V8 is a

free and open-source Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...

JavaScript engine A JavaScript engine is a software component that executes JavaScript code. The first JavaScript engines were mere interpreters, but all relevant modern engines use just-in-time compilation for improved performance. JavaScript engines are typical ...

developed by the Chromium Project for

Google Chrome Google Chrome is a cross-platform web browser developed by Google. It was first released in 2008 for Microsoft Windows, built with free software components from Apple WebKit and Mozilla Firefox. Versions were later released for Linux, macOS ...

and

Chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardne ...

web browsers. The project’s creator is

Lars Bak Lars Ytting Bak (born 16 January 1980) is a Danish former professional road bicycle racer, who rode professionally between 2002 and 2019 for the Fakta, , , , and squads. From 2022, Bak will act as team manager for UCI Women's WorldTeam . Ba ...

. The first version of the V8 engine was released at the same time as the first version of Chrome: 2 September 2008. It has also been used on the server side, for example in Couchbase and

Node.js Node.js is an open-source server environment. Node.js is cross-platform and runs on Windows, Linux, Unix, and macOS. Node.js is a back-end JavaScript runtime environment. Node.js runs on the V8 JavaScript Engine and executes JavaScript code ou ...

History

The V8 assembler is based on the

Strongtalk Strongtalk is a Smalltalk environment with optional static typing support. Strongtalk can make some compile time checks, and offer ''stronger'' type safety guarantees; this is the source of its name. It is non-commercial, though it was originally ...

assembler. On 7 December 2010, a new compiling infrastructure named Crankshaft was released, with speed improvements. In version 41 of Chrome in 2015, project TurboFan was added to provide more performance improvements with previously challenging workloads such as

asm.js asm.js is a subset of JavaScript designed to allow computer software written in languages such as C to be run as web applications while maintaining performance characteristics considerably better than standard JavaScript, which is the typical l ...

. Much of V8's development is strongly inspired by the Java HotSpot Virtual Machine developed by

Sun Microsystems Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the ...

, with the newer execution pipelines being very similar to those of HotSpot's. In 2016, the Ignition interpreter was added to V8 with the design goal of reducing the memory usage on small memory

Android Android may refer to: Science and technology * Android (robot), a humanoid robot or synthetic organism designed to imitate a human * Android (operating system), Google's mobile operating system ** Bugdroid, a Google mascot sometimes referred to ...

phones in comparison with TurboFan and Crankshaft. 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. 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.

Design

V8 first generates an abstract syntax tree with its own parser. Then, Ignition generates

bytecode Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (norma ...

from this syntax tree using the internal V8 bytecode format. TurboFan compiles this bytecode into machine code. In other words, V8 compiles

ECMAScript ECMAScript (; ES) is a JavaScript standard intended to ensure the interoperability of web pages across different browsers. It is standardized by Ecma International in the documenECMA-262 ECMAScript is commonly used for client-side scripting o ...

directly to native machine code using just-in-time compilation before executing it. 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 In linguistics, an elision or deletion is the omission of one or more sounds (such as a vowel, a consonant, or a whole syllable) in a word or phrase. However, these terms are also used to refer more narrowly to cases where two words are run toget ...

of expensive runtime properties, and

inline caching Inline caching is an optimization technique employed by some language runtimes, and first developed for Smalltalk. The goal of inline caching is to speed up runtime method binding by remembering the results of a previous method lookup directly a ...

. The

garbage collector A waste collector, also known as a garbageman, garbage collector, trashman (in the US), binman or (rarely) dustman (in the UK), is a person employed by a public or private enterprise to collect and dispose of municipal solid waste (refuse) and r ...

is a generational incremental collector.

Usage

V8 can compile to

x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introd ...

, ARM or MIPS

instruction set architecture In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ' ...

s in both their

32-bit In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in 32-bit units. Compared to smaller bit widths, 32-bit computers can perform large calculation ...

and

64-bit In computer architecture, 64-bit Integer (computer science), integers, memory addresses, or other Data (computing), data units are those that are 64 bits wide. Also, 64-bit central processing unit, CPUs and arithmetic logic unit, ALUs are those ...

editions; it has additionally been ported to

PowerPC PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...

and IBM s390 for use in servers. V8 can be used in a browser or integrated into independent projects. V8 is used in the following software: *

-based

web browser A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used on ...

s -

, Brave,

Opera Opera is a form of theatre in which music is a fundamental component and dramatic roles are taken by singers. Such a "work" (the literal translation of the Italian word "opera") is typically a collaboration between a composer and a librett ...

Vivaldi Antonio Lucio Vivaldi (4 March 1678 – 28 July 1741) was an Italian composer, virtuoso violinist and impresario of Baroque music. Regarded as one of the greatest Baroque composers, Vivaldi's influence during his lifetime was widespread a ...

and Microsoft Edge. * Couchbase database server * Deno runtime environment *

Electron The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no kn ...

desktop application framework, used by the

Atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, and ...

and Visual Studio Code text editors *

MarkLogic MarkLogic Corporation is an American software business that develops and provides an enterprise NoSQL database, also named ''MarkLogic''. The company was founded in 2001 and is based in San Carlos, California. MarkLogic is a privately held compa ...

database server * NativeScript mobile application framework *

runtime environment *

Qt Quick Qt Quick is a free software application framework developed and maintained by the Qt Project within the Qt framework. It provides a way of building custom, highly dynamic graphical user interfaces with fluid transitions and effects, which are b ...

runtime environment

References

External links

* {{NodeJs 2008 software Free compilers and interpreters Google Chrome Google software JavaScript engines Software using the BSD license Virtual machines

History

Design

Usage

See also

References

External links