{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE ConstrainedClassMethods #-}
{-# LANGUAGE MagicHash #-}
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE DefaultSignatures #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE ScopedTypeVariables #-}
module Haskus.Format.Binary.Bits.Finite
( FiniteBits (..)
)
where
import Haskus.Utils.Types
import Haskus.Format.Binary.Word
import Haskus.Format.Binary.Bits.Bitwise
import GHC.Exts
#include "MachDeps.h"
class FiniteBits a where
type BitSize a :: Nat
bitSize :: (Integral i, KnownNat (BitSize a)) => a -> i
bitSize _ = natValue @(BitSize a)
zeroBits :: a
oneBits :: a
default oneBits :: Bitwise a => a
oneBits = complement zeroBits
countLeadingZeros :: a -> Word
countTrailingZeros :: a -> Word
instance FiniteBits Word where
type BitSize Word = WORD_SIZE_IN_BITS
zeroBits = 0
oneBits = maxBound
countLeadingZeros (W# x#) = W# (clz# x#)
countTrailingZeros (W# x#) = W# (ctz# x#)
instance FiniteBits Word8 where
type BitSize Word8 = 8
zeroBits = 0
oneBits = maxBound
countLeadingZeros (W8# x#) = W# (clz8# x#)
countTrailingZeros (W8# x#) = W# (ctz8# x#)
instance FiniteBits Word16 where
type BitSize Word16 = 16
zeroBits = 0
oneBits = maxBound
countLeadingZeros (W16# x#) = W# (clz16# x#)
countTrailingZeros (W16# x#) = W# (ctz16# x#)
instance FiniteBits Word32 where
type BitSize Word32 = 32
zeroBits = 0
oneBits = maxBound
countLeadingZeros (W32# x#) = W# (clz32# x#)
countTrailingZeros (W32# x#) = W# (ctz32# x#)
instance FiniteBits Word64 where
type BitSize Word64 = 64
zeroBits = 0
oneBits = maxBound
countLeadingZeros (W64# x#) = W# (clz64# x#)
countTrailingZeros (W64# x#) = W# (ctz64# x#)
instance FiniteBits Int where
type BitSize Int = WORD_SIZE_IN_BITS
zeroBits = 0
oneBits = (-1)
countLeadingZeros (I# x#) = W# (clz# (int2Word# x#))
countTrailingZeros (I# x#) = W# (ctz# (int2Word# x#))
instance FiniteBits Int8 where
type BitSize Int8 = 8
zeroBits = 0
oneBits = (-1)
countLeadingZeros (I8# x#) = W# (clz8# (int2Word# x#))
countTrailingZeros (I8# x#) = W# (ctz8# (int2Word# x#))
instance FiniteBits Int16 where
type BitSize Int16 = 16
zeroBits = 0
oneBits = (-1)
countLeadingZeros (I16# x#) = W# (clz16# (int2Word# x#))
countTrailingZeros (I16# x#) = W# (ctz16# (int2Word# x#))
instance FiniteBits Int32 where
type BitSize Int32 = 32
zeroBits = 0
oneBits = (-1)
countLeadingZeros (I32# x#) = W# (clz32# (int2Word# x#))
countTrailingZeros (I32# x#) = W# (ctz32# (int2Word# x#))
instance FiniteBits Int64 where
type BitSize Int64 = 64
zeroBits = 0
oneBits = (-1)
countLeadingZeros (I64# x#) = W# (clz64# (int2Word# x#))
countTrailingZeros (I64# x#) = W# (ctz64# (int2Word# x#))