nonperm.fix.diff

diff --git a/src/share/vm/c1/c1_GraphBuilder.cpp b/src/share/vm/c1/c1_GraphBuilder.cpp
--- a/src/share/vm/c1/c1_GraphBuilder.cpp
+++ b/src/share/vm/c1/c1_GraphBuilder.cpp
@@ -1442,7 +1442,7 @@
         switch (field_type) {
         case T_ARRAY:
         case T_OBJECT:
-          if (field_val.as_object()->has_encoding()) {
+          if (field_val.as_object()->should_be_constant()) {
             constant =  new Constant(as_ValueType(field_val));
           }
           break;
diff --git a/src/share/vm/ci/ciObject.cpp b/src/share/vm/ci/ciObject.cpp
--- a/src/share/vm/ci/ciObject.cpp
+++ b/src/share/vm/ci/ciObject.cpp
@@ -181,7 +181,14 @@
 // ------------------------------------------------------------------
 // ciObject::has_encoding
 bool ciObject::has_encoding() {
-  if (NonPermCodeRefs)  return true;  // everybody codes now
+  if (NonPermCodeRefs >= 1)  return true;  // everybody codes now
+  return handle() == NULL || is_perm();
+}
+
+// ------------------------------------------------------------------
+// ciObject::should_be_constant()
+bool ciObject::should_be_constant() {
+  if (NonPermCodeRefs >= 2)  return true;  // force everybody to code
   return handle() == NULL || is_perm();
 }
 
diff --git a/src/share/vm/ci/ciObject.hpp b/src/share/vm/ci/ciObject.hpp
--- a/src/share/vm/ci/ciObject.hpp
+++ b/src/share/vm/ci/ciObject.hpp
@@ -92,12 +92,17 @@
   int hash();
 
   // Tells if this oop has an encoding.  (I.e., is it null or perm?)
-  // If NonPermCodeRefs is true, all oops have encodings.
+  // If NonPermCodeRefs is non-zero, all oops have encodings.
   // If it does not have an encoding, the compiler is responsible for
   // making other arrangements for dealing with the oop.
   // See ciEnv::make_perm_array
   bool has_encoding();
 
+  // Tells if this oop should be made a constant.
+  // The property has_encoding must be true for this object to be a constant.
+  // If NonPermCodeRefs<=1, is_null_object or is_perm must also be true.
+  bool should_be_constant();
+
   // Is this object guaranteed to be in the permanent part of the heap?
   // If so, CollectedHeap::can_elide_permanent_oop_store_barriers is relevant.
   // If the answer is false, no guarantees are made.
diff --git a/src/share/vm/opto/parse3.cpp b/src/share/vm/opto/parse3.cpp
--- a/src/share/vm/opto/parse3.cpp
+++ b/src/share/vm/opto/parse3.cpp
@@ -279,13 +279,18 @@
   case T_LONG:     push_pair( longcon(constant.as_long()) ); break;
   case T_ARRAY:
   case T_OBJECT: {
-    // the oop is in perm space if the ciObject "has_encoding"
-    // or else NonPermCodeRefs must be true
+    // cases:
+    //   oop == null || oop in perm space
+    //          => has_encoding && should_be_constant
+    //   oop in non-perm space && NonPermCodeRefs<2
+    //          => has_encoding==NonPermCodeRefs && !should_be_constant
+    //   oop in non-perm space && NonPermCodeRefs=2
+    //          => has_encoding && should_be_constant
     ciObject* oop_constant = constant.as_object();
     if (oop_constant->is_null_object()) {
       push( zerocon(T_OBJECT) );
       break;
-    } else if (oop_constant->has_encoding()) {
+    } else if (oop_constant->should_be_constant()) {
       push( makecon(TypeOopPtr::make_from_constant(oop_constant)) );
       break;
     } else {
diff --git a/src/share/vm/runtime/globals.hpp b/src/share/vm/runtime/globals.hpp
--- a/src/share/vm/runtime/globals.hpp
+++ b/src/share/vm/runtime/globals.hpp
@@ -714,8 +714,8 @@
   diagnostic(bool, TraceNMethodInstalls, false,                             \
              "Trace nmethod intallation")                                   \
                                                                             \
-  diagnostic(bool, NonPermCodeRefs, true,                                   \
-             "allow non-perm references in the code cache")                 \
+  diagnostic(int, NonPermCodeRefs, 1,                                       \
+             "0: disallow non-perm oops in the code cache; 2: emit many")   \
                                                                             \
   diagnostic(bool, TraceOSRBreakpoint, false,                               \
              "Trace OSR Breakpoint ")                                       \