1 /* 2 * Copyright (c) 2018, 2019, 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/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, but may float above safepoints. 46 const DecoratorSet C2_UNKNOWN_CONTROL_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_TIGHTLY_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 ConnectionGraph; 60 class GraphKit; 61 class IdealKit; 62 class Node; 63 class PhaseGVN; 64 class PhaseIdealLoop; 65 class PhaseMacroExpand; 66 class Type; 67 class TypePtr; 68 class Unique_Node_List; 69 70 // This class wraps a node and a type. 71 class C2AccessValue: public StackObj { 72 protected: 73 Node* _node; 74 const Type* _type; 75 76 public: 77 C2AccessValue(Node* node, const Type* type) : 78 _node(node), 79 _type(type) {} 80 81 Node* node() const { return _node; } 82 const Type* type() const { return _type; } 83 84 void set_node(Node* node) { _node = node; } 85 }; 86 87 // This class wraps a node and a pointer type. 88 class C2AccessValuePtr: public C2AccessValue { 89 90 public: 91 C2AccessValuePtr(Node* node, const TypePtr* type) : 92 C2AccessValue(node, reinterpret_cast<const Type*>(type)) {} 93 94 const TypePtr* type() const { return reinterpret_cast<const TypePtr*>(_type); } 95 }; 96 97 // This class wraps a bunch of context parameters thare are passed around in the 98 // BarrierSetC2 backend hierarchy, for loads and stores, to reduce boiler plate. 99 class C2Access: public StackObj { 100 protected: 101 DecoratorSet _decorators; 102 BasicType _type; 103 Node* _base; 104 C2AccessValuePtr& _addr; 105 Node* _raw_access; 106 107 void fixup_decorators(); 108 109 public: 110 C2Access(DecoratorSet decorators, 111 BasicType type, Node* base, C2AccessValuePtr& addr) : 112 _decorators(decorators), 113 _type(type), 114 _base(base), 115 _addr(addr), 116 _raw_access(NULL) 117 {} 118 119 DecoratorSet decorators() const { return _decorators; } 120 Node* base() const { return _base; } 121 C2AccessValuePtr& addr() const { return _addr; } 122 BasicType type() const { return _type; } 123 bool is_oop() const { return _type == T_OBJECT || _type == T_ARRAY; } 124 bool is_raw() const { return (_decorators & AS_RAW) != 0; } 125 Node* raw_access() const { return _raw_access; } 126 127 void set_raw_access(Node* raw_access) { _raw_access = raw_access; } 128 virtual void set_memory() {} // no-op for normal accesses, but not for atomic accesses. 129 130 MemNode::MemOrd mem_node_mo() const; 131 bool needs_cpu_membar() const; 132 133 virtual PhaseGVN& gvn() const = 0; 134 virtual bool is_parse_access() const { return false; } 135 virtual bool is_opt_access() const { return false; } 136 }; 137 138 // C2Access for parse time calls to the BarrierSetC2 backend. 139 class C2ParseAccess: public C2Access { 140 protected: 141 GraphKit* _kit; 142 143 void* barrier_set_state() const; 144 145 public: 146 C2ParseAccess(GraphKit* kit, DecoratorSet decorators, 147 BasicType type, Node* base, C2AccessValuePtr& addr) : 148 C2Access(decorators, type, base, addr), 149 _kit(kit) { 150 fixup_decorators(); 151 } 152 153 GraphKit* kit() const { return _kit; } 154 155 template <typename T> 156 T barrier_set_state_as() const { 157 return reinterpret_cast<T>(barrier_set_state()); 158 } 159 160 virtual PhaseGVN& gvn() const; 161 virtual bool is_parse_access() const { return true; } 162 }; 163 164 // This class wraps a bunch of context parameters thare are passed around in the 165 // BarrierSetC2 backend hierarchy, for atomic accesses, to reduce boiler plate. 166 class C2AtomicParseAccess: public C2ParseAccess { 167 Node* _memory; 168 uint _alias_idx; 169 bool _needs_pinning; 170 171 public: 172 C2AtomicParseAccess(GraphKit* kit, DecoratorSet decorators, BasicType type, 173 Node* base, C2AccessValuePtr& addr, uint alias_idx) : 174 C2ParseAccess(kit, decorators, type, base, addr), 175 _memory(NULL), 176 _alias_idx(alias_idx), 177 _needs_pinning(true) {} 178 179 // Set the memory node based on the current memory slice. 180 virtual void set_memory(); 181 182 Node* memory() const { return _memory; } 183 uint alias_idx() const { return _alias_idx; } 184 bool needs_pinning() const { return _needs_pinning; } 185 186 void set_needs_pinning(bool value) { _needs_pinning = value; } 187 }; 188 189 // C2Access for optimization time calls to the BarrierSetC2 backend. 190 class C2OptAccess: public C2Access { 191 PhaseGVN& _gvn; 192 MergeMemNode* _mem; 193 Node* _ctl; 194 195 public: 196 C2OptAccess(PhaseGVN& gvn, Node* ctl, MergeMemNode* mem, DecoratorSet decorators, 197 BasicType type, Node* base, C2AccessValuePtr& addr) : 198 C2Access(decorators, type, base, addr), 199 _gvn(gvn), _mem(mem), _ctl(ctl) { 200 fixup_decorators(); 201 } 202 203 204 MergeMemNode* mem() const { return _mem; } 205 Node* ctl() const { return _ctl; } 206 // void set_mem(Node* mem) { _mem = mem; } 207 void set_ctl(Node* ctl) { _ctl = ctl; } 208 209 virtual PhaseGVN& gvn() const { return _gvn; } 210 virtual bool is_opt_access() const { return true; } 211 }; 212 213 214 // This is the top-level class for the backend of the Access API in C2. 215 // The top-level class is responsible for performing raw accesses. The 216 // various GC barrier sets inherit from the BarrierSetC2 class to sprinkle 217 // barriers into the accesses. 218 class BarrierSetC2: public CHeapObj<mtGC> { 219 protected: 220 virtual void resolve_address(C2Access& access) const; 221 virtual Node* store_at_resolved(C2Access& access, C2AccessValue& val) const; 222 virtual Node* load_at_resolved(C2Access& access, const Type* val_type) const; 223 224 virtual Node* atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 225 Node* new_val, const Type* val_type) const; 226 virtual Node* atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 227 Node* new_val, const Type* value_type) const; 228 virtual Node* atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* val_type) const; 229 virtual Node* atomic_add_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* val_type) const; 230 void pin_atomic_op(C2AtomicParseAccess& access) const; 231 232 public: 233 // This is the entry-point for the backend to perform accesses through the Access API. 234 virtual Node* store_at(C2Access& access, C2AccessValue& val) const; 235 virtual Node* load_at(C2Access& access, const Type* val_type) const; 236 237 virtual Node* atomic_cmpxchg_val_at(C2AtomicParseAccess& access, Node* expected_val, 238 Node* new_val, const Type* val_type) const; 239 virtual Node* atomic_cmpxchg_bool_at(C2AtomicParseAccess& access, Node* expected_val, 240 Node* new_val, const Type* val_type) const; 241 virtual Node* atomic_xchg_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const; 242 virtual Node* atomic_add_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const; 243 244 virtual void clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const; 245 246 virtual Node* resolve(GraphKit* kit, Node* n, DecoratorSet decorators) const { return n; } 247 248 virtual Node* obj_allocate(PhaseMacroExpand* macro, Node* ctrl, Node* mem, Node* toobig_false, Node* size_in_bytes, 249 Node*& i_o, Node*& needgc_ctrl, 250 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem, 251 intx prefetch_lines) const; 252 253 virtual Node* ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const { return NULL; } 254 virtual Node* identity_node(PhaseGVN* phase, Node* n) const { return n; } 255 256 // These are general helper methods used by C2 257 enum ArrayCopyPhase { 258 Parsing, 259 Optimization, 260 Expansion 261 }; 262 263 virtual bool array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const { return false; } 264 virtual void clone_barrier_at_expansion(ArrayCopyNode* ac, Node* call, PhaseIterGVN& igvn) const; 265 266 // Support for GC barriers emitted during parsing 267 virtual bool has_load_barriers() const { return false; } 268 virtual bool is_gc_barrier_node(Node* node) const { return false; } 269 virtual Node* step_over_gc_barrier(Node* c) const { return c; } 270 virtual Node* step_over_gc_barrier_ctrl(Node* c) const { return c; } 271 272 // Support for macro expanded GC barriers 273 virtual void register_potential_barrier_node(Node* node) const { } 274 virtual void unregister_potential_barrier_node(Node* node) const { } 275 virtual void eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const { } 276 virtual void enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const {} 277 virtual void eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const {} 278 279 // Allow barrier sets to have shared state that is preserved across a compilation unit. 280 // This could for example comprise macro nodes to be expanded during macro expansion. 281 virtual void* create_barrier_state(Arena* comp_arena) const { return NULL; } 282 // If the BarrierSetC2 state has barrier nodes in its compilation 283 // unit state to be expanded later, then now is the time to do so. 284 virtual bool expand_barriers(Compile* C, PhaseIterGVN& igvn) const { return false; } 285 virtual bool optimize_loops(PhaseIdealLoop* phase, LoopOptsMode mode, VectorSet& visited, Node_Stack& nstack, Node_List& worklist) const { return false; } 286 virtual bool strip_mined_loops_expanded(LoopOptsMode mode) const { return false; } 287 virtual bool is_gc_specific_loop_opts_pass(LoopOptsMode mode) const { return false; } 288 289 virtual bool has_special_unique_user(const Node* node) const { return false; } 290 virtual bool needs_anti_dependence_check(const Node* node) const { return true; } 291 292 virtual void barrier_insertion_phase(Compile* C, PhaseIterGVN &igvn) const { } 293 294 enum CompilePhase { 295 BeforeOptimize, 296 BeforeLateInsertion, 297 BeforeMacroExpand, 298 BeforeCodeGen 299 }; 300 301 virtual bool flatten_gc_alias_type(const TypePtr*& adr_type) const { return false; } 302 #ifdef ASSERT 303 virtual bool verify_gc_alias_type(const TypePtr* adr_type, int offset) const { return false; } 304 virtual void verify_gc_barriers(Compile* compile, CompilePhase phase) const {} 305 #endif 306 307 virtual bool final_graph_reshaping(Compile* compile, Node* n, uint opcode) const { return false; } 308 309 virtual bool escape_add_to_con_graph(ConnectionGraph* conn_graph, PhaseGVN* gvn, Unique_Node_List* delayed_worklist, Node* n, uint opcode) const { return false; } 310 virtual bool escape_add_final_edges(ConnectionGraph* conn_graph, PhaseGVN* gvn, Node* n, uint opcode) const { return false; } 311 virtual bool escape_has_out_with_unsafe_object(Node* n) const { return false; } 312 313 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; }; 314 virtual bool matcher_find_shared_post_visit(Matcher* matcher, Node* n, uint opcode) const { return false; }; 315 virtual bool matcher_is_store_load_barrier(Node* x, uint xop) const { return false; } 316 317 virtual void igvn_add_users_to_worklist(PhaseIterGVN* igvn, Node* use) const { } 318 virtual void ccp_analyze(PhaseCCP* ccp, Unique_Node_List& worklist, Node* use) const { } 319 320 virtual Node* split_if_pre(PhaseIdealLoop* phase, Node* n) const { return NULL; } 321 virtual bool build_loop_late_post(PhaseIdealLoop* phase, Node* n) const { return false; } 322 virtual bool sink_node(PhaseIdealLoop* phase, Node* n, Node* x, Node* x_ctrl, Node* n_ctrl) const { return false; } 323 }; 324 325 #endif // SHARE_GC_SHARED_C2_BARRIERSETC2_HPP