57 lines
1.4 KiB
C++
57 lines
1.4 KiB
C++
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// Copyright (c) 2018, Arm Limited and affiliates. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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#include "util/crc32c_arm64.h"
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#if defined(__linux__) && defined(HAVE_ARM64_CRC)
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#include <asm/hwcap.h>
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#include <sys/auxv.h>
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#ifndef HWCAP_CRC32
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#define HWCAP_CRC32 (1 << 7)
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#endif
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uint32_t crc32c_runtime_check(void) {
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uint64_t auxv = getauxval(AT_HWCAP);
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return (auxv & HWCAP_CRC32) != 0;
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}
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uint32_t crc32c_arm64(uint32_t crc, unsigned char const *data,
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unsigned len) {
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const uint8_t *buf1;
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const uint16_t *buf2;
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const uint32_t *buf4;
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const uint64_t *buf8;
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int64_t length = (int64_t)len;
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crc ^= 0xffffffff;
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buf8 = (const uint64_t *)data;
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while ((length -= sizeof(uint64_t)) >= 0) {
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crc = __crc32cd(crc, *buf8++);
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}
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/* The following is more efficient than the straight loop */
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buf4 = (const uint32_t *)buf8;
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if (length & sizeof(uint32_t)) {
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crc = __crc32cw(crc, *buf4++);
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length -= 4;
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}
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buf2 = (const uint16_t *)buf4;
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if (length & sizeof(uint16_t)) {
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crc = __crc32ch(crc, *buf2++);
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length -= 2;
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}
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buf1 = (const uint8_t *)buf2;
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if (length & sizeof(uint8_t))
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crc = __crc32cb(crc, *buf1);
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crc ^= 0xffffffff;
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return crc;
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}
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#endif
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