1 /*
2 * Copyright (c) 2018, 2025, 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 #include "asm/macroAssembler.inline.hpp"
26 #include "code/aotCodeCache.hpp"
27 #include "gc/g1/g1BarrierSet.hpp"
28 #include "gc/g1/g1BarrierSetAssembler.hpp"
29 #include "gc/g1/g1BarrierSetRuntime.hpp"
30 #include "gc/g1/g1CardTable.hpp"
31 #include "gc/g1/g1HeapRegion.hpp"
32 #include "gc/g1/g1ThreadLocalData.hpp"
33 #include "interpreter/interp_masm.hpp"
34 #include "runtime/sharedRuntime.hpp"
35 #include "utilities/debug.hpp"
36 #include "utilities/macros.hpp"
37 #ifdef COMPILER1
38 #include "c1/c1_LIRAssembler.hpp"
39 #include "c1/c1_MacroAssembler.hpp"
40 #include "gc/g1/c1/g1BarrierSetC1.hpp"
41 #endif // COMPILER1
42 #ifdef COMPILER2
43 #include "gc/g1/c2/g1BarrierSetC2.hpp"
44 #endif // COMPILER2
45
46 #define __ masm->
47
48 void G1BarrierSetAssembler::gen_write_ref_array_pre_barrier(MacroAssembler* masm, DecoratorSet decorators,
49 Register addr, Register count) {
50 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
51
52 if (!dest_uninitialized) {
53 Register thread = r15_thread;
54
55 Label filtered;
56 Address in_progress(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()));
57 // Is marking active?
58 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
59 __ cmpl(in_progress, 0);
60 } else {
61 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
62 __ cmpb(in_progress, 0);
63 }
64
65 __ jcc(Assembler::equal, filtered);
66
67 __ push_call_clobbered_registers(false /* save_fpu */);
68 if (count == c_rarg0) {
69 if (addr == c_rarg1) {
70 // exactly backwards!!
71 __ xchgptr(c_rarg1, c_rarg0);
72 } else {
73 __ movptr(c_rarg1, count);
74 __ movptr(c_rarg0, addr);
75 }
76 } else {
77 __ movptr(c_rarg0, addr);
78 __ movptr(c_rarg1, count);
79 }
80 if (UseCompressedOops) {
81 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_narrow_oop_entry), 2);
82 } else {
83 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_oop_entry), 2);
84 }
85 __ pop_call_clobbered_registers(false /* save_fpu */);
86
87 __ bind(filtered);
88 }
89 }
90
91 void G1BarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
92 Register addr, Register count, Register tmp) {
93 __ push_call_clobbered_registers(false /* save_fpu */);
94 if (c_rarg0 == count) { // On win64 c_rarg0 == rcx
95 assert_different_registers(c_rarg1, addr);
96 __ mov(c_rarg1, count);
97 __ mov(c_rarg0, addr);
98 } else {
99 assert_different_registers(c_rarg0, count);
100 __ mov(c_rarg0, addr);
101 __ mov(c_rarg1, count);
102 }
103 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_post_entry), 2);
104 __ pop_call_clobbered_registers(false /* save_fpu */);
105
106 }
107
108 void G1BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
109 Register dst, Address src, Register tmp1) {
110 bool on_oop = is_reference_type(type);
111 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
112 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
113 bool on_reference = on_weak || on_phantom;
114 ModRefBarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1);
115 if (on_oop && on_reference) {
116 // Generate the G1 pre-barrier code to log the value of
117 // the referent field in an SATB buffer.
118 g1_write_barrier_pre(masm /* masm */,
119 noreg /* obj */,
120 dst /* pre_val */,
121 tmp1 /* tmp */,
122 true /* tosca_live */,
123 true /* expand_call */);
124 }
125 }
126
127 static void generate_queue_insertion(MacroAssembler* masm, ByteSize index_offset, ByteSize buffer_offset, Label& runtime,
128 const Register thread, const Register value, const Register temp) {
129 // This code assumes that buffer index is pointer sized.
130 STATIC_ASSERT(in_bytes(SATBMarkQueue::byte_width_of_index()) == sizeof(intptr_t));
131 // Can we store a value in the given thread's buffer?
132 // (The index field is typed as size_t.)
133 __ movptr(temp, Address(thread, in_bytes(index_offset))); // temp := *(index address)
134 __ testptr(temp, temp); // index == 0?
135 __ jcc(Assembler::zero, runtime); // jump to runtime if index == 0 (full buffer)
136 // The buffer is not full, store value into it.
137 __ subptr(temp, wordSize); // temp := next index
138 __ movptr(Address(thread, in_bytes(index_offset)), temp); // *(index address) := next index
139 __ addptr(temp, Address(thread, in_bytes(buffer_offset))); // temp := buffer address + next index
140 __ movptr(Address(temp, 0), value); // *(buffer address + next index) := value
141 }
142
143 static void generate_pre_barrier_fast_path(MacroAssembler* masm,
144 const Register thread) {
145 Address in_progress(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()));
146 // Is marking active?
147 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
148 __ cmpl(in_progress, 0);
149 } else {
150 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
151 __ cmpb(in_progress, 0);
152 }
153 }
154
155 static void generate_pre_barrier_slow_path(MacroAssembler* masm,
156 const Register obj,
157 const Register pre_val,
158 const Register thread,
159 const Register tmp,
160 Label& done,
161 Label& runtime) {
162 // Do we need to load the previous value?
163 if (obj != noreg) {
164 __ load_heap_oop(pre_val, Address(obj, 0), noreg, AS_RAW);
165 }
166 // Is the previous value null?
167 __ cmpptr(pre_val, NULL_WORD);
168 __ jcc(Assembler::equal, done);
169 generate_queue_insertion(masm,
170 G1ThreadLocalData::satb_mark_queue_index_offset(),
171 G1ThreadLocalData::satb_mark_queue_buffer_offset(),
172 runtime,
173 thread, pre_val, tmp);
174 __ jmp(done);
175 }
176
177 void G1BarrierSetAssembler::g1_write_barrier_pre(MacroAssembler* masm,
178 Register obj,
179 Register pre_val,
180 Register tmp,
181 bool tosca_live,
182 bool expand_call) {
183 // If expand_call is true then we expand the call_VM_leaf macro
184 // directly to skip generating the check by
185 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
186
187 const Register thread = r15_thread;
188
189 Label done;
190 Label runtime;
191
192 assert(pre_val != noreg, "check this code");
193
194 if (obj != noreg) {
195 assert_different_registers(obj, pre_val, tmp);
196 assert(pre_val != rax, "check this code");
197 }
198
199 generate_pre_barrier_fast_path(masm, thread);
200 // If marking is not active (*(mark queue active address) == 0), jump to done
201 __ jcc(Assembler::equal, done);
202 generate_pre_barrier_slow_path(masm, obj, pre_val, thread, tmp, done, runtime);
203
204 __ bind(runtime);
205
206 // Determine and save the live input values
207 __ push_call_clobbered_registers();
208
209 // Calling the runtime using the regular call_VM_leaf mechanism generates
210 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
211 // that checks that the *(ebp+frame::interpreter_frame_last_sp) == nullptr.
212 //
213 // If we care generating the pre-barrier without a frame (e.g. in the
214 // intrinsified Reference.get() routine) then ebp might be pointing to
215 // the caller frame and so this check will most likely fail at runtime.
216 //
217 // Expanding the call directly bypasses the generation of the check.
218 // So when we do not have have a full interpreter frame on the stack
219 // expand_call should be passed true.
220
221 if (expand_call) {
222 assert(pre_val != c_rarg1, "smashed arg");
223 if (c_rarg1 != thread) {
224 __ mov(c_rarg1, thread);
225 }
226 if (c_rarg0 != pre_val) {
227 __ mov(c_rarg0, pre_val);
228 }
229 __ MacroAssembler::call_VM_leaf_base(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), 2);
230 } else {
231 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), pre_val, thread);
232 }
233
234 __ pop_call_clobbered_registers();
235
236 __ bind(done);
237 }
238
239 // return a register that differs from reg1, reg2, reg3 and is not rcx
240
241 static Register pick_different_reg(Register reg1, Register reg2 = noreg, Register reg3= noreg, Register reg4 = noreg) {
242 RegSet available = (RegSet::of(rscratch1, rscratch2, rax, rbx) + rdx -
243 RegSet::of(reg1, reg2, reg3, reg4));
244 return *(available.begin());
245 }
246
247 static void generate_post_barrier_fast_path(MacroAssembler* masm,
248 const Register store_addr,
249 const Register new_val,
250 const Register tmp,
251 const Register tmp2,
252 Label& done,
253 bool new_val_may_be_null) {
254 CardTableBarrierSet* ct = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
255 // Does store cross heap regions?
256 #if INCLUDE_CDS
257 // AOT code needs to load the barrier grain shift from the aot
258 // runtime constants area in the code cache otherwise we can compile
259 // it as an immediate operand
260
261 if (AOTCodeCache::is_on_for_dump()) {
262 address grain_shift_addr = AOTRuntimeConstants::grain_shift_address();
263 Register save = pick_different_reg(rcx, tmp, new_val, store_addr);
264 __ push(save);
265 __ movptr(save, store_addr);
266 __ xorptr(save, new_val);
267 __ push(rcx);
268 __ lea(rcx, ExternalAddress(grain_shift_addr));
269 __ movptr(rcx, Address(rcx, 0));
270 __ shrptr(save);
271 __ pop(rcx);
272 __ mov(tmp, save);
273 __ pop(save);
274 __ jcc(Assembler::equal, done);
275 } else
276 #endif // INCLUDE_CDS
277 {
278 __ movptr(tmp, store_addr); // tmp := store address
279 __ xorptr(tmp, new_val); // tmp := store address ^ new value
280 __ shrptr(tmp, G1HeapRegion::LogOfHRGrainBytes); // ((store address ^ new value) >> LogOfHRGrainBytes) == 0?
281 __ jcc(Assembler::equal, done);
282 }
283
284 // Crosses regions, storing null?
285 if (new_val_may_be_null) {
286 __ cmpptr(new_val, NULL_WORD); // new value == null?
287 __ jcc(Assembler::equal, done);
288 }
289 // Storing region crossing non-null, is card young?
290 __ movptr(tmp, store_addr); // tmp := store address
291 #if INCLUDE_CDS
292 // AOT code needs to load the barrier card shift from the aot
293 // runtime constants area in the code cache otherwise we can compile
294 // it as an immediate operand
295 if (AOTCodeCache::is_on_for_dump()) {
296 address card_shift_addr = AOTRuntimeConstants::card_shift_address();
297 Register save = pick_different_reg(rcx, tmp);
298 __ push(save);
299 __ mov(save, tmp);
300 __ push(rcx);
301 __ lea(rcx, ExternalAddress(card_shift_addr));
302 __ movptr(rcx, Address(rcx, 0));
303 __ shrptr(save);
304 __ pop(rcx);
305 __ mov(tmp, save);
306 __ pop(save);
307 } else
308 #endif // INCLUDE_CDS
309 {
310 __ shrptr(tmp, CardTable::card_shift()); // tmp := card address relative to card table base
311 }
312 // Do not use ExternalAddress to load 'byte_map_base', since 'byte_map_base' is NOT
313 // a valid address and therefore is not properly handled by the relocation code.
314 if (AOTCodeCache::is_on_for_dump()) {
315 // AOT code needs relocation info for this address
316 __ lea(tmp2, ExternalAddress((address)ct->card_table()->byte_map_base())); // tmp2 := card table base address
317 } else {
318 __ movptr(tmp2, (intptr_t)ct->card_table()->byte_map_base()); // tmp2 := card table base address
319 }
320 __ addptr(tmp, tmp2); // tmp := card address
321 __ cmpb(Address(tmp, 0), G1CardTable::g1_young_card_val()); // *(card address) == young_card_val?
322 }
323
324 static void generate_post_barrier_slow_path(MacroAssembler* masm,
325 const Register thread,
326 const Register tmp,
327 const Register tmp2,
328 Label& done,
329 Label& runtime) {
330 __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad)); // StoreLoad membar
331 __ cmpb(Address(tmp, 0), G1CardTable::dirty_card_val()); // *(card address) == dirty_card_val?
332 __ jcc(Assembler::equal, done);
333 // Storing a region crossing, non-null oop, card is clean.
334 // Dirty card and log.
335 __ movb(Address(tmp, 0), G1CardTable::dirty_card_val()); // *(card address) := dirty_card_val
336 generate_queue_insertion(masm,
337 G1ThreadLocalData::dirty_card_queue_index_offset(),
338 G1ThreadLocalData::dirty_card_queue_buffer_offset(),
339 runtime,
340 thread, tmp, tmp2);
341 __ jmp(done);
342 }
343
344 void G1BarrierSetAssembler::g1_write_barrier_post(MacroAssembler* masm,
345 Register store_addr,
346 Register new_val,
347 Register tmp,
348 Register tmp2) {
349 const Register thread = r15_thread;
350
351 Label done;
352 Label runtime;
353
354 generate_post_barrier_fast_path(masm, store_addr, new_val, tmp, tmp2, done, true /* new_val_may_be_null */);
355 // If card is young, jump to done
356 __ jcc(Assembler::equal, done);
357 generate_post_barrier_slow_path(masm, thread, tmp, tmp2, done, runtime);
358
359 __ bind(runtime);
360 // save the live input values
361 RegSet saved = RegSet::of(store_addr);
362 __ push_set(saved);
363 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_post_entry), tmp, thread);
364 __ pop_set(saved);
365
366 __ bind(done);
367 }
368
369 #if defined(COMPILER2)
370
371 static void generate_c2_barrier_runtime_call(MacroAssembler* masm, G1BarrierStubC2* stub, const Register arg, const address runtime_path) {
372 SaveLiveRegisters save_registers(masm, stub);
373 if (c_rarg0 != arg) {
374 __ mov(c_rarg0, arg);
375 }
376 __ mov(c_rarg1, r15_thread);
377 // rax is a caller-saved, non-argument-passing register, so it does not
378 // interfere with c_rarg0 or c_rarg1. If it contained any live value before
379 // entering this stub, it is saved at this point, and restored after the
380 // call. If it did not contain any live value, it is free to be used. In
381 // either case, it is safe to use it here as a call scratch register.
382 __ call(RuntimeAddress(runtime_path), rax);
383 }
384
385 void G1BarrierSetAssembler::g1_write_barrier_pre_c2(MacroAssembler* masm,
386 Register obj,
387 Register pre_val,
388 Register tmp,
389 G1PreBarrierStubC2* stub) {
390 const Register thread = r15_thread;
391
392 assert(pre_val != noreg, "check this code");
393 if (obj != noreg) {
394 assert_different_registers(obj, pre_val, tmp);
395 }
396
397 stub->initialize_registers(obj, pre_val, thread, tmp);
398
399 generate_pre_barrier_fast_path(masm, thread);
400 // If marking is active (*(mark queue active address) != 0), jump to stub (slow path)
401 __ jcc(Assembler::notEqual, *stub->entry());
402
403 __ bind(*stub->continuation());
404 }
405
406 void G1BarrierSetAssembler::generate_c2_pre_barrier_stub(MacroAssembler* masm,
407 G1PreBarrierStubC2* stub) const {
408 Assembler::InlineSkippedInstructionsCounter skip_counter(masm);
409 Label runtime;
410 Register obj = stub->obj();
411 Register pre_val = stub->pre_val();
412 Register thread = stub->thread();
413 Register tmp = stub->tmp1();
414 assert(stub->tmp2() == noreg, "not needed in this platform");
415
416 __ bind(*stub->entry());
417 generate_pre_barrier_slow_path(masm, obj, pre_val, thread, tmp, *stub->continuation(), runtime);
418
419 __ bind(runtime);
420 generate_c2_barrier_runtime_call(masm, stub, pre_val, CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry));
421 __ jmp(*stub->continuation());
422 }
423
424 void G1BarrierSetAssembler::g1_write_barrier_post_c2(MacroAssembler* masm,
425 Register store_addr,
426 Register new_val,
427 Register tmp,
428 Register tmp2,
429 G1PostBarrierStubC2* stub) {
430 const Register thread = r15_thread;
431 stub->initialize_registers(thread, tmp, tmp2);
432
433 bool new_val_may_be_null = (stub->barrier_data() & G1C2BarrierPostNotNull) == 0;
434 generate_post_barrier_fast_path(masm, store_addr, new_val, tmp, tmp2, *stub->continuation(), new_val_may_be_null);
435 // If card is not young, jump to stub (slow path)
436 __ jcc(Assembler::notEqual, *stub->entry());
437
438 __ bind(*stub->continuation());
439 }
440
441 void G1BarrierSetAssembler::generate_c2_post_barrier_stub(MacroAssembler* masm,
442 G1PostBarrierStubC2* stub) const {
443 Assembler::InlineSkippedInstructionsCounter skip_counter(masm);
444 Label runtime;
445 Register thread = stub->thread();
446 Register tmp = stub->tmp1(); // tmp holds the card address.
447 Register tmp2 = stub->tmp2();
448 assert(stub->tmp3() == noreg, "not needed in this platform");
449
450 __ bind(*stub->entry());
451 generate_post_barrier_slow_path(masm, thread, tmp, tmp2, *stub->continuation(), runtime);
452
453 __ bind(runtime);
454 generate_c2_barrier_runtime_call(masm, stub, tmp, CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_post_entry));
455 __ jmp(*stub->continuation());
456 }
457
458 #endif // COMPILER2
459
460 void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
461 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
462 bool in_heap = (decorators & IN_HEAP) != 0;
463 bool as_normal = (decorators & AS_NORMAL) != 0;
464
465 bool needs_pre_barrier = as_normal;
466 bool needs_post_barrier = val != noreg && in_heap;
467
468 // flatten object address if needed
469 // We do it regardless of precise because we need the registers
470 if (dst.index() == noreg && dst.disp() == 0) {
471 if (dst.base() != tmp1) {
472 __ movptr(tmp1, dst.base());
473 }
474 } else {
475 __ lea(tmp1, dst);
476 }
477
478 if (needs_pre_barrier) {
479 g1_write_barrier_pre(masm /*masm*/,
480 tmp1 /* obj */,
481 tmp2 /* pre_val */,
482 tmp3 /* tmp */,
483 val != noreg /* tosca_live */,
484 false /* expand_call */);
485 }
486 if (val == noreg) {
487 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp1, 0), val, noreg, noreg, noreg);
488 } else {
489 Register new_val = val;
490 if (needs_post_barrier) {
491 // G1 barrier needs uncompressed oop for region cross check.
492 if (UseCompressedOops) {
493 new_val = tmp2;
494 __ movptr(new_val, val);
495 }
496 }
497 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp1, 0), val, noreg, noreg, noreg);
498 if (needs_post_barrier) {
499 g1_write_barrier_post(masm /*masm*/,
500 tmp1 /* store_adr */,
501 new_val /* new_val */,
502 tmp3 /* tmp */,
503 tmp2 /* tmp2 */);
504 }
505 }
506 }
507
508 #ifdef COMPILER1
509
510 #undef __
511 #define __ ce->masm()->
512
513 void G1BarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, G1PreBarrierStub* stub) {
514 G1BarrierSetC1* bs = (G1BarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
515 // At this point we know that marking is in progress.
516 // If do_load() is true then we have to emit the
517 // load of the previous value; otherwise it has already
518 // been loaded into _pre_val.
519
520 __ bind(*stub->entry());
521 assert(stub->pre_val()->is_register(), "Precondition.");
522
523 Register pre_val_reg = stub->pre_val()->as_register();
524
525 if (stub->do_load()) {
526 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/);
527 }
528
529 __ cmpptr(pre_val_reg, NULL_WORD);
530 __ jcc(Assembler::equal, *stub->continuation());
531 ce->store_parameter(stub->pre_val()->as_register(), 0);
532 __ call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
533 __ jmp(*stub->continuation());
534
535 }
536
537 void G1BarrierSetAssembler::gen_post_barrier_stub(LIR_Assembler* ce, G1PostBarrierStub* stub) {
538 G1BarrierSetC1* bs = (G1BarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
539 __ bind(*stub->entry());
540 assert(stub->addr()->is_register(), "Precondition.");
541 assert(stub->new_val()->is_register(), "Precondition.");
542 Register new_val_reg = stub->new_val()->as_register();
543 __ cmpptr(new_val_reg, NULL_WORD);
544 __ jcc(Assembler::equal, *stub->continuation());
545 ce->store_parameter(stub->addr()->as_pointer_register(), 0);
546 __ call(RuntimeAddress(bs->post_barrier_c1_runtime_code_blob()->code_begin()));
547 __ jmp(*stub->continuation());
548 }
549
550 #undef __
551
552 #define __ sasm->
553
554 void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
555 // Generated code assumes that buffer index is pointer sized.
556 STATIC_ASSERT(in_bytes(SATBMarkQueue::byte_width_of_index()) == sizeof(intptr_t));
557
558 __ prologue("g1_pre_barrier", false);
559 // arg0 : previous value of memory
560
561 __ push(rax);
562 __ push(rdx);
563
564 const Register pre_val = rax;
565 const Register thread = r15_thread;
566 const Register tmp = rdx;
567
568 Address queue_active(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()));
569 Address queue_index(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_index_offset()));
570 Address buffer(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset()));
571
572 Label done;
573 Label runtime;
574
575 // Is marking still active?
576 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
577 __ cmpl(queue_active, 0);
578 } else {
579 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
580 __ cmpb(queue_active, 0);
581 }
582 __ jcc(Assembler::equal, done);
583
584 // Can we store original value in the thread's buffer?
585
586 __ movptr(tmp, queue_index);
587 __ testptr(tmp, tmp);
588 __ jcc(Assembler::zero, runtime);
589 __ subptr(tmp, wordSize);
590 __ movptr(queue_index, tmp);
591 __ addptr(tmp, buffer);
592
593 // prev_val (rax)
594 __ load_parameter(0, pre_val);
595 __ movptr(Address(tmp, 0), pre_val);
596 __ jmp(done);
597
598 __ bind(runtime);
599
600 __ push_call_clobbered_registers();
601
602 // load the pre-value
603 __ load_parameter(0, rcx);
604 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), rcx, thread);
605
606 __ pop_call_clobbered_registers();
607
608 __ bind(done);
609
610 __ pop(rdx);
611 __ pop(rax);
612
613 __ epilogue();
614 }
615
616 void G1BarrierSetAssembler::generate_c1_post_barrier_runtime_stub(StubAssembler* sasm) {
617 __ prologue("g1_post_barrier", false);
618
619 CardTableBarrierSet* ct =
620 barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
621
622 Label done;
623 Label enqueued;
624 Label runtime;
625
626 // At this point we know new_value is non-null and the new_value crosses regions.
627 // Must check to see if card is already dirty
628
629 const Register thread = r15_thread;
630
631 Address queue_index(thread, in_bytes(G1ThreadLocalData::dirty_card_queue_index_offset()));
632 Address buffer(thread, in_bytes(G1ThreadLocalData::dirty_card_queue_buffer_offset()));
633
634 __ push(rax);
635 __ push(rcx);
636
637 const Register cardtable = rax;
638 const Register card_addr = rcx;
639
640 __ load_parameter(0, card_addr);
641 __ shrptr(card_addr, CardTable::card_shift());
642 // Do not use ExternalAddress to load 'byte_map_base', since 'byte_map_base' is NOT
643 // a valid address and therefore is not properly handled by the relocation code.
644 if (AOTCodeCache::is_on()) {
645 // AOT code needs relocation info for this address
646 __ lea(cardtable, ExternalAddress((address)ct->card_table()->byte_map_base()));
647 } else {
648 __ movptr(cardtable, (intptr_t)ct->card_table()->byte_map_base());
649 }
650 __ addptr(card_addr, cardtable);
651
652 __ cmpb(Address(card_addr, 0), G1CardTable::g1_young_card_val());
653 __ jcc(Assembler::equal, done);
654
655 __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
656 __ cmpb(Address(card_addr, 0), CardTable::dirty_card_val());
657 __ jcc(Assembler::equal, done);
658
659 // storing region crossing non-null, card is clean.
660 // dirty card and log.
661
662 __ movb(Address(card_addr, 0), CardTable::dirty_card_val());
663
664 const Register tmp = rdx;
665 __ push(rdx);
666
667 __ movptr(tmp, queue_index);
668 __ testptr(tmp, tmp);
669 __ jcc(Assembler::zero, runtime);
670 __ subptr(tmp, wordSize);
671 __ movptr(queue_index, tmp);
672 __ addptr(tmp, buffer);
673 __ movptr(Address(tmp, 0), card_addr);
674 __ jmp(enqueued);
675
676 __ bind(runtime);
677 __ push_call_clobbered_registers();
678
679 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_post_entry), card_addr, thread);
680
681 __ pop_call_clobbered_registers();
682
683 __ bind(enqueued);
684 __ pop(rdx);
685
686 __ bind(done);
687 __ pop(rcx);
688 __ pop(rax);
689
690 __ epilogue();
691 }
692
693 #undef __
694
695 #endif // COMPILER1