yadda yadda yadda
maskshift:
	.option	O2
	.frame	$sp, 0, $31
	.loc	2 16
 #  16		j |= j>>1;
	sra	$14, $4, 1
	or	$4, $4, $14
	.loc	2 17
 #  17		j |= j>>2;
	sra	$15, $4, 2
	or	$4, $4, $15
	.loc	2 18
 #  18		j |= j>>4;
	sra	$24, $4, 4
	or	$4, $4, $24
	.loc	2 19
 #  19		j |= j>>8;
	sra	$25, $4, 8
	or	$4, $4, $25
	.loc	2 20
 #  20		j |= j>>16;
	sra	$8, $4, 16
	or	$4, $4, $8
	.loc	2 21
 #  21		return j;
	move	$2, $4
yadda yadda yadda