| Here's a brief introduction. I intend to write up (on the performance page on | the wiki) a list of things we've done to improve the shootout entries. Yes, do put what you wrote before on the Wiki. (The performance-advice page seems to have vanished but it should be on the user-documentation wiki somewhere. I'm sure we'll find it.) | Multiple calls to sin. Hmm :/ And similar for cos, as well as k*k. Not sure | why GHC isn't removing these (SimonM?), so let's do that by hand GHC doesn't do full CSE. It'd be a relatively easy pass for someone to add, but it can cause space leaks. And it can replace two strictly-evaluated calls with one lazy thunk: let { x = case e of ....; y = case e of .... } in ... ==> let { v = e; x = case v of ...; y = case v of ... } in ... Instead GHC does "opportunistic CSE". If you have let x = e in .... let y = e in .... then it'll discard the duplicate binding. But that's very weak. I've added this to the GHC FAQ Simon