Instructions grouped into instruction groups are optimized across group boundaries. Instruction sequences spanning multiple groups are optimized by retaining information relating to an instruction at the end of one instruction group to be co-optimized with an instruction at the beginning of a subsequent instruction group. This retained information is then used in optimization of one or more instructions of the subsequent group. Optimization may be performed across n group boundaries, where n is equal to two or greater. Additionally, optimization of instructions within a group may be performed, in addition to the optimizations across group boundaries.