src/share/vm/opto/stringopts.cpp

*** 1601,1610 ****
--- 1601,1611 ----
        // below will overwrite the entire array
        AllocateArrayNode* char_alloc = AllocateArrayNode::Ideal_array_allocation(char_array, _gvn);
        char_alloc->maybe_set_complete(_gvn);
  
        // Now copy the string representations into the final char[]
+       char_array = __ shenandoah_write_barrier(char_array);
        Node* start = __ intcon(0);
        for (int argi = 0; argi < sc->num_arguments(); argi++) {
          Node* arg = sc->argument(argi);
          switch (sc->mode(argi)) {
            case StringConcat::IntMode: {