1. A method for processing a plurality of instructions in a computer system, comprising: flattening an n-bit value of a first register in a register window into an x-bit value, wherein x is greater than n, and wherein the x-bit value corresponds to the first register; flattening a p-bit value of a second register in the register window into a q-bit value, wherein q is greater than p, and wherein the q-bit value corresponds to the second register; and checking a register dependency among the plurality of instructions using the x-bit value and the q-bit value.