[PATCH] D153505: [ConstantRange] Handle `Intrinsic::cttz` and `Intrinsic::ctpop`

[Nikita Popov via Phabricator via llvm-commits]

nikic requested changes to this revision.
nikic added a comment.
This revision now requires changes to proceed.

If it's not possible to have efficient precise implementations for these, please just use simple approximations like this:

  ConstantRange ConstantRange::ctpop() const {
    if (isEmptySet())
      return getEmpty();     
      
    KnownBits Known = toKnownBits();
    return getNonEmpty(APInt(getBitWidth(), Known.countMinPopulation()),
                       APInt(getBitWidth(), Known.countMaxPopulation() + 1));
  }   

I'm not willing to have linear time ConstantRange methods.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D153505/new/

https://reviews.llvm.org/D153505