Though this sort of bit-twiddling code can be hard to understand (which is why I agree with hv that your constants are more clearly expressed in binary or hex) it can also be lots of fun, and mind-bogglingly fast, as I learned a few years ago (in both Perl and C++) when implementing Conway's Game of Life.

• Re^2: More Betterer Game of Life : The Perl bit-twiddling version reduced the running time from 1635 seconds to 17 seconds ... where tweaking the code, via a long series of micro-optimizations, reduced the running time from 1635 secs to 450 secs (3.6 times faster), while finding a better algorithm reduced it from 450 secs to 17 secs (26.5 times faster).
• Re^2: More Betterer Game of Life : The C++ version of the simple GoL algorithm was 450/36 = 12.5 times faster than the Perl version; for the complex algorithm C++ was 17/0.08 = 212.5 times faster; C++ memory use was 2.8 times lower than Perl for the simple algorithm, 10.1 times lower for the complex one.

References Added Later

• perlfaq3 (perldoc: see "Where can I learn about linking C with Perl?" section)
• perlxs (perldoc)
• ExtUtils::ParseXS (perldoc)
• Integer Arithmetic (perldoc)

• Inline by Ingy
• Inline::C and Inline::C::Cookbook by Ingy et al, recently released by Ed J aka etj
• FFI::Platypus by Graham Ollis

• Re^2: How to do popcount (aka Hamming weight) in Perl by marioroy (sample Inline C code supporting both 64 and 32 bits)
• How to do popcount (aka Hamming weight) in Perl (popcount References)

• Re: How can I set a bit to 0 ? (Add Two Numbers Using Only Bitwise Operators) by me (2022) - add two numbers using only Bitwise Operators in both Perl and C++
• geeksforgeeks.org - add two numbers without using arithmetic operators
• sanfoundry - perform addition with bitwise operators in C

• vec (perl vec function)
• perlfaq4 (see "How do I convert between numeric representations" section)

• Bit::Vector by Steffen Beyer
• Bit::Fast by Dmitri Tikhonov
• Algorithm::BitVector by Avinash Kak

• Bit::Util by salva
• Bit::Grep by salva
• Class::Bits by salva
• Math::Int64 by salva
• Math::Int128 by salva

• Bit string manipulation made easy with Bit::Manip by stevieb
• Bit::Manip by stevieb
• Bit::Manip::PP by stevieb

• Bit manipulation (wikipedia)
• Bloom filter (wikipedia)
• gcc builtins - mostly used for optimization purposes

• Most Significant Set Bit by coldr3ality (2024) - many useful replies
• GCC::Builtins by bliako (2024) - access GCC compiler builtin functions via XS (see Re: Most Significant Set Bit)

• Difference between Perl and Java for << operator? by davidfilmer (2021) - compares bit operations in Java vs Perl
• Re: Difference between Perl and Java for << operator? by BillKSmith (2021) - note that use integer subtly affects bit operations in Perl (signed vs unsigned int)

PDL:

• PDL bitfield type - wanted? by etj (2024)

See Also

• Re^2: Inline::C : passing parameters to functions, modifying by reference (Inline::C References)
• Re: Primes software drag race (Mathematical References)

Updated: fixed broken links. Added more references. Adjusted attribution of Inline modules (thanks etj).

👁️🍾👍🦟