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| author | Krzysztof Gogolewski <krzysztof.gogolewski@tweag.io> | 2022-03-28 15:59:04 +0200 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2022-04-22 08:00:18 -0400 |
| commit | f435d55fe969e739eb92bbb681069020d0622137 (patch) | |
| tree | 84816a862da56d35646f7f767195920a4f5cb9db | |
| parent | 76bb8cb3fd0f376b6af4bff12c29cb4226c24a72 (diff) | |
| download | haskell-f435d55fe969e739eb92bbb681069020d0622137.tar.gz | |
Fixes to rubbish literals
* In CoreToStg, the application 'RUBBISH[rep] x' was simplified
to 'RUBBISH[rep]'. But it is possible that the result of the function
is represented differently than the function.
* In Unarise, 'LitRubbish (primRepToType prep)'
is incorrect: LitRubbish takes a RuntimeRep such as IntRep,
while primRepToType returns a type such as Any @(TYPE IntRep). Use
primRepToRuntimeRep instead.
This code is never run in the testsuite.
* In StgToByteCode, all rubbish literals were assumed to be boxed.
This code predates representation-polymorphic RubbishLit and I think
it was not updated.
I don't have a testcase for any of those issues, but the code looks
wrong.
| -rw-r--r-- | compiler/GHC/CoreToStg.hs | 6 | ||||
| -rw-r--r-- | compiler/GHC/Stg/Unarise.hs | 2 | ||||
| -rw-r--r-- | compiler/GHC/StgToByteCode.hs | 4 | ||||
| -rw-r--r-- | compiler/GHC/Types/RepType.hs | 2 |
4 files changed, 10 insertions, 4 deletions
diff --git a/compiler/GHC/CoreToStg.hs b/compiler/GHC/CoreToStg.hs index 79be8e6e11..268c427f09 100644 --- a/compiler/GHC/CoreToStg.hs +++ b/compiler/GHC/CoreToStg.hs @@ -402,7 +402,11 @@ coreToStgExpr expr@(App _ _) = case app_head of Var f -> coreToStgApp f args ticks -- Regular application Lit l | isLitRubbish l -- If there is LitRubbish at the head, - -> return (StgLit l) -- discard the arguments + -- discard the arguments + -- Recompute representation, because in + -- '(RUBBISH[rep] x) :: (T :: TYPE rep2)' + -- rep might not be equal to rep2 + -> return (StgLit $ LitRubbish $ getRuntimeRep (exprType expr)) _ -> pprPanic "coreToStgExpr - Invalid app head:" (ppr expr) where diff --git a/compiler/GHC/Stg/Unarise.hs b/compiler/GHC/Stg/Unarise.hs index 23c2646f73..30234fe57c 100644 --- a/compiler/GHC/Stg/Unarise.hs +++ b/compiler/GHC/Stg/Unarise.hs @@ -456,7 +456,7 @@ unariseRubbish_maybe (LitRubbish rep) = Nothing -- Single, non-void PrimRep. Nothing to do! | otherwise -- Multiple reps, possibly with VoidRep. Eliminate via elimCase - = Just [ StgLitArg (LitRubbish (primRepToType prep)) + = Just [ StgLitArg (LitRubbish (primRepToRuntimeRep prep)) | prep <- preps, not (isVoidRep prep) ] where preps = runtimeRepPrimRep (text "unariseRubbish_maybe") rep diff --git a/compiler/GHC/StgToByteCode.hs b/compiler/GHC/StgToByteCode.hs index 0d6af799de..c3a1d6ff94 100644 --- a/compiler/GHC/StgToByteCode.hs +++ b/compiler/GHC/StgToByteCode.hs @@ -1722,7 +1722,9 @@ pushLiteral padded lit = LitChar {} -> code WordRep LitNullAddr -> code AddrRep LitString {} -> code AddrRep - LitRubbish {} -> code WordRep + LitRubbish rep -> case runtimeRepPrimRep (text "pushLiteral") rep of + [pr] -> code pr + _ -> pprPanic "pushLiteral" (ppr lit) LitNumber nt _ -> case nt of LitNumInt -> code IntRep LitNumWord -> code WordRep diff --git a/compiler/GHC/Types/RepType.hs b/compiler/GHC/Types/RepType.hs index b565bd7400..e09164dc9a 100644 --- a/compiler/GHC/Types/RepType.hs +++ b/compiler/GHC/Types/RepType.hs @@ -13,7 +13,7 @@ module GHC.Types.RepType -- * Type representation for the code generator typePrimRep, typePrimRep1, runtimeRepPrimRep, typePrimRepArgs, - PrimRep(..), primRepToType, + PrimRep(..), primRepToRuntimeRep, primRepToType, countFunRepArgs, countConRepArgs, dataConRuntimeRepStrictness, tyConPrimRep, tyConPrimRep1, |