gather_first_layer_queries

calc.py

@@ -1,3 +1,3 @@
 DEFAULT_PRIME = 2**251 + 17 * 2**192 + 1
 
-print((pow(193456804421077096570009938751278224656090409051406060084, 193456804421077096570009938751278224656090409051406060084, DEFAULT_PRIME)))
+print((pow(3, DEFAULT_PRIME-2, DEFAULT_PRIME)))

src/common/tests/test_math.cairo

@@ -53,15 +53,24 @@ fn test_mul_inverse_3() {
 #[test]
 #[available_gas(9999999999)]
 fn test_mul_inverse_4() {
+    let x = 3;
+    let inv_x = mul_inverse(x);
+    assert(inv_x == 1206167596222043737899107594365023368541035738443865566657697352045290673494, 'Invalid value');
+    assert(x * inv_x == 1, 'Invalid value');
+}
+
+#[test]
+#[available_gas(9999999999)]
+fn test_mul_inverse_5() {
     let x = 193456804421077096570009938751278224656090409051406060084;
     let inv_inv_x = mul_inverse(mul_inverse(x));
     assert(x == inv_inv_x, 'Invalid value');
 }
 
 #[test]
 #[available_gas(9999999999)]
-fn test_mul_inverse_5() {
+fn test_mul_inverse_6() {
     let x = 19345680409051406060084;
     let inv_inv_x = mul_inverse(mul_inverse(x));
     assert(x == inv_inv_x, 'Invalid value');
-}
+}

src/fri.cairo

@@ -2,6 +2,7 @@ mod fri_formula;
 mod fri_group;
 mod fri_layer;
 mod fri_config;
+mod fri_first_layer;
 mod fri_last_layer;
 mod fri;
 

src/fri/fri_first_layer.cairo

@@ -0,0 +1,34 @@
+use core::array::SpanTrait;
+use core::option::OptionTrait;
+use core::array::ArrayTrait;
+use core::traits::TryInto;
+
+use cairo_verifier::common::math;
+use cairo_verifier::fri::fri_layer::FriLayerQuery;
+use cairo_verifier::FIELD_GENERATOR_INV;
+
+fn gather_first_layer_queries(
+    n_queries: felt252, queries: Span<felt252>, evaluations: Span<felt252>, x_values: Span<felt252>
+) {
+    let mut fri_queries = ArrayTrait::<FriLayerQuery>::new();
+
+    let len: u32 = n_queries.try_into().unwrap();
+    let mut i: u32 = 0;
+    loop {
+        if i == len {
+            break;
+        }
+
+        // Translate the coset to the homogenous group to have simple FRI equations.
+        let shifted_x_value = *(x_values.at(i)) * FIELD_GENERATOR_INV;
+
+        fri_queries
+            .append(
+                FriLayerQuery {
+                    index: *(queries.at(i)),
+                    y_value: *(evaluations.at(i)),
+                    x_inv_value: math::mul_inverse(shifted_x_value),
+                }
+            )
+    }
+}

src/lib.cairo

@@ -1,3 +1,6 @@
+const FIELD_GENERATOR: felt252 = 3;
+const FIELD_GENERATOR_INV: felt252 = 1206167596222043737899107594365023368541035738443865566657697352045290673494;
+
 mod channel;
 mod common;
 mod structs;