGLE(op, crc, type, buf, len) \
31 if ((len) >= sizeof(type)) { \
32 (crc) = op((crc), *(type *)(buf)); \
33 (len) -= sizeof(type); \
34 buf += sizeof(type); \
35 }
36
37 /* Return 32-bit CRC for the input buffer.
38 * Polynomial is 0x1EDC6F41.
39 */
40
av1_get_crc32c_value_arm_crc32(void * crc_calculator,uint8_t * p,size_t len)41 uint32_t av1_get_crc32c_value_arm_crc32(void *crc_calculator, uint8_t *p,
42 size_t len) {
43 (void)crc_calculator;
44 const uint8_t *buf = p;
45 uint32_t crc = 0xFFFFFFFF;
46
47 #if !AOM_ARCH_AARCH64
48 // Align input to 8-byte boundary (only necessary for 32-bit builds.)
49 while (len && ((uintptr_t)buf & 7)) {
50 crc = __crc32cb(crc, *buf++);
51 len--;
52 }
53 #endif
54
55 CRC_LOOP(__crc32cd, crc, uint64_t, buf, len)
56 CRC_SINGLE(__crc32cw, crc, uint32_t, buf, len)
57 CRC_SINGLE(__crc32ch, crc, uint16_t, buf, len)
58 CRC_SINGLE(__crc32cb, crc, uint8_t, buf, len)
59
60 return ~crc;
61 }
62