1 /*
   2  * Copyright (c) 2018, Red Hat, Inc. All rights reserved.
   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_GC_SHENANDOAH_C2_SHENANDOAHBARRIERSETC2_HPP
  25 #define SHARE_GC_SHENANDOAH_C2_SHENANDOAHBARRIERSETC2_HPP
  26 
  27 #include "gc/shared/c2/barrierSetC2.hpp"
  28 #include "gc/shenandoah/c2/shenandoahSupport.hpp"
  29 #include "utilities/growableArray.hpp"
  30 
  31 class ShenandoahBarrierSetC2State : public ResourceObj {
  32 private:
  33   GrowableArray<ShenandoahEnqueueBarrierNode*>* _enqueue_barriers;
  34   GrowableArray<ShenandoahLoadReferenceBarrierNode*>* _load_reference_barriers;
  35 
  36 public:
  37   ShenandoahBarrierSetC2State(Arena* comp_arena);
  38 
  39   int enqueue_barriers_count() const;
  40   ShenandoahEnqueueBarrierNode* enqueue_barrier(int idx) const;
  41   void add_enqueue_barrier(ShenandoahEnqueueBarrierNode* n);
  42   void remove_enqueue_barrier(ShenandoahEnqueueBarrierNode * n);
  43 
  44   int load_reference_barriers_count() const;
  45   ShenandoahLoadReferenceBarrierNode* load_reference_barrier(int idx) const;
  46   void add_load_reference_barrier(ShenandoahLoadReferenceBarrierNode* n);
  47   void remove_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n);
  48 };
  49 
  50 class ShenandoahBarrierSetC2 : public BarrierSetC2 {
  51 private:
  52   void shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const;
  53 
  54   bool satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr,
  55                                    BasicType bt, uint adr_idx) const;
  56   void satb_write_barrier_pre(GraphKit* kit, bool do_load,
  57                               Node* obj,
  58                               Node* adr,
  59                               uint alias_idx,
  60                               Node* val,
  61                               const TypeOopPtr* val_type,
  62                               Node* pre_val,
  63                               BasicType bt) const;
  64 
  65   void shenandoah_write_barrier_pre(GraphKit* kit,
  66                                     bool do_load,
  67                                     Node* obj,
  68                                     Node* adr,
  69                                     uint alias_idx,
  70                                     Node* val,
  71                                     const TypeOopPtr* val_type,
  72                                     Node* pre_val,
  73                                     BasicType bt) const;
  74 
  75   Node* shenandoah_enqueue_barrier(GraphKit* kit, Node* val) const;
  76   Node* shenandoah_storeval_barrier(GraphKit* kit, Node* obj) const;
  77 
  78   void insert_pre_barrier(GraphKit* kit, Node* base_oop, Node* offset,
  79                           Node* pre_val, bool need_mem_bar) const;
  80 
  81   static bool clone_needs_postbarrier(ArrayCopyNode *ac, PhaseIterGVN& igvn);
  82 
  83 protected:
  84   virtual Node* load_at_resolved(C2Access& access, const Type* val_type) const;
  85   virtual Node* store_at_resolved(C2Access& access, C2AccessValue& val) const;
  86   virtual Node* atomic_cmpxchg_val_at_resolved(C2AtomicAccess& access, Node* expected_val,
  87                                                Node* new_val, const Type* val_type) const;
  88   virtual Node* atomic_cmpxchg_bool_at_resolved(C2AtomicAccess& access, Node* expected_val,
  89                                                 Node* new_val, const Type* value_type) const;
  90   virtual Node* atomic_xchg_at_resolved(C2AtomicAccess& access, Node* new_val, const Type* val_type) const;
  91 
  92 public:
  93   static ShenandoahBarrierSetC2* bsc2();
  94 
  95   static bool is_shenandoah_wb_pre_call(Node* call);
  96   static bool is_shenandoah_lrb_call(Node* call);
  97   static bool is_shenandoah_marking_if(PhaseTransform *phase, Node* n);
  98   static bool is_shenandoah_state_load(Node* n);
  99   static bool has_only_shenandoah_wb_pre_uses(Node* n);
 100 
 101   ShenandoahBarrierSetC2State* state() const;
 102 
 103   static const TypeFunc* write_ref_field_pre_entry_Type();
 104   static const TypeFunc* shenandoah_clone_barrier_Type();
 105   static const TypeFunc* shenandoah_load_reference_barrier_Type();
 106   virtual bool has_load_barriers() const { return true; }
 107 
 108   // This is the entry-point for the backend to perform accesses through the Access API.
 109   virtual void clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const;
 110 
 111   // These are general helper methods used by C2
 112   virtual bool array_copy_requires_gc_barriers(BasicType type) const;
 113 
 114   // Support for GC barriers emitted during parsing
 115   virtual bool is_gc_barrier_node(Node* node) const;
 116   virtual Node* step_over_gc_barrier(Node* c) const;
 117   virtual bool expand_barriers(Compile* C, PhaseIterGVN& igvn) const;
 118   virtual bool optimize_loops(PhaseIdealLoop* phase, LoopOptsMode mode, VectorSet& visited, Node_Stack& nstack, Node_List& worklist) const;
 119   virtual bool strip_mined_loops_expanded(LoopOptsMode mode) const { return mode == LoopOptsShenandoahExpand || mode == LoopOptsShenandoahPostExpand; }
 120   virtual bool is_gc_specific_loop_opts_pass(LoopOptsMode mode) const { return mode == LoopOptsShenandoahExpand || mode == LoopOptsShenandoahPostExpand; }
 121 
 122   // Support for macro expanded GC barriers
 123   virtual void register_potential_barrier_node(Node* node) const;
 124   virtual void unregister_potential_barrier_node(Node* node) const;
 125   virtual void eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const;
 126   virtual void enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const;
 127   virtual void eliminate_useless_gc_barriers(Unique_Node_List &useful) const;
 128   virtual void add_users_to_worklist(Unique_Node_List* worklist) const;
 129 
 130   // Allow barrier sets to have shared state that is preserved across a compilation unit.
 131   // This could for example comprise macro nodes to be expanded during macro expansion.
 132   virtual void* create_barrier_state(Arena* comp_arena) const;
 133   // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be
 134   // expanded later, then now is the time to do so.
 135   virtual bool expand_macro_nodes(PhaseMacroExpand* macro) const;
 136 
 137 #ifdef ASSERT
 138   virtual void verify_gc_barriers(bool post_parse) const;
 139 #endif
 140 
 141   virtual Node* ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const;
 142 };
 143 
 144 #endif // SHARE_GC_SHENANDOAH_C2_SHENANDOAHBARRIERSETC2_HPP