- ghc-tickets - Haskell.org

Re: [GHC] #4900: Consider usage files in the GHCi recompilation check
by GHC 09 Oct '18

09 Oct '18

#4900: Consider usage files in the GHCi recompilation check -------------------------------------+------------------------------------- Reporter: cdsmith | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: TH_Depends Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by nh2): Patrick, is this something you still want to do? It would be awesome to get `addDependentFile` support in ghci, as Haskell projects are only getting larger and being able to iterate quickly with ghci makes it bearable. I personally would be very happy even with an intial mainlined version of this that explicitly doesn't support boot modules, as they are quite rare outside of GHC itself. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4900#comment:81> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4900: Consider usage files in the GHCi recompilation check
by GHC 09 Oct '18

09 Oct '18

#4900: Consider usage files in the GHCi recompilation check -------------------------------------+------------------------------------- Reporter: cdsmith | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: TH_Depends Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by nh2): * cc: nh2 (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4900#comment:80> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15727: bug: all generations are collected sequentially when compacting collection kicks in
by GHC 09 Oct '18

09 Oct '18

#15727: bug: all generations are collected sequentially when compacting collection kicks in -------------------------------------+------------------------------------- Reporter: lolotp | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Runtime | Version: 8.6.1 System | 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: -------------------------------------+------------------------------------- According to GHC documentation [https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/runtime_con… #rts-options-to-control-the-garbage-collector here], compacting collection should only be used for the oldest generation. I found out however while testing one of our programs that when compacting kicks in, Gen 0 were not being collected in parallel as well. Looking at the code, the bug looks to be [https://github.com/ghc/ghc/blob/5d5307f943d7581d7013ffe20af22233273fba06/rt… here], fixing this should be a simple change to the condition in the if phrase. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15727> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12932: -fexternal-interpreter` fails to find symbols
by GHC 09 Oct '18

09 Oct '18

#12932: -fexternal-interpreter` fails to find symbols ----------------------------------------+---------------------------- Reporter: dominic | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: MacOS X Architecture: Unknown/Multiple | Type of failure: Other Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+---------------------------- {{{-fexternal-interpreter}}} fails to find symbols but if I run without it all is well. Is this a bug or am I doing something wrong? {{{ ~/Dropbox/Private/Stochastic/demo $ ghci -fexternal-interpreter -prof fe- handling-example.o -i../../monad-bayes/src -package-db=.cabal- sandbox/x86_64-osx-ghc-8.0.1-packages.conf.d -L/usr/local/opt/openblas/lib -lopenblas ghci -fexternal-interpreter -prof fe-handling-example.o -i../../monad- bayes/src -package-db=.cabal-sandbox/x86_64-osx-ghc-8.0.1-packages.conf.d -L/usr/local/opt/openblas/lib -lopenblas GHCi, version 8.0.1: http://www.haskell.org/ghc/ :? for help Prelude> :l app/Main.hs :l app/Main.hs [ 1 of 16] Compiling Control.Monad.Bayes.LogDomain ( ../../monad- bayes/src/Control/Monad/Bayes/LogDomain.hs, interpreted ) [ 2 of 16] Compiling Control.Monad.Bayes.Primitive ( ../../monad- bayes/src/Control/Monad/Bayes/Primitive.hs, interpreted ) [ 3 of 16] Compiling Control.Monad.Bayes.Class ( ../../monad- bayes/src/Control/Monad/Bayes/Class.hs, interpreted ) [ 4 of 16] Compiling Control.Monad.Bayes.Sampler ( ../../monad- bayes/src/Control/Monad/Bayes/Sampler.hs, interpreted ) [ 5 of 16] Compiling Control.Monad.Bayes.Sequential ( ../../monad- bayes/src/Control/Monad/Bayes/Sequential.hs, interpreted ) [ 6 of 16] Compiling Control.Monad.Bayes.Prior ( ../../monad- bayes/src/Control/Monad/Bayes/Prior.hs, interpreted ) [ 7 of 16] Compiling Control.Monad.Bayes.Rejection ( ../../monad- bayes/src/Control/Monad/Bayes/Rejection.hs, interpreted ) [ 8 of 16] Compiling Control.Monad.Bayes.Weighted ( ../../monad- bayes/src/Control/Monad/Bayes/Weighted.hs, interpreted ) [ 9 of 16] Compiling Control.Monad.Bayes.Population ( ../../monad- bayes/src/Control/Monad/Bayes/Population.hs, interpreted ) [10 of 16] Compiling Control.Monad.Bayes.Deterministic ( ../../monad- bayes/src/Control/Monad/Bayes/Deterministic.hs, interpreted ) [11 of 16] Compiling Control.Monad.Bayes.Conditional ( ../../monad- bayes/src/Control/Monad/Bayes/Conditional.hs, interpreted ) [12 of 16] Compiling Control.Monad.Bayes.Dist ( ../../monad- bayes/src/Control/Monad/Bayes/Dist.hs, interpreted ) [13 of 16] Compiling Control.Monad.Bayes.Coprimitive ( ../../monad- bayes/src/Control/Monad/Bayes/Coprimitive.hs, interpreted ) [14 of 16] Compiling Control.Monad.Bayes.Trace ( ../../monad- bayes/src/Control/Monad/Bayes/Trace.hs, interpreted ) [15 of 16] Compiling Control.Monad.Bayes.Inference ( ../../monad- bayes/src/Control/Monad/Bayes/Inference.hs, interpreted ) [16 of 16] Compiling Main ( app/Main.hs, interpreted ) Ok, modules loaded: Main, Control.Monad.Bayes.LogDomain, Control.Monad.Bayes.Primitive, Control.Monad.Bayes.Class, Control.Monad.Bayes.Population, Control.Monad.Bayes.Conditional, Control.Monad.Bayes.Inference, Control.Monad.Bayes.Sampler, Control.Monad.Bayes.Rejection, Control.Monad.Bayes.Weighted, Control.Monad.Bayes.Sequential, Control.Monad.Bayes.Trace, Control.Monad.Bayes.Dist, Control.Monad.Bayes.Prior, Control.Monad.Bayes.Deterministic, Control.Monad.Bayes.Coprimitive. *Main> main main ghc-iserv-prof: lookupSymbol failed in relocateSection (relocate external) /Users/dom/Dropbox/Private/Stochastic/demo/.cabal-sandbox/lib/x86_64-osx- ghc-8.0.1/hmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6/libHShmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6_p.a: unknown symbol `___ieee_divdc3' ghc-iserv-prof: Could not on-demand load symbol '_vectorScan' ghc-iserv-prof: lookupSymbol failed in relocateSection (relocate external) /Users/dom/Dropbox/Private/Stochastic/demo/.cabal-sandbox/lib/x86_64-osx- ghc-8.0.1/hmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6/libHShmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6_p.a: unknown symbol `_vectorScan' ghc-iserv-prof: Could not on-demand load symbol '_hmatrixzm0zi18zi0zi0zmASQ7f3Yo6PP5MiGTxN80a6_InternalziVectorizzed_constantAux_closure' ghc-iserv-prof: lookupSymbol failed in relocateSection (relocate external) /Users/dom/Dropbox/Private/Stochastic/demo/.cabal-sandbox/lib/x86_64-osx- ghc-8.0.1/hmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6/libHShmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6_p.a: unknown symbol `_hmatrixzm0zi18zi0zi0zmASQ7f3Yo6PP5MiGTxN80a6_InternalziVectorizzed_constantAux_closure' ghc-iserv-prof: Could not on-demand load symbol '_hmatrixzm0zi18zi0zi0zmASQ7f3Yo6PP5MiGTxN80a6_InternalziMatrix_Matrix_con_info' ghc-iserv-prof: lookupSymbol failed in relocateSection (relocate external) /Users/dom/Dropbox/Private/Stochastic/demo/.cabal-sandbox/lib/x86_64-osx- ghc-8.0.1/hmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6/libHShmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6_p.a: unknown symbol `_hmatrixzm0zi18zi0zi0zmASQ7f3Yo6PP5MiGTxN80a6_InternalziMatrix_Matrix_con_info' ghc-iserv-prof: Could not on-demand load symbol '_hmatrixzm0zi18zi0zi0zmASQ7f3Yo6PP5MiGTxN80a6_InternalziElement_zgzl_info' ghc-iserv-prof: lookupSymbol failed in relocateSection (relocate external) /Users/dom/Dropbox/Private/Stochastic/demo/.cabal-sandbox/lib/x86_64-osx- ghc-8.0.1/hmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6/libHShmatrix-0.18.0.0-ASQ7f3Yo6PP5MiGTxN80a6_p.a: unknown symbol `_hmatrixzm0zi18zi0zi0zmASQ7f3Yo6PP5MiGTxN80a6_InternalziElement_zgzl_info' ghc-iserv-prof: Could not on-demand load symbol '_hmatrixzm0zi18zi0zi0zmASQ7f3Yo6PP5MiGTxN80a6_InternalziUtil_zdfIndexableVectorDouble_closure' ByteCodeLink.lookupCE During interactive linking, GHCi couldn't find the following symbol: hmatrixzm0zi18zi0zi0zmASQ7f3Yo6PP5MiGTxN80a6_InternalziUtil_zdfIndexableVectorDouble_closure This may be due to you not asking GHCi to load extra object files, archives or DLLs needed by your current session. Restart GHCi, specifying the missing library using the -L/path/to/object/dir and -lmissinglibname flags, or simply by naming the relevant files on the GHCi command line. Alternatively, this link failure might indicate a bug in GHCi. If you suspect the latter, please send a bug report to: glasgow-haskell-bugs(a)haskell.org *Main> }}} But without {{{-fexternal-interpreter}}} all is well. {{{ ~/Dropbox/Private/Stochastic/demo $ ghci -prof fe-handling-example.o -i ../../monad-bayes/src -package-db=.cabal-sandbox/x86_64-osx- ghc-8.0.1-packages.conf.d -L/usr/local/opt/openblas/lib -lopenblas ghci -prof fe-handling-example.o -i../../monad-bayes/src -package-db =.cabal-sandbox/x86_64-osx-ghc-8.0.1-packages.conf.d -L/usr/local/opt/openblas/lib -lopenblas GHCi, version 8.0.1: http://www.haskell.org/ghc/ :? for help Prelude> :l app/Main.hs :l app/Main.hs [ 1 of 16] Compiling Control.Monad.Bayes.LogDomain ( ../../monad- bayes/src/Control/Monad/Bayes/LogDomain.hs, interpreted ) [ 2 of 16] Compiling Control.Monad.Bayes.Primitive ( ../../monad- bayes/src/Control/Monad/Bayes/Primitive.hs, interpreted ) [ 3 of 16] Compiling Control.Monad.Bayes.Class ( ../../monad- bayes/src/Control/Monad/Bayes/Class.hs, interpreted ) [ 4 of 16] Compiling Control.Monad.Bayes.Sampler ( ../../monad- bayes/src/Control/Monad/Bayes/Sampler.hs, interpreted ) [ 5 of 16] Compiling Control.Monad.Bayes.Sequential ( ../../monad- bayes/src/Control/Monad/Bayes/Sequential.hs, interpreted ) [ 6 of 16] Compiling Control.Monad.Bayes.Prior ( ../../monad- bayes/src/Control/Monad/Bayes/Prior.hs, interpreted ) [ 7 of 16] Compiling Control.Monad.Bayes.Rejection ( ../../monad- bayes/src/Control/Monad/Bayes/Rejection.hs, interpreted ) [ 8 of 16] Compiling Control.Monad.Bayes.Weighted ( ../../monad- bayes/src/Control/Monad/Bayes/Weighted.hs, interpreted ) [ 9 of 16] Compiling Control.Monad.Bayes.Population ( ../../monad- bayes/src/Control/Monad/Bayes/Population.hs, interpreted ) [10 of 16] Compiling Control.Monad.Bayes.Deterministic ( ../../monad- bayes/src/Control/Monad/Bayes/Deterministic.hs, interpreted ) [11 of 16] Compiling Control.Monad.Bayes.Conditional ( ../../monad- bayes/src/Control/Monad/Bayes/Conditional.hs, interpreted ) [12 of 16] Compiling Control.Monad.Bayes.Dist ( ../../monad- bayes/src/Control/Monad/Bayes/Dist.hs, interpreted ) [13 of 16] Compiling Control.Monad.Bayes.Coprimitive ( ../../monad- bayes/src/Control/Monad/Bayes/Coprimitive.hs, interpreted ) [14 of 16] Compiling Control.Monad.Bayes.Trace ( ../../monad- bayes/src/Control/Monad/Bayes/Trace.hs, interpreted ) [15 of 16] Compiling Control.Monad.Bayes.Inference ( ../../monad- bayes/src/Control/Monad/Bayes/Inference.hs, interpreted ) [16 of 16] Compiling Main ( app/Main.hs, interpreted ) Ok, modules loaded: Main, Control.Monad.Bayes.LogDomain, Control.Monad.Bayes.Primitive, Control.Monad.Bayes.Class, Control.Monad.Bayes.Population, Control.Monad.Bayes.Conditional, Control.Monad.Bayes.Inference, Control.Monad.Bayes.Sampler, Control.Monad.Bayes.Rejection, Control.Monad.Bayes.Weighted, Control.Monad.Bayes.Sequential, Control.Monad.Bayes.Trace, Control.Monad.Bayes.Dist, Control.Monad.Bayes.Prior, Control.Monad.Bayes.Deterministic, Control.Monad.Bayes.Coprimitive. *Main> main main Old State: S {p = 96.41248458072532, z = 59.16931688468654, log_alpha = -3.3251317115519465} New state: S {p = 85.18277032500659, z = 47.518663747379414, log_alpha = -0.8056624325046409} Old State: S {p = 110.26606081933504, z = 47.25472896292412, log_alpha = -7.942692650345256} New state: S {p = 99.8466327066433, z = 38.81428385855752, log_alpha = -0.712367347081303} Old State: S {p = 101.53403093173365, z = 54.69189565042656, log_alpha = 0.797288536547407} New state: S {p = 101.52281529166201, z = 44.30057747486097, log_alpha = -2.015330785654092} Old State: S {p = 77.31689464064326, z = 46.619899785065876, log_alpha = 2.2759251158534526} New state: S {p = 116.2875593953072, z = 38.966471329788355, log_alpha = -0.7142394862058071} Old State: S {p = 76.9380013726558, z = 50.125629063113514, log_alpha = -3.2499432321011583} New state: S {p = 69.40844025380522, z = 41.55282023557805, log_alpha = -3.0159942091527503e-2} Old State: S {p = 69.40844025380522, z = 41.55282023557805, log_alpha = -3.0159942091527503e-2} New state: S {p = 68.03763906369906, z = 35.283787110815105, log_alpha = 1.3054304633451674} Old State: S {p = 69.40844025380522, z = 41.55282023557805, log_alpha = -3.0159942091527503e-2} New state: S {p = 68.03763906369906, z = 35.283787110815105, log_alpha = -0.9916988019989725} Old State: S {p = 69.40844025380522, z = 41.55282023557805, log_alpha = -3.0159942091527503e-2} New state: S {p = 68.03763906369906, z = 35.283787110815105, log_alpha = -3.611295894501775} Old State: S {p = 69.40844025380522, z = 41.55282023557805, log_alpha = -3.0159942091527503e-2} New state: S {p = 68.03763906369906, z = 35.283787110815105, log_alpha = -0.7617210597518349} Old State: S {p = 116.2875593953072, z = 38.966471329788355, log_alpha = -0.7142394862058071} New state: S {p = 109.6078122188652, z = 32.55851436113107, log_alpha = -0.4233108619474501} Old State: S {p = 68.03763906369906, z = 35.283787110815105, log_alpha = 1.3054304633451674} New state: S {p = 79.79830336014518, z = 30.422294131721443, log_alpha = 0.6993690927536277} Old State: S {p = 68.03763906369906, z = 35.283787110815105, log_alpha = -0.9916988019989725} New state: S {p = 64.90164005295357, z = 30.422294131721443, log_alpha = -0.3152970276116467} Old State: S {p = 68.03763906369906, z = 35.283787110815105, log_alpha = -0.9916988019989725} New state: S {p = 64.90164005295357, z = 30.422294131721443, log_alpha = -0.8415339406842459} Old State: S {p = 68.03763906369906, z = 35.283787110815105, log_alpha = 1.3054304633451674} New state: S {p = 79.79830336014518, z = 30.422294131721443, log_alpha = -0.755338763976243} Old State: S {p = 68.03763906369906, z = 35.283787110815105, log_alpha = -0.9916988019989725} New state: S {p = 64.90164005295357, z = 30.422294131721443, log_alpha = -0.12244882682932601} Old State: S {p = 103.98419668715715, z = 51.46501997223569, log_alpha = NaN} New state: S {p = NaN, z = 41.96850310814045, log_alpha = -2.6446936218209336} Old State: S {p = 101.59457288618177, z = 50.895296415987694, log_alpha = NaN} New state: S {p = NaN, z = 41.61054780428653, log_alpha = -3.429882621028084} Old State: S {p = 87.94516676609489, z = 49.33016788299561, log_alpha = NaN} New state: S {p = NaN, z = 40.75469030451892, log_alpha = -0.3548643358912281} Old State: S {p = 85.99795164317248, z = 49.168021162595345, log_alpha = NaN} New state: S {p = NaN, z = 40.67497206346814, log_alpha = 2.1104720283005785} Old State: S {p = 78.54647250550833, z = 42.630247908299566, log_alpha = NaN} New state: S {p = NaN, z = 35.95097968042852, log_alpha = -0.6513484233809421} Old State: S {p = NaN, z = 40.75469030451892, log_alpha = -0.3548643358912281} New state: S {p = NaN, z = NaN, log_alpha = -1.5720943792122584} Old State: S {p = NaN, z = 40.75469030451892, log_alpha = -0.3548643358912281} New state: S {p = NaN, z = NaN, log_alpha = -1.6631770526157945} Old State: S {p = NaN, z = 40.67497206346814, log_alpha = 2.1104720283005785} New state: S {p = NaN, z = NaN, log_alpha = -1.2345329390236304} Old State: S {p = NaN, z = 35.95097968042852, log_alpha = -0.6513484233809421} New state: S {p = NaN, z = NaN, log_alpha = -1.820929341136602} Old State: S {p = NaN, z = 40.67497206346814, log_alpha = 2.1104720283005785} New state: S {p = NaN, z = NaN, log_alpha = -2.520535318849168} Old State: S {p = NaN, z = NaN, log_alpha = -1.5720943792122584} New state: S {p = NaN, z = NaN, log_alpha = -0.9471390581854239} Old State: S {p = NaN, z = NaN, log_alpha = -1.6631770526157945} New state: S {p = NaN, z = NaN, log_alpha = -1.0755021237404696} Old State: S {p = NaN, z = NaN, log_alpha = -1.2345329390236304} New state: S {p = NaN, z = NaN, log_alpha = -1.1239335260594507} Old State: S {p = NaN, z = NaN, log_alpha = -1.820929341136602} New state: S {p = NaN, z = NaN, log_alpha = -1.2944498914356701} Old State: S {p = NaN, z = NaN, log_alpha = -2.520535318849168} New state: S {p = NaN, z = NaN, log_alpha = -0.27411572356967484} Accept: False Old State: S {p = 111.8506804060528, z = 49.43995360167743, log_alpha = -9.192660539879242} New state: S {p = 100.79139727821112, z = 40.36178045350178, log_alpha = 1.3407944594098864} Old State: S {p = 112.56620850387993, z = 51.36209895306485, log_alpha = -2.625437037736268} New state: S {p = 101.35925858189091, z = 41.718829881234356, log_alpha = -0.7240542276022712} Old State: S {p = 124.03888190950703, z = 60.73043151177312, log_alpha = -5.946495216000299} New state: S {p = 108.98533165239414, z = 47.91166969904897, log_alpha = -0.8873500091662709} Old State: S {p = 98.02675197633516, z = 52.91365067391672, log_alpha = 2.312571443928833} New state: S {p = 138.1350004691826, z = 43.12261446736768, log_alpha = -0.2792667910662988} Old State: S {p = 94.54575888175407, z = 42.83674832921917, log_alpha = -7.3217354704711175} New state: S {p = 86.44898836218327, z = 35.83329122968358, log_alpha = -0.6931069199421952} Old State: S {p = 86.44898836218327, z = 35.83329122968358, log_alpha = -0.6931069199421952} New state: S {p = 82.70767613536381, z = 30.592809349196145, log_alpha = 0.3349397265296642} Old State: S {p = 86.44898836218327, z = 35.83329122968358, log_alpha = -0.6931069199421952} New state: S {p = 82.70767613536381, z = 30.592809349196145, log_alpha = -1.3495963112508207} Old State: S {p = 138.1350004691826, z = 43.12261446736768, log_alpha = -0.2792667910662988} New state: S {p = 129.45324316753013, z = 35.29589318379763, log_alpha = -0.386669465854595} Old State: S {p = 138.1350004691826, z = 43.12261446736768, log_alpha = -0.2792667910662988} New state: S {p = 129.45324316753013, z = 35.29589318379763, log_alpha = -0.2946746748816039} Old State: S {p = 138.1350004691826, z = 43.12261446736768, log_alpha = -0.2792667910662988} New state: S {p = 129.45324316753013, z = 35.29589318379763, log_alpha = 6.008701708774278e-2} Old State: S {p = 82.70767613536381, z = 30.592809349196145, log_alpha = 0.3349397265296642} New state: S {p = 84.42743985481702, z = 26.485152940386072, log_alpha = -0.8565266788034482} Old State: S {p = 82.70767613536381, z = 30.592809349196145, log_alpha = -1.3495963112508207} New state: S {p = 78.90510523061384, z = 26.485152940386072, log_alpha = -0.23947594100584424} Old State: S {p = 82.70767613536381, z = 30.592809349196145, log_alpha = -1.3495963112508207} New state: S {p = 78.90510523061384, z = 26.485152940386072, log_alpha = -1.6400685168014388} Old State: S {p = 82.70767613536381, z = 30.592809349196145, log_alpha = -1.3495963112508207} New state: S {p = 78.90510523061384, z = 26.485152940386072, log_alpha = -2.309718174473867} Old State: S {p = 82.70767613536381, z = 30.592809349196145, log_alpha = 0.3349397265296642} New state: S {p = 84.42743985481702, z = 26.485152940386072, log_alpha = 0.39960426429090445} Old State: S {p = 103.15456652417501, z = 48.70703230482669, log_alpha = 3.261489684559035} New state: S {p = 223.41791271148057, z = 40.00425989911341, log_alpha = -1.6654810839749887} Old State: S {p = 78.21539356172975, z = 49.34769089107648, log_alpha = 2.9941081783405235} New state: S {p = 165.5956281460007, z = 40.9594944371077, log_alpha = -0.6807278054716505} Old State: S {p = 121.27107377910983, z = 50.9432853913191, log_alpha = -8.126318808529764} New state: S {p = 108.916591323712, z = 41.2439385542472, log_alpha = 0.4369643557823619} Old State: S {p = 98.33533600637841, z = 50.915794054555995, log_alpha = -0.47638340582836275} New state: S {p = 91.42595876935069, z = 41.6915974374073, log_alpha = -1.570488913622821} Old State: S {p = 106.35901771371051, z = 58.39939541846798, log_alpha = 2.4859548939567686} New state: S {p = 153.7564635774571, z = 46.75791989853097, log_alpha = -0.7265425179819862} Old State: S {p = 165.5956281460007, z = 40.9594944371077, log_alpha = -0.6807278054716505} New state: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = -1.6781162212290632} Old State: S {p = 165.5956281460007, z = 40.9594944371077, log_alpha = -0.6807278054716505} New state: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = 0.7148953771487301} Old State: S {p = 165.5956281460007, z = 40.9594944371077, log_alpha = -0.6807278054716505} New state: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = 1.2994581914331431} Old State: S {p = 165.5956281460007, z = 40.9594944371077, log_alpha = -0.6807278054716505} New state: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = -0.6908099313919266} Old State: S {p = 165.5956281460007, z = 40.9594944371077, log_alpha = -0.6807278054716505} New state: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = 0.6115450247483429} Old State: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = 0.6115450247483429} New state: S {p = 149.84673299439467, z = 27.669736758576065, log_alpha = 2.249112097719827} Old State: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = 0.7148953771487301} New state: S {p = 150.56328821556426, z = 27.669736758576065, log_alpha = -1.6634676360703886} Old State: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = 0.6115450247483429} New state: S {p = 149.84673299439467, z = 27.669736758576065, log_alpha = -1.1143896901497614} Old State: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = -1.6781162212290632} New state: S {p = 143.93225309113896, z = 27.669736758576065, log_alpha = 1.2174133795952156} Old State: S {p = 153.47230437543251, z = 33.25266900659429, log_alpha = -1.6781162212290632} New state: S {p = 143.93225309113896, z = 27.669736758576065, log_alpha = 0.2956142597127277} Accept: False 4.962072576592402e-2 7.408640679453008 *Main> }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12932> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14626: No need to enter a scrutinised value
by GHC 08 Oct '18

08 Oct '18

#14626: No need to enter a scrutinised value -------------------------------------+------------------------------------- Reporter: heisenbug | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.2 Keywords: performance | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: #13861 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- While analysing the output of #13861 I stumbled over an unnecessary pessimisation in handling of scrutinised values. With words of Simon (from https://phabricator.haskell.org/D4267 with minor edits added): Interesting. Yes, please make a ticket! (And transfer the info below into it.) I think the issue is this. Given (the STG-ish code) {{{#!hs data Colour = Red | Green | Blue f x = case x of y Red -> Green DEFAULT -> y }}} (here `y` is the case binder) we can just return `x` rather than entering it in DEFAULT branch, because `y` will be fully evaluated and its pointer will be correctly tagged. You absolutely can't check for an `OccName` of `"wild"`!! That is neither necessary nor sufficient :-). Instead, check `isEvaldUnfolding (idUnfolding y)`. See `Note [Preserve evaluatedness]` in `CoreTidy.hs`. And be sure to augment that note if you make the change. I would expect perf benefits to be small on average, but it's simple to implement. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14626> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15724: GHC panic with malformed pragma
by GHC 08 Oct '18

08 Oct '18

#15724: GHC panic with malformed pragma -------------------------------------+------------------------------------- Reporter: etorreborre | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.4.3 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: -------------------------------------+------------------------------------- This comment crashes GHC (the comment is not properly closed) {{{#!hs {-# OPTIONS_GHC -f-nowarn-orphans #} }}} {{{ ghc: panic! (the 'impossible' happened) (GHC version 8.4.3 for x86_64-apple-darwin): getOptions'.parseToks: Couldn't read " \"|\")) <> rand_bytes\n pure $ (==) hashed rehashed\n final = either (FailedToParse . show) (bool InValid Valid) result\n\n{-# ANN StateNamePrefix (Just (\"Test\" :: Text)) " as String }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15724> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15720: Assign to literals is allowed in ghci
by GHC 08 Oct '18

08 Oct '18

#15720: Assign to literals is allowed in ghci -------------------------------------+------------------------------------- Reporter: sighingnow | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 8.6.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC accepts Unknown/Multiple | invalid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I have been asked that why `1 = 2` is allowed in ghci, which is quite confusing for beginners. {{{ > 1 = 2 > 1 1 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15720> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15716: GHC hangs on default implementation of type family
by GHC 08 Oct '18

08 Oct '18

#15716: GHC hangs on default implementation of type family -------------------------------------+------------------------------------- Reporter: Heimdell | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.4.1 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: -------------------------------------+------------------------------------- I have this code: {{{ {-# language TypeFamilies #-} {-# language MultiParamTypeClasses #-} {-# language FlexibleInstances #-} import Control.Monad.Except class Component comp where data Error comp :: * type ComponentT comp :: * -> * type ComponentT comp = ExceptT (Error comp) }}} I expect it to either compile or fail with error. Instead, GHC[i] hangs every time. It prints {{{ <interactive>:10:28: error: }}} and then hangs. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15716> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14152: Float exit paths out of recursive functions
by GHC 08 Oct '18

08 Oct '18

#14152: Float exit paths out of recursive functions -------------------------------------+------------------------------------- Reporter: nomeata | Owner: (none) Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: #14137 #10918 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This is a spin off of a discussion from #14137. == The problem == We generally avoid inlining or floating a binding into a recursive function, because we do not want to duplicat work/allocations. But sometimes the binding is only used inside the recursive function on the “exit path”. In which case it would be good to inline. Example: {{{#!hs let x = f x0 in let go 10 = h x go i = go (i+1) in go (0::Int) + 100 }}} It would be beneficial to inline `x`. The problem is that it is not very obvious that this occurence of `x` is ok for inlining. In particular, it is not syntactically visible. == Proposed solution == If we apply loopification (#14068), this would turn into {{{#!hs let x = f x0 in let go n = joinrec jgo 10 = h x jgo i = call jgo (i+1) in call jgo n in go (0::Int) + 100 }}} I’d like to call this ''first joinrec normal form'', defined as “every recursive function where all recursive calls are tail-recursive is a recursive join point”. This ticket proposes to transform this even further and ''float out all case alternatives that do not mention `jgo` as non-recursive join- points'', as so: {{{#!hs let x = f x0 in let go n = join jexit = h x joinrec jgo 10 = call jexit jgo i = call jgo (i+1) in call jgo n in go (0::Int) + 100 }}} I’d like to call this ''second `joinrec` normal form'', defined as “in first `joinrec` normal form, and all subexpressions of a recursive join point `j` that are in tail-call position and do not mention `j` are join calls”. If the floated expression has free variables that are bound inside the `joinrec`, they turn into parameters of the newly created joinpoint. At this point, GHC can tell that `go` is called at most once, and will therefore happily inline `x` into the right hand side of `jexit. == Alternative solutions == Ticket #10918 uses Call Arity results to learn that `x` is one-Shot, and inline it even in the original code. This works, but the problem is that float-out will undo this. See [ticket:10918#comment:5]. == Limitation === It only works for recursive functions that are join points, or can be turned into join points by loopification (#14068). It does not work forexample for {{{#!hs let x = f x0 let go 0 = h x go n = (go (n-1) + 1 in go 10 }}} although it would be equally desirable to float `h x` out of `go` so that `x` can be inlined. == Preservation == A remaining tricky point is that we need to stop one of these carefully- constructed non-recursive join points being inlined into a recursive join point, even if it is invoked at just one place. That should not be hard. And in a final run of the simplifer (or in CorePrep) we could switch off that restriction and let it inline. (Ticket #14137 is about inlining ''more'' join points into recursive join points, so it is the antithesis to the present ticket.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14152> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15719: Primitive atomic logical operations
by GHC 08 Oct '18

08 Oct '18

#15719: Primitive atomic logical operations -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: 8.8.1 Component: Compiler | Version: 8.6.1 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: -------------------------------------+------------------------------------- We offer fetch-and-and, fetch-and-or, etc., which are available as GCC intrinsics. Unfortunately, as far as I can tell those operations are ''not'' actually offered by x86_64. So I ''believe'' GCC must be implementing them using CAS loops on that (rather important) architecture. On the other hand, that instruction set does offer a plain atomic-and, atomic-or, etc., that do not fetch. In some cases, that may be sufficient. For example, I'm currently designing a potential replacement for the stable pointer system that uses a bitmap to represent a free list. Each deletion operation needs to update the bitmap (or) and then check whether a certain threshold number of entries are free (popcnt). One straightforward way to accomplish this with available instructions would be 1. Atomic OR to mark an entry free 2. Load the bitmap 3. Perform the popcnt test Of course, it would be ''nice'' to have fetch-and-or here, but we don't actually need it--if a bunch of deletions happen concurrently, then at least one of them will see the popcnt over the threshold. Could we (and should we) offer non-fetching atomic operations implemented natively where they're available? One important question is of course whether we'd actually get better performance this way than using a CAS loop. I would conjecture that this is this case under contention, but I don't actually know. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15719> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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