// with op == [token.SHL] or [token.SHR] (<< or >>). x must be
// an [Int] or an [Unknown]. If x is [Unknown], the result is x.
func Shift(x Value, op token.Token, s uint) Value {
	switch x := x.(type) {
	case unknownVal:
		return x

	case int64Val:
		if s == 0 {
			return x
		}
		switch op {
		case token.SHL:
			z := i64toi(x).val
			return makeInt(z.Lsh(z, s))

	/*11081*/ uint16(xSetOp), uint16(SHL),
	/*11083*/ uint16(xArgRM16),
	/*11084*/ uint16(xArg1),
	/*11085*/ uint16(xMatch),
	/*11086*/ uint16(xSetOp), uint16(SHL),
	/*11088*/ uint16(xArgRM32),
	/*11089*/ uint16(xArg1),
	/*11090*/ uint16(xMatch),
	/*11091*/ uint16(xCondDataSize), 11081, 11086, 11095,
	/*11095*/ uint16(xSetOp), uint16(SHL),
	/*11097*/ uint16(xArgRM64),
	/*11098*/ uint16(xArg1),

	syntax.Sub: ir.OSUB,
	syntax.Or:  ir.OOR,
	syntax.Xor: ir.OXOR,

	syntax.Mul:    ir.OMUL,
	syntax.Div:    ir.ODIV,
	syntax.Rem:    ir.OMOD,
	syntax.And:    ir.OAND,
	syntax.AndNot: ir.OANDNOT,
	syntax.Shl:    ir.OLSH,
	syntax.Shr:    ir.ORSH,
}

// error is called concurrently if files are parsed concurrently.
func (p *noder) error(err error) {
	p.err <- err.(syntax.Error)
}

		//
		//	U(k) = D⁻¹ (2 V(k+1) - P V(k))
		//
		// Since we are checking for U(k) == 0 it suffices to check 2 V(k+1) == P V(k) mod n,
		// or P V(k) - 2 V(k+1) == 0 mod n.
		t1 := t1.mul(vk, natP)
		t2 := t2.shl(vk1, 1)
		if t1.cmp(t2) < 0 {
			t1, t2 = t2, t1
		}
		t1 = t1.sub(t1, t2)
		t3 := vk1 // steal vk1, no longer needed below
		vk1 = nil
		_ = vk1
		t2, t3 = t2.div(t3, t1, n)
		if len(t3) == 0 {

	syntax.Xor: token.XOR,

	syntax.Mul:    token.MUL,
	syntax.Div:    token.QUO,
	syntax.Rem:    token.REM,
	syntax.And:    token.AND,
	syntax.AndNot: token.AND_NOT,
	syntax.Shl:    token.SHL,
	syntax.Shr:    token.SHR,

	case '<':
		s.nextch()
		if s.ch == '=' {
			s.nextch()
			s.op, s.prec = Leq, precCmp
			s.tok = _Operator
			break
		}
		if s.ch == '<' {
			s.nextch()
			s.op, s.prec = Shl, precMul
			goto assignop
		}
		if s.ch == '-' {
			s.nextch()
			s.tok = _Arrow
			break
		}
		s.op, s.prec = Lss, precCmp
		s.tok = _Operator

	case '>':
		s.nextch()

}

// This is only used for operations that may cause overflow.
var op2str2 = [...]string{
	token.ADD: "addition",
	token.SUB: "subtraction",
	token.XOR: "bitwise XOR",
	token.MUL: "multiplication",
	token.SHL: "shift",
}

// If typ is a type parameter, underIs returns the result of typ.underIs(f).
// Otherwise, underIs returns the result of f(under(typ)).
func underIs(typ Type, f func(Type) bool) bool {
	typ = Unalias(typ)

SuffixLoop:
	for i, a := range inst.Args {
		if a == nil {
			break
		}
		switch a := a.(type) {
		case Reg:
			switch inst.Op {
			case MOVSX, MOVZX:
				continue

			case SHL, SHR, RCL, RCR, ROL, ROR, SAR:
				if i == 1 {
					// shift count does not tell us operand size
					continue
				}

			case CRC32:
				// The source argument does tell us operand size,

  }

  @Test fun streamIdHasReservedBit() {
    val writer = Http2Writer(Buffer(), true)
    assertFailsWith<IllegalArgumentException> {
      var streamId = 3
      streamId = streamId or (1L shl 31).toInt() // set reserved bit
      writer.frameHeader(streamId, Http2.INITIAL_MAX_FRAME_SIZE, Http2.TYPE_DATA, FLAG_NONE)
    }.also { expected ->
      assertThat(expected.message).isEqualTo("reserved bit set: -2147483645")

		case '^':
			tok = s.switch2(token.XOR, token.XOR_ASSIGN)
		case '<':
			if s.ch == '-' {
				s.next()
				tok = token.ARROW
			} else {
				tok = s.switch4(token.LSS, token.LEQ, '<', token.SHL, token.SHL_ASSIGN)
			}
		case '>':
			tok = s.switch4(token.GTR, token.GEQ, '>', token.SHR, token.SHR_ASSIGN)
		case '=':
			tok = s.switch2(token.ASSIGN, token.EQL)
		case '!':