return fmt.Sprintf("Cond%d%s", int((c-Cond0LT)/4), [4]string{"LT", "GT", "EQ", "SO"}[(c-Cond0LT)%4])
	}
}

// SpReg is a special register, its meaning depends on Op.
type SpReg uint16

const (
	SpRegZero SpReg = 0
)

func (SpReg) IsArg() {}
func (s SpReg) String() string {
	return fmt.Sprintf("SpReg(%d)", int(s))
}

// PCRel is a PC-relative offset, used only in branch instructions.
type PCRel int32

	case TypeVecSReg:
		return VS0 + Reg(a.BitFields.Parse(i))
	case TypeVecSpReg:
		return VS0 + Reg(a.BitFields.Parse(i))*2
	case TypeMMAReg:
		return A0 + Reg(a.BitFields.Parse(i))
	case TypeSpReg:
		return SpReg(a.BitFields.Parse(i))
	case TypeImmSigned:
		return Imm(a.BitFields.ParseSigned(i) << a.Shift)
	case TypeImmUnsigned:
		return Imm(a.BitFields.Parse(i) << a.Shift)
	case TypePCRel: