MOVZW $(20<<16), R8     <=>      movz w8, #20, lsl #16
	MOVK $(0<<16), R10 will be reported as an error by the assembler.

Special Cases.

(1) umov is written as VMOV.

(2) br is renamed JMP, blr is renamed CALL.

(3) No need to add "W" suffix: LDARB, LDARH, LDAXRB, LDAXRH, LDTRH, LDXRB, LDXRH.

(4) In Go assembly syntax, NOP is a zero-width pseudo-instruction serves generic purpose, nothing

	"ADDMEV",
	"ADDE",
	"ADDECC",
	"ADDEVCC",
	"ADDEV",
	"ADDZE",
	"ADDZECC",
	"ADDZEVCC",
	"ADDZEV",
	"ADDEX",
	"AND",
	"ANDCC",
	"ANDN",
	"ANDNCC",
	"ANDISCC",
	"BC",
	"BCL",
	"BEQ",
	"BGE",
	"BGT",
	"BLE",
	"BLT",
	"BNE",
	"BVC",
	"BVS",
	"BDNZ",
	"BDZ",
	"CMP",
	"CMPU",
	"CMPEQB",
	"CNTLZW",
	"CNTLZWCC",
	"CRAND",
	"CRANDN",
	"CREQV",

	"CLFDBR",
	"CLGEBR",
	"CLGDBR",
	"CMP",
	"CMPU",
	"CMPW",
	"CMPWU",
	"TMHH",
	"TMHL",
	"TMLH",
	"TMLL",
	"IPM",
	"SPM",
	"CS",
	"CSG",
	"SYNC",
	"BC",
	"BCL",
	"BRC",
	"BEQ",
	"BGE",
	"BGT",
	"BLE",
	"BLT",
	"BLEU",
	"BLTU",
	"BNE",
	"BVC",
	"BVS",
	"SYSCALL",
	"BRCT",
	"BRCTG",
	"CRJ",
	"CGRJ",
	"CLRJ",

	AMINU
	ASEXTB
	ASEXTH
	AZEXTH

	// 1.3: Bitwise Rotation (Zbb)
	AROL
	AROLW
	AROR
	ARORI
	ARORIW
	ARORW
	AORCB
	AREV8

	// 1.5: Single-bit Instructions (Zbs)
	ABCLR
	ABCLRI
	ABEXT
	ABEXTI
	ABINV
	ABINVI
	ABSET
	ABSETI

	// The escape hatch. Inserts a single 32-bit word.
	AWORD

		return &inst{0x33, 0x7, 0x0, 0, 0x0}
	case AANDI:
		return &inst{0x13, 0x7, 0x0, 0, 0x0}
	case AANDN:
		return &inst{0x33, 0x7, 0x0, 1024, 0x20}
	case AAUIPC:
		return &inst{0x17, 0x0, 0x0, 0, 0x0}
	case ABCLR:
		return &inst{0x33, 0x1, 0x0, 1152, 0x24}
	case ABCLRI:
		return &inst{0x13, 0x1, 0x0, 1152, 0x24}
	case ABEQ:
		return &inst{0x63, 0x0, 0x0, 0, 0x0}
	case ABEXT:
		return &inst{0x33, 0x5, 0x0, 1152, 0x24}

		}
	}
	var e ValueError
	fmt.Fprint(bytes.NewBuffer([]byte(e.v[:])), n)
	return 0, e
}

// normRegion returns a region if r is deprecated or 0 otherwise.
// TODO: consider supporting BYS (-> BLR), CSK (-> 200 or CZ), PHI (-> PHL) and AFI (-> DJ).
// TODO: consider mapping split up regions to new most populous one (like CLDR).
func normRegion(r Region) Region {
	m := regionOldMap

				// no suffix
			case AddrPreIndex:
				suffix = ".W"
			case AddrPostIndex:
				suffix = ".P"
			}
		}
	}

	switch inst.Op {
	case BL:
		return "CALL " + args[0]

	case BLR:
		r := inst.Args[0].(Reg)
		regno := uint16(r) & 31
		return fmt.Sprintf("CALL (R%d)", regno)

	case RET:
		if r, ok := inst.Args[0].(Reg); ok && r == X30 {
			return "RET"
		}

	case B:

		$2 ~ /^O?XTABS$/ ||
		$2 ~ /^TC[IO](ON|OFF)$/ ||
		$2 ~ /^IN_/ ||
		$2 ~ /^KCM/ ||
		$2 ~ /^LANDLOCK_/ ||
		$2 ~ /^LOCK_(SH|EX|NB|UN)$/ ||
		$2 ~ /^LO_(KEY|NAME)_SIZE$/ ||
		$2 ~ /^LOOP_(CLR|CTL|GET|SET)_/ ||
		$2 == "LOOP_CONFIGURE" ||
		$2 ~ /^(AF|SOCK|SO|SOL|IPPROTO|IP|IPV6|TCP|MCAST|EVFILT|NOTE|SHUT|PROT|MAP|MREMAP|MFD|T?PACKET|MSG|SCM|MCL|DT|MADV|PR|LOCAL|TCPOPT|UDP)_/ ||

			AREM, AREMU, AREMW, AREMUW,
			AADDUW, ASH1ADD, ASH1ADDUW, ASH2ADD, ASH2ADDUW, ASH3ADD, ASH3ADDUW, ASLLIUW,
			AANDN, AORN, AXNOR, AMAX, AMAXU, AMIN, AMINU, AROL, AROLW, AROR, ARORW, ARORI, ARORIW,
			ABCLR, ABCLRI, ABEXT, ABEXTI, ABINV, ABINVI, ABSET, ABSETI:
			p.Reg = p.To.Reg
		}
	}

	// Rewrite instructions with constant operands to refer to the immediate
	// form of the instruction.

func (r *rewriter) ifNext(op syntax.Operator, c int, zeroNext bool, thens ...syntax.Stmt) syntax.Stmt {
	var thenList []syntax.Stmt
	if zeroNext {
		clr := &syntax.AssignStmt{
			Lhs: r.next(),
			Rhs: r.intConst(0),
		}
		thenList = append(thenList, clr)
	}
	for _, then := range thens {
		thenList = append(thenList, then)
	}
	nif := &syntax.IfStmt{
		Cond: r.cond(op, r.next(), r.intConst(c)),