A Compiler-Blockable Algorithm for QR Decomposition

Because of an imbalance between computation and memory speed in modern processors, programmers are explicitly restructuring codes to perform well on particular memory systems, leading to machine-speciic programs. This paper describes a block algorithm for QR decomposition that is derivable by the compiler and has good performance on small matrices | sizes that are typically run on nodes of a massively parallel system or workstation. The advantage of our algorithm over the one found in LAPACK is that it can be derived by the compiler and needs no hand optimization.