Re: [GHC] #11126: Entered absent arg in a Repa program

#11126: Entered absent arg in a Repa program -------------------------------------+------------------------------------- Reporter: tuplanolla | Owner: Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by jscholl): I could halfway reproduce this: The following program has an intermediate state where a value ({{{arr2}}}) is marked with {{{}}} which is later used again (in the unfolding of {{{getIt}}}). This does however not completely trigger the bug as {{{arr2}}} gets marked too early, i.e. worker-wrapper is not yet running. Then the simplifier inlines {{{getIt}}} and {{{arr2}}} is referenced again, so when worker-wrapper runs everything has the correct strictness. However, if I somehow could convince the compiler to run the worker- wrapper transformation before phase 0 the program has a good chance to trigger the bug. Even if it does not, I think the usage of {{{arr2}}} should not be {{{}}} as it could be still referenced if {{{getIt}}} is inlined. I used the following command to generate the core2core log (ghc 7.10.3): {{{ghc -c Unfold.hs -ddump-simpl -dsuppress-coercions -dsuppress-type- applications -dsuppress-uniques -dsuppress-module-prefixes -dverbose- core2core -O -fstrictness-before=0}}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11126#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler