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
66 static void collect_nodes_above_barrier(Unique_Node_List &nodes_above_barrier, PhaseIdealLoop* phase, Node* ctrl,
67 Node* init_raw_mem);
68
69 static void test_in_cset(Node*& ctrl, Node*& not_cset_ctrl, Node* val, Node* raw_mem, PhaseIdealLoop* phase);
70 static void move_gc_state_test_out_of_loop(IfNode* iff, PhaseIdealLoop* phase);
71 static void merge_back_to_back_tests(Node* n, PhaseIdealLoop* phase);
72 static bool merge_point_safe(Node* region);
73 static bool identical_backtoback_ifs(Node *n, PhaseIdealLoop* phase);
74 static void fix_ctrl(Node* barrier, Node* region, const MemoryGraphFixer& fixer, Unique_Node_List& uses, Unique_Node_List& nodes_above_barrier, uint last, PhaseIdealLoop* phase);
75 static IfNode* find_unswitching_candidate(const IdealLoopTree *loop, PhaseIdealLoop* phase);
76
77 static Node* get_load_addr(PhaseIdealLoop* phase, VectorSet& visited, Node* lrb);
78 public:
79 static bool is_dominator(Node* d_c, Node* n_c, Node* d, Node* n, PhaseIdealLoop* phase);
80 static bool is_dominator_same_ctrl(Node* c, Node* d, Node* n, PhaseIdealLoop* phase);
81
82 static bool is_gc_state_load(Node* n);
83 static bool is_heap_stable_test(Node* iff);
84
85 static bool expand(Compile* C, PhaseIterGVN& igvn);
86 static void pin_and_expand(PhaseIdealLoop* phase);
87 static void optimize_after_expansion(VectorSet& visited, Node_Stack& nstack, Node_List& old_new, PhaseIdealLoop* phase);
88
89 static void push_data_inputs_at_control(PhaseIdealLoop* phase, Node* n, Node* ctrl,
90 Unique_Node_List &wq);
91 static bool is_anti_dependent_load_at_control(PhaseIdealLoop* phase, Node* maybe_load, Node* store, Node* control);
92
93 static void maybe_push_anti_dependent_loads(PhaseIdealLoop* phase, Node* maybe_store, Node* control, Unique_Node_List &wq);
94 #ifdef ASSERT
95 static void verify(RootNode* root);
96 #endif
97 };
98
99 class ShenandoahIUBarrierNode : public Node {
100 public:
101 ShenandoahIUBarrierNode(Node* val);
102
103 const Type *bottom_type() const;
104 const Type* Value(PhaseGVN* phase) const;
105 Node* Identity(PhaseGVN* phase);
106
107 int Opcode() const;
108
109 private:
110 enum { Needed, NotNeeded, MaybeNeeded };
111
112 static int needed(Node* n);
113 static Node* next(Node* n);
114 };
115
116 class MemoryGraphFixer : public ResourceObj {
117 private:
118 Node_List _memory_nodes;
119 int _alias;
120 PhaseIdealLoop* _phase;
121 bool _include_lsm;
122
123 void collect_memory_nodes();
124 Node* get_ctrl(Node* n) const;
125 Node* ctrl_or_self(Node* n) const;
126 bool mem_is_valid(Node* m, Node* c) const;
127 MergeMemNode* allocate_merge_mem(Node* mem, Node* rep_proj, Node* rep_ctrl) const;
128 MergeMemNode* clone_merge_mem(Node* u, Node* mem, Node* rep_proj, Node* rep_ctrl, DUIterator& i) const;
129 void fix_memory_uses(Node* mem, Node* replacement, Node* rep_proj, Node* rep_ctrl) const;
130 bool should_process_phi(Node* phi) const;
131 bool has_mem_phi(Node* region) const;
132
133 public:
134 MemoryGraphFixer(int alias, bool include_lsm, PhaseIdealLoop* phase) :
135 _alias(alias), _phase(phase), _include_lsm(include_lsm) {
136 assert(_alias != Compile::AliasIdxBot, "unsupported");
137 collect_memory_nodes();
138 }
139
140 Node* find_mem(Node* ctrl, Node* n) const;
141 void fix_mem(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl, Node* mem_phi, Unique_Node_List& uses);
142 int alias() const { return _alias; }
143
144 Node* collect_memory_for_infinite_loop(const Node* in);
145
146 void record_new_ctrl(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl);
147 };
148
149 class ShenandoahCompareAndSwapPNode : public CompareAndSwapPNode {
150 public:
151 ShenandoahCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
152 : CompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
153
154 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
155 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
156 return new CompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
157 }
158 return nullptr;
159 }
160
161 virtual int Opcode() const;
162 };
163
164 class ShenandoahCompareAndSwapNNode : public CompareAndSwapNNode {
165 public:
166 ShenandoahCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
167 : CompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
168
169 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
170 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
171 return new CompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
172 }
173 return nullptr;
174 }
175
176 virtual int Opcode() const;
177 };
178
179 class ShenandoahWeakCompareAndSwapPNode : public WeakCompareAndSwapPNode {
180 public:
181 ShenandoahWeakCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
182 : WeakCompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
183
184 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
185 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
186 return new WeakCompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
187 }
188 return nullptr;
189 }
190
191 virtual int Opcode() const;
192 };
193
194 class ShenandoahWeakCompareAndSwapNNode : public WeakCompareAndSwapNNode {
195 public:
196 ShenandoahWeakCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
197 : WeakCompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
198
199 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
200 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
201 return new WeakCompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
202 }
203 return nullptr;
204 }
205
206 virtual int Opcode() const;
207 };
208
209 class ShenandoahCompareAndExchangePNode : public CompareAndExchangePNode {
210 public:
211 ShenandoahCompareAndExchangePNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
212 : CompareAndExchangePNode(c, mem, adr, val, ex, at, t, mem_ord) { }
213
214 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
215 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
216 return new CompareAndExchangePNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
217 }
218 return nullptr;
219 }
220
221 virtual int Opcode() const;
222 };
223
224 class ShenandoahCompareAndExchangeNNode : public CompareAndExchangeNNode {
225 public:
226 ShenandoahCompareAndExchangeNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
227 : CompareAndExchangeNNode(c, mem, adr, val, ex, at, t, mem_ord) { }
228
229 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
230 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
231 return new CompareAndExchangeNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
232 }
233 return nullptr;
234 }
235
236 virtual int Opcode() const;
237 };
238
239 class ShenandoahLoadReferenceBarrierNode : public Node {
240 public:
241 enum {
242 Control,
243 ValueIn
244 };
245
246 private:
247 DecoratorSet _decorators;
248
249 public:
250 ShenandoahLoadReferenceBarrierNode(Node* ctrl, Node* val, DecoratorSet decorators);
251
252 DecoratorSet decorators() const;
253 virtual int Opcode() const;
254 virtual const Type* bottom_type() const;
255 virtual const Type* Value(PhaseGVN* phase) const;
256 virtual const class TypePtr *adr_type() const { return TypeOopPtr::BOTTOM; }
257 virtual uint match_edge(uint idx) const {
258 return idx >= ValueIn;
259 }
260 virtual uint ideal_reg() const { return Op_RegP; }
261
262 virtual Node* Identity(PhaseGVN* phase);
263
264 virtual uint size_of() const;
265 virtual uint hash() const;
266 virtual bool cmp( const Node &n ) const;
267
268 private:
269 bool needs_barrier(PhaseGVN* phase, Node* n);
270 bool needs_barrier_impl(PhaseGVN* phase, Node* n, Unique_Node_List &visited);
271 };
272
273
274 #endif // SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP