/* The copyright in this software is being made available under the BSD
 * License, included below. This software may be subject to other third party
 * and contributor rights, including patent rights, and no such rights are
 * granted under this license.
 *
 * Copyright (c) 2010-2020, ITU/ISO/IEC
 * 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 ITU/ISO/IEC 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 HOLDER 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.
 */

/*
 * \ingroup CommonLib
 * \file    CommondefX86.cpp
 * \brief   This file contains the SIMD x86 common used functions.
 */

#include <sstream>
#include <map>
#include <iostream>
#include <stdint.h>
#include <string>
#include "CommonLib/CommonDef.h"


#ifdef TARGET_SIMD_X86


#if __GNUC__ // valid for GCC and clang
#define NO_USE_SIMD __attribute__((optimize("no-tree-vectorize")))
#else
#define NO_USE_SIMD
#endif


#if defined ( __MINGW32__ ) && !defined (  __MINGW64__ )
# define SIMD_UP_TO_SSE42 1
#else
# define SIMD_UP_TO_SSE42 0
#endif

/* use __cpuid for windows or inline assembler for gcc and clang */
#if defined( _WIN32 ) && !defined( __MINGW32__ )
#include <intrin.h>
#define do_cpuid    __cpuid
#define do_cpuidex  __cpuidex
#else
#include <cpuid.h>
void do_cpuid(int CPUInfo[4], int InfoType){
    __get_cpuid( (unsigned)InfoType, (unsigned*)&CPUInfo[0], (unsigned*)&CPUInfo[1], (unsigned*)&CPUInfo[2], (unsigned*)&CPUInfo[3] );
}
#if !SIMD_UP_TO_SSE42
#define do_cpuidex(cd, v0, v1) __cpuid_count(v0, v1, cd[0], cd[1], cd[2], cd[3])
#endif
#endif

static inline int64_t xgetbv (int ctr) {
#if (defined (_MSC_FULL_VER) && _MSC_FULL_VER >= 160040000) || (defined (__INTEL_COMPILER) && __INTEL_COMPILER >= 1200) // Microsoft or Intel compiler supporting _xgetbv intrinsic

    return _xgetbv(ctr);                                   // intrinsic function for XGETBV

#elif defined(__GNUC__)                                    // use inline assembly, Gnu/AT&T syntax

   uint32_t a, d;
#if GCC_VERSION_AT_LEAST(4,4) || CLANG_VERSION_AT_LEAST(3,3)
   __asm("xgetbv" : "=a"(a),"=d"(d) : "c"(ctr) : );
#else
   __asm(".byte 0x0f, 0x01, 0xd0" : "=a"(a),"=d"(d) : "c"(ctr) : );
#endif
   return a | (uint64_t(d) << 32);

#else  // #elif defined (_MSC_FULL_VER) || (defined (__INTEL_COMPILER)...) // other compiler. try inline assembly with masm/intel/MS syntax

   uint32_t a, d;
    __asm {
        mov ecx, ctr
        _emit 0x0f
        _emit 0x01
        _emit 0xd0 ; // xgetbv
        mov a, eax
        mov d, edx
    }
   return a | (uint64_t(d) << 32);

#endif
}


#define BIT_HAS_MMX                    (1 << 23)
#define BIT_HAS_SSE                    (1 << 25)
#define BIT_HAS_SSE2                   (1 << 26)
#define BIT_HAS_SSE3                   (1 <<  0)
#define BIT_HAS_SSSE3                  (1 <<  9)
#define BIT_HAS_SSE41                  (1 << 19)
#define BIT_HAS_SSE42                  (1 << 20)
#define BIT_HAS_SSE4a                  (1 <<  6)
#define BIT_HAS_OSXSAVE                (1 << 27)
#define BIT_HAS_AVX                   ((1 << 28)|BIT_HAS_OSXSAVE)
#define BIT_HAS_AVX2                   (1 <<  5)
#define BIT_HAS_AVX512F                (1 << 16)
#define BIT_HAS_AVX512DQ               (1 << 17)
#define BIT_HAS_AVX512BW               (1 << 30)
#define BIT_HAS_FMA3                   (1 << 12)
#define BIT_HAS_FMA4                   (1 << 16)
#define BIT_HAS_X64                    (1 << 29)
#define BIT_HAS_XOP                    (1 << 11)


/**
 * \brief Read instruction set extension support flags from CPU register;
 */
NO_USE_SIMD
X86_VEXT _get_x86_extensions()
{
    int regs[4] = {0, 0, 0, 0};
    X86_VEXT ext;
    ext = SCALAR;

    do_cpuid( regs, 0 );
    if( regs[0] == 0 ) return ext;
    do_cpuid( regs, 1 );
    if (!(regs[2] & BIT_HAS_SSE41)) return ext;
    ext = SSE41;
    if (!(regs[2] & BIT_HAS_SSE42)) return ext;
    ext = SSE42;
#if !SIMD_UP_TO_SSE42
    do_cpuidex( regs, 1, 1 );
    if (!((regs[2] & BIT_HAS_AVX) == BIT_HAS_AVX ))   return ext; // first check if the cpu supports avx
    if ((xgetbv(0) & 6) != 6)       return ext; // then see if the os uses YMM state management via XSAVE etc...
    ext = AVX;
// #ifdef USE_AVX2
    do_cpuidex( regs, 7, 0 );
    if (!(regs[1] & BIT_HAS_AVX2))  return ext;
    ext = AVX2;
// #endif
#ifdef USE_AVX512
    if ((xgetbv(0) & 0xE0) != 0xE0) return ext; // see if OPMASK state and ZMM are availabe and enabled
    do_cpuidex( regs, 7, 0 );
    if (!(regs[1] & BIT_HAS_AVX512F ))  return ext;
    if (!(regs[1] & BIT_HAS_AVX512DQ))  return ext;
    if (!(regs[1] & BIT_HAS_AVX512BW))  return ext;
    ext = AVX512;
#endif
#endif

    return ext;
}

typedef std::map<std::string, X86_VEXT> translate;
static translate m
{ { "SCALAR", SCALAR },{ "SSE41", SSE41 },{ "SSE42", SSE42 },
  { "AVX", AVX },{ "AVX2", AVX2 },{ "AVX512", AVX512 } };

NO_USE_SIMD
X86_VEXT read_x86_extension_flags(const std::string &extStrId)
{
  //static std::atomic<bool> b_detection_finished(false);
  static bool b_detection_finished( false );
  static X86_VEXT ext_flags = SCALAR;

  {
    if( !b_detection_finished )
    {
      if( !extStrId.empty() )
      {
        translate::iterator search = m.find( extStrId );
        if( search != m.end() )
        {
          ext_flags = search->second;
        }
        else
        {
          EXIT( "Mode not supported: " << ext_flags << "\n" );
        }
      }
      else
      {
        ext_flags = _get_x86_extensions();
      }

      b_detection_finished = true;
    }
  }

  return ext_flags;
}

const char* read_x86_extension(const std::string &extStrId)
{
  static const char extension_not_available[] = "NA";

  X86_VEXT vext = read_x86_extension_flags(extStrId);

  for( translate::const_iterator it = m.begin(); it != m.end(); ++it )
    if( it->second == vext )
      return it->first.c_str();

  return extension_not_available;
}

#endif // __x86_64
