Template class Stencil2D provides the implementation of Equation (2) and (3), in which function laplacian realizes the Equation (2) and function propagate realizes the Equation (3). The laplacian function (also called stencil in Figure 1) applies line buffers and shifting registers to achieve high spatial parallism. By assigning a value e.g. 2 to the template variable t_nPE, the HLS will synthesize a compute IP with the ability to compute the laplacian operation for 2 grid points in one clock cycle. The propagate function (also called time upate in Figure 1) processes multiple data streams in parallel to compute multiple data points of the next wavefield simultaneously.