Model-guided empirical tuning of loop fusion
Apan Qasem, Ken Kennedy · International Journal of High Performance Systems Architecture · 2008
Loop fusion is recognised as an effective transformation for improving memory hierarchy performance. However, unconstrained loop fusion can lead to poor performance because of increased register pressure and cache conflict misses. In this paper, we present a cache-conscious analytical model for profitable loop fusion. We use this model to tune fusion parameters for different architectures through empirical search. Experiments on four different platforms for a set of applications show significant speedup over fully optimised code generated by state-of-the-art commercial compilers.