[PATCH] D126043: [LSR] Drop LSR solution if it is less profitable than baseline

[Yueh-Ting (eop) Chen via Phabricator via llvm-commits]

eopXD added inline comments.


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Comment at: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:3372
+    F.initialMatch(S, L, SE);
+    if (!BaselineCost.isLoser())
+      BaselineCost.RateFormula(F, Regs, VisitedRegs, LU);
----------------
Meinersbur wrote:
> How can the baseline immediately become the loser?
I have encounter cases that the `BaselineCost` is updated to loser when compiling spec2k6 benchmarks. This if-statement is used for us to prevent assertion errors as `RateFormula` assumes the cost to not be a loser when called.

I have a patch (D125670) that is pretty simple to free us from using this if-statement? I think its pretty simple and we can land it first?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D126043/new/

https://reviews.llvm.org/D126043