--- a/src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp	Wed Mar 21 19:45:24 2018 -0400
+++ b/src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp	Tue Mar 20 22:54:02 2018 +0800
@@ -79,8 +79,8 @@
 
   void call_VM_helper(Register oop_result, address entry_point, int number_of_arguments, bool check_exceptions = true);
 
-  // Maximum size of class area in Metaspace when compressed
-  uint64_t use_XOR_for_compressed_class_base;
+  // True if an XOR can be used to expand narrow klass references.
+  bool use_XOR_for_compressed_class_base;
 
  public:
   MacroAssembler(CodeBuffer* code) : Assembler(code) {
@@ -88,7 +88,7 @@
       = (operand_valid_for_logical_immediate(false /*is32*/,
                                              (uint64_t)Universe::narrow_klass_base())
          && ((uint64_t)Universe::narrow_klass_base()
-             > (1u << log2_intptr(CompressedClassSpaceSize))));
+             > (1UL << log2_intptr(Universe::narrow_klass_range()))));
   }
 
  // These routines should emit JVMTI PopFrame and ForceEarlyReturn handling code.

--- a/src/hotspot/share/memory/metaspaceShared.cpp	Wed Mar 21 19:45:24 2018 -0400
+++ b/src/hotspot/share/memory/metaspaceShared.cpp	Tue Mar 20 22:54:02 2018 +0800
@@ -234,6 +234,7 @@
       // with the archived ones, so it must be done after all encodings are determined.
       mapinfo->map_heap_regions();
     }
+    Universe::set_narrow_klass_range(CompressedClassSpaceSize);
 #endif // _LP64
   } else {
     assert(!mapinfo->is_open() && !UseSharedSpaces,
@@ -299,6 +300,8 @@
   // Set narrow_klass_shift to be LogKlassAlignmentInBytes. This is consistent
   // with AOT.
   Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes);
+  // Set the range of klass addresses to 4GB.
+  Universe::set_narrow_klass_range(cds_total);
 
   Metaspace::initialize_class_space(tmp_class_space);
   tty->print_cr("narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",

--- a/src/hotspot/share/memory/universe.cpp	Wed Mar 21 19:45:24 2018 -0400
+++ b/src/hotspot/share/memory/universe.cpp	Tue Mar 20 22:54:02 2018 +0800
@@ -165,6 +165,7 @@
 NarrowPtrStruct Universe::_narrow_oop = { NULL, 0, true };
 NarrowPtrStruct Universe::_narrow_klass = { NULL, 0, true };
 address Universe::_narrow_ptrs_base;
+uint64_t Universe::_narrow_klass_range = (uint64_t(max_juint)+1);
 
 void Universe::basic_type_classes_do(void f(Klass*)) {
   f(boolArrayKlassObj());

--- a/src/hotspot/share/memory/universe.hpp	Wed Mar 21 19:45:24 2018 -0400
+++ b/src/hotspot/share/memory/universe.hpp	Tue Mar 20 22:54:02 2018 +0800
@@ -194,7 +194,8 @@
   // For UseCompressedClassPointers.
   static struct NarrowPtrStruct _narrow_klass;
   static address _narrow_ptrs_base;
-
+  // CompressedClassSpaceSize set to 1GB, but appear 3GB away from _narrow_ptrs_base during CDS dump.
+  static uint64_t _narrow_klass_range;
   // array of dummy objects used with +FullGCAlot
   debug_only(static objArrayOop _fullgc_alot_dummy_array;)
   // index of next entry to clear
@@ -244,6 +245,10 @@
     assert(UseCompressedClassPointers, "no compressed klass ptrs?");
     _narrow_klass._base   = base;
   }
+  static void     set_narrow_klass_range(uint64_t range) {
+     assert(UseCompressedClassPointers, "no compressed klass ptrs?");
+     _narrow_klass_range = range;
+  }
   static void     set_narrow_oop_use_implicit_null_checks(bool use) {
     assert(UseCompressedOops, "no compressed ptrs?");
     _narrow_oop._use_implicit_null_checks   = use;
@@ -429,6 +434,7 @@
   // For UseCompressedClassPointers
   static address  narrow_klass_base()                     { return  _narrow_klass._base; }
   static bool  is_narrow_klass_base(void* addr)           { return (narrow_klass_base() == (address)addr); }
+  static uint64_t narrow_klass_range()                    { return  _narrow_klass_range; }
   static int      narrow_klass_shift()                    { return  _narrow_klass._shift; }
   static bool     narrow_klass_use_implicit_null_checks() { return  _narrow_klass._use_implicit_null_checks; }