1.2 Low Level Virtual Machine Back-end for GHC................... 4

This thesis details the motivation, design and implementation of a new back-end for the Glasgow Haskell Compiler which uses the Low Level Virtual Machine compiler infrastructure for code generation.Haskell as implemented by GHC was found to map remarkably well onto the LLVM Assembly language, although some new approaches were required. The most notable of these being the use of a custom calling convention in order to implement GHC’s optimisation feature of pinning STG virtual registers to hardware registers. In the evaluation of the LLVM back-end in regards to GHC’s C and native code generator back-end, the LLVM back-end was found to offer comparable results in regards to performance in most situations with the surprising finding that LLVM’s optimisations didn’t offer any improvement to the run-time of the generated code. The complexity of the LLVM back-end proved to be far simpler though then either the native code generator or C back-ends and as such it offers a compelling primary back-end target for GHC. Acknowledgements I would like to first and foremost thank my parents. My mother Ann Terei and my father