Three Dirac operators on two architectures with one piece of code and no hassle
2019 May 29
A simple minded approach to implement three discretizations of the Dirac operator (staggered, Wilson, Brillouin) on two architectures (KNL and core-i7) is presented. The idea is to use a high-level compiler along with OpenMP parallelization and SIMD pragmas, but to stay away from cache-line optimization and/or assembly-tuning. The implementation is for $N_v$ right-hand-sides, and this extra index is used to fill the SIMD pipeline. On one KNL node single precision performance figures for $N_c=3$, $N_v=12$ read 475 Gflop/s, 345 Gflop/s, and 790 Gflop/s for the three discretization schemes, respectively.