modify cast from hp to mx to help inductor fuse#1786
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🔗 Helpful Links🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/ao/1786
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Summary: Thanks to investigation from @eellison, moving the reshape to the end of the cast helps inductor fuse the cast into a single kernel. This doesn't yet work with fp4, but let's unblock fp8 and deal with fp4 later. Fixes #1690 Note: in the repro with swizzling from #1773, we go from 3 to 2 kernels. Further investigation is needed whether we can fuse the swizzling. Test Plan: ``` pytest test/prototype/mx_formats/test_mx_tensor.py -x -s -k test_to_mx_inductor_single_kernel ``` Reviewers: Subscribers: Tasks: Tags:
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eellison
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Looks good as a workaround ! I'm still planning on making the code fuse as it was previously.. but worth landing in interim
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Summary: Thanks to investigation from @eellison, moving the reshape to the end of the cast helps inductor fuse the cast into a single kernel. This doesn't yet work with fp4, but let's unblock fp8 and deal with fp4 later. Fixes #1690 Note: in the repro with swizzling from #1773, we go from 3 to 2 kernels. Further investigation is needed whether we can fuse the swizzling. Test Plan: ``` pytest test/prototype/mx_formats/test_mx_tensor.py -x -s -k test_to_mx_inductor_single_kernel ``` Reviewers: Subscribers: Tasks: Tags:
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Summary:
Thanks to investigation from @eellison, moving the reshape to the end of the cast helps inductor fuse the cast into a single kernel. This doesn't yet work with fp4, but let's unblock fp8 and deal with fp4 later.
Fixes #1769
Note: in the repro with swizzling from
#1773, we go from 3 to 2 kernels. Further investigation is needed whether we can fuse the swizzling.
Test Plan:
Reviewers:
Subscribers:
Tasks:
Tags: