[PATCH] D68189: [InstCombine] recognize popcount implemented in hacker's delight.

[Dávid Bolvanský via Phabricator via llvm-commits]

xbolva00 added a comment.

Maybe this pattern is also interesting? ICC catches it.

  int popcount (unsigned long long a)
  {
      unsigned long long b = a;
      b -= ((b>>1) & 0x5555555555555555ULL);
      b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
      b = ((b>>4) + b) & 0x0F0F0F0F0F0F0F0FULL;
      b *= 0x0101010101010101ULL;
      return (int)(b >> 56);
  }


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D68189/new/

https://reviews.llvm.org/D68189