#15488: GHC takes up huge amount of memory when compiling accelerate 1.2.0 -------------------------------------+------------------------------------- Reporter: noah | Owner: tdammers Type: bug | Status: new Priority: high | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 Resolution: | Keywords: | accelerate,memory,compile Operating System: Linux | Architecture: x86_64 | (amd64) Type of failure: Compile-time | Test Case: accelerate performance bug | 1.2.0 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by tdammers): Ah, yes, that makes sense. A lot, actually. The situation fits the description like a glove - we have the nested cases, we have small expressions at the leaves, and we have the "-O2 triggers exponential blowup" part. However, the patch proposed in https://ghc.haskell.org/trac/ghc/ticket/13253#comment:24 does not make things any better - core size still blows up the same (114k terms), and compilation time is about the same. In fact, no matter what conditions I put in that particular spot, I always get the same result, suggesting that this particular program never hits the `OneOcc` branch at all. I still think case-of-case is the direction to investigate, but this particular patch does not seem to be the solution. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15488#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler