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Parrot Assembly Language
The Parrot assembly language (PASM) is the basic assembly language used by the Parrot virtual machine. PASM is the lowest level assembly language in the Parrot stack. The Parrot intermediate representation (PIR) is PASM extended to simplify development of compilers. The hello world program in PASM is simply: print "Hello world!\n" end Although it appears similar to source code in some high-level programming languages, more complex PASM programs will resemble other assembly languages. The main exceptions to this low level programming in PASM are string handling and, as shown above, input and output. Additionally, PASM has automatic garbage collection from the virtual machine, and it does not allow pointer arithmetic. Parrot assembly language has more instructions than hardware assembly languages, even CISC processors. This is because the marginal cost of creating a new instruction in Parrot is low compared to the marginal cost of doing so in hardware, and the creators of Par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assembly Language
In computer programming, assembly language (or assembler language, or symbolic machine code), often referred to simply as Assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence between the instructions in the language and the architecture's machine code instructions. Assembly language usually has one statement per machine instruction (1:1), but constants, comments, assembler directives, symbolic labels of, e.g., memory locations, registers, and macros are generally also supported. The first assembly code in which a language is used to represent machine code instructions is found in Kathleen and Andrew Donald Booth's 1947 work, ''Coding for A.R.C.''. Assembly code is converted into executable machine code by a utility program referred to as an '' assembler''. The term "assembler" is generally attributed to Wilkes, Wheeler and Gill in their 1951 book '' The Preparation of Programs for an Electronic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parrot Virtual Machine
Parrot was a register-based process virtual machine designed to run dynamic languages efficiently. It is possible to compile Parrot assembly language and Parrot intermediate representation (PIR, an intermediate language) to Parrot bytecode and execute it. Parrot is free and open source software. Parrot was started by the Perl community and is developed with help from the open source and free software communities. As a result, it is focused on license compatibility with Perl ( Artistic License 2.0), platform compatibility across a broad array of systems, processor architecture compatibility across most modern processors, speed of execution, small size (around 700k depending on platform), and the flexibility to handle the varying demands made by Raku and other modern dynamic languages. Version 1.0, with a stable application programming interface (API) for development, was released on March 17, 2009. The last version is release 8.1.0 "Andean Parakeet". Parrot was officiall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parrot Intermediate Representation
The Parrot intermediate representation (PIR), previously called Intermediate code (IMC), is one of the two assembly languages for the Parrot virtual machine. The other is Parrot assembly language or PASM. Compared to PASM, PIR exists at a slightly higher abstraction layer, and provides temporary registers and named registers, simplifying code generation. While Parrot is still evolving, it is currently being used in many different capacities, and has undergone several releases. Overview PIR provides a set of abstractions that allow the programmer to ignore certain redundancies in the Parrot bytecode and quickly write code that adheres to the complexities of Parrot, such as the calling conventions. Abstractions PIR provides both type abstraction and polymorphism to some degree. For example, the "+" operator can be used with int, num or both: .local int a .local num b a = 1 b = 1.1 .local num c c = a + b Calling conventions The calling conventions in Parrot are complex, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hello World Program
''Hello'' is a salutation or greeting in the English language. It is first attested in writing from 1826. Early uses ''Hello'', with that spelling, was used in publications in the U.S. as early as the 18 October 1826 edition of the '' Norwich Courier'' of Norwich, Connecticut. Another early use was an 1833 American book called ''The Sketches and Eccentricities of Col. David Crockett, of West Tennessee'', which was reprinted that same year in '' The London Literary Gazette''. The word was extensively used in literature by the 1860s. Etymology According to the ''Oxford English Dictionary'', ''hello'' is an alteration of ''hallo'', ''hollo'', which came from Old High German "''halâ'', ''holâ'', emphatic imperative of ''halôn'', ''holôn'' to fetch, used especially in hailing a ferryman". It also connects the development of ''hello'' to the influence of an earlier form, ''holla'', whose origin is in the French ''holà'' (roughly, 'whoa there!', from French ''là'' 'there'). As i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Source Code
In computing, source code, or simply code, is any collection of code, with or without comment (computer programming), comments, written using a human-readable programming language, usually as plain text. The source code of a Computer program, program is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source code. The source code is often transformed by an assembler (computing), assembler or compiler into Binary number, binary machine code that can be executed by the computer. The machine code is then available for execution (computing), execution at a later time. Most application software is distributed in a form that includes only executable files. If the source code were included it would be useful to a user (computing), user, programmer or a system administrator, any of whom might wish to study or modify the program. Alternatively, depending on the technology being used, source code m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-level Programming Language
In computer science, a high-level programming language is a programming language with strong abstraction from the details of the computer. In contrast to low-level programming languages, it may use natural language ''elements'', be easier to use, or may automate (or even hide entirely) significant areas of computing systems (e.g. memory management), making the process of developing a program simpler and more understandable than when using a lower-level language. The amount of abstraction provided defines how "high-level" a programming language is. In the 1960s, a high-level programming language using a compiler was commonly called an '' autocode''. Examples of autocodes are COBOL and Fortran. The first high-level programming language designed for computers was Plankalkül, created by Konrad Zuse. However, it was not implemented in his time, and his original contributions were largely isolated from other developments due to World War II, aside from the language's influenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-level Programming Language
A low-level programming language is a programming language that provides little or no abstraction from a computer's instruction set architecture—commands or functions in the language map that are structurally similar to processor's instructions. Generally, this refers to either machine code or assembly language. Because of the low (hence the word) abstraction between the language and machine language, low-level languages are sometimes described as being "close to the hardware". Programs written in low-level languages tend to be relatively non-portable, due to being optimized for a certain type of system architecture. Low-level languages can convert to machine code without a compiler or interpreter—second-generation programming languages use a simpler processor called an assembler—and the resulting code runs directly on the processor. A program written in a low-level language can be made to run very quickly, with a small memory footprint. An equivalent program in a high- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garbage Collection (computer Science)
In computer science, garbage collection (GC) is a form of automatic memory management. The ''garbage collector'' attempts to reclaim memory which was allocated by the program, but is no longer referenced; such memory is called '' garbage''. Garbage collection was invented by American computer scientist John McCarthy around 1959 to simplify manual memory management in Lisp. Garbage collection relieves the programmer from doing manual memory management, where the programmer specifies what objects to de-allocate and return to the memory system and when to do so. Other, similar techniques include stack allocation, region inference, and memory ownership, and combinations thereof. Garbage collection may take a significant proportion of a program's total processing time, and affect performance as a result. Resources other than memory, such as network sockets, database handles, windows, file descriptors, and device descriptors, are not typically handled by garbage collectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pointer Arithmetic
In computer science, a pointer is an object in many programming languages that stores a memory address. This can be that of another value located in computer memory, or in some cases, that of memory-mapped computer hardware. A pointer ''references'' a location in memory, and obtaining the value stored at that location is known as ''dereferencing'' the pointer. As an analogy, a page number in a book's index could be considered a pointer to the corresponding page; dereferencing such a pointer would be done by flipping to the page with the given page number and reading the text found on that page. The actual format and content of a pointer variable is dependent on the underlying computer architecture. Using pointers significantly improves performance for repetitive operations, like traversing iterable data structures (e.g. strings, lookup tables, control tables and tree structures). In particular, it is often much cheaper in time and space to copy and dereference pointers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex Instruction Set Computer
A complex instruction set computer (CISC ) is a computer architecture in which single instructions can execute several low-level operations (such as a load from memory, an arithmetic operation, and a memory store) or are capable of multi-step operations or addressing modes within single instructions. The term was retroactively coined in contrast to reduced instruction set computer (RISC) and has therefore become something of an umbrella term for everything that is not RISC, where the typical differentiating characteristic is that most RISC designs use uniform instruction length for almost all instructions, and employ strictly separate load and store instructions. Examples of CISC architectures include complex mainframe computers to simplistic microcontrollers where memory load and store operations are not separated from arithmetic instructions. Specific instruction set architectures that have been retroactively labeled CISC are System/360 through z/Architecture, the PDP-11 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marginal Cost
In economics, the marginal cost is the change in the total cost that arises when the quantity produced is incremented, the cost of producing additional quantity. In some contexts, it refers to an increment of one unit of output, and in others it refers to the rate of change of total cost as output is increased by an infinitesimal amount. As Figure 1 shows, the marginal cost is measured in dollars per unit, whereas total cost is in dollars, and the marginal cost is the slope of the total cost, the rate at which it increases with output. Marginal cost is different from average cost, which is the total cost divided by the number of units produced. At each level of production and time period being considered, marginal cost includes all costs that vary with the level of production, whereas costs that do not vary with production are fixed. For example, the marginal cost of producing an automobile will include the costs of labor and parts needed for the additional automobile but not th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimalism (computing)
In computing, minimalism refers to the application of minimalist philosophies and principles in the design and use of hardware and software. Minimalism, in this sense, means designing systems that use the least hardware and software resources possible. History In the late 1970s and early 1980s, programmers worked within the confines of relatively expensive and limited resources of common platforms. Eight or sixteen kilobytes of RAM was common; 64 kilobytes was considered a vast amount and was the entire address space accessible to the 8-bit CPUs predominant during the earliest generations of personal computers. The most common storage medium was the 5.25 inch floppy disk holding from 88 to 170 kilobytes. Hard drives with capacities from five to ten megabytes cost thousands of dollars. Over time, personal-computer memory capacities expanded by orders of magnitude and mainstream programmers took advantage of the added storage to increase their software's capabilities a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
