An alternative to branch prediction: pre-computed branches

What is it about?

Through this paper we developed an alternative approach to the present -- day two level dynamic branch prediction structures. Instead of predicting branches based on history information, we propose to pre - calculate the branch outcome. A pre - calculated branch prediction (PCB) determines the outcome of a branch as soon as all of the branch's operands are known. The instruction that produced the last branch's operand will trigger a supplementary branch condition estimation and, after this operation, it correspondingly computes the branch outcome. This outcome is cached into prediction table. The new proposed PCB algorithm clearly outperforms all the classical branch prediction schemes, simulations on SPEC and Stanford HSA benchmarks, proving to be very efficient. Also, our investigations related to architectural complexity and timing costs are quite optimistic, involving an original alternative to the present-day in branch prediction approach.

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