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/shenandoahConnectionMatrix.hpp"
28 #include "gc/shenandoah/shenandoahHeap.hpp"
29 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
30 #include "gc/shenandoah/shenandoahHeuristics.hpp"
31 #include "gc/shenandoah/shenandoahRuntime.hpp"
32 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "interpreter/interp_masm.hpp"
35 #include "runtime/sharedRuntime.hpp"
36 #include "runtime/thread.hpp"
37 #ifdef COMPILER1
38 #include "c1/c1_LIRAssembler.hpp"
39 #include "c1/c1_MacroAssembler.hpp"
40 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
41 #endif
42
43 #define __ masm->
44
45 address ShenandoahBarrierSetAssembler::_shenandoah_wb = NULL;
46 address ShenandoahBarrierSetAssembler::_shenandoah_wb_C = NULL;
47
48 void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
49 Register addr, Register count, RegSet saved_regs) {
50 if (is_oop) {
51 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
52 if (!dest_uninitialized && !ShenandoahHeap::heap()->heuristics()->can_do_traversal_gc()) {
53 __ push(saved_regs, sp);
54 if (count == c_rarg0) {
55 if (addr == c_rarg1) {
56 // exactly backwards!!
57 __ mov(rscratch1, c_rarg0);
58 __ mov(c_rarg0, c_rarg1);
59 __ mov(c_rarg1, rscratch1);
60 } else {
61 __ mov(c_rarg1, count);
62 __ mov(c_rarg0, addr);
63 }
64 } else {
65 __ mov(c_rarg0, addr);
66 __ mov(c_rarg1, count);
67 }
68 if (UseCompressedOops) {
69 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry), 2);
70 } else {
71 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry), 2);
72 }
73 __ pop(saved_regs, sp);
74 }
75 }
76 }
77
78 void ShenandoahBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
79 Register start, Register end, Register scratch, RegSet saved_regs) {
80 if (is_oop) {
81 __ push(saved_regs, sp);
82 // must compute element count unless barrier set interface is changed (other platforms supply count)
83 assert_different_registers(start, end, scratch);
84 __ lea(scratch, Address(end, BytesPerHeapOop));
85 __ sub(scratch, scratch, start); // subtract start to get #bytes
86 __ lsr(scratch, scratch, LogBytesPerHeapOop); // convert to element count
87 __ mov(c_rarg0, start);
88 __ mov(c_rarg1, scratch);
89 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_post_entry), 2);
90 __ pop(saved_regs, sp);
91 }
92 }
93
94 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm,
95 Register obj,
96 Register pre_val,
97 Register thread,
98 Register tmp,
99 bool tosca_live,
100 bool expand_call) {
101 if (ShenandoahSATBBarrier) {
102 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call);
103 }
104 }
105
106 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm,
107 Register obj,
108 Register pre_val,
109 Register thread,
110 Register tmp,
111 bool tosca_live,
112 bool expand_call) {
113 // If expand_call is true then we expand the call_VM_leaf macro
114 // directly to skip generating the check by
115 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
116
117 assert(thread == rthread, "must be");
118
119 Label done;
120 Label runtime;
121
122 assert_different_registers(obj, pre_val, tmp, rscratch1);
123 assert(pre_val != noreg && tmp != noreg, "expecting a register");
124
125 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()));
126 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
127 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
128
129 // Is marking active?
130 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
131 __ ldrw(tmp, in_progress);
132 } else {
133 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
134 __ ldrb(tmp, in_progress);
135 }
136 __ cbzw(tmp, done);
137
138 // Do we need to load the previous value?
139 if (obj != noreg) {
140 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW);
141 }
142
143 // Is the previous value null?
144 __ cbz(pre_val, done);
145
146 // Can we store original value in the thread's buffer?
147 // Is index == 0?
148 // (The index field is typed as size_t.)
149
150 __ ldr(tmp, index); // tmp := *index_adr
151 __ cbz(tmp, runtime); // tmp == 0?
152 // If yes, goto runtime
153
154 __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize
155 __ str(tmp, index); // *index_adr := tmp
156 __ ldr(rscratch1, buffer);
157 __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr
158
159 // Record the previous value
160 __ str(pre_val, Address(tmp, 0));
161 __ b(done);
162
163 __ bind(runtime);
164 // save the live input values
165 RegSet saved = RegSet::of(pre_val);
166 if (tosca_live) saved += RegSet::of(r0);
167 if (obj != noreg) saved += RegSet::of(obj);
168
169 __ push(saved, sp);
170
171 // Calling the runtime using the regular call_VM_leaf mechanism generates
172 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
173 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
174 //
175 // If we care generating the pre-barrier without a frame (e.g. in the
176 // intrinsified Reference.get() routine) then ebp might be pointing to
177 // the caller frame and so this check will most likely fail at runtime.
178 //
179 // Expanding the call directly bypasses the generation of the check.
180 // So when we do not have have a full interpreter frame on the stack
181 // expand_call should be passed true.
182
183 if (expand_call) {
184 assert(pre_val != c_rarg1, "smashed arg");
185 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
186 } else {
187 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
188 }
189
190 __ pop(saved, sp);
191
192 __ bind(done);
193 }
194
195 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_post(MacroAssembler* masm,
196 Register store_addr,
197 Register new_val,
198 Register thread,
199 Register tmp,
200 Register tmp2) {
201 assert(thread == rthread, "must be");
202 assert(UseShenandoahGC, "expect Shenandoah GC");
203
204 if (! UseShenandoahMatrix) {
205 // No need for that barrier if not using matrix.
206 return;
207 }
208
209 assert_different_registers(store_addr, new_val, thread, tmp, tmp2, rscratch1);
210
211 Label done;
212 __ cbz(new_val, done);
213
214 ShenandoahConnectionMatrix* matrix = ShenandoahHeap::heap()->connection_matrix();
215
216 // Compute to-region index
217 __ lsr(tmp, new_val, ShenandoahHeapRegion::region_size_bytes_shift_jint());
218
219 // Compute from-region index
220 __ lsr(tmp2, store_addr, ShenandoahHeapRegion::region_size_bytes_shift_jint());
221
222 // Compute matrix index
223 __ mov(rscratch1, matrix->stride_jint());
224 // Address is _matrix[to * stride + from]
225 __ madd(tmp, tmp, rscratch1, tmp2);
226 __ mov(rscratch1, matrix->magic_offset());
227 Address loc(tmp, rscratch1);
228
229 __ ldrb(tmp2, loc);
230 __ cbnz(tmp2, done);
231 __ mov(tmp2, 1);
232 __ strb(tmp2, loc);
233 __ bind(done);
234 }
235
236 void ShenandoahBarrierSetAssembler::read_barrier(MacroAssembler* masm, Register dst) {
237 if (ShenandoahReadBarrier) {
238 read_barrier_impl(masm, dst);
239 }
240 }
241
242 void ShenandoahBarrierSetAssembler::read_barrier_impl(MacroAssembler* masm, Register dst) {
243 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier), "should be enabled");
244 Label is_null;
245 __ cbz(dst, is_null);
246 read_barrier_not_null_impl(masm, dst);
247 __ bind(is_null);
248 }
249
250 void ShenandoahBarrierSetAssembler::read_barrier_not_null(MacroAssembler* masm, Register dst) {
251 if (ShenandoahReadBarrier) {
252 read_barrier_not_null_impl(masm, dst);
253 }
254 }
255
256
257 void ShenandoahBarrierSetAssembler::read_barrier_not_null_impl(MacroAssembler* masm, Register dst) {
258 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier), "should be enabled");
259 __ ldr(dst, Address(dst, BrooksPointer::byte_offset()));
260 }
261
262 void ShenandoahBarrierSetAssembler::write_barrier(MacroAssembler* masm, Register dst) {
263 if (ShenandoahWriteBarrier) {
264 write_barrier_impl(masm, dst);
265 }
266 }
267
268 void ShenandoahBarrierSetAssembler::write_barrier_impl(MacroAssembler* masm, Register dst) {
269 assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier), "Should be enabled");
270 assert(dst != rscratch1, "need rscratch1");
271 assert(dst != rscratch2, "need rscratch2");
272
273 Label done;
274
275 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
276 __ ldrb(rscratch1, gc_state);
277
278 // Check for heap stability
279 __ mov(rscratch2, ShenandoahHeap::HAS_FORWARDED | ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
280 __ tst(rscratch1, rscratch2);
281 __ br(Assembler::EQ, done);
282
283 // Heap is unstable, need to perform the read-barrier even if WB is inactive
284 if (ShenandoahWriteBarrierRB) {
285 __ ldr(dst, Address(dst, BrooksPointer::byte_offset()));
286 }
287
288 // Check for evacuation-in-progress and jump to WB slow-path if needed
289 __ mov(rscratch2, ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
290 __ tst(rscratch1, rscratch2);
291 __ br(Assembler::EQ, done);
292
293 RegSet to_save = RegSet::of(r0);
294 if (dst != r0) {
295 __ push(to_save, sp);
296 __ mov(r0, dst);
297 }
298
299 __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_wb())));
300
301 if (dst != r0) {
302 __ mov(dst, r0);
303 __ pop(to_save, sp);
304 }
305
306 __ bind(done);
307 }
308
309 void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) {
310 if (ShenandoahStoreValEnqueueBarrier) {
311 Label is_null;
312 __ cbz(dst, is_null);
313 write_barrier_impl(masm, dst);
314 __ bind(is_null);
315 // Save possibly live regs.
316 RegSet live_regs = RegSet::range(r0, r4) - dst;
317 __ push(live_regs, sp);
318 __ strd(v0, __ pre(sp, 2 * -wordSize));
319
320 satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false);
321
322 // Restore possibly live regs.
323 __ ldrd(v0, __ post(sp, 2 * wordSize));
324 __ pop(live_regs, sp);
325 }
326 if (ShenandoahStoreValReadBarrier) {
327 read_barrier_impl(masm, dst);
328 }
329 }
330
331 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
332 Register dst, Address src, Register tmp1, Register tmp_thread) {
333 bool on_oop = type == T_OBJECT || type == T_ARRAY;
334 bool in_heap = (decorators & IN_HEAP) != 0;
335 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
336 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
337 bool on_reference = on_weak || on_phantom;
338
339 if (in_heap) {
340 read_barrier_not_null(masm, src.base());
341 }
342
343 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
344 if (ShenandoahKeepAliveBarrier && on_oop && on_reference) {
345 __ enter();
346 satb_write_barrier_pre(masm /* masm */,
347 noreg /* obj */,
348 dst /* pre_val */,
349 rthread /* thread */,
350 tmp1 /* tmp */,
351 true /* tosca_live */,
352 true /* expand_call */);
353 __ leave();
354 }
355 }
356
357 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
358 Address dst, Register val, Register tmp1, Register tmp2) {
359 bool on_oop = type == T_OBJECT || type == T_ARRAY;
360 bool in_heap = (decorators & IN_HEAP) != 0;
361 if (in_heap) {
362 write_barrier(masm, dst.base());
363 }
364 if (!on_oop) {
365 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2);
366 return;
367 }
368
369 // flatten object address if needed
370 if (dst.index() == noreg && dst.offset() == 0) {
371 if (dst.base() != r3) {
372 __ mov(r3, dst.base());
373 }
374 } else {
375 __ lea(r3, dst);
376 }
377
378 shenandoah_write_barrier_pre(masm,
379 r3 /* obj */,
380 tmp2 /* pre_val */,
381 rthread /* thread */,
382 tmp1 /* tmp */,
383 val != noreg /* tosca_live */,
384 false /* expand_call */);
385
386 if (val == noreg) {
387 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg);
388 } else {
389 storeval_barrier(masm, val, tmp1);
390 // G1 barrier needs uncompressed oop for region cross check.
391 Register new_val = val;
392 if (UseCompressedOops) {
393 new_val = rscratch2;
394 __ mov(new_val, val);
395 }
396 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg);
397 shenandoah_write_barrier_post(masm,
398 r3 /* store_adr */,
399 new_val /* new_val */,
400 rthread /* thread */,
401 tmp1 /* tmp */,
402 tmp2 /* tmp2 */);
403 }
404
405 }
406
407 void ShenandoahBarrierSetAssembler::obj_equals(MacroAssembler* masm, Register op1, Register op2) {
408 __ cmp(op1, op2);
409 if (ShenandoahAcmpBarrier) {
410 Label done;
411 __ br(Assembler::EQ, done);
412 // The object may have been evacuated, but we won't see it without a
413 // membar here.
414 __ membar(Assembler::LoadStore| Assembler::LoadLoad);
415 read_barrier(masm, op1);
416 read_barrier(masm, op2);
417 __ cmp(op1, op2);
418 __ bind(done);
419 }
420 }
421
422 void ShenandoahBarrierSetAssembler::tlab_allocate(MacroAssembler* masm, Register obj,
423 Register var_size_in_bytes,
424 int con_size_in_bytes,
425 Register t1,
426 Register t2,
427 Label& slow_case) {
428
429 assert_different_registers(obj, t2);
430 assert_different_registers(obj, var_size_in_bytes);
431 Register end = t2;
432
433 int oop_extra_words = Universe::heap()->oop_extra_words();
434
435 __ ldr(obj, Address(rthread, JavaThread::tlab_top_offset()));
436 if (var_size_in_bytes == noreg) {
437 __ lea(end, Address(obj, (int) (con_size_in_bytes + BrooksPointer::byte_size())));
438 } else {
439 __ add(var_size_in_bytes, var_size_in_bytes, BrooksPointer::byte_size());
440 __ lea(end, Address(obj, var_size_in_bytes));
441 }
442 __ ldr(rscratch1, Address(rthread, JavaThread::tlab_end_offset()));
443 __ cmp(end, rscratch1);
444 __ br(Assembler::HI, slow_case);
445
446 // update the tlab top pointer
447 __ str(end, Address(rthread, JavaThread::tlab_top_offset()));
448
449 __ add(obj, obj, BrooksPointer::byte_size());
450 __ str(obj, Address(obj, BrooksPointer::byte_offset()));
451
452 // recover var_size_in_bytes if necessary
453 if (var_size_in_bytes == end) {
454 __ sub(var_size_in_bytes, var_size_in_bytes, obj);
455 }
456 }
457
458 void ShenandoahBarrierSetAssembler::resolve_for_read(MacroAssembler* masm, DecoratorSet decorators, Register obj) {
459 bool oop_not_null = (decorators & IS_NOT_NULL) != 0;
460 if (oop_not_null) {
461 read_barrier_not_null(masm, obj);
462 } else {
463 read_barrier(masm, obj);
464 }
465 }
466
467 void ShenandoahBarrierSetAssembler::resolve_for_write(MacroAssembler* masm, DecoratorSet decorators, Register obj) {
468 bool oop_not_null = (decorators & IS_NOT_NULL) != 0;
469 if (oop_not_null) {
470 write_barrier(masm, obj);
471 } else {
472 Label is_null;
473 __ cbz(obj, is_null);
474 write_barrier(masm, obj);
475 __ bind(is_null);
476 }
477 }
478
479 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val,
480 bool acquire, bool release, bool weak, bool encode,
481 Register tmp1, Register tmp2, Register tmp3,
482 Register result) {
483
484 if (encode) {
485 storeval_barrier(masm, new_val, tmp3);
486 }
487
488 if (UseCompressedOops) {
489 if (encode) {
490 __ encode_heap_oop(tmp1, expected);
491 expected = tmp1;
492 __ encode_heap_oop(tmp2, new_val);
493 new_val = tmp2;
494 }
495 }
496 bool is_cae = (result != noreg);
497 bool is_narrow = UseCompressedOops;
498 Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword;
499 if (! is_cae) result = rscratch1;
500
501 assert_different_registers(addr, expected, new_val, result, tmp3);
502
503 Label retry, done, fail;
504
505 // CAS, using LL/SC pair.
506 __ bind(retry);
507 __ load_exclusive(result, addr, size, acquire);
508 if (is_narrow) {
509 __ cmpw(result, expected);
510 } else {
511 __ cmp(result, expected);
512 }
513 __ br(Assembler::NE, fail);
514 __ store_exclusive(tmp3, new_val, addr, size, release);
515 if (weak) {
516 __ cmpw(tmp3, 0u); // If the store fails, return NE to our caller
517 } else {
518 __ cbnzw(tmp3, retry);
519 }
520 __ b(done);
521
522 __ bind(fail);
523 // Check if rb(expected)==rb(result)
524 // Shuffle registers so that we have memory value ready for next expected.
525 __ mov(tmp3, expected);
526 __ mov(expected, result);
527 if (is_narrow) {
528 __ decode_heap_oop(result, result);
529 __ decode_heap_oop(tmp3, tmp3);
530 }
531 __ resolve_for_read(0, result);
532 __ resolve_for_read(0, tmp3);
533 __ cmp(result, tmp3);
534 // Retry with expected now being the value we just loaded from addr.
535 __ br(Assembler::EQ, retry);
536 if (is_narrow && is_cae) {
537 // For cmp-and-exchange and narrow oops, we need to restore
538 // the compressed old-value. We moved it to 'expected' a few lines up.
539 __ mov(result, expected);
540 }
541 __ bind(done);
542
543 }
544
545 #ifdef COMPILER1
546
547 #undef __
548 #define __ ce->masm()->
549
550 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) {
551 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
552 // At this point we know that marking is in progress.
553 // If do_load() is true then we have to emit the
554 // load of the previous value; otherwise it has already
555 // been loaded into _pre_val.
556
557 __ bind(*stub->entry());
558
559 assert(stub->pre_val()->is_register(), "Precondition.");
560
561 Register pre_val_reg = stub->pre_val()->as_register();
562
563 if (stub->do_load()) {
564 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/);
565 }
566 __ cbz(pre_val_reg, *stub->continuation());
567 ce->store_parameter(stub->pre_val()->as_register(), 0);
568 __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
569 __ b(*stub->continuation());
570 }
571
572 void ShenandoahBarrierSetAssembler::gen_write_barrier_stub(LIR_Assembler* ce, ShenandoahWriteBarrierStub* stub) {
573
574 Register obj = stub->obj()->as_register();
575 Register res = stub->result()->as_register();
576
577 Label done;
578
579 __ bind(*stub->entry());
580
581 if (res != obj) {
582 __ mov(res, obj);
583 }
584 // Check for null.
585 if (stub->needs_null_check()) {
586 __ cbz(res, done);
587 }
588
589 write_barrier(ce->masm(), res);
590
591 __ bind(done);
592 __ b(*stub->continuation());
593 }
594
595 #undef __
596
597 #define __ sasm->
598
599 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
600 __ prologue("shenandoah_pre_barrier", false);
601
602 // arg0 : previous value of memory
603
604 BarrierSet* bs = BarrierSet::barrier_set();
605
606 const Register pre_val = r0;
607 const Register thread = rthread;
608 const Register tmp = rscratch1;
609
610 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
611 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
612
613 Label done;
614 Label runtime;
615
616 // Is marking still active?
617 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
618 __ ldrb(tmp, gc_state);
619 __ mov(rscratch2, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL);
620 __ tst(tmp, rscratch2);
621 __ br(Assembler::EQ, done);
622
623 // Can we store original value in the thread's buffer?
624 __ ldr(tmp, queue_index);
625 __ cbz(tmp, runtime);
626
627 __ sub(tmp, tmp, wordSize);
628 __ str(tmp, queue_index);
629 __ ldr(rscratch2, buffer);
630 __ add(tmp, tmp, rscratch2);
631 __ load_parameter(0, rscratch2);
632 __ str(rscratch2, Address(tmp, 0));
633 __ b(done);
634
635 __ bind(runtime);
636 __ push_call_clobbered_registers();
637 __ load_parameter(0, pre_val);
638 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
639 __ pop_call_clobbered_registers();
640 __ bind(done);
641
642 __ epilogue();
643 }
644
645 #undef __
646
647 #endif // COMPILER1
648
649 address ShenandoahBarrierSetAssembler::shenandoah_wb() {
650 assert(_shenandoah_wb != NULL, "need write barrier stub");
651 return _shenandoah_wb;
652 }
653
654 address ShenandoahBarrierSetAssembler::shenandoah_wb_C() {
655 assert(_shenandoah_wb_C != NULL, "need write barrier stub");
656 return _shenandoah_wb_C;
657 }
658
659 #define __ cgen->assembler()->
660
661 // Shenandoah write barrier.
662 //
663 // Input:
664 // r0: OOP to evacuate. Not null.
665 //
666 // Output:
667 // r0: Pointer to evacuated OOP.
668 //
669 // Trash rscratch1, rscratch2. Preserve everything else.
670 address ShenandoahBarrierSetAssembler::generate_shenandoah_wb(StubCodeGenerator* cgen, bool c_abi, bool do_cset_test) {
671
672 __ align(6);
673 StubCodeMark mark(cgen, "StubRoutines", "shenandoah_wb");
674 address start = __ pc();
675
676 if (do_cset_test) {
677 Label work;
678 __ mov(rscratch2, ShenandoahHeap::in_cset_fast_test_addr());
679 __ lsr(rscratch1, r0, ShenandoahHeapRegion::region_size_bytes_shift_jint());
680 __ ldrb(rscratch2, Address(rscratch2, rscratch1));
681 __ tbnz(rscratch2, 0, work);
682 __ ret(lr);
683 __ bind(work);
684 }
685
686 Register obj = r0;
687
688 __ enter(); // required for proper stackwalking of RuntimeStub frame
689
690 if (!c_abi) {
691 __ push_call_clobbered_registers();
692 } else {
693 __ push_call_clobbered_fp_registers();
694 }
695
696 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_JRT));
697 __ blrt(lr, 1, 0, MacroAssembler::ret_type_integral);
698 if (!c_abi) {
699 __ mov(rscratch1, obj);
700 __ pop_call_clobbered_registers();
701 __ mov(obj, rscratch1);
702 } else {
703 __ pop_call_clobbered_fp_registers();
704 }
705
706 __ leave(); // required for proper stackwalking of RuntimeStub frame
707 __ ret(lr);
708
709 return start;
710 }
711
712 #undef __
713
714 void ShenandoahBarrierSetAssembler::barrier_stubs_init() {
715 if (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier) {
716 int stub_code_size = 2048;
717 ResourceMark rm;
718 BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size);
719 CodeBuffer buf(bb);
720 StubCodeGenerator cgen(&buf);
721 _shenandoah_wb = generate_shenandoah_wb(&cgen, false, true);
722 _shenandoah_wb_C = generate_shenandoah_wb(&cgen, true, !ShenandoahWriteBarrierCsetTestInIR);
723 }
724 }