Opcode/Machine: handle MCOPY instruction (EIP-5656)

https://eips.ethereum.org/EIPS/eip-5656

core/src/eval/misc.rs

@@ -110,6 +110,28 @@ pub fn mstore8(state: &mut Machine) -> Control {
 	}
 }
 
+#[inline]
+pub fn mcopy(state: &mut Machine) -> Control {
+	pop_u256!(state, dst, src, len);
+
+	try_or_fail!(state.memory.resize_offset(dst, len));
+
+	if len == U256::zero() {
+		return Control::Continue(1);
+	}
+
+	let src_usize = as_usize_or_fail!(src);
+	let len_usize = as_usize_or_fail!(len);
+	let data = state.memory.get(src_usize, len_usize);
+
+	// NB: using `set` would be more straighforward but it lacks
+	// of internal checks.
+	match state.memory.copy_large(dst, U256::zero(), len, &data) {
+		Ok(()) => Control::Continue(1),
+		Err(e) => Control::Exit(e.into()),
+	}
+}
+
 #[inline]
 pub fn jump(state: &mut Machine) -> Control {
 	pop_u256!(state, dest);

core/src/eval/mod.rs

@@ -156,6 +156,10 @@ fn eval_mstore8(state: &mut Machine, _opcode: Opcode, _position: usize) -> Contr
 	self::misc::mstore8(state)
 }
 
+fn eval_mcopy(state: &mut Machine, _opcode: Opcode, _position: usize) -> Control {
+	self::misc::mcopy(state)
+}
+
 fn eval_jump(state: &mut Machine, _opcode: Opcode, _position: usize) -> Control {
 	self::misc::jump(state)
 }
@@ -492,6 +496,7 @@ pub fn eval(state: &mut Machine, opcode: Opcode, position: usize) -> Control {
 		table[Opcode::MLOAD.as_usize()] = eval_mload as _;
 		table[Opcode::MSTORE.as_usize()] = eval_mstore as _;
 		table[Opcode::MSTORE8.as_usize()] = eval_mstore8 as _;
+		table[Opcode::MCOPY.as_usize()] = eval_mcopy as _;
 		table[Opcode::JUMP.as_usize()] = eval_jump as _;
 		table[Opcode::JUMPI.as_usize()] = eval_jumpi as _;
 		table[Opcode::PC.as_usize()] = eval_pc as _;

core/src/opcode.rs

@@ -83,6 +83,8 @@ impl Opcode {
 	pub const MSTORE: Opcode = Opcode(0x52);
 	/// `MSTORE8`
 	pub const MSTORE8: Opcode = Opcode(0x53);
+	/// `MCOPY`
+	pub const MCOPY: Opcode = Opcode(0x5e);
 	/// `JUMP`
 	pub const JUMP: Opcode = Opcode(0x56);
 	/// `JUMPI`