August 2017 - ghc-tickets

[GHC] #14073: Testsuite should pass even with LANG=C
by GHC 01 Aug '17

01 Aug '17

#14073: Testsuite should pass even with LANG=C -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Test Suite | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- It seems that our testsuite has some sensitivity to the setting of the `LANG` environment variable. Namely the driver seems to encounter encoding issues in a few cases, {{{ Framework failures: ghci/scripts/T5975a.run T5975a [ghci] ('ascii' codec can't encode characters in position 41-42: ordinal not in range(128)) ghci/scripts/T5975b.run T5975b [ghci] ('ascii' codec can't encode characters in position 41-42: ordinal not in range(128)) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14073> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1600: Optimisation: CPR the results of IO
by GHC 01 Aug '17

01 Aug '17

#1600: Optimisation: CPR the results of IO -------------------------------------+------------------------------------- Reporter: simonmar | Owner: (none) Type: task | Status: new Priority: lowest | Milestone: Component: Compiler | Version: 6.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #8598 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by nomeata): Let me know when the branch is cleaned up. I can have a look (although I probably forgot everything since then…). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1600#comment:77> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14007: CI builds for integer-simple variant of GHC for Windows
by GHC 01 Aug '17

01 Aug '17

#14007: CI builds for integer-simple variant of GHC for Windows ---------------------------------------+--------------------------------- Reporter: varosi | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Windows Architecture: x86_64 (amd64) | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ---------------------------------------+--------------------------------- Currently for Haskell production non-open-source software integer-simple builds of GHC for Windows are needed. GMP Integer library is GPL and cannot be used for such production software. Is it possible to make such official builds of GHC? This will stimulate more Haskell as a production language. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14007> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14072: Code generated by GHC 8.2.1 faster than 8.0.1 but still somewhat slower than 7.10.3
by GHC 01 Aug '17

01 Aug '17

#14072: Code generated by GHC 8.2.1 faster than 8.0.1 but still somewhat slower than 7.10.3 -------------------------------------+------------------------------------- Reporter: harendra | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 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: -------------------------------------+------------------------------------- Unicode normalization library (https://github.com/harendra-kumar/unicode- transforms) shows around 10% improvement with GHC 8.2.1 when compared to GHC 8.0.1, across most benchmarks. However, it is still somewhat slower when compared to GHC 7.10.3. On the other hand, when compared to GHC 7.8.4, GHC 8.2.1 is marginally better. This library has been optimized with an objective to match or better (in some cases it is better) the performance of the equivalent ICU C++ library (compare only decompose normalization). Some of the last hurdles to match the best case of C++ were in the code generated by GHC. I filed a couple of ghc trac tickets earlier on that. You can reproduce these results easily as follows: {{{ $ git clone https://github.com/harendra-kumar/unicode-transforms.git $ git checkout -b v0.3.3 v0.3.3 $ echo ghc-8.0 $ stack bench $ stack bench --stack-yaml stack-7.10.yaml $ stack bench --stack-yaml stack-8.2.yaml }}} Here are some excerpts from the benchmarks: GHC 7.10.3: {{{ benchmarking unicode-transforms-text/NFD/English time 4.823 ms (4.765 ms .. 4.902 ms) benchmarking unicode-transforms-text/NFD/Deutsch time 5.607 ms (5.522 ms .. 5.673 ms) }}} GHC 8.0.1 {{{ benchmarking unicode-transforms-text/NFD/English time 6.330 ms (6.232 ms .. 6.439 ms) benchmarking unicode-transforms-text/NFD/Deutsch time 7.109 ms (7.034 ms .. 7.183 ms) }}} GHC 8.2.1 {{{ benchmarking unicode-transforms-text/NFD/English time 5.659 ms (5.594 ms .. 5.740 ms) benchmarking unicode-transforms-text/NFD/Deutsch time 6.406 ms (6.329 ms .. 6.478 ms) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14072> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1600: Optimisation: CPR the results of IO
by GHC 01 Aug '17

01 Aug '17

#1600: Optimisation: CPR the results of IO -------------------------------------+------------------------------------- Reporter: simonmar | Owner: (none) Type: task | Status: new Priority: lowest | Milestone: Component: Compiler | Version: 6.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #8598 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * cc: nomeata (added) Comment: I still feel that this is the Right Thing To Do. The performance results are not so exciting... but it would not surprise me if there was more to be had. > I'm currently cleaning up the branch before submitting a Diff. Great. I'd like Joachim to review your code, if he is willing; after all, he had the first go at this. And sometimes a review leads to improvements and clean ups. On your wiki page [wiki:NestedCPR/Akio2017] you speak of "nested strictness", "more aggressive worker/wrapper", "correct handling of strict contructor field", etc, but in each case I have little idea of what you mean. Could you expand with more specifics? Really I'd like to have a page describing the ''design''. (E.g. do you have a convergence analyser? Could we use that for other things?) Having such a description would make it much easier to read the code. There's a paper in here somewhere. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1600#comment:76> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14061: `instance Eq Dyn`
by GHC 01 Aug '17

01 Aug '17

#14061: `instance Eq Dyn` -------------------------------------+------------------------------------- Reporter: zaoqi | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs {-# LANGUAGE KindSignatures, GADTs #-} data Dyn :: * where Dyn :: a -> Dyn }}} How to write the correct `instance Eq Dyn`, do not change `data Dyn`? {{{#!hs {-# LANGUAGE MultiParamTypeClasses, FlexibleInstances #-} class GEq a b where geq :: a -> b -> Bool instance {-# OVERLAPPABLE #-} (Eq a) => GEq a a where geq = (==) instance {-# OVERLAPPING #-} GEq a b where geq _ _ = False }}} {{{#!hs instance Eq Dyn where Dyn a == Dyn b = geq a b }}} {{{ GHCi, version 8.0.2: http://www.haskell.org/ghc/ :? for help Prelude> :load Dyn.hs [1 of 1] Compiling Main ( Dyn.hs, interpreted ) Ok, modules loaded: Main. *Main> Dyn () == Dyn () False }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14061> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13567: Do loopification using join points
by GHC 01 Aug '17

01 Aug '17

#13567: Do loopification using join points -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Here's an idea: use join points to accomplish all that the existing "loopification" patch does, and more. The idea is described under "New idea: use join points" in [wiki:Commentary/Compiler/Loopification]. This ticket is to discuss and track progress. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13567> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1600: Optimisation: CPR the results of IO
by GHC 31 Jul '17

31 Jul '17

#1600: Optimisation: CPR the results of IO -------------------------------------+------------------------------------- Reporter: simonmar | Owner: (none) Type: task | Status: new Priority: lowest | Milestone: Component: Compiler | Version: 6.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #8598 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by akio): I'm currently cleaning up the branch before submitting a Diff. > Well, 2.6% improvement in runtime is quite sizeable. The runtime numbers are probably unreliable because I didn't try to keep machine unloaded while running nofib. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1600#comment:75> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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