diff --git a/src/ast.h b/src/ast.h
index 8e717a6c8c..927a9f5035 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -1,4 +1,4 @@
-// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -199,6 +199,10 @@ class Expression: public AstNode {
   // evaluated.
   virtual bool IsLeaf() { return false; }
 
+  // True if the expression has no side effects and is safe to
+  // evaluate out of order.
+  virtual bool IsTrivial() { return false; }
+
   // Mark the expression as being compiled as an expression
   // statement. This is used to transform postfix increments to
   // (faster) prefix increments.
@@ -738,6 +742,7 @@ class Literal: public Expression {
   }
 
   virtual bool IsLeaf() { return true; }
+  virtual bool IsTrivial() { return true; }
 
   // Identity testers.
   bool IsNull() const { return handle_.is_identical_to(Factory::null_value()); }
@@ -926,6 +931,10 @@ class VariableProxy: public Expression {
     return var()->is_global() || var()->rewrite()->IsLeaf();
   }
 
+  // Reading from a mutable variable is a side effect, but 'this' is
+  // immutable.
+  virtual bool IsTrivial() { return is_this(); }
+
   bool IsVariable(Handle<String> n) {
     return !is_this() && name().is_identical_to(n);
   }
diff --git a/src/ia32/codegen-ia32.cc b/src/ia32/codegen-ia32.cc
index 7ec3ff4c50..edf221bfb2 100644
--- a/src/ia32/codegen-ia32.cc
+++ b/src/ia32/codegen-ia32.cc
@@ -4762,8 +4762,9 @@ void CodeGenerator::EmitNamedPropertyAssignment(Assignment* node) {
   Property* prop = node->target()->AsProperty();
   ASSERT(var == NULL || (prop == NULL && var->is_global()));
 
-  // Initialize name and evaluate the receiver subexpression.
+  // Initialize name and evaluate the receiver subexpression if necessary.
   Handle<String> name;
+  bool is_trivial_receiver = false;
   if (var != NULL) {
     name = var->name();
     LoadGlobal();
@@ -4771,17 +4772,23 @@ void CodeGenerator::EmitNamedPropertyAssignment(Assignment* node) {
     Literal* lit = prop->key()->AsLiteral();
     ASSERT(lit != NULL);
     name = Handle<String>::cast(lit->handle());
-    Load(prop->obj());
+    // Do not materialize the receiver on the frame if it is trivial.
+    is_trivial_receiver = prop->obj()->IsTrivial();
+    if (!is_trivial_receiver) Load(prop->obj());
   }
 
   if (node->starts_initialization_block()) {
     // Change to slow case in the beginning of an initialization block to
     // avoid the quadratic behavior of repeatedly adding fast properties.
-    frame()->Dup();
+    if (is_trivial_receiver) {
+      frame()->Push(prop->obj());
+    } else {
+      frame()->Dup();
+    }
     Result ignored = frame()->CallRuntime(Runtime::kToSlowProperties, 1);
   }
 
-  if (node->ends_initialization_block()) {
+  if (node->ends_initialization_block() && !is_trivial_receiver) {
     // Add an extra copy of the receiver to the frame, so that it can be
     // converted back to fast case after the assignment.
     frame()->Dup();
@@ -4789,7 +4796,11 @@ void CodeGenerator::EmitNamedPropertyAssignment(Assignment* node) {
 
   // Evaluate the right-hand side.
   if (node->is_compound()) {
-    frame()->Dup();
+    if (is_trivial_receiver) {
+      frame()->Push(prop->obj());
+    } else {
+      frame()->Dup();
+    }
     Result value = EmitNamedLoad(name, var != NULL);
     frame()->Push(&value);
     Load(node->value());
@@ -4807,18 +4818,27 @@ void CodeGenerator::EmitNamedPropertyAssignment(Assignment* node) {
   // Perform the assignment.  It is safe to ignore constants here.
   ASSERT(var == NULL || var->mode() != Variable::CONST);
   ASSERT(node->op() != Token::INIT_CONST);
+  if (is_trivial_receiver) {
+    Result value = frame()->Pop();
+    frame()->Push(prop->obj());
+    frame()->Push(&value);
+  }
   CodeForSourcePosition(node->position());
   Result answer = EmitNamedStore(name);
   frame()->Push(&answer);
 
   if (node->ends_initialization_block()) {
-    // The argument to the runtime call is the extra copy of the receiver,
-    // which is below the value of the assignment.  Swap the receiver and
-    // the value of the assignment expression.
-    Result result = frame()->Pop();
-    Result receiver = frame()->Pop();
-    frame()->Push(&result);
-    frame()->Push(&receiver);
+    // The argument to the runtime call is the receiver.
+    if (is_trivial_receiver) {
+      frame()->Push(prop->obj());
+    } else {
+      // A copy of the receiver is below the value of the assignment.  Swap
+      // the receiver and the value of the assignment expression.
+      Result result = frame()->Pop();
+      Result receiver = frame()->Pop();
+      frame()->Push(&result);
+      frame()->Push(&receiver);
+    }
     Result ignored = frame_->CallRuntime(Runtime::kToFastProperties, 1);
   }
 
diff --git a/src/ia32/virtual-frame-ia32.cc b/src/ia32/virtual-frame-ia32.cc
index d2485392f5..5e44f94d0c 100644
--- a/src/ia32/virtual-frame-ia32.cc
+++ b/src/ia32/virtual-frame-ia32.cc
@@ -1175,6 +1175,25 @@ void VirtualFrame::EmitPush(Immediate immediate, NumberInfo::Type info) {
 }
 
 
+void VirtualFrame::Push(Expression* expr) {
+  ASSERT(expr->IsTrivial());
+
+  Literal* lit = expr->AsLiteral();
+  if (lit != NULL) {
+    Push(lit->handle());
+    return;
+  }
+
+  VariableProxy* proxy = expr->AsVariableProxy();
+  if (proxy != NULL && proxy->is_this()) {
+    PushParameterAt(-1);
+    return;
+  }
+
+  UNREACHABLE();
+}
+
+
 #undef __
 
 } }  // namespace v8::internal
diff --git a/src/ia32/virtual-frame-ia32.h b/src/ia32/virtual-frame-ia32.h
index b078ba0897..59142b40e2 100644
--- a/src/ia32/virtual-frame-ia32.h
+++ b/src/ia32/virtual-frame-ia32.h
@@ -415,6 +415,10 @@ class VirtualFrame: public ZoneObject {
     result->Unuse();
   }
 
+  // Pushing an expression expects that the expression is trivial (according
+  // to Expression::IsTrivial).
+  void Push(Expression* expr);
+
   // Nip removes zero or more elements from immediately below the top
   // of the frame, leaving the previous top-of-frame value on top of
   // the frame.  Nip(k) is equivalent to x = Pop(), Drop(k), Push(x).