#9848: List.all does not fuse -------------------------------------+------------------------------------- Reporter: klapaucius | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: libraries/base | Version: 7.9 Keywords: | Operating System: Windows Architecture: x86 | Type of failure: Runtime Difficulty: Easy (less than 1 | performance bug hour) | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- {{{ primes = 2:3:filter isPrime [5,7..] :: [Int] isPrime x = all (/= 0) . map (x `rem`) . takeWhile ((<= x) . (^2)) $ primes main = print . length . takeWhile (<= 2^24) $ primes }}} {{{ 12,133,812,164 bytes allocated in the heap 53,433,372 bytes copied during GC 14,235,488 bytes maximum residency (7 sample(s)) 1,110,916 bytes maximum slop 30 MB total memory in use (0 MB lost due to fragmentation) Tot time (elapsed) Avg pause Max pause Gen 0 56357 colls, 0 par 0.094s 0.125s 0.0000s 0.0001s Gen 1 7 colls, 0 par 0.031s 0.034s 0.0049s 0.0154s INIT time 0.000s ( 0.000s elapsed) MUT time 8.094s ( 8.069s elapsed) GC time 0.125s ( 0.159s elapsed) EXIT time 0.000s ( 0.003s elapsed) Total time 8.219s ( 8.231s elapsed) %GC time 1.5% (1.9% elapsed) Alloc rate 1,499,158,259 bytes per MUT second Productivity 98.5% of total user, 98.3% of total elapsed }}} {{{ Rec { $sgo1_r2RE :: GHC.Prim.Int# -> [Int] -> Data.Monoid.All [GblId, Arity=2, Caf=NoCafRefs, Str=DmdType ] $sgo1_r2RE = \ (sc_s2PS :: GHC.Prim.Int#) (sc1_s2PT :: [Int]) -> case sc_s2PS of _ [Occ=Dead] { __DEFAULT -> go_r2RF sc1_s2PT; 0 -> GHC.Types.False `cast` (Sym Data.Monoid.NTCo:All[0] :: Bool ~R# Data.Monoid.All) } go_r2RF :: [Int] -> Data.Monoid.All [GblId, Arity=1, Caf=NoCafRefs, Str=DmdType ] go_r2RF = \ (ds_a1YK :: [Int]) -> case ds_a1YK of _ [Occ=Dead] { [] -> GHC.Types.True `cast` (Sym Data.Monoid.NTCo:All[0] :: Bool ~R# Data.Monoid.All); : y_a1YP ys_a1YQ -> case y_a1YP of _ [Occ=Dead] { GHC.Types.I# x_a1Tk -> case x_a1Tk of _ [Occ=Dead] { __DEFAULT -> go_r2RF ys_a1YQ; 0 -> GHC.Types.False `cast` (Sym Data.Monoid.NTCo:All[0] :: Bool ~R# Data.Monoid.All) } } } end Rec } lvl4_r2RG :: Int -> Data.Monoid.All [GblId, Arity=1, Str=DmdType] lvl4_r2RG = \ (x_aqY [OS=ProbOneShot] :: Int) -> case x_aqY of _ [Occ=Dead] { GHC.Types.I# y_a1Uc -> case GHC.Prim.tagToEnum# @ Bool (GHC.Prim.<=# 4 y_a1Uc) of _ [Occ=Dead] { False -> GHC.Types.True `cast` (Sym Data.Monoid.NTCo:All[0] :: Bool ~R# Data.Monoid.All); True -> $sgo1_r2RE (GHC.Prim.remInt# y_a1Uc 2) (letrec { go1_a1S5 [Occ=LoopBreaker] :: [Int] -> [Int] [LclId, Arity=1, Str=DmdType ] go1_a1S5 = \ (ds_a1S6 :: [Int]) -> case ds_a1S6 of _ [Occ=Dead] { [] -> GHC.Types.[] @ Int; : y1_X1T4 ys_X1T6 -> case y1_X1T4 of _ [Occ=Dead] { GHC.Types.I# x1_X1VM -> case GHC.Prim.tagToEnum# @ Bool (GHC.Prim.<=# (GHC.Prim.*# x1_X1VM x1_X1VM) y_a1Uc) of _ [Occ=Dead] { False -> GHC.Types.[] @ Int; True -> GHC.Types.: @ Int (case x1_X1VM of wild5_a1TE { __DEFAULT -> case GHC.Prim.remInt# y_a1Uc wild5_a1TE of wild6_a1TJ { __DEFAULT -> GHC.Types.I# wild6_a1TJ }; (-1) -> GHC.Real.$fIntegralInt1; 0 -> GHC.Real.divZeroError @ Int }) (go1_a1S5 ys_X1T6) } } }; } in go1_a1S5 Main.main3) } } }}} foldr, however, fuse just fine: {{{ primes = 2:3:filter isPrime [5,7..] :: [Int] isPrime x = foldr (&&) True . map (/= 0) . map (x `rem`) . takeWhile ((<= x) . (^2)) $ primes main = print . length . takeWhile (<= 2^24) $ primes }}} {{{ 365,770,752 bytes allocated in the heap 48,197,488 bytes copied during GC 13,031,232 bytes maximum residency (7 sample(s)) 1,570,524 bytes maximum slop 28 MB total memory in use (0 MB lost due to fragmentation) Tot time (elapsed) Avg pause Max pause Gen 0 694 colls, 0 par 0.016s 0.029s 0.0000s 0.0005s Gen 1 7 colls, 0 par 0.031s 0.032s 0.0046s 0.0146s INIT time 0.000s ( 0.000s elapsed) MUT time 3.438s ( 3.439s elapsed) GC time 0.047s ( 0.062s elapsed) EXIT time 0.000s ( 0.003s elapsed) Total time 3.484s ( 3.504s elapsed) %GC time 1.3% (1.8% elapsed) Alloc rate 106,406,036 bytes per MUT second Productivity 98.7% of total user, 98.1% of total elapsed }}} {{{ lvl4_r2qr :: Int -> Bool [GblId, Arity=1, Str=DmdType] lvl4_r2qr = \ (x_aqW [OS=ProbOneShot] :: Int) -> case x_aqW of _ [Occ=Dead] { GHC.Types.I# y_a1tq -> case GHC.Prim.tagToEnum# @ Bool (GHC.Prim.<=# 4 y_a1tq) of _ [Occ=Dead] { False -> GHC.Types.True; True -> case GHC.Prim.remInt# y_a1tq 2 of _ [Occ=Dead] { __DEFAULT -> letrec { go_a1ud [Occ=LoopBreaker] :: [Int] -> Bool [LclId, Arity=1, Str=DmdType ] go_a1ud = \ (ds_a1ue :: [Int]) -> case ds_a1ue of _ [Occ=Dead] { [] -> GHC.Types.True; : y1_X1vf ys_X1vh -> case y1_X1vf of _ [Occ=Dead] { GHC.Types.I# x1_X1x9 -> case GHC.Prim.tagToEnum# @ Bool (GHC.Prim.<=# (GHC.Prim.*# x1_X1x9 x1_X1x9) y_a1tq) of _ [Occ=Dead] { False -> GHC.Types.True; True -> case x1_X1x9 of wild6_X1x3 { __DEFAULT -> case GHC.Prim.remInt# y_a1tq wild6_X1x3 of _ [Occ=Dead] { __DEFAULT -> go_a1ud ys_X1vh; 0 -> GHC.Types.False }; (-1) -> GHC.Types.False; 0 -> case GHC.Real.divZeroError of wild7_00 { } } } } }; } in go_a1ud Main.main3; 0 -> GHC.Types.False } } } }}} And List.all from ghc 7.8 base library does fuse, so this is regression. Windows 8.1 x64, ghc --info: {{{ [("Project name","The Glorious Glasgow Haskell Compilation System") ,("GCC extra via C opts"," -fwrapv") ,("C compiler command","$topdir/../mingw/bin/gcc.exe") ,("C compiler flags"," -U__i686 -march=i686 -fno-stack-protector") ,("C compiler link flags","") ,("Haskell CPP command","$topdir/../mingw/bin/gcc.exe") ,("Haskell CPP flags","-E -undef -traditional ") ,("ld command","$topdir/../mingw/bin/ld.exe") ,("ld flags","") ,("ld supports compact unwind","YES") ,("ld supports build-id","NO") ,("ld supports filelist","NO") ,("ld is GNU ld","YES") ,("ar command","$topdir/../mingw/bin/ar.exe") ,("ar flags","q") ,("ar supports at file","YES") ,("touch command","$topdir/touchy.exe") ,("dllwrap command","$topdir/../mingw/bin/dllwrap.exe") ,("windres command","$topdir/../mingw/bin/windres.exe") ,("libtool command","") ,("perl command","$topdir/../perl/perl.exe") ,("target os","OSMinGW32") ,("target arch","ArchX86") ,("target word size","4") ,("target has GNU nonexec stack","False") ,("target has .ident directive","True") ,("target has subsections via symbols","False") ,("Unregisterised","NO") ,("LLVM llc command","llc") ,("LLVM opt command","opt") ,("Project version","7.9.20141129") ,("Project Git commit id","447f592697fef04d1e19a2045ec707cfcd1eb59f") ,("Booter version","7.8.3") ,("Stage","2") ,("Build platform","i386-unknown-mingw32") ,("Host platform","i386-unknown-mingw32") ,("Target platform","i386-unknown-mingw32") ,("Have interpreter","YES") ,("Object splitting supported","YES") ,("Have native code generator","YES") ,("Support SMP","YES") ,("Tables next to code","YES") ,("RTS ways","l debug thr thr_debug thr_l thr_p ") ,("Support dynamic-too","NO") ,("Support parallel --make","YES") ,("Support reexported-modules","YES") ,("Support thinning and renaming package flags","YES") ,("Uses package keys","YES") ,("Dynamic by default","NO") ,("GHC Dynamic","NO") ,("Leading underscore","YES") ,("Debug on","False") ,("LibDir","D:\\msys32\\usr\\local\\lib") ,("Global Package DB","D:\\msys32\\usr\\local\\lib\\package.conf.d") ] }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9848 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler