Channels last stored in tensor (#23391)
Summary:
Define 4D tensor as stored in channels last memory format, when dimensions order is NCHW and C-strides < W-strides < H-strides < N-strides (If size of any dimension is equal to 1, this dimension strides value is not taken into account).
Channels last contiguous tensor is channel last tensor which occupies contiguous memory block. So x.is_contiguous(memory_format=torch.channels_last) checks if tensor is channels last contiguous.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23391
Differential Revision: D16601414
Pulled By: VitalyFedyunin
fbshipit-source-id: 8d098e7eec2f00fb1d12261bc240b3645d4f5b73
