B2Sim:: a fast micro-architecture simulator based on basic block characterization

State-of-the-art architectural simulators support cycle accurate pipeline execution of application programs. However, it takes days and weeks to complete the simulation of even a moderate- size program. During the execution of a program, program behavior does not change randomly but changes over time in a predictable/periodic manner. This behavior provides the opportunity to limit the use of a pipeline simulator. More precisely, this paper presents a hybrid simulation engine, named B²Sim for (cycle-characterized) Basic Block based Simulator, where a fast cache simulator e.g., sim-cache and a slow pipeline simulator e.g., sim-outorder are employed together. B²Sim reduces the runtime of architectural simulation engines by making use of the instruction behavior within executed basic blocks. We have integrated B²Sim into SimpleScalar and have achieved on average a factor of 3.3 times speedup on the SPEC2000 benchmark and Media-bench programs compared to conventional pipeline simulator while maintaining the accuracy of the simulation results with less than 1% CPI error on average.