[PATCH] D142253: [InstCombine] Transform ctpop(Pow2) -> icmp ne Pow2, 0

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n added inline comments.


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp:673
     return BinaryOperator::CreateLShr(
         Op0, ConstantInt::get(Ty, (~Known.Zero).exactLogBase2()));
 
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nikic wrote:
> If the new pattern reliably subsumes this one, we should drop it in a followup.
> If the new pattern reliably subsumes this one, we should drop it in a followup.

Got it. I test removing it but remembered seeing some differences but didn't investigate deeply. I can add a `TODO` before i commit?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D142253/new/

https://reviews.llvm.org/D142253