Add backward pass for softmax kernel #744
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stack-info: PR: #744, branch: karthickai/stack/4
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examples/softmax.py
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| m, n = grad_output.size() | ||
| grad_input = torch.empty_like(grad_output) | ||
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| block_size_m = hl.register_block_size(m) |
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Yeah it is not need, I followed the implementation from softmax two pass, now I've updated the code.
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| x: torch.Tensor, | ||
| ) -> torch.Tensor: | ||
| """Softmax with forward + backward support.""" | ||
| return SoftmaxFunction.apply(x) # type: ignore[no-any-return] |
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Would you like to also add integration in benchmarks/run.py (similar to rms_norm-bwd), and test accuracy via tritonbench --metrics accuracy?
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backward pass for softmax is disabled in tritonbench. I enabled it in this PR meta-pytorch/tritonbench#528 and added softmax-bwd in benchmarks/run.py
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HELION_USE_DEFAULT_CONFIG=1 python benchmarks/run.py --op softmax-bwd --num-inputs 3 --metrics accuracy
(M, N) triton_softmax-accuracy quack-accuracy torch_compile_softmax-accuracy helion_softmax_tritonbench-accuracy
----------- ------------------------- ---------------- -------------------------------- -------------------------------------
(4096, 256) 1 1 1 1
(4096, 384) 1 1 1 1
(4096, 512) 1 1 1 1
average 1 1 1 1HELION_USE_DEFAULT_CONFIG=1 python benchmarks/run.py --op softmax --num-inputs 3 --metrics accuracy
(M, N) triton_softmax-accuracy quack-accuracy torch_compile_softmax-accuracy helion_softmax_tritonbench-accuracy
----------- ------------------------- ---------------- -------------------------------- -------------------------------------
(4096, 256) 1 1 1 1
(4096, 384) 1 1 1 1
(4096, 512) 1 1 1 1
average 1 1 1 1There was a problem hiding this comment.
update: tirtonbench softmax-bwd is landed meta-pytorch/tritonbench#528
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Add backward pass for softmax kernel