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 GraphKit; 58 class IdealKit; 59 class Node; 60 class Type; 61 class TypePtr; 62 class PhaseMacroExpand; 63 64 // This class wraps a node and a type. 65 class C2AccessValue: public StackObj { 66 protected: 67 Node* _node; 68 const Type* _type; 69 70 public: 71 C2AccessValue(Node* node, const Type* type) : 72 _node(node), 73 _type(type) {} 74 75 Node* node() const { return _node; } 76 const Type* type() const { return _type; } 77 78 void set_node(Node* node) { _node = node; } 79 }; 80 81 // This class wraps a node and a pointer type. 82 class C2AccessValuePtr: public C2AccessValue { 83 84 public: 85 C2AccessValuePtr(Node* node, const TypePtr* type) : 86 C2AccessValue(node, reinterpret_cast<const Type*>(type)) {} 87 88 const TypePtr* type() const { return reinterpret_cast<const TypePtr*>(_type); } 89 }; 90 91 // This class wraps a bunch of context parameters thare are passed around in the 92 // BarrierSetC2 backend hierarchy, for loads and stores, to reduce boiler plate. 93 class C2Access: public StackObj { 94 protected: 95 DecoratorSet _decorators; 96 BasicType _type; 97 Node* _base; 98 C2AccessValuePtr& _addr; 99 Node* _raw_access; 100 101 void fixup_decorators(); 102 103 public: 104 C2Access(DecoratorSet decorators, 105 BasicType type, Node* base, C2AccessValuePtr& addr) : 106 _decorators(decorators), 107 _type(type), 108 _base(base), 109 _addr(addr), 110 _raw_access(NULL) 111 {} 112 113 DecoratorSet decorators() const { return _decorators; } 114 Node* base() const { return _base; } 115 C2AccessValuePtr& addr() const { return _addr; } 116 BasicType type() const { return _type; } 117 bool is_oop() const { return _type == T_OBJECT || _type == T_ARRAY; } 118 bool is_raw() const { return (_decorators & AS_RAW) != 0; } 119 Node* raw_access() const { return _raw_access; } 120 121 void set_raw_access(Node* raw_access) { _raw_access = raw_access; } 122 virtual void set_memory() {} // no-op for normal accesses, but not for atomic accesses. 123 124 MemNode::MemOrd mem_node_mo() const; 125 bool needs_cpu_membar() const; 126 127 virtual PhaseGVN& gvn() const = 0; 128 virtual bool is_parse_access() const { return false; } 129 virtual bool is_opt_access() const { return false; } 130 }; 131 132 // C2Access for parse time calls to the BarrierSetC2 backend. 133 class C2ParseAccess: public C2Access { 134 protected: 135 GraphKit* _kit; 136 137 void* barrier_set_state() const; 138 139 public: 140 C2ParseAccess(GraphKit* kit, DecoratorSet decorators, 141 BasicType type, Node* base, C2AccessValuePtr& addr) : 142 C2Access(decorators, type, base, addr), 143 _kit(kit) { 144 fixup_decorators(); 145 } 146 147 GraphKit* kit() const { return _kit; } 148 149 template <typename T> 150 T barrier_set_state_as() const { 151 return reinterpret_cast<T>(barrier_set_state()); 152 } 153 154 virtual PhaseGVN& gvn() const; 155 virtual bool is_parse_access() const { return true; } 156 }; 157 158 // This class wraps a bunch of context parameters thare are passed around in the 159 // BarrierSetC2 backend hierarchy, for atomic accesses, to reduce boiler plate. 160 class C2AtomicParseAccess: public C2ParseAccess { 161 Node* _memory; 162 uint _alias_idx; 163 bool _needs_pinning; 164 165 public: 166 C2AtomicParseAccess(GraphKit* kit, DecoratorSet decorators, BasicType type, 167 Node* base, C2AccessValuePtr& addr, uint alias_idx) : 168 C2ParseAccess(kit, decorators, type, base, addr), 169 _memory(NULL), 170 _alias_idx(alias_idx), 171 _needs_pinning(true) {} 172 173 // Set the memory node based on the current memory slice. 174 virtual void set_memory(); 175 176 Node* memory() const { return _memory; } 177 uint alias_idx() const { return _alias_idx; } 178 bool needs_pinning() const { return _needs_pinning; } 179 180 void set_needs_pinning(bool value) { _needs_pinning = value; } 181 }; 182 183 // C2Access for optimization time calls to the BarrierSetC2 backend. 184 class C2OptAccess: public C2Access { 185 PhaseGVN& _gvn; 186 MergeMemNode* _mem; 187 Node* _ctl; 188 189 public: 190 C2OptAccess(PhaseGVN& gvn, Node* ctl, MergeMemNode* mem, DecoratorSet decorators, 191 BasicType type, Node* base, C2AccessValuePtr& addr) : 192 C2Access(decorators, type, base, addr), 193 _gvn(gvn), _mem(mem), _ctl(ctl) { 194 fixup_decorators(); 195 } 196 197 198 MergeMemNode* mem() const { return _mem; } 199 Node* ctl() const { return _ctl; } 200 // void set_mem(Node* mem) { _mem = mem; } 201 void set_ctl(Node* ctl) { _ctl = ctl; } 202 203 virtual PhaseGVN& gvn() const { return _gvn; } 204 virtual bool is_opt_access() const { return true; } 205 }; 206 207 208 // This is the top-level class for the backend of the Access API in C2. 209 // The top-level class is responsible for performing raw accesses. The 210 // various GC barrier sets inherit from the BarrierSetC2 class to sprinkle 211 // barriers into the accesses. 212 class BarrierSetC2: public CHeapObj<mtGC> { 213 protected: 214 virtual void resolve_address(C2Access& access) const; 215 virtual Node* store_at_resolved(C2Access& access, C2AccessValue& val) const; 216 virtual Node* load_at_resolved(C2Access& access, const Type* val_type) const; 217 218 virtual Node* atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 219 Node* new_val, const Type* val_type) const; 220 virtual Node* atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 221 Node* new_val, const Type* value_type) const; 222 virtual Node* atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* val_type) const; 223 virtual Node* atomic_add_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* val_type) const; 224 void pin_atomic_op(C2AtomicParseAccess& access) const; 225 226 public: 227 // This is the entry-point for the backend to perform accesses through the Access API. 228 virtual Node* store_at(C2Access& access, C2AccessValue& val) const; 229 virtual Node* load_at(C2Access& access, const Type* val_type) const; 230 231 virtual Node* atomic_cmpxchg_val_at(C2AtomicParseAccess& access, Node* expected_val, 232 Node* new_val, const Type* val_type) const; 233 virtual Node* atomic_cmpxchg_bool_at(C2AtomicParseAccess& access, Node* expected_val, 234 Node* new_val, const Type* val_type) const; 235 virtual Node* atomic_xchg_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const; 236 virtual Node* atomic_add_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const; 237 238 virtual void clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const; 239 240 virtual Node* resolve(GraphKit* kit, Node* n, DecoratorSet decorators) const { return n; } 241 242 virtual Node* obj_allocate(PhaseMacroExpand* macro, Node* ctrl, Node* mem, Node* toobig_false, Node* size_in_bytes, 243 Node*& i_o, Node*& needgc_ctrl, 244 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem, 245 intx prefetch_lines) const; 246 247 // These are general helper methods used by C2 248 enum ArrayCopyPhase { 249 Parsing, 250 Optimization, 251 Expansion 252 }; 253 virtual bool array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const { return false; } 254 virtual void clone_barrier_at_expansion(ArrayCopyNode* ac, Node* call, PhaseIterGVN& igvn) const; 255 256 // Support for GC barriers emitted during parsing 257 virtual bool has_load_barriers() const { return false; } 258 virtual bool is_gc_barrier_node(Node* node) const { return false; } 259 virtual Node* step_over_gc_barrier(Node* c) const { return c; } 260 261 // Support for macro expanded GC barriers 262 virtual void register_potential_barrier_node(Node* node) const { } 263 virtual void unregister_potential_barrier_node(Node* node) const { } 264 virtual void eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const { } 265 virtual void enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const {} 266 virtual void eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const {} 267 virtual void add_users_to_worklist(Unique_Node_List* worklist) const {} 268 269 // Allow barrier sets to have shared state that is preserved across a compilation unit. 270 // This could for example comprise macro nodes to be expanded during macro expansion. 271 virtual void* create_barrier_state(Arena* comp_arena) const { return NULL; } 272 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be 273 // expanded later, then now is the time to do so. 274 virtual bool expand_macro_nodes(PhaseMacroExpand* macro) const { return false; } 275 virtual void verify_gc_barriers(bool post_parse) const {} 276 }; 277 278 #endif // SHARE_GC_SHARED_C2_BARRIERSETC2_HPP