1 /*

     2  * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 #ifndef SHARE_GC_Z_C2_ZBARRIERSETC2_HPP

    25 #define SHARE_GC_Z_C2_ZBARRIERSETC2_HPP

    26 

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

    28 #include "memory/allocation.hpp"

    29 #include "opto/node.hpp"

    30 #include "utilities/growableArray.hpp"

    31 

    32 class LoadBarrierNode : public MultiNode {

    33 private:

    34   bool _weak;

    35   bool _writeback;          // Controls if the barrier writes the healed oop back to memory

    36                             // A swap on a memory location must never write back the healed oop

    37   bool _oop_reload_allowed; // Controls if the barrier are allowed to reload the oop from memory

    38                             // before healing, otherwise both the oop and the address must be passed to the

    39                             // barrier from the oop

    40 

    41   static bool is_dominator(PhaseIdealLoop* phase, bool linear_only, Node *d, Node *n);

    42   void push_dominated_barriers(PhaseIterGVN* igvn) const;

    43 

    44 public:

    45   enum {

    46     Control,

    47     Memory,

    48     Oop,

    49     Address,

    50     Number_of_Outputs = Address,

    51     Similar,

    52     Number_of_Inputs

    53   };

    54 

    55   LoadBarrierNode(Compile* C,

    56                   Node* c,

    57                   Node* mem,

    58                   Node* val,

    59                   Node* adr,

    60                   bool weak,

    61                   bool writeback,

    62                   bool oop_reload_allowed);

    63 

    64   virtual int Opcode() const;

    65   virtual const Type *bottom_type() const;

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

    67   virtual Node *Identity(PhaseGVN *phase);

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

    69 

    70   LoadBarrierNode* has_dominating_barrier(PhaseIdealLoop* phase,

    71                                           bool linear_only,

    72                                           bool look_for_similar);

    73 

    74   void fix_similar_in_uses(PhaseIterGVN* igvn);

    75 

    76   bool has_true_uses() const;

    77 

    78   bool can_be_eliminated() const {

    79     return !in(Similar)->is_top();

    80   }

    81 

    82   bool is_weak() const {

    83     return _weak;

    84   }

    85 

    86   bool is_writeback() const {

    87     return _writeback;

    88   }

    89 

    90   bool oop_reload_allowed() const {

    91     return _oop_reload_allowed;

    92   }

    93 };

    94 

    95 class LoadBarrierSlowRegNode : public LoadPNode {

    96 public:

    97   LoadBarrierSlowRegNode(Node *c,

    98                          Node *mem,

    99                          Node *adr,

   100                          const TypePtr *at,

   101                          const TypePtr* t,

   102                          MemOrd mo,

   103                          ControlDependency control_dependency = DependsOnlyOnTest)

   104     : LoadPNode(c, mem, adr, at, t, mo, control_dependency) {}

   105 

   106   virtual const char * name() {

   107     return "LoadBarrierSlowRegNode";

   108   }

   109 

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

   111     return NULL;

   112   }

   113 

   114   virtual int Opcode() const;

   115 };

   116 

   117 class LoadBarrierWeakSlowRegNode : public LoadPNode {

   118 public:

   119   LoadBarrierWeakSlowRegNode(Node *c,

   120                              Node *mem,

   121                              Node *adr,

   122                              const TypePtr *at,

   123                              const TypePtr* t,

   124                              MemOrd mo,

   125                              ControlDependency control_dependency = DependsOnlyOnTest)

   126     : LoadPNode(c, mem, adr, at, t, mo, control_dependency) {}

   127 

   128   virtual const char * name() {

   129     return "LoadBarrierWeakSlowRegNode";

   130   }

   131 

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

   133     return NULL;

   134   }

   135 

   136   virtual int Opcode() const;

   137 };

   138 

   139 class ZBarrierSetC2State : public ResourceObj {

   140 private:

   141   // List of load barrier nodes which need to be expanded before matching

   142   GrowableArray<LoadBarrierNode*>* _load_barrier_nodes;

   143 

   144 public:

   145   ZBarrierSetC2State(Arena* comp_arena);

   146   int load_barrier_count() const;

   147   void add_load_barrier_node(LoadBarrierNode* n);

   148   void remove_load_barrier_node(LoadBarrierNode* n);

   149   LoadBarrierNode* load_barrier_node(int idx) const;

   150 };

   151 

   152 class ZBarrierSetC2 : public BarrierSetC2 {

   153 private:

   154   ZBarrierSetC2State* state() const;

   155   Node* make_cas_loadbarrier(C2AtomicAccess& access) const;

   156   Node* make_cmpx_loadbarrier(C2AtomicAccess& access) const;

   157   void expand_loadbarrier_basic(PhaseMacroExpand* phase, LoadBarrierNode *barrier) const;

   158   void expand_loadbarrier_node(PhaseMacroExpand* phase, LoadBarrierNode* barrier) const;

   159   void expand_loadbarrier_optimized(PhaseMacroExpand* phase, LoadBarrierNode *barrier) const;

   160   const TypeFunc* load_barrier_Type() const;

   161 

   162 protected:

   163   virtual Node* load_at_resolved(C2Access& access, const Type* val_type) const;

   164   virtual Node* atomic_cmpxchg_val_at_resolved(C2AtomicAccess& access,

   165                                                Node* expected_val,

   166                                                Node* new_val,

   167                                                const Type* val_type) const;

   168   virtual Node* atomic_cmpxchg_bool_at_resolved(C2AtomicAccess& access,

   169                                                 Node* expected_val,

   170                                                 Node* new_val,

   171                                                 const Type* value_type) const;

   172   virtual Node* atomic_xchg_at_resolved(C2AtomicAccess& access,

   173                                         Node* new_val,

   174                                         const Type* val_type) const;

   175 

   176 public:

   177   Node* load_barrier(GraphKit* kit,

   178                      Node* val,

   179                      Node* adr,

   180                      bool weak = false,

   181                      bool writeback = true,

   182                      bool oop_reload_allowed = true) const;

   183 

   184   virtual void* create_barrier_state(Arena* comp_arena) const;

   185   virtual bool is_gc_barrier_node(Node* node) const;

   186   virtual void eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const { }

   187   virtual void eliminate_useless_gc_barriers(Unique_Node_List &useful) const;

   188   virtual void add_users_to_worklist(Unique_Node_List* worklist) const;

   189   virtual void enqueue_useful_gc_barrier(Unique_Node_List &worklist, Node* node) const;

   190   virtual void register_potential_barrier_node(Node* node) const;

   191   virtual void unregister_potential_barrier_node(Node* node) const;

   192   virtual bool array_copy_requires_gc_barriers(BasicType type) const { return true; }

   193   virtual Node* step_over_gc_barrier(Node* c) const { return c; }

   194   // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be

   195   // expanded later, then now is the time to do so.

   196   virtual bool expand_macro_nodes(PhaseMacroExpand* macro) const;

   197 

   198   static void find_dominating_barriers(PhaseIterGVN& igvn);

   199   static void loop_optimize_gc_barrier(PhaseIdealLoop* phase, Node* node, bool last_round);

   200 

   201 #ifdef ASSERT

   202   virtual void verify_gc_barriers(bool post_parse) const;

   203 #endif

   204 };

   205 

   206 #endif // SHARE_GC_Z_C2_ZBARRIERSETC2_HPP