Abstract: The present invention optimizes an executable software program containing a plurality of basic blocks for several different operational environments or modes by identifying the basic blocks which execute for each particular operational environment or mode, and the frequency of each blocks' execution in the environment or mode. For each environment or mode, the frequency of execution for the block in that environment or mode is compared against a predetermined threshold value. Each basic block whose frequency of execution exceeds the predetermined threshold value is copied into a program segment for that environment or mode. Basic blocks whose frequency of execution does not exceed the predetermined threshold value are copied into a common code segment accessible from each of the program segments. The code in each program segment is then optimized to provide an executable code segment optimized for operation in several different environments or modes.