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

src/arm/full-codegen-arm.cc

 // Copyright 2009 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 765 matching lines @@
   __ mov(r1, Operand(expr->flags()));
   __ stm(db_w, sp, r4.bit() | r3.bit() | r2.bit() | r1.bit());
   __ CallRuntime(Runtime::kMaterializeRegExpLiteral, 4);
   __ bind(&done);
   Apply(context_, r0);
 }
 
 
 void FullCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
   Comment cmnt(masm_, "[ ObjectLiteral");
-  __ ldr(r2, MemOperand(fp,  JavaScriptFrameConstants::kFunctionOffset));
-  __ ldr(r2, FieldMemOperand(r2, JSFunction::kLiteralsOffset));
-  __ mov(r1, Operand(Smi::FromInt(expr->literal_index())));
-  __ mov(r0, Operand(expr->constant_properties()));
-  __ stm(db_w, sp, r2.bit() | r1.bit() | r0.bit());
+  __ ldr(r3, MemOperand(fp,  JavaScriptFrameConstants::kFunctionOffset));
+  __ ldr(r3, FieldMemOperand(r3, JSFunction::kLiteralsOffset));
+  __ mov(r2, Operand(Smi::FromInt(expr->literal_index())));
+  __ mov(r1, Operand(expr->constant_properties()));
+  __ mov(r0, Operand(Smi::FromInt(expr->fast_elements() ? 1 : 0)));
+  __ stm(db_w, sp, r3.bit() | r2.bit() | r1.bit() | r0.bit());
   if (expr->depth() > 1) {
-    __ CallRuntime(Runtime::kCreateObjectLiteral, 3);
+    __ CallRuntime(Runtime::kCreateObjectLiteral, 4);
   } else {
-    __ CallRuntime(Runtime::kCreateObjectLiteralShallow, 3);
+    __ CallRuntime(Runtime::kCreateObjectLiteralShallow, 4);
   }
 
   // If result_saved is true the result is on top of the stack.  If
   // result_saved is false the result is in r0.
   bool result_saved = false;
 
   for (int i = 0; i < expr->properties()->length(); i++) {
     ObjectLiteral::Property* property = expr->properties()->at(i);
     if (property->IsCompileTimeValue()) continue;
 
@@ skipping 1053 matching lines @@
   __ pop(result_register());
   ASSERT_EQ(1, kSmiTagSize + kSmiShiftSize);
   __ mov(r1, Operand(r1, ASR, 1));  // Un-smi-tag value.
   __ add(pc, r1, Operand(masm_->CodeObject()));
 }
 
 
 #undef __
 
 } }  // namespace v8::internal