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*& result_mem, Node* raw_mem, 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 public:
  75   static bool is_dominator(Node* d_c, Node* n_c, Node* d, Node* n, PhaseIdealLoop* phase);
  76   static bool is_dominator_same_ctrl(Node* c, Node* d, Node* n, PhaseIdealLoop* phase);
  77 
  78   static bool is_gc_state_load(Node* n);
  79   static bool is_heap_stable_test(Node* iff);
  80 
  81   static bool expand(Compile* C, PhaseIterGVN& igvn);
  82   static void pin_and_expand(PhaseIdealLoop* phase);
  83   static void optimize_after_expansion(VectorSet& visited, Node_Stack& nstack, Node_List& old_new, PhaseIdealLoop* phase);
  84 
  85 #ifdef ASSERT
  86   static void verify(RootNode* root);
  87 #endif
  88 };
  89 
  90 class ShenandoahEnqueueBarrierNode : public Node {
  91 public:
  92   ShenandoahEnqueueBarrierNode(Node* val);
  93 
  94   const Type *bottom_type() const;
  95   const Type* Value(PhaseGVN* phase) const;
  96   Node* Identity(PhaseGVN* phase);
  97 
  98   int Opcode() const;
  99 
 100 private:
 101   enum { Needed, NotNeeded, MaybeNeeded };
 102 
 103   static int needed(Node* n);
 104   static Node* next(Node* n);
 105 };
 106 
 107 class MemoryGraphFixer : public ResourceObj {
 108 private:
 109   Node_List _memory_nodes;
 110   int _alias;
 111   PhaseIdealLoop* _phase;
 112   bool _include_lsm;
 113 
 114   void collect_memory_nodes();
 115   Node* get_ctrl(Node* n) const;
 116   Node* ctrl_or_self(Node* n) const;
 117   bool mem_is_valid(Node* m, Node* c) const;
 118   MergeMemNode* allocate_merge_mem(Node* mem, Node* rep_proj, Node* rep_ctrl) const;
 119   MergeMemNode* clone_merge_mem(Node* u, Node* mem, Node* rep_proj, Node* rep_ctrl, DUIterator& i) const;
 120   void fix_memory_uses(Node* mem, Node* replacement, Node* rep_proj, Node* rep_ctrl) const;
 121   bool should_process_phi(Node* phi) const;
 122   bool has_mem_phi(Node* region) const;
 123 
 124 public:
 125   MemoryGraphFixer(int alias, bool include_lsm, PhaseIdealLoop* phase) :
 126     _alias(alias), _phase(phase), _include_lsm(include_lsm) {
 127     assert(_alias != Compile::AliasIdxBot, "unsupported");
 128     collect_memory_nodes();
 129   }
 130 
 131   Node* find_mem(Node* ctrl, Node* n) const;
 132   void fix_mem(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl, Node* mem_phi, Unique_Node_List& uses);
 133   int alias() const { return _alias; }
 134 };
 135 
 136 class ShenandoahCompareAndSwapPNode : public CompareAndSwapPNode {
 137 public:
 138   ShenandoahCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 139     : CompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
 140 
 141   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 142     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
 143       return new CompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 144     }
 145     return NULL;
 146   }
 147 
 148   virtual int Opcode() const;
 149 };
 150 
 151 class ShenandoahCompareAndSwapNNode : public CompareAndSwapNNode {
 152 public:
 153   ShenandoahCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 154     : CompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
 155 
 156   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 157     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
 158       return new CompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 159     }
 160     return NULL;
 161   }
 162 
 163   virtual int Opcode() const;
 164 };
 165 
 166 class ShenandoahWeakCompareAndSwapPNode : public WeakCompareAndSwapPNode {
 167 public:
 168   ShenandoahWeakCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 169     : WeakCompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
 170 
 171   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 172     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
 173       return new WeakCompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 174     }
 175     return NULL;
 176   }
 177 
 178   virtual int Opcode() const;
 179 };
 180 
 181 class ShenandoahWeakCompareAndSwapNNode : public WeakCompareAndSwapNNode {
 182 public:
 183   ShenandoahWeakCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
 184     : WeakCompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
 185 
 186   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 187     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
 188       return new WeakCompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
 189     }
 190     return NULL;
 191   }
 192 
 193   virtual int Opcode() const;
 194 };
 195 
 196 class ShenandoahCompareAndExchangePNode : public CompareAndExchangePNode {
 197 public:
 198   ShenandoahCompareAndExchangePNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
 199     : CompareAndExchangePNode(c, mem, adr, val, ex, at, t, mem_ord) { }
 200 
 201   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 202     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
 203       return new CompareAndExchangePNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
 204     }
 205     return NULL;
 206   }
 207 
 208   virtual int Opcode() const;
 209 };
 210 
 211 class ShenandoahCompareAndExchangeNNode : public CompareAndExchangeNNode {
 212 public:
 213   ShenandoahCompareAndExchangeNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
 214     : CompareAndExchangeNNode(c, mem, adr, val, ex, at, t, mem_ord) { }
 215 
 216   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
 217     if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
 218       return new CompareAndExchangeNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
 219     }
 220     return NULL;
 221   }
 222 
 223   virtual int Opcode() const;
 224 };
 225 
 226 class ShenandoahLoadReferenceBarrierNode : public Node {
 227 public:
 228   enum {
 229     Control,
 230     ValueIn
 231   };
 232 
 233   enum Strength {
 234     NONE, STRONG
 235   };
 236 
 237   ShenandoahLoadReferenceBarrierNode(Node* ctrl, Node* val);
 238 
 239   virtual int Opcode() const;
 240   virtual const Type* bottom_type() const;
 241   virtual const Type* Value(PhaseGVN* phase) const;
 242   virtual const class TypePtr *adr_type() const { return TypeOopPtr::BOTTOM; }
 243   virtual uint match_edge(uint idx) const {
 244     return idx >= ValueIn;
 245   }
 246   virtual uint ideal_reg() const { return Op_RegP; }
 247 
 248   virtual Node* Identity(PhaseGVN* phase);
 249 
 250   uint size_of() const {
 251     return sizeof(*this);
 252   }
 253 
 254   Strength get_barrier_strength();
 255   CallStaticJavaNode* pin_and_expand_null_check(PhaseIterGVN& igvn);
 256 
 257 private:
 258   bool needs_barrier(PhaseGVN* phase, Node* n);
 259   bool needs_barrier_impl(PhaseGVN* phase, Node* n, Unique_Node_List &visited);
 260 };
 261 
 262 
 263 #endif // SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP