class CTimer

{

public:

       __forceinline CTimer( void )

       {

              QueryPerformanceFrequency( &m_Frequency );

              QueryPerformanceCounter( &m_StartCount );

       }

       __forceinline void Reset( void )

       {

              QueryPerformanceCounter( &m_StartCount );

       }

       __forceinline double End( void )

       {

              static __int64 nCurCount;

              QueryPerformanceCounter( (PLARGE_INTEGER)&nCurCount );

              return double( nCurCount * ( *(__int64*)&m_StartCount ) ) / double( *(__int64*)&m_Frequency );

       }

private:

       LARGE_INTEGER m_Frequency;

       LARGE_INTEGER m_StartCount;

};

void ScaleValue1( float *pArray, DWORD dwCount, float fScale )

{

      DWORD dwGroupCount = dwCount / 4;

       __m128 e_Scale = _mm_set_ps1( fScale );

       for ( DWORD i = 0; i < dwGroupCount; i++ )

       {

              *(__m128*)( pArray + i * 4 ) = _mm_mul_ps( *(__m128*)( pArray + i * 4 ), e_Scale );

       }

}

void ScaleValue2( float *pArray, DWORD dwCount, float fScale )

{

       for ( DWORD i = 0; i < dwCount; i++ )

       {

              pArray[i] *= fScale;

       }

}

#define ARRAYCOUNT 10000

int __cdecl main()

{

       float __declspec(align(16)) Array[ARRAYCOUNT];

       memset( Array, 0, sizeof(float) * ARRAYCOUNT );

       CTimer t;

       double dTime;

       t.Reset();

     for ( int i = 0; i < 100000; i++ )

       {

              ScaleValue1( Array, ARRAYCOUNT, 1000.0f );

       }

       dTime = t.End();

       cout << "Use SSE：" << dTime << "秒" << endl;

       t.Reset();

       for ( int i = 0; i < 100000; i++ )

       {

              ScaleValue2( Array, ARRAYCOUNT, 1000.0f );

       }

       dTime = t.End();

       cout << "Not Use SSE：" << dTime << "秒" << endl;

       system( "pause" );

       return 0;

}

Use SSE：0.997817

Not Use SSE：2.84963