perf: use is_coalesced flag in sparse_eye instead of .coalesce()#66
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theo-barfoot merged 2 commits intocai4cai:mainfrom Jan 13, 2026
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Since indices are constructed in sorted order with no duplicates, pass is_coalesced=True to torch.sparse_coo_tensor() instead of calling .coalesce() after creation. This avoids unnecessary index scanning and provides a speedup.
aymuos15
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Indices from torch.arange (lines 880, 885) are inherently sorted with no duplicates. So is_coalesced=True safe. |
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Looks good, I have added a comment to clarify in the code: "is_coalesced=True since there are no duplicate indices in identity matrix, flag avails in PyTorch 2.1+"
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My local benchmarks (in the style of the repo) show nice improvements on this.