n.Rhs = []ir.Node{r}
		return n
	}
	init.Append(r)

	ll := ascompatet(n.Lhs, r.Type())
	return ir.NewBlockStmt(src.NoXPos, ll)
}

// walkAssignList walks an OAS2 node.
func walkAssignList(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
	init.Append(ir.TakeInit(n)...)
	return ir.NewBlockStmt(src.NoXPos, ascompatee(ir.OAS, n.Lhs, n.Rhs))
}

	case ir.OCFUNC:
		return n

	case ir.OCALLINTER, ir.OCALLFUNC:
		n := n.(*ir.CallExpr)
		return walkCall(n, init)

	case ir.OAS, ir.OASOP:
		return walkAssign(init, n)

	case ir.OAS2:
		n := n.(*ir.AssignListStmt)
		return walkAssignList(init, n)

	// a,b,... = fn()
	case ir.OAS2FUNC:
		n := n.(*ir.AssignListStmt)
		return walkAssignFunc(init, n)

	// x, y = <-c

		call := mkcall1(fn.Nname, fn.Type().ResultsTuple(), init, ir.NewInt(base.Pos, sliceType.Elem().Size()), typecheck.Conv(typecheck.Conv(len, lenType), types.Types[types.TUINTPTR]))
		appendWalkStmt(init, ir.NewAssignListStmt(base.Pos, ir.OAS2, []ir.Node{mem, overflow}, []ir.Node{call}))

		// if overflow || mem > -uintptr(ptr) {
		//     if ptr == nil {
		//         panicunsafesliceptrnil()
		//     }
		//     panicunsafeslicelen()
		// }