%
-% (c) The GRASP Project, Glasgow University, 1992-1996
+% (c) The GRASP Project, Glasgow University, 1992-1998
%
\section[PrimRep]{Primitive machine-level kinds of things.}
types.
\begin{code}
-#include "HsVersions.h"
-
-module PrimRep (
- PrimRep(..),
-
- separateByPtrFollowness, isFollowableRep, isFloatingRep,
- getPrimRepSize, retPrimRepSize,
- showPrimRep,
- guessPrimRep
- ) where
+module PrimRep
+ (
+ PrimRep(..)
+ , separateByPtrFollowness
+ , isFollowableRep
+ , isFloatingRep
+ , is64BitRep
+ , getPrimRepSize
+ , getPrimRepSizeInBytes
+ , retPrimRepSize
+ , showPrimRep
+ , primRepString
+ , showPrimRepToUser
+ ) where
-IMP_Ubiq()
-
-import Pretty -- pretty-printing code
-import Util
+#include "HsVersions.h"
-#include "../../includes/GhcConstants.h"
+import Constants ( dOUBLE_SIZE, iNT64_SIZE, wORD64_SIZE, wORD_SIZE )
+import Outputable
\end{code}
%************************************************************************
| CostCentreRep -- Pointer to a cost centre
| CharRep -- Machine characters
- | IntRep -- integers (at least 32 bits)
+ | Int8Rep -- 8 bit integers
+ | IntRep -- integers (same size as ptr on this arch)
| WordRep -- ditto (but *unsigned*)
| AddrRep -- addresses ("C pointers")
| FloatRep -- floats
| DoubleRep -- doubles
-
- | ForeignObjRep -- This has to be a special kind because ccall
- -- generates special code when passing/returning
- -- one of these. [ADR]
-
- | StablePtrRep -- We could replace this with IntRep but maybe
- -- there's some documentation gain from having
- -- it special? [ADR]
+ | Word64Rep -- guaranteed to be 64 bits (no more, no less.)
+ | Int64Rep -- guaranteed to be 64 bits (no more, no less.)
+
+ -- Perhaps all sized integers and words should be primitive types.
+
+ -- Int8Rep is currently used to simulate some old CharRep usages
+ -- when Char changed size from 8 to 31 bits. It does not correspond
+ -- to a Haskell unboxed type, in particular it's not used by Int8.
+
+ | WeakPtrRep
+ | ForeignObjRep
+ | BCORep
+
+ | StablePtrRep -- guaranteed to be represented by a pointer
+
+ | StableNameRep -- A stable name is a real heap object, unpointed,
+ -- with one field containing an index into the
+ -- stable pointer table. It has to be a heap
+ -- object so the garbage collector can track these
+ -- objects and reclaim stable pointer entries.
+
+ | ThreadIdRep -- Really a pointer to a TSO
| ArrayRep -- Primitive array of Haskell pointers
| ByteArrayRep -- Primitive array of bytes (no Haskell pointers)
+ | PrimPtrRep -- Used for MutVars and MVars;
+ -- a pointer to a primitive object
+ -- ToDo: subsumes WeakPtrRep, ThreadIdRep,
+ -- StableNameRep, ForeignObjRep, and BCORep ?
+
| VoidRep -- Occupies no space at all!
-- (Primitive states are mapped onto this)
deriving (Eq, Ord)
-- Kinds are used in PrimTyCons, which need both Eq and Ord
\end{code}
+These pretty much correspond to the C types declared in StgTypes.h,
+with the following exceptions:
+
+ - when an Array or ByteArray is passed to C, we again pass a pointer
+ to the contents. The actual type that is passed is StgPtr for
+ ArrayRep, and StgByteArray (probably a char *) for ByteArrayRep.
+
+These hacks are left until the final printing of the C, in
+PprAbsC.lhs.
+
%************************************************************************
%* *
\subsection[PrimRep-predicates]{Follow-ness, sizes, and such---on @PrimitiveKinds@}
%************************************************************************
Whether or not the thing is a pointer that the garbage-collector
-should follow.
+should follow. Or, to put it another (less confusing) way, whether
+the object in question is a heap object.
-Or, to put it another (less confusing) way, whether the object in
-question is a heap object.
+Depending on the outcome, this predicate determines what stack
+the pointer/object possibly will have to be saved onto, and the
+computation of GC liveness info.
\begin{code}
isFollowableRep :: PrimRep -> Bool
isFollowableRep PtrRep = True
-isFollowableRep ArrayRep = True
-isFollowableRep ByteArrayRep = True
--- why is a MallocPtr followable? 4/96 SOF
--- isFollowableRep ForeignObjRep = True
+isFollowableRep ArrayRep = True -- all heap objects:
+isFollowableRep ByteArrayRep = True -- ''
+isFollowableRep WeakPtrRep = True -- ''
+isFollowableRep ForeignObjRep = True -- ''
+isFollowableRep StableNameRep = True -- ''
+isFollowableRep PrimPtrRep = True -- ''
+isFollowableRep ThreadIdRep = True -- pointer to a TSO
-isFollowableRep StablePtrRep = False
--- StablePtrs aren't followable because they are just indices into a
--- table for which explicit allocation/ deallocation is required.
-
-isFollowableRep other = False
+isFollowableRep other = False
separateByPtrFollowness :: (a -> PrimRep) -> [a] -> ([a], [a])
isFloatingRep DoubleRep = True
isFloatingRep FloatRep = True
isFloatingRep other = False
+
\end{code}
\begin{code}
+is64BitRep :: PrimRep -> Bool
+
+is64BitRep Int64Rep = True
+is64BitRep Word64Rep = True
+is64BitRep other = False
+
+\end{code}
+
+
+
+\begin{code}
getPrimRepSize :: PrimRep -> Int
-getPrimRepSize DoubleRep = DOUBLE_SIZE -- "words", of course
+getPrimRepSize DoubleRep = dOUBLE_SIZE -- "words", of course
+getPrimRepSize Word64Rep = wORD64_SIZE
+getPrimRepSize Int64Rep = iNT64_SIZE
--getPrimRepSize FloatRep = 1
--getPrimRepSize CharRep = 1 -- ToDo: count in bytes?
--getPrimRepSize ArrayRep = 1 -- Listed specifically for *documentation*
getPrimRepSize other = 1
retPrimRepSize = getPrimRepSize RetRep
+
+-- sizes in bytes.
+-- (used in some settings to figure out how many bytes
+-- we have to push onto the stack when calling external
+-- entry points (e.g., stdcalling on win32)
+getPrimRepSizeInBytes :: PrimRep -> Int
+getPrimRepSizeInBytes pr =
+ case pr of
+ CharRep -> 4
+ Int8Rep -> 1
+ IntRep -> wORD_SIZE
+ AddrRep -> wORD_SIZE
+ FloatRep -> wORD_SIZE
+ DoubleRep -> dOUBLE_SIZE * wORD_SIZE
+ Word64Rep -> wORD64_SIZE * wORD_SIZE
+ Int64Rep -> iNT64_SIZE * wORD_SIZE
+ WeakPtrRep -> wORD_SIZE
+ ForeignObjRep -> wORD_SIZE
+ StablePtrRep -> wORD_SIZE
+ StableNameRep -> wORD_SIZE
+ ArrayRep -> wORD_SIZE
+ ByteArrayRep -> wORD_SIZE
+ _ -> panic "getPrimRepSize: ouch - this wasn't supposed to happen!"
+
\end{code}
%************************************************************************
\begin{code}
instance Outputable PrimRep where
- ppr sty kind = ppStr (showPrimRep kind)
+ ppr kind = text (showPrimRep kind)
showPrimRep :: PrimRep -> String
-guessPrimRep :: String -> PrimRep -- a horrible "inverse" function
-
-showPrimRep PtrRep = "P_" -- short for StgPtr
-
-showPrimRep CodePtrRep = "P_" -- DEATH to StgFunPtr! (94/02/22 WDP)
- -- but aren't code pointers and function pointers different sizes
- -- on some machines (eg 80x86)? ADR
- -- Are you trying to ruin my life, or what? (WDP)
-
-showPrimRep DataPtrRep = "D_"
-showPrimRep RetRep = "StgRetAddr"
-showPrimRep CostCentreRep = "CostCentre"
-showPrimRep CharRep = "StgChar"
-showPrimRep IntRep = "I_" -- short for StgInt
-showPrimRep WordRep = "W_" -- short for StgWord
-showPrimRep AddrRep = "StgAddr"
-showPrimRep FloatRep = "StgFloat"
-showPrimRep DoubleRep = "StgDouble"
-showPrimRep ArrayRep = "StgArray" -- see comment below
-showPrimRep ByteArrayRep = "StgByteArray"
-showPrimRep StablePtrRep = "StgStablePtr"
-showPrimRep ForeignObjRep = "StgPtr" -- see comment below
-showPrimRep VoidRep = "!!VOID_KIND!!"
-
-guessPrimRep "D_" = DataPtrRep
-guessPrimRep "StgRetAddr" = RetRep
-guessPrimRep "StgChar" = CharRep
-guessPrimRep "I_" = IntRep
-guessPrimRep "W_" = WordRep
-guessPrimRep "StgAddr" = AddrRep
-guessPrimRep "StgFloat" = FloatRep
-guessPrimRep "StgDouble" = DoubleRep
-guessPrimRep "StgArray" = ArrayRep
-guessPrimRep "StgByteArray" = ByteArrayRep
-guessPrimRep "StgStablePtr" = StablePtrRep
+showPrimRepToUser :: PrimRep -> String
+
+showPrimRep PtrRep = "P_" -- short for StgPtr
+showPrimRep CodePtrRep = "P_" -- DEATH to StgFunPtr! (94/02/22 WDP)
+showPrimRep DataPtrRep = "D_"
+showPrimRep RetRep = "P_"
+showPrimRep CostCentreRep = "CostCentre"
+showPrimRep CharRep = "C_"
+showPrimRep Int8Rep = "StgInt8"
+showPrimRep IntRep = "I_" -- short for StgInt
+showPrimRep WordRep = "W_" -- short for StgWord
+showPrimRep Int64Rep = "LI_" -- short for StgLongInt
+showPrimRep Word64Rep = "LW_" -- short for StgLongWord
+showPrimRep AddrRep = "StgAddr"
+showPrimRep FloatRep = "StgFloat"
+showPrimRep DoubleRep = "StgDouble"
+showPrimRep ArrayRep = "P_" -- see comment below
+showPrimRep PrimPtrRep = "P_"
+showPrimRep ByteArrayRep = "StgByteArray"
+showPrimRep StablePtrRep = "StgStablePtr"
+showPrimRep StableNameRep = "P_"
+showPrimRep ThreadIdRep = "StgTSO*"
+showPrimRep WeakPtrRep = "P_"
+showPrimRep ForeignObjRep = "StgAddr"
+showPrimRep VoidRep = "!!VOID_KIND!!"
+
+primRepString CharRep = "Char"
+primRepString Int8Rep = "Char" -- To have names like newCharArray#
+primRepString IntRep = "Int"
+primRepString WordRep = "Word"
+primRepString Int64Rep = "Int64"
+primRepString Word64Rep = "Word64"
+primRepString AddrRep = "Addr"
+primRepString FloatRep = "Float"
+primRepString DoubleRep = "Double"
+primRepString WeakPtrRep = "Weak"
+primRepString ForeignObjRep = "ForeignObj"
+primRepString StablePtrRep = "StablePtr"
+primRepString StableNameRep = "StableName"
+primRepString other = pprPanic "primRepString" (ppr other)
+
+showPrimRepToUser pr = primRepString pr
\end{code}
-All local C variables of @ArrayRep@ are declared in C as type
-@StgArray@. The coercion to a more precise C type is done just before
-indexing (by the relevant C primitive-op macro).
-
-Nota Bene. There are three types associated with @ForeignObj@ (MallocPtr++):
-\begin{itemize}
-\item
-@StgForeignObjClosure@ is the type of the thing the prim. op @mkForeignObj@ returns.
-{- old comment for MallocPtr
-(This typename is hardwired into @ppr_casm_results@ in
-@PprAbsC.lhs@.)
--}
-
-\item
-@StgForeignObj@ is the type of the thing we give the C world.
-
-\item
-@StgPtr@ is the type of the (pointer to the) heap object which we
-pass around inside the STG machine.
-\end{itemize}
-
-It is really easy to confuse the two. (I'm not sure this choice of
-type names helps.) [ADR]
+Foreign Objects and Arrays are treated specially by the code for
+_ccall_s: we pass a pointer to the contents of the object, not the
+object itself.
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