Sorting exceed the 1G keys/sec on GPUs

This project implements a very fast, efficient radix sorting method for CUDA-capable devices. For sorting large sequences of fixed-length keys (and values), we believe our sorting primitive to be the fastest available for any fully-programmable microarchitecture: our stock NVIDIA GTX480 sorting results exceed the 1G keys/sec average sorting rate (i.e., one billion 32-bit keys sorted per second).