Wikipedia

V8 (JavaScript engine)

V8 is a JavaScript and WebAssembly engine developed by Google for its Chrome browser.[1][4] V8 is free and open-source software that is part of the Chromium project and also used separately in non-browser contexts, notably the Node.js runtime system.[1]

V8
Developer(s)Google[1]
Initial release2 September 2008; 15 years ago (2008-09-02)
Stable release
11.4[2] Edit this on Wikidata / 24 May 2023; 11 months ago (24 May 2023)
Repository
Written inC++[1]
PlatformIA-32, x86-64, 32-bit ARM, AArch64, 32-bit MIPS, MIPS64, PowerPC, IBM ESA/390, z/Architecture
TypeJavaScript and WebAssembly engine
LicenseBSD[3]
Websitev8.dev Edit this on Wikidata

History edit

Google created V8 for its Chrome browser, and both were first released in 2008.[4] The lead developer of V8 was Lars Bak, and it was named for the powerful car engine.[5] For several years, Chrome was faster than other browsers at executing JavaScript.[6][7][8]

The V8 assembler is based on the Strongtalk assembler.[9] On 7 December 2010, a new compiling infrastructure named Crankshaft was released, with speed improvements.[10] In version 41 of Chrome in 2015, project TurboFan was added to provide more performance improvements with previously challenging workloads such as asm.js.[11] Much of V8's development is strongly inspired by the Java HotSpot Virtual Machine developed by Sun Microsystems, with the newer execution pipelines being very similar to those of HotSpot's.

Support for the new WebAssembly language began in 2015.[12]

In 2016, the Ignition interpreter was added to V8 with the design goal of reducing the memory usage on small memory Android phones in comparison with TurboFan and Crankshaft.[13] Ignition is a register based machine and shares a similar (albeit not the exact same) design to the templating interpreter utilized by HotSpot.

In 2017, V8 shipped a brand-new compiler pipeline, consisting of Ignition (the interpreter) and TurboFan (the optimizing compiler). Starting with V8 version 5.9, Full-codegen (the early baseline compiler) and Crankshaft are no longer used in V8 for JavaScript execution, since the team believed they were no longer able to keep pace with new JavaScript language features and the optimizations those features required.[14]

In 2021, a new tiered compilation pipeline was introduced with the release of the SparkPlug compiler, which supplements the existing TurboFan compiler within V8, in a direct parallel to the profiling C1 Compiler used by HotSpot.

In 2023, the Maglev SSA-based compiler was added, which is 10 times slower than Sparkplug but 10 times faster than TurboFan, bridging the gap between Sparkplug and TurboFan for less frequently run loops that do not get "hot" enough to be optimised by TurboFan, as is the case for most web applications that spend more time interacting with the browser than in JavaScript execution. [15]

Design edit

V8 first generates an abstract syntax tree with its own parser.[16] Then, Ignition generates bytecode from this syntax tree using the internal V8 bytecode format.[17] TurboFan compiles this bytecode into machine code. In other words, V8 compiles ECMAScript directly to native machine code using just-in-time compilation before executing it.[18] The compiled code is additionally optimized (and re-optimized) dynamically at runtime, based on heuristics of the code's execution profile. Optimization techniques used include inlining, elision of expensive runtime properties, and inline caching. The garbage collector is a generational incremental collector.[19]

Usage edit

V8 can compile to x86, ARM or MIPS instruction set architectures in both their 32-bit and 64-bit editions; it has additionally been ported to PowerPC,[20][21] and to IBM ESA/390 and z/Architecture,[22][20] for use in servers.[23]

V8 can be used in a browser or integrated into independent projects. V8 is used in the following software:

See also edit

  • Blink, the Chromium browser engine

References edit

  1. ^ a b c d "Documentation · V8". Google. Retrieved 3 March 2024.
  2. ^ "Chrome Platform Status". Retrieved 29 June 2023.
  3. ^ "v8/LICENSE.v8 at master". Github.
  4. ^ a b Lenssen, Philipp (1 September 2008). "Google on Google Chrome - comic book". Google Blogoscoped. Retrieved 17 August 2010.
  5. ^ "V8: an open source JavaScript engine". YouTube. Google. Retrieved 15 March 2024.
  6. ^ "Big browser comparison test: Internet Explorer vs. Firefox, Opera, Safari and Chrome". PC Games Hardware. Computec Media AG. 3 July 2009. Archived from the original on 2 May 2012. Retrieved 28 June 2010.
  7. ^ Purdy, Kevin (11 June 2009). "Lifehacker Speed Tests: Safari 4, Chrome 2". Lifehacker. Archived from the original on 14 April 2021. Retrieved 8 May 2021.
  8. ^ "Mozilla asks, 'Are we fast yet?'". Wired. Archived from the original on 22 June 2018. Retrieved 18 January 2019.
  9. ^ "V8 JavaScript Engine: License". Google Code. Archived from the original on 22 July 2010. Retrieved 17 August 2010.
  10. ^ "A New Crankshaft for V8". Chromium Blog. 7 December 2010. Retrieved 22 April 2011.
  11. ^ "Revving up JavaScript performance with TurboFan". 7 July 2015. Retrieved 5 March 2016.
  12. ^ "Experimental support for WebAssembly in V8". v8.dev. Retrieved 12 March 2024.
  13. ^ "BlinkOn 6 Day 1 Talk 2: Ignition - an interpreter for V8". YouTube. 26 June 2016. Archived from the original on 21 December 2021. Retrieved 2 September 2016.
  14. ^ "Launching Ignition and TurboFan". 16 May 2017. Retrieved 13 July 2017.
  15. ^ "Maglev - V8's Fastest Optimizing JIT". 5 December 2023. Retrieved 26 January 2024.
  16. ^ Verwaest, Toon (25 March 2019). "Blazingly fast parsing, part 1: optimizing the scanner · V8". v8.dev. Archived from the original on 21 April 2021. Retrieved 1 June 2021.
  17. ^ Hinkelmann, Franziska (19 December 2017). "Understanding V8's Bytecode". Medium. Retrieved 17 October 2019.
  18. ^ "Firing up the Ignition interpreter · V8". v8.dev. Retrieved 30 September 2020.
  19. ^ "A game changer for interactive performance". blog.chromium.org. 21 November 2011. Retrieved 6 February 2022.
  20. ^ a b "PPC support for Google V8 goes mainstream". 30 June 2015. Archived from the original on 12 September 2015.
  21. ^ "GitHub - ibmruntimes/v8ppc: Port of Google V8 javascript engine to PowerPC®". 21 April 2019 – via GitHub.
  22. ^ "Port of Google V8 JavaScript engine to z/OS. The Linux on Z port is maintained in the community: ibmruntimes/v8z". 2 April 2019 – via GitHub.
  23. ^ "V8 Changelog v3.8.2". Archived from the original on 22 October 2012. Retrieved 23 October 2012.
  24. ^ "A secure JavaScript/TypeScript runtime built with V8, Rust, and Tokio: denoland/deno". 8 July 2019 – via GitHub.
  25. ^ "Overview - NativeScript Docs". docs.nativescript.org.
  26. ^ Jolie O'Dell (10 March 2011). "Why Everyone Is Talking About Node". Mashable.
  27. ^ "Difference between qt qml and qt quick". Stack Overflow. Retrieved 26 September 2020.

External links edit

 
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