/*

 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "asm/macroAssembler.inline.hpp"

#include "gc/shared/barrierSet.hpp"

#include "gc/shared/cardTable.hpp"

#include "gc/shared/cardTableBarrierSet.hpp"

#include "gc/shared/cardTableBarrierSetAssembler.hpp"

#include "interpreter/interp_masm.hpp"

#define __ masm->

void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register obj, Address dst) {

  assert(bs->kind() == BarrierSet::CardTableBarrierSet, "Wrong barrier set kind");

  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);

  CardTable* ct = ctbs->card_table();

  assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");

  __ lsr(obj, obj, CardTable::card_shift);

  assert(CardTable::dirty_card_val() == 0, "must be");

  __ load_byte_map_base(rscratch1);

  if (UseCondCardMark) {

    Label L_already_dirty;

    __ membar(Assembler::StoreLoad);

    __ ldrb(rscratch2,  Address(obj, rscratch1));

    __ cbz(rscratch2, L_already_dirty);

    __ strb(zr, Address(obj, rscratch1));

    __ bind(L_already_dirty);

  } else {

    if (UseConcMarkSweepGC && CMSPrecleaningEnabled) {

      __ membar(Assembler::StoreStore);

    }

    __ strb(zr, Address(obj, rscratch1));

  }

}

void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,

                                                                    Register start, Register end, Register scratch, RegSet saved_regs) {

  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);

  CardTable* ct = ctbs->card_table();

  assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");

  Label L_loop;

  __ lsr(start, start, CardTable::card_shift);

  __ lsr(end, end, CardTable::card_shift);

  __ sub(end, end, start); // number of bytes to copy

  const Register count = end; // 'end' register contains bytes count now

  __ load_byte_map_base(scratch);

  __ add(start, start, scratch);

  if (UseConcMarkSweepGC) {

    __ membar(__ StoreStore);

  }

  __ bind(L_loop);

  __ strb(zr, Address(start, count));

  __ subs(count, count, 1);

  __ br(Assembler::GE, L_loop);

}

void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,

                                                Address dst, Register val, Register tmp1, Register tmp2) {

  bool on_array = (decorators & IN_HEAP_ARRAY) != 0;

  bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;

  bool precise = on_array || on_anonymous;

  if (val == noreg) {

    __ store_heap_oop_null(dst);

  } else {

    __ store_heap_oop(dst, val);

    // flatten object address if needed

    if (!precise || (dst.index() == noreg && dst.offset() == 0)) {

      store_check(masm, dst.base(), dst);

    } else {

      __ lea(r3, dst);

      store_check(masm, r3, dst);

    }

  }

}