orig_op->MutableAttrs()->CacheKey(orig_op->DeviceName());
  // Include soft placement policy in cache key since the placement strategy
  // can change and thus affect which kernel is picked.
  auto x = FingerprintCat64(cache_key.high64, cache_key.low64);
  std::string fname =
      absl::StrCat("_expanded_", ndef.name(), "_", std::to_string(x));
  if (!ctx.FindFunctionByName(fname)) {