Editing Bytecode (section)

{{Short description|Form of instruction set designed to be run by a software interpreter}}
{{redirect2|Portable code|P-code|other uses|software portability|and|P-Code (disambiguation)}}
{{More citations needed|date=January 2009}}
{{Use dmy dates|date=May 2019|cs1-dates=y}}
{{Program execution}}

'''Bytecode''' (also called '''portable code''' or '''p-code''') is a form of [[instruction set]] designed for efficient execution by a software [[interpreter (computing)|interpreter]]. Unlike [[Human-readable code|human-readable]]<ref name="Dynamic_Machine_Code"/> [[source code]], bytecodes are compact numeric codes, constants, and references (normally numeric addresses) that encode the result of [[compiler]] parsing and performing [[Semantic analysis (compilers)|semantic analysis]] of things like type, scope, and nesting depths of program objects.

The name ''bytecode'' stems from instruction sets that have one-[[byte]] [[opcode]]s followed by optional parameters. [[Intermediate representation]]s such as bytecode may be output by [[programming language]] implementations to ease [[interpreter (computing)|interpretation]], or it may be used to reduce hardware and [[operating system]] dependence by allowing the same code to run [[cross-platform]], on different devices. Bytecode may often be either directly executed on a [[virtual machine]] (a [[p-code machine]], i.e., interpreter), or it may be further compiled into [[machine code]] for better performance.

Since bytecode instructions are processed by software, they may be arbitrarily complex, but are nonetheless often akin to traditional hardware instructions: virtual [[stack machine]]s are the most common, but virtual [[register machine]]s have been built also.<ref name="Jucs_Lua"/><ref name="Dalvik"/> Different parts may often be stored in separate files, similar to [[object file|object modules]], but dynamically loaded during execution.