Correction! The problem happens in integer-gmp: https://github.com/ghc/ghc/blob/master/libraries/integer-gmp/src/GHC/Integer/Type.hs#L761-L770
On Mon, Nov 5, 2018 at 5:27 PM Csaba Hruska <csaba.hru...@gmail.com> wrote: > An example for the duplication please check the divModInteger > <https://github.com/ghc/ghc/blob/master/libraries/integer-simple/GHC/Integer/Type.hs#L373-L380> > function from integer-simple GHC.Integer.Type. > The STG (GHC 8.2.2) generated from *divModInteger **:: Integer -> Integer > -> (# Integer, Integer #) *contains duplications in a closure binder list. > > Using my custom STG printer it looks like: > module GHC.Integer.Type where > > using GHC.Prim > using GHC.Tuple > using GHC.Types > > GHC.Integer.Type.divModInteger {-083-} = > closure (F:) (B: > n.s84123 {-s84123-} > d.s84124 {-s84124-}) { > case GHC.Integer.Type.quotRemInteger {-084-} > n.s84123 {-s84123-} > d.s84124 {-s84124-} > of qr.s84125 {-s84125-} { > GHC.Prim.(#,#) {-86-} ipv.s84126 {-s84126-} ipv1.s84127 {-s84127-} -> > let $j.s84128 {-s84128-} = > closure (F: > d.s84124 {-s84124-} > * ipv.s84126 {-s84126-}* > * ipv1.s84127 {-s84127-}* > * ipv.s84126 {-s84126-}* > *ipv1.s84127 {-s84127-}*) (B: > wild.s84129 {-s84129-}) { > let $j1.s84130 {-s84130-} = > closure (F: > d.s84124 {-s84124-} > ipv.s84126 {-s84126-} > ipv1.s84127 {-s84127-} > ipv.s84126 {-s84126-} > ipv1.s84127 {-s84127-} > wild.s84129 {-s84129-}) (B: > wild1.s84131 {-s84131-}) { > case _stg_prim_negateInt# > wild.s84129 {-s84129-} > of sat.s84132 {-s84132-} { > DEFAULT -> > case _stg_prim_==# > wild1.s84131 {-s84131-} > sat.s84132 {-s84132-} > of sat.s84133 {-s84133-} { > DEFAULT -> > case _stg_prim_tagToEnum# > sat.s84133 {-s84133-} > of wild2.s84134 {-s84134-} { > GHC.Types.False {-612-} -> > GHC.Prim.(#,#) {-86-} > ipv.s84126 {-s84126-} > ipv1.s84127 {-s84127-} > GHC.Types.True {-645-} -> > case GHC.Integer.Type.plusInteger {-066-} > ipv1.s84127 {-s84127-} > d.s84124 {-s84124-} > of r'.s84135 {-s84135-} { > DEFAULT -> > case GHC.Integer.Type.plusInteger {-066-} > ipv.s84126 {-s84126-} > GHC.Integer.Type.lvl11 {-r50574-} > of q'.s84136 {-s84136-} { > DEFAULT -> > GHC.Prim.(#,#) {-86-} > q'.s84136 {-s84136-} > r'.s84135 {-s84135-} > } > } > } > } > }} > > in case ipv1.s84127 {-s84127-} > of wild1.s84137 {-s84137-} { > GHC.Integer.Type.S# {-621-} i#.s84138 {-s84138-} -> > case _stg_prim_<# > i#.s84138 {-s84138-} 0# > of sat.s84140 {-s84140-} { > DEFAULT -> > case _stg_prim_># > i#.s84138 {-s84138-} 0# > of sat.s84139 {-s84139-} { > DEFAULT -> > case _stg_prim_-# > sat.s84139 {-s84139-} > sat.s84140 {-s84140-} > of sat.s84141 {-s84141-} { > DEFAULT -> > $j1.s84130 {-s84130-} > sat.s84141 {-s84141-} > } > } > } > GHC.Integer.Type.Jp# {-r5813-} dt.s84142 {-s84142-} -> > $j1.s84130 {-s84130-} 1# > GHC.Integer.Type.Jn# {-r5814-} dt.s84143 {-s84143-} -> > $j1.s84130 {-s84130-} -1# > }} > > in case d.s84124 {-s84124-} > of wild.s84144 {-s84144-} { > GHC.Integer.Type.S# {-621-} i#.s84145 {-s84145-} -> > case _stg_prim_<# > i#.s84145 {-s84145-} 0# > of sat.s84147 {-s84147-} { > DEFAULT -> > case _stg_prim_># > i#.s84145 {-s84145-} 0# > of sat.s84146 {-s84146-} { > DEFAULT -> > case _stg_prim_-# > sat.s84146 {-s84146-} > sat.s84147 {-s84147-} > of sat.s84148 {-s84148-} { > DEFAULT -> > $j.s84128 {-s84128-} > sat.s84148 {-s84148-} > } > } > } > GHC.Integer.Type.Jp# {-r5813-} dt.s84149 {-s84149-} -> > $j.s84128 {-s84128-} 1# > GHC.Integer.Type.Jn# {-r5814-} dt.s84150 {-s84150-} -> > $j.s84128 {-s84128-} -1# > } > }} > > > On Mon, Nov 5, 2018 at 2:08 PM Simon Peyton Jones <simo...@microsoft.com> > wrote: > >> I don’t think there should be duplicates in either. Do you have a test >> case that shows duplicates? >> >> >> >> Simon >> >> >> >> *From:* ghc-devs <ghc-devs-boun...@haskell.org> *On Behalf Of *Csaba >> Hruska >> *Sent:* 04 November 2018 11:22 >> *To:* ghc-devs@haskell.org >> *Subject:* Re: StgRhsClosure freevar and argument name duplicates >> >> >> >> Is it possible that GHC generates STG with invalid binding semantics for >> certain cases that the Cmm codegen fix or ignore? >> >> This could explain my observations. >> >> I've checked the Stg linter source (StgLint.hs ; GHC 8.2.2 and github >> master) and it does not check StgRhsClosure free var and binder list at all. >> >> And the scope checker function (addInScopeVars) does not check for >> duplicates. >> >> >> >> Any thoughts? >> >> >> >> Cheers, >> >> Csaba >> >> >> >> On Sat, Nov 3, 2018 at 9:53 AM Csaba Hruska <csaba.hru...@gmail.com> >> wrote: >> >> Hi, >> >> >> >> Can StgRhsClosure's freevar list ([occ]) or argument list ([bndr]) >> contain duplicates? >> >> >> >> Cheers, >> >> Csaba >> >> >> >> data GenStgRhs bndr occ >> = StgRhsClosure >> CostCentreStack -- CCS to be attached (default is >> CurrentCCS) >> StgBinderInfo -- Info about how this binder is used >> (see below) >> *[occ]* -- non-global free vars; a list, >> rather than >> -- a set, because order is important >> !UpdateFlag -- ReEntrant | Updatable | SingleEntry >> *[bndr]* -- arguments; if empty, then not a >> function; >> -- as above, order is important. >> (GenStgExpr bndr occ) -- body >> >> >> >>
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