simd_type = loong64.LSX
	case reg >= loong64.REG_X0 && reg <= loong64.REG_X31:
		simd_type = loong64.LASX
	default:
		return errors.New("Loong64 extension: invalid LSX/LASX register: " + fmt.Sprintf("%d", reg))
	}

	if isIndex {
		arng_type, ok = loong64ElemExtMap[ext]
		if !ok {
			return errors.New("Loong64 extension: invalid LSX/LASX arrangement type: " + ext)
		}

		a.Reg = loong64.REG_ELEM