Methods and products for processing a software kernel of instructions are disclosed. The software kernel has stages representing a loop nest. The software kernel is processed by partitioning iterations of an outermost loop into groups with each group representing iterations of the outermost loop, running the software kernel and rotating a register file for each stage of the software kernel preceding an innermost loop to generate code to prepare for filling and executing instructions in software pipelines for a current group, running the software kernel for each stage of the software kernel in the innermost loop to generate code to fill the software pipelines for the current group with the register file being rotated after at least one run of the software kernel for the innermost loop, and repeatedly running the software kernel to unroll inner loops to generate code to further fill the software pipelines for the current group.