Enum Blake2bBackend 

#[repr(u8)]
pub enum Blake2bBackend {
    Scalar = 0,
    Sse41 = 1,
    Avx2 = 2,
    Avx512 = 3,
}

The compression implementations available to BLAKE2b on this target.

This is deliberately separate from crate::fill_block::Backend. One BLAKE2b compression has four naturally parallel G functions. SSE4.1 handles them as two pairs; AVX2 handles all four in one register. The AVX-512 backend requires AVX2, AVX-512F and AVX-512VL, and uses a native 256-bit rotate instead of widening into half-empty ZMM registers.

A two-register NEON version was also measured on Apple ARM64 and rejected: it made the 72-byte digest 16% slower and the 1 KiB expansion 26% slower than scalar. On x86, upstream’s SSE4.1 schedule was retained because it made Argon2’s 72-to-1024-byte expansion 15-16% faster on AMD EPYC. SSE2 and SSSE3 were rejected because they regressed longer inputs substantially.

Variants

Scalar = 0

Portable scalar code. Always available.

Sse41 = 1

x86/x86-64 SSE4.1, two 64-bit lanes per register.

Avx2 = 2

x86/x86-64 AVX2, four 64-bit lanes.

Avx512 = 3

x86/x86-64 AVX2 + AVX-512F + AVX-512VL, with native rotates.

Implementations

impl Blake2bBackend

pub const ALL: &'static [Blake2bBackend]

Every BLAKE2b backend compiled for this target.

pub const fn name(self) -> &'static str

A short diagnostic/benchmark name.

pub fn is_available(self) -> bool

Whether this CPU can execute the backend right now.

Trait Implementations

impl Clone for Blake2bBackend

fn clone(&self) -> Blake2bBackend

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Blake2bBackend

impl Debug for Blake2bBackend

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

Formats the value using the given formatter.

impl Display for Blake2bBackend

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

Formats the value using the given formatter.

impl Eq for Blake2bBackend

impl PartialEq for Blake2bBackend

fn eq(&self, other: &Blake2bBackend) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Blake2bBackend