%
-% (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}
-module PrimRep
- (
- PrimRep(..)
- , separateByPtrFollowness
- , isFollowableRep
- , isFloatingRep
- , is64BitRep
- , getPrimRepSize
- , getPrimRepSizeInBytes
- , retPrimRepSize
- , showPrimRep
- , showPrimRepToUser
- , ppPrimRep
- , guessPrimRep
- , decodePrimRep
- ) where
+module PrimRep (
+ PrimRep(..),
+ separateByPtrFollowness,
+ isFollowableRep,
+ isFloatingRep,
+ isNonPtrRep,
+ is64BitRep,
+ getPrimRepSize,
+ getPrimRepSizeInBytes,
+ retPrimRepSize,
+
+ ArgRep(..), primRepToArgRep,
+ ) where
#include "HsVersions.h"
-import Util
+import Constants ( dOUBLE_SIZE, iNT64_SIZE, wORD64_SIZE, wORD_SIZE )
import Outputable
-
--- Oh dear.
--- NOTE: we have to reach out and grab this header file
--- in our current source/build tree, and not the one supplied
--- by whoever's compiling us.
-#include "../../includes/GhcConstants.h"
\end{code}
%************************************************************************
%* *
%************************************************************************
+These pretty much correspond to the C types declared in StgTypes.h.
+
\begin{code}
data PrimRep
= -- These pointer-kinds are all really the same, but we keep
| CostCentreRep -- Pointer to a cost centre
| CharRep -- Machine characters
- | IntRep -- integers (at least 32 bits)
- | WordRep -- ditto (but *unsigned*)
- | AddrRep -- addresses ("C pointers")
+ | IntRep -- signed integers (same size as ptr on this arch)
+ | WordRep -- unsigned integers (same size as ptr on this arch)
+ | AddrRep -- addresses (C pointers)
| FloatRep -- floats
| DoubleRep -- doubles
- | Word64Rep -- guaranteed to be 64 bits (no more, no less.)
- | Int64Rep -- guaranteed to be 64 bits (no more, no less.)
- | ForeignObjRep -- This has to be a special kind because ccall
- -- generates special code when passing/returning
- -- one of these. [ADR]
+ | Int8Rep -- 8 bit signed integers
+ | Int16Rep -- 16 bit signed integers
+ | Int32Rep -- 32 bit signed integers
+ | Int64Rep -- 64 bit signed integers
+ | Word8Rep -- 8 bit unsigned integers
+ | Word16Rep -- 16 bit unsigned integers
+ | Word32Rep -- 32 bit unsigned integers
+ | Word64Rep -- 64 bit unsigned integers
- | StablePtrRep -- We could replace this with IntRep but maybe
- -- there's some documentation gain from having
- -- it special? [ADR]
-
- | ArrayRep -- Primitive array of Haskell pointers
- | ByteArrayRep -- Primitive array of bytes (no Haskell pointers)
+ | StablePtrRep -- guaranteed to be represented by a pointer
| 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}
+
%************************************************************************
%* *
\subsection[PrimRep-predicates]{Follow-ness, sizes, and such---on @PrimitiveKinds@}
computation of GC liveness info.
\begin{code}
-isFollowableRep :: PrimRep -> Bool
-
-isFollowableRep PtrRep = True
-isFollowableRep ArrayRep = True
-isFollowableRep ByteArrayRep = True
--- why is a ForeignObj followable? 4/96 SOF
---
--- A: they're followable because these objects
--- should be lugged around by the storage manager
--- (==> registers containing them are live) -- 3/97 SOF
-isFollowableRep ForeignObjRep = True
-
-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 :: PrimRep -> Bool -- True <=> points to a heap object
+isFollowableRep PtrRep = True
+isFollowableRep other = False
separateByPtrFollowness :: (a -> PrimRep) -> [a] -> ([a], [a])
-
separateByPtrFollowness kind_fun things
= sep_things kind_fun things [] []
-- accumulating params for follow-able and don't-follow things...
\begin{code}
isFloatingRep :: PrimRep -> Bool
-
isFloatingRep DoubleRep = True
isFloatingRep FloatRep = True
-isFloatingRep other = False
+isFloatingRep _ = False
+\end{code}
+Identify anything which is one word large and not a pointer.
+
+\begin{code}
+isNonPtrRep :: PrimRep -> Bool
+isNonPtrRep PtrRep = False
+isNonPtrRep VoidRep = False
+isNonPtrRep r = not (isFloatingRep r) && not (is64BitRep r)
\end{code}
\begin{code}
is64BitRep :: PrimRep -> Bool
-
is64BitRep Int64Rep = True
is64BitRep Word64Rep = True
-is64BitRep other = False
-
-\end{code}
+is64BitRep _ = False
+-- Size in words.
-
-\begin{code}
getPrimRepSize :: PrimRep -> Int
+getPrimRepSize DoubleRep = dOUBLE_SIZE
+getPrimRepSize Word64Rep = wORD64_SIZE
+getPrimRepSize Int64Rep = iNT64_SIZE
+getPrimRepSize VoidRep = 0
+getPrimRepSize _ = 1
-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 ByteArrayRep = 1
-getPrimRepSize VoidRep = 0
-getPrimRepSize other = 1
-
+retPrimRepSize :: Int
retPrimRepSize = getPrimRepSize RetRep
--- size in bytes, ToDo: cpp in the right vals.
--- (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))
+-- 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)
+
+-- Note: the "size in bytes" is also the scaling factor used when we
+-- have an array of these things. For example, a ByteArray# of
+-- Int16Rep will use a scaling factor of 2 when accessing the
+-- elements.
+
getPrimRepSizeInBytes :: PrimRep -> Int
-getPrimRepSizeInBytes pr =
- case pr of
- CharRep -> 1
- IntRep -> 4
- AddrRep -> 4
- FloatRep -> 4
- DoubleRep -> 8
- Word64Rep -> 8
- Int64Rep -> 8
- ForeignObjRep -> 4
- StablePtrRep -> 4
- ArrayRep -> 4
- ByteArrayRep -> 4
- _ -> panic "getPrimRepSize: ouch - this wasn't supposed to happen!"
+getPrimRepSizeInBytes PtrRep = wORD_SIZE
+getPrimRepSizeInBytes CodePtrRep = wORD_SIZE
+getPrimRepSizeInBytes DataPtrRep = wORD_SIZE
+getPrimRepSizeInBytes RetRep = wORD_SIZE
+getPrimRepSizeInBytes CostCentreRep = wORD_SIZE
+getPrimRepSizeInBytes CharRep = 4
+getPrimRepSizeInBytes IntRep = wORD_SIZE
+getPrimRepSizeInBytes WordRep = wORD_SIZE
+getPrimRepSizeInBytes AddrRep = wORD_SIZE
+getPrimRepSizeInBytes FloatRep = wORD_SIZE
+getPrimRepSizeInBytes DoubleRep = dOUBLE_SIZE * wORD_SIZE
+getPrimRepSizeInBytes Int8Rep = 1
+getPrimRepSizeInBytes Int16Rep = 2
+getPrimRepSizeInBytes Int32Rep = 4
+getPrimRepSizeInBytes Int64Rep = 8
+getPrimRepSizeInBytes Word8Rep = 1
+getPrimRepSizeInBytes Word16Rep = 2
+getPrimRepSizeInBytes Word32Rep = 4
+getPrimRepSizeInBytes Word64Rep = 8
+getPrimRepSizeInBytes StablePtrRep = wORD_SIZE
+getPrimRepSizeInBytes other = pprPanic "getPrimRepSizeInBytes" (ppr other)
+\end{code}
+%************************************************************************
+%* *
+\subsection{ArgReps}
+%* *
+%************************************************************************
+
+An ArgRep is similar to a PrimRep, except that it is slightly
+narrower. It corresponds to the distinctions we make between
+different type of function arguments for the purposes of a function's
+calling convention. These reps are used to decide which of the RTS's
+generic apply functions to call when applying an unknown function.
+
+All 64-bit PrimReps map to the same ArgRep, because they're passed in
+the same register, but a PtrRep is still different from an IntRep
+(RepP vs. RepN respectively) because the function's entry convention
+has to take into account the pointer-hood of arguments for the
+purposes of describing the stack on entry to the garbage collector.
+
+\begin{code}
+data ArgRep = RepV | RepP | RepN | RepF | RepD | RepL
+
+primRepToArgRep VoidRep = RepV
+primRepToArgRep FloatRep = RepF
+primRepToArgRep DoubleRep = RepD
+primRepToArgRep r
+ | isFollowableRep r = RepP
+ | is64BitRep r = RepL
+ | otherwise = ASSERT(getPrimRepSize r == 1) RepN
\end{code}
%************************************************************************
ppr kind = text (showPrimRep kind)
showPrimRep :: PrimRep -> String
-showPrimRepToUser :: PrimRep -> String
--- dumping PrimRep tag for unfoldings
-ppPrimRep :: PrimRep -> SDoc
-
-guessPrimRep :: String -> PrimRep -- a horrible "inverse" function
-decodePrimRep :: Char -> PrimRep -- of equal nature
-
-ppPrimRep k =
- char
- (case k of
- PtrRep -> 'P'
- CodePtrRep -> 'p'
- DataPtrRep -> 'd'
- CostCentreRep -> 'c' -- Pointer to a cost centre
- RetRep -> 'R'
- CharRep -> 'C'
- IntRep -> 'I'
- Int64Rep -> 'i'
- WordRep -> 'W'
- Word64Rep -> 'w'
- AddrRep -> 'A'
- FloatRep -> 'F'
- DoubleRep -> 'D'
- ArrayRep -> 'a'
- ByteArrayRep -> 'b'
- StablePtrRep -> 'S'
- ForeignObjRep -> 'f'
- VoidRep -> 'V'
- _ -> panic "ppPrimRep")
-
-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 Int64Rep = "LI_" -- short for StgLongInt
-showPrimRep Word64Rep = "LW_" -- short for StgLongWord
-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!!"
-
-showPrimRepToUser pr =
- case pr of
- CharRep -> "StgChar"
- IntRep -> "StgInt"
- WordRep -> "StgWord"
- Int64Rep -> "StgInt64"
- Word64Rep -> "StgWord64"
- AddrRep -> "StgAddr"
- FloatRep -> "StgFloat"
- DoubleRep -> "StgDouble"
- ArrayRep -> "StgArray"
- ByteArrayRep -> "StgByteArray"
- StablePtrRep -> "StgStablePtr"
- ForeignObjRep -> "StgPtr"
- _ -> panic ("showPrimRepToUser: " ++ showPrimRep pr)
-
-
-decodePrimRep ch =
- case ch of
- 'P' -> PtrRep
- 'p' -> CodePtrRep
- 'd' -> DataPtrRep
- 'c' -> CostCentreRep
- 'R' -> RetRep
- 'C' -> CharRep
- 'I' -> IntRep
- 'W' -> WordRep
- 'i' -> Int64Rep
- 'w' -> Word64Rep
- 'A' -> AddrRep
- 'F' -> FloatRep
- 'D' -> DoubleRep
- 'a' -> ArrayRep
- 'b' -> ByteArrayRep
- 'S' -> StablePtrRep
- 'f' -> ForeignObjRep
- 'V' -> VoidRep
- _ -> panic "decodePrimRep"
-
-guessPrimRep "D_" = DataPtrRep
-guessPrimRep "StgRetAddr" = RetRep
-guessPrimRep "StgChar" = CharRep
-guessPrimRep "I_" = IntRep
-guessPrimRep "LI_" = Int64Rep
-guessPrimRep "W_" = WordRep
-guessPrimRep "LW_" = Word64Rep
-guessPrimRep "StgAddr" = AddrRep
-guessPrimRep "StgFloat" = FloatRep
-guessPrimRep "StgDouble" = DoubleRep
-guessPrimRep "StgArray" = ArrayRep
-guessPrimRep "StgByteArray" = ByteArrayRep
-guessPrimRep "StgStablePtr" = StablePtrRep
+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 Int16Rep = "StgInt16"
+showPrimRep Int32Rep = "StgInt32"
+showPrimRep Word8Rep = "StgWord8"
+showPrimRep Word16Rep = "StgWord16"
+showPrimRep Word32Rep = "StgWord32"
+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 StablePtrRep = "StgStablePtr"
+showPrimRep VoidRep = "!!VOID_KIND!!"
\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]
+