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.
22 *
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/memnode.hpp"
32 #include "utilities/globalDefinitions.hpp"
33
34 // This means the access is mismatched. This means the value of an access
35 // is not equivalent to the value pointed to by the address.
36 const DecoratorSet C2_MISMATCHED = DECORATOR_LAST << 1;
37 // The access may not be aligned to its natural size.
38 const DecoratorSet C2_UNALIGNED = DECORATOR_LAST << 2;
39 // The atomic cmpxchg is weak, meaning that spurious false negatives are allowed,
40 // but never false positives.
41 const DecoratorSet C2_WEAK_CMPXCHG = DECORATOR_LAST << 3;
42 // This denotes that a load has control dependency.
43 const DecoratorSet C2_CONTROL_DEPENDENT_LOAD = DECORATOR_LAST << 4;
44 // This denotes that a load that must be pinned.
45 const DecoratorSet C2_PINNED_LOAD = DECORATOR_LAST << 5;
46 // This denotes that the access is produced from the sun.misc.Unsafe intrinsics.
47 const DecoratorSet C2_UNSAFE_ACCESS = DECORATOR_LAST << 6;
48 // This denotes that the access mutates state.
49 const DecoratorSet C2_WRITE_ACCESS = DECORATOR_LAST << 7;
50 // This denotes that the access reads state.
51 const DecoratorSet C2_READ_ACCESS = DECORATOR_LAST << 8;
52 // A nearby allocation?
53 const DecoratorSet C2_TIGHLY_COUPLED_ALLOC = DECORATOR_LAST << 9;
54 // Loads and stores from an arraycopy being optimized
55 const DecoratorSet C2_ARRAY_COPY = DECORATOR_LAST << 10;
56
57 class Compile;
58 class ConnectionGraph;
59 class GraphKit;
60 class IdealKit;
61 class Node;
62 class PhaseGVN;
63 class PhaseMacroExpand;
64 class Type;
65 class TypePtr;
66 class Unique_Node_List;
67
68 // This class wraps a node and a type.
69 class C2AccessValue: public StackObj {
70 protected:
71 Node* _node;
72 const Type* _type;
73
74 public:
75 C2AccessValue(Node* node, const Type* type) :
76 _node(node),
77 _type(type) {}
78
79 Node* node() const { return _node; }
80 const Type* type() const { return _type; }
81
82 void set_node(Node* node) { _node = node; }
83 };
84
85 // This class wraps a node and a pointer type.
86 class C2AccessValuePtr: public C2AccessValue {
87
88 public:
89 C2AccessValuePtr(Node* node, const TypePtr* type) :
90 C2AccessValue(node, reinterpret_cast<const Type*>(type)) {}
91
92 const TypePtr* type() const { return reinterpret_cast<const TypePtr*>(_type); }
93 };
94
95 // This class wraps a bunch of context parameters thare are passed around in the
96 // BarrierSetC2 backend hierarchy, for loads and stores, to reduce boiler plate.
97 class C2Access: public StackObj {
98 protected:
99 DecoratorSet _decorators;
100 BasicType _type;
101 Node* _base;
102 C2AccessValuePtr& _addr;
103 Node* _raw_access;
104
105 void fixup_decorators();
106
107 public:
108 C2Access(DecoratorSet decorators,
109 BasicType type, Node* base, C2AccessValuePtr& addr) :
110 _decorators(decorators),
111 _type(type),
112 _base(base),
113 _addr(addr),
114 _raw_access(NULL)
115 {}
116
117 DecoratorSet decorators() const { return _decorators; }
118 Node* base() const { return _base; }
119 C2AccessValuePtr& addr() const { return _addr; }
120 BasicType type() const { return _type; }
121 bool is_oop() const { return _type == T_OBJECT || _type == T_ARRAY; }
122 bool is_raw() const { return (_decorators & AS_RAW) != 0; }
123 Node* raw_access() const { return _raw_access; }
124
125 void set_raw_access(Node* raw_access) { _raw_access = raw_access; }
126 virtual void set_memory() {} // no-op for normal accesses, but not for atomic accesses.
127
128 MemNode::MemOrd mem_node_mo() const;
129 bool needs_cpu_membar() const;
130
131 virtual PhaseGVN& gvn() const = 0;
132 virtual bool is_parse_access() const { return false; }
133 virtual bool is_opt_access() const { return false; }
134 };
135
136 // C2Access for parse time calls to the BarrierSetC2 backend.
137 class C2ParseAccess: public C2Access {
138 protected:
139 GraphKit* _kit;
140
141 void* barrier_set_state() const;
142
143 public:
144 C2ParseAccess(GraphKit* kit, DecoratorSet decorators,
145 BasicType type, Node* base, C2AccessValuePtr& addr) :
146 C2Access(decorators, type, base, addr),
147 _kit(kit) {
148 fixup_decorators();
149 }
150
151 GraphKit* kit() const { return _kit; }
152
153 template <typename T>
154 T barrier_set_state_as() const {
155 return reinterpret_cast<T>(barrier_set_state());
156 }
157
158 virtual PhaseGVN& gvn() const;
159 virtual bool is_parse_access() const { return true; }
160 };
161
162 // This class wraps a bunch of context parameters thare are passed around in the
163 // BarrierSetC2 backend hierarchy, for atomic accesses, to reduce boiler plate.
164 class C2AtomicParseAccess: public C2ParseAccess {
165 Node* _memory;
166 uint _alias_idx;
167 bool _needs_pinning;
168
169 public:
170 C2AtomicParseAccess(GraphKit* kit, DecoratorSet decorators, BasicType type,
171 Node* base, C2AccessValuePtr& addr, uint alias_idx) :
172 C2ParseAccess(kit, decorators, type, base, addr),
173 _memory(NULL),
174 _alias_idx(alias_idx),
175 _needs_pinning(true) {}
176
177 // Set the memory node based on the current memory slice.
178 virtual void set_memory();
179
180 Node* memory() const { return _memory; }
181 uint alias_idx() const { return _alias_idx; }
182 bool needs_pinning() const { return _needs_pinning; }
183
184 void set_needs_pinning(bool value) { _needs_pinning = value; }
185 };
186
187 // C2Access for optimization time calls to the BarrierSetC2 backend.
188 class C2OptAccess: public C2Access {
189 PhaseGVN& _gvn;
190 MergeMemNode* _mem;
191 Node* _ctl;
192
193 public:
194 C2OptAccess(PhaseGVN& gvn, Node* ctl, MergeMemNode* mem, DecoratorSet decorators,
195 BasicType type, Node* base, C2AccessValuePtr& addr) :
196 C2Access(decorators, type, base, addr),
197 _gvn(gvn), _mem(mem), _ctl(ctl) {
198 fixup_decorators();
199 }
200
201
202 MergeMemNode* mem() const { return _mem; }
203 Node* ctl() const { return _ctl; }
204 // void set_mem(Node* mem) { _mem = mem; }
205 void set_ctl(Node* ctl) { _ctl = ctl; }
206
207 virtual PhaseGVN& gvn() const { return _gvn; }
208 virtual bool is_opt_access() const { return true; }
209 };
210
211
212 // This is the top-level class for the backend of the Access API in C2.
213 // The top-level class is responsible for performing raw accesses. The
214 // various GC barrier sets inherit from the BarrierSetC2 class to sprinkle
215 // barriers into the accesses.
216 class BarrierSetC2: public CHeapObj<mtGC> {
217 protected:
218 virtual void resolve_address(C2Access& access) const;
219 virtual Node* store_at_resolved(C2Access& access, C2AccessValue& val) const;
220 virtual Node* load_at_resolved(C2Access& access, const Type* val_type) const;
221
222 virtual Node* atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
223 Node* new_val, const Type* val_type) const;
224 virtual Node* atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
225 Node* new_val, const Type* value_type) const;
226 virtual Node* atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* val_type) const;
227 virtual Node* atomic_add_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* val_type) const;
228 void pin_atomic_op(C2AtomicParseAccess& access) const;
229
230 public:
231 // This is the entry-point for the backend to perform accesses through the Access API.
232 virtual Node* store_at(C2Access& access, C2AccessValue& val) const;
233 virtual Node* load_at(C2Access& access, const Type* val_type) const;
234
235 virtual Node* atomic_cmpxchg_val_at(C2AtomicParseAccess& access, Node* expected_val,
236 Node* new_val, const Type* val_type) const;
237 virtual Node* atomic_cmpxchg_bool_at(C2AtomicParseAccess& access, Node* expected_val,
238 Node* new_val, const Type* val_type) const;
239 virtual Node* atomic_xchg_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const;
240 virtual Node* atomic_add_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const;
241
242 virtual void clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const;
243
244 virtual Node* resolve(GraphKit* kit, Node* n, DecoratorSet decorators) const { return n; }
245
246 virtual Node* obj_allocate(PhaseMacroExpand* macro, Node* ctrl, Node* mem, Node* toobig_false, Node* size_in_bytes,
247 Node*& i_o, Node*& needgc_ctrl,
248 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem,
249 intx prefetch_lines) const;
250
251 virtual Node* ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const { return NULL; }
252 virtual Node* identity_node(PhaseGVN* phase, Node* n) const { return n; }
253
254 // These are general helper methods used by C2
255 enum ArrayCopyPhase {
256 Parsing,
257 Optimization,
258 Expansion
259 };
260 virtual bool array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const { return false; }
261 virtual void clone_barrier_at_expansion(ArrayCopyNode* ac, Node* call, PhaseIterGVN& igvn) const;
262
263 // Support for GC barriers emitted during parsing
264 virtual bool has_load_barriers() const { return false; }
265 virtual bool is_gc_barrier_node(Node* node) const { return false; }
266 virtual Node* step_over_gc_barrier(Node* c) const { return c; }
267
268 // Support for macro expanded GC barriers
269 virtual void register_potential_barrier_node(Node* node) const { }
270 virtual void unregister_potential_barrier_node(Node* node) const { }
271 virtual void eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const { }
272 virtual void enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const {}
273 virtual void eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const {}
274 virtual void add_users_to_worklist(Unique_Node_List* worklist) const {}
275
276 // Allow barrier sets to have shared state that is preserved across a compilation unit.
277 // This could for example comprise macro nodes to be expanded during macro expansion.
278 virtual void* create_barrier_state(Arena* comp_arena) const { return NULL; }
279 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be
280 // expanded later, then now is the time to do so.
281 virtual bool expand_macro_nodes(PhaseMacroExpand* macro) const { return false; }
282
283 enum CompilePhase {
284 BeforeOptimize, /* post_parse = true */
285 BeforeExpand, /* post_parse = false */
286 BeforeCodeGen
287 };
288 virtual void verify_gc_barriers(Compile* compile, CompilePhase phase) const {}
289
290 virtual bool flatten_gc_alias_type(const TypePtr*& adr_type) const { return false; }
291 #ifdef ASSERT
292 virtual bool verify_gc_alias_type(const TypePtr* adr_type, int offset) const { return false; }
293 #endif
294
295 virtual bool final_graph_reshaping(Compile* compile, Node* n, uint opcode) const { return false; }
296
297 virtual bool escape_add_to_con_graph(ConnectionGraph* conn_graph, PhaseGVN* gvn, Unique_Node_List* delayed_worklist, Node* n, uint opcode) const { return false; }
298 virtual bool escape_add_final_edges(ConnectionGraph* conn_graph, PhaseGVN* gvn, Node* n, uint opcode) const { return false; }
299 virtual bool escape_has_out_with_unsafe_object(Node* n) const { return false; }
300 virtual bool escape_is_barrier_node(Node* n) const { return false; }
301 };
302
303 #endif // SHARE_GC_SHARED_C2_BARRIERSETC2_HPP