Optimization of the Brillouin operator on the KNL architecture
Experiences with optimizing the matrix-times-vector application of the Brillouin operator on the Intel KNL processor are reported. Without any adjustments to the memory layout, performances figures of 300 Gflop/s in sp and 230 Gflop/s in dp are observed. This is with Nc=3 colors, Nv=12 right-hand-sides, Nthr=256 threads, on lattices of size 32^3*64, using exclusively OMP pragmas. Interestingly, the same routine performs quite well on standard Intel Core i7 architectures, too. Time permitting, some observations on the much harder Wilson fermion matrix-times-vector optimization problem will be added.