Predicting program behavior using real or estimated profiles

  • Authors:
  • David W. Wall

  • Affiliations:
  • Transmeta Corporation, Santa Clara, CA

  • Venue:
  • ACM SIGPLAN Notices - Best of PLDI 1979-1999
  • Year:
  • 2004

Quantified Score

Hi-index 0.00

Visualization

Abstract

There is a growing interest in optimizations that depend on or benefit from an execution profile that tells where time is spent. How well does a profile from one run describe the behavior of a different run, and how does this compare with the behavior predicted by static analysis of the program? This paper defines two abstract measures of how well a profile predicts actual behavior. According to these measures, real profiles indeed do better than estimated profiles, usually. A perfect profile from an earlier run with the same data set, however, does better still, sometimes by a factor of two. Unfortunately, using such a profile is unrealistic, and can lead to inflated expectations of a profile-driven optimization.