Clash.Class.Resize

Documentation

class Resize (f :: Nat -> Type) where

Coerce a value to be represented by a different number of bits

Minimal complete definition

resize, zeroExtend, truncateB

Methods

resize :: (KnownNat a, KnownNat b) => f a -> f b

A sign-preserving resize operation

• For signed datatypes: Increasing the size of the number replicates the sign bit to the left. Truncating a number to length L keeps the sign bit and the rightmost L-1 bits.
• For unsigned datatypes: Increasing the size of the number extends with zeros to the left. Truncating a number of length N to a length L just removes the left (most significant) N-L bits.

extend :: (KnownNat a, KnownNat b) => f a -> f (b + a)

Perform a zeroExtend for unsigned datatypes, and signExtend for a signed datatypes

zeroExtend :: (KnownNat a, KnownNat b) => f a -> f (b + a)

Add extra zero bits in front of the MSB

signExtend :: (KnownNat a, KnownNat b) => f a -> f (b + a)

Add extra sign bits in front of the MSB

truncateB :: KnownNat a => f (a + b) -> f a

Remove bits from the MSB

Instances

Resize BitVector

Defined in Clash.Sized.Internal.BitVector

Methods

resize :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => BitVector a -> BitVector b

extend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => BitVector a -> BitVector (b + a)

zeroExtend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => BitVector a -> BitVector (b + a)

signExtend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => BitVector a -> BitVector (b + a)

truncateB :: forall (a :: Nat) (b :: Nat). KnownNat a => BitVector (a + b) -> BitVector a

Resize Index

Defined in Clash.Sized.Internal.Index

Methods

resize :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Index a -> Index b

extend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Index a -> Index (b + a)

zeroExtend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Index a -> Index (b + a)

signExtend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Index a -> Index (b + a)

truncateB :: forall (a :: Nat) (b :: Nat). KnownNat a => Index (a + b) -> Index a

Resize Unsigned

Defined in Clash.Sized.Internal.Unsigned

Methods

resize :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Unsigned a -> Unsigned b

extend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Unsigned a -> Unsigned (b + a)

zeroExtend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Unsigned a -> Unsigned (b + a)

signExtend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Unsigned a -> Unsigned (b + a)

truncateB :: forall (a :: Nat) (b :: Nat). KnownNat a => Unsigned (a + b) -> Unsigned a

Resize Signed

Defined in Clash.Sized.Internal.Signed

Methods

resize :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Signed a -> Signed b

extend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Signed a -> Signed (b + a)

zeroExtend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Signed a -> Signed (b + a)

signExtend :: forall (a :: Nat) (b :: Nat). (KnownNat a, KnownNat b) => Signed a -> Signed (b + a)

truncateB :: forall (a :: Nat) (b :: Nat). KnownNat a => Signed (a + b) -> Signed a

Resize helpers

checkedResize :: forall a b f. (HasCallStack, Resize f, KnownNat a, Integral (f a), KnownNat b, Integral (f b), Bounded (f b)) => f a -> f b

Like resize, but errors if f a is out of bounds for f b. Useful when you "know" f a can't be out of bounds, but would like to have your assumptions checked.

N.B.: Check only affects simulation. I.e., no checks will be inserted into the generated HDL

checkedFromIntegral :: forall a b. HasCallStack => (Integral a, Integral b, Bounded b) => a -> b

Like fromIntegral, but errors if a is out of bounds for b. Useful when you "know" a can't be out of bounds, but would like to have your assumptions checked.

N.B.: Check only affects simulation. I.e., no checks will be inserted into the generated HDL

checkedTruncateB :: forall a b f. (HasCallStack, Resize f, KnownNat b, Integral (f (a + b)), KnownNat a, Integral (f a), Bounded (f a)) => f (a + b) -> f a

Like truncateB, but errors if f (a + b) is out of bounds for f a. Useful when you "know" f (a + b) can't be out of bounds, but would like to have your assumptions checked.

N.B.: Check only affects simulation. I.e., no checks will be inserted into the generated HDL