[PATCH] D89665: [LSR] ignore profitable chain optimization when instruction number is the major cost

[ChenZheng via Phabricator via llvm-commits]

shchenz added inline comments.


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Comment at: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:3097
   }
   // Remove any unprofitable chains.
   unsigned ChainIdx = 0;
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steven.zhang wrote:
> I am not familiar with the code logic. But it makes more sense to bail out here when the instruction is the major cost.
agree with your concern here. return early always good for compiling time. But the logic here should be specific for `isProfitableChain`, it would make more sense to keep it inside `isProfitableChain`. For example what if we have more than one caller of `isProfitableChain` function?


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  https://reviews.llvm.org/D89665/new/

https://reviews.llvm.org/D89665