theoretica::bits Namespace Reference

Operations on bits. More...

Functions
constexpr void	mul_uint128 (uint64_t a, uint64_t b, uint64_t &c_low, uint64_t &c_high)
	Multiply two 64-bit unsigned integers and store the result in two 64-bit variables, keeping 128 bits of the result.
constexpr uint64_t	mix_mum (uint64_t a, uint64_t b)
	MUM bit mixing function, computes the 128-bit product of a and b and the XOR of their high and low 64-bit parts.
template<typename UnsignedIntType >
constexpr UnsignedIntType	bit_rotate (UnsignedIntType x, unsigned int i)
	Bit rotation of unsigned integer types using shifts.
template<typename Vector , enable_vector< Vector > = true>
constexpr void	swap_bit_reverse (Vector &x, unsigned int m)
	Swap the elements of a vector pair-wise, by exchanging elements with indices related by bit reversion (e.g.

Detailed Description

Operations on bits.

Function Documentation

bit_rotate()

template<typename UnsignedIntType >

constexpr UnsignedIntType theoretica::bits::bit_rotate ( UnsignedIntType  x, unsigned int  i  )

inlineconstexpr

Bit rotation of unsigned integer types using shifts.

Parameters

x	The unsigned integer to rotate the bits of
i	The index of the rotated bits

Returns

The unsigned integer with the given bits rotated

mix_mum()

constexpr uint64_t theoretica::bits::mix_mum ( uint64_t  a, uint64_t  b  )

inlineconstexpr

MUM bit mixing function, computes the 128-bit product of a and b and the XOR of their high and low 64-bit parts.

Parameters

a	The first operand
b	The second operand

Returns

The XOR of the high and low bits of the 128-bit product of a and b.

mul_uint128()

constexpr void theoretica::bits::mul_uint128 ( uint64_t  a, uint64_t  b, uint64_t &  c_low, uint64_t &  c_high  )

inlineconstexpr

Multiply two 64-bit unsigned integers and store the result in two 64-bit variables, keeping 128 bits of the result.

Parameters

a	The first number to multiply
b	The second number to multiply
c_low	The variable to store the lowest 64 bits of the result.
c_high	The variable to store the highest 64 bits of the result.

swap_bit_reverse()

template<typename Vector , enable_vector< Vector > = true>

constexpr void theoretica::bits::swap_bit_reverse ( Vector &  x, unsigned int  m  )

inlineconstexpr

Swap the elements of a vector pair-wise, by exchanging elements with indices related by bit reversion (e.g.

\(110_2\) and \(011_2\)).

Parameters

x	The vector of elements to swap in-place
m	The maximum bit to consider when computing bit reversion