// For maps tmp is just one word so it hardly matters.
			r := n.X
			n.X = o.copyExpr(r)

			// n.Prealloc is the temp for the iterator.
			// MapIterType contains pointers and needs to be zeroed.
			n.Prealloc = o.newTemp(reflectdata.MapIterType(), true)
		}
		n.Key = o.exprInPlace(n.Key)
		n.Value = o.exprInPlace(n.Value)
		if orderBody {
			orderBlock(&n.Body, o.free)
		}
		o.out = append(o.out, n)