#12765: Don't optimize coercions with -O0 -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: task | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- During the call today Simon and I discussed the possibility of omitting coercion optimization from the desugarer's simple optimization (`simpleOptPgm`) when compiling with `-O0`. The justification here was to perhaps speed-up unoptimized compilation times for programs like that of #12506, which has very large coercions (presumably due to #8095). The rationale was that while this first pass of coercion simplification during desugaring may reduce the size of some of these coercions, we only walk over them once more during code generation, so there's little benefit given the cost. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12765 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler