simplify the generated C a little by removing some casts.

diff --git a/compiler/cmm/PprC.hs b/compiler/cmm/PprC.hs
index 6d63e87..62bdb31 100644 (file)
--- a/compiler/cmm/PprC.hs
+++ b/compiler/cmm/PprC.hs
@@ -609,18 +609,15 @@ pprAssign :: CmmReg -> CmmExpr -> SDoc
 
 -- dest is a reg, rhs is a reg
 pprAssign r1 (CmmReg r2)
 
 -- dest is a reg, rhs is a reg
 pprAssign r1 (CmmReg r2)

-   | not (isStrangeTypeReg r1) && not (isStrangeTypeReg r2)
-   || isPtrReg r1 && isPtrReg r2
+   | isPtrReg r1 && isPtrReg r2

    = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, semi ]
 
 -- dest is a reg, rhs is a CmmRegOff
 pprAssign r1 (CmmRegOff r2 off)
    = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, semi ]
 
 -- dest is a reg, rhs is a CmmRegOff
 pprAssign r1 (CmmRegOff r2 off)

-   | not (isStrangeTypeReg r1) && not (isStrangeTypeReg r2)
-   || isPtrReg r1 && isPtrReg r2
+   | isPtrReg r1 && isPtrReg r2 && (off `rem` wORD_SIZE == 0)

    = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, op, int off', semi ]
   where
    = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, op, int off', semi ]
   where

-       off1 | isPtrReg r2 = off `shiftR` wordShift
-            | otherwise   = off
+       off1 = off `shiftR` wordShift

 
        (op,off') | off >= 0  = (char '+', off1)
                  | otherwise = (char '-', -off1)
 
        (op,off') | off >= 0  = (char '+', off1)
                  | otherwise = (char '-', -off1)

@@ -629,8 +626,8 @@ pprAssign r1 (CmmRegOff r2 off)
 -- We can't cast the lvalue, so we have to cast the rhs if necessary.  Casting
 -- the lvalue elicits a warning from new GCC versions (3.4+).
 pprAssign r1 r2
 -- We can't cast the lvalue, so we have to cast the rhs if necessary.  Casting
 -- the lvalue elicits a warning from new GCC versions (3.4+).
 pprAssign r1 r2

-  | isPtrReg r1
-  = pprAsPtrReg r1 <> ptext SLIT(" = ") <> mkP_ <> pprExpr1 r2 <> semi
+  | isFixedPtrReg r1
+  = pprReg r1 <> ptext SLIT(" = ") <> mkP_ <> pprExpr1 r2 <> semi

   | Just ty <- strangeRegType r1
   = pprReg r1 <> ptext SLIT(" = ") <> parens ty <> pprExpr1 r2 <> semi
   | otherwise
   | Just ty <- strangeRegType r1
   = pprReg r1 <> ptext SLIT(" = ") <> parens ty <> pprExpr1 r2 <> semi
   | otherwise

@@ -643,20 +640,26 @@ pprCastReg reg
    | isStrangeTypeReg reg = mkW_ <> pprReg reg
    | otherwise            = pprReg reg
 
    | isStrangeTypeReg reg = mkW_ <> pprReg reg
    | otherwise            = pprReg reg
 

--- True if the register has type StgPtr in C, otherwise it has an
--- integer type.  We need to take care with pointer arithmetic on registers
--- with type StgPtr.
-isPtrReg :: CmmReg -> Bool
-isPtrReg (CmmLocal _) = False
-isPtrReg (CmmGlobal r) = isPtrGlobalReg r
+-- True if (pprReg reg) will give an expression with type StgPtr.  We
+-- need to take care with pointer arithmetic on registers with type
+-- StgPtr.
+isFixedPtrReg :: CmmReg -> Bool
+isFixedPtrReg (CmmLocal _) = False
+isFixedPtrReg (CmmGlobal r) = isFixedPtrGlobalReg r

 
 

-isPtrGlobalReg :: GlobalReg -> Bool
-isPtrGlobalReg (VanillaReg n)  = True
-isPtrGlobalReg Sp              = True
-isPtrGlobalReg Hp              = True
-isPtrGlobalReg HpLim           = True
-isPtrGlobalReg SpLim           = True
-isPtrGlobalReg _               = False
+-- True if (pprAsPtrReg reg) will give an expression with type StgPtr
+isPtrReg :: CmmReg -> Bool
+isPtrReg (CmmLocal _)              = False
+isPtrReg (CmmGlobal (VanillaReg n)) = True -- if we print via pprAsPtrReg
+isPtrReg (CmmGlobal reg)           = isFixedPtrGlobalReg reg
+
+-- True if this global reg has type StgPtr
+isFixedPtrGlobalReg :: GlobalReg -> Bool
+isFixedPtrGlobalReg Sp                 = True
+isFixedPtrGlobalReg Hp                 = True
+isFixedPtrGlobalReg HpLim      = True
+isFixedPtrGlobalReg SpLim      = True
+isFixedPtrGlobalReg _          = False

 
 -- True if in C this register doesn't have the type given by 
 -- (machRepCType (cmmRegRep reg)), so it has to be cast.
 
 -- True if in C this register doesn't have the type given by 
 -- (machRepCType (cmmRegRep reg)), so it has to be cast.

@@ -668,7 +671,7 @@ isStrangeTypeGlobal :: GlobalReg -> Bool
 isStrangeTypeGlobal CurrentTSO         = True
 isStrangeTypeGlobal CurrentNursery     = True
 isStrangeTypeGlobal BaseReg            = True
 isStrangeTypeGlobal CurrentTSO         = True
 isStrangeTypeGlobal CurrentNursery     = True
 isStrangeTypeGlobal BaseReg            = True

-isStrangeTypeGlobal r                  = isPtrGlobalReg r
+isStrangeTypeGlobal r                  = isFixedPtrGlobalReg r

 
 strangeRegType :: CmmReg -> Maybe SDoc
 strangeRegType (CmmGlobal CurrentTSO) = Just (ptext SLIT("struct StgTSO_ *"))
 
 strangeRegType :: CmmReg -> Maybe SDoc
 strangeRegType (CmmGlobal CurrentTSO) = Just (ptext SLIT("struct StgTSO_ *"))