case unknownVal:
		return 0, false
	default:
		panic(fmt.Sprintf("%v not an Int", x))
	}
}

// Uint64Val returns the Go uint64 value of x and whether the result is exact;
// x must be an [Int] or an [Unknown]. If the result is not exact, its value is undefined.
// If x is [Unknown], the result is (0, false).
func Uint64Val(x Value) (uint64, bool) {
	switch x := x.(type) {
	case int64Val:

func ConstOverflow(v constant.Value, t *types.Type) bool {
	switch {
	case t.IsInteger():
		bits := uint(8 * t.Size())
		if t.IsUnsigned() {
			x, ok := constant.Uint64Val(v)
			return !ok || x>>bits != 0
		}
		x, ok := constant.Int64Val(v)
		if x < 0 {
			x = ^x
		}
		return !ok || x>>(bits-1) != 0
	case t.IsFloat():
		switch t.Size() {
		case 4:
			f, _ := constant.Float32Val(v)

	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:

	{"22\n", &int8Val, int8(22)},
	{"23\n", &int16Val, int16(23)},
	{"24\n", &int32Val, int32(24)},
	{"25\n", &int64Val, int64(25)},
	{"127\n", &int8Val, int8(127)},
	{"-21\n", &intVal, -21},
	{"-22\n", &int8Val, int8(-22)},
	{"-23\n", &int16Val, int16(-23)},
	{"-24\n", &int32Val, int32(-24)},
	{"-25\n", &int64Val, int64(-25)},
	{"-128\n", &int8Val, int8(-128)},
	{"+21\n", &intVal, +21},
	{"+22\n", &int8Val, int8(+22)},

		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
	}

	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