benchmark

e141d183 - Fix broken main branch. Disable half when using CPU device. (#667)

Fix broken main branch. Disable half when using CPU device. (#667) Summary: In https://github.com/pytorch/benchmark/pull/663 we enabled fp16 by default for both CPU and GPU. This actually breaks the test because CPU doesn't support `half()`. This PR clears up the fp16 and fx2trt code, and disables fp16 by default on CPU. Pull Request resolved: https://github.com/pytorch/benchmark/pull/667 Reviewed By: aaronenyeshi, eircfb Differential Revision: D33242063 Pulled By: xuzhao9 fbshipit-source-id: 2a9c3f1d2f7660b40c28f33d95131d815ab3634c