accelerate-1.0.0.0: An embedded language for accelerated array processing

Copyright[2016..2017] Manuel M T Chakravarty Gabriele Keller Trevor L. McDonell
LicenseBSD3
MaintainerTrevor L. McDonell <tmcdonell@cse.unsw.edu.au>
Stabilityexperimental
Portabilitynon-portable (GHC extensions)
Safe HaskellNone
LanguageHaskell98

Data.Array.Accelerate.Data.Bits

Description

Bitwise operations for signed and unsigned integer expressions.

Synopsis

Documentation

class Eq a => Bits a where #

The Bits class defines bitwise operations over integral scalar expression types. As usual, bits are numbered from zero, with zero being the least significant bit.

Minimal complete definition

(.&.), (.|.), xor, complement, (shift | shiftL, shiftR), (rotate | rotateL, rotateR), isSigned, testBit, bit, popCount

Methods

(.&.) :: Exp a -> Exp a -> Exp a infixl 7 #

Bitwise "and"

(.|.) :: Exp a -> Exp a -> Exp a infixl 5 #

Bitwise "or"

xor :: Exp a -> Exp a -> Exp a infixl 6 #

Bitwise "xor"

complement :: Exp a -> Exp a #

Reverse all bits in the argument

shift :: Exp a -> Exp Int -> Exp a infixl 8 #

shift x i shifts x left by i bits if i is positive, or right by -i bits otherwise. Right shifts perform sign extension on signed number types; i.e. they fill the top bits with 1 if the x is negative and with 0 otherwise.

rotate :: Exp a -> Exp Int -> Exp a infixl 8 #

rotate x i rotates x left by i bits if i is positive, or right by -i bits otherwise.

zeroBits :: Exp a #

The value with all bits unset

bit :: Exp Int -> Exp a #

bit i is a value with the ith bit set and all other bits clear.

setBit :: Exp a -> Exp Int -> Exp a #

x `setBit` i is the same as x .|. bit i

clearBit :: Exp a -> Exp Int -> Exp a #

x `clearBit` i is the same as x .&. complement (bit i)

complementBit :: Exp a -> Exp Int -> Exp a #

x `complementBit` i is the same as x `xor` bit i

testBit :: Exp a -> Exp Int -> Exp Bool #

Return True if the nth bit of the argument is 1

isSigned :: Exp a -> Exp Bool #

Return True if the argument is a signed type.

shiftL :: Exp a -> Exp Int -> Exp a infixl 8 #

Shift the argument left by the specified number of bits (which must be non-negative).

unsafeShiftL :: Exp a -> Exp Int -> Exp a #

Shift the argument left by the specified number of bits. The result is undefined for negative shift amounts and shift amounts greater or equal to the finiteBitSize.

shiftR :: Exp a -> Exp Int -> Exp a infixl 8 #

Shift the first argument right by the specified number of bits (which must be non-negative).

Right shifts perform sign extension on signed number types; i.e. they fill the top bits with 1 if x is negative and with 0 otherwise.

unsafeShiftR :: Exp a -> Exp Int -> Exp a #

Shift the first argument right by the specified number of bits. The result is undefined for negative shift amounts and shift amounts greater or equal to the finiteBitSize.

rotateL :: Exp a -> Exp Int -> Exp a infixl 8 #

Rotate the argument left by the specified number of bits (which must be non-negative).

rotateR :: Exp a -> Exp Int -> Exp a infixl 8 #

Rotate the argument right by the specified number of bits (which must be non-negative).

popCount :: Exp a -> Exp Int #

Return the number of set bits in the argument. This number is known as the population count or the Hamming weight.

Instances

Bits Bool # 
Bits Int # 
Bits Int8 # 
Bits Int16 # 
Bits Int32 # 
Bits Int64 # 
Bits Word # 
Bits Word8 # 
Bits Word16 # 
Bits Word32 # 
Bits Word64 # 
Bits CShort # 
Bits CUShort # 
Bits CInt # 
Bits CUInt # 
Bits CLong # 
Bits CULong # 
Bits CLLong # 
Bits CULLong # 

class Bits b => FiniteBits b where #

Methods

finiteBitSize :: Exp b -> Exp Int #

Return the number of bits in the type of the argument.

countLeadingZeros :: Exp b -> Exp Int #

Count the number of zero bits preceding the most significant set bit. This can be used to compute a base-2 logarithm via:

logBase2 x = finiteBitSize x - 1 - countLeadingZeros x

countTrailingZeros :: Exp b -> Exp Int #

Count the number of zero bits following the least significant set bit. The related find-first-set operation can be expressed in terms of this as:

findFirstSet x = 1 + countTrailingZeros x

Instances

FiniteBits Bool # 
FiniteBits Int # 
FiniteBits Int8 # 
FiniteBits Int16 # 
FiniteBits Int32 # 
FiniteBits Int64 # 
FiniteBits Word # 
FiniteBits Word8 # 
FiniteBits Word16 # 
FiniteBits Word32 # 
FiniteBits Word64 # 
FiniteBits CShort # 
FiniteBits CUShort # 
FiniteBits CInt # 
FiniteBits CUInt # 
FiniteBits CLong # 
FiniteBits CULong # 
FiniteBits CLLong # 
FiniteBits CULLong #