/*

 * Copyright (c) 2018, Red Hat, Inc. All rights reserved.

 *

 * 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 "c1/c1_LIRAssembler.hpp"

#include "c1/c1_MacroAssembler.hpp"

#include "gc/shenandoah/shenandoahBarrierSet.hpp"

#include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"

#include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"

#define __ masm->masm()->

void LIR_OpShenandoahCompareAndSwap::emit_code(LIR_Assembler* masm) {

  Register addr = _addr->as_register_lo();

  Register newval = _new_value->as_register();

  Register cmpval = _cmp_value->as_register();

  Register tmp1 = _tmp1->as_register();

  Register tmp2 = _tmp2->as_register();

  Register result = result_opr()->as_register();

  assert(cmpval == rax, "wrong register");

  assert(newval != NULL, "new val must be register");

  assert(cmpval != newval, "cmp and new values must be in different registers");

  assert(cmpval != addr, "cmp and addr must be in different registers");

  assert(newval != addr, "new value and addr must be in different registers");

  // Apply storeval barrier to newval.

  ShenandoahBarrierSet::assembler()->storeval_barrier(masm->masm(), newval, tmp1);

  if (UseCompressedOops) {

    __ encode_heap_oop(cmpval);

    __ mov(rscratch1, newval);

    __ encode_heap_oop(rscratch1);

    newval = rscratch1;

  }

  ShenandoahBarrierSet::assembler()->cmpxchg_oop(masm->masm(), result, Address(addr, 0), cmpval, newval, false, tmp1, tmp2);

}

#undef __

#ifdef ASSERT

#define __ gen->lir(__FILE__, __LINE__)->

#else

#define __ gen->lir()->

#endif

LIR_Opr ShenandoahBarrierSetC1::atomic_cmpxchg_at_resolved(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) {

  if (access.is_oop()) {

    LIRGenerator* gen = access.gen();

    if (ShenandoahSATBBarrier) {

      pre_barrier(gen, access.access_emit_info(), access.decorators(), access.resolved_addr(),

                  LIR_OprFact::illegalOpr /* pre_val */);

    }

    if (ShenandoahCASBarrier) {

      cmp_value.load_item_force(FrameMap::rax_oop_opr);

      new_value.load_item();

      LIR_Opr t1 = gen->new_register(T_OBJECT);

      LIR_Opr t2 = gen->new_register(T_OBJECT);

      LIR_Opr addr = access.resolved_addr()->as_address_ptr()->base();

      LIR_Opr result = gen->new_register(T_INT);

      __ append(new LIR_OpShenandoahCompareAndSwap(addr, cmp_value.result(), new_value.result(), t1, t2, result));

      return result;

    }

  }

  return BarrierSetC1::atomic_cmpxchg_at_resolved(access, cmp_value, new_value);

}

LIR_Opr ShenandoahBarrierSetC1::atomic_xchg_at_resolved(LIRAccess& access, LIRItem& value) {

  LIRGenerator* gen = access.gen();

  BasicType type = access.type();

  LIR_Opr result = gen->new_register(type);

  value.load_item();

  LIR_Opr value_opr = value.result();

  if (access.is_oop()) {

    value_opr = storeval_barrier(access.gen(), value_opr, access.access_emit_info(), access.decorators());

  }

  // Because we want a 2-arg form of xchg and xadd

  __ move(value_opr, result);

  assert(type == T_INT || type == T_OBJECT || type == T_ARRAY LP64_ONLY( || type == T_LONG ), "unexpected type");

  __ xchg(access.resolved_addr(), result, result, LIR_OprFact::illegalOpr);

  if (access.is_oop()) {

    result = load_reference_barrier(access.gen(), result, access.access_emit_info(), true);

    if (ShenandoahSATBBarrier) {

      pre_barrier(access.gen(), access.access_emit_info(), access.decorators(), LIR_OprFact::illegalOpr,

                  result /* pre_val */);

    }

  }

  return result;

}