Struct NumericsKnobs 

pub struct NumericsKnobs {
    pub fidelity: Fidelity,
    pub fp32_dest_acc: bool,
    pub packer_l1_acc: bool,
    pub pcc_floor: f64,
}

The three numerics knobs the measurement harness varies, and the PCC the program then requires of itself. scripts/tt-matmul-measure.sh sets them as LOGOS_TT_FIDELITY / _FP32 / _L1ACC, and every ledger row records what the program PRINTED rather than what was asked for — so this parser is part of the measurement contract, not a convenience.

★ SALVAGED FROM THE RETIRED EMITTER, and narrowed on the way in. It used to carry its own math-fidelity enum beside this crate’s Fidelity — two spellings of one concept, each with its own parse/as_str — and a register-budget helper that halved the tile count under fp32 accumulate while taking a SECOND chip descriptor to do it. SpatialTarget::effective_acc_tiles already expresses that exactly, so the dependency on a duplicate description of the part dissolved rather than moved.

Fields

fidelity: Fidelity

fp32_dest_acc: bool

Accumulate in fp32 in the register file: halves the tile budget, raises PCC.

packer_l1_acc: bool

Accumulate K-block partials in local memory through the packer instead of reloading registers.

pcc_floor: f64

The PCC the emitted program requires of itself before it prints LOGOS_MM_PASS.

Implementations

impl NumericsKnobs

pub fn from_env() -> Result<Self, String>

Read the harness’s environment contract.

pub fn from_vars( fidelity: Option<&str>, fp32: Option<&str>, l1acc: Option<&str>, ) -> Result<Self, String>

The pure core of NumericsKnobs::from_env — every refusal is typed and names the variable, so a mistyped knob stops the measurement instead of silently recording a different program.

pub fn policy(&self) -> NumericsPolicy

The numerics policy these knobs express: fp32 accumulate is what keeps partial sums exact.

Trait Implementations

impl Clone for NumericsKnobs

fn clone(&self) -> NumericsKnobs

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NumericsKnobs

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

Formats the value using the given formatter.

impl Default for NumericsKnobs

fn default() -> Self

★ ttnn’s OWN bf16 default numerics — HiFi2, bf16 dest-accumulate — so a head-to-head against the vendor is matched by construction rather than by remembering to pass a flag. Defaulting to HiFi4 would silently compare our four-pass arithmetic against the vendor’s two-pass and call the difference a compiler result.

impl PartialEq for NumericsKnobs

fn eq(&self, other: &NumericsKnobs) -> 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 NumericsKnobs

impl StructuralPartialEq for NumericsKnobs