The Results of: Profiling Large-Scale Lazy Functional Programs Stephen A. Jarvis 1 and Richard G. Morgan 2 1 Oxford University Computing Laboratory, Wolfson Building, Parks Road, Oxford, England. Stephen.Jarvis@comlab.ox.ac.uk 2 Department of Computer Science, Durham University, South Road, Durham, England. R.G.Morgan@durham.ac.uk Abstract. At the High Performance Functional Computing conference in Denver [MoJ95] a new approach to profiling was presented, this al- lowed the complete set of program costs to be recorded in so-called cost centre stacks. It was proposed that these program costs could then be manipulated using a post-processor which would speed up the task of profiling a Haskell program and would also produce more accurate pro- filing results. This paper presents the results of using this new profiling tool in the analysis of a number of Haskell programs. The overheads of the scheme are discussed and the benefits of this new system are considered. The paper also outlines how this approach can be modified to trace and debug Haskell programs.