Remove obsolete method for computing unit_distance (#10)

triton-vm/src/stark.rs

@@ -27,9 +27,7 @@ use crate::cross_table_arguments::{
 use crate::fri_domain::FriDomain;
 use crate::proof_item::ProofItem;
 use crate::table::challenges_endpoints::{AllChallenges, AllInitials};
-use crate::table::table_collection::{
-    derive_omicron, unit_distance, BaseTableCollection, ExtTableCollection,
-};
+use crate::table::table_collection::{derive_omicron, BaseTableCollection, ExtTableCollection};
 use crate::triton_xfri::{self, Fri};
 
 use super::table::base_matrix::BaseMatrices;
@@ -269,8 +267,9 @@ impl Stark {
         }
         timer.elapsed("fri.prove");
 
+        // the relation between the FRI domain and the omicron domain
+        let unit_distance = self.xfri.domain.length / base_tables.padded_height;
         // Open leafs of zipped codewords at indicated positions
-        let unit_distance = unit_distance(base_tables.padded_height, self.xfri.domain.length);
         let revealed_indices =
             self.get_revealed_indices(unit_distance, &cross_codeword_slice_indices);
 
@@ -683,9 +682,9 @@ impl Stark {
         self.xfri.verify(proof_stream, &combination_root)?;
         timer.elapsed("Verified FRI proof");
 
+        // the relation between the FRI domain and the omicron domain
+        let unit_distance = self.xfri.domain.length / ext_table_collection.padded_height;
         // Open leafs of zipped codewords at indicated positions
-        let unit_distance =
-            unit_distance(ext_table_collection.padded_height, self.xfri.domain.length);
         let revealed_indices = self.get_revealed_indices(unit_distance, &combination_check_indices);
         timer.elapsed("Calculated revealed indices");
 

triton-vm/src/table/extension_table.rs

@@ -13,7 +13,7 @@ use twenty_first::timing_reporter::TimingReporter;
 use crate::fri_domain::FriDomain;
 use crate::stark::{Stark, StarkHasher};
 use crate::table::challenges_endpoints::AllTerminals;
-use crate::table::table_collection::{interpolant_degree, unit_distance};
+use crate::table::table_collection::interpolant_degree;
 
 use super::base_table::TableLike;
 use super::challenges_endpoints::AllChallenges;
@@ -264,7 +264,8 @@ pub trait Quotientable: ExtensionTable + Evaluable {
             .zip_eq(subgroup_zerofier_inverse.into_par_iter())
             .map(|(fri_dom_v, sub_z_inv)| (fri_dom_v - omicron_inverse) * sub_z_inv)
             .collect();
-        let unit_distance = unit_distance(padded_height, fri_domain.length);
+        // the relation between the FRI domain and the omicron domain
+        let unit_distance = fri_domain.length / padded_height;
 
         let transposed_quotient_codewords: Vec<_> = zerofier_inverse
             .par_iter()

triton-vm/src/table/table_collection.rs

@@ -88,15 +88,6 @@ pub fn derive_omicron<DataPF: FiniteField>(padded_height: u64) -> DataPF {
     DataPF::primitive_root_of_unity(padded_height).unwrap()
 }
 
-/// Returns the relation between the FRI domain and the omicron domain
-pub fn unit_distance(padded_height: usize, omega_order: usize) -> usize {
-    if padded_height == 0 {
-        0
-    } else {
-        omega_order / padded_height
-    }
-}
-
 impl BaseTableCollection {
     pub fn from_base_matrices(base_matrices: &BaseMatrices) -> Self {
         let padded_height = Self::padded_height(base_matrices);