diff --git a/ChangeLog b/ChangeLog
index 1a11cc4..52aae8b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+Sun Sep  7 00:58:49 2008  Minero Aoki  <aamine@loveruby.net>
+
+	* net/loveruby/cflat/compiler/CodeGenerator.java: implement cast.
+
+	* net/loveruby/cflat/asm/Assembler.java: new method #movsx,
+	  #movzx.
+
+	* net/loveruby/cflat/type/PointerType.java: provide #isSigned for
+	  cast.
+
+	* net/loveruby/cflat/type/ArrayType.java: ditto.
+
+	* net/loveruby/cflat/type/UserType.java: ditto.
+
+	* test: test cast operation.
+
 Sat Sep  6 23:19:48 2008  Minero Aoki  <aamine@loveruby.net>
 
 	* net/loveruby/cflat/ast/Entity.java (alignment): fetch value from
diff --git a/ToDo b/ToDo
index c20705b..be76962 100644
--- a/ToDo
+++ b/ToDo
@@ -2,7 +2,7 @@
 
 == Current
 
-* remove FIXME from Entity.java
+* use %rax for address calculation
 * prohibit multi-dimension array without size
 * dump UTF-8 string byte by byte.
 * simple vararg retrieve (get vararg address)
@@ -210,3 +210,5 @@
 - duplicated import did not propagate symbols
 - test if static function is really static
 - test switch stmt
+- remove FIXME from Entity.java
+- implement cast
diff --git a/net/loveruby/cflat/asm/Assembler.java b/net/loveruby/cflat/asm/Assembler.java
index 6789af9..1c9012f 100644
--- a/net/loveruby/cflat/asm/Assembler.java
+++ b/net/loveruby/cflat/asm/Assembler.java
@@ -163,10 +163,14 @@ public class Assembler {
     }
 
     protected String addSuffix(String op, Type t) {
+        return op + typeSuffix(t);
+    }
+
+    protected String typeSuffix(Type t) {
         switch ((int)t.size()) {
-        case 1: return op + "b";
-        case 2: return op + "w";
-        case 4: return op + "l";
+        case 1: return "b";
+        case 2: return "w";
+        case 4: return "l";
         default:
             throw new Error("unknown type size: " + t.size());
         }
@@ -258,6 +262,10 @@ public class Assembler {
         typedOp(type, "mov", src, dest);
     }
 
+    public void movsx(Type from, Type to, AsmEntity src, AsmEntity dest) {
+        op("movs" + typeSuffix(from) + typeSuffix(to), src, dest);
+    }
+
     public void movsbl(AsmEntity src, AsmEntity dest) {
         op("movsbl", src, dest);
     }
@@ -266,6 +274,10 @@ public class Assembler {
         op("movswl", src, dest);
     }
 
+    public void movzx(Type from, Type to, AsmEntity src, AsmEntity dest) {
+        op("movz" + typeSuffix(from) + typeSuffix(to), src, dest);
+    }
+
     public void movzb(Type type, AsmEntity src, AsmEntity dest) {
         typedOp(type, "movzb", src, dest);
     }
diff --git a/net/loveruby/cflat/compiler/CodeGenerator.java b/net/loveruby/cflat/compiler/CodeGenerator.java
index 25a8436..0856073 100644
--- a/net/loveruby/cflat/compiler/CodeGenerator.java
+++ b/net/loveruby/cflat/compiler/CodeGenerator.java
@@ -688,8 +688,21 @@ static public void p(String s) { System.err.println(s); }
     }
 
     public void visit(CastNode node) {
-        // FIXME: insert cast op here
         compile(node.expr());
+        Type src = node.expr().type();
+        Type dest = node.type();
+        // We need not execute downcast because we can cast big value
+        // to small value by just cutting off higer bits.
+        if (dest.size() > src.size()) {
+            if (src.isSigned()) {
+                movsx(src, dest,
+                      reg("ax").forType(src), reg("ax").forType(dest));
+            }
+            else {
+                movzx(src, dest,
+                      reg("ax").forType(src), reg("ax").forType(dest));
+            }
+        }
     }
 
     public void visit(VariableNode node) {
@@ -933,6 +946,8 @@ comment("compileLHS: }");
     public void ret() { as.ret(); }
     public void mov(AsmEntity src, AsmEntity dest) { as.mov(src, dest); }
     public void mov(Type type, AsmEntity src, AsmEntity dest) { as.mov(type, src, dest); }
+    public void movsx(Type from, Type to, AsmEntity src, AsmEntity dest) { as.movsx(from, to, src, dest); }
+    public void movzx(Type from, Type to, AsmEntity src, AsmEntity dest) { as.movzx(from, to, src, dest); }
     public void movsbl(AsmEntity src, AsmEntity dest) { as.movsbl(src, dest); }
     public void movswl(AsmEntity src, AsmEntity dest) { as.movswl(src, dest); }
     public void movzb(Type type, AsmEntity src, AsmEntity dest) { as.movzb(type, src, dest); }
diff --git a/net/loveruby/cflat/type/ArrayType.java b/net/loveruby/cflat/type/ArrayType.java
index 0dd5690..6dde6eb 100644
--- a/net/loveruby/cflat/type/ArrayType.java
+++ b/net/loveruby/cflat/type/ArrayType.java
@@ -23,6 +23,7 @@ public class ArrayType extends Type {
     public boolean isDereferable() { return true; }
     public boolean isPointerAlike() { return isUnallocatedArray(); }
     public boolean isScalar() { return true; }
+    public boolean isSigned() { return false; }
 
     public Type baseType() {
         return baseType;
diff --git a/net/loveruby/cflat/type/PointerType.java b/net/loveruby/cflat/type/PointerType.java
index 204b4a5..10ed326 100644
--- a/net/loveruby/cflat/type/PointerType.java
+++ b/net/loveruby/cflat/type/PointerType.java
@@ -12,6 +12,7 @@ public class PointerType extends Type {
     public boolean isPointer() { return true; }
     public boolean isPointerAlike() { return true; }
     public boolean isScalar() { return true; }
+    public boolean isSigned() { return false; }
     public boolean isDereferable() { return true; }
     public boolean isCallable() { return baseType.isFunction(); }
 
diff --git a/net/loveruby/cflat/type/Type.java b/net/loveruby/cflat/type/Type.java
index 6145a39..246ad5a 100644
--- a/net/loveruby/cflat/type/Type.java
+++ b/net/loveruby/cflat/type/Type.java
@@ -4,13 +4,13 @@ import net.loveruby.cflat.exception.*;
 public abstract class Type {
     static final public long sizeUnknown = -1;
 
+    abstract public long size();
+    public long allocSize() { return size(); }
+
     public long alignment() {
         return size();
     }
 
-    abstract public long size();
-    public long allocSize() { return size(); }
-
     abstract public boolean isSameType(Type other);
 
     public boolean isVoid() { return false; }
@@ -22,9 +22,9 @@ public abstract class Type {
     public boolean isArray() { return false; }
     public boolean isAllocatedArray() { return false; }
     public boolean isUnallocatedArray() { return false; }
+    public boolean isComplexType() { return false; }
     public boolean isStruct() { return false; }
     public boolean isUnion() { return false; }
-    public boolean isComplexType() { return false; }
     public boolean isUserType() { return false; }
     public boolean isFunction() { return false; }
 
diff --git a/net/loveruby/cflat/type/UserType.java b/net/loveruby/cflat/type/UserType.java
index 20f29f1..0219af5 100644
--- a/net/loveruby/cflat/type/UserType.java
+++ b/net/loveruby/cflat/type/UserType.java
@@ -22,13 +22,18 @@ public class UserType extends NamedType {
     // Forward methods to real type.
     //
 
-    public long alignment() { return realType().alignment(); }
     public long size() { return realType().size(); }
+    public long allocSize() { return realType().allocSize(); }
+    public long alignment() { return realType().alignment(); }
 
+    public boolean isVoid() { return realType().isVoid(); }
     public boolean isInt() { return realType().isInt(); }
     public boolean isInteger() { return realType().isInteger(); }
+    public boolean isSigned() { return realType().isSigned(); }
     public boolean isPointer() { return realType().isPointer(); }
     public boolean isArray() { return realType().isArray(); }
+    public boolean isAllocatedArray() { return realType().isAllocatedArray(); }
+    public boolean isUnallocatedArray() { return realType().isUnallocatedArray(); }
     public boolean isComplexType() { return realType().isComplexType(); }
     public boolean isStruct() { return realType().isStruct(); }
     public boolean isUnion() { return realType().isUnion(); }
@@ -36,7 +41,9 @@ public class UserType extends NamedType {
     public boolean isFunction() { return realType().isFunction(); }
 
     public boolean isDereferable() { return realType().isDereferable(); }
+    public boolean isPointerAlike() { return realType().isPointerAlike(); }
     public boolean isCallable() { return realType().isCallable(); }
+    public boolean isScalar() { return realType().isScalar(); }
 
     public Type baseType() { return realType().baseType(); }
 
diff --git a/test/cast.cb b/test/cast.cb
index 3e6d962..cf94cc3 100644
--- a/test/cast.cb
+++ b/test/cast.cb
@@ -4,6 +4,21 @@ int
 main(int argc, char **argv)
 {
     short n = 5000;
-    printf("%ld\n", (long)((long)n * (long)n));
+    char a = 1;
+    char b = -1;
+    short c = 1;
+    short d = -1;
+
+    printf("%ld", ((long)n * (long)n));
+    printf(";%d", (int)a);
+    printf(";%ld", (long)a);
+    printf(";%d", (int)b);
+    printf(";%ld", (long)b);
+    printf(";%d", (int)c);
+    printf(";%ld", (long)c);
+    printf(";%d", (int)d);
+    printf(";%ld", (long)d);
+
+    puts("");
     return 0;
 }
diff --git a/test/charops2.cb b/test/charops2.cb
new file mode 100644
index 0000000..9812afe
--- /dev/null
+++ b/test/charops2.cb
@@ -0,0 +1,18 @@
+import stdio;
+
+int
+main(int argc, char **argv)
+{
+    char i = -1;
+    
+    i <<= 1;
+    printf("%hhd", i);
+    i <<= 5;
+    printf(";%hhd", i);
+    i <<= 1;
+    printf(";%hhd", i);
+    i <<= 1;
+    printf(";%hhd", i);
+    puts("");
+    return 0;
+}
diff --git a/test/shortops.cb b/test/shortops.cb
index bb28d9a..6a5ed1d 100644
--- a/test/shortops.cb
+++ b/test/shortops.cb
@@ -7,7 +7,7 @@ main(int argc, char **argv)
     
     i <<= 1;
     printf("%hd", i);
-    i <<= (short)13;
+    i <<= 13;
     printf(";%hd", i);
     i <<= 1;
     printf(";%hd", i);
diff --git a/test/shortops2.cb b/test/shortops2.cb
new file mode 100644
index 0000000..ad1298b
--- /dev/null
+++ b/test/shortops2.cb
@@ -0,0 +1,18 @@
+import stdio;
+
+int
+main(int argc, char **argv)
+{
+    short i = -1;
+    
+    i <<= 1;
+    printf("%hd", i);
+    i <<= 13;
+    printf(";%hd", i);
+    i <<= 1;
+    printf(";%hd", i);
+    i <<= 1;
+    printf(";%hd", i);
+    puts("");
+    return 0;
+}
diff --git a/test/test_cbc.sh b/test/test_cbc.sh
index 4da43b3..43ae2da 100644
--- a/test/test_cbc.sh
+++ b/test/test_cbc.sh
@@ -196,9 +196,13 @@ test_22_pointer() {
 
 test_23_limits() {
     assert_out "2;64;-128;0" ./charops
+    assert_out "-2;-64;-128;0" ./charops2
     assert_out "2;64;128;0" ./ucharops
+    assert_out "254;192;128;0" ./ucharops2
     assert_out "2;16384;-32768;0" ./shortops
+    assert_out "-2;-16384;-32768;0" ./shortops2
     assert_out "2;16384;32768;0" ./ushortops
+    assert_out "65534;49152;32768;0" ./ushortops2
     assert_out "2;1073741824;-2147483648;0" ./intops
     assert_out "2;1073741824;2147483648;0" ./uintops
     assert_out "1;2;1073741824;-2147483648;0" ./longops  # 32bit
@@ -206,7 +210,7 @@ test_23_limits() {
 }
 
 test_24_cast() {
-    assert_out "25000000" ./cast
+    assert_out "25000000;1;1;-1;-1;1;1;-1;-1" ./cast
     assert_out "777;666" ./cast2
 }
 
diff --git a/test/ucharops2.cb b/test/ucharops2.cb
new file mode 100644
index 0000000..5085384
--- /dev/null
+++ b/test/ucharops2.cb
@@ -0,0 +1,18 @@
+import stdio;
+
+int
+main(int argc, char **argv)
+{
+    unsigned char i = -1;
+    
+    i <<= 1;
+    printf("%hhu", i);
+    i <<= 5;
+    printf(";%hhu", i);
+    i <<= 1;
+    printf(";%hhu", i);
+    i <<= 1;
+    printf(";%hhu", i);
+    puts("");
+    return 0;
+}
diff --git a/test/ushortops2.cb b/test/ushortops2.cb
new file mode 100644
index 0000000..1d0b6b3
--- /dev/null
+++ b/test/ushortops2.cb
@@ -0,0 +1,18 @@
+import stdio;
+
+int
+main(int argc, char **argv)
+{
+    unsigned short i = -1;
+    
+    i <<= 1;
+    printf("%hu", i);
+    i <<= 13;
+    printf(";%hu", i);
+    i <<= 1;
+    printf(";%hu", i);
+    i <<= 1;
+    printf(";%hu", i);
+    puts("");
+    return 0;
+}