Abstract: The method uses statistical information obtained by running the computer code with test data to determine a new ordering for the code blocks. The new order places code blocks that are often executed after one another close to one another in the computer's memory. The method first generates chains of basic blocks, and then merges the chains. Finally, basic blocks that were not executed by the test data that was used to generate the statistical information are moved to a distant location to allow the blocks that were used to be more closely grouped together.