Clash.Prelude.BitReduction

Documentation

>>> :set -XDataKinds
>>> import Clash.Prelude

reduceAnd :: (BitPack a, KnownNat (BitSize a)) => a -> Bit

Are all bits set to '1'?

>>> pack (-2 :: Signed 6)
11_1110
>>> reduceAnd (-2 :: Signed 6)
0
>>> pack (-1 :: Signed 6)
11_1111
>>> reduceAnd (-1 :: Signed 6)
1

Zero width types will evaluate to '1':

>>> reduceAnd (0 :: Unsigned 0)
1

reduceOr :: (BitPack a, KnownNat (BitSize a)) => a -> Bit

Is there at least one bit set to '1'?

>>> pack (5 :: Signed 6)
00_0101
>>> reduceOr (5 :: Signed 6)
1
>>> pack (0 :: Signed 6)
00_0000
>>> reduceOr (0 :: Signed 6)
0

Zero width types will evaluate to '0':

>>> reduceOr (0 :: Unsigned 0)
0

reduceXor :: (BitPack a, KnownNat (BitSize a)) => a -> Bit

Is the number of bits set to '1' uneven?

>>> pack (5 :: Signed 6)
00_0101
>>> reduceXor (5 :: Signed 6)
0
>>> pack (28 :: Signed 6)
01_1100
>>> reduceXor (28 :: Signed 6)
1
>>> pack (-5 :: Signed 6)
11_1011
>>> reduceXor (-5 :: Signed 6)
1

Zero width types will evaluate to '0':

>>> reduceXor (0 :: Unsigned 0)
0