[Haskell-cafe] ghc-prof-options and libraries on Hackage

[Eric Seidel]

> To provide an example, I'm currently working on a little game engine that
> uses JuicyPixels to load images. I have a problem in my code that needs
> optimizing, but the current state of things results in profiles that are
> very difficult to work with. JuicyPixels specifies -auto-all in its cabal
> file, which means I have no alternative but to profile JuicyPixels code. In
> this scenario, the bottleneck is actually within my FRP game loop and
> nothing to do with image loading! As a result, the profiles are fairly
> useless to me.

While in this case the extra profiling data may be useless, it seems to me that in general you won't know a priori. I would prefer to have as much data available as possible, and then filter it.

HPC works sort of like this, it gathers coverage data for all of the modules compiled with -fhpc, but has command-line options to only report coverage for certain modules. Perhaps GHC's rts could add a similar flag to only report profiling data from certain modules or functions?