Extension of superblock technique to hyperblock using predicate hierarchy graph

Abstract

Compiler optimization and transformation techniques focus on eliminating branches from the instruction stream and overlapping the execution of multiple control flow paths using the conditional execution capabilities provided by predication. The compiler support for predicate[1] execution is based on hyperblock, which is a generalized form of superblock that takes advantage of both predicated and speculative execution. The paper discusses the compilation techniques of hyperblock. The algorithm works well for inner most loops. However, for general acyclic code, external boundaries do not exist. As a result, the hyperblocks tend to grow along particular paths of control. New technique (PHG is used) to form efficient hyperblocks in acyclic code will increase the effectiveness of hyperblock techniques across all the bench marks. © 2010 Springer-Verlag Berlin Heidelberg.