Compositional approach applied to loop specialization

  • Authors:
  • Lamia Djoudi;Jean-Thomas Acquaviva;Denis Barthou

  • Affiliations:
  • Université de Versailles, France;Université de Versailles, France;Université de Versailles, France

  • Venue:
  • Euro-Par'07 Proceedings of the 13th international Euro-Par conference on Parallel Processing
  • Year:
  • 2007

Quantified Score

Hi-index 0.00

Visualization

Abstract

An optimizing compiler has a hard time to generate a code which will perform at top speed for an arbitrary data set size. In general, the low level optimization process must take into account parameters such as loop trip count for generating efficient code. The code can be specialized depending upon data set size ranges, at the expense of code expansion and decision tree overhead. We propose for loop structures a new method to specialize code at the assembly level, cutting drastically the overhead cost with a new folding approach. Our technique can generate and combine sequentially at the assembly level several versions, tuned for small, medium and large iteration number. We first show on the SPEC benchmarks the need for specialization on small loops. Then we demonstrate the benefit of our method on kernels with detailed results.