1 /*
   2  * Copyright (c) 2018, Red Hat, Inc. and/or its affiliates.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #ifndef SHARE_VM_GC_SHENANDOAH_C2_SHENANDOAHBASEBARRIERSETC2_HPP
  25 #define SHARE_VM_GC_SHENANDOAH_C2_SHENANDOAHBASEBARRIERSETC2_HPP
  26 
  27 #include "gc/shared/c2/barrierSetC2.hpp"
  28 
  29 class ShenandoahBarrierSetC2State : public ResourceObj {
  30 private:
  31     GrowableArray<ShenandoahWriteBarrierNode*>* _shenandoah_barriers;
  32 
  33 public:
  34     ShenandoahBarrierSetC2State(Arena* comp_arena);
  35     int shenandoah_barriers_count() const;
  36     ShenandoahWriteBarrierNode* shenandoah_barrier(int idx) const;
  37     void add_shenandoah_barrier(ShenandoahWriteBarrierNode * n);
  38     void remove_shenandoah_barrier(ShenandoahWriteBarrierNode * n);
  39 };
  40 
  41 class ShenandoahBaseBarrierSetC2 : public BarrierSetC2 {
  42 private:
  43 
  44   void shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const;
  45 
  46   bool satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr,
  47                                    BasicType bt, uint adr_idx) const;
  48 
  49   Node* shenandoah_read_barrier_impl(GraphKit* kit, Node* obj, bool use_ctrl, bool use_mem, bool allow_fromspace) const;
  50   Node* shenandoah_write_barrier_impl(GraphKit* kit, Node* obj) const;
  51   Node* shenandoah_write_barrier_helper(GraphKit* kit, Node* obj, const TypePtr* adr_type) const;
  52 
  53 protected:
  54   Node* shenandoah_read_barrier(GraphKit* kit, Node* obj) const;
  55   Node* shenandoah_write_barrier(GraphKit* kit, Node* obj) const;
  56   Node* shenandoah_storeval_barrier(GraphKit* kit, Node* obj) const;
  57   void shenandoah_write_barrier_pre(GraphKit* kit,
  58                                     bool do_load,
  59                                     Node* obj,
  60                                     Node* adr,
  61                                     uint alias_idx,
  62                                     Node* val,
  63                                     const TypeOopPtr* val_type,
  64                                     Node* pre_val,
  65                                     BasicType bt) const;
  66 
  67   void satb_write_barrier_pre(GraphKit* kit, bool do_load,
  68                               Node* obj,
  69                               Node* adr,
  70                               uint alias_idx,
  71                               Node* val,
  72                               const TypeOopPtr* val_type,
  73                               Node* pre_val,
  74                               BasicType bt) const;
  75 
  76   void insert_pre_barrier(GraphKit* kit, Node* base_oop, Node* offset,
  77                           Node* pre_val, bool need_mem_bar) const;
  78 
  79   Node* shenandoah_enqueue_barrier(GraphKit* kit, Node* val) const;
  80 
  81 public:
  82   static ShenandoahBaseBarrierSetC2* bsc2();
  83 
  84   static bool is_shenandoah_wb_pre_call(Node* call);
  85   static bool is_shenandoah_marking_if(PhaseTransform *phase, Node* n);
  86   static bool is_shenandoah_state_load(Node* n);
  87   static bool has_only_shenandoah_wb_pre_uses(Node* n);
  88 
  89   ShenandoahBarrierSetC2State* state() const;
  90 
  91   static const TypeFunc* write_ref_field_pre_entry_Type();
  92   static const TypeFunc* shenandoah_clone_barrier_Type();
  93   static const TypeFunc* shenandoah_write_barrier_Type();
  94 
  95   // This is the entry-point for the backend to perform accesses through the Access API.
  96   virtual void clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const;
  97 
  98   // These are general helper methods used by C2
  99   virtual bool array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const;
 100 
 101   // Support for GC barriers emitted during parsing
 102   virtual bool is_gc_barrier_node(Node* node) const;
 103   virtual Node* step_over_gc_barrier(Node* c) const;
 104   virtual Node* peek_thru_gc_barrier(Node* v) const;
 105 
 106   // Support for macro expanded GC barriers
 107   virtual void register_potential_barrier_node(Node* node) const;
 108   virtual void unregister_potential_barrier_node(Node* node) const;
 109   virtual void eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const;
 110   virtual void enqueue_useful_gc_barrier(Unique_Node_List &worklist, Node* node) const;
 111   virtual void eliminate_useless_gc_barriers(Unique_Node_List &useful) const;
 112   virtual void add_users_to_worklist(Unique_Node_List* worklist) const;
 113 
 114   // Allow barrier sets to have shared state that is preserved across a compilation unit.
 115   // This could for example comprise macro nodes to be expanded during macro expansion.
 116   virtual void* create_barrier_state(Arena* comp_arena) const;
 117   // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be
 118   // expanded later, then now is the time to do so.
 119   virtual bool expand_macro_nodes(PhaseMacroExpand* macro) const;
 120   virtual void verify_gc_barriers(bool post_parse) const;
 121 
 122   virtual Node* ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const;
 123 };
 124 
 125 #endif // SHARE_VM_GC_SHENANDOAH_C2_SHENANDOAHBASEBARRIERSETC2_HPP