Tpetra::BlockCrsMatrix: Add LU factorization, solve, & inverse for small dense blocks
Created by: mhoemmen
@trilinos/tpetra Add GETRF (LU factorization), GETRS (solve linear system(s) using results of GETRF), and GETRI (compute explicit matrix inverse, using results of GETRF) for LittleBlock in BlockCrsMatrix.
GETRI will help accelerate block Jacobi (a.k.a. point implicit), by pushing solve costs to setup and making computation during the actual apply step just little dense matrix-vector multiplies. This should be easier to vectorize.