    {-# LANGUAGE FlexibleContexts #-}

    module GHC.Types.RepType
      (
        -- * Code generator views onto Types
        UnaryType, NvUnaryType, isNvUnaryRep,
        unwrapType,

        -- * Predicates on types
        isZeroBitTy,

        -- * Type representation for the code generator
        typePrimRep, typePrimRep1, typePrimRepU,
        runtimeRepPrimRep,
        PrimRep(..), primRepToRuntimeRep, primRepToType,
        countFunRepArgs, countConRepArgs, dataConRuntimeRepStrictness,
        tyConPrimRep,
        runtimeRepPrimRep_maybe, kindPrimRep_maybe, typePrimRep_maybe,

        -- * Unboxed sum representation type
        ubxSumRepType, layoutUbxSum, repSlotTy, SlotTy (..),
        slotPrimRep, primRepSlot,

        -- * Is this type known to be data?
        mightBeFunTy

        ) where

    import GHC.Prelude

    import GHC.Types.Basic (Arity, RepArity)
    import GHC.Core.DataCon
    import GHC.Core.Coercion
    import GHC.Core.TyCon
    import GHC.Core.TyCon.RecWalk
    import GHC.Core.TyCo.Rep
    import GHC.Core.Type
    import {-# SOURCE #-} GHC.Builtin.Types ( anyTypeOfKind
      , vecRepDataConTyCon
      , liftedRepTy, unliftedRepTy
      , intRepDataConTy
      , int8RepDataConTy, int16RepDataConTy, int32RepDataConTy, int64RepDataConTy
      , wordRepDataConTy
      , word16RepDataConTy, word8RepDataConTy, word32RepDataConTy, word64RepDataConTy
      , addrRepDataConTy
      , floatRepDataConTy, doubleRepDataConTy
      , vec2DataConTy, vec4DataConTy, vec8DataConTy, vec16DataConTy, vec32DataConTy
      , vec64DataConTy
      , int8ElemRepDataConTy, int16ElemRepDataConTy, int32ElemRepDataConTy
      , int64ElemRepDataConTy, word8ElemRepDataConTy, word16ElemRepDataConTy
      , word32ElemRepDataConTy, word64ElemRepDataConTy, floatElemRepDataConTy
      , doubleElemRepDataConTy )

    import GHC.Utils.Misc
    import GHC.Utils.Outputable
    import GHC.Utils.Panic

    import Data.List.NonEmpty (NonEmpty (..))
    import Data.List (sort)
    import qualified Data.IntSet as IS

    {- **********************************************************************
    *                                                                       *
                    Representation types
    *                                                                       *
    ********************************************************************** -}

    type NvUnaryType = Type
    type UnaryType   = Type
         -- Both are always a value type; i.e. its kind is TYPE rr
         -- for some rr; moreover the rr is never a variable.
         --
         --   NvUnaryType : never an unboxed tuple or sum, or void
         --
         --   UnaryType   : never an unboxed tuple or sum;
         --                 can be Void# or (# #)

    isNvUnaryRep :: [PrimRep] -> Bool
    isNvUnaryRep :: [PrimRep] -> Bool
    isNvUnaryRep [PrimRep
    _] = Bool
    True
    isNvUnaryRep [PrimRep]
    _ = Bool
    False

    -- | Gets rid of the stuff that prevents us from understanding the
    -- runtime representation of a type. Including:
    --   1. Casts
    --   2. Newtypes
    --   3. Foralls
    --   4. Synonyms
    -- But not type/data families, because we don't have the envs to hand.
    unwrapType :: Type -> Type
    unwrapType :: Type -> Type
    unwrapType Type
    ty
      | Just (()
    _, Type
    unwrapped)
          <- NormaliseStepper () -> (() -> () -> ()) -> Type -> Maybe ((), Type)
    forall ev.
    NormaliseStepper ev -> (ev -> ev -> ev) -> Type -> Maybe (ev, Type)
    topNormaliseTypeX NormaliseStepper ()
    stepper () -> () -> ()
    forall a. Monoid a => a -> a -> a
    mappend Type
    inner_ty
      = Type
    unwrapped
      | Bool
    otherwise
      = Type
    inner_ty
      where
        inner_ty :: Type
    inner_ty = Type -> Type
    go Type
    ty

        go :: Type -> Type
    go Type
    t | Just Type
    t' <- Type -> Maybe Type
    coreView Type
    t = Type -> Type
    go Type
    t'
        go (ForAllTy ForAllTyBinder
    _ Type
    t)            = Type -> Type
    go Type
    t
        go (CastTy Type
    t KindCoercion
    _)              = Type -> Type
    go Type
    t
        go Type
    t                         = Type
    t

         -- cf. Coercion.unwrapNewTypeStepper
        stepper :: NormaliseStepper ()
    stepper RecTcChecker
    rec_nts TyCon
    tc [Type]
    tys
          | Just (Type
    ty', KindCoercion
    _) <- TyCon -> [Type] -> Maybe (Type, KindCoercion)
    instNewTyCon_maybe TyCon
    tc [Type]
    tys
          = case RecTcChecker -> TyCon -> Maybe RecTcChecker
    checkRecTc RecTcChecker
    rec_nts TyCon
    tc of
              Just RecTcChecker
    rec_nts' -> RecTcChecker -> Type -> () -> NormaliseStepResult ()
    forall ev. RecTcChecker -> Type -> ev -> NormaliseStepResult ev
    NS_Step RecTcChecker
    rec_nts' (Type -> Type
    go Type
    ty') ()
              Maybe RecTcChecker
    Nothing       -> NormaliseStepResult ()
    forall ev. NormaliseStepResult ev
    NS_Abort   -- infinite newtypes
          | Bool
    otherwise
          = NormaliseStepResult ()
    forall ev. NormaliseStepResult ev
    NS_Done

    -- | Count the arity of a function post-unarisation, including zero-width arguments.
    --
    -- The post-unarisation arity may be larger than the arity of the original
    -- function type. See Note [Unarisation].
    countFunRepArgs :: Arity -> Type -> RepArity
    countFunRepArgs :: Int -> Type -> Int
    countFunRepArgs Int
    0 Type
    _
      = Int
    0
    countFunRepArgs Int
    n Type
    ty
      | FunTy FunTyFlag
    _ Type
    _ Type
    arg Type
    res <- Type -> Type
    unwrapType Type
    ty
      = ([PrimRep] -> Int
    forall a. [a] -> Int
    forall (t :: * -> *) a. Foldable t => t a -> Int
    length (HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    arg) Int -> Int -> Int
    forall a. Ord a => a -> a -> a
    `max` Int
    1)
        Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Int -> Type -> Int
    countFunRepArgs (Int
    n Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    1) Type
    res
        -- If typePrimRep returns [] that means a void arg,
        -- and we count 1 for that
      | Bool
    otherwise
      = String -> SDoc -> Int
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "countFunRepArgs: arity greater than type can handle" ((Int, Type, [PrimRep]) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (Int
    n, Type
    ty, HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    ty))

    countConRepArgs :: DataCon -> RepArity
    countConRepArgs :: DataCon -> Int
    countConRepArgs DataCon
    dc = Int -> Type -> Int
    go (DataCon -> Int
    dataConRepArity DataCon
    dc) (DataCon -> Type
    dataConRepType DataCon
    dc)
      where
        go :: Arity -> Type -> RepArity
        go :: Int -> Type -> Int
    go Int
    0 Type
    _
          = Int
    0
        go Int
    n Type
    ty
          | FunTy FunTyFlag
    _ Type
    _ Type
    arg Type
    res <- Type -> Type
    unwrapType Type
    ty
          = [PrimRep] -> Int
    forall a. [a] -> Int
    forall (t :: * -> *) a. Foldable t => t a -> Int
    length (HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    arg) Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Int -> Type -> Int
    go (Int
    n Int -> Int -> Int
    forall a. Num a => a -> a -> a
    - Int
    1) Type
    res
          | Bool
    otherwise
          = String -> SDoc -> Int
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "countConRepArgs: arity greater than type can handle" ((Int, Type, [PrimRep]) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (Int
    n, Type
    ty, HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    ty))

    dataConRuntimeRepStrictness :: HasDebugCallStack => DataCon -> [StrictnessMark]
    -- ^ Give the demands on the arguments of a
    -- Core constructor application (Con dc args) at runtime.
    -- Assumes the constructor is not levity polymorphic. For example
    -- unboxed tuples won't work.
    dataConRuntimeRepStrictness :: HasDebugCallStack => DataCon -> [StrictnessMark]
    dataConRuntimeRepStrictness DataCon
    dc =

      -- pprTrace "dataConRuntimeRepStrictness" (ppr dc $$ ppr (dataConRepArgTys dc)) $

      let repMarks :: [StrictnessMark]
    repMarks = DataCon -> [StrictnessMark]
    dataConRepStrictness DataCon
    dc
          repTys :: [Type]
    repTys = (Scaled Type -> Type) -> [Scaled Type] -> [Type]
    forall a b. (a -> b) -> [a] -> [b]
    map Scaled Type -> Type
    forall a. Scaled a -> a
    irrelevantMult ([Scaled Type] -> [Type]) -> [Scaled Type] -> [Type]
    forall a b. (a -> b) -> a -> b
    $ DataCon -> [Scaled Type]
    dataConRepArgTys DataCon
    dc
      in -- todo: assert dc != unboxedTuple/unboxedSum
         [StrictnessMark] -> [Type] -> [StrictnessMark] -> [StrictnessMark]
    go [StrictnessMark]
    repMarks [Type]
    repTys []
      where
        go :: [StrictnessMark] -> [Type] -> [StrictnessMark] -> [StrictnessMark]
    go (StrictnessMark
    mark:[StrictnessMark]
    marks) (Type
    ty:[Type]
    types) [StrictnessMark]
    out_marks
          = case [PrimRep]
    reps of
              -- Zero-width argument, mark is irrelevant at runtime.
              [] -> -- pprTrace "VoidTy" (ppr ty) $
                    [StrictnessMark] -> [Type] -> [StrictnessMark] -> [StrictnessMark]
    go [StrictnessMark]
    marks [Type]
    types [StrictnessMark]
    out_marks
              -- Single rep argument, e.g. Int
              -- Keep mark as-is
              [PrimRep
    _] -> [StrictnessMark] -> [Type] -> [StrictnessMark] -> [StrictnessMark]
    go [StrictnessMark]
    marks [Type]
    types (StrictnessMark
    markStrictnessMark -> [StrictnessMark] -> [StrictnessMark]
    forall a. a -> [a] -> [a]
    :[StrictnessMark]
    out_marks)
              -- Multi-rep argument, e.g. (# Int, Bool #) or (# Int | Bool #)
              -- Make up one non-strict mark per runtime argument.
              [PrimRep]
    _ -> [StrictnessMark] -> [Type] -> [StrictnessMark] -> [StrictnessMark]
    go [StrictnessMark]
    marks [Type]
    types ((Int -> StrictnessMark -> [StrictnessMark]
    forall a. Int -> a -> [a]
    replicate ([PrimRep] -> Int
    forall a. [a] -> Int
    forall (t :: * -> *) a. Foldable t => t a -> Int
    length [PrimRep]
    reps) StrictnessMark
    NotMarkedStrict)[StrictnessMark] -> [StrictnessMark] -> [StrictnessMark]
    forall a. [a] -> [a] -> [a]
    ++[StrictnessMark]
    out_marks)
          where
            reps :: [PrimRep]
    reps = HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    ty
        go [] [] [StrictnessMark]
    out_marks = [StrictnessMark] -> [StrictnessMark]
    forall a. [a] -> [a]
    reverse [StrictnessMark]
    out_marks
        go [StrictnessMark]
    _m [Type]
    _t [StrictnessMark]
    _o = String -> SDoc -> [StrictnessMark]
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "dataConRuntimeRepStrictness2" (DataCon -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr DataCon
    dc SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ [StrictnessMark] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [StrictnessMark]
    _m SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ [Type] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [Type]
    _t SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ [StrictnessMark] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [StrictnessMark]
    _o)

    -- | True if the type has zero width.
    isZeroBitTy :: HasDebugCallStack => Type -> Bool
    isZeroBitTy :: HasDebugCallStack => Type -> Bool
    isZeroBitTy = [PrimRep] -> Bool
    forall a. [a] -> Bool
    forall (t :: * -> *) a. Foldable t => t a -> Bool
    null ([PrimRep] -> Bool) -> (Type -> [PrimRep]) -> Type -> Bool
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep

    {- **********************************************************************
    *                                                                       *
                    Unboxed sums
     See Note [Translating unboxed sums to unboxed tuples] in GHC.Stg.Unarise
    *                                                                       *
    ********************************************************************** -}

    type SortedSlotTys = [SlotTy]

    -- | Given the arguments of a sum type constructor application,
    --   return the unboxed sum rep type.
    --
    -- E.g.
    --
    --   (# Int# | Maybe Int | (# Int#, Float# #) #)
    --
    -- We call `ubxSumRepType [ [IntRep], [LiftedRep], [IntRep, FloatRep] ]`,
    -- which returns [WordSlot, PtrSlot, WordSlot, FloatSlot]
    --
    -- INVARIANT: Result slots are sorted (via Ord SlotTy), except that at the head
    -- of the list we have the slot for the tag.
    ubxSumRepType :: [[PrimRep]] -> NonEmpty SlotTy
    ubxSumRepType :: [[PrimRep]] -> NonEmpty SlotTy
    ubxSumRepType [[PrimRep]]
    constrs0
      -- These first two cases never classify an actual unboxed sum, which always
      -- has at least two disjuncts. But it could happen if a user writes, e.g.,
      -- forall (a :: TYPE (SumRep [IntRep])). ...
      -- which could never be instantiated. We still don't want to panic.
      | [[PrimRep]]
    constrs0 [[PrimRep]] -> Int -> Bool
    forall a. [a] -> Int -> Bool
    `lengthLessThan` Int
    2
      = SlotTy
    WordSlot SlotTy -> [SlotTy] -> NonEmpty SlotTy
    forall a. a -> [a] -> NonEmpty a
    :| []

      | Bool
    otherwise
      = let
          combine_alts :: [SortedSlotTys]  -- slots of constructors
                       -> SortedSlotTys    -- final slots
          combine_alts :: [[SlotTy]] -> [SlotTy]
    combine_alts [[SlotTy]]
    constrs = ([SlotTy] -> [SlotTy] -> [SlotTy])
    -> [SlotTy] -> [[SlotTy]] -> [SlotTy]
    forall b a. (b -> a -> b) -> b -> [a] -> b
    forall (t :: * -> *) b a.
    Foldable t =>
    (b -> a -> b) -> b -> t a -> b
    foldl' [SlotTy] -> [SlotTy] -> [SlotTy]
    merge [] [[SlotTy]]
    constrs

          merge :: SortedSlotTys -> SortedSlotTys -> SortedSlotTys
          merge :: [SlotTy] -> [SlotTy] -> [SlotTy]
    merge [SlotTy]
    existing_slots []
            = [SlotTy]
    existing_slots
          merge [] [SlotTy]
    needed_slots
            = [SlotTy]
    needed_slots
          merge (SlotTy
    es : [SlotTy]
    ess) (SlotTy
    s : [SlotTy]
    ss)
            | Just SlotTy
    s' <- SlotTy
    s SlotTy -> SlotTy -> Maybe SlotTy
    `fitsIn` SlotTy
    es
            = -- found a slot, use it
              SlotTy
    s' SlotTy -> [SlotTy] -> [SlotTy]
    forall a. a -> [a] -> [a]
    : [SlotTy] -> [SlotTy] -> [SlotTy]
    merge [SlotTy]
    ess [SlotTy]
    ss
            | SlotTy
    s SlotTy -> SlotTy -> Bool
    forall a. Ord a => a -> a -> Bool
    < SlotTy
    es
            = -- we need a new slot and this is the right place for it
              SlotTy
    s SlotTy -> [SlotTy] -> [SlotTy]
    forall a. a -> [a] -> [a]
    : [SlotTy] -> [SlotTy] -> [SlotTy]
    merge (SlotTy
    es SlotTy -> [SlotTy] -> [SlotTy]
    forall a. a -> [a] -> [a]
    : [SlotTy]
    ess) [SlotTy]
    ss
            | Bool
    otherwise
            = -- keep searching for a slot
              SlotTy
    es SlotTy -> [SlotTy] -> [SlotTy]
    forall a. a -> [a] -> [a]
    : [SlotTy] -> [SlotTy] -> [SlotTy]
    merge [SlotTy]
    ess (SlotTy
    s SlotTy -> [SlotTy] -> [SlotTy]
    forall a. a -> [a] -> [a]
    : [SlotTy]
    ss)

          -- Nesting unboxed tuples and sums is OK, so we need to flatten first.
          rep :: [PrimRep] -> SortedSlotTys
          rep :: [PrimRep] -> [SlotTy]
    rep [PrimRep]
    ty = [SlotTy] -> [SlotTy]
    forall a. Ord a => [a] -> [a]
    sort ((PrimRep -> SlotTy) -> [PrimRep] -> [SlotTy]
    forall a b. (a -> b) -> [a] -> [b]
    map PrimRep -> SlotTy
    primRepSlot [PrimRep]
    ty)

          sumRep :: NonEmpty SlotTy
    sumRep = SlotTy
    WordSlot SlotTy -> [SlotTy] -> NonEmpty SlotTy
    forall a. a -> [a] -> NonEmpty a
    :| [[SlotTy]] -> [SlotTy]
    combine_alts (([PrimRep] -> [SlotTy]) -> [[PrimRep]] -> [[SlotTy]]
    forall a b. (a -> b) -> [a] -> [b]
    map [PrimRep] -> [SlotTy]
    rep [[PrimRep]]
    constrs0)
                   -- WordSlot: for the tag of the sum
        in
          NonEmpty SlotTy
    sumRep

    layoutUbxSum :: HasDebugCallStack
                 => SortedSlotTys -- Layout of sum. Does not include tag.
                                  -- We assume that they are in increasing order
                 -> [SlotTy]      -- Slot types of things we want to map to locations in the
                                  -- sum layout
                 -> [Int]         -- Where to map 'things' in the sum layout
    layoutUbxSum :: HasDebugCallStack => [SlotTy] -> [SlotTy] -> [Int]
    layoutUbxSum [SlotTy]
    sum_slots0 [SlotTy]
    arg_slots0 =
        [SlotTy] -> IntSet -> [Int]
    go [SlotTy]
    arg_slots0 IntSet
    IS.empty
      where
        go :: [SlotTy] -> IS.IntSet -> [Int]
        go :: [SlotTy] -> IntSet -> [Int]
    go [] IntSet
    _
          = []
        go (SlotTy
    arg : [SlotTy]
    args) IntSet
    used
          = let slot_idx :: Int
    slot_idx = SlotTy -> Int -> [SlotTy] -> IntSet -> Int
    findSlot SlotTy
    arg Int
    0 [SlotTy]
    sum_slots0 IntSet
    used
             in Int
    slot_idx Int -> [Int] -> [Int]
    forall a. a -> [a] -> [a]
    : [SlotTy] -> IntSet -> [Int]
    go [SlotTy]
    args (Int -> IntSet -> IntSet
    IS.insert Int
    slot_idx IntSet
    used)

        findSlot :: SlotTy -> Int -> SortedSlotTys -> IS.IntSet -> Int
        findSlot :: SlotTy -> Int -> [SlotTy] -> IntSet -> Int
    findSlot SlotTy
    arg Int
    slot_idx (SlotTy
    slot : [SlotTy]
    slots) IntSet
    useds
          | Bool -> Bool
    not (Int -> IntSet -> Bool
    IS.member Int
    slot_idx IntSet
    useds)
          , SlotTy -> Maybe SlotTy
    forall a. a -> Maybe a
    Just SlotTy
    slot Maybe SlotTy -> Maybe SlotTy -> Bool
    forall a. Eq a => a -> a -> Bool
    == SlotTy
    arg SlotTy -> SlotTy -> Maybe SlotTy
    `fitsIn` SlotTy
    slot
          = Int
    slot_idx
          | Bool
    otherwise
          = SlotTy -> Int -> [SlotTy] -> IntSet -> Int
    findSlot SlotTy
    arg (Int
    slot_idx Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Int
    1) [SlotTy]
    slots IntSet
    useds
        findSlot SlotTy
    _ Int
    _ [] IntSet
    _
          = String -> SDoc -> Int
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "findSlot" (String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "Can't find slot" SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "sum_slots:" SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <> [SlotTy] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [SlotTy]
    sum_slots0
                                                        SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "arg_slots:" SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <> [SlotTy] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [SlotTy]
    arg_slots0 )

    --------------------------------------------------------------------------------

    -- We have 3 kinds of slots:
    --
    --   - Pointer slot: Only shared between actual pointers to Haskell heap (i.e.
    --     boxed objects). These come in two variants: Lifted and unlifted (see
    --     #19645).
    --
    --   - Word slots: Shared between IntRep, WordRep, Int64Rep, Word64Rep, AddrRep.
    --
    --   - Float slots: Shared between floating point types.
    --
    --   - Void slots: Shared between void types. Not used in sums.
    --
    -- TODO(michalt): We should probably introduce `SlotTy`s for 8-/16-/32-bit
    -- values, so that we can pack things more tightly.
    data SlotTy = PtrLiftedSlot | PtrUnliftedSlot | WordSlot | Word64Slot | FloatSlot | DoubleSlot | VecSlot Int PrimElemRep
      deriving (SlotTy -> SlotTy -> Bool
    (SlotTy -> SlotTy -> Bool)
    -> (SlotTy -> SlotTy -> Bool) -> Eq SlotTy
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: SlotTy -> SlotTy -> Bool
    == :: SlotTy -> SlotTy -> Bool
    $c/= :: SlotTy -> SlotTy -> Bool
    /= :: SlotTy -> SlotTy -> Bool
    Eq, Eq SlotTy
    Eq SlotTy =>
    (SlotTy -> SlotTy -> Ordering)
    -> (SlotTy -> SlotTy -> Bool)
    -> (SlotTy -> SlotTy -> Bool)
    -> (SlotTy -> SlotTy -> Bool)
    -> (SlotTy -> SlotTy -> Bool)
    -> (SlotTy -> SlotTy -> SlotTy)
    -> (SlotTy -> SlotTy -> SlotTy)
    -> Ord SlotTy
    SlotTy -> SlotTy -> Bool
    SlotTy -> SlotTy -> Ordering
    SlotTy -> SlotTy -> SlotTy
    forall a.
    Eq a =>
    (a -> a -> Ordering)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> a)
    -> (a -> a -> a)
    -> Ord a
    $ccompare :: SlotTy -> SlotTy -> Ordering
    compare :: SlotTy -> SlotTy -> Ordering
    $c< :: SlotTy -> SlotTy -> Bool
    < :: SlotTy -> SlotTy -> Bool
    $c<= :: SlotTy -> SlotTy -> Bool
    <= :: SlotTy -> SlotTy -> Bool
    $c> :: SlotTy -> SlotTy -> Bool
    > :: SlotTy -> SlotTy -> Bool
    $c>= :: SlotTy -> SlotTy -> Bool
    >= :: SlotTy -> SlotTy -> Bool
    $cmax :: SlotTy -> SlotTy -> SlotTy
    max :: SlotTy -> SlotTy -> SlotTy
    $cmin :: SlotTy -> SlotTy -> SlotTy
    min :: SlotTy -> SlotTy -> SlotTy
    Ord)
        -- Constructor order is important! If slot A could fit into slot B
        -- then slot A must occur first.  E.g.  FloatSlot before DoubleSlot
        --
        -- We are assuming that WordSlot is smaller than or equal to Word64Slot
        -- (would not be true on a 128-bit machine)

    instance Outputable SlotTy where
      ppr :: SlotTy -> SDoc
    ppr SlotTy
    PtrLiftedSlot   = String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "PtrLiftedSlot"
      ppr SlotTy
    PtrUnliftedSlot = String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "PtrUnliftedSlot"
      ppr SlotTy
    Word64Slot      = String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "Word64Slot"
      ppr SlotTy
    WordSlot        = String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "WordSlot"
      ppr SlotTy
    DoubleSlot      = String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "DoubleSlot"
      ppr SlotTy
    FloatSlot       = String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "FloatSlot"
      ppr (VecSlot Int
    n PrimElemRep
    e)   = String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "VecSlot" SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <+> Int -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Int
    n SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <+> PrimElemRep -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr PrimElemRep
    e

    repSlotTy :: [PrimRep] -> Maybe SlotTy
    repSlotTy :: [PrimRep] -> Maybe SlotTy
    repSlotTy [PrimRep]
    reps = case [PrimRep]
    reps of
                      [] -> Maybe SlotTy
    forall a. Maybe a
    Nothing
                      [PrimRep
    rep] -> SlotTy -> Maybe SlotTy
    forall a. a -> Maybe a
    Just (PrimRep -> SlotTy
    primRepSlot PrimRep
    rep)
                      [PrimRep]
    _ -> String -> SDoc -> Maybe SlotTy
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "repSlotTy" ([PrimRep] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [PrimRep]
    reps)

    primRepSlot :: PrimRep -> SlotTy
    primRepSlot :: PrimRep -> SlotTy
    primRepSlot (BoxedRep Maybe Levity
    mlev) = case Maybe Levity
    mlev of
      Maybe Levity
    Nothing       -> String -> SlotTy
    forall a. HasCallStack => String -> a
    panic String
    "primRepSlot: levity polymorphic BoxedRep"
      Just Levity
    Lifted   -> SlotTy
    PtrLiftedSlot
      Just Levity
    Unlifted -> SlotTy
    PtrUnliftedSlot
    primRepSlot PrimRep
    IntRep      = SlotTy
    WordSlot
    primRepSlot PrimRep
    Int8Rep     = SlotTy
    WordSlot
    primRepSlot PrimRep
    Int16Rep    = SlotTy
    WordSlot
    primRepSlot PrimRep
    Int32Rep    = SlotTy
    WordSlot
    primRepSlot PrimRep
    Int64Rep    = SlotTy
    Word64Slot
    primRepSlot PrimRep
    WordRep     = SlotTy
    WordSlot
    primRepSlot PrimRep
    Word8Rep    = SlotTy
    WordSlot
    primRepSlot PrimRep
    Word16Rep   = SlotTy
    WordSlot
    primRepSlot PrimRep
    Word32Rep   = SlotTy
    WordSlot
    primRepSlot PrimRep
    Word64Rep   = SlotTy
    Word64Slot
    primRepSlot PrimRep
    AddrRep     = SlotTy
    WordSlot
    primRepSlot PrimRep
    FloatRep    = SlotTy
    FloatSlot
    primRepSlot PrimRep
    DoubleRep   = SlotTy
    DoubleSlot
    primRepSlot (VecRep Int
    n PrimElemRep
    e) = Int -> PrimElemRep -> SlotTy
    VecSlot Int
    n PrimElemRep
    e

    slotPrimRep :: SlotTy -> PrimRep
    slotPrimRep :: SlotTy -> PrimRep
    slotPrimRep SlotTy
    PtrLiftedSlot   = Maybe Levity -> PrimRep
    BoxedRep (Levity -> Maybe Levity
    forall a. a -> Maybe a
    Just Levity
    Lifted)
    slotPrimRep SlotTy
    PtrUnliftedSlot = Maybe Levity -> PrimRep
    BoxedRep (Levity -> Maybe Levity
    forall a. a -> Maybe a
    Just Levity
    Unlifted)
    slotPrimRep SlotTy
    Word64Slot      = PrimRep
    Word64Rep
    slotPrimRep SlotTy
    WordSlot        = PrimRep
    WordRep
    slotPrimRep SlotTy
    DoubleSlot      = PrimRep
    DoubleRep
    slotPrimRep SlotTy
    FloatSlot       = PrimRep
    FloatRep
    slotPrimRep (VecSlot Int
    n PrimElemRep
    e)   = Int -> PrimElemRep -> PrimRep
    VecRep Int
    n PrimElemRep
    e

    -- | Returns the bigger type if one fits into the other. (commutative)
    --
    -- Note that lifted and unlifted pointers are *not* in a fits-in relation for
    -- the reasons described in Note [Don't merge lifted and unlifted slots] in
    -- GHC.Stg.Unarise.
    fitsIn :: SlotTy -> SlotTy -> Maybe SlotTy
    fitsIn :: SlotTy -> SlotTy -> Maybe SlotTy
    fitsIn SlotTy
    ty1 SlotTy
    ty2
      | SlotTy
    ty1 SlotTy -> SlotTy -> Bool
    forall a. Eq a => a -> a -> Bool
    == SlotTy
    ty2
      = SlotTy -> Maybe SlotTy
    forall a. a -> Maybe a
    Just SlotTy
    ty1
      | SlotTy -> Bool
    isWordSlot SlotTy
    ty1 Bool -> Bool -> Bool
    && SlotTy -> Bool
    isWordSlot SlotTy
    ty2
      = SlotTy -> Maybe SlotTy
    forall a. a -> Maybe a
    Just (SlotTy -> SlotTy -> SlotTy
    forall a. Ord a => a -> a -> a
    max SlotTy
    ty1 SlotTy
    ty2)
      | Bool
    otherwise
      = Maybe SlotTy
    forall a. Maybe a
    Nothing
      -- We used to share slots between Float/Double but currently we can't easily
      -- covert between float/double in a way that is both work free and safe.
      -- So we put them in different slots.
      -- See Note [Casting slot arguments]
      where
        isWordSlot :: SlotTy -> Bool
    isWordSlot SlotTy
    Word64Slot = Bool
    True
        isWordSlot SlotTy
    WordSlot   = Bool
    True
        isWordSlot SlotTy
    _          = Bool
    False

    {- **********************************************************************
    *                                                                       *
                       PrimRep
    *                                                                       *
    *************************************************************************

    Note [RuntimeRep and PrimRep]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    This Note describes the relationship between GHC.Types.RuntimeRep
    (of levity/representation polymorphism fame) and GHC.Core.TyCon.PrimRep,
    as these types are closely related.

    A "primitive entity" is one that can be
     * stored in one register
     * manipulated with one machine instruction

    Examples include:
     * a 32-bit integer
     * a 32-bit float
     * a 64-bit float
     * a machine address (heap pointer), etc.
     * a quad-float (on a machine with SIMD register and instructions)
     * ...etc...

    The "representation or a primitive entity" specifies what kind of register is
    needed and how many bits are required. The data type GHC.Core.TyCon.PrimRep
    enumerates all the possibilities.

    data PrimRep
      = LiftedRep     -- ^ Lifted pointer
      | UnliftedRep   -- ^ Unlifted pointer
      | Int8Rep       -- ^ Signed, 8-bit value
      | Int16Rep      -- ^ Signed, 16-bit value
      ...etc...
      | VecRep Int PrimElemRep  -- ^ SIMD fixed-width vector

    The Haskell source language is a bit more flexible: a single value may need multiple PrimReps.
    For example

      utup :: (# Int, Int #) -> Bool
      utup x = ...

    Here x :: (# Int, Int #), and that takes two registers, and two instructions to move around.
    Unboxed sums are similar.

    Every Haskell expression e has a type ty, whose kind is of form TYPE rep
       e :: ty :: TYPE rep
    where rep :: RuntimeRep. Here rep describes the runtime representation for e's value,
    but RuntimeRep has some extra cases:

    data RuntimeRep = VecRep VecCount VecElem   -- ^ a SIMD vector type
                    | TupleRep [RuntimeRep]     -- ^ An unboxed tuple of the given reps
                    | SumRep [RuntimeRep]       -- ^ An unboxed sum of the given reps
                    | BoxedRep Levity -- ^ boxed; represented by a pointer
                    | IntRep          -- ^ signed, word-sized value
                    ...etc...
    data Levity     = Lifted
                    | Unlifted

    It's all in 1-1 correspondence with PrimRep except for TupleRep and SumRep,
    which describe unboxed products and sums respectively. RuntimeRep is defined
    in the library ghc-prim:GHC.Types. It is also "wired-in" to GHC: see
    GHC.Builtin.Types.runtimeRepTyCon. The unarisation pass, in GHC.Stg.Unarise, transforms the
    program, so that every variable has a type that has a PrimRep. For
    example, unarisation transforms our utup function above, to take two Int
    arguments instead of one (# Int, Int #) argument.

    Also, note that boxed types are represented slightly differently in RuntimeRep
    and PrimRep. PrimRep just has the nullary LiftedRep and UnliftedRep data
    constructors. RuntimeRep has a BoxedRep data constructor, which accepts a
    Levity. The subtle distinction is that since BoxedRep can accept a variable
    argument, RuntimeRep can talk about levity polymorphic types. PrimRep, by
    contrast, cannot.

    See also Note [Getting from RuntimeRep to PrimRep] and Note [VoidRep].

    Note [VoidRep]
    ~~~~~~~~~~~~~~
    PrimRep is used to denote one primitive representation.
    Because of unboxed tuples and sums, the representation of a value
    in general is a list of PrimReps. (See also Note [RuntimeRep and PrimRep].)

    For example:
        typePrimRep Int#             = [IntRep]
        typePrimRep Int              = [LiftedRep]
        typePrimRep (# Int#, Int# #) = [IntRep,IntRep]
        typePrimRep (# #)            = []
        typePrimRep (State# s)       = []

    After the unariser, all identifiers have at most one PrimRep
    (that is, the [PrimRep] for each identifier is empty or a singleton list).
    More precisely: typePrimRep1 will succeed (not crash) on every binder
    and argument type.
    (See Note [Post-unarisation invariants] in GHC.Stg.Unarise.)

    Thus, we have

    1. typePrimRep :: Type -> [PrimRep]
       which returns the list

    2. typePrimRepU :: Type -> PrimRep
       which asserts that the type has exactly one PrimRep and returns it

    3. typePrimRep1 :: Type -> PrimOrVoidRep
       data PrimOrVoidRep = VoidRep | NVRep PrimRep
       which asserts that the type either has exactly one PrimRep or is void.

    Likewise, we have idPrimRepU and idPrimRep1, stgArgRepU and stgArgRep1,
    which have analogous preconditions.

    Note [Getting from RuntimeRep to PrimRep]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    General info on RuntimeRep and PrimRep is in Note [RuntimeRep and PrimRep].

    How do we get from an Id to the list or PrimReps used to store it? We get
    the Id's type ty (using idType), then ty's kind ki (using typeKind), then
    pattern-match on ki to extract rep (in kindPrimRep), then extract the PrimRep
    from the RuntimeRep (in runtimeRepPrimRep).

    We now must convert the RuntimeRep to a list of PrimReps. Let's look at two
    examples:

      1. x :: Int#
      2. y :: (# Int, Word# #)

    With these types, we can extract these kinds:

      1. Int# :: TYPE IntRep
      2. (# Int, Word# #) :: TYPE (TupleRep [LiftedRep, WordRep])

    In the end, we will get these PrimReps:

      1. [IntRep]
      2. [LiftedRep, WordRep]

    It would thus seem that we should have a function somewhere of
    type `RuntimeRep -> [PrimRep]`. This doesn't work though: when we
    look at the argument of TYPE, we get something of type Type (of course).
    RuntimeRep exists in the user's program, but not in GHC as such.
    Instead, we must decompose the Type of kind RuntimeRep into tycons and
    extract the PrimReps from the TyCons. This is what runtimeRepPrimRep does:
    it takes a Type and returns a [PrimRep]

    runtimeRepPrimRep works by using tyConRuntimeRepInfo. That function
    should be passed the TyCon produced by promoting one of the constructors
    of RuntimeRep into type-level data. The RuntimeRep promoted datacons are
    associated with a RuntimeRepInfo (stored directly in the PromotedDataCon
    constructor of TyCon, field promDcRepInfo).
    This pairing happens in GHC.Builtin.Types. A RuntimeRepInfo
    usually(*) contains a function from [Type] to [PrimRep]: the [Type] are
    the arguments to the promoted datacon. These arguments are necessary
    for the TupleRep and SumRep constructors, so that this process can recur,
    producing a flattened list of PrimReps. Calling this extracted function
    happens in runtimeRepPrimRep; the functions themselves are defined in
    tupleRepDataCon and sumRepDataCon, both in GHC.Builtin.Types.

    The (*) above is to support vector representations. RuntimeRep refers
    to VecCount and VecElem, whose promoted datacons have nuggets of information
    related to vectors; these form the other alternatives for RuntimeRepInfo.

    Returning to our examples, the Types we get (after stripping off TYPE) are

      1. TyConApp (PromotedDataCon "IntRep") []
      2. TyConApp (PromotedDataCon "TupleRep")
                  [TyConApp (PromotedDataCon ":")
                            [ TyConApp (AlgTyCon "RuntimeRep") []
                            , TyConApp (PromotedDataCon "LiftedRep") []
                            , TyConApp (PromotedDataCon ":")
                                       [ TyConApp (AlgTyCon "RuntimeRep") []
                                       , TyConApp (PromotedDataCon "WordRep") []
                                       , TyConApp (PromotedDataCon "'[]")
                                                  [TyConApp (AlgTyCon "RuntimeRep") []]]]]

    runtimeRepPrimRep calls tyConRuntimeRepInfo on (PromotedDataCon "IntRep"), resp.
    (PromotedDataCon "TupleRep"), extracting a function that will produce the PrimReps.
    In example 1, this function is passed an empty list (the empty list of args to IntRep)
    and returns the PrimRep IntRep. (See the definition of runtimeRepSimpleDataCons in
    GHC.Builtin.Types and its helper function mk_runtime_rep_dc.) Example 2 passes the promoted
    list as the one argument to the extracted function. The extracted function is defined
    as prim_rep_fun within tupleRepDataCon in GHC.Builtin.Types. It takes one argument, decomposes
    the promoted list (with extractPromotedList), and then recurses back to runtimeRepPrimRep
    to process the LiftedRep and WordRep, concatenating the results.

    -}

    -- | Discovers the primitive representation of a 'Type'. Returns
    -- a list of 'PrimRep': it's a list because of the possibility of
    -- no runtime representation (void) or multiple (unboxed tuple/sum)
    -- See also Note [Getting from RuntimeRep to PrimRep]
    typePrimRep :: HasDebugCallStack => Type -> [PrimRep]
    typePrimRep :: HasDebugCallStack => Type -> [PrimRep]
    typePrimRep Type
    ty = HasDebugCallStack => SDoc -> Type -> [PrimRep]
    SDoc -> Type -> [PrimRep]
    kindPrimRep (String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "typePrimRep" SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <+>
                                  SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc
    parens (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    ty SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <+> SDoc
    dcolon SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (HasDebugCallStack => Type -> Type
    Type -> Type
    typeKind Type
    ty)))
                                 (HasDebugCallStack => Type -> Type
    Type -> Type
    typeKind Type
    ty)

    -- | Discovers the primitive representation of a 'Type'. Returns
    -- a list of 'PrimRep': it's a list because of the possibility of
    -- no runtime representation (void) or multiple (unboxed tuple/sum)
    -- See also Note [Getting from RuntimeRep to PrimRep]
    -- Returns Nothing if rep can't be determined. Eg. levity polymorphic types.
    typePrimRep_maybe :: Type -> Maybe [PrimRep]
    typePrimRep_maybe :: Type -> Maybe [PrimRep]
    typePrimRep_maybe Type
    ty = HasDebugCallStack => Type -> Maybe [PrimRep]
    Type -> Maybe [PrimRep]
    kindPrimRep_maybe (HasDebugCallStack => Type -> Type
    Type -> Type
    typeKind Type
    ty)

    -- | Like 'typePrimRep', but assumes that there is at most one 'PrimRep' output;
    -- an empty list of PrimReps becomes a VoidRep.
    -- This assumption holds after unarise, see Note [Post-unarisation invariants].
    -- Before unarise it may or may not hold.
    -- See also Note [RuntimeRep and PrimRep] and Note [VoidRep]
    typePrimRep1 :: HasDebugCallStack => UnaryType -> PrimOrVoidRep
    typePrimRep1 :: HasDebugCallStack => Type -> PrimOrVoidRep
    typePrimRep1 Type
    ty = case HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    ty of
      []    -> PrimOrVoidRep
    VoidRep
      [PrimRep
    rep] -> PrimRep -> PrimOrVoidRep
    NVRep PrimRep
    rep
      [PrimRep]
    _     -> String -> SDoc -> PrimOrVoidRep
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "typePrimRep1" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    ty SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ [PrimRep] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    ty))

    typePrimRepU :: HasDebugCallStack => NvUnaryType -> PrimRep
    typePrimRepU :: HasDebugCallStack => Type -> PrimRep
    typePrimRepU Type
    ty = case HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    ty of
      [PrimRep
    rep] -> PrimRep
    rep
      [PrimRep]
    _     -> String -> SDoc -> PrimRep
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "typePrimRepU" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    ty SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ [PrimRep] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    ty))

    -- | Find the runtime representation of a 'TyCon'. Defined here to
    -- avoid module loops. Returns a list of the register shapes necessary.
    -- See also Note [Getting from RuntimeRep to PrimRep]
    tyConPrimRep :: HasDebugCallStack => TyCon -> [PrimRep]
    tyConPrimRep :: HasDebugCallStack => TyCon -> [PrimRep]
    tyConPrimRep TyCon
    tc
      = HasDebugCallStack => SDoc -> Type -> [PrimRep]
    SDoc -> Type -> [PrimRep]
    kindPrimRep (String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "kindRep tc" SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <+> TyCon -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyCon
    tc SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    res_kind)
                    Type
    res_kind
      where
        res_kind :: Type
    res_kind = TyCon -> Type
    tyConResKind TyCon
    tc

    -- | Take a kind (of shape @TYPE rr@) and produce the 'PrimRep's
    -- of values of types of this kind.
    -- See also Note [Getting from RuntimeRep to PrimRep]
    kindPrimRep :: HasDebugCallStack => SDoc -> Kind -> [PrimRep]
    kindPrimRep :: HasDebugCallStack => SDoc -> Type -> [PrimRep]
    kindPrimRep SDoc
    doc Type
    ki
      | Just Type
    runtime_rep <- HasDebugCallStack => Type -> Maybe Type
    Type -> Maybe Type
    kindRep_maybe Type
    ki
      = HasDebugCallStack => SDoc -> Type -> [PrimRep]
    SDoc -> Type -> [PrimRep]
    runtimeRepPrimRep SDoc
    doc Type
    runtime_rep
    kindPrimRep SDoc
    doc Type
    ki
      = String -> SDoc -> [PrimRep]
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "kindPrimRep" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    ki SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ SDoc
    doc)

    -- NB: We could implement the partial methods by calling into the maybe
    -- variants here. But then both would need to pass around the doc argument.

    -- | Take a kind (of shape `TYPE rr` or `CONSTRAINT rr`) and produce the 'PrimRep's
    -- of values of types of this kind.
    -- See also Note [Getting from RuntimeRep to PrimRep]
    -- Returns Nothing if rep can't be determined. Eg. levity polymorphic types.
    kindPrimRep_maybe :: HasDebugCallStack => Kind -> Maybe [PrimRep]
    kindPrimRep_maybe :: HasDebugCallStack => Type -> Maybe [PrimRep]
    kindPrimRep_maybe Type
    ki
      | Just (TypeOrConstraint
    _torc, Type
    rep) <- Type -> Maybe (TypeOrConstraint, Type)
    sORTKind_maybe Type
    ki
      = Type -> Maybe [PrimRep]
    runtimeRepPrimRep_maybe Type
    rep
      | Bool
    otherwise
      = String -> SDoc -> Maybe [PrimRep]
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "kindPrimRep" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    ki)

    -- | Take a type of kind RuntimeRep and extract the list of 'PrimRep' that
    -- it encodes. See also Note [Getting from RuntimeRep to PrimRep].
    -- The @[PrimRep]@ is the final runtime representation /after/ unarisation.
    runtimeRepPrimRep :: HasDebugCallStack => SDoc -> RuntimeRepType -> [PrimRep]
    runtimeRepPrimRep :: HasDebugCallStack => SDoc -> Type -> [PrimRep]
    runtimeRepPrimRep SDoc
    doc Type
    rr_ty
      | Just Type
    rr_ty' <- Type -> Maybe Type
    coreView Type
    rr_ty
      = HasDebugCallStack => SDoc -> Type -> [PrimRep]
    SDoc -> Type -> [PrimRep]
    runtimeRepPrimRep SDoc
    doc Type
    rr_ty'
      | TyConApp TyCon
    rr_dc [Type]
    args <- Type
    rr_ty
      , RuntimeRep [Type] -> [PrimRep]
    fun <- TyCon -> PromDataConInfo
    tyConPromDataConInfo TyCon
    rr_dc
      = [Type] -> [PrimRep]
    fun [Type]
    args
      | Bool
    otherwise
      = String -> SDoc -> [PrimRep]
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "runtimeRepPrimRep" (SDoc
    doc SDoc -> SDoc -> SDoc
    forall doc. IsDoc doc => doc -> doc -> doc
    $$ Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    rr_ty)

    -- | Take a type of kind RuntimeRep and extract the list of 'PrimRep' that
    -- it encodes. See also Note [Getting from RuntimeRep to PrimRep].
    -- The @[PrimRep]@ is the final runtime representation /after/ unarisation.
    --
    -- Returns @Nothing@ if rep can't be determined. Eg. levity polymorphic types.
    runtimeRepPrimRep_maybe :: Type -> Maybe [PrimRep]
    runtimeRepPrimRep_maybe :: Type -> Maybe [PrimRep]
    runtimeRepPrimRep_maybe Type
    rr_ty
      | Just Type
    rr_ty' <- Type -> Maybe Type
    coreView Type
    rr_ty
      = Type -> Maybe [PrimRep]
    runtimeRepPrimRep_maybe Type
    rr_ty'
      | TyConApp TyCon
    rr_dc [Type]
    args <- Type
    rr_ty
      , RuntimeRep [Type] -> [PrimRep]
    fun <- TyCon -> PromDataConInfo
    tyConPromDataConInfo TyCon
    rr_dc
      = [PrimRep] -> Maybe [PrimRep]
    forall a. a -> Maybe a
    Just ([PrimRep] -> Maybe [PrimRep]) -> [PrimRep] -> Maybe [PrimRep]
    forall a b. (a -> b) -> a -> b
    $! [Type] -> [PrimRep]
    fun [Type]
    args
      | Bool
    otherwise
      = Maybe [PrimRep]
    forall a. Maybe a
    Nothing

    -- | Convert a 'PrimRep' to a 'Type' of kind RuntimeRep
    primRepToRuntimeRep :: PrimRep -> RuntimeRepType
    primRepToRuntimeRep :: PrimRep -> Type
    primRepToRuntimeRep PrimRep
    rep = case PrimRep
    rep of
      BoxedRep Maybe Levity
    mlev -> case Maybe Levity
    mlev of
        Maybe Levity
    Nothing       -> String -> Type
    forall a. HasCallStack => String -> a
    panic String
    "primRepToRuntimeRep: levity polymorphic BoxedRep"
        Just Levity
    Lifted   -> Type
    liftedRepTy
        Just Levity
    Unlifted -> Type
    unliftedRepTy
      PrimRep
    IntRep        -> Type
    intRepDataConTy
      PrimRep
    Int8Rep       -> Type
    int8RepDataConTy
      PrimRep
    Int16Rep      -> Type
    int16RepDataConTy
      PrimRep
    Int32Rep      -> Type
    int32RepDataConTy
      PrimRep
    Int64Rep      -> Type
    int64RepDataConTy
      PrimRep
    WordRep       -> Type
    wordRepDataConTy
      PrimRep
    Word8Rep      -> Type
    word8RepDataConTy
      PrimRep
    Word16Rep     -> Type
    word16RepDataConTy
      PrimRep
    Word32Rep     -> Type
    word32RepDataConTy
      PrimRep
    Word64Rep     -> Type
    word64RepDataConTy
      PrimRep
    AddrRep       -> Type
    addrRepDataConTy
      PrimRep
    FloatRep      -> Type
    floatRepDataConTy
      PrimRep
    DoubleRep     -> Type
    doubleRepDataConTy
      VecRep Int
    n PrimElemRep
    elem -> TyCon -> [Type] -> Type
    TyConApp TyCon
    vecRepDataConTyCon [Type
    n', Type
    elem']
        where
          n' :: Type
    n' = case Int
    n of
            Int
    2  -> Type
    vec2DataConTy
            Int
    4  -> Type
    vec4DataConTy
            Int
    8  -> Type
    vec8DataConTy
            Int
    16 -> Type
    vec16DataConTy
            Int
    32 -> Type
    vec32DataConTy
            Int
    64 -> Type
    vec64DataConTy
            Int
    _  -> String -> SDoc -> Type
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "Disallowed VecCount" (Int -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Int
    n)

          elem' :: Type
    elem' = case PrimElemRep
    elem of
            PrimElemRep
    Int8ElemRep   -> Type
    int8ElemRepDataConTy
            PrimElemRep
    Int16ElemRep  -> Type
    int16ElemRepDataConTy
            PrimElemRep
    Int32ElemRep  -> Type
    int32ElemRepDataConTy
            PrimElemRep
    Int64ElemRep  -> Type
    int64ElemRepDataConTy
            PrimElemRep
    Word8ElemRep  -> Type
    word8ElemRepDataConTy
            PrimElemRep
    Word16ElemRep -> Type
    word16ElemRepDataConTy
            PrimElemRep
    Word32ElemRep -> Type
    word32ElemRepDataConTy
            PrimElemRep
    Word64ElemRep -> Type
    word64ElemRepDataConTy
            PrimElemRep
    FloatElemRep  -> Type
    floatElemRepDataConTy
            PrimElemRep
    DoubleElemRep -> Type
    doubleElemRepDataConTy

    -- | Convert a PrimRep back to a Type. Used only in the unariser to give types
    -- to fresh Ids. Really, only the type's representation matters.
    -- See also Note [RuntimeRep and PrimRep]
    primRepToType :: PrimRep -> Type
    primRepToType :: PrimRep -> Type
    primRepToType = Type -> Type
    anyTypeOfKind (Type -> Type) -> (PrimRep -> Type) -> PrimRep -> Type
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Type -> Type
    mkTYPEapp (Type -> Type) -> (PrimRep -> Type) -> PrimRep -> Type
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . PrimRep -> Type
    primRepToRuntimeRep

    --------------
    mightBeFunTy :: Type -> Bool
    -- Return False only if we are *sure* it's a data type
    -- Look through newtypes etc as much as possible. Used to
    -- decide if we need to enter a closure via a slow call.
    --
    -- AK: It would be nice to figure out and document the difference
    -- between this and isFunTy at some point.
    mightBeFunTy :: Type -> Bool
    mightBeFunTy Type
    ty
      -- Currently ghc has no unlifted functions.
      | Type -> Bool
    definitelyUnliftedType Type
    ty
      = Bool
    False
      | [BoxedRep Maybe Levity
    _] <- HasDebugCallStack => Type -> [PrimRep]
    Type -> [PrimRep]
    typePrimRep Type
    ty
      , Just TyCon
    tc <- Type -> Maybe TyCon
    tyConAppTyCon_maybe (Type -> Type
    unwrapType Type
    ty)
      , TyCon -> Bool
    isDataTyCon TyCon
    tc
      = Bool
    False
      | Bool
    otherwise
      = Bool
    True