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_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP
  25 #define SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP
  26 
  27 #include "memory/allocation.hpp"
  28 #include "opto/addnode.hpp"
  29 #include "opto/graphKit.hpp"
  30 #include "opto/machnode.hpp"
  31 #include "opto/memnode.hpp"
  32 #include "opto/multnode.hpp"
  33 #include "opto/node.hpp"
  34 
  35 class PhaseGVN;
  36 class MemoryGraphFixer;
  37 
  38 class ShenandoahBarrierC2Support : public AllStatic {
  39 private:
  40 #ifdef ASSERT
  41   enum verify_type {
  42     ShenandoahLoad,
  43     ShenandoahStore,
  44     ShenandoahValue,
  45     ShenandoahOopStore,
  46     ShenandoahNone
  47   };
  48 
  49   static bool verify_helper(Node* in, Node_Stack& phis, VectorSet& visited, verify_type t, bool trace, Unique_Node_List& barriers_used);
  50   static void report_verify_failure(const char* msg, Node* n1 = NULL, Node* n2 = NULL);
  51   static void verify_raw_mem(RootNode* root);
  52 #endif
  53   static Node* dom_mem(Node* mem, Node* ctrl, int alias, Node*& mem_ctrl, PhaseIdealLoop* phase);
  54   static Node* no_branches(Node* c, Node* dom, bool allow_one_proj, PhaseIdealLoop* phase);
  55   static bool is_heap_state_test(Node* iff, int mask);
  56   static bool try_common_gc_state_load(Node *n, PhaseIdealLoop *phase);
  57   static bool has_safepoint_between(Node* start, Node* stop, PhaseIdealLoop *phase);
  58   static Node* find_bottom_mem(Node* ctrl, PhaseIdealLoop* phase);
  59   static void follow_barrier_uses(Node* n, Node* ctrl, Unique_Node_List& uses, PhaseIdealLoop* phase);
  60   static void test_null(Node*& ctrl, Node* val, Node*& null_ctrl, PhaseIdealLoop* phase);
  61   static void test_heap_stable(Node*& ctrl, Node* raw_mem, Node*& heap_stable_ctrl,
  62                                PhaseIdealLoop* phase);
  63   static void call_lrb_stub(Node*& ctrl, Node*& val, Node* load_addr, Node*& result_mem, Node* raw_mem, bool is_native, PhaseIdealLoop* phase);
  64   static Node* clone_null_check(Node*& c, Node* val, Node* unc_ctrl, PhaseIdealLoop* phase);
  65   static void fix_null_check(Node* unc, Node* unc_ctrl, Node* new_unc_ctrl, Unique_Node_List& uses,
  66                              PhaseIdealLoop* phase);
  67   static void in_cset_fast_test(Node*& ctrl, Node*& not_cset_ctrl, Node* val, Node* raw_mem, PhaseIdealLoop* phase);
  68   static void move_heap_stable_test_out_of_loop(IfNode* iff, PhaseIdealLoop* phase);
  69   static void merge_back_to_back_tests(Node* n, PhaseIdealLoop* phase);
  70   static bool identical_backtoback_ifs(Node *n, PhaseIdealLoop* phase);
  71   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);
  72   static IfNode* find_unswitching_candidate(const IdealLoopTree *loop, PhaseIdealLoop* phase);
  73 
  74   static Node* get_load_addr(PhaseIdealLoop* phase, VectorSet& visited, Node* lrb);
  75 public:
  76   static bool is_dominator(Node* d_c, Node* n_c, Node* d, Node* n, PhaseIdealLoop* phase);
  77   static bool is_dominator_same_ctrl(Node* c, Node* d, Node* n, PhaseIdealLoop* phase);
  78 
  79   static bool is_gc_state_load(Node* n);
  80   static bool is_heap_stable_test(Node* iff);
  81 
  82   static bool expand(Compile* C, PhaseIterGVN& igvn);
  83   static void pin_and_expand(PhaseIdealLoop* phase);
  84   static void optimize_after_expansion(VectorSet& visited, Node_Stack& nstack, Node_List& old_new, PhaseIdealLoop* phase);
  85 
  86 #ifdef ASSERT
  87   static void verify(RootNode* root);
  88 #endif
  89 };
  90 
  91 class ShenandoahEnqueueBarrierNode : public Node {
  92 public:
  93   ShenandoahEnqueueBarrierNode(Node* val);
  94 
  95   const Type *bottom_type() const;
  96   const Type* Value(PhaseGVN* phase) const;
  97   Node* Identity(PhaseGVN* phase);
  98 
  99   int Opcode() const;
 100 
 101 private:
 102   enum { Needed, NotNeeded, MaybeNeeded };
 103 
 104   static int needed(Node* n);
 105   static Node* next(Node* n);
 106 };
 107 
 108 class MemoryGraphFixer : public ResourceObj {
 109 private:
 110   Node_List _memory_nodes;
 111   int _alias;
 112   PhaseIdealLoop* _phase;
 113   bool _include_lsm;
 114 
 115   void collect_memory_nodes();
 116   Node* get_ctrl(Node* n) const;
 117   Node* ctrl_or_self(Node* n) const;
 118   bool mem_is_valid(Node* m, Node* c) const;
 119   MergeMemNode* allocate_merge_mem(Node* mem, Node* rep_proj, Node* rep_ctrl) const;
 120   MergeMemNode* clone_merge_mem(Node* u, Node* mem, Node* rep_proj, Node* rep_ctrl, DUIterator& i) const;
 121   void fix_memory_uses(Node* mem, Node* replacement, Node* rep_proj, Node* rep_ctrl) const;
 122   bool should_process_phi(Node* phi) const;
 123   bool has_mem_phi(Node* region) const;
 124 
 125 public:
 126   MemoryGraphFixer(int alias, bool include_lsm, PhaseIdealLoop* phase) :
 127     _alias(alias), _phase(phase), _include_lsm(include_lsm) {
 128     assert(_alias != Compile::AliasIdxBot, "unsupported");
 129     collect_memory_nodes();
 130   }
 131 
 132   Node* find_mem(Node* ctrl, Node* n) const;
 133   void fix_mem(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl, Node* mem_phi, Unique_Node_List& uses);
 134   int alias() const { return _alias; }
 135 };
 136 
 137 class ShenandoahCompareAndSwapPNode : public CompareAndSwapPNode {
 138 public:
 139   ShenandoahCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 140     : CompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
 141 
 142   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 143     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
 144       return new CompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 145     }
 146     return NULL;
 147   }
 148 
 149   virtual int Opcode() const;
 150 };
 151 
 152 class ShenandoahCompareAndSwapNNode : public CompareAndSwapNNode {
 153 public:
 154   ShenandoahCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 155     : CompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
 156 
 157   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 158     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
 159       return new CompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 160     }
 161     return NULL;
 162   }
 163 
 164   virtual int Opcode() const;
 165 };
 166 
 167 class ShenandoahWeakCompareAndSwapPNode : public WeakCompareAndSwapPNode {
 168 public:
 169   ShenandoahWeakCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 170     : WeakCompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
 171 
 172   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 173     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
 174       return new WeakCompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 175     }
 176     return NULL;
 177   }
 178 
 179   virtual int Opcode() const;
 180 };
 181 
 182 class ShenandoahWeakCompareAndSwapNNode : public WeakCompareAndSwapNNode {
 183 public:
 184   ShenandoahWeakCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 185     : WeakCompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
 186 
 187   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 188     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
 189       return new WeakCompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 190     }
 191     return NULL;
 192   }
 193 
 194   virtual int Opcode() const;
 195 };
 196 
 197 class ShenandoahCompareAndExchangePNode : public CompareAndExchangePNode {
 198 public:
 199   ShenandoahCompareAndExchangePNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
 200     : CompareAndExchangePNode(c, mem, adr, val, ex, at, t, mem_ord) { }
 201 
 202   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 203     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
 204       return new CompareAndExchangePNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
 205     }
 206     return NULL;
 207   }
 208 
 209   virtual int Opcode() const;
 210 };
 211 
 212 class ShenandoahCompareAndExchangeNNode : public CompareAndExchangeNNode {
 213 public:
 214   ShenandoahCompareAndExchangeNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
 215     : CompareAndExchangeNNode(c, mem, adr, val, ex, at, t, mem_ord) { }
 216 
 217   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 218     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
 219       return new CompareAndExchangeNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
 220     }
 221     return NULL;
 222   }
 223 
 224   virtual int Opcode() const;
 225 };
 226 
 227 class ShenandoahLoadReferenceBarrierNode : public Node {
 228 public:
 229   enum {
 230     Control,
 231     ValueIn
 232   };
 233 
 234   enum Strength {
 235     NONE, STRONG
 236   };
 237 
 238 private:
 239   bool _native;
 240 
 241 public:
 242   ShenandoahLoadReferenceBarrierNode(Node* ctrl, Node* val, bool native);
 243 
 244   bool is_native() const;
 245   virtual int Opcode() const;
 246   virtual const Type* bottom_type() const;
 247   virtual const Type* Value(PhaseGVN* phase) const;
 248   virtual const class TypePtr *adr_type() const { return TypeOopPtr::BOTTOM; }
 249   virtual uint match_edge(uint idx) const {
 250     return idx >= ValueIn;
 251   }
 252   virtual uint ideal_reg() const { return Op_RegP; }
 253 
 254   virtual Node* Identity(PhaseGVN* phase);
 255 
 256   virtual uint size_of() const;
 257   virtual uint hash() const;
 258   virtual bool cmp( const Node &n ) const;
 259 
 260   Strength get_barrier_strength();
 261   CallStaticJavaNode* pin_and_expand_null_check(PhaseIterGVN& igvn);
 262 
 263 private:
 264   bool needs_barrier(PhaseGVN* phase, Node* n);
 265   bool needs_barrier_impl(PhaseGVN* phase, Node* n, Unique_Node_List &visited);
 266 };
 267 
 268 
 269 #endif // SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP