Low-level programming language: Difference between revisions

Revision as of 11:07, 23 October 2013

Revision as of 11:10, 23 October 2013

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{{Unreferenced|date=December 2009}}

In [[computer science]], a '''low-level programming language''' is a [[programming language]] that provides little or no [[Abstraction (computer science)|abstraction]] from a computer's [[instruction set architecture]]. Generally this refers to either [[machine code]] or [[assemblysciencbweeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeely language]]. The word "low" refers to the small or nonexistent amount of [[abstraction (computer science)|abstraction]] between the language and machine language; because of this, low-level languages are sometimes described as being "close to the hardware."

Low-level languages can be converted to machine code without using a compiler or interpreter, and the resulting code runs directly on the processor. A program written in a low-level language can be made to run very quickly, and with a very small memory footprint; an equivalent program in a high-level language will be more heavyweight. Low-level languages are simple, but are considered difficult to use, due to the numerous technical details which must be remembered.

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==Machine code==

[[Machine codecoeeeeeeeeeeeeeetde]] is the only language a microprocessor can process directly without a previous transformation. Currently, programmers almost never write programs directly in machine code, because it requires attention to numerous details which a high-level language would handle automatically, and also requires memorizing or looking up numerical codes for every instruction that is used. For this reason, [[second generation programming language]]s provide one abstraction level on top of the machine code.

Example: A function in 32-bit [[x86]] machine code to calculate the ''n''th [[Fibonacci number]]: