Branch Effect Reduction Techniques

T here is an insatiable demand for computers ofever-increasing performance. Old applicationsare applied to more complex data and new appli-cations demand improved capabilities. Developers must exploit parallelism for all types of programs to realize gains. Multiprocessor, multithreaded, vector, and dataflow computers achieve speedups up to the 1,000’s for programs with large amounts of data par-allelism or independent control flow. For general-pur-pose code, however—which comprises most executed code—parallel execution has been only two or three times faster than sequential. General-purpose code has many conditional branches, irregular control flow, and much less data parallelism. These code characteristics and their detrimental consequences, in the form of branch effects, have severely limited the parallelism that ca