ほれ
struct vector{
union{__m128 vect;struct{float x,y,z,w;};};
vector(){}
vector(float x,float y,float z,float w)
{vect = _mm_set_ps(w,z,y,x);}
inline vector& operator=(const vector& v)
{vect = v.vect;return *this;}
inline vector operator*(const vector& v) const
{vector result;result.vect = _mm_mul_ps(vect,v.vect); return result;}};