types.
\begin{code}
-module PrimRep
- (
- PrimRep(..)
- , separateByPtrFollowness
- , isFollowableRep
- , isFloatingRep
- , is64BitRep
- , getPrimRepSize
- , getPrimRepSizeInBytes
- , retPrimRepSize
- , showPrimRep
- , primRepString
- , showPrimRepToUser
- ) where
+module PrimRep (
+ PrimRep(..),
+ separateByPtrFollowness,
+ isFollowableRep,
+ isFloatingRep,
+ isNonPtrRep,
+ is64BitRep,
+ getPrimRepSize,
+ getPrimRepSizeInBytes,
+ retPrimRepSize,
+
+ ArgRep(..), primRepToArgRep,
+ ) where
#include "HsVersions.h"
%* *
%************************************************************************
+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
- | Int8Rep -- 8 bit integers
- | IntRep -- integers (same size as ptr on this arch)
- | 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.)
-
- -- 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.
+ | 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
- | ThreadIdRep -- Really a pointer to a TSO
-
- | 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}
-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.
%************************************************************************
%* *
computation of GC liveness info.
\begin{code}
-isFollowableRep :: PrimRep -> Bool
-
-isFollowableRep PtrRep = True
-isFollowableRep ArrayRep = True -- all heap objects:
-isFollowableRep ByteArrayRep = True -- ''
-isFollowableRep WeakPtrRep = True -- ''
-isFollowableRep ForeignObjRep = True -- ''
-isFollowableRep StableNameRep = True -- ''
-isFollowableRep ThreadIdRep = True -- pointer to a TSO
-
+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)
\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
--- 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)
+-- 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 -> 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!"
+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
-
showPrimRep PtrRep = "P_" -- short for StgPtr
showPrimRep CodePtrRep = "P_" -- DEATH to StgFunPtr! (94/02/22 WDP)
showPrimRep DataPtrRep = "D_"
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 AddrRep = "StgAddr"
showPrimRep FloatRep = "StgFloat"
showPrimRep DoubleRep = "StgDouble"
-showPrimRep ArrayRep = "P_" -- see comment below
-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}
-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.
+