Abstract
A method for pipelining instructions on a PAC processor includes determining a minimum initial interval, and grouping the instructions so that the operands of dependent instructions are assigned to the same local register file. The virtual registers of the instructions that have data dependency across the first functional unit and the second functional unit are assigned to a global register file. The instructions are then modulo scheduled based on a current value of initial interval. The virtual registers of the scheduled instructions are allocated to the corresponding register files. If the allocation fails, a set of virtual registers is transferred from the first or second register file to the global register file.