Design & Implementation of a Framework for Integrating Front-End & Back-End Compilers

Abstract

We propose a new universal High-Level Information (HLI) format to effectively integrate front-end and back-end compilers by passing front-end information to the back-end compiler. Importing this information into an existing back-end leverages the state-of-the-art analysis and transformation capabilities of existing front-end compilers to allow the back-end greater optimization potential than it has when relying on only locally-extracted information. A version of the HLI has been implemented in the SUIF parallelizing compiler and the GCC back-end compiler. Experimental results with the SPEC benchmarks show that HLI can provide GCC with substantially more accurate data dependence information than it can obtain on its own. Our results show that the number of dependence edges in GCC can be reduced substantially for the benchmark programs studied, which provides greater flexibility to GCC's code scheduling pass, common subexpression elimination pass, loop invariant code removal pass and register local allocation pass. Even with GCC's optimizations limited to basic blocks, the use of HLI produces moderate speedups compared to usng only GCC's dependence tests when the optimized programs are executed on a MIPS R10000 processor.