Matt Godbolt
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matt.godbolt.org
Matt Godbolt
@matt.godbolt.org
4.2K followers 680 following 990 posts
Sometime verb, real person, lover of 8-bit computers, husband & father, trying to be a kind person. #blacklivesmatter; trans rights are human rights.
he/him
Posts Replies Media Videos
Reposted by Matt Godbolt
bwjones.bsky.social
David Bowie
8/1/1947 - 01/10/2016

Let’s flood Bluesky with our favorite Bowie songs today:

youtu.be/bsYp9q3QNaQ?...
January 10, 2026 at 12:03 PM
Reposted by Matt Godbolt
cppnow.bsky.social
We cordially invite all members of the C++ community, to submit session proposals for the 14th annual C++Now Conference, to be held May 4th – May 8th, 2026, in Aspen, Colorado.

Read the announcement at cppnow.org/announcement...

#Coding #Cpp #Cppnow #Programming
January 10, 2026 at 1:42 PM
Reposted by Matt Godbolt
lefticus.bsky.social
Fun fact, this "world's most complicated/important machine" that Veritasium just covered runs C++!

youtu.be/MiUHjLxm3V0

I know because I have had students from ASML on multiple occasions (they had me out there for training and to speak at a meetup back in 2018!)

@veritasium.bsky.social
The Ridiculous Engineering Of The World's Most Important Machine
The insane machines that make the most advanced computer chips. Sponsored by Brilliant - To learn for free for a full 30 days, go to https://brilliant.org/veritasium and get started. Plus, our…
youtu.be
January 6, 2026 at 5:01 PM
matt.godbolt.org
I just rediscovered that I have a Wikipedia page.... But only in German(!). Not quite sure how that came to be so...
January 4, 2026 at 3:34 PM
matt.godbolt.org
The music for the Advent of Code Optimisation is available for you listening pleasure: youtu.be/6ZlVRMkFB9c?... and check out nocturnalplant's bandcamp too: nocturnalplant.bandcamp.com/music

Thanks @nocturnalplant.bsky.social !
nocturnalplant - Techie Christmas
YouTube video by nocturnalplant
youtu.be
January 4, 2026 at 3:10 AM
Reposted by Matt Godbolt
jansuchy.bsky.social
6:00 Added the missing -O2 flag. Lovely vid!
The programer used "oldschool" shifts to multiply by a constant, the compiler optimized his code.
January 2, 2026 at 9:33 PM
Reposted by Matt Godbolt
potato-lust.bsky.social
My first CYO @effinbirds.com of the year. Asked the spouse for the adjective without context. Feel it's an accurate description of the news this morning.
January 3, 2026 at 4:18 PM
Reposted by Matt Godbolt
markmoxon.bsky.social
I am delighted to announce the release of my latest project:

Fully documented source code for The Sentinel, Geoff Crammond’s 1986 masterpiece.

Here’s the repository; deep dives coming soon.

See thread for details.

1/9

github.com/markmoxon/th...

#retrocomputing #retrogaming #bbcmicro #c64 #8bit
GitHub - markmoxon/the-sentinel-source-code-bbc-micro: Fully documented and annotated source code for The Sentinel on the BBC Micro
Fully documented and annotated source code for The Sentinel on the BBC Micro - markmoxon/the-sentinel-source-code-bbc-micro
github.com
January 2, 2026 at 4:29 PM
matt.godbolt.org
For your viewing pleasure, some outtakes from the #AoCO2025 - see some of how the sausage was made!
youtu.be/8gASKxx6mCc?...
[AoCO 26/25] Outtakes
YouTube video by Matt Godbolt
youtu.be
January 2, 2026 at 5:37 AM
matt.godbolt.org
Thanks to my Advent of Code Optimisation #AoCO2025 Compiler Explorer's shop sales have raised $1,780! Huge thanks to all who bought mugs, t shirts, desk mats and hoodies!!

Order yours: shop.compiler-explorer.com

I'll do a detailed breakdown of CE costs soon. Thanks everyone and Happy New Year!
Compiler Explorer
The official Compiler Explorer shop! Come show your support for CE and get cool gear!
shop.compiler-explorer.com
December 31, 2025 at 6:14 PM
Reposted by Matt Godbolt
lefticus.bsky.social
I tried to sell my last generation @Garmin.com watches, but then realized they weren't keeping charges very well.

The guy I gave them to for free sent me this lovely note and $50.

I'm forwarding the $ to ALS research in honor of Rainer Grimm, consider contributing to ALS research if you can.
Dear Jason, I hope you remember me. A few weeks ago, you were trying to sell your 2 Garmin watches on Craigslist. You decided to just give me the watches because they were not working properly. I was able to get one of them to work, so I am sending you a check for $50. I thought about paying your generosity forward, but paying it back works too. Thank you again for your kind gesture and please put this $50 to good use. Merry XMAS + Happy New Year!
December 31, 2025 at 12:22 AM
Reposted by Matt Godbolt
kevlin.bsky.social
New on the blog: You Will Never Know Enough — Make peace (and progress) with incomplete knowledge
kevlinhenney.medium.com/you-will-nev...
You Will Never Know Enough
Make peace (and progress) with incomplete knowledge
kevlinhenney.medium.com
December 29, 2025 at 4:03 PM
Reposted by Matt Godbolt
nicolas17.xyz
@matt.godbolt.org is this a compiler explorer competitor? www.youtube.com/watch?v=pJ-2...
Call the compiler, fax it your code
YouTube video by Computing: the Details
www.youtube.com
December 29, 2025 at 2:28 AM
matt.godbolt.org
A few folks have asked if there's a single list of the #AoCO2025 posts and there is: xania.org/AoCO2025-arc...

It's in reverse order but they're all there!
AoCO2025 Archive — Matt Godbolt’s blog
xania.org
December 26, 2025 at 8:13 PM
matt.godbolt.org
Day 25 of #AoCO2025! 🎄 The final day! Thank you for joining this journey through compiler optimisations. From xor to vectorisation, it's been a wild ride. Happy holidays! 🎁

xania.org/202512/25-th...
youtu.be/N1sRfYwzmso
Thank you — Matt Godbolt’s blog
The end of the 2025 Advent of Compiler Optimisation
xania.org
December 25, 2025 at 1:34 PM
matt.godbolt.org
On third glass of mulled wine. Final post of advent tomorrow might be a bit delayed :)
December 25, 2025 at 1:30 AM
matt.godbolt.org
Secret Santa, @tomvii.bsky.social edition: youtu.be/4pG8_bWpmaE?...

And....another cameo from yours truly :-)
Mathematically extra-complicated Secretest Santa 2025
YouTube video by suckerpinch
youtu.be
December 24, 2025 at 11:35 PM
matt.godbolt.org
Day 24 of #AoCO2025! A loop summing 0+1+2+...+n. GCC unrolls it. Clang does something jaw-dropping: the loop vanishes entirely, replaced by a direct calculation. How?!

xania.org/202512/24-cu...
youtu.be/V9dy34slaxA
When compilers surprise you — Matt Godbolt’s blog
Sometimes compilers can surprise and delight even a jaded old engineer like me
xania.org
December 24, 2025 at 1:21 PM
matt.godbolt.org
If you weren't already sick of me: here's a recording of a talk I gave in November at Jane Street on Intel's Skylake Microarchitecture:

youtu.be/BVVNtG5dgks?...
Microarchitecture: What Happens Beneath
YouTube video by Jane Street
youtu.be
December 23, 2025 at 11:01 PM
matt.godbolt.org
Day 23 of #AoCO2025! Switch → jump table? Sometimes. Other times: arithmetic, bitmasks, or something cleverer. Compilers have more tricks than you think.

xania.org/202512/23-sw...
youtu.be/aSljdPafBAw
xania.org
December 23, 2025 at 12:35 PM
Reposted by Matt Godbolt
jimblimey.com
In case you missed it Roojliek, my classic ASCII roguelike, is now available for the Sega #MasterSystem

Download now from jimblimey.itch.io/roojliek
Screenshot of the main title screen. ROOJLIEK A Rogue-like game Press Start
December 23, 2025 at 8:58 AM
Reposted by Matt Godbolt
colinhoad.com
A huge thank you to everyone who has chosen to subscribe to my Acorn nonsense on YouTube, there are 2,250 of you now, for which I feel immensely honoured. Thanks for all the likes, comments and goodwill, all of which keeps me wanting to make more videos. Have a lovely Christmas!
December 23, 2025 at 10:49 AM
Reposted by Matt Godbolt
lefticus.bsky.social
Ep 512 - reinterpret_cast is Finally Fixed!
youtu.be/JtFVyXQ00PQ
C++ Weekly - Ep 512 - reinterpret_cast is Finally Fixed!
☟☟ Awesome T-Shirts! Sponsors! Books! ☟☟ Episode details: https://github.com/lefticus/cpp_weekly/issues/179 T-SHIRTS AVAILABLE! ► The best C++ T-Shirts anywhere!…
youtu.be
December 22, 2025 at 4:31 PM
matt.godbolt.org
Day 22: String comparison against "ABCDEFG" should call memcmp, but Clang inlines it with some clever memory tricks. How does it compare 7 bytes so efficiently? xania.org/202512/22-me... youtu.be/kXmqwJoaapg #AoCO2025
Clever memory tricks — Matt Godbolt’s blog
We learn that compilers have tricks to access memory efficiently
xania.org
December 22, 2025 at 12:57 PM
matt.godbolt.org
Just edited the last of the #AoCO2025. It's been a blast but holy smoke is it a bunch of work! Now time to go remind my wife what I look like :-)
December 21, 2025 at 8:56 PM