Accelerating a PARSEC Benchmark Using Portable Subword SIMD

We present a case study of the GNU Compiler Collection (GCC) Vector Extensions in GCC 4.7. In particular, we examine the relative performance of explicit vector code using the GCC Vector Extensions to that of automatically vectorized code from the Intel C++ Compiler (ICC). Our analysis focuses on the interactions between data-level and thread-level parallelism in the streamcluster benchmark from the PARSEC benchmark suite, in particular examining tradeoffs between portability and performance across different vectorization techniques.