/*
 * Copyright (c) 2016, 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 "ci/ciValueKlass.hpp"
#include "opto/addnode.hpp"
#include "opto/graphKit.hpp"
#include "opto/rootnode.hpp"
#include "opto/valuetypenode.hpp"
#include "opto/phaseX.hpp"

Node* ValueTypeNode::make(PhaseGVN& gvn, ciValueKlass* klass) {
  // Create a new ValueTypeNode with uninitialized values and NULL oop
  const TypeValueType* type = TypeValueType::make(klass);
  return new ValueTypeNode(type, gvn.zerocon(T_VALUETYPE));
}

Node* ValueTypeNode::make(PhaseGVN& gvn, Node* mem, Node* oop) {
  // Create and initialize a ValueTypeNode by loading all field
  // values from memory and also save the oop to the heap allocated version.
  const TypeValueTypePtr* vtptr = gvn.type(oop)->is_valuetypeptr();
  ValueTypeNode* vt = new ValueTypeNode(vtptr->value_type(), oop);
  for (uint index = 0; index < vt->field_count(); ++index) {
    int offset = vt->get_field_offset(index);
    const TypePtr* adr_type = vtptr->add_offset(offset);
    const Type* field_type = Type::get_const_basic_type(vt->get_field_type(index));
    Node* adr = gvn.transform(new AddPNode(oop, oop, gvn.longcon(offset)));
    Node* ld = LoadNode::make(gvn, NULL, mem, adr, adr_type, field_type, field_type->basic_type(), MemNode::unordered);
    vt->set_field_value(index, gvn.transform(ld));
  }
  return gvn.transform(vt);
}

Node* ValueTypeNode::store_to_memory(GraphKit* kit) {
  Node* in_oop = get_oop();
  Node* null_ctl = kit->top();
  // Check if value type is already allocated
  Node* not_null_oop = kit->null_check_oop(in_oop, &null_ctl);
  if (null_ctl->is_top()) {
    // Value type is allocated
    return not_null_oop;
  }
  // Not able to prove that value type is allocated.
  // Emit runtime check that may be folded later.
  const Type* oop_type = kit->gvn().type(in_oop);
  assert(TypePtr::NULL_PTR->higher_equal(oop_type), "should not be allocated");

  const TypeValueTypePtr* vtptr_type = TypeValueTypePtr::make(bottom_type()->isa_valuetype(), TypePtr::NotNull);
  RegionNode* region = new RegionNode(3);
  PhiNode* oop = new PhiNode(region, vtptr_type);
  PhiNode* io  = new PhiNode(region, Type::ABIO);
  PhiNode* mem = new PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);

  // Oop is non-NULL, use it
  region->init_req(1, kit->control());
  // Fixme if we cast oop to not null we fail if the control path is not folded
  // castnode.cpp:69: #  assert(ft == Type::TOP) failed: special case #3
  //oop   ->init_req(1, not_null_oop);
  oop   ->init_req(1, in_oop);
  io    ->init_req(1, kit->i_o());
  mem   ->init_req(1, kit->merged_memory());

  // Oop is NULL, allocate value type
  kit->set_control(null_ctl);
  kit->kill_dead_locals();
  Node* klass_node = kit->makecon(TypeKlassPtr::make(get_value_klass()));
  Node* alloc_oop  = kit->new_instance(klass_node);
  // Write field values to memory
  for (uint index = 0; index < field_count(); ++index) {
    int offset = get_field_offset(index);
    const TypePtr* adr_type = vtptr_type->add_offset(offset);
    Node* adr = kit->basic_plus_adr(alloc_oop, alloc_oop, offset);
    kit->store_to_memory(kit->control(), adr, get_field_value(index), get_field_type(index), adr_type, MemNode::unordered);
  }
  region->init_req(2, kit->control());
  oop   ->init_req(2, alloc_oop);
  io    ->init_req(2, kit->i_o());
  mem   ->init_req(2, kit->merged_memory());

  // Update GraphKit
  kit->set_control(kit->gvn().transform(region));
  kit->set_i_o(kit->gvn().transform(io));
  kit->set_all_memory(kit->gvn().transform(mem));
  kit->record_for_igvn(region);
  kit->record_for_igvn(oop);
  kit->record_for_igvn(io);
  kit->record_for_igvn(mem);

  Node* res_oop = kit->gvn().transform(oop);
  ValueTypeNode* vt = clone()->as_ValueType();
  vt->set_oop(res_oop);
  kit->replace_in_map(this, kit->gvn().transform(vt));
  return res_oop;
}

Node* ValueTypeNode::get_field_value(uint index) const {
  assert(index < field_count(), "index out of bounds");
  return in(Values + index);
}

Node* ValueTypeNode::get_field_value_by_offset(int field_offset) const {
  int index = get_value_klass()->get_field_index_by_offset(field_offset);
  return get_field_value(index);
}

void ValueTypeNode::set_field_value(uint index, Node* value) {
  assert(index < field_count(), "index out of bounds");
  set_req(Values + index, value);
}

int ValueTypeNode::get_field_offset(uint index) const {
  assert(index < field_count(), "index out of bounds");
  return get_value_klass()->get_field_offset_by_index(index);
}

BasicType ValueTypeNode::get_field_type(uint index) const {
  assert(index < field_count(), "index out of bounds");
  return get_value_klass()->get_field_type_by_index(index);
}

void ValueTypeNode::make_scalar_in_safepoints(Compile* C) {
  const TypeValueTypePtr* res_type = TypeValueTypePtr::make(bottom_type()->isa_valuetype(), TypePtr::NotNull);
  uint nfields = field_count();
  for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
    Node* u = fast_out(i);
    if (u->is_SafePoint() && (!u->is_Call() || u->as_Call()->has_debug_use(this))) {
      Node* in_oop = get_oop();
      const Type* oop_type = in_oop->bottom_type();
      SafePointNode* sfpt = u->as_SafePoint();
      JVMState* jvms = sfpt->jvms();
      int start = jvms->debug_start();
      int end   = jvms->debug_end();
      if (oop_type->meet(TypePtr::NULL_PTR) != oop_type) {
        int nb = sfpt->replace_edges_in_range(this, in_oop, start, end);
        --i; imax -= nb;
      } else {
        assert(jvms != NULL, "missing JVMS");
        uint first_ind = (sfpt->req() - jvms->scloff());
        SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type,
#ifdef ASSERT
                                                                        NULL,
#endif
                                                                        first_ind, nfields);
        sobj->init_req(0, C->root());
        // fields must be added to the safepoint in order of increasing offset
        int min = 0;
        for (uint j = 0; j < nfields; j++) {
          int off = INT_MAX;
          uint next = 0;
          for (uint k = 0; k < nfields; k++) {
            int offset = get_field_offset(k);
            if (offset > min && offset < off) {
              off = offset;
              next = k;
            }
          }
          min = get_field_offset(next);
          sfpt->add_req(in(Values + next));
        }
        jvms->set_endoff(sfpt->req());
        int nb = sfpt->replace_edges_in_range(this, sobj, start, end);
        --i; imax -= nb;
      }
    }
  }
}

Node* ValueTypeNode::Ideal(PhaseGVN* phase, bool can_reshape) {
  // No optimizations for now
  return NULL;
}

#ifndef PRODUCT

void ValueTypeNode::dump_spec(outputStream* st) const {
  TypeNode::dump_spec(st);
  if (!get_oop()->is_top()) {
    st->print(" #oop");
  }
}

#endif