CAnDL: a domain specific language for compiler analysis

Optimizing compilers require sophisticated program analysis and transformations to exploit modern hardware. Implementing the appropriate analysis for a compiler optimization is a time consuming activity. For example, in LLVM, tens of thousands of lines of code are required to detect appropriate places to apply peephole optimizations. It is a barrier to the rapid prototyping and evaluation of new optimizations. In this paper we present the Compiler Analysis Description Language (CAnDL), a domain specific language for compiler analysis. CAnDL is a constraint based language that operates over LLVM's intermediate representation. The compiler developer writes a CAnDL program, which is then compiled by the CAnDL compiler into a C++ LLVM pass. It provides a uniform manner in which to describe compiler analysis and can be applied to a range of compiler analysis problems, reducing code length and complexity. We implemented and evaluated CAnDL on a number of real world use cases: eliminating redundant operations; graphics code optimization; identifying static control flow regions. In all cases were we able to express the analysis more briefly than competing approaches.