pytorch

6e1a5b11 - [PyTorch] Use real if constexpr behind macro in hot template (#51368)

[PyTorch] Use real if constexpr behind macro in hot template (#51368) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/51368 This seems to noticably reduce build times, at least for RegisterCPU.cpp. It makes sense that a compiler builtin would be faster than simulating the same builtin with templates. Identified with templight. ghstack-source-id: 121378959 Test Plan: Confirmed this speeds up RegisterCPU.cpp optimized build by simply running builds under `time(1)`: previous diff: [50.53, 50.41, 50.57, 50.67, 50.94] mean: 50.6 std: 0.179 this diff: [45.71, 45.89, 46.21, 48.51, 45.84] mean: 46.4 std: 1.05 Reviewed By: bhosmer Differential Revision: D26154964 fbshipit-source-id: 62ee2f5a872007db032dfebf7ad4d1b6e1ce63d1