From 3b79a7362fe2f6d79adb65716654cca3d2a0f8ca Mon Sep 17 00:00:00 2001
From: Jan Ferdinand Sauer <ferdinand@neptune.cash>
Date: Tue, 15 Nov 2022 01:56:43 +0100
Subject: [PATCH] use `fri_domain_generator` instead of `omega`

---
 triton-vm/src/domain.rs |  8 ++++----
 triton-vm/src/fri.rs    | 12 ++++++------
 triton-vm/src/stark.rs  |  4 ++--
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/triton-vm/src/domain.rs b/triton-vm/src/domain.rs
index b9c064c1b..9ea2d1c75 100644
--- a/triton-vm/src/domain.rs
+++ b/triton-vm/src/domain.rs
@@ -77,13 +77,13 @@ mod domain_tests {
         let poly = Polynomial::<BFieldElement>::new(x_squared_coefficients.clone());
 
         for order in [4, 8, 32] {
-            let omega = BFieldElement::primitive_root_of_unity(order).unwrap();
+            let generator = BFieldElement::primitive_root_of_unity(order).unwrap();
             let offset = BFieldElement::generator();
-            let b_domain = Domain::<BFieldElement>::new(offset, omega, order as usize);
-            let x_domain = Domain::<XFieldElement>::new(offset, omega, order as usize);
+            let b_domain = Domain::<BFieldElement>::new(offset, generator, order as usize);
+            let x_domain = Domain::<XFieldElement>::new(offset, generator, order as usize);
 
             let expected_b_values: Vec<BFieldElement> =
-                (0..order).map(|i| offset * omega.mod_pow(i)).collect();
+                (0..order).map(|i| offset * generator.mod_pow(i)).collect();
             let actual_b_values_1 = b_domain.domain_values();
             let actual_b_values_2 = (0..order as u32)
                 .map(|i| b_domain.domain_value(i))
diff --git a/triton-vm/src/fri.rs b/triton-vm/src/fri.rs
index 514b9b1c7..5236c8680 100644
--- a/triton-vm/src/fri.rs
+++ b/triton-vm/src/fri.rs
@@ -57,12 +57,12 @@ pub struct Fri<H> {
 impl<H: AlgebraicHasher> Fri<H> {
     pub fn new(
         offset: BFieldElement,
-        omega: BFieldElement,
+        fri_domain_generator: BFieldElement,
         domain_length: usize,
         expansion_factor: usize,
         colinearity_checks_count: usize,
     ) -> Self {
-        let domain = Domain::new(offset, omega, domain_length);
+        let domain = Domain::new(offset, fri_domain_generator, domain_length);
         let _hasher = PhantomData;
         Self {
             domain,
@@ -346,11 +346,11 @@ impl<H: AlgebraicHasher> Fri<H> {
         let log_2_of_n = log_2_floor(last_codeword.len() as u128) as u32;
         let mut last_polynomial = last_codeword.clone();
 
-        let last_omega = self
+        let last_fri_domain_generator = self
             .domain
             .generator
             .mod_pow_u32(2u32.pow(num_rounds as u32));
-        intt::<XFieldElement>(&mut last_polynomial, last_omega, log_2_of_n);
+        intt::<XFieldElement>(&mut last_polynomial, last_fri_domain_generator, log_2_of_n);
 
         let last_poly_degree: isize = (Polynomial::<XFieldElement> {
             coefficients: last_polynomial,
@@ -666,7 +666,7 @@ mod triton_xfri_tests {
         expansion_factor: usize,
         colinearity_checks: usize,
     ) -> Fri<H> {
-        let omega = BFieldElement::primitive_root_of_unity(subgroup_order).unwrap();
+        let fri_domain_generator = BFieldElement::primitive_root_of_unity(subgroup_order).unwrap();
 
         // The following offset was picked arbitrarily by copying the one found in
         // `get_b_field_fri_test_object`. It does not generate the full Z_p\{0}, but
@@ -675,7 +675,7 @@ mod triton_xfri_tests {
 
         let fri: Fri<H> = Fri::new(
             offset,
-            omega,
+            fri_domain_generator,
             subgroup_order as usize,
             expansion_factor,
             colinearity_checks,
diff --git a/triton-vm/src/stark.rs b/triton-vm/src/stark.rs
index e8f734d26..14fedecb8 100644
--- a/triton-vm/src/stark.rs
+++ b/triton-vm/src/stark.rs
@@ -120,12 +120,12 @@ impl Stark {
             empty_table_collection.max_degree_with_origin(parameters.num_trace_randomizers);
         let max_degree = (other::roundup_npo2(max_degree_with_origin.degree as u64) - 1) as i64;
         let fri_domain_length = parameters.fri_expansion_factor * (max_degree as usize + 1);
-        let omega =
+        let fri_domain_generator =
             BFieldElement::primitive_root_of_unity(fri_domain_length.try_into().unwrap()).unwrap();
         let coset_offset = BFieldElement::generator();
         let fri = Fri::new(
             coset_offset,
-            omega,
+            fri_domain_generator,
             fri_domain_length,
             parameters.fri_expansion_factor,
             parameters.num_colinearity_checks,