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| author | sheaf <sam.derbyshire@gmail.com> | 2021-07-12 11:49:48 +0200 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-07-23 21:06:56 -0400 |
| commit | 5d670abd1c2c53a6c0918b1fe52b8ff581b9a394 (patch) | |
| tree | 9680ed332a62328e5a33c85e793168fd984e35e3 /utils/genprimopcode | |
| parent | ba3028778942f63e888142e5b4d036423049006c (diff) | |
| download | haskell-5d670abd1c2c53a6c0918b1fe52b8ff581b9a394.tar.gz | |
Generalise reallyUnsafePtrEquality# and use it
fixes #9192 and #17126
updates containers submodule
1. Changes the type of the primop `reallyUnsafePtrEquality#` to the most
general version possible (heterogeneous as well as levity-polymorphic):
> reallyUnsafePtrEquality#
> :: forall {l :: Levity} {k :: Levity}
> (a :: TYPE (BoxedRep l)) (b :: TYPE (BoxedRep k))
> . a -> b -> Int#
2. Adds a new internal module, `GHC.Ext.PtrEq`, which contains pointer
equality operations that are now subsumed by `reallyUnsafePtrEquality#`.
These functions are then re-exported by `GHC.Exts` (so that no function
goes missing from the export list of `GHC.Exts`, which is user-facing).
More specifically, `GHC.Ext.PtrEq` defines:
- A new function:
* reallyUnsafePtrEquality :: forall (a :: Type). a -> a -> Int#
- Library definitions of ex-primops:
* `sameMutableArray#`
* `sameSmallMutableArray`
* `sameMutableByteArray#`
* `sameMutableArrayArray#`
* `sameMutVar#`
* `sameTVar#`
* `sameMVar#`
* `sameIOPort#`
* `eqStableName#`
- New functions for comparing non-mutable arrays:
* `sameArray#`
* `sameSmallArray#`
* `sameByteArray#`
* `sameArrayArray#`
These were requested in #9192.
Generally speaking, existing libraries that
use `reallyUnsafePtrEquality#` will continue to work with the new,
levity-polymorphic version. But not all!
Some (`containers`, `unordered-containers`, `dependent-map`) contain
the following:
> unsafeCoerce# reallyUnsafePtrEquality# a b
If we make `reallyUnsafePtrEquality#` levity-polymorphic, this code
fails the current GHC representation-polymorphism checks.
We agreed that the right solution here is to modify the library;
in this case by deleting the call to `unsafeCoerce#`,
since `reallyUnsafePtrEquality#` is now type-heterogeneous too.
Diffstat (limited to 'utils/genprimopcode')
| -rw-r--r-- | utils/genprimopcode/Main.hs | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/utils/genprimopcode/Main.hs b/utils/genprimopcode/Main.hs index f5eaf757e2..06a4922aa3 100644 --- a/utils/genprimopcode/Main.hs +++ b/utils/genprimopcode/Main.hs @@ -854,8 +854,11 @@ ppTyVar "c" = "gammaTyVarSpec" ppTyVar "s" = "deltaTyVarSpec" ppTyVar "o" = "runtimeRep1TyVarInf, openAlphaTyVarSpec" ppTyVar "p" = "runtimeRep2TyVarInf, openBetaTyVarSpec" -ppTyVar "v" = "levity1TyVarInf, levPolyTyVar1Spec" +ppTyVar "v" = "levity1TyVarInf, levPolyAlphaTyVarSpec" +ppTyVar "w" = "levity2TyVarInf, levPolyBetaTyVarSpec" ppTyVar _ = error "Unknown type var" +-- o, p, v and w have a special meaning. See primops.txt.pp +-- Note [Levity and representation polymorphic primops] ppType :: Ty -> String ppType (TyApp (TyCon "Any") []) = "anyTy" @@ -889,7 +892,10 @@ ppType (TyVar "c") = "gammaTy" ppType (TyVar "s") = "deltaTy" ppType (TyVar "o") = "openAlphaTy" ppType (TyVar "p") = "openBetaTy" -ppType (TyVar "v") = "levPolyTy1" +ppType (TyVar "v") = "levPolyAlphaTy" +ppType (TyVar "w") = "levPolyBetaTy" +-- o, p, v and w have a special meaning. See primops.txt.pp +-- Note [Levity and representation polymorphic primops] ppType (TyApp (TyCon "State#") [x]) = "mkStatePrimTy " ++ ppType x ppType (TyApp (TyCon "MutVar#") [x,y]) = "mkMutVarPrimTy " ++ ppType x |