Chapel, the Cascade High Productivity Language, is a parallel programming language that was developed by

Cray Cray Inc., a subsidiary of Hewlett Packard Enterprise, is an American supercomputer manufacturer headquartered in Seattle, Washington. It also manufactures systems for data storage and analytics. Several Cray supercomputer systems are listed ...

, and later by Hewlett Packard Enterprise which acquired Cray. It was being developed as part of the Cray Cascade project, a participant in

DARPA The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Adva ...

's High Productivity Computing Systems (HPCS) program, which had the goal of increasing

supercomputer A supercomputer is a type of computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second (FLOPS) instead of million instruc ...

productivity by 2010. It is being developed as an

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...

project, under version 2 of the

Apache license The Apache License is a permissive free software license written by the Apache Software Foundation (ASF). It allows users to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software ...

. The Chapel compiler is written in C and C++ (

C++14 C14, C.XIV or C-14 may refer to: Time * The 14th century * Carbon-14, a radioactive isotope of carbon ** Radiocarbon dating, C-14 dating, a method for dating events Science * IEC 60320#C14, IEC 60320 C14, a polarised, three pole socket electrical ...

). The backend (i.e. the optimizer) is

LLVM LLVM, also called LLVM Core, is a target-independent optimizer and code generator. It can be used to develop a Compiler#Front end, frontend for any programming language and a Compiler#Back end, backend for any instruction set architecture. LLVM i ...

, written in C++. Python 3.7 or newer is required for some optional components such Chapel’s test system and c2chapel, a tool to generate C bindings for Chapel. By default Chapel compiles to binary executables, but it can also compile to C code, and then LLVM is not used. Chapel code can be compiled to libraries to be callable from C, or Fortran or e.g. Python also supported. Chapel supports GPU programming through code generation for NVIDIA and AMD graphics processing units.

Goals

Chapel aims to improve the programmability of

parallel computer Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different for ...

s in general and the Cascade system in particular, by providing a higher level of expression than current programming languages do and by improving the separation between algorithmic expression and

data structure In computer science, a data structure is a data organization and storage format that is usually chosen for Efficiency, efficient Data access, access to data. More precisely, a data structure is a collection of data values, the relationships amo ...

implementation details. The language designers aspire for Chapel to bridge the gap between current

high-performance computing High-performance computing (HPC) is the use of supercomputers and computer clusters to solve advanced computation problems. Overview HPC integrates systems administration (including network and security knowledge) and parallel programming into ...

(HPC) programming practitioners, who they describe as Fortran, C or C++ users writing

procedural code Procedural programming is a programming paradigm, classified as imperative programming, that involves implementing the behavior of a computer program as Function (computer programming), procedures (a.k.a. functions, subroutines) that call each o ...

using technologies like

OpenMP OpenMP is an application programming interface (API) that supports multi-platform shared-memory multiprocessing programming in C, C++, and Fortran, on many platforms, instruction-set architectures and operating systems, including Solaris, ...

and

MPI MPI or Mpi may refer to: Science and technology Biology and medicine * Magnetic particle imaging, a tomographic technique * Myocardial perfusion imaging, a medical procedure that illustrates heart function * Mannose phosphate isomerase, an enzyme ...

on one side, and newly graduating computer programmers who tend to prefer Java, Python or Matlab with only some of them having experience with C++ or C. Chapel should offer the productivity advances offered by the latter suite of languages while not alienating the users of the first.

Features

Chapel supports a multithreaded parallel programming model at a high level by supporting abstractions for

data parallelism Data parallelism is parallelization across multiple processors in parallel computing environments. It focuses on distributing the data across different nodes, which operate on the data in parallel. It can be applied on regular data structures like ...

task parallelism Task parallelism (also known as function parallelism and control parallelism) is a form of parallelization of computer code across multiple processors in parallel computing environments. Task parallelism focuses on distributing tasks—concurre ...

, and nested parallelism. It enables optimizations for the locality of data and computation in the program via abstractions for data distribution and

data-driven Data ( , ) are a collection of discrete or continuous value (semiotics), values that convey information, describing the quantity, qualitative property, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols t ...

placement of subcomputations. It allows for

code reuse Code reuse is the practice of using existing source code to develop software instead of writing new code. ''Software reuse'' is a broader term that implies using any existing software asset to develop software instead of developing it again. An as ...

and generality through

object-oriented Object-oriented programming (OOP) is a programming paradigm based on the concept of '' objects''. Objects can contain data (called fields, attributes or properties) and have actions they can perform (called procedures or methods and impleme ...

concepts and

generic programming Generic programming is a style of computer programming in which algorithms are written in terms of data types ''to-be-specified-later'' that are then ''instantiated'' when needed for specific types provided as parameters. This approach, pioneer ...

features. For instance, Chapel allows for the declaration of locales. While Chapel borrows concepts from many preceding languages, its parallel concepts are most closely based on ideas from

High Performance Fortran High Performance Fortran (HPF) is an extension of Fortran 90 designed to support parallel computing, developed by the ''High Performance Fortran Forum'' (HPFF). The HPFF was convened and chaired by Ken Kennedy of Rice University. The first version ...

(HPF), ZPL, and the Cray MTA's extensions to Fortran and C.

Notes

References

External links

* *

{{Numerical analysis software Cray Array programming languages C programming language family Concurrent programming languages Object-oriented programming languages Programming languages created in 2009 2009 software Free software projects Statically typed programming languages

Goals

Features

See also

Notes

References

Further reading

External links