Compiler Support for Parallel Evaluation of C++ Constant Expressions

Abstract

Metaprogramming, the practice of writing programs that manipulate other programs at compile-time, continues to impact software development; enabling new approaches to optimisation, static analysis, and reflection. Nevertheless, a significant challenge associated with advanced metaprogramming techniques, including the constexpr functionality introduced to C++ in 2011, is an increase in compilation times. This paper presents ClangOz, a novel Clang-based research compiler that addresses this issue by evaluating relevant constant expressions in parallel, thereby reducing compilation time.