[GHC] #16283: StaticPointers pragma changes generated code even when the feature is not used
#16283: StaticPointers pragma changes generated code even when the feature is not used -------------------------------------+------------------------------------- Reporter: osa1 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 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: -------------------------------------+------------------------------------- Tried with GHC HEAD. Program: {{{ module Main where import Control.Concurrent import System.Mem nats :: [Int] nats = [0 .. ] main = do let z = nats !! 400 print z performGC threadDelay 1000000 print (nats !! 900) }}} Compile without any flags: {{{ ==================== Tidy Core ==================== 2019-02-04 09:16:26.121849511 UTC Result size of Tidy Core = {terms: 45, types: 26, coercions: 0, joins: 0/0} -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0} $trModule1_r1zg :: GHC.Prim.Addr# [GblId, Caf=NoCafRefs, Unf=OtherCon []] $trModule1_r1zg = "main"# -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} $trModule2_r1zt :: GHC.Types.TrName [GblId, Caf=NoCafRefs, Unf=OtherCon []] $trModule2_r1zt = GHC.Types.TrNameS $trModule1_r1zg -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0} $trModule3_r1zu :: GHC.Prim.Addr# [GblId, Caf=NoCafRefs, Unf=OtherCon []] $trModule3_r1zu = "Main"# -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} $trModule4_r1zv :: GHC.Types.TrName [GblId, Caf=NoCafRefs, Unf=OtherCon []] $trModule4_r1zv = GHC.Types.TrNameS $trModule3_r1zu -- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0} Main.$trModule :: GHC.Types.Module [GblId, Caf=NoCafRefs, Unf=OtherCon []] Main.$trModule = GHC.Types.Module $trModule2_r1zt $trModule4_r1zv -- RHS size: {terms: 4, types: 1, coercions: 0, joins: 0/0} nats :: [Int] [GblId] nats = enumFrom @ Int GHC.Enum.$fEnumInt (GHC.Types.I# 0#) -- RHS size: {terms: 22, types: 13, coercions: 0, joins: 0/0} main :: IO () [GblId] main = >> @ IO GHC.Base.$fMonadIO @ () @ () (print @ Int GHC.Show.$fShowInt (!! @ Int nats (GHC.Types.I# 400#))) (>> @ IO GHC.Base.$fMonadIO @ () @ () performGC (>> @ IO GHC.Base.$fMonadIO @ () @ () (threadDelay (GHC.Types.I# 1000000#)) (print @ Int GHC.Show.$fShowInt (!! @ Int nats (GHC.Types.I# 900#))))) -- RHS size: {terms: 2, types: 1, coercions: 0, joins: 0/0} :Main.main :: IO () [GblId] :Main.main = GHC.TopHandler.runMainIO @ () main }}} Compile with `-XStaticPointers`: {{{ ==================== Tidy Core ==================== 2019-02-04 09:16:35.678350955 UTC Result size of Tidy Core = {terms: 67, types: 42, coercions: 0, joins: 0/0} -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0} $trModule1_r1zg :: GHC.Prim.Addr# [GblId, Caf=NoCafRefs, Unf=OtherCon []] $trModule1_r1zg = "main"# -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} $trModule2_r1zF :: GHC.Types.TrName [GblId, Caf=NoCafRefs, Unf=OtherCon []] $trModule2_r1zF = GHC.Types.TrNameS $trModule1_r1zg -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0} $trModule3_r1zG :: GHC.Prim.Addr# [GblId, Caf=NoCafRefs, Unf=OtherCon []] $trModule3_r1zG = "Main"# -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} $trModule4_r1zH :: GHC.Types.TrName [GblId, Caf=NoCafRefs, Unf=OtherCon []] $trModule4_r1zH = GHC.Types.TrNameS $trModule3_r1zG -- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0} Main.$trModule :: GHC.Types.Module [GblId, Caf=NoCafRefs, Unf=OtherCon []] Main.$trModule = GHC.Types.Module $trModule2_r1zF $trModule4_r1zH -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} lvl_r1zI :: Int [GblId, Caf=NoCafRefs, Unf=OtherCon []] lvl_r1zI = GHC.Types.I# 0# -- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} nats :: [Int] [GblId] nats = enumFrom @ Int GHC.Enum.$fEnumInt lvl_r1zI -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} lvl1_r1zJ :: Int [GblId, Caf=NoCafRefs, Unf=OtherCon []] lvl1_r1zJ = GHC.Types.I# 400# -- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} lvl2_r1zK :: Int [GblId] lvl2_r1zK = !! @ Int nats lvl1_r1zJ -- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} lvl3_r1zL :: IO () [GblId] lvl3_r1zL = print @ Int GHC.Show.$fShowInt lvl2_r1zK -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} lvl4_r1zM :: Int [GblId, Caf=NoCafRefs, Unf=OtherCon []] lvl4_r1zM = GHC.Types.I# 1000000# -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} lvl5_r1zN :: IO () [GblId] lvl5_r1zN = threadDelay lvl4_r1zM -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} lvl6_r1zO :: Int [GblId, Caf=NoCafRefs, Unf=OtherCon []] lvl6_r1zO = GHC.Types.I# 900# -- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} lvl7_r1zP :: Int [GblId] lvl7_r1zP = !! @ Int nats lvl6_r1zO -- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} lvl8_r1zQ :: IO () [GblId] lvl8_r1zQ = print @ Int GHC.Show.$fShowInt lvl7_r1zP -- RHS size: {terms: 4, types: 3, coercions: 0, joins: 0/0} lvl9_r1zR :: IO () [GblId] lvl9_r1zR = >> @ IO GHC.Base.$fMonadIO @ () @ () lvl5_r1zN lvl8_r1zQ -- RHS size: {terms: 4, types: 3, coercions: 0, joins: 0/0} lvl10_r1zS :: IO () [GblId] lvl10_r1zS = >> @ IO GHC.Base.$fMonadIO @ () @ () performGC lvl9_r1zR -- RHS size: {terms: 4, types: 3, coercions: 0, joins: 0/0} main :: IO () [GblId] main = >> @ IO GHC.Base.$fMonadIO @ () @ () lvl3_r1zL lvl10_r1zS -- RHS size: {terms: 2, types: 1, coercions: 0, joins: 0/0} :Main.main :: IO () [GblId] :Main.main = GHC.TopHandler.runMainIO @ () main }}} Diff: {{{ --- no_static_ptrs/GcStaticPointers.dump-simpl 2019-02-04 12:16:26.120066655 +0300 +++ static_ptrs/GcStaticPointers.dump-simpl 2019-02-04 12:16:35.675924328 +0300 @@ -1,9 +1,9 @@ ==================== Tidy Core ==================== -2019-02-04 09:16:26.121849511 UTC +2019-02-04 09:16:35.678350955 UTC Result size of Tidy Core - = {terms: 45, types: 26, coercions: 0, joins: 0/0} + = {terms: 67, types: 42, coercions: 0, joins: 0/0} -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0} $trModule1_r1zg :: GHC.Prim.Addr# @@ -11,55 +11,91 @@ $trModule1_r1zg = "main"# -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} -$trModule2_r1zt :: GHC.Types.TrName +$trModule2_r1zF :: GHC.Types.TrName [GblId, Caf=NoCafRefs, Unf=OtherCon []] -$trModule2_r1zt = GHC.Types.TrNameS $trModule1_r1zg +$trModule2_r1zF = GHC.Types.TrNameS $trModule1_r1zg -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0} -$trModule3_r1zu :: GHC.Prim.Addr# +$trModule3_r1zG :: GHC.Prim.Addr# [GblId, Caf=NoCafRefs, Unf=OtherCon []] -$trModule3_r1zu = "Main"# +$trModule3_r1zG = "Main"# -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} -$trModule4_r1zv :: GHC.Types.TrName +$trModule4_r1zH :: GHC.Types.TrName [GblId, Caf=NoCafRefs, Unf=OtherCon []] -$trModule4_r1zv = GHC.Types.TrNameS $trModule3_r1zu +$trModule4_r1zH = GHC.Types.TrNameS $trModule3_r1zG -- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0} Main.$trModule :: GHC.Types.Module [GblId, Caf=NoCafRefs, Unf=OtherCon []] -Main.$trModule = GHC.Types.Module $trModule2_r1zt $trModule4_r1zv +Main.$trModule = GHC.Types.Module $trModule2_r1zF $trModule4_r1zH --- RHS size: {terms: 4, types: 1, coercions: 0, joins: 0/0} +-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} +lvl_r1zI :: Int +[GblId, Caf=NoCafRefs, Unf=OtherCon []] +lvl_r1zI = GHC.Types.I# 0# + +-- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} nats :: [Int] [GblId] -nats = enumFrom @ Int GHC.Enum.$fEnumInt (GHC.Types.I# 0#) +nats = enumFrom @ Int GHC.Enum.$fEnumInt lvl_r1zI + +-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} +lvl1_r1zJ :: Int +[GblId, Caf=NoCafRefs, Unf=OtherCon []] +lvl1_r1zJ = GHC.Types.I# 400# + +-- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} +lvl2_r1zK :: Int +[GblId] +lvl2_r1zK = !! @ Int nats lvl1_r1zJ + +-- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} +lvl3_r1zL :: IO () +[GblId] +lvl3_r1zL = print @ Int GHC.Show.$fShowInt lvl2_r1zK + +-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} +lvl4_r1zM :: Int +[GblId, Caf=NoCafRefs, Unf=OtherCon []] +lvl4_r1zM = GHC.Types.I# 1000000# + +-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} +lvl5_r1zN :: IO () +[GblId] +lvl5_r1zN = threadDelay lvl4_r1zM + +-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0} +lvl6_r1zO :: Int +[GblId, Caf=NoCafRefs, Unf=OtherCon []] +lvl6_r1zO = GHC.Types.I# 900# + +-- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} +lvl7_r1zP :: Int +[GblId] +lvl7_r1zP = !! @ Int nats lvl6_r1zO + +-- RHS size: {terms: 3, types: 1, coercions: 0, joins: 0/0} +lvl8_r1zQ :: IO () +[GblId] +lvl8_r1zQ = print @ Int GHC.Show.$fShowInt lvl7_r1zP + +-- RHS size: {terms: 4, types: 3, coercions: 0, joins: 0/0} +lvl9_r1zR :: IO () +[GblId] +lvl9_r1zR + = >> @ IO GHC.Base.$fMonadIO @ () @ () lvl5_r1zN lvl8_r1zQ + +-- RHS size: {terms: 4, types: 3, coercions: 0, joins: 0/0} +lvl10_r1zS :: IO () +[GblId] +lvl10_r1zS + = >> @ IO GHC.Base.$fMonadIO @ () @ () performGC lvl9_r1zR --- RHS size: {terms: 22, types: 13, coercions: 0, joins: 0/0} +-- RHS size: {terms: 4, types: 3, coercions: 0, joins: 0/0} main :: IO () [GblId] -main - = >> - @ IO - GHC.Base.$fMonadIO - @ () - @ () - (print - @ Int GHC.Show.$fShowInt (!! @ Int nats (GHC.Types.I# 400#))) - (>> - @ IO - GHC.Base.$fMonadIO - @ () - @ () - performGC - (>> - @ IO - GHC.Base.$fMonadIO - @ () - @ () - (threadDelay (GHC.Types.I# 1000000#)) - (print - @ Int GHC.Show.$fShowInt (!! @ Int nats (GHC.Types.I# 900#))))) +main = >> @ IO GHC.Base.$fMonadIO @ () @ () lvl3_r1zL lvl10_r1zS -- RHS size: {terms: 2, types: 1, coercions: 0, joins: 0/0} :Main.main :: IO () }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16283 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16283: StaticPointers pragma changes generated code even when the feature is not used -------------------------------------+------------------------------------- Reporter: osa1 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 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 mpickering): The extension does turn on another partial run of the simplified so perhaps this isn't surprising. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16283#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16283: StaticPointers pragma changes generated code even when the feature is not used -------------------------------------+------------------------------------- Reporter: osa1 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 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 osa1): It's not surprising when you read the code, the question is whether this behavior makes sense or right from a user's point of view. I see no mentions of this in the user manual, and as a user I wouldn't expect enabling an unused feature to change runtime behavior of my programs. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16283#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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