Fix generated code for String.charCodeAt.

src/ia32/codegen-ia32.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 12620 matching lines @@
     MacroAssembler* masm, const RuntimeCallHelper& call_helper) {
   __ Abort("Unexpected fallthrough to CharCodeAt slow case");
 
   // Index is not a smi.
   __ bind(&index_not_smi_);
   // If index is a heap number, try converting it to an integer.
   __ CheckMap(index_, Factory::heap_number_map(), index_not_number_, true);
   call_helper.BeforeCall(masm);
   __ push(object_);
   __ push(index_);
-  __ push(result_);
   __ push(index_);  // Consumed by runtime conversion function.
   if (index_flags_ == STRING_INDEX_IS_NUMBER) {
     __ CallRuntime(Runtime::kNumberToIntegerMapMinusZero, 1);
   } else {
     ASSERT(index_flags_ == STRING_INDEX_IS_ARRAY_INDEX);
     // NumberToSmi discards numbers that are not exact integers.
     __ CallRuntime(Runtime::kNumberToSmi, 1);
   }
   if (!scratch_.is(eax)) {
     // Save the conversion result before the pop instructions below
     // have a chance to overwrite it.
     __ mov(scratch_, eax);
   }
-  __ pop(result_);
   __ pop(index_);
   __ pop(object_);
+  // Reload the instance type.
+  __ mov(result_, FieldOperand(object_, HeapObject::kMapOffset));
+  __ movzx_b(result_, FieldOperand(result_, Map::kInstanceTypeOffset));
   call_helper.AfterCall(masm);
   // If index is still not a smi, it must be out of range.
   ASSERT(kSmiTag == 0);
   __ test(scratch_, Immediate(kSmiTagMask));
   __ j(not_zero, index_out_of_range_);
   // Otherwise, return to the fast path.
   __ jmp(&got_smi_index_);
 
   // Call runtime. We get here when the receiver is a string and the
   // index is a number, but the code of getting the actual character
@@ skipping 820 matching lines @@
   // tagged as a small integer.
   __ bind(&runtime);
   __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32