doPrefetchByteArrayOp :: Int
                      -> [CmmExpr]
                      -> FCode ()
doPrefetchByteArrayOp locality  [addr,idx]
   = do dflags <- getDynFlags
        mkBasicPrefetch locality (arrWordsHdrSize dflags)  addr idx
doPrefetchByteArrayOp :: Int
                      -> [CmmExpr]
                      -> FCode ()
doPrefetchByteArrayOp locality  [addr,idx]
   = do dflags <- getDynFlags
        mkBasicPrefetch locality (arrWordsHdrSize dflags)  addr idx
doPrefetchByteArrayOp locality  [addr,idx]
   = do dflags <- getDynFlags
        mkBasicPrefetch locality (arrWordsHdrSize dflags)  addr idx