From 3cf1aa03b172d1de2139ac3f177834e577c74129 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Sun, 30 Apr 2023 01:07:36 +0200
Subject: [PATCH] Implement MCOPY

---
 lib/evmone/instructions.hpp         | 23 +++++++++++++++++++++++
 lib/evmone/instructions_opcodes.hpp |  1 +
 lib/evmone/instructions_traits.hpp  |  2 ++
 3 files changed, 26 insertions(+)

diff --git a/lib/evmone/instructions.hpp b/lib/evmone/instructions.hpp
index 1d82e6d3a6..2ed200df70 100644
--- a/lib/evmone/instructions.hpp
+++ b/lib/evmone/instructions.hpp
@@ -900,6 +900,29 @@ inline code_iterator swapn(StackTop stack, ExecutionState& state, code_iterator
     return pos + 2;
 }
 
+inline Result mcopy(StackTop stack, int64_t gas_left, ExecutionState& state) noexcept
+{
+    const auto& dst_index = stack.pop();
+    const auto& src_index = stack.pop();
+    const auto& size = stack.pop();
+
+    if (!check_memory(gas_left, state.memory, std::max(dst_index, src_index), size))
+        return {EVMC_OUT_OF_GAS, gas_left};
+
+    auto dst = static_cast<size_t>(dst_index);
+    auto src = static_cast<size_t>(src_index);
+    auto copy_size = static_cast<size_t>(size);
+
+    const auto copy_cost = num_words(copy_size) * 3;
+    if ((gas_left -= copy_cost) < 0)
+        return {EVMC_OUT_OF_GAS, gas_left};
+
+    if (copy_size > 0)
+        std::memcpy(&state.memory[dst], &state.memory[src], copy_size);
+
+    return {EVMC_SUCCESS, gas_left};
+}
+
 template <size_t NumTopics>
 inline Result log(StackTop stack, int64_t gas_left, ExecutionState& state) noexcept
 {
diff --git a/lib/evmone/instructions_opcodes.hpp b/lib/evmone/instructions_opcodes.hpp
index 9b430ce47a..90fb930cba 100644
--- a/lib/evmone/instructions_opcodes.hpp
+++ b/lib/evmone/instructions_opcodes.hpp
@@ -162,6 +162,7 @@ enum Opcode : uint8_t
 
     OP_DUPN = 0xb5,
     OP_SWAPN = 0xb6,
+    OP_MCOPY = 0xb7,
 
     OP_CREATE = 0xf0,
     OP_CALL = 0xf1,
diff --git a/lib/evmone/instructions_traits.hpp b/lib/evmone/instructions_traits.hpp
index fc4bb85776..30b80692e9 100644
--- a/lib/evmone/instructions_traits.hpp
+++ b/lib/evmone/instructions_traits.hpp
@@ -164,6 +164,7 @@ constexpr inline GasCostTable gas_costs = []() noexcept {
     table[EVMC_SHANGHAI][OP_PUSH0] = 2;
 
     table[EVMC_CANCUN] = table[EVMC_SHANGHAI];
+    table[EVMC_CANCUN][OP_MCOPY] = 3;
     table[EVMC_CANCUN][OP_DUPN] = 3;
     table[EVMC_CANCUN][OP_SWAPN] = 3;
     table[EVMC_CANCUN][OP_RJUMP] = 2;
@@ -375,6 +376,7 @@ constexpr inline std::array<Traits, 256> traits = []() noexcept {
 
     table[OP_DUPN] = {"DUPN", 1, false, 0, 1, EVMC_CANCUN};
     table[OP_SWAPN] = {"SWAPN", 1, false, 0, 0, EVMC_CANCUN};
+    table[OP_MCOPY] = {"MCOPY", 0, false, 3, -3, EVMC_CANCUN};
 
     table[OP_CREATE] = {"CREATE", 0, false, 3, -2, EVMC_FRONTIER};
     table[OP_CALL] = {"CALL", 0, false, 7, -6, EVMC_FRONTIER};