/*
 * Copyright (c) 2017, 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/c2ModRefBSCodeGen.hpp"
#include "utilities/macros.hpp"

Node* C2ModRefBSCodeGen::store_at_resolved(GraphKit* kit, Node* obj, Node* adr, const TypePtr* adr_type, Node* val, const Type* val_type, BasicType bt, C2DecoratorSet decorators) {
  bool on_array = (decorators & C2_ACCESS_ON_ARRAY) != 0;
  bool anonymous = (decorators & C2_ACCESS_ON_ANONYMOUS) != 0;
  bool on_heap = (decorators & C2_ACCESS_ON_HEAP) != 0;
  bool use_precise = on_array || anonymous;
  bool is_obj = bt == T_OBJECT || bt == T_ARRAY;

  if (!is_obj || (!on_heap && !anonymous)) {
    return C2BarrierSetCodeGen::store_at_resolved(kit, obj, adr, adr_type, val, val_type, bt, decorators);
  }

  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(), obj, adr, adr_idx, val,
              static_cast<const TypeOopPtr*>(val_type), NULL /* pre_val */, bt);
  Node* store = C2BarrierSetCodeGen::store_at_resolved(kit, obj, adr, adr_type, val, val_type, bt, decorators);
  post_barrier(kit, kit->control(), store, obj, adr, adr_idx, val, bt, use_precise);

  return store;
}

Node* C2ModRefBSCodeGen::cas_val_at_resolved(GraphKit* kit, Node* obj, Node* adr, const TypePtr* adr_type, int alias_idx, Node* expected_val, Node* new_val, const Type* value_type, Node* mem, Node*& load_store, BasicType bt, C2DecoratorSet decorators) {
  bool is_obj = bt == T_OBJECT || bt == T_ARRAY;
  if (!is_obj) {
    return C2BarrierSetCodeGen::cas_val_at_resolved(kit, obj, adr, adr_type, alias_idx, expected_val, new_val, value_type, mem, load_store, bt, decorators);
  }

  pre_barrier(kit, false /* do_load */,
              kit->control(), NULL, NULL, max_juint, NULL, NULL,
              expected_val /* pre_val */,
              T_OBJECT);

  Node* result = C2BarrierSetCodeGen::cas_val_at_resolved(kit, obj, adr, adr_type, alias_idx, expected_val, new_val, value_type, mem, load_store, bt, decorators);

  post_barrier(kit, kit->control(), load_store, obj, adr, alias_idx, new_val, T_OBJECT, true);

  return result;
}

Node* C2ModRefBSCodeGen::cas_bool_at_resolved(GraphKit* kit, Node* obj, Node* adr, const TypePtr* adr_type, int alias_idx, Node* expected_val, Node* new_val, const Type* value_type, Node* mem, BasicType bt, C2DecoratorSet decorators) {
  bool is_obj = bt == T_OBJECT || bt == T_ARRAY;
  if (!is_obj) {
    return C2BarrierSetCodeGen::cas_bool_at_resolved(kit, obj, adr, adr_type, alias_idx, expected_val, new_val, value_type, mem, bt, decorators);
  }

  pre_barrier(kit, false /* do_load */,
              kit->control(), NULL, NULL, max_juint, NULL, NULL,
              expected_val /* pre_val */,
              T_OBJECT);

  Node* load_store = C2BarrierSetCodeGen::cas_bool_at_resolved(kit, obj, adr, adr_type, alias_idx, expected_val, new_val, value_type, mem, bt, decorators);

  // 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(), load_store, obj, adr, alias_idx, new_val, T_OBJECT, true);
    ideal.sync_kit(kit);
  } ideal.end_if();
  kit->final_sync(ideal);

  return load_store;
}

Node* C2ModRefBSCodeGen::swap_at_resolved(GraphKit* kit, Node* obj, Node* adr, const TypePtr* adr_type, int alias_idx, Node* new_val, const Type* value_type, Node* mem, Node*& load_store, BasicType bt, C2DecoratorSet decorators) {
  bool is_obj = bt == T_OBJECT || bt == T_ARRAY;
  Node* result = C2BarrierSetCodeGen::swap_at_resolved(kit, obj, adr, adr_type, alias_idx, new_val, value_type, mem, load_store, bt, decorators);
  if (!is_obj) {
    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(), load_store, obj, adr, alias_idx, new_val, T_OBJECT, true);

  return result;
}