#include <stdio.h>
#include <mmintrin.h>

#define AS_WORDS "%4.4x %4.4x %4.4x %4.4x"

__m64   a;
__m64   b = { 0x0004000300020001 };
__m64   c = { 0xff7fff800080007f };

void main()
  {
    a = _m_punpckhwd( b, c );
    printf( "m2="AS_WORDS" "
            "m1="AS_WORDS"\n"
            "mm="AS_WORDS"\n",
        c._16[3], c._16[2], c._16[1], c._16[0],
        b._16[3], b._16[2], b._16[1], b._16[0],
        a._16[3], a._16[2], a._16[1], a._16[0] );
  }