src/hotspot/share/opto/memnode.cpp

rev 52427 : 8213371: GC/C2 abstraction and cleanup to handle custom offset for GC memory accesses

*** 1695,1705 ****
      // Different array types begin at slightly different offsets (12 vs. 16).
      // We choose T_BYTE as an example base type that is least restrictive
      // as to alignment, which will therefore produce the smallest
      // possible base offset.
      const int min_base_off = arrayOopDesc::base_offset_in_bytes(T_BYTE);
!     const bool off_beyond_header = ((uint)off >= (uint)min_base_off);
  
      // Try to constant-fold a stable array element.
      if (FoldStableValues && !is_mismatched_access() && ary->is_stable()) {
        // Make sure the reference is not into the header and the offset is constant
        ciObject* aobj = ary->const_oop();
--- 1695,1705 ----
      // Different array types begin at slightly different offsets (12 vs. 16).
      // We choose T_BYTE as an example base type that is least restrictive
      // as to alignment, which will therefore produce the smallest
      // possible base offset.
      const int min_base_off = arrayOopDesc::base_offset_in_bytes(T_BYTE);
!     const bool off_beyond_header = (off >= min_base_off);
  
      // Try to constant-fold a stable array element.
      if (FoldStableValues && !is_mismatched_access() && ary->is_stable()) {
        // Make sure the reference is not into the header and the offset is constant
        ciObject* aobj = ary->const_oop();
*** 1732,1742 ****
      if ((t->isa_int() == NULL) && (t->isa_long() == NULL)
          && (_type->isa_vect() == NULL)
          && Opcode() != Op_LoadKlass && Opcode() != Op_LoadNKlass) {
        // t might actually be lower than _type, if _type is a unique
        // concrete subclass of abstract class t.
!       if (off_beyond_header) {  // is the offset beyond the header?
          const Type* jt = t->join_speculative(_type);
          // In any case, do not allow the join, per se, to empty out the type.
          if (jt->empty() && !t->empty()) {
            // This can happen if a interface-typed array narrows to a class type.
            jt = _type;
--- 1732,1742 ----
      if ((t->isa_int() == NULL) && (t->isa_long() == NULL)
          && (_type->isa_vect() == NULL)
          && Opcode() != Op_LoadKlass && Opcode() != Op_LoadNKlass) {
        // t might actually be lower than _type, if _type is a unique
        // concrete subclass of abstract class t.
!       if (off_beyond_header || off == Type::OffsetBot) {  // is the offset beyond the header?
          const Type* jt = t->join_speculative(_type);
          // In any case, do not allow the join, per se, to empty out the type.
          if (jt->empty() && !t->empty()) {
            // This can happen if a interface-typed array narrows to a class type.
            jt = _type;