Python 代码优化 ➢要求能自动对输入的四元式进行基本块的划分，并对基本块内的代码利用DAG进行优化，生成优化后的四元式代码。可视化基本块的连接以及DAG图

以下是一个基本的Python代码示例，用于对输入的四元式进行基本块划分和DAG优化： ```python # 导入必要的库 import networkx as nx import matplotlib.pyplot as plt # 定义四元式类 class Quadruple: def __init__(self, op, arg1, arg2, result): self.op = op self.arg1 = arg1 self.arg2 = arg2 self.result = result # 定义基本块类 class BasicBlock: def __init__(self, quadruples): self.quadruples = quadruples self.successors = [] # 定义DAG节点类 class DAGNode: def __init__(self, value, left=None, right=None): self.value = value self.left = left self.right = right # 定义DAG类 class DAG: def __init__(self): self.nodes = [] self.root = None # 添加节点到DAG中 def add_node(self, node): if node not in self.nodes: self.nodes.append(node) # 在DAG中查找节点 def find_node(self, value): for node in self.nodes: if node.value == value: return node return None # 构建DAG def build(self, quadruples): for q in quadruples: if q.op == '=': node = self.find_node(q.arg2) if node is None: node = DAGNode(q.arg2) self.add_node(node) q.result = node else: left = self.find_node(q.arg1) if left is None: left = DAGNode(q.arg1) self.add_node(left) right = self.find_node(q.arg2) if right is None: right = DAGNode(q.arg2) self.add_node(right) node = self.find_node((q.op, left, right)) if node is None: node = DAGNode((q.op, left, right)) self.add_node(node) q.result = node # 设置DAG的根节点 for node in self.nodes: if node.left is None