i==20-21 r=0-1 l=2 ;r=i& %00001
i==22 r=0 l=3 ;r=i& %00000
l=lut_l[i/2]={0,0,0,0,0,0,0,0,1,1,2,3}[i>>1];// 11 10'01 01'00 00'00 00'00 00'00 00 => 0xE50000
i==20-21 r=0-1 l=2 ;r=i& %00001
i==22 r=0 l=3 ;r=i& %00000
l=lut_l[i/2]={0,0,0,0,0,0,0,0,1,1,2,3}[i>>1];// 11 10'01 01'00 00'00 00'00 00'00 00 => 0xE50000