Compiling Stencils in High Performance Fortran

In many Fortran90 and HPF programs performing dense matrix computations, the main computational work is performed by a class of kernels known as stencils. We present a general- purpose compiler optimization strategy that generates efficient code for a wide class of stencil computations expressed using Fortran90 array constructs. This strategy optimizes both single and multi-statement stencils by orchestrating a set of program transformations that minimize both intraprocessor and interprocessor data movement implied by Fortran90 array operations. Our experimental results show that our approach can produce highly optimized code in situations where other compilers do not. In some cases the improvements are as much as several orders of magnitude.