Reexecution and selective reuse in checkpoint processors

Resource-efficient checkpoint processors have been shown to recover to an earlier safe state very fast. Yet in order to complete the misprediction recovery they also need to reexecute the code segment between the recovered checkpoint and the mispredicted instruction. This paper evaluates two novel reuse methods which accelerate reexecution paths by reusing the results of instructions and the outcome of branches obtained during the first run. The paper also evaluates, in the context of checkpoint processors, two other reuse methods targeting trivial and repetitive arithmetic operations. A reuse approach combining all four methods requires an area of 0.87[mm²], consumes 51.6[mW], and improves the energy-delay product by 4.8% and 11.85% for the integer and floating point benchmarks respectively.