Struct Fp8TwinSet 

pub struct Fp8TwinSet {
    pub q: bool,
    pub k: bool,
    pub v: bool,
    pub o: bool,
}

Which of the four attention projections get an FP8 [K, N] transposed twin built by Qwen3AttentionLayer::transpose_fp8_for_prefill.

WHY per projection and not one flag (#915): the four are reached by DIFFERENT prefill chains and only two of them are W8A8-gated.

• K and V are read by prefill/cache_skip_qkv.rs:218 / :235, whose dispatch chain has no W8A8 arm at all — and cache_skip is the first-chunk path (trait_impl/prefill_inner.rs:138, seq_len_start == 0) taken by every request. Their twins are never dead.
• Q on that chain is behind ATLAS_ATTN_PREFILL_Q_T=1 (cache_skip_qkv.rs:142); otherwise it is reached only after the W8A8 arm in prefill/paged_qkv.rs:220 declines.
• O is routed to prefill/paged_oproj.rs from both chains, so it is reached only after the W8A8 arm at paged_oproj.rs:94 declines.

On 1xH100 (Qwen3.8-27B-FP8) the four cost 100 MiB/layer x 16 layers = 1,600 MB — the weight_map/quantized.rs:643 ledger row.

Fields

q: bool

k: bool

v: bool

o: bool

Implementations

impl Fp8TwinSet

pub const NONE: Self

pub const ALL: Self

Every twin — what a loader that has not opted into the #915 plan asks for, i.e. the pre-#915 behaviour.

pub fn any(self) -> bool

Trait Implementations

impl Clone for Fp8TwinSet

fn clone(&self) -> Fp8TwinSet

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Fp8TwinSet

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

Formats the value using the given formatter.

impl Default for Fp8TwinSet

fn default() -> Fp8TwinSet

Returns the “default value” for a type.

impl PartialEq for Fp8TwinSet

fn eq(&self, other: &Fp8TwinSet) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Fp8TwinSet

impl Eq for Fp8TwinSet

impl StructuralPartialEq for Fp8TwinSet