performance regressions

Richard Eisenberg eir at
Sat Dec 13 02:51:32 UTC 2014

Hi devs,

Phab has shown up some performance regressions in my recent commits. See The failures except for haddock.base are new, and evidently my fault. They didn't show up on Travis. Will look into it shortly, but I doubt over the weekend.

I don't think this should hold up the 7.10 fork, however. I have a suspicion as to what caused the problem -- the reimplementation of TcInteract.matchFam. That reimplementation was solely to reduce code repetition between TcInteract.matchFam and FamInstEnv.reduceTyFamApp_maybe. It can safely be rolled back -- just use the implementation of matchFam that existed before my commits.

I'll look into this Monday at the latest, but if a remedy is needed sooner, try the technique above.

Why would these failures show up on Phab but not on Travis?

Sorry about the bother!

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the ghc-devs mailing list