feat(tests): add codecopy and extcodecopy for clz opcode (#1858)

* feat(tests): add codecopy and extcodecopy for clz opcode

* fix: resolve rebase issue

* refactor: combine codecopy operation test

* feat(tests): load memory for clz opcode parameter

* fix(tests): correct clz result storage in opcode tests

* fix(tests): add prestate storage for CLZ opcode tests

Author: LouisTsai-Csie

tests/osaka/eip7939_count_leading_zeros/spec.py

@@ -18,6 +18,7 @@ class ReferenceSpec:
 class Spec:
     """Constants and helpers for the CLZ opcode."""
 
+    CLZ = 0x1E
     CLZ_GAS_COST = 5
 
     @classmethod

tests/osaka/eip7939_count_leading_zeros/test_count_leading_zeros.py

@@ -5,6 +5,7 @@
 
 import pytest
 
+from ethereum_test_base_types import Storage
 from ethereum_test_forks import Fork
 from ethereum_test_tools import (
     Account,
@@ -310,3 +311,101 @@ def test_clz_jump_operation(
         post[callee_address] = Account(storage={"0x00": expected_clz})
 
     state_test(pre=pre, post=post, tx=tx)
+
+
+@pytest.mark.valid_from("Osaka")
+@pytest.mark.parametrize("bits", [0, 64, 255])
+@pytest.mark.parametrize("opcode", [Op.CODECOPY, Op.EXTCODECOPY])
+def test_clz_code_copy_operation(state_test: StateTestFiller, pre: Alloc, bits: int, opcode: Op):
+    """Test CLZ opcode with code copy operation."""
+    storage = Storage()
+
+    expected_value = 255 - bits
+    clz_code_offset = len(Op.CLZ(1 << bits)) - 1  # Offset to CLZ opcode
+
+    mload_value = Spec.CLZ << 248  # CLZ opcode in MSB position (0x1E000...000)
+
+    target_address = pre.deploy_contract(code=Op.CLZ(1 << bits))
+
+    clz_contract_address = pre.deploy_contract(
+        code=(
+            Op.CLZ(1 << bits)  # Calculate CLZ of the value
+            + Op.SSTORE(storage.store_next(expected_value), Op.CLZ(1 << bits))  # Store CLZ result
+            + (  # Load CLZ byte from code with CODECOPY or EXTCODECOPY
+                Op.CODECOPY(dest_offset=0, offset=clz_code_offset, size=1)
+                if opcode == Op.CODECOPY
+                else Op.EXTCODECOPY(
+                    address=target_address, dest_offset=0, offset=clz_code_offset, size=1
+                )
+            )
+            + Op.SSTORE(storage.store_next(mload_value), Op.MLOAD(0))  # Store loaded CLZ byte
+        ),
+        storage={"0x00": "0xdeadbeef"},
+    )
+
+    post = {
+        clz_contract_address: Account(
+            storage={
+                "0x00": expected_value,
+                "0x01": mload_value,
+            }
+        )
+    }
+    tx = Transaction(
+        to=clz_contract_address,
+        sender=pre.fund_eoa(),
+        gas_limit=200_000,
+    )
+
+    state_test(pre=pre, post=post, tx=tx)
+
+
+@pytest.mark.valid_from("Osaka")
+@pytest.mark.parametrize("bits", [0, 64, 255])
+@pytest.mark.parametrize("opcode", [Op.CODECOPY, Op.EXTCODECOPY])
+def test_clz_with_memory_operation(state_test: StateTestFiller, pre: Alloc, bits: int, opcode: Op):
+    """Test CLZ opcode with memory operation."""
+    storage = Storage()
+
+    expected_value = 255 - bits
+
+    # Target code pattern:
+    #   PUSH32 (1 << bits)
+    #   PUSH0
+    #   MSTORE
+    #
+    # This sequence stores a 32-byte value in memory.
+    # Later, we copy the immediate value from the PUSH32 instruction into memory
+    # using CODECOPY or EXTCODECOPY, and then load it with MLOAD for the CLZ test.
+    target_code = Op.PUSH32(1 << bits)
+    offset = 1
+
+    target_address = pre.deploy_contract(code=target_code)
+
+    clz_contract_address = pre.deploy_contract(
+        code=(
+            target_code
+            + Op.SSTORE(storage.store_next(expected_value), Op.CLZ(1 << bits))  # Store CLZ result
+            + (
+                Op.CODECOPY(dest_offset=0, offset=offset, size=0x20)
+                if opcode == Op.CODECOPY
+                else Op.EXTCODECOPY(
+                    address=target_address, dest_offset=0, offset=offset, size=0x20
+                )
+            )
+            + Op.SSTORE(storage.store_next(expected_value), Op.CLZ(Op.MLOAD(0)))
+        ),
+        storage={"0x00": "0xdeadbeef"},
+    )
+
+    post = {
+        clz_contract_address: Account(storage={"0x00": expected_value, "0x01": expected_value}),
+    }
+
+    tx = Transaction(
+        to=clz_contract_address,
+        sender=pre.fund_eoa(),
+        gas_limit=200_000,
+    )
+
+    state_test(pre=pre, post=post, tx=tx)