Technical Perspective: Can High Performance be Portable?

The development of high-performance software has always suffered from a tension between achieving high performance on the one hand and portability and simplicity on the other hand. By specializing an algorithm for optimal performance, considering the memory hierarchy and other architectural particulars, we introduce architecture-specific detail. This obscures algorithmic structure and conflates the general with the specific, compromising simplicity and clarity. It also hurts portability to all but very similar architectures--simple changes, such as different cache sizes, can have substantial performance implications. Moreover, distinctly different architectures, such as CPUs versus GPUs versus DSPs, often require fundamentally different optimization strategies.