From d928a70b6f34cc1bf12ac34ddd374bf68c7e7505 Mon Sep 17 00:00:00 2001
From: Dmitry Vagner <dmitry.vagner@gmail.com>
Date: Wed, 26 Apr 2023 09:54:46 -0700
Subject: [PATCH] clean

---
 evm/src/bn254_pairing.rs | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/evm/src/bn254_pairing.rs b/evm/src/bn254_pairing.rs
index 93d0d1e9..138f23e7 100644
--- a/evm/src/bn254_pairing.rs
+++ b/evm/src/bn254_pairing.rs
@@ -1,4 +1,4 @@
-use std::ops::Add;
+use std::ops::{Add, Mul, Neg};
 
 use ethereum_types::U256;
 use rand::Rng;
@@ -42,6 +42,38 @@ impl Add for Curve {
     }
 }
 
+impl Neg for Curve {
+    type Output = Curve;
+
+    fn neg(self) -> Self {
+        Curve {
+            x: self.x,
+            y: -self.y,
+        }
+    }
+}
+
+impl Mul<i32> for Curve {
+    type Output = Curve;
+
+    fn mul(self, other: i32) -> Self {
+        let mut result: Curve = self;
+        if other.is_negative() {
+            result = -result;
+        }
+        let mut multiplier = result;
+        let mut exp = other.abs() as usize;
+        while exp > 0 {
+            if exp % 2 == 1 {
+                result = result + multiplier;
+            }
+            exp >>= 1;
+            multiplier = multiplier + multiplier;
+        }
+        result
+    }
+}
+
 // The twisted curve consists of pairs (x, y): (Fp2, Fp2) | y^2 = x^3 + 3/(9 + i)
 #[derive(Debug, Copy, Clone, PartialEq)]
 pub struct TwistedCurve {