# Reversing Bits in C

DevFeed: [Reversing Bits in C](<https://devfeed.tech/articles/reversing-bits-in-c-15826.md>)

Original publisher: [Read original article](<https://developer.squareup.com/blog/reversing-bits-in-c>)

Author: Square Engineering

Published: 2013-08-01T16:03:00Z

Content type: article

Language: en

Sources: [Square Corner Blog RSS Feed](<https://devfeed.tech/sources/square-corner-blog-rss-feed.md>)

Topics: [C](<https://devfeed.tech/topics/c.md>), [Algorithms](<https://devfeed.tech/topics/algorithms.md>), [cpu](<https://devfeed.tech/topics/cpu.md>), [Arm](<https://devfeed.tech/topics/arm.md>), [Caching](<https://devfeed.tech/topics/caching.md>), [iOS](<https://devfeed.tech/topics/ios.md>)

Tags: [algorithm](<https://devfeed.tech/tags/algorithm.md>), [arm](<https://devfeed.tech/tags/arm.md>), [c](<https://devfeed.tech/tags/c.md>), [cache](<https://devfeed.tech/tags/cache.md>), [cpu](<https://devfeed.tech/tags/cpu.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [ios](<https://devfeed.tech/tags/ios.md>), [performance](<https://devfeed.tech/tags/performance.md>)

## AI overview

This article investigates how different algorithms for reversing the bits in a byte perform in C on real hardware. It compares operation counts with instruction counts, memory access patterns, cache behavior, and low-level CPU instructions, including ARM's RBIT instruction.

## Source excerpt

A small performance investigation into innocent-looking code.