I don't know the innards of the Haskell compiler well enough, but, as chrisseaton writes above, tracing Haskell could lead to speedups better than Dynamo. For

I don't know the innards of the Haskell compiler well enough, but, as chrisseaton writes above, tracing Haskell could lead to speedups better than Dynamo. For example data for generic functions in hot code could be unboxed, maybe laziness could be 'switched off' locally etc. But the easy gains that you see for dynamically typed languages, as we agree, are unlikely to be achievable. Nevertheless SPJ has suggested to the PyPy/RPython people to write a meta-tracer for Haskell, just to be able to measure what's possible. As to Dynamo, I think some of the key gains came from the ability to shortcut jumps to jumps to jumps to ... that could arise from linking separately compiled code. However, modern CPUs diminish the penalty such frivolous jumping incurs, so Dynamo became less and less competitive with tracing on higher-level languages. (BTW, Dynamo can trace everything, not just C executables.)