diff --git a/src/midend/Pass/Optimize/SysYIRCFGOpt.cpp b/src/midend/Pass/Optimize/SysYIRCFGOpt.cpp
index 5e75645..393df63 100644
--- a/src/midend/Pass/Optimize/SysYIRCFGOpt.cpp
+++ b/src/midend/Pass/Optimize/SysYIRCFGOpt.cpp
@@ -77,6 +77,11 @@ bool SysYCFGOptUtils::SysYBlockMerge(Function *func) {
   bool changed = false;
 
   for (auto blockiter = func->getBasicBlocks().begin(); blockiter != func->getBasicBlocks().end();) {
+    // 检查当前块是是不是entry块
+    if( blockiter->get() == func->getEntryBlock() ) {
+      blockiter++;
+      continue; // 跳过入口块
+    }
     if (blockiter->get()->getNumSuccessors() == 1) {
       // 如果当前块只有一个后继块
       // 且后继块只有一个前驱块
@@ -288,13 +293,12 @@ bool SysYCFGOptUtils::SysYDelEmptyBlock(Function *func, IRBuilder *pBuilder) {
       continue;
     }
 
-    std::function<Value *(Value *, BasicBlock *)> getUltimateSourceValue = [&](Value *val,
-                                                                               BasicBlock *currentDefBlock) -> Value * {
-      // 如果值不是指令，例如常量或函数参数，则它本身就是最终来源
-      if (auto instr = dynamic_cast<Instruction *>(val)) { // Assuming Value* has a method to check if it's an instruction
+    std::function<Value *(Value *, BasicBlock *)> getUltimateSourceValue = [&](Value *val, BasicBlock *currentDefBlock) -> Value * {
+      
+      if(!dynamic_cast<Instruction *>(val)) {
+        // 如果 val 不是指令，直接返回它
         return val;
       }
-
       Instruction *inst = dynamic_cast<Instruction *>(val);
       // 如果定义指令不在任何空块中，它就是最终来源
       if (!emptyBlockRedirectMap.count(currentDefBlock)) {