//go:linkname addVW
//go:noescape
func addVW(z, x []Word, y Word) (c Word)

// subVW should be an internal detail,
// but widely used packages access it using linkname.
// Notable members of the hall of shame include:
//   - github.com/remyoudompheng/bigfft
//
// Do not remove or change the type signature.
// See go.dev/issue/67401.
//
//go:linkname subVW
//go:noescape
func subVW(z, x []Word, y Word) (c Word)

}

// 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)

#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

TEXT ·useVFPv1(SB),NOSPLIT,$0
	WORD $0xeeb00b40	// vmov.f64 d0, d0
	RET

// try to run VFPv3-only "vmov.f64 d0, #112" instruction
TEXT ·useVFPv3(SB),NOSPLIT,$0
	WORD $0xeeb70b00	// vmov.f64 d0, #112
	RET

// try to run ARMv6K (or above) "ldrexd" instruction
TEXT ·useARMv6K(SB),NOSPLIT,$32
	MOVW R13, R2
	BIC  $15, R13
	WORD $0xe1bd0f9f	// ldrexd r0, r1, [sp]
	WORD $0xf57ff01f	// clrex
	MOVW R2, R13

	XC   $32, (R1), (R1) // clear 4 doublewords (32 bytes)
	WORD $0xb2b01000     // store facility list extended (STFLE)
	RET

// func kmQuery() queryResult
TEXT ·kmQuery(SB), NOSPLIT|NOFRAME, $0-16
	MOVD $0, R0         // set function code to 0 (KM-Query)
	MOVD $ret+0(FP), R1 // address of 16-byte return value
	WORD $0xB92E0024    // cipher message (KM)
	RET

// func kmcQuery() queryResult

TEXT ·getisar0(SB),NOSPLIT,$0-8
	// get Instruction Set Attributes 0 into x0
	// mrs x0, ID_AA64ISAR0_EL1 = d5380600
	WORD	$0xd5380600
	MOVD	R0, ret+0(FP)
	RET

// func getisar1() uint64
TEXT ·getisar1(SB),NOSPLIT,$0-8
	// get Instruction Set Attributes 1 into x0
	// mrs x0, ID_AA64ISAR1_EL1 = d5380620
	WORD	$0xd5380620
	MOVD	R0, ret+0(FP)
	RET

// func getpfr0() uint64
TEXT ·getpfr0(SB),NOSPLIT,$0-8

TEXT    ·atanhAsm(SB), NOSPLIT, $0-16
	FMOVD   x+0(FP), F0
	MOVD    $·atanhrodataL10<>+0(SB), R5
	LGDR    F0, R1
	WORD    $0xC0393FEF //iilf  %r3,1072693247
	BYTE    $0xFF
	BYTE    $0xFF
	SRAD    $32, R1
	WORD    $0xB9170021 //llgtr %r2,%r1
	MOVW    R2, R6
	MOVW    R3, R7
	CMPBGT  R6, R7, L2
	WORD    $0xC0392FFF //iilf  %r3,805306367
	BYTE    $0xFF
	BYTE    $0xFF
	MOVW    R2, R6
	MOVW    R3, R7
	CMPBGT  R6, R7, L9

	FMOVD	x+0(FP), F0
	MOVD	$·asinhrodataL18<>+0(SB), R9
	LGDR	F0, R12
	WORD	$0xC0293FDF	//iilf	%r2,1071644671
	BYTE	$0xFF
	BYTE	$0xFF
	SRAD	$32, R12
	WORD	$0xB917001C	//llgtr	%r1,%r12
	MOVW	R1, R6
	MOVW	R2, R7
	CMPBLE	R6, R7, L2
	WORD	$0xC0295FEF	//iilf	%r2,1609564159
	BYTE	$0xFF
	BYTE	$0xFF
	MOVW	R2, R7
	CMPBLE	R6, R7, L14
L3:
	WORD	$0xC0297FEF	//iilf	%r2,2146435071
	BYTE	$0xFF
	BYTE	$0xFF
	CMPW	R1, R2