case IMM1_8BY4:
imm = ((nibs[2] << 4) | nibs[3]) << 2;
goto ok;
+ case REG_N_D:
+ if ((nibs[n] & 1) != 0)
+ goto fail;
+ /* fall through */
case REG_N:
rn = nibs[n];
break;
case REG_M:
rm = nibs[n];
break;
+ case REG_N_B01:
+ if ((nibs[n] & 0x3) != 1 /* binary 01 */)
+ goto fail;
+ rn = (nibs[n] & 0xc) >> 2;
+ break;
case REG_NM:
rn = (nibs[n] & 0xc) >> 2;
rm = (nibs[n] & 0x3);