/*

 * 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 "gc/shenandoah/shenandoahBrooksPointer.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 ShenandoahBarrierNode : public TypeNode {

private:

  bool _allow_fromspace;

#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);

#endif

public:

  enum { Control,

         Memory,

         ValueIn

  };

  ShenandoahBarrierNode(Node* ctrl, Node* mem, Node* obj, bool allow_fromspace)

    : TypeNode(obj->bottom_type()->isa_oopptr() ? obj->bottom_type()->is_oopptr()->cast_to_nonconst() : obj->bottom_type(), 3),

      _allow_fromspace(allow_fromspace) {

    init_req(Control, ctrl);

    init_req(Memory, mem);

    init_req(ValueIn, obj);

    init_class_id(Class_ShenandoahBarrier);

  }

  static Node* skip_through_barrier(Node* n);

  static const TypeOopPtr* brooks_pointer_type(const Type* t) {

    return t->is_oopptr()->cast_to_nonconst()->add_offset(ShenandoahBrooksPointer::byte_offset())->is_oopptr();

  }

  virtual const TypePtr* adr_type() const {

    if (bottom_type() == Type::TOP) {

      return NULL;

    }

    //const TypePtr* adr_type = in(MemNode::Address)->bottom_type()->is_ptr();

    const TypePtr* adr_type = brooks_pointer_type(bottom_type());

    assert(adr_type->offset() == ShenandoahBrooksPointer::byte_offset(), "sane offset");

    assert(Compile::current()->alias_type(adr_type)->is_rewritable(), "brooks ptr must be rewritable");

    return adr_type;

  }

  virtual uint  ideal_reg() const { return Op_RegP; }

  virtual uint match_edge(uint idx) const {

    return idx >= ValueIn;

  }

  Node* Identity_impl(PhaseGVN* phase);

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

  virtual bool depends_only_on_test() const {

    return true;

  };

  static bool needs_barrier(PhaseGVN* phase, ShenandoahBarrierNode* orig, Node* n, Node* rb_mem, bool allow_fromspace);

#ifdef ASSERT

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

  static void verify(RootNode* root);

  static void verify_raw_mem(RootNode* root);

#endif

#ifndef PRODUCT

  virtual void dump_spec(outputStream *st) const;

#endif

  // protected:

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

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

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

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

  bool sink_node(PhaseIdealLoop* phase, Node* ctrl, Node* n_ctrl);

protected:

  uint hash() const;

  bool cmp(const Node& n) const;

  uint size_of() const;

private:

  static bool needs_barrier_impl(PhaseGVN* phase, ShenandoahBarrierNode* orig, Node* n, Node* rb_mem, bool allow_fromspace, Unique_Node_List &visited);

  static bool dominates_memory(PhaseGVN* phase, Node* b1, Node* b2, bool linear);

  static bool dominates_memory_impl(PhaseGVN* phase, Node* b1, Node* b2, Node* current, bool linear);

};

class ShenandoahReadBarrierNode : public ShenandoahBarrierNode {

public:

  ShenandoahReadBarrierNode(Node* ctrl, Node* mem, Node* obj)

    : ShenandoahBarrierNode(ctrl, mem, obj, true) {

    assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier ||

                               ShenandoahWriteBarrier || ShenandoahAcmpBarrier),

           "should be enabled");

  }

  ShenandoahReadBarrierNode(Node* ctrl, Node* mem, Node* obj, bool allow_fromspace)

    : ShenandoahBarrierNode(ctrl, mem, obj, allow_fromspace) {

    assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier ||

                               ShenandoahWriteBarrier || ShenandoahAcmpBarrier),

           "should be enabled");

  }

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

  virtual Node* Identity(PhaseGVN* phase);

  virtual int Opcode() const;

  bool is_independent(Node* mem);

  void try_move(PhaseIdealLoop* phase);

private:

  static bool is_independent(const Type* in_type, const Type* this_type);

  static bool dominates_memory_rb(PhaseGVN* phase, Node* b1, Node* b2, bool linear);

  static bool dominates_memory_rb_impl(PhaseGVN* phase, Node* b1, Node* b2, Node* current, bool linear);

};

class ShenandoahWriteBarrierNode : public ShenandoahBarrierNode {

public:

  ShenandoahWriteBarrierNode(Compile* C, Node* ctrl, Node* mem, Node* obj);

  virtual int Opcode() const;

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

  virtual Node* Identity(PhaseGVN* phase);

  virtual bool depends_only_on_test() const { return false; }

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

  static bool is_gc_state_load(Node *n);

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

  static bool is_heap_stable_test(Node* iff);

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

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

  static LoopNode* try_move_before_pre_loop(Node* c, Node* val_ctrl, PhaseIdealLoop* phase);

  static Node* move_above_predicates(LoopNode* cl, Node* val_ctrl, PhaseIdealLoop* phase);

#ifdef ASSERT

  static bool memory_dominates_all_paths(Node* mem, Node* rep_ctrl, int alias, PhaseIdealLoop* phase);

  static void memory_dominates_all_paths_helper(Node* c, Node* rep_ctrl, Unique_Node_List& controls, PhaseIdealLoop* phase);

#endif

  void try_move_before_loop(GrowableArray<MemoryGraphFixer*>& memory_graph_fixers, PhaseIdealLoop* phase, bool include_lsm, Unique_Node_List& uses);

  void try_move_before_loop_helper(LoopNode* cl, Node* val_ctrl, GrowableArray<MemoryGraphFixer*>& memory_graph_fixers, PhaseIdealLoop* phase, bool include_lsm, Unique_Node_List& uses);

  static void pin_and_expand(PhaseIdealLoop* phase);

  CallStaticJavaNode* pin_and_expand_null_check(PhaseIterGVN& igvn);

  void pin_and_expand_move_barrier(PhaseIdealLoop* phase, GrowableArray<MemoryGraphFixer*>& memory_graph_fixers, Unique_Node_List& uses);

  void pin_and_expand_helper(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 void call_wb_stub(Node*& ctrl, Node*& val, Node*& result_mem,

                           Node* raw_mem, Node* wb_mem, int alias,

                           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 optimize_after_expansion(VectorSet &visited, Node_Stack &nstack, Node_List &old_new, 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 void optimize_before_expansion(PhaseIdealLoop* phase, GrowableArray<MemoryGraphFixer*> memory_graph_fixers, bool include_lsm);

  Node* would_subsume(ShenandoahBarrierNode* other, PhaseIdealLoop* phase);

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

  Node* try_split_thru_phi(PhaseIdealLoop* phase);

};

class ShenandoahWBMemProjNode : public Node {

public:

  enum { Control,

         WriteBarrier };

  ShenandoahWBMemProjNode(Node *src) : Node(NULL, src) {

    assert(UseShenandoahGC && ShenandoahWriteBarrier, "should be enabled");

    assert(src->Opcode() == Op_ShenandoahWriteBarrier || src->is_Mach(), "epxect wb");

  }

  virtual Node* Identity(PhaseGVN* phase);

  virtual int Opcode() const;

  virtual bool      is_CFG() const  { return false; }

  virtual const Type *bottom_type() const {return Type::MEMORY;}

  virtual const TypePtr *adr_type() const {

    Node* wb = in(WriteBarrier);

    if (wb == NULL || wb->is_top())  return NULL; // node is dead

    assert(wb->Opcode() == Op_ShenandoahWriteBarrier || (wb->is_Mach() && wb->as_Mach()->ideal_Opcode() == Op_ShenandoahWriteBarrier) || wb->is_Phi(), "expect wb");

    return ShenandoahBarrierNode::brooks_pointer_type(wb->bottom_type());

  }

  virtual uint ideal_reg() const { return 0;} // memory projections don't have a register

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

    return bottom_type();

  }

#ifndef PRODUCT

  virtual void dump_spec(outputStream *st) const {};

#endif

};

class ShenandoahEnqueueBarrierNode : public Node {

public:

  ShenandoahEnqueueBarrierNode(Node* val) : Node(NULL, 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; }

  void remove(Node* n);

};

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;

};

#endif // SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP