Using PGI Accelerator™ compilers, programmers can accelerate applications on CPU+accelerator platforms by adding OpenACC compiler directives to existing high-level standard-compliant Fortran, C and C++ programs and then recompiling with appropriate compiler options.

Sample Fortran matrix multiplication loop, tagged to be compiled for an accelerator.

Until now, developers targeting HPC accelerators have had to rely on language extensions to their programs. CPU+accelerators programmers have been required to program at a detailed level including a need to understand and specify data usage information and manually construct sequences of calls to manage all movement of data between the CPU host and the accelerator.



The PGI Accelerator compilers automatically analyze whole program structure and data, split portions of the application between the host CPU and the accelerator device as specified by a standard set of user directives, and define and generate an optimized mapping of loops to automatically use the parallel cores, hardware threading capabilities and SIMD vector capabilities of modern accelerators. In addition to directives and pragmas that specify regions of code or functions to be accelerated, other directives give the programmer fine-grained control over the mapping of loops, allocation of memory, and optimization for the accelerator memory hierarchy. The PGI Accelerator compilers generate unified object files and executables that manage all movement of data to and from the accelerator while leveraging all existing host-side utilities—linker, librarians, makefiles—and require no changes to the existing standard HPC Linux programming environment.