Eecient Address Translation

The address calculation for distributed data access plays a major role for the performance of ne-grained data-parallel applications. This paper reports about the hardware centrifuge of the Cray T3E which enables the shift of the address calculation from software into hardware. This shift minimizes address calculation overhead reducing communication cost of dynamic communication patterns. The centrifuge is compared with complex integer division and modulo and with integer mask and shift operations. The measurements show for a one-dimensional dynamic communication pattern for several distributions a runtime advantage of T3E's hardware centrifuge of at least a factor 1.9 over integer division arithmetic. But, the centrifuge is barely faster compared with integer mask and shift operations.