I have a question. Do unique names have SSA semantic in STG? Can multiple (StgRec/StgNonRec) binding id have the same unique value?
On Tue, Nov 6, 2018 at 5:10 PM Csaba Hruska <csaba.hru...@gmail.com> wrote: > https://ghc.haskell.org/trac/ghc/ticket/15867 > > On Tue, Nov 6, 2018 at 4:47 PM Csaba Hruska <csaba.hru...@gmail.com> > wrote: > >> Ok, I'll open a ticket. >> To reproduce: >> >> 1. patch GHC head: *git apply StgScopeCheck.patch* >> 2. make sure every compiled stg is linted: *add -dstg-lint* to >> GhcStage2HcOpts >> GhcLibHcOpts GhcRtsHcOpts config vars >> 3. compile GHC HEAD >> >> >> On Tue, Nov 6, 2018 at 4:39 PM Simon Peyton Jones <simo...@microsoft.com> >> wrote: >> >>> can you open a Trac ticket, and explain how to reproduce it? Does it >>> require a patch, or does -ddump-stg show it? >>> >>> >>> >>> thanks >>> >>> >>> >>> Simion >>> >>> >>> >>> *From:* Csaba Hruska <csaba.hru...@gmail.com> >>> *Sent:* 06 November 2018 15:36 >>> *To:* Simon Peyton Jones <simo...@microsoft.com> >>> *Cc:* ghc-devs@haskell.org >>> *Subject:* Re: StgRhsClosure freevar and argument name duplicates >>> >>> >>> >>> You can reproduce the error with the GHC HEAD and with the attached >>> patch for StgLinter. >>> >>> The patch adds scope checking for the linter. >>> >>> I've also attached the linter's error output against GHC HEAD. >>> >>> Compile GHC HEAD with the following settings: >>> >>> GhcStage1HcOpts= >>> GhcStage2HcOpts=-O2 -haddock -dstg-lint >>> GhcStage3HcOpts=-O2 -haddock -dstg-lint >>> >>> >>> >>> Regards, >>> >>> Csaba >>> >>> >>> >>> >>> >>> On Tue, Nov 6, 2018 at 12:19 PM Csaba Hruska <csaba.hru...@gmail.com> >>> wrote: >>> >>> Correction: I've also noticed that there are two Main.main top-level >>> binders in the generated STG with different uniques. >>> >>> >>> >>> On Tue, Nov 6, 2018 at 12:19 PM Csaba Hruska <csaba.hru...@gmail.com> >>> wrote: >>> >>> I've also noticed that there are two Main.main top-level binders in the >>> generated STG with different uniques? >>> >>> And GHC produces a working executable. >>> >>> Is Main.main an exception or does top-level names have some kind of >>> "should be exported" property? >>> >>> >>> >>> On Tue, Nov 6, 2018 at 12:02 PM Simon Peyton Jones < >>> simo...@microsoft.com> wrote: >>> >>> I think top level names should be unique in occ-names; because those >>> occ-names generate the symbols in the binary. >>> >>> >>> >>> Simon >>> >>> >>> >>> *From:* Csaba Hruska <csaba.hru...@gmail.com> >>> *Sent:* 06 November 2018 11:01 >>> *To:* Simon Peyton Jones <simo...@microsoft.com> >>> *Cc:* ghc-devs@haskell.org >>> *Subject:* Re: StgRhsClosure freevar and argument name duplicates >>> >>> >>> >>> My plan is to extend GHC's STG linter to check the following properties: >>> >>> - uniqueness of free var and arg list of StgRhsClosure >>> - top level binding name uniqueness >>> >>> I'll patch my local GHC 8.2.2 and GHC HEAD. I'll also attach the patch >>> to the ticket. >>> >>> I have a question regarding top level names. >>> >>> Should the top-level names be unique as occ names or just in unique >>> values? >>> >>> If not, then what is the rule? >>> >>> >>> >>> Thanks, >>> >>> Csaba >>> >>> >>> >>> On Tue, Nov 6, 2018 at 11:13 AM Simon Peyton Jones < >>> simo...@microsoft.com> wrote: >>> >>> Does this happen in HEAD with GHC’s own STG printer? If so, could you >>> file a Trac ticket – it’s clearly wrong. >>> >>> >>> >>> But I do wonder if it could perhaps be something to do with your branch? >>> >>> >>> >>> Thanks >>> >>> >>> >>> Simon >>> >>> >>> >>> *From:* Csaba Hruska <csaba.hru...@gmail.com> >>> *Sent:* 05 November 2018 16:33 >>> *To:* Simon Peyton Jones <simo...@microsoft.com> >>> *Cc:* ghc-devs@haskell.org >>> *Subject:* Re: StgRhsClosure freevar and argument name duplicates >>> >>> >>> >>> Correction! >>> >>> The problem happens in integer-gmp: >>> >>> https://github.com/ghc/ghc/blob/master/libraries/integer-gmp/src/GHC/Integer/Type.hs#L761-L770 >>> <https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fghc%2Fghc%2Fblob%2Fmaster%2Flibraries%2Finteger-gmp%2Fsrc%2FGHC%2FInteger%2FType.hs%23L761-L770&data=02%7C01%7Csimonpj%40microsoft.com%7C8ed5614402be4321be6908d643fda441%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636771154034475485&sdata=tglY4lglir%2FKqm3ApXo9gW4gHCWeRIBjP7UMEytNjxQ%3D&reserved=0> >>> >>> >>> >>> 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://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fghc%2Fghc%2Fblob%2Fmaster%2Flibraries%2Finteger-simple%2FGHC%2FInteger%2FType.hs%23L373-L380&data=02%7C01%7Csimonpj%40microsoft.com%7C8ed5614402be4321be6908d643fda441%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636771154034485494&sdata=6u7J6besY3OM9zfcr0x0LRuo7zJRphr6iHOq6xwO7mo%3D&reserved=0> >>> 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# >>> <https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2FGHC.Integer.Type.Jp%23&data=02%7C01%7Csimonpj%40microsoft.com%7C8ed5614402be4321be6908d643fda441%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636771154034495502&sdata=2WLaJGm7NgH0FvibSDarfwBraI9nn0uAZVUH6CwaMno%3D&reserved=0> >>> {-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# >>> <https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2FGHC.Integer.Type.Jp%23&data=02%7C01%7Csimonpj%40microsoft.com%7C8ed5614402be4321be6908d643fda441%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636771154034495502&sdata=2WLaJGm7NgH0FvibSDarfwBraI9nn0uAZVUH6CwaMno%3D&reserved=0> >>> {-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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