1. A method for operating a computer system having a memory, a processor, and a code specifying the performance of the computer system and/or the processor, the method comprising: storing a first program and in the memory, and storing a filter program in the memory to compile the first program into executable code, wherein the first program includes instructions and at least one section with a selection and reference criterion and at least two alternate passages having instructions; and generating the executable code from the first program with the filter program, wherein; instructions of only one of the at least two alternate passages are selected and converted into object code in accord with the selection and reference criterion of the section relative to the code specifying the performance of the computer system and/or the processor so that performance of the computer system and the processor when executing the first program are exploited to the best possible degree.