1 /*
2 * Copyright (c) 2018, 2022, Red Hat, Inc. 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 #include "precompiled.hpp"
26 #include "c1/c1_IR.hpp"
27 #include "gc/shared/satbMarkQueue.hpp"
28 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
29 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
30 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
31 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
32 #include "gc/shenandoah/shenandoahRuntime.hpp"
33 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
34 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
35
36 #ifdef ASSERT
37 #define __ gen->lir(__FILE__, __LINE__)->
38 #else
39 #define __ gen->lir()->
40 #endif
41
42 void ShenandoahPreBarrierStub::emit_code(LIR_Assembler* ce) {
43 ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
44 bs->gen_pre_barrier_stub(ce, this);
45 }
46
47 void ShenandoahLoadReferenceBarrierStub::emit_code(LIR_Assembler* ce) {
48 ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
49 bs->gen_load_reference_barrier_stub(ce, this);
50 }
51
52 ShenandoahBarrierSetC1::ShenandoahBarrierSetC1() :
53 _pre_barrier_c1_runtime_code_blob(nullptr),
54 _load_reference_barrier_strong_rt_code_blob(nullptr),
55 _load_reference_barrier_strong_native_rt_code_blob(nullptr),
56 _load_reference_barrier_weak_rt_code_blob(nullptr),
57 _load_reference_barrier_phantom_rt_code_blob(nullptr) {}
58
59 void ShenandoahBarrierSetC1::pre_barrier(LIRGenerator* gen, CodeEmitInfo* info, DecoratorSet decorators, LIR_Opr addr_opr, LIR_Opr pre_val) {
60 // First we test whether marking is in progress.
61
62 bool patch = (decorators & C1_NEEDS_PATCHING) != 0;
63 bool do_load = pre_val == LIR_OprFact::illegalOpr;
64
65 LIR_Opr thrd = gen->getThreadPointer();
66 LIR_Address* gc_state_addr =
67 new LIR_Address(thrd,
68 in_bytes(ShenandoahThreadLocalData::gc_state_offset()),
69 T_BYTE);
70 // Read the gc_state flag.
71 LIR_Opr flag_val = gen->new_register(T_INT);
72 __ load(gc_state_addr, flag_val);
73
74 // Create a mask to test if the marking bit is set.
75 // TODO: can we directly test if bit is set?
76 LIR_Opr mask = LIR_OprFact::intConst(ShenandoahHeap::MARKING);
77 LIR_Opr mask_reg = gen->new_register(T_INT);
78 __ move(mask, mask_reg);
79
80 if (two_operand_lir_form) {
81 __ logical_and(flag_val, mask_reg, flag_val);
82 } else {
83 LIR_Opr masked_flag = gen->new_register(T_INT);
84 __ logical_and(flag_val, mask_reg, masked_flag);
85 flag_val = masked_flag;
86 }
87 __ cmp(lir_cond_notEqual, flag_val, LIR_OprFact::intConst(0));
88
89 LIR_PatchCode pre_val_patch_code = lir_patch_none;
90
91 CodeStub* slow;
92
93 if (do_load) {
94 assert(pre_val == LIR_OprFact::illegalOpr, "sanity");
95 assert(addr_opr != LIR_OprFact::illegalOpr, "sanity");
96
97 if (patch)
98 pre_val_patch_code = lir_patch_normal;
99
100 pre_val = gen->new_register(T_OBJECT);
101
102 if (!addr_opr->is_address()) {
103 assert(addr_opr->is_register(), "must be");
104 addr_opr = LIR_OprFact::address(new LIR_Address(addr_opr, T_OBJECT));
105 }
106 slow = new ShenandoahPreBarrierStub(addr_opr, pre_val, pre_val_patch_code, info ? new CodeEmitInfo(info) : nullptr);
107 } else {
108 assert(addr_opr == LIR_OprFact::illegalOpr, "sanity");
109 assert(pre_val->is_register(), "must be");
110 assert(pre_val->type() == T_OBJECT, "must be an object");
111
112 slow = new ShenandoahPreBarrierStub(pre_val);
113 }
114
115 __ branch(lir_cond_notEqual, slow);
116 __ branch_destination(slow->continuation());
117 }
118
119 LIR_Opr ShenandoahBarrierSetC1::load_reference_barrier(LIRGenerator* gen, LIR_Opr obj, LIR_Opr addr, DecoratorSet decorators) {
120 if (ShenandoahLoadRefBarrier) {
121 return load_reference_barrier_impl(gen, obj, addr, decorators);
122 } else {
123 return obj;
124 }
125 }
126
127 LIR_Opr ShenandoahBarrierSetC1::load_reference_barrier_impl(LIRGenerator* gen, LIR_Opr obj, LIR_Opr addr, DecoratorSet decorators) {
128 assert(ShenandoahLoadRefBarrier, "Should be enabled");
129
130 obj = ensure_in_register(gen, obj, T_OBJECT);
131 assert(obj->is_register(), "must be a register at this point");
132 addr = ensure_in_register(gen, addr, T_ADDRESS);
133 assert(addr->is_register(), "must be a register at this point");
134 LIR_Opr result = gen->result_register_for(obj->value_type());
135 __ move(obj, result);
136 LIR_Opr tmp1 = gen->new_register(T_ADDRESS);
137 LIR_Opr tmp2 = gen->new_register(T_ADDRESS);
138
139 LIR_Opr thrd = gen->getThreadPointer();
140 LIR_Address* active_flag_addr =
141 new LIR_Address(thrd,
142 in_bytes(ShenandoahThreadLocalData::gc_state_offset()),
143 T_BYTE);
144 // Read and check the gc-state-flag.
145 LIR_Opr flag_val = gen->new_register(T_INT);
146 __ load(active_flag_addr, flag_val);
147 int flags = ShenandoahHeap::HAS_FORWARDED;
148 if (!ShenandoahBarrierSet::is_strong_access(decorators)) {
149 flags |= ShenandoahHeap::WEAK_ROOTS;
150 }
151 LIR_Opr mask = LIR_OprFact::intConst(flags);
152 LIR_Opr mask_reg = gen->new_register(T_INT);
153 __ move(mask, mask_reg);
154
155 if (two_operand_lir_form) {
156 __ logical_and(flag_val, mask_reg, flag_val);
157 } else {
158 LIR_Opr masked_flag = gen->new_register(T_INT);
159 __ logical_and(flag_val, mask_reg, masked_flag);
160 flag_val = masked_flag;
161 }
162 __ cmp(lir_cond_notEqual, flag_val, LIR_OprFact::intConst(0));
163
164 CodeStub* slow = new ShenandoahLoadReferenceBarrierStub(obj, addr, result, tmp1, tmp2, decorators);
165 __ branch(lir_cond_notEqual, slow);
166 __ branch_destination(slow->continuation());
167
168 return result;
169 }
170
171 LIR_Opr ShenandoahBarrierSetC1::ensure_in_register(LIRGenerator* gen, LIR_Opr obj, BasicType type) {
172 if (!obj->is_register()) {
173 LIR_Opr obj_reg;
174 if (obj->is_constant()) {
175 obj_reg = gen->new_register(type);
176 __ move(obj, obj_reg);
177 } else {
178 obj_reg = gen->new_pointer_register();
179 __ leal(obj, obj_reg);
180 }
181 obj = obj_reg;
182 }
183 return obj;
184 }
185
186 LIR_Opr ShenandoahBarrierSetC1::iu_barrier(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, DecoratorSet decorators) {
187 if (ShenandoahIUBarrier) {
188 obj = ensure_in_register(gen, obj, T_OBJECT);
189 pre_barrier(gen, info, decorators, LIR_OprFact::illegalOpr, obj);
190 }
191 return obj;
192 }
193
194 void ShenandoahBarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) {
195 if (access.is_oop()) {
196 if (ShenandoahSATBBarrier) {
197 pre_barrier(access.gen(), access.access_emit_info(), access.decorators(), access.resolved_addr(), LIR_OprFact::illegalOpr /* pre_val */);
198 }
199 value = iu_barrier(access.gen(), value, access.access_emit_info(), access.decorators());
200 }
201 BarrierSetC1::store_at_resolved(access, value);
202 }
203
204 LIR_Opr ShenandoahBarrierSetC1::resolve_address(LIRAccess& access, bool resolve_in_register) {
205 // We must resolve in register when patching. This is to avoid
206 // having a patch area in the load barrier stub, since the call
207 // into the runtime to patch will not have the proper oop map.
208 const bool patch_before_barrier = access.is_oop() && (access.decorators() & C1_NEEDS_PATCHING) != 0;
209 return BarrierSetC1::resolve_address(access, resolve_in_register || patch_before_barrier);
210 }
211
212 void ShenandoahBarrierSetC1::load_at_resolved(LIRAccess& access, LIR_Opr result) {
213 // 1: non-reference load, no additional barrier is needed
214 if (!access.is_oop()) {
215 BarrierSetC1::load_at_resolved(access, result);
216 return;
217 }
218
219 LIRGenerator* gen = access.gen();
220 DecoratorSet decorators = access.decorators();
221 BasicType type = access.type();
222
223 // 2: load a reference from src location and apply LRB if ShenandoahLoadRefBarrier is set
224 if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) {
225 LIR_Opr tmp = gen->new_register(T_OBJECT);
226 BarrierSetC1::load_at_resolved(access, tmp);
227 tmp = load_reference_barrier(gen, tmp, access.resolved_addr(), decorators);
228 __ move(tmp, result);
229 } else {
230 BarrierSetC1::load_at_resolved(access, result);
231 }
232
233 // 3: apply keep-alive barrier for java.lang.ref.Reference if needed
234 if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) {
235 bool is_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
236
237 // Register the value in the referent field with the pre-barrier
238 LabelObj *Lcont_anonymous;
239 if (is_anonymous) {
240 Lcont_anonymous = new LabelObj();
241 generate_referent_check(access, Lcont_anonymous);
242 }
243 pre_barrier(gen, access.access_emit_info(), decorators, LIR_OprFact::illegalOpr /* addr_opr */,
244 result /* pre_val */);
245 if (is_anonymous) {
246 __ branch_destination(Lcont_anonymous->label());
247 }
248 }
249 }
250
251 class C1ShenandoahPreBarrierCodeGenClosure : public StubAssemblerCodeGenClosure {
252 virtual OopMapSet* generate_code(StubAssembler* sasm) {
253 ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
254 bs->generate_c1_pre_barrier_runtime_stub(sasm);
255 return nullptr;
256 }
257 };
258
259 class C1ShenandoahLoadReferenceBarrierCodeGenClosure : public StubAssemblerCodeGenClosure {
260 private:
261 const DecoratorSet _decorators;
262
263 public:
264 C1ShenandoahLoadReferenceBarrierCodeGenClosure(DecoratorSet decorators) : _decorators(decorators) {}
265
266 virtual OopMapSet* generate_code(StubAssembler* sasm) {
267 ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
268 bs->generate_c1_load_reference_barrier_runtime_stub(sasm, _decorators);
269 return nullptr;
270 }
271 };
272
273 void ShenandoahBarrierSetC1::generate_c1_runtime_stubs(BufferBlob* buffer_blob) {
274 C1ShenandoahPreBarrierCodeGenClosure pre_code_gen_cl;
275 _pre_barrier_c1_runtime_code_blob = Runtime1::generate_blob(buffer_blob, -1,
276 "shenandoah_pre_barrier_slow",
277 false, &pre_code_gen_cl);
278 if (ShenandoahLoadRefBarrier) {
279 C1ShenandoahLoadReferenceBarrierCodeGenClosure lrb_strong_code_gen_cl(ON_STRONG_OOP_REF);
280 _load_reference_barrier_strong_rt_code_blob = Runtime1::generate_blob(buffer_blob, -1,
281 "shenandoah_load_reference_barrier_strong_slow",
282 false, &lrb_strong_code_gen_cl);
283
284 C1ShenandoahLoadReferenceBarrierCodeGenClosure lrb_strong_native_code_gen_cl(ON_STRONG_OOP_REF | IN_NATIVE);
285 _load_reference_barrier_strong_native_rt_code_blob = Runtime1::generate_blob(buffer_blob, -1,
286 "shenandoah_load_reference_barrier_strong_native_slow",
287 false, &lrb_strong_native_code_gen_cl);
288
289 C1ShenandoahLoadReferenceBarrierCodeGenClosure lrb_weak_code_gen_cl(ON_WEAK_OOP_REF);
290 _load_reference_barrier_weak_rt_code_blob = Runtime1::generate_blob(buffer_blob, -1,
291 "shenandoah_load_reference_barrier_weak_slow",
292 false, &lrb_weak_code_gen_cl);
293
294 C1ShenandoahLoadReferenceBarrierCodeGenClosure lrb_phantom_code_gen_cl(ON_PHANTOM_OOP_REF | IN_NATIVE);
295 _load_reference_barrier_phantom_rt_code_blob = Runtime1::generate_blob(buffer_blob, -1,
296 "shenandoah_load_reference_barrier_phantom_slow",
297 false, &lrb_phantom_code_gen_cl);
298 }
299 }