add TODO

Author: TomWambsgans

crates/lookup/src/quotient_gkr.rs

@@ -236,6 +236,9 @@ where
 
     let mut eq_poly_packed = pack_extension(&eq_poly);
 
+    // TODO for the top layer, the denomiators have a structured form: constant - index.
+    // We can skip one EE multilication in the sumcheck computation.
+
     let sum_x_packed: EFPacking<EF> = (0..n_non_zeros_numerator - quarter_len_packed)
         .into_par_iter()
         .map(|i| {
@@ -411,37 +414,6 @@ where
     Ok(Evaluation::new(next_point, next_claim))
 }
 
-pub struct GKRQuotientComputation<EF> {
-    u4_const: EF,
-    u5_const: EF,
-}
-
-impl<IF: ExtensionField<PF<EF>>, EF: ExtensionField<IF>> SumcheckComputation<IF, EF>
-    for GKRQuotientComputation<EF>
-{
-    fn eval(&self, point: &[IF], _: &[EF]) -> EF {
-        // U4.U2.U3 + U5.[U0.U3 + U1.U2]
-        self.u4_const * point[2] * point[3]
-            + self.u5_const * (point[0] * point[3] + point[1] * point[2])
-    }
-    fn degree(&self) -> usize {
-        2
-    }
-}
-
-impl<EF: ExtensionField<PF<EF>>> SumcheckComputationPacked<EF> for GKRQuotientComputation<EF> {
-    fn eval_packed_base(&self, _: &[PFPacking<EF>], _: &[EF]) -> EFPacking<EF> {
-        todo!()
-    }
-    fn eval_packed_extension(&self, point: &[EFPacking<EF>], _: &[EF]) -> EFPacking<EF> {
-        point[2] * point[3] * self.u4_const
-            + (point[0] * point[3] + point[1] * point[2]) * self.u5_const
-    }
-    fn degree(&self) -> usize {
-        2
-    }
-}
-
 fn sum_quotients_2_by_2<EF: PrimeCharacteristicRing + Sync + Send + Copy>(
     layer: &[EF],
     n_non_zeros_numerator: Option<usize>,