https://xania.org/202511/advent-of-compiler-optimisation

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Introducing the Advent of Compiler Optimisations 2025

Today I'm announcing a project that's been in the making for around a
year. As my time off draws to a close, I've been working on an
"Advent of" type project, to be released one a day from the 1st of
December until the 25th.

This December will be the Advent of Compiler Optimisations: I'll
release one blog post and video each day, each detailing a fun and
interesting C or C++ optimisation that your compiler can do. I'll go
into the details of when it applies, how to interpret the assembly,
and perhaps as importantly, when it doesn't apply.

I'll be covering some very low-level, architecture-specific tricks as
well as larger, more high-level optimisations. While I mostly cover
x86-64, I do touch on 64-bit and 32-bit ARM as well.

You can follow along by watching the AoCO2025 tag on this blog,
subscribing to me on YouTube, or following the YouTube playlist.

It's been a colossal amount of work, but a lot of fun too. I hope you
enjoy learning how amazing compilers are as much as I do!

See you on the first of December!

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Filed under: Coding AoCO2025
Posted at 13:40:00 CST on 13^th November 2025.

About Matt Godbolt

Matt Godbolt is a C++ developer living in Chicago. He works for
Hudson River Trading on super fun but secret things. He is one half
of the Two's Complement podcast. Follow him on Mastodon or Bluesky.

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