[commit: ghc] master: Update CmmRegOff shorthand for CmmMachOp. (b20d5a3)

[Edward Z. Yang]

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/b20d5a36b35cf8260554259dc3887a90171c6495

>---------------------------------------------------------------

commit b20d5a36b35cf8260554259dc3887a90171c6495
Author: Edward Z. Yang <ezyang at mit.edu>
Date:   Wed Apr 13 11:09:09 2011 +0100

    Update CmmRegOff shorthand for CmmMachOp.
    
    Signed-off-by: Edward Z. Yang <ezyang at mit.edu>

>---------------------------------------------------------------

 compiler/cmm/CmmExpr.hs |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/compiler/cmm/CmmExpr.hs b/compiler/cmm/CmmExpr.hs
index 3ae2996..55a5b73 100644
--- a/compiler/cmm/CmmExpr.hs
+++ b/compiler/cmm/CmmExpr.hs
@@ -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