From 7588b211ff51d58315b402a0e54e627764a49294 Mon Sep 17 00:00:00 2001
From: Dr Maxim Orlovsky <orlovsky@pandoracore.com>
Date: Thu, 18 Jun 2020 18:36:09 +0200
Subject: [PATCH 1/2] Adding Rem op (%) to Uint128 & Uint256 types

---
 src/util/uint.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/util/uint.rs b/src/util/uint.rs
index 9456df0a..e05e9b99 100644
--- a/src/util/uint.rs
+++ b/src/util/uint.rs
@@ -166,6 +166,15 @@ macro_rules! construct_uint {
             }
         }
 
+        impl ::std::ops::Rem<$name> for $name {
+            type Output = $name;
+
+            fn rem(self, other: $name) -> $name {
+                let times = self / other;
+                self - (times * other)
+            }
+        }
+
         impl $crate::util::BitArray for $name {
             #[inline]
             fn bit(&self, index: usize) -> bool {
@@ -479,6 +488,14 @@ mod tests {
                    Uint256::from_u64(21).unwrap());
         let div = mult / Uint256::from_u64(300).unwrap();
         assert_eq!(div, Uint256([0x9F30411021524112u64, 0x0001BD5B7DDFBD5A, 0, 0]));
+
+        assert_eq!(Uint256::from_u64(105).unwrap() % Uint256::from_u64(5).unwrap(),
+                   Uint256::from_u64(0).unwrap());
+        assert_eq!(Uint256::from_u64(35498456).unwrap() % Uint256::from_u64(3435).unwrap(),
+                   Uint256::from_u64(1166).unwrap());
+        let rem_src = mult * Uint256::from_u64(39842).unwrap() + Uint256::from_u64(9054).unwrap();
+        assert_eq!(rem_src % Uint256::from_u64(39842).unwrap(),
+                   Uint256::from_u64(9054).unwrap());
         // TODO: bit inversion
     }
 

From 19f88212afcdffbf6c14c21441e3474faebb5650 Mon Sep 17 00:00:00 2001
From: Dr Maxim Orlovsky <orlovsky@pandoracore.com>
Date: Tue, 21 Jul 2020 14:54:56 +0200
Subject: [PATCH 2/2] Fuzz tests for u128 modulo division

---
 fuzz/fuzz_targets/uint128_fuzz.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fuzz/fuzz_targets/uint128_fuzz.rs b/fuzz/fuzz_targets/uint128_fuzz.rs
index ce00c350..11b2b620 100644
--- a/fuzz/fuzz_targets/uint128_fuzz.rs
+++ b/fuzz/fuzz_targets/uint128_fuzz.rs
@@ -40,6 +40,7 @@ fn do_test(data: &[u8]) {
     check_eq!(a_native.wrapping_sub(b_native), a - b);
     if b_native != 0 {
         check_eq!(a_native.wrapping_div(b_native), a / b);
+        check_eq!(a_native.wrapping_rem(b_native), a % b);
     }
     check_eq!(a_native.wrapping_mul(b_native), a * b);
     check_eq!(a_native & b_native, a & b);