chromium/third_party/abseil-cpp/absl/crc/internal/crc_memcpy.h

// Copyright 2022 The Abseil Authors
//
// 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
//
//     https://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.

#ifndef ABSL_CRC_INTERNAL_CRC_MEMCPY_H_
#define ABSL_CRC_INTERNAL_CRC_MEMCPY_H_

#include <cstddef>
#include <memory>

#include "absl/base/config.h"
#include "absl/crc/crc32c.h"
#include "absl/crc/internal/crc32_x86_arm_combined_simd.h"

// Defined if the class AcceleratedCrcMemcpyEngine exists.
// TODO(b/299127771): Consider relaxing the pclmul requirement once the other
// intrinsics are conditionally compiled without it.
#if defined(ABSL_CRC_INTERNAL_HAVE_X86_SIMD)
#define ABSL_INTERNAL_HAVE_X86_64_ACCELERATED_CRC_MEMCPY_ENGINE …
#elif defined(ABSL_CRC_INTERNAL_HAVE_ARM_SIMD)
#define ABSL_INTERNAL_HAVE_ARM_ACCELERATED_CRC_MEMCPY_ENGINE …
#endif

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace crc_internal {

class CrcMemcpyEngine { … };

class CrcMemcpy { … };

// Fallback CRC-memcpy engine.
class FallbackCrcMemcpyEngine : public CrcMemcpyEngine { … };

// CRC Non-Temporal-Memcpy engine.
class CrcNonTemporalMemcpyEngine : public CrcMemcpyEngine { … };

// CRC Non-Temporal-Memcpy AVX engine.
class CrcNonTemporalMemcpyAVXEngine : public CrcMemcpyEngine { … };

// Copy source to destination and return the CRC32C of the data copied.  If an
// accelerated version is available, use the accelerated version, otherwise use
// the generic fallback version.
inline crc32c_t Crc32CAndCopy(void* __restrict dst, const void* __restrict src,
                              std::size_t length,
                              crc32c_t initial_crc = crc32c_t{ … }

}  // namespace crc_internal
ABSL_NAMESPACE_END
}  // namespace absl

#endif  // ABSL_CRC_INTERNAL_CRC_MEMCPY_H_