8. Conclusions

Efficiently parallelizing the sparse direct solver in SPICE-like circuit simulators is a practical problem and also an industrial challenge. The high sparsity and the irregular symbolic pattern of circuit matrices, and the strong data dependence during sparse LU factorization, make the sparse direct solver extremely difficult to parallelize. In this book, we have introduced NICSLU, a parallel sparse direct solver which is specially targeted at circuit simulation applications. We have described algorithmic methods and parallelization techniques that aim to realize a parallel sparse direct solver for SPICE-like circuit simulators. Based on the baseline G-P sparse left-looking algorithm [1], we have presented an innovative parallelization framework and novel parallel algorithms of the sparse direct solver in detail. We have also shown how to improve the performance by simple yet effective numerical techniques. Not only the features of circuit matrices, but also the features of the circuit simulation flow are fully taken into account when developing NICSLU. In particular, we have developed the following innovative techniques in NICSLU.