3023 #ifndef AARCH64

  3028 #else // AARCH64

  3029   ReservedSpace metaspace_rs;

  3030 

  3031   // Our compressed klass pointers may fit nicely into the lower 32

  3032   // bits.

  3033   if ((uint64_t)requested_addr + compressed_class_space_size() < 4*G) {

  3034     metaspace_rs = ReservedSpace(compressed_class_space_size(),

  3035                                              _reserve_alignment,

  3036                                              large_pages,

  3037                                              requested_addr, 0);

  3038   }

  3039 

  3040   if (! metaspace_rs.is_reserved()) {

  3041     // Try to align metaspace so that we can decode a compressed klass

  3042     // with a single MOVK instruction.  We can do this iff the

  3043     // compressed class base is a multiple of 4G.

  3044     for (char *a = (char*)align_ptr_up(requested_addr, 4*G);

  3045          a < (char*)(1024*G);

  3046          a += 4*G) {

  3047 

  3048 #if INCLUDE_CDS

  3049       if (UseSharedSpaces

  3050           && ! can_use_cds_with_metaspace_addr(a, cds_base)) {

  3051         // We failed to find an aligned base that will reach.  Fall

  3052         // back to using our requested addr.

  3053         metaspace_rs = ReservedSpace(compressed_class_space_size(),

  3054                                      _reserve_alignment,

  3055                                      large_pages,

  3056                                      requested_addr, 0);

  3057         break;

  3058       }

  3059 #endif

  3060 

  3061       metaspace_rs = ReservedSpace(compressed_class_space_size(),

  3062                                    _reserve_alignment,

  3063                                    large_pages,

  3064                                    a, 0);

  3065       if (metaspace_rs.is_reserved())

  3066         break;

  3067     }

  3068   }

  3069 

  3070 #endif // AARCH64

  3071