use crate::model::ParsingContext;
use crate::pb::NodeProto;
use tract_core::ops::cast::cast;
use tract_core::ops::math::{add, mul, rsqrt};
use tract_core::ops::nn::{Reduce, Reducer};
use tract_hir::internal::*;
use tract_hir::ops::logic::wire_with_rank_broadcast;
pub fn rms_normalization(
_ctx: &ParsingContext,
node: &NodeProto,
) -> TractResult<(Box<dyn InferenceOp>, Vec<String>)> {
let axis = node.get_attr_opt::<isize>("axis")?.unwrap_or(-1);
let epsilon = node.get_attr_opt("epsilon")?.unwrap_or(1e-5f32);
let have_bias = node.input.len() >= 3 && !node.input[2].is_empty();
Ok((expand(RmsNormalization { axis, epsilon, have_bias }), vec![]))
}
#[derive(Debug, Clone)]
struct RmsNormalization {
axis: isize,
epsilon: f32,
have_bias: bool,
}
impl Expansion for RmsNormalization {
fn name(&self) -> StaticName {
"RmsNormalization".into()
}
fn rules<'r, 'p: 'r, 's: 'r>(
&'s self,
s: &mut Solver<'r>,
inputs: &'p [TensorProxy],
outputs: &'p [TensorProxy],
) -> InferenceResult {
check_input_arity(inputs, 2 + self.have_bias as usize)?;
check_output_arity(outputs, 1)?;
s.equals(&inputs[0].datum_type, &outputs[0].datum_type)?;
s.equals(&inputs[0].shape, &outputs[0].shape)?;
Ok(())
}
fn wire(
&self,
prefix: &str,
model: &mut TypedModel,
inputs: &[OutletId],
) -> TractResult<TVec<OutletId>> {
let x_fact = model.outlet_fact(inputs[0])?.clone();
let rank = x_fact.rank();
let axis =
if self.axis < 0 { (self.axis + rank as isize) as usize } else { self.axis as usize };
let dt = x_fact.datum_type;
let stash_dt = DatumType::F32;
let axes: TVec<usize> = (axis..rank).collect();
let x_cast = model.wire_node(format!("{prefix}.cast_x"), cast(stash_dt), &[inputs[0]])?[0];
let mean_sq = model.wire_node(
format!("{prefix}.mean_sq"),
Reduce { axes, reducer: Reducer::MeanOfSquares },
&[x_cast],
)?[0];
let eps = model.add_const(
format!("{prefix}.eps"),
tensor0(self.epsilon).cast_to_dt(stash_dt)?.into_owned(),
)?;
let mean_sq_eps =
wire_with_rank_broadcast(format!("{prefix}.add_eps"), model, add(), &[mean_sq, eps])?
[0];
let inv_rms = model.wire_node(format!("{prefix}.rsqrt"), rsqrt(), &[mean_sq_eps])?[0];
let normalized =
wire_with_rank_broadcast(format!("{prefix}.norm"), model, mul(), &[x_cast, inv_rms])?
[0];
let normalized_cast =
model.wire_node(format!("{prefix}.cast_out"), cast(dt), &[normalized])?[0];
let scaled = wire_with_rank_broadcast(
format!("{prefix}.scaled"),
model,
mul(),
&[normalized_cast, inputs[1]],
)?[0];
if self.have_bias {
wire_with_rank_broadcast(prefix, model, add(), &[scaled, inputs[2]])
} else {
Ok(tvec![scaled])
}
}
}