}
}

// TODO(gri) mulAddVWW and divWVW are symmetric operations but
// their signature is not symmetric. Try to unify.

type funWVW func(z []Word, xn Word, x []Word, y Word) (r Word)
type argWVW struct {
	z  nat
	xn Word
	x  nat
	y  Word
	r  Word
}

func testFunWVW(t *testing.T, msg string, f funWVW, a argWVW) {
	z := make(nat, len(a.z))
	r := f(z, a.xn, a.x, a.y)
	for i, zi := range z {

	FMOVD   x+0(FP), F0  // F0=x
	FSTCW   -2(SP)       // save old Control Word
	MOVW    -2(SP), AX
	ANDW    $0xf3ff, AX
	ORW     $0x0800, AX  // Rounding Control set to +Inf
	MOVW    AX, -4(SP)   // store new Control Word
	FLDCW   -4(SP)       // load new Control Word
	FRNDINT              // F0=Ceil(x)
	FLDCW   -2(SP)       // load old Control Word
	FMOVDP  F0, ret+8(FP)
	RET

// func archFloor(x float64) float64

	RET


// func shrVU(z, x []Word, s uint) (c Word)
TEXT ·shrVU(SB),NOSPLIT,$0
	MOVW	z_len+4(FP), R5
	TEQ	$0, R5
	BEQ	X6

	MOVW	z+0(FP), R1
	MOVW	x+12(FP), R2
	ADD	R5<<2, R1, R5
	MOVW	s+24(FP), R3
	TEQ	$0, R3	// shift 0 is special
	BEQ Y6
	SUB	$4, R5	// stop one word early
	MOVW	$32, R4
	SUB	R3, R4
	MOVW	$0, R7

	// first word
	MOVW.P	4(R2), R6
	MOVW	R6>>R3, R7

  }

  abstract String normalizeWord(String word);

  String normalizeFirstWord(String word) {
    return normalizeWord(word);
  }

  private static String firstCharOnlyToUpper(String word) {
    return word.isEmpty()
        ? word
        : Ascii.toUpperCase(word.charAt(0)) + Ascii.toLowerCase(word.substring(1));
  }

// z1<<_W + z0 = x*y
func mulWW(x, y Word) (z1, z0 Word) {
	hi, lo := bits.Mul(uint(x), uint(y))
	return Word(hi), Word(lo)
}

// z1<<_W + z0 = x*y + c
func mulAddWWW_g(x, y, c Word) (z1, z0 Word) {
	hi, lo := bits.Mul(uint(x), uint(y))
	var cc uint
	lo, cc = bits.Add(lo, uint(c), 0)
	return Word(hi + cc), Word(lo)
}

// nlz returns the number of leading zeros in x.

}

// Decode decodes an RFC 2047 encoded-word.
func (d *WordDecoder) Decode(word string) (string, error) {
	// See https://tools.ietf.org/html/rfc2047#section-2 for details.
	// Our decoder is permissive, we accept empty encoded-text.
	if len(word) < 8 || !strings.HasPrefix(word, "=?") || !strings.HasSuffix(word, "?=") || strings.Count(word, "?") != 4 {
		return "", errInvalidWord
	}
	word = word[2 : len(word)-2]

  }

  abstract String normalizeWord(String word);

  String normalizeFirstWord(String word) {
    return normalizeWord(word);
  }

  private static String firstCharOnlyToUpper(String word) {
    return word.isEmpty()
        ? word
        : Ascii.toUpperCase(word.charAt(0)) + Ascii.toLowerCase(word.substring(1));
  }

	SBBL (CX)(BX*4), AX
	SBBL DX, DX		// save CF
	MOVL AX, (DI)(BX*4)
	ADDL $1, BX		// i++

E2:	CMPL BX, BP		// i < n
	JL L2

	NEGL DX
	MOVL DX, c+36(FP)
	RET


// func addVW(z, x []Word, y Word) (c Word)
TEXT ·addVW(SB),NOSPLIT,$0
	MOVL z+0(FP), DI
	MOVL x+12(FP), SI
	MOVL y+24(FP), AX	// c = y
	MOVL z_len+4(FP), BP
	MOVL $0, BX		// i = 0
	JMP E3

L3:	ADDL (SI)(BX*4), AX
	MOVL AX, (DI)(BX*4)

	AXOR
	AXORCC
	AXORIS

	ADCBF
	ADCBI
	ADCBST
	ADCBT
	ADCBTST
	ADCBZ
	AEIEIO
	AICBI
	AISYNC
	APTESYNC
	ATLBIE
	ATLBIEL
	ATLBSYNC
	ATW

	ASYSCALL
	AWORD

	ARFCI

	AFCPSGN
	AFCPSGNCC
	/* optional on 32-bit */
	AFRES
	AFRESCC
	AFRIM
	AFRIMCC
	AFRIP
	AFRIPCC
	AFRIZ
	AFRIZCC
	AFRIN
	AFRINCC
	AFRSQRTE
	AFRSQRTECC

#define TLS_linux
#endif
#ifdef TLS_linux
#define MRS_TPIDR_R0 WORD $0xd53bd040 // MRS TPIDR_EL0, R0
#endif

#ifdef GOOS_darwin
#define TLS_darwin
#endif
#ifdef GOOS_ios
#define TLS_darwin
#endif
#ifdef TLS_darwin
#define TLSG_IS_VARIABLE
#define MRS_TPIDR_R0 WORD $0xd53bd060 // MRS TPIDRRO_EL0, R0
#endif

#ifdef GOOS_freebsd
#define MRS_TPIDR_R0 WORD $0xd53bd040 // MRS TPIDR_EL0, R0
#endif

#ifdef GOOS_netbsd