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It's worth noting that modern x86 CPUs have specialized extensions for bit manipulation. Furthermore C23 added stdbit.h that has some operations for bit manipulation

https://en.wikipedia.org/wiki/X86_Bit_manipulation_instructi...

https://thephd.dev/_vendor/future_cxx/papers/C%20-%20Modern%...

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Absolutely, look into your standard library, CPU built-ins and intrinsics first.

However, these tricks are not useless even on modern CPUs. There are scalar instructions for a lot of this stuff, but if you are working with SIMD, several of them are not available.

Recently I wrote bit interleaving stuff with Morton codes. Maybe the scalar instruction would be faster in isolation but I already have my data in SSE registers for other arithmetic so in total it was probably faster. I used the code in this article as a basis.

The last link doesn't work.

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