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| author | Simon Peyton Jones <simon.peytonjones@gmail.com> | 2023-05-16 13:38:46 +0100 |
|---|---|---|
| committer | Simon Peyton Jones <simon.peytonjones@gmail.com> | 2023-05-17 20:52:36 +0100 |
| commit | fe0e8c9c13916d4e32b65543c083d227db256d23 (patch) | |
| tree | e9a671f33076881f64504f3c1280904837b908e1 /compiler/GHC/Core/Predicate.hs | |
| parent | 2972fd66f91cb51426a1df86b8166a067015e231 (diff) | |
| download | haskell-wip/T23398.tar.gz | |
Allow the demand analyser to unpack tuple and equality dictionarieswip/T23398
Addresses #23398. The demand analyser usually does not unpack class
dictionaries: see Note [Do not unbox class dictionaries] in
GHC.Core.Opt.DmdAnal.
This patch makes an exception for tuple dictionaries and equality
dictionaries, for reasons explained in wrinkles (DNB1) and (DNB2) of
the above Note.
Diffstat (limited to 'compiler/GHC/Core/Predicate.hs')
| -rw-r--r-- | compiler/GHC/Core/Predicate.hs | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/compiler/GHC/Core/Predicate.hs b/compiler/GHC/Core/Predicate.hs index 2fc07e1be1..d6d5dd6520 100644 --- a/compiler/GHC/Core/Predicate.hs +++ b/compiler/GHC/Core/Predicate.hs @@ -20,7 +20,7 @@ module GHC.Core.Predicate ( -- Class predicates mkClassPred, isDictTy, typeDeterminesValue, - isClassPred, isEqPredClass, isCTupleClass, + isClassPred, isEqPredClass, isCTupleClass, isEqualityClass, getClassPredTys, getClassPredTys_maybe, classMethodTy, classMethodInstTy, @@ -219,11 +219,6 @@ isEvVarType :: Type -> Bool -- See Note [Evidence for quantified constraints] isEvVarType ty = isCoVarType ty || isPredTy ty -isEqPredClass :: Class -> Bool --- True of (~) and (~~) -isEqPredClass cls = cls `hasKey` eqTyConKey - || cls `hasKey` heqTyConKey - isClassPred :: PredType -> Bool isClassPred ty = case tyConAppTyCon_maybe ty of Just tc -> isClassTyCon tc @@ -245,6 +240,20 @@ isEqPrimPred ty = isCoVarType ty isCTupleClass :: Class -> Bool isCTupleClass cls = isTupleTyCon (classTyCon cls) +isEqPredClass :: Class -> Bool +-- True of (~) and (~~) +isEqPredClass cls = cls `hasKey` eqTyConKey + || cls `hasKey` heqTyConKey + +isEqualityClass :: Class -> Bool +-- True of (~), (~~), and Coercible +-- These all have a single primitive-equality superclass, either (~N# or ~R#) +isEqualityClass cls + = cls `hasKey` heqTyConKey + || cls `hasKey` eqTyConKey + || cls `hasKey` coercibleTyConKey + + {- ********************************************************************* * * Implicit parameters |