// true:
// 1) None of the job/replica/task is specified in the device name.
// 2) The job/replica/task in the device name are explicitly specified as
//    /job:localhost/replica:0/task:0.
bool IsOnLocalHost(llvm::StringRef device) {
  std::string host = GetHost(device);
  return host == kLocalhost;
}

// This structure contains the metadata of the per-host function. All operations