1 /*
  2  * Copyright (c) 2015, 2021, Red Hat, Inc. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #ifndef SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP
 26 #define SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP
 27 
 28 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
 29 #include "memory/allocation.hpp"
 30 #include "opto/addnode.hpp"
 31 #include "opto/graphKit.hpp"
 32 #include "opto/machnode.hpp"
 33 #include "opto/memnode.hpp"
 34 #include "opto/multnode.hpp"
 35 #include "opto/node.hpp"
 36 
 37 class PhaseGVN;
 38 class MemoryGraphFixer;
 39 
 40 class ShenandoahBarrierC2Support : public AllStatic {
 41 private:
 42 #ifdef ASSERT
 43   enum verify_type {
 44     ShenandoahLoad,
 45     ShenandoahStore,
 46     ShenandoahValue,
 47     ShenandoahOopStore,
 48     ShenandoahNone
 49   };
 50 
 51   static bool verify_helper(Node* in, Node_Stack& phis, VectorSet& visited, verify_type t, bool trace, Unique_Node_List& barriers_used);
 52   static void report_verify_failure(const char* msg, Node* n1 = nullptr, Node* n2 = nullptr);
 53 #endif
 54   static Node* dom_mem(Node* mem, Node* ctrl, int alias, Node*& mem_ctrl, PhaseIdealLoop* phase);
 55   static Node* no_branches(Node* c, Node* dom, bool allow_one_proj, PhaseIdealLoop* phase);
 56   static bool is_gc_state_test(Node* iff, int mask);
 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_gc_state(Node*& ctrl, Node* raw_mem, Node*& heap_stable_ctrl,
 62                             PhaseIdealLoop* phase, int flags);
 63   static void call_lrb_stub(Node*& ctrl, Node*& val, Node* load_addr,
 64                             DecoratorSet decorators, PhaseIdealLoop* phase);
 65   static void test_in_cset(Node*& ctrl, Node*& not_cset_ctrl, Node* val, Node* raw_mem, PhaseIdealLoop* phase);
 66   static void move_gc_state_test_out_of_loop(IfNode* iff, PhaseIdealLoop* phase);
 67   static void merge_back_to_back_tests(Node* n, PhaseIdealLoop* phase);
 68   static bool identical_backtoback_ifs(Node *n, PhaseIdealLoop* phase);
 69   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);
 70   static IfNode* find_unswitching_candidate(const IdealLoopTree *loop, PhaseIdealLoop* phase);
 71 
 72   static Node* get_load_addr(PhaseIdealLoop* phase, VectorSet& visited, Node* lrb);
 73 public:
 74   static bool is_dominator(Node* d_c, Node* n_c, Node* d, Node* n, PhaseIdealLoop* phase);
 75   static bool is_dominator_same_ctrl(Node* c, Node* d, Node* n, PhaseIdealLoop* phase);
 76 
 77   static bool is_gc_state_load(Node* n);
 78   static bool is_heap_stable_test(Node* iff);
 79 
 80   static bool expand(Compile* C, PhaseIterGVN& igvn);
 81   static void pin_and_expand(PhaseIdealLoop* phase);
 82   static void optimize_after_expansion(VectorSet& visited, Node_Stack& nstack, Node_List& old_new, PhaseIdealLoop* phase);
 83 
 84 #ifdef ASSERT
 85   static void verify(RootNode* root);
 86 #endif
 87 };
 88 
 89 class ShenandoahIUBarrierNode : public Node {
 90 public:
 91   ShenandoahIUBarrierNode(Node* val);
 92 
 93   const Type *bottom_type() const;
 94   const Type* Value(PhaseGVN* phase) const;
 95   Node* Identity(PhaseGVN* phase);
 96 
 97   int Opcode() const;
 98 
 99 private:
100   enum { Needed, NotNeeded, MaybeNeeded };
101 
102   static int needed(Node* n);
103   static Node* next(Node* n);
104 };
105 
106 class MemoryGraphFixer : public ResourceObj {
107 private:
108   Node_List _memory_nodes;
109   int _alias;
110   PhaseIdealLoop* _phase;
111   bool _include_lsm;
112 
113   void collect_memory_nodes();
114   Node* get_ctrl(Node* n) const;
115   Node* ctrl_or_self(Node* n) const;
116   bool mem_is_valid(Node* m, Node* c) const;
117   MergeMemNode* allocate_merge_mem(Node* mem, Node* rep_proj, Node* rep_ctrl) const;
118   MergeMemNode* clone_merge_mem(Node* u, Node* mem, Node* rep_proj, Node* rep_ctrl, DUIterator& i) const;
119   void fix_memory_uses(Node* mem, Node* replacement, Node* rep_proj, Node* rep_ctrl) const;
120   bool should_process_phi(Node* phi) const;
121   bool has_mem_phi(Node* region) const;
122 
123 public:
124   MemoryGraphFixer(int alias, bool include_lsm, PhaseIdealLoop* phase) :
125     _alias(alias), _phase(phase), _include_lsm(include_lsm) {
126     assert(_alias != Compile::AliasIdxBot, "unsupported");
127     collect_memory_nodes();
128   }
129 
130   Node* find_mem(Node* ctrl, Node* n) const;
131   void fix_mem(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl, Node* mem_phi, Unique_Node_List& uses);
132   int alias() const { return _alias; }
133 
134   Node* collect_memory_for_infinite_loop(const Node* in);
135 
136   void record_new_ctrl(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl);
137 };
138 
139 class ShenandoahCompareAndSwapPNode : public CompareAndSwapPNode {
140 public:
141   ShenandoahCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
142     : CompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
143 
144   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
145     if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
146       return new CompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
147     }
148     return nullptr;
149   }
150 
151   virtual int Opcode() const;
152 };
153 
154 class ShenandoahCompareAndSwapNNode : public CompareAndSwapNNode {
155 public:
156   ShenandoahCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
157     : CompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
158 
159   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
160     if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
161       return new CompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
162     }
163     return nullptr;
164   }
165 
166   virtual int Opcode() const;
167 };
168 
169 class ShenandoahWeakCompareAndSwapPNode : public WeakCompareAndSwapPNode {
170 public:
171   ShenandoahWeakCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
172     : WeakCompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
173 
174   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
175     if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
176       return new WeakCompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
177     }
178     return nullptr;
179   }
180 
181   virtual int Opcode() const;
182 };
183 
184 class ShenandoahWeakCompareAndSwapNNode : public WeakCompareAndSwapNNode {
185 public:
186   ShenandoahWeakCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
187     : WeakCompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
188 
189   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
190     if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
191       return new WeakCompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
192     }
193     return nullptr;
194   }
195 
196   virtual int Opcode() const;
197 };
198 
199 class ShenandoahCompareAndExchangePNode : public CompareAndExchangePNode {
200 public:
201   ShenandoahCompareAndExchangePNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
202     : CompareAndExchangePNode(c, mem, adr, val, ex, at, t, mem_ord) { }
203 
204   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
205     if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
206       return new CompareAndExchangePNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
207     }
208     return nullptr;
209   }
210 
211   virtual int Opcode() const;
212 };
213 
214 class ShenandoahCompareAndExchangeNNode : public CompareAndExchangeNNode {
215 public:
216   ShenandoahCompareAndExchangeNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
217     : CompareAndExchangeNNode(c, mem, adr, val, ex, at, t, mem_ord) { }
218 
219   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
220     if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
221       return new CompareAndExchangeNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
222     }
223     return nullptr;
224   }
225 
226   virtual int Opcode() const;
227 };
228 
229 class ShenandoahLoadReferenceBarrierNode : public Node {
230 public:
231   enum {
232     Control,
233     ValueIn
234   };
235 
236 private:
237   DecoratorSet _decorators;
238 
239 public:
240   ShenandoahLoadReferenceBarrierNode(Node* ctrl, Node* val, DecoratorSet decorators);
241 
242   DecoratorSet decorators() const;
243   virtual int Opcode() const;
244   virtual const Type* bottom_type() const;
245   virtual const Type* Value(PhaseGVN* phase) const;
246   virtual const class TypePtr *adr_type() const { return TypeOopPtr::BOTTOM; }
247   virtual uint match_edge(uint idx) const {
248     return idx >= ValueIn;
249   }
250   virtual uint ideal_reg() const { return Op_RegP; }
251 
252   virtual Node* Identity(PhaseGVN* phase);
253 
254   virtual uint size_of() const;
255   virtual uint hash() const;
256   virtual bool cmp( const Node &n ) const;
257 
258 private:
259   bool needs_barrier(PhaseGVN* phase, Node* n);
260   bool needs_barrier_impl(PhaseGVN* phase, Node* n, Unique_Node_List &visited);
261 };
262 
263 
264 #endif // SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP