Struct gf::support::bitpat::BitPat

pub struct BitPat { /* fields omitted */ }

A 128-bit pattern.

Implementations

impl BitPat

pub fn new(bits: u128, mask: u128) -> Self

Create a new bit pattern from bits and mask.

pub fn bits(&self) -> u128

Return pattern bits, with masked out bits normalized to 0.

pub fn mask(&self) -> u128

Return pattern mask.

pub fn is_empty(&self) -> bool

Return true iff this pattern has a zero mask and therefore accepts any input.

pub fn len(&self) -> usize

Return pattern length, based on position of most significant set bit in the mask.

pub fn restrict_mask(&mut self, mask: u128)

Restrict pattern mask; the resulting mask is the logical AND between the current mask and the mask argument.

pub fn accepts(&self, bits: u128) -> bool

Check if this pattern accepts bits as a match from the start.

pub fn gather(&self) -> u128

Gather the bits selected by the mask into lower bits of the result and set the remaining upper bits to zero.

On x86-64 processors supporting BMI2, this is implemented through the PEXT instruction.

Example

assert_eq!(BitPat::new(0x1234_5678, 0xFF00_FFF0).gather(), 0x0001_2567);

pub fn gather_bit_vec(&self) -> BitVec

Gather the bits selected by the mask into a bit vector. The bit vector length is the number of set bits in mask.

pub fn scatter(value: u128, mask: u128) -> Self

Scatter the lower bits of value using mask and set the remaining bits to zero.

On x86-64 processors supporting BMI2, this is implemented through the PDEP instruction.

Example

assert_eq!(BitPat::scatter(0x0001_2567, 0xFF00_FFF0), BitPat::new(0x1200_5670, 0xFF00_FFF0));

Trait Implementations

impl Clone for BitPat

fn clone(&self) -> BitPat

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for BitPat

impl Debug for BitPat

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for BitPat

fn default() -> Self

Returns the "default value" for a type.

impl Display for BitPat

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for BitPat

impl Hash for BitPat

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl PartialEq<BitPat> for BitPat

fn eq(&self, other: &BitPat) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &BitPat) -> bool

This method tests for !=.

impl StructuralEq for BitPat

impl StructuralPartialEq for BitPat