/*

 * Copyright (c) 2015-2016 Spotify AB

 *

 * 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 <array>

#include <cstdint>

#if defined(_MSC_VER)

#include <intrin.h>

#endif

#include <spotify/json/detail/macros.hpp>

namespace spotify {

namespace json {

namespace detail {

class cpuid {

 public:

  cpuid() {

#if defined(json_arch_x86)

    const uint32_t cpuid_function(1);

#if defined(_MSC_VER)

    ::__cpuid(reinterpret_cast<int *>(_registers.data()), cpuid_function);

#elif defined(__GNUC__)

    __asm__ __volatile__ (

        "cpuid ;\n"

        : "=a" (_registers[cpu_register::eax]),

          "=b" (_registers[cpu_register::ebx]),

          "=c" (_registers[cpu_register::ecx]),

          "=d" (_registers[cpu_register::edx])

        : "a" (cpuid_function)

        :);

#endif  // defined(_MSC_VER)

#endif  // defined(json_arch_x86)

  }

  bool has_sse42() const {

    return has_feature_bit(cpu_register::ecx, cpu_feature_bit::sse_42);

  }

 private:

  struct cpu_register {

    enum type {

      eax = 0,

      ebx = 1,

      ecx = 2,

      edx = 3

    };

  };

  struct cpu_feature_bit {

    enum type {

      sse_42 = 20,

    };

  };

  bool has_feature_bit(

      const cpu_register::type &reg,

      const cpu_feature_bit::type &bit) const {

    return (_registers[reg] & (1 << bit)) != 0;

  }

  std::array<uint32_t, 4> _registers;

};

}  // namespace detail

}  // namespace json

}  // namespace spotify