From 12d9af8a00d0909598c67e1a18dc1577e0833137 Mon Sep 17 00:00:00 2001
From: Rod Vagg <rod@vagg.org>
Date: Wed, 9 Oct 2024 04:15:03 +1100
Subject: [PATCH] chore(mcopy): add contract with test (#1583)

* chore(mcopy): add contract with test

* fix mcopy test

---------

Co-authored-by: Steven Allen <steven@stebalien.com>
---
 actors/evm/tests/basic.rs                | 27 ++++++++++++++++++++++++
 actors/evm/tests/contracts/MCOPYTest.hex |  1 +
 actors/evm/tests/contracts/MCOPYTest.sol | 21 ++++++++++++++++++
 3 files changed, 49 insertions(+)
 create mode 100644 actors/evm/tests/contracts/MCOPYTest.hex
 create mode 100644 actors/evm/tests/contracts/MCOPYTest.sol

diff --git a/actors/evm/tests/basic.rs b/actors/evm/tests/basic.rs
index be57a4fb7..d59518049 100644
--- a/actors/evm/tests/basic.rs
+++ b/actors/evm/tests/basic.rs
@@ -202,3 +202,30 @@ fn test_push_last_byte() {
 
     util::invoke_contract(&rt, &[]);
 }
+
+#[test]
+fn mcopy() {
+    let bytecode = hex::decode(include_str!("contracts/MCOPYTest.hex")).unwrap();
+    mcopy_test(bytecode);
+}
+
+fn mcopy_test(bytecode: Vec<u8>) {
+    let contract = Address::new_id(100);
+
+    let rt = util::init_construct_and_verify(bytecode, |rt| {
+        rt.actor_code_cids.borrow_mut().insert(contract, *EVM_ACTOR_CODE_ID);
+        rt.set_origin(contract);
+    });
+
+    // invoke contract
+
+    let encoded_testdata = hex::decode("000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000087465737464617461000000000000000000000000000000000000000000000000").unwrap();
+
+    let mut solidity_params = vec![];
+
+    solidity_params.extend_from_slice(&hex::decode("73358055").unwrap()); // function selector, "optimizedCopy(bytes)"
+    solidity_params.extend_from_slice(&encoded_testdata);
+
+    let result = util::invoke_contract(&rt, &solidity_params);
+    assert_eq!(&*result, &*encoded_testdata);
+}
diff --git a/actors/evm/tests/contracts/MCOPYTest.hex b/actors/evm/tests/contracts/MCOPYTest.hex
new file mode 100644
index 000000000..72db0fa73
--- /dev/null
+++ b/actors/evm/tests/contracts/MCOPYTest.hex
@@ -0,0 +1 @@
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
\ No newline at end of file
diff --git a/actors/evm/tests/contracts/MCOPYTest.sol b/actors/evm/tests/contracts/MCOPYTest.sol
new file mode 100644
index 000000000..21e0ed397
--- /dev/null
+++ b/actors/evm/tests/contracts/MCOPYTest.sol
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.26;
+
+contract MCOPYTest {
+    function optimizedCopy(bytes memory data) public pure returns (bytes memory) {
+        bytes memory result = new bytes(data.length);
+        assembly {
+            let length := mload(data) // Get the length of the input data
+            let source := add(data, 0x20) // Point to the start of the data (skip the length)
+            let destination := add(result, 0x20) // Point to the start of the result memory (skip the length)
+
+            // Use MCOPY opcode directly for memory copying
+            // destination: destination memory pointer
+            // source: source memory pointer
+            // length: number of bytes to copy
+            mcopy(destination, source, length)
+        }
+        return result;
+    }
+
+}