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.

Data Dependence Profiling for Speculative Optimizations

“…Existing approaches usually require a very sophisticated interprocedural pointer alias analysis followed by a shape analysis [4,5,6]. The effectiveness of such approaches is often limited because of the increasing use of shared libraries, complex recursive data structures, and dynamically allocated objects in applications [7,8].…”

InstantCheck: Checking the Determinism of Parallel Programs Using On-the-Fly Incremental Hashing

“…In our current SW-InstantCheck T r prototype, we add these annotations manually. Two challenges complicate automation of this annotation task: (1) application-specific functions that wrap malloc/free, which is a coding practice used to enhance error checking and modularity [16]; and (2) starting the usage of allocated memory several bytes after the first allocated byte to improve cache behavior. HW-InstantCheck Inc is not only faster than SW-InstantCheck T r but also more automated as it does not require these annotations.…”

Graph Rewriting for Hardware Dependent Program Optimizations

“…Therefore, a good alias analysis is essential for our needs. We use a so-called memory disambiguator built into our compiler [9]. Special normalizations.…”