January 2013 - ghc-tickets

Re: [GHC] #7542: GHC doesn't optimize (strict) composition with id
by GHC 14 Jan '13

14 Jan '13

#7542: GHC doesn't optimize (strict) composition with id ---------------------------------+------------------------------------------ Reporter: shachaf | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.1 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Runtime performance bug Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ Changes (by liyang): * cc: hackage.haskell.org@… (added) -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7542#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #2110: Rules to eliminate casted id's
by GHC 14 Jan '13

14 Jan '13

#2110: Rules to eliminate casted id's ---------------------------------+------------------------------------------ Reporter: igloo | Owner: Type: feature request | Status: new Priority: lowest | Milestone: 7.6.2 Component: Compiler | Version: 6.8.2 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ Changes (by liyang): * cc: hackage.haskell.org@… (added) -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2110#comment:31> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7542: GHC doesn't optimize (strict) composition with id
by GHC 14 Jan '13

14 Jan '13

#7542: GHC doesn't optimize (strict) composition with id ---------------------------------+------------------------------------------ Reporter: shachaf | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.1 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Runtime performance bug Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ Changes (by jwlato): * cc: jwlato@… (added) -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7542#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7578: Instance selection regression from 7.4 to 7.6
by GHC 14 Jan '13

14 Jan '13

#7578: Instance selection regression from 7.4 to 7.6 -----------------------------+---------------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: normal | Component: Compiler (Type checker) Version: 7.6.1 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- The following code (useless due to minification) works in GHC 7.4.1: {{{ {-# LANGUAGE FlexibleInstances, UndecidableInstances, OverlappingInstances #-} class CollectArgs a where randomEvaluate :: a -> () instance CollectArgs b => CollectArgs (a -> b) where randomEvaluate f = randomEvaluate (f undefined) where () = randomEvaluate (f undefined) instance Show a => CollectArgs a where randomEvaluate x = () }}} In 7.6.2-rc1, I get this error message {{{ test.hs:8:20: Could not deduce (Show b) arising from a use of `randomEvaluate' from the context (CollectArgs b) bound by the instance declaration at test.hs:6:10-46 Possible fix: add (Show b) to the context of the instance declaration In the expression: randomEvaluate (f undefined) In a pattern binding: () = randomEvaluate (f undefined) In an equation for `randomEvaluate': randomEvaluate f = randomEvaluate (f undefined) where () = randomEvaluate (f undefined) }}} The error message goes away if I remove the {{{() = randomEvaluate (f undefined)}}} binding, i.e. the first recursive use of {{{randomEvaluate}}} works fine. (This came up at http://stackoverflow.com/questions/14294802/evaluating- function-at-random-arguments-using-quickcheck/14295179#14295179) -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7578> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7534: allocateRegsAndSpill: Cannot read from uninitialized register
by GHC 14 Jan '13

14 Jan '13

#7534: allocateRegsAndSpill: Cannot read from uninitialized register --------------------------+------------------------------------------------- Reporter: erikd | Owner: simonmar Type: bug | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Os: Linux Architecture: powerpc64 | Failure: Building GHC failed Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | --------------------------+------------------------------------------------- Comment(by PHO): Replying to [comment:7 simonmar]: > I don't immediately see the connection to #7442? Just a thought. Even though PPC/Linux doesn't have the problem described in the note `[inconsistent-pic-reg]`, `PIC.initialisePicBase_ppc` still semms to be assuming only the first block is an entry point. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7534#comment:8> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7562: Parse error with {-# UNPACK #-} Int
by GHC 14 Jan '13

14 Jan '13

#7562: Parse error with {-# UNPACK #-} Int -----------------------------+---------------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.1 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- Comment(by simonpj@…): commit deec5b74dee7f676b8a9f840ec7b5a813e7e0956 {{{ Author: Simon Peyton Jones <simonpj(a)microsoft.com> Date: Thu Jan 10 16:50:25 2013 +0000 Be willing to parse {-# UNPACK #-} without '!' This change gives a more helpful error message when the user says data T = MkT {-# UNPACK #-} Int which should have a strictness '!' as well. Rather than just a parse error, we get T7562.hs:3:14: Warning: UNPACK pragma lacks '!' on the first argument of `MkT' Fixes Trac #7562 compiler/basicTypes/DataCon.lhs | 40 +++++++++++++++++++++------------- compiler/basicTypes/MkId.lhs | 29 +++++++++++++++++------- compiler/deSugar/DsMeta.hs | 4 +- compiler/hsSyn/Convert.lhs | 4 +- compiler/iface/MkIface.lhs | 2 +- compiler/main/PprTyThing.hs | 4 +- compiler/parser/Parser.y.pp | 10 ++++++-- compiler/typecheck/TcSplice.lhs | 11 +++++---- compiler/typecheck/TcTyClsDecls.lhs | 13 +++++++---- 9 files changed, 73 insertions(+), 44 deletions(-) }}} -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7562#comment:1> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7372: Lint failure in GHC 7.6.1
by GHC 14 Jan '13

14 Jan '13

#7372: Lint failure in GHC 7.6.1 -------------------------------+-------------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: closed Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.6.1 Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase: | Blockedby: Blocking: | Related: -------------------------------+-------------------------------------------- Comment(by simonpj): Thanks for checking, monoidal Simon -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7372#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7534: allocateRegsAndSpill: Cannot read from uninitialized register
by GHC 14 Jan '13

14 Jan '13

#7534: allocateRegsAndSpill: Cannot read from uninitialized register --------------------------+------------------------------------------------- Reporter: erikd | Owner: simonmar Type: bug | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Os: Linux Architecture: powerpc64 | Failure: Building GHC failed Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | --------------------------+------------------------------------------------- Comment(by simonmar): I don't immediately see the connection to #7442? -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7534#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1241: Functional dependency Coverage Condition is lifted, and should not be
by GHC 13 Jan '13

13 Jan '13

#1241: Functional dependency Coverage Condition is lifted, and should not be --------------------------------------+------------------------------------- Reporter: guest | Owner: Type: bug | Status: closed Priority: normal | Milestone: _|_ Component: Compiler (Type checker) | Version: 6.6 Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase: | Blockedby: Blocking: | Related: --------------------------------------+------------------------------------- Changes (by diatchki): * status: new => closed * failure: => None/Unknown * resolution: => fixed -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1241#comment:21> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7436: Derived Foldable and Traversable instances become extremely inefficient due to eta-expansion
by GHC 13 Jan '13

13 Jan '13

#7436: Derived Foldable and Traversable instances become extremely inefficient due to eta-expansion --------------------------------------+------------------------------------- Reporter: shachaf | Owner: Type: bug | Status: merge Priority: normal | Milestone: Component: Compiler | Version: 7.6.1 Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: Runtime performance bug | Difficulty: Unknown Testcase: perf/should_runt/T7436 | Blockedby: Blocking: | Related: --------------------------------------+------------------------------------- Changes (by jwlato): * cc: jwlato@… (added) -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7436#comment:20> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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