/*

Copyright (c) 2015-2017, 2019-2020, Arvid Norberg

Copyright (c) 2016-2018, Alden Torres

Copyright (c) 2016, Andrei Kurushin

Copyright (c) 2018, Alexandre Janniaux

All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions

are met:

    * Redistributions of source code must retain the above copyright

      notice, this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright

      notice, this list of conditions and the following disclaimer in

      the documentation and/or other materials provided with the distribution.

    * Neither the name of the author nor the names of its

      contributors may be used to endorse or promote products derived

      from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

POSSIBILITY OF SUCH DAMAGE.

*/

#include "libtorrent/config.hpp"

#include "libtorrent/aux_/cpuid.hpp"

#include <cstdint>

#if defined _MSC_VER && TORRENT_HAS_SSE

#include <intrin.h>

#include <nmmintrin.h>

#endif

#if TORRENT_HAS_SSE && defined __GNUC__

#include <cpuid.h>

#else

#include <cstring> // for std::memset

#endif

#if defined __GLIBC__ && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 16))

#define TORRENT_HAS_AUXV 1

#elif defined TORRENT_ANDROID

#define TORRENT_HAS_AUXV 1

#else

#define TORRENT_HAS_AUXV 0

#endif

#if TORRENT_HAS_ARM && TORRENT_HAS_AUXV

#if defined TORRENT_ANDROID

#include <dlfcn.h>

namespace {

unsigned long int helper_getauxval(unsigned long int type)

{

    using getauxval_t = unsigned long int(*)(unsigned long int);

    getauxval_t pf_getauxval = reinterpret_cast<getauxval_t>(dlsym(RTLD_DEFAULT, "getauxval"));

    if (pf_getauxval == nullptr)

        return 0;

    return pf_getauxval(type);

}

}

#else // TORRENT_ANDROID

#include <sys/auxv.h>

#define helper_getauxval getauxval

#endif

#endif // TORRENT_HAS_ARM && TORRENT_HAS_AUXV

namespace libtorrent {

namespace aux {

namespace {

#if TORRENT_HAS_SSE

  // internal

  void cpuid(std::uint32_t* info, int type) noexcept

  {

#if defined _MSC_VER

    __cpuid(reinterpret_cast<int*>(info), type);

#elif defined __GNUC__

    __get_cpuid(std::uint32_t(type), &info[0], &info[1], &info[2], &info[3]);

#else

    TORRENT_UNUSED(type);

    // for non-x86 and non-amd64, just return zeroes

    std::memset(&info[0], 0, sizeof(std::uint32_t) * 4);

#endif

  }

#endif

  bool supports_sse42() noexcept

  {

#if TORRENT_HAS_SSE

    std::uint32_t cpui[4] = {0};

    cpuid(cpui, 1);

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

#else

    return false;

#endif

  }

  bool supports_mmx() noexcept

  {

#if TORRENT_HAS_SSE

    std::uint32_t cpui[4] = {0};

    cpuid(cpui, 1);

    return (cpui[2] & (1 << 23)) != 0;

#else

    return false;

#endif

  }

  bool supports_arm_neon() noexcept

  {

#if TORRENT_HAS_ARM_NEON && TORRENT_HAS_AUXV

#if defined __arm__

    //return (getauxval(AT_HWCAP) & HWCAP_NEON);

    return (helper_getauxval(16) & (1 << 12));

#elif defined __aarch64__

    //return (getauxval(AT_HWCAP) & HWCAP_ASIMD);

    //return (getauxval(16) & (1 << 1));

    // TODO: enable when aarch64 is really tested

    return false;

#endif

#else

    return false;

#endif

  }

  bool supports_arm_crc32c() noexcept

  {

#if TORRENT_HAS_ARM_CRC32 && TORRENT_HAS_AUXV

#if defined TORRENT_FORCE_ARM_CRC32

    return true;

#elif defined __arm__

    //return (getauxval(AT_HWCAP2) & HWCAP2_CRC32);

    return (helper_getauxval(26) & (1 << 4));

#elif defined __aarch64__

    //return (getauxval(AT_HWCAP) & HWCAP_CRC32);

    return (helper_getauxval(16) & (1 << 7));

#endif

#else

    return false;

#endif

  }

} // anonymous namespace

  bool const sse42_support = supports_sse42();

  bool const mmx_support = supports_mmx();

  bool const arm_neon_support = supports_arm_neon();

  bool const arm_crc32c_support = supports_arm_crc32c();

} }