  In this paper, we investigate GPU based parallel triangular solvers
systematically. The parallel triangular solvers are fundamental to incomplete
LU factorization family preconditioners and algebraic multigrid solvers. We
develop a new matrix format suitable for GPU devices. Parallel lower triangular
solvers and upper triangular solvers are developed for this new data structure.
With these solvers, ILU preconditioners and domain decomposition
preconditioners are developed. Numerical results show that we can speed
triangular solvers around seven times faster.
