7171824: assert(_offset >= 1) failed: illegal call to offset()

Summary: C1 value numbering hits unloaded klass.
Reviewed-by: kvn, twisti

src/share/vm/c1/c1_ValueMap.cpp

@@ -190,7 +190,7 @@ Value ValueMap::find_insert(Value x) {
   LoadField* lf = value->as_LoadField();                                                 \
   bool must_kill = lf != NULL                                                            \
                    && lf->field()->holder() == field->holder()                           \
-                   && lf->field()->offset() == field->offset();
+                   && (all_offsets || lf->field()->offset() == field->offset());
 
 #define MUST_KILL_EXCEPTION(must_kill, entry, value)                                     \
   assert(entry->nesting() < nesting(), "must not find bigger nesting than current");     \
@@ -205,7 +205,7 @@ void ValueMap::kill_array(ValueType* type) {
   GENERIC_KILL_VALUE(MUST_KILL_ARRAY);
 }
 
-void ValueMap::kill_field(ciField* field) {
+void ValueMap::kill_field(ciField* field, bool all_offsets) {
   GENERIC_KILL_VALUE(MUST_KILL_FIELD);
 }
 
@@ -280,9 +280,9 @@ class ShortLoopOptimizer : public ValueNumberingVisitor {
   ValueMap* value_map_of(BlockBegin* block)      { return _gvn->value_map_of(block); }
 
   // implementation for abstract methods of ValueNumberingVisitor
-  void      kill_memory()                        { _too_complicated_loop = true; }
-  void      kill_field(ciField* field)           { current_map()->kill_field(field); };
-  void      kill_array(ValueType* type)          { current_map()->kill_array(type); };
+  void      kill_memory()                                 { _too_complicated_loop = true; }
+  void      kill_field(ciField* field, bool all_offsets)  { current_map()->kill_field(field, all_offsets); };
+  void      kill_array(ValueType* type)                   { current_map()->kill_array(type); };
 
  public:
   ShortLoopOptimizer(GlobalValueNumbering* gvn)

src/share/vm/c1/c1_ValueMap.hpp

@@ -114,7 +114,7 @@ class ValueMap: public CompilationResourceObj {
   Value find_insert(Value x);
 
   void kill_memory();
-  void kill_field(ciField* field);
+  void kill_field(ciField* field, bool all_offsets);
   void kill_array(ValueType* type);
   void kill_exception();
   void kill_map(ValueMap* map);
@@ -136,7 +136,7 @@ class ValueNumberingVisitor: public InstructionVisitor {
  protected:
   // called by visitor functions for instructions that kill values
   virtual void kill_memory() = 0;
-  virtual void kill_field(ciField* field) = 0;
+  virtual void kill_field(ciField* field, bool all_offsets) = 0;
   virtual void kill_array(ValueType* type) = 0;
 
   // visitor functions
@@ -148,7 +148,7 @@ class ValueNumberingVisitor: public InstructionVisitor {
         x->field()->is_volatile()) {
       kill_memory();
     } else {
-      kill_field(x->field());
+      kill_field(x->field(), x->needs_patching());
     }
   }
   void do_StoreIndexed   (StoreIndexed*    x) { kill_array(x->type()); }
@@ -214,9 +214,9 @@ class ValueNumberingEffects: public ValueNumberingVisitor {
 
  public:
   // implementation for abstract methods of ValueNumberingVisitor
-  void          kill_memory()                    { _map->kill_memory(); }
-  void          kill_field(ciField* field)       { _map->kill_field(field); }
-  void          kill_array(ValueType* type)      { _map->kill_array(type); }
+  void          kill_memory()                                 { _map->kill_memory(); }
+  void          kill_field(ciField* field, bool all_offsets)  { _map->kill_field(field, all_offsets); }
+  void          kill_array(ValueType* type)                   { _map->kill_array(type); }
 
   ValueNumberingEffects(ValueMap* map): _map(map) {}
 };
@@ -234,9 +234,9 @@ class GlobalValueNumbering: public ValueNumberingVisitor {
   void          set_value_map_of(BlockBegin* block, ValueMap* map)   { assert(value_map_of(block) == NULL, ""); _value_maps.at_put(block->linear_scan_number(), map); }
 
   // implementation for abstract methods of ValueNumberingVisitor
-  void          kill_memory()                    { current_map()->kill_memory(); }
-  void          kill_field(ciField* field)       { current_map()->kill_field(field); }
-  void          kill_array(ValueType* type)      { current_map()->kill_array(type); }
+  void          kill_memory()                                 { current_map()->kill_memory(); }
+  void          kill_field(ciField* field, bool all_offsets)  { current_map()->kill_field(field, all_offsets); }
+  void          kill_array(ValueType* type)                   { current_map()->kill_array(type); }
 
   // main entry point that performs global value numbering
   GlobalValueNumbering(IR* ir);