To fully support hydrogen code stubs which accept a variable number of arguments,

src/ia32/deoptimizer-ia32.cc

Index: src/ia32/deoptimizer-ia32.cc
diff --git a/src/ia32/deoptimizer-ia32.cc b/src/ia32/deoptimizer-ia32.cc
index 667f1319cde10cbea37d02ffdf2164745097cba8..23dfbaedf009485fb3e83d4c8306d4ccc3d2574f 100644
--- a/src/ia32/deoptimizer-ia32.cc
+++ b/src/ia32/deoptimizer-ia32.cc
@@ -575,6 +575,10 @@ void Deoptimizer::DoComputeCompiledStubFrame(TranslationIterator* iterator,
 
   int caller_arg_count = 0;
   if (descriptor->stack_parameter_count_ != NULL) {
+    // TODO(mvstanton): when a hydrogen stub with multiple arguments of any
+    // complexity comes along this code will fail because the register is likely
+    // consumed with another value. Retrieve the caller_arg_count from the
+    // environment instead via iterator.
     caller_arg_count =
         input_->GetRegister(descriptor->stack_parameter_count_->code());
   }