iiinova — where your digital self keeps evolving

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Colin Hoad @colinhoad.com · 22/06/2026

Loving my new @compiler-explorer.com desk topper! Really nice quality and a huge improvement on my old IKEA one that had seen better days 😅 Thanks, @matt.godbolt.org and team!

My desk looking unusually tidy (it won't last) with my new Compiler Explorer desk topper

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Mathieu Ropert @matropert.bsky.social · 04/07/2026

People were literally giving up on C++ before @compiler-explorer.com because they didn't trust the generated assembly would be good enough. That was only 10 years ago.

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Matt Godbolt @matt.godbolt.org · 09/06/2026

I did Compiler Explorer's monthly accounts, and for the first time in ages we only broke even. Usually we run at a small surplus (which I save) & we have a year contingency saved up. If you want to support us: * Buy stuff: shop.compiler-explorer.com * Patron/GH: "Other" menu on CE Please repost. thx

shop.compiler-explorer.com

Compiler Explorer

The official Compiler Explorer shop! Come show your support for CE and get cool gear!

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Matt Godbolt @matt.godbolt.org · 13/11/2025

This December, I'll be posting an article & video each day until Christmas in the Advent of Compiler Optimisations! #AoCO2025 Each day we'll explore a fun optimisation in C or C++; some low-level, x86 or ARM-specific, some high-level. Hope you'll join me! YT: youtube.com/mattgodbolt Blog: xania.org

xania.org

Matt Godbolt’s blog

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Compiler Explorer @compiler-explorer.com · 07/10/2025

Investigating why Windows compilers are down! Watch this space, and sorry for any inconvenience -mg

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Matt Godbolt @matt.godbolt.org · 21/09/2025

LLM-explanation is now live in @compiler-explorer.com - An example: compiler-explorer.com/z/rvvx7MxKq * LLMs make mistakes and are overconfident * We'll never force LLMs or AI on you, it's opt in (like clang-tidy, PVS Studio or other tools) * It is *beta* quality Initial results are promising(1/3)

explain.compiler-explorer.com

Compiler Explorer - C++ (x86-64 clang 21.1.0)

// setup constexpr auto valid_chars = "0123456789abcdef"; bool is_valid_id(std::string_view maybe_id) { if (maybe_id.size() != 16) { return false; } if (maybe_id.find_first_not_of(valid_ch...

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Matt Godbolt @matt.godbolt.org · 11/09/2025

@compiler-explorer.com is now running with a completely new storage mechanism in the back end. It's taken me quite a long time to get to the point where I felt confident enough to switch over to it and it seems like it's gone without a hitch. Details: xania.org/202509/cefs

xania.org

CEFS: Finally Solving CE's Mount(ing) Problems — Matt Godbolt’s blog

In which CE's boot times are finally brought under control

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Matt Godbolt @matt.godbolt.org · 22/08/2025

Hey folks! @compiler-explorer.com is free & open for everyone, but if you're planning to use our API for bulk executions though, please ping us! CE is a shared resource and heavy use can slow things down for the whole community. DM me to chat - happy to help figure out what works for everyone! :)

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Compiler Explorer @compiler-explorer.com · 22/08/2025

Support friend of the site Jason by going to one of his excellent courses! Jason was instrumental in publicising CE in the early days and his courses are awesome too! -mg

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Compiler Explorer @compiler-explorer.com · 24/07/2025

CE relies on your support! How you can help: * Submit PRs & report issues: github.com/compiler-exp... * Become a Patron: patreon.com/mattgodbolt * Sponsor us: github.com/sponsors/com... * Buy CE swag: shop.compiler-explorer.com * Join our Discord: discord.gg/B5WacA7

github.com

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Matt Godbolt @matt.godbolt.org · 20/07/2025

I've been getting more anecdotal reports that @compiler-explorer.com is slow. Seems to be folks' simple code taking a while, likely queued up behind a longer compile. We've done some digging and it seems to have gotten worse since December last year. Doesn't seem to be bot traffic. Have you noticed?

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Compiler Explorer @compiler-explorer.com · 30/06/2025

Huge news! AWS has approved Compiler Explorer for their Open Source Credits program, covering our infrastructure costs for the next year! Thank you AWS for supporting open source! This means faster compiles, better queuing & more improvements coming. Exciting times ahead!

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Matt Godbolt @matt.godbolt.org · 11/06/2025

I'm frequently asked "how much does @compiler-explorer.com cost to run". I've done some digging and posted xania.org/202506/compi... which is a high-level breakdown of the costs (and revenue); and links to a more in depth report if you want all the gory details.

xania.org

Compiler Explorer Cost Transparency — Matt Godbolt’s blog

In which I try and show how we spend your kind Patreon donations

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Matt Godbolt @matt.godbolt.org · 08/06/2025

I'm half way through my career break, and taking stock. Plan was to do conf talks (check), work on @compiler-explorer.com (check), spend time with family (sort of) and even do some hobby code (also sort of). Higher level goal still is to get CE "on its feet" a bit...

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Matt Godbolt @matt.godbolt.org · 05/06/2025

A fantastic walk through of some @compiler-explorer.com features by one of our core maintainers @ofekshilon.bsky.social . Thanks Ofek! youtu.be/_9sGKcvT-TA

youtu.be

Get More Out of Compiler-Explorer ('godbolt') :: Ofek Shilon

YouTube video by CoreCppIL

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Matt Godbolt @matt.godbolt.org · 03/06/2025

It's been a while since I've written about the innards of @compiler-explorer.com. xania.org/202506/how-c... has the details, some statistics and some fun war stories.

xania.org

How Compiler Explorer Works in 2025 — Matt Godbolt’s blog

How we handle 92 million compilations a year without everything catching fire

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Matt Godbolt @matt.godbolt.org · 23/05/2025

Experimenting with something like this for @compiler-explorer.com - wondering what your thoughts are? AI is getting everywhere, and can be divisive. I'm hoping something like this - so long as I can get the output quality high enough - is a net benefit to help folks learn more about their code.

$A screenshot of Compiler Explorer showing an "AI Explain this" view. The source code is: bool isspc(char c) { return c == '\n' || c == '\r' || c == '\t' || c == ' '; } The asm is: isspc(char): mov ecx, edi cmp cl, 33 setb dl movabs rax, 4294977024 shr rax, cl and al, dl ret Below is a "Claude Explain" window with: The function isspc(char) is compiled to an efficient bit manipulation technique to check for whitespace characters. Let's break down the assembly instructions: mov ecx, edi Copies the input character from the edi register (first function argument) to ecx cl will contain the lowest 8 bits (the character) cmp cl, 33 Compares the character against decimal 33 This is a preliminary check to quickly filter out non-whitespace characters setb dl Sets the dl register to 1 if the character is below 33 (space, tab, newline, etc.) Uses a conditional set instruction movabs rax, 4294977024 Loads a pre-computed 64-bit constant This constant represents a bit mask for whitespace detection shr rax, cl Shifts the bit mask right by the character's value This dynamically positions the mask based on the input character and al, dl Performs a bitwise AND between the shifted mask and the previous condition Produces the final boolean result in al ret Returns the result (0 or 1) in al This implementation is a highly optimized branchless method for checking whitespace characters, using bit manipulation instead of multiple comparisons. It avoids conditional jumps, which can be slower on modern CPUs. The code checks for space (' '), newline ('\n'), carriage return ('\r'), and tab ('\t') in a single, efficient operation.$

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Matt Godbolt @matt.godbolt.org · 23/04/2025

Thrilled to share that @compiler-explorer.com has received a $10K grant from NVIDIA's FOSS Fund! This support will help keep our GPU instances running and allow developers worldwide to experiment with CUDA code. Thank you NVIDIA AI Dev for supporting open source tools! #NVIDIAGrant

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Shafik Yaghmour @shafik.bsky.social · 08/02/2025

Once again #programming

Bernie once again meme with

I am once again asking

you to remember that if turning on optimizations changes the behavior of your program, it is likely you are missing some undefined behavior

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Compiler Explorer @compiler-explorer.com · 06/01/2025

We just blocked a TW-based IPv6 address from making many many back-to-back requests, most of which seemed to hit our caches (and thus were duplicates). If this affected you, please DM us or reply and we can help diagnose what went wrong. -mg

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Compiler Explorer @compiler-explorer.com · 31/12/2024

Compiler Explorer in 2024! 0.017 cents per compilation for 190M compilations. Tons of new features, Matt takes stock: www.patreon.com/posts/compil...

patreon.com

Compiler Explorer in 2024 | Matt Godbolt

Get more from Matt Godbolt on Patreon

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Matt Godbolt @matt.godbolt.org · 07/12/2024

Sent my first proper Patreon/GitHub sponsor update for @compiler-explorer.com work today. Surreal experience, I'm kinda giving my first update to my new boss(es) :-)

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Matt Godbolt @matt.godbolt.org · 22/11/2024

So, after over 5 years at Aquatic, I made the tough call to leave and try something else. I had a wonderful time there, enjoyed the work and made some great friends. I'll be taking some time between jobs and will be working on @compiler-explorer.com and other OSS projects. I'm excited!

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Matt Godbolt @matt.godbolt.org · 23/11/2024

Only 2 days left 15% off stuff at the CE shop. I just uploaded a dark-friendly logo too! Get some stuff to show off your love of CE and know you're helping the site at the same time! compiler-explorer.myspreadshop.com

compiler-explorer.myspreadshop.com

Compiler Explorer

Support Compiler Explorer by buying awesome branded kit!

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Compiler Explorer @compiler-explorer.com · 17/11/2024

Investigating a DDoS attack (looks like script kiddies again). Getting a bunch of weird POSTs to our noscript API. Site is handling it but it's alerting me, so have temporarily blocked some things. Apologies if you're caught in the crossfire! -mg

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Matt Godbolt @matt.godbolt.org · 12/11/2024

We have so many compilers on @compiler-explorer.com that the "configuration JSON" we send on /every pageload/ totals 60GiB/day (!!) I think we can probably do better...

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Compiler Explorer @compiler-explorer.com · 11/11/2024

CE relies on your support! How you can help: * Submit PRs & report issues: github.com/compiler-exp... * Become a Patron: patreon.com/mattgodbolt * Sponsor us: github.com/sponsors/com... * Buy CE swag: shop.spreadshirt.com/compiler-exp... * Join our Discord: discord.gg/B5WacA7

github.com

GitHub - compiler-explorer/compiler-explorer: Run compilers interactively from your web browser and interact with the assembly

Run compilers interactively from your web browser and interact with the assembly - compiler-explorer/compiler-explorer

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