1. A computer implemented method comprising: accessing memory capability of one of a plurality of processing units for a memory capability requirement, the plurality of processing units including central processing units (CPUs) and graphics processing units (GPUs); loading an executable compiled from a program source to be executed in the one of a plurality of processing units coupled with a stream memory according to the memory capability requirement; and allocating memory location for a variable in the program source by the executable according to the memory capability.