// we must have lost the race, and therefore n is not nil
			// anymore.
			n = (*traceMapNode)(m.Load())
		}
		if n.hash == hash && uintptr(len(n.data)) == size {
			if memequal(unsafe.Pointer(&n.data[0]), data, size) {
				return n.id, false
			}
		}
		m = &n.children[hashIter>>(8*goarch.PtrSize-2)]
		hashIter <<= 2
	}
}