refactor permcheck

arithmetic/src/lib.rs

@@ -7,8 +7,9 @@ mod virtual_polynomial;
 pub use errors::ArithErrors;
 pub use multilinear_polynomial::{
     evaluate_no_par, evaluate_opt, fix_last_variables, fix_last_variables_no_par, fix_variables,
-    identity_permutation_mle, merge_polynomials, random_mle_list, random_permutation_mle,
-    random_zero_mle_list, DenseMultilinearExtension,
+    identity_permutation_mle, identity_permutation_mles, merge_polynomials, random_mle_list,
+    random_permutation_mle, random_permutation_mles, random_zero_mle_list,
+    DenseMultilinearExtension,
 };
 pub use univariate_polynomial::{build_l, get_uni_domain};
 pub use util::{bit_decompose, gen_eval_point, get_batched_nv, get_index};

arithmetic/src/multilinear_polynomial.rs

@@ -73,6 +73,7 @@ pub fn random_zero_mle_list<F: PrimeField, R: RngCore>(
 }
 
 /// An MLE that represent an identity permutation: `f(index) \mapto index`
+/// TODO(binyi): remove
 pub fn identity_permutation_mle<F: PrimeField>(
     num_vars: usize,
 ) -> Rc<DenseMultilinearExtension<F>> {
@@ -83,6 +84,7 @@ pub fn identity_permutation_mle<F: PrimeField>(
 }
 
 /// An MLE that represent a random permutation
+/// TODO(binyi): remove
 pub fn random_permutation_mle<F: PrimeField, R: RngCore>(
     num_vars: usize,
     rng: &mut R,
@@ -99,6 +101,46 @@ pub fn random_permutation_mle<F: PrimeField, R: RngCore>(
     ))
 }
 
+/// A list of MLEs that represents an identity permutation
+pub fn identity_permutation_mles<F: PrimeField>(
+    num_vars: usize,
+    num_chunks: usize,
+) -> Vec<Rc<DenseMultilinearExtension<F>>> {
+    let mut res = vec![];
+    for i in 0..num_chunks {
+        let shift = (i * (1 << num_vars)) as u64;
+        let s_id_vec = (shift..shift + (1u64 << num_vars)).map(F::from).collect();
+        res.push(Rc::new(DenseMultilinearExtension::from_evaluations_vec(
+            num_vars, s_id_vec,
+        )));
+    }
+    res
+}
+
+/// A list of MLEs that represent a random permutation
+pub fn random_permutation_mles<F: PrimeField, R: RngCore>(
+    num_vars: usize,
+    num_chunks: usize,
+    rng: &mut R,
+) -> Vec<Rc<DenseMultilinearExtension<F>>> {
+    let len = (num_chunks as u64) * (1u64 << num_vars);
+    let mut s_id_vec: Vec<F> = (0..len).map(F::from).collect();
+    let mut s_perm_vec = vec![];
+    for _ in 0..len {
+        let index = rng.next_u64() as usize % s_id_vec.len();
+        s_perm_vec.push(s_id_vec.remove(index));
+    }
+    let mut res = vec![];
+    let n = 1 << num_vars;
+    for i in 0..num_chunks {
+        res.push(Rc::new(DenseMultilinearExtension::from_evaluations_vec(
+            num_vars,
+            s_perm_vec[i * n..i * n + n].to_vec(),
+        )));
+    }
+    res
+}
+
 pub fn evaluate_opt<F: Field>(poly: &DenseMultilinearExtension<F>, point: &[F]) -> F {
     assert_eq!(poly.num_vars, point.len());
     fix_variables(poly, point).evaluations[0]