Transfer free register allocation in cyclic data flow graphs

Discusses an algorithm for the optimal register allocation problem in cyclic data flow graphs. Cyclic data flow graphs result from high level behavioral descriptions that contain loops. Algorithms published up till now did not consider cyclic data flow graphs specifically. When these algorithms are applied to data flow graphs with loops, unnecessary register transfer operations may be introduced. In the paper a new algorithm is presented that performs a minimal register allocation eliminating all superfluous register transfer operations. Experiments on a benchmark set have shown that in all cases all superfluous register transfers could be eliminated at no increase in register cost