Implement regslot inlining, document soundness concerns.

[ghc-hetmet.git] / compiler / cmm / CmmExpr.hs

diff --git a/compiler/cmm/CmmExpr.hs b/compiler/cmm/CmmExpr.hs
index 3ae2996..b8cd328 100644 (file)
--- a/compiler/cmm/CmmExpr.hs
+++ b/compiler/cmm/CmmExpr.hs
@@ -4,13 +4,13 @@ module CmmExpr
     , CmmReg(..), cmmRegType
     , CmmLit(..), cmmLitType
     , LocalReg(..), localRegType
-    , GlobalReg(..), globalRegType, spReg, hpReg, spLimReg, nodeReg, node
+    , GlobalReg(..), globalRegType, spReg, hpReg, spLimReg, nodeReg, node, baseReg
     , VGcPtr(..), vgcFlag      -- Temporary!
     , DefinerOfLocalRegs, UserOfLocalRegs, foldRegsDefd, foldRegsUsed, filterRegsUsed
     , DefinerOfSlots, UserOfSlots, foldSlotsDefd, foldSlotsUsed
     , RegSet, emptyRegSet, elemRegSet, extendRegSet, deleteFromRegSet, mkRegSet
             , plusRegSet, minusRegSet, timesRegSet
-    , regUsedIn
+    , regUsedIn, regSlot
     , Area(..), AreaId(..), SubArea, SubAreaSet, AreaMap, isStackSlotOf
     , module CmmMachOp
     , module CmmType
@@ -42,8 +42,8 @@ data CmmExpr
   | CmmRegOff CmmReg Int       
        -- CmmRegOff reg i
        --        ** is shorthand only, meaning **
-       -- CmmMachOp (MO_S_Add rep (CmmReg reg) (CmmLit (CmmInt i rep)))
-       --      where rep = cmmRegType reg
+       -- CmmMachOp (MO_Add rep) [x, CmmLit (CmmInt (fromIntegral i) rep)]
+       --      where rep = typeWidth (cmmRegType reg)
 
 instance Eq CmmExpr where      -- Equality ignores the types
   CmmLit l1                == CmmLit l2         = l1==l2
@@ -124,6 +124,8 @@ cmmExprType (CmmReg reg)            = cmmRegType reg
 cmmExprType (CmmMachOp op args) = machOpResultType op (map cmmExprType args)
 cmmExprType (CmmRegOff reg _)   = cmmRegType reg
 cmmExprType (CmmStackSlot _ _)  = bWord -- an address
+-- Careful though: what is stored at the stack slot may be bigger than
+-- an address
 
 cmmLitType :: CmmLit -> CmmType
 cmmLitType (CmmInt _ width)     = cmmBits  width
@@ -265,6 +267,9 @@ isStackSlotOf :: CmmExpr -> LocalReg -> Bool
 isStackSlotOf (CmmStackSlot (RegSlot r) _) r' = r == r'
 isStackSlotOf _ _ = False
 
+regSlot :: LocalReg -> CmmExpr
+regSlot r = CmmStackSlot (RegSlot r) (widthInBytes $ typeWidth $ localRegType r)
+
 -----------------------------------------------------------------------------
 --    Stack slot use information for expressions and other types [_$_]
 -----------------------------------------------------------------------------
@@ -423,7 +428,8 @@ instance Ord GlobalReg where
    compare _ EagerBlackholeInfo = GT
 
 -- convenient aliases
-spReg, hpReg, spLimReg, nodeReg :: CmmReg
+baseReg, spReg, hpReg, spLimReg, nodeReg :: CmmReg
+baseReg = CmmGlobal BaseReg
 spReg = CmmGlobal Sp
 hpReg = CmmGlobal Hp
 spLimReg = CmmGlobal SpLim