[project @ 2001-08-29 14:20:14 by rje]

[ghc-hetmet.git] / ghc / compiler / codeGen / CgUsages.lhs

diff --git a/ghc/compiler/codeGen/CgUsages.lhs b/ghc/compiler/codeGen/CgUsages.lhs
index 6f3353d..8c40c9a 100644 (file)
--- a/ghc/compiler/codeGen/CgUsages.lhs
+++ b/ghc/compiler/codeGen/CgUsages.lhs
@@ -39,43 +39,47 @@ heap usage.
 It is usually a prelude to performing a GC check, so everything must
 be in a tidy and consistent state.
 
+rje: Note the slightly suble fixed point behaviour needed here
 \begin{code}
 initHeapUsage :: (VirtualHeapOffset -> Code) -> Code
 
-initHeapUsage fcode info_down (MkCgState absC binds (stk_usage, heap_usage))
-  = state3
-  where
-    state1 = MkCgState absC binds (stk_usage, (0, 0))
-    state2 = fcode (heapHWM heap_usage2) info_down state1
-    (MkCgState absC2 binds2 (stk_usage2, heap_usage2)) = state2
-    state3 = MkCgState  absC2
-                       binds2
-                       (stk_usage2, heap_usage {- unchanged -})
+initHeapUsage fcode = do 
+       (stk_usage, heap_usage) <- getUsage
+       setUsage (stk_usage, (0,0))
+       fixC (\heap_usage2 -> do
+               fcode (heapHWM heap_usage2)
+               (_, heap_usage2) <- getUsage
+               return heap_usage2)
+       (stk_usage2, heap_usage2) <- getUsage
+       setUsage (stk_usage2, heap_usage {-unchanged -})
 \end{code}
 
 \begin{code}
 setVirtHp :: VirtualHeapOffset -> Code
-setVirtHp new_virtHp info_down
-         state@(MkCgState absC binds (stk, (virtHp, realHp)))
-  = MkCgState absC binds (stk, (new_virtHp, realHp))
+setVirtHp new_virtHp = do
+       (stk, (virtHp, realHp)) <- getUsage
+       setUsage (stk, (new_virtHp, realHp))
 \end{code}
 
 \begin{code}
 getVirtAndRealHp :: FCode (VirtualHeapOffset, VirtualHeapOffset)
-getVirtAndRealHp info_down state@(MkCgState _ _ (_, (virtHp, realHp)))
-  = ((virtHp, realHp), state)
+getVirtAndRealHp = do 
+       (_, (virtHp, realHp)) <- getUsage
+       return (virtHp, realHp)
 \end{code}
 
 \begin{code}
 setRealHp ::  VirtualHeapOffset -> Code
-setRealHp realHp info_down (MkCgState absC binds (stk_usage, (vHp, _)))
-  = MkCgState absC binds (stk_usage, (vHp, realHp))
+setRealHp realHp = do
+       (stk_usage, (vHp, _)) <- getUsage
+       setUsage (stk_usage, (vHp, realHp))
 \end{code}
 
 \begin{code}
 getHpRelOffset :: VirtualHeapOffset -> FCode RegRelative
-getHpRelOffset virtual_offset info_down state@(MkCgState _ _ (_,(_,realHp)))
-  = (hpRel realHp virtual_offset, state)
+getHpRelOffset virtual_offset = do
+       (_,(_,realHp)) <- getUsage
+       return $ hpRel realHp virtual_offset
 \end{code}
 
 The heap high water mark is the larger of virtHp and hwHp.  The latter is
@@ -102,27 +106,29 @@ It is used to initialise things at the beginning of a closure body.
 setRealAndVirtualSp :: VirtualSpOffset         -- New real Sp
                     -> Code
 
-setRealAndVirtualSp sp info_down (MkCgState absC binds
-                                       ((vsp,f,realSp,hwsp), h_usage))
-  = MkCgState absC binds new_usage
-  where
-    new_usage = ((sp, f, sp, sp), h_usage)
+setRealAndVirtualSp sp = do
+       ((vsp,f,realSp,hwsp), h_usage) <- getUsage
+       let new_usage = ((sp, f, sp, sp), h_usage)
+       setUsage new_usage
 \end{code}
 
 \begin{code}
 getVirtSp :: FCode VirtualSpOffset
-getVirtSp info_down state@(MkCgState absC binds ((virtSp,_,_,_), _))
-  = (virtSp, state)
+getVirtSp = do 
+       ((virtSp,_,_,_), _) <- getUsage
+       return virtSp
 
 getRealSp :: FCode VirtualSpOffset
-getRealSp info_down state@(MkCgState absC binds ((_,_,realSp,_),_)) 
-  = (realSp,state)
+getRealSp = do
+       ((_,_,realSp,_),_) <- getUsage
+       return realSp
 \end{code}
 
 \begin{code}
 getSpRelOffset :: VirtualSpOffset -> FCode RegRelative
-getSpRelOffset virtual_offset info_down state@(MkCgState _ _ ((_,_,realSp,_),_))
-  = (spRel realSp virtual_offset, state)
+getSpRelOffset virtual_offset = do
+       ((_,_,realSp,_),_) <- getUsage
+       return $ spRel realSp virtual_offset
 \end{code}
 
 %************************************************************************
@@ -144,25 +150,21 @@ That's done by functions which allocate stack space.
 \begin{code}
 adjustSpAndHp :: VirtualSpOffset       -- New offset for Arg stack ptr
              -> Code
-adjustSpAndHp newRealSp (MkCgInfoDown _ _ _ ticky_ctr _)
-                       (MkCgState absC binds
-                                  ((vSp,fSp,realSp,hwSp),      
-                                  (vHp, rHp)))
-  = MkCgState (mkAbstractCs [absC,move_sp,move_hp]) binds new_usage
-    where
-
-    move_sp = if (newRealSp == realSp) then AbsCNop
+adjustSpAndHp newRealSp = do
+       (MkCgInfoDown _ _ _ ticky_ctr _) <- getInfoDown
+       (MkCgState absC binds
+                  ((vSp,fSp,realSp,hwSp),      
+                  (vHp, rHp))) <- getState
+       let move_sp = if (newRealSp == realSp) then AbsCNop
              else (CAssign (CReg Sp)
                            (CAddr (spRel realSp newRealSp)))
-
-       -- Adjust the heap pointer backwards in case we over-allocated
-       -- Analogously, we also remove bytes from the ticky counter
-    move_hp = if (rHp == vHp) then AbsCNop
-             else mkAbstractCs [
-                       CAssign (CReg Hp) (CAddr (hpRel rHp vHp)),
+       let move_hp = 
+               if (rHp == vHp) then AbsCNop
+               else mkAbstractCs [
+               CAssign (CReg Hp) (CAddr (hpRel rHp vHp)),
                        profCtrAbsC SLIT("TICK_ALLOC_HEAP") 
-                           [ mkIntCLit (vHp - rHp), CLbl ticky_ctr DataPtrRep ]
-             ]
-
-    new_usage = ((vSp, fSp, newRealSp, hwSp), (vHp,vHp))
+                       [ mkIntCLit (vHp - rHp), CLbl ticky_ctr DataPtrRep ]
+               ]
+       let new_usage = ((vSp, fSp, newRealSp, hwSp), (vHp,vHp))
+       setState $ MkCgState (mkAbstractCs [absC,move_sp,move_hp]) binds new_usage
 \end{code}