diff options
Diffstat (limited to 'compiler/GHC/Core/Opt/ConstantFold.hs')
| -rw-r--r-- | compiler/GHC/Core/Opt/ConstantFold.hs | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/compiler/GHC/Core/Opt/ConstantFold.hs b/compiler/GHC/Core/Opt/ConstantFold.hs index 2e5c6aabf6..86fdc5cdb5 100644 --- a/compiler/GHC/Core/Opt/ConstantFold.hs +++ b/compiler/GHC/Core/Opt/ConstantFold.hs @@ -55,7 +55,7 @@ import GHC.Core.TyCo.Compare( eqType ) import GHC.Core.TyCon ( tyConDataCons_maybe, isAlgTyCon, isEnumerationTyCon , isNewTyCon, tyConDataCons - , tyConFamilySize ) + , tyConFamilySize, isTypeDataTyCon ) import GHC.Core.Map.Expr ( eqCoreExpr ) import GHC.Builtin.PrimOps ( PrimOp(..), tagToEnumKey ) @@ -3184,6 +3184,8 @@ caseRules _ (App (App (Var f) (Type ty)) v) -- dataToTag x | Just DataToTagOp <- isPrimOpId_maybe f , Just (tc, _) <- tcSplitTyConApp_maybe ty , isAlgTyCon tc + , not (isTypeDataTyCon tc) -- See wrinkle (W2c) in GHC.Rename.Module + -- Note [Type data declarations] = Just (v, tx_con_dtt ty , \v -> App (App (Var f) (Type ty)) (Var v)) |