%
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
-% $Id: AbsCSyn.lhs,v 1.32 2000/08/02 14:13:26 rrt Exp $
+% $Id: AbsCSyn.lhs,v 1.45 2002/02/06 11:13:47 sewardj Exp $
%
\section[AbstractC]{Abstract C: the last stop before machine code}
module AbsCSyn {- (
-- export everything
AbstractC(..),
+ C_SRT(..)
CStmtMacro(..),
CExprMacro(..),
CAddrMode(..),
mAX_Double_REG, spRelToInt )
import CostCentre ( CostCentre, CostCentreStack )
import Literal ( mkMachInt, Literal(..) )
+import ForeignCall ( CCallSpec )
import PrimRep ( PrimRep(..) )
-import PrimOp ( PrimOp, CCall )
+import MachOp ( MachOp(..) )
import Unique ( Unique )
-import StgSyn ( SRT(..) )
+import StgSyn ( StgOp )
import TyCon ( TyCon )
import BitSet -- for liveness masks
+import FastTypes
+import Outputable
\end{code}
@AbstractC@ is a list of Abstract~C statements, but the data structure
| CInitHdr -- to initialise the header of a closure (both fixed/var parts)
ClosureInfo
CAddrMode -- address of the info ptr
- CAddrMode -- cost centre to place in closure
+ !CAddrMode -- cost centre to place in closure
-- CReg CurCostCentre or CC_HDR(R1.p{-Node-})
+ Int -- size of closure, for profiling
+
+ -- NEW CASES FOR EXPANDED PRIMOPS
+
+ | CMachOpStmt -- Machine-level operation
+ CAddrMode -- result
+ MachOp
+ [CAddrMode] -- Arguments
+ (Maybe [MagicId]) -- list of regs which need to be preserved
+ -- across the primop. This is allowed to be Nothing only if
+ -- machOpIsDefinitelyInline returns True. And that in turn may
+ -- only return True if we are absolutely sure that the mach op
+ -- can be done inline on all platforms.
+
+ | CSequential -- Do the nested AbstractCs sequentially.
+ [AbstractC] -- In particular, as far as the AbsCUtils.doSimultaneously
+ -- is concerned, these stmts are to be treated as atomic
+ -- and are not to be reordered.
+
+ -- end of NEW CASES FOR EXPANDED PRIMOPS
| COpStmt
[CAddrMode] -- Results
- PrimOp
+ StgOp
[CAddrMode] -- Arguments
[MagicId] -- Potentially volatile/live registers
-- (to save/restore around the call/op)
| CRetDirect -- Direct return
!Unique -- for making labels
AbstractC -- return code
- (CLabel,SRT) -- SRT info
+ C_SRT -- SRT info
Liveness -- stack liveness at the return point
-- see the notes about these next few; they follow below...
compiling 'foreign import dynamic's)
-}
| CCallTypedef Bool {- True => use "typedef"; False => use "extern"-}
- CCall [CAddrMode] [CAddrMode]
+ CCallSpec Unique [CAddrMode] [CAddrMode]
-- *** the next three [or so...] are DATA (those above are CODE) ***
| CStaticClosure
- CLabel -- The (full, not base) label to use for labelling the closure.
- ClosureInfo
+ ClosureInfo -- Todo: maybe info_lbl & closure_lbl instead?
CAddrMode -- cost centre identifier to place in closure
[CAddrMode] -- free vars; ptrs, then non-ptrs.
| CSRT CLabel [CLabel] -- SRT declarations: basically an array of
-- pointers to static closures.
- | CBitmap CLabel LivenessMask -- A larger-than-32-bits bitmap.
+ | CBitmap CLabel LivenessMask -- A bitmap to be emitted if and only if
+ -- it is larger than a target machine word.
| CClosureInfoAndCode
ClosureInfo -- Explains placement and layout of closure
| CRetVector -- A labelled block of static data
CLabel
[CAddrMode]
- (CLabel,SRT) -- SRT info
+ C_SRT -- SRT info
Liveness -- stack liveness at the return point
| CClosureTbl -- table of constructors for enumerated types
-- CostCentre.lhs)
| CSplitMarker -- Split into separate object modules here
+
+-- C_SRT is what StgSyn.SRT gets translated to...
+-- we add a label for the table, and expect only the 'offset/length' form
+
+data C_SRT = NoC_SRT
+ | C_SRT CLabel !Int{-offset-} !Int{-length-}
+
+needsSRT :: C_SRT -> Bool
+needsSRT NoC_SRT = False
+needsSRT (C_SRT _ _ _) = True
\end{code}
About @CMacroStmt@, etc.: notionally, they all just call some
-- which gives the magic location itself
-- (NB: superceded by CReg)
+ -- JRS 2002-02-05: CAddr is really scummy and should be fixed.
+ -- The effect is that the semantics of CAddr depend on what the
+ -- contained RegRelative is; it is decidely non-orthogonal.
+
| CReg MagicId -- To replace (CAddr MagicId 0)
| CTemp !Unique !PrimRep -- Temporary locations
| CCharLike CAddrMode -- The address of a static char-like closure for
-- the specified character. It is guaranteed to be in
- -- the range 0..255.
+ -- the range mIN_CHARLIKE..mAX_CHARLIKE
| CIntLike CAddrMode -- The address of a static int-like closure for the
-- specified small integer. It is guaranteed to be in
!PrimRep -- the kind of the result
CExprMacro -- the macro to generate a value
[CAddrMode] -- and its arguments
+
+ | CBytesPerWord -- Word size, in bytes, on this platform
+ -- required for: half-word loads (used in fishing tags
+ -- out of info tables), and sizeofByteArray#.
\end{code}
Various C macros for values which are dependent on the back-end layout.
\begin{code}
data RegRelative
- = HpRel FAST_INT -- }
- | SpRel FAST_INT -- }- offsets in StgWords
- | NodeRel FAST_INT -- }
+ = HpRel FastInt -- }
+ | SpRel FastInt -- }- offsets in StgWords
+ | NodeRel FastInt -- }
| CIndex CAddrMode CAddrMode PrimRep -- pointer arithmetic :-)
-- CIndex a b k === (k*)a[b]
hpRel :: VirtualHeapOffset -- virtual offset of Hp
-> VirtualHeapOffset -- virtual offset of The Thing
-> RegRelative -- integer offset
-hpRel IBOX(hp) IBOX(off) = HpRel (hp _SUB_ off)
+hpRel hp off = HpRel (iUnbox (hp - off))
spRel :: VirtualSpOffset -- virtual offset of Sp
-> VirtualSpOffset -- virtual offset of The Thing
-> RegRelative -- integer offset
-spRel sp off = SpRel (case spRelToInt sp off of { IBOX(i) -> i })
+spRel sp off = SpRel (iUnbox (spRelToInt sp off))
nodeRel :: VirtualHeapOffset
-> RegRelative
-nodeRel IBOX(off) = NodeRel off
+nodeRel off = NodeRel (iUnbox off)
\end{code}
representation really is a bitmap). These are pinned onto case return
vectors to indicate the state of the stack for the garbage collector.
+In the compiled program, liveness bitmaps that fit inside a single
+word (StgWord) are stored as a single word, while larger bitmaps are
+stored as a pointer to an array of words. When we compile via C
+(especially when we bootstrap via HC files), we generate identical C
+code regardless of whether words are 32- or 64-bit on the target
+machine, by postponing the decision of how to store each liveness
+bitmap to C compilation time (or rather, C preprocessing time).
+
\begin{code}
type LivenessMask = [BitSet]
-data Liveness = LvSmall BitSet
- | LvLarge CLabel
+data Liveness = Liveness CLabel LivenessMask
\end{code}
%************************************************************************
-- Argument and return registers
| VanillaReg -- pointers, unboxed ints and chars
PrimRep
- FAST_INT -- its number (1 .. mAX_Vanilla_REG)
+ FastInt -- its number (1 .. mAX_Vanilla_REG)
| FloatReg -- single-precision floating-point registers
- FAST_INT -- its number (1 .. mAX_Float_REG)
+ FastInt -- its number (1 .. mAX_Float_REG)
| DoubleReg -- double-precision floating-point registers
- FAST_INT -- its number (1 .. mAX_Double_REG)
+ FastInt -- its number (1 .. mAX_Double_REG)
-- STG registers
| Sp -- Stack ptr; points to last occupied stack location.
-- no actual register
| LongReg -- long int registers (64-bit, really)
PrimRep -- Int64Rep or Word64Rep
- FAST_INT -- its number (1 .. mAX_Long_REG)
+ FastInt -- its number (1 .. mAX_Long_REG)
| CurrentTSO -- pointer to current thread's TSO
| CurrentNursery -- pointer to allocation area
+ | HpAlloc -- allocation count for heap check failure
-node = VanillaReg PtrRep ILIT(1) -- A convenient alias for Node
-tagreg = VanillaReg WordRep ILIT(2) -- A convenient alias for TagReg
+node = VanillaReg PtrRep (_ILIT 1) -- A convenient alias for Node
+tagreg = VanillaReg WordRep (_ILIT 2) -- A convenient alias for TagReg
nodeReg = CReg node
\end{code}
\begin{code}
instance Eq MagicId where
- reg1 == reg2 = tag reg1 _EQ_ tag reg2
+ reg1 == reg2 = tag reg1 ==# tag reg2
where
- tag BaseReg = (ILIT(0) :: FAST_INT)
- tag Sp = ILIT(1)
- tag Su = ILIT(2)
- tag SpLim = ILIT(3)
- tag Hp = ILIT(4)
- tag HpLim = ILIT(5)
- tag CurCostCentre = ILIT(6)
- tag VoidReg = ILIT(7)
-
- tag (VanillaReg _ i) = ILIT(8) _ADD_ i
-
- tag (FloatReg i) = ILIT(8) _ADD_ maxv _ADD_ i
- tag (DoubleReg i) = ILIT(8) _ADD_ maxv _ADD_ maxf _ADD_ i
- tag (LongReg _ i) = ILIT(8) _ADD_ maxv _ADD_ maxf _ADD_ maxd _ADD_ i
-
- maxv = case mAX_Vanilla_REG of { IBOX(x) -> x }
- maxf = case mAX_Float_REG of { IBOX(x) -> x }
- maxd = case mAX_Double_REG of { IBOX(x) -> x }
+ tag BaseReg = (_ILIT(0) :: FastInt)
+ tag Sp = _ILIT(1)
+ tag Su = _ILIT(2)
+ tag SpLim = _ILIT(3)
+ tag Hp = _ILIT(4)
+ tag HpLim = _ILIT(5)
+ tag CurCostCentre = _ILIT(6)
+ tag VoidReg = _ILIT(7)
+
+ tag (VanillaReg _ i) = _ILIT(8) +# i
+
+ tag (FloatReg i) = _ILIT(8) +# maxv +# i
+ tag (DoubleReg i) = _ILIT(8) +# maxv +# maxf +# i
+ tag (LongReg _ i) = _ILIT(8) +# maxv +# maxf +# maxd +# i
+
+ maxv = iUnbox mAX_Vanilla_REG
+ maxf = iUnbox mAX_Float_REG
+ maxd = iUnbox mAX_Double_REG
\end{code}
Returns True for any register that {\em potentially} dies across
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