A computer implemented tool is provided for assisting in the mapping of a computer program to an asymmetric multiprocessing apparatus 2 incorporating an asymmetric memory hierarchy formed of a plurality of memories 12, 14. An at least partial architectural description 22, 40 is provided as an input variable to the tool and used to infer missing annotations within a source computer program 24, such as which functions are to be executed by which execution mechanisms 4, 6, 8 and which variables are to be stored within which memories 12, 14. The tool also adds mapping support commands, such as cache flush commands, cache invalidate commands, DMA move commands and the like as necessary to support the mapping of the computer program to the asymmetric multiprocessing apparatus 2.