diff --git a/ep20/src/main/java/org/teachfx/antlr4/ep20/Compiler.java b/ep20/src/main/java/org/teachfx/antlr4/ep20/Compiler.java
index e111f4c..0ace290 100644
--- a/ep20/src/main/java/org/teachfx/antlr4/ep20/Compiler.java
+++ b/ep20/src/main/java/org/teachfx/antlr4/ep20/Compiler.java
@@ -76,9 +76,9 @@ public static void main(String[] args) throws IOException {
     protected static void saveToEp18Res(String buffer) {
         String modulePath = "../ep18/src/main/resources"; // 替换 "my-module" 为你的模块名称
         File moduleDirectory = new File(modulePath);
-        logger.info("file path %s".formatted(moduleDirectory.getAbsolutePath()));
+        logger.trace("file path %s".formatted(moduleDirectory.getAbsolutePath()));
         if (moduleDirectory.exists()) {
-            logger.info("模块路径：" + moduleDirectory.getAbsolutePath());
+            logger.trace("模块路径：" + moduleDirectory.getAbsolutePath());
             var filePath = modulePath+"/t.vm";
             File file = new File(filePath);
             try (var outputStream = new FileOutputStream(file)) {
diff --git a/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/cfg/CFG.java b/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/cfg/CFG.java
index d3d5c26..aca02ff 100644
--- a/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/cfg/CFG.java
+++ b/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/cfg/CFG.java
@@ -115,14 +115,6 @@ public String toString() {
         return graphRenderBuffer.toString();
     }
 
-    /// 1. receive two params : srcBlockId and destBlockId
-    /// 2. remove edge from edges and links
-    public void removeEdge(int srcBlockId, int destBlockId,int weight) {
-        edges.remove(Triple.of(srcBlockId, destBlockId,weight));
-        links.get(srcBlockId).getRight().remove(destBlockId);
-        links.get(destBlockId).getLeft().remove(srcBlockId);
-    }
-
 
     /**
      * remove edge from edges and links
@@ -141,11 +133,6 @@ public void removeEdge(Triple<Integer,Integer,Integer> edge) {
         }
     }
 
-    /// 1. receive one param : id
-    public void removeNodeById(int id) {
-        /// 2. remove node from nodes by its id
-        nodes.removeIf(bb -> bb.getId() == id);
-    }
     public void removeNode(BasicBlock<I> node) {
         /// 2. remove node from nodes by its id
         nodes.removeIf(bb -> bb.equals(node));
diff --git a/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/cfg/LinearIRBlock.java b/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/cfg/LinearIRBlock.java
index db0b52d..441dc9c 100644
--- a/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/cfg/LinearIRBlock.java
+++ b/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/cfg/LinearIRBlock.java
@@ -32,7 +32,7 @@ public LinearIRBlock(Scope scope) {
         predecessors = new ArrayList<>();
         ord = LABEL_SEQ++;
         this.scope = scope;
-        logger.info(ord);
+        logger.trace(ord);
     }
 
     public LinearIRBlock() {
@@ -41,7 +41,7 @@ public LinearIRBlock() {
         predecessors = new ArrayList<>();
         ord = LABEL_SEQ++;
         this.scope = null;
-        logger.info(ord);
+        logger.trace(ord);
     }
     public static boolean isBasicBlock(Stmt stmt) {
         return !(stmt instanceof CJMP) && !(stmt instanceof JMP);
diff --git a/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/ir/CymbolIRBuilder.java b/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/ir/CymbolIRBuilder.java
index cf6f4fb..4a83e05 100644
--- a/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/ir/CymbolIRBuilder.java
+++ b/ep20/src/main/java/org/teachfx/antlr4/ep20/pass/ir/CymbolIRBuilder.java
@@ -47,7 +47,7 @@ public class CymbolIRBuilder implements ASTVisitor<Void, VarSlot> {
     @Override
     public Void visit(CompileUnit compileUnit) {
         prog = new Prog();
-        logger.info("visit root");
+        logger.debug("visit root");
         compileUnit.getFuncDeclarations().forEach(x -> x.accept(this));
 
         return null;
@@ -55,7 +55,7 @@ public Void visit(CompileUnit compileUnit) {
 
     @Override
     public Void visit(VarDeclNode varDeclNode) {
-        logger.info("visit %s".formatted(varDeclNode.toString()));
+        logger.debug("visit %s".formatted(varDeclNode.toString()));
 
         if(varDeclNode.hasInitializer()){
             var lhsNode = (IDExprNode)varDeclNode.getIdExprNode();
@@ -70,7 +70,7 @@ public Void visit(VarDeclNode varDeclNode) {
 
     @Override
     public Void visit(FuncDeclNode funcDeclNode) {
-        logger.info("visit %s".formatted(funcDeclNode.toString()));
+        logger.debug("visit %s".formatted(funcDeclNode.toString()));
 
         curNode = funcDeclNode;
         var methodSymbol = (MethodSymbol) funcDeclNode.getRefSymbol();
@@ -103,7 +103,7 @@ public Void visit(FuncDeclNode funcDeclNode) {
 
     @Override
     public Void visit(VarDeclStmtNode varDeclStmtNode) {
-        logger.info("visit %s".formatted(varDeclStmtNode.toString()));
+        logger.debug("visit %s".formatted(varDeclStmtNode.toString()));
         if (varDeclStmtNode.getVarDeclNode().hasInitializer()) {
             varDeclStmtNode.getVarDeclNode().accept(this);
         }
@@ -392,7 +392,7 @@ public void popContinueStack() {
     protected VarSlot pushEvalOperand(Operand operand) {
 
         if (curNode != null) {
-            logger.info(curNode.toString());
+            logger.debug(curNode.toString());
         }
 
         if (!(operand instanceof OperandSlot)){
@@ -400,11 +400,11 @@ protected VarSlot pushEvalOperand(Operand operand) {
             var assignee = OperandSlot.pushStack();
             evalExprStack.push(assignee);
             addInstr(Assign.with(assignee, operand));
-            logger.info("-> eval stack %s%n", evalExprStack.toString());
+            logger.debug("-> eval stack %s%n", evalExprStack.toString());
 
             return assignee;
         } else {
-            logger.info("-> eval stack %s%n", evalExprStack.toString());
+            logger.debug("-> eval stack %s%n", evalExprStack.toString());
             evalExprStack.push((VarSlot) operand);
             return (VarSlot) operand;
         }
@@ -413,8 +413,8 @@ protected VarSlot pushEvalOperand(Operand operand) {
 
     protected VarSlot popEvalOperand() {
         var res = evalExprStack.pop();
-        logger.info("pop eval operand %s",res);
-        logger.info("pop stack");
+        logger.debug("pop eval operand %s",res);
+        logger.debug("pop stack");
         OperandSlot.popStack();
         if (OperandSlot.getOrdSeq() < 0) {
             throw new RuntimeException("un matched pop");
diff --git a/ep21/src/main/java/org/teachfx/antlr4/ep21/pass/ir/CymbolIRBuilder.java b/ep21/src/main/java/org/teachfx/antlr4/ep21/pass/ir/CymbolIRBuilder.java
index 3d05027..202081b 100644
--- a/ep21/src/main/java/org/teachfx/antlr4/ep21/pass/ir/CymbolIRBuilder.java
+++ b/ep21/src/main/java/org/teachfx/antlr4/ep21/pass/ir/CymbolIRBuilder.java
@@ -58,7 +58,7 @@ public Void visit(VarDeclNode varDeclNode) {
 
     @Override
     public Void visit(FuncDeclNode funcDeclNode) {
-        logger.info("enter %s".formatted(funcDeclNode.toString()));
+        logger.debug("enter %s".formatted(funcDeclNode.toString()));
         methodSymbolStack.push((MethodSymbol) funcDeclNode.getRefSymbol());
         /**/
         stmts = new ArrayList<>();