V8 is a free and open-source JavaScript engine developed by the Chromium Project for Google Chrome 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 h ...

web browsers. The project’s creator is

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. 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.

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

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, 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 directly to native machine code using

just-in-time compilation In computing, just-in-time (JIT) compilation (also dynamic translation or run-time compilations) is a way of executing computer code that involves compiler, compilation during execution of a program (at run time (program lifecycle phase), run tim ...

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,

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of expensive runtime properties, and inline caching. The garbage collector is a generational incremental collector.

Usage

V8 can compile to x86, ARM or MIPS

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s in both their 32-bit and 64-bit 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– IBM ...

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 - Google Chrome,

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

Electron The electron (, or in nuclear reactions) 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 partic ...

desktop application framework, used by the

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and Visual Studio Code text editors * MarkLogic database server * NativeScript mobile application framework * Node.js runtime environment * Qt Quick 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