doIndexByteArrayOpAs :: Maybe MachOp
                    -> CmmType
                    -> CmmType
                    -> [LocalReg]
                    -> [CmmExpr]
                    -> FCode ()
doIndexByteArrayOpAs maybe_post_read_cast rep idx_rep [res] [addr,idx]
   = do dflags <- getDynFlags
        mkBasicIndexedRead (arrWordsHdrSize dflags) maybe_post_read_cast rep res addr idx_rep idx
doIndexByteArrayOpAs :: Maybe MachOp
                    -> CmmType
                    -> CmmType
                    -> [LocalReg]
                    -> [CmmExpr]
                    -> FCode ()
doIndexByteArrayOpAs maybe_post_read_cast rep idx_rep [res] [addr,idx]
   = do dflags <- getDynFlags
        mkBasicIndexedRead (arrWordsHdrSize dflags) maybe_post_read_cast rep res addr idx_rep idx
doIndexByteArrayOpAs maybe_post_read_cast rep idx_rep [res] [addr,idx]
   = do dflags <- getDynFlags
        mkBasicIndexedRead (arrWordsHdrSize dflags) maybe_post_read_cast rep res addr idx_rep idx