Oliver Medhurst
LightNews LightNews
banner
goose.icu
Oliver Medhurst
@goose.icu
2.2K followers 530 following 150 posts
compiling JavaScript: https://porffor.dev
TC39 & WinterTC invited expert
20. they/them 🌈
Posts Replies Media Videos
goose.icu
My ahead-of-time JS engine Porffor eliminates JS cold starts on AWS Lambda. 12x faster and 2x cheaper than managed Node. Still very early but these results should speak for themselves :)

goose.icu/lambda/
A graph of Porffor cold starts. P50: 16.3ms, P90: 27.5ms, P99: 41.1ms.
August 15, 2025 at 3:01 AM
goose.icu
Porffor now passes over 60% of Test262, thanks to a new custom regex engine!
Porffor's graph of Test262 passing over time, currently at 60.30%
July 5, 2025 at 10:39 PM
goose.icu
Porffor now has its own fuzzer which abuses the compiler with randomly generated JS code in an attempt to find bugs which would otherwise not be found to help stability!
fuzzing complete 🧪 78500 | 🤠 92% | ❌ 0.0% | 💀 0.33% | 🏗️ 3.7% | 💥 0.0% | ⏰ 3.6% | 📝 0.0% 3.6% timeout 2.3% CompileError: WebAssembly.Module(): Compiling function #0 failed: expected 2 elements on the stack for branch, found 0 0.68% CompileError: WebAssembly.Module(): Compiling function #0 failed: invalid branch depth: 3 0.39% CompileError: WebAssembly.Module(): Compiling function #0 failed: invalid branch depth: 4294967295 0.23% CompileError: WebAssembly.Module(): Compiling function #0 failed: invalid branch depth: 4 0.23% RangeError: Maximum call stack size exceeded 0.10% RuntimeError: memory access out of bounds 0.059% CompileError: WebAssembly.Module(): Compiling function #0 failed: invalid branch depth: 5 0.023% CompileError: WebAssembly.Module(): Compiling function #0 failed: invalid branch depth: 6 0.0025% CompileError: WebAssembly.Module(): Compiling function #0 failed: invalid branch depth: 8
July 5, 2025 at 11:24 AM
goose.icu
Porffor now passes over 59% of Test262!
Screenshot of a terminal showing: ~/porffor$ node test262 test: 29837/50424 passed - 59.17% (+0.45) (14 to go until 59.2%, 417 to go until 60%) 29837 7425 12893 🧪 50424 | 🤠 29837 (+227) | ❌ 7425 (-71) | 💀 12878 (-157) | 📝 0 | ⏰ 15 (+1) | 🏗️ 7 | 💥 262
May 26, 2025 at 12:49 AM
goose.icu
Porffor's Wasm is now faster than *native* Node JITless at richards.js, an old V8 benchmark!

new improvement is thanks to a new compiler feature and a minor object rewrite I'll post about this weekend. I still have ideas which can make this hopefully almost 2x faster this month!
~/porffor$ node bench/avg.js 10 "node --jitless bench/richards.js" 313 ~/porffor$ node bench/avg.js 10 "./porf bench/richards.js" 272
May 2, 2025 at 2:22 AM
goose.icu
introducing porffor profile, an easy to use but detailed profiler, with shareable links!
A screenshot of a web flamegraph/profiler UI
April 21, 2025 at 12:52 AM
goose.icu
Porffor now supports BigInt typed arrays: just this (plus some related changes) boosts Test262 passing by over 0.7%!
A Porffor JS REPL: > let foo = new BigInt64Array(4) undefined > foo[0] = 1337n // just a bigint 1337n > foo[0] = 1 // not a bigint, error and ignore Uncaught TypeError: Cannot convert to BigInt > foo[1] = 4294967296n // over 32 bit unsigned limit 4294967296n > foo[2] = 4611686018427387904n // near 64 bit signed limit, over accurate float limit 4611686018427387904n > foo BigInt64Array(4) [ 1337n, 4294967296n, 4611686018427387904n, 0n ]
March 19, 2025 at 11:02 AM
goose.icu
Porffor now passes over 57% of Test262! This latest bump was thanks to a refactor makes functions and methods distinct to be more conformant for this, construction, etc
"test262: 57.02% (+0.27)"
March 6, 2025 at 10:15 PM
goose.icu
Porffor compiling to Wasm is now faster than QuickJS interpreting natively for an older V8 benchmark!
~/porffor$ qjs bench/richards.js # quickjs, lower is better 384 ~/porffor$ ./porf bench/richards.js # new porffor, lower is better 303 ~/porffor$ git stash -q ~/porffor$ ./porf bench/richards.js # old porffor, lower is better 420
February 9, 2025 at 3:44 PM
goose.icu
net negative diff btw ;)
"+1637 -1666"
January 24, 2025 at 4:16 AM
goose.icu
optimization made conformance go up a bunch while making slightly smaller+faster Wasm 🚀📈
"test262: 56.29% (+0.47)"
January 24, 2025 at 2:41 AM
goose.icu
stretching the definition of weekend project but
A screenshot of the code editor Zed showing a file explorer and 3 columns of code with a dark theme.
December 15, 2024 at 1:44 AM
goose.icu
Now 56%!
A screenshot of the Test262 graph from porffor.dev showing progression over time with it currently passing 56.45%
December 11, 2024 at 2:32 AM
goose.icu
Porffor now passes over 55% of Test262, jumping by over 4% thanks to fixing a bug which broke class expressions 😅
"test262: 55.40% (+4.32)"
December 9, 2024 at 4:33 AM
goose.icu
Porffor compiler line count over time; the distinction between languages is very useful as JS = compiler, TS = built-ins
A screenshot of a line graph over time with both a JS and TS line shown, the JS line rises slowly over the whole time while TS quickly spikes half way through
December 5, 2024 at 1:56 AM
goose.icu
Checking if a value is "fully" truthy (like !!foo) is now ~2x as fast as before in Porffor
Screenshot of a terminal: ~/porffor$ ./porf bench/truthy.js # old, lower is better 4734 ~/porffor$ git stash pop -q ~/porffor$ ./porf bench/truthy.js # new, lower is better 2419
December 4, 2024 at 7:59 PM
goose.icu
bluesky still popping off
Screenshot of Bluesky UI showing "30+ notifications"
December 3, 2024 at 3:23 PM
goose.icu
new Porffor website out now! porffor.dev
Screenshot of https://porffor.dev
December 3, 2024 at 3:39 AM
goose.icu
what if I don't have production, oh no
"crash production"
November 26, 2024 at 4:56 PM
goose.icu
the UK is now IRL not for broadcast[1]

[1] en.wikipedia.org/wiki/Not_For...
A screenshot of a tweet: "Keir Starmer on ITV's This Morning has agreed to host a cooking segment."
November 25, 2024 at 9:34 PM
goose.icu
the same optimizationa lso makes the output wasm over 3x smaller!
Screenshot of a terminal: ~/porffor$ ./porf wasm bench/richards.js richards_new.wasm ~/porffor$ git stash -q ~/porffor$ ./porf wasm bench/richards.js richards_old.wasm ~/porffor$ du -h richards* 116K richards_new.wasm 412K richards_old.wasm
November 25, 2024 at 4:16 PM
goose.icu
fixed now 🎉
Screenshot of a terminal: ~/porffor$ ./porf r.cjs strict mode: false ~/porffor$ node r.cjs strict mode: false
November 25, 2024 at 10:35 AM
goose.icu
this is fine
Screenshot of a terminal: ~/porffor$ ./porf r.cjs strict mode: true ~/porffor$ node r.cjs strict mode: false
November 25, 2024 at 10:25 AM
goose.icu
Porffor's new timeline
A timeline showing: Creation - June 2023 Full-time - August 2024 Alpha - Q2 2025 Beta - Q1 2026
November 25, 2024 at 8:39 AM
goose.icu
🤠
A screenshot of a terminal: ~/porffor$ ./porf bench/object_get.js # old, lower is better 8032 ~/porffor$ git stash pop -q ~/porffor$ ./porf bench/object_get.js # new! lower is better 3276 ~/porffor$
November 13, 2024 at 12:25 AM