Techniques for Accurate, Accelerated Processor Simulation: Analysis of Reduced Inputs and Sampling

Abstract

Detailed execution-driven simulation is an important tool for computer architecture research. It is desirable to drive these simulations with standard benchmark programs that are commonly used to evaluate existing computer systems, such as the SPEC2000 suite. Unfortunately, simulating these benchmark programs to completion using full-detail, cycle-accurate simulation on the designated reference input sets results in intractably long simulation durations. This study evaluates and compares two techniques for combating long simulation times: reduced inputs and sampling. Our objective is to assess the ability of each to reduce simulation running times, while simultaneously minimizing the difference in the results generated by using these techniques relative to the results generated by simulating the benchmark programs to completion using the reference inputs. With the reduced input technique, new input sets are carefully generated by hand to produce run-time characteristics of the benchmark programs that are comparable to the overall characteristics produced when the programs are run with the standard inputs. Sampling, on the other hand, simulates only a small fraction of the program's overall execution in full, cycle-accurate detail using the reference inputs.