+iselExpr64 (CmmMachOp (MO_U_Conv I32 I64) [expr]) = do
+ (expr_reg,expr_code) <- getSomeReg expr
+ (rlo, rhi) <- getNewRegPairNat I32
+ let mov_hi = LI rhi (ImmInt 0)
+ mov_lo = MR rlo expr_reg
+ return $ ChildCode64 (expr_code `snocOL` mov_lo `snocOL` mov_hi)
+ rlo