| namespace at { | |
| // If an operator doesn't have a batching rule implemented then we fallback | |
| // to this implementation. The fallback only works on out-of-place operators | |
| // that return only tensors with new memory. (e.g., no in-place operators, no | |
| // view operations). | |
| // | |
| // The fallback effectively takes all of the BatchedTensors in `stack`, slices | |
| // them, and runs `op` on all of the corresponding slices to produce slices | |
| // of the outputs. The output slices then get `torch.stack`ed to create the | |
| // final returns. | |
| // | |
| // The performance of the fallback is not very good because it introduces an | |
| // extra copy from stacking the sliced outputs. Because of this, we prefer to | |
| // write batching rules for operators whenever possible. | |
| void batchedTensorForLoopFallback( | |
| const c10::OperatorHandle& op, | |
| torch::jit::Stack* stack); | |
| } // namespace at | |