From f13e0741a0b3af0f83f900be6500c244df9f1110 Mon Sep 17 00:00:00 2001
From: "rogerl%netscape.com" <rogerl%netscape.com>
Date: Thu, 1 Feb 2001 00:59:21 +0000
Subject: [PATCH] Changed Cast to take a JSValue containing a type instead of
 type directly. Added LoadType to help support that. Also added LoadNull.

---
 js/js2/icode.h             | 28 +++++++++---
 js/js2/icodegenerator.cpp  | 20 ++++++++-
 js/js2/icodegenerator.h    |  2 +
 js/js2/icodemap.h          | 88 ++++++++++++++++++++------------------
 js/js2/interpreter.cpp     | 22 +++++-----
 js/js2/tools/jsicodes.pm   |  8 +++-
 js2/src/icode.h            | 28 +++++++++---
 js2/src/icodegenerator.cpp | 20 ++++++++-
 js2/src/icodegenerator.h   |  2 +
 js2/src/icodemap.h         | 88 ++++++++++++++++++++------------------
 js2/src/interpreter.cpp    | 22 +++++-----
 js2/tools/jsicodes.pm      |  8 +++-
 12 files changed, 218 insertions(+), 118 deletions(-)

diff --git a/js/js2/icode.h b/js/js2/icode.h
index 962bd0ee0d25..d399b7b81242 100644
--- a/js/js2/icode.h
+++ b/js/js2/icode.h
@@ -41,6 +41,7 @@
         LOAD_NULL, /* dest */
         LOAD_STRING, /* dest, immediate value (string) */
         LOAD_TRUE, /* dest */
+        LOAD_TYPE, /* dest, type */
         MOVE, /* dest, source */
         MULTIPLY, /* dest, source1, source2 */
         NAME_XCR, /* dest, name, value */
@@ -191,18 +192,18 @@
         }
     };
 
-    class Cast : public Instruction_3<TypedRegister, TypedRegister, JSType*> {
+    class Cast : public Instruction_3<TypedRegister, TypedRegister, TypedRegister> {
     public:
         /* dest, rvalue, toType */
-        Cast (TypedRegister aOp1, TypedRegister aOp2, JSType* aOp3) :
-            Instruction_3<TypedRegister, TypedRegister, JSType*>
+        Cast (TypedRegister aOp1, TypedRegister aOp2, TypedRegister aOp3) :
+            Instruction_3<TypedRegister, TypedRegister, TypedRegister>
             (CAST, aOp1, aOp2, aOp3) {};
         virtual Formatter& print(Formatter& f) {
-            f << opcodeNames[CAST] << "\t" << mOp1 << ", " << mOp2 << ", " << "'" << mOp3->getName() << "'";
+            f << opcodeNames[CAST] << "\t" << mOp1 << ", " << mOp2 << ", " << mOp3;
             return f;
         }
         virtual Formatter& printOperands(Formatter& f, const JSValues& registers) {
-            f << getRegisterValue(registers, mOp1.first) << ", " << getRegisterValue(registers, mOp2.first);
+            f << getRegisterValue(registers, mOp1.first) << ", " << getRegisterValue(registers, mOp2.first) << ", " << getRegisterValue(registers, mOp3.first);
             return f;
         }
     };
@@ -646,6 +647,22 @@
         }
     };
 
+    class LoadType : public Instruction_2<TypedRegister, JSType*> {
+    public:
+        /* dest, type */
+        LoadType (TypedRegister aOp1, JSType* aOp2) :
+            Instruction_2<TypedRegister, JSType*>
+            (LOAD_TYPE, aOp1, aOp2) {};
+        virtual Formatter& print(Formatter& f) {
+            f << opcodeNames[LOAD_TYPE] << "\t" << mOp1 << ", " << "'" << mOp2->getName() << "'";
+            return f;
+        }
+        virtual Formatter& printOperands(Formatter& f, const JSValues& registers) {
+            f << getRegisterValue(registers, mOp1.first);
+            return f;
+        }
+    };
+
     class Move : public Instruction_2<TypedRegister, TypedRegister> {
     public:
         /* dest, source */
@@ -1265,6 +1282,7 @@
         "LOAD_NULL         ",
         "LOAD_STRING       ",
         "LOAD_TRUE         ",
+        "LOAD_TYPE         ",
         "MOVE              ",
         "MULTIPLY          ",
         "NAME_XCR          ",
diff --git a/js/js2/icodegenerator.cpp b/js/js2/icodegenerator.cpp
index 1deddc30e182..664ba95c9f7e 100644
--- a/js/js2/icodegenerator.cpp
+++ b/js/js2/icodegenerator.cpp
@@ -225,6 +225,21 @@ TypedRegister ICodeGenerator::loadBoolean(bool value)
     return dest;
 }
 
+TypedRegister ICodeGenerator::loadNull()
+{
+    TypedRegister dest(getTempRegister(), &Any_Type);
+    iCode->push_back(new LoadNull(dest));
+    return dest;
+}
+
+TypedRegister ICodeGenerator::loadType(JSType *type)
+{
+    TypedRegister dest(getTempRegister(), type);
+    iCode->push_back(new LoadType(dest, type));
+    return dest;
+}
+
+
 TypedRegister ICodeGenerator::newObject(TypedRegister constructor)
 {
     TypedRegister dest(getTempRegister(), &Any_Type);
@@ -535,7 +550,7 @@ TypedRegister ICodeGenerator::super()
 TypedRegister ICodeGenerator::cast(TypedRegister arg, JSType *toType)
 {
     TypedRegister dest(getTempRegister(), toType);
-    Cast *instr = new Cast(dest, arg, toType);
+    Cast *instr = new Cast(dest, arg, loadType(toType));
     iCode->push_back(instr);
     return dest;
 }
@@ -1249,6 +1264,9 @@ TypedRegister ICodeGenerator::genExpr(ExprNode *p,
         else
             ret = loadBoolean(false);
         break;
+    case ExprNode::Null:
+        ret = loadNull();
+        break;
     case ExprNode::parentheses:
         {
             UnaryExprNode *u = static_cast<UnaryExprNode *>(p);
diff --git a/js/js2/icodegenerator.h b/js/js2/icodegenerator.h
index dea8d866f2e2..43f4cf538835 100644
--- a/js/js2/icodegenerator.h
+++ b/js/js2/icodegenerator.h
@@ -378,6 +378,8 @@ namespace ICG {
         TypedRegister loadImmediate(double value);
         TypedRegister loadString(const String &value);
         TypedRegister loadString(const StringAtom &name);
+        TypedRegister loadNull();
+        TypedRegister loadType(JSType *toType);
                 
         TypedRegister newObject(TypedRegister constructor);
         TypedRegister newArray();
diff --git a/js/js2/icodemap.h b/js/js2/icodemap.h
index 9949741f559e..485ce905565a 100644
--- a/js/js2/icodemap.h
+++ b/js/js2/icodemap.h
@@ -45,7 +45,7 @@
 namespace JavaScript {
 namespace ICodeASM {
 
-    static uint icodemap_size = 78;
+    static uint icodemap_size = 79;
 
     static struct {
         char *name;
@@ -60,7 +60,7 @@ namespace ICodeASM {
         {"BRANCH_INITIALIZED", {otLabel, otRegister}},
         {"BRANCH_TRUE", {otLabel, otRegister}},
         {"CALL", {otRegister, otRegister, otArgumentList}},
-        {"CAST", {otRegister, otRegister, otJSType}},
+        {"CAST", {otRegister, otRegister, otRegister}},
         {"CLASS", {otRegister, otRegister}},
         {"COMPARE_EQ", {otRegister, otRegister, otRegister}},
         {"COMPARE_GE", {otRegister, otRegister, otRegister}},
@@ -89,6 +89,7 @@ namespace ICodeASM {
         {"LOAD_NULL", {otRegister}},
         {"LOAD_STRING", {otRegister, otJSString}},
         {"LOAD_TRUE", {otRegister}},
+        {"LOAD_TYPE", {otRegister, otJSType}},
         {"MOVE", {otRegister, otRegister}},
         {"MULTIPLY", {otRegister, otRegister, otRegister}},
         {"NAME_XCR", {otRegister, otStringAtom, otDouble}},
@@ -167,7 +168,7 @@ namespace ICodeASM {
                 i = new Call (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), reinterpret_cast<ArgumentList*>(node->operand[2].data));
                 break;
             case 9:
-                i = new Cast (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), reinterpret_cast<JSType*>(node->operand[2].data));
+                i = new Cast (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 10:
                 i = new Class (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
@@ -254,123 +255,126 @@ namespace ICodeASM {
                 i = new LoadTrue (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 38:
-                i = new Move (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new LoadType (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSType*>(node->operand[1].data));
                 break;
             case 39:
-                i = new Multiply (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new Move (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 40:
-                i = new NameXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<const StringAtom*>(node->operand[1].data), static_cast<double>(node->operand[2].data));
+                i = new Multiply (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 41:
-                i = new Negate (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new NameXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<const StringAtom*>(node->operand[1].data), static_cast<double>(node->operand[2].data));
                 break;
             case 42:
-                i = new NewArray (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new Negate (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 43:
-                i = new NewClass (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSClass*>(node->operand[1].data));
+                i = new NewArray (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 44:
-                i = new NewClosure (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<ICodeModule*>(node->operand[1].data));
+                i = new NewClass (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSClass*>(node->operand[1].data));
                 break;
             case 45:
-                i = new NewFunction (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<ICodeModule*>(node->operand[1].data));
+                i = new NewClosure (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<ICodeModule*>(node->operand[1].data));
                 break;
             case 46:
-                i = new NewObject (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new NewFunction (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<ICodeModule*>(node->operand[1].data));
                 break;
             case 47:
-                i = new Nop ();
+                i = new NewObject (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 48:
-                i = new Not (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new Nop ();
                 break;
             case 49:
-                i = new Or (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new Not (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 50:
-                i = new Posate (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new Or (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 51:
-                i = new PropXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), reinterpret_cast<const StringAtom*>(node->operand[2].data), static_cast<double>(node->operand[3].data));
+                i = new Posate (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 52:
-                i = new Remainder (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new PropXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), reinterpret_cast<const StringAtom*>(node->operand[2].data), static_cast<double>(node->operand[3].data));
                 break;
             case 53:
-                i = new Return (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new Remainder (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 54:
-                i = new ReturnVoid ();
+                i = new Return (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 55:
-                i = new Rts ();
+                i = new ReturnVoid ();
                 break;
             case 56:
-                i = new SaveName (reinterpret_cast<const StringAtom*>(node->operand[0].data), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new Rts ();
                 break;
             case 57:
-                i = new SetElement (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SaveName (reinterpret_cast<const StringAtom*>(node->operand[0].data), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 58:
-                i = new SetProp (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<const StringAtom*>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SetElement (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 59:
-                i = new SetSlot (TypedRegister(static_cast<Register>(node->operand[0].data), 0), static_cast<uint32>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SetProp (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<const StringAtom*>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 60:
-                i = new SetStatic (reinterpret_cast<JSClass*>(node->operand[0].data), static_cast<uint32>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SetSlot (TypedRegister(static_cast<Register>(node->operand[0].data), 0), static_cast<uint32>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 61:
-                i = new Shiftleft (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SetStatic (reinterpret_cast<JSClass*>(node->operand[0].data), static_cast<uint32>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 62:
-                i = new Shiftright (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new Shiftleft (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 63:
-                i = new SlotXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), static_cast<uint32>(node->operand[2].data), static_cast<double>(node->operand[3].data));
+                i = new Shiftright (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 64:
-                i = new StaticXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSClass*>(node->operand[1].data), static_cast<uint32>(node->operand[2].data), static_cast<double>(node->operand[3].data));
+                i = new SlotXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), static_cast<uint32>(node->operand[2].data), static_cast<double>(node->operand[3].data));
                 break;
             case 65:
-                i = new StrictEQ (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new StaticXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSClass*>(node->operand[1].data), static_cast<uint32>(node->operand[2].data), static_cast<double>(node->operand[3].data));
                 break;
             case 66:
-                i = new StrictNE (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new StrictEQ (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 67:
-                i = new Subtract (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new StrictNE (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 68:
-                i = new Super (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new Subtract (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 69:
-                i = new Test (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new Super (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 70:
-                i = new Throw (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new Test (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 71:
-                i = new Tryin (reinterpret_cast<Label*>(node->operand[0].data), reinterpret_cast<Label*>(node->operand[1].data));
+                i = new Throw (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 72:
-                i = new Tryout ();
+                i = new Tryin (reinterpret_cast<Label*>(node->operand[0].data), reinterpret_cast<Label*>(node->operand[1].data));
                 break;
             case 73:
-                i = new Ushiftright (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new Tryout ();
                 break;
             case 74:
-                i = new VarXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), static_cast<double>(node->operand[2].data));
+                i = new Ushiftright (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 75:
-                i = new Within (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new VarXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), static_cast<double>(node->operand[2].data));
                 break;
             case 76:
-                i = new Without ();
+                i = new Within (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 77:
+                i = new Without ();
+                break;
+            case 78:
                 i = new Xor (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
 
diff --git a/js/js2/interpreter.cpp b/js/js2/interpreter.cpp
index 02e89123a87e..63886ef4f0f4 100644
--- a/js/js2/interpreter.cpp
+++ b/js/js2/interpreter.cpp
@@ -108,12 +108,6 @@ JSValue Context::readEvalFile(FILE* in, const String& fileName)
     JSValues emptyArgs;
     JSValue result;
         
-    // save off important member variables, to enable recursive call to interpret.
-    // this is a little stinky, but should be exception-safe.
-    autosaver<Activation*> activation(mActivation, 0);
-    autosaver<Linkage*> linkage(mLinkage, 0);
-    autosaver<InstructionIterator> pc(mPC);
-
     try {
         Arena a;
         Parser p(getWorld(), a, buffer, fileName);
@@ -133,11 +127,12 @@ JSValue Context::readEvalFile(FILE* in, const String& fileName)
     	stdOut << '\n';
 /*******/
 
-	    // Generate code for parsedStatements, which is a linked 
+        // Generate code for parsedStatements, which is a linked 
         // list of zero or more statements
         ICodeModule* icm = genCode(parsedStatements, fileName);
         if (icm) {
-            result = interpret(icm, emptyArgs);
+            Context cx(getWorld(), getGlobalObject());
+            result = cx.interpret(icm, emptyArgs);
             delete icm;
         }
     } catch (Exception &e) {
@@ -538,8 +533,15 @@ JSValue Context::interpret(ICodeModule* iCode, const JSValues& args)
             case CAST:
                 {
                     Cast* c = static_cast<Cast*>(instruction);
-                    JSType *toType = op3(c);
-                    (*registers)[dst(c).first] = (*registers)[src1(c).first].convert(toType);
+                    JSValue toTypeValue = (*registers)[op3(c).first];
+                    ASSERT(toTypeValue.isType());
+                    (*registers)[dst(c).first] = (*registers)[src1(c).first].convert(toTypeValue.type);
+                }
+                break;
+            case LOAD_TYPE:
+                {
+                    LoadType *lt = static_cast<LoadType*>(instruction);
+                    (*registers)[dst(lt).first] = src1(lt);
                 }
                 break;
             case CLASS:
diff --git a/js/js2/tools/jsicodes.pm b/js/js2/tools/jsicodes.pm
index 12835e8b2072..c2764a269a3d 100644
--- a/js/js2/tools/jsicodes.pm
+++ b/js/js2/tools/jsicodes.pm
@@ -175,6 +175,12 @@ $ops{"LOAD_NAME"} =
    rem    => "dest, name",
    params => [ ("TypedRegister", "const StringAtom*" ) ]
   };
+$ops{"LOAD_TYPE"} =
+  {
+   super  => "Instruction_2",
+   rem    => "dest, type",
+   params => [ ("TypedRegister", "JSType*" ) ]
+  };
 $ops{"SUPER"} =
   {
    super  => "Instruction_1",
@@ -426,7 +432,7 @@ $ops{"CAST"} =
   {
    super  => "Instruction_3",
    rem    => "dest, rvalue, toType",
-   params => [ ("TypedRegister", "TypedRegister", "JSType*") ]
+   params => [ ("TypedRegister", "TypedRegister", "TypedRegister") ]
   };
 $ops{"CLASS"} =
   {
diff --git a/js2/src/icode.h b/js2/src/icode.h
index 962bd0ee0d25..d399b7b81242 100644
--- a/js2/src/icode.h
+++ b/js2/src/icode.h
@@ -41,6 +41,7 @@
         LOAD_NULL, /* dest */
         LOAD_STRING, /* dest, immediate value (string) */
         LOAD_TRUE, /* dest */
+        LOAD_TYPE, /* dest, type */
         MOVE, /* dest, source */
         MULTIPLY, /* dest, source1, source2 */
         NAME_XCR, /* dest, name, value */
@@ -191,18 +192,18 @@
         }
     };
 
-    class Cast : public Instruction_3<TypedRegister, TypedRegister, JSType*> {
+    class Cast : public Instruction_3<TypedRegister, TypedRegister, TypedRegister> {
     public:
         /* dest, rvalue, toType */
-        Cast (TypedRegister aOp1, TypedRegister aOp2, JSType* aOp3) :
-            Instruction_3<TypedRegister, TypedRegister, JSType*>
+        Cast (TypedRegister aOp1, TypedRegister aOp2, TypedRegister aOp3) :
+            Instruction_3<TypedRegister, TypedRegister, TypedRegister>
             (CAST, aOp1, aOp2, aOp3) {};
         virtual Formatter& print(Formatter& f) {
-            f << opcodeNames[CAST] << "\t" << mOp1 << ", " << mOp2 << ", " << "'" << mOp3->getName() << "'";
+            f << opcodeNames[CAST] << "\t" << mOp1 << ", " << mOp2 << ", " << mOp3;
             return f;
         }
         virtual Formatter& printOperands(Formatter& f, const JSValues& registers) {
-            f << getRegisterValue(registers, mOp1.first) << ", " << getRegisterValue(registers, mOp2.first);
+            f << getRegisterValue(registers, mOp1.first) << ", " << getRegisterValue(registers, mOp2.first) << ", " << getRegisterValue(registers, mOp3.first);
             return f;
         }
     };
@@ -646,6 +647,22 @@
         }
     };
 
+    class LoadType : public Instruction_2<TypedRegister, JSType*> {
+    public:
+        /* dest, type */
+        LoadType (TypedRegister aOp1, JSType* aOp2) :
+            Instruction_2<TypedRegister, JSType*>
+            (LOAD_TYPE, aOp1, aOp2) {};
+        virtual Formatter& print(Formatter& f) {
+            f << opcodeNames[LOAD_TYPE] << "\t" << mOp1 << ", " << "'" << mOp2->getName() << "'";
+            return f;
+        }
+        virtual Formatter& printOperands(Formatter& f, const JSValues& registers) {
+            f << getRegisterValue(registers, mOp1.first);
+            return f;
+        }
+    };
+
     class Move : public Instruction_2<TypedRegister, TypedRegister> {
     public:
         /* dest, source */
@@ -1265,6 +1282,7 @@
         "LOAD_NULL         ",
         "LOAD_STRING       ",
         "LOAD_TRUE         ",
+        "LOAD_TYPE         ",
         "MOVE              ",
         "MULTIPLY          ",
         "NAME_XCR          ",
diff --git a/js2/src/icodegenerator.cpp b/js2/src/icodegenerator.cpp
index 1deddc30e182..664ba95c9f7e 100644
--- a/js2/src/icodegenerator.cpp
+++ b/js2/src/icodegenerator.cpp
@@ -225,6 +225,21 @@ TypedRegister ICodeGenerator::loadBoolean(bool value)
     return dest;
 }
 
+TypedRegister ICodeGenerator::loadNull()
+{
+    TypedRegister dest(getTempRegister(), &Any_Type);
+    iCode->push_back(new LoadNull(dest));
+    return dest;
+}
+
+TypedRegister ICodeGenerator::loadType(JSType *type)
+{
+    TypedRegister dest(getTempRegister(), type);
+    iCode->push_back(new LoadType(dest, type));
+    return dest;
+}
+
+
 TypedRegister ICodeGenerator::newObject(TypedRegister constructor)
 {
     TypedRegister dest(getTempRegister(), &Any_Type);
@@ -535,7 +550,7 @@ TypedRegister ICodeGenerator::super()
 TypedRegister ICodeGenerator::cast(TypedRegister arg, JSType *toType)
 {
     TypedRegister dest(getTempRegister(), toType);
-    Cast *instr = new Cast(dest, arg, toType);
+    Cast *instr = new Cast(dest, arg, loadType(toType));
     iCode->push_back(instr);
     return dest;
 }
@@ -1249,6 +1264,9 @@ TypedRegister ICodeGenerator::genExpr(ExprNode *p,
         else
             ret = loadBoolean(false);
         break;
+    case ExprNode::Null:
+        ret = loadNull();
+        break;
     case ExprNode::parentheses:
         {
             UnaryExprNode *u = static_cast<UnaryExprNode *>(p);
diff --git a/js2/src/icodegenerator.h b/js2/src/icodegenerator.h
index dea8d866f2e2..43f4cf538835 100644
--- a/js2/src/icodegenerator.h
+++ b/js2/src/icodegenerator.h
@@ -378,6 +378,8 @@ namespace ICG {
         TypedRegister loadImmediate(double value);
         TypedRegister loadString(const String &value);
         TypedRegister loadString(const StringAtom &name);
+        TypedRegister loadNull();
+        TypedRegister loadType(JSType *toType);
                 
         TypedRegister newObject(TypedRegister constructor);
         TypedRegister newArray();
diff --git a/js2/src/icodemap.h b/js2/src/icodemap.h
index 9949741f559e..485ce905565a 100644
--- a/js2/src/icodemap.h
+++ b/js2/src/icodemap.h
@@ -45,7 +45,7 @@
 namespace JavaScript {
 namespace ICodeASM {
 
-    static uint icodemap_size = 78;
+    static uint icodemap_size = 79;
 
     static struct {
         char *name;
@@ -60,7 +60,7 @@ namespace ICodeASM {
         {"BRANCH_INITIALIZED", {otLabel, otRegister}},
         {"BRANCH_TRUE", {otLabel, otRegister}},
         {"CALL", {otRegister, otRegister, otArgumentList}},
-        {"CAST", {otRegister, otRegister, otJSType}},
+        {"CAST", {otRegister, otRegister, otRegister}},
         {"CLASS", {otRegister, otRegister}},
         {"COMPARE_EQ", {otRegister, otRegister, otRegister}},
         {"COMPARE_GE", {otRegister, otRegister, otRegister}},
@@ -89,6 +89,7 @@ namespace ICodeASM {
         {"LOAD_NULL", {otRegister}},
         {"LOAD_STRING", {otRegister, otJSString}},
         {"LOAD_TRUE", {otRegister}},
+        {"LOAD_TYPE", {otRegister, otJSType}},
         {"MOVE", {otRegister, otRegister}},
         {"MULTIPLY", {otRegister, otRegister, otRegister}},
         {"NAME_XCR", {otRegister, otStringAtom, otDouble}},
@@ -167,7 +168,7 @@ namespace ICodeASM {
                 i = new Call (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), reinterpret_cast<ArgumentList*>(node->operand[2].data));
                 break;
             case 9:
-                i = new Cast (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), reinterpret_cast<JSType*>(node->operand[2].data));
+                i = new Cast (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 10:
                 i = new Class (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
@@ -254,123 +255,126 @@ namespace ICodeASM {
                 i = new LoadTrue (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 38:
-                i = new Move (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new LoadType (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSType*>(node->operand[1].data));
                 break;
             case 39:
-                i = new Multiply (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new Move (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 40:
-                i = new NameXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<const StringAtom*>(node->operand[1].data), static_cast<double>(node->operand[2].data));
+                i = new Multiply (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 41:
-                i = new Negate (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new NameXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<const StringAtom*>(node->operand[1].data), static_cast<double>(node->operand[2].data));
                 break;
             case 42:
-                i = new NewArray (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new Negate (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 43:
-                i = new NewClass (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSClass*>(node->operand[1].data));
+                i = new NewArray (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 44:
-                i = new NewClosure (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<ICodeModule*>(node->operand[1].data));
+                i = new NewClass (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSClass*>(node->operand[1].data));
                 break;
             case 45:
-                i = new NewFunction (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<ICodeModule*>(node->operand[1].data));
+                i = new NewClosure (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<ICodeModule*>(node->operand[1].data));
                 break;
             case 46:
-                i = new NewObject (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new NewFunction (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<ICodeModule*>(node->operand[1].data));
                 break;
             case 47:
-                i = new Nop ();
+                i = new NewObject (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 48:
-                i = new Not (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new Nop ();
                 break;
             case 49:
-                i = new Or (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new Not (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 50:
-                i = new Posate (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new Or (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 51:
-                i = new PropXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), reinterpret_cast<const StringAtom*>(node->operand[2].data), static_cast<double>(node->operand[3].data));
+                i = new Posate (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 52:
-                i = new Remainder (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new PropXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), reinterpret_cast<const StringAtom*>(node->operand[2].data), static_cast<double>(node->operand[3].data));
                 break;
             case 53:
-                i = new Return (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new Remainder (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 54:
-                i = new ReturnVoid ();
+                i = new Return (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 55:
-                i = new Rts ();
+                i = new ReturnVoid ();
                 break;
             case 56:
-                i = new SaveName (reinterpret_cast<const StringAtom*>(node->operand[0].data), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new Rts ();
                 break;
             case 57:
-                i = new SetElement (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SaveName (reinterpret_cast<const StringAtom*>(node->operand[0].data), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 58:
-                i = new SetProp (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<const StringAtom*>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SetElement (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 59:
-                i = new SetSlot (TypedRegister(static_cast<Register>(node->operand[0].data), 0), static_cast<uint32>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SetProp (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<const StringAtom*>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 60:
-                i = new SetStatic (reinterpret_cast<JSClass*>(node->operand[0].data), static_cast<uint32>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SetSlot (TypedRegister(static_cast<Register>(node->operand[0].data), 0), static_cast<uint32>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 61:
-                i = new Shiftleft (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new SetStatic (reinterpret_cast<JSClass*>(node->operand[0].data), static_cast<uint32>(node->operand[1].data), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 62:
-                i = new Shiftright (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new Shiftleft (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 63:
-                i = new SlotXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), static_cast<uint32>(node->operand[2].data), static_cast<double>(node->operand[3].data));
+                i = new Shiftright (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 64:
-                i = new StaticXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSClass*>(node->operand[1].data), static_cast<uint32>(node->operand[2].data), static_cast<double>(node->operand[3].data));
+                i = new SlotXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), static_cast<uint32>(node->operand[2].data), static_cast<double>(node->operand[3].data));
                 break;
             case 65:
-                i = new StrictEQ (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new StaticXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), reinterpret_cast<JSClass*>(node->operand[1].data), static_cast<uint32>(node->operand[2].data), static_cast<double>(node->operand[3].data));
                 break;
             case 66:
-                i = new StrictNE (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new StrictEQ (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 67:
-                i = new Subtract (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new StrictNE (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 68:
-                i = new Super (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new Subtract (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 69:
-                i = new Test (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
+                i = new Super (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 70:
-                i = new Throw (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new Test (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0));
                 break;
             case 71:
-                i = new Tryin (reinterpret_cast<Label*>(node->operand[0].data), reinterpret_cast<Label*>(node->operand[1].data));
+                i = new Throw (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 72:
-                i = new Tryout ();
+                i = new Tryin (reinterpret_cast<Label*>(node->operand[0].data), reinterpret_cast<Label*>(node->operand[1].data));
                 break;
             case 73:
-                i = new Ushiftright (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
+                i = new Tryout ();
                 break;
             case 74:
-                i = new VarXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), static_cast<double>(node->operand[2].data));
+                i = new Ushiftright (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
             case 75:
-                i = new Within (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
+                i = new VarXcr (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), static_cast<double>(node->operand[2].data));
                 break;
             case 76:
-                i = new Without ();
+                i = new Within (TypedRegister(static_cast<Register>(node->operand[0].data), 0));
                 break;
             case 77:
+                i = new Without ();
+                break;
+            case 78:
                 i = new Xor (TypedRegister(static_cast<Register>(node->operand[0].data), 0), TypedRegister(static_cast<Register>(node->operand[1].data), 0), TypedRegister(static_cast<Register>(node->operand[2].data), 0));
                 break;
 
diff --git a/js2/src/interpreter.cpp b/js2/src/interpreter.cpp
index 02e89123a87e..63886ef4f0f4 100644
--- a/js2/src/interpreter.cpp
+++ b/js2/src/interpreter.cpp
@@ -108,12 +108,6 @@ JSValue Context::readEvalFile(FILE* in, const String& fileName)
     JSValues emptyArgs;
     JSValue result;
         
-    // save off important member variables, to enable recursive call to interpret.
-    // this is a little stinky, but should be exception-safe.
-    autosaver<Activation*> activation(mActivation, 0);
-    autosaver<Linkage*> linkage(mLinkage, 0);
-    autosaver<InstructionIterator> pc(mPC);
-
     try {
         Arena a;
         Parser p(getWorld(), a, buffer, fileName);
@@ -133,11 +127,12 @@ JSValue Context::readEvalFile(FILE* in, const String& fileName)
     	stdOut << '\n';
 /*******/
 
-	    // Generate code for parsedStatements, which is a linked 
+        // Generate code for parsedStatements, which is a linked 
         // list of zero or more statements
         ICodeModule* icm = genCode(parsedStatements, fileName);
         if (icm) {
-            result = interpret(icm, emptyArgs);
+            Context cx(getWorld(), getGlobalObject());
+            result = cx.interpret(icm, emptyArgs);
             delete icm;
         }
     } catch (Exception &e) {
@@ -538,8 +533,15 @@ JSValue Context::interpret(ICodeModule* iCode, const JSValues& args)
             case CAST:
                 {
                     Cast* c = static_cast<Cast*>(instruction);
-                    JSType *toType = op3(c);
-                    (*registers)[dst(c).first] = (*registers)[src1(c).first].convert(toType);
+                    JSValue toTypeValue = (*registers)[op3(c).first];
+                    ASSERT(toTypeValue.isType());
+                    (*registers)[dst(c).first] = (*registers)[src1(c).first].convert(toTypeValue.type);
+                }
+                break;
+            case LOAD_TYPE:
+                {
+                    LoadType *lt = static_cast<LoadType*>(instruction);
+                    (*registers)[dst(lt).first] = src1(lt);
                 }
                 break;
             case CLASS:
diff --git a/js2/tools/jsicodes.pm b/js2/tools/jsicodes.pm
index 12835e8b2072..c2764a269a3d 100644
--- a/js2/tools/jsicodes.pm
+++ b/js2/tools/jsicodes.pm
@@ -175,6 +175,12 @@ $ops{"LOAD_NAME"} =
    rem    => "dest, name",
    params => [ ("TypedRegister", "const StringAtom*" ) ]
   };
+$ops{"LOAD_TYPE"} =
+  {
+   super  => "Instruction_2",
+   rem    => "dest, type",
+   params => [ ("TypedRegister", "JSType*" ) ]
+  };
 $ops{"SUPER"} =
   {
    super  => "Instruction_1",
@@ -426,7 +432,7 @@ $ops{"CAST"} =
   {
    super  => "Instruction_3",
    rem    => "dest, rvalue, toType",
-   params => [ ("TypedRegister", "TypedRegister", "JSType*") ]
+   params => [ ("TypedRegister", "TypedRegister", "TypedRegister") ]
   };
 $ops{"CLASS"} =
   {