February 2013 - ghc-tickets

[GHC] #7677: Proposal: add attached README.md to GHC repo
by GHC 12 Feb '13

12 Feb '13

#7677: Proposal: add attached README.md to GHC repo -----------------------------+---------------------------------------------- Reporter: morabbin | Owner: Type: task | Status: new Priority: normal | Component: Build System Version: 7.6.2 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- Have a look at my [https://github.com/Morabbin/ghc accidental github fork of GHC] to see how this would look on the GHC github page. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7677> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7046: Simplifier failing to unbox join point
by GHC 12 Feb '13

12 Feb '13

#7046: Simplifier failing to unbox join point ------------------------------------+--------------------------------------- Reporter: simonpj | Owner: simonpj Type: bug | Status: closed Priority: high | Milestone: 7.8.1 Component: Compiler | Version: Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase: perf/should_run/T5113 | Blockedby: Blocking: | Related: ------------------------------------+--------------------------------------- Changes (by simonpj): * status: new => closed * resolution: => fixed Comment: Fixed: see #5113 -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7046#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7353: Make system IO interruptible on Windows
by GHC 12 Feb '13

12 Feb '13

#7353: Make system IO interruptible on Windows ---------------------------------+------------------------------------------ Reporter: joeyadams | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: libraries/base | Version: 7.6.1 Keywords: | Os: Windows Architecture: Unknown/Multiple | Failure: Incorrect result at runtime Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ Changes (by bos): * cc: bos@… (added) -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7353#comment:14> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7383: implement proper type promotion in compilation of C calls
by GHC 12 Feb '13

12 Feb '13

#7383: implement proper type promotion in compilation of C calls ---------------------------------+------------------------------------------ Reporter: igloo | Owner: Type: bug | Status: new Priority: high | Milestone: 7.6.2 Component: Compiler | Version: 7.6.1 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: 7684 | ---------------------------------+------------------------------------------ Changes (by tibbe): * cc: johan.tibell@… (added) -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7383#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7383: implement proper type promotion in compilation of C calls
by GHC 12 Feb '13

12 Feb '13

#7383: implement proper type promotion in compilation of C calls ---------------------------------+------------------------------------------ Reporter: igloo | Owner: Type: bug | Status: new Priority: high | Milestone: 7.6.2 Component: Compiler | Version: 7.6.1 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: 7684 | ---------------------------------+------------------------------------------ Changes (by tibbe): * related: => 7684 Comment: cgrun071 now segfaults. See linked ticket. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7383#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #876: Length is not a good consumer
by GHC 12 Feb '13

12 Feb '13

#876: Length is not a good consumer --------------------------------------+------------------------------------- Reporter: ariep@… | Owner: Type: bug | Status: new Priority: lowest | Milestone: 7.6.2 Component: libraries/base | Version: 6.5 Resolution: | Keywords: length Os: Linux | Architecture: Unknown/Multiple Failure: Runtime performance bug | Difficulty: Unknown Testcase: list003 | Blockedby: Blocking: | Related: --------------------------------------+------------------------------------- Comment(by simonpj): OK, so the problem in Ian's comment 6 years ago (ha ha!) was that the naive version of `length` using `foldr` does not lead to a tail recursive function. But after a little reflection I realise that what we want is `foldl` with a strict accumulating parameter; and that can be expressed using `foldr`. So here is a version that does work (notice the strict apply) in `incL`: {{{ len :: [a] -> Int len xs = foldr incL id xs 0 incL :: a -> (Int -> Int) -> Int -> Int incL = \_ g x -> g $! (x+1) }}} To demonstrate: {{{ foo :: Int -> Int -> Int foo p q = len [p..q] }}} Compile with -O to get this nice tight code {{{ Len.$wfoo :: GHC.Prim.Int# -> GHC.Prim.Int# -> GHC.Prim.Int# Len.$wfoo = \ (ww_sgn :: GHC.Prim.Int#) (ww1_sgr :: GHC.Prim.Int#) -> case GHC.Prim.># ww_sgn ww1_sgr of _ { GHC.Types.False -> letrec { $wgo_sgA [Occ=LoopBreaker] :: GHC.Prim.Int# -> GHC.Prim.Int# -> GHC.Prim.Int# [LclId, Arity=2, Str=DmdType LL] $wgo_sgA = \ (w_sga :: GHC.Prim.Int#) (ww2_sgd :: GHC.Prim.Int#) -> case GHC.Prim.==# w_sga ww1_sgr of _ { GHC.Types.False -> $wgo_sgA (GHC.Prim.+# w_sga 1) (GHC.Prim.+# ww2_sgd 1); GHC.Types.True -> GHC.Prim.+# ww2_sgd 1 }; } in $wgo_sgA ww_sgn 0; GHC.Types.True -> 0 } }}} So I think we can do this for length in the library. I need a clean nofib run to test, though. Simon -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/876#comment:25> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7192: Bug in -fregs-graph with -fnew-codegen
by GHC 12 Feb '13

12 Feb '13

#7192: Bug in -fregs-graph with -fnew-codegen -------------------------------+-------------------------------------------- Reporter: simonmar | Owner: benl Type: bug | Status: closed Priority: highest | Milestone: 7.8.1 Component: Compiler | Version: 7.7 Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase: | Blockedby: Blocking: 4258 | Related: -------------------------------+-------------------------------------------- Comment(by shelarcy): Replying to [comment:14 simonmar]: > #7679 I see. Thank you. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7192#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7681: Panic on quoting empty case
by GHC 11 Feb '13

11 Feb '13

#7681: Panic on quoting empty case -----------------------------+---------------------------------------------- Reporter: monoidal | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.7 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- With -XEmptyCase on, {{{ Prelude Language.Haskell.TH> runQ [| case 0 of {} |] ghc: panic! (the 'impossible' happened) (GHC version 7.7.20130209 for x86_64-unknown-linux): coreList: empty argument }}} -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7681> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #876: Length is not a good consumer
by GHC 11 Feb '13

11 Feb '13

#876: Length is not a good consumer --------------------------------------+------------------------------------- Reporter: ariep@… | Owner: Type: bug | Status: new Priority: lowest | Milestone: 7.6.2 Component: libraries/base | Version: 6.5 Resolution: | Keywords: length Os: Linux | Architecture: Unknown/Multiple Failure: Runtime performance bug | Difficulty: Unknown Testcase: list003 | Blockedby: Blocking: | Related: --------------------------------------+------------------------------------- Changes (by morabbin): * owner: simonpj => * status: closed => new * resolution: invalid => Comment: Premature; reopening as a performance bug. #915 was about the general stream fusion technique, which needs moar research. This is a good place to track an exemplar of the problem. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/876#comment:24> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1845: unconditional relative branch out of range (GHC version 6.8.1-6.10.4 for powerpc_apple_darwin)
by GHC 11 Feb '13

11 Feb '13

#1845: unconditional relative branch out of range (GHC version 6.8.1-6.10.4 for powerpc_apple_darwin) ---------------------------------+------------------------------------------ Reporter: guest | Owner: igloo Type: bug | Status: closed Priority: high | Milestone: 7.0.2 Component: Compiler | Version: 7.1 Resolution: fixed | Keywords: Os: MacOS X | Architecture: powerpc Failure: Compile-time crash | Difficulty: Unknown Testcase: ghci024 | Blockedby: Blocking: | Related: ---------------------------------+------------------------------------------ Changes (by igloo): * testcase: => ghci024 -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1845#comment:31> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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