Make the FastCloneShallowArrayStub a bit prettier....

bleeding_edge/src/ia32/codegen-ia32.cc

 // Copyright 2006-2009 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 6644 matching lines @@
   __ TailCallRuntime(ExternalReference(Runtime::kNewContext), 1, 1);
 }
 
 
 void FastCloneShallowArrayStub::Generate(MacroAssembler* masm) {
   int elements_size = (length_ > 0) ? FixedArray::SizeFor(length_) : 0;
   int size = JSArray::kSize + elements_size;
 
   // Load boilerplate object into ecx and check if we need to create a
   // boilerplate.
+  Label slow_case;
   __ mov(ecx, Operand(esp, 3 * kPointerSize));
   __ mov(eax, Operand(esp, 2 * kPointerSize));
-  ASSERT(kPointerSize == 4);
-  __ mov(ecx, FieldOperand(ecx,
-                           eax,
-                           times_2,
-                           FixedArray::kHeaderSize));
+  ASSERT((kPointerSize == 4) && (kSmiTagSize == 1) && (kSmiTag == 0));
+  __ mov(ecx, FieldOperand(ecx, eax, times_2, FixedArray::kHeaderSize));
   __ cmp(ecx, Factory::undefined_value());
-  Label slow_case;
   __ j(equal, &slow_case);
 
-
   // Allocate both the JS array and the elements array in one big
   // allocation. This avoids multiple limit checks.
   __ AllocateInNewSpace(size, eax, ebx, edx, &slow_case, TAG_OBJECT);
 
   // Copy the JS array part.
   for (int i = 0; i < JSArray::kSize; i += kPointerSize) {
     if ((i != JSArray::kElementsOffset) || (length_ == 0)) {
       __ mov(ebx, FieldOperand(ecx, i));
       __ mov(FieldOperand(eax, i), ebx);
     }
@@ skipping 2217 matching lines @@
     __ add(Operand(dest), Immediate(2));
   }
   __ sub(Operand(count), Immediate(1));
   __ j(not_zero, &loop);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal