n.Y = walkExpr(n.Y, init)
		return n

	case ir.OUNSAFESLICE:
		n := n.(*ir.BinaryExpr)
		return walkUnsafeSlice(n, init)

	case ir.OUNSAFESTRING:
		n := n.(*ir.BinaryExpr)
		return walkUnsafeString(n, init)

	case ir.OUNSAFESTRINGDATA, ir.OUNSAFESLICEDATA:
		n := n.(*ir.UnaryExpr)
		return walkUnsafeData(n, init)

	case ir.ODOT, ir.ODOTPTR:
		n := n.(*ir.SelectorExpr)
		return walkDot(n, init)

		typecheck.Conv(len, types.Types[types.TINT]))
	return walkExpr(typecheck.Expr(h), init)
}

var math_MulUintptr = &types.Sym{Pkg: types.NewPkg("runtime/internal/math", "math"), Name: "MulUintptr"}

func walkUnsafeString(n *ir.BinaryExpr, init *ir.Nodes) ir.Node {
	ptr := safeExpr(n.X, init)
	len := safeExpr(n.Y, init)

	lenType := types.Types[types.TINT64]
	unsafePtr := typecheck.Conv(ptr, types.Types[types.TUNSAFEPTR])