[Git][ghc/ghc][wip/fix-ubx-cast] Properly convert values before/after storing them in unboxed sums.
Andreas Klebinger (@AndreasK)
gitlab at gitlab.haskell.org
Tue Sep 27 15:24:16 UTC 2022
Andreas Klebinger pushed to branch wip/fix-ubx-cast at Glasgow Haskell Compiler / GHC
Commits:
4f859687 by Andreas Klebinger at 2022-09-27T17:23:14+02:00
Properly convert values before/after storing them in unboxed sums.
See Note [Casting slot arguments] for the details.
- - - - -
14 changed files:
- + compiler/GHC/Builtin/PrimOps/Casts.hs
- compiler/GHC/Cmm/CLabel.hs
- compiler/GHC/Core/TyCon.hs
- compiler/GHC/Driver/Flags.hs
- compiler/GHC/Driver/Session.hs
- compiler/GHC/Stg/Syntax.hs
- compiler/GHC/Stg/Unarise.hs
- compiler/GHC/Types/RepType.hs
- compiler/GHC/Utils/Outputable.hs
- compiler/ghc.cabal.in
- docs/users_guide/debugging.rst
- testsuite/driver/testlib.py
- + testsuite/tests/unboxedsums/T22208.hs
- testsuite/tests/unboxedsums/all.T
Changes:
=====================================
compiler/GHC/Builtin/PrimOps/Casts.hs
=====================================
@@ -0,0 +1,206 @@
+
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE TupleSections #-}
+
+{-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
+
+{-
+This module contains helpers to cast variables
+between different Int/WordReps in StgLand.
+-}
+
+module GHC.Builtin.PrimOps.Casts
+ ( getCasts )
+where
+
+import GHC.Prelude
+
+import GHC.Core.TyCon
+import GHC.Utils.Outputable
+import GHC.Utils.Panic
+import GHC.Utils.Panic.Plain
+import GHC.Types.RepType
+import GHC.Core.Type
+import GHC.Builtin.Types.Prim
+import GHC.Builtin.Types
+
+import GHC.Builtin.PrimOps
+import GHC.Plugins (HasDebugCallStack)
+
+{- Note [PrimRep based casting]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+This module contains a number of utility functions useful when
+converting between variables of differing PrimReps.
+
+The general pattern is that we have two primReps `from_rep` and `to_rep`.
+We want a list of PrimOps we can apply to a variable of rep `from_rep`
+in order to get to a variable of rep `to_rep`.
+
+E.g. we call `getCasts from_rep to_rep` and get back [(op1#,ty1),(op2#,ty2)].
+We can use this list of primOps to construct a function of type
+`StgExpr -> StgExpr` by construction an expression
+
+ case op1# <from> of (x' :: ty1) -> case op2# x' of x' -> <rhs_hole>
+-}
+
+-- | `getCasts from_rep to_rep` gives us a list of primops which when applied in order convert from_rep to to_rep.
+-- See Note [PrimRep based casting]
+getCasts :: PrimRep -> PrimRep -> [(PrimOp,Type)]
+getCasts from_rep to_rep
+ -- No-op
+ | to_rep == from_rep
+ = []
+ -- Float <-> Double
+ | to_rep == FloatRep =
+ assertPpr (from_rep == DoubleRep) (ppr from_rep <+> ppr to_rep) $
+ [(DoubleToFloatOp,floatPrimTy)]
+ | to_rep == DoubleRep =
+ assertPpr (from_rep == FloatRep) (ppr from_rep <+> ppr to_rep) $
+ [(FloatToDoubleOp,doublePrimTy)]
+ -- Addr <-> Word/Int
+ | to_rep == AddrRep = wordOrIntToAddrRep from_rep
+ | from_rep == AddrRep = addrToWordOrIntRep from_rep
+
+ -- Int* -> Int*
+ | primRepIsInt from_rep
+ , primRepIsInt to_rep
+ = sizedIntToSizedInt from_rep to_rep
+
+ -- Word* -> Word*
+ | primRepIsWord from_rep
+ , primRepIsWord to_rep
+ = sizedWordToSizedWord from_rep to_rep
+
+ -- Word* -> Int*
+ | primRepIsWord from_rep
+ , primRepIsInt to_rep
+ = let (op1,r1) = wordToIntRep from_rep
+ in (op1,primRepToType r1):sizedIntToSizedInt r1 to_rep
+
+ -- Int* -> Word*
+ | primRepIsInt from_rep
+ , primRepIsWord to_rep
+ = let (op1,r1) = intToWordRep from_rep
+ in (op1,primRepToType r1):sizedWordToSizedWord r1 to_rep
+
+ | otherwise = pprPanic "getCasts:Unexpect rep combination"
+ (ppr (from_rep,to_rep))
+
+wordOrIntToAddrRep :: HasDebugCallStack => PrimRep -> [(PrimOp,Type)]
+wordOrIntToAddrRep AddrRep = []
+wordOrIntToAddrRep IntRep = [(IntToAddrOp, addrPrimTy)]
+wordOrIntToAddrRep WordRep = [(WordToIntOp,intPrimTy), (IntToAddrOp,addrPrimTy)]
+wordOrIntToAddrRep r
+ | primRepIsInt r = (intToMachineInt r,intPrimTy):[(IntToAddrOp,addrPrimTy)]
+ | primRepIsWord r =
+ let (op1,r) = wordToIntRep r
+ in (op1, primRepToType r):[(intToMachineInt r,intPrimTy), (IntToAddrOp,addrPrimTy)]
+ | otherwise = pprPanic "Rep not word or int rep" (ppr r)
+
+addrToWordOrIntRep :: HasDebugCallStack => PrimRep -> [(PrimOp,Type)]
+-- Machine sizes
+addrToWordOrIntRep IntRep = [(AddrToIntOp, intPrimTy)]
+addrToWordOrIntRep WordRep = [(AddrToIntOp,intPrimTy), (IntToWordOp,wordPrimTy)]
+-- Explicitly sized reps
+addrToWordOrIntRep r
+ | primRepIsWord r = (AddrToIntOp,intPrimTy) : (IntToWordOp,wordPrimTy) : sizedWordToSizedWord WordRep r
+ | primRepIsInt r = (AddrToIntOp,intPrimTy) : sizedIntToSizedInt IntRep r
+ | otherwise = pprPanic "Target rep not word or int rep" (ppr r)
+
+
+-- WordX# -> IntX# (same size), argument is source rep
+wordToIntRep :: HasDebugCallStack => PrimRep -> (PrimOp,PrimRep)
+wordToIntRep rep
+ = case rep of
+ (WordRep) -> (WordToIntOp, IntRep)
+ (Word8Rep) -> (Word8ToInt8Op, Int8Rep)
+ (Word16Rep) -> (Word16ToInt16Op, Int16Rep)
+ (Word32Rep) -> (Word32ToInt32Op, Int32Rep)
+ (Word64Rep) -> (Word64ToInt64Op, Int64Rep)
+ _ -> pprPanic "Rep not a wordRep" (ppr rep)
+
+-- IntX# -> WordX#, argument is source rep
+intToWordRep :: HasDebugCallStack => PrimRep -> (PrimOp,PrimRep)
+intToWordRep rep
+ = case rep of
+ (IntRep) -> (IntToWordOp, WordRep)
+ (Int8Rep) -> (Int8ToWord8Op, Word8Rep)
+ (Int16Rep) -> (Int16ToWord16Op, Word16Rep)
+ (Int32Rep) -> (Int32ToWord32Op, Word32Rep)
+ (Int64Rep) -> (Int64ToWord64Op, Word64Rep)
+ _ -> pprPanic "Rep not a wordRep" (ppr rep)
+
+-- Casts between any size int to any other size of int
+sizedIntToSizedInt :: HasDebugCallStack => PrimRep -> PrimRep -> [(PrimOp,Type)]
+sizedIntToSizedInt r1 r2
+ | r1 == r2 = []
+-- Cast to Int#
+sizedIntToSizedInt r IntRep = [(intToMachineInt r,intTy)]
+-- Cast from Int#
+sizedIntToSizedInt IntRep r = [(intFromMachineInt r,primRepToType r)]
+-- Sized to differently sized must go over machine word.
+sizedIntToSizedInt r1 r2 = (intToMachineInt r1,intTy) : [(intFromMachineInt r2,primRepToType r2)]
+
+-- Casts between any size Word to any other size of Word
+sizedWordToSizedWord :: HasDebugCallStack => PrimRep -> PrimRep -> [(PrimOp,Type)]
+sizedWordToSizedWord r1 r2
+ | r1 == r2 = []
+-- Cast to Word#
+sizedWordToSizedWord r WordRep = [(wordToMachineWord r,wordPrimTy)]
+-- Cast from Word#
+sizedWordToSizedWord WordRep r = [(wordFromMachineWord r, primRepToType r)]
+-- Sized to differently sized must go over machine word.
+sizedWordToSizedWord r1 r2 = (wordToMachineWord r1,wordPrimTy) : [(wordFromMachineWord r2, primRepToType r2)]
+
+
+-- Prefer the definitions above this line if possible
+----------------------
+
+
+-- Int*# to Int#
+{-# INLINE intToMachineInt #-}
+intToMachineInt :: HasDebugCallStack => PrimRep -> PrimOp
+intToMachineInt r =
+ assertPpr (primRepIsInt r) (ppr r) $
+ case r of
+ (Int8Rep) -> Int8ToIntOp
+ (Int16Rep) -> Int16ToIntOp
+ (Int32Rep) -> Int32ToIntOp
+ (Int64Rep) -> Int64ToIntOp
+ _ -> pprPanic "Source rep not int" $ ppr r
+
+-- Int# to Int*#
+{-# INLINE intFromMachineInt #-}
+intFromMachineInt :: HasDebugCallStack => PrimRep -> PrimOp
+intFromMachineInt r =
+ assertPpr (primRepIsInt r) (ppr r) $
+ case r of
+ Int8Rep -> IntToInt8Op
+ Int16Rep -> IntToInt16Op
+ Int32Rep -> IntToInt32Op
+ Int64Rep -> IntToInt64Op
+ _ -> pprPanic "Dest rep not sized int" $ ppr r
+
+-- Word# to Word*#
+{-# INLINE wordFromMachineWord #-}
+wordFromMachineWord :: HasDebugCallStack => PrimRep -> PrimOp
+wordFromMachineWord r =
+ assert (primRepIsWord r) $
+ case r of
+ Word8Rep -> WordToWord8Op
+ Word16Rep -> WordToWord16Op
+ Word32Rep -> WordToWord32Op
+ Word64Rep -> WordToWord64Op
+ _ -> pprPanic "Dest rep not sized word" $ ppr r
+
+-- Word*# to Word#
+{-# INLINE wordToMachineWord #-}
+wordToMachineWord :: HasDebugCallStack => PrimRep -> PrimOp
+wordToMachineWord r =
+ assertPpr (primRepIsWord r) (text "Not a word rep:" <> ppr r) $
+ case r of
+ Word8Rep -> Word8ToWordOp
+ Word16Rep -> Word16ToWordOp
+ Word32Rep -> Word32ToWordOp
+ Word64Rep -> Word64ToWordOp
+ _ -> pprPanic "Dest rep not sized word" $ ppr r
\ No newline at end of file
=====================================
compiler/GHC/Cmm/CLabel.hs
=====================================
@@ -1399,7 +1399,10 @@ instance OutputableP Platform CLabel where
pdoc !platform lbl = getPprStyle $ \pp_sty ->
case pp_sty of
PprDump{} -> pprCLabel platform CStyle lbl
- _ -> pprPanic "Labels in code should be printed with pprCLabel" (pprCLabel platform CStyle lbl)
+ -- Workaround for #22218
+ _ -> (pprCLabel platform CStyle lbl)
+ -- _ -> pprPanic "Labels in code should be printed with pprCLabel" (pprCLabel platform CStyle lbl)
+
pprCLabel :: Platform -> LabelStyle -> CLabel -> SDoc
pprCLabel !platform !sty lbl = -- see Note [Bangs in CLabel]
=====================================
compiler/GHC/Core/TyCon.hs
=====================================
@@ -129,6 +129,7 @@ module GHC.Core.TyCon(
primRepIsFloat,
primRepsCompatible,
primRepCompatible,
+ primRepIsWord, primRepIsInt,
) where
@@ -1785,6 +1786,24 @@ primRepIsFloat DoubleRep = Just True
primRepIsFloat (VecRep _ _) = Nothing
primRepIsFloat _ = Just False
+-- Rep is one of the word reps.
+primRepIsWord :: PrimRep -> Bool
+primRepIsWord WordRep = True
+primRepIsWord (Word8Rep) = True
+primRepIsWord (Word16Rep) = True
+primRepIsWord (Word32Rep) = True
+primRepIsWord (Word64Rep) = True
+primRepIsWord _ = False
+
+-- Rep is one of the int reps.
+primRepIsInt :: PrimRep -> Bool
+primRepIsInt (IntRep) = True
+primRepIsInt (Int8Rep) = True
+primRepIsInt (Int16Rep) = True
+primRepIsInt (Int32Rep) = True
+primRepIsInt (Int64Rep) = True
+primRepIsInt _ = False
+
{-
************************************************************************
* *
=====================================
compiler/GHC/Driver/Flags.hs
=====================================
@@ -422,6 +422,7 @@ data GeneralFlag
-- variables that have otherwise identical names.
| Opt_SuppressUniques
| Opt_SuppressStgExts
+ | Opt_SuppressStgReps
| Opt_SuppressTicks -- Replaces Opt_PprShowTicks
| Opt_SuppressTimestamps -- ^ Suppress timestamps in dumps
| Opt_SuppressCoreSizes -- ^ Suppress per binding Core size stats in dumps
=====================================
compiler/GHC/Driver/Session.hs
=====================================
@@ -2393,6 +2393,7 @@ dynamic_flags_deps = [
setGeneralFlag Opt_SuppressIdInfo
setGeneralFlag Opt_SuppressTicks
setGeneralFlag Opt_SuppressStgExts
+ setGeneralFlag Opt_SuppressStgReps
setGeneralFlag Opt_SuppressTypeSignatures
setGeneralFlag Opt_SuppressCoreSizes
setGeneralFlag Opt_SuppressTimestamps)
@@ -3344,6 +3345,7 @@ dFlagsDeps = [
depFlagSpec' "suppress-stg-free-vars" Opt_SuppressStgExts
(useInstead "-d" "suppress-stg-exts"),
flagSpec "suppress-stg-exts" Opt_SuppressStgExts,
+ flagSpec "suppress-stg-reps" Opt_SuppressStgReps,
flagSpec "suppress-coercions" Opt_SuppressCoercions,
flagSpec "suppress-coercion-types" Opt_SuppressCoercionTypes,
flagSpec "suppress-idinfo" Opt_SuppressIdInfo,
@@ -3796,7 +3798,8 @@ defaultFlags settings
Opt_VersionMacros,
Opt_RPath,
Opt_DumpWithWays,
- Opt_CompactUnwind
+ Opt_CompactUnwind,
+ Opt_SuppressStgReps
]
++ [f | (ns,f) <- optLevelFlags, 0 `elem` ns]
@@ -5020,6 +5023,7 @@ initSDocContext dflags style = SDC
, sdocSuppressUniques = gopt Opt_SuppressUniques dflags
, sdocSuppressModulePrefixes = gopt Opt_SuppressModulePrefixes dflags
, sdocSuppressStgExts = gopt Opt_SuppressStgExts dflags
+ , sdocSuppressStgReps = gopt Opt_SuppressStgReps dflags
, sdocErrorSpans = gopt Opt_ErrorSpans dflags
, sdocStarIsType = xopt LangExt.StarIsType dflags
, sdocLinearTypes = xopt LangExt.LinearTypes dflags
=====================================
compiler/GHC/Stg/Syntax.hs
=====================================
@@ -87,7 +87,7 @@ import GHC.Core.Ppr( {- instances -} )
import GHC.Builtin.PrimOps ( PrimOp, PrimCall )
import GHC.Core.TyCon ( PrimRep(..), TyCon )
import GHC.Core.Type ( Type )
-import GHC.Types.RepType ( typePrimRep1 )
+import GHC.Types.RepType ( typePrimRep1, typePrimRep )
import GHC.Utils.Panic.Plain
{-
@@ -740,12 +740,23 @@ pprStgTopBinding = pprGenStgTopBinding
pprStgTopBindings :: OutputablePass pass => StgPprOpts -> [GenStgTopBinding pass] -> SDoc
pprStgTopBindings = pprGenStgTopBindings
+pprIdWithRep :: Id -> SDoc
+pprIdWithRep v = ppr v <> pprTypeRep (idType v)
+
+pprTypeRep :: Type -> SDoc
+pprTypeRep ty =
+ ppUnlessOption sdocSuppressStgReps $
+ char ':' <> case typePrimRep ty of
+ [r] -> ppr r
+ r -> ppr r
+
+
instance Outputable StgArg where
ppr = pprStgArg
pprStgArg :: StgArg -> SDoc
-pprStgArg (StgVarArg var) = ppr var
-pprStgArg (StgLitArg con) = ppr con
+pprStgArg (StgVarArg var) = pprIdWithRep var
+pprStgArg (StgLitArg con) = ppr con <> pprTypeRep (literalType con)
instance OutputablePass pass => Outputable (GenStgExpr pass) where
ppr = pprStgExpr panicStgPprOpts
=====================================
compiler/GHC/Stg/Unarise.hs
=====================================
@@ -186,6 +186,39 @@ So we pass type arguments of the DataCon's TyCon in StgConApp to decide what
layout to use. Note that unlifted values can't be let-bound, so we don't need
types in StgRhsCon.
+Note [Casting slot arguments]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Consider this function which selects between Float# and Double# from a unboxed sum.
+
+ foo :: (# Float# | Double# #) -> FD
+ foo x = case x of
+ (# x1 | #) -> F x1
+ (# | x2 #) -> D x2
+
+Naturally we would expect x1 to have a PrimRep of FloatRep and x2 of DoubleRep.
+However we used to generate this (bogus) code after Unarise giving rise to #22208:
+
+ M.foo :: (# GHC.Prim.Float# | GHC.Prim.Double# #) -> M.FD
+ [GblId, Arity=1, Unf=OtherCon []] =
+ {} \r [sum_tag sum_field]
+ case sum_tag of tag_gsc {
+ __DEFAULT -> M.F [sum_field];
+ 2# -> M.D [sum_field];
+ };
+
+Where sum_field is used both as Float# and Double# depending on the branch.
+This usually works out since we put floats/doubles in the same sort of register.
+However this caused issues down the road where we would assign between variables
+of different reps causing lint errors or in the case of #22208 even compiler panics.
+For now our solution is to construct proper casts between the PrimRep of the slot and
+the variables we want to store in, or read out of these slots.
+
+This means when we have a sum (# Float# | Double# #) if we want to store a float
+we convert it to a double on construction of the tuple value, and convert it back
+to a float once when want to use the field.
+Conversion for values coming out of a strict field happen in mapSumIdBinders. While
+conversion during the construction of sums happen inside mkUbxSum.
+
Note [UnariseEnv]
~~~~~~~~~~~~~~~~~~
At any variable occurrence 'v',
@@ -258,8 +291,8 @@ import GHC.Prelude
import GHC.Types.Basic
import GHC.Core
import GHC.Core.DataCon
-import GHC.Core.TyCon ( isVoidRep )
-import GHC.Data.FastString (FastString, mkFastString)
+import GHC.Core.TyCon
+import GHC.Data.FastString (FastString, mkFastString, fsLit, appendFS)
import GHC.Types.Id
import GHC.Types.Literal
import GHC.Core.Make (aBSENT_SUM_FIELD_ERROR_ID)
@@ -281,6 +314,11 @@ import GHC.Types.Var.Env
import Data.Bifunctor (second)
import Data.Maybe (mapMaybe)
import qualified Data.IntMap as IM
+import GHC.Utils.Trace
+import GHC.Builtin.PrimOps
+import GHC.Builtin.PrimOps.Casts
+import Data.List (mapAccumL)
+import GHC.Types.Name
--------------------------------------------------------------------------------
@@ -306,8 +344,10 @@ import qualified Data.IntMap as IM
-- INVARIANT: OutStgArgs in the range only have NvUnaryTypes
-- (i.e. no unboxed tuples, sums or voids)
--
-type UnariseEnv = VarEnv UnariseVal
+newtype UnariseEnv = UnariseEnv { ue_rho :: (VarEnv UnariseVal) }
+initUnariseEnv :: VarEnv UnariseVal -> UnariseEnv
+initUnariseEnv = UnariseEnv
data UnariseVal
= MultiVal [OutStgArg] -- MultiVal to tuple. Can be empty list (void).
| UnaryVal OutStgArg -- See Note [Renaming during unarisation].
@@ -320,25 +360,27 @@ instance Outputable UnariseVal where
-- The id is mapped to one or more things.
-- See Note [UnariseEnv]
extendRho :: UnariseEnv -> Id -> UnariseVal -> UnariseEnv
-extendRho rho x (MultiVal args)
+extendRho env x (MultiVal args)
= assert (all (isNvUnaryType . stgArgType) args)
- extendVarEnv rho x (MultiVal args)
-extendRho rho x (UnaryVal val)
+ env { ue_rho = extendVarEnv (ue_rho env) x (MultiVal args) }
+extendRho env x (UnaryVal val)
= assert (isNvUnaryType (stgArgType val))
- extendVarEnv rho x (UnaryVal val)
+ env { ue_rho = extendVarEnv (ue_rho env) x (UnaryVal val) }
-- Properly shadow things from an outer scope.
-- See Note [UnariseEnv]
-- The id stands for itself so we don't record a mapping.
-- See Note [UnariseEnv]
extendRhoWithoutValue :: UnariseEnv -> Id -> UnariseEnv
-extendRhoWithoutValue rho x = delVarEnv rho x
+extendRhoWithoutValue env x = env { ue_rho = delVarEnv (ue_rho env) x }
+lookupRho :: UnariseEnv -> Id -> Maybe UnariseVal
+lookupRho env v = lookupVarEnv (ue_rho env) v
--------------------------------------------------------------------------------
unarise :: UniqSupply -> [StgTopBinding] -> [StgTopBinding]
-unarise us binds = initUs_ us (mapM (unariseTopBinding emptyVarEnv) binds)
+unarise us binds = initUs_ us (mapM (unariseTopBinding (initUnariseEnv emptyVarEnv)) binds)
unariseTopBinding :: UnariseEnv -> StgTopBinding -> UniqSM StgTopBinding
unariseTopBinding rho (StgTopLifted bind)
@@ -366,7 +408,7 @@ unariseRhs rho (StgRhsCon ccs con mu ts args)
unariseExpr :: UnariseEnv -> StgExpr -> UniqSM StgExpr
unariseExpr rho e@(StgApp f [])
- = case lookupVarEnv rho f of
+ = case lookupRho rho f of
Just (MultiVal args) -- Including empty tuples
-> return (mkTuple args)
Just (UnaryVal (StgVarArg f'))
@@ -379,7 +421,7 @@ unariseExpr rho e@(StgApp f [])
unariseExpr rho e@(StgApp f args)
= return (StgApp f' (unariseFunArgs rho args))
where
- f' = case lookupVarEnv rho f of
+ f' = case lookupRho rho f of
Just (UnaryVal (StgVarArg f')) -> f'
Nothing -> f
err -> pprPanic "unariseExpr - app2" (pprStgExpr panicStgPprOpts e $$ ppr err)
@@ -390,12 +432,17 @@ unariseExpr _ (StgLit l)
= return (StgLit l)
unariseExpr rho (StgConApp dc n args ty_args)
- | Just args' <- unariseMulti_maybe rho dc args ty_args
- = return (mkTuple args')
-
- | otherwise
- , let args' = unariseConArgs rho args
- = return (StgConApp dc n args' (map stgArgType args'))
+ | isUnboxedSumDataCon dc || isUnboxedTupleDataCon dc
+ = do
+ us <- getUniqueSupplyM
+ case unariseUbxSumTupleArgs rho us dc args ty_args of
+ (args', Just cast_wrapper)
+ -> return $ cast_wrapper (mkTuple args')
+ (args', Nothing)
+ -> return $ (mkTuple args')
+ | otherwise =
+ let args' = unariseConArgs rho args in
+ return $ (StgConApp dc n args' (map stgArgType args'))
unariseExpr rho (StgOpApp op args ty)
= return (StgOpApp op (unariseFunArgs rho args) ty)
@@ -403,15 +450,19 @@ unariseExpr rho (StgOpApp op args ty)
unariseExpr rho (StgCase scrut bndr alt_ty alts)
-- tuple/sum binders in the scrutinee can always be eliminated
| StgApp v [] <- scrut
- , Just (MultiVal xs) <- lookupVarEnv rho v
+ , Just (MultiVal xs) <- lookupRho rho v
= elimCase rho xs bndr alt_ty alts
-- Handle strict lets for tuples and sums:
-- case (# a,b #) of r -> rhs
-- and analogously for sums
| StgConApp dc _n args ty_args <- scrut
- , Just args' <- unariseMulti_maybe rho dc args ty_args
- = elimCase rho args' bndr alt_ty alts
+ , isUnboxedSumDataCon dc || isUnboxedTupleDataCon dc
+ = do
+ us <- getUniqueSupplyM
+ case unariseUbxSumTupleArgs rho us dc args ty_args of
+ (args',Just wrapper) -> wrapper <$> elimCase rho args' bndr alt_ty alts
+ (args',Nothing) -> elimCase rho args' bndr alt_ty alts
-- See (3) of Note [Rubbish literals] in GHC.Types.Literal
| StgLit lit <- scrut
@@ -436,17 +487,21 @@ unariseExpr rho (StgTick tick e)
= StgTick tick <$> unariseExpr rho e
-- Doesn't return void args.
-unariseMulti_maybe :: UnariseEnv -> DataCon -> [InStgArg] -> [Type] -> Maybe [OutStgArg]
-unariseMulti_maybe rho dc args ty_args
+unariseUbxSumTupleArgs :: UnariseEnv -> UniqSupply -> DataCon -> [InStgArg] -> [Type]
+ -> ( [OutStgArg] -- Arguments representing the unboxed sum
+ , Maybe (StgExpr -> StgExpr)) -- Transformation to apply to the arguments, to bring them
+ -- into the right Rep
+unariseUbxSumTupleArgs rho us dc args ty_args
| isUnboxedTupleDataCon dc
- = Just (unariseConArgs rho args)
+ = (unariseConArgs rho args, Nothing)
| isUnboxedSumDataCon dc
, let args1 = assert (isSingleton args) (unariseConArgs rho args)
- = Just (mkUbxSum dc ty_args args1)
+ = let (args2, cast_wrapper) = mkUbxSum dc ty_args args1 us
+ in (args2, Just cast_wrapper)
| otherwise
- = Nothing
+ = panic "unariseUbxSumTupleArgs: Constructor not a unboxed sum or tuple"
-- Doesn't return void args.
unariseRubbish_maybe :: Literal -> Maybe [OutStgArg]
@@ -473,15 +528,15 @@ elimCase rho args bndr (MultiValAlt _) [GenStgAlt{ alt_con = _
, alt_bndrs = bndrs
, alt_rhs = rhs}]
= do let rho1 = extendRho rho bndr (MultiVal args)
- rho2
+ (rho2, rhs')
| isUnboxedTupleBndr bndr
- = mapTupleIdBinders bndrs args rho1
+ = (mapTupleIdBinders bndrs args rho1, rhs)
| otherwise
= assert (isUnboxedSumBndr bndr) $
- if null bndrs then rho1
- else mapSumIdBinders bndrs args rho1
+ if null bndrs then (rho1, rhs)
+ else mapSumIdBinders bndrs args rhs rho1
- unariseExpr rho2 rhs
+ unariseExpr rho2 rhs'
elimCase rho args bndr (MultiValAlt _) alts
| isUnboxedSumBndr bndr
@@ -576,12 +631,12 @@ unariseSumAlt rho args GenStgAlt{ alt_con = DataAlt sumCon
, alt_bndrs = bs
, alt_rhs = e
}
- = do let rho' = mapSumIdBinders bs args rho
- lit_case = LitAlt (LitNumber LitNumInt (fromIntegral (dataConTag sumCon)))
- GenStgAlt lit_case mempty <$> unariseExpr rho' e
+ = do let (rho',e') = mapSumIdBinders bs args e rho
+ lit_case = LitAlt (LitNumber LitNumInt (fromIntegral (dataConTag sumCon)))
+ GenStgAlt lit_case mempty <$> unariseExpr rho' e'
unariseSumAlt _ scrt alt
- = pprPanic "unariseSumAlt" (ppr scrt $$ pprPanicAlt alt)
+ = pprPanic "unariseSumAlt3" (ppr scrt $$ pprPanicAlt alt)
--------------------------------------------------------------------------------
@@ -623,24 +678,75 @@ mapSumIdBinders
-- only have one binder, so this list should be a singleton)
-> [OutStgArg] -- Arguments that form the sum (NOT including the tag).
-- Can't have void args.
+ -> InStgExpr
-> UnariseEnv
- -> UnariseEnv
+ -> (UnariseEnv, OutStgExpr)
-mapSumIdBinders [id] args rho0
+mapSumIdBinders [id] args rhs rho0
= assert (not (any (isZeroBitTy . stgArgType) args)) $
let
+ -- Slots representing the whole sum
arg_slots = map primRepSlot $ concatMap (typePrimRep . stgArgType) args
+ -- The slots representing the field of the sum we bind.
id_slots = map primRepSlot $ typePrimRep (idType id)
layout1 = layoutUbxSum arg_slots id_slots
+
+ -- Arg id's which make up the field.
+ id_arg_exprs = [ args !! i | i <- layout1 ]
+ id_vars = [v | StgVarArg v <- id_arg_exprs]
+
+ update_id_type v ty
+ | (typePrimRep $ idType v) == (typePrimRep ty) = v
+ | otherwise = setIdType v ty
+
+ -- rep-based types for the field binders
+ id_tys = map primRepToType $ typePrimRep (idType id)
+ -- Arg id's with the typ set to one matching the fields rep.
+ typed_id_args = zipWithEqual "typed_id_args" (\var t -> StgVarArg (update_id_type var t)) id_vars id_tys
+ -- See Note [Casting slot arguments]
+ -- We can shadow the original argument id here since the binder for the field will only be used
+ -- at one specific type in this branch.
+ (rhs_with_casts) = foldr castArgShadow rhs $ zip id_vars id_tys
in
+ -- pprTrace "mapSumIdBinders"
+ -- (text "id_tys" <+> ppr id_tys $$
+ -- text "id_args" <+> ppr id_arg_exprs $$
+ -- text "rhs" <+> ppr rhs $$
+ -- text "rhs_with_casts" <+> ppr rhs_with_casts
+ -- ) $
if isMultiValBndr id
- then extendRho rho0 id (MultiVal [ args !! i | i <- layout1 ])
- else assert (layout1 `lengthIs` 1)
- extendRho rho0 id (UnaryVal (args !! head layout1))
+ then (extendRho rho0 id (MultiVal typed_id_args), rhs_with_casts)
+ else assert (typed_id_args `lengthIs` 1)
+ (extendRho rho0 id (UnaryVal (head typed_id_args)), rhs_with_casts)
-mapSumIdBinders ids sum_args _
+mapSumIdBinders ids sum_args _rhs _
= pprPanic "mapSumIdBinders" (ppr ids $$ ppr sum_args)
+-- Convert the argument to the given type, and wrap the conversion
+-- around the given expression.
+castArgShadow :: (Id,Type) -> StgExpr -> StgExpr
+castArgShadow (arg, fld_ty) (in_rhs) =
+ let ops = getCasts (typePrimRep1 $ idType arg) (typePrimRep1 fld_ty)
+ in foldr (mkCast (StgVarArg arg) arg) (in_rhs) ops
+
+-- Convert the argument to the given type, and wrap the conversion
+-- around the given expression. Use the given Id as a name for the
+-- converted value.
+castArgRename :: StgArg -> Id -> StgExpr -> StgExpr
+castArgRename in_arg out_id in_rhs =
+ pprTrace "castArgRename" (ppr (in_arg,out_id)) $
+ let ops = getCasts (typePrimRep1 $ stgArgType in_arg) $ typePrimRep1 (idType out_id)
+ in foldr (mkCast in_arg out_id) (in_rhs) ops
+
+-- Variable to cast, (type to cast to, result_ty), rhs
+mkCast :: StgArg -> OutId -> (PrimOp,Type) -> (StgExpr) -> (StgExpr)
+mkCast arg_in out_id (cast_op,ty2) (in_rhs) =
+ let scrut = StgOpApp (StgPrimOp cast_op) [arg_in] ty2
+ alt = GenStgAlt { alt_con = DEFAULT, alt_bndrs = [], alt_rhs = in_rhs}
+ r2 = typePrimRep1 ty2
+ alt_ty = PrimAlt r2
+ in (StgCase scrut (setIdType out_id ty2) alt_ty [alt])
+
-- | Build a unboxed sum term from arguments of an alternative.
--
-- Example, for (# x | #) :: (# (# #) | Int #) we call
@@ -655,8 +761,11 @@ mkUbxSum
:: DataCon -- Sum data con
-> [Type] -- Type arguments of the sum data con
-> [OutStgArg] -- Actual arguments of the alternative.
- -> [OutStgArg] -- Final tuple arguments
-mkUbxSum dc ty_args args0
+ -> UniqSupply
+ -> ([OutStgArg] -- Final tuple arguments
+ ,(StgExpr->StgExpr) -- We might need to cast the args first
+ )
+mkUbxSum dc ty_args args0 us
= let
(_ : sum_slots) = ubxSumRepType (map typePrimRep ty_args)
-- drop tag slot
@@ -667,16 +776,51 @@ mkUbxSum dc ty_args args0
tag_arg = StgLitArg (LitNumber LitNumInt (fromIntegral tag))
arg_idxs = IM.fromList (zipEqual "mkUbxSum" layout' args0)
- mkTupArgs :: Int -> [SlotTy] -> IM.IntMap StgArg -> [StgArg]
- mkTupArgs _ [] _
- = []
- mkTupArgs arg_idx (slot : slots_left) arg_map
- | Just stg_arg <- IM.lookup arg_idx arg_map
- = stg_arg : mkTupArgs (arg_idx + 1) slots_left arg_map
- | otherwise
- = ubxSumRubbishArg slot : mkTupArgs (arg_idx + 1) slots_left arg_map
+ ((_idx,_idx_map,_us,wrapper),slot_args)
+ = assert (length arg_idxs <= length sum_slots ) $
+ mapAccumL mkTupArg (0,arg_idxs,us,id) sum_slots
+
+ mkTupArg :: (Int, IM.IntMap StgArg,UniqSupply,StgExpr->StgExpr)
+ -> SlotTy
+ -> ((Int,IM.IntMap StgArg,UniqSupply,StgExpr->StgExpr), StgArg)
+ mkTupArg (arg_idx, arg_map, us, wrapper) slot
+ | Just stg_arg <- IM.lookup arg_idx arg_map
+ = case castArg us slot stg_arg of
+ Just (casted_arg,us',wrapper') ->
+ ( (arg_idx+1, arg_map, us', wrapper')
+ , casted_arg)
+ Nothing ->
+ ( (arg_idx+1, arg_map, us, wrapper)
+ , stg_arg)
+ | otherwise
+ = ( (arg_idx+1, arg_map, us, wrapper)
+ , ubxSumRubbishArg slot)
+
+ castArg :: UniqSupply -> SlotTy -> StgArg -> Maybe (StgArg,UniqSupply,StgExpr -> StgExpr)
+ castArg us slot_ty arg
+ -- Cast the argument to the type of the slot if required
+ | slotPrimRep slot_ty /= typePrimRep1 (stgArgType arg)
+ = let (u1,us') = takeUniqFromSupply us
+ -- cast_ops = getCasts (typePrimRep1 $ idType arg_id) (slotPrimRep slot_ty)
+ out_ty = primRepToType $ slotPrimRep slot_ty
+ out_name_fs
+ | (StgVarArg v_arg) <- arg
+ = getOccFS v_arg `appendFS` fsLit "_cst"
+ | otherwise = fsLit "cst_lit"
+ out_id = mkSysLocal out_name_fs u1 Many out_ty :: Id
+ casts = castArgRename arg out_id :: StgExpr -> StgExpr
+ in Just (arg,us',casts)
+ -- No need for casting
+ | otherwise = Nothing
+
+ tup_args = tag_arg : slot_args
in
- tag_arg : mkTupArgs 0 sum_slots arg_idxs
+ -- pprTrace "mkUbxSum" (
+ -- text "ty_args (slots)" <+> ppr ty_args $$
+ -- text "args0" <+> ppr args0 $$
+ -- text "wrapper" <+>
+ -- (ppr $ wrapper $ StgLit $ LitChar '_')
+ (tup_args, wrapper)
-- | Return a rubbish value for the given slot type.
@@ -787,7 +931,7 @@ unariseArgBinder is_con_arg rho x =
-- | MultiVal a function argument. Never returns an empty list.
unariseFunArg :: UnariseEnv -> StgArg -> [StgArg]
unariseFunArg rho (StgVarArg x) =
- case lookupVarEnv rho x of
+ case lookupRho rho x of
Just (MultiVal []) -> [voidArg] -- NB: do not remove void args
Just (MultiVal as) -> as
Just (UnaryVal arg) -> [arg]
@@ -809,7 +953,7 @@ unariseFunArgBinder = unariseArgBinder False
-- | MultiVal a DataCon argument. Returns an empty list when argument is void.
unariseConArg :: UnariseEnv -> InStgArg -> [OutStgArg]
unariseConArg rho (StgVarArg x) =
- case lookupVarEnv rho x of
+ case lookupRho rho x of
Just (UnaryVal arg) -> [arg]
Just (MultiVal as) -> as -- 'as' can be empty
Nothing
=====================================
compiler/GHC/Types/RepType.hs
=====================================
@@ -245,7 +245,8 @@ ubxSumRepType constrs0
in
sumRep
-layoutUbxSum :: SortedSlotTys -- Layout of sum. Does not include tag.
+layoutUbxSum :: HasDebugCallStack
+ => SortedSlotTys -- Layout of sum. Does not include tag.
-- We assume that they are in increasing order
-> [SlotTy] -- Slot types of things we want to map to locations in the
-- sum layout
@@ -268,7 +269,8 @@ layoutUbxSum sum_slots0 arg_slots0 =
| otherwise
= findSlot arg (slot_idx + 1) slots useds
findSlot _ _ [] _
- = pprPanic "findSlot" (text "Can't find slot" $$ ppr sum_slots0 $$ ppr arg_slots0)
+ = pprPanic "findSlot" (text "Can't find slot" $$ text "sum_slots:" <> ppr sum_slots0
+ $$ text "arg_slots:" <> ppr arg_slots0 )
--------------------------------------------------------------------------------
=====================================
compiler/GHC/Utils/Outputable.hs
=====================================
@@ -387,6 +387,7 @@ data SDocContext = SDC
, sdocSuppressUniques :: !Bool
, sdocSuppressModulePrefixes :: !Bool
, sdocSuppressStgExts :: !Bool
+ , sdocSuppressStgReps :: !Bool
, sdocErrorSpans :: !Bool
, sdocStarIsType :: !Bool
, sdocLinearTypes :: !Bool
@@ -447,6 +448,7 @@ defaultSDocContext = SDC
, sdocSuppressUniques = False
, sdocSuppressModulePrefixes = False
, sdocSuppressStgExts = False
+ , sdocSuppressStgReps = True
, sdocErrorSpans = False
, sdocStarIsType = False
, sdocLinearTypes = False
=====================================
compiler/ghc.cabal.in
=====================================
@@ -168,6 +168,7 @@ Library
GHC.Builtin.Names
GHC.Builtin.Names.TH
GHC.Builtin.PrimOps
+ GHC.Builtin.PrimOps.Casts
GHC.Builtin.PrimOps.Ids
GHC.Builtin.Types
GHC.Builtin.Types.Literals
=====================================
docs/users_guide/debugging.rst
=====================================
@@ -946,6 +946,16 @@ parts that you are not interested in.
Suppress the printing of core size stats per binding
+.. ghc-flag:: -dsuppress-stg-reps
+ :shortdesc: Suppress rep annotations on STG args.
+ :type: dynamic
+
+ :since: 9.6.1
+
+ default: enabled
+
+ Disabling this will annoate certain stg arguments with their prim rep.
+
.. _checking-consistency:
=====================================
testsuite/driver/testlib.py
=====================================
@@ -1447,7 +1447,8 @@ def compile_cmp_asm(name: TestName,
ext: str,
extra_hc_opts: str
) -> PassFail:
- print('Compile only, extra args = ', extra_hc_opts)
+ if extra_hc_opts:
+ print('Compile only, extra args = ', extra_hc_opts)
result = simple_build(name + '.' + ext, way, '-keep-s-files -O ' + extra_hc_opts, False, None, [], False, False)
if badResult(result):
@@ -1474,7 +1475,8 @@ def compile_grep_asm(name: TestName,
is_substring: bool,
extra_hc_opts: str
) -> PassFail:
- print('Compile only, extra args = ', extra_hc_opts)
+ if extra_hc_opts:
+ print('Compile and grep asm, extra args = ', extra_hc_opts)
result = simple_build(name + '.' + ext, way, '-keep-s-files -O ' + extra_hc_opts, False, None, [], False, False)
if badResult(result):
@@ -1495,7 +1497,8 @@ def compile_grep_core(name: TestName,
way: WayName,
extra_hc_opts: str
) -> PassFail:
- print('Compile only, extra args = ', extra_hc_opts)
+ if extra_hc_opts:
+ print('Compile only, extra args = ', extra_hc_opts)
result = simple_build(name + '.hs', way, '-ddump-to-file -dsuppress-all -ddump-simpl -O ' + extra_hc_opts, False, None, [], False, False)
if badResult(result):
=====================================
testsuite/tests/unboxedsums/T22208.hs
=====================================
@@ -0,0 +1,41 @@
+{-# LANGUAGE MagicHash #-}
+{-# LANGUAGE UnboxedSums #-}
+{-# LANGUAGE UnboxedTuples #-}
+module M where
+
+import GHC.Base
+
+-- Reproducer from #22208
+foo :: (# Float# | Double# #) -> (# Float# | Float #)
+foo (# x | #) = (# x | #)
+bar :: (# Word# | Int64# #) -> (# Double# | Word# #)
+bar (# y | #) = let x = y in (# | x #)
+baz :: (# Word# | Word64# #) -> (# Word# | (##) #)
+baz (# x | #) = (# x | #)
+
+foo1 :: (# Float# | Double# #) -> (# Float# | Float #)
+foo1 (# x | #) = (# x | #)
+bar1 :: (# Word# | Int64# #) -> (# Double# | Word# #)
+bar1 (# y | #) = let x = y in (# | x #)
+baz1 :: (# Word# | Word64# #) -> (# Word# | (##) #)
+baz1 (# x | #) = (# x | #)
+
+-- i8 value from w64 slot
+baz2 :: (# Int8# | Word64# #) -> (# Int8# | (##) #)
+baz2 (# x | #) = (# x | #)
+
+-- w8 value from w64 slot
+baz3 :: (# Word8# | Word64# #) -> (# Word8# | (##) #)
+baz3 (# x | #) = (# x | #)
+
+-- w8 from w slot
+baz4 :: (# Word8# | Word# #) -> (# Word8# | (##) #)
+baz4 (# x | #) = (# x | #)
+
+-- w from w slot
+baz5 :: (# Word8# | Word# #) -> (# Word# | (##) #)
+baz5 (# | x #) = (# x | #)
+
+-- addr from w slot
+baz6 :: (# Addr# | Word# #) -> (# Addr# | (##) #)
+baz6 (# x | #) = (# x | #)
\ No newline at end of file
=====================================
testsuite/tests/unboxedsums/all.T
=====================================
@@ -35,3 +35,4 @@ test('T20858b', [extra_files(['T20858.hs'])
,extra_hc_opts("-fprint-explicit-runtime-reps -fprint-explicit-kinds")]
, ghci_script, ['T20858b.script'])
test('T20859', normal, compile, [''])
+test('T22208', normal, compile, ['-dstg-lint -dcmm-lint'])
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/4f859687ee1fcecf6cdae66dd25a15b4f168128a
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/4f859687ee1fcecf6cdae66dd25a15b4f168128a
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