GBTLX: A First Look

We provide a first look at GBTLX, a code generator that translates graph processing programs written using the GraphBLAS Template Library (GBTL) into high-performance C programs that match the performance of hand-tuned implementations. GBTLX refactors code written using GBTL into problems that capture the signature of algorithms and solvers that capture the semantics (input/output behavior of algorithms. Users provide classes that implement these two aspects using standard GBTL functions and encapsulate the targeted algorithm. GBTLX then performs a sequence of inspection, code generation, and high-performance execution. First, the user code is traced while running with the original GBTL. Then, the trace is used to define the semantics and signature of the algorithm to be produced in code generation. The SPIRAL system is used to generate high-performance C code that implements the user-specified algorithm, specializing the code for algorithm and hardware-dependent optimizations. Finally, the user-provided GBTL-based implementation is replaced by the SPIRAL generated C code. For triangle counting and k-truss enumeration, the resulting executables provide performance equivalent to hand-tuned implementations, while the source code is maintainable as it only uses the C++ GBTL library.