1 /*
   2  * Copyright (c) 2015, 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_VM_GC_SHENANDOAH_C2_SHENANDOAH_SUPPORT_HPP
  25 #define SHARE_VM_GC_SHENANDOAH_C2_SHENANDOAH_SUPPORT_HPP
  26 
  27 #include "gc/shenandoah/shenandoahBrooksPointer.hpp"
  28 #include "memory/allocation.hpp"
  29 #include "opto/addnode.hpp"
  30 #include "opto/graphKit.hpp"
  31 #include "opto/machnode.hpp"
  32 #include "opto/memnode.hpp"
  33 #include "opto/multnode.hpp"
  34 #include "opto/node.hpp"
  35 
  36 class PhaseGVN;
  37 class MemoryGraphFixer;
  38 
  39 class ShenandoahBarrierNode : public TypeNode {
  40 private:
  41   bool _allow_fromspace;
  42 
  43 #ifdef ASSERT
  44   enum verify_type {
  45     ShenandoahLoad,
  46     ShenandoahStore,
  47     ShenandoahValue,
  48     ShenandoahOopStore,
  49     ShenandoahNone,
  50   };
  51 
  52   static bool verify_helper(Node* in, Node_Stack& phis, VectorSet& visited, verify_type t, bool trace, Unique_Node_List& barriers_used);
  53 #endif
  54 
  55 public:
  56   enum { Control,
  57          Memory,
  58          ValueIn
  59   };
  60 
  61   ShenandoahBarrierNode(Node* ctrl, Node* mem, Node* obj, bool allow_fromspace)
  62     : TypeNode(obj->bottom_type()->isa_oopptr() ? obj->bottom_type()->is_oopptr()->cast_to_nonconst() : obj->bottom_type(), 3),
  63       _allow_fromspace(allow_fromspace) {
  64 
  65     init_req(Control, ctrl);
  66     init_req(Memory, mem);
  67     init_req(ValueIn, obj);
  68 
  69     init_class_id(Class_ShenandoahBarrier);
  70   }
  71 
  72   static Node* skip_through_barrier(Node* n);
  73 
  74   static const TypeOopPtr* brooks_pointer_type(const Type* t) {
  75     return t->is_oopptr()->cast_to_nonconst()->add_offset(ShenandoahBrooksPointer::byte_offset())->is_oopptr();
  76   }
  77 
  78   virtual const TypePtr* adr_type() const {
  79     if (bottom_type() == Type::TOP) {
  80       return NULL;
  81     }
  82     //const TypePtr* adr_type = in(MemNode::Address)->bottom_type()->is_ptr();
  83     const TypePtr* adr_type = brooks_pointer_type(bottom_type());
  84     assert(adr_type->offset() == ShenandoahBrooksPointer::byte_offset(), "sane offset");
  85     assert(Compile::current()->alias_type(adr_type)->is_rewritable(), "brooks ptr must be rewritable");
  86     return adr_type;
  87   }
  88 
  89   virtual uint  ideal_reg() const { return Op_RegP; }
  90   virtual uint match_edge(uint idx) const {
  91     return idx >= ValueIn;
  92   }
  93 
  94   Node* Identity_impl(PhaseGVN* phase);
  95 
  96   virtual const Type* Value(PhaseGVN* phase) const;
  97   virtual bool depends_only_on_test() const {
  98     return true;
  99   };
 100 
 101   static bool needs_barrier(PhaseGVN* phase, ShenandoahBarrierNode* orig, Node* n, Node* rb_mem, bool allow_fromspace);
 102 
 103 #ifdef ASSERT
 104   static void report_verify_failure(const char* msg, Node* n1 = NULL, Node* n2 = NULL);
 105   static void verify(RootNode* root);
 106   static void verify_raw_mem(RootNode* root);
 107 #endif
 108 #ifndef PRODUCT
 109   virtual void dump_spec(outputStream *st) const;
 110 #endif
 111 
 112   // protected:
 113   static Node* dom_mem(Node* mem, Node*& mem_ctrl, Node* n, Node* rep_ctrl, int alias, PhaseIdealLoop* phase);
 114   static Node* dom_mem(Node* mem, Node* ctrl, int alias, Node*& mem_ctrl, PhaseIdealLoop* phase);
 115   static bool is_dominator(Node *d_c, Node *n_c, Node* d, Node* n, PhaseIdealLoop* phase);
 116   static bool is_dominator_same_ctrl(Node* c, Node* d, Node* n, PhaseIdealLoop* phase);
 117   static Node* no_branches(Node* c, Node* dom, bool allow_one_proj, PhaseIdealLoop* phase);
 118   static bool build_loop_late_post(PhaseIdealLoop* phase, Node* n);
 119   bool sink_node(PhaseIdealLoop* phase, Node* ctrl, Node* n_ctrl);
 120 
 121 protected:
 122   uint hash() const;
 123   uint cmp(const Node& n) const;
 124   uint size_of() const;
 125 
 126 private:
 127   static bool needs_barrier_impl(PhaseGVN* phase, ShenandoahBarrierNode* orig, Node* n, Node* rb_mem, bool allow_fromspace, Unique_Node_List &visited);
 128 
 129   static bool dominates_memory(PhaseGVN* phase, Node* b1, Node* b2, bool linear);
 130   static bool dominates_memory_impl(PhaseGVN* phase, Node* b1, Node* b2, Node* current, bool linear);
 131 };
 132 
 133 class ShenandoahReadBarrierNode : public ShenandoahBarrierNode {
 134 public:
 135   ShenandoahReadBarrierNode(Node* ctrl, Node* mem, Node* obj)
 136     : ShenandoahBarrierNode(ctrl, mem, obj, true) {
 137     assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier ||
 138                                ShenandoahWriteBarrier || ShenandoahAcmpBarrier),
 139            "should be enabled");
 140   }
 141   ShenandoahReadBarrierNode(Node* ctrl, Node* mem, Node* obj, bool allow_fromspace)
 142     : ShenandoahBarrierNode(ctrl, mem, obj, allow_fromspace) {
 143     assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier ||
 144                                ShenandoahWriteBarrier || ShenandoahAcmpBarrier),
 145            "should be enabled");
 146   }
 147 
 148   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 149   virtual Node* Identity(PhaseGVN* phase);
 150   virtual int Opcode() const;
 151 
 152   bool is_independent(Node* mem);
 153 
 154   void try_move(PhaseIdealLoop* phase);
 155 
 156 private:
 157   static bool is_independent(const Type* in_type, const Type* this_type);
 158   static bool dominates_memory_rb(PhaseGVN* phase, Node* b1, Node* b2, bool linear);
 159   static bool dominates_memory_rb_impl(PhaseGVN* phase, Node* b1, Node* b2, Node* current, bool linear);
 160 };
 161 
 162 class ShenandoahWriteBarrierNode : public ShenandoahBarrierNode {
 163 public:
 164   ShenandoahWriteBarrierNode(Compile* C, Node* ctrl, Node* mem, Node* obj);
 165 
 166   virtual int Opcode() const;
 167   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 168   virtual Node* Identity(PhaseGVN* phase);
 169   virtual bool depends_only_on_test() const { return false; }
 170 
 171   static bool expand(Compile* C, PhaseIterGVN& igvn);
 172   static bool is_gc_state_load(Node *n);
 173   static bool is_heap_state_test(Node* iff, int mask);
 174   static bool is_heap_stable_test(Node* iff);
 175   static bool try_common_gc_state_load(Node *n, PhaseIdealLoop *phase);
 176   static bool has_safepoint_between(Node* start, Node* stop, PhaseIdealLoop *phase);
 177 
 178   static LoopNode* try_move_before_pre_loop(Node* c, Node* val_ctrl, PhaseIdealLoop* phase);
 179   static Node* move_above_predicates(LoopNode* cl, Node* val_ctrl, PhaseIdealLoop* phase);
 180 #ifdef ASSERT
 181   static bool memory_dominates_all_paths(Node* mem, Node* rep_ctrl, int alias, PhaseIdealLoop* phase);
 182   static void memory_dominates_all_paths_helper(Node* c, Node* rep_ctrl, Unique_Node_List& controls, PhaseIdealLoop* phase);
 183 #endif
 184   void try_move_before_loop(GrowableArray<MemoryGraphFixer*>& memory_graph_fixers, PhaseIdealLoop* phase, bool include_lsm, Unique_Node_List& uses);
 185   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);
 186   static void pin_and_expand(PhaseIdealLoop* phase);
 187   CallStaticJavaNode* pin_and_expand_null_check(PhaseIterGVN& igvn);
 188   void pin_and_expand_move_barrier(PhaseIdealLoop* phase, GrowableArray<MemoryGraphFixer*>& memory_graph_fixers, Unique_Node_List& uses);
 189   void pin_and_expand_helper(PhaseIdealLoop* phase);
 190   static Node* find_bottom_mem(Node* ctrl, PhaseIdealLoop* phase);
 191   static void follow_barrier_uses(Node* n, Node* ctrl, Unique_Node_List& uses, PhaseIdealLoop* phase);
 192   static void test_null(Node*& ctrl, Node* val, Node*& null_ctrl, PhaseIdealLoop* phase);
 193 
 194   static void test_heap_stable(Node*& ctrl, Node* raw_mem, Node*& heap_stable_ctrl,
 195                                PhaseIdealLoop* phase);
 196   static void call_wb_stub(Node*& ctrl, Node*& val, Node*& result_mem,
 197                            Node* raw_mem, Node* wb_mem, int alias,
 198                            PhaseIdealLoop* phase);
 199   static Node* clone_null_check(Node*& c, Node* val, Node* unc_ctrl, PhaseIdealLoop* phase);
 200   static void fix_null_check(Node* unc, Node* unc_ctrl, Node* new_unc_ctrl, Unique_Node_List& uses,
 201                              PhaseIdealLoop* phase);
 202   static void in_cset_fast_test(Node*& ctrl, Node*& not_cset_ctrl, Node* val, Node* raw_mem, PhaseIdealLoop* phase);
 203   static void move_heap_stable_test_out_of_loop(IfNode* iff, PhaseIdealLoop* phase);
 204 
 205   static void optimize_after_expansion(VectorSet &visited, Node_Stack &nstack, Node_List &old_new, PhaseIdealLoop* phase);
 206   static void merge_back_to_back_tests(Node* n, PhaseIdealLoop* phase);
 207   static bool identical_backtoback_ifs(Node *n, PhaseIdealLoop* phase);
 208   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);
 209 
 210   static void optimize_before_expansion(PhaseIdealLoop* phase, GrowableArray<MemoryGraphFixer*> memory_graph_fixers, bool include_lsm);
 211   Node* would_subsume(ShenandoahBarrierNode* other, PhaseIdealLoop* phase);
 212   static IfNode* find_unswitching_candidate(const IdealLoopTree *loop, PhaseIdealLoop* phase);
 213 
 214   Node* try_split_thru_phi(PhaseIdealLoop* phase);
 215 };
 216 
 217 class ShenandoahWBMemProjNode : public Node {
 218 public:
 219   enum { Control,
 220          WriteBarrier };
 221 
 222   ShenandoahWBMemProjNode(Node *src) : Node(NULL, src) {
 223     assert(UseShenandoahGC && ShenandoahWriteBarrier, "should be enabled");
 224     assert(src->Opcode() == Op_ShenandoahWriteBarrier || src->is_Mach(), "epxect wb");
 225   }
 226   virtual Node* Identity(PhaseGVN* phase);
 227 
 228   virtual int Opcode() const;
 229   virtual bool      is_CFG() const  { return false; }
 230   virtual const Type *bottom_type() const {return Type::MEMORY;}
 231   virtual const TypePtr *adr_type() const {
 232     Node* wb = in(WriteBarrier);
 233     if (wb == NULL || wb->is_top())  return NULL; // node is dead
 234     assert(wb->Opcode() == Op_ShenandoahWriteBarrier || (wb->is_Mach() && wb->as_Mach()->ideal_Opcode() == Op_ShenandoahWriteBarrier) || wb->is_Phi(), "expect wb");
 235     return ShenandoahBarrierNode::brooks_pointer_type(wb->bottom_type());
 236   }
 237 
 238   virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
 239   virtual const Type *Value(PhaseGVN* phase ) const {
 240     return bottom_type();
 241   }
 242 #ifndef PRODUCT
 243   virtual void dump_spec(outputStream *st) const {};
 244 #endif
 245 };
 246 
 247 class ShenandoahEnqueueBarrierNode : public Node {
 248 public:
 249   ShenandoahEnqueueBarrierNode(Node* val) : Node(NULL, val) {
 250   }
 251 
 252   const Type *bottom_type() const;
 253   const Type* Value(PhaseGVN* phase) const;
 254   Node* Identity(PhaseGVN* phase);
 255 
 256   int Opcode() const;
 257 
 258 private:
 259   enum { Needed, NotNeeded, MaybeNeeded };
 260 
 261   static int needed(Node* n);
 262   static Node* next(Node* n);
 263 };
 264 
 265 class MemoryGraphFixer : public ResourceObj {
 266 private:
 267   Node_List _memory_nodes;
 268   int _alias;
 269   PhaseIdealLoop* _phase;
 270   bool _include_lsm;
 271 
 272   void collect_memory_nodes();
 273   Node* get_ctrl(Node* n) const;
 274   Node* ctrl_or_self(Node* n) const;
 275   bool mem_is_valid(Node* m, Node* c) const;
 276   MergeMemNode* allocate_merge_mem(Node* mem, Node* rep_proj, Node* rep_ctrl) const;
 277   MergeMemNode* clone_merge_mem(Node* u, Node* mem, Node* rep_proj, Node* rep_ctrl, DUIterator& i) const;
 278   void fix_memory_uses(Node* mem, Node* replacement, Node* rep_proj, Node* rep_ctrl) const;
 279   bool should_process_phi(Node* phi) const;
 280   bool has_mem_phi(Node* region) const;
 281 
 282 public:
 283   MemoryGraphFixer(int alias, bool include_lsm, PhaseIdealLoop* phase) :
 284     _alias(alias), _phase(phase), _include_lsm(include_lsm) {
 285     assert(_alias != Compile::AliasIdxBot, "unsupported");
 286     collect_memory_nodes();
 287   }
 288 
 289   Node* find_mem(Node* ctrl, Node* n) const;
 290   void fix_mem(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl, Node* mem_phi, Unique_Node_List& uses);
 291   int alias() const { return _alias; }
 292   void remove(Node* n);
 293 };
 294 
 295 class ShenandoahCompareAndSwapPNode : public CompareAndSwapPNode {
 296 public:
 297   ShenandoahCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 298     : CompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
 299 
 300   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 301     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
 302       return new CompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 303     }
 304     return NULL;
 305   }
 306 
 307   virtual int Opcode() const;
 308 };
 309 
 310 class ShenandoahCompareAndSwapNNode : public CompareAndSwapNNode {
 311 public:
 312   ShenandoahCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 313     : CompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
 314 
 315   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 316     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
 317       return new CompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 318     }
 319     return NULL;
 320   }
 321 
 322   virtual int Opcode() const;
 323 };
 324 
 325 class ShenandoahWeakCompareAndSwapPNode : public WeakCompareAndSwapPNode {
 326 public:
 327   ShenandoahWeakCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 328     : WeakCompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
 329 
 330   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 331     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
 332       return new WeakCompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 333     }
 334     return NULL;
 335   }
 336 
 337   virtual int Opcode() const;
 338 };
 339 
 340 class ShenandoahWeakCompareAndSwapNNode : public WeakCompareAndSwapNNode {
 341 public:
 342   ShenandoahWeakCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 343     : WeakCompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
 344 
 345   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 346     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
 347       return new WeakCompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 348     }
 349     return NULL;
 350   }
 351 
 352   virtual int Opcode() const;
 353 };
 354 
 355 class ShenandoahCompareAndExchangePNode : public CompareAndExchangePNode {
 356 public:
 357   ShenandoahCompareAndExchangePNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
 358     : CompareAndExchangePNode(c, mem, adr, val, ex, at, t, mem_ord) { }
 359 
 360   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 361     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
 362       return new CompareAndExchangePNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
 363     }
 364     return NULL;
 365   }
 366 
 367   virtual int Opcode() const;
 368 };
 369 
 370 class ShenandoahCompareAndExchangeNNode : public CompareAndExchangeNNode {
 371 public:
 372   ShenandoahCompareAndExchangeNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
 373     : CompareAndExchangeNNode(c, mem, adr, val, ex, at, t, mem_ord) { }
 374 
 375   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 376     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
 377       return new CompareAndExchangeNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
 378     }
 379     return NULL;
 380   }
 381 
 382   virtual int Opcode() const;
 383 };
 384 
 385 #endif // SHARE_VM_GC_SHENANDOAH_C2_SHENANDOAH_SUPPORT_HPP