__asm __volatile("pxor %%mm7, %%mm7":::"memory");
__asm __volatile("pxor %%mm7, %%mm7":);
static void get_pixels_mmx(DCTELEM *block, const UINT8 *pixels, int line_size){    DCTELEM *p;    const UINT8 *pix;    int i;    /* read the pixels */    p = block;    pix = pixels;    __asm __volatile("pxor %%mm7, %%mm7":::"memory");    for(i=0;i<4;i++) {	__asm __volatile(		"movq	%1, %%mm0\n\t"		"movq	%2, %%mm1\n\t"		"movq	%%mm0, %%mm2\n\t"		"movq	%%mm1, %%mm3\n\t"		"punpcklbw %%mm7, %%mm0\n\t"		"punpckhbw %%mm7, %%mm2\n\t"		"punpcklbw %%mm7, %%mm1\n\t"		"punpckhbw %%mm7, %%mm3\n\t"		"movq	%%mm0, %0\n\t"		"movq	%%mm2, 8%0\n\t"		"movq	%%mm1, 16%0\n\t"		"movq	%%mm3, 24%0\n\t"		:"=m"(*p)		:"m"(*pix), "m"(*(pix+line_size))		:"memory");        pix += line_size*2;        p += 16;    }}