May 2017 - ghc-tickets

[GHC] #8082: Ordering of assembly blocks affects performance
by GHC 09 May '17

09 May '17

#8082: Ordering of assembly blocks affects performance ----------------------------------+--------------------------------- Reporter: jstolarek | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (NCG) | Version: 7.6.3 Keywords: | Operating System: Linux Architecture: x86_64 (amd64) | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+--------------------------------- During my work on #6135 I noticed that performance of reverse-complem benchmark in nofib depends highly on the order in which assembly block are laid out. With my patches I am consistently getting a 18-20% speed-up. In theory my patches should not impact performance of existing programs, but for some reason they affect the ordering of generated assembly blocks. On of the earlier versions of my patch I noticed that kahan benchmark suffered a 16% performance hit and again the only difference I noticed in the generated assembly was ordering of blocks. I did a more in-depth investigation in case of kahan and it turned out that this difference results from the way Core is generated: the difference between HEAD and my patches was that a worker function had its three parameters passed in different order. I did not investigate this for reverse-complem because Core is considerably larger, but I could spend some time on it if it might be relevant. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8082> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7461: Error messages about "do" statements contain false information
by GHC 09 May '17

09 May '17

#7461: Error messages about "do" statements contain false information -------------------------------------+------------------------------------- Reporter: EyalLotem | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.0.2 Component: Compiler (Type | Version: 7.6.1 checker) | Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => closed * resolution: => fixed * milestone: => 8.0.2 Comment: GHC 8.0 produces, {{{ hi.hs:2:3: error: • Couldn't match expected type ‘Char’ with actual type ‘IO Char’ • In a stmt of a 'do' block: getLine In the second argument of ‘($)’, namely ‘do { getLine; return 'x' }’ In the expression: putChar $ do { getLine; return 'x' } }}} Which seems quite reasonable. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7461#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7337: GHC does not generate great code for bit-level rotation
by GHC 09 May '17

09 May '17

#7337: GHC does not generate great code for bit-level rotation -------------------------------------+------------------------------------- Reporter: bos | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (NCG) | Version: 7.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): Any progress on this? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7337#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7320: GHC crashes when building on 32-bit Linux in a Linode
by GHC 09 May '17

09 May '17

#7320: GHC crashes when building on 32-bit Linux in a Linode ---------------------------------------+-------------------------------- Reporter: benl | Owner: simonmar Type: bug | Status: closed Priority: normal | Milestone: Component: Runtime System | Version: 7.6.1 Resolution: worksforme | Keywords: Operating System: Linux | Architecture: x86 Type of failure: Compile-time crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | ---------------------------------------+-------------------------------- Changes (by bgamari): * status: new => closed * resolution: => worksforme Comment: Closing due to inactivity. Feel free to reopen if this is still the case with a recent release. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7320#comment:13> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7104: Add tryWriteTBQueue to Control.Concurrent.STM.TBQueue
by GHC 09 May '17

09 May '17

#7104: Add tryWriteTBQueue to Control.Concurrent.STM.TBQueue -------------------------------------+------------------------------------- Reporter: joeyadams | Owner: simonmar Type: feature request | Status: patch Priority: normal | Milestone: Component: Core Libraries | Version: 7.4.2 Resolution: | Keywords: stm Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => patch Comment: We should probably act on these one way or another. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7104#comment:10> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4102: Bit manipulation built-ins
by GHC 09 May '17

09 May '17

#4102: Bit manipulation built-ins -------------------------------------+------------------------------------- Reporter: uzytkownik | Owner: (none) Type: feature request | Status: closed Priority: normal | Milestone: 8.0.2 Component: Core Libraries | Version: 6.12.2 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => closed * resolution: => fixed * milestone: => 8.0.2 Comment: I believe all of the suggested operations have been implemented in `Data.Bits`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4102#comment:24> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #3021: A way to programmatically insert marks into heap profiling output
by GHC 09 May '17

09 May '17

#3021: A way to programmatically insert marks into heap profiling output -------------------------------------+------------------------------------- Reporter: SamB | Owner: (none) Type: feature request | Status: closed Priority: normal | Milestone: ⊥ Component: Profiling | Version: 6.10.1 Resolution: fixed | Keywords: profiling Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #11094 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => closed * resolution: => fixed Comment: Profiler records can now be sent to the event log, making the request in this ticket possible. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/3021#comment:17> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #3024: Rewrite hp2ps in Haskell
by GHC 09 May '17

09 May '17

#3024: Rewrite hp2ps in Haskell -------------------------------------+------------------------------------- Reporter: SamB | Owner: (none) Type: task | Status: closed Priority: normal | Milestone: ⊥ Component: Profiling | Version: 6.10.1 Resolution: wontfix | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: 5641, 7291 Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => closed * resolution: => wontfix Comment: For what it is worth there are now numerous alternatives to hp2ps on Hackage (e.g. `hp2pretty`). Moreover, we are now able to emit profiler records to the event log, making parsing much simpler. Closing. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/3024#comment:12> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1349: Generalise the ! and UNPACK mechanism for data types, to unpack function arguments
by GHC 09 May '17

09 May '17

#1349: Generalise the ! and UNPACK mechanism for data types, to unpack function arguments -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 6.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * cc: dfeuer (added) Comment: Dfeuer, I believe this is relevant to your recent proposal. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1349#comment:44> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1318: add warning for prefix negate operator and flag to replace it with negative numeric literals
by GHC 09 May '17

09 May '17

#1318: add warning for prefix negate operator and flag to replace it with negative numeric literals -------------------------------------+------------------------------------- Reporter: Isaac Dupree | Owner: (none) Type: feature request | Status: closed Priority: normal | Milestone: ⊥ Component: Compiler | Version: 6.6.1 (Parser) | Resolution: wontfix | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => closed * resolution: => wontfix Comment: We have `-XNegativeLiterals` now but I don't think that removing the `-` operator is going to happen at this point. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1318#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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