From dbe565765645bdc1ff5eafc4d4d1aeb8dff4102e Mon Sep 17 00:00:00 2001
From: Weikeng Chen <w.k@berkeley.edu>
Date: Fri, 5 Feb 2021 17:51:01 -0800
Subject: [PATCH] Fix mul_without_reduce when self is a constant (#36)

* fix

* fix
---
 src/nonnative_field_var.rs | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/nonnative_field_var.rs b/src/nonnative_field_var.rs
index d687abfe..3e8d8ebf 100644
--- a/src/nonnative_field_var.rs
+++ b/src/nonnative_field_var.rs
@@ -455,7 +455,19 @@ impl<TargetField: PrimeField, BaseField: PrimeField> NonNativeFieldVar<TargetFie
         other: &Self,
     ) -> R1CSResult<NonNativeFieldMulResultVar<TargetField, BaseField>> {
         match self {
-            Self::Constant(c) => Ok(NonNativeFieldMulResultVar::Constant(*c)),
+            Self::Constant(c) => match other {
+                Self::Constant(other_c) => Ok(NonNativeFieldMulResultVar::Constant(*c * other_c)),
+                Self::Var(other_v) => {
+                    let self_v =
+                        AllocatedNonNativeFieldVar::<TargetField, BaseField>::new_constant(
+                            self.cs(),
+                            c,
+                        )?;
+                    Ok(NonNativeFieldMulResultVar::Var(
+                        other_v.mul_without_reduce(&self_v)?,
+                    ))
+                }
+            },
             Self::Var(v) => {
                 let other_v = match other {
                     Self::Constant(other_c) => {