unquant_even:
static void dct_unquantize_mpeg1_mmx(MpegEncContext *s,                                     DCTELEM *block, int n, int qscale){    int i, level, nCoeffs;    const UINT16 *quant_matrix;        if(s->alternate_scan) nCoeffs= 64;    else nCoeffs= nCoeffs= zigzag_end[ s->block_last_index[n] ];    if (s->mb_intra) {        if (n < 4)             block[0] = block[0] * s->y_dc_scale;        else            block[0] = block[0] * s->c_dc_scale;        /* isnt used anymore (we have a h263 unquantizer since some time)	if (s->out_format == FMT_H263) {            i = 1;            goto unquant_even;        }*/        /* XXX: only mpeg1 */        quant_matrix = s->intra_matrix;	i=1;	/* Align on 4 elements boundary */	while(i&3)	{            level = block[i];            if (level) {                if (level < 0) level = -level;                    level = (int)(level * qscale * quant_matrix[i]) >> 3;                    level = (level - 1) | 1;                if (block[i] < 0) level = -level;                block[i] = level;            }	    i++;	}	__asm __volatile(	"movd	%0, %%mm6\n\t"       /* mm6 = qscale | 0  */	"punpckldq %%mm6, %%mm6\n\t" /* mm6 = qscale | qscale */	"movq	%2, %%mm4\n\t"	"movq	%%mm6, %%mm7\n\t"	"movq	%1, %%mm5\n\t"	"packssdw %%mm6, %%mm7\n\t" /* mm7 = qscale | qscale | qscale | qscale */	"pxor	%%mm6, %%mm6\n\t"	::"g"(qscale),"m"(mm_wone),"m"(mm_wabs):"memory");        for(;i<nCoeffs;i+=4) {		__asm __volatile(			"movq	%1, %%mm0\n\t"			"movq	%%mm7, %%mm1\n\t"			"movq	%%mm0, %%mm2\n\t"			"movq	%%mm0, %%mm3\n\t"			"pcmpgtw %%mm6, %%mm2\n\t"			"pmullw	%2, %%mm1\n\t"			"pandn	%%mm4, %%mm2\n\t"			"por	%%mm5, %%mm2\n\t"			"pmullw	%%mm2, %%mm0\n\t" /* mm0 = abs(block[i]). */			"pcmpeqw %%mm6, %%mm3\n\t"			"pmullw	%%mm0, %%mm1\n\t"			"psraw	$3, %%mm1\n\t"			"psubw	%%mm5, %%mm1\n\t"   /* block[i] --; */			"pandn	%%mm4, %%mm3\n\t"  /* fake of pcmpneqw : mm0 != 0 then mm1 = -1 */			"por	%%mm5, %%mm1\n\t"   /* block[i] |= 1 */			"pmullw %%mm2, %%mm1\n\t"   /* change signs again */			"pand	%%mm3, %%mm1\n\t" /* nullify if was zero */			"movq	%%mm1, %0"			:"=m"(block[i])			:"m"(block[i]), "m"(quant_matrix[i])			:"memory");        }    } else {        i = 0;    unquant_even:        quant_matrix = s->non_intra_matrix;	/* Align on 4 elements boundary */	while(i&7)	{	    level = block[i];            if (level) {                if (level < 0) level = -level;                    level = (((level << 1) + 1) * qscale *                             ((int) quant_matrix[i])) >> 4;                    level = (level - 1) | 1;                if(block[i] < 0) level = -level;                block[i] = level;	    }	    i++;	}asm volatile(		"pcmpeqw %%mm7, %%mm7		\n\t"		"psrlw $15, %%mm7		\n\t"		"movd %2, %%mm6			\n\t"		"packssdw %%mm6, %%mm6		\n\t"		"packssdw %%mm6, %%mm6		\n\t"		".balign 16\n\t"		"1:				\n\t"		"movq (%0, %3), %%mm0		\n\t"		"movq 8(%0, %3), %%mm1		\n\t"		"movq (%1, %3), %%mm4		\n\t"		"movq 8(%1, %3), %%mm5		\n\t"		"pmullw %%mm6, %%mm4		\n\t" // q=qscale*quant_matrix[i]		"pmullw %%mm6, %%mm5		\n\t" // q=qscale*quant_matrix[i]		"pxor %%mm2, %%mm2		\n\t"		"pxor %%mm3, %%mm3		\n\t"		"pcmpgtw %%mm0, %%mm2		\n\t" // block[i] < 0 ? -1 : 0		"pcmpgtw %%mm1, %%mm3		\n\t" // block[i] < 0 ? -1 : 0		"pxor %%mm2, %%mm0		\n\t"		"pxor %%mm3, %%mm1		\n\t"		"psubw %%mm2, %%mm0		\n\t" // abs(block[i])		"psubw %%mm3, %%mm1		\n\t" // abs(block[i])		"paddw %%mm0, %%mm0		\n\t" // abs(block[i])*2		"paddw %%mm1, %%mm1		\n\t" // abs(block[i])*2		"paddw %%mm7, %%mm0		\n\t" // abs(block[i])*2 + 1		"paddw %%mm7, %%mm1		\n\t" // abs(block[i])*2 + 1		"pmullw %%mm4, %%mm0		\n\t" // (abs(block[i])*2 + 1)*q		"pmullw %%mm5, %%mm1		\n\t" // (abs(block[i])*2 + 1)*q		"pxor %%mm4, %%mm4		\n\t"		"pxor %%mm5, %%mm5		\n\t" // FIXME slow		"pcmpeqw (%0, %3), %%mm4	\n\t" // block[i] == 0 ? -1 : 0		"pcmpeqw 8(%0, %3), %%mm5	\n\t" // block[i] == 0 ? -1 : 0		"psraw $4, %%mm0		\n\t"		"psraw $4, %%mm1		\n\t"		"psubw %%mm7, %%mm0		\n\t"		"psubw %%mm7, %%mm1		\n\t"		"por %%mm7, %%mm0		\n\t"		"por %%mm7, %%mm1		\n\t"		"pxor %%mm2, %%mm0		\n\t"		"pxor %%mm3, %%mm1		\n\t"		"psubw %%mm2, %%mm0		\n\t"		"psubw %%mm3, %%mm1		\n\t"		"pandn %%mm0, %%mm4		\n\t"		"pandn %%mm1, %%mm5		\n\t"		"movq %%mm4, (%0, %3)		\n\t"		"movq %%mm5, 8(%0, %3)		\n\t"		"addl $16, %3			\n\t"		"js 1b				\n\t"		::"r" (block+nCoeffs), "r"(quant_matrix+nCoeffs), "g" (qscale), "r" (2*(i-nCoeffs))		: "memory"	);    }}