#4012: Compilation results are not deterministic -------------------------------------+------------------------------------- Reporter: kili | Owner: niteria Type: bug | Status: patch Priority: high | Milestone: 8.0.1 Component: Compiler | Version: 6.12.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: #10424 | Differential Rev(s): Phab:D910, | Phab:D1073, Phab:D1133, Phab:D1192, | Phab:D1268, Phab:D1360, Phab:D1373, | Phab:D1396, Phab:D1457, Phab:D1468, Wiki Page: | Phab:D1487, Phab:D1504, Phab:D1508 -------------------------------------+------------------------------------- Comment (by Bartosz Nitka ): In [changeset:"5b2b7e338c822c34f86e8bd3ff442a979711d1fe/ghc" 5b2b7e33/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="5b2b7e338c822c34f86e8bd3ff442a979711d1fe" Make callToPats deterministic in SpecConstr This fixes a non-determinism bug where where depending on the order of uniques allocated, the specialized workers would have different order of arguments. Compare: ``` $s$wgo_s1CN :: Int# -> Int -> Int# [LclId, Arity=2, Str=DmdType ] $s$wgo_s1CN = \ (sc_s1CI :: Int#) (sc_s1CJ :: Int) -> case tagToEnum# @ Bool (<=# sc_s1CI 0#) of _ [Occ=Dead] { False -> $wgo_s1BU (Just @ Int (I# (-# sc_s1CI 1#))) (Just @ Int sc_s1CJ); True -> 0# } ``` vs ``` $s$wgo_s18mTj :: Int -> Int# -> Int# [LclId, Arity=2, Str=DmdType ] $s$wgo_s18mTj = \ (sc_s18mTn :: Int) (sc_s18mTo :: Int#) -> case tagToEnum# @ Bool (<=# sc_s18mTo 0#) of _ [Occ=Dead] { False -> $wgo_s18mUc (Just @ Int (I# (-# sc_s18mTo 1#))) (Just @ Int sc_s18mTn); True -> 0# } ``` Test Plan: I've added a new testcase ./validate Reviewers: simonmar, simonpj, austin, goldfire, bgamari Reviewed By: bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1508 GHC Trac Issues: #4012 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/4012#comment:138 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler