quick performance measurements

[Richard Eisenberg]

Hi devs,

I have a few ideas for tweaks to improve compiler performance. (For example, reversing the order of comparisons in a short-circuiting comparison operation.) I don't have a particular test case with a profile that tells me where the smoking gun is. But I'd like to try these easy tweaks just to see if performance improves.

My question:
Is there an easy way to run some command that will give me helpful feedback on my performance tweak?

Of course, I could push to a branch and have perf.haskell.org tell me. But that takes a long time. I could compile a few files and examine the output manually. But that's a bit painful. Ideally, there would be a way to run a portion of the testsuite and have the testsuite tool aggregate performance characteristics and report. Or perhaps there's a way to get cabal to aggregate performance characteristics, and I could just try compiling a few libraries. Any ideas out there?

Thanks!
Richard