From ecdfcff254a120c1594c469499ae1a96addf14b8 Mon Sep 17 00:00:00 2001
From: Minero Aoki <mineroaoki@gmail.com>
Date: Sun, 19 Apr 2009 14:52:48 +0000
Subject: [PATCH] * new class Simplifier (it is really a IR generator).  Passes
 compilation, but not tested.

git-svn-id: file:///Users/aamine/c/gitwork/public/cbc/trunk@4140 1b9489fe-b721-0410-924e-b54b9192deb8
---
 ChangeLog                                     |   5 +
 net/loveruby/cflat/ast/ASTVisitor.java        |   4 +
 net/loveruby/cflat/ast/AssignStmtNode.java    |  28 +
 net/loveruby/cflat/ast/BranchIfNode.java      |  36 +
 net/loveruby/cflat/ast/BreakNode.java         |  13 -
 net/loveruby/cflat/ast/ContinueNode.java      |  13 -
 net/loveruby/cflat/ast/DefinedFunction.java   |  66 +-
 net/loveruby/cflat/ast/DefinedVariable.java   |   4 +
 net/loveruby/cflat/ast/DereferenceNode.java   |   4 +
 net/loveruby/cflat/ast/DoWhileNode.java       |  12 +-
 net/loveruby/cflat/ast/ForNode.java           |  16 +-
 net/loveruby/cflat/ast/FuncallNode.java       |   4 +
 net/loveruby/cflat/ast/GotoNode.java          |  12 +-
 net/loveruby/cflat/ast/IfNode.java            |  16 -
 net/loveruby/cflat/ast/LabelNode.java         |   9 +-
 net/loveruby/cflat/ast/LoopNode.java          |  33 -
 net/loveruby/cflat/ast/ReturnNode.java        |  13 -
 net/loveruby/cflat/ast/UnaryOpNode.java       |   4 +
 net/loveruby/cflat/ast/VariableNode.java      |   4 +
 net/loveruby/cflat/ast/WhileNode.java         |  14 +-
 .../cflat/compiler/CodeGenerator.java         | 436 ++---------
 net/loveruby/cflat/compiler/Compiler.java     |   5 +-
 net/loveruby/cflat/compiler/CompilerMode.java |   2 +
 net/loveruby/cflat/compiler/JumpResolver.java | 133 ----
 net/loveruby/cflat/compiler/Options.java      |   1 +
 net/loveruby/cflat/compiler/Simplifier.java   | 685 +++++++++++++++++-
 net/loveruby/cflat/compiler/Visitor.java      |  12 +
 net/loveruby/cflat/exception/JumpError.java   |   7 +
 28 files changed, 881 insertions(+), 710 deletions(-)
 create mode 100644 net/loveruby/cflat/ast/AssignStmtNode.java
 create mode 100644 net/loveruby/cflat/ast/BranchIfNode.java
 delete mode 100644 net/loveruby/cflat/ast/LoopNode.java
 delete mode 100644 net/loveruby/cflat/compiler/JumpResolver.java
 create mode 100644 net/loveruby/cflat/exception/JumpError.java

diff --git a/ChangeLog b/ChangeLog
index a3ec82d..abbba0e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Apr 19 23:52:37 2009  Minero Aoki  <aamine@loveruby.net>
+
+	* new class Simplifier (it is really a IR generator).  Passes
+	  compilation, but not tested.
+
 Sun Apr 19 14:57:22 2009  Minero Aoki  <aamine@loveruby.net>
 
 	* refactoring: rename class: compiler/Simplifier.java ->
diff --git a/net/loveruby/cflat/ast/ASTVisitor.java b/net/loveruby/cflat/ast/ASTVisitor.java
index 9e08cc0..00e2c32 100644
--- a/net/loveruby/cflat/ast/ASTVisitor.java
+++ b/net/loveruby/cflat/ast/ASTVisitor.java
@@ -47,4 +47,8 @@ public interface ASTVisitor<S, E> {
     public E visit(VariableNode node);
     public E visit(IntegerLiteralNode node);
     public E visit(StringLiteralNode node);
+
+    // does exists only in IR tree
+    public S visit(AssignStmtNode node);
+    public S visit(BranchIfNode node);
 }
diff --git a/net/loveruby/cflat/ast/AssignStmtNode.java b/net/loveruby/cflat/ast/AssignStmtNode.java
new file mode 100644
index 0000000..bf8e7de
--- /dev/null
+++ b/net/loveruby/cflat/ast/AssignStmtNode.java
@@ -0,0 +1,28 @@
+package net.loveruby.cflat.ast;
+
+public class AssignStmtNode extends StmtNode {
+    protected ExprNode lhs, rhs;
+
+    public AssignStmtNode(ExprNode lhs, ExprNode rhs) {
+        super(null);
+        this.lhs = lhs;
+        this.rhs = rhs;
+    }
+
+    public ExprNode lhs() {
+        return lhs;
+    }
+
+    public ExprNode rhs() {
+        return rhs;
+    }
+
+    public <S,E> S accept(ASTVisitor<S,E> visitor) {
+        return visitor.visit(this);
+    }
+
+    protected void _dump(Dumper d) {
+        d.printMember("lhs", lhs);
+        d.printMember("rhs", rhs);
+    }
+}
diff --git a/net/loveruby/cflat/ast/BranchIfNode.java b/net/loveruby/cflat/ast/BranchIfNode.java
new file mode 100644
index 0000000..e4a5e73
--- /dev/null
+++ b/net/loveruby/cflat/ast/BranchIfNode.java
@@ -0,0 +1,36 @@
+package net.loveruby.cflat.ast;
+import net.loveruby.cflat.asm.Label;
+
+public class BranchIfNode extends StmtNode {
+    protected ExprNode cond;
+    protected Label thenLabel;
+    protected Label elseLabel;
+
+    public BranchIfNode(Location loc, ExprNode cond,
+                    Label thenLabel, Label elseLabel) {
+        super(loc);
+        this.cond = cond;
+        this.thenLabel = thenLabel;
+        this.elseLabel = elseLabel;
+    }
+
+    public ExprNode cond() {
+        return cond;
+    }
+
+    public Label thenLabel() {
+        return thenLabel;
+    }
+
+    public Label elseLabel() {
+        return elseLabel;
+    }
+
+    public <S,E> S accept(ASTVisitor<S,E> visitor) {
+        return visitor.visit(this);
+    }
+
+    protected void _dump(Dumper d) {
+        d.printMember("cond", cond);
+    }
+}
diff --git a/net/loveruby/cflat/ast/BreakNode.java b/net/loveruby/cflat/ast/BreakNode.java
index ccbe531..e9c5444 100644
--- a/net/loveruby/cflat/ast/BreakNode.java
+++ b/net/loveruby/cflat/ast/BreakNode.java
@@ -6,19 +6,6 @@ public class BreakNode extends StmtNode {
         super(loc);
     }
 
-    protected Label label;
-
-    public void setTargetLabel(Label label) {
-        this.label = label;
-    }
-
-    public Label targetLabel() {
-        if (label == null) {
-            throw new Error("break label is null");
-        }
-        return label;
-    }
-
     public Location location() {
         return location;
     }
diff --git a/net/loveruby/cflat/ast/ContinueNode.java b/net/loveruby/cflat/ast/ContinueNode.java
index faca9ec..af25d3e 100644
--- a/net/loveruby/cflat/ast/ContinueNode.java
+++ b/net/loveruby/cflat/ast/ContinueNode.java
@@ -6,19 +6,6 @@ public class ContinueNode extends StmtNode {
         super(loc);
     }
 
-    protected Label label;
-
-    public void setTargetLabel(Label label) {
-        this.label = label;
-    }
-
-    public Label targetLabel() {
-        if (label == null) {
-            throw new Error("continue target label is null");
-        }
-        return label;
-    }
-
     protected void _dump(Dumper d) {
     }
 
diff --git a/net/loveruby/cflat/ast/DefinedFunction.java b/net/loveruby/cflat/ast/DefinedFunction.java
index a139731..8084260 100644
--- a/net/loveruby/cflat/ast/DefinedFunction.java
+++ b/net/loveruby/cflat/ast/DefinedFunction.java
@@ -8,9 +8,9 @@ import java.util.*;
 public class DefinedFunction extends Function {
     protected Params params;
     protected BlockNode body;
-    protected Map<String, JumpEntry> jumpMap;
     protected LocalScope scope;
     protected Label epilogueLabel;
+    protected List<StmtNode> ir;
 
     public DefinedFunction(boolean priv,
                            TypeNode type,
@@ -20,7 +20,6 @@ public class DefinedFunction extends Function {
         super(priv, type, name);
         this.params = params;
         this.body = body;
-        this.jumpMap = new HashMap<String, JumpEntry>();
         this.epilogueLabel = new Label();
     }
 
@@ -36,6 +35,14 @@ public class DefinedFunction extends Function {
         return body;
     }
 
+    public List<StmtNode> ir() {
+        return ir;
+    }
+
+    public void setIR(List<StmtNode> ir) {
+        this.ir = ir;
+    }
+
     public void setScope(LocalScope scope) {
         this.scope = scope;
     }
@@ -53,61 +60,6 @@ public class DefinedFunction extends Function {
         return this.epilogueLabel;
     }
 
-    class JumpEntry {
-        public Label label;
-        public long numRefered;
-        public boolean isDefined;
-        public Location location;
-
-        public JumpEntry(Label label) {
-            this.label = label;
-            numRefered = 0;
-            isDefined = false;
-        }
-    }
-
-    public Label defineLabel(String name, Location loc)
-                                    throws SemanticException {
-        JumpEntry ent = getJumpEntry(name);
-        if (ent.isDefined) {
-            throw new SemanticException(
-                "duplicated jump labels in " + name + "(): " + name);
-        }
-        ent.isDefined = true;
-        ent.location = loc;
-        return ent.label;
-    }
-
-    public Label referLabel(String name) {
-        JumpEntry ent = getJumpEntry(name);
-        ent.numRefered++;
-        return ent.label;
-    }
-
-    protected JumpEntry getJumpEntry(String name) {
-        JumpEntry ent = jumpMap.get(name);
-        if (ent == null) {
-            ent = new JumpEntry(new Label());
-            jumpMap.put(name, ent);
-        }
-        return ent;
-    }
-
-    public void checkJumpLinks(ErrorHandler handler) {
-        for (Map.Entry<String, JumpEntry> ent : jumpMap.entrySet()) {
-            String labelName = ent.getKey();
-            JumpEntry jump = ent.getValue();
-            if (!jump.isDefined) {
-                handler.error(jump.location,
-                              name + ": undefined label: " + labelName);
-            }
-            if (jump.numRefered == 0) {
-                handler.warn(jump.location,
-                             name + ": useless label: " + labelName);
-            }
-        }
-    }
-
     protected void _dump(Dumper d) {
         d.printMember("name", name);
         d.printMember("isPrivate", isPrivate);
diff --git a/net/loveruby/cflat/ast/DefinedVariable.java b/net/loveruby/cflat/ast/DefinedVariable.java
index 520b63f..35764d9 100644
--- a/net/loveruby/cflat/ast/DefinedVariable.java
+++ b/net/loveruby/cflat/ast/DefinedVariable.java
@@ -15,6 +15,10 @@ public class DefinedVariable extends Variable {
         sequence = -1;
     }
 
+    static public DefinedVariable tmp(Type t) {
+        return new DefinedVariable(false, new TypeNode(t), "@tmp", null);
+    }
+
     public boolean isDefined() {
         return true;
     }
diff --git a/net/loveruby/cflat/ast/DereferenceNode.java b/net/loveruby/cflat/ast/DereferenceNode.java
index a80afd2..19b6ec3 100644
--- a/net/loveruby/cflat/ast/DereferenceNode.java
+++ b/net/loveruby/cflat/ast/DereferenceNode.java
@@ -10,6 +10,10 @@ public class DereferenceNode extends UnaryOpNode {
         return expr().type().baseType();
     }
 
+    public void setExpr(ExprNode expr) {
+        this.expr = expr;
+    }
+
     public boolean isAssignable() { return true; }
     public boolean isConstantAddress() { return false; }
 
diff --git a/net/loveruby/cflat/ast/DoWhileNode.java b/net/loveruby/cflat/ast/DoWhileNode.java
index 1f20cfb..0b1afc6 100644
--- a/net/loveruby/cflat/ast/DoWhileNode.java
+++ b/net/loveruby/cflat/ast/DoWhileNode.java
@@ -1,22 +1,22 @@
 package net.loveruby.cflat.ast;
 import net.loveruby.cflat.asm.Label;
 
-public class DoWhileNode extends LoopNode {
+public class DoWhileNode extends StmtNode {
     protected StmtNode body;
-    protected Label continueLabel;
+    protected ExprNode cond;
 
     public DoWhileNode(Location loc, StmtNode body, ExprNode cond) {
-        super(loc, cond);
+        super(loc);
         this.body = body;
-        this.continueLabel = new Label();
+        this.cond = cond;
     }
 
     public StmtNode body() {
         return body;
     }
 
-    public Label continueLabel() {
-        return continueLabel;
+    public ExprNode cond() {
+        return cond;
     }
 
     protected void _dump(Dumper d) {
diff --git a/net/loveruby/cflat/ast/ForNode.java b/net/loveruby/cflat/ast/ForNode.java
index ae14612..f31cec6 100644
--- a/net/loveruby/cflat/ast/ForNode.java
+++ b/net/loveruby/cflat/ast/ForNode.java
@@ -1,25 +1,29 @@
 package net.loveruby.cflat.ast;
 import net.loveruby.cflat.asm.Label;
 
-public class ForNode extends LoopNode {
+public class ForNode extends StmtNode {
     protected StmtNode init;
+    protected ExprNode cond;
     protected StmtNode incr;
     protected StmtNode body;
-    protected Label continueLabel;
 
     public ForNode(Location loc, 
                    ExprNode init, ExprNode cond, ExprNode incr, StmtNode body) {
-        super(loc, cond);
+        super(loc);
         this.init = new ExprStmtNode(init.location(), init);
+        this.cond = cond;
         this.incr = new ExprStmtNode(incr.location(), incr);
         this.body = body;
-        this.continueLabel = new Label();
     }
 
     public StmtNode init() {
         return init;
     }
 
+    public ExprNode cond() {
+        return cond;
+    }
+
     public StmtNode incr() {
         return incr;
     }
@@ -28,10 +32,6 @@ public class ForNode extends LoopNode {
         return body;
     }
 
-    public Label continueLabel() {
-        return continueLabel;
-    }
-
     protected void _dump(Dumper d) {
         d.printMember("init", init);
         d.printMember("cond", cond);
diff --git a/net/loveruby/cflat/ast/FuncallNode.java b/net/loveruby/cflat/ast/FuncallNode.java
index c4ba28b..feb4e98 100644
--- a/net/loveruby/cflat/ast/FuncallNode.java
+++ b/net/loveruby/cflat/ast/FuncallNode.java
@@ -16,6 +16,10 @@ public class FuncallNode extends ExprNode {
         return expr;
     }
 
+    public void setExpr(ExprNode expr) {
+        this.expr = expr;
+    }
+
     /** Returns true if this funcall is NOT a function pointer call. */
     public boolean isStaticCall() {
         return (expr instanceof VariableNode) &&
diff --git a/net/loveruby/cflat/ast/GotoNode.java b/net/loveruby/cflat/ast/GotoNode.java
index ba6551c..2cab7f5 100644
--- a/net/loveruby/cflat/ast/GotoNode.java
+++ b/net/loveruby/cflat/ast/GotoNode.java
@@ -10,16 +10,16 @@ public class GotoNode extends StmtNode {
         this.target = target;
     }
 
+    public GotoNode(Label target) {
+        super(null);
+        label = target;
+    }
+
     public String target() {
         return target;
     }
 
-    public void setTargetLabel(Label label) {
-        this.label = label;
-    }
-
-    public Label targetLabel() {
-        if (label == null) throw new Error("goto target label is null");
+    public Label label() {
         return label;
     }
 
diff --git a/net/loveruby/cflat/ast/IfNode.java b/net/loveruby/cflat/ast/IfNode.java
index 4dc77b0..39450f9 100644
--- a/net/loveruby/cflat/ast/IfNode.java
+++ b/net/loveruby/cflat/ast/IfNode.java
@@ -5,26 +5,18 @@ public class IfNode extends StmtNode {
     protected ExprNode cond;
     protected StmtNode thenBody;
     protected StmtNode elseBody;
-    protected Label elseLabel;
-    protected Label endLabel;
 
     public IfNode(Location loc, ExprNode c, StmtNode t, StmtNode e) {
         super(loc);
         this.cond = c;
         this.thenBody = t;
         this.elseBody = e;
-        this.elseLabel = new Label();
-        this.endLabel = new Label();
     }
 
     public ExprNode cond() {
         return cond;
     }
 
-    public void setCond(ExprNode cond) {
-        this.cond = cond;
-    }
-
     public StmtNode thenBody() {
         return thenBody;
     }
@@ -33,14 +25,6 @@ public class IfNode extends StmtNode {
         return elseBody;
     }
 
-    public Label elseLabel() {
-        return elseLabel;
-    }
-
-    public Label endLabel() {
-        return endLabel;
-    }
-
     protected void _dump(Dumper d) {
         d.printMember("cond", cond);
         d.printMember("thenBody", thenBody);
diff --git a/net/loveruby/cflat/ast/LabelNode.java b/net/loveruby/cflat/ast/LabelNode.java
index 23c4807..23e3d3c 100644
--- a/net/loveruby/cflat/ast/LabelNode.java
+++ b/net/loveruby/cflat/ast/LabelNode.java
@@ -12,6 +12,11 @@ public class LabelNode extends StmtNode {
         this.stmt = stmt;
     }
 
+    public LabelNode(Label label) {
+        super(null);
+        this.label = label;
+    }
+
     public String name() {
         return name;
     }
@@ -20,10 +25,6 @@ public class LabelNode extends StmtNode {
         return stmt;
     }
 
-    public void setLabel(Label label) {
-        this.label = label;
-    }
-
     public Label label() {
         if (label == null) throw new Error("label is null");
         return label;
diff --git a/net/loveruby/cflat/ast/LoopNode.java b/net/loveruby/cflat/ast/LoopNode.java
deleted file mode 100644
index 47bc3be..0000000
--- a/net/loveruby/cflat/ast/LoopNode.java
+++ /dev/null
@@ -1,33 +0,0 @@
-package net.loveruby.cflat.ast;
-import net.loveruby.cflat.asm.Label;
-
-abstract public class LoopNode extends StmtNode
-        implements BreakableStmt, ContinueableStmt {
-    protected ExprNode cond;
-    protected Label begLabel, endLabel;
-
-    public LoopNode(Location loc, ExprNode cond) {
-        super(loc);
-        this.cond = cond;
-        this.begLabel = new Label();
-        this.endLabel = new Label();
-    }
-
-    public ExprNode cond() {
-        return cond;
-    }
-
-    public void setCond(ExprNode cond) {
-        this.cond = cond;
-    }
-
-    public Label begLabel() {
-        return begLabel;
-    }
-
-    public Label endLabel() {
-        return endLabel;
-    }
-
-    abstract public Label continueLabel();
-}
diff --git a/net/loveruby/cflat/ast/ReturnNode.java b/net/loveruby/cflat/ast/ReturnNode.java
index fdffa8f..4fbbc84 100644
--- a/net/loveruby/cflat/ast/ReturnNode.java
+++ b/net/loveruby/cflat/ast/ReturnNode.java
@@ -2,7 +2,6 @@ package net.loveruby.cflat.ast;
 
 public class ReturnNode extends StmtNode {
     protected ExprNode expr;
-    protected Function function;
 
     public ReturnNode(Location loc, ExprNode expr) {
         super(loc);
@@ -17,18 +16,6 @@ public class ReturnNode extends StmtNode {
         this.expr = expr;
     }
 
-    public void setFunction(Function f) {
-        if (this.function != null)
-            throw new Error("setFunction called twice");
-        this.function = f;
-    }
-
-    public Function function() {
-        if (this.function == null)
-            throw new Error("ReturnNode#function called before setFunction");
-        return this.function;
-    }
-
     protected void _dump(Dumper d) {
         d.printMember("expr", expr);
     }
diff --git a/net/loveruby/cflat/ast/UnaryOpNode.java b/net/loveruby/cflat/ast/UnaryOpNode.java
index d7bad9c..500588d 100644
--- a/net/loveruby/cflat/ast/UnaryOpNode.java
+++ b/net/loveruby/cflat/ast/UnaryOpNode.java
@@ -31,6 +31,10 @@ public class UnaryOpNode extends ExprNode {
         return expr;
     }
 
+    public void setExpr(ExprNode expr) {
+        this.expr = expr;
+    }
+
     public Location location() {
         return expr.location();
     }
diff --git a/net/loveruby/cflat/ast/VariableNode.java b/net/loveruby/cflat/ast/VariableNode.java
index 165c1a5..fd41d4a 100644
--- a/net/loveruby/cflat/ast/VariableNode.java
+++ b/net/loveruby/cflat/ast/VariableNode.java
@@ -14,6 +14,10 @@ public class VariableNode extends ExprNode {
         this.name = name;
     }
 
+    public VariableNode(DefinedVariable var) {
+        this.entity = var;
+    }
+
     public String name() {
         return name;
     }
diff --git a/net/loveruby/cflat/ast/WhileNode.java b/net/loveruby/cflat/ast/WhileNode.java
index 31ac3be..c3bd39b 100644
--- a/net/loveruby/cflat/ast/WhileNode.java
+++ b/net/loveruby/cflat/ast/WhileNode.java
@@ -1,22 +1,24 @@
 package net.loveruby.cflat.ast;
 import net.loveruby.cflat.asm.Label;
 
-public class WhileNode extends LoopNode {
+public class WhileNode extends StmtNode {
     protected StmtNode body;
+    protected ExprNode cond;
 
     public WhileNode(Location loc, ExprNode cond, StmtNode body) {
-        super(loc, cond);
+        super(loc);
+        this.cond = cond;
         this.body = body;
     }
 
+    public ExprNode cond() {
+        return cond;
+    }
+
     public StmtNode body() {
         return body;
     }
 
-    public Label continueLabel() {
-        return begLabel();
-    }
-
     protected void _dump(Dumper d) {
         d.printMember("cond", cond);
         d.printMember("body", body);
diff --git a/net/loveruby/cflat/compiler/CodeGenerator.java b/net/loveruby/cflat/compiler/CodeGenerator.java
index ca7cd98..a002241 100644
--- a/net/loveruby/cflat/compiler/CodeGenerator.java
+++ b/net/loveruby/cflat/compiler/CodeGenerator.java
@@ -4,15 +4,14 @@ import net.loveruby.cflat.type.*;
 import net.loveruby.cflat.asm.*;
 import java.util.*;
 
-public class CodeGenerator
-                extends Visitor implements ASTLHSVisitor, ELFConstants {
+public class CodeGenerator implements ASTVisitor<Void,Void>, ELFConstants {
     // #@@range/ctor{
     protected CodeGeneratorOptions options;
     protected ErrorHandler errorHandler;
     protected LinkedList<Assembler> asStack;
     protected Assembler as;
     protected TypeTable typeTable;
-    protected DefinedFunction currentFunction;
+    protected Label epilogue;
 
     public CodeGenerator(CodeGeneratorOptions options,
                          ErrorHandler errorHandler) {
@@ -22,22 +21,22 @@ public class CodeGenerator
     }
     // #@@}
 
-    /** Compiles "ast" and generates assembly code. */
+    /** Compiles IR and generates assembly code. */
     // #@@range/generate{
-    public String generate(AST ast) {
-        this.typeTable = ast.typeTable();
+    public String generate(AST ir) {
+        this.typeTable = ir.typeTable();
         pushAssembler();
         SymbolTable constSymbols = new SymbolTable(Assembler.CONST_SYMBOL_BASE);
-        for (ConstantEntry ent : ast.constantTable().entries()) {
+        for (ConstantEntry ent : ir.constantTable().entries()) {
             locateConstant(ent, constSymbols);
         }
-        for (Variable var : ast.allGlobalVariables()) {
+        for (Variable var : ir.allGlobalVariables()) {
             locateGlobalVariable(var);
         }
-        for (Function func : ast.allFunctions()) {
+        for (Function func : ir.allFunctions()) {
             locateFunction(func);
         }
-        compileAST(ast);
+        compileIR(ir);
         return popAssembler().toSource();
     }
     // #@@}
@@ -63,32 +62,32 @@ public class CodeGenerator
     }
     // #@@}
 
-    // #@@range/compileAST{
-    public void compileAST(AST ast) {
-        _file(ast.fileName());
+    // #@@range/compileIR{
+    public void compileIR(AST ir) {
+        _file(ir.fileName());
         // .data
-        List<DefinedVariable> gvars = ast.definedGlobalVariables();
+        List<DefinedVariable> gvars = ir.definedGlobalVariables();
         if (!gvars.isEmpty()) {
             _data();
             for (DefinedVariable gvar : gvars) {
                 dataEntry(gvar);
             }
         }
-        if (!ast.constantTable().isEmpty()) {
+        if (!ir.constantTable().isEmpty()) {
             _section(".rodata");
-            for (ConstantEntry ent : ast.constantTable()) {
+            for (ConstantEntry ent : ir.constantTable()) {
                 compileStringLiteral(ent);
             }
         }
         // .text
-        if (ast.functionDefined()) {
+        if (ir.functionDefined()) {
             _text();
-            for (DefinedFunction func : ast.definedFunctions()) {
-                compileFunction(func);
+            for (DefinedFunction func : ir.definedFunctions()) {
+                visit(func);
             }
         }
         // .bss
-        for (DefinedVariable var : ast.definedCommonSymbols()) {
+        for (DefinedVariable var : ir.definedCommonSymbols()) {
             compileCommonSymbol(var);
         }
         // others
@@ -366,7 +365,7 @@ public class CodeGenerator
 
     /** Compiles a function. */
     // #@@range/compileFunction{
-    protected void compileFunction(DefinedFunction func) {
+    public Void visit(DefinedFunction func) {
         allocateParameters(func);
         allocateLocalVariablesTemp(func.body().scope());
 
@@ -378,6 +377,7 @@ public class CodeGenerator
         label(sym);
         compileFunctionBody(func);
         _size(sym, ".-" + sym.toSource());
+        return null;
     }
     // #@@}
 
@@ -454,10 +454,11 @@ public class CodeGenerator
     // #@@range/compileStmts{
     protected List<Assembly> compileStmts(DefinedFunction func) {
         pushAssembler();
-        currentFunction = func;
-        compileStmt(func.body());
-        label(func.epilogueLabel());
-        currentFunction = null;
+        epilogue = new Label();
+        for (StmtNode s : func.ir()) {
+            compileStmt(s);
+        }
+        label(epilogue);
         return options.optimizer().optimize(popAssembler().assemblies());
     }
     // #@@}
@@ -739,7 +740,7 @@ public class CodeGenerator
         if (node.expr() != null) {
             compile(node.expr());
         }
-        jmp(currentFunction.epilogueLabel());
+        jmp(epilogue);
         return null;
     }
     // #@@}
@@ -748,21 +749,6 @@ public class CodeGenerator
     // Statements
     //
 
-    // #@@range/compile_Block{
-    public Void visit(BlockNode node) {
-        for (DefinedVariable var : node.scope().localVariables()) {
-            if (var.initializer() != null) {
-                compile(var.initializer());
-                save(var.type(), reg("ax"), var.memref());
-            }
-        }
-        for (StmtNode stmt : node.stmts()) {
-            compileStmt(stmt);
-        }
-        return null;
-    }
-    // #@@}
-
     // #@@range/compileStmt{
     protected void compileStmt(StmtNode node) {
         if (options.isVerboseAsm()) {
@@ -783,37 +769,12 @@ public class CodeGenerator
     }
     // #@@}
 
-    // #@@range/compile_If{
-    public Void visit(IfNode node) {
+    // #@@range/compile_BranchIf{
+    public Void visit(BranchIfNode node) {
         compile(node.cond());
         testCond(node.cond().type(), reg("ax"));
-        if (node.elseBody() != null) {
-            jz(node.elseLabel());
-            compileStmt(node.thenBody());
-            jmp(node.endLabel());
-            label(node.elseLabel());
-            compileStmt(node.elseBody());
-            label(node.endLabel());
-        }
-        else {
-            jz(node.endLabel());
-            compileStmt(node.thenBody());
-            label(node.endLabel());
-        }
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_CondExpr{
-    public Void visit(CondExprNode node) {
-        compile(node.cond());
-        testCond(node.cond().type(), reg("ax"));
-        jz(node.elseLabel());
-        compile(node.thenExpr());
-        jmp(node.endLabel());
-        label(node.elseLabel());
-        compile(node.elseExpr());
-        label(node.endLabel());
+        jnz(node.thenLabel());
+        jmp(node.elseLabel());
         return null;
     }
     // #@@}
@@ -836,94 +797,6 @@ public class CodeGenerator
             }
         }
         jmp(node.endLabel());
-        for (CaseNode n : node.cases()) {
-            compileStmt(n);
-        }
-        label(node.endLabel());
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_Case{
-    public Void visit(CaseNode node) {
-        label(node.beginLabel());
-        compileStmt(node.body());
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_LogicalAnd{
-    public Void visit(LogicalAndNode node) {
-        compile(node.left());
-        testCond(node.left().type(), reg("ax"));
-        jz(node.endLabel());
-        compile(node.right());
-        label(node.endLabel());
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_LogicalOr{
-    public Void visit(LogicalOrNode node) {
-        compile(node.left());
-        testCond(node.left().type(), reg("ax"));
-        jnz(node.endLabel());
-        compile(node.right());
-        label(node.endLabel());
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_While{
-    public Void visit(WhileNode node) {
-        label(node.begLabel());
-        compile(node.cond());
-        testCond(node.cond().type(), reg("ax"));
-        jz(node.endLabel());
-        compileStmt(node.body());
-        jmp(node.begLabel());
-        label(node.endLabel());
-        return null;
-    }
-    // #@@}
-
-    public Void visit(DoWhileNode node) {
-        label(node.begLabel());
-        compileStmt(node.body());
-        label(node.continueLabel());
-        compile(node.cond());
-        testCond(node.cond().type(), reg("ax"));
-        jnz(node.begLabel());
-        label(node.endLabel());
-        return null;
-    }
-
-    // #@@range/compile_For{
-    public Void visit(ForNode node) {
-        compileStmt(node.init());
-        label(node.begLabel());
-        compile(node.cond());
-        testCond(node.cond().type(), reg("ax"));
-        jz(node.endLabel());
-        compileStmt(node.body());
-        label(node.continueLabel());
-        compileStmt(node.incr());
-        jmp(node.begLabel());
-        label(node.endLabel());
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_Break{
-    public Void visit(BreakNode node) {
-        jmp(node.targetLabel());
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_Continue{
-    public Void visit(ContinueNode node) {
-        jmp(node.targetLabel());
         return null;
     }
     // #@@}
@@ -931,18 +804,35 @@ public class CodeGenerator
     // #@@range/compile_Label{
     public Void visit(LabelNode node) {
         label(node.label());
-        compileStmt(node.stmt());
         return null;
     }
     // #@@}
 
     // #@@range/compile_Goto{
     public Void visit(GotoNode node) {
-        jmp(node.targetLabel());
+        jmp(node.label());
         return null;
     }
     // #@@}
 
+    public Void visit(BlockNode node) { throw new Error("BlockNode"); }
+    public Void visit(IfNode node) { throw new Error("IfNode"); }
+    public Void visit(CondExprNode node) { throw new Error("CondExprNode"); }
+    public Void visit(CaseNode node) { throw new Error("CaseNode"); }
+    public Void visit(LogicalAndNode node) { throw new Error("LogicalAndNode");}
+    public Void visit(LogicalOrNode node) { throw new Error("LogicalOrNode"); }
+    public Void visit(WhileNode node) { throw new Error("WhileNode"); }
+    public Void visit(DoWhileNode node) { throw new Error("DoWhileNode"); }
+    public Void visit(ForNode node) { throw new Error("ForNode"); }
+    public Void visit(BreakNode node) { throw new Error("BreakNode"); }
+    public Void visit(ContinueNode node) { throw new Error("ContinueNode"); }
+    public Void visit(UndefinedFunction f) { throw new Error("UndefinedFunction"); }
+    public Void visit(DefinedVariable v) { throw new Error("DefinedVariable"); }
+    public Void visit(UndefinedVariable v){throw new Error("UndefinedVariable");}
+    public Void visit(StructNode node) { throw new Error("StructNode"); }
+    public Void visit(UnionNode node) { throw new Error("UnionNode"); }
+    public Void visit(TypedefNode node) { throw new Error("TypedefNode"); }
+
     //
     // Expressions
     //
@@ -1087,7 +977,7 @@ public class CodeGenerator
     public Void visit(UnaryOpNode node) {
         compile(node.expr());
         if (node.operator().equals("+")) {
-            ;
+            throw new Error("unary +");
         }
         else if (node.operator().equals("-")) {
             neg(node.expr().type(), reg("ax", node.expr().type()));
@@ -1104,44 +994,6 @@ public class CodeGenerator
     }
     // #@@}
 
-    // #@@range/compile_PrefixOp{
-    public Void visit(PrefixOpNode node) {
-        if (node.expr().isConstantAddress()) {
-            load(node.expr().type(), node.expr().memref(), reg("ax"));
-            compileUnaryArithmetic(node, reg("ax"));
-            save(node.expr().type(), reg("ax"), node.expr().memref());
-        }
-        else {
-            compileLHS(node.expr());
-            mov(reg("ax"), reg("cx"));
-            load(node.expr().type(), mem(reg("cx")), reg("ax"));
-            compileUnaryArithmetic(node, reg("ax"));
-            save(node.expr().type(), reg("ax"), mem(reg("cx")));
-        }
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_SuffixOp{
-    public Void visit(SuffixOpNode node) {
-        if (node.expr().isConstantAddress()) {
-            load(node.expr().type(), node.expr().memref(), reg("ax"));
-            mov(reg("ax"), reg("cx"));
-            compileUnaryArithmetic(node, reg("cx"));
-            save(node.expr().type(), reg("cx"), node.expr().memref());
-        }
-        else {
-            compileLHS(node.expr());
-            mov(reg("ax"), reg("cx"));
-            load(node.expr().type(), mem(reg("cx")), reg("ax"));
-            mov(reg("ax"), reg("dx"));
-            compileUnaryArithmetic(node, reg("dx"));
-            save(node.expr().type(), reg("dx"), mem(reg("cx")));
-        }
-        return null;
-    }
-    // #@@}
-
     // spills: (none)
     // #@@range/compile_UnaryArithmetic{
     protected void compileUnaryArithmetic(UnaryArithmeticOpNode node,
@@ -1179,22 +1031,6 @@ public class CodeGenerator
     }
     // #@@}
 
-    // #@@range/compile_SizeofExpr{
-    public Void visit(SizeofExprNode node) {
-        long val = node.expr().type().allocSize();
-        mov(node.type(), imm(val), reg("ax", node.type()));
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_SizeofType{
-    public Void visit(SizeofTypeNode node) {
-        long val = node.operand().allocSize();
-        mov(node.type(), imm(val), reg("ax", node.type()));
-        return null;
-    }
-    // #@@}
-
     // #@@range/compile_Variable{
     public Void visit(VariableNode node) {
         loadVariable(node, reg("ax"));
@@ -1216,21 +1052,39 @@ public class CodeGenerator
     }
     // #@@}
 
+    public Void visit(PrefixOpNode node) { throw new Error("PrefixOpNode"); }
+    public Void visit(SuffixOpNode node) { throw new Error("SuffixOpNode"); }
+    public Void visit(ArefNode node) { throw new Error("ArefNode"); }
+    public Void visit(MemberNode node) { throw new Error("MemberNode"); }
+    public Void visit(PtrMemberNode node) { throw new Error("PtrMemberNode"); }
+    public Void visit(SizeofExprNode node) { throw new Error("SizeofExprNode");}
+    public Void visit(SizeofTypeNode node) { throw new Error("SizeofTypeNode");}
+    public Void visit(AssignNode node) { throw new Error("AssignNode"); }
+    public Void visit(OpAssignNode node) { throw new Error("OpAssignNode"); }
+
     //
     // Assignable expressions
     //
 
+    private void compileLHS(ExprNode lhs) {
+        // FIXME FIXME FIXME
+        // for variables: apply loadVariableAddress
+        // for *expr: remove DereferenceNode
+        // otherwise: fatal error
+        compile(lhs);
+    }
+
     // #@@range/compile_Assign{
-    public Void visit(AssignNode node) {
+    public Void visit(AssignStmtNode node) {
         if (node.lhs().isConstantAddress() && node.lhs().memref() != null) {
             compile(node.rhs());
-            save(node.type(), reg("ax"), node.lhs().memref());
+            save(node.lhs().type(), reg("ax"), node.lhs().memref());
         }
         else if (node.rhs().isConstant()) {
             compileLHS(node.lhs());
             mov(reg("ax"), reg("cx"));
             loadConstant(node.rhs(), reg("ax"));
-            save(node.type(), reg("ax"), mem(reg("cx")));
+            save(node.lhs().type(), reg("ax"), mem(reg("cx")));
         }
         else {
             compile(node.rhs());
@@ -1238,87 +1092,7 @@ public class CodeGenerator
             compileLHS(node.lhs());
             mov(reg("ax"), reg("cx"));
             pop(reg("ax"));
-            save(node.type(), reg("ax"), mem(reg("cx")));
-        }
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_OpAssign{
-    public Void visit(OpAssignNode node) {
-        if (node.lhs().isConstantAddress() && node.lhs().memref() != null) {
-            // const += ANY
-            compile(node.rhs());
-            mov(reg("ax"), reg("cx"));
-            load(node.type(), node.lhs().memref(), reg("ax"));
-            compileBinaryOp(node.operator(), node.type(), reg("cx"));
-            save(node.type(), reg("ax"), node.lhs().memref());
-        }
-        else if (node.rhs().isConstant() && !doesRequireRegister(node.operator())) {
-            // ANY += const
-            compileLHS(node.lhs());
-            mov(reg("ax"), reg("cx"));
-            load(node.type(), mem(reg("cx")), reg("ax"));
-            AsmOperand rhs = node.rhs().asmValue();
-            compileBinaryOp(node.operator(), node.type(), rhs);
-            save(node.type(), reg("ax"), mem(reg("cx")));
-        }
-        else if (node.rhs().isConstantAddress()) {
-            // ANY += var
-            compileLHS(node.lhs());
-            push(reg("ax"));
-            load(node.type(), mem(reg("ax")), reg("ax"));
-            loadVariable(node.rhs(), reg("cx"));
-            compileBinaryOp(node.operator(), node.type(), reg("cx"));
-            pop(reg("cx"));
-            save(node.type(), reg("ax"), mem(reg("cx")));
-        }
-        else {
-            // ANY += ANY
-            // no optimization
-            compile(node.rhs());
-            push(reg("ax"));
-            compileLHS(node.lhs());
-            Register lhs = doesSpillDX(node.operator()) ? reg("si") : reg("dx");
-            mov(reg("ax"), lhs);
-            load(node.type(), mem(lhs), reg("ax"));
-            pop(reg("cx"));
-            compileBinaryOp(node.operator(), node.type(), reg("cx"));
-            save(node.type(), reg("ax"), mem(lhs));
-        }
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_Aref{
-    public Void visit(ArefNode node) {
-        compileLHS(node);
-        load(node.type(), mem(reg("ax")), reg("ax"));
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_Member{
-    public Void visit(MemberNode node) {
-        compileLHS(node.expr());
-        if (node.shouldEvaluatedToAddress()) {
-            add(imm(node.offset()), reg("ax"));
-        }
-        else {
-            load(node.type(), mem(node.offset(), reg("ax")), reg("ax"));
-        }
-        return null;
-    }
-    // #@@}
-
-    // #@@range/compile_PtrMember{
-    public Void visit(PtrMemberNode node) {
-        compile(node.expr());
-        if (node.shouldEvaluatedToAddress()) {
-            add(imm(node.offset()), reg("ax"));
-        }
-        else {
-            load(node.type(), mem(node.offset(), reg("ax")), reg("ax"));
+            save(node.lhs().type(), reg("ax"), mem(reg("cx")));
         }
         return null;
     }
@@ -1339,70 +1113,6 @@ public class CodeGenerator
     }
     // #@@}
 
-    // #@@range/compileLHS{
-    protected void compileLHS(Node node) {
-        if (options.isVerboseAsm()) {
-            comment("compileLHS: " + node.getClass().getSimpleName() + " {");
-            as.indentComment();
-        }
-        node.acceptLHS(this);
-        if (options.isVerboseAsm()) {
-            as.unindentComment();
-            comment("compileLHS: }");
-        }
-    }
-    // #@@}
-
-    // #@@range/compileLHS_Variable{
-    public void visitLHS(VariableNode node) {
-        loadVariableAddress(node, reg("ax"));
-    }
-    // #@@}
-
-    // #@@range/compileLHS_Aref{
-    public void visitLHS(ArefNode node) {
-        compileArrayIndex(node);
-        imul(imm(node.elementSize()), reg("ax"));
-        push(reg("ax"));
-        compile(node.baseExpr());
-        pop(reg("cx"));
-        add(reg("cx"), reg("ax"));
-    }
-    // #@@}
-
-    // #@@range/compileArrayIndex{
-    protected void compileArrayIndex(ArefNode node) {
-        compile(node.index());
-        if (node.isMultiDimension()) {
-            push(reg("ax"));
-            compileArrayIndex((ArefNode)node.expr());
-            imul(imm(node.length()), reg("ax"));
-            pop(reg("cx"));
-            add(reg("cx"), reg("ax"));
-        }
-    }
-    // #@@}
-
-    // #@@range/compileLHS_Member{
-    public void visitLHS(MemberNode node) {
-        compileLHS(node.expr());
-        add(imm(node.offset()), reg("ax"));
-    }
-    // #@@}
-
-    // #@@range/compileLHS_Dereference{
-    public void visitLHS(DereferenceNode node) {
-        compile(node.expr());
-    }
-    // #@@}
-
-    // #@@range/compileLHS_PtrMember{
-    public void visitLHS(PtrMemberNode node) {
-        compile(node.expr());
-        add(imm(node.offset()), reg("ax"));
-    }
-    // #@@}
-
     //
     // Utilities
     //
diff --git a/net/loveruby/cflat/compiler/Compiler.java b/net/loveruby/cflat/compiler/Compiler.java
index e428bfc..3d616ae 100644
--- a/net/loveruby/cflat/compiler/Compiler.java
+++ b/net/loveruby/cflat/compiler/Compiler.java
@@ -114,7 +114,10 @@ public class Compiler {
                 return;
             }
             AST ir = new Simplifier(errorHandler).transform(ast);
-            new JumpResolver(errorHandler).resolve(ir);
+            if (opts.mode() == CompilerMode.DumpIR) {
+                ir.dump();
+                return;
+            }
             String asm = generateAssembly(ir, opts);
             if (opts.mode() == CompilerMode.DumpAsm) {
                 System.out.println(asm);
diff --git a/net/loveruby/cflat/compiler/CompilerMode.java b/net/loveruby/cflat/compiler/CompilerMode.java
index 8303598..cb49aae 100644
--- a/net/loveruby/cflat/compiler/CompilerMode.java
+++ b/net/loveruby/cflat/compiler/CompilerMode.java
@@ -10,6 +10,7 @@ enum CompilerMode {
     DumpStmt ("--dump-stmt"),
     DumpSemantic ("--dump-semantic"),
     DumpReference ("--dump-reference"),
+    DumpIR ("--dump-ir"),
     DumpAsm ("--dump-asm"),
     Compile ("-S"),
     Assemble ("-c"),
@@ -24,6 +25,7 @@ enum CompilerMode {
         modes.put("--dump-stmt", DumpStmt);
         modes.put("--dump-semantic", DumpSemantic);
         modes.put("--dump-reference", DumpReference);
+        modes.put("--dump-ir", DumpIR);
         modes.put("--dump-asm", DumpAsm);
         modes.put("-S", Compile);
         modes.put("-c", Assemble);
diff --git a/net/loveruby/cflat/compiler/JumpResolver.java b/net/loveruby/cflat/compiler/JumpResolver.java
deleted file mode 100644
index c3c675d..0000000
--- a/net/loveruby/cflat/compiler/JumpResolver.java
+++ /dev/null
@@ -1,133 +0,0 @@
-package net.loveruby.cflat.compiler;
-import net.loveruby.cflat.ast.*;
-import net.loveruby.cflat.asm.Label;
-import net.loveruby.cflat.exception.*;
-import java.util.*;
-
-public class JumpResolver extends Visitor {
-    // #@@range/ctor{
-    protected ErrorHandler errorHandler;
-    protected LinkedList<BreakableStmt> breakTargetStack;
-    protected LinkedList<ContinueableStmt> continueTargetStack;
-    protected DefinedFunction currentFunction;
-
-    public JumpResolver(ErrorHandler h) {
-        errorHandler = h;
-    }
-    // #@@}
-
-    // #@@range/resolve{
-    public void resolve(AST ast) throws SemanticException {
-        breakTargetStack = new LinkedList<BreakableStmt>();
-        continueTargetStack = new LinkedList<ContinueableStmt>();
-        for (DefinedFunction f : ast.definedFunctions()) {
-            currentFunction = f;
-            resolve(f.body());
-            f.checkJumpLinks(errorHandler);
-        }
-        if (errorHandler.errorOccured()) {
-            throw new SemanticException("compile failed.");
-        }
-    }
-    // #@@}
-
-    protected void resolve(StmtNode n) {
-        n.accept(this);
-    }
-
-    protected void resolve(ExprNode n) {
-        n.accept(this);
-    }
-
-    public Void visit(SwitchNode node) {
-        resolve(node.cond());
-        breakTargetStack.add(node);
-        visitStmts(node.cases());
-        breakTargetStack.removeLast();
-        return null;
-    }
-
-    // #@@range/_while{
-    public Void visit(WhileNode node) {
-        resolve(node.cond());
-        breakTargetStack.add(node);
-        continueTargetStack.add(node);
-        resolve(node.body());
-        continueTargetStack.removeLast();
-        breakTargetStack.removeLast();
-        return null;
-    }
-    // #@@}
-
-    public Void visit(DoWhileNode node) {
-        breakTargetStack.add(node);
-        continueTargetStack.add(node);
-        resolve(node.body());
-        continueTargetStack.removeLast();
-        breakTargetStack.removeLast();
-        resolve(node.cond());
-        return null;
-    }
-
-    // #@@range/_for{
-    public Void visit(ForNode node) {
-        resolve(node.init());
-        resolve(node.cond());
-        breakTargetStack.add(node);
-        continueTargetStack.add(node);
-        resolve(node.body());
-        resolve(node.incr());
-        continueTargetStack.removeLast();
-        breakTargetStack.removeLast();
-        return null;
-    }
-    // #@@}
-
-    // #@@range/_break{
-    public Void visit(BreakNode node) {
-        if (breakTargetStack.isEmpty()) {
-            errorHandler.error(node.location(),
-                    "break from out of while/do-while/for/switch");
-            return null;
-        }
-        BreakableStmt target = breakTargetStack.getLast();
-        node.setTargetLabel(target.endLabel());
-        return null;
-    }
-    // #@@}
-
-    // #@@range/_continue{
-    public Void visit(ContinueNode node) {
-        if (breakTargetStack.isEmpty()) {
-            errorHandler.error(node.location(),
-                        "continue from out of while/do-while/for");
-            return null;
-        }
-        ContinueableStmt target = continueTargetStack.getLast();
-        node.setTargetLabel(target.continueLabel());
-        return null;
-    }
-    // #@@}
-
-    public Void visit(LabelNode node) {
-        try {
-            Label label = currentFunction.defineLabel(node.name(),
-                                                      node.location());
-            node.setLabel(label);
-        }
-        catch (SemanticException ex) {
-            errorHandler.error(node.location(), ex.getMessage());
-        }
-        return null;
-    }
-
-    public Void visit(GotoNode node) {
-        node.setTargetLabel(currentFunction.referLabel(node.target()));
-        return null;
-    }
-
-    public Void visit(ReturnNode node) {
-        node.setFunction(currentFunction);
-        return null;
-    }
-}
diff --git a/net/loveruby/cflat/compiler/Options.java b/net/loveruby/cflat/compiler/Options.java
index 0a1f090..74aefe7 100644
--- a/net/loveruby/cflat/compiler/Options.java
+++ b/net/loveruby/cflat/compiler/Options.java
@@ -300,6 +300,7 @@ class Options {
         out.println("  --dump-ast       Dumps AST and quit.");
         out.println("  --dump-semantic  Dumps AST after semantic check and quit.");
         // --dump-reference is a hidden option.
+        out.println("  --dump-ir        Dumps IR and quit.");
         out.println("  --dump-asm       Prints an assembly source and quit.");
         out.println("  -S               Generates an assembly file and quit.");
         out.println("  -c               Generates an object file and quit.");
diff --git a/net/loveruby/cflat/compiler/Simplifier.java b/net/loveruby/cflat/compiler/Simplifier.java
index c12732f..6fbea01 100644
--- a/net/loveruby/cflat/compiler/Simplifier.java
+++ b/net/loveruby/cflat/compiler/Simplifier.java
@@ -1,12 +1,15 @@
 package net.loveruby.cflat.compiler;
 import net.loveruby.cflat.ast.*;
-import net.loveruby.cflat.type.*;
+import net.loveruby.cflat.type.Type;
+import net.loveruby.cflat.type.TypeRef;
+import net.loveruby.cflat.type.TypeTable;
+import net.loveruby.cflat.asm.Label;
 import net.loveruby.cflat.exception.*;
 import java.util.*;
 
-class Simplifier extends Visitor {
-    protected ErrorHandler errorHandler;
-    protected TypeTable typeTable;
+class Simplifier implements ASTVisitor<Void, ExprNode> {
+    private ErrorHandler errorHandler;
+    private TypeTable typeTable;
 
     // #@@range/ctor{
     public Simplifier(ErrorHandler errorHandler) {
@@ -14,14 +17,6 @@ class Simplifier extends Visitor {
     }
     // #@@}
 
-    protected void compile(StmtNode node) {
-        visitStmt(node);
-    }
-
-    protected void compile(ExprNode node) {
-        visitExpr(node);
-    }
-
     // #@@range/transform{
     public AST transform(AST ast) throws SemanticException {
         typeTable = ast.typeTable();
@@ -29,61 +24,675 @@ class Simplifier extends Visitor {
             visit(var);
         }
         for (DefinedFunction f : ast.definedFunctions()) {
-            compile(f.body());
+            visit(f);
         }
         if (errorHandler.errorOccured()) {
-            throw new SemanticException("IR generation failed.");
+            throw new SemanticException("Simplify failed.");
         }
         return ast;
     }
     // #@@}
 
-    public Void visit(OpAssignNode node) {
-        super.visit(node);
-        if (node.operator().equals("+") || node.operator().equals("-")) {
-            if (node.lhs().type().isDereferable()) {
-                node.setRHS(multiplyPtrBaseSize(node.rhs(), node.lhs()));
+    //
+    // Definitions
+    //
+
+    private List<StmtNode> stmts;
+    private LinkedList<Label> breakStack;
+    private LinkedList<Label> continueStack;
+    private Map<String, JumpEntry> jumpMap;
+
+    public Void visit(DefinedFunction f) {
+        stmts = new ArrayList<StmtNode>();
+        breakStack = new LinkedList<Label>();
+        continueStack = new LinkedList<Label>();
+        jumpMap = new HashMap<String, JumpEntry>();
+        transform(f.body());
+        checkJumpLinks(jumpMap);
+        f.setIR(stmts);
+        return null;
+    }
+
+    private int beforeStmt;
+    private int exprNestLevel = 0;
+
+    private void transform(StmtNode node) {
+        beforeStmt = stmts.size();
+        node.accept(this);
+    }
+
+    private ExprNode transform(ExprNode node) {
+        exprNestLevel++;
+        ExprNode e = node.accept(this);
+        exprNestLevel--;
+        return e;
+    }
+
+    private boolean isStatement() {
+        return (exprNestLevel <= 1);
+    }
+
+    // insert node before the current statement.
+    private void assignBeforeStmt(ExprNode lhs, ExprNode rhs) {
+        stmts.add(beforeStmt, new AssignStmtNode(lhs, rhs));
+        beforeStmt++;
+    }
+
+    private void addExprStmt(ExprNode expr) {
+        ExprNode n = transform(expr);
+        if (n != null) {
+            stmts.add(new ExprStmtNode(expr.location(), n));
+        }
+    }
+
+    private void label(Label id) {
+        stmts.add(new LabelNode(id));
+    }
+
+    private void jump(Label target) {
+        stmts.add(new GotoNode(target));
+    }
+
+    private void pushBreak(Label label) {
+        breakStack.add(label);
+    }
+
+    private void popBreak() {
+        if (breakStack.isEmpty()) {
+            throw new Error("unmatched push/pop for break stack");
+        }
+        breakStack.removeLast();
+    }
+
+    private Label currentBreakTarget() {
+        if (breakStack.isEmpty()) {
+            throw new JumpError("break from out of loop");
+        }
+        return breakStack.getLast();
+    }
+
+    private void pushContinue(Label label) {
+        continueStack.add(label);
+    }
+
+    private void popContinue() {
+        if (continueStack.isEmpty()) {
+            throw new Error("unmatched push/pop for continue stack");
+        }
+        continueStack.removeLast();
+    }
+
+    private Label currentContinueTarget() {
+        if (continueStack.isEmpty()) {
+            throw new JumpError("continue from out of loop");
+        }
+        return continueStack.getLast();
+    }
+
+    //
+    // Statements
+    //
+
+    public Void visit(BlockNode node) {
+        for (DefinedVariable var : node.variables()) {
+            if (var.initializer() != null) {
+                addExprStmt(var.initializer());
             }
         }
+        for (StmtNode s : node.stmts()) {
+            transform(s);
+        }
         return null;
     }
 
-    // #@@range/BinaryOpNode{
-    public Void visit(BinaryOpNode node) {
-        super.visit(node);
-        if (node.operator().equals("+") || node.operator().equals("-")) {
-            if (node.left().type().isDereferable()) {
-                node.setRight(multiplyPtrBaseSize(node.right(), node.left()));
-            }
-            else if (node.right().type().isDereferable()) {
-                node.setLeft(multiplyPtrBaseSize(node.left(), node.right()));
-            }
+    public Void visit(ExprStmtNode node) {
+        addExprStmt(node.expr());
+        return null;
+    }
+
+    public Void visit(IfNode node) {
+        Label thenLabel = new Label();
+        Label elseLabel = new Label();
+        Label endLabel = new Label();
+        branch(transform(node.cond()),
+                thenLabel,
+                node.elseBody() == null ? endLabel : elseLabel);
+        label(thenLabel);
+        transform(node.thenBody());
+        jump(endLabel);
+        if (node.elseBody() != null) {
+            label(elseLabel);
+            transform(node.elseBody());
+            jump(endLabel);
+        }
+        label(endLabel);
+        return null;
+    }
+
+    public Void visit(SwitchNode node) {
+        stmts.add(node);
+        node.setCond(transform(node.cond()));
+        for (CaseNode c : node.cases()) {
+            label(c.beginLabel());
+            transform(c.body());
+            jump(node.endLabel());
         }
         return null;
     }
+
+    public Void visit(CaseNode node) {
+        throw new Error("must not happen");
+    }
+
+    public Void visit(WhileNode node) {
+        Label begLabel = new Label();
+        Label bodyLabel = new Label();
+        Label endLabel = new Label();
+        label(begLabel);
+        branch(transform(node.cond()), bodyLabel, endLabel);
+        label(bodyLabel);
+        pushContinue(begLabel);
+        pushBreak(endLabel);
+        transform(node.body());
+        popBreak();
+        popContinue();
+        label(endLabel);
+        return null;
+    }
+
+    public Void visit(DoWhileNode node) {
+        Label begLabel = new Label();
+        Label contLabel = new Label();  // before cond (end of body)
+        Label endLabel = new Label();
+
+        pushContinue(contLabel);
+        pushBreak(endLabel);
+        label(begLabel);
+        transform(node.body());
+        popBreak();
+        popContinue();
+        label(contLabel);
+        branch(transform(node.cond()), begLabel, endLabel);
+        label(endLabel);
+        return null;
+    }
+
+    public Void visit(ForNode node) {
+        Label begLabel = new Label();
+        Label bodyLabel = new Label();
+        Label contLabel = new Label();
+        Label endLabel = new Label();
+
+        transform(node.init());
+        label(begLabel);
+        branch(transform(node.cond()), bodyLabel, endLabel);
+        label(bodyLabel);
+        pushContinue(contLabel);
+        pushBreak(endLabel);
+        transform(node.body());
+        popBreak();
+        popContinue();
+        label(contLabel);
+        transform(node.incr());
+        jump(begLabel);
+        label(endLabel);
+        return null;
+    }
+
+    public Void visit(BreakNode node) {
+        try {
+            jump(currentBreakTarget());
+        }
+        catch (JumpError err) {
+            error(node, err.getMessage());
+        }
+        return null;
+    }
+
+    public Void visit(ContinueNode node) {
+        try {
+            jump(currentContinueTarget());
+        }
+        catch (JumpError err) {
+            error(node, err.getMessage());
+        }
+        return null;
+    }
+
+    public Void visit(LabelNode node) {
+        try {
+            label(defineLabel(node.name(), node.location()));
+            if (node.stmt() != null) {
+                transform(node.stmt());
+            }
+        }
+        catch (SemanticException ex) {
+            error(node, ex.getMessage());
+        }
+        return null;
+    }
+
+    public Void visit(GotoNode node) {
+        jump(referLabel(node.target()));
+        return null;
+    }
+
+    public Void visit(ReturnNode node) {
+        node.setExpr(transform(node.expr()));
+        stmts.add(node);
+        return null;
+    }
+
+    private void branch(ExprNode cond, Label thenLabel, Label elseLabel) {
+        stmts.add(new BranchIfNode(cond.location(),
+                cond, thenLabel, elseLabel));
+    }
+
+    private void assign(ExprNode lhs, ExprNode rhs) {
+        stmts.add(new AssignStmtNode(lhs, rhs));
+    }
+
+    private DefinedVariable tmpVar(Type t) {
+        // FIXME: allocate in scope??
+        return DefinedVariable.tmp(t);
+    }
+
+    class JumpEntry {
+        public Label label;
+        public long numRefered;
+        public boolean isDefined;
+        public Location location;
+
+        public JumpEntry(Label label) {
+            this.label = label;
+            numRefered = 0;
+            isDefined = false;
+        }
+    }
+
+    private Label defineLabel(String name, Location loc)
+                                    throws SemanticException {
+        JumpEntry ent = getJumpEntry(name);
+        if (ent.isDefined) {
+            throw new SemanticException(
+                "duplicated jump labels in " + name + "(): " + name);
+        }
+        ent.isDefined = true;
+        ent.location = loc;
+        return ent.label;
+    }
+
+    private Label referLabel(String name) {
+        JumpEntry ent = getJumpEntry(name);
+        ent.numRefered++;
+        return ent.label;
+    }
+
+    private JumpEntry getJumpEntry(String name) {
+        JumpEntry ent = jumpMap.get(name);
+        if (ent == null) {
+            ent = new JumpEntry(new Label());
+            jumpMap.put(name, ent);
+        }
+        return ent;
+    }
+
+    private void checkJumpLinks(Map<String, JumpEntry> jumpMap) {
+        for (Map.Entry<String, JumpEntry> ent : jumpMap.entrySet()) {
+            String labelName = ent.getKey();
+            JumpEntry jump = ent.getValue();
+            if (!jump.isDefined) {
+                errorHandler.error(jump.location,
+                        "undefined label: " + labelName);
+            }
+            if (jump.numRefered == 0) {
+                errorHandler.warn(jump.location,
+                        "useless label: " + labelName);
+            }
+        }
+    }
+
+    //
+    // Expressions (with side effects)
+    //
+
+    public ExprNode visit(CondExprNode node) {
+        Label thenLabel = new Label();
+        Label elseLabel = new Label();
+        Label endLabel = new Label();
+        DefinedVariable var = tmpVar(node.type());
+
+        ExprNode cond = transform(node.cond());
+        branch(cond, thenLabel, elseLabel);
+        label(thenLabel);
+        assign(ref(var), transform(node.thenExpr()));
+        jump(endLabel);
+        label(elseLabel);
+        assign(ref(var), transform(node.elseExpr()));
+        jump(endLabel);
+        label(endLabel);
+        return ref(var);
+    }
+
+    public ExprNode visit(LogicalAndNode node) {
+        Label rightLabel = new Label();
+        Label endLabel = new Label();
+        DefinedVariable var = tmpVar(node.type());
+
+        assign(ref(var), transform(node.left()));
+        branch(ref(var), rightLabel, endLabel);
+        label(rightLabel);
+        assign(ref(var), transform(node.right()));
+        label(endLabel);
+        return ref(var);
+    }
+
+    public ExprNode visit(LogicalOrNode node) {
+        Label rightLabel = new Label();
+        Label endLabel = new Label();
+        DefinedVariable var = tmpVar(node.type());
+
+        assign(ref(var), transform(node.left()));
+        branch(ref(var), endLabel, rightLabel);
+        label(rightLabel);
+        assign(ref(var), transform(node.right()));
+        label(endLabel);
+        return ref(var);
+    }
+
+    public ExprNode visit(AssignNode node) {
+        if (isStatement()) {
+            assign(transform(node.lhs()), transform(node.rhs()));
+            return null;
+        }
+        else {
+            DefinedVariable tmp = tmpVar(node.rhs().type());
+            assignBeforeStmt(ref(tmp), transform(node.rhs()));
+            assignBeforeStmt(transform(node.lhs()), ref(tmp));
+            return ref(tmp);
+        }
+    }
+
+    public ExprNode visit(OpAssignNode node) {
+        // evaluate rhs before lhs.
+        ExprNode rhs = transform(node.rhs());
+        ExprNode lhs = transform(node.lhs());
+        return transformOpAssign(lhs, node.operator(), rhs);
+    }
+
+    private ExprNode transformOpAssign(ExprNode lhs, String op, ExprNode rhs) {
+        rhs = expandPointerArithmetic(rhs, op, lhs);
+        if (isStatement()) {
+            assignBeforeStmt(lhs, rhs);
+            return null;
+        }
+        else {
+            DefinedVariable tmp = tmpVar(rhs.type());
+            assignBeforeStmt(ref(tmp), rhs);
+            return ref(tmp);
+        }
+    }
+
+    private ExprNode expandPointerArithmetic(ExprNode rhs, String op, ExprNode lhs) {
+        if ((op.equals("+") || op.equals("-")) && lhs.type().isDereferable()) {
+            return multiplyPtrBaseSize(rhs, lhs);
+        }
+        else {
+            return rhs;
+        }
+    }
+
+    // transform node into: lhs += 1 or lhs -= 1
+    public ExprNode visit(PrefixOpNode node) {
+        return transformOpAssign(transform(node.expr()),
+                binOp(node.operator()),
+                intValue(1));
+    }
+
+    public ExprNode visit(SuffixOpNode node) {
+        if (isStatement()) {
+            return transformOpAssign(transform(node.expr()),
+                    binOp(node.operator()),
+                    intValue(1));
+        }
+        else {
+            // f(expr++) -> a = &expr, *a += 1, f(*a - 1)
+            // f(expr--) -> a = &expr, *a -= 1, f(*a + 1)
+            ExprNode addr = addressOf(transform(node.expr()));
+            DefinedVariable tmp = tmpVar(addr.type());
+            String op = binOp(node.operator());
+            assignBeforeStmt(ref(tmp), addr);
+            ExprNode lhs = transformOpAssign(ref(tmp), op, intValue(1));
+            ExprNode rhs = expandPointerArithmetic(intValue(1), op, lhs);
+            return binaryOp(lhs, invert(op), rhs);
+        }
+    }
+
+    public ExprNode visit(FuncallNode node) {
+        List<ExprNode> newArgs = new ArrayList<ExprNode>();
+        ListIterator<ExprNode> args = node.finalArg();
+        while (args.hasPrevious()) {
+            newArgs.add(0, transform(args.previous()));
+        }
+        node.setExpr(transform(node.expr()));
+        node.replaceArgs(newArgs);
+        return node;
+    }
+
+    //
+    // Expressions (no side effects)
+    //
+
+    // #@@range/BinaryOpNode{
+    public ExprNode visit(BinaryOpNode node) {
+        ExprNode left = transform(node.left());
+        ExprNode right = transform(node.right());
+        if (node.operator().equals("+") || node.operator().equals("-")) {
+            if (left.type().isDereferable()) {
+                right = multiplyPtrBaseSize(right, left);
+            }
+            else if (right.type().isDereferable()) {
+                left = multiplyPtrBaseSize(left, right);
+            }
+        }
+        node.setLeft(left);
+        node.setRight(right);
+        return node;
+    }
     // #@@}
 
-    protected BinaryOpNode multiplyPtrBaseSize(ExprNode expr, ExprNode ptr) {
-        return new BinaryOpNode(expr, "*", ptrBaseSize(ptr));
+    private BinaryOpNode multiplyPtrBaseSize(ExprNode expr, ExprNode ptr) {
+        return binaryOp(expr, "*", ptrBaseSize(ptr));
     }
 
-    protected IntegerLiteralNode ptrBaseSize(ExprNode ptr) {
-        return integerLiteral(ptr.location(),
-                              typeTable.ptrDiffTypeRef(),
-                              ptr.type().baseType().size());
+    private IntegerLiteralNode ptrBaseSize(ExprNode ptr) {
+        return ptrDiff(ptr.type().baseType().size(), ptr.location());
     }
 
-    protected IntegerLiteralNode integerLiteral(Location loc, TypeRef ref, long n) {
+    public ExprNode visit(UnaryOpNode node) {
+        if (node.operator().equals("+")) {
+            // +expr -> expr
+            return transform(node.expr());
+        }
+        else {
+            node.setExpr(transform(node.expr()));
+            return node;
+        }
+    }
+
+    public ExprNode visit(ArefNode node) {
+        ExprNode offset = binaryOp(intValue(node.elementSize()),
+                            "*", transformArrayIndex(node));
+        return binaryOp(transform(node.baseExpr()), "+", offset);
+    }
+
+    // For multidimension array: t[e][d][c][b][a];
+    // &a[a0][b0][c0][d0][e0]
+    //     = &a + edcb*a0 + edc*b0 + ed*c0 + e*d0 + e0
+    //     = &a + (((((a0)*b + b0)*c + c0)*d + d0)*e + e0) * sizeof(t)
+    //
+    // #@@range/transformArrayIndex{
+    private ExprNode transformArrayIndex(ArefNode node) {
+        if (node.isMultiDimension()) {
+            return binaryOp(transform(node.index()),
+                    "+", binaryOp(intValue(node.length()),
+                            "*", transformArrayIndex((ArefNode)node.expr())));
+        }
+        else {
+            return transform(node.index());
+        }
+    }
+    // #@@}
+
+    public ExprNode visit(MemberNode node) {
+        ExprNode addr = binaryOp(addressOf(transform(node.expr())),
+                                "+", intValue(node.offset()));
+        return node.shouldEvaluatedToAddress() ? addr : deref(addr);
+    }
+
+    public ExprNode visit(PtrMemberNode node) {
+        ExprNode addr = binaryOp(transform(node.expr()),
+                                "+", intValue(node.offset()));
+        return node.shouldEvaluatedToAddress() ? addr : deref(addr);
+    }
+
+    public ExprNode visit(DereferenceNode node) {
+        node.setExpr(node.expr());
+        return node;
+    }
+
+    public ExprNode visit(AddressNode node) {
+        node.setExpr(node.expr());
+        return node;
+    }
+
+    public ExprNode visit(CastNode node) {
+        return new CastNode(node.typeNode(), transform(node.expr()));
+    }
+
+    public ExprNode visit(SizeofExprNode node) {
+        return intValue(node.expr().type().allocSize());
+    }
+
+    public ExprNode visit(SizeofTypeNode node) {
+        return intValue(node.operand().allocSize());
+    }
+
+    public ExprNode visit(VariableNode node) {
+        if (node.shouldEvaluatedToAddress()) {
+            return addressOf(node);
+        }
+        else {
+            return node;
+        }
+    }
+
+    public ExprNode visit(IntegerLiteralNode node) {
+        return node;
+    }
+
+    public ExprNode visit(StringLiteralNode node) {
+        return node;
+    }
+
+    //
+    // Utilities
+    //
+
+    // unary ops -> binary ops
+    private String binOp(String uniOp) {
+        return uniOp.equals("++") ? "+" : "-";
+    }
+
+    // invert binary ops
+    private String invert(String op) {
+        return op.equals("+") ? "-" : "+";
+    }
+
+    // add AddressNode on top of the expr.
+    private ExprNode addressOf(ExprNode expr) {
+        if (expr instanceof AddressNode) {
+            return ((AddressNode)expr).expr();
+        }
+        else {
+            return new AddressNode(expr);
+        }
+    }
+
+    private VariableNode ref(DefinedVariable var) {
+        return new VariableNode(var);
+    }
+
+    // add DereferenceNode on top of the expr.
+    private DereferenceNode deref(ExprNode expr) {
+        return new DereferenceNode(expr);
+    }
+
+    // add DereferenceNode on top of the var.
+    private DereferenceNode deref(DefinedVariable var) {
+        return new DereferenceNode(new VariableNode(var));
+    }
+
+    private BinaryOpNode binaryOp(ExprNode left, String op, ExprNode right) {
+        return new BinaryOpNode(left, op, right);
+    }
+
+    private IntegerLiteralNode intValue(long n) {
+        // FIXME?: location
+        return ptrDiff(n, null);
+    }
+
+    private IntegerLiteralNode ptrDiff(long n, Location loc) {
+        return integerLiteral(loc, typeTable.ptrDiffTypeRef(), n);
+    }
+
+    private IntegerLiteralNode integerLiteral(Location loc, TypeRef ref, long n) {
         IntegerLiteralNode node = new IntegerLiteralNode(loc, ref, n);
         bindType(node.typeNode());
         return node;
     }
 
-    protected void bindType(TypeNode t) {
+    private void bindType(TypeNode t) {
         t.setType(typeTable.get(t.typeRef()));
     }
 
-    protected void error(Node n, String msg) {
+    private void error(Node n, String msg) {
         errorHandler.error(n.location(), msg);
     }
+
+    //
+    // must not reached
+    //
+
+    public Void visit(UndefinedFunction func) {
+        throw new Error("must not happen");
+    }
+
+    public Void visit(DefinedVariable var) {
+        throw new Error("must not happen");
+    }
+
+    public Void visit(UndefinedVariable func) {
+        throw new Error("must not happen");
+    }
+
+    public Void visit(StructNode struct) {
+        throw new Error("must not happen");
+    }
+
+    public Void visit(UnionNode union) {
+        throw new Error("must not happen");
+    }
+
+    public Void visit(TypedefNode typedef) {
+        throw new Error("must not happen");
+    }
+
+    public Void visit(AssignStmtNode node) {
+        throw new Error("must not happen");
+    }
+
+    public Void visit(BranchIfNode node) {
+        throw new Error("must not happen");
+    }
 }
diff --git a/net/loveruby/cflat/compiler/Visitor.java b/net/loveruby/cflat/compiler/Visitor.java
index d1f923d..f782c5d 100644
--- a/net/loveruby/cflat/compiler/Visitor.java
+++ b/net/loveruby/cflat/compiler/Visitor.java
@@ -259,4 +259,16 @@ abstract public class Visitor implements ASTVisitor<Void, Void> {
     public Void visit(StringLiteralNode node) {
         return null;
     }
+
+    //
+    // IR tree
+    //
+
+    public Void visit(AssignStmtNode n) {
+        throw new Error("must not happen");
+    }
+
+    public Void visit(BranchIfNode n) {
+        throw new Error("must not happen");
+    }
 }
diff --git a/net/loveruby/cflat/exception/JumpError.java b/net/loveruby/cflat/exception/JumpError.java
new file mode 100644
index 0000000..9efd28e
--- /dev/null
+++ b/net/loveruby/cflat/exception/JumpError.java
@@ -0,0 +1,7 @@
+package net.loveruby.cflat.exception;
+
+public class JumpError extends SemanticError {
+    public JumpError(String msg) {
+        super(msg);
+    }
+}