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Definition: Assembly Language |
Assembly LanguageNoun1. A low-level programing language; close approximation to machine language. Source: WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved. |
| Domain | Definition |
Computing | Assembly language |
Source: compiled by the editor from various references; see credits. | |
(From Wikipedia, the free Encyclopedia)
So, while a computer will recognize what the IA-32 machine instruction
10110000 01100001does, for programmers it is easier to remember the equivalent assembly language representation
mov %al,$0x61(it means to move the hexadecimal value 61 (97 decimal) into the register 'al'.)
Unlike in high-level languages, there is (to a close approximation) a 1-to-1 correspondence between simple assembly to machine language. Transforming assembly into machine languages is accomplished by an assembler, the other direction by a disassembler.
Every computer architecture has its own machine language, and therefore its own assembly language (the example above is from the i386). These languages differ by the number and type of operations that they support. They may also have different sizes and numbers of registers, and different representations of data types in storage. While all general-purpose computers are able to carry out esentially the same functionality, the way they do it differs.
In addition, multiple sets of mnemonics or assembly-language syntax may exist for a single instruction set. In these cases, the most popular one is usually that used by the manufacturer in their documentation.
Similar basic operations are available in almost all instruction sets.
In addition to codes for machine instructions, assembly languages have extra directives for assembling blocks of data, and assigning address locations for instructions or code.
They usually have a simple symbolic capability for defining values as symbolic expressions which are evaluated at assembly time, making it possible to write code that is easier to read and understand.
Like most computer languages, textual comments can be added to the source code which are ignored by the computer.
They also usually have an embedded macro language to make it easier to generate complex pieces of code or data.
In practice, the absence of comments and the replacement of symbols with actual numbers makes the human interpretation of disassembled code considerably more difficult than the original source would be.
There is some debate over the usefulness of assembly language. It is often said that modern compilers can render higher-level languages into code as that runs as fast as hand-written assembler, but counter-examples can be made, and there is no clear consensus on this topic. It is reasonabily certain that, given the increase in complexity of modern processors, effective hand-optimization is increasingly difficult and requires a great deal of knowledge.
However, some discrete calculations can still be rendered into faster running code in assembler, and some low-level programming is simply easier to do in assembler. Some system-dependent tasks performed by operating systems simply cannot be expressed in high-level languages. Many compilers also render high-level languages into assembler first before fully compiling, allowing the assembler code to be viewed for debugging and optimization purposes.
Many embedded systems are also programmed in assembly to squeeze the absolute maximum functionality out of what is often very limited computational resources, though this is gradually changing in some areas as more powerful chips become available for the same minimal cost.
Machine instructions
Specific instruction sets will often have single, or a few instructions for operations which would otherwise take many instructions. Examples:
Assembly language directives
Usage of assembly language
See also:
External Links:
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Assembly language."
| Domain | Title |
Books |
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Source: compiled by the editor from various references; see credits. | |
Expressions using "assembly language": algorithmic ASsembly language ♦ array Processor Assembly Language ♦ assembly Language Compiler ♦ assembly Language for Multics ♦ basic Assembly Language ♦ DSP32 Assembly Language ♦ micro Assembly Language ♦ PDP Assembly Language. Additional references. | |
| Source: compiled by the editor from various references; see credits. |
| The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com. |
| Language | Translations for "assembly language"; alternative meanings/domain in parentheses. | ||||||||||||||||||||||
Danish | assemblersprog (assembler language, symbolic programming language), assembler (assembler, assembler language, assembler program, assembly program, assembly routine, symbolic programming language), symbolsk maskinsprog (assembler language, symbolic programming language). (various references) | ||||||||||||||||||||||
Dutch | assemblertaal (assembler language, symbolic programming language), assembler (assembler), assembleertaal (assembler language, symbolic programming language). (various references) | ||||||||||||||||||||||
Finnish | assembler-kieli (assembler language, symbolic programming language), symbolinen konekieli (assembler language, symbolic programming language), koostekieli (assembler language, symbolic programming language). (various references) | ||||||||||||||||||||||
French | langage d'assemblage (assembler language), langage assembleur (assembler language). (various references) | ||||||||||||||||||||||
German | Assemblersprache (assembler language). (various references) | ||||||||||||||||||||||
Greek | συμβολική γλώσσα (assembler language, symbolic programming language). (various references) | ||||||||||||||||||||||
Italian | linguaggio di assemblatore (assembler language, symbolic programming language), linguaggio di assemblaggio (assembler language, symbolic programming language). (various references) | ||||||||||||||||||||||
Japanese Kanji | アセンブリー言語 , アセンブリー言葉 . (various references) | ||||||||||||||||||||||
Japanese Katakana | アセンブリー"とば, アセンブリー'"". (various references) | ||||||||||||||||||||||
Pig Latin | assemblyay anguagelay linguagem do assemblador (assembler language, symbolic programming language), linguagem de assembly (assembler language, symbolic programming language), linguagem de assembler (assembler language, symbolic programming language). (various references) lenguaje ensamblador (assembler language, symbolic programming language). (various references) assemblerspråk (assembler language, symbolic programming language), assembleringsspråk. (various references) | ||||||||||||||||||||||
Scrabble® YAWL-Verified Anagrams | |
| Words within the letters "a-a-a-b-e-e-g-g-l-l-m-n-s-s-u-y" | |
-4 letters: languageless. | |
| Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. | |
Hexadecimal (or equivalents, 770AD-1900s) (references)41 73 73 65 6D 62 6C 79 4C 61 6E 67 75 61 67 65 |
| Leonardo da Vinci (1452-1519; backwards) (references)
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Binary Code (1918-1938, probably earlier) (references)01000001 01110011 01110011 01100101 01101101 01100010 01101100 01111001 00100000 01001100 01100001 01101110 01100111 01110101 01100001 01100111 01100101 |
HTML Code (1990) (references)A s s e m b l y   L a n g u a g e |
ISO 10646 (1991-1993) (references)0041 0073 0073 0065 006D 0062 006C 0079 004C 0061 006E 0067 0075 0061 0067 0065 |
Encryption (beginner's substitution cypher): (references)358585717968789124667807387677371 |
| 1. Definition 2. Synonyms 3. Crosswords 4. Usage: Commercial | 5. Expressions 6. Expressions: Internet 7. Translations: Modern 8. Anagrams | 9. Orthography 10. Bibliography |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
