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 merge_point_safe(Node* region);
69 static bool identical_backtoback_ifs(Node *n, PhaseIdealLoop* phase);
70 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);
71 static IfNode* find_unswitching_candidate(const IdealLoopTree *loop, PhaseIdealLoop* phase);
72
73 static Node* get_load_addr(PhaseIdealLoop* phase, VectorSet& visited, Node* lrb);
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 ShenandoahIUBarrierNode : public Node {
91 public:
92 ShenandoahIUBarrierNode(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 Node* collect_memory_for_infinite_loop(const Node* in);
136
137 void record_new_ctrl(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl);
138 };
139
140 class ShenandoahCompareAndSwapPNode : public CompareAndSwapPNode {
141 public:
142 ShenandoahCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
143 : CompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
144
145 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
146 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
147 return new CompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
148 }
149 return nullptr;
150 }
151
152 virtual int Opcode() const;
153 };
154
155 class ShenandoahCompareAndSwapNNode : public CompareAndSwapNNode {
156 public:
157 ShenandoahCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
158 : CompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
159
160 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
161 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
162 return new CompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
163 }
164 return nullptr;
165 }
166
167 virtual int Opcode() const;
168 };
169
170 class ShenandoahWeakCompareAndSwapPNode : public WeakCompareAndSwapPNode {
171 public:
172 ShenandoahWeakCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
173 : WeakCompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
174
175 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
176 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
177 return new WeakCompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
178 }
179 return nullptr;
180 }
181
182 virtual int Opcode() const;
183 };
184
185 class ShenandoahWeakCompareAndSwapNNode : public WeakCompareAndSwapNNode {
186 public:
187 ShenandoahWeakCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
188 : WeakCompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
189
190 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
191 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
192 return new WeakCompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
193 }
194 return nullptr;
195 }
196
197 virtual int Opcode() const;
198 };
199
200 class ShenandoahCompareAndExchangePNode : public CompareAndExchangePNode {
201 public:
202 ShenandoahCompareAndExchangePNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
203 : CompareAndExchangePNode(c, mem, adr, val, ex, at, t, mem_ord) { }
204
205 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
206 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
207 return new CompareAndExchangePNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
208 }
209 return nullptr;
210 }
211
212 virtual int Opcode() const;
213 };
214
215 class ShenandoahCompareAndExchangeNNode : public CompareAndExchangeNNode {
216 public:
217 ShenandoahCompareAndExchangeNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
218 : CompareAndExchangeNNode(c, mem, adr, val, ex, at, t, mem_ord) { }
219
220 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
221 if (in(ExpectedIn) != nullptr && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
222 return new CompareAndExchangeNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
223 }
224 return nullptr;
225 }
226
227 virtual int Opcode() const;
228 };
229
230 class ShenandoahLoadReferenceBarrierNode : public Node {
231 public:
232 enum {
233 Control,
234 ValueIn
235 };
236
237 private:
238 DecoratorSet _decorators;
239
240 public:
241 ShenandoahLoadReferenceBarrierNode(Node* ctrl, Node* val, DecoratorSet decorators);
242
243 DecoratorSet decorators() const;
244 virtual int Opcode() const;
245 virtual const Type* bottom_type() const;
246 virtual const Type* Value(PhaseGVN* phase) const;
247 virtual const class TypePtr *adr_type() const { return TypeOopPtr::BOTTOM; }
248 virtual uint match_edge(uint idx) const {
249 return idx >= ValueIn;
250 }
251 virtual uint ideal_reg() const { return Op_RegP; }
252
253 virtual Node* Identity(PhaseGVN* phase);
254
255 virtual uint size_of() const;
256 virtual uint hash() const;
257 virtual bool cmp( const Node &n ) const;
258
259 private:
260 bool needs_barrier(PhaseGVN* phase, Node* n);
261 bool needs_barrier_impl(PhaseGVN* phase, Node* n, Unique_Node_List &visited);
262 };
263
264
265 #endif // SHARE_GC_SHENANDOAH_C2_SHENANDOAHSUPPORT_HPP