From c9ba4bf4e77fc7f37a42d29c525cc3968fdbfd6b Mon Sep 17 00:00:00 2001
From: kevaundray <kevtheappdev@gmail.com>
Date: Sat, 25 Nov 2023 18:53:39 +0000
Subject: [PATCH 1/5] deterministically sort
 `cached_partial_non_native_field_multiplication`

---
 .../circuit_builder/ultra_circuit_builder.hpp | 29 +++++++++++++++----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
index 25c35737a12..fb9baec7e15 100644
--- a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
+++ b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
@@ -211,12 +211,31 @@ class UltraCircuitBuilder_ : public CircuitBuilderBase<typename Arithmetization:
             if (a < other.a) {
                 return true;
             }
-            if (a == other.a) {
-                if (b < other.b) {
-                    return true;
-                }
+            if (other.a < a) {
+                return false;
+            }
+            if (b < other.b) {
+                return true;
+            }
+            if (other.b < b) {
+                return false;
+            }
+
+            if (uint256_t(lo_0) < uint256_t(other.lo_0)) {
+                return true;
             }
-            return false;
+            if (uint256_t(other.lo_0) < uint256_t(lo_0)) {
+                return false;
+            }
+
+            if (uint256_t(hi_0) < uint256_t(other.hi_0)) {
+                return true;
+            }
+            if (uint256_t(other.hi_0) < uint256_t(hi_0)) {
+                return false;
+            }
+
+            return uint256_t(hi_1) < uint256_t(other.hi_1);
         }
     };
 

From c22db4b9355036cda4a2bd237ef487c831f44ba7 Mon Sep 17 00:00:00 2001
From: kevaundray <kevtheappdev@gmail.com>
Date: Mon, 27 Nov 2023 19:20:35 +0000
Subject: [PATCH 2/5] use stable_sort

---
 .../circuit_builder/ultra_circuit_builder.cpp |  4 ++--
 .../circuit_builder/ultra_circuit_builder.hpp | 20 +------------------
 2 files changed, 3 insertions(+), 21 deletions(-)

diff --git a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.cpp b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.cpp
index e51cacc67d4..78c3f3ba370 100644
--- a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.cpp
+++ b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.cpp
@@ -1665,8 +1665,8 @@ void UltraCircuitBuilder_<Arithmetization>::process_non_native_field_multiplicat
             c.b[j] = this->real_variable_index[c.b[j]];
         }
     }
-    std::sort(cached_partial_non_native_field_multiplications.begin(),
-              cached_partial_non_native_field_multiplications.end());
+    std::stable_sort(cached_partial_non_native_field_multiplications.begin(),
+                     cached_partial_non_native_field_multiplications.end());
 
     auto last = std::unique(cached_partial_non_native_field_multiplications.begin(),
                             cached_partial_non_native_field_multiplications.end());
diff --git a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
index fb9baec7e15..41b43a0d683 100644
--- a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
+++ b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
@@ -217,25 +217,7 @@ class UltraCircuitBuilder_ : public CircuitBuilderBase<typename Arithmetization:
             if (b < other.b) {
                 return true;
             }
-            if (other.b < b) {
-                return false;
-            }
-
-            if (uint256_t(lo_0) < uint256_t(other.lo_0)) {
-                return true;
-            }
-            if (uint256_t(other.lo_0) < uint256_t(lo_0)) {
-                return false;
-            }
-
-            if (uint256_t(hi_0) < uint256_t(other.hi_0)) {
-                return true;
-            }
-            if (uint256_t(other.hi_0) < uint256_t(hi_0)) {
-                return false;
-            }
-
-            return uint256_t(hi_1) < uint256_t(other.hi_1);
+            return other.b < b;
         }
     };
 

From 591e9af8cceb8192232fa6760de4e8f0e3fb99f1 Mon Sep 17 00:00:00 2001
From: kevaundray <kevtheappdev@gmail.com>
Date: Mon, 27 Nov 2023 19:36:52 +0000
Subject: [PATCH 3/5] Allow empty commit


From 13e3716295401b194df4b43b6490f2fa12607366 Mon Sep 17 00:00:00 2001
From: kevaundray <kevtheappdev@gmail.com>
Date: Mon, 27 Nov 2023 21:20:56 +0000
Subject: [PATCH 4/5] use hashset

---
 .../circuit_builder/ultra_circuit_builder.cpp | 12 +----
 .../circuit_builder/ultra_circuit_builder.hpp | 49 +++++++++++++++++++
 2 files changed, 51 insertions(+), 10 deletions(-)

diff --git a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.cpp b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.cpp
index 78c3f3ba370..047e3e8489e 100644
--- a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.cpp
+++ b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.cpp
@@ -1665,17 +1665,10 @@ void UltraCircuitBuilder_<Arithmetization>::process_non_native_field_multiplicat
             c.b[j] = this->real_variable_index[c.b[j]];
         }
     }
-    std::stable_sort(cached_partial_non_native_field_multiplications.begin(),
-                     cached_partial_non_native_field_multiplications.end());
-
-    auto last = std::unique(cached_partial_non_native_field_multiplications.begin(),
-                            cached_partial_non_native_field_multiplications.end());
-
-    auto it = cached_partial_non_native_field_multiplications.begin();
+    cached_partial_non_native_field_multiplication::deduplicate(cached_partial_non_native_field_multiplications);
 
     // iterate over the cached items and create constraints
-    while (it != last) {
-        const auto input = *it;
+    for (const auto& input : cached_partial_non_native_field_multiplications) {
 
         w_l.emplace_back(input.a[1]);
         w_r.emplace_back(input.b[1]);
@@ -1701,7 +1694,6 @@ void UltraCircuitBuilder_<Arithmetization>::process_non_native_field_multiplicat
         w_4.emplace_back(input.hi_1);
         apply_aux_selectors(AUX_SELECTORS::NONE);
         ++this->num_gates;
-        ++it;
     }
 }
 
diff --git a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
index 41b43a0d683..21e11c1078a 100644
--- a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
+++ b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
@@ -206,6 +206,25 @@ class UltraCircuitBuilder_ : public CircuitBuilderBase<typename Arithmetization:
             return valid;
         }
 
+        static void deduplicate(std::vector<cached_partial_non_native_field_multiplication>& vec)
+        {
+            std::unordered_set<cached_partial_non_native_field_multiplication,
+                               CachedPartialNonNativeFieldMultiplicationHash,
+                               CachedPartialNonNativeFieldMultiplicationEqual>
+                seen;
+
+            std::vector<cached_partial_non_native_field_multiplication> uniqueVec;
+
+            for (const auto& item : vec) {
+                if (seen.find(item) == seen.end()) {
+                    seen.insert(item);
+                    uniqueVec.push_back(item);
+                }
+            }
+
+            vec.swap(uniqueVec);
+        }
+
         bool operator<(const cached_partial_non_native_field_multiplication& other) const
         {
             if (a < other.a) {
@@ -221,6 +240,36 @@ class UltraCircuitBuilder_ : public CircuitBuilderBase<typename Arithmetization:
         }
     };
 
+    struct CachedPartialNonNativeFieldMultiplicationHash {
+        size_t operator()(const cached_partial_non_native_field_multiplication& obj) const
+        {
+            size_t combined_hash = 0;
+
+            // Hash combiner function
+            auto hash_combiner = [](size_t lhs, size_t rhs) {
+                return lhs ^ (rhs + 0x9e3779b9 + (lhs << 6) + (lhs >> 2));
+            };
+
+            // Combine hash for each element in arrays 'a' and 'b'
+            for (const auto& elem : obj.a) {
+                combined_hash = hash_combiner(combined_hash, std::hash<uint32_t>()(elem));
+            }
+            for (const auto& elem : obj.b) {
+                combined_hash = hash_combiner(combined_hash, std::hash<uint32_t>()(elem));
+            }
+
+            return combined_hash;
+        }
+    };
+
+    struct CachedPartialNonNativeFieldMultiplicationEqual {
+        bool operator()(const cached_partial_non_native_field_multiplication& lhs,
+                        const cached_partial_non_native_field_multiplication& rhs) const
+        {
+            return lhs == rhs;
+        }
+    };
+
     struct non_native_field_multiplication_cross_terms {
         uint32_t lo_0_idx;
         uint32_t lo_1_idx;

From 7fc85894db00e80626cab9fc824030ab9ff75bae Mon Sep 17 00:00:00 2001
From: kevaundray <kevtheappdev@gmail.com>
Date: Mon, 27 Nov 2023 21:31:45 +0000
Subject: [PATCH 5/5] cleanup

---
 .../circuit_builder/ultra_circuit_builder.hpp | 57 ++++++++-----------
 1 file changed, 24 insertions(+), 33 deletions(-)

diff --git a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
index 21e11c1078a..a8186c477dc 100644
--- a/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
+++ b/barretenberg/cpp/src/barretenberg/proof_system/circuit_builder/ultra_circuit_builder.hpp
@@ -208,16 +208,12 @@ class UltraCircuitBuilder_ : public CircuitBuilderBase<typename Arithmetization:
 
         static void deduplicate(std::vector<cached_partial_non_native_field_multiplication>& vec)
         {
-            std::unordered_set<cached_partial_non_native_field_multiplication,
-                               CachedPartialNonNativeFieldMultiplicationHash,
-                               CachedPartialNonNativeFieldMultiplicationEqual>
-                seen;
+            std::unordered_set<cached_partial_non_native_field_multiplication, Hash, std::equal_to<>> seen;
 
             std::vector<cached_partial_non_native_field_multiplication> uniqueVec;
 
             for (const auto& item : vec) {
-                if (seen.find(item) == seen.end()) {
-                    seen.insert(item);
+                if (seen.insert(item).second) {
                     uniqueVec.push_back(item);
                 }
             }
@@ -238,36 +234,31 @@ class UltraCircuitBuilder_ : public CircuitBuilderBase<typename Arithmetization:
             }
             return other.b < b;
         }
-    };
-
-    struct CachedPartialNonNativeFieldMultiplicationHash {
-        size_t operator()(const cached_partial_non_native_field_multiplication& obj) const
-        {
-            size_t combined_hash = 0;
 
-            // Hash combiner function
-            auto hash_combiner = [](size_t lhs, size_t rhs) {
-                return lhs ^ (rhs + 0x9e3779b9 + (lhs << 6) + (lhs >> 2));
-            };
+        struct Hash {
+            size_t operator()(const cached_partial_non_native_field_multiplication& obj) const
+            {
+                size_t combined_hash = 0;
+
+                // C++ does not have a standard way to hash values, so we use the
+                // common algorithm that boot uses.
+                // You can search for 'cpp hash_combine' to find more information.
+                // Here is one reference:
+                // https://stackoverflow.com/questions/2590677/how-do-i-combine-hash-values-in-c0x
+                auto hash_combiner = [](size_t lhs, size_t rhs) {
+                    return lhs ^ (rhs + 0x9e3779b9 + (lhs << 6) + (lhs >> 2));
+                };
+
+                for (const auto& elem : obj.a) {
+                    combined_hash = hash_combiner(combined_hash, std::hash<uint32_t>()(elem));
+                }
+                for (const auto& elem : obj.b) {
+                    combined_hash = hash_combiner(combined_hash, std::hash<uint32_t>()(elem));
+                }
 
-            // Combine hash for each element in arrays 'a' and 'b'
-            for (const auto& elem : obj.a) {
-                combined_hash = hash_combiner(combined_hash, std::hash<uint32_t>()(elem));
-            }
-            for (const auto& elem : obj.b) {
-                combined_hash = hash_combiner(combined_hash, std::hash<uint32_t>()(elem));
+                return combined_hash;
             }
-
-            return combined_hash;
-        }
-    };
-
-    struct CachedPartialNonNativeFieldMultiplicationEqual {
-        bool operator()(const cached_partial_non_native_field_multiplication& lhs,
-                        const cached_partial_non_native_field_multiplication& rhs) const
-        {
-            return lhs == rhs;
-        }
+        };
     };
 
     struct non_native_field_multiplication_cross_terms {