GHC thinks it is smarter than me [was: RE: Transitive inlining]
Manuel M. T. Chakravarty
Mon, 25 Dec 2000 22:11:02 +1100
Simon Peyton-Jones <[email protected]> wrote,
> Yes, all the inlining you expect should indeed happen. If
> it doesn't can you show us an example?
Meanwhile, I think, the lack of inlining that I saw isn't
connected to modules. Instead, the problem is that GHC
thinks it knows more about my program than I do. More
precisely, it seems to take an INLINE pragma just as an
encouragement rather than a command to inline. In
particular - at least if a function is large enough - it
doesn't inline the function anymore if the function is used
more than once.
This behaviour is a problem for our array library. We need
very aggressive inlining. Would it maybe be possible to
make -O2 interpret INLINE pragmas as obligatory?
 The function in question actually uses an INLINE 2
pragma - I guess that this doesn't matter.