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| author | Ben Gamari <ben@smart-cactus.org> | 2021-11-15 23:22:06 -0500 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-11-17 05:10:27 -0500 |
| commit | 083a7583d70c190b090fedcf9f955eff65d4baeb (patch) | |
| tree | 8706cc9ee591bf2a05c23efcaa7251a0489e4c24 /compiler/GHC/Core/TyCo | |
| parent | 3e94b5a7ebddf156f00599c6bd2e9ba1af437a6c (diff) | |
| download | haskell-083a7583d70c190b090fedcf9f955eff65d4baeb.tar.gz | |
Increase type sharing
Fixes #20541 by making mkTyConApp do more sharing of types.
In particular, replace
* BoxedRep Lifted ==> LiftedRep
* BoxedRep Unlifted ==> UnliftedRep
* TupleRep '[] ==> ZeroBitRep
* TYPE ZeroBitRep ==> ZeroBitType
In each case, the thing on the right is a type synonym
for the thing on the left, declared in ghc-prim:GHC.Types.
See Note [Using synonyms to compress types] in GHC.Core.Type.
The synonyms for ZeroBitRep and ZeroBitType are new, but absolutely
in the same spirit as the other ones. (These synonyms are mainly
for internal use, though the programmer can use them too.)
I also renamed GHC.Core.Ty.Rep.isVoidTy to isZeroBitTy, to be
compatible with the "zero-bit" nomenclature above. See discussion
on !6806.
There is a tricky wrinkle: see GHC.Core.Types
Note [Care using synonyms to compress types]
Compiler allocation decreases by up to 0.8%.
Diffstat (limited to 'compiler/GHC/Core/TyCo')
| -rw-r--r-- | compiler/GHC/Core/TyCo/Rep.hs | 14 | ||||
| -rw-r--r-- | compiler/GHC/Core/TyCo/Rep.hs-boot | 2 | ||||
| -rw-r--r-- | compiler/GHC/Core/TyCo/Subst.hs | 4 |
3 files changed, 11 insertions, 9 deletions
diff --git a/compiler/GHC/Core/TyCo/Rep.hs b/compiler/GHC/Core/TyCo/Rep.hs index b9986e0a36..bb7280dd0d 100644 --- a/compiler/GHC/Core/TyCo/Rep.hs +++ b/compiler/GHC/Core/TyCo/Rep.hs @@ -42,7 +42,7 @@ module GHC.Core.TyCo.Rep ( MCoercion(..), MCoercionR, MCoercionN, -- * Functions over types - mkTyConTy_, mkTyVarTy, mkTyVarTys, + mkNakedTyConTy, mkTyVarTy, mkTyVarTys, mkTyCoVarTy, mkTyCoVarTys, mkFunTy, mkVisFunTy, mkInvisFunTy, mkVisFunTys, mkForAllTy, mkForAllTys, mkInvisForAllTys, @@ -1062,11 +1062,13 @@ mkPiTy (Named (Bndr tv vis)) ty = mkForAllTy tv vis ty mkPiTys :: [TyCoBinder] -> Type -> Type mkPiTys tbs ty = foldr mkPiTy ty tbs --- | Create a nullary 'TyConApp'. In general you should rather use --- 'GHC.Core.Type.mkTyConTy'. This merely exists to break the import cycle --- between 'GHC.Core.TyCon' and this module. -mkTyConTy_ :: TyCon -> Type -mkTyConTy_ tycon = TyConApp tycon [] +-- | 'mkNakedTyConTy' creates a nullary 'TyConApp'. In general you +-- should rather use 'GHC.Core.Type.mkTyConTy', which picks the shared +-- nullary TyConApp from inside the TyCon (via tyConNullaryTy. But +-- we have to build the TyConApp tc [] in that TyCon field; that's +-- what 'mkNakedTyConTy' is for. +mkNakedTyConTy :: TyCon -> Type +mkNakedTyConTy tycon = TyConApp tycon [] {- %************************************************************************ diff --git a/compiler/GHC/Core/TyCo/Rep.hs-boot b/compiler/GHC/Core/TyCo/Rep.hs-boot index 0c89a2f077..f2e59d534f 100644 --- a/compiler/GHC/Core/TyCo/Rep.hs-boot +++ b/compiler/GHC/Core/TyCo/Rep.hs-boot @@ -24,7 +24,7 @@ type MCoercionN = MCoercion mkFunTyMany :: AnonArgFlag -> Type -> Type -> Type mkForAllTy :: Var -> ArgFlag -> Type -> Type -mkTyConTy_ :: TyCon -> Type +mkNakedTyConTy :: TyCon -> Type instance Data Type -- To support Data instances in GHC.Core.Coercion.Axiom instance Outputable Type diff --git a/compiler/GHC/Core/TyCo/Subst.hs b/compiler/GHC/Core/TyCo/Subst.hs index 5d060cb7cd..ec77cd2671 100644 --- a/compiler/GHC/Core/TyCo/Subst.hs +++ b/compiler/GHC/Core/TyCo/Subst.hs @@ -746,8 +746,8 @@ subst_ty subst ty go (TyConApp tc tys) = (mkTyConApp $! tc) $! strictMap go tys -- NB: mkTyConApp, not TyConApp. -- mkTyConApp has optimizations. - -- See Note [Prefer Type over TYPE 'LiftedRep] - -- in GHC.Core.TyCo.Rep + -- See Note [Using synonyms to compress types] + -- in GHC.Core.Type go ty@(FunTy { ft_mult = mult, ft_arg = arg, ft_res = res }) = let !mult' = go mult !arg' = go arg |