import Data.List ( intersperse, sortBy, zip4, zip6, partition )
import Foreign ( Ptr, castPtr, mallocBytes, pokeByteOff, Word8,
- withForeignPtr, castFunPtrToPtr )
-import Foreign.C ( CInt )
+ withForeignPtr, castFunPtrToPtr, nullPtr, plusPtr )
+import Foreign.C
import Control.Exception ( throwDyn )
import GHC.Exts ( Int(..), ByteArray# )
import Control.Monad ( when )
import Data.Char ( ord, chr )
+import UniqSupply
+import BreakArray
+import Data.Maybe
+import Module
+import IdInfo
+
-- -----------------------------------------------------------------------------
-- Generating byte code for a complete module
byteCodeGen :: DynFlags
-> [CoreBind]
-> [TyCon]
+ -> ModBreaks
-> IO CompiledByteCode
-byteCodeGen dflags binds tycs
+byteCodeGen dflags binds tycs modBreaks
= do showPass dflags "ByteCodeGen"
let flatBinds = [ (bndr, freeVars rhs)
| (bndr, rhs) <- flattenBinds binds]
- (BcM_State final_ctr mallocd, proto_bcos)
- <- runBc (mapM schemeTopBind flatBinds)
+ us <- mkSplitUniqSupply 'y'
+ (BcM_State _us final_ctr mallocd _, proto_bcos)
+ <- runBc us modBreaks (mapM schemeTopBind flatBinds)
when (notNull mallocd)
(panic "ByteCodeGen.byteCodeGen: missing final emitBc?")
let invented_name = mkSystemVarName (mkPseudoUniqueE 0) FSLIT("ExprTopLevel")
invented_id = Id.mkLocalId invented_name (panic "invented_id's type")
- (BcM_State final_ctr mallocd, proto_bco)
- <- runBc (schemeTopBind (invented_id, freeVars expr))
+ -- the uniques are needed to generate fresh variables when we introduce new
+ -- let bindings for ticked expressions
+ us <- mkSplitUniqSupply 'y'
+ (BcM_State _us final_ctr mallocd _ , proto_bco)
+ <- runBc us emptyModBreaks (schemeTopBind (invented_id, freeVars expr))
when (notNull mallocd)
(panic "ByteCodeGen.coreExprToBCOs: missing final emitBc?")
-> Bool -- True <=> is a return point, rather than a function
-> [BcPtr]
-> ProtoBCO name
-mkProtoBCO nm instrs_ordlist origin arity bitmap_size bitmap
- is_ret mallocd_blocks
+mkProtoBCO nm instrs_ordlist origin arity bitmap_size bitmap is_ret mallocd_blocks
= ProtoBCO {
protoBCOName = nm,
protoBCOInstrs = maybe_with_stack_check,
schemeTopBind :: (Id, AnnExpr Id VarSet) -> BcM (ProtoBCO Name)
-schemeTopBind (id, rhs)
+schemeTopBind (id, rhs)
| Just data_con <- isDataConWorkId_maybe id,
- isNullaryRepDataCon data_con
- = -- Special case for the worker of a nullary data con.
+ isNullaryRepDataCon data_con = do
+ -- Special case for the worker of a nullary data con.
-- It'll look like this: Nil = /\a -> Nil a
-- If we feed it into schemeR, we'll get
-- Nil = Nil
-- because mkConAppCode treats nullary constructor applications
-- by just re-using the single top-level definition. So
-- for the worker itself, we must allocate it directly.
+ -- ioToBc (putStrLn $ "top level BCO")
emitBc (mkProtoBCO (getName id) (toOL [PACK data_con 0, ENTER])
- (Right rhs) 0 0 [{-no bitmap-}] False{-not alts-})
+ (Right rhs) 0 0 [{-no bitmap-}] False{-not alts-})
| otherwise
= schemeR [{- No free variables -}] (id, rhs)
+
-- -----------------------------------------------------------------------------
-- schemeR
-- top-level things, which have no free vars.
-> (Id, AnnExpr Id VarSet)
-> BcM (ProtoBCO Name)
-schemeR fvs (nm, rhs)
+schemeR fvs (nm, rhs)
{-
| trace (showSDoc (
(char ' '
-}
= schemeR_wrk fvs nm rhs (collect [] rhs)
+collect :: [Var] -> AnnExpr Id VarSet -> ([Var], AnnExpr' Id VarSet)
collect xs (_, AnnNote note e) = collect xs e
collect xs (_, AnnCast e _) = collect xs e
collect xs (_, AnnLam x e) = collect (if isTyVar x then xs else (x:xs)) e
collect xs (_, not_lambda) = (reverse xs, not_lambda)
+schemeR_wrk :: [Id] -> Id -> AnnExpr Id VarSet -> ([Var], AnnExpr' Var VarSet) -> BcM (ProtoBCO Name)
schemeR_wrk fvs nm original_body (args, body)
= let
all_args = reverse args ++ fvs
bitmap_size = length bits
bitmap = mkBitmap bits
in do
- body_code <- schemeE szw_args 0 p_init body
+ body_code <- schemeER_wrk szw_args p_init body
+
emitBc (mkProtoBCO (getName nm) body_code (Right original_body)
arity bitmap_size bitmap False{-not alts-})
+-- introduce break instructions for ticked expressions
+schemeER_wrk :: Int -> BCEnv -> AnnExpr' Id VarSet -> BcM BCInstrList
+schemeER_wrk d p rhs
+ | Just (tickInfo, (_annot, newRhs)) <- isTickedExp' rhs = do
+ code <- schemeE d 0 p newRhs
+ arr <- getBreakArray
+ let idOffSets = getVarOffSets d p tickInfo
+ let tickNumber = tickInfo_number tickInfo
+ let breakInfo = BreakInfo
+ { breakInfo_module = tickInfo_module tickInfo
+ , breakInfo_number = tickNumber
+ , breakInfo_vars = idOffSets
+ , breakInfo_resty = exprType (deAnnotate' newRhs)
+ }
+ let breakInstr = case arr of (BA arr#) -> BRK_FUN arr# tickNumber breakInfo
+ return $ breakInstr `consOL` code
+ | otherwise = schemeE d 0 p rhs
+
+getVarOffSets :: Int -> BCEnv -> TickInfo -> [(Id, Int)]
+getVarOffSets d p = catMaybes . map (getOffSet d p) . tickInfo_locals
+
+getOffSet :: Int -> BCEnv -> Id -> Maybe (Id, Int)
+getOffSet d env id
+ = case lookupBCEnv_maybe env id of
+ Nothing -> Nothing
+ Just offset -> Just (id, d - offset)
fvsToEnv :: BCEnv -> VarSet -> [Id]
-- Takes the free variables of a right-hand side, and
-- -----------------------------------------------------------------------------
-- schemeE
+data TickInfo
+ = TickInfo
+ { tickInfo_number :: Int -- the (module) unique number of the tick
+ , tickInfo_module :: Module -- the origin of the ticked expression
+ , tickInfo_locals :: [Id] -- the local vars in scope at the ticked expression
+ }
+
+instance Outputable TickInfo where
+ ppr info = text "TickInfo" <+>
+ parens (int (tickInfo_number info) <+> ppr (tickInfo_module info) <+>
+ ppr (tickInfo_locals info))
+
-- Compile code to apply the given expression to the remaining args
-- on the stack, returning a HNF.
schemeE :: Int -> Sequel -> BCEnv -> AnnExpr' Id VarSet -> BcM BCInstrList
thunk_codes <- sequence compile_binds
return (alloc_code `appOL` concatOL thunk_codes `appOL` body_code)
-
+-- introduce a let binding for a ticked case expression. This rule
+-- *should* only fire when the expression was not already let-bound
+-- (the code gen for let bindings should take care of that). Todo: we
+-- call exprFreeVars on a deAnnotated expression, this may not be the
+-- best way to calculate the free vars but it seemed like the least
+-- intrusive thing to do
+schemeE d s p exp@(AnnCase {})
+ | Just (tickInfo,rhs) <- isTickedExp' exp
+ = if isUnLiftedType ty
+ then schemeE d s p (snd rhs)
+ else do
+ id <- newId ty
+ -- Todo: is emptyVarSet correct on the next line?
+ let letExp = AnnLet (AnnNonRec id (fvs, exp)) (emptyVarSet, AnnVar id)
+ schemeE d s p letExp
+ where exp' = deAnnotate' exp
+ fvs = exprFreeVars exp'
+ ty = exprType exp'
schemeE d s p (AnnCase scrut bndr _ [(DataAlt dc, [bind1, bind2], rhs)])
| isUnboxedTupleCon dc, VoidArg <- typeCgRep (idType bind1)
-- envt (it won't be bound now) because we never look such things up.
= --trace "automagic mashing of case alts (# VoidArg, a #)" $
- doCase d s p scrut bind2 [(DEFAULT, [], rhs)] True{-unboxed tuple-}
+ doCase d s p scrut bind2 [(DEFAULT, [], rhs)] True{-unboxed tuple-}
| isUnboxedTupleCon dc, VoidArg <- typeCgRep (idType bind2)
= --trace "automagic mashing of case alts (# a, VoidArg #)" $
- doCase d s p scrut bind1 [(DEFAULT, [], rhs)] True{-unboxed tuple-}
+ doCase d s p scrut bind1 [(DEFAULT, [], rhs)] True{-unboxed tuple-}
schemeE d s p (AnnCase scrut bndr _ [(DataAlt dc, [bind1], rhs)])
| isUnboxedTupleCon dc
-- to
-- case .... of a { DEFAULT -> ... }
= --trace "automagic mashing of case alts (# a #)" $
- doCase d s p scrut bind1 [(DEFAULT, [], rhs)] True{-unboxed tuple-}
+ doCase d s p scrut bind1 [(DEFAULT, [], rhs)] True{-unboxed tuple-}
schemeE d s p (AnnCase scrut bndr _ alts)
- = doCase d s p scrut bndr alts False{-not an unboxed tuple-}
+ = doCase d s p scrut bndr alts False{-not an unboxed tuple-}
schemeE d s p (AnnNote note (_, body))
= schemeE d s p body
= pprPanic "ByteCodeGen.schemeE: unhandled case"
(pprCoreExpr (deAnnotate' other))
+{-
+ Ticked Expressions
+ ------------------
+
+ A ticked expression looks like this:
+
+ case tick<n> var1 ... varN of DEFAULT -> e
+
+ (*) <n> is the number of the tick, which is unique within a module
+ (*) var1 ... varN are the local variables in scope at the tick site
+
+ If we find a ticked expression we return:
+
+ Just ((n, [var1 ... varN]), e)
+
+ otherwise we return Nothing.
+
+ The idea is that the "case tick<n> ..." is really just an annotation on
+ the code. When we find such a thing, we pull out the useful information,
+ and then compile the code as if it was just the expression "e".
+
+-}
+
+isTickedExp :: AnnExpr Id a -> Maybe (TickInfo, AnnExpr Id a)
+isTickedExp (annot, expr) = isTickedExp' expr
+
+isTickedExp' :: AnnExpr' Id a -> Maybe (TickInfo, AnnExpr Id a)
+isTickedExp' (AnnCase scrut _bndr _type alts)
+ | Just tickInfo <- isTickedScrut scrut,
+ [(DEFAULT, _bndr, rhs)] <- alts
+ = Just (tickInfo, rhs)
+ where
+ isTickedScrut :: (AnnExpr Id a) -> Maybe TickInfo
+ isTickedScrut expr
+ | Var id <- f,
+ Just (TickBox modName tickNumber) <- isTickBoxOp_maybe id
+ = Just $ TickInfo { tickInfo_number = tickNumber
+ , tickInfo_module = modName
+ , tickInfo_locals = idsOfArgs args
+ }
+ | otherwise = Nothing
+ where
+ (f, args) = collectArgs $ deAnnotate expr
+ idsOfArgs :: [Expr Id] -> [Id]
+ idsOfArgs = catMaybes . map exprId
+ exprId :: Expr Id -> Maybe Id
+ exprId (Var id) = Just id
+ exprId other = Nothing
+
+isTickedExp' other = Nothing
-- Compile code to do a tail call. Specifically, push the fn,
-- slide the on-stack app back down to the sequel depth,
-> AnnExpr Id VarSet -> Id -> [AnnAlt Id VarSet]
-> Bool -- True <=> is an unboxed tuple case, don't enter the result
-> BcM BCInstrList
-doCase d s p (_,scrut)
- bndr alts is_unboxed_tuple
+doCase d s p (_,scrut) bndr alts is_unboxed_tuple
= let
-- Top of stack is the return itbl, as usual.
-- underneath it is the pointer to the alt_code BCO.
isAlgCase = not (isUnLiftedType bndr_ty) && not is_unboxed_tuple
-- given an alt, return a discr and code for it.
- codeALt alt@(DEFAULT, _, (_,rhs))
+ codeAlt alt@(DEFAULT, _, (_,rhs))
= do rhs_code <- schemeE d_alts s p_alts rhs
return (NoDiscr, rhs_code)
+
codeAlt alt@(discr, bndrs, (_,rhs))
-- primitive or nullary constructor alt: no need to UNPACK
| null real_bndrs = do
where
real_bndrs = filter (not.isTyVar) bndrs
-
my_discr (DEFAULT, binds, rhs) = NoDiscr {-shouldn't really happen-}
my_discr (DataAlt dc, binds, rhs)
| isUnboxedTupleCon dc
in do
alt_stuff <- mapM codeAlt alts
alt_final <- mkMultiBranch maybe_ncons alt_stuff
+
let
alt_bco_name = getName bndr
alt_bco = mkProtoBCO alt_bco_name alt_final (Left alts)
(pprCoreExpr (deAnnotate (undefined, other)))
foreign import ccall unsafe "memcpy"
- memcpy :: Ptr a -> Ptr b -> CInt -> IO ()
+ memcpy :: Ptr a -> Ptr b -> CSize -> IO ()
-- -----------------------------------------------------------------------------
idSizeW :: Id -> Int
idSizeW id = cgRepSizeW (typeCgRep (idType id))
+-- See bug #1257
unboxedTupleException :: a
unboxedTupleException
= throwDyn
- (Panic
- ("Bytecode generator can't handle unboxed tuples. Possibly due\n" ++
- "\tto foreign import/export decls in source. Workaround:\n" ++
- "\tcompile this module to a .o file, then restart session."))
+ (ProgramError
+ ("Error: bytecode compiler can't handle unboxed tuples.\n"++
+ " Possibly due to foreign import/export decls in source.\n"++
+ " Workaround: use -fobject-code, or compile this module to .o separately."))
mkSLIDE n d = if d == 0 then nilOL else unitOL (SLIDE n d)
data BcM_State
= BcM_State {
+ uniqSupply :: UniqSupply, -- for generating fresh variable names
nextlabel :: Int, -- for generating local labels
- malloced :: [BcPtr] } -- thunks malloced for current BCO
+ malloced :: [BcPtr], -- thunks malloced for current BCO
-- Should be free()d when it is GCd
+ breakArray :: BreakArray -- array of breakpoint flags
+ }
newtype BcM r = BcM (BcM_State -> IO (BcM_State, r))
x <- io
return (st, x)
-runBc :: BcM r -> IO (BcM_State, r)
-runBc (BcM m) = m (BcM_State 0 [])
+runBc :: UniqSupply -> ModBreaks -> BcM r -> IO (BcM_State, r)
+runBc us modBreaks (BcM m)
+ = m (BcM_State us 0 [] breakArray)
+ where
+ breakArray = modBreaks_flags modBreaks
thenBc :: BcM a -> (a -> BcM b) -> BcM b
thenBc (BcM expr) cont = BcM $ \st0 -> do
getLabelsBc n
= BcM $ \st -> let ctr = nextlabel st
in return (st{nextlabel = ctr+n}, [ctr .. ctr+n-1])
+
+getBreakArray :: BcM BreakArray
+getBreakArray = BcM $ \st -> return (st, breakArray st)
+
+newUnique :: BcM Unique
+newUnique = BcM $
+ \st -> case splitUniqSupply (uniqSupply st) of
+ (us1, us2) -> let newState = st { uniqSupply = us2 }
+ in return (newState, uniqFromSupply us1)
+
+newId :: Type -> BcM Id
+newId ty = do
+ uniq <- newUnique
+ return $ mkSysLocal FSLIT("ticked") uniq ty
\end{code}