[all-commits] [llvm/llvm-project] d51750: [InstCombine] add test for ctpop; NFC

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  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d5175005abe15b041021f36de20cb5fde9a0685c
      https://github.com/llvm/llvm-project/commit/d5175005abe15b041021f36de20cb5fde9a0685c
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-04-23 (Fri, 23 Apr 2021)

  Changed paths:
    M llvm/test/Transforms/InstCombine/ctpop.ll

  Log Message:
  -----------
  [InstCombine] add test for ctpop; NFC

Goes with 2912f42a / PR50096.


  Commit: e10d7d455d4ec0dccab9a74764a8988e1301069f
      https://github.com/llvm/llvm-project/commit/e10d7d455d4ec0dccab9a74764a8988e1301069f
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-04-23 (Fri, 23 Apr 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
    M llvm/test/Transforms/InstCombine/ctpop.ll

  Log Message:
  -----------
  [InstCombine] fold 'not' of ctpop in parity pattern

As discussed in https://llvm.org/PR50096 , we could
convert the 'not' into a 'sub' and see the same
fold. That's because we already have another demanded
bits optimization for 'sub'.

We could add a related transform for
odd-number-of-type-bits, but that seems unlikely
to be practical.

https://alive2.llvm.org/ce/z/TWJZXr


Compare: https://github.com/llvm/llvm-project/compare/a683abe5c026...e10d7d455d4e