V8 @v8js Twitter profile

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V8

@v8js

5 years

🔥 Optional chaining syntax is coming to JavaScript! This feature enables readable and concise expression of property accesses with built-in nullish checking. @MayaLekova explains:

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@v8js

4 years

V8 hits its long-awaited v8.0, now with optional chaining, nullish coalescing, faster higher-order builtins — oh and 40% less memory use thanks to pointer compression, no big deal. h8rs gonna h8, V8ers gonna V8 🔥🔥🔥

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@v8js

6 years

Starting with Chrome 66, @v8js compiles JavaScript source code on a background thread, reducing main thread compile time up to 20%!

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@v8js

5 years

🚀 Top-level await makes it possible to use the `await` keyword outside of async functions in JavaScript modules! @mylesborins explains:

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@v8js

6 years

🚀 In Chrome 64 and Node.js v10, your JavaScript apps now continue execution while the @v8js garbage collector scans the heap to find and mark live objects! Free the main thread \o/

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@v8js

6 years

📣 V8 has native support for JavaScript code coverage. Tools like @ChromeDevTools and Istanbul can now access V8’s coverage information without instrumenting the code!

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@v8js

5 years

🔥 Nullish coalescing syntax is coming to JavaScript! This feature enables safer default expressions.

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@v8js

6 years

🚀 Chrome 66 reduces parse and compilation time for JavaScript code by 20-40% during initial load. How? V8’s code caching now also kicks in after top-level execution!

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@v8js

5 years

🔥 Weak references and finalizers are (finally) coming to JavaScript! @_gsathya and @mathias explain:

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@v8js

6 years

🎉 The V8 project has a new website: Just like V8 itself, we tried to make it fast and usable. Let us know what you think!

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@v8js

6 years

🔥 What’s new in ES2018? Let @bmeurer and @mathias walk you through major new JavaScript features:

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@v8js

5 years

As of @v8js v7.3 / Chrome 73, all of these ES2019 features are available by default. Enjoy!

Mathias Bynens

@mathias

5 years

🎉 New JavaScript features in ES2019: ➡️ Array#{flat,flatMap} ➡️ Object.fromEntries ➡️ String#{trimStart,trimEnd} ➡️ Symbol #description ➡️ try { } catch {} // optional binding ➡️ JSON ⊂ ECMAScript ➡️ well-formed JSON.stringify ➡️ stable Array #sort ➡️ revised Function #toString

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@v8js

6 years

🚀 Faster and easier-to-debug async functions and promises are coming to V8 v7.2 & Chrome 72! @MayaLekova and @bmeurer shed some light on the recent @v8js improvements:

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@v8js

6 years

🎉 Debugging memory leaks using @ChromeDevTools just became much easier! Find out what’s new:

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@v8js

6 years

Every single one of the new ES2018 language features is available by default in @v8js v6.4 and Chrome 64.

Mathias Bynens

@mathias

6 years

🎉 New JavaScript features in ES2018: - async iterators/generators - object rest/spread - Promise.prototype.finally - various RegExp features

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@v8js

5 years

👻 Recently, React core hit a scary V8 performance cliff. Here’s a technical deep dive explaining what happened behind the scenes in V8, and how we fixed it!

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@v8js

6 years

🔥 Jest reduced their test runner time by 20% by switching from plain JavaScript objects to Maps where it made sense. In general, don’t be afraid to use modern features! Focus on writing idiomatic code, and let JS engines worry about making it fast.

HasteMap with native maps by rubennorte · Pull Request #6960 · jestjs/jest

Summary This changes the data structure used to store the metadata for files, modules, mocks and duplicated modules in the Haste Map from Object (without prototypes) to Map. The performance of Map ...

github.com

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@v8js

5 years

🔥 Emscripten is switching to the LLVM WebAssembly backend, resulting in… ➡️ much faster link times ➡️ smaller and faster code ➡️ support for all LLVM IR ➡️ new WebAssembly features ➡️ faster general updates from upstream LLVM @kripken explains:

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@v8js

4 years

Learn how we reduced our heap size by up to 43% in the deep dive of “Pointer Compression in V8”! 📉 🔥

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@v8js

5 years

🔥 What’s new in JavaScript and @v8js ? Check out @mathias and @_gsathya ’s #io19 presentation to find out!

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@v8js

5 years

Orinoco (V8’s garbage collector) evolved from a sequential stop-the-world implementation into a mostly parallel and concurrent collector with incremental fallback. @hooraybuffer talks trash:

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@v8js

3 years

static { console.log('🎉 JavaScript classes get dedicated syntax for static initialization!'); // Check out the feature explainer location.href = ''; }

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@v8js

6 years

🚀 V8 v6.9 includes Liftoff, a new baseline compiler for WebAssembly! Liftoff vastly reduces start-up time of WebAssembly applications with a simple and fast code generator.

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@v8js

5 years

The dominant costs of processing JavaScript are: ➡️ download ➡️ CPU execution time @addyosmani on the cost of JavaScript in 2019:

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@v8js

6 years

🎉 V8 v6.7 ships with BigInt support enabled by default! BigInts are a new numeric primitive in JavaScript that can represent integers with arbitrary precision. @mathias walks through the functionality here:

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@v8js

5 years

🔥 V8 v7.4 supports a JIT-less or “interpreter-only” mode, where JavaScript executes without allocating executable memory at runtime.

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@v8js

3 years

🕚 WebAssembly SIMD will be shipped by default in Chrome 91. We have updated our SIMD feature explainer and added new instructions for feature detection, cross-compilation of code targeted for SSE/AVX/NEON to Wasm, and usage from Rust.

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@v8js

6 years

V8 v6.9 embeds built-in code into the binary’s `.text` section, reducing the median V8 heap size per website by 19%.

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@v8js

3 years

V8, step back from the regex! Or maybe don't 😏 V8 now has an additional RegExp engine that can prevent many instances of catastrophic backtracking:

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@v8js

3 years

⚡ The more the merrier: we've added Sparkplug - a new non-optimizing JS compiler - in V8 v9.1 to improve performance on real-world pages by 5-15%. Let @leszekswirski take you on a tour:

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@v8js

3 years

📨 You can now import JSON directly from JavaScript. This works via a new import assertions feature - already in Chrome 91! Learn how to use it from this feature explainer by @dandclark1 from Microsoft:

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@v8js

5 years

🔥 What’s new in V8 v7.2? High-speed JavaScript parsing, faster async-await, reduced memory consumption on ia32, public class fields, and much more!

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@v8js

7 years

The V8 project now has its own Twitter account. Follow @v8js for the latest updates from the world of JavaScript engines! 🚀

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@v8js

5 years

🔥 (Byte)code caching reduces the start-up time of commonly visited websites by caching the result of JavaScript parsing + compilation. How can JavaScript developers get the most out of @v8js code caching in @ChromiumDev ? @leszekswirski explains:

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@v8js

3 years

How it started: 🐢 (...) How it's going: 🐇 Object.hasOwn(...)

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@v8js

5 years

🔥 V8 v7.2 / Chrome 72 greatly improves the performance of spread elements of the form [...x] or [...x, y, z]. Here’s how we did it:

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@v8js

4 years

What’s in that .wasm? 🔍 Introducing: wasm-decompile! Read the contents of WebAssembly modules in a more friendly and familiar way.

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@v8js

5 years

🔥 As it turns out, NOT parsing is faster than parsing. That’s why JavaScript engines implement a preparser which enables lazy parsing and compilation. Here’s how that works in V8:

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@v8js

5 years

🔥 Regular expressions just got faster *and* more memory-efficient in V8:

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@v8js

6 years

🔥 What’s new in JavaScript and @v8js ? Check out @mathias and @_gsathya ’s #io18 presentation to find out!

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@v8js

6 years

Happy 10th birthday to @v8js and @ChromiumDev ! 🎂 Here’s an overview of how the @v8js project evolved during the last 10 years:

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@v8js

4 years

🚀 Atomics API gains ability to asynchronously wait on shared memory locations! In this new JavaScript feature explainer, @marjakh demonstrates how to use Atomics to implement a mutex with blocking and non-blocking modes.

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@v8js

6 years

🔥 JavaScript engines: The Good Parts™ An overview of the key fundamentals that are common to all JavaScript engines (and not just @v8js !) by @bmeurer and @mathias :

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@v8js

6 years

What’s new in V8 v6.9? Reduced memory usage through embedded built-ins, faster WebAssembly startup through Liftoff, better DataView and WeakMap performance, and much more!

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@v8js

6 years

🔥 JavaScript engine fundamentals: optimizing prototypes ➡️ Why do some engines have 2+ optimization tiers? ➡️ Why not just optimize everything? ➡️ How do engines speed up classes? ➡️ Bonus: One Weird Performance Trick™ by @bmeurer & @mathias

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@v8js

4 years

Logical &&= assignment ||= feature ??= explainer 🔥 In which @_shu shows how to use a new ECMAScript syntax for conditional assignments. (Experimental implementation is available in V8 v8.4 behind the --harmony-logical-assignment flag.)

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@v8js

6 years

Array.prototype.sort is now stable in @v8js v7.0 / Chrome 70! 🎉 @nimODota explains how and why we made this happen:

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@v8js

5 years

🔥 What’s new in V8 v7.3? Wasm and async performance improvements, async stack traces, Object.fromEntries, String #matchAll , and much more!

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@v8js

6 years

In JavaScript, Map/Set/WeakSet/WeakMap all use hash tables under the hood. @_gsathya recently boosted their performance by improving the way V8 stores the keys in hash tables:

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@v8js

5 years

JavaScript gains first-class support for global substring replacement! 🔥 @mathias explains the new String.prototype.replaceAll API: (V8 v8.0 has an experimental implementation behind the --harmony-string-replaceall flag.)

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@v8js

6 years

What’s new in V8 v6.8? Reduced memory consumption and several performance improvements!

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@v8js

3 years

🔍 JS arrays supported searching items for a while now via `.find` and `.findIndex` methods. However, they always return the first match. What if you want to find the last matching item instead? Now you can with `findLast` and `findLastIndex`!

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@v8js

4 years

WebAssembly brings SIMD support to the Web. What is it? @dptig and @tlively52 explain and demonstrate how to use it to run native code on the Web even faster! 🔥 (This feature is currently experimental and available under a flag.)

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@v8js

5 months

We shipped a new compiler named Maglev! It's a mid-tier "good enough, fast enough" compiler that improves our Speedometer score by some 5-6% while dropping power consumption by around 10%:

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@v8js

6 years

Lazy deserialization in @v8js reduces memory consumption by 500 KB per @GoogleChrome browser tab. 🔥 @jgruber explains how it works:

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@v8js

7 years

🔥 The brand-new Web Tooling Benchmark helps identify & fix @v8js performance bottlenecks in Babel, TypeScript, etc.

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@v8js

6 years

🎥 Video for @agoggel ’s @amsterdamjs presentation titled “ECMAScript Modules: Past, Present, and Future”:

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@v8js

6 years

📢 Chrome 68 on Windows, Linux, Mac and ChromeOS supports SharedArrayBuffers again. Please note that Atomics.wake was renamed to Atomics.notify. More context in

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@v8js

6 years

The implementation of the BigInt proposal for ECMAScript is almost feature complete in latest @v8js . 😎 And the performance of this baseline implementation looks very promising already! 🔥

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@v8js

3 years

Why was an Error thrown? Just 'cause 🤷‍♂️ You can now chain errors via a new `cause` property to provide more context when they're re-thrown:

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@v8js

6 years

As webpack/V8/Node.js version numbers increase, build times decrease: TL;DR Regularly install updates 🚀

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@v8js

5 years

🔥 What’s new in V8 v7.8? Streaming compilation on preload, WebAssembly C API, faster object destructuring and RegExp matching, and improved startup times!

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@v8js

5 years

Same great V8 t̵a̵s̵t̵e performance 🔥, now with 20% less s̵u̵g̵a̵r memory overhead ♻️.

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@v8js

4 years

Understanding the ECMAScript spec, part 1: In this article, @marjakh explains how JavaScript built-ins are specified, and how to make sense of the spec text. 🔥

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@v8js

7 years

🚀 V8 now inlines closure allocations. The arrow-declare benchmark shows a 50% speed-up!

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@v8js

4 years

JavaScript is now equipped with a new regular expression enhancement! @MayaLekova shows how it can be used for finding positions of matched groups. (This feature is available starting from V8 v7.9 behind a --harmony-regexp-match-indices flag.)

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@v8js

5 years

🔥 One of the most underrated ES2019 features is “subsume JSON”, a.k.a. “JSON ⊂ ECMAScript”. It simplifies the language & enables interesting meta-programming use cases. JSON.stringify output can now be embedded as a literal within JavaScript programs!

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@v8js

5 years

WebAssembly code caching is a new optimization in Chrome and V8 that tries to avoid code compilation by caching the native code produced by the compiler. @BillB walks through the implementation and gives a few tips for WebAssembly developers:

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@v8js

6 months

WebAssembly now has direct support for GC! Read our new technical article to learn about how it works as well as what the team has been doing in this space both in V8 and in the toolchain:

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@v8js

6 years

🔥 DataViews are now as efficient as TypedArrays in @v8js v6.9, finally making DataViews a viable choice in performance-critical situations. Here’s how we boosted DataView performance:

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@v8js

3 years

⌚ Who's got the time to pass all the arguments to the function? We thought so too. V8 can now invoke functions with argument number mismatch even faster! 🚅 Learn how from a deep dive by Victor Gomes:

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@v8js

6 years

The @v8js and @ChakraCore teams share their secret to making sure your JavaScript runs fast in every browser: Spoiler: focus on writing idiomatic, readable, and maintainable code.

Modernizing Node.js with idiomatic JavaScript

This blog post was written by Peter Marshall, Software Engineer at Google, V8 and Arunesh Chandra, Sr. Program Manager at Microsoft, Chakra

medium.com

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@v8js

5 years

👻 A year with Spectre: a V8 perspective In which the V8 team details their analysis and mitigation strategy for Spectre, one of the top computer security issues of 2018.

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@v8js

6 years

🚀 The Chrome team welcomes Speedometer 2.0! gives an overview of the performance improvements we’ve made so far in Blink and V8 based on the new version of the Speedometer benchmark.

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@v8js

3 years

🔥 V8 v9.6 ships support for WebAssembly reference types!

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@v8js

5 years

🔥 What’s new in V8 v7.7? Lazy feedback allocation, faster WebAssembly background compilation, stack trace improvements, and new Intl.NumberFormat functionality!

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@v8js

5 years

🔥 What’s new in V8 v7.4? Wasm threads/Atomics, private class fields, performance and memory improvements, and much more!

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@v8js

4 years

🔥 You can now use up to 4GB of memory in WebAssembly applications - and beyond! Andreas Haas, Jakob Kummerow and Alon Zakai explain the work that went into Chrome (V8) and Emscripten to make this happen:

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@v8js

4 years

Tired of spending your time fixing C++ memory issues? 😫 📚 Learn how Oilpan provides a safe high-performance garbage collection for C++.

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@v8js

5 years

🎓 In this Chrome University talk, @_gsathya and @JakobKummerow explain how scripts are executed in @ChromiumDev . Learn how @v8js handles parsing, bytecode generation, interpretation, JIT compilation, and deoptimization:

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@v8js

5 years

WasmBoy is a Game Boy Emulation Library for running ROMs in browsers and in Node.js, written in AssemblyScript. In this presentation, @torch2424 explains why WebAssembly’s predictable performance is the perfect fit for WasmBoy:

WebAssembly for Javascript Developers, by Aaron Turner

Original event: https://www.meetup.com/wasmsf/events/258613527/Slides: https://docs.google.com/presentation/d/1gFS7lWfBcqkIApLOQctbbIDi8uuqenO_fz9BqjPZHlE/ed...

www.youtube.com

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@v8js

2 months

Iterator helpers are a collection of new methods on Iterator prototype that help in general use of iterators. V8 shipped these helpers in v12.2! Please check out for more information.

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@v8js

4 years

🔥 What’s new in V8 v8.4? Weak references and finalizers, improved WebAssembly start-up and debugging performance, and updated SIMD support.

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@v8js

6 years

V8 now uses a parallel Scavenger to garbage-collect the young generation. Find out what that means and why it’s better:

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@v8js

3 years

🔥 What’s new in V8 v8.9? Top-level `await` enabled by default in Blink and performance improvements for calls with argument size mismatch.

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@v8js

3 years

🎯 Ever wanted to easily access items from the end of a collection? Well now you can! Check out the feature explainer for the new `.at()` method on arrays, strings and TypedArrays:

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@v8js

6 years

What’s new in V8 v7.0? WebAssembly threads, Symbol #description , and embedded built-ins on more platforms!

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@v8js

3 years

🔥 What’s new in V8 v9.0? RegExp match indices, faster super property access, inlined JS-to-Wasm calls and more!

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@v8js

6 years

🔥 Modern JavaScript idioms are good for performance! 📹 In this presentation, @sigurdschn explains why. 🚀 Widening the fast-path of TurboFan builtins

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@v8js

4 years

🔥 What’s new in V8 v8.3? Faster ArrayBuffer tracking, bigger WebAssembly memories, bug fixes and API changes.

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@v8js

6 years

What’s new in V8 v6.6? Optional catch binding, extended string trimming, several parse/compile/runtime performance improvements, and much more!

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@v8js

5 months

🎀 We may have been quiet on the V8 blog, but it's been a busy year for the V8 team! WasmGC, security work, two(!) new compilers, new JS and Wasm features, and even some V8-adjacent Chromium optimisations — with a 34% Speedometer score improvement overall:

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@v8js

4 years

Emscripten now supports a standalone mode, to better serve the various ways WebAssembly is being used outside of the Web. It enables building and using Wasm modules even in runtimes without JavaScript support.

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@v8js

4 years

🤔 How does V8 figure out which properties get to live on site and which ones have to work from home? A deep dive into the classic V8 internals:

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@v8js

7 years

TurboFan now folds away calls like `Object(value)` when `value` is already a JavaScript object. This speeds up webpack v3-generated code.

Benedikt Meurer

@bmeurer

7 years

🗞️ New blog post "Object constructor calls in webpack bundles" with some background on the recent webpack findings

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@v8js

4 years

🔥 What’s new in V8 v8.5? Promise.any, String #replaceAll , logical assignment operators, WebAssembly multi-value and BigInt support, and performance improvements!

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@v8js

6 years

What’s new in V8 v6.4? Better performance, reduced memory consumption, and new ECMAScript features!

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@v8js

1 month

🔒We've been working on a custom in-process sandbox for V8. Find out more about the motivation behind this project and its goals in our new blog post:

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@v8js

5 years

Let's [not] keep you in the dark anymore... Introducing dark mode for ! By default we're going to display the blog according to your system theme, but feel free to override the preference using a toggle in the footer. (h/t @tomayac )

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@v8js

3 years

💭 WebAssembly has support for 64-bit integers. But how can it communicate with JavaScript which traditionally couldn't even represent values this large? Learn from a new feature explainer by @kripken :

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