the STG paper.
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module ClosureInfo (
ClosureInfo(..), LambdaFormInfo(..), -- would be abstract but
StandardFormInfo(..), -- mkCmmInfo looks inside
mkLFThunk, mkLFReEntrant, mkConLFInfo, mkSelectorLFInfo,
mkApLFInfo, mkLFImported, mkLFArgument, mkLFLetNoEscape,
- mkClosureInfo, mkConInfo,
+ mkClosureInfo, mkConInfo, maybeIsLFCon,
closureSize, closureNonHdrSize,
closureGoodStuffSize, closurePtrsSize,
slopSize,
closureName, infoTableLabelFromCI,
- closureLabelFromCI, closureSRT,
+ closureLabelFromCI,
closureLFInfo, isLFThunk,closureSMRep, closureUpdReqd,
closureNeedsUpdSpace, closureIsThunk,
closureSingleEntry, closureReEntrant, isConstrClosure_maybe,
closureFunInfo, isStandardFormThunk, isKnownFun,
+ funTag, funTagLFInfo, tagForArity,
enterIdLabel, enterLocalIdLabel, enterReturnPtLabel,
closureValDescr, closureTypeDescr, -- profiling
isStaticClosure,
- cafBlackHoleClosureInfo, seCafBlackHoleClosureInfo,
+ cafBlackHoleClosureInfo,
staticClosureNeedsLink,
) where
#include "../includes/MachDeps.h"
#include "HsVersions.h"
+--import CgUtils
import StgSyn
import SMRep
import PackageConfig
import StaticFlags
import Id
+import IdInfo
import DataCon
import Name
import OccName
-- the constructor's info table), and they don't have an SRT.
| ConInfo {
closureCon :: !DataCon,
- closureSMRep :: !SMRep,
- closureDllCon :: !Bool -- is in a separate DLL
+ closureSMRep :: !SMRep
}
-- C_SRT is what StgSyn.SRT gets translated to...
data C_SRT = NoC_SRT
| C_SRT !CLabel !WordOff !StgHalfWord {-bitmap or escape-}
+ deriving (Eq)
needsSRT :: C_SRT -> Bool
needsSRT NoC_SRT = False
needsSRT (C_SRT _ _ _) = True
instance Outputable C_SRT where
- ppr (NoC_SRT) = ptext SLIT("_no_srt_")
+ ppr (NoC_SRT) = ptext (sLit "_no_srt_")
ppr (C_SRT label off bitmap) = parens (ppr label <> comma <> ppr off <> comma <> text (show bitmap))
\end{code}
mkConLFInfo :: DataCon -> LambdaFormInfo
mkConLFInfo con = LFCon con
+maybeIsLFCon :: LambdaFormInfo -> Maybe DataCon
+maybeIsLFCon (LFCon con) = Just con
+maybeIsLFCon _ = Nothing
+
mkSelectorLFInfo id offset updatable
= LFThunk NotTopLevel False updatable (SelectorThunk offset)
(might_be_a_function (idType id))
name = idName id
sm_rep = chooseSMRep is_static lf_info tot_wds ptr_wds
-mkConInfo :: PackageId
- -> Bool -- Is static
+mkConInfo :: Bool -- Is static
-> DataCon
-> Int -> Int -- Total and pointer words
-> ClosureInfo
-mkConInfo this_pkg is_static data_con tot_wds ptr_wds
+mkConInfo is_static data_con tot_wds ptr_wds
= ConInfo { closureSMRep = sm_rep,
- closureCon = data_con,
- closureDllCon = isDllName this_pkg (dataConName data_con) }
+ closureCon = data_con }
where
sm_rep = chooseSMRep is_static (mkConLFInfo data_con) tot_wds ptr_wds
\end{code}
CLabel -- The code label
Int -- Its arity
-getCallMethod :: PackageId
- -> Name -- Function being applied
+getCallMethod :: Name -- Function being applied
+ -> CafInfo -- Can it refer to CAF's?
-> LambdaFormInfo -- Its info
-> Int -- Number of available arguments
-> CallMethod
-getCallMethod this_pkg name lf_info n_args
+getCallMethod name _ lf_info n_args
| nodeMustPointToIt lf_info && opt_Parallel
= -- If we're parallel, then we must always enter via node.
-- The reason is that the closure may have been
-- fetched since we allocated it.
EnterIt
-getCallMethod this_pkg name (LFReEntrant _ arity _ _) n_args
+getCallMethod name caf (LFReEntrant _ arity _ _) n_args
| n_args == 0 = ASSERT( arity /= 0 )
ReturnIt -- No args at all
| n_args < arity = SlowCall -- Not enough args
- | otherwise = DirectEntry (enterIdLabel this_pkg name) arity
+ | otherwise = DirectEntry (enterIdLabel name caf) arity
-getCallMethod this_pkg name (LFCon con) n_args
+getCallMethod name _ (LFCon con) n_args
= ASSERT( n_args == 0 )
ReturnCon con
-getCallMethod this_pkg name (LFThunk _ _ updatable std_form_info is_fun) n_args
- | is_fun -- *Might* be a function, so we must "call" it (which is always safe)
+getCallMethod name caf (LFThunk _ _ updatable std_form_info is_fun) n_args
+ | is_fun -- it *might* be a function, so we must "call" it (which is
+ -- always safe)
= SlowCall -- We cannot just enter it [in eval/apply, the entry code
-- is the fast-entry code]
| otherwise -- Jump direct to code for single-entry thunks
= ASSERT( n_args == 0 )
- JumpToIt (thunkEntryLabel this_pkg name std_form_info updatable)
+ JumpToIt (thunkEntryLabel name caf std_form_info updatable)
-getCallMethod this_pkg name (LFUnknown True) n_args
- = SlowCall -- might be a function
+getCallMethod name _ (LFUnknown True) n_args
+ = SlowCall -- Might be a function
-getCallMethod this_pkg name (LFUnknown False) n_args
- = ASSERT2 ( n_args == 0, ppr name <+> ppr n_args )
- EnterIt -- Not a function
+getCallMethod name _ (LFUnknown False) n_args
+ | n_args > 0
+ = WARN( True, ppr name <+> ppr n_args )
+ SlowCall -- Note [Unsafe coerce complications]
+
+ | otherwise
+ = EnterIt -- Not a function
-getCallMethod this_pkg name (LFBlackHole _) n_args
+getCallMethod name _ (LFBlackHole _) n_args
= SlowCall -- Presumably the black hole has by now
-- been updated, but we don't know with
-- what, so we slow call it
-getCallMethod this_pkg name (LFLetNoEscape 0) n_args
+getCallMethod name _ (LFLetNoEscape 0) n_args
= JumpToIt (enterReturnPtLabel (nameUnique name))
-getCallMethod this_pkg name (LFLetNoEscape arity) n_args
+getCallMethod name _ (LFLetNoEscape arity) n_args
| n_args == arity = DirectEntry (enterReturnPtLabel (nameUnique name)) arity
| otherwise = pprPanic "let-no-escape: " (ppr name <+> ppr arity)
isKnownFun _ = False
\end{code}
+Note [Unsafe coerce complications]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+In some (badly-optimised) DPH code we see this
+ Module X: rr :: Int = error Int "Urk"
+ Module Y: ...((X.rr |> g) True) ...
+ where g is an (unsafe) coercion of kind (Int ~ Bool->Bool), say
+
+It's badly optimised, because knowing that 'X.rr' is bottom, we should
+have dumped the application to True. But it should still work. These
+strange unsafe coercions arise from the case-of-error transformation:
+ (case (error Int "foo") of { ... }) True
+---> (error Int "foo" |> g) True
+
+Anyway, the net effect is that in STG-land, when casts are discarded,
+we *can* see a value of type Int applied to an argument. This only happens
+if (a) the programmer made a mistake, or (b) the value of type Int is
+actually bottom.
+
+So it's wrong to trigger an ASSERT failure in this circumstance. Instead
+we now emit a WARN -- mainly to draw attention to a probably-badly-optimised
+program fragment -- and do the conservative thing which is SlowCall.
+
+
-----------------------------------------------------------------------------
SRT-related stuff
isConstrClosure_maybe _ = Nothing
closureFunInfo :: ClosureInfo -> Maybe (Int, ArgDescr)
-closureFunInfo (ClosureInfo { closureLFInfo = LFReEntrant _ arity _ arg_desc})
- = Just (arity, arg_desc)
-closureFunInfo _
- = Nothing
+closureFunInfo (ClosureInfo { closureLFInfo = lf_info }) = lfFunInfo lf_info
+closureFunInfo _ = Nothing
+
+lfFunInfo :: LambdaFormInfo -> Maybe (Int, ArgDescr)
+lfFunInfo (LFReEntrant _ arity _ arg_desc) = Just (arity, arg_desc)
+lfFunInfo _ = Nothing
+
+funTag :: ClosureInfo -> Int
+funTag (ClosureInfo { closureLFInfo = lf_info }) = funTagLFInfo lf_info
+funTag _ = 0
+
+-- maybe this should do constructor tags too?
+funTagLFInfo :: LambdaFormInfo -> Int
+funTagLFInfo lf
+ -- A function is tagged with its arity
+ | Just (arity,_) <- lfFunInfo lf,
+ Just tag <- tagForArity arity
+ = tag
+
+ -- other closures (and unknown ones) are not tagged
+ | otherwise
+ = 0
+
+tagForArity :: Int -> Maybe Int
+tagForArity i | i <= mAX_PTR_TAG = Just i
+ | otherwise = Nothing
\end{code}
\begin{code}
Label generation.
\begin{code}
-infoTableLabelFromCI :: ClosureInfo -> CLabel
+infoTableLabelFromCI :: ClosureInfo -> CafInfo -> CLabel
infoTableLabelFromCI (ClosureInfo { closureName = name,
closureLFInfo = lf_info,
- closureSMRep = rep })
+ closureSMRep = rep }) caf
= case lf_info of
LFBlackHole info -> info
LFThunk _ _ upd_flag (ApThunk arity) _ ->
mkApInfoTableLabel upd_flag arity
- LFThunk{} -> mkLocalInfoTableLabel name
+ LFThunk{} -> mkLocalInfoTableLabel name caf
- LFReEntrant _ _ _ _ -> mkLocalInfoTableLabel name
+ LFReEntrant _ _ _ _ -> mkLocalInfoTableLabel name caf
other -> panic "infoTableLabelFromCI"
infoTableLabelFromCI (ConInfo { closureCon = con,
- closureSMRep = rep,
- closureDllCon = dll })
- | isStaticRep rep = mkStaticInfoTableLabel name dll
- | otherwise = mkConInfoTableLabel name dll
+ closureSMRep = rep }) caf
+ | isStaticRep rep = mkStaticInfoTableLabel name caf
+ | otherwise = mkConInfoTableLabel name caf
where
name = dataConName con
-- ClosureInfo for a closure (as opposed to a constructor) is always local
-closureLabelFromCI (ClosureInfo { closureName = nm }) = mkLocalClosureLabel nm
-closureLabelFromCI _ = panic "closureLabelFromCI"
+closureLabelFromCI (ClosureInfo { closureName = nm }) caf = mkLocalClosureLabel nm caf
+closureLabelFromCI _ _ = panic "closureLabelFromCI"
-- thunkEntryLabel is a local help function, not exported. It's used from both
-- entryLabelFromCI and getCallMethod.
-thunkEntryLabel this_pkg thunk_id (ApThunk arity) is_updatable
+thunkEntryLabel thunk_id _ (ApThunk arity) is_updatable
= enterApLabel is_updatable arity
-thunkEntryLabel this_pkg thunk_id (SelectorThunk offset) upd_flag
+thunkEntryLabel thunk_id _ (SelectorThunk offset) upd_flag
= enterSelectorLabel upd_flag offset
-thunkEntryLabel this_pkg thunk_id _ is_updatable
- = enterIdLabel this_pkg thunk_id
+thunkEntryLabel thunk_id caf _ is_updatable
+ = enterIdLabel thunk_id caf
enterApLabel is_updatable arity
| tablesNextToCode = mkApInfoTableLabel is_updatable arity
| tablesNextToCode = mkSelectorInfoLabel upd_flag offset
| otherwise = mkSelectorEntryLabel upd_flag offset
-enterIdLabel this_pkg id
- | tablesNextToCode = mkInfoTableLabel this_pkg id
- | otherwise = mkEntryLabel this_pkg id
+enterIdLabel id
+ | tablesNextToCode = mkInfoTableLabel id
+ | otherwise = mkEntryLabel id
enterLocalIdLabel id
| tablesNextToCode = mkLocalInfoTableLabel id
closureType = ty,
closureDescr = "" }
cafBlackHoleClosureInfo _ = panic "cafBlackHoleClosureInfo"
-
-seCafBlackHoleClosureInfo (ClosureInfo { closureName = nm,
- closureType = ty })
- = ClosureInfo { closureName = nm,
- closureLFInfo = LFBlackHole mkSECAFBlackHoleInfoTableLabel,
- closureSMRep = BlackHoleRep,
- closureSRT = NoC_SRT,
- closureType = ty,
- closureDescr = "" }
-seCafBlackHoleClosureInfo _ = panic "seCafBlackHoleClosureInfo"
\end{code}
%************************************************************************
AppTy fun _ -> getTyDescription fun
FunTy _ res -> '-' : '>' : fun_result res
TyConApp tycon _ -> getOccString tycon
- NoteTy (FTVNote _) ty -> getTyDescription ty
PredTy sty -> getPredTyDescription sty
ForAllTy _ ty -> getTyDescription ty
}
projects / ghc-hetmet.git / blobdiff