I was surprised by this, because I would expect HEAD and 7.6.3 to generate very similar code with respect to spilling before a call. #8905 is about an improvement we can make in the new code generator, that wasn't
#8900: Strictness analysis regression --------------------------------------------+------------------------------ Reporter: tibbe | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc2 Resolution: fixed | Keywords: Operating System: MacOS X | Architecture: x86_64 Type of failure: Runtime performance bug | (amd64) Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: --------------------------------------------+------------------------------ Comment (by tibbe): Replying to [comment:24 simonmar]: possible in the old codegen. My mistake. I've been reading too much Cmm lately.
they look identical to me modulo reordering and things falling into different stack slots. Maybe the problematic bit is somewhere else - could you point to it?
I have no idea then. There's a lot of Cmm and diff tools don't work well because blocks have been reordered a lot between 7.6.3 and HEAD. Since the difference is so small I suggest we ignore it for now. I'm more interested in getting #8905 into a production-ready state. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8900#comment:25 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler