/*

 * Copyright (c) 2015, 2018, Red Hat, Inc. All rights reserved.

 *

 * 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.

 *

 */

#ifndef SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP

#define SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP

#include "memory/allocation.hpp"

#include "opto/addnode.hpp"

#include "opto/graphKit.hpp"

#include "opto/machnode.hpp"

#include "opto/memnode.hpp"

#include "opto/multnode.hpp"

#include "opto/node.hpp"

class PhaseGVN;

class MemoryGraphFixer;

class ShenandoahBarrierC2Support : public AllStatic {

private:

#ifdef ASSERT

  enum verify_type {

    ShenandoahLoad,

    ShenandoahStore,

    ShenandoahValue,

    ShenandoahOopStore,

    ShenandoahNone

  };

  static bool verify_helper(Node* in, Node_Stack& phis, VectorSet& visited, verify_type t, bool trace, Unique_Node_List& barriers_used);

  static void report_verify_failure(const char* msg, Node* n1 = NULL, Node* n2 = NULL);

  static void verify_raw_mem(RootNode* root);

#endif

  static Node* dom_mem(Node* mem, Node* ctrl, int alias, Node*& mem_ctrl, PhaseIdealLoop* phase);

  static Node* no_branches(Node* c, Node* dom, bool allow_one_proj, PhaseIdealLoop* phase);

  static bool is_heap_state_test(Node* iff, int mask);

  static bool try_common_gc_state_load(Node *n, PhaseIdealLoop *phase);

  static bool has_safepoint_between(Node* start, Node* stop, PhaseIdealLoop *phase);

  static Node* find_bottom_mem(Node* ctrl, PhaseIdealLoop* phase);

  static void follow_barrier_uses(Node* n, Node* ctrl, Unique_Node_List& uses, PhaseIdealLoop* phase);

  static void test_null(Node*& ctrl, Node* val, Node*& null_ctrl, PhaseIdealLoop* phase);

  static void test_heap_stable(Node*& ctrl, Node* raw_mem, Node*& heap_stable_ctrl,

                               PhaseIdealLoop* phase);

  static Node* clone_null_check(Node*& c, Node* val, Node* unc_ctrl, PhaseIdealLoop* phase);

  static void fix_null_check(Node* unc, Node* unc_ctrl, Node* new_unc_ctrl, Unique_Node_List& uses,

                             PhaseIdealLoop* phase);

  static void in_cset_fast_test(Node*& ctrl, Node*& not_cset_ctrl, Node* val, Node* raw_mem, PhaseIdealLoop* phase);

  static void move_heap_stable_test_out_of_loop(IfNode* iff, PhaseIdealLoop* phase);

  static void merge_back_to_back_tests(Node* n, PhaseIdealLoop* phase);

  static bool identical_backtoback_ifs(Node *n, PhaseIdealLoop* phase);

  static void fix_ctrl(Node* barrier, Node* region, const MemoryGraphFixer& fixer, Unique_Node_List& uses, Unique_Node_List& uses_to_ignore, uint last, PhaseIdealLoop* phase);

  static IfNode* find_unswitching_candidate(const IdealLoopTree *loop, PhaseIdealLoop* phase);

public:

  static bool is_dominator(Node* d_c, Node* n_c, Node* d, Node* n, PhaseIdealLoop* phase);

  static bool is_dominator_same_ctrl(Node* c, Node* d, Node* n, PhaseIdealLoop* phase);

  static bool is_gc_state_load(Node* n);

  static bool is_heap_stable_test(Node* iff);

  static bool expand(Compile* C, PhaseIterGVN& igvn);

  static void pin_and_expand(PhaseIdealLoop* phase);

  static void optimize_after_expansion(VectorSet& visited, Node_Stack& nstack, Node_List& old_new, PhaseIdealLoop* phase);

#ifdef ASSERT

  static void verify(RootNode* root);

#endif

};

class ShenandoahEnqueueBarrierNode : public Node {

public:

  ShenandoahEnqueueBarrierNode(Node* val);

  const Type *bottom_type() const;

  const Type* Value(PhaseGVN* phase) const;

  Node* Identity(PhaseGVN* phase);

  int Opcode() const;

private:

  enum { Needed, NotNeeded, MaybeNeeded };

  static int needed(Node* n);

  static Node* next(Node* n);

};

class MemoryGraphFixer : public ResourceObj {

private:

  Node_List _memory_nodes;

  int _alias;

  PhaseIdealLoop* _phase;

  bool _include_lsm;

  void collect_memory_nodes();

  Node* get_ctrl(Node* n) const;

  Node* ctrl_or_self(Node* n) const;

  bool mem_is_valid(Node* m, Node* c) const;

  MergeMemNode* allocate_merge_mem(Node* mem, Node* rep_proj, Node* rep_ctrl) const;

  MergeMemNode* clone_merge_mem(Node* u, Node* mem, Node* rep_proj, Node* rep_ctrl, DUIterator& i) const;

  void fix_memory_uses(Node* mem, Node* replacement, Node* rep_proj, Node* rep_ctrl) const;

  bool should_process_phi(Node* phi) const;

  bool has_mem_phi(Node* region) const;

public:

  MemoryGraphFixer(int alias, bool include_lsm, PhaseIdealLoop* phase) :

    _alias(alias), _phase(phase), _include_lsm(include_lsm) {

    assert(_alias != Compile::AliasIdxBot, "unsupported");

    collect_memory_nodes();

  }

  Node* find_mem(Node* ctrl, Node* n) const;

  void fix_mem(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl, Node* mem_phi, Unique_Node_List& uses);

  int alias() const { return _alias; }

};

class ShenandoahCompareAndSwapPNode : public CompareAndSwapPNode {

public:

  ShenandoahCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)

    : CompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }

  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {

    if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {

      return new CompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());

    }

    return NULL;

  }

  virtual int Opcode() const;

};

class ShenandoahCompareAndSwapNNode : public CompareAndSwapNNode {

public:

  ShenandoahCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)

    : CompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }

  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {

    if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {

      return new CompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());

    }

    return NULL;

  }

  virtual int Opcode() const;

};

class ShenandoahWeakCompareAndSwapPNode : public WeakCompareAndSwapPNode {

public:

  ShenandoahWeakCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)

    : WeakCompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }

  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {

    if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {

      return new WeakCompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());

    }

    return NULL;

  }

  virtual int Opcode() const;

};

class ShenandoahWeakCompareAndSwapNNode : public WeakCompareAndSwapNNode {

public:

  ShenandoahWeakCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)

    : WeakCompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }

  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {

    if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {

      return new WeakCompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());

    }

    return NULL;

  }

  virtual int Opcode() const;

};

class ShenandoahCompareAndExchangePNode : public CompareAndExchangePNode {

public:

  ShenandoahCompareAndExchangePNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)

    : CompareAndExchangePNode(c, mem, adr, val, ex, at, t, mem_ord) { }

  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {

    if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {

      return new CompareAndExchangePNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());

    }

    return NULL;

  }

  virtual int Opcode() const;

};

class ShenandoahCompareAndExchangeNNode : public CompareAndExchangeNNode {

public:

  ShenandoahCompareAndExchangeNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)

    : CompareAndExchangeNNode(c, mem, adr, val, ex, at, t, mem_ord) { }

  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {

    if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {

      return new CompareAndExchangeNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());

    }

    return NULL;

  }

  virtual int Opcode() const;

};

class ShenandoahLoadReferenceBarrierNode : public Node {

public:

  enum {

    Control,

    ValueIn

  };

  enum Strength {

    NONE, WEAK, STRONG, NA

  };

  virtual int Opcode() const;

  virtual const Type* bottom_type() const;

  virtual const Type* Value(PhaseGVN* phase) const;

  virtual const class TypePtr *adr_type() const { return TypeOopPtr::BOTTOM; }

  virtual uint match_edge(uint idx) const {

    return idx >= ValueIn;

  }

  virtual uint ideal_reg() const { return Op_RegP; }

  virtual Node* Identity(PhaseGVN* phase);

  Strength get_barrier_strength();

  CallStaticJavaNode* pin_and_expand_null_check(PhaseIterGVN& igvn);

private:

  bool needs_barrier(PhaseGVN* phase, Node* n);

  bool needs_barrier_impl(PhaseGVN* phase, Node* n, Unique_Node_List &visited);

};

#endif // SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP