doVecPackOp :: Maybe MachOp  -- Cast from element to vector component
            -> CmmType       -- Type of vector
            -> CmmExpr       -- Initial vector
            -> [CmmExpr]     -- Elements
            -> CmmFormal     -- Destination for result
            -> FCode ()
doVecPackOp maybe_pre_write_cast ty z es res = do
    dst <- newTemp ty
    emitAssign (CmmLocal dst) z
    vecPack dst es 0
  where
    vecPack :: CmmFormal -> [CmmExpr] -> Int -> FCode ()
    vecPack src [] _ =
        emitAssign (CmmLocal res) (CmmReg (CmmLocal src))

    vecPack src (e : es) i = do
        dst <- newTemp ty
        if isFloatType (vecElemType ty)
          then emitAssign (CmmLocal dst) (CmmMachOp (MO_VF_Insert len wid)
                                                    [CmmReg (CmmLocal src), cast e, iLit])
          else emitAssign (CmmLocal dst) (CmmMachOp (MO_V_Insert len wid)
                                                    [CmmReg (CmmLocal src), cast e, iLit])
        vecPack dst es (i + 1)
      where
        -- vector indices are always 32-bits
        iLit = CmmLit (CmmInt (toInteger i) W32)

    cast :: CmmExpr -> CmmExpr
    cast val = case maybe_pre_write_cast of
                 Nothing   -> val
                 Just cast -> CmmMachOp cast [val]

    len :: Length
    len = vecLength ty

    wid :: Width
    wid = typeWidth (vecElemType ty)
doVecPackOp :: Maybe MachOp  -- Cast from element to vector component
            -> CmmType       -- Type of vector
            -> CmmExpr       -- Initial vector
            -> [CmmExpr]     -- Elements
            -> CmmFormal     -- Destination for result
            -> FCode ()
doVecPackOp maybe_pre_write_cast ty z es res = do
    dst <- newTemp ty
    emitAssign (CmmLocal dst) z
    vecPack dst es 0
  where
    vecPack :: CmmFormal -> [CmmExpr] -> Int -> FCode ()
    vecPack src [] _ =
        emitAssign (CmmLocal res) (CmmReg (CmmLocal src))

    vecPack src (e : es) i = do
        dst <- newTemp ty
        if isFloatType (vecElemType ty)
          then emitAssign (CmmLocal dst) (CmmMachOp (MO_VF_Insert len wid)
                                                    [CmmReg (CmmLocal src), cast e, iLit])
          else emitAssign (CmmLocal dst) (CmmMachOp (MO_V_Insert len wid)
                                                    [CmmReg (CmmLocal src), cast e, iLit])
        vecPack dst es (i + 1)
      where
        -- vector indices are always 32-bits
        iLit = CmmLit (CmmInt (toInteger i) W32)

    cast :: CmmExpr -> CmmExpr
    cast val = case maybe_pre_write_cast of
                 Nothing   -> val
                 Just cast -> CmmMachOp cast [val]

    len :: Length
    len = vecLength ty

    wid :: Width
    wid = typeWidth (vecElemType ty)
doVecPackOp maybe_pre_write_cast ty z es res = do
    dst <- newTemp ty
    emitAssign (CmmLocal dst) z
    vecPack dst es 0
  where
    vecPack :: CmmFormal -> [CmmExpr] -> Int -> FCode ()
    vecPack src [] _ =
        emitAssign (CmmLocal res) (CmmReg (CmmLocal src))

    vecPack src (e : es) i = do
        dst <- newTemp ty
        if isFloatType (vecElemType ty)
          then emitAssign (CmmLocal dst) (CmmMachOp (MO_VF_Insert len wid)
                                                    [CmmReg (CmmLocal src), cast e, iLit])
          else emitAssign (CmmLocal dst) (CmmMachOp (MO_V_Insert len wid)
                                                    [CmmReg (CmmLocal src), cast e, iLit])
        vecPack dst es (i + 1)
      where
        -- vector indices are always 32-bits
        iLit = CmmLit (CmmInt (toInteger i) W32)

    cast :: CmmExpr -> CmmExpr
    cast val = case maybe_pre_write_cast of
                 Nothing   -> val
                 Just cast -> CmmMachOp cast [val]

    len :: Length
    len = vecLength ty

    wid :: Width
    wid = typeWidth (vecElemType ty)