[PATCH] D135808: [LoopInterchange] Correcting the profitability checking for vectorization

[Bardia Mahjour via Phabricator via llvm-commits]

bmahjour added a comment.

The proper profitability analysis for loop interchange uses `CacheCost`, although there are cases where it may be unable to analyze certain accesses (eg due to delinearization issues). It would be good to understand why we don't go through the CacheCost path in your use case.

The legacy heuristic doesn't look right to me, although your changes make the logic more aligned with the comments in the code.



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Comment at: llvm/test/Transforms/LoopInterchange/pr43797-lcssa-for-multiple-outer-loop-blocks.ll:11
 
+; CHECK:      Name:            InterchangeNotProfitable
+; CHECK-NEXT: Function:        test1
----------------
I'm worried about losing functional coverage by avoiding interchange here due to profitability. Can you play with `-loop-interchange-threshold` or make slight changes to the memory accesses to make the test case profitable?


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https://reviews.llvm.org/D135808