1 /*
2 * Copyright (c) 2018, Red Hat, Inc. and/or its affiliates.
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 #include "precompiled.hpp"
25 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
26 #include "gc/shenandoah/shenandoahHeap.hpp"
27 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
28 #include "gc/shenandoah/shenandoahHeuristics.hpp"
29 #include "gc/shenandoah/shenandoahRuntime.hpp"
30 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "interpreter/interp_masm.hpp"
33 #include "runtime/sharedRuntime.hpp"
34 #include "runtime/thread.hpp"
35 #ifdef COMPILER1
36 #include "c1/c1_LIRAssembler.hpp"
37 #include "c1/c1_MacroAssembler.hpp"
38 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
39 #endif
40
41 #define __ masm->
42
43 address ShenandoahBarrierSetAssembler::_shenandoah_wb = NULL;
44
45 void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
46 Register addr, Register count, RegSet saved_regs) {
47 if (is_oop) {
48 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
49 if (!dest_uninitialized && !ShenandoahHeap::heap()->heuristics()->can_do_traversal_gc()) {
50 __ push(saved_regs, sp);
51 if (count == c_rarg0) {
52 if (addr == c_rarg1) {
53 // exactly backwards!!
54 __ mov(rscratch1, c_rarg0);
55 __ mov(c_rarg0, c_rarg1);
56 __ mov(c_rarg1, rscratch1);
57 } else {
58 __ mov(c_rarg1, count);
59 __ mov(c_rarg0, addr);
60 }
61 } else {
62 __ mov(c_rarg0, addr);
63 __ mov(c_rarg1, count);
64 }
65 if (UseCompressedOops) {
66 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry), 2);
67 } else {
68 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry), 2);
69 }
70 __ pop(saved_regs, sp);
71 }
72 }
73 }
74
75 void ShenandoahBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
76 Register start, Register end, Register scratch, RegSet saved_regs) {
77 if (is_oop) {
78 __ push(saved_regs, sp);
79 // must compute element count unless barrier set interface is changed (other platforms supply count)
80 assert_different_registers(start, end, scratch);
81 __ lea(scratch, Address(end, BytesPerHeapOop));
82 __ sub(scratch, scratch, start); // subtract start to get #bytes
83 __ lsr(scratch, scratch, LogBytesPerHeapOop); // convert to element count
84 __ mov(c_rarg0, start);
85 __ mov(c_rarg1, scratch);
86 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_post_entry), 2);
87 __ pop(saved_regs, sp);
88 }
89 }
90
91 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm,
92 Register obj,
93 Register pre_val,
94 Register thread,
95 Register tmp,
96 bool tosca_live,
97 bool expand_call) {
98 if (ShenandoahSATBBarrier) {
99 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call);
100 }
101 }
102
103 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm,
104 Register obj,
105 Register pre_val,
106 Register thread,
107 Register tmp,
108 bool tosca_live,
109 bool expand_call) {
110 // If expand_call is true then we expand the call_VM_leaf macro
111 // directly to skip generating the check by
112 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
113
114 assert(thread == rthread, "must be");
115
116 Label done;
117 Label runtime;
118
119 assert_different_registers(obj, pre_val, tmp, rscratch1);
120 assert(pre_val != noreg && tmp != noreg, "expecting a register");
121
122 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()));
123 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
124 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
125
126 // Is marking active?
127 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
128 __ ldrw(tmp, in_progress);
129 } else {
130 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
131 __ ldrb(tmp, in_progress);
132 }
133 __ cbzw(tmp, done);
134
135 // Do we need to load the previous value?
136 if (obj != noreg) {
137 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW);
138 }
139
140 // Is the previous value null?
141 __ cbz(pre_val, done);
142
143 // Can we store original value in the thread's buffer?
144 // Is index == 0?
145 // (The index field is typed as size_t.)
146
147 __ ldr(tmp, index); // tmp := *index_adr
148 __ cbz(tmp, runtime); // tmp == 0?
149 // If yes, goto runtime
150
151 __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize
152 __ str(tmp, index); // *index_adr := tmp
153 __ ldr(rscratch1, buffer);
154 __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr
155
156 // Record the previous value
157 __ str(pre_val, Address(tmp, 0));
158 __ b(done);
159
160 __ bind(runtime);
161 // save the live input values
162 RegSet saved = RegSet::of(pre_val);
163 if (tosca_live) saved += RegSet::of(r0);
164 if (obj != noreg) saved += RegSet::of(obj);
165
166 __ push(saved, sp);
167
168 // Calling the runtime using the regular call_VM_leaf mechanism generates
169 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
170 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
171 //
172 // If we care generating the pre-barrier without a frame (e.g. in the
173 // intrinsified Reference.get() routine) then ebp might be pointing to
174 // the caller frame and so this check will most likely fail at runtime.
175 //
176 // Expanding the call directly bypasses the generation of the check.
177 // So when we do not have have a full interpreter frame on the stack
178 // expand_call should be passed true.
179
180 if (expand_call) {
181 assert(pre_val != c_rarg1, "smashed arg");
182 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
183 } else {
184 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
185 }
186
187 __ pop(saved, sp);
188
189 __ bind(done);
190 }
191
192 void ShenandoahBarrierSetAssembler::read_barrier(MacroAssembler* masm, Register dst) {
193 if (ShenandoahReadBarrier) {
194 read_barrier_impl(masm, dst);
195 }
196 }
197
198 void ShenandoahBarrierSetAssembler::read_barrier_impl(MacroAssembler* masm, Register dst) {
199 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier || ShenandoahCASBarrier), "should be enabled");
200 Label is_null;
201 __ cbz(dst, is_null);
202 read_barrier_not_null_impl(masm, dst);
203 __ bind(is_null);
204 }
205
206 void ShenandoahBarrierSetAssembler::read_barrier_not_null(MacroAssembler* masm, Register dst) {
207 if (ShenandoahReadBarrier) {
208 read_barrier_not_null_impl(masm, dst);
209 }
210 }
211
212
213 void ShenandoahBarrierSetAssembler::read_barrier_not_null_impl(MacroAssembler* masm, Register dst) {
214 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier || ShenandoahCASBarrier), "should be enabled");
215 __ ldr(dst, Address(dst, ShenandoahBrooksPointer::byte_offset()));
216 }
217
218 void ShenandoahBarrierSetAssembler::write_barrier(MacroAssembler* masm, Register dst) {
219 if (ShenandoahWriteBarrier) {
220 write_barrier_impl(masm, dst);
221 }
222 }
223
224 void ShenandoahBarrierSetAssembler::write_barrier_impl(MacroAssembler* masm, Register dst) {
225 assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier), "Should be enabled");
226 assert(dst != rscratch1, "need rscratch1");
227 assert(dst != rscratch2, "need rscratch2");
228
229 Label done;
230
231 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
232 __ ldrb(rscratch1, gc_state);
233
234 // Check for heap stability
235 __ mov(rscratch2, ShenandoahHeap::HAS_FORWARDED | ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
236 __ tst(rscratch1, rscratch2);
237 __ br(Assembler::EQ, done);
238
239 // Heap is unstable, need to perform the read-barrier even if WB is inactive
240 if (ShenandoahWriteBarrierRB) {
241 __ ldr(dst, Address(dst, ShenandoahBrooksPointer::byte_offset()));
242 }
243
244 // Check for evacuation-in-progress and jump to WB slow-path if needed
245 __ mov(rscratch2, ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
246 __ tst(rscratch1, rscratch2);
247 __ br(Assembler::EQ, done);
248
249 RegSet to_save = RegSet::of(r0);
250 if (dst != r0) {
251 __ push(to_save, sp);
252 __ mov(r0, dst);
253 }
254
255 __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_wb())));
256
257 if (dst != r0) {
258 __ mov(dst, r0);
259 __ pop(to_save, sp);
260 }
261
262 __ bind(done);
263 }
264
265 void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) {
266 if (ShenandoahStoreValEnqueueBarrier) {
267 Label is_null;
268 __ cbz(dst, is_null);
269 write_barrier_impl(masm, dst);
270 __ bind(is_null);
271 // Save possibly live regs.
272 RegSet live_regs = RegSet::range(r0, r4) - dst;
273 __ push(live_regs, sp);
274 __ strd(v0, __ pre(sp, 2 * -wordSize));
275
276 satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false);
277
278 // Restore possibly live regs.
279 __ ldrd(v0, __ post(sp, 2 * wordSize));
280 __ pop(live_regs, sp);
281 }
282 if (ShenandoahStoreValReadBarrier) {
283 read_barrier_impl(masm, dst);
284 }
285 }
286
287 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
288 Register dst, Address src, Register tmp1, Register tmp_thread) {
289 bool on_oop = type == T_OBJECT || type == T_ARRAY;
290 bool in_heap = (decorators & IN_HEAP) != 0;
291 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
292 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
293 bool on_reference = on_weak || on_phantom;
294
295 if (in_heap) {
296 read_barrier_not_null(masm, src.base());
297 }
298
299 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
300 if (ShenandoahKeepAliveBarrier && on_oop && on_reference) {
301 __ enter();
302 satb_write_barrier_pre(masm /* masm */,
303 noreg /* obj */,
304 dst /* pre_val */,
305 rthread /* thread */,
306 tmp1 /* tmp */,
307 true /* tosca_live */,
308 true /* expand_call */);
309 __ leave();
310 }
311 }
312
313 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
314 Address dst, Register val, Register tmp1, Register tmp2) {
315 bool on_oop = type == T_OBJECT || type == T_ARRAY;
316 bool in_heap = (decorators & IN_HEAP) != 0;
317 if (in_heap) {
318 write_barrier(masm, dst.base());
319 }
320 if (!on_oop) {
321 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2);
322 return;
323 }
324
325 // flatten object address if needed
326 if (dst.index() == noreg && dst.offset() == 0) {
327 if (dst.base() != r3) {
328 __ mov(r3, dst.base());
329 }
330 } else {
331 __ lea(r3, dst);
332 }
333
334 shenandoah_write_barrier_pre(masm,
335 r3 /* obj */,
336 tmp2 /* pre_val */,
337 rthread /* thread */,
338 tmp1 /* tmp */,
339 val != noreg /* tosca_live */,
340 false /* expand_call */);
341
342 if (val == noreg) {
343 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg);
344 } else {
345 storeval_barrier(masm, val, tmp1);
346 // G1 barrier needs uncompressed oop for region cross check.
347 Register new_val = val;
348 if (UseCompressedOops) {
349 new_val = rscratch2;
350 __ mov(new_val, val);
351 }
352 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg);
353 }
354
355 }
356
357 void ShenandoahBarrierSetAssembler::obj_equals(MacroAssembler* masm, Register op1, Register op2) {
358 __ cmp(op1, op2);
359 if (ShenandoahAcmpBarrier) {
360 Label done;
361 __ br(Assembler::EQ, done);
362 // The object may have been evacuated, but we won't see it without a
363 // membar here.
364 __ membar(Assembler::LoadStore| Assembler::LoadLoad);
365 read_barrier(masm, op1);
366 read_barrier(masm, op2);
367 __ cmp(op1, op2);
368 __ bind(done);
369 }
370 }
371
372 void ShenandoahBarrierSetAssembler::tlab_allocate(MacroAssembler* masm, Register obj,
373 Register var_size_in_bytes,
374 int con_size_in_bytes,
375 Register t1,
376 Register t2,
377 Label& slow_case) {
378
379 assert_different_registers(obj, t2);
380 assert_different_registers(obj, var_size_in_bytes);
381 Register end = t2;
382
383 __ ldr(obj, Address(rthread, JavaThread::tlab_top_offset()));
384 if (var_size_in_bytes == noreg) {
385 __ lea(end, Address(obj, (int) (con_size_in_bytes + ShenandoahBrooksPointer::byte_size())));
386 } else {
387 __ add(var_size_in_bytes, var_size_in_bytes, ShenandoahBrooksPointer::byte_size());
388 __ lea(end, Address(obj, var_size_in_bytes));
389 }
390 __ ldr(rscratch1, Address(rthread, JavaThread::tlab_end_offset()));
391 __ cmp(end, rscratch1);
392 __ br(Assembler::HI, slow_case);
393
394 // update the tlab top pointer
395 __ str(end, Address(rthread, JavaThread::tlab_top_offset()));
396
397 __ add(obj, obj, ShenandoahBrooksPointer::byte_size());
398 __ str(obj, Address(obj, ShenandoahBrooksPointer::byte_offset()));
399
400 // recover var_size_in_bytes if necessary
401 if (var_size_in_bytes == end) {
402 __ sub(var_size_in_bytes, var_size_in_bytes, obj);
403 }
404 }
405
406 void ShenandoahBarrierSetAssembler::resolve(MacroAssembler* masm, DecoratorSet decorators, Register obj) {
407 bool oop_not_null = (decorators & IS_NOT_NULL) != 0;
408 bool is_write = (decorators & ACCESS_WRITE) != 0;
409 if (is_write) {
410 if (oop_not_null) {
411 write_barrier(masm, obj);
412 } else {
413 Label done;
414 __ cbz(obj, done);
415 write_barrier(masm, obj);
416 __ bind(done);
417 }
418 } else {
419 if (oop_not_null) {
420 read_barrier_not_null(masm, obj);
421 } else {
422 read_barrier(masm, obj);
423 }
424 }
425 }
426
427 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val,
428 bool acquire, bool release, bool weak, bool encode,
429 Register tmp1, Register tmp2, Register tmp3,
430 Register result) {
431
432 if (!ShenandoahCASBarrier) {
433 if (UseCompressedOops) {
434 if (encode) {
435 __ encode_heap_oop(tmp1, expected);
436 expected = tmp1;
437 __ encode_heap_oop(tmp3, new_val);
438 new_val = tmp3;
439 }
440 __ cmpxchg(addr, expected, new_val, Assembler::word, /* acquire*/ true, /* release*/ true, /* weak*/ false, rscratch1);
441 __ membar(__ AnyAny);
442 } else {
443 __ cmpxchg(addr, expected, new_val, Assembler::xword, /* acquire*/ true, /* release*/ true, /* weak*/ false, rscratch1);
444 __ membar(__ AnyAny);
445 }
446 return;
447 }
448
449 if (encode) {
450 storeval_barrier(masm, new_val, tmp3);
451 }
452
453 if (UseCompressedOops) {
454 if (encode) {
455 __ encode_heap_oop(tmp1, expected);
456 expected = tmp1;
457 __ encode_heap_oop(tmp2, new_val);
458 new_val = tmp2;
459 }
460 }
461 bool is_cae = (result != noreg);
462 bool is_narrow = UseCompressedOops;
463 Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword;
464 if (! is_cae) result = rscratch1;
465
466 assert_different_registers(addr, expected, new_val, result, tmp3);
467
468 Label retry, done, fail;
469
470 // CAS, using LL/SC pair.
471 __ bind(retry);
472 __ load_exclusive(result, addr, size, acquire);
473 if (is_narrow) {
474 __ cmpw(result, expected);
475 } else {
476 __ cmp(result, expected);
477 }
478 __ br(Assembler::NE, fail);
479 __ store_exclusive(tmp3, new_val, addr, size, release);
480 if (weak) {
481 __ cmpw(tmp3, 0u); // If the store fails, return NE to our caller
482 } else {
483 __ cbnzw(tmp3, retry);
484 }
485 __ b(done);
486
487 __ bind(fail);
488 // Check if rb(expected)==rb(result)
489 // Shuffle registers so that we have memory value ready for next expected.
490 __ mov(tmp3, expected);
491 __ mov(expected, result);
492 if (is_narrow) {
493 __ decode_heap_oop(result, result);
494 __ decode_heap_oop(tmp3, tmp3);
495 }
496 read_barrier_impl(masm, result);
497 read_barrier_impl(masm, tmp3);
498 __ cmp(result, tmp3);
499 // Retry with expected now being the value we just loaded from addr.
500 __ br(Assembler::EQ, retry);
501 if (is_narrow && is_cae) {
502 // For cmp-and-exchange and narrow oops, we need to restore
503 // the compressed old-value. We moved it to 'expected' a few lines up.
504 __ mov(result, expected);
505 }
506 __ bind(done);
507
508 }
509
510 #ifdef COMPILER1
511
512 #undef __
513 #define __ ce->masm()->
514
515 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) {
516 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
517 // At this point we know that marking is in progress.
518 // If do_load() is true then we have to emit the
519 // load of the previous value; otherwise it has already
520 // been loaded into _pre_val.
521
522 __ bind(*stub->entry());
523
524 assert(stub->pre_val()->is_register(), "Precondition.");
525
526 Register pre_val_reg = stub->pre_val()->as_register();
527
528 if (stub->do_load()) {
529 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/);
530 }
531 __ cbz(pre_val_reg, *stub->continuation());
532 ce->store_parameter(stub->pre_val()->as_register(), 0);
533 __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
534 __ b(*stub->continuation());
535 }
536
537 void ShenandoahBarrierSetAssembler::gen_write_barrier_stub(LIR_Assembler* ce, ShenandoahWriteBarrierStub* stub) {
538
539 Register obj = stub->obj()->as_register();
540 Register res = stub->result()->as_register();
541
542 Label done;
543
544 __ bind(*stub->entry());
545
546 if (res != obj) {
547 __ mov(res, obj);
548 }
549 // Check for null.
550 if (stub->needs_null_check()) {
551 __ cbz(res, done);
552 }
553
554 write_barrier(ce->masm(), res);
555
556 __ bind(done);
557 __ b(*stub->continuation());
558 }
559
560 #undef __
561
562 #define __ sasm->
563
564 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
565 __ prologue("shenandoah_pre_barrier", false);
566
567 // arg0 : previous value of memory
568
569 BarrierSet* bs = BarrierSet::barrier_set();
570
571 const Register pre_val = r0;
572 const Register thread = rthread;
573 const Register tmp = rscratch1;
574
575 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
576 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
577
578 Label done;
579 Label runtime;
580
581 // Is marking still active?
582 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
583 __ ldrb(tmp, gc_state);
584 __ mov(rscratch2, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL);
585 __ tst(tmp, rscratch2);
586 __ br(Assembler::EQ, done);
587
588 // Can we store original value in the thread's buffer?
589 __ ldr(tmp, queue_index);
590 __ cbz(tmp, runtime);
591
592 __ sub(tmp, tmp, wordSize);
593 __ str(tmp, queue_index);
594 __ ldr(rscratch2, buffer);
595 __ add(tmp, tmp, rscratch2);
596 __ load_parameter(0, rscratch2);
597 __ str(rscratch2, Address(tmp, 0));
598 __ b(done);
599
600 __ bind(runtime);
601 __ push_call_clobbered_registers();
602 __ load_parameter(0, pre_val);
603 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
604 __ pop_call_clobbered_registers();
605 __ bind(done);
606
607 __ epilogue();
608 }
609
610 #undef __
611
612 #endif // COMPILER1
613
614 address ShenandoahBarrierSetAssembler::shenandoah_wb() {
615 assert(_shenandoah_wb != NULL, "need write barrier stub");
616 return _shenandoah_wb;
617 }
618
619 #define __ cgen->assembler()->
620
621 // Shenandoah write barrier.
622 //
623 // Input:
624 // r0: OOP to evacuate. Not null.
625 //
626 // Output:
627 // r0: Pointer to evacuated OOP.
628 //
629 // Trash rscratch1, rscratch2. Preserve everything else.
630 address ShenandoahBarrierSetAssembler::generate_shenandoah_wb(StubCodeGenerator* cgen) {
631
632 __ align(6);
633 StubCodeMark mark(cgen, "StubRoutines", "shenandoah_wb");
634 address start = __ pc();
635
636 Label work;
637 __ mov(rscratch2, ShenandoahHeap::in_cset_fast_test_addr());
638 __ lsr(rscratch1, r0, ShenandoahHeapRegion::region_size_bytes_shift_jint());
639 __ ldrb(rscratch2, Address(rscratch2, rscratch1));
640 __ tbnz(rscratch2, 0, work);
641 __ ret(lr);
642 __ bind(work);
643
644 Register obj = r0;
645
646 __ enter(); // required for proper stackwalking of RuntimeStub frame
647
648 __ push_call_clobbered_registers();
649
650 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_JRT));
651 __ blrt(lr, 1, 0, MacroAssembler::ret_type_integral);
652 __ mov(rscratch1, obj);
653 __ pop_call_clobbered_registers();
654 __ mov(obj, rscratch1);
655
656 __ leave(); // required for proper stackwalking of RuntimeStub frame
657 __ ret(lr);
658
659 return start;
660 }
661
662 #undef __
663
664 void ShenandoahBarrierSetAssembler::barrier_stubs_init() {
665 if (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier) {
666 int stub_code_size = 2048;
667 ResourceMark rm;
668 BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size);
669 CodeBuffer buf(bb);
670 StubCodeGenerator cgen(&buf);
671 _shenandoah_wb = generate_shenandoah_wb(&cgen);
672 }
673 }