/* * Copyright (c) Meta Platforms, Inc. and affiliates. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #pragma once #include <folly/Portability.h> #if FOLLY_SSE_PREREQ(4, 2) #include <immintrin.h> #endif #include <stdint.h> #include <cstddef> namespace folly { namespace detail { /** * Compute a CRC-32C checksum of a buffer using a hardware-accelerated * implementation. * * @note This function is exposed to support special cases where the * calling code is absolutely certain it ought to invoke a hardware- * accelerated CRC-32C implementation - unit tests, for example. For * all other scenarios, please call crc32c() and let it pick an * implementation based on the capabilities of the underlying CPU. */ uint32_t crc32c_hw( const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U); /** * Check whether a SSE4.2 hardware-accelerated CRC-32C implementation is * supported on the current CPU. */ bool crc32c_hw_supported(); /** * Check whether an AVX512VL hardware-accelerated CRC-32C implementation is * supported on the current CPU. */ bool crc32c_hw_supported_avx512(); /** * Compute a CRC-32C checksum of a buffer using a portable, * software-only implementation. * * @note This function is exposed to support special cases where the * calling code is absolutely certain it wants to use the software * implementation instead of the hardware-accelerated code - unit * tests, for example. For all other scenarios, please call crc32c() * and let it pick an implementation based on the capabilities of * the underlying CPU. */ uint32_t crc32c_sw( const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U); /** * Compute a CRC-32 checksum of a buffer using a hardware-accelerated * implementation. * * @note This function is exposed to support special cases where the * calling code is absolutely certain it ought to invoke a hardware- * accelerated CRC-32 implementation - unit tests, for example. For * all other scenarios, please call crc32() and let it pick an * implementation based on the capabilities of the underlying CPU. */ uint32_t crc32_hw( const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U); #if FOLLY_SSE_PREREQ(4, 2) uint32_t crc32_hw_aligned( uint32_t remainder, const __m128i* p, size_t vec_count); #endif /** * Check whether a hardware-accelerated CRC-32 implementation is * supported on the current CPU. */ bool crc32_hw_supported(); /** * Compute a CRC-32 checksum of a buffer using a portable, * software-only implementation. * * @note This function is exposed to support special cases where the * calling code is absolutely certain it wants to use the software * implementation instead of the hardware-accelerated code - unit * tests, for example. For all other scenarios, please call crc32() * and let it pick an implementation based on the capabilities of * the underlying CPU. */ uint32_t crc32_sw( const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U); /* See Checksum.h for details. * * crc2len *must* be a power of two >= 4. */ uint32_t crc32_combine_sw(uint32_t crc1, uint32_t crc2, size_t crc2len); uint32_t crc32_combine_hw(uint32_t crc1, uint32_t crc2, size_t crc2len); uint32_t crc32c_combine_sw(uint32_t crc1, uint32_t crc2, size_t crc2len); uint32_t crc32c_combine_hw(uint32_t crc1, uint32_t crc2, size_t crc2len); } // namespace detail } // namespace folly
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