src/share/vm/opto/arraycopynode.hpp

rev 12726 : 8179678: ArrayCopy with same src and dst can cause incorrect execution or compiler crash
Summary: replacing load on dst with load on src only valid if copy doesn't modify src element to load
Reviewed-by:

@@ -165,11 +165,12 @@
   bool is_alloc_tightly_coupled() const { return _alloc_tightly_coupled; }
 
   bool has_negative_length_guard() const { return _has_negative_length_guard; }
 
   static bool may_modify(const TypeOopPtr *t_oop, MemBarNode* mb, PhaseTransform *phase, ArrayCopyNode*& ac);
-  bool modifies(intptr_t offset_lo, intptr_t offset_hi, PhaseTransform* phase, bool must_modify);
+  bool modifies(intptr_t offset_lo, intptr_t offset_hi, PhaseTransform* phase, bool must_modify) const;
+  bool can_replace_dest_load_with_src_load(intptr_t offset_lo, intptr_t offset_hi, PhaseTransform* phase) const;
 
 #ifndef PRODUCT
   virtual void dump_spec(outputStream *st) const;
   virtual void dump_compact_spec(outputStream* st) const;
 #endif