rno = uint16(r)
		} else {
			rno = uint16(inst.Args[0].(RegSP))
		}
		if rno <= uint16(WZR) {
			op = "MOVWU" + suffix
		} else if rno >= uint16(B0) && rno <= uint16(B31) {
			op = "FMOVB" + suffix
			args[0] = fmt.Sprintf("F%d", rno&31)
		} else if rno >= uint16(H0) && rno <= uint16(H31) {
			op = "FMOVH" + suffix
			args[0] = fmt.Sprintf("F%d", rno&31)

	"FDIVRL",
	"FDIVRW",
	"FDIVW",
	"FFREE",
	"FINCSTP",
	"FINIT",
	"FLD1",
	"FLDCW",
	"FLDENV",
	"FLDL2E",
	"FLDL2T",
	"FLDLG2",
	"FLDLN2",
	"FLDPI",
	"FLDZ",
	"FMOVB",
	"FMOVBP",
	"FMOVD",
	"FMOVDP",
	"FMOVF",
	"FMOVFP",
	"FMOVL",
	"FMOVLP",
	"FMOVV",
	"FMOVVP",
	"FMOVW",
	"FMOVWP",
	"FMOVX",
	"FMOVXP",
	"FMULD",
	"FMULDP",

		return roff(rm, 1, num)
	case REG_UXTW <= r && r < REG_UXTX:
		if a.Type == obj.TYPE_MEM {
			if num == 0 {
				// According to the arm64 specification, for instructions MOVB, MOVBU and FMOVB,
				// the extension amount must be 0, encoded in "S" as 0 if omitted, or as 1 if present.
				// But in Go, we don't distinguish between Rn.UXTW and Rn.UXTW<<0, so we encode it as