Do not waste space for the fast-case elements backing storage for ...

src/arm/codegen-arm.cc

 // 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:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2691 matching lines @@
 
 
 void CodeGenerator::VisitObjectLiteral(ObjectLiteral* node) {
 #ifdef DEBUG
   int original_height = frame_->height();
 #endif
   VirtualFrame::SpilledScope spilled_scope;
   Comment cmnt(masm_, "[ ObjectLiteral");
 
   // Load the function of this activation.
-  __ ldr(r2, frame_->Function());
+  __ ldr(r3, frame_->Function());
   // Literal array.
-  __ ldr(r2, FieldMemOperand(r2, JSFunction::kLiteralsOffset));
+  __ ldr(r3, FieldMemOperand(r3, JSFunction::kLiteralsOffset));
   // Literal index.
-  __ mov(r1, Operand(Smi::FromInt(node->literal_index())));
+  __ mov(r2, Operand(Smi::FromInt(node->literal_index())));
   // Constant properties.
-  __ mov(r0, Operand(node->constant_properties()));
-  frame_->EmitPushMultiple(3, r2.bit() | r1.bit() | r0.bit());
+  __ mov(r1, Operand(node->constant_properties()));
+  // Should the object literal have fast elements?
+  __ mov(r0, Operand(Smi::FromInt(node->fast_elements() ? 1 : 0)));
+  frame_->EmitPushMultiple(4, r3.bit() | r2.bit() | r1.bit() | r0.bit());
   if (node->depth() > 1) {
-    frame_->CallRuntime(Runtime::kCreateObjectLiteral, 3);
+    frame_->CallRuntime(Runtime::kCreateObjectLiteral, 4);
   } else {
-    frame_->CallRuntime(Runtime::kCreateObjectLiteralShallow, 3);
+    frame_->CallRuntime(Runtime::kCreateObjectLiteralShallow, 4);
   }
   frame_->EmitPush(r0);  // save the result
   for (int i = 0; i < node->properties()->length(); i++) {
     // At the start of each iteration, the top of stack contains
     // the newly created object literal.
     ObjectLiteral::Property* property = node->properties()->at(i);
     Literal* key = property->key();
     Expression* value = property->value();
     switch (property->kind()) {
       case ObjectLiteral::Property::CONSTANT:
@@ skipping 5221 matching lines @@
 
   // Just jump to runtime to add the two strings.
   __ bind(&string_add_runtime);
   __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal