/*

 * Copyright (c) 2016, 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 "gc/shared/barrierSet.hpp"

#include "gc/shared/c2/barrierSetC2.hpp"

#include "gc/shared/c2/cardTableBarrierSetC2.hpp"

#include "opto/arraycopynode.hpp"

#include "opto/graphKit.hpp"

#include "runtime/sharedRuntime.hpp"

#include "utilities/macros.hpp"

ArrayCopyNode::ArrayCopyNode(Compile* C, bool alloc_tightly_coupled, bool has_negative_length_guard)

  : CallNode(arraycopy_type(), NULL, TypeRawPtr::BOTTOM),

    _alloc_tightly_coupled(alloc_tightly_coupled),

    _has_negative_length_guard(has_negative_length_guard),

    _kind(None),

    _arguments_validated(false),

    _src_type(TypeOopPtr::BOTTOM),

    _dest_type(TypeOopPtr::BOTTOM) {

  init_class_id(Class_ArrayCopy);

  init_flags(Flag_is_macro);

  C->add_macro_node(this);

}

uint ArrayCopyNode::size_of() const { return sizeof(*this); }

ArrayCopyNode* ArrayCopyNode::make(GraphKit* kit, bool may_throw,

                                   Node* src, Node* src_offset,

                                   Node* dest, Node* dest_offset,

                                   Node* length,

                                   bool alloc_tightly_coupled,

                                   bool has_negative_length_guard,

                                   Node* src_klass, Node* dest_klass,

                                   Node* src_length, Node* dest_length) {

  ArrayCopyNode* ac = new ArrayCopyNode(kit->C, alloc_tightly_coupled, has_negative_length_guard);

  Node* prev_mem = kit->set_predefined_input_for_runtime_call(ac);

  ac->init_req(ArrayCopyNode::Src, src);

  ac->init_req(ArrayCopyNode::SrcPos, src_offset);

  ac->init_req(ArrayCopyNode::Dest, dest);

  ac->init_req(ArrayCopyNode::DestPos, dest_offset);

  ac->init_req(ArrayCopyNode::Length, length);

  ac->init_req(ArrayCopyNode::SrcLen, src_length);

  ac->init_req(ArrayCopyNode::DestLen, dest_length);

  ac->init_req(ArrayCopyNode::SrcKlass, src_klass);

  ac->init_req(ArrayCopyNode::DestKlass, dest_klass);

  if (may_throw) {

    ac->set_req(TypeFunc::I_O , kit->i_o());

    kit->add_safepoint_edges(ac, false);

  }

  return ac;

}

void ArrayCopyNode::connect_outputs(GraphKit* kit) {

  kit->set_all_memory_call(this, true);

  kit->set_control(kit->gvn().transform(new ProjNode(this,TypeFunc::Control)));

  kit->set_i_o(kit->gvn().transform(new ProjNode(this, TypeFunc::I_O)));

  kit->make_slow_call_ex(this, kit->env()->Throwable_klass(), true);

  kit->set_all_memory_call(this);

}

#ifndef PRODUCT

const char* ArrayCopyNode::_kind_names[] = {"arraycopy", "arraycopy, validated arguments", "clone", "oop array clone", "CopyOf", "CopyOfRange"};

void ArrayCopyNode::dump_spec(outputStream *st) const {

  CallNode::dump_spec(st);

  st->print(" (%s%s)", _kind_names[_kind], _alloc_tightly_coupled ? ", tightly coupled allocation" : "");

}

void ArrayCopyNode::dump_compact_spec(outputStream* st) const {

  st->print("%s%s", _kind_names[_kind], _alloc_tightly_coupled ? ",tight" : "");

}

#endif

intptr_t ArrayCopyNode::get_length_if_constant(PhaseGVN *phase) const {

  // check that length is constant

  Node* length = in(ArrayCopyNode::Length);

  const Type* length_type = phase->type(length);

  if (length_type == Type::TOP) {

    return -1;

  }

  assert(is_clonebasic() || is_arraycopy() || is_copyof() || is_copyofrange(), "unexpected array copy type");

  return is_clonebasic() ? length->find_intptr_t_con(-1) : length->find_int_con(-1);

}

int ArrayCopyNode::get_count(PhaseGVN *phase) const {

  Node* src = in(ArrayCopyNode::Src);

  const Type* src_type = phase->type(src);

  if (is_clonebasic()) {

    if (src_type->isa_instptr()) {

      const TypeInstPtr* inst_src = src_type->is_instptr();

      ciInstanceKlass* ik = inst_src->klass()->as_instance_klass();

      // ciInstanceKlass::nof_nonstatic_fields() doesn't take injected

      // fields into account. They are rare anyway so easier to simply

      // skip instances with injected fields.

      if ((!inst_src->klass_is_exact() && (ik->is_interface() || ik->has_subklass())) || ik->has_injected_fields()) {

        return -1;

      }

      int nb_fields = ik->nof_nonstatic_fields();

      return nb_fields;

    } else {

      const TypeAryPtr* ary_src = src_type->isa_aryptr();

      assert (ary_src != NULL, "not an array or instance?");

      // clone passes a length as a rounded number of longs. If we're

      // cloning an array we'll do it element by element. If the

      // length input to ArrayCopyNode is constant, length of input

      // array must be too.

      assert((get_length_if_constant(phase) == -1) == !ary_src->size()->is_con() ||

             phase->is_IterGVN(), "inconsistent");

      if (ary_src->size()->is_con()) {

        return ary_src->size()->get_con();

      }

      return -1;

    }

  }

  return get_length_if_constant(phase);

}

Node* ArrayCopyNode::try_clone_instance(PhaseGVN *phase, bool can_reshape, int count) {

  if (!is_clonebasic()) {

    return NULL;

  }

  Node* src = in(ArrayCopyNode::Src);

  Node* dest = in(ArrayCopyNode::Dest);

  Node* ctl = in(TypeFunc::Control);

  Node* in_mem = in(TypeFunc::Memory);

  const Type* src_type = phase->type(src);

  assert(src->is_AddP(), "should be base + off");

  assert(dest->is_AddP(), "should be base + off");

  Node* base_src = src->in(AddPNode::Base);

  Node* base_dest = dest->in(AddPNode::Base);

  MergeMemNode* mem = MergeMemNode::make(in_mem);

  const TypeInstPtr* inst_src = src_type->isa_instptr();

  if (inst_src == NULL) {

    return NULL;

  }

  if (!inst_src->klass_is_exact()) {

    ciInstanceKlass* ik = inst_src->klass()->as_instance_klass();

    assert(!ik->is_interface() && !ik->has_subklass(), "inconsistent klass hierarchy");

    phase->C->dependencies()->assert_leaf_type(ik);

  }

  ciInstanceKlass* ik = inst_src->klass()->as_instance_klass();

  assert(ik->nof_nonstatic_fields() <= ArrayCopyLoadStoreMaxElem, "too many fields");

  for (int i = 0; i < count; i++) {

    ciField* field = ik->nonstatic_field_at(i);

    int fieldidx = phase->C->alias_type(field)->index();

    const TypePtr* adr_type = phase->C->alias_type(field)->adr_type();

    Node* off = phase->MakeConX(field->offset());

    Node* next_src = phase->transform(new AddPNode(base_src,base_src,off));

    Node* next_dest = phase->transform(new AddPNode(base_dest,base_dest,off));

    BasicType bt = field->layout_type();

    const Type *type;

    if (bt == T_OBJECT) {

      if (!field->type()->is_loaded()) {

        type = TypeInstPtr::BOTTOM;

      } else {

        ciType* field_klass = field->type();

        type = TypeOopPtr::make_from_klass(field_klass->as_klass());

      }

    } else {

      type = Type::get_const_basic_type(bt);

    }

    Node* v = LoadNode::make(*phase, ctl, mem->memory_at(fieldidx), next_src, adr_type, type, bt, MemNode::unordered);

    v = phase->transform(v);

    Node* s = StoreNode::make(*phase, ctl, mem->memory_at(fieldidx), next_dest, adr_type, v, bt, MemNode::unordered);

    s = phase->transform(s);

    mem->set_memory_at(fieldidx, s);

  }

  if (!finish_transform(phase, can_reshape, ctl, mem)) {

    // Return NodeSentinel to indicate that the transform failed

    return NodeSentinel;

  }

  return mem;

}

bool ArrayCopyNode::prepare_array_copy(PhaseGVN *phase, bool can_reshape,

                                       Node*& adr_src,

                                       Node*& base_src,

                                       Node*& adr_dest,

                                       Node*& base_dest,

                                       BasicType& copy_type,

                                       const Type*& value_type,

                                       bool& disjoint_bases) {

  Node* src = in(ArrayCopyNode::Src);

  Node* dest = in(ArrayCopyNode::Dest);

  const Type* src_type = phase->type(src);

  const TypeAryPtr* ary_src = src_type->isa_aryptr();

  if (is_arraycopy() || is_copyofrange() || is_copyof()) {

    const Type* dest_type = phase->type(dest);

    const TypeAryPtr* ary_dest = dest_type->isa_aryptr();

    Node* src_offset = in(ArrayCopyNode::SrcPos);

    Node* dest_offset = in(ArrayCopyNode::DestPos);

    // newly allocated object is guaranteed to not overlap with source object

    disjoint_bases = is_alloc_tightly_coupled();

    if (ary_src  == NULL || ary_src->klass()  == NULL ||

        ary_dest == NULL || ary_dest->klass() == NULL) {

      // We don't know if arguments are arrays

      return false;

    }

    BasicType src_elem  = ary_src->klass()->as_array_klass()->element_type()->basic_type();

    BasicType dest_elem = ary_dest->klass()->as_array_klass()->element_type()->basic_type();

    if (src_elem  == T_ARRAY)  src_elem  = T_OBJECT;

    if (dest_elem == T_ARRAY)  dest_elem = T_OBJECT;

    if (src_elem != dest_elem || dest_elem == T_VOID) {

      // We don't know if arguments are arrays of the same type

      return false;

    }

    BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();

    if (dest_elem == T_OBJECT && (!is_alloc_tightly_coupled() ||

                                  bs->array_copy_requires_gc_barriers(T_OBJECT))) {

      // It's an object array copy but we can't emit the card marking

      // that is needed

      return false;

    }

    value_type = ary_src->elem();

    base_src = src;

    base_dest = dest;

    uint shift  = exact_log2(type2aelembytes(dest_elem));

    uint header = arrayOopDesc::base_offset_in_bytes(dest_elem);

    adr_src = src;

    adr_dest = dest;

    src_offset = Compile::conv_I2X_index(phase, src_offset, ary_src->size());

    dest_offset = Compile::conv_I2X_index(phase, dest_offset, ary_dest->size());

    Node* src_scale = phase->transform(new LShiftXNode(src_offset, phase->intcon(shift)));

    Node* dest_scale = phase->transform(new LShiftXNode(dest_offset, phase->intcon(shift)));

    adr_src = phase->transform(new AddPNode(base_src, adr_src, src_scale));

    adr_dest = phase->transform(new AddPNode(base_dest, adr_dest, dest_scale));

    adr_src = new AddPNode(base_src, adr_src, phase->MakeConX(header));

    adr_dest = new AddPNode(base_dest, adr_dest, phase->MakeConX(header));

    adr_src = phase->transform(adr_src);

    adr_dest = phase->transform(adr_dest);

    copy_type = dest_elem;

  } else {

    assert(ary_src != NULL, "should be a clone");

    assert(is_clonebasic(), "should be");

    disjoint_bases = true;

    assert(src->is_AddP(), "should be base + off");

    assert(dest->is_AddP(), "should be base + off");

    adr_src = src;

    base_src = src->in(AddPNode::Base);

    adr_dest = dest;

    base_dest = dest->in(AddPNode::Base);

    assert(phase->type(src->in(AddPNode::Offset))->is_intptr_t()->get_con() == phase->type(dest->in(AddPNode::Offset))->is_intptr_t()->get_con(), "same start offset?");

    BasicType elem = ary_src->klass()->as_array_klass()->element_type()->basic_type();

    if (elem == T_ARRAY)  elem = T_OBJECT;

    int diff = arrayOopDesc::base_offset_in_bytes(elem) - phase->type(src->in(AddPNode::Offset))->is_intptr_t()->get_con();

    assert(diff >= 0, "clone should not start after 1st array element");

    if (diff > 0) {

      adr_src = phase->transform(new AddPNode(base_src, adr_src, phase->MakeConX(diff)));

      adr_dest = phase->transform(new AddPNode(base_dest, adr_dest, phase->MakeConX(diff)));

    }

    copy_type = elem;

    value_type = ary_src->elem();

  }

  return true;

}

const TypePtr* ArrayCopyNode::get_address_type(PhaseGVN *phase, Node* n) {

  const Type* at = phase->type(n);

  assert(at != Type::TOP, "unexpected type");

  const TypePtr* atp = at->isa_ptr();

  // adjust atp to be the correct array element address type

  atp = atp->add_offset(Type::OffsetBot);

  return atp;

}

void ArrayCopyNode::array_copy_test_overlap(PhaseGVN *phase, bool can_reshape, bool disjoint_bases, int count, Node*& forward_ctl, Node*& backward_ctl) {

  Node* ctl = in(TypeFunc::Control);

  if (!disjoint_bases && count > 1) {

    Node* src_offset = in(ArrayCopyNode::SrcPos);

    Node* dest_offset = in(ArrayCopyNode::DestPos);

    assert(src_offset != NULL && dest_offset != NULL, "should be");

    Node* cmp = phase->transform(new CmpINode(src_offset, dest_offset));

    Node *bol = phase->transform(new BoolNode(cmp, BoolTest::lt));

    IfNode *iff = new IfNode(ctl, bol, PROB_FAIR, COUNT_UNKNOWN);

    phase->transform(iff);

    forward_ctl = phase->transform(new IfFalseNode(iff));

    backward_ctl = phase->transform(new IfTrueNode(iff));

  } else {

    forward_ctl = ctl;

  }

}

Node* ArrayCopyNode::array_copy_forward(PhaseGVN *phase,

                                        bool can_reshape,

                                        Node* forward_ctl,

                                        Node* start_mem_src,

                                        Node* start_mem_dest,

                                        const TypePtr* atp_src,

                                        const TypePtr* atp_dest,

                                        Node* adr_src,

                                        Node* base_src,

                                        Node* adr_dest,

                                        Node* base_dest,

                                        BasicType copy_type,

                                        const Type* value_type,

                                        int count) {

  Node* mem = phase->C->top();

  if (!forward_ctl->is_top()) {

    // copy forward

    mem = start_mem_dest;

    if (count > 0) {

      Node* v = LoadNode::make(*phase, forward_ctl, start_mem_src, adr_src, atp_src, value_type, copy_type, MemNode::unordered);

      v = phase->transform(v);

      mem = StoreNode::make(*phase, forward_ctl, mem, adr_dest, atp_dest, v, copy_type, MemNode::unordered);

      mem = phase->transform(mem);

      for (int i = 1; i < count; i++) {

        Node* off  = phase->MakeConX(type2aelembytes(copy_type) * i);

        Node* next_src = phase->transform(new AddPNode(base_src,adr_src,off));

        Node* next_dest = phase->transform(new AddPNode(base_dest,adr_dest,off));

        v = phase->transform(v);

        mem = StoreNode::make(*phase, forward_ctl,mem,next_dest,atp_dest,v, copy_type, MemNode::unordered);

        mem = phase->transform(mem);

      }

    } else if(can_reshape) {

      PhaseIterGVN* igvn = phase->is_IterGVN();

      igvn->_worklist.push(adr_src);

      igvn->_worklist.push(adr_dest);

    }

  }

  return mem;

}

Node* ArrayCopyNode::array_copy_backward(PhaseGVN *phase,

                                         bool can_reshape,

                                         Node* backward_ctl,

                                         Node* start_mem_src,

                                         Node* start_mem_dest,

                                         const TypePtr* atp_src,

                                         const TypePtr* atp_dest,

                                         Node* adr_src,

                                         Node* base_src,

                                         Node* adr_dest,

                                         Node* base_dest,

                                         BasicType copy_type,

                                         const Type* value_type,

                                         int count) {

  Node* mem = phase->C->top();

  if (!backward_ctl->is_top()) {

    // copy backward

    mem = start_mem_dest;

    if (count > 0) {

      for (int i = count-1; i >= 1; i--) {

        Node* off  = phase->MakeConX(type2aelembytes(copy_type) * i);

        Node* next_src = phase->transform(new AddPNode(base_src,adr_src,off));

        Node* next_dest = phase->transform(new AddPNode(base_dest,adr_dest,off));

        v = phase->transform(v);

        mem = StoreNode::make(*phase, backward_ctl,mem,next_dest,atp_dest,v, copy_type, MemNode::unordered);

        mem = phase->transform(mem);

      }

      v = phase->transform(v);

      mem = StoreNode::make(*phase, backward_ctl, mem, adr_dest, atp_dest, v, copy_type, MemNode::unordered);

      mem = phase->transform(mem);

    } else if(can_reshape) {

      PhaseIterGVN* igvn = phase->is_IterGVN();

      igvn->_worklist.push(adr_src);

      igvn->_worklist.push(adr_dest);

    }

  }

  return mem;

}

bool ArrayCopyNode::finish_transform(PhaseGVN *phase, bool can_reshape,

                                     Node* ctl, Node *mem) {

  if (can_reshape) {

    PhaseIterGVN* igvn = phase->is_IterGVN();

    igvn->set_delay_transform(false);

    if (is_clonebasic()) {

      Node* out_mem = proj_out(TypeFunc::Memory);

      BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();

      if (out_mem->outcnt() != 1 || !out_mem->raw_out(0)->is_MergeMem() ||

          out_mem->raw_out(0)->outcnt() != 1 || !out_mem->raw_out(0)->raw_out(0)->is_MemBar()) {

        assert(bs->array_copy_requires_gc_barriers(T_OBJECT), "can only happen with card marking");

        return false;

      }

      igvn->replace_node(out_mem->raw_out(0), mem);

      Node* out_ctl = proj_out(TypeFunc::Control);

      igvn->replace_node(out_ctl, ctl);

    } else {

      // replace fallthrough projections of the ArrayCopyNode by the

      // new memory, control and the input IO.

      CallProjections callprojs;

      extract_projections(&callprojs, true, false);

      if (callprojs.fallthrough_ioproj != NULL) {

        igvn->replace_node(callprojs.fallthrough_ioproj, in(TypeFunc::I_O));

      }

      if (callprojs.fallthrough_memproj != NULL) {

        igvn->replace_node(callprojs.fallthrough_memproj, mem);

      }

      if (callprojs.fallthrough_catchproj != NULL) {

        igvn->replace_node(callprojs.fallthrough_catchproj, ctl);

      }

      // The ArrayCopyNode is not disconnected. It still has the

      // projections for the exception case. Replace current

      // ArrayCopyNode with a dummy new one with a top() control so

      // that this part of the graph stays consistent but is

      // eventually removed.

      set_req(0, phase->C->top());

      remove_dead_region(phase, can_reshape);

    }

  } else {

    if (in(TypeFunc::Control) != ctl) {

      // we can't return new memory and control from Ideal at parse time

      assert(!is_clonebasic(), "added control for clone?");

      return false;

    }

  }

  return true;

}

Node *ArrayCopyNode::Ideal(PhaseGVN *phase, bool can_reshape) {

  if (remove_dead_region(phase, can_reshape))  return this;

  if (StressArrayCopyMacroNode && !can_reshape) {

    phase->record_for_igvn(this);

    return NULL;

  }

  // See if it's a small array copy and we can inline it as

  // loads/stores

  // Here we can only do:

  // - arraycopy if all arguments were validated before and we don't

  // need card marking

  // - clone for which we don't need to do card marking

  if (!is_clonebasic() && !is_arraycopy_validated() &&

      !is_copyofrange_validated() && !is_copyof_validated()) {

    return NULL;

  }

  assert(in(TypeFunc::Control) != NULL &&

         in(TypeFunc::Memory) != NULL &&

         in(ArrayCopyNode::Src) != NULL &&

         in(ArrayCopyNode::Dest) != NULL &&

         in(ArrayCopyNode::Length) != NULL &&

         ((in(ArrayCopyNode::SrcPos) != NULL && in(ArrayCopyNode::DestPos) != NULL) ||