DIF_OP_OR
dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_OR);
dt_cg_arithmetic_op(dnp, dlp, drp, DIF_OP_OR);
instr = DIF_INSTR_FMT(DIF_OP_OR, r1, r2, r1);
case DIF_OP_OR:
case DIF_OP_OR:
case DIF_OP_OR: