A Comparative Analysis of HPL-PD and MIPS Architectures by Using Integrated Approach for IS and RA for Exploiting ILP

In this article, the authors have proposed an integrated algorithm for instruction scheduling and register allocation, and implemented it for compiler optimization in a machine description in a trimaran infrastructure for exploitation of instruction-level parallelism. For this experimental work, the authors added machine descriptions (MDES) targeted to HL-PD architecture. As a result, only a few spills were needed and the quality of the code generated was improved. The application of abstract base graph has been applied for experimental purposes. For these experiments, this article used 20 benchmarks available with trimaran infrastructure for HPL-PD architecture. This article compares some of these results with results obtained performed on LLVM compiler on an MIPS architecture. The implemented algorithm is based on subgraph isomorphism. The input program is represented in the form of directed acyclic graph (DAG). The vertices of the DAG represent the instructions, input, and output operands of the program, while the edges represent dependencies among the instructions.

Extrinsic faulting in 3Cclose-packed crystal structures: computational mechanics analysis

Extrinsic faulting has been discussed previously within the so-called difference method and random walk calculation. In this contribution it is revisited under the framework of computational mechanics, which allows expressions to be derived for the statistical complexity, entropy density and excess entropy as a function of faulting probability. The approach allows one to compare the disordering process of an extrinsic fault with other faulting types. The ∊-machine description of the faulting mechanics is presented. Several useful analytical expressions such as probability of consecutive symbols in the Hägg coding are presented, as well as hexagonality. The analytical expression for the pairwise correlation function of the layers is derived and compared with results previously reported. The effect of faulting on the interference function is discussed in relation to the diffraction pattern.

Description and Optimization of Abstract Machines in a Dialect of Prolog

In order to achieve competitive performance, abstract machines for Prolog and related languages end up being large and intricate, and incorporate sophisticated optimizations, both at the design and at the implementation levels. At the same time, efficiency considerations make it necessary to use low-level languages in their implementation. This makes them laborious to code, optimize, and, especially, maintain and extend. Writing the abstract machine (and ancillary code) in a higher-level language can help tame this inherent complexity. We show how the semantics of most basic components of an efficient virtual machine for Prolog can be described using (a variant of) Prolog. These descriptions are then compiled to C and assembled to build a complete bytecode emulator. Thanks to the high-level of the language used and its closeness to Prolog, the abstract machine description can be manipulated using standard Prolog compilation and optimization techniques with relative ease. We also show how, by applying program transformations selectively, we obtain abstract machine implementations whose performance can match and even exceed that of state-of-the-art, highly-tuned, hand-crafted emulators.

Dynamic Modeling of a Nuclear Gas Turbine Plant: Application to Surge Prediction

This work concerns the dynamic modeling of closed cycle gas turbine with a nuclear heat source. The paper focuses on a particular safety question: the consequences of a hypothetical large break accident. A model of the whole circuit of the Gas Fast Reactor (GFR) has been built using a specific turbo-machine description. The compressor modeling presented in a separate paper [1] is completed with turbine modeling. Transient simulation results point out the importance of the location of the pipe rupture: in some detailed cases, back flow through the core can occur during the first seconds. The other safety question concerns the capacity of the power conversion unit to extract the decay heat from the nuclear core after the break event.