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 #include "config/av1_rtcd.h"
23
24 #define CRC_LOOP(op, crc, type, buf, len) \
25 while ((len) >= sizeof(type)) { \
26 (crc) = op((crc), *(type *)(buf)); \
27 (len) -= sizeof(type); \
28 buf += sizeof(type); \
29 }
30
31 #define CRC_SINGLE(op, crc, type, buf, len) \
32 if ((len) >= sizeof(type)) { \
33 (crc) = op((crc), *(type *)(buf)); \
34 (len) -= sizeof(type); \
35 buf += sizeof(type); \
36 }
37
38 /* Return 32-bit CRC for the input buffer.
39 * Polynomial is 0x1EDC6F41.
40 */
41
av1_get_crc32c_value_arm_crc32(void * crc_calculator,uint8_t * p,size_t len)42 uint32_t av1_get_crc32c_value_arm_crc32(void *crc_calculator, uint8_t *p,
43 size_t len) {
44 (void)crc_calculator;
45 const uint8_t *buf = p;
46 uint32_t crc = 0xFFFFFFFF;
47
48 #if !AOM_ARCH_AARCH64
49 // Align input to 8-byte boundary (only necessary for 32-bit builds.)
50 while (len && ((uintptr_t)buf & 7)) {
51 crc = __crc32cb(crc, *buf++);
52 len--;
53 }
54 #endif
55
56 CRC_LOOP(__crc32cd, crc, uint64_t, buf, len)
57 CRC_SINGLE(__crc32cw, crc, uint32_t, buf, len)
58 CRC_SINGLE(__crc32ch, crc, uint16_t, buf, len)
59 CRC_SINGLE(__crc32cb, crc, uint8_t, buf, len)
60
61 return ~crc;
62 }
63