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UNCOL
UNCOL (Universal Computer Oriented Language) is a universal intermediate language for compilers. The idea was introduced in 1958, by a SHARE ad-hoc committee. It was never fully specified or implemented; in many ways it was more a concept than a language. UNCOL was intended to make compilers economically available for each new instruction set architecture and programming language, thereby reducing an N×M problem to N+M. Each machine architecture would require just one compiler back end, and each programming language would require one compiler front end. This was a very ambitious goal because compiler technology was in its infancy, and little was standardized in computer hardware and software. History The concept of such a universal intermediate language is old: the SHARE report (1958) already says "t hasbeen discussed by many independent persons as long ago as 1954." Macrakis (1993) summarizes its fate: UNCOL is sometimes used as a generic term for the idea of a universal in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermediate Language
An intermediate representation (IR) is the data structure or code used internally by a compiler or virtual machine to represent source code. An IR is designed to be conducive to further processing, such as optimization and translation. A "good" IR must be ''accurate'' – capable of representing the source code without loss of information – and ''independent'' of any particular source or target language. An IR may take one of several forms: an in-memory data structure, or a special tuple- or stack-based code readable by the program. In the latter case it is also called an ''intermediate language''. A canonical example is found in most modern compilers. For example, the CPython interpreter transforms the linear human-readable text representing a program into an intermediate graph structure that allows flow analysis and re-arrangement before execution. Use of an intermediate representation such as this allows compiler systems like the GNU Compiler Collection and LLVM to be u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programming Language
A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming language is usually split into the two components of syntax (form) and semantics (meaning), which are usually defined by a formal language. Some languages are defined by a specification document (for example, the C programming language is specified by an ISO Standard) while other languages (such as Perl) have a dominant implementation that is treated as a reference. Some languages have both, with the basic language defined by a standard and extensions taken from the dominant implementation being common. Programming language theory is the subfield of computer science that studies the design, implementation, analysis, characterization, and classification of programming languages. Definitions There are many considerations when defining ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Architecture Neutral Distribution Format
The Architecture Neutral Distribution Format (ANDF) in computing is a technology allowing common "shrink wrapped" binary application programs to be distributed for use on conformant Unix systems, translated to run on different underlying hardware platforms. ANDF was defined by the Open Software Foundation and was expected to be a "truly revolutionary technology that will significantly advance the cause of portability and open systems", but it was never widely adopted. As with other OSF offerings, ANDF was specified through an open selection process. OSF issued a Request for Technology for architecture-neutral software distribution technologies in April, 1989. Fifteen proposals were received, based on a variety of technical approaches, including obscured source code, compiler intermediate languages, and annotated executable code. The technology of ANDF, chosen after an evaluation of competing approaches and implementations, was Ten15 Distribution Format, later renamed TenDRA Di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compiler
In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs that translate source code from a high-level programming language to a low-level programming language (e.g. assembly language, object code, or machine code) to create an executable program. Compilers: Principles, Techniques, and Tools by Alfred V. Aho, Ravi Sethi, Jeffrey D. Ullman - Second Edition, 2007 There are many different types of compilers which produce output in different useful forms. A '' cross-compiler'' produces code for a different CPU or operating system than the one on which the cross-compiler itself runs. A '' bootstrap compiler'' is often a temporary compiler, used for compiling a more permanent or better optimised compiler for a language. Related software include, a program that translates from a low-level language ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHARE (computing)
SHARE Inc. is a volunteer-run user group for IBM mainframe computers that was founded in 1955 by Los Angeles-area users of the IBM 701 computer system. It evolved into a forum for exchanging technical information about programming languages, operating systems, database systems, and user experiences for enterprise users of small, medium, and large-scale IBM computers such as IBM S/360, IBM S/370, zSeries, pSeries, and xSeries. Despite the capitalization of all letters in the name, the official website says "SHARE is not an acronym; it's what we do." Overview A major resource of SHARE from the beginning was the SHARE library. Originally, IBM distributed what software it provided in source form and systems programmers commonly made small local additions or modifications and exchanged them with other users. The SHARE library and the process of distributed development it fostered was one of the major origins of open source software. In 1959 SHARE released the SHARE Operating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Set
In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ''implementation''. In general, an ISA defines the supported instructions, data types, registers, the hardware support for managing main memory, fundamental features (such as the memory consistency, addressing modes, virtual memory), and the input/output model of a family of implementations of the ISA. An ISA specifies the behavior of machine code running on implementations of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as performance, physical size, and monetary cost (among other things), but that are capable of running the same machine code, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Architecture
In computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. At a more detailed level, the description may include the instruction set architecture design, microarchitecture design, logic design, and implementation. History The first documented computer architecture was in the correspondence between Charles Babbage and Ada Lovelace, describing the analytical engine. When building the computer Z1 (computer), Z1 in 1936, Konrad Zuse described in two patent applications for his future projects that machine instructions could be stored in the same storage used for data, i.e., the Stored-program computer, stored-program concept. Two other early and important examples are: * John von Neumann's 1945 paper, First Draft of a Report on the EDVAC, which described an organization of logical elements; and *Alan M. Turing, Alan Turing's mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Levine
John R. Levine is an Internet author and consultant specializing in email infrastructure, spam filtering, and software patents. He chaired the Anti-Spam Research Group ( ASRG) of the Internet Research Task Force (IRTF), is president of CAUCE (the Coalition Against Unsolicited Commercial Email), is a member of the ICANN (Internet Corporation For Assigned Names and Numbers) Stability and Security Advisory Committee, and runs Taughannock Networks. He has co-authored many books, including ''The Internet For Dummies'' (with Carol Baroudi and Margaret Levine Young), ''UNIX For Dummies'' (with Margaret Levine Young), ''Fighting Spam for Dummies'' (with Margaret Levine Young, Ray Everett-Church), and ''flex & bison'' (O'Reilly). He was also the mayor of the village of Trumansburg, New York, United States from March 2004 until March 2007. Levine graduated from Yale University in 1975 and earned his Ph.D. in computer science from Yale in 1984 with a thesis about the design and implem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compiler-compiler
In computer science, a compiler-compiler or compiler generator is a programming tool that creates a parser, interpreter, or compiler from some form of formal description of a programming language and machine. The most common type of compiler-compiler is more precisely called a parser generator. It only handles syntactic analysis. The input of a parser generator is a grammar file, typically written in Backus–Naur form (BNF) or extended Backus–Naur form (EBNF) that defines the syntax of a target programming language. The output is the source code of a parser for the programming language. The output of the (compiled) parser source code is a parser. It may be either standalone or embedded. This parser takes as an input the source code of the target programming language source and performs some action or outputs an abstract syntax tree (AST). Parser generators do not handle the semantics of the AST, or the generation of machine code for the target machine."A Syntax Direc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 (normally numeric addresses) that encode the result of compiler parsing and performing semantic analysis of things like type, scope, and nesting depths of program objects. The name bytecode stems from instruction sets that have one-byte opcodes followed by optional parameters. Intermediate representations such as bytecode may be output by programming language implementations to ease Interpreter (computer software), 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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UCSD Pascal
UCSD Pascal is a Pascal programming language system that runs on the UCSD p-System, a portable, highly machine-independent operating system. UCSD Pascal was first released in 1977. It was developed at the University of California, San Diego (UCSD). UCSD Pascal and the p-System In 1977, the University of California, San Diego (UCSD) Institute for Information Systems developed UCSD Pascal to provide students with a common environment that could run on any of the then available microcomputers as well as campus DEC PDP-11 minicomputers. The operating system became known as UCSD p-System. There were three operating systems that IBM offered for its original IBM PC. The first was UCSD p-System, with IBM PC DOS and CP/M-86 as the other two. Vendor SofTech Microsystems emphasized p-System's application portability, with virtual machines for 20 CPUs as of the IBM PC's release. It predicted that users would be able to use applications they purchased on future computers running p-System ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-code Machine
In computer programming, a p-code machine (portable code machine) is a virtual machine designed to execute ''p-code'' (the assembly language or machine code of a hypothetical central processing unit (CPU)). This term is applied both generically to all such machines (such as the Java virtual machine (JVM) and MATLAB precompiled code), and to specific implementations, the most famous being the p-Machine of the Pascal-P system, particularly the UCSD Pascal implementation, among whose developers, the ''p'' in ''p-code'' was construed to mean ''pseudo'' more often than ''portable'', thus ''pseudo-code'' meaning instructions for a pseudo-machine. Although the concept was first implemented circa 1966—as O-code for the Basic Combined Programming Language (BCPL) and P code for the language Euler—the ''term'' p-code first appeared in the early 1970s. Two early compilers generating p-code were the Pascal-P compiler in 1973, by Kesav V. Nori, Urs Ammann, Kathleen Jensen, Hans-Heinrich N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
