Introducing Parallelism to the Ranges TS

The current interface provided by the C++17 parallel algorithms poses some limitations with respect to parallel data access and heterogeneous systems, such as personal computers and server nodes with GPUs, smartphones, and embedded System on a Chip chipsets. In this paper, we present a summary of why we believe the Ranges TS solves these problems, and also improves both programmability and performance on heterogeneous platforms. The complete paper has been submitted to WG21 for consideration, and here we present a summary of the changes proposed alongside new performance results. To the best of our knowledge, this is the first paper presented to WG21 that unifies the Ranges TS with the parallel algorithms introduced in C++17. Although there are various points of intersection, we will focus on the composability of functions, and the benefit that this brings to accelerator devices via kernel fusion

High-level Multicore Programming with C++11

Nowadays, one of the most important challenges in programming is the efficient usage of multicore processors. All modern programming languages support multicore programming at native or library level. C++11, the next standard of the C++ programming language, also supports multithreading at a low level. In this paper we argue for some extensions of the C++ Standard Template Library based on the features of C++11. These extensions enhance the standard library to be more powerful in the multicore realm. Our approach is based on functors and lambda expressions, which are major extensions in the language. We contribute three case studies: how to efficiently compose functors in pipelines, how to evaluate boolean operators in parallel, and how to efficiently accumulate over associative functors

Study of Tools Interoperability

Interoperability of tools usually refers to a combination of methods and techniques that address the problem of making a collection of tools to work together. In this study we survey different notions that are used in this context: interoperability, interaction and integration. We point out relation between these notions, and how it maps to the interoperability problem. We narrow the problem area to the tools development in academia. Tools developed in such environment have a small basis for development, documentation and maintenance. We scrutinise some of the problems and potential solutions related with tools interoperability in such environment. Moreover, we look at two tools developed in the Formal Methods and Tools group1, and analyse the use of different integration techniques

TRIQS: A Toolbox for Research on Interacting Quantum Systems

We present the TRIQS library, a Toolbox for Research on Interacting Quantum Systems. It is an open-source, computational physics library providing a framework for the quick development of applications in the field of many-body quantum physics, and in particular, strongly-correlated electronic systems. It supplies components to develop codes in a modern, concise and efficient way: e.g. Green's function containers, a generic Monte Carlo class, and simple interfaces to HDF5. TRIQS is a C++/Python library that can be used from either language. It is distributed under the GNU General Public License (GPLv3). State-of-the-art applications based on the library, such as modern quantum many-body solvers and interfaces between density-functional-theory codes and dynamical mean-field theory (DMFT) codes are distributed along with it.Comment: 27 page

C++ Standard Template Library by infinite iterators

The C++ Standard Template Library (STL) is an essential part of pro- fessional C++ programs. STL is a type-safe template library that is based on the generic programming paradigm and helps to avoid some possible dangerous C++ constructs. With its usage, the efficiency, safety and quality of the code is increased. However, professional C++ programmers are eager for some missing STLrelated opportunities. For instance, infinite ranges are hardly supported by C++ STL. STL does not contain iterators that use a predicate during traversal. STL’s design is not good at all from the view of predicates. In this paper we present some extensions of C++ STL that supports effective generic programming. We show scenarios where these extensions can be used pretty gracefully. We present the implementation of our infinite iterators

Performance testing of STL and Qt library elements in multi-threaded processing

In recent years multithreaded processing has become a important programming aspect. Computers with a multi-core processor are now widely available, enabling the creation of more efficient applications. Many libraries support multithreaded solutions, but performance information is often lacking. The use of appropriate data structures and algorithms significantly speeds up the process of creation and development of applications. Article describes selected elements of the Qt and STL library and compares their performance in concurrent programming. The time needed to perform individual operations was analysed

Boost.simd: generic programming for portable simdization

ABSTRACT SIMD extensions have been a feature of choice for processor manufacturers for a couple of decades. Designed to exploit data parallelism in applications at the instruction level, these extensions still require a high level of expertise or the use of potentially fragile compiler support or vendor-specific libraries. While a large fraction of their theoretical accelerations can be obtained using such tools, exploiting such hardware becomes tedious as soon as application portability across hardware is required. In this paper, we describe Boost.SIMD, a C++ template library that simplifies the exploitation of SIMD hardware within a standard C++ programming model. Boost.SIMD provides a portable way to vectorize computation on Altivec, SSE or AVX while providing a generic way to extend the set of supported functions and hardwares. We introduce a C++ standard compliant interface for the users which increases expressiveness by providing a high-level abstraction to handle SIMD operations, an extension-specific optimization pass and a set of SIMD aware standard compliant algorithms which allow to reuse classical C++ abstractions for SIMD computation. We assess Boost.SIMD performance and applicability by providing an implementation of BLAS and image processing algorithms