Data type | EPFL Graph Search

In computer science and computer programming, a data type (or simply type) is a collection or grouping of data values, usually specified by a set of possible values, a set of allowed operations on these values, and/or a representation of these values as machine types. A data type specification in a program constrains the possible values that an expression, such as a variable or a function call, might take. On literal data, it tells the compiler or interpreter how the programmer intends to use the data. Most programming languages support basic data types of integer numbers (of varying sizes), floating-point numbers (which approximate real numbers), characters and Booleans. Concept A data type may be specified for many reasons: similarity, convenience, or to focus the attention. It is frequently a matter of good organization that aids the understanding of complex definitions. Almost all programming languages explicitly include the notion of data type, though the possible d

Interoperation between Miniboxing and Other Generics Translations

Milos Stojanovic

Generics allow programmers to design algorithms and data structures that operate in the same way regardless of the data used by abstracting over data types. Generics are useful as they improve the programmer’s productivity by raising the level of abstraction, which in turn leads to reducing code duplication and uniform interfaces. However, as data on the low-level comes in different shapes and sizes, it is not a trivial job of compiler to bridge the gap between the uniform interface and the non-uniform low level implementation. Different approaches are used for generics translation and all of them can be categorized either into homogeneous or heterogeneous group. The characteristic of homogeneous translations is that all different data representations are transformed into an identical representation and use the same low-level code for this purpose. In the heterogeneous translations, code is duplicated and adapted for each incompatible data type. From a programmer’s point of view, there should be no difference between a generic method or class compiled using some homogeneous or heterogeneous translation. Therefore, the programmer can combine different types of translations together on different parts of the code and the program has to be correct. But, as different generics translations are implemented in different ways, interoperation between them introduces noticeable slowdowns as values need to be converted to the foreign object’s desired representation, incurring significant performance losses. In this thesis, it will be explored why slowdowns happen when different translations interact together and proposed the ways how they can interoperate more efficiently. Proposed approaches are implemented and their effectiveness is presented by benchmarking the implementation.

2015

Synthesis of Flexible Accelerators for Early Adoption of Ring-LWE Post-quantum Cryptography

Subhadeep Banik, Hamid Nejatollahi, Francesco Regazzoni

The advent of the quantum computer makes current public-key infrastructure insecure. Cryptography community is addressing this problem by designing, efficiently implementing, and evaluating novel public-key algorithms capable of withstanding quantum computational power. Governmental agencies, such as NIST, are promoting standardization of quantum-resistant algorithms that is expected to run for 7 years. Several modern applications must maintain permanent data secrecy; therefore, they ultimately require the use of quantum-resistant algorithms. Because algorithms are still under scrutiny for eventual standardization, the deployment of the hardware implementation of quantum-resistant algorithms is still in early stages. In this article, we propose a methodology to design programmable hardware accelerators for lattice-based algorithms, and we use the proposed methodology to implement flexible and energy efficient post-quantum cache-based accelerators for NewHope, Kyber, Dilithium, Key Consensus from Lattice (KCL), and R.EMBLEM submissions to the NIST standardization contest. To the best of our knowledge, we propose the first efficient domain-specific, programmable cache-based accelerators for lattice-based algorithms. We design a single accelerator for a common kernel among various schemes with different kernel sizes, i.e., loop count, and data types. This is in contrast to the traditional approach of designing one special purpose accelerators for each scheme. We validate our methodology by integrating our accelerators into an HLS-based SoC infrastructure based on the X86 processor and evaluate overall performance. Our experiments demonstrate the suitability of the approach and allow us to collect insightful information about the performance bottlenecks and the energy efficiency of the explored algorithms. Our results provide guidelines for hardware designers, highlighting the optimization points to address for achieving the highest energy minimization and performance increase. At the same time, our proposed design allows us to specify and execute new variants of lattice-based schemes with superior energy efficiency compared to the main application processor without changing the hardware acceleration platform. For example, we manage to reduce the energy consumption up to 2.1x and energy-delay product (EDP) up to 5.2x and improve the speedup up to 2.5x.

ASSOC COMPUTING MACHINERY2020

QEF – Supporting Complex Query Applications

Othman Tajmouati

This paper describes QEF a query evaluation framework designed to support complex applications on the grid. QEF has been extended to support querying within a number of different applications, including supporting scientific visualization and implementing a web service semantic search engine. Application requests take a form of a workflow in which tasks are represented as algebraic operators and specific data types are enveloped into a common tuple structure. The implemented system is automatically deployed into schedule grid nodes and autonomously manages query evaluation according to grid environment conditions. The generality of our approach has been tested with a number of applications leading to a full grid web service implementation available at http://codims.epfl.ch

IEEE Computer Society2007

Synthesis of Flexible Accelerators for Early Adoption of Ring-LWE Post-quantum Cryptography

Subhadeep Banik, Hamid Nejatollahi, Francesco Regazzoni

ASSOC COMPUTING MACHINERY2020