Update CmmRegOff shorthand for CmmMachOp.

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>

diff --git a/compiler/cmm/CmmExpr.hs b/compiler/cmm/CmmExpr.hs
index 3ae2996..55a5b73 100644 (file)
--- 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