Performance Tuning To Close Ninja Gap For Accelerator Physics Emulation System (Apes) On Intel (R) Xeon Phi (Tm) Processors

Radio frequency field and particle interaction is of critical importance in modern synchrotrons. Accelerator Physics Emulation System (APES) is a C++ code written with the purpose of simulating the particle dynamics in ring-shaped accelerators. During the tracking process, the particles interact with each other indirectly through the EM field excited by the charged particles in the RF cavity. This a hot spot in the algorithm that takes up roughly 90% of the execution time. We show how a set of well-known code restructuring and algorithmic changes coupled with advancements in modern compiler technology can bring down the Ninja gap to provide more than 7x performance improvements. These changes typically require low programming effort, as compared to the very high effort in producing Ninja code.