NGS: Collaborative Research: Transactional Execution: Making Unsafe Compiler Optimizations Work at Run Time

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

This project proposes to develop a framework for hardware-assisted speculative program optimization (H-SPOT). H-SPOT optimizes programs aggressively based on actually observed program properties by speculatively performing optimizations that are profitable but cannot be guaranteed to be safe at static compile time. The project develops a transactional processor model that provides architectural support to ensure the correctness of optimizations at run time. The project's technical contributions are: (1) The H-SPOT compiler that provides a reformulation of compiler optimizations to apply them even in cases when traditional static compilers would not be able to perform them. It implements dynamic program analysis to obtain information about program properties and uses a cost-benefit model to apply the most promising optimizations. The compiler also develops a static recovery and fix-up code analysis to determine the run-time actions required to ensure the correctness of optimized programs.