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05 Jul '17

#13926: Panic! -------------------------------------+------------------------------------- Reporter: Deus | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Hi, I only use haskell for an asingement so I don't have any clues, but ghc told me to do a bug report: [1 of 1] Compiling Main ( plant.hs, plant.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): initTc: unsolved constraints WC {wc_insol = [W] true_a1Gg :: t_a1Gf[tau:1] (CHoleCan: true) [W] false_a1Gj :: t_a1Gi[tau:1] (CHoleCan: false) [W] true_a1Qq :: t_a1Qp[tau:1] (CHoleCan: true)} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13926> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13925: Panic!
by GHC 05 Jul '17

05 Jul '17

#13925: Panic! -------------------------------------+------------------------------------- Reporter: Deus | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Hi, I only use haskell for an asingement so I don't have any clues, but ghc told me to do a bug report: [1 of 1] Compiling Main ( plant.hs, plant.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): initTc: unsolved constraints WC {wc_insol = [W] true_a1Gg :: t_a1Gf[tau:1] (CHoleCan: true) [W] false_a1Gj :: t_a1Gi[tau:1] (CHoleCan: false) [W] true_a1Qq :: t_a1Qp[tau:1] (CHoleCan: true)} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13925> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13924: join001 doesn't test anything related to join points
by GHC 05 Jul '17

05 Jul '17

#13924: join001 doesn't test anything related to join points -------------------------------------+------------------------------------- Reporter: mpickering | 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: -------------------------------------+------------------------------------- As far as I can see the same core is produced by 8.0.2 (before join points) and 8.2.1 (after join points). The test just tests whether the file `join001.hs` compiles without inspecting whether any join points are found and exploited. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13924> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7741: Add SIMD support to x86/x86_64 NCG
by GHC 04 Jul '17

04 Jul '17

#7741: Add SIMD support to x86/x86_64 NCG -------------------------------------+------------------------------------- Reporter: shelarcy | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (NCG) | Version: 7.7 Resolution: | Keywords: SIMD Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #3557 | Differential Rev(s): Wiki Page: wiki:SIMD | -------------------------------------+------------------------------------- Comment (by winter): I see, ghc-prim's current SIMD APIs seems support up to 512bits instructions. Does that means we are going to support up to AVX512? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7741#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13921: LANGUAGE pragma is accepted in module body
by GHC 04 Jul '17

04 Jul '17

#13921: LANGUAGE pragma is accepted in module body -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 (Parser) | 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: -------------------------------------+------------------------------------- As pointed out in #13918, the [[https://www.haskell.org/onlinereport/haskell2010/haskellch12.html#x19-19100… Report]] stipulates that, > The LANGUAGE pragma is a file-header pragma. A file-header pragma must precede the module keyword in a source file. However, GHC accepts this program, {{{#!hs module Hi where h = {-# LANGUAGE BangPatterns #-} 0 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13921> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13918: No "warning: [-Wunrecognised-pragmas] Unrecognised pragma" when there is no name of pragmas
by GHC 04 Jul '17

04 Jul '17

#13918: No "warning: [-Wunrecognised-pragmas] Unrecognised pragma" when there is no name of pragmas -------------------------------------+------------------------------------- Reporter: vanto | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect Unknown/Multiple | error/warning at compile-time Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{ module Qwer where a = ({-# LANGUAGE #-}) main :: IO () main = print (if True then () else ()) }}} if {{{a = ({-# #-})}}} then GHC compiles with a warning\\ {{{ qwer.hs:3:6: warning: [-Wunrecognised-pragmas] Unrecognised pragma | 3 | a = ({-# #-}) | ^^^ Ok, modules loaded: Qwer. }}} if you write {{{a = ({-# LANGUAGE #-})}}} without writing the name GHC compiles the file without specifying a warning.\\ {{{ *Qwer> :l qwer.hs [1 of 1] Compiling Qwer ( qwer.hs, interpreted ) Ok, modules loaded: Qwer. }}} GHCi, version 8.2.0.20170507 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13918> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7741: Add SIMD support to x86/x86_64 NCG
by GHC 04 Jul '17

04 Jul '17

#7741: Add SIMD support to x86/x86_64 NCG -------------------------------------+------------------------------------- Reporter: shelarcy | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (NCG) | Version: 7.7 Resolution: | Keywords: SIMD Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #3557 | Differential Rev(s): Wiki Page: wiki:SIMD | -------------------------------------+------------------------------------- Comment (by bgamari): > After thinking about this over. I think we'd be better split SIMD primitives into GHC.Prim.SSE4, GHC.Prim.AVX, etc. modules to avoid this compatibility hell. I'm afraid all of the primops will likely remain in `GHC.Prim` for tiresome engineering reasons (namely the `GHC.Prim` module is treated specially by the compiler; while we perhaps could add more wired-in modules, we'd rather not). However `GHC.Prim` isn't intended to be used by the user anyways. Perhaps we could reexport the SIMD primitives in a new `GHC.Exts.SIMD` module. Regardless, I don't think we want to bake architecture-specific details into GHC's module naming. Really, the SIMD support provided by GHC is, like all primops, intended to be a substrate over which library authors can write safer, more convenient abstractions. > BTW, is SSE4 suppose to be the baseline of x86_64 now? Builds on `x86_64` assume SSE2 and no more, AFAIK. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7741#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7741: Add SIMD support to x86/x86_64 NCG
by GHC 04 Jul '17

04 Jul '17

#7741: Add SIMD support to x86/x86_64 NCG -------------------------------------+------------------------------------- Reporter: shelarcy | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (NCG) | Version: 7.7 Resolution: | Keywords: SIMD Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #3557 | Differential Rev(s): Wiki Page: wiki:SIMD | -------------------------------------+------------------------------------- Comment (by winter): Wow, this is a good news! One thing makes situation complicated is that there're several versions of SIMD implementations out there(SSE4, AVX, AVX2...), and we seems don't have a clear plan to support which version, or provide user compile flag to do fallback. After thinking about this over. I think we'd be better split SIMD primitive into `GHC.Prim.SSE4`, `GHC.PrimAVX` modules to avoid this compatibility hell. Compiler should be able to produce whatever instructions programmer want it to. We also have to provide runtime detections in RTS, use some unsafe magic we should be able to provide SIMD supporting conditions as constants. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7741#comment:14> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13894: isByteArrayPinned# should consider BF_LARGE
by GHC 04 Jul '17

04 Jul '17

#13894: isByteArrayPinned# should consider BF_LARGE -------------------------------------+------------------------------------- Reporter: winter | 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: -------------------------------------+------------------------------------- First of all, i want to make sure `isByteArrayPinned#` is intended to let user know if a given 'ByteArray#/MutableByteArray#' is movable during safe FFI call, isn't it? If that is the case, then the code for `stg_isByteArrayPinnedzh` is not enough, since not only bytes marked with `BF_PINNED` flag is not movable, but also the bytes which is marked with `BF_LARGE`. (I read the gc code and i'm confident this holds, but if it's not, please correct me). Currently i'm using a FFI trick[https://github.com/winterland1989/stdio/blob/master/cbits/bytes.c#L33] to get `isByteArrayPinned#` on older GHCs, i want to make sure if `BF_LARGE` works. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13894> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13242: Panic "StgCmmEnv: variable not found" with ApplicativeDo and ExistentialQuantification
by GHC 03 Jul '17

03 Jul '17

#13242: Panic "StgCmmEnv: variable not found" with ApplicativeDo and ExistentialQuantification -------------------------------------+------------------------------------- Reporter: ljli | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 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: -------------------------------------+------------------------------------- {{{#!hs -- Panic.hs {-# LANGUAGE ApplicativeDo #-} {-# LANGUAGE ExistentialQuantification #-} module Panic where import Data.STRef import Control.Monad.ST data A = forall a. A a st :: ST s () st = do A _ <- pure $ A True ref <- newSTRef 1 readSTRef ref pure () }}} {{{ $ ghc Panic.hs [1 of 1] Compiling Panic ( Panic.hs, Panic.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.1.20170106 for x86_64-unknown-linux): StgCmmEnv: variable not found $dMonad_aGQ local binds for: $trModule $tcA $tc'A $tcA1_rSi $tc'A1_rSJ $trModule1_rSK $trModule2_rSL sat_sT5 sat_sT9 sat_sTa Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1133:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in ghc:Outputable pprPanic, called at compiler/codeGen/StgCmmEnv.hs:137:9 in ghc:StgCmmEnv Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} The above module fails to compile, giving the pasted panic message. Without the ApplicativeDo pragma compilation succeeds. Reproduced with GHC 8.0.2 and a recent head, courtesy of nixpkgs: {{{ gp84vpgar3n3rqvkwj47yyhxvsvbsmi6-ghc-8.1.20170106 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13242> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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