--- old/src/share/vm/opto/stringopts.cpp	Thu Jul  5 12:02:29 2012
+++ new/src/share/vm/opto/stringopts.cpp	Thu Jul  5 12:02:28 2012
@@ -534,7 +534,22 @@
           CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
           if (csj->method() != NULL &&
               csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString) {
-            sc->add_control(csj);
+            if (arg->outcnt() == 1) {
+              // _control is the list of StringBuilder calls nodes which
+              // will be eliminated by this String concatenation optimization.
+              // Integer::toString() call is not part of StringBuilder calls
+              // chain. It's node could be eliminated only if it's result
+              // is used only by this chain.
+              // An other limitation: it should be used only once because
+              // it is unknown that it is used only by this SB calls chain
+              // until all chain's nodes are collected.
+              //
+              // Note, it is fine to not eliminate Integer::toString() call
+              // node. It will be inlined later and it's code will fold if
+              // it's result is not used.
+              assert(arg->unique_out() == cnode, "sanity");
+              sc->add_control(csj);
+            }
             sc->push_int(csj->in(TypeFunc::Parms));
             continue;
           }