src/hotspot/cpu/arm/gc/shared/cardTableBarrierSetAssembler_arm.cpp

*** 117,127 ****
       showed that loading of card table base from thread descriptor is
       7-18% slower compared to loading of literal embedded into the code.
       Possible cause is a cache miss (card table base address resides in a
       rarely accessed area of thread descriptor).
    */
-   // TODO-AARCH64 Investigate if mov_slow is faster than ldr from Rthread on AArch64
    __ mov_address(card_table_base, (address)ct->byte_map_base(), symbolic_Relocation::card_table_reference);
  }
  
  // The 2nd part of the store check.
  void CardTableBarrierSetAssembler::store_check_part2(MacroAssembler* masm, Register obj, Register card_table_base, Register tmp) {
--- 117,126 ----
*** 134,149 ****
    CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
    CardTable* ct = ctbs->card_table();
    assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "Adjust store check code");
  
    assert(CardTable::dirty_card_val() == 0, "Dirty card value must be 0 due to optimizations.");
- #ifdef AARCH64
-   add(card_table_base, card_table_base, AsmOperand(obj, lsr, CardTable::card_shift));
-   Address card_table_addr(card_table_base);
- #else
    Address card_table_addr(card_table_base, obj, lsr, CardTable::card_shift);
- #endif
  
    if (UseCondCardMark) {
      if (ct->scanned_concurrently()) {
        __ membar(MacroAssembler::Membar_mask_bits(MacroAssembler::StoreLoad), noreg);
      }
--- 133,143 ----
*** 162,174 ****
      set_card(masm, card_table_base, card_table_addr, tmp);
    }
  }
  
  void CardTableBarrierSetAssembler::set_card(MacroAssembler* masm, Register card_table_base, Address card_table_addr, Register tmp) {
- #ifdef AARCH64
-   strb(ZR, card_table_addr);
- #else
    CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
    CardTable* ct = ctbs->card_table();
    if ((((uintptr_t)ct->byte_map_base() & 0xff) == 0)) {
      // Card table is aligned so the lowest byte of the table address base is zero.
      // This works only if the code is not saved for later use, possibly
--- 156,165 ----
*** 176,182 ****
      __ strb(card_table_base, card_table_addr);
    } else {
      __ mov(tmp, 0);
      __ strb(tmp, card_table_addr);
    }
- #endif // AARCH64
  }
--- 167,172 ----