Parallelize and rename methods in msm.rs

src/poly/commitment.rs

@@ -293,7 +293,7 @@ fn test_opening_proof() {
             let opening_proof = opening_proof.unwrap();
             // Verify the opening proof
             let mut commitment_msm = params.empty_msm();
-            commitment_msm.add_term(Field::one(), p);
+            commitment_msm.append_term(Field::one(), p);
             let guard = opening_proof
                 .verify(
                     &params,
@@ -320,7 +320,7 @@ fn test_opening_proof() {
             // Check another proof to populate `msm.g_scalars`
             let msm = guard.use_challenges();
             let mut commitment_msm = params.empty_msm();
-            commitment_msm.add_term(Field::one(), p);
+            commitment_msm.append_term(Field::one(), p);
             let guard = opening_proof
                 .verify(
                     &params,

src/poly/commitment/msm.rs

@@ -1,5 +1,5 @@
 use super::Params;
-use crate::arithmetic::{best_multiexp, Curve, CurveAffine};
+use crate::arithmetic::{best_multiexp, parallelize, Curve, CurveAffine};
 
 /// A multiscalar multiplication in the polynomial commitment scheme
 #[derive(Debug, Clone)]
@@ -34,52 +34,58 @@ impl<'a, C: CurveAffine> MSM<'a, C> {
         self.other_bases.extend(other.other_bases.iter());
 
         if let Some(g_scalars) = &other.g_scalars {
-            self.add_to_g(&g_scalars);
+            self.add_to_g_scalars(&g_scalars);
         }
 
         if let Some(h_scalar) = &other.h_scalar {
-            self.add_to_h(*h_scalar);
+            self.add_to_h_scalar(*h_scalar);
         }
     }
 
     /// Add arbitrary term (the scalar and the point)
-    pub fn add_term(&mut self, scalar: C::Scalar, point: C) {
+    pub fn append_term(&mut self, scalar: C::Scalar, point: C) {
         self.other_scalars.push(scalar);
         self.other_bases.push(point);
     }
 
     /// Add a vector of scalars to `g_scalars`. This function will panic if the
     /// caller provides a slice of scalars that is not of length `params.n`.
-    // TODO: parallelize
+    pub fn add_to_g_scalars(&mut self, scalars: &[C::Scalar]) {
-    pub fn add_to_g(&mut self, scalars: &[C::Scalar]) {
         assert_eq!(scalars.len(), self.params.n as usize);
         if let Some(g_scalars) = &mut self.g_scalars {
-            for (g_scalar, scalar) in g_scalars.iter_mut().zip(scalars.iter()) {
+            parallelize(g_scalars, |g_scalars, start| {
-                *g_scalar += scalar;
+                for (g_scalar, scalar) in g_scalars.iter_mut().zip(scalars[start..].iter()) {
-            }
+                    *g_scalar += scalar;
+                }
+            })
         } else {
             self.g_scalars = Some(scalars.to_vec());
         }
     }
 
-    /// Add term to h
+    /// Add to `h_scalar`
-    pub fn add_to_h(&mut self, scalar: C::Scalar) {
+    pub fn add_to_h_scalar(&mut self, scalar: C::Scalar) {
         self.h_scalar = self.h_scalar.map_or(Some(scalar), |a| Some(a + &scalar));
     }
 
     /// Scale all scalars in the MSM by some scaling factor
-    // TODO: parallelize
     pub fn scale(&mut self, factor: C::Scalar) {
         if let Some(g_scalars) = &mut self.g_scalars {
-            for g_scalar in g_scalars.iter_mut() {
+            parallelize(g_scalars, |g_scalars, _| {
-                *g_scalar *= &factor;
+                for g_scalar in g_scalars {
-            }
+                    *g_scalar *= &factor;
+                }
+            })
         }
 
-        // TODO: parallelize
+        if !self.other_scalars.is_empty() {
-        for other_scalar in self.other_scalars.iter_mut() {
+            parallelize(&mut self.other_scalars, |other_scalars, _| {
-            *other_scalar *= &factor;
+                for other_scalar in other_scalars {
+                    *other_scalar *= &factor;
+                }
+            })
         }
+
         self.h_scalar = self.h_scalar.map(|a| a * &factor);
     }
 

src/poly/commitment/verifier.rs

@@ -32,8 +32,8 @@ impl<'a, C: CurveAffine> Guard<'a, C> {
     /// scalars and points.
     pub fn use_challenges(mut self) -> MSM<'a, C> {
         let s = compute_s(&self.challenges_sq, self.allinv * &self.neg_z1);
-        self.msm.add_to_g(&s);
+        self.msm.add_to_g_scalars(&s);
-        self.msm.add_to_h(self.neg_z1);
+        self.msm.add_to_h_scalar(self.neg_z1);
 
         self.msm
     }
@@ -41,7 +41,7 @@ impl<'a, C: CurveAffine> Guard<'a, C> {
     /// Lets caller supply the purported G point and simply appends it to
     /// return an updated MSM.
     pub fn use_g(mut self, g: C) -> (MSM<'a, C>, Accumulator<C>) {
-        self.msm.add_term(self.neg_z1, g);
+        self.msm.append_term(self.neg_z1, g);
 
         let accumulator = Accumulator {
             g,
@@ -176,17 +176,17 @@ impl<C: CurveAffine> Proof<C> {
         }
 
         for (scalar, base) in extra_scalars.iter().zip(extra_bases.iter()) {
-            msm.add_term(*scalar, *base);
+            msm.append_term(*scalar, *base);
         }
 
         // [c * v] U - [z1 * b] U
-        msm.add_term((c * &v) + &(neg_z1 * &b), u);
+        msm.append_term((c * &v) + &(neg_z1 * &b), u);
 
         // delta
-        msm.add_term(Field::one(), self.delta);
+        msm.append_term(Field::one(), self.delta);
 
         // - [z1 - z2] H
-        msm.add_to_h(self.z1 - &self.z2);
+        msm.add_to_h_scalar(self.z1 - &self.z2);
 
         let guard = Guard {
             msm,

src/poly/multiopen/verifier.rs

@@ -54,7 +54,7 @@ impl<C: CurveAffine> Proof<C> {
         {
             let mut accumulate = |set_idx: usize, new_commitment, evals: Vec<C::Scalar>| {
                 q_commitments[set_idx].scale(x_4);
-                q_commitments[set_idx].add_term(C::Scalar::one(), new_commitment);
+                q_commitments[set_idx].append_term(C::Scalar::one(), new_commitment);
                 for (eval, set_eval) in evals.iter().zip(q_eval_sets[set_idx].iter_mut()) {
                     *set_eval *= &x_4;
                     *set_eval += eval;
@@ -109,7 +109,7 @@ impl<C: CurveAffine> Proof<C> {
 
         // Compute the final commitment that has to be opened
         let mut commitment_msm = params.empty_msm();
-        commitment_msm.add_term(C::Scalar::one(), self.f_commitment);
+        commitment_msm.append_term(C::Scalar::one(), self.f_commitment);
         let (commitment_msm, msm_eval) = q_commitments.into_iter().zip(self.q_evals.iter()).fold(
             (commitment_msm, msm_eval),
             |(mut commitment_msm, msm_eval), (q_commitment, q_eval)| {