1 /*
2 * Copyright (c) 2018, Oracle and/or its affiliates. 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.
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23 */
24
25 #ifndef SHARE_GC_SHARED_C2_BARRIERSETC2_HPP
26 #define SHARE_GC_SHARED_C2_BARRIERSETC2_HPP
27
28 #include "memory/allocation.hpp"
29 #include "oops/accessDecorators.hpp"
30 #include "opto/loopnode.hpp"
31 #include "opto/matcher.hpp"
32 #include "opto/memnode.hpp"
33 #include "utilities/globalDefinitions.hpp"
34
35 // This means the access is mismatched. This means the value of an access
36 // is not equivalent to the value pointed to by the address.
37 const DecoratorSet C2_MISMATCHED = DECORATOR_LAST << 1;
38 // The access may not be aligned to its natural size.
39 const DecoratorSet C2_UNALIGNED = DECORATOR_LAST << 2;
40 // The atomic cmpxchg is weak, meaning that spurious false negatives are allowed,
41 // but never false positives.
42 const DecoratorSet C2_WEAK_CMPXCHG = DECORATOR_LAST << 3;
43 // This denotes that a load has control dependency.
44 const DecoratorSet C2_CONTROL_DEPENDENT_LOAD = DECORATOR_LAST << 4;
45 // This denotes that a load that must be pinned.
46 const DecoratorSet C2_PINNED_LOAD = DECORATOR_LAST << 5;
47 // This denotes that the access is produced from the sun.misc.Unsafe intrinsics.
48 const DecoratorSet C2_UNSAFE_ACCESS = DECORATOR_LAST << 6;
49 // This denotes that the access mutates state.
50 const DecoratorSet C2_WRITE_ACCESS = DECORATOR_LAST << 7;
51 // This denotes that the access reads state.
52 const DecoratorSet C2_READ_ACCESS = DECORATOR_LAST << 8;
53 // A nearby allocation?
54 const DecoratorSet C2_TIGHLY_COUPLED_ALLOC = DECORATOR_LAST << 9;
55 // Loads and stores from an arraycopy being optimized
56 const DecoratorSet C2_ARRAY_COPY = DECORATOR_LAST << 10;
57
58 class Compile;
59 class GraphKit;
60 class IdealKit;
61 class Node;
62 class Type;
63 class TypePtr;
64 class PhaseMacroExpand;
65
66 // This class wraps a node and a type.
67 class C2AccessValue: public StackObj {
68 protected:
69 Node* _node;
70 const Type* _type;
71
72 public:
73 C2AccessValue(Node* node, const Type* type) :
74 _node(node),
75 _type(type) {}
76
77 Node* node() const { return _node; }
78 const Type* type() const { return _type; }
79
80 void set_node(Node* node) { _node = node; }
81 };
82
83 // This class wraps a node and a pointer type.
84 class C2AccessValuePtr: public C2AccessValue {
85
86 public:
87 C2AccessValuePtr(Node* node, const TypePtr* type) :
88 C2AccessValue(node, reinterpret_cast<const Type*>(type)) {}
89
90 const TypePtr* type() const { return reinterpret_cast<const TypePtr*>(_type); }
91 };
92
93 // This class wraps a bunch of context parameters thare are passed around in the
94 // BarrierSetC2 backend hierarchy, for loads and stores, to reduce boiler plate.
95 class C2Access: public StackObj {
96 protected:
97 DecoratorSet _decorators;
98 BasicType _type;
99 Node* _base;
100 C2AccessValuePtr& _addr;
101 Node* _raw_access;
102
103 void fixup_decorators();
104
105 public:
106 C2Access(DecoratorSet decorators,
107 BasicType type, Node* base, C2AccessValuePtr& addr) :
108 _decorators(decorators),
109 _type(type),
110 _base(base),
111 _addr(addr),
112 _raw_access(NULL)
113 {}
114
115 DecoratorSet decorators() const { return _decorators; }
116 Node* base() const { return _base; }
117 C2AccessValuePtr& addr() const { return _addr; }
118 BasicType type() const { return _type; }
119 bool is_oop() const { return _type == T_OBJECT || _type == T_ARRAY; }
120 bool is_raw() const { return (_decorators & AS_RAW) != 0; }
121 Node* raw_access() const { return _raw_access; }
122
123 void set_raw_access(Node* raw_access) { _raw_access = raw_access; }
124 virtual void set_memory() {} // no-op for normal accesses, but not for atomic accesses.
125
126 MemNode::MemOrd mem_node_mo() const;
127 bool needs_cpu_membar() const;
128
129 virtual PhaseGVN& gvn() const = 0;
130 virtual bool is_parse_access() const { return false; }
131 virtual bool is_opt_access() const { return false; }
132 };
133
134 // C2Access for parse time calls to the BarrierSetC2 backend.
135 class C2ParseAccess: public C2Access {
136 protected:
137 GraphKit* _kit;
138
139 void* barrier_set_state() const;
140
141 public:
142 C2ParseAccess(GraphKit* kit, DecoratorSet decorators,
143 BasicType type, Node* base, C2AccessValuePtr& addr) :
144 C2Access(decorators, type, base, addr),
145 _kit(kit) {
146 fixup_decorators();
147 }
148
149 GraphKit* kit() const { return _kit; }
150
151 template <typename T>
152 T barrier_set_state_as() const {
153 return reinterpret_cast<T>(barrier_set_state());
154 }
155
156 virtual PhaseGVN& gvn() const;
157 virtual bool is_parse_access() const { return true; }
158 };
159
160 // This class wraps a bunch of context parameters thare are passed around in the
161 // BarrierSetC2 backend hierarchy, for atomic accesses, to reduce boiler plate.
162 class C2AtomicParseAccess: public C2ParseAccess {
163 Node* _memory;
164 uint _alias_idx;
165 bool _needs_pinning;
166
167 public:
168 C2AtomicParseAccess(GraphKit* kit, DecoratorSet decorators, BasicType type,
169 Node* base, C2AccessValuePtr& addr, uint alias_idx) :
170 C2ParseAccess(kit, decorators, type, base, addr),
171 _memory(NULL),
172 _alias_idx(alias_idx),
173 _needs_pinning(true) {}
174
175 // Set the memory node based on the current memory slice.
176 virtual void set_memory();
177
178 Node* memory() const { return _memory; }
179 uint alias_idx() const { return _alias_idx; }
180 bool needs_pinning() const { return _needs_pinning; }
181
182 void set_needs_pinning(bool value) { _needs_pinning = value; }
183 };
184
185 // C2Access for optimization time calls to the BarrierSetC2 backend.
186 class C2OptAccess: public C2Access {
187 PhaseGVN& _gvn;
188 MergeMemNode* _mem;
189 Node* _ctl;
190
191 public:
192 C2OptAccess(PhaseGVN& gvn, Node* ctl, MergeMemNode* mem, DecoratorSet decorators,
193 BasicType type, Node* base, C2AccessValuePtr& addr) :
194 C2Access(decorators, type, base, addr),
195 _gvn(gvn), _mem(mem), _ctl(ctl) {
196 fixup_decorators();
197 }
198
199
200 MergeMemNode* mem() const { return _mem; }
201 Node* ctl() const { return _ctl; }
202 // void set_mem(Node* mem) { _mem = mem; }
203 void set_ctl(Node* ctl) { _ctl = ctl; }
204
205 virtual PhaseGVN& gvn() const { return _gvn; }
206 virtual bool is_opt_access() const { return true; }
207 };
208
209
210 // This is the top-level class for the backend of the Access API in C2.
211 // The top-level class is responsible for performing raw accesses. The
212 // various GC barrier sets inherit from the BarrierSetC2 class to sprinkle
213 // barriers into the accesses.
214 class BarrierSetC2: public CHeapObj<mtGC> {
215 protected:
216 virtual void resolve_address(C2Access& access) const;
217 virtual Node* store_at_resolved(C2Access& access, C2AccessValue& val) const;
218 virtual Node* load_at_resolved(C2Access& access, const Type* val_type) const;
219
220 virtual Node* atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
221 Node* new_val, const Type* val_type) const;
222 virtual Node* atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
223 Node* new_val, const Type* value_type) const;
224 virtual Node* atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* val_type) const;
225 virtual Node* atomic_add_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* val_type) const;
226 void pin_atomic_op(C2AtomicParseAccess& access) const;
227
228 public:
229 // This is the entry-point for the backend to perform accesses through the Access API.
230 virtual Node* store_at(C2Access& access, C2AccessValue& val) const;
231 virtual Node* load_at(C2Access& access, const Type* val_type) const;
232
233 virtual Node* atomic_cmpxchg_val_at(C2AtomicParseAccess& access, Node* expected_val,
234 Node* new_val, const Type* val_type) const;
235 virtual Node* atomic_cmpxchg_bool_at(C2AtomicParseAccess& access, Node* expected_val,
236 Node* new_val, const Type* val_type) const;
237 virtual Node* atomic_xchg_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const;
238 virtual Node* atomic_add_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const;
239
240 virtual void clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const;
241
242 virtual Node* resolve(GraphKit* kit, Node* n, DecoratorSet decorators) const { return n; }
243
244 virtual Node* obj_allocate(PhaseMacroExpand* macro, Node* ctrl, Node* mem, Node* toobig_false, Node* size_in_bytes,
245 Node*& i_o, Node*& needgc_ctrl,
246 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem,
247 intx prefetch_lines) const;
248
249 virtual Node* ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const { return NULL; }
250 virtual Node* identity_node(PhaseGVN* phase, Node* n) const { return n; }
251
252 // These are general helper methods used by C2
253 enum ArrayCopyPhase {
254 Parsing,
255 Optimization,
256 Expansion
257 };
258 virtual bool array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const { return false; }
259 virtual void clone_barrier_at_expansion(ArrayCopyNode* ac, Node* call, PhaseIterGVN& igvn) const;
260
261 // Support for GC barriers emitted during parsing
262 virtual bool has_load_barriers() const { return false; }
263 virtual bool is_gc_barrier_node(Node* node) const { return false; }
264 virtual Node* step_over_gc_barrier(Node* c) const { return c; }
265
266 // Support for macro expanded GC barriers
267 virtual void register_potential_barrier_node(Node* node) const { }
268 virtual void unregister_potential_barrier_node(Node* node) const { }
269 virtual void eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const { }
270 virtual void enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const {}
271 virtual void eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const {}
272 virtual void add_users_to_worklist(Unique_Node_List* worklist) const {}
273
274 // Allow barrier sets to have shared state that is preserved across a compilation unit.
275 // This could for example comprise macro nodes to be expanded during macro expansion.
276 virtual void* create_barrier_state(Arena* comp_arena) const { return NULL; }
277 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be
278 // expanded later, then now is the time to do so.
279 virtual bool expand_macro_nodes(PhaseMacroExpand* macro) const { return false; }
280
281 enum CompilePhase {
282 BeforeOptimize, /* post_parse = true */
283 BeforeExpand, /* post_parse = false */
284 BeforeCodeGen
285 };
286 virtual void verify_gc_barriers(Compile* compile, CompilePhase phase) const {}
287
288 virtual bool flatten_gc_alias_type(const TypePtr*& adr_type) const { return false; }
289 #ifdef ASSERT
290 virtual bool verify_gc_alias_type(const TypePtr* adr_type, int offset) const { return false; }
291 #endif
292
293 virtual bool final_graph_reshaping(Compile* compile, Node* n, uint opcode) const { return false; }
294
295 virtual bool matcher_find_shared_visit(Matcher* matcher, Matcher::MStack& mstack, Node* n, uint opcode, bool& mem_op, int& mem_addr_idx) const { return false; };
296 virtual bool matcher_find_shared_post_visit(Matcher* matcher, Node* n, uint opcode) const { return false; };
297 virtual bool matcher_is_store_load_barrier(Node* x, uint xop) const { return false; }
298 };
299
300 #endif // SHARE_GC_SHARED_C2_BARRIERSETC2_HPP