Division — Matt Godbolt’s blog
Division doesn't have to be slow with some clever tricks
Day 6 of Advent of Compiler Optimisations! Divide by 512—just a shift, right? But the compiler adds extra instructions. Why? A subtle difference between what you asked and what you meant!
xania.org/202512/06-di...
youtu.be/7Rtk0qOX9zs
#AoCO2025
06.12.2025 12:49 — 👍 32 🔁 9 💬 1 📌 0
ARM's barrel shifter tricks — Matt Godbolt’s blog
The ARM architecture has a cool feature, and compilers know how to use it
Day 5 of Advent of Compiler Optimisations! x86 has LEA, but ARM has the barrel shifter—instructions can shift operands cheaply. The compiler uses this to multiply without multiplying!
xania.org/202512/05-ba...
youtu.be/TZubUyr2UEY
#AoCO2025
05.12.2025 12:05 — 👍 25 🔁 5 💬 2 📌 0
Day 4 of Advent of Compiler Optimisations! Multiply by constants—which ones use actual multiply? The compiler has tricks to avoid it, then saves you from your own clever hacks.
xania.org/202512/04-mu...
youtu.be/1X88od0miHs
#AoCO2025
04.12.2025 12:07 — 👍 46 🔁 9 💬 6 📌 0
You can't fool the optimiser — Matt Godbolt’s blog
Pattern recognition can see through obfuscated code to find the right instruction
Day 3 of Advent of Compiler Optimisations! A while loop, recursion, direct addition—all compile to one instruction. The compiler sees the pattern beneath the code.
xania.org/202512/03-mo...
youtu.be/wHg9lYPMvvE
#AoCO2025
03.12.2025 12:00 — 👍 44 🔁 7 💬 0 📌 0
Addressing the adding situation — Matt Godbolt’s blog
We learn why adding on x86 isn't as obvious as you might think
Day 2: Adding two integers on x86? Not with `add`! The compiler uses a completely different instruction—one designed for memory addressing. Why? xania.org/202512/02-ad... youtu.be/BOvg0sGJnes #AoCO2025
02.12.2025 11:28 — 👍 76 🔁 18 💬 4 📌 0
Why xor eax, eax? — Matt Godbolt’s blog
Why do compilers love xor-ing registers so much?
Ever wonder why compilers use `xor eax, eax` to zero registers? It's smaller AND faster—CPUs optimise it out entirely!
Day 1 of Advent of Compiler Optimisations: xania.org/202512/01-xo...
Video: youtu.be/eLjZ48gqbyg
#AoCO2025
01.12.2025 12:12 — 👍 133 🔁 25 💬 5 📌 4
SC'25 recap
The annual SC conference was held last week, drawing over 16,000 registrants and 560 exhibitors to in St. Louis, Missouri to talk ab...
I wrote up my notes from #SC25. Have a look: blog.glennklockwood.com/2025/12/sc25...
I’ll keep picking away at the editing, but would love to hear more from others about what stood out to them. I wasn’t at the conference itself as much this years as in the past, so I know I missed a lot.
#HPC
01.12.2025 19:27 — 👍 24 🔁 10 💬 3 📌 3
📣 The procurement contract for #AliceRecoque, the new European #exascale supercomputer 🖥️ ⚡ located in #France, has been signed by @eurohpc-ju.bsky.social and the selected vendor Eviden! It will be one of the backbones for Europe's network of #AIFactories
🔗 www.eurohpc-ju.europa.eu/contract-sig...
18.11.2025 11:01 — 👍 1 🔁 1 💬 0 📌 0
We’re delighted to welcome Modules to the High Performance Software Foundation as an established project 🎊
Read the announcement ➡️ hpsf.io/blog/2025/hi...
10.11.2025 14:25 — 👍 3 🔁 1 💬 1 📌 0
#AMD #Zen6 znver6 ISA:
- #AVX512_BMM (CPUID.80000021.EAX[23], VBMACOR16x16x16, VBMACXOR16x16x16, VBITREV)
- #AVX512_FP16
- #AVX_NE_CONVERT
- #AVX_IFMA
- #AVX_VNNI_INT8
Source:
sourceware.org/pipermail/bi...
08.11.2025 01:11 — 👍 2 🔁 1 💬 1 📌 1
Extrait de l'ordonnance de création du CEA datant du 18 octobre 1945 © Archives Nationales \ Stéphane Méziache
#anniversaire 🎂 | Le CEA fête ses 80 🕯️ .
Le 18/10/1945, le Général de Gaulle signe l’ordonnance fondatrice du CEA.
⚛️L'organisme a pour ambition d’offrir à la 🇫🇷 la maîtrise de l’atome dans différents domaines de la science, de l’industrie & de la défense nationale
👇Extrait
18.10.2025 06:58 — 👍 23 🔁 11 💬 1 📌 0
It means “French” 🥖
17.10.2025 20:50 — 👍 0 🔁 0 💬 0 📌 0
Colleges do a terrible job of teaching C++.
It’s not “C with Classes”. Injected into curriculums as a demonstration of early CS concepts, it leaves many with a sour taste.
Students later immediately fall in love with the first language that *doesn’t* feel that way.
13.10.2025 21:21 — 👍 57 🔁 5 💬 8 📌 1
#AMD & #Intel unified future instructions:
#FRED #AVX10 #ChkTag #ACE (=ACE (Advanced Matrix Extensions for Matrix Multiplication): www.amd.com/en/blogs/202...
14.10.2025 07:17 — 👍 9 🔁 6 💬 1 📌 0
September feels like it goes on forever, then october breezes by in an instant
13.10.2025 12:24 — 👍 0 🔁 0 💬 0 📌 0
HPSF Board Member & Kokkos Project Maintainer, Damien Lebrun-Grandié, of Oak Ridge National Laboratory (ORNL) will share a maintainer's perspective on Sustainable HPC Software in #HPC Best Practices Webinar - Oct 15 at 1:00pm EDT 🔎 Learn more:
ideas-productivity.org/events/hpcbp...
07.10.2025 19:54 — 👍 2 🔁 3 💬 0 📌 0
YouTube video by Jon Gjengset
Sguaba: Type-safe spatial math in Rust
About a month ago, I gave a talk at the Rust Amsterdam meetup about Sguaba (the type-safe spatial math Rust crate), and the recording of that is now online for anyone who wants their head to hurt with frames of reference and coordinate transforms 😅
youtu.be/kESBAiTYMoQ
29.09.2025 14:26 — 👍 25 🔁 4 💬 1 📌 0
A Look into Intel Xeon 6’s Memory Subsystem
Intel’s server dominance has been shaken by high core count competition from the likes of AMD and Arm.
Hello you fine Internet folks,
Today we are taking a look Intel's Xeon 6 Memory Subsystem and the changes that Intel made in order to fit up to 128 cores in a single CPU.
Hope y'all enjoy!
chipsandcheese.com/p/a-look-int...
old.chipsandcheese.com/2025/09/26/a...
26.09.2025 16:44 — 👍 11 🔁 2 💬 0 📌 0
Screenshot of @john_attridge’s tweet (in a sans-serif font) saying “It’s nice but do you have any sans-seraph fonts?” with a photo of a winged angel kneeling, supporting a basin
This is a font joke.
20.09.2025 20:19 — 👍 338 🔁 45 💬 21 📌 4
Personal achievement: Relentlessly correcting Exaflops and the likes to ExaFLOP/s, and seeing that it slowly sticks, also in articles of the press 💪 #HPC
06.09.2025 08:16 — 👍 2 🔁 1 💬 0 📌 0
Designer / Developer @ Oxide. Formerly Pentagram
High Performance Computing with GPUs and other spaceships. At Jülich Supercomputing Centre.
Mastodon: https://mastodon.social/@andih #HPC #GPU #LaTeX
definitely pat gelsinger
im also apparently retired
A programming language empowering everyone to build reliable and efficient software.
Website: https://rust-lang.org/
Blog: https://blog.rust-lang.org/
Mastodon: https://social.rust-lang.org/@rust
Rust live-coder and OSS tinkerer who loves teaching. I try to maintain a high SNR. Wrote Rust for Rustaceans. At Helsing.ai. Formerly AWS. Co-founded ReadySet. @jonhoo elsewhere. he/him/they
Code synthesizing Carbon-Silicon based lifeform 🖥️🧬
#Coding #Math #Physics
#HPC & #AI
#RetroTech
#Aerospace
#ＡＥＳＴＨＥＴＩＣＳ
Random #Nerdiness & #Shitposting
Systems and machine learning programmer pushing .NET performance to the limits for real-time 24/7 edge applications.
@nietras@mastodon.social (he/him)
Compte officiel de l'Université Paris-Saclay : 48 000 étudiants, 9 000 chercheurs et enseignants-chercheurs, 4 600 doctorants #Formation #Recherche
Research Scientist NVIDIA • YouTube Content Creator • Host of ADSP, ArrayCast, Tacit Talk, The R4 Running Podcast • Organizer of PLVM Meetup
computers enthusiast, "assembly language drag racer", made out of meat
CEO of @gitbutler.com, previously cofounder of @github.com. All opinions are my own, but also objectively the best.
The only version control tool built from the ground up for modern, AI-powered workflows.
https://gitbutler.com/
Principal Architect at @NVIDIA working on programming languages. C++ Library Evolution chair emeritus. Frequent @traveloneworld flyer. Horology nerd.
#rustlang, #jj-vcs, atproto, shitposts, urbanism. I contain multitudes.
Working on #ruelang but just for fun.
Currently in Austin, TX, but from Pittsburgh. Previously in Bushwick, the Mission, LA.
Building the Future of High Performance Software
CTO at Genci the 🇫🇷 #HPC agency deploying supercomputers for numerical #simulation, #AI and #quantum computing
Systems Editor at TheRegister / SitPub
— hiker, animal lover, photographer, blogger, and tech journo.
IT Professional, Tech enthusiast, gardener, cat parent,
Common sense is the ability to make inferences about what might happen that are reasonable guesses but do not require you to experience a mistake to learn from that in advance.
