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/brooksPointer.hpp"
26 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
27 #include "gc/shenandoah/shenandoahHeap.hpp"
28 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
29 #include "gc/shenandoah/shenandoahHeuristics.hpp"
30 #include "gc/shenandoah/shenandoahRuntime.hpp"
31 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/interp_masm.hpp"
34 #include "runtime/sharedRuntime.hpp"
35 #include "runtime/thread.hpp"
36 #ifdef COMPILER1
37 #include "c1/c1_LIRAssembler.hpp"
38 #include "c1/c1_MacroAssembler.hpp"
39 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
40 #endif
41
42 #define __ masm->
43
44 address ShenandoahBarrierSetAssembler::_shenandoah_wb = NULL;
45 address ShenandoahBarrierSetAssembler::_shenandoah_wb_C = NULL;
46
47 void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
48 Register addr, Register count, RegSet saved_regs) {
49 if (is_oop) {
50 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
51 if (!dest_uninitialized && !ShenandoahHeap::heap()->heuristics()->can_do_traversal_gc()) {
52 __ push(saved_regs, sp);
53 if (count == c_rarg0) {
54 if (addr == c_rarg1) {
55 // exactly backwards!!
56 __ mov(rscratch1, c_rarg0);
57 __ mov(c_rarg0, c_rarg1);
58 __ mov(c_rarg1, rscratch1);
59 } else {
60 __ mov(c_rarg1, count);
61 __ mov(c_rarg0, addr);
62 }
63 } else {
64 __ mov(c_rarg0, addr);
65 __ mov(c_rarg1, count);
66 }
67 if (UseCompressedOops) {
68 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry), 2);
69 } else {
70 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry), 2);
71 }
72 __ pop(saved_regs, sp);
73 }
74 }
75 }
76
77 void ShenandoahBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
78 Register start, Register end, Register scratch, RegSet saved_regs) {
79 if (is_oop) {
80 __ push(saved_regs, sp);
81 // must compute element count unless barrier set interface is changed (other platforms supply count)
82 assert_different_registers(start, end, scratch);
83 __ lea(scratch, Address(end, BytesPerHeapOop));
84 __ sub(scratch, scratch, start); // subtract start to get #bytes
85 __ lsr(scratch, scratch, LogBytesPerHeapOop); // convert to element count
86 __ mov(c_rarg0, start);
87 __ mov(c_rarg1, scratch);
88 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_post_entry), 2);
89 __ pop(saved_regs, sp);
90 }
91 }
92
93 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm,
94 Register obj,
95 Register pre_val,
96 Register thread,
97 Register tmp,
98 bool tosca_live,
99 bool expand_call) {
100 if (ShenandoahSATBBarrier) {
101 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call);
102 }
103 }
104
105 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm,
106 Register obj,
107 Register pre_val,
108 Register thread,
109 Register tmp,
110 bool tosca_live,
111 bool expand_call) {
112 // If expand_call is true then we expand the call_VM_leaf macro
113 // directly to skip generating the check by
114 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
115
116 assert(thread == rthread, "must be");
117
118 Label done;
119 Label runtime;
120
121 assert_different_registers(obj, pre_val, tmp, rscratch1);
122 assert(pre_val != noreg && tmp != noreg, "expecting a register");
123
124 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()));
125 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
126 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
127
128 // Is marking active?
129 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
130 __ ldrw(tmp, in_progress);
131 } else {
132 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
133 __ ldrb(tmp, in_progress);
134 }
135 __ cbzw(tmp, done);
136
137 // Do we need to load the previous value?
138 if (obj != noreg) {
139 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW);
140 }
141
142 // Is the previous value null?
143 __ cbz(pre_val, done);
144
145 // Can we store original value in the thread's buffer?
146 // Is index == 0?
147 // (The index field is typed as size_t.)
148
149 __ ldr(tmp, index); // tmp := *index_adr
150 __ cbz(tmp, runtime); // tmp == 0?
151 // If yes, goto runtime
152
153 __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize
154 __ str(tmp, index); // *index_adr := tmp
155 __ ldr(rscratch1, buffer);
156 __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr
157
158 // Record the previous value
159 __ str(pre_val, Address(tmp, 0));
160 __ b(done);
161
162 __ bind(runtime);
163 // save the live input values
164 RegSet saved = RegSet::of(pre_val);
165 if (tosca_live) saved += RegSet::of(r0);
166 if (obj != noreg) saved += RegSet::of(obj);
167
168 __ push(saved, sp);
169
170 // Calling the runtime using the regular call_VM_leaf mechanism generates
171 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
172 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
173 //
174 // If we care generating the pre-barrier without a frame (e.g. in the
175 // intrinsified Reference.get() routine) then ebp might be pointing to
176 // the caller frame and so this check will most likely fail at runtime.
177 //
178 // Expanding the call directly bypasses the generation of the check.
179 // So when we do not have have a full interpreter frame on the stack
180 // expand_call should be passed true.
181
182 if (expand_call) {
183 assert(pre_val != c_rarg1, "smashed arg");
184 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
185 } else {
186 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
187 }
188
189 __ pop(saved, sp);
190
191 __ bind(done);
192 }
193
194 void ShenandoahBarrierSetAssembler::read_barrier(MacroAssembler* masm, Register dst) {
195 if (ShenandoahReadBarrier) {
196 read_barrier_impl(masm, dst);
197 }
198 }
199
200 void ShenandoahBarrierSetAssembler::read_barrier_impl(MacroAssembler* masm, Register dst) {
201 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier || ShenandoahCASBarrier), "should be enabled");
202 Label is_null;
203 __ cbz(dst, is_null);
204 read_barrier_not_null_impl(masm, dst);
205 __ bind(is_null);
206 }
207
208 void ShenandoahBarrierSetAssembler::read_barrier_not_null(MacroAssembler* masm, Register dst) {
209 if (ShenandoahReadBarrier) {
210 read_barrier_not_null_impl(masm, dst);
211 }
212 }
213
214
215 void ShenandoahBarrierSetAssembler::read_barrier_not_null_impl(MacroAssembler* masm, Register dst) {
216 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier || ShenandoahCASBarrier), "should be enabled");
217 __ ldr(dst, Address(dst, BrooksPointer::byte_offset()));
218 }
219
220 void ShenandoahBarrierSetAssembler::write_barrier(MacroAssembler* masm, Register dst) {
221 if (ShenandoahWriteBarrier) {
222 write_barrier_impl(masm, dst);
223 }
224 }
225
226 void ShenandoahBarrierSetAssembler::write_barrier_impl(MacroAssembler* masm, Register dst) {
227 assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier), "Should be enabled");
228 assert(dst != rscratch1, "need rscratch1");
229 assert(dst != rscratch2, "need rscratch2");
230
231 Label done;
232
233 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
234 __ ldrb(rscratch1, gc_state);
235
236 // Check for heap stability
237 __ mov(rscratch2, ShenandoahHeap::HAS_FORWARDED | ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
238 __ tst(rscratch1, rscratch2);
239 __ br(Assembler::EQ, done);
240
241 // Heap is unstable, need to perform the read-barrier even if WB is inactive
242 if (ShenandoahWriteBarrierRB) {
243 __ ldr(dst, Address(dst, BrooksPointer::byte_offset()));
244 }
245
246 // Check for evacuation-in-progress and jump to WB slow-path if needed
247 __ mov(rscratch2, ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
248 __ tst(rscratch1, rscratch2);
249 __ br(Assembler::EQ, done);
250
251 RegSet to_save = RegSet::of(r0);
252 if (dst != r0) {
253 __ push(to_save, sp);
254 __ mov(r0, dst);
255 }
256
257 __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_wb())));
258
259 if (dst != r0) {
260 __ mov(dst, r0);
261 __ pop(to_save, sp);
262 }
263
264 __ bind(done);
265 }
266
267 void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) {
268 if (ShenandoahStoreValEnqueueBarrier) {
269 Label is_null;
270 __ cbz(dst, is_null);
271 write_barrier_impl(masm, dst);
272 __ bind(is_null);
273 // Save possibly live regs.
274 RegSet live_regs = RegSet::range(r0, r4) - dst;
275 __ push(live_regs, sp);
276 __ strd(v0, __ pre(sp, 2 * -wordSize));
277
278 satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false);
279
280 // Restore possibly live regs.
281 __ ldrd(v0, __ post(sp, 2 * wordSize));
282 __ pop(live_regs, sp);
283 }
284 if (ShenandoahStoreValReadBarrier) {
285 read_barrier_impl(masm, dst);
286 }
287 }
288
289 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
290 Register dst, Address src, Register tmp1, Register tmp_thread) {
291 bool on_oop = type == T_OBJECT || type == T_ARRAY;
292 bool in_heap = (decorators & IN_HEAP) != 0;
293 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
294 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
295 bool on_reference = on_weak || on_phantom;
296
297 if (in_heap) {
298 read_barrier_not_null(masm, src.base());
299 }
300
301 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
302 if (ShenandoahKeepAliveBarrier && on_oop && on_reference) {
303 __ enter();
304 satb_write_barrier_pre(masm /* masm */,
305 noreg /* obj */,
306 dst /* pre_val */,
307 rthread /* thread */,
308 tmp1 /* tmp */,
309 true /* tosca_live */,
310 true /* expand_call */);
311 __ leave();
312 }
313 }
314
315 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
316 Address dst, Register val, Register tmp1, Register tmp2) {
317 bool on_oop = type == T_OBJECT || type == T_ARRAY;
318 bool in_heap = (decorators & IN_HEAP) != 0;
319 if (in_heap) {
320 write_barrier(masm, dst.base());
321 }
322 if (!on_oop) {
323 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2);
324 return;
325 }
326
327 // flatten object address if needed
328 if (dst.index() == noreg && dst.offset() == 0) {
329 if (dst.base() != r3) {
330 __ mov(r3, dst.base());
331 }
332 } else {
333 __ lea(r3, dst);
334 }
335
336 shenandoah_write_barrier_pre(masm,
337 r3 /* obj */,
338 tmp2 /* pre_val */,
339 rthread /* thread */,
340 tmp1 /* tmp */,
341 val != noreg /* tosca_live */,
342 false /* expand_call */);
343
344 if (val == noreg) {
345 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg);
346 } else {
347 storeval_barrier(masm, val, tmp1);
348 // G1 barrier needs uncompressed oop for region cross check.
349 Register new_val = val;
350 if (UseCompressedOops) {
351 new_val = rscratch2;
352 __ mov(new_val, val);
353 }
354 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg);
355 }
356
357 }
358
359 void ShenandoahBarrierSetAssembler::obj_equals(MacroAssembler* masm, Register op1, Register op2) {
360 __ cmp(op1, op2);
361 if (ShenandoahAcmpBarrier) {
362 Label done;
363 __ br(Assembler::EQ, done);
364 // The object may have been evacuated, but we won't see it without a
365 // membar here.
366 __ membar(Assembler::LoadStore| Assembler::LoadLoad);
367 read_barrier(masm, op1);
368 read_barrier(masm, op2);
369 __ cmp(op1, op2);
370 __ bind(done);
371 }
372 }
373
374 void ShenandoahBarrierSetAssembler::tlab_allocate(MacroAssembler* masm, Register obj,
375 Register var_size_in_bytes,
376 int con_size_in_bytes,
377 Register t1,
378 Register t2,
379 Label& slow_case) {
380
381 assert_different_registers(obj, t2);
382 assert_different_registers(obj, var_size_in_bytes);
383 Register end = t2;
384
385 int oop_extra_words = Universe::heap()->oop_extra_words();
386
387 __ ldr(obj, Address(rthread, JavaThread::tlab_top_offset()));
388 if (var_size_in_bytes == noreg) {
389 __ lea(end, Address(obj, (int) (con_size_in_bytes + BrooksPointer::byte_size())));
390 } else {
391 __ add(var_size_in_bytes, var_size_in_bytes, BrooksPointer::byte_size());
392 __ lea(end, Address(obj, var_size_in_bytes));
393 }
394 __ ldr(rscratch1, Address(rthread, JavaThread::tlab_end_offset()));
395 __ cmp(end, rscratch1);
396 __ br(Assembler::HI, slow_case);
397
398 // update the tlab top pointer
399 __ str(end, Address(rthread, JavaThread::tlab_top_offset()));
400
401 __ add(obj, obj, BrooksPointer::byte_size());
402 __ str(obj, Address(obj, BrooksPointer::byte_offset()));
403
404 // recover var_size_in_bytes if necessary
405 if (var_size_in_bytes == end) {
406 __ sub(var_size_in_bytes, var_size_in_bytes, obj);
407 }
408 }
409
410 void ShenandoahBarrierSetAssembler::resolve(MacroAssembler* masm, DecoratorSet decorators, Register obj) {
411 bool oop_not_null = (decorators & IS_NOT_NULL) != 0;
412 bool is_write = (decorators & ACCESS_WRITE) != 0;
413 if (is_write) {
414 if (oop_not_null) {
415 write_barrier(masm, obj);
416 } else {
417 Label done;
418 __ cbz(obj, done);
419 write_barrier(masm, obj);
420 __ bind(done);
421 }
422 } else {
423 if (oop_not_null) {
424 read_barrier_not_null(masm, obj);
425 } else {
426 read_barrier(masm, obj);
427 }
428 }
429 }
430
431 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val,
432 bool acquire, bool release, bool weak, bool encode,
433 Register tmp1, Register tmp2, Register tmp3,
434 Register result) {
435
436 if (!ShenandoahCASBarrier) {
437 if (UseCompressedOops) {
438 if (encode) {
439 __ encode_heap_oop(tmp1, expected);
440 expected = tmp1;
441 __ encode_heap_oop(tmp3, new_val);
442 new_val = tmp3;
443 }
444 __ cmpxchg(addr, expected, new_val, Assembler::word, /* acquire*/ true, /* release*/ true, /* weak*/ false, rscratch1);
445 __ membar(__ AnyAny);
446 } else {
447 __ cmpxchg(addr, expected, new_val, Assembler::xword, /* acquire*/ true, /* release*/ true, /* weak*/ false, rscratch1);
448 __ membar(__ AnyAny);
449 }
450 return;
451 }
452
453 if (encode) {
454 storeval_barrier(masm, new_val, tmp3);
455 }
456
457 if (UseCompressedOops) {
458 if (encode) {
459 __ encode_heap_oop(tmp1, expected);
460 expected = tmp1;
461 __ encode_heap_oop(tmp2, new_val);
462 new_val = tmp2;
463 }
464 }
465 bool is_cae = (result != noreg);
466 bool is_narrow = UseCompressedOops;
467 Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword;
468 if (! is_cae) result = rscratch1;
469
470 assert_different_registers(addr, expected, new_val, result, tmp3);
471
472 Label retry, done, fail;
473
474 // CAS, using LL/SC pair.
475 __ bind(retry);
476 __ load_exclusive(result, addr, size, acquire);
477 if (is_narrow) {
478 __ cmpw(result, expected);
479 } else {
480 __ cmp(result, expected);
481 }
482 __ br(Assembler::NE, fail);
483 __ store_exclusive(tmp3, new_val, addr, size, release);
484 if (weak) {
485 __ cmpw(tmp3, 0u); // If the store fails, return NE to our caller
486 } else {
487 __ cbnzw(tmp3, retry);
488 }
489 __ b(done);
490
491 __ bind(fail);
492 // Check if rb(expected)==rb(result)
493 // Shuffle registers so that we have memory value ready for next expected.
494 __ mov(tmp3, expected);
495 __ mov(expected, result);
496 if (is_narrow) {
497 __ decode_heap_oop(result, result);
498 __ decode_heap_oop(tmp3, tmp3);
499 }
500 read_barrier_impl(masm, result);
501 read_barrier_impl(masm, tmp3);
502 __ cmp(result, tmp3);
503 // Retry with expected now being the value we just loaded from addr.
504 __ br(Assembler::EQ, retry);
505 if (is_narrow && is_cae) {
506 // For cmp-and-exchange and narrow oops, we need to restore
507 // the compressed old-value. We moved it to 'expected' a few lines up.
508 __ mov(result, expected);
509 }
510 __ bind(done);
511
512 }
513
514 #ifdef COMPILER1
515
516 #undef __
517 #define __ ce->masm()->
518
519 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) {
520 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
521 // At this point we know that marking is in progress.
522 // If do_load() is true then we have to emit the
523 // load of the previous value; otherwise it has already
524 // been loaded into _pre_val.
525
526 __ bind(*stub->entry());
527
528 assert(stub->pre_val()->is_register(), "Precondition.");
529
530 Register pre_val_reg = stub->pre_val()->as_register();
531
532 if (stub->do_load()) {
533 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/);
534 }
535 __ cbz(pre_val_reg, *stub->continuation());
536 ce->store_parameter(stub->pre_val()->as_register(), 0);
537 __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
538 __ b(*stub->continuation());
539 }
540
541 void ShenandoahBarrierSetAssembler::gen_write_barrier_stub(LIR_Assembler* ce, ShenandoahWriteBarrierStub* stub) {
542
543 Register obj = stub->obj()->as_register();
544 Register res = stub->result()->as_register();
545
546 Label done;
547
548 __ bind(*stub->entry());
549
550 if (res != obj) {
551 __ mov(res, obj);
552 }
553 // Check for null.
554 if (stub->needs_null_check()) {
555 __ cbz(res, done);
556 }
557
558 write_barrier(ce->masm(), res);
559
560 __ bind(done);
561 __ b(*stub->continuation());
562 }
563
564 #undef __
565
566 #define __ sasm->
567
568 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
569 __ prologue("shenandoah_pre_barrier", false);
570
571 // arg0 : previous value of memory
572
573 BarrierSet* bs = BarrierSet::barrier_set();
574
575 const Register pre_val = r0;
576 const Register thread = rthread;
577 const Register tmp = rscratch1;
578
579 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
580 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
581
582 Label done;
583 Label runtime;
584
585 // Is marking still active?
586 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
587 __ ldrb(tmp, gc_state);
588 __ mov(rscratch2, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL);
589 __ tst(tmp, rscratch2);
590 __ br(Assembler::EQ, done);
591
592 // Can we store original value in the thread's buffer?
593 __ ldr(tmp, queue_index);
594 __ cbz(tmp, runtime);
595
596 __ sub(tmp, tmp, wordSize);
597 __ str(tmp, queue_index);
598 __ ldr(rscratch2, buffer);
599 __ add(tmp, tmp, rscratch2);
600 __ load_parameter(0, rscratch2);
601 __ str(rscratch2, Address(tmp, 0));
602 __ b(done);
603
604 __ bind(runtime);
605 __ push_call_clobbered_registers();
606 __ load_parameter(0, pre_val);
607 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
608 __ pop_call_clobbered_registers();
609 __ bind(done);
610
611 __ epilogue();
612 }
613
614 #undef __
615
616 #endif // COMPILER1
617
618 address ShenandoahBarrierSetAssembler::shenandoah_wb() {
619 assert(_shenandoah_wb != NULL, "need write barrier stub");
620 return _shenandoah_wb;
621 }
622
623 address ShenandoahBarrierSetAssembler::shenandoah_wb_C() {
624 assert(_shenandoah_wb_C != NULL, "need write barrier stub");
625 return _shenandoah_wb_C;
626 }
627
628 #define __ cgen->assembler()->
629
630 // Shenandoah write barrier.
631 //
632 // Input:
633 // r0: OOP to evacuate. Not null.
634 //
635 // Output:
636 // r0: Pointer to evacuated OOP.
637 //
638 // Trash rscratch1, rscratch2. Preserve everything else.
639 address ShenandoahBarrierSetAssembler::generate_shenandoah_wb(StubCodeGenerator* cgen, bool c_abi, bool do_cset_test) {
640
641 __ align(6);
642 StubCodeMark mark(cgen, "StubRoutines", "shenandoah_wb");
643 address start = __ pc();
644
645 if (do_cset_test) {
646 Label work;
647 __ mov(rscratch2, ShenandoahHeap::in_cset_fast_test_addr());
648 __ lsr(rscratch1, r0, ShenandoahHeapRegion::region_size_bytes_shift_jint());
649 __ ldrb(rscratch2, Address(rscratch2, rscratch1));
650 __ tbnz(rscratch2, 0, work);
651 __ ret(lr);
652 __ bind(work);
653 }
654
655 Register obj = r0;
656
657 __ enter(); // required for proper stackwalking of RuntimeStub frame
658
659 if (!c_abi) {
660 __ push_call_clobbered_registers();
661 } else {
662 __ push_call_clobbered_fp_registers();
663 }
664
665 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_JRT));
666 __ blrt(lr, 1, 0, MacroAssembler::ret_type_integral);
667 if (!c_abi) {
668 __ mov(rscratch1, obj);
669 __ pop_call_clobbered_registers();
670 __ mov(obj, rscratch1);
671 } else {
672 __ pop_call_clobbered_fp_registers();
673 }
674
675 __ leave(); // required for proper stackwalking of RuntimeStub frame
676 __ ret(lr);
677
678 return start;
679 }
680
681 #undef __
682
683 void ShenandoahBarrierSetAssembler::barrier_stubs_init() {
684 if (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier) {
685 int stub_code_size = 2048;
686 ResourceMark rm;
687 BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size);
688 CodeBuffer buf(bb);
689 StubCodeGenerator cgen(&buf);
690 _shenandoah_wb = generate_shenandoah_wb(&cgen, false, true);
691 _shenandoah_wb_C = generate_shenandoah_wb(&cgen, true, !ShenandoahWriteBarrierCsetTestInIR);
692 }
693 }