---

detect_3dnow.cpp

Go to the documentation of this file.

#include "Core/precomp.h"
#include "API/Core/System/system.h"
#include "API/Core/System/cl_assert.h"

static bool do_3dnow_test();

bool CL_System::detect_3dnow()
{
        static bool has_3dnow = false;
        static bool first_time = true;
        
        if (first_time)
        {
                first_time = false;
                has_3dnow = do_3dnow_test();
        }
        
        return has_3dnow;
}

static bool do_3dnow_test()
{
#ifdef USE_I386_ASSEMBLER
#ifdef __MSC__
        unsigned long RegEDX = 0;
        unsigned long RegEAX = 0;

        try 
        {
                _asm
                {
                        mov             eax, 0x80000000         // set up CPUID to return processor extended functions
                        CPUID                                           // code bytes = 0fh,  0a2h
                        mov             RegEAX, eax
                }

                if (!(RegEAX & 0x80000000))             // no functions > 0x80000000 ?
                        return false;                           //we don't have any extended features, quit
                else
                        _asm
                        {
                                mov     eax, 0x80000001         // CPUID ext. function 0x80000001
                                CPUID                       // EDX contains extended feature flags
                                mov             RegEDX, edx                     // extended features returned in edx
                        }

        }
        catch(...)                                      // catch everything
        {
                return false;
        }

        if (RegEDX & 0x80000000)        // bit 31 indicates presence of 3DNow! technology
        {
                try
                {
                        //DB 0Fh, 0Eh                   // try executing the 3DNow! instruction "femms"
                        _asm _emit 0x0f;
                        _asm _emit 0x0e;
                }
                catch(...) { return false; }
        }
        else
                return false;

        return true;
#elif __BORLANDC__

//This is for detecting assembly when using the Borland compilers
//If you do not have TASM then this will not compile
//If you do have TASM then uncomment the code below, otherwise ignore it

        #ifdef USE_TASM
        int RegEDX=0,RegEAX=0;
  try
  {
        asm
    {
        mov             eax, 0x80000000         // set up CPUID to return processor extended functions
        CPUID                                           // code bytes = 0fh,  0a2h
        mov             RegEAX, eax
    }
  }
  catch(...) { return false; }

  if(RegEAX > 0x80000000)
  {
        asm
    {
                        mov     eax, 0x80000001         // CPUID ext. function 0x80000001
        CPUID                       // EDX contains extended feature flags
        mov             RegEDX, edx                     // extended features returned in edx
    }
  }
  else
        return false;

  if( RegEDX & 0x80000000)
  {
        try
                {
                        //DB 0Fh, 0Eh                   // try executing the 3DNow! instruction "femms"
      __emit__(0x0f,0x0e);
                }
                catch(...) { return false; }
  }
  return true;
  #else

        std::cout<<"3DNow not supported by this version of library.  Please check source(detect_3dnow.cpp)."<<std::endl;
  return false;
        #endif
#elif __GNUC__

        unsigned int RegEDX=0,RegEAX=0;
        try
        {
                asm(
                "mov 0x80000000, %%eax \n" //Get ready for extended functions
                "CPUID \n" //Access CPUID
                : "=a"(RegEAX));
        }
        catch(...) 
        {
                return false;
        }
        if(RegEDX > 0x80000000) 
        {
                asm(
                                "mov 0x80000001, %%eax \n" //Access extended features
                                "CPUID \n"  //Query CPU
                                : "=d"(RegEDX));
        }
        else 
        {
                return false;
        }

        if(!(RegEDX & 0x80000000))
        {
                return false;
        }
        try
        {
                asm("femms");
        }
        catch(...)
        {
                return false;
        }
        return true;

#endif
#else
        static bool warning = true;
        if (warning)
        {
                cl_info(0, "CL_System::detect_3dnow() not implemented under unix yet.");
                warning = false;
        }
        return false;
#endif //Endif USE_I386_ASSEMBLER
}

---