Reducing Branch Costs via Branch Alignment

Several researchers have proposed algorithms for basic block reordering. We call these branch alignment algorithms. The primary emphasis of these algorithms has been on improving instruction cache locality, and the few studies concerned with branch prediction reported small or minimal improvements. As wide-issue architectures become increasingly popular the importance of reducing branch costs will increase, and branch alignment is one mechanism which can effectively reduce these costs. In this paper, we propose an improved branch alignment algorithm that takes into consideration the architectural cost model and the branch prediction architecture when performing the basic block reordering. We show that branchalignment algorithms can improve a broad range of static and dynamicbranch prediction architectures. We also show that a programs performance can be improved by approximately 5% even whenusing recently proposed,highly accurate branch prediction architectures. The programs are compi...

• Type: Conference
• Year: 1994
• Where: ASPLOS
• Authors: Brad Calder, Dirk Grunwald
• Keywords: ASPLOS 1994, Branch Alignment, Branch Alignment Algorithm, Branch Prediction, Programming Languages