    module GHC.Cmm.Type
        ( CmmType   -- Abstract
        , b8, b16, b32, b64, b128, b256, b512, f32, f64, bWord, bHalfWord, gcWord
        , cInt
        , cmmBits, cmmFloat
        , typeWidth, cmmEqType, cmmEqType_ignoring_ptrhood
        , isFloatType, isGcPtrType, isBitsType
        , isWord32, isWord64, isFloat64, isFloat32

        , Width(..)
        , widthInBits, widthInBytes, widthInLog, widthFromBytes
        , wordWidth, halfWordWidth, cIntWidth
        , halfWordMask
        , narrowU, narrowS
        , rEP_CostCentreStack_mem_alloc
        , rEP_CostCentreStack_scc_count
        , rEP_StgEntCounter_allocs
        , rEP_StgEntCounter_allocd

        , ForeignHint(..)

        , Length
        , vec, vec2, vec4, vec8, vec16
        , vec2f64, vec2b64, vec4f32, vec4b32, vec8b16, vec16b8
        , cmmVec
        , vecLength, vecElemType
        , isVecType
       )
    where

    import GHC.Prelude

    import GHC.Platform
    import GHC.Data.FastString
    import GHC.Utils.Outputable
    import GHC.Utils.Panic

    import Data.Word
    import Data.Int

    -----------------------------------------------------------------------------
    --              CmmType
    -----------------------------------------------------------------------------

      -- NOTE: CmmType is an abstract type, not exported from this
      --       module so you can easily change its representation
      --
      -- However Width is exported in a concrete way,
      -- and is used extensively in pattern-matching

    data CmmType    -- The important one!
      = CmmType CmmCat !Width
      deriving Int -> CmmType -> ShowS
    [CmmType] -> ShowS
    CmmType -> String
    (Int -> CmmType -> ShowS)
    -> (CmmType -> String) -> ([CmmType] -> ShowS) -> Show CmmType
    forall a.
    (Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
    showList :: [CmmType] -> ShowS
    $cshowList :: [CmmType] -> ShowS
    show :: CmmType -> String
    $cshow :: CmmType -> String
    showsPrec :: Int -> CmmType -> ShowS
    $cshowsPrec :: Int -> CmmType -> ShowS
    Show

    data CmmCat                -- "Category" (not exported)
       = GcPtrCat              -- GC pointer
       | BitsCat               -- Non-pointer
       | FloatCat              -- Float
       | VecCat Length CmmCat  -- Vector
       deriving( CmmCat -> CmmCat -> Bool
    (CmmCat -> CmmCat -> Bool)
    -> (CmmCat -> CmmCat -> Bool) -> Eq CmmCat
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    /= :: CmmCat -> CmmCat -> Bool
    $c/= :: CmmCat -> CmmCat -> Bool
    == :: CmmCat -> CmmCat -> Bool
    $c== :: CmmCat -> CmmCat -> Bool
    Eq, Int -> CmmCat -> ShowS
    [CmmCat] -> ShowS
    CmmCat -> String
    (Int -> CmmCat -> ShowS)
    -> (CmmCat -> String) -> ([CmmCat] -> ShowS) -> Show CmmCat
    forall a.
    (Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
    showList :: [CmmCat] -> ShowS
    $cshowList :: [CmmCat] -> ShowS
    show :: CmmCat -> String
    $cshow :: CmmCat -> String
    showsPrec :: Int -> CmmCat -> ShowS
    $cshowsPrec :: Int -> CmmCat -> ShowS
    Show )
            -- See Note [Signed vs unsigned] at the end

    instance Outputable CmmType where
      ppr :: CmmType -> SDoc
    ppr (CmmType CmmCat
    cat Width
    wid) = CmmCat -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr CmmCat
    cat SDoc -> SDoc -> SDoc
    <> Int -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (Width -> Int
    widthInBits Width
    wid)

    instance Outputable CmmCat where
      ppr :: CmmCat -> SDoc
    ppr CmmCat
    FloatCat       = String -> SDoc
    text String
    "F"
      ppr CmmCat
    GcPtrCat       = String -> SDoc
    text String
    "P"
      ppr CmmCat
    BitsCat        = String -> SDoc
    text String
    "I"
      ppr (VecCat Int
    n CmmCat
    cat) = CmmCat -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr CmmCat
    cat SDoc -> SDoc -> SDoc
    <> String -> SDoc
    text String
    "x" SDoc -> SDoc -> SDoc
    <> Int -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Int
    n SDoc -> SDoc -> SDoc
    <> String -> SDoc
    text String
    "V"

    -- Why is CmmType stratified?  For native code generation,
    -- most of the time you just want to know what sort of register
    -- to put the thing in, and for this you need to know how
    -- many bits thing has, and whether it goes in a floating-point
    -- register.  By contrast, the distinction between GcPtr and
    -- GcNonPtr is of interest to only a few parts of the code generator.

    -------- Equality on CmmType --------------
    -- CmmType is *not* an instance of Eq; sometimes we care about the
    -- Gc/NonGc distinction, and sometimes we don't
    -- So we use an explicit function to force you to think about it
    cmmEqType :: CmmType -> CmmType -> Bool -- Exact equality
    cmmEqType :: CmmType -> CmmType -> Bool
    cmmEqType (CmmType CmmCat
    c1 Width
    w1) (CmmType CmmCat
    c2 Width
    w2) = CmmCat
    c1CmmCat -> CmmCat -> Bool
    forall a. Eq a => a -> a -> Bool
    ==CmmCat
    c2 Bool -> Bool -> Bool
    && Width
    w1Width -> Width -> Bool
    forall a. Eq a => a -> a -> Bool
    ==Width
    w2

    cmmEqType_ignoring_ptrhood :: CmmType -> CmmType -> Bool
      -- This equality is temporary; used in CmmLint
      -- but the RTS files are not yet well-typed wrt pointers
    cmmEqType_ignoring_ptrhood :: CmmType -> CmmType -> Bool
    cmmEqType_ignoring_ptrhood (CmmType CmmCat
    c1 Width
    w1) (CmmType CmmCat
    c2 Width
    w2)
       = CmmCat
    c1 CmmCat -> CmmCat -> Bool
    `weak_eq` CmmCat
    c2 Bool -> Bool -> Bool
    && Width
    w1Width -> Width -> Bool
    forall a. Eq a => a -> a -> Bool
    ==Width
    w2
       where
         weak_eq :: CmmCat -> CmmCat -> Bool
         CmmCat
    FloatCat         weak_eq :: CmmCat -> CmmCat -> Bool
    `weak_eq` CmmCat
    FloatCat         = Bool
    True
         CmmCat
    FloatCat         `weak_eq` CmmCat
    _other           = Bool
    False
         CmmCat
    _other           `weak_eq` CmmCat
    FloatCat         = Bool
    False
         (VecCat Int
    l1 CmmCat
    cat1) `weak_eq` (VecCat Int
    l2 CmmCat
    cat2) = Int
    l1 Int -> Int -> Bool
    forall a. Eq a => a -> a -> Bool
    == Int
    l2
                                                       Bool -> Bool -> Bool
    && CmmCat
    cat1 CmmCat -> CmmCat -> Bool
    `weak_eq` CmmCat
    cat2
         (VecCat {})      `weak_eq` CmmCat
    _other           = Bool
    False
         CmmCat
    _other           `weak_eq` (VecCat {})      = Bool
    False
         CmmCat
    _word1           `weak_eq` CmmCat
    _word2           = Bool
    True        -- Ignores GcPtr

    --- Simple operations on CmmType -----
    typeWidth :: CmmType -> Width
    typeWidth :: CmmType -> Width
    typeWidth (CmmType CmmCat
    _ Width
    w) = Width
    w

    cmmBits, cmmFloat :: Width -> CmmType
    cmmBits :: Width -> CmmType
    cmmBits  = CmmCat -> Width -> CmmType
    CmmType CmmCat
    BitsCat
    cmmFloat :: Width -> CmmType
    cmmFloat = CmmCat -> Width -> CmmType
    CmmType CmmCat
    FloatCat

    -------- Common CmmTypes ------------
    -- Floats and words of specific widths
    b8, b16, b32, b64, b128, b256, b512, f32, f64 :: CmmType
    b8 :: CmmType
    b8     = Width -> CmmType
    cmmBits Width
    W8
    b16 :: CmmType
    b16    = Width -> CmmType
    cmmBits Width
    W16
    b32 :: CmmType
    b32    = Width -> CmmType
    cmmBits Width
    W32
    b64 :: CmmType
    b64    = Width -> CmmType
    cmmBits Width
    W64
    b128 :: CmmType
    b128   = Width -> CmmType
    cmmBits Width
    W128
    b256 :: CmmType
    b256   = Width -> CmmType
    cmmBits Width
    W256
    b512 :: CmmType
    b512   = Width -> CmmType
    cmmBits Width
    W512
    f32 :: CmmType
    f32    = Width -> CmmType
    cmmFloat Width
    W32
    f64 :: CmmType
    f64    = Width -> CmmType
    cmmFloat Width
    W64

    -- CmmTypes of native word widths
    bWord :: Platform -> CmmType
    bWord :: Platform -> CmmType
    bWord Platform
    platform = Width -> CmmType
    cmmBits (Platform -> Width
    wordWidth Platform
    platform)

    bHalfWord :: Platform -> CmmType
    bHalfWord :: Platform -> CmmType
    bHalfWord Platform
    platform = Width -> CmmType
    cmmBits (Platform -> Width
    halfWordWidth Platform
    platform)

    gcWord :: Platform -> CmmType
    gcWord :: Platform -> CmmType
    gcWord Platform
    platform = CmmCat -> Width -> CmmType
    CmmType CmmCat
    GcPtrCat (Platform -> Width
    wordWidth Platform
    platform)

    cInt :: Platform -> CmmType
    cInt :: Platform -> CmmType
    cInt Platform
    platform = Width -> CmmType
    cmmBits (Platform -> Width
    cIntWidth Platform
    platform)

    ------------ Predicates ----------------
    isFloatType, isGcPtrType, isBitsType :: CmmType -> Bool
    isFloatType :: CmmType -> Bool
    isFloatType (CmmType CmmCat
    FloatCat    Width
    _) = Bool
    True
    isFloatType CmmType
    _other                  = Bool
    False

    isGcPtrType :: CmmType -> Bool
    isGcPtrType (CmmType CmmCat
    GcPtrCat Width
    _) = Bool
    True
    isGcPtrType CmmType
    _other               = Bool
    False

    isBitsType :: CmmType -> Bool
    isBitsType (CmmType CmmCat
    BitsCat Width
    _) = Bool
    True
    isBitsType CmmType
    _                   = Bool
    False

    isWord32, isWord64, isFloat32, isFloat64 :: CmmType -> Bool
    -- isWord64 is true of 64-bit non-floats (both gc-ptrs and otherwise)
    -- isFloat32 and 64 are obvious

    isWord64 :: CmmType -> Bool
    isWord64 (CmmType CmmCat
    BitsCat  Width
    W64) = Bool
    True
    isWord64 (CmmType CmmCat
    GcPtrCat Width
    W64) = Bool
    True
    isWord64 CmmType
    _other                 = Bool
    False

    isWord32 :: CmmType -> Bool
    isWord32 (CmmType CmmCat
    BitsCat  Width
    W32) = Bool
    True
    isWord32 (CmmType CmmCat
    GcPtrCat Width
    W32) = Bool
    True
    isWord32 CmmType
    _other                 = Bool
    False

    isFloat32 :: CmmType -> Bool
    isFloat32 (CmmType CmmCat
    FloatCat Width
    W32) = Bool
    True
    isFloat32 CmmType
    _other                 = Bool
    False

    isFloat64 :: CmmType -> Bool
    isFloat64 (CmmType CmmCat
    FloatCat Width
    W64) = Bool
    True
    isFloat64 CmmType
    _other                 = Bool
    False

    -----------------------------------------------------------------------------
    --              Width
    -----------------------------------------------------------------------------

    data Width   = W8 | W16 | W32 | W64
                 | W128
                 | W256
                 | W512
                 deriving (Width -> Width -> Bool
    (Width -> Width -> Bool) -> (Width -> Width -> Bool) -> Eq Width
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    /= :: Width -> Width -> Bool
    $c/= :: Width -> Width -> Bool
    == :: Width -> Width -> Bool
    $c== :: Width -> Width -> Bool
    Eq, Eq Width
    Eq Width
    -> (Width -> Width -> Ordering)
    -> (Width -> Width -> Bool)
    -> (Width -> Width -> Bool)
    -> (Width -> Width -> Bool)
    -> (Width -> Width -> Bool)
    -> (Width -> Width -> Width)
    -> (Width -> Width -> Width)
    -> Ord Width
    Width -> Width -> Bool
    Width -> Width -> Ordering
    Width -> Width -> Width
    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
    min :: Width -> Width -> Width
    $cmin :: Width -> Width -> Width
    max :: Width -> Width -> Width
    $cmax :: Width -> Width -> Width
    >= :: Width -> Width -> Bool
    $c>= :: Width -> Width -> Bool
    > :: Width -> Width -> Bool
    $c> :: Width -> Width -> Bool
    <= :: Width -> Width -> Bool
    $c<= :: Width -> Width -> Bool
    < :: Width -> Width -> Bool
    $c< :: Width -> Width -> Bool
    compare :: Width -> Width -> Ordering
    $ccompare :: Width -> Width -> Ordering
    Ord, Int -> Width -> ShowS
    [Width] -> ShowS
    Width -> String
    (Int -> Width -> ShowS)
    -> (Width -> String) -> ([Width] -> ShowS) -> Show Width
    forall a.
    (Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
    showList :: [Width] -> ShowS
    $cshowList :: [Width] -> ShowS
    show :: Width -> String
    $cshow :: Width -> String
    showsPrec :: Int -> Width -> ShowS
    $cshowsPrec :: Int -> Width -> ShowS
    Show)

    instance Outputable Width where
       ppr :: Width -> SDoc
    ppr Width
    rep = PtrString -> SDoc
    ptext (Width -> PtrString
    mrStr Width
    rep)

    mrStr :: Width -> PtrString
    mrStr :: Width -> PtrString
    mrStr = String -> PtrString
    sLit (String -> PtrString) -> (Width -> String) -> Width -> PtrString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Width -> String
    forall a. Show a => a -> String
    show

    -------- Common Widths  ------------
    wordWidth :: Platform -> Width
    wordWidth :: Platform -> Width
    wordWidth Platform
    platform = case Platform -> PlatformWordSize
    platformWordSize Platform
    platform of
     PlatformWordSize
    PW4 -> Width
    W32
     PlatformWordSize
    PW8 -> Width
    W64

    halfWordWidth :: Platform -> Width
    halfWordWidth :: Platform -> Width
    halfWordWidth Platform
    platform = case Platform -> PlatformWordSize
    platformWordSize Platform
    platform of
     PlatformWordSize
    PW4 -> Width
    W16
     PlatformWordSize
    PW8 -> Width
    W32

    halfWordMask :: Platform -> Integer
    halfWordMask :: Platform -> Integer
    halfWordMask Platform
    platform = case Platform -> PlatformWordSize
    platformWordSize Platform
    platform of
     PlatformWordSize
    PW4 -> Integer
    0xFFFF
     PlatformWordSize
    PW8 -> Integer
    0xFFFFFFFF

    -- cIntRep is the Width for a C-language 'int'
    cIntWidth :: Platform -> Width
    cIntWidth :: Platform -> Width
    cIntWidth Platform
    platform = case PlatformConstants -> Int
    pc_CINT_SIZE (Platform -> PlatformConstants
    platformConstants Platform
    platform) of
                       Int
    4 -> Width
    W32
                       Int
    8 -> Width
    W64
                       Int
    s -> String -> Width
    forall a. String -> a
    panic (String
    "cIntWidth: Unknown cINT_SIZE: " String -> ShowS
    forall a. [a] -> [a] -> [a]
    ++ Int -> String
    forall a. Show a => a -> String
    show Int
    s)

    widthInBits :: Width -> Int
    widthInBits :: Width -> Int
    widthInBits Width
    W8   = Int
    8
    widthInBits Width
    W16  = Int
    16
    widthInBits Width
    W32  = Int
    32
    widthInBits Width
    W64  = Int
    64
    widthInBits Width
    W128 = Int
    128
    widthInBits Width
    W256 = Int
    256
    widthInBits Width
    W512 = Int
    512

    widthInBytes :: Width -> Int
    widthInBytes :: Width -> Int
    widthInBytes Width
    W8   = Int
    1
    widthInBytes Width
    W16  = Int
    2
    widthInBytes Width
    W32  = Int
    4
    widthInBytes Width
    W64  = Int
    8
    widthInBytes Width
    W128 = Int
    16
    widthInBytes Width
    W256 = Int
    32
    widthInBytes Width
    W512 = Int
    64

    widthFromBytes :: Int -> Width
    widthFromBytes :: Int -> Width
    widthFromBytes Int
    1  = Width
    W8
    widthFromBytes Int
    2  = Width
    W16
    widthFromBytes Int
    4  = Width
    W32
    widthFromBytes Int
    8  = Width
    W64
    widthFromBytes Int
    16 = Width
    W128
    widthFromBytes Int
    32 = Width
    W256
    widthFromBytes Int
    64 = Width
    W512

    widthFromBytes Int
    n  = String -> SDoc -> Width
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "no width for given number of bytes" (Int -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Int
    n)

    -- log_2 of the width in bytes, useful for generating shifts.
    widthInLog :: Width -> Int
    widthInLog :: Width -> Int
    widthInLog Width
    W8   = Int
    0
    widthInLog Width
    W16  = Int
    1
    widthInLog Width
    W32  = Int
    2
    widthInLog Width
    W64  = Int
    3
    widthInLog Width
    W128 = Int
    4
    widthInLog Width
    W256 = Int
    5
    widthInLog Width
    W512 = Int
    6

    -- widening / narrowing

    narrowU :: Width -> Integer -> Integer
    narrowU :: Width -> Integer -> Integer
    narrowU Width
    W8  Integer
    x = Word8 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Integer -> Word8
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Integer
    x :: Word8)
    narrowU Width
    W16 Integer
    x = Word16 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Integer -> Word16
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Integer
    x :: Word16)
    narrowU Width
    W32 Integer
    x = Word32 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Integer -> Word32
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Integer
    x :: Word32)
    narrowU Width
    W64 Integer
    x = Word64 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Integer -> Word64
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Integer
    x :: Word64)
    narrowU Width
    _ Integer
    _ = String -> Integer
    forall a. String -> a
    panic String
    "narrowTo"

    narrowS :: Width -> Integer -> Integer
    narrowS :: Width -> Integer -> Integer
    narrowS Width
    W8  Integer
    x = Int8 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Integer -> Int8
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Integer
    x :: Int8)
    narrowS Width
    W16 Integer
    x = Int16 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Integer -> Int16
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Integer
    x :: Int16)
    narrowS Width
    W32 Integer
    x = Int32 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Integer -> Int32
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Integer
    x :: Int32)
    narrowS Width
    W64 Integer
    x = Int64 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Integer -> Int64
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Integer
    x :: Int64)
    narrowS Width
    _ Integer
    _ = String -> Integer
    forall a. String -> a
    panic String
    "narrowTo"

    -----------------------------------------------------------------------------
    --              SIMD
    -----------------------------------------------------------------------------

    type Length = Int

    vec :: Length -> CmmType -> CmmType
    vec :: Int -> CmmType -> CmmType
    vec Int
    l (CmmType CmmCat
    cat Width
    w) = CmmCat -> Width -> CmmType
    CmmType (Int -> CmmCat -> CmmCat
    VecCat Int
    l CmmCat
    cat) Width
    vecw
      where
        vecw :: Width
        vecw :: Width
    vecw = Int -> Width
    widthFromBytes (Int
    lInt -> Int -> Int
    forall a. Num a => a -> a -> a
    *Width -> Int
    widthInBytes Width
    w)

    vec2, vec4, vec8, vec16 :: CmmType -> CmmType
    vec2 :: CmmType -> CmmType
    vec2  = Int -> CmmType -> CmmType
    vec Int
    2
    vec4 :: CmmType -> CmmType
    vec4  = Int -> CmmType -> CmmType
    vec Int
    4
    vec8 :: CmmType -> CmmType
    vec8  = Int -> CmmType -> CmmType
    vec Int
    8
    vec16 :: CmmType -> CmmType
    vec16 = Int -> CmmType -> CmmType
    vec Int
    16

    vec2f64, vec2b64, vec4f32, vec4b32, vec8b16, vec16b8 :: CmmType
    vec2f64 :: CmmType
    vec2f64 = Int -> CmmType -> CmmType
    vec Int
    2 CmmType
    f64
    vec2b64 :: CmmType
    vec2b64 = Int -> CmmType -> CmmType
    vec Int
    2 CmmType
    b64
    vec4f32 :: CmmType
    vec4f32 = Int -> CmmType -> CmmType
    vec Int
    4 CmmType
    f32
    vec4b32 :: CmmType
    vec4b32 = Int -> CmmType -> CmmType
    vec Int
    4 CmmType
    b32
    vec8b16 :: CmmType
    vec8b16 = Int -> CmmType -> CmmType
    vec Int
    8 CmmType
    b16
    vec16b8 :: CmmType
    vec16b8 = Int -> CmmType -> CmmType
    vec Int
    16 CmmType
    b8

    cmmVec :: Int -> CmmType -> CmmType
    cmmVec :: Int -> CmmType -> CmmType
    cmmVec Int
    n (CmmType CmmCat
    cat Width
    w) =
        CmmCat -> Width -> CmmType
    CmmType (Int -> CmmCat -> CmmCat
    VecCat Int
    n CmmCat
    cat) (Int -> Width
    widthFromBytes (Int
    nInt -> Int -> Int
    forall a. Num a => a -> a -> a
    *Width -> Int
    widthInBytes Width
    w))

    vecLength :: CmmType -> Length
    vecLength :: CmmType -> Int
    vecLength (CmmType (VecCat Int
    l CmmCat
    _) Width
    _) = Int
    l
    vecLength CmmType
    _                        = String -> Int
    forall a. String -> a
    panic String
    "vecLength: not a vector"

    vecElemType :: CmmType -> CmmType
    vecElemType :: CmmType -> CmmType
    vecElemType (CmmType (VecCat Int
    l CmmCat
    cat) Width
    w) = CmmCat -> Width -> CmmType
    CmmType CmmCat
    cat Width
    scalw
      where
        scalw :: Width
        scalw :: Width
    scalw = Int -> Width
    widthFromBytes (Width -> Int
    widthInBytes Width
    w Int -> Int -> Int
    forall a. Integral a => a -> a -> a
    `div` Int
    l)
    vecElemType CmmType
    _ = String -> CmmType
    forall a. String -> a
    panic String
    "vecElemType: not a vector"

    isVecType :: CmmType -> Bool
    isVecType :: CmmType -> Bool
    isVecType (CmmType (VecCat {}) Width
    _) = Bool
    True
    isVecType CmmType
    _                       = Bool
    False

    -------------------------------------------------------------------------
    -- Hints

    -- Hints are extra type information we attach to the arguments and
    -- results of a foreign call, where more type information is sometimes
    -- needed by the ABI to make the correct kind of call.
    --
    -- See Note [Signed vs unsigned] for one case where this is used.

    data ForeignHint
      = NoHint | AddrHint | SignedHint
      deriving( ForeignHint -> ForeignHint -> Bool
    (ForeignHint -> ForeignHint -> Bool)
    -> (ForeignHint -> ForeignHint -> Bool) -> Eq ForeignHint
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    /= :: ForeignHint -> ForeignHint -> Bool
    $c/= :: ForeignHint -> ForeignHint -> Bool
    == :: ForeignHint -> ForeignHint -> Bool
    $c== :: ForeignHint -> ForeignHint -> Bool
    Eq )
            -- Used to give extra per-argument or per-result
            -- information needed by foreign calling conventions

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

    -- These don't really belong here, but I don't know where is best to
    -- put them.

    rEP_CostCentreStack_mem_alloc :: Platform -> CmmType
    rEP_CostCentreStack_mem_alloc :: Platform -> CmmType
    rEP_CostCentreStack_mem_alloc Platform
    platform
        = Width -> CmmType
    cmmBits (Int -> Width
    widthFromBytes (PlatformConstants -> Int
    pc_REP_CostCentreStack_mem_alloc PlatformConstants
    pc))
        where pc :: PlatformConstants
    pc = Platform -> PlatformConstants
    platformConstants Platform
    platform

    rEP_CostCentreStack_scc_count :: Platform -> CmmType
    rEP_CostCentreStack_scc_count :: Platform -> CmmType
    rEP_CostCentreStack_scc_count Platform
    platform
        = Width -> CmmType
    cmmBits (Int -> Width
    widthFromBytes (PlatformConstants -> Int
    pc_REP_CostCentreStack_scc_count PlatformConstants
    pc))
        where pc :: PlatformConstants
    pc = Platform -> PlatformConstants
    platformConstants Platform
    platform

    rEP_StgEntCounter_allocs :: Platform -> CmmType
    rEP_StgEntCounter_allocs :: Platform -> CmmType
    rEP_StgEntCounter_allocs Platform
    platform
        = Width -> CmmType
    cmmBits (Int -> Width
    widthFromBytes (PlatformConstants -> Int
    pc_REP_StgEntCounter_allocs PlatformConstants
    pc))
        where pc :: PlatformConstants
    pc = Platform -> PlatformConstants
    platformConstants Platform
    platform

    rEP_StgEntCounter_allocd :: Platform -> CmmType
    rEP_StgEntCounter_allocd :: Platform -> CmmType
    rEP_StgEntCounter_allocd Platform
    platform
        = Width -> CmmType
    cmmBits (Int -> Width
    widthFromBytes (PlatformConstants -> Int
    pc_REP_StgEntCounter_allocd PlatformConstants
    pc))
        where pc :: PlatformConstants
    pc = Platform -> PlatformConstants
    platformConstants Platform
    platform

    -------------------------------------------------------------------------
    {-      Note [Signed vs unsigned]
            ~~~~~~~~~~~~~~~~~~~~~~~~~
    Should a CmmType include a signed vs. unsigned distinction?

    This is very much like a "hint" in C-- terminology: it isn't necessary
    in order to generate correct code, but it might be useful in that the
    compiler can generate better code if it has access to higher-level
    hints about data.  This is important at call boundaries, because the
    definition of a function is not visible at all of its call sites, so
    the compiler cannot infer the hints.

    Here in Cmm, we're taking a slightly different approach.  We include
    the int vs. float hint in the CmmType, because (a) the majority of
    platforms have a strong distinction between float and int registers,
    and (b) we don't want to do any heavyweight hint-inference in the
    native code backend in order to get good code.  We're treating the
    hint more like a type: our Cmm is always completely consistent with
    respect to hints.  All coercions between float and int are explicit.

    What about the signed vs. unsigned hint?  This information might be
    useful if we want to keep sub-word-sized values in word-size
    registers, which we must do if we only have word-sized registers.

    On such a system, there are two straightforward conventions for
    representing sub-word-sized values:

    (a) Leave the upper bits undefined.  Comparison operations must
        sign- or zero-extend both operands before comparing them,
        depending on whether the comparison is signed or unsigned.

    (b) Always keep the values sign- or zero-extended as appropriate.
        Arithmetic operations must narrow the result to the appropriate
        size.

    A clever compiler might not use either (a) or (b) exclusively, instead
    it would attempt to minimize the coercions by analysis: the same kind
    of analysis that propagates hints around.  In Cmm we don't want to
    have to do this, so we plump for having richer types and keeping the
    type information consistent.

    If signed/unsigned hints are missing from CmmType, then the only
    choice we have is (a), because we don't know whether the result of an
    operation should be sign- or zero-extended.

    Many architectures have extending load operations, which work well
    with (b).  To make use of them with (a), you need to know whether the
    value is going to be sign- or zero-extended by an enclosing comparison
    (for example), which involves knowing above the context.  This is
    doable but more complex.

    Further complicating the issue is foreign calls: a foreign calling
    convention can specify that signed 8-bit quantities are passed as
    sign-extended 32 bit quantities, for example (this is the case on the
    PowerPC).  So we *do* need sign information on foreign call arguments.

    Pros for adding signed vs. unsigned to CmmType:

      - It would let us use convention (b) above, and get easier
        code generation for extending loads.

      - Less information required on foreign calls.

      - MachOp type would be simpler

    Cons:

      - More complexity

      - What is the CmmType for a VanillaReg?  Currently it is
        always wordRep, but now we have to decide whether it is
        signed or unsigned.  The same VanillaReg can thus have
        different CmmType in different parts of the program.

      - Extra coercions cluttering up expressions.

    Currently for GHC, the foreign call point is moot, because we do our
    own promotion of sub-word-sized values to word-sized values.  The Int8
    type is represented by an Int# which is kept sign-extended at all times
    (this is slightly naughty, because we're making assumptions about the
    C calling convention rather early on in the compiler).  However, given
    this, the cons outweigh the pros.

    -}