insn_scd
[insn_scd] = {0, 0},
[insn_scd] = {M(scd_op, 0, 0, 0, 0, 0), RS | RT | SIMM},
[insn_scd] = {M6(spec3_op, 0, 0, 0, scd6_op), RS | RT | SIMM9},