/*
 * 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"

ValueTypeNode* 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_default(PhaseGVN& gvn, ciValueKlass* vk) {
  // TODO re-use constant oop of pre-allocated default value type here?
  // Create a new ValueTypeNode with default values
  ValueTypeNode* vt = ValueTypeNode::make(gvn, vk);
  for (uint i = 0; i < vt->field_count(); ++i) {
    ciType* field_type = vt->field_type(i);
    Node* value = NULL;
    if (field_type->is_primitive_type()) {
      value = gvn.zerocon(field_type->basic_type());
    } else {
      value = ValueTypeNode::make_default(gvn, field_type->as_value_klass());
    }
    vt->set_field_value(i, value);
  }
  return gvn.transform(vt);
}

Node* ValueTypeNode::make(PhaseGVN& gvn, Node* mem, Node* oop) {
  // Create and initialize a ValueTypeNode by loading all field
  // values from a heap-allocated version and also save the oop.
  const TypeValueTypePtr* vtptr = gvn.type(oop)->is_valuetypeptr();
  ValueTypeNode* vt = new ValueTypeNode(vtptr->value_type(), oop);
  vt->load_values(gvn, mem, oop, oop);
  return gvn.transform(vt);
}

Node* ValueTypeNode::make(PhaseGVN& gvn, ciValueKlass* vk, Node* mem, Node* obj, Node* ptr, ciKlass* holder, int field_offset) {
  // Create and initialize a ValueTypeNode by loading all field values from
  // a flattened value type field at 'field_offset' or from a value type array.
  ValueTypeNode* vt = make(gvn, vk);
  int base_offset = 0;
  if (holder->is_value_array_klass()) {
    assert(field_offset == 0, "field offset not supported for arrays");
  } else {
    // The value type is flattened into the object without an oop header. Subtract the
    // offset of the first field to account for the missing header when loading the values.
    base_offset = field_offset - vk->first_field_offset();
  }
  vt->load_values(gvn, mem, obj, ptr, holder, base_offset);
  return gvn.transform(vt);
}

void ValueTypeNode::load_values(PhaseGVN& gvn, Node* mem, Node* base, Node* ptr, ciKlass* holder, int f_offset) {
  ciInstanceKlass* lookup;
  if (holder) {
    // Flattened
    if (holder->is_value_array_klass()) {
      lookup = value_klass();
    } else {
      lookup = holder->as_instance_klass();
    }
  } else {
    // Not flattened
    assert(f_offset == 0, "must be");
    lookup = value_klass();
  }
  // Initialize the value type by loading its field values from
  // memory and adding the values as input edges to the node.
  for (uint i = 0; i < field_count(); ++i) {
    int offset = f_offset + field_offset(i);
    ciField* field = lookup->get_field_by_offset(offset, false);
    ciType* f_type = field_type(i);
    Node* value = NULL;
    if (f_type->is_valuetype()) {
      if (holder && holder->is_value_array_klass()) {
        offset -= value_klass()->first_field_offset();
      }
      // Recursively load the flattened value type field
      value = ValueTypeNode::make(gvn, f_type->as_value_klass(), mem, base, ptr, lookup, offset);
    } else {
      const Type* con_type = NULL;
      if (base->is_Con()) {
        // If the oop to the value type is constant (static final field), we can
        // also treat the fields as constants because the value type is immutable.
        const TypeOopPtr* oop_ptr = base->bottom_type()->isa_oopptr();
        ciObject* constant_oop = oop_ptr->const_oop();
        ciConstant constant = constant_oop->as_instance()->field_value(field);
        con_type = Type::make_from_constant(constant, /*require_const=*/ true);
      }
      if (con_type != NULL) {
        // Found a constant field value
        value = gvn.makecon(con_type);
      } else {
        // Load field value from memory
        const Type* base_type = gvn.type(base);
        const TypePtr* adr_type = NULL;
        if (base_type->isa_aryptr()) {
          adr_type = base_type->is_aryptr()->add_offset(Type::OffsetBot);
        } else {
          adr_type = gvn.C->alias_type(field)->adr_type();
        }
        if (holder && holder->is_value_array_klass()) {
          offset -= value_klass()->first_field_offset();
        }
        Node* adr = gvn.transform(new AddPNode(base, ptr, gvn.MakeConX(offset)));
        value = LoadNode::make(gvn, NULL, mem, adr, adr_type, Type::get_const_type(f_type), f_type->basic_type(), MemNode::unordered);
      }
    }
    set_field_value(i, gvn.transform(value));
  }
}

void ValueTypeNode::store_to_field(GraphKit* kit, Node* obj, Node* ptr, ciInstanceKlass* instance_type, int field_offset) const {
  // The value type is embedded into the object without an oop header. Subtract the
  // offset of the first field to account for the missing header when storing the values.
  int base_offset = field_offset - value_klass()->first_field_offset();
  store_values(kit, obj, ptr, instance_type, base_offset);
}

void ValueTypeNode::store_values(GraphKit* kit, Node* base, Node* ptr, ciKlass* holder, int holder_offset) const {
  ciInstanceKlass* lookup;
  if (holder) {
    // flattened
    if (holder->is_value_array_klass()) {
      assert(holder_offset == 0, "must be");
      lookup = value_klass();
    } else {
      lookup = holder->as_instance_klass();
    }
  } else {
    // not flattened
    assert(holder_offset == 0, "must be");
    lookup = value_klass();
  }
  // Write field values to memory
  for (uint i = 0; i < field_count(); ++i) {
    int offset = holder_offset + field_offset(i);
    Node* value = field_value(i);
    if (value->is_ValueType()) {
      // Recursively store the flattened value type field
      if (holder && holder->is_value_array_klass()) {
        offset -= value_klass()->first_field_offset();
      }
      value->isa_ValueType()->store_to_field(kit, base, ptr, lookup, offset);
    } else {
      const Type* base_type = kit->gvn().type(base);
      const TypePtr* adr_type = NULL;
      if (base_type->isa_aryptr()) {
        adr_type = base_type->is_aryptr()->add_offset(Type::OffsetBot);
      } else {
        ciField* field = lookup->get_field_by_offset(offset, false);
        adr_type = kit->gvn().C->alias_type(field)->adr_type();
      }
      if (holder && holder->is_value_array_klass()) {
        offset -= value_klass()->first_field_offset();
      }
      Node* adr = kit->basic_plus_adr(base, ptr, offset);
      kit->store_to_memory(kit->control(), adr, value, field_type(i)->basic_type(), adr_type, MemNode::unordered);
    }
  }
}

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(value_klass()));
  Node* alloc_oop  = kit->new_instance(klass_node);
  AllocateNode* alloc = AllocateNode::Ideal_allocation(alloc_oop, &kit->gvn());
  // TODO enable/fix this
  // alloc->initialization()->set_complete_with_arraycopy();
  // Write field values to memory
  store_values(kit, alloc_oop, alloc_oop);
  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);

  // Use cloned ValueTypeNode to propagate oop from now on
  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;
}

// Clones the values type to handle control flow merges involving multiple value types.
// The inputs are replaced by PhiNodes to represent the merged values for the given region.
ValueTypeNode* ValueTypeNode::clone_with_phis(PhaseGVN& gvn, Node* region) {
  ValueTypeNode* vt = clone()->as_ValueType();

  // Create a PhiNode for merging the oop values
  const TypeValueTypePtr* vtptr = TypeValueTypePtr::make(vt->bottom_type()->isa_valuetype());
  PhiNode* oop = PhiNode::make(region, vt->get_oop(), vtptr);
  gvn.set_type(oop, vtptr);
  vt->set_oop(oop);

  // Create a PhiNode each for merging the field values
  for (uint i = 0; i < vt->field_count(); ++i) {
    ciType* type = vt->field_type(i);
    Node*  value = vt->field_value(i);
    if (type->is_valuetype()) {
      // Handle flattened value type fields recursively
      value = value->as_ValueType()->clone_with_phis(gvn, region);
    } else {
      const Type* phi_type = Type::get_const_type(type);
      value = PhiNode::make(region, value, phi_type);
      gvn.set_type(value, phi_type);
    }
    vt->set_field_value(i, value);
  }
  gvn.set_type(vt, vt->bottom_type());
  return vt;
}

// Checks if the inputs of the ValueTypeNode were replaced by PhiNodes
// for the given region (see ValueTypeNode::clone_with_phis).
bool ValueTypeNode::has_phi_inputs(Node* region) {
  // Check oop input
  bool result = get_oop()->is_Phi() && get_oop()->as_Phi()->region() == region;
#ifdef ASSERT
  if (result) {
    // Check all field value inputs for consistency
    for (uint i = 0; i < field_count(); ++i) {
      Node* value = field_value(i);
      if (value->is_ValueType()) {
        assert(value->as_ValueType()->has_phi_inputs(region), "inconsistent phi inputs");
      } else {
        assert(value->is_Phi() && value->as_Phi()->region() == region, "inconsistent phi inputs");
      }
    }
  }
#endif
  return result;
}

// Merges 'this' with 'other' by updating the input PhiNodes added by 'clone_with_phis'
Node* ValueTypeNode::merge_with(GraphKit* kit, const ValueTypeNode* other, int pnum) {
  // Merge oop inputs
  PhiNode* phi = get_oop()->as_Phi();
  phi->set_req(pnum, other->get_oop());
  if (pnum == PhiNode::Input) {
    // Last merge
    set_oop(kit->gvn().transform_no_reclaim(phi));
    kit->record_for_igvn(phi);
  }
  // Merge field values
  for (uint i = 0; i < field_count(); ++i) {
    Node* val1 =        field_value(i);
    Node* val2 = other->field_value(i);
    if (val1->isa_ValueType()) {
      val1->as_ValueType()->merge_with(kit, val2->as_ValueType(), pnum);
    } else {
      assert(!val2->is_ValueType(), "inconsistent merge values");
      val1->set_req(pnum, val2);
    }
    if (pnum == PhiNode::Input) {
      // Last merge
      set_field_value(i, kit->gvn().transform_no_reclaim(val1));
      kit->record_for_igvn(val1);
    }
  }
  if (pnum == PhiNode::Input) {
    // Last merge for this value type.
   kit->record_for_igvn(this);
   return kit->gvn().transform_no_reclaim(this);
  }
  return this;
}

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

// Get the value of the field at the given offset.
// If 'recursive' is true, flattened value type fields will be resolved recursively.
Node* ValueTypeNode::field_value_by_offset(int offset, bool recursive) const {
  // If the field at 'offset' belongs to a flattened value type field, 'index' refers to the
  // corresponding ValueTypeNode input and 'sub_offset' is the offset in flattened value type.
  int index = value_klass()->field_index_by_offset(offset);
  int sub_offset = offset - field_offset(index);
  Node* value = field_value(index);
  if (recursive && value->is_ValueType()) {
    // Flattened value type field
    ValueTypeNode* vt = value->as_ValueType();
    sub_offset += vt->value_klass()->first_field_offset(); // Add header size
    return vt->field_value_by_offset(sub_offset);
  }
  assert(!(recursive && value->is_ValueType()), "should not be a value type");
  assert(sub_offset == 0, "offset mismatch");
  return value;
}

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

int ValueTypeNode::field_offset(uint index) const {
  assert(index < field_count(), "index out of bounds");
  return value_klass()->field_offset_by_index(index);
}

ciType* ValueTypeNode::field_type(uint index) const {
  assert(index < field_count(), "index out of bounds");
  return value_klass()->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);
  ciValueKlass* vk = value_klass();
  uint nfields = vk->flattened_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) {
        // Replace safepoint edge by oop
        int nb = sfpt->replace_edges_in_range(this, in_oop, start, end);
        --i; imax -= nb;
      } else {
        // Replace safepoint edge by SafePointScalarObjectNode and add field values
        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());
        // Iterate over the value type fields in order of increasing
        // offset and add the field values to the safepoint.
        for (uint j = 0; j < nfields; ++j) {
          int offset = vk->nonstatic_field_at(j)->offset();
          Node* value = field_value_by_offset(offset, true /* include flattened value type fields */);
          sfpt->add_req(value);
        }
        jvms->set_endoff(sfpt->req());
        int nb = sfpt->replace_edges_in_range(this, sobj, start, end);
        --i; imax -= nb;
      }
    }
  }
}

uint ValueTypeNode::set_arguments_for_java_call(CallJavaNode* call, int base_input, const GraphKit& kit, ciValueKlass* base_vk, int base_offset) {
  ciValueKlass* vk = value_klass();
  if (base_vk == NULL) {
    base_vk = vk;
  }
  uint edges = 0;
  for (uint i = 0; i < field_count(); i++) {
    ciType* f_type = field_type(i);
    int offset = base_offset + field_offset(i) - (base_offset > 0 ? vk->first_field_offset() : 0);
    Node* arg = field_value(i);
    if (f_type->is_valuetype()) {
      ciValueKlass* embedded_vk = f_type->as_value_klass();
      edges += arg->as_ValueType()->set_arguments_for_java_call(call, base_input, kit, base_vk, offset);
    } else {
      int j = 0; int extra = 0;
      for (; j < base_vk->nof_nonstatic_fields(); j++) {
        ciField* f = base_vk->nonstatic_field_at(j);
        if (offset == f->offset()) {
          assert(f->type() == f_type, "inconsistent field type");
          break;
        }
        BasicType bt = f->type()->basic_type();
        if (bt == T_LONG || bt == T_DOUBLE) {
          extra++;
        }
      }
      call->init_req(base_input + j + extra, arg);
      edges++;
      BasicType bt = f_type->basic_type();
      if (bt == T_LONG || bt == T_DOUBLE) {
        call->init_req(base_input + j + extra + 1, kit.top());
        edges++;
      }
    }
  }
  return edges;
}

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);
}

#endif