bits := int32(8 * n.Type().Size())

	if ir.IsSmallIntConst(n) {
		v := ir.Int64Val(n)
		return 0 <= v && v < max
	}

	switch n.Op() {
	case ir.OAND, ir.OANDNOT:
		n := n.(*ir.BinaryExpr)
		v := int64(-1)
		switch {
		case ir.IsSmallIntConst(n.X):
			v = ir.Int64Val(n.X)
		case ir.IsSmallIntConst(n.Y):
			v = ir.Int64Val(n.Y)
			if n.Op() == ir.OANDNOT {
				v = ^v
				if !sign {

		return
	}

	v := pass.TypesInfo.Types[y].Value
	if v == nil {
		return
	}
	u := constant.ToInt(v) // either an Int or Unknown
	amt, ok := constant.Int64Val(u)
	if !ok {
		return
	}
	t := pass.TypesInfo.Types[x].Type
	if t == nil {
		return
	}
	var structuralTypes []types.Type
	switch t := aliases.Unalias(t).(type) {
	case *types.TypeParam:

		return s
	}

	switch {
	case isInteger(typ):
		x := constant.ToInt(x)
		if x.Kind() != constant.Int {
			return false
		}
		if rounded != nil {
			*rounded = x
		}
		if x, ok := constant.Int64Val(x); ok {
			switch typ.kind {
			case Int:
				var s = uint(sizeof(typ)) * 8
				return int64(-1)<<(s-1) <= x && x <= int64(1)<<(s-1)-1
			case Int8:
				const s = 8
				return -1<<(s-1) <= x && x <= 1<<(s-1)-1

		return s
	}

	switch {
	case isInteger(typ):
		x := constant.ToInt(x)
		if x.Kind() != constant.Int {
			return false
		}
		if rounded != nil {
			*rounded = x
		}
		if x, ok := constant.Int64Val(x); ok {
			switch typ.kind {
			case Int:
				var s = uint(sizeof(typ)) * 8
				return int64(-1)<<(s-1) <= x && x <= int64(1)<<(s-1)-1
			case Int8:
				const s = 8
				return -1<<(s-1) <= x && x <= 1<<(s-1)-1

	n.Cap = DefaultLit(Expr(n.Cap), types.Types[types.TINT])

	if ir.IsConst(n.Len, constant.Int) && ir.Int64Val(n.Len) < 0 {
		base.Fatalf("len for OSLICEHEADER must be non-negative")
	}

	if ir.IsConst(n.Cap, constant.Int) && ir.Int64Val(n.Cap) < 0 {
		base.Fatalf("cap for OSLICEHEADER must be non-negative")
	}

		return
	}

	if x.mode != constant_ {
		return x.typ, -1
	}

	if x.val.Kind() == constant.Unknown {
		return
	}

	v, ok := constant.Int64Val(x.val)
	assert(ok)
	if max >= 0 && v >= max {
		check.errorf(&x, InvalidIndex, invalidArg+"index %s out of bounds [0:%d]", x.val.String(), max)
		return
	}

	// 0 <= v [ && v < max ]
	return x.typ, v

		}
		return -1
	}

	if isUntyped(x.typ) || isInteger(x.typ) {
		if val := constant.ToInt(x.val); val.Kind() == constant.Int {
			if representableConst(val, check, Typ[Int], nil) {
				if n, ok := constant.Int64Val(val); ok && n >= 0 {
					return n
				}
			}
		}
	}

	var msg string
	if isInteger(x.typ) {
		msg = "invalid array length %s"
	} else {
		msg = "array length %s must be integer"
	}

		}
		return -1
	}

	if isUntyped(x.typ) || isInteger(x.typ) {
		if val := constant.ToInt(x.val); val.Kind() == constant.Int {
			if representableConst(val, check, Typ[Int], nil) {
				if n, ok := constant.Int64Val(val); ok && n >= 0 {
					return n
				}
			}
		}
	}

	var msg string
	if isInteger(x.typ) {
		msg = "invalid array length %s"
	} else {
		msg = "array length %s must be integer"
	}

	// and string values, so only create Go values for these
	// types.
	switch val.Kind() {
	case constant.Int:
		if x, ok := constant.Int64Val(val); ok {
			return x
		}
		if x, ok := constant.Uint64Val(val); ok {
			return x
		}
	case constant.Float:
		if x, ok := constant.Float64Val(val); ok {
			return x
		}
	case constant.String:
		return constant.StringVal(val)

	// and string values, so only create Go values for these
	// types.
	switch val.Kind() {
	case constant.Int:
		if x, ok := constant.Int64Val(val); ok {
			return x
		}
		if x, ok := constant.Uint64Val(val); ok {
			return x
		}
	case constant.Float:
		if x, ok := constant.Float64Val(val); ok {
			return x
		}
	case constant.String:
		return constant.StringVal(val)