3 research outputs found
The Probability of Casting a Decisive Vote: From IC to IAC trhough Ehrhart's Polynomials and Strong Mixing
The main purpose of this paper is to estimate the probability of casting a decisive vote for a class or random electorate models encompassing the celebrated IC and IAC models. The emphasis is on the impact of correlation across votes on the order of magnitude of this event. Our proof techniques use arguments from probability theory on one hand and the geometry of convex polytopes on the other hand
Refactoring intermediately executed code to reduce cache capacity misses
The growing memory wall requires that more attention is given to the data cache behavior of programs. In this paper, attention is given to the capacity misses i.e. the misses that occur because the cache size is smaller than the data footprint between the use and the reuse of the same data. The data footprint is measured with the reuse distance metric, by counting the distinct memory locations accessed between use and reuse. For reuse distances larger than the cache size, the associated code needs to be refactored in a way that reduces the reuse distance to below the cache size so that the capacity misses are eliminated. In a number of simple loops, the reuse distance can be calculated analytically. However, in most cases profiling is needed to pinpoint the areas where the program needs to be transformed for better data locality. This is achieved by the reuse distance visualizer, RDVIS, which shows the intermediately executed code for critical data reuses. In addition, another tool, SLO, annotates the source program with suggestions for locality ptimization. Both tools have been used to analyze and to refactor a number of SPEC2000 benchmark programs with very positive results
Counting integer points in parametric polytopes using Barvinok's rational functions
Many compiler optimization techniques depend on the ability to calculate the number of elements that satisfy certain conditions. If these conditions can be represented by linear constraints, then such problems are equivalent to counting the number of integer points in (possibly) parametric polytopes.status: publishe