Performance evaluation for omni XcalableMP compiler on many-core cluster system based on knights landing

To reduce the programming cost on a cluster system, Partitioned Global Address Space (PGAS) languages are used. We have designed an XcalableMP (XMP) PGAS language and developed the Omni XMP compiler (Omni compiler) for XMP. In the present study, we evaluated the performance of the Omni compiler on Oakforest-PACS, which is a cluster system based on Knights Landing, and on a general Linux cluster system. We performed performance tuning for the Omni compiler using a Lattice QCD mini-application and some mathematical functions appearing in that application. As a result, the performance of the Omni compiler after tuning was improved compared to before tuning on both systems. Furthermore, we compared the performance of MPI and OpenMP (MPI+OpenMP), which is an existing programming model, to that of XMP with the tuned Omni compiler. The results showed that the performance of the Lattice QCD mini-application using XMP was achieving more than 94% of the implementation written in MPI + OpenMP.