#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 Ben Gamari <ben@…>): In [changeset:"2325bd4e0fad0e5872556c5a78d1a6a1873e7201/ghc" 2325bd4/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="2325bd4e0fad0e5872556c5a78d1a6a1873e7201" Create a deterministic version of tyVarsOfType I've run into situations where I need deterministic `tyVarsOfType` and this implementation achieves that and also brings an algorithmic improvement. Union of two `VarSet`s takes linear time the size of the sets and in the worst case we can have `n` unions of sets of sizes `(n-1, 1), (n-2, 1)...` making it quadratic. One reason why we need deterministic `tyVarsOfType` is in `abstractVars` in `SetLevels`. When we abstract type variables when floating we want them to be abstracted in deterministic order. Test Plan: harbormaster Reviewers: simonpj, goldfire, austin, hvr, simonmar, bgamari Reviewed By: simonmar Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1468 GHC Trac Issues: #4012 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4012#comment:132> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler