On the importance of points-to analysis and other memory disambiguation methods for C programs

Abstract

In this paper, we evaluate the benefits achievable from pointer analysis and other memory disambiguation techniques for C/C++ programs, using the framework of the production compiler for the Intel® Itanium™ processor. Most of the prior work on memory disambiguation has primarily focused on pointer analysis, and either presents only static estimates of the accuracy of the analysis (such as average points-to set size), or provides performance data in the context of certain individual optimizations. In contrast, our study is based on a complete memory disambiguation framework that uses a whole set of techniques including pointer analysis. Further, it presents how various compiler analyses and optimizations interact with the memory disambiguator, evaluates how much they benefit from disambiguation, and measures the eventual impact on the performance of the program. The paper also analyzes the types of disambiguation queries that are typically received by the disambiguator, which disambiguation techniques prove most effective in resolving them, and what type of queries prove difficult to be resolved. The study is based on empirical data collected for the SPEC CINT2000 C/C++ programs, running on the Itanium processor.