feat: Graph methods for circuit analysis (part 1) (#7948)

Boomerang value detection in ultra circuits not using poseidon and auxiliary gates

Author: DanielKotov

barretenberg/cpp/src/CMakeLists.txt

@@ -63,6 +63,7 @@ endif()
 
 add_subdirectory(barretenberg/client_ivc)
 add_subdirectory(barretenberg/bb)
+add_subdirectory(barretenberg/boomerang_value_detection)
 add_subdirectory(barretenberg/circuit_checker)
 add_subdirectory(barretenberg/commitment_schemes)
 add_subdirectory(barretenberg/commitment_schemes_recursion)

barretenberg/cpp/src/barretenberg/boomerang_value_detection/CMakeLists.txt

@@ -0,0 +1 @@
+barretenberg_module(boomerang_value_detection stdlib_circuit_builders circuit_checker stdlib_primitives numeric stdlib_aes128 stdlib_sha256 stdlib_blake2s stdlib_blake3s)

barretenberg/cpp/src/barretenberg/boomerang_value_detection/graph.cpp

@@ -0,0 +1,119 @@
+#pragma once
+#include "barretenberg/stdlib_circuit_builders/standard_circuit_builder.hpp"
+#include "barretenberg/stdlib_circuit_builders/ultra_circuit_builder.hpp"
+#include <list>
+#include <set>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+/*
+ * this class describes arithmetic circuit as an undirected graph, where vertices are variables from circuit.
+ * edges describe connections between variables through gates. We want to find variables that weren't properly
+ * constrainted/some connections were missed using additional metrics, like in how much gate variable was and number of
+ * connected components in the graph. if variable was in one connected component, it means that this variable wasn't
+ * constrained properly. if number of connected components > 1, it means that there were missed some connections between
+ * variables.
+ */
+template <typename FF> class Graph_ {
+  public:
+    Graph_() = default;
+    Graph_(const Graph_& other) = delete;
+    Graph_(Graph_&& other) = delete;
+    Graph_& operator=(const Graph_& other) = delete;
+    Graph_&& operator=(Graph_&& other) = delete;
+    Graph_(const bb::StandardCircuitBuilder_<FF>& circuit_constructor);
+    Graph_(bb::UltraCircuitBuilder& ultra_circuit_constructor);
+
+    uint32_t to_real(bb::UltraCircuitBuilder& ultra_circuit_constructor, const uint32_t& variable_index)
+    {
+        return ultra_circuit_constructor.real_variable_index[variable_index];
+    };
+    void process_gate_variables(bb::UltraCircuitBuilder& ultra_circuit_constructor,
+                                std::vector<uint32_t>& gate_variables);
+
+    std::unordered_map<uint32_t, size_t> get_variables_gate_counts() { return this->variables_gate_counts; };
+
+    std::vector<uint32_t> get_arithmetic_gate_connected_component(bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                                                  size_t index);
+    std::vector<uint32_t> get_elliptic_gate_connected_component(bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                                                size_t index);
+    std::vector<uint32_t> get_plookup_gate_connected_component(bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                                               size_t index);
+    std::vector<uint32_t> get_sort_constraint_connected_component(bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                                                  size_t index);
+
+    void add_new_edge(const uint32_t& first_variable_index, const uint32_t& second_variable_index);
+    std::vector<uint32_t> get_variable_adjacency_list(const uint32_t& variable_index)
+    {
+        return variable_adjacency_lists[variable_index];
+    };
+
+    void depth_first_search(const uint32_t& variable_index,
+                            std::unordered_set<uint32_t>& is_used,
+                            std::vector<uint32_t>& connected_component);
+    std::vector<std::vector<uint32_t>> find_connected_components();
+
+    std::vector<uint32_t> find_variables_with_degree_one();
+    std::unordered_set<uint32_t> get_variables_in_one_gate();
+
+    bool find_arithmetic_gate_for_variable(bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                           const uint32_t& variable_idx);
+    bool find_elliptic_gate_for_variable(bb::UltraCircuitBuilder& ultra_circuit_builder, const uint32_t& variable_idx);
+    bool find_lookup_gate_for_variable(bb::UltraCircuitBuilder& ultra_circuit_builder, const uint32_t& variable_idx);
+
+    size_t get_distance_between_variables(const uint32_t& first_variable_index, const uint32_t& second_variable_index);
+    bool check_vertex_in_connected_component(const std::vector<uint32_t>& connected_component,
+                                             const uint32_t& var_index);
+
+    void connect_all_variables_in_vector(bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                         const std::vector<uint32_t>& variables_vector,
+                                         bool is_sorted_variables);
+    bool check_is_not_constant_variable(bb::UltraCircuitBuilder& ultra_circuit_builder, const uint32_t& variable_index);
+
+    std::pair<std::vector<uint32_t>, size_t> get_connected_component_with_index(
+        const std::vector<std::vector<uint32_t>>& connected_components, size_t index);
+
+    std::unordered_set<uint32_t> get_variables_in_one_gate_without_range_constraints(
+        bb::UltraCircuitBuilder& ultra_circuit_builder);
+
+    size_t process_current_decompose_chain(bb::UltraCircuitBuilder& ultra_circuit_constructor,
+                                           std::unordered_set<uint32_t>& variables_in_one_gate,
+                                           size_t index);
+    void process_current_plookup_gate(bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                      std::unordered_set<uint32_t>& variables_in_one_gate,
+                                      size_t gate_index);
+    void remove_unnecessary_decompose_variables(bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                                std::unordered_set<uint32_t>& variables_in_on_gate,
+                                                const std::unordered_set<uint32_t>& decompose_variables);
+    void remove_unnecessary_plookup_variables(bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                              std::unordered_set<uint32_t>& variables_in_on_gate);
+    std::unordered_set<uint32_t> show_variables_in_one_gate(bb::UltraCircuitBuilder& ultra_circuit_builder);
+
+    void remove_unnecessary_aes_plookup_variables(std::unordered_set<uint32_t>& variables_in_one_gate,
+                                                  bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                                  bb::plookup::BasicTableId& table_id,
+                                                  size_t gate_index);
+    void remove_unnecessary_sha256_plookup_variables(std::unordered_set<uint32_t>& variables_in_one_gate,
+                                                     bb::UltraCircuitBuilder& ultra_circuit_builder,
+                                                     bb::plookup::BasicTableId& table_id,
+                                                     size_t gate_index);
+
+    void print_graph();
+    void print_connected_components();
+    void print_variables_gate_counts();
+    void print_variables_edge_counts();
+    ~Graph_() = default;
+
+  private:
+    std::unordered_map<uint32_t, std::vector<uint32_t>>
+        variable_adjacency_lists; // we use this data structure to contain information about variables and their
+                                  // connections between each other
+    std::unordered_map<uint32_t, size_t>
+        variables_gate_counts; // we use this data structure to count, how many gates use every variable
+    std::unordered_map<uint32_t, size_t>
+        variables_degree; // we use this data structure to count, how many every variable have edges
+};
+
+using Graph = Graph_<bb::fr>;