// Copyright 2017 The CRC32C Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file. See the AUTHORS file for names of contributors.

#ifndef CRC32C_CRC32C_SSE42_CHECK_H_

#define CRC32C_CRC32C_SSE42_CHECK_H_

// X86-specific code checking the availability of SSE4.2 instructions.

#include <cstddef>

#include <cstdint>

#ifdef CRC32C_HAVE_CONFIG_H

#include "crc32c/crc32c_config.h"

#endif

#if HAVE_SSE42 && (defined(_M_X64) || defined(__x86_64__))

// If the compiler supports SSE4.2, it definitely supports X86.

#if defined(_MSC_VER)

#include <intrin.h>

namespace crc32c {

inline bool CanUseSse42() {

  int cpu_info[4];

  __cpuid(cpu_info, 1);

  return (cpu_info[2] & (1 << 20)) != 0;

}

}  // namespace crc32c

#else  // !defined(_MSC_VER)

#include <cpuid.h>

namespace crc32c {

inline bool CanUseSse42() {

  unsigned int eax, ebx, ecx, edx;

  return __get_cpuid(1, &eax, &ebx, &ecx, &edx) && ((ecx & (1 << 20)) != 0);

}

}  // namespace crc32c

#endif  // defined(_MSC_VER)

#endif  // HAVE_SSE42 && (defined(_M_X64) || defined(__x86_64__))

#endif  // CRC32C_CRC32C_SSE42_CHECK_H_