//----------------------------------------------------------------------------
//  EgalTech 2015-2019
//----------------------------------------------------------------------------
// File : GetCpuInfo.cpp       Data : 27.12.19        Versione : 2.2a1
// Contenuto : Funzioni per informazioni sulla CPU.
//
//
//
// Modifiche : 11.03.15 DS Creazione modulo.
//             27.12.19 DS Aggiunta lettura supporto AVX e AVX2.
//
//----------------------------------------------------------------------------

//--------------------------- Include ----------------------------------------
#include "stdafx.h"
#include "/EgtDEv/Include/EGnPcInfo.h"
#include "/EgtDEv/Include/EGnStringUtils.h"
#include <intrin.h>
#define NOMINMAX
#include "Windows.h"

using namespace std ;

//------------------------------ Costanti ------------------------------------
// Bit indici estensioni della CPU
static const int BIT_MMX =   0x00800000 ;
static const int BIT_SSE =   0x02000000 ;
static const int BIT_SSE2 =  0x04000000 ;
static const int BIT_AVX =   0x20000000 ;
static const int BIT_AVX2 =  0x00000020 ;
static const int BIT_3DNOW = 0x80000000 ;
// lunghezza nomi
static const int VNAME_LEN = 3*sizeof(int) ;

//------------------------------ Strutture -------------------------------------
struct CpuInfo {
    string sVendorName ;     // nome del venditore
    string sBrandName ;      // brand
    int nFamily ;            // family of the processor
    int nExtModel ;          // extended model of processor
    int nModel ;             // model of processor
    int nStepping ;          // processor revision number
} ;
   
//------------------------------ Prototipi locali ------------------------------
static int ReadCpuInfo( CpuInfo& Info) ;
static bool OsSupport( int nExtra) ;
static string GetModelName( const char* szVendorName, int nFamily, int nExtModel, int nModel, int nStepping) ;
static string GetExtraString( int nExtra) ;
static int GetProcNbr( void) ;

//------------------------------------------------------------------------------
bool
GetCpuInfo( string& sCpuInfo)
{
  // verifico validità stringa di ritorno
   if ( &sCpuInfo == nullptr)
      return false ;

  // recupero informazioni sulla CPU
   CpuInfo Info ;
   int nExtra = ReadCpuInfo( Info) ;

  // costruisco stringa per estensioni
   string sExtra = GetExtraString( nExtra) ;

  // recupero il numero di processori
   int nProc = GetProcNbr() ;

   sCpuInfo = "CPU " + Info.sBrandName ;
   sCpuInfo += " - " + ToString( nProc) + " threads" ;
   sCpuInfo += " - " + sExtra ;

   return true ;
}

//------------------------------------------------------------------------------
// Ritorna nella struttura informazioni sulla CPU.
// Valore di ritorno 0 se impossibile usare CPUID, altrimenti extra abilitate.
//------------------------------------------------------------------------------
int
ReadCpuInfo( CpuInfo& Info)
{
   int CPUInfo[4] ;

  // lettura info base 0
   CPUInfo[0] = 0 ;
   __cpuid( CPUInfo, 0) ;
   unsigned Ids = CPUInfo[0] ;
   if ( Ids == 0)
      return 0 ;
   // nome del venditore
   char CPUString[VNAME_LEN+1] ;
   *((int*)CPUString) = CPUInfo[1] ;
   *((int*)(CPUString+sizeof(int))) = CPUInfo[3] ;
   *((int*)(CPUString+2*sizeof(int))) = CPUInfo[2] ;
   CPUString[VNAME_LEN] = 0 ;
   Info.sVendorName = CPUString ;

  // lettura info base 1
   __cpuid( CPUInfo, 1) ;
  // stepping, model, family, extended model
   Info.nStepping = CPUInfo[0] & 0xF ;
   Info.nModel = ( CPUInfo[0] >> 4) & 0xF ;
   Info.nFamily = ( CPUInfo[0] >> 8) & 0xF ;
   Info.nExtModel = ( CPUInfo[0] >> 16) & 0xF ;

   int nExtra = 0 ;
   if ( ( CPUInfo[3] & BIT_MMX)  &&  OsSupport( BIT_MMX))
      nExtra |= BIT_MMX ;
   if ( ( CPUInfo[3] & BIT_SSE)  &&  OsSupport( BIT_SSE))
      nExtra |= BIT_SSE ;
   if ( (CPUInfo[3] & BIT_SSE2)  &&  OsSupport( BIT_SSE2))
      nExtra |= BIT_SSE2 ;
   if ( (CPUInfo[2] & BIT_AVX))
      nExtra |= BIT_AVX ;

  // lettura info base 7
   if ( Ids >= 7) {
      __cpuid( CPUInfo, 7) ;
      if ( (CPUInfo[1] & BIT_AVX2))
         nExtra |= BIT_AVX2 ;
   }

  // lettura info estese 0
   __cpuid( CPUInfo, 0x80000000) ;
   unsigned nExIds = CPUInfo[0] ;

  // lettura info estese 1
   if ( nExIds >= 0x80000001) {
      __cpuid( CPUInfo, 0x80000001) ;
      if ( (CPUInfo[3] & BIT_3DNOW)  &&  OsSupport( BIT_3DNOW))
         nExtra |= BIT_3DNOW ;
   }

  // lettura info estese 2, 3 e 4
   if ( nExIds >= 0x80000004) {
      char CPUBrandString[4 * sizeof(CPUInfo)] ;
      memset( CPUBrandString, 0, sizeof( CPUBrandString)) ;
      __cpuid( CPUInfo, 0x80000002) ;
      memcpy( CPUBrandString, CPUInfo, sizeof(CPUInfo)) ;
      __cpuid( CPUInfo, 0x80000003) ;
      memcpy( CPUBrandString + sizeof(CPUInfo), CPUInfo, sizeof(CPUInfo));
      __cpuid( CPUInfo, 0x80000004) ;
      memcpy( CPUBrandString + 2 * sizeof(CPUInfo), CPUInfo, sizeof(CPUInfo));
      Info.sBrandName = CPUBrandString ;
      Trim( Info.sBrandName) ;
   }
   else
     // costruisco stringa per nome modello
      Info.sBrandName = GetModelName( Info.sVendorName.c_str(),
                                      Info.nFamily, 
                                      Info.nExtModel,
                                      Info.nModel,
                                      Info.nStepping) ;

   return nExtra ;
}

//------------------------------------------------------------------------------
// Verifica se il sistema operativo supporta la prestazione extra passata.
//------------------------------------------------------------------------------
bool
OsSupport( int nExtra)
{
#ifndef _WIN64
   try {
      switch ( nExtra) {
      case BIT_MMX :
         __asm {
            pxor mm0, mm0           // executing MMX instruction
            emms
         }
         break ;
      case BIT_SSE :
         __asm {
            xorps xmm0, xmm0        // executing SSE instruction
         }
         break ;
      case BIT_SSE2 :
         __asm {
            xorpd xmm0, xmm0        // executing SSE2 instruction
         }
         break ;
      case BIT_3DNOW :
         __asm {
            pfrcp mm0, mm0          // executing 3DNow! instruction
            emms
         }
         break ;
      }
   }

   //#pragma warning (suppress: 6320)

   catch ( ...) {
      return false ;
   }
#endif
   return true ;
}

//------------------------------------------------------------------------------
string
GetModelName( const char* szVendorName, int nFamily, int nExtModel, int nModel, int nStepping)
{
   string sModelName ;
  // se AMD
   if ( strncmp( "AuthenticAMD", szVendorName, VNAME_LEN) == 0)
      sModelName = "AMD " ;
  // se Intel
   else if ( strncmp( "GenuineIntel", szVendorName, VNAME_LEN) == 0)
      sModelName = "INTEL " ;
  // se Cyrix
   else if ( strncmp( "CyrixInstead", szVendorName, VNAME_LEN) == 0)
      sModelName = "Cyrix " ;
  // se Centaur
   else if ( strncmp( "CentaurHauls", szVendorName, VNAME_LEN) == 0)
      sModelName = "Centaur " ;
  // se Transmeta
   else if ( strncmp( "TransmetaCPU", szVendorName, VNAME_LEN) == 0  ||
             strncmp( "GenuineTMx86", szVendorName, VNAME_LEN) == 0)
      sModelName = "Transmeta " ;
  // se VIA
   else if ( strncmp( "VIA VIA VIA ", szVendorName, VNAME_LEN) == 0)
      sModelName = "VIA " ;
  // altrimenti
   else
      sModelName = "Unknown " ;

  // completo la stringa
   sModelName += "(F" + ToString( nFamily) ;
   sModelName += "E" + ToString( nExtModel) ;
   sModelName += "M" + ToString( nModel) ;
   sModelName += "S" + ToString( nStepping) + ")" ;

   return sModelName ;
}

//------------------------------------------------------------------------------
string
GetExtraString( int nExtra)
{
   string sExtra ;
   if ( nExtra & BIT_MMX)
      sExtra += "MMX+" ;
   if ( nExtra & BIT_SSE)
      sExtra += "SSE+" ;
   if ( nExtra & BIT_SSE2)
      sExtra += "SSE2+" ; 
   if ( nExtra & BIT_3DNOW)
      sExtra += "3DNOW!+" ;
   if ( nExtra & BIT_AVX)
      sExtra += "AVX+" ; 
   if ( nExtra & BIT_AVX2)
      sExtra += "AVX2+" ; 
   sExtra.pop_back() ;
   return sExtra ;
}

//------------------------------------------------------------------------------
int
GetProcNbr( void)
{
   SYSTEM_INFO sInfo ;
   GetSystemInfo( &sInfo) ;

   return sInfo.dwNumberOfProcessors ;
}