change softmax input shape (#28836)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28836
as title
Test Plan:
```
buck run mode/opt //caffe2/benchmarks/operator_benchmark/pt:softmax_test
Invalidating internal cached state: Buck configuration options changed between invocations. This may cause slower builds.
Changed value project.buck_out='buck-out/opt' (was 'buck-out/dev')
... and 56 more. See logs for all changes
Parsing buck files: finished in 6.2 sec
Creating action graph: finished in 8.8 sec
Building: finished in 05:42.6 min (100%) 28336/28336 jobs, 23707 updated
Total time: 05:57.7 min
# ----------------------------------------
# PyTorch/Caffe2 Operator Micro-benchmarks
# ----------------------------------------
# Tag : short
# Benchmarking PyTorch: Softmax
/proc/self/fd/4/softmax_test.py:57: UserWarning: Implicit dimension choice for softmax has been deprecated. Change the call to include dim=X as an argument.
"""
# Mode: Eager
# Name: Softmax_N4_C3_H256_W256
# Input: N: 4, C: 3, H: 256, W: 256
Forward Execution Time (us) : 18422.487
Reviewed By: hl475
Differential Revision: D18202335
fbshipit-source-id: 0bb376cb465d998a49196e148d48d436126ae334