pytorch

f396b019 - Remove one unnecessary copy of the output during the type promotion. (#26816)

Remove one unnecessary copy of the output during the type promotion. (#26816) Summary: Output tensors doesn't need to be copied during type promotion as we are not using any data from them. Simple allocation gives steady 10% performance gain. BEFORE ``` In [1]: x = torch.randn(64, 2048, 7,7) In [2]: y = torch.randn(64, 2048, 7,7, dtype=torch.float64) In [3]: timeit x.add_(y) 77.3 ms ± 257 µs per loop (mean ± std. dev. of 7 runs, 10 loops each) ``` AFTER ``` In [1]: x = torch.randn(64, 2048, 7,7) In [2]: y = torch.randn(64, 2048, 7,7, dtype=torch.float64) In [3]: timeit x.add_(y) 68.2 ms ± 713 µs per loop (mean ± std. dev. of 7 runs, 10 loops each) ``` Pull Request resolved: https://github.com/pytorch/pytorch/pull/26816 Differential Revision: D17573455 Pulled By: VitalyFedyunin fbshipit-source-id: 47286abce5e7e665eb61e46ae358c896e945bef2