chore(avm): separate some fixed tables (#7163)

An experiment in separating fixed tables and (for now mannually)
creating a `merge_into` function to merge them into the main trace.

TODO:
* Avoid having to create dummy relations
* autogen merge_into
* apply concept to other non-fixed tables

barretenberg/cpp/pil/avm/binary.pil

@@ -1,6 +1,4 @@
-
-include "byte_lookup.pil";
-include "main.pil";
+include "fixed/byte_lookup.pil";
 
 namespace binary(256);
 

barretenberg/cpp/pil/avm/byte_lookup.pil → barretenberg/cpp/pil/avm/fixed/byte_lookup.pil

@@ -1,4 +1,3 @@
-
 namespace byte_lookup(256);
     // These columns are commited for now, but will be migrated to constant/fixed when
     // we support more *exotic* code generation options

barretenberg/cpp/pil/avm/gas.pil → barretenberg/cpp/pil/avm/fixed/gas.pil

@@ -5,4 +5,9 @@ namespace gas(256);
 
     // TODO(ISSUE_NUMBER): Constrain variable gas costs
     pol commit l2_gas_fixed_table;
-    pol commit da_gas_fixed_table;
+    pol commit da_gas_fixed_table;
+
+    // DUMMY RELATIONS to force creation of hpp.
+    sel_gas_cost - sel_gas_cost = 0;
+    l2_gas_fixed_table - l2_gas_fixed_table = 0;
+    da_gas_fixed_table - da_gas_fixed_table = 0;

barretenberg/cpp/pil/avm/fixed/powers.pil

@@ -0,0 +1,9 @@
+// This table should eventually be fixed.
+// Contains 256 rows with the powers of 2 for 8-bit numbers.
+// power_of_2 = 1 << clk;
+namespace powers(256);
+    // clk will be the implicit power.
+    pol commit power_of_2;
+
+    // DUMMY RELATION to force creation of hpp.
+    power_of_2 - power_of_2 = 0;

barretenberg/cpp/pil/avm/main.pil

@@ -3,7 +3,8 @@ include "alu.pil";
 include "binary.pil";
 include "constants.pil";
 include "kernel.pil";
-include "gas.pil";
+include "fixed/gas.pil";
+include "fixed/powers.pil";
 include "gadgets/conversion.pil";
 include "gadgets/sha256.pil";
 include "gadgets/poseidon2.pil";
@@ -139,9 +140,6 @@ namespace main(256);
     pol commit sel_rng_8;  // Boolean selector for the  8-bit range check lookup
     pol commit sel_rng_16; // Boolean selector for the 16-bit range check lookup
 
-    //===== Lookup table powers of 2 =============================================
-    pol commit table_pow_2; // Table of powers of 2 for 8-bit numbers. 
-
     //===== CONTROL FLOW ==========================================================
     // Program counter
     pol commit pc; 
@@ -773,11 +771,11 @@ namespace main(256);
 
     // Lookup for 2**(ib)
     #[LOOKUP_POW_2_0]
-    alu.sel_shift_which {alu.ib, alu.two_pow_s} in sel_rng_8 {clk, table_pow_2};
+    alu.sel_shift_which {alu.ib, alu.two_pow_s} in sel_rng_8 {clk, powers.power_of_2};
 
     // Lookup for 2**(t-ib)
     #[LOOKUP_POW_2_1]
-    alu.sel_shift_which {alu.t_sub_s_bits , alu.two_pow_t_sub_s} in sel_rng_8 {clk, table_pow_2};
+    alu.sel_shift_which {alu.t_sub_s_bits , alu.two_pow_t_sub_s} in sel_rng_8 {clk, powers.power_of_2};
 
     //====== Inter-table Constraints (Range Checks) ============================================
     // TODO: Investigate optimising these range checks. Handling non-FF elements should require less range checks.

barretenberg/cpp/src/barretenberg/relations/generated/avm/declare_views.hpp

@@ -251,7 +251,6 @@
     [[maybe_unused]] auto main_sel_rng_16 = View(new_term.main_sel_rng_16);                                            \
     [[maybe_unused]] auto main_sel_rng_8 = View(new_term.main_sel_rng_8);                                              \
     [[maybe_unused]] auto main_space_id = View(new_term.main_space_id);                                                \
-    [[maybe_unused]] auto main_table_pow_2 = View(new_term.main_table_pow_2);                                          \
     [[maybe_unused]] auto main_tag_err = View(new_term.main_tag_err);                                                  \
     [[maybe_unused]] auto main_w_in_tag = View(new_term.main_w_in_tag);                                                \
     [[maybe_unused]] auto mem_addr = View(new_term.mem_addr);                                                          \
@@ -293,6 +292,7 @@
     [[maybe_unused]] auto poseidon2_input = View(new_term.poseidon2_input);                                            \
     [[maybe_unused]] auto poseidon2_output = View(new_term.poseidon2_output);                                          \
     [[maybe_unused]] auto poseidon2_sel_poseidon_perm = View(new_term.poseidon2_sel_poseidon_perm);                    \
+    [[maybe_unused]] auto powers_power_of_2 = View(new_term.powers_power_of_2);                                        \
     [[maybe_unused]] auto sha256_clk = View(new_term.sha256_clk);                                                      \
     [[maybe_unused]] auto sha256_input = View(new_term.sha256_input);                                                  \
     [[maybe_unused]] auto sha256_output = View(new_term.sha256_output);                                                \

barretenberg/cpp/src/barretenberg/relations/generated/avm/gas.hpp

@@ -0,0 +1,69 @@
+
+#pragma once
+#include "../../relation_parameters.hpp"
+#include "../../relation_types.hpp"
+#include "./declare_views.hpp"
+
+namespace bb::Avm_vm {
+
+template <typename FF> struct GasRow {
+    FF gas_da_gas_fixed_table{};
+    FF gas_l2_gas_fixed_table{};
+    FF gas_sel_gas_cost{};
+
+    [[maybe_unused]] static std::vector<std::string> names();
+};
+
+inline std::string get_relation_label_gas(int index)
+{
+    switch (index) {}
+    return std::to_string(index);
+}
+
+template <typename FF_> class gasImpl {
+  public:
+    using FF = FF_;
+
+    static constexpr std::array<size_t, 3> SUBRELATION_PARTIAL_LENGTHS{
+        2,
+        2,
+        2,
+    };
+
+    template <typename ContainerOverSubrelations, typename AllEntities>
+    void static accumulate(ContainerOverSubrelations& evals,
+                           const AllEntities& new_term,
+                           [[maybe_unused]] const RelationParameters<FF>&,
+                           [[maybe_unused]] const FF& scaling_factor)
+    {
+
+        // Contribution 0
+        {
+            Avm_DECLARE_VIEWS(0);
+
+            auto tmp = (gas_sel_gas_cost - gas_sel_gas_cost);
+            tmp *= scaling_factor;
+            std::get<0>(evals) += tmp;
+        }
+        // Contribution 1
+        {
+            Avm_DECLARE_VIEWS(1);
+
+            auto tmp = (gas_l2_gas_fixed_table - gas_l2_gas_fixed_table);
+            tmp *= scaling_factor;
+            std::get<1>(evals) += tmp;
+        }
+        // Contribution 2
+        {
+            Avm_DECLARE_VIEWS(2);
+
+            auto tmp = (gas_da_gas_fixed_table - gas_da_gas_fixed_table);
+            tmp *= scaling_factor;
+            std::get<2>(evals) += tmp;
+        }
+    }
+};
+
+template <typename FF> using gas = Relation<gasImpl<FF>>;
+
+} // namespace bb::Avm_vm

barretenberg/cpp/src/barretenberg/relations/generated/avm/lookup_pow_2_0.hpp

@@ -140,7 +140,7 @@ class lookup_pow_2_0_lookup_settings {
                                      in.alu_ib,
                                      in.alu_two_pow_s,
                                      in.main_clk,
-                                     in.main_table_pow_2);
+                                     in.powers_power_of_2);
     }
 
     /**
@@ -160,7 +160,7 @@ class lookup_pow_2_0_lookup_settings {
                                      in.alu_ib,
                                      in.alu_two_pow_s,
                                      in.main_clk,
-                                     in.main_table_pow_2);
+                                     in.powers_power_of_2);
     }
 };
 

barretenberg/cpp/src/barretenberg/relations/generated/avm/lookup_pow_2_1.hpp

@@ -140,7 +140,7 @@ class lookup_pow_2_1_lookup_settings {
                                      in.alu_t_sub_s_bits,
                                      in.alu_two_pow_t_sub_s,
                                      in.main_clk,
-                                     in.main_table_pow_2);
+                                     in.powers_power_of_2);
     }
 
     /**
@@ -160,7 +160,7 @@ class lookup_pow_2_1_lookup_settings {
                                      in.alu_t_sub_s_bits,
                                      in.alu_two_pow_t_sub_s,
                                      in.main_clk,
-                                     in.main_table_pow_2);
+                                     in.powers_power_of_2);
     }
 };
 

barretenberg/cpp/src/barretenberg/relations/generated/avm/powers.hpp

@@ -0,0 +1,49 @@
+
+#pragma once
+#include "../../relation_parameters.hpp"
+#include "../../relation_types.hpp"
+#include "./declare_views.hpp"
+
+namespace bb::Avm_vm {
+
+template <typename FF> struct PowersRow {
+    FF powers_power_of_2{};
+
+    [[maybe_unused]] static std::vector<std::string> names();
+};
+
+inline std::string get_relation_label_powers(int index)
+{
+    switch (index) {}
+    return std::to_string(index);
+}
+
+template <typename FF_> class powersImpl {
+  public:
+    using FF = FF_;
+
+    static constexpr std::array<size_t, 1> SUBRELATION_PARTIAL_LENGTHS{
+        2,
+    };
+
+    template <typename ContainerOverSubrelations, typename AllEntities>
+    void static accumulate(ContainerOverSubrelations& evals,
+                           const AllEntities& new_term,
+                           [[maybe_unused]] const RelationParameters<FF>&,
+                           [[maybe_unused]] const FF& scaling_factor)
+    {
+
+        // Contribution 0
+        {
+            Avm_DECLARE_VIEWS(0);
+
+            auto tmp = (powers_power_of_2 - powers_power_of_2);
+            tmp *= scaling_factor;
+            std::get<0>(evals) += tmp;
+        }
+    }
+};
+
+template <typename FF> using powers = Relation<powersImpl<FF>>;
+
+} // namespace bb::Avm_vm

barretenberg/cpp/src/barretenberg/vm/avm_trace/avm_gas_trace.cpp

@@ -1,5 +1,10 @@
 #include "barretenberg/vm/avm_trace/avm_gas_trace.hpp"
+
+#include <cstddef>
+#include <cstdint>
+
 #include "barretenberg/vm/avm_trace/avm_opcode.hpp"
+#include "barretenberg/vm/avm_trace/fixed_gas.hpp"
 
 namespace bb::avm_trace {
 
@@ -39,8 +44,9 @@ void AvmGasTraceBuilder::constrain_gas_lookup(uint32_t clk, OpCode opcode)
     gas_opcode_lookup_counter[opcode]++;
 
     // Get the gas prices for this opcode
-    uint32_t l2_gas_cost = GAS_COST_TABLE.at(opcode).l2_fixed_gas_cost;
-    uint32_t da_gas_cost = GAS_COST_TABLE.at(opcode).da_fixed_gas_cost;
+    const auto& GAS_COST_TABLE = FixedGasTable::get();
+    auto l2_gas_cost = static_cast<uint32_t>(GAS_COST_TABLE.at(opcode).gas_l2_gas_fixed_table);
+    auto da_gas_cost = static_cast<uint32_t>(GAS_COST_TABLE.at(opcode).gas_da_gas_fixed_table);
 
     remaining_l2_gas -= l2_gas_cost;
     remaining_da_gas -= da_gas_cost;
@@ -69,8 +75,9 @@ void AvmGasTraceBuilder::constrain_gas_for_external_call(uint32_t clk,
     // gas_opcode_lookup_counter[opcode]++;
 
     // Get the gas prices for this opcode
-    uint32_t opcode_l2_gas_cost = GAS_COST_TABLE.at(opcode).l2_fixed_gas_cost;
-    uint32_t opcode_da_gas_cost = GAS_COST_TABLE.at(opcode).da_fixed_gas_cost;
+    const auto& GAS_COST_TABLE = FixedGasTable::get();
+    auto opcode_l2_gas_cost = static_cast<uint32_t>(GAS_COST_TABLE.at(opcode).gas_l2_gas_fixed_table);
+    auto opcode_da_gas_cost = static_cast<uint32_t>(GAS_COST_TABLE.at(opcode).gas_da_gas_fixed_table);
 
     remaining_l2_gas -= opcode_l2_gas_cost + nested_l2_gas_cost;
     remaining_da_gas -= opcode_da_gas_cost + nested_da_gas_cost;