A method and system for parallelization of sequential computer program code are described. How to parallelize a sequential program ase bucuresti. Though the quality of automatic parallelization has improved in the past several decades, fully automatic parallelization of sequential programs by compilers remains a grand challenge due to its need for complex program analysis and the unknown factors such as input data range during compilation. A costdriven compilation framework for speculative.
Parallelization of sequential programs the easiest way to parallelize a sequential program is to use a compiler that detects, automatically or based on the compiling directives specified by the user, the parallelism of the program and generates the parallel version with the aid of the interdependencies found in the source code. Download, build and install all the following tools. Abstract runtime parallelization of sequential database. In general, the major steps included in the parallelization process are. The utility of compass rests in part on the premise that. This tool provides users with the assistance needed for openmp parallelization of a sequential program. A typical sequential process consists of a thread of execution executing the program starting with main.
Various ways of parallelization of sequential programs ijert. Online learning with dcu connected gives you remote access to all the resources of an established university. To take full advantage of this new execution model, a program needs to be programmed or compiled in such a way that it exhibits high degree of speculative threadlevel parallelism. Johan litsfeldt degree project in program system technology at kth information and communication technology supervisor. Bucharest abstract the main reason of parallelization a sequential program is to run the program faster. One of the programmers main tasks is to identify parts of the programs that are to be executed in parallel. This presentation discusses an approach that handles code written in a highlevel language such as c and fortran and doesnt require user assistance. Though trees are widely used in sequential programming, it is hard to write efficient. A costdriven compilation framework for speculative parallelization of sequential programs.
The execution model we employ is based upon state separation, an approach for. The problem programs underutilize the parallelism of the powerful modern computers. An approach towards parallelisation of sequential programs in an. The emerging hardware support for threadlevel speculation opens new opportunities to parallelize sequential programs beyond the traditional limits. Control and data dependence consider statements s, t in a sequential program st possible scope of analysis is typically a function, i. In this paper we present a novel solution for efficiently supporting software based speculative parallelization of sequential loops on multicore processors.
Pdf a calculational framework for parallelization of. Executing sequential programs on a taskbased parallel runtime. Computer science distributed, parallel, and cluster computing. Automatic parallelization of a sequential program by a compiler is the holy grail of parallel computing, especially with the aforementioned limit of processor frequency. This work proposes a new approach for achieving such goal. Parallelization of sequential programs for mimd computers is considered.
Dcu connectedconnectedwhat if you could work towards a worldclass online irish university degree on your own schedule, from the comfort of your own home, in your own town, in any place in the world. We propose a comprehensive costdriven compilation framework to perform speculative parallelization. This new approach is built on top of the paragen autoparallelization system which exploits the powerful directed search technique of genetic programming. The sequential code is divided into small units for execution, and these units are executed concurrently as separate transactions. Automatic parallelization for distributed memory machines. The main reason of parallelization is to compute large and complex program as fast as possible. Optimization and parallelization of sequential programs. However, automatic parallelization remains a grand challenge due to its need for complex program analysis and the existence of. We present quickstep, a novel system for parallelizing sequential programs. A novel compiler support for automatic parallelization on. Predicting parallelization of sequential programs using. The freedom to generate parallel programs whose output may differ within statistical accuracy bounds from the output of the sequential program enables a. Various ways of parallelization of sequential programs ankita bhalla m.
In one embodiment, an automatic parallelization system includes a syntactic analyser to analyze the structure of the sequential computer grogram code to identify the positions to insert spi to the sequential computer code. Tech cse gndu amritsar abstract parallelization is becoming necessity of parallel computing field. We begin our study of parallel programming by building a solid foundation. Automated enhanced parallelization of sequential c to. As a proofofconcept we ran an experiment in industrial settings by applying the proposed parallelization method to an existing industrial system running sequential code. There are billions of lines of sequential code inside nowadays software which do not benefit from the parallelism available in modern multicore architectures. Transformation of sequential programs into parallel forms. Partitioning find possible ways to split the data among the workers as finegrain as possible. This dissertation proposes program demultiplexing or pd, a speculative parallelization model that has two novel contributions. The advent of multicores presents a promising opportunity for speeding up the execution of sequential programs through their parallelization. A sequential program is one that runs on a single processor and has a single line of control. One way to develop a parallel program is to write its sequential version in the initial stage. Parallelizing sequential programs with statistical.
Various ways of parallelization of sequential programs. Pdf visualizing potential parallelism in sequential programs. Request pdf predicting parallelization of sequential programs using supervised learning we investigate an automatic method for classifying which regions of sequential programs could be. The parallelization described above was implemented in software using the sgs and sis gslib fortran source code as a starting point deutsch and journel, 1992, together with the geoms version of the dss alexandre and almeida, 1998 with correction for local bias soares, 2001. However, in view of the complexity of writing parallel programs, the parallelization of myriads of sequential legacy programs presents a. The stagnation of singlecore performance leaves application developers with software parallelism as the only option to further benefit from moores law. In contrast, the profiler shown in this thesis addresses the problem via signature based memory management and a lockfree parallel design. In order to execute a database program written in sequential code efficiently on a parallel processor, we develop the use of transaction concurrency control paradigms to resolve data dependencies dynamically. However, in view of the complexity of writing parallel programs, the parallelization of myriads of sequential legacy programs presents a serious economic challenge. Wo2010064260a1 method and system for parallelization of. Despite decades of work by compiler researchers, automatic parallelization has had only limited success. This tool is implemented as a set of functions on the emacs editor. Discovery of potential parallelism in sequential programs tuprints.
Automatic parallelization of sequential applications by mojtaba mehrara a dissertation submitted in partial ful. Keywords speculative parallelization, program behavior. The program decomposed in this way is a parallel program. To make many processors collectively work on a single program, the program must be divided into smaller independent chunks so that each processor can work on separate chunks of the problem. For example, tlp can sometimes be exploited in the outermost loop. Visualizing potential parallelism in sequential programs.
Tools used for auto parallelization either cannot convert complex code or only help with creating a parallel version. A communitydriven parallelization advisor for sequential software. All the activities related to program parallelization, such as selecting a target portion of the program, invoking an assistance command, and modifying the program based on. This paper presents a new technique for the automatic parallelization of loops on distributed memory machines. The problem hpc is a pervasive technology hpc is a competitive business advantage hpc is crucial to address grand scientific challenges. Smirnov keldysh institute of applied mathematics russian academy of sciences1, lomonosov moscow state university2 optimization and parallelization of programs suppose an execution of a sequence analysis and. Unveiling parallelization opportunities in sequential programs. Paragen is modified to be able to transform sequential loops and restructure them to achieve the maximum degree of parallelism. Communicationfree parallelization via affine transformation, in. Computation asc suggests that it is possible to parallelize sequential computation by building a model of wholeprogram execution, using. We are able to automatically parallelize programs with linked data structures that are not amenable to other forms of automatic parallelization. However it is difficult to parallelize the sequential program. Parallelization of sequential programs alecu felician, preassistant lecturer, economic informatics department, a. Software behavior oriented parallelization rochester cs.
Sequential program an overview sciencedirect topics. It uses hierarchical task graph htg as an intermediate representation of a parallel program. Doacross parallelization, inspectorexecutor method speculative parallelization as time permits autotuning later, if time foundations. Commodity hardware using a lowcost software transactional memory. Automated parallelization of sequential c programs on the example of two applications from the field of laser material processing m. In some cases auto parallelization and autovectorization can be combined to enhance performance. In pd, a speculative thread is composed of a method in a program.
The contribution of this thesis is a generic parallelization method for introducing parallelization into sequential software using multicore cpus and gpus. A calculational framework for parallelization of sequential programs. This graph is constructed starting from the entire sequential. A costdriven compilation framework for speculative parallelization of sequential programs zhaohui du intel china research center intel china ltd.
The road to parallelism leads through sequential programming. Unlike standard parallelizing compilers which are designed to preserve the semantics of the original sequential computation, quickstep is instead designed to generate potentially nondeterministic parallel programs that produce acceptably accurate results acceptably often. Automated enhanced parallelization of sequential c to parallel openmp dheeraj d. This paper describes about loop parallelization that allows parallelizing the loops of the programs as. Compass a communitydriven parallelization advisor for sequential software proffers advice to programmers based on information collected from observing a community of programmers parallelize their code. Executing sequential programs on a taskbased parallel runtime article pdf available in international journal of parallel programming 446 april 2016 with 115 reads. Automatically parallelizing sequential code, to promote an efficient use of the available parallelism, has been a research goal for some time now. Dataflow based speculative parallelization of methods in sequential programs saisanthosh balakrishnan and gurindar s. Automatic parallelization of sequential applications is the ideal solution for making parallel programming as easy as writing programs for sequential computers. A parallelizing sequential programs with statistical.
There are billions of lines of sequential code inside nowadays software which do not benefit from. Kaiser, gail e the widespread adoption of multicores has renewed the emphasis on the use of parallelism to improve performance. Ian foster describes four basic steps in his book designing and building parallel programs. On the parallelization of sequential programs springerlink.