Polly's Polyhedral Scheduling in the Presence of Reductions

The polyhedral model provides a powerful mathematical abstraction to enable effective optimization of loop nests with respect to a given optimization goal, e.g., exploiting parallelism. Unexploited reduction properties are a frequent reason for polyhedral optimizers to assume parallelism prohibiting dependences. To our knowledge, no polyhedral loop optimizer available in any production compiler provides support for reductions. In this paper, we show that leveraging the parallelism of reductions can lead to a significant performance increase. We give a precise, dependence based, definition of reductions and discuss ways to extend polyhedral optimization to exploit the associativity and commutativity of reduction computations. We have implemented a reduction-enabled scheduling approach in the Polly polyhedral optimizer and evaluate it on the standard Polybench 3.2 benchmark suite. We were able to detect and model all 52 arithmetic reductions and achieve speedups up to 2.21$\times$ on a quad core machine by exploiting the multidimensional reduction in the BiCG benchmark.Comment: Presented at the IMPACT15 worksho

Idiom matching: an optimization technique for an APL compiler

This thesis describes the design of an idiom matching technique in a compiler for APL. Idioms are programming language constructs used by programmers for the logical primitive operations for which no language primitives exist. Due to APL\u27s richness of operators, idioms tend to appear at the expression level. APL users have to pay a very high price to execute their APL programs with operator-by-operator execution in conventional translators. However, each idiom can be treated as a unit. It has been shown (2) that the saving from optimizing such idioms can be very impressive. Other researchers (1,3) have collected lists of idioms for APL;Idiom matching consists of two problems, recognition and selection, which are dealt with in this work. The idiom recognition problem is solved by a finite tree automaton. This approach constructs an automaton directly from a regular tree expression for a set of idioms. A practical automaton minimization algorithm is developed that obtains a time bound of O(n(\u272)(.)log n) for any binary tree automaton with n states. The selection problem, locating the best non-overlapping idioms in an expression tree, is solved in O(n) time;1. Brown, W. E. Toward an Optimizing Compiler for a Very HighLevel Language. Ph.D. dissertation, Iowa State University, 1979;2. Miller, T. C. Tentative Compilation: A Design for an APLCompiler. Ph.D. dissertation, Yale University, 1978;3. Perlis, A. J. and Rugaber, S. The APL Idiom List. ResearchReport #87, Department of Computer Science, Yale University,April, 1977

Automatic matching of legacy code to heterogeneous APIs: An idiomatic approach

Heterogeneous accelerators often disappoint. They provide the prospect of great performance, but only deliver it when using vendor specific optimized libraries or domain specific languages. This requires considerable legacy code modifications, hindering the adoption of heterogeneous computing. This paper develops a novel approach to automatically detect opportunities for accelerator exploitation. We focus on calculations that are well supported by established APIs: sparse and dense linear algebra, stencil codes and generalized reductions and histograms. We call them idioms and use a custom constraint-based Idiom Description Language (IDL) to discover them within user code. Detected idioms are then mapped to BLAS libraries, cuSPARSE and clSPARSE and two DSLs: Halide and Lift. We implemented the approach in LLVM and evaluated it on the NAS and Parboil sequential C/C++ benchmarks, where we detect 60 idiom instances. In those cases where idioms are a significant part of the sequential execution time, we generate code that achieves 1.26× to over 20× speedup on integrated and external GPUs

On the Feasibility of Malware Authorship Attribution

There are many occasions in which the security community is interested to discover the authorship of malware binaries, either for digital forensics analysis of malware corpora or for thwarting live threats of malware invasion. Such a discovery of authorship might be possible due to stylistic features inherent to software codes written by human programmers. Existing studies of authorship attribution of general purpose software mainly focus on source code, which is typically based on the style of programs and environment. However, those features critically depend on the availability of the program source code, which is usually not the case when dealing with malware binaries. Such program binaries often do not retain many semantic or stylistic features due to the compilation process. Therefore, authorship attribution in the domain of malware binaries based on features and styles that will survive the compilation process is challenging. This paper provides the state of the art in this literature. Further, we analyze the features involved in those techniques. By using a case study, we identify features that can survive the compilation process. Finally, we analyze existing works on binary authorship attribution and study their applicability to real malware binaries.Comment: FPS 201

Vapor SIMD: Auto-Vectorize Once, Run Everywhere

International audienceJust-in-Time (JIT) compiler technology offers portability while facilitating target- and context-specific specialization. Single-Instruction-Multiple-Data (SIMD) hardware is ubiquitous and markedly diverse, but can be difficult for JIT compilers to efficiently target due to resource and budget constraints. We present our design for a synergistic auto-vectorizing compilation scheme. The scheme is composed of an aggressive, generic offline stage coupled with a lightweight, target-specific online stage. Our method leverages the optimized intermediate results provided by the first stage across disparate SIMD architectures from different vendors, having distinct characteristics ranging from different vector sizes, memory alignment and access constraints, to special computational idioms.We demonstrate the effectiveness of our design using a set of kernels that exercise innermost loop, outer loop, as well as straight-line code vectorization, all automatically extracted by the common offline compilation stage. This results in performance comparable to that provided by specialized monolithic offline compilers. Our framework is implemented using open-source tools and standards, thereby promoting interoperability and extendibility

A marketing plan for smart bengali idiomatic proverb serv

Trabalho de projecto apresentado como requisito parcial para a obtenção do grau de Mestre em Gestão de Informação, especialização em Inteligência de MarketingBengali is one of the most verbal communications, graded seventh in the globe bearing in mind the situation of the country. This paper offers an online model for smart Bengali Idiomatic proverb service as well as intelligence marketing plan for revenue. In present circumstances Google translator service is not respectable, specially proverb translator because Google is not tranquil interpreted Bengali proverb precisely and nobody has planned to provide Bengali Idiomatic proverb service that will bring revenue. Now a day’s information is actual significant for real decisions making. The information can be gained from several bases and can able to use different kinds of tools for effective decision making. Marketing Intelligence is a new topic in marketing, there are not several possessions in works. The marketing plans by using information system sustained from marketing intelligence. Kotler's definition says, Intelligence Scheme of marketing is more than a scheme of information gathering or a set of information technologies. Software marketing make vital tactical decisions to exploit profits and success of the business (Öztürk, S., Okumuş, A., & Mutlu, F. 2012). As a result, the proposed project aims to improve online Bengali Idiomatic Proverb Service Model for service of excellence as well as create a business model canvas with marketing plan to observe current market situation of proposed service model that will forecast sales of profit. Therefore, the proposed research has used technological model to get good decision for marketing plan. Good decision assists to increase high number of productivity and profitability because computerized systems which assist the marketing decision to improve marketing plan (Dragomir, C., & Surugiu, F. 2015). In this case, the proposed project has chosen four different types of steps. There are Bengali Idiomatic Proverb Service Model, Online payment model, Business Model Canvas with Marketing plan. The propose project has used visual studio.net, HTML, CSS, nine building blocks for Business model canvas and kotler’s and keller’s marketing plan to develop a model for Bengali Idiomatic proverb service