From 47e55a77a7a8da6175f4cfa546185a4584352182 Mon Sep 17 00:00:00 2001
From: "kmillikin@chromium.org"
 <kmillikin@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Wed, 5 Nov 2008 08:44:54 +0000
Subject: [PATCH] Initial port of VirtualFrame to the ARM architecture.  To
 reduce the size of the change, the initial implementation provides read
 access to the frame (eg, locals, parameters, and expression stack elements)
 but no mutation. Review URL: http://codereview.chromium.org/7302

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@694 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/codegen-arm.cc | 159 +++++++++++++++++++++++++--------------------
 src/codegen-arm.h  |  68 ++++++++++++-------
 2 files changed, 135 insertions(+), 92 deletions(-)

diff --git a/src/codegen-arm.cc b/src/codegen-arm.cc
index 85500c4ea..69455a7a0 100644
--- a/src/codegen-arm.cc
+++ b/src/codegen-arm.cc
@@ -35,6 +35,20 @@
 
 namespace v8 { namespace internal {
 
+#define __ masm_->
+
+// -------------------------------------------------------------------------
+// VirtualFrame implementation.
+
+VirtualFrame::VirtualFrame(CodeGenerator* cgen) {
+  ASSERT(cgen->scope() != NULL);
+
+  masm_ = cgen->masm();
+  frame_local_count_ = cgen->scope()->num_stack_slots();
+  parameter_count_ = cgen->scope()->num_parameters();
+}
+
+
 // -------------------------------------------------------------------------
 // CodeGenState implementation.
 
@@ -67,11 +81,9 @@ CodeGenState::~CodeGenState() {
 }
 
 
-// -----------------------------------------------------------------------------
+// -------------------------------------------------------------------------
 // CodeGenerator implementation
 
-#define __ masm_->
-
 CodeGenerator::CodeGenerator(int buffer_size, Handle<Script> script,
                              bool is_eval)
     : is_eval_(is_eval),
@@ -79,6 +91,7 @@ CodeGenerator::CodeGenerator(int buffer_size, Handle<Script> script,
       deferred_(8),
       masm_(new MacroAssembler(NULL, buffer_size)),
       scope_(NULL),
+      frame_(NULL),
       cc_reg_(al),
       state_(NULL),
       break_stack_height_(0) {
@@ -94,13 +107,17 @@ CodeGenerator::CodeGenerator(int buffer_size, Handle<Script> script,
 // cp: callee's context
 
 void CodeGenerator::GenCode(FunctionLiteral* fun) {
-  Scope* scope = fun->scope();
   ZoneList<Statement*>* body = fun->body();
 
   // Initialize state.
-  { CodeGenState state(this);
-    scope_ = scope;
-    cc_reg_ = al;
+  ASSERT(scope_ == NULL);
+  scope_ = fun->scope();
+  ASSERT(frame_ == NULL);
+  VirtualFrame virtual_frame(this);
+  frame_ = &virtual_frame;
+  cc_reg_ = al;
+  {
+    CodeGenState state(this);
 
     // Entry
     // stack: function, receiver, arguments, return address
@@ -122,19 +139,19 @@ void CodeGenerator::GenCode(FunctionLiteral* fun) {
 #endif
 
     // Allocate space for locals and initialize them.
-    if (scope->num_stack_slots() > 0) {
+    if (scope_->num_stack_slots() > 0) {
       Comment cmnt(masm_, "[ allocate space for locals");
       // Initialize stack slots with 'undefined' value.
       __ mov(ip, Operand(Factory::undefined_value()));
-      for (int i = 0; i < scope->num_stack_slots(); i++) {
+      for (int i = 0; i < scope_->num_stack_slots(); i++) {
         __ push(ip);
       }
     }
 
-    if (scope->num_heap_slots() > 0) {
+    if (scope_->num_heap_slots() > 0) {
       // Allocate local context.
       // Get outer context and create a new context based on it.
-      __ ldr(r0, FunctionOperand());
+      __ ldr(r0, frame_->Function());
       __ push(r0);
       __ CallRuntime(Runtime::kNewContext, 1);  // r0 holds the result
 
@@ -146,7 +163,7 @@ void CodeGenerator::GenCode(FunctionLiteral* fun) {
         __ bind(&verified_true);
       }
       // Update context local.
-      __ str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+      __ str(cp, frame_->Context());
     }
 
     // TODO(1241774): Improve this code!!!
@@ -164,12 +181,12 @@ void CodeGenerator::GenCode(FunctionLiteral* fun) {
       // order: such a parameter is copied repeatedly into the same
       // context location and thus the last value is what is seen inside
       // the function.
-      for (int i = 0; i < scope->num_parameters(); i++) {
-        Variable* par = scope->parameter(i);
+      for (int i = 0; i < scope_->num_parameters(); i++) {
+        Variable* par = scope_->parameter(i);
         Slot* slot = par->slot();
         if (slot != NULL && slot->type() == Slot::CONTEXT) {
-          ASSERT(!scope->is_global_scope());  // no parameters in global scope
-          __ ldr(r1, ParameterOperand(i));
+          ASSERT(!scope_->is_global_scope());  // no parameters in global scope
+          __ ldr(r1, frame_->Parameter(i));
           // Loads r2 with context; used below in RecordWrite.
           __ str(r1, SlotOperand(slot, r2));
           // Load the offset into r3.
@@ -184,18 +201,18 @@ void CodeGenerator::GenCode(FunctionLiteral* fun) {
     // Store the arguments object.
     // This must happen after context initialization because
     // the arguments array may be stored in the context!
-    if (scope->arguments() != NULL) {
-      ASSERT(scope->arguments_shadow() != NULL);
+    if (scope_->arguments() != NULL) {
+      ASSERT(scope_->arguments_shadow() != NULL);
       Comment cmnt(masm_, "[ allocate arguments object");
-      { Reference shadow_ref(this, scope->arguments_shadow());
-        { Reference arguments_ref(this, scope->arguments());
+      { Reference shadow_ref(this, scope_->arguments_shadow());
+        { Reference arguments_ref(this, scope_->arguments());
           ArgumentsAccessStub stub(ArgumentsAccessStub::NEW_OBJECT);
-          __ ldr(r2, FunctionOperand());
+          __ ldr(r2, frame_->Function());
           // The receiver is below the arguments, the return address,
           // and the frame pointer on the stack.
-          const int kReceiverDisplacement = 2 + scope->num_parameters();
+          const int kReceiverDisplacement = 2 + scope_->num_parameters();
           __ add(r1, fp, Operand(kReceiverDisplacement * kPointerSize));
-          __ mov(r0, Operand(Smi::FromInt(scope->num_parameters())));
+          __ mov(r0, Operand(Smi::FromInt(scope_->num_parameters())));
           __ stm(db_w, sp, r0.bit() | r1.bit() | r2.bit());
           __ CallStub(&stub);
           __ push(r0);
@@ -210,13 +227,13 @@ void CodeGenerator::GenCode(FunctionLiteral* fun) {
     // functions (source elements). In case of an illegal
     // redeclaration we need to handle that instead of processing the
     // declarations.
-    if (scope->HasIllegalRedeclaration()) {
+    if (scope_->HasIllegalRedeclaration()) {
       Comment cmnt(masm_, "[ illegal redeclarations");
-      scope->VisitIllegalRedeclaration(this);
+      scope_->VisitIllegalRedeclaration(this);
     } else {
       Comment cmnt(masm_, "[ declarations");
       // ProcessDeclarations calls DeclareGlobals indirectly
-      ProcessDeclarations(scope->declarations());
+      ProcessDeclarations(scope_->declarations());
 
       // Bail out if a stack-overflow exception occurred when
       // processing declarations.
@@ -233,7 +250,7 @@ void CodeGenerator::GenCode(FunctionLiteral* fun) {
     // Compile the body of the function in a vanilla state. Don't
     // bother compiling all the code if the scope has an illegal
     // redeclaration.
-    if (!scope->HasIllegalRedeclaration()) {
+    if (!scope_->HasIllegalRedeclaration()) {
       Comment cmnt(masm_, "[ function body");
 #ifdef DEBUG
       bool is_builtin = Bootstrapper::IsActive();
@@ -272,6 +289,7 @@ void CodeGenerator::GenCode(FunctionLiteral* fun) {
 
   // Code generation state must be reset.
   scope_ = NULL;
+  frame_ = NULL;
   ASSERT(!has_cc());
   ASSERT(state_ == NULL);
 }
@@ -290,13 +308,10 @@ MemOperand CodeGenerator::SlotOperand(Slot* slot, Register tmp) {
   int index = slot->index();
   switch (slot->type()) {
     case Slot::PARAMETER:
-      return ParameterOperand(index);
+      return frame_->Parameter(index);
 
-    case Slot::LOCAL: {
-      ASSERT(0 <= index && index < scope()->num_stack_slots());
-      const int kLocalOffset = JavaScriptFrameConstants::kLocal0Offset;
-      return MemOperand(fp, kLocalOffset - index * kPointerSize);
-    }
+    case Slot::LOCAL:
+      return frame_->Local(index);
 
     case Slot::CONTEXT: {
       // Follow the context chain if necessary.
@@ -979,7 +994,7 @@ void CodeGenerator::CallWithArguments(ZoneList<Expression*>* args,
   __ CallStub(&call_function);
 
   // Restore context and pop function from the stack.
-  __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  __ ldr(cp, frame_->Context());
   __ pop();  // discard the TOS
 }
 
@@ -1214,7 +1229,7 @@ void CodeGenerator::VisitWithEnterStatement(WithEnterStatement* node) {
     __ bind(&verified_true);
   }
   // Update context local.
-  __ str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  __ str(cp, frame_->Context());
 }
 
 
@@ -1223,7 +1238,7 @@ void CodeGenerator::VisitWithExitStatement(WithExitStatement* node) {
   // Pop context.
   __ ldr(cp, ContextOperand(cp, Context::PREVIOUS_INDEX));
   // Update context local.
-  __ str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  __ str(cp, frame_->Context());
 }
 
 
@@ -1324,7 +1339,7 @@ void CodeGenerator::VisitSwitchStatement(SwitchStatement* node) {
     } else {
       __ bind(&next);
       next.Unuse();
-      __ ldr(r0, MemOperand(sp, 0));
+      __ ldr(r0, frame_->Top());
       __ push(r0);  // duplicate TOS
       Load(clause->label());
       Comparison(eq, true);
@@ -1543,29 +1558,29 @@ void CodeGenerator::VisitForInStatement(ForInStatement* node) {
   // sp[2] : array or enum cache
   // sp[3] : 0 or map
   // sp[4] : enumerable
-  __ ldr(r0, MemOperand(sp, 0 * kPointerSize));  // load the current count
-  __ ldr(r1, MemOperand(sp, 1 * kPointerSize));  // load the length
+  __ ldr(r0, frame_->Element(0));  // load the current count
+  __ ldr(r1, frame_->Element(1));  // load the length
   __ cmp(r0, Operand(r1));  // compare to the array length
   __ b(hs, &cleanup);
 
-  __ ldr(r0, MemOperand(sp, 0 * kPointerSize));
+  __ ldr(r0, frame_->Element(0));
 
   // Get the i'th entry of the array.
-  __ ldr(r2, MemOperand(sp, 2 * kPointerSize));
+  __ ldr(r2, frame_->Element(2));
   __ add(r2, r2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
   __ ldr(r3, MemOperand(r2, r0, LSL, kPointerSizeLog2 - kSmiTagSize));
 
   // Get Map or 0.
-  __ ldr(r2, MemOperand(sp, 3 * kPointerSize));
+  __ ldr(r2, frame_->Element(3));
   // Check if this (still) matches the map of the enumerable.
   // If not, we have to filter the key.
-  __ ldr(r1, MemOperand(sp, 4 * kPointerSize));
+  __ ldr(r1, frame_->Element(4));
   __ ldr(r1, FieldMemOperand(r1, HeapObject::kMapOffset));
   __ cmp(r1, Operand(r2));
   __ b(eq, &end_del_check);
 
   // Convert the entry to a string (or null if it isn't a property anymore).
-  __ ldr(r0, MemOperand(sp, 4 * kPointerSize));  // push enumerable
+  __ ldr(r0, frame_->Element(4));  // push enumerable
   __ push(r0);
   __ push(r3);  // push entry
   __ mov(r0, Operand(1));
@@ -1585,7 +1600,7 @@ void CodeGenerator::VisitForInStatement(ForInStatement* node) {
   { Reference each(this, node->each());
     if (!each.is_illegal()) {
       if (each.size() > 0) {
-        __ ldr(r0, MemOperand(sp, kPointerSize * each.size()));
+        __ ldr(r0, frame_->Element(each.size()));
         __ push(r0);
       }
       // If the reference was to a slot we rely on the convenient property
@@ -1680,9 +1695,10 @@ void CodeGenerator::VisitTryCatch(TryCatch* node) {
 
   // Unlink from try chain.
   // TOS contains code slot
-  const int kNextOffset = StackHandlerConstants::kNextOffset +
-      StackHandlerConstants::kAddressDisplacement;
-  __ ldr(r1, MemOperand(sp, kNextOffset));  // read next_sp
+  const int kNextIndex = (StackHandlerConstants::kNextOffset
+                          + StackHandlerConstants::kAddressDisplacement)
+                       / kPointerSize;
+  __ ldr(r1, frame_->Element(kNextIndex));  // read next_sp
   __ mov(r3, Operand(ExternalReference(Top::k_handler_address)));
   __ str(r1, MemOperand(r3));
   ASSERT(StackHandlerConstants::kCodeOffset == 0);  // first field is code
@@ -1702,7 +1718,7 @@ void CodeGenerator::VisitTryCatch(TryCatch* node) {
       __ mov(r3, Operand(ExternalReference(Top::k_handler_address)));
       __ ldr(sp, MemOperand(r3));
 
-      __ ldr(r1, MemOperand(sp, kNextOffset));
+      __ ldr(r1, frame_->Element(kNextIndex));
       __ str(r1, MemOperand(r3));
       ASSERT(StackHandlerConstants::kCodeOffset == 0);  // first field is code
       __ add(sp, sp, Operand(StackHandlerConstants::kSize - kPointerSize));
@@ -1797,9 +1813,10 @@ void CodeGenerator::VisitTryFinally(TryFinally* node) {
   // break from (eg, for...in) may have left stuff on the stack.
   __ mov(r3, Operand(ExternalReference(Top::k_handler_address)));
   __ ldr(sp, MemOperand(r3));
-  const int kNextOffset = StackHandlerConstants::kNextOffset +
-      StackHandlerConstants::kAddressDisplacement;
-  __ ldr(r1, MemOperand(sp, kNextOffset));
+  const int kNextIndex = (StackHandlerConstants::kNextOffset
+                          + StackHandlerConstants::kAddressDisplacement)
+                       / kPointerSize;
+  __ ldr(r1, frame_->Element(kNextIndex));
   __ str(r1, MemOperand(r3));
   ASSERT(StackHandlerConstants::kCodeOffset == 0);  // first field is code
   __ add(sp, sp, Operand(StackHandlerConstants::kSize - kPointerSize));
@@ -1982,7 +1999,7 @@ void CodeGenerator::VisitRegExpLiteral(RegExpLiteral* node) {
   // Retrieve the literal array and check the allocated entry.
 
   // Load the function of this activation.
-  __ ldr(r1, FunctionOperand());
+  __ ldr(r1, frame_->Function());
 
   // Load the literals array of the function.
   __ ldr(r1, FieldMemOperand(r1, JSFunction::kLiteralsOffset));
@@ -2055,7 +2072,7 @@ void CodeGenerator::VisitObjectLiteral(ObjectLiteral* node) {
   // Retrieve the literal array and check the allocated entry.
 
   // Load the function of this activation.
-  __ ldr(r1, FunctionOperand());
+  __ ldr(r1, frame_->Function());
 
   // Load the literals array of the function.
   __ ldr(r1, FieldMemOperand(r1, JSFunction::kLiteralsOffset));
@@ -2092,7 +2109,7 @@ void CodeGenerator::VisitObjectLiteral(ObjectLiteral* node) {
         Load(value);
         __ CallRuntime(Runtime::kSetProperty, 3);
         // restore r0
-        __ ldr(r0, MemOperand(sp, 0));
+        __ ldr(r0, frame_->Top());
         break;
       }
       case ObjectLiteral::Property::SETTER: {
@@ -2102,7 +2119,7 @@ void CodeGenerator::VisitObjectLiteral(ObjectLiteral* node) {
         __ push(r0);
         Load(value);
         __ CallRuntime(Runtime::kDefineAccessor, 4);
-        __ ldr(r0, MemOperand(sp, 0));
+        __ ldr(r0, frame_->Top());
         break;
       }
       case ObjectLiteral::Property::GETTER: {
@@ -2112,7 +2129,7 @@ void CodeGenerator::VisitObjectLiteral(ObjectLiteral* node) {
         __ push(r0);
         Load(value);
         __ CallRuntime(Runtime::kDefineAccessor, 4);
-        __ ldr(r0, MemOperand(sp, 0));
+        __ ldr(r0, frame_->Top());
         break;
       }
     }
@@ -2127,7 +2144,7 @@ void CodeGenerator::VisitArrayLiteral(ArrayLiteral* node) {
   __ mov(r0, Operand(node->literals()));
   __ push(r0);
   // Load the function of this frame.
-  __ ldr(r0, FunctionOperand());
+  __ ldr(r0, frame_->Function());
   __ ldr(r0, FieldMemOperand(r0, JSFunction::kLiteralsOffset));
   __ push(r0);
   __ CallRuntime(Runtime::kCreateArrayLiteral, 2);
@@ -2148,7 +2165,7 @@ void CodeGenerator::VisitArrayLiteral(ArrayLiteral* node) {
       __ pop(r0);
 
       // Fetch the object literal
-      __ ldr(r1, MemOperand(sp, 0));
+      __ ldr(r1, frame_->Top());
         // Get the elements array.
       __ ldr(r1, FieldMemOperand(r1, JSObject::kElementsOffset));
 
@@ -2271,7 +2288,7 @@ void CodeGenerator::VisitCall(Call* node) {
     Handle<Code> stub = ComputeCallInitialize(args->length());
     __ RecordPosition(node->position());
     __ Call(stub, RelocInfo::CODE_TARGET_CONTEXT);
-    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+    __ ldr(cp, frame_->Context());
     // Remove the function from the stack.
     __ pop();
     __ push(r0);
@@ -2318,7 +2335,7 @@ void CodeGenerator::VisitCall(Call* node) {
       Handle<Code> stub = ComputeCallInitialize(args->length());
       __ RecordPosition(node->position());
       __ Call(stub, RelocInfo::CODE_TARGET);
-      __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+      __ ldr(cp, frame_->Context());
 
       // Remove the function from the stack.
       __ pop();
@@ -2335,7 +2352,7 @@ void CodeGenerator::VisitCall(Call* node) {
       ref.GetValue(NOT_INSIDE_TYPEOF);  // receiver
 
       // Pass receiver to called function.
-      __ ldr(r0, MemOperand(sp, ref.size() * kPointerSize));
+      __ ldr(r0, frame_->Element(ref.size()));
       __ push(r0);
       // Call the function.
       CallWithArguments(args, node->position());
@@ -2383,7 +2400,7 @@ void CodeGenerator::VisitCallNew(CallNew* node) {
   __ mov(r0, Operand(args->length()));
 
   // Load the function into r1 as per calling convention.
-  __ ldr(r1, MemOperand(sp, (args->length() + 1) * kPointerSize));
+  __ ldr(r1, frame_->Element(args->length() + 1));
 
   // Call the construct call builtin that handles allocation and
   // constructor invocation.
@@ -2392,7 +2409,7 @@ void CodeGenerator::VisitCallNew(CallNew* node) {
           RelocInfo::CONSTRUCT_CALL);
 
   // Discard old TOS value and push r0 on the stack (same as Pop(), push(r0)).
-  __ str(r0, MemOperand(sp, 0 * kPointerSize));
+  __ str(r0, frame_->Top());
 }
 
 
@@ -2565,7 +2582,7 @@ void CodeGenerator::VisitCallRuntime(CallRuntime* node) {
     // Call the JS runtime function.
     Handle<Code> stub = ComputeCallInitialize(args->length());
     __ Call(stub, RelocInfo::CODE_TARGET);
-    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+    __ ldr(cp, frame_->Context());
     __ pop();
     __ push(r0);
   }
@@ -2727,7 +2744,9 @@ void CodeGenerator::VisitCountOperation(CountOperation* node) {
     __ b(ne, &slow);
 
     // Postfix: Store the old value as the result.
-    if (is_postfix) __ str(r0, MemOperand(sp, target.size() * kPointerSize));
+    if (is_postfix) {
+      __ str(r0, frame_->Element(target.size()));
+    }
 
     // Perform optimistic increment/decrement.
     if (is_increment) {
@@ -2754,7 +2773,7 @@ void CodeGenerator::VisitCountOperation(CountOperation* node) {
       InvokeBuiltinStub stub(InvokeBuiltinStub::ToNumber, 2);
       __ CallStub(&stub);
       // Store to result (on the stack).
-      __ str(r0, MemOperand(sp, target.size() * kPointerSize));
+      __ str(r0, frame_->Element(target.size()));
     }
 
     // Compute the new value by calling the right JavaScript native.
@@ -2814,7 +2833,7 @@ void CodeGenerator::VisitBinaryOperation(BinaryOperation* node) {
     } else {
       Label pop_and_continue, exit;
 
-      __ ldr(r0, MemOperand(sp, 0));  // dup the stack top
+      __ ldr(r0, frame_->Top());  // dup the stack top
       __ push(r0);
       // Avoid popping the result if it converts to 'false' using the
       // standard ToBoolean() conversion as described in ECMA-262,
@@ -2855,7 +2874,7 @@ void CodeGenerator::VisitBinaryOperation(BinaryOperation* node) {
     } else {
       Label pop_and_continue, exit;
 
-      __ ldr(r0, MemOperand(sp, 0));
+      __ ldr(r0, frame_->Top());
       __ push(r0);
       // Avoid popping the result if it converts to 'true' using the
       // standard ToBoolean() conversion as described in ECMA-262,
@@ -2900,7 +2919,7 @@ void CodeGenerator::VisitBinaryOperation(BinaryOperation* node) {
 
 
 void CodeGenerator::VisitThisFunction(ThisFunction* node) {
-  __ ldr(r0, FunctionOperand());
+  __ ldr(r0, frame_->Function());
   __ push(r0);
 }
 
diff --git a/src/codegen-arm.h b/src/codegen-arm.h
index 8058138bd..c8d235db1 100644
--- a/src/codegen-arm.h
+++ b/src/codegen-arm.h
@@ -38,8 +38,50 @@ class DeferredCode;
 // Mode to overwrite BinaryExpression values.
 enum OverwriteMode { NO_OVERWRITE, OVERWRITE_LEFT, OVERWRITE_RIGHT };
 
+enum InitState { CONST_INIT, NOT_CONST_INIT };
+enum TypeofState { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
+
+
+// -------------------------------------------------------------------------
+// Virtual frame
+
+class VirtualFrame BASE_EMBEDDED {
+ public:
+  explicit VirtualFrame(CodeGenerator* cgen);
+
+  MemOperand Top() const { return MemOperand(sp, 0); }
+
+  MemOperand Element(int index) const {
+    return MemOperand(sp, index * kPointerSize);
+  }
+
+  MemOperand Local(int index) const {
+    ASSERT(0 <= index && index < frame_local_count_);
+    return MemOperand(fp, kLocal0Offset - index * kPointerSize);
+  }
+
+  MemOperand Function() const { return MemOperand(fp, kFunctionOffset); }
+
+  MemOperand Context() const { return MemOperand(fp, kContextOffset); }
+
+  MemOperand Parameter(int index) const {
+    // Index -1 corresponds to the receiver.
+    ASSERT(-1 <= index && index <= parameter_count_);
+    return MemOperand(fp, (1 + parameter_count_ - index) * kPointerSize);
+  }
+
+ private:
+  static const int kLocal0Offset = JavaScriptFrameConstants::kLocal0Offset;
+  static const int kFunctionOffset = JavaScriptFrameConstants::kFunctionOffset;
+  static const int kContextOffset = StandardFrameConstants::kContextOffset;
+
+  MacroAssembler* masm_;
+  int frame_local_count_;
+  int parameter_count_;
+};
+
 
-// -----------------------------------------------------------------------------
+// -------------------------------------------------------------------------
 // Reference support
 
 // A reference is a C++ stack-allocated object that keeps an ECMA
@@ -49,9 +91,6 @@ enum OverwriteMode { NO_OVERWRITE, OVERWRITE_LEFT, OVERWRITE_RIGHT };
 // For properties, we keep either one (named) or two (indexed) values
 // on the execution stack to represent the reference.
 
-enum InitState { CONST_INIT, NOT_CONST_INIT };
-enum TypeofState { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
-
 class Reference BASE_EMBEDDED {
  public:
   // The values of the types is important, see size().
@@ -133,7 +172,7 @@ class CodeGenState BASE_EMBEDDED {
 };
 
 
-// -----------------------------------------------------------------------------
+// -------------------------------------------------------------------------
 // CodeGenerator
 
 class CodeGenerator: public Visitor {
@@ -193,20 +232,6 @@ class CodeGenerator: public Visitor {
   void LoadReference(Reference* ref);
   void UnloadReference(Reference* ref);
 
-  // Support functions for accessing parameters and other operands.
-  MemOperand ParameterOperand(int index) const {
-    int num_parameters = scope()->num_parameters();
-    // index -2 corresponds to the activated closure, -1 corresponds
-    // to the receiver
-    ASSERT(-2 <= index && index < num_parameters);
-    int offset = (1 + num_parameters - index) * kPointerSize;
-    return MemOperand(fp, offset);
-  }
-
-  MemOperand FunctionOperand() const {
-    return MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset);
-  }
-
   MemOperand ContextOperand(Register context, int index) const {
     return MemOperand(context, Context::SlotOffset(index));
   }
@@ -355,6 +380,7 @@ class CodeGenerator: public Visitor {
 
   // Code generation state
   Scope* scope_;
+  VirtualFrame* frame_;
   Condition cc_reg_;
   CodeGenState* state_;
   bool is_inside_try_;
@@ -363,10 +389,8 @@ class CodeGenerator: public Visitor {
   // Labels
   Label function_return_;
 
+  friend class VirtualFrame;
   friend class Reference;
-  friend class Property;
-  friend class VariableProxy;
-  friend class Slot;
 
   DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
 };
-- 
2.34.1