4 ms·

Thanks for sharing that, love the simplicity behind it which is more intuitive than the example I had gone with. I think the reason why I chose that particular

Thanks for sharing that, love the simplicity behind it which is more intuitive than the example I had gone with. I think the reason why I chose that particular one was to show how thinking about a problem from an entirely different angle can yield great (and rewarding) results.

saagarjha 5y ago
Ideally, you'd want your compiler to use the hardware population count instructions though. So this might be one of the places where a simpler algorithm might win out because the compiler can recognize it.
- juxhindb 5y ago
  In fact that is one of the follow-ups I want to have out of this. Have architecture-specific optimisations (popcnt on x86) either manually through something like the `asm` crate, or by having a simpler algorithm that the compiler can optimise away.
  - juxhindb 5y ago
    An extension to this infact is the following - https://github.com/llvm-mirror/llvm/blob/f36485f7ac2a8d72ad0e0f2134c17fd365272285/lib/Transforms/Scalar/LoopIdiomRecognize.cpp#L960 https://github.com/llvm-mirror/llvm/blob/f36485f7ac2a8d72ad0... So the original user's comment might infact get detected by this and get optimised down to using popcnt. Will need to try it out. :-)