[GHC] #14978: GADTs don't seem to unpack properly
#14978: GADTs don't seem to unpack properly -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Runtime Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Consider this simple code: {{{#!hs type family Foo a b data Goof a b where Goof :: !(Foo a b :~: Int) -> Goof a b }}} `(:~:)` has just one constructor (`Refl`) with no arguments, so I'd expect it to unpack to a void representation: {{{#!hs GoofConstr :: Foo a b ~N# Int => Goof a b WGoof :: Foo a b :~: Int -> Goof a b WGoof eq = case eq of Refl -> GoofConstr }}} But it doesn't seem to unpack at all. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14978> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#14978: GADTs don't seem to unpack properly -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"9187d5fb1d3d38a4e607b0d61784c21447c8195b/ghc" 9187d5fb/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="9187d5fb1d3d38a4e607b0d61784c21447c8195b" Allow unpacking of single-data-con GADTs Trac #14978 pointed out that single-constructor GADTs should be unpackable without trouble. Acutally I realise that even existentials should be unpackable too, but that's a bit more work, so it's not part of this patch. See Note [Unpacking GADTs and existentials] in MkId. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14978#comment:1> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#14978: GADTs don't seem to unpack properly -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime | Test Case: performance bug | simplCore/should_compile/T14978 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * testcase: => simplCore/should_compile/T14978 Comment: Fixed. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14978#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#14978: GADTs don't seem to unpack properly -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime | Test Case: performance bug | simplCore/should_compile/T14978 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): Thanks! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14978#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#14978: GADTs don't seem to unpack properly -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime | Test Case: performance bug | simplCore/should_compile/T14978 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): Do we want a new ticket to track existentials? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14978#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#14978: GADTs don't seem to unpack properly -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime | Test Case: performance bug | simplCore/should_compile/T14978 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
Do we want a new ticket to track existentials?
It's #10016 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14978#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#14978: GADTs don't seem to unpack properly -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.2.2 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime | Test Case: performance bug | simplCore/should_compile/T14978 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => closed * resolution: => fixed Comment: It looks like this is resolved. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14978#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
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