From de3e232beb4312a2cf1573761ca4b04fe9681095 Mon Sep 17 00:00:00 2001
From: Andrei Maiboroda <andrei@ethereum.org>
Date: Wed, 3 May 2023 14:10:43 +0200
Subject: [PATCH] Unit tests for MCOPY

---
 test/unittests/evm_memory_test.cpp | 40 +++++++++++++++++++++++++++++-
 test/utils/bytecode.hpp            |  5 ++++
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/test/unittests/evm_memory_test.cpp b/test/unittests/evm_memory_test.cpp
index 2ef008555e..7887fd0542 100644
--- a/test/unittests/evm_memory_test.cpp
+++ b/test/unittests/evm_memory_test.cpp
@@ -121,6 +121,8 @@ memory_access_opcode memory_access_opcodes[] = {
     {OP_MLOAD, 0, -1},
     {OP_MSTORE, 0, -1},
     {OP_MSTORE8, 0, -1},
+    {OP_MCOPY, 0, 2},
+    {OP_MCOPY, 1, 2},
     {OP_EXTCODECOPY, 1, 3},
     {OP_RETURNDATACOPY, 0, 2},
     {OP_LOG0, 0, 1},
@@ -176,7 +178,7 @@ TEST_P(evm, memory_access)
 {
     // This test checks if instructions accessing memory properly respond with out-of-gas
     // error for combinations of memory offset and memory size arguments.
-    rev = EVMC_CONSTANTINOPLE;
+    rev = EVMC_CANCUN;
 
     for (const auto& p : memory_access_test_cases)
     {
@@ -238,3 +240,39 @@ TEST_P(evm, memory_access)
         }
     }
 }
+
+TEST_P(evm, mcopy)
+{
+    rev = EVMC_CANCUN;
+    bytecode s;
+    s += mstore(0, push(0x0123456789abcdef000000000000000000000000000000000000000000000000_u256)) +
+         mcopy(32, 0, 8) + ret(32, 8);
+    execute(s);
+    EXPECT_EQ(result.status_code, EVMC_SUCCESS);
+    ASSERT_EQ(result.output_size, 8);
+    EXPECT_EQ(bytes_view(&result.output_data[0], 8), "0123456789abcdef"_hex);
+
+    // copy uninitialized memory
+    s = mstore(0, push(0x0000000000000000000000000000000000000000000000000123456789abcdef_u256)) +
+        mcopy(64, 24, 16) + ret(64, 16);
+    execute(s);
+    EXPECT_EQ(result.status_code, EVMC_SUCCESS);
+    ASSERT_EQ(result.output_size, 16);
+    EXPECT_EQ(bytes_view(&result.output_data[0], 16), "0123456789abcdef0000000000000000"_hex);
+
+    // overlapped
+    s = mstore(0, push(0x0123456789abcdef000000000000000000000000000000000000000000000000_u256)) +
+        mcopy(4, 0, 8) + ret(0, 16);
+    execute(s);
+    EXPECT_EQ(result.status_code, EVMC_SUCCESS);
+    ASSERT_EQ(result.output_size, 16);
+    EXPECT_EQ(bytes_view(&result.output_data[0], 16), "012345670123456789abcdef00000000"_hex);
+}
+
+TEST_P(evm, mcopy_memory_cost)
+{
+    rev = EVMC_CANCUN;
+    const auto code = mcopy(0, 0, 1);
+    execute(18, code);
+    EXPECT_GAS_USED(EVMC_SUCCESS, 18);
+}
diff --git a/test/utils/bytecode.hpp b/test/utils/bytecode.hpp
index cab98883b5..471386f421 100644
--- a/test/utils/bytecode.hpp
+++ b/test/utils/bytecode.hpp
@@ -234,6 +234,11 @@ inline bytecode mstore8(bytecode index, bytecode value)
     return value + index + OP_MSTORE8;
 }
 
+inline bytecode mcopy(bytecode dst, bytecode src, bytecode length)
+{
+    return length + src + dst + OP_MCOPY;
+}
+
 inline bytecode jump(bytecode target)
 {
     return target + OP_JUMP;