pytorch

a9f5e722 - [PyTorch] Remove reference_cast in make_boxed_from_unboxed_functor (#51319)

[PyTorch] Remove reference_cast in make_boxed_from_unboxed_functor (#51319) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/51319 We were going out of our way to accommodate `IValue::to<Tensor>` returning a copy of the inner Tensor. `IValue::toTensor` is capable of returning a reference without copying, so if we use it directly, we can allow kernels that want to take `Tensor &` to do so! As a bonus, we get reduced build times. ghstack-source-id: 121378961 Test Plan: Rely on CI for correctness. Profiled build time with -ftime-trace for RegisterCPU.cpp using an extracted build invocation. Before: P168244900 After: P168245014 Note reduced time spent compiling make_boxed_from_unboxed_functor. I also ran the AdIndexer benchmark (https://fb.quip.com/ztERAYjuzdlr) with static runtime disabled and batch size 1 to see how big the effect on boxed call performance was (any kernels that take `Tensor&` or `const Tensor&` should now actually save a refcount bump). Looks like it was roughly 1% better: Before: 124-125 usec/iter After: 122-123 usec/iter Reviewed By: bhosmer Differential Revision: D26138549 fbshipit-source-id: b0f830527da360c542c815bef2f7e1692615b32a