Lab4: Implement basic scalar optimizations and lower Phi nodes to assembly

src/ir/passes/PassManager.cpp

@@ -1 +1,35 @@
-// IR Pass 管理骨架。
+#include "ir/PassManager.h"
+#include <iostream>
+
+namespace ir {
+
+void RunFunctionOptimizationPasses(Function* func, Context& ctx) {
+  // 1. Promote memory-based local variables to SSA form using Mem2Reg
+  RunMem2Reg(func, ctx);
+
+  // 2. Run scalar optimizations iteratively until convergence (no changes observed)
+  bool changed = true;
+  int iterations = 0;
+  const int max_iterations = 16; // Safe limit to prevent compile-time infinite loops
+
+  while (changed && iterations < max_iterations) {
+    changed = false;
+    iterations++;
+
+    changed |= RunConstProp(func, ctx);
+    changed |= RunConstFold(func, ctx);
+    changed |= RunCSE(func);
+    changed |= RunDCE(func);
+    changed |= RunCFGSimplify(func);
+  }
+}
+
+void RunOptimizationPasses(Module& module) {
+  for (const auto& funcPtr : module.GetFunctions()) {
+    if (!funcPtr->GetBlocks().empty()) {
+      RunFunctionOptimizationPasses(funcPtr.get(), module.GetContext());
+    }
+  }
+}
+
+} // namespace ir