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One-pass Compiler
In computer programming, a one-pass compiler is a compiler that processes each compilation unit only once, sequentially translating each source statement or declaration into something close to its final machine code. This is in contrast to a multi-pass compiler which converts the program into one or more intermediate representations in steps between source code and machine code, and which reprocesses the entire compilation unit in each sequential pass. A one-pass compiler initially has to leave addresses for forward jumps unresolved. These can be handled in various ways (e.g. tables of forward jumps and targets) without needing to have another complete pass. Some nominally one-pass compilers effectively 'pass the buck' by generating assembly language and letting the assembler sort out the forward references, but this requires one or more passes in the assembler. One-pass compilers are smaller and faster than multi-pass compilers. One-pass compilers are unable to generate as eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Programming
Computer programming or coding is the composition of sequences of instructions, called computer program, programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of procedures, by writing source code, code in one or more programming languages. Programmers typically use high-level programming languages that are more easily intelligible to humans than machine code, which is directly executed by the central processing unit. Proficient programming usually requires expertise in several different subjects, including knowledge of the Domain (software engineering), application domain, details of programming languages and generic code library (computing), libraries, specialized algorithms, and Logic#Formal logic, formal logic. Auxiliary tasks accompanying and related to programming include Requirements analysis, analyzing requirements, Software testing, testing, debugging (investigating and fixing problems), imple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compiler
In computing, a compiler is a computer program that Translator (computing), 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 lower level language, 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 Central processing unit, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compilation Unit
In C and C++ programming language terminology, a translation unit (or more casually a compilation unit) is the ultimate input to a C or C++ compiler from which an object file is generated. A translation unit roughly consists of a source file after it has been processed by the C preprocessor, meaning that header files listed in #include directives are literally included, sections of code within #ifndef may be included, and macros have been expanded. A C++ module is also a translation unit. Context A C program consists of ''units'' called '' source files'' (or ''preprocessing files''), which, in addition to source code, includes directives for the C preprocessor. A translation unit is the output of the C preprocessor – a source file after it has been preprocessed. Preprocessing notably consists of expanding a source file to recursively replace all #include directives with the literal file declared in the directive (usually header files, but possibly other source files); t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-pass Compiler
A multi-pass compiler is a type of compiler that processes the source code or abstract syntax tree of a program several times. This is in contrast to a one-pass compiler, which traverses the program only once. Each pass takes the result of the previous pass as the input, and creates an intermediate output. In this way, the (intermediate) code is improved pass by pass, until the final pass produces the final code. Multi-pass compilers are sometimes called wide compilers, referring to the greater scope of the passes: they can "see" the entire program being compiled, instead of just a small portion of it. The wider scope thus available to these compilers allows better Code generation (compiler), code generation (e.g. smaller code size, faster code) compared to the output of one-pass compilers, at the cost of higher compiler time and memory consumption. In addition, some programming language, languages cannot be compiled in a single pass, as a result of their design. Typical multi-pas ... [...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] |
Source Code
In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer. Since a computer, at base, only understands machine code, source code must be Translator (computing), translated before a computer can Execution (computing), execute it. The translation process can be implemented three ways. Source code can be converted into machine code by a compiler or an assembler (computing), assembler. The resulting executable is machine code ready for the computer. Alternatively, source code can be executed without conversion via an interpreter (computing), interpreter. An interpreter loads the source code into memory. It simultaneously translates and executes each statement (computer science), statement. A method that combines compilation and interpretation is to first produce bytecode. Bytecode is an intermediate representation of source code tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compiler Optimization
An optimizing compiler is a compiler designed to generate code that is optimized in aspects such as minimizing program execution time, memory usage, storage size, and power consumption. Optimization is generally implemented as a sequence of optimizing transformations, a.k.a. compiler optimizations algorithms that transform code to produce semantically equivalent code optimized for some aspect. Optimization is limited by a number of factors. Theoretical analysis indicates that some optimization problems are NP-complete, or even undecidable. Also, producing perfectly ''optimal'' code is not possible since optimizing for one aspect often degrades performance for another. Optimization is a collection of heuristic methods for improving resource usage in typical programs. Categorization Local vs. global scope Scope describes how much of the input code is considered to apply optimizations. Local scope optimizations use information local to a basic block. Since basic blocks cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basic Block
In compiler construction, a basic block is a straight-line code sequence with no branches in except to the entry and no branches out except at the exit. This restricted form makes a basic block highly amenable to analysis. Compilers usually decompose programs into their basic blocks as a first step in the analysis process. Basic blocks form the vertices or nodes in a control-flow graph. Definition The code in a basic block has: * One entry point, meaning that no code within it is the destination of a jump instruction anywhere in the program. * One exit point, meaning that only the last instruction can cause the program to begin executing code in a different basic block. Under these circumstances, whenever the first instruction in a basic block is executed, the rest of the instructions are necessarily executed exactly once and in order. The code may be source code, assembly code, or some other sequence of instructions. More formally, a sequence of instructions forms a basic b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programming Language
A programming language is a system of notation for writing computer programs. Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually defined by a formal language. Languages usually provide features such as a type system, Variable (computer science), variables, and mechanisms for Exception handling (programming), error handling. An Programming language implementation, implementation of a programming language is required in order to Execution (computing), execute programs, namely an Interpreter (computing), interpreter or a compiler. An interpreter directly executes the source code, while a compiler produces an executable program. Computer architecture has strongly influenced the design of programming languages, with the most common type (imperative languages—which implement operations in a specified order) developed to perform well on the popular von Neumann architecture. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALGOL 68R
ALGOL 68-R was the first implementation of the Algorithmic Language ALGOL 68. In December 1968, the report on the Algorithmic Language ALGOL 68 was published. On 20–24 July 1970 a working conference was arranged by the International Federation for Information Processing (IFIP) to discuss the problems of implementing the language, a small team from the Royal Radar Establishment (RRE) attended to present their compiler, written by I. F. Currie, Susan G. Bond, and J. D. Morrison. In the face of estimates of up to 100 man-years to implement the language, using multi-pass compilers with up to seven passes, they described how they had already implemented a one-pass compiler which was in production for engineering and scientific uses. The compiler The ALGOL 68-R compiler was initially written in a local dialect of ALGOL 60 with extensions for address manipulation and list processing. The parser was written using J. M. Foster's ''Syntax Improving Device'' (SID) parser generator. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burroughs Large Systems
The Burroughs Large Systems Group produced a family of large 48-bit computing, 48-bit mainframe computer, mainframes using stack machine instruction sets with dense Syllable (computing), syllables.E.g., 12-bit syllables for B5000, 8-bit syllables for B6500 The first machine in the family was the B5000 in 1961, which was optimized for compiling ALGOL 60 programs extremely well, using single-pass compilers. The B5000 evolved into the B5500 (disk rather than drum) and the B5700 (up to four systems running as a cluster). Subsequent major redesigns include the B6500/B6700 line and its successors, as well as the separate B8500 line. In the 1970s, the Burroughs Corporation was organized into three divisions with very different product line architectures for high-end, mid-range, and entry-level business computer systems. Each division's product line grew from a different concept for how to optimize a computer's instruction set for particular programming languages. "Burroughs Large Systems" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NELIAC
The Navy Electronics Laboratory International ALGOL Compiler (NELIAC) is a dialect and compiler implementation of the programming language ALGOL 58, developed by the Navy Electronics Laboratory (NEL) in 1958. It was designed for numeric and logical computations and was the first language to provide a bootstrap implementation. Origin NELIAC was the brainchild of Harry Huskey, then chairperson of the Association for Computing Machinery (ACM) and a well known computer scientist, and supported by Maurice Halstead, the head of the computing center at NEL. The earliest version was implemented on the prototype AN/USQ-17 computer (called ''the Countess'', after Countess Ada Lovelace) at the laboratory. It was the world's first self-compiling compiler, a trait called bootstrapping. This means that the compiler was first coded in simplified form in assembly language "the bootstrap", and then rewritten in its own language, compiled by this "bootstrap" compiler, and recompiled by itself ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
