1 /*
2 * Copyright (c) 2015, 2018, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #ifndef SHARE_VM_GC_SHENANDOAH_C2_SHENANDOAH_SUPPORT_HPP
25 #define SHARE_VM_GC_SHENANDOAH_C2_SHENANDOAH_SUPPORT_HPP
26
27 #include "gc/shenandoah/shenandoahBrooksPointer.hpp"
28 #include "memory/allocation.hpp"
29 #include "opto/addnode.hpp"
30 #include "opto/graphKit.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/memnode.hpp"
33 #include "opto/multnode.hpp"
34 #include "opto/node.hpp"
35
36 class PhaseGVN;
37 class MemoryGraphFixer;
38
39 class ShenandoahBarrierNode : public TypeNode {
40 private:
41 bool _allow_fromspace;
42
43 #ifdef ASSERT
44 enum verify_type {
45 ShenandoahLoad,
46 ShenandoahStore,
47 ShenandoahValue,
48 ShenandoahOopStore,
49 ShenandoahNone,
50 };
51
52 static bool verify_helper(Node* in, Node_Stack& phis, VectorSet& visited, verify_type t, bool trace, Unique_Node_List& barriers_used);
53 #endif
54
55 public:
56 enum { Control,
57 Memory,
58 ValueIn
59 };
60
61 ShenandoahBarrierNode(Node* ctrl, Node* mem, Node* obj, bool allow_fromspace)
62 : TypeNode(obj->bottom_type()->isa_oopptr() ? obj->bottom_type()->is_oopptr()->cast_to_nonconst() : obj->bottom_type(), 3),
63 _allow_fromspace(allow_fromspace) {
64
65 init_req(Control, ctrl);
66 init_req(Memory, mem);
67 init_req(ValueIn, obj);
68
69 init_class_id(Class_ShenandoahBarrier);
70 }
71
72 static Node* skip_through_barrier(Node* n);
73
74 static const TypeOopPtr* brooks_pointer_type(const Type* t) {
75 return t->is_oopptr()->cast_to_nonconst()->add_offset(ShenandoahBrooksPointer::byte_offset())->is_oopptr();
76 }
77
78 virtual const TypePtr* adr_type() const {
79 if (bottom_type() == Type::TOP) {
80 return NULL;
81 }
82 //const TypePtr* adr_type = in(MemNode::Address)->bottom_type()->is_ptr();
83 const TypePtr* adr_type = brooks_pointer_type(bottom_type());
84 assert(adr_type->offset() == ShenandoahBrooksPointer::byte_offset(), "sane offset");
85 assert(Compile::current()->alias_type(adr_type)->is_rewritable(), "brooks ptr must be rewritable");
86 return adr_type;
87 }
88
89 virtual uint ideal_reg() const { return Op_RegP; }
90 virtual uint match_edge(uint idx) const {
91 return idx >= ValueIn;
92 }
93
94 Node* Identity_impl(PhaseGVN* phase);
95
96 virtual const Type* Value(PhaseGVN* phase) const;
97 virtual bool depends_only_on_test() const {
98 return true;
99 };
100
101 static bool needs_barrier(PhaseGVN* phase, ShenandoahBarrierNode* orig, Node* n, Node* rb_mem, bool allow_fromspace);
102
103 #ifdef ASSERT
104 static void report_verify_failure(const char* msg, Node* n1 = NULL, Node* n2 = NULL);
105 static void verify(RootNode* root);
106 static void verify_raw_mem(RootNode* root);
107 #endif
108 #ifndef PRODUCT
109 virtual void dump_spec(outputStream *st) const;
110 #endif
111
112 // protected:
113 static Node* dom_mem(Node* mem, Node*& mem_ctrl, Node* n, Node* rep_ctrl, int alias, PhaseIdealLoop* phase);
114 static Node* dom_mem(Node* mem, Node* ctrl, int alias, Node*& mem_ctrl, PhaseIdealLoop* phase);
115 static bool is_dominator(Node *d_c, Node *n_c, Node* d, Node* n, PhaseIdealLoop* phase);
116 static bool is_dominator_same_ctrl(Node* c, Node* d, Node* n, PhaseIdealLoop* phase);
117 static Node* no_branches(Node* c, Node* dom, bool allow_one_proj, PhaseIdealLoop* phase);
118
119 protected:
120 uint hash() const;
121 uint cmp(const Node& n) const;
122 uint size_of() const;
123
124 private:
125 static bool needs_barrier_impl(PhaseGVN* phase, ShenandoahBarrierNode* orig, Node* n, Node* rb_mem, bool allow_fromspace, Unique_Node_List &visited);
126
127 static bool dominates_memory(PhaseGVN* phase, Node* b1, Node* b2, bool linear);
128 static bool dominates_memory_impl(PhaseGVN* phase, Node* b1, Node* b2, Node* current, bool linear);
129 };
130
131 class ShenandoahReadBarrierNode : public ShenandoahBarrierNode {
132 public:
133 ShenandoahReadBarrierNode(Node* ctrl, Node* mem, Node* obj)
134 : ShenandoahBarrierNode(ctrl, mem, obj, true) {
135 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier ||
136 ShenandoahWriteBarrier || ShenandoahAcmpBarrier),
137 "should be enabled");
138 }
139 ShenandoahReadBarrierNode(Node* ctrl, Node* mem, Node* obj, bool allow_fromspace)
140 : ShenandoahBarrierNode(ctrl, mem, obj, allow_fromspace) {
141 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier ||
142 ShenandoahWriteBarrier || ShenandoahAcmpBarrier),
143 "should be enabled");
144 }
145
146 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
147 virtual Node* Identity(PhaseGVN* phase);
148 virtual int Opcode() const;
149
150 bool is_independent(Node* mem);
151
152 void try_move(Node *n_ctrl, PhaseIdealLoop* phase);
153
154 private:
155 static bool is_independent(const Type* in_type, const Type* this_type);
156 static bool dominates_memory_rb(PhaseGVN* phase, Node* b1, Node* b2, bool linear);
157 static bool dominates_memory_rb_impl(PhaseGVN* phase, Node* b1, Node* b2, Node* current, bool linear);
158 };
159
160 class ShenandoahWriteBarrierNode : public ShenandoahBarrierNode {
161 public:
162 ShenandoahWriteBarrierNode(Compile* C, Node* ctrl, Node* mem, Node* obj);
163
164 virtual int Opcode() const;
165 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
166 virtual Node* Identity(PhaseGVN* phase);
167 virtual bool depends_only_on_test() const { return false; }
168
169 static bool expand(Compile* C, PhaseIterGVN& igvn, int& loop_opts_cnt);
170 static bool is_gc_state_load(Node *n);
171 static bool is_heap_state_test(Node* iff, int mask);
172 static bool is_heap_stable_test(Node* iff);
173 static bool try_common_gc_state_load(Node *n, PhaseIdealLoop *phase);
174 static bool has_safepoint_between(Node* start, Node* stop, PhaseIdealLoop *phase);
175
176 static LoopNode* try_move_before_pre_loop(Node* c, Node* val_ctrl, PhaseIdealLoop* phase);
177 static Node* move_above_predicates(LoopNode* cl, Node* val_ctrl, PhaseIdealLoop* phase);
178 #ifdef ASSERT
179 static bool memory_dominates_all_paths(Node* mem, Node* rep_ctrl, int alias, PhaseIdealLoop* phase);
180 static void memory_dominates_all_paths_helper(Node* c, Node* rep_ctrl, Unique_Node_List& controls, PhaseIdealLoop* phase);
181 #endif
182 void try_move_before_loop(GrowableArray<MemoryGraphFixer*>& memory_graph_fixers, PhaseIdealLoop* phase, bool include_lsm, Unique_Node_List& uses);
183 void try_move_before_loop_helper(LoopNode* cl, Node* val_ctrl, GrowableArray<MemoryGraphFixer*>& memory_graph_fixers, PhaseIdealLoop* phase, bool include_lsm, Unique_Node_List& uses);
184 static void pin_and_expand(PhaseIdealLoop* phase);
185 CallStaticJavaNode* pin_and_expand_null_check(PhaseIterGVN& igvn);
186 void pin_and_expand_move_barrier(PhaseIdealLoop* phase, GrowableArray<MemoryGraphFixer*>& memory_graph_fixers, Unique_Node_List& uses);
187 void pin_and_expand_helper(PhaseIdealLoop* phase);
188 static Node* find_bottom_mem(Node* ctrl, PhaseIdealLoop* phase);
189 static void follow_barrier_uses(Node* n, Node* ctrl, Unique_Node_List& uses, PhaseIdealLoop* phase);
190 static void test_null(Node*& ctrl, Node* val, Node*& null_ctrl, PhaseIdealLoop* phase);
191
192 static void test_heap_stable(Node*& ctrl, Node* raw_mem, Node*& heap_stable_ctrl,
193 PhaseIdealLoop* phase);
194 static void call_wb_stub(Node*& ctrl, Node*& val, Node*& result_mem,
195 Node* raw_mem, Node* wb_mem, int alias,
196 PhaseIdealLoop* phase);
197 static Node* clone_null_check(Node*& c, Node* val, Node* unc_ctrl, PhaseIdealLoop* phase);
198 static void fix_null_check(Node* unc, Node* unc_ctrl, Node* new_unc_ctrl, Unique_Node_List& uses,
199 PhaseIdealLoop* phase);
200 static void in_cset_fast_test(Node*& ctrl, Node*& not_cset_ctrl, Node* val, Node* raw_mem, PhaseIdealLoop* phase);
201 static void move_heap_stable_test_out_of_loop(IfNode* iff, PhaseIdealLoop* phase);
202
203 static void optimize_after_expansion(VectorSet &visited, Node_Stack &nstack, Node_List &old_new, PhaseIdealLoop* phase);
204 static void merge_back_to_back_tests(Node* n, PhaseIdealLoop* phase);
205 static bool identical_backtoback_ifs(Node *n, PhaseIdealLoop* phase);
206 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);
207
208 static void optimize_before_expansion(PhaseIdealLoop* phase, GrowableArray<MemoryGraphFixer*> memory_graph_fixers, bool include_lsm);
209 Node* would_subsume(ShenandoahBarrierNode* other, PhaseIdealLoop* phase);
210 static IfNode* find_unswitching_candidate(const IdealLoopTree *loop, PhaseIdealLoop* phase);
211 };
212
213 class ShenandoahWBMemProjNode : public Node {
214 public:
215 enum { Control,
216 WriteBarrier };
217
218 ShenandoahWBMemProjNode(Node *src) : Node(NULL, src) {
219 assert(UseShenandoahGC && ShenandoahWriteBarrier, "should be enabled");
220 assert(src->Opcode() == Op_ShenandoahWriteBarrier || src->is_Mach(), "epxect wb");
221 }
222 virtual Node* Identity(PhaseGVN* phase);
223
224 virtual int Opcode() const;
225 virtual bool is_CFG() const { return false; }
226 virtual const Type *bottom_type() const {return Type::MEMORY;}
227 virtual const TypePtr *adr_type() const {
228 Node* wb = in(WriteBarrier);
229 if (wb == NULL || wb->is_top()) return NULL; // node is dead
230 assert(wb->Opcode() == Op_ShenandoahWriteBarrier || (wb->is_Mach() && wb->as_Mach()->ideal_Opcode() == Op_ShenandoahWriteBarrier) || wb->is_Phi(), "expect wb");
231 return ShenandoahBarrierNode::brooks_pointer_type(wb->bottom_type());
232 }
233
234 virtual uint ideal_reg() const { return 0;} // memory projections don't have a register
235 virtual const Type *Value(PhaseGVN* phase ) const {
236 return bottom_type();
237 }
238 #ifndef PRODUCT
239 virtual void dump_spec(outputStream *st) const {};
240 #endif
241 };
242
243 class ShenandoahEnqueueBarrierNode : public Node {
244 public:
245 ShenandoahEnqueueBarrierNode(Node* val) : Node(NULL, val) {
246 }
247
248 const Type *bottom_type() const;
249 const Type* Value(PhaseGVN* phase) const;
250 Node* Identity(PhaseGVN* phase);
251
252 int Opcode() const;
253
254 private:
255 enum { Needed, NotNeeded, MaybeNeeded };
256
257 static int needed(Node* n);
258 static Node* next(Node* n);
259 };
260
261 class MemoryGraphFixer : public ResourceObj {
262 private:
263 Node_List _memory_nodes;
264 int _alias;
265 PhaseIdealLoop* _phase;
266 bool _include_lsm;
267
268 void collect_memory_nodes();
269 Node* get_ctrl(Node* n) const;
270 Node* ctrl_or_self(Node* n) const;
271 bool mem_is_valid(Node* m, Node* c) const;
272 MergeMemNode* allocate_merge_mem(Node* mem, Node* rep_proj, Node* rep_ctrl) const;
273 MergeMemNode* clone_merge_mem(Node* u, Node* mem, Node* rep_proj, Node* rep_ctrl, DUIterator& i) const;
274 void fix_memory_uses(Node* mem, Node* replacement, Node* rep_proj, Node* rep_ctrl) const;
275 bool should_process_phi(Node* phi) const;
276 bool has_mem_phi(Node* region) const;
277
278 public:
279 MemoryGraphFixer(int alias, bool include_lsm, PhaseIdealLoop* phase) :
280 _alias(alias), _phase(phase), _include_lsm(include_lsm) {
281 assert(_alias != Compile::AliasIdxBot, "unsupported");
282 collect_memory_nodes();
283 }
284
285 Node* find_mem(Node* ctrl, Node* n) const;
286 void fix_mem(Node* ctrl, Node* region, Node* mem, Node* mem_for_ctrl, Node* mem_phi, Unique_Node_List& uses);
287 int alias() const { return _alias; }
288 void remove(Node* n);
289 };
290
291 class ShenandoahCompareAndSwapPNode : public CompareAndSwapPNode {
292 public:
293 ShenandoahCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
294 : CompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
295
296 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
297 if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
298 return new CompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
299 }
300 return NULL;
301 }
302
303 virtual int Opcode() const;
304 };
305
306 class ShenandoahCompareAndSwapNNode : public CompareAndSwapNNode {
307 public:
308 ShenandoahCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
309 : CompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
310
311 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
312 if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
313 return new CompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
314 }
315 return NULL;
316 }
317
318 virtual int Opcode() const;
319 };
320
321 class ShenandoahWeakCompareAndSwapPNode : public WeakCompareAndSwapPNode {
322 public:
323 ShenandoahWeakCompareAndSwapPNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
324 : WeakCompareAndSwapPNode(c, mem, adr, val, ex, mem_ord) { }
325
326 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
327 if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
328 return new WeakCompareAndSwapPNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
329 }
330 return NULL;
331 }
332
333 virtual int Opcode() const;
334 };
335
336 class ShenandoahWeakCompareAndSwapNNode : public WeakCompareAndSwapNNode {
337 public:
338 ShenandoahWeakCompareAndSwapNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, MemNode::MemOrd mem_ord)
339 : WeakCompareAndSwapNNode(c, mem, adr, val, ex, mem_ord) { }
340
341 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
342 if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
343 return new WeakCompareAndSwapNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), order());
344 }
345 return NULL;
346 }
347
348 virtual int Opcode() const;
349 };
350
351 class ShenandoahCompareAndExchangePNode : public CompareAndExchangePNode {
352 public:
353 ShenandoahCompareAndExchangePNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
354 : CompareAndExchangePNode(c, mem, adr, val, ex, at, t, mem_ord) { }
355
356 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
357 if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypePtr::NULL_PTR) {
358 return new CompareAndExchangePNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
359 }
360 return NULL;
361 }
362
363 virtual int Opcode() const;
364 };
365
366 class ShenandoahCompareAndExchangeNNode : public CompareAndExchangeNNode {
367 public:
368 ShenandoahCompareAndExchangeNNode(Node *c, Node *mem, Node *adr, Node *val, Node *ex, const TypePtr* at, const Type* t, MemNode::MemOrd mem_ord)
369 : CompareAndExchangeNNode(c, mem, adr, val, ex, at, t, mem_ord) { }
370
371 virtual Node *Ideal(PhaseGVN *phase, bool can_reshape) {
372 if (in(ExpectedIn) != NULL && phase->type(in(ExpectedIn)) == TypeNarrowOop::NULL_PTR) {
373 return new CompareAndExchangeNNode(in(MemNode::Control), in(MemNode::Memory), in(MemNode::Address), in(MemNode::ValueIn), in(ExpectedIn), adr_type(), bottom_type(), order());
374 }
375 return NULL;
376 }
377
378 virtual int Opcode() const;
379 };
380
381 #endif // SHARE_VM_GC_SHENANDOAH_C2_SHENANDOAH_SUPPORT_HPP