/*

 * 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 "opto/arraycopynode.hpp"

#include "opto/graphKit.hpp"

#include "opto/idealKit.hpp"

#include "opto/narrowptrnode.hpp"

#include "gc/shared/c2/modRefBarrierSetC2.hpp"

#include "utilities/macros.hpp"

Node* ModRefBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const {

  DecoratorSet decorators = access.decorators();

  GraphKit* kit = access.kit();

  const TypePtr* adr_type = access.addr().type();

  Node* adr = access.addr().node();

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

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

  bool use_precise = on_array || anonymous;

    return BarrierSetC2::store_at_resolved(access, val);

  }

  uint adr_idx = kit->C->get_alias_index(adr_type);

  assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );

  pre_barrier(kit, true /* do_load */, kit->control(), access.base(), adr, adr_idx, val.node(),

              static_cast<const TypeOopPtr*>(val.type()), NULL /* pre_val */, access.type());

  Node* store = BarrierSetC2::store_at_resolved(access, val);

  post_barrier(kit, kit->control(), access.raw_access(), access.base(), adr, adr_idx, val.node(),

               access.type(), use_precise);

  return store;

}

Node* ModRefBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicAccess& access, Node* expected_val,

                                                         Node* new_val, const Type* value_type) const {

  GraphKit* kit = access.kit();

  if (!access.is_oop()) {

    return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);

  }

  pre_barrier(kit, false /* do_load */,

              kit->control(), NULL, NULL, max_juint, NULL, NULL,

              expected_val /* pre_val */, T_OBJECT);

  Node* result = BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);

  post_barrier(kit, kit->control(), access.raw_access(), access.base(),

               access.addr().node(), access.alias_idx(), new_val, T_OBJECT, true);

  return result;

}

Node* ModRefBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicAccess& access, Node* expected_val,

                                                          Node* new_val, const Type* value_type) const {

  GraphKit* kit = access.kit();

  if (!access.is_oop()) {

    return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);

  }

  pre_barrier(kit, false /* do_load */,

              kit->control(), NULL, NULL, max_juint, NULL, NULL,

              expected_val /* pre_val */, T_OBJECT);

  Node* load_store = BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);

  // Emit the post barrier only when the actual store happened. This makes sense

  // to check only for LS_cmp_* that can fail to set the value.

  // LS_cmp_exchange does not produce any branches by default, so there is no

  // boolean result to piggyback on. TODO: When we merge CompareAndSwap with

  // CompareAndExchange and move branches here, it would make sense to conditionalize

  // post_barriers for LS_cmp_exchange as well.

  //

  // CAS success path is marked more likely since we anticipate this is a performance

  // critical path, while CAS failure path can use the penalty for going through unlikely

  // path as backoff. Which is still better than doing a store barrier there.

  IdealKit ideal(kit);

  ideal.if_then(load_store, BoolTest::ne, ideal.ConI(0), PROB_STATIC_FREQUENT); {

    kit->sync_kit(ideal);

    post_barrier(kit, ideal.ctrl(), access.raw_access(), access.base(),

                 access.addr().node(), access.alias_idx(), new_val, T_OBJECT, true);

    ideal.sync_kit(kit);

  } ideal.end_if();

  kit->final_sync(ideal);

  return load_store;

}

Node* ModRefBarrierSetC2::atomic_xchg_at_resolved(C2AtomicAccess& access, Node* new_val, const Type* value_type) const {

  GraphKit* kit = access.kit();

  Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, new_val, value_type);

  if (!access.is_oop()) {

    return result;

  }

  // Don't need to load pre_val. The old value is returned by load_store.

  // The pre_barrier can execute after the xchg as long as no safepoint

  // gets inserted between them.

  pre_barrier(kit, false /* do_load */,

              kit->control(), NULL, NULL, max_juint, NULL, NULL,

              result /* pre_val */, T_OBJECT);

  post_barrier(kit, kit->control(), access.raw_access(), access.base(), access.addr().node(),

               access.alias_idx(), new_val, T_OBJECT, true);

  return result;

}