1 /*
2 * Copyright (c) 2018, 2021, 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/mode/shenandoahMode.hpp"
29 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
30 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
31 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
32 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
33 #include "gc/shenandoah/shenandoahRuntime.hpp"
34 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
35 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
36
37 #ifdef ASSERT
38 #define __ gen->lir(__FILE__, __LINE__)->
39 #else
40 #define __ gen->lir()->
41 #endif
42
43 void ShenandoahPreBarrierStub::emit_code(LIR_Assembler* ce) {
44 ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
45 bs->gen_pre_barrier_stub(ce, this);
46 }
47
48 void ShenandoahLoadReferenceBarrierStub::emit_code(LIR_Assembler* ce) {
49 ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
50 bs->gen_load_reference_barrier_stub(ce, this);
51 }
52
53 ShenandoahBarrierSetC1::ShenandoahBarrierSetC1() :
54 _pre_barrier_c1_runtime_code_blob(NULL),
55 _load_reference_barrier_strong_rt_code_blob(NULL),
56 _load_reference_barrier_strong_native_rt_code_blob(NULL),
57 _load_reference_barrier_weak_rt_code_blob(NULL),
58 _load_reference_barrier_phantom_rt_code_blob(NULL) {}
59
60 void ShenandoahBarrierSetC1::pre_barrier(LIRGenerator* gen, CodeEmitInfo* info, DecoratorSet decorators, LIR_Opr addr_opr, LIR_Opr pre_val) {
61 // First we test whether marking is in progress.
62 BasicType flag_type;
63 bool patch = (decorators & C1_NEEDS_PATCHING) != 0;
64 bool do_load = pre_val == LIR_OprFact::illegalOpr;
65 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
66 flag_type = T_INT;
67 } else {
68 guarantee(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1,
69 "Assumption");
70 // Use unsigned type T_BOOLEAN here rather than signed T_BYTE since some platforms, eg. ARM,
71 // need to use unsigned instructions to use the large offset to load the satb_mark_queue.
72 flag_type = T_BOOLEAN;
73 }
74 LIR_Opr thrd = gen->getThreadPointer();
75 LIR_Address* mark_active_flag_addr =
76 new LIR_Address(thrd,
77 in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()),
78 flag_type);
79 // Read the marking-in-progress flag.
80 LIR_Opr flag_val = gen->new_register(T_INT);
81 __ load(mark_active_flag_addr, flag_val);
82 __ cmp(lir_cond_notEqual, flag_val, LIR_OprFact::intConst(0));
83
84 LIR_PatchCode pre_val_patch_code = lir_patch_none;
85
86 CodeStub* slow;
87
88 if (do_load) {
89 assert(pre_val == LIR_OprFact::illegalOpr, "sanity");
90 assert(addr_opr != LIR_OprFact::illegalOpr, "sanity");
91
92 if (patch)
93 pre_val_patch_code = lir_patch_normal;
94
95 pre_val = gen->new_register(T_OBJECT);
96
97 if (!addr_opr->is_address()) {
98 assert(addr_opr->is_register(), "must be");
99 addr_opr = LIR_OprFact::address(new LIR_Address(addr_opr, T_OBJECT));
100 }
101 slow = new ShenandoahPreBarrierStub(addr_opr, pre_val, pre_val_patch_code, info ? new CodeEmitInfo(info) : NULL);
102 } else {
103 assert(addr_opr == LIR_OprFact::illegalOpr, "sanity");
104 assert(pre_val->is_register(), "must be");
105 assert(pre_val->type() == T_OBJECT, "must be an object");
106
107 slow = new ShenandoahPreBarrierStub(pre_val);
108 }
109
110 __ branch(lir_cond_notEqual, slow);
111 __ branch_destination(slow->continuation());
112 }
113
114 LIR_Opr ShenandoahBarrierSetC1::load_reference_barrier(LIRGenerator* gen, LIR_Opr obj, LIR_Opr addr, DecoratorSet decorators) {
115 if (ShenandoahLoadRefBarrier) {
116 return load_reference_barrier_impl(gen, obj, addr, decorators);
117 } else {
118 return obj;
119 }
120 }
121
122 LIR_Opr ShenandoahBarrierSetC1::load_reference_barrier_impl(LIRGenerator* gen, LIR_Opr obj, LIR_Opr addr, DecoratorSet decorators) {
123 assert(ShenandoahLoadRefBarrier, "Should be enabled");
124
125 obj = ensure_in_register(gen, obj, T_OBJECT);
126 assert(obj->is_register(), "must be a register at this point");
127 addr = ensure_in_register(gen, addr, T_ADDRESS);
128 assert(addr->is_register(), "must be a register at this point");
129 LIR_Opr result = gen->result_register_for(obj->value_type());
130 __ move(obj, result);
131 LIR_Opr tmp1 = gen->new_register(T_ADDRESS);
132 LIR_Opr tmp2 = gen->new_register(T_ADDRESS);
133
134 LIR_Opr thrd = gen->getThreadPointer();
135 LIR_Address* active_flag_addr =
136 new LIR_Address(thrd,
137 in_bytes(ShenandoahThreadLocalData::gc_state_offset()),
138 T_BYTE);
139 // Read and check the gc-state-flag.
140 LIR_Opr flag_val = gen->new_register(T_INT);
141 __ load(active_flag_addr, flag_val);
142 int flags = ShenandoahHeap::HAS_FORWARDED;
143 if (!ShenandoahBarrierSet::is_strong_access(decorators)) {
144 flags |= ShenandoahHeap::WEAK_ROOTS;
145 }
146 LIR_Opr mask = LIR_OprFact::intConst(flags);
147 LIR_Opr mask_reg = gen->new_register(T_INT);
148 __ move(mask, mask_reg);
149
150 if (TwoOperandLIRForm) {
151 __ logical_and(flag_val, mask_reg, flag_val);
152 } else {
153 LIR_Opr masked_flag = gen->new_register(T_INT);
154 __ logical_and(flag_val, mask_reg, masked_flag);
155 flag_val = masked_flag;
156 }
157 __ cmp(lir_cond_notEqual, flag_val, LIR_OprFact::intConst(0));
158
159 CodeStub* slow = new ShenandoahLoadReferenceBarrierStub(obj, addr, result, tmp1, tmp2, decorators);
160 __ branch(lir_cond_notEqual, slow);
161 __ branch_destination(slow->continuation());
162
163 return result;
164 }
165
166 LIR_Opr ShenandoahBarrierSetC1::ensure_in_register(LIRGenerator* gen, LIR_Opr obj, BasicType type) {
167 if (!obj->is_register()) {
168 LIR_Opr obj_reg;
169 if (obj->is_constant()) {
170 obj_reg = gen->new_register(type);
171 __ move(obj, obj_reg);
172 } else {
173 obj_reg = gen->new_pointer_register();
174 __ leal(obj, obj_reg);
175 }
176 obj = obj_reg;
177 }
178 return obj;
179 }
180
181 LIR_Opr ShenandoahBarrierSetC1::iu_barrier(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, DecoratorSet decorators) {
182 if (ShenandoahIUBarrier) {
183 obj = ensure_in_register(gen, obj, T_OBJECT);
184 pre_barrier(gen, info, decorators, LIR_OprFact::illegalOpr, obj);
185 }
186 return obj;
187 }
188
189 void ShenandoahBarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) {
190 if (access.is_oop()) {
191 if (ShenandoahSATBBarrier) {
192 pre_barrier(access.gen(), access.access_emit_info(), access.decorators(), access.resolved_addr(), LIR_OprFact::illegalOpr /* pre_val */);
193 }
194 value = iu_barrier(access.gen(), value, access.access_emit_info(), access.decorators());
195 }
196 BarrierSetC1::store_at_resolved(access, value);
197
198 if (access.is_oop()) {
199 DecoratorSet decorators = access.decorators();
200 bool is_array = (decorators & IS_ARRAY) != 0;
201 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
202
203 bool precise = is_array || on_anonymous;
204 LIR_Opr post_addr = precise ? access.resolved_addr() : access.base().opr();
205 post_barrier(access, post_addr, value);
206 }
207 }
208
209 LIR_Opr ShenandoahBarrierSetC1::resolve_address(LIRAccess& access, bool resolve_in_register) {
210 // We must resolve in register when patching. This is to avoid
211 // having a patch area in the load barrier stub, since the call
212 // into the runtime to patch will not have the proper oop map.
213 const bool patch_before_barrier = access.is_oop() && (access.decorators() & C1_NEEDS_PATCHING) != 0;
214 return BarrierSetC1::resolve_address(access, resolve_in_register || patch_before_barrier);
215 }
216
217 void ShenandoahBarrierSetC1::load_at_resolved(LIRAccess& access, LIR_Opr result) {
218 // 1: non-reference load, no additional barrier is needed
219 if (!access.is_oop()) {
220 BarrierSetC1::load_at_resolved(access, result);
221 return;
222 }
223
224 LIRGenerator* gen = access.gen();
225 DecoratorSet decorators = access.decorators();
226 BasicType type = access.type();
227
228 // 2: load a reference from src location and apply LRB if ShenandoahLoadRefBarrier is set
229 if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) {
230 LIR_Opr tmp = gen->new_register(T_OBJECT);
231 BarrierSetC1::load_at_resolved(access, tmp);
232 tmp = load_reference_barrier(gen, tmp, access.resolved_addr(), decorators);
233 __ move(tmp, result);
234 } else {
235 BarrierSetC1::load_at_resolved(access, result);
236 }
237
238 // 3: apply keep-alive barrier for java.lang.ref.Reference if needed
239 if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) {
240 bool is_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
241
242 // Register the value in the referent field with the pre-barrier
243 LabelObj *Lcont_anonymous;
244 if (is_anonymous) {
245 Lcont_anonymous = new LabelObj();
246 generate_referent_check(access, Lcont_anonymous);
247 }
248 pre_barrier(gen, access.access_emit_info(), decorators, LIR_OprFact::illegalOpr /* addr_opr */,
249 result /* pre_val */);
250 if (is_anonymous) {
251 __ branch_destination(Lcont_anonymous->label());
252 }
253 }
254 }
255
256 class C1ShenandoahPreBarrierCodeGenClosure : public StubAssemblerCodeGenClosure {
257 virtual OopMapSet* generate_code(StubAssembler* sasm) {
258 ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
259 bs->generate_c1_pre_barrier_runtime_stub(sasm);
260 return NULL;
261 }
262 };
263
264 class C1ShenandoahLoadReferenceBarrierCodeGenClosure : public StubAssemblerCodeGenClosure {
265 private:
266 const DecoratorSet _decorators;
267
268 public:
269 C1ShenandoahLoadReferenceBarrierCodeGenClosure(DecoratorSet decorators) : _decorators(decorators) {}
270
271 virtual OopMapSet* generate_code(StubAssembler* sasm) {
272 ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
273 bs->generate_c1_load_reference_barrier_runtime_stub(sasm, _decorators);
274 return NULL;
275 }
276 };
277
278 void ShenandoahBarrierSetC1::generate_c1_runtime_stubs(BufferBlob* buffer_blob) {
279 C1ShenandoahPreBarrierCodeGenClosure pre_code_gen_cl;
280 _pre_barrier_c1_runtime_code_blob = Runtime1::generate_blob(buffer_blob, -1,
281 "shenandoah_pre_barrier_slow",
282 false, &pre_code_gen_cl);
283 if (ShenandoahLoadRefBarrier) {
284 C1ShenandoahLoadReferenceBarrierCodeGenClosure lrb_strong_code_gen_cl(ON_STRONG_OOP_REF);
285 _load_reference_barrier_strong_rt_code_blob = Runtime1::generate_blob(buffer_blob, -1,
286 "shenandoah_load_reference_barrier_strong_slow",
287 false, &lrb_strong_code_gen_cl);
288
289 C1ShenandoahLoadReferenceBarrierCodeGenClosure lrb_strong_native_code_gen_cl(ON_STRONG_OOP_REF | IN_NATIVE);
290 _load_reference_barrier_strong_native_rt_code_blob = Runtime1::generate_blob(buffer_blob, -1,
291 "shenandoah_load_reference_barrier_strong_native_slow",
292 false, &lrb_strong_native_code_gen_cl);
293
294 C1ShenandoahLoadReferenceBarrierCodeGenClosure lrb_weak_code_gen_cl(ON_WEAK_OOP_REF);
295 _load_reference_barrier_weak_rt_code_blob = Runtime1::generate_blob(buffer_blob, -1,
296 "shenandoah_load_reference_barrier_weak_slow",
297 false, &lrb_weak_code_gen_cl);
298
299 C1ShenandoahLoadReferenceBarrierCodeGenClosure lrb_phantom_code_gen_cl(ON_PHANTOM_OOP_REF | IN_NATIVE);
300 _load_reference_barrier_phantom_rt_code_blob = Runtime1::generate_blob(buffer_blob, -1,
301 "shenandoah_load_reference_barrier_phantom_slow",
302 false, &lrb_phantom_code_gen_cl);
303 }
304 }
305
306 void ShenandoahBarrierSetC1::post_barrier(LIRAccess& access, LIR_OprDesc* addr, LIR_OprDesc* new_val) {
307 if (!ShenandoahHeap::heap()->mode()->is_generational()) {
308 return;
309 }
310
311 DecoratorSet decorators = access.decorators();
312 LIRGenerator* gen = access.gen();
313 bool in_heap = (decorators & IN_HEAP) != 0;
314 if (!in_heap) {
315 return;
316 }
317
318 BarrierSet* bs = BarrierSet::barrier_set();
319 ShenandoahBarrierSet* ctbs = barrier_set_cast<ShenandoahBarrierSet>(bs);
320 CardTable* ct = ctbs->card_table();
321 LIR_Const* card_table_base = new LIR_Const(ct->byte_map_base());
322 if (addr->is_address()) {
323 LIR_Address* address = addr->as_address_ptr();
324 // ptr cannot be an object because we use this barrier for array card marks
325 // and addr can point in the middle of an array.
326 LIR_Opr ptr = gen->new_pointer_register();
327 if (!address->index()->is_valid() && address->disp() == 0) {
328 __ move(address->base(), ptr);
329 } else {
330 assert(address->disp() != max_jint, "lea doesn't support patched addresses!");
331 __ leal(addr, ptr);
332 }
333 addr = ptr;
334 }
335 assert(addr->is_register(), "must be a register at this point");
336
337 LIR_Opr tmp = gen->new_pointer_register();
338 if (TwoOperandLIRForm) {
339 __ move(addr, tmp);
340 __ unsigned_shift_right(tmp, CardTable::card_shift, tmp);
341 } else {
342 __ unsigned_shift_right(addr, CardTable::card_shift, tmp);
343 }
344
345 LIR_Address* card_addr;
346 if (gen->can_inline_as_constant(card_table_base)) {
347 card_addr = new LIR_Address(tmp, card_table_base->as_jint(), T_BYTE);
348 } else {
349 card_addr = new LIR_Address(tmp, gen->load_constant(card_table_base), T_BYTE);
350 }
351
352 LIR_Opr dirty = LIR_OprFact::intConst(CardTable::dirty_card_val());
353 if (UseCondCardMark) {
354 LIR_Opr cur_value = gen->new_register(T_INT);
355 __ move(card_addr, cur_value);
356
357 LabelObj* L_already_dirty = new LabelObj();
358 __ cmp(lir_cond_equal, cur_value, dirty);
359 __ branch(lir_cond_equal, L_already_dirty->label());
360 __ move(dirty, card_addr);
361 __ branch_destination(L_already_dirty->label());
362 } else {
363 __ move(dirty, card_addr);
364 }
365 }