Machine Code

Machine code or machine language is a system of impartible instructions executed directly by a computer's central processing unit (CPU). Each instruction performs a very specific task, typically either an operation on a unit of data (in a register or in memory, e.g. add or move), or a jump operation (deciding which instruction executes next, often conditional on the results of a previous instruction). Every executable program is made up of a series of these atomic instructions. Machine code may be regarded as an extremely hardware-dependent programming language or as the lowest-level representation of a compiled and/or assembled computer program. While it is possible to write programs in machine code, because of the tedious difficulty in managing CPU resources, it is rarely done today, except for situations that require the most extreme optimization.

Almost all executable programs are written in higher-level languages, and translated to executable machine code by a compiler and linker. Machine code is sometimes called native code when referring to platform-dependent parts of language features or libraries.

Programs in interpreted languages are not translated to machine code; however, their interpreter (which may be seen as a processor executing the higher-level program) often is. Machine code should not be confused with so-called "bytecode", which is executed by an interpreter.

Read more about Machine Code:  Machine Code Instructions, Programs, Assembly Languages, Example, Relationship To Microcode, Storing in Memory, Readability By Humans

Other articles related to "machine, code, machine code":

AOT Compiler
... IBM System/38 or IBM System i "Technology Independent Machine Interface" code, into a system-dependent binary ... Most languages with a managed code runtime that can be compiled to an intermediate language take advantage of just-in-time (JIT) ... This, briefly, compiles intermediate code into machine code for a native run while the intermediate code is executing, which may decrease an application's performance ...
Machine Code - Readability By Humans
... It has been said that machine code is so unreadable that the United States Copyright Office cannot even identify whether a particular encoded program is an original work ... Hofstadter compares machine code with the genetic code "Looking at a program written in machine language is vaguely comparable to looking at a DNA molecule atom by atom." ...
Proof-carrying Code - Packet Filter Example
... The original publication on proof-carrying code in 1996 used packet filters as an example a user-mode application hands a function written in machine code ... of the system if it contains malicious code that writes to kernel data structures ... all have severe performance disadvantages for code as frequently run as a packet filter ...
Metamorphic Code
... Metamorphic code is code that when run outputs a logical equivalent version of its own code under some interpretation ... This is similar to a quine, except that the quines source code are exactly equivalent to their own output ... Metamorphic code also usually output machine code and not its own source code ...
English Electric KDF8 - Basic Features - Processor/main Store
... KDF8 was a transistor based machine with magnetic core memory ... The core memory of the machine installed at the Kidsgrove (Staffordshire) site of The English Electric Company's computer bureau was considered large for its time having been upgraded from 64k ... A machine-code instruction was fixed length, ten octal characters long and the instruction set was specifically designed for ease of commercial use ...

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