1 /*
2 * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
27 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
28 #include "gc/shenandoah/shenandoahForwarding.hpp"
29 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
30 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
31 #include "gc/shenandoah/shenandoahHeuristics.hpp"
32 #include "gc/shenandoah/shenandoahRuntime.hpp"
33 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "interpreter/interp_masm.hpp"
36 #include "runtime/sharedRuntime.hpp"
37 #include "runtime/thread.hpp"
38 #ifdef COMPILER1
39 #include "c1/c1_LIRAssembler.hpp"
40 #include "c1/c1_MacroAssembler.hpp"
41 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
42 #endif
43
44 #define __ masm->
45
46 address ShenandoahBarrierSetAssembler::_shenandoah_lrb = NULL;
47
48 void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
49 Register src, Register dst, Register count, RegSet saved_regs) {
50 if (is_oop) {
51 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
52 if ((ShenandoahSATBBarrier && !dest_uninitialized) || ShenandoahLoadRefBarrier) {
53
54 Label done;
55
56 // Avoid calling runtime if count == 0
57 __ cbz(count, done);
58
59 // Is marking active?
60 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
61 __ ldrb(rscratch1, gc_state);
62 if (dest_uninitialized) {
63 __ tbz(rscratch1, ShenandoahHeap::HAS_FORWARDED_BITPOS, done);
64 } else {
65 __ mov(rscratch2, ShenandoahHeap::HAS_FORWARDED | ShenandoahHeap::MARKING);
66 __ tst(rscratch1, rscratch2);
67 __ br(Assembler::EQ, done);
68 }
69
70 __ push(saved_regs, sp);
71 if (UseCompressedOops) {
72 if (dest_uninitialized) {
73 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_duinit_narrow_oop_entry), src, dst, count);
74 } else {
75 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry), src, dst, count);
76 }
77 } else {
78 if (dest_uninitialized) {
79 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_duinit_oop_entry), src, dst, count);
80 } else {
81 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry), src, dst, count);
82 }
83 }
84 __ pop(saved_regs, sp);
85 __ bind(done);
86 }
87 }
88 }
89
90 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm,
91 Register obj,
92 Register pre_val,
93 Register thread,
94 Register tmp,
95 bool tosca_live,
96 bool expand_call) {
97 if (ShenandoahSATBBarrier) {
98 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call);
99 }
100 }
101
102 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm,
103 Register obj,
104 Register pre_val,
105 Register thread,
106 Register tmp,
107 bool tosca_live,
108 bool expand_call) {
109 // If expand_call is true then we expand the call_VM_leaf macro
110 // directly to skip generating the check by
111 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
112
113 assert(thread == rthread, "must be");
114
115 Label done;
116 Label runtime;
117
118 assert_different_registers(obj, pre_val, tmp, rscratch1);
119 assert(pre_val != noreg && tmp != noreg, "expecting a register");
120
121 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()));
122 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
123 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
124
125 // Is marking active?
126 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
127 __ ldrw(tmp, in_progress);
128 } else {
129 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
130 __ ldrb(tmp, in_progress);
131 }
132 __ cbzw(tmp, done);
133
134 // Do we need to load the previous value?
135 if (obj != noreg) {
136 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW);
137 }
138
139 // Is the previous value null?
140 __ cbz(pre_val, done);
141
142 // Can we store original value in the thread's buffer?
143 // Is index == 0?
144 // (The index field is typed as size_t.)
145
146 __ ldr(tmp, index); // tmp := *index_adr
147 __ cbz(tmp, runtime); // tmp == 0?
148 // If yes, goto runtime
149
150 __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize
151 __ str(tmp, index); // *index_adr := tmp
152 __ ldr(rscratch1, buffer);
153 __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr
154
155 // Record the previous value
156 __ str(pre_val, Address(tmp, 0));
157 __ b(done);
158
159 __ bind(runtime);
160 // save the live input values
161 RegSet saved = RegSet::of(pre_val);
162 if (tosca_live) saved += RegSet::of(r0);
163 if (obj != noreg) saved += RegSet::of(obj);
164
165 __ push(saved, sp);
166
167 // Calling the runtime using the regular call_VM_leaf mechanism generates
168 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
169 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
170 //
171 // If we care generating the pre-barrier without a frame (e.g. in the
172 // intrinsified Reference.get() routine) then ebp might be pointing to
173 // the caller frame and so this check will most likely fail at runtime.
174 //
175 // Expanding the call directly bypasses the generation of the check.
176 // So when we do not have have a full interpreter frame on the stack
177 // expand_call should be passed true.
178
179 if (expand_call) {
180 assert(pre_val != c_rarg1, "smashed arg");
181 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
182 } else {
183 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
184 }
185
186 __ pop(saved, sp);
187
188 __ bind(done);
189 }
190
191 void ShenandoahBarrierSetAssembler::resolve_forward_pointer(MacroAssembler* masm, Register dst, Register tmp) {
192 assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled");
193 Label is_null;
194 __ cbz(dst, is_null);
195 resolve_forward_pointer_not_null(masm, dst, tmp);
196 __ bind(is_null);
197 }
198
199 // IMPORTANT: This must preserve all registers, even rscratch1 and rscratch2, except those explicitely
200 // passed in.
201 void ShenandoahBarrierSetAssembler::resolve_forward_pointer_not_null(MacroAssembler* masm, Register dst, Register tmp) {
202 assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled");
203 // The below loads the mark word, checks if the lowest two bits are
204 // set, and if so, clear the lowest two bits and copy the result
205 // to dst. Otherwise it leaves dst alone.
206 // Implementing this is surprisingly awkward. I do it here by:
207 // - Inverting the mark word
208 // - Test lowest two bits == 0
209 // - If so, set the lowest two bits
210 // - Invert the result back, and copy to dst
211
212 bool borrow_reg = (tmp == noreg);
213 if (borrow_reg) {
214 // No free registers available. Make one useful.
215 tmp = rscratch1;
216 if (tmp == dst) {
217 tmp = rscratch2;
218 }
219 __ push(RegSet::of(tmp), sp);
220 }
221
222 assert_different_registers(tmp, dst);
223
224 Label done;
225 __ ldr(tmp, Address(dst, oopDesc::mark_offset_in_bytes()));
226 __ eon(tmp, tmp, zr);
227 __ ands(zr, tmp, markWord::lock_mask_in_place);
228 __ br(Assembler::NE, done);
229 __ orr(tmp, tmp, markWord::marked_value);
230 __ eon(dst, tmp, zr);
231 __ bind(done);
232
233 if (borrow_reg) {
234 __ pop(RegSet::of(tmp), sp);
235 }
236 }
237
238 void ShenandoahBarrierSetAssembler::load_reference_barrier_not_null(MacroAssembler* masm, Register dst, Address load_addr) {
239 assert(ShenandoahLoadRefBarrier, "Should be enabled");
240 assert(dst != rscratch2, "need rscratch2");
241 assert_different_registers(load_addr.base(), load_addr.index(), rscratch1, rscratch2);
242
243 Label done;
244 __ enter();
245 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
246 __ ldrb(rscratch2, gc_state);
247
248 // Check for heap stability
249 __ tbz(rscratch2, ShenandoahHeap::HAS_FORWARDED_BITPOS, done);
250
251 // use r1 for load address
252 Register result_dst = dst;
253 if (dst == r1) {
254 __ mov(rscratch1, dst);
255 dst = rscratch1;
256 }
257
258 // Save r0 and r1, unless it is an output register
259 RegSet to_save = RegSet::of(r0, r1) - result_dst;
260 __ push(to_save, sp);
261 __ lea(r1, load_addr);
262 __ mov(r0, dst);
263
264 __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_lrb())));
265
266 __ mov(result_dst, r0);
267 __ pop(to_save, sp);
268
269 __ bind(done);
270 __ leave();
271 }
272
273 void ShenandoahBarrierSetAssembler::load_reference_barrier_native(MacroAssembler* masm, Register dst, Address load_addr) {
274 if (!ShenandoahLoadRefBarrier) {
275 return;
276 }
277
278 assert(dst != rscratch2, "need rscratch2");
279
280 Label is_null;
281 Label done;
282
283 __ block_comment("load_reference_barrier_native { ");
284
285 __ cbz(dst, is_null);
286
287 __ enter();
288
289 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
290 __ ldrb(rscratch2, gc_state);
291
292 // Check for heap in evacuation phase
293 __ tbz(rscratch2, ShenandoahHeap::EVACUATION_BITPOS, done);
294
295 __ mov(rscratch2, dst);
296 __ push_call_clobbered_registers();
297 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_native));
298 __ lea(r1, load_addr);
299 __ mov(r0, rscratch2);
300 __ blr(lr);
301 __ mov(rscratch2, r0);
302 __ pop_call_clobbered_registers();
303 __ mov(dst, rscratch2);
304
305 __ bind(done);
306 __ leave();
307 __ bind(is_null);
308 __ block_comment("} load_reference_barrier_native");
309 }
310
311 void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) {
312 if (ShenandoahStoreValEnqueueBarrier) {
313 // Save possibly live regs.
314 RegSet live_regs = RegSet::range(r0, r4) - dst;
315 __ push(live_regs, sp);
316 __ strd(v0, __ pre(sp, 2 * -wordSize));
317
318 satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false);
319
320 // Restore possibly live regs.
321 __ ldrd(v0, __ post(sp, 2 * wordSize));
322 __ pop(live_regs, sp);
323 }
324 }
325
326 void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm, Register dst, Address load_addr) {
327 if (ShenandoahLoadRefBarrier) {
328 Label is_null;
329 __ cbz(dst, is_null);
330 load_reference_barrier_not_null(masm, dst, load_addr);
331 __ bind(is_null);
332 }
333 }
334
335 //
336 // Arguments:
337 //
338 // Inputs:
339 // src: oop location to load from, might be clobbered
340 //
341 // Output:
342 // dst: oop loaded from src location
343 //
344 // Kill:
345 // rscratch1 (scratch reg)
346 //
347 // Alias:
348 // dst: rscratch1 (might use rscratch1 as temporary output register to avoid clobbering src)
349 //
350 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
351 Register dst, Address src, Register tmp1, Register tmp_thread) {
352 // 1: non-reference load, no additional barrier is needed
353 if (!is_reference_type(type)) {
354 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
355 return;
356 }
357
358 // 2: load a reference from src location and apply LRB if needed
359 if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) {
360 Register result_dst = dst;
361
362 // Preserve src location for LRB
363 if (dst == src.base() || dst == src.index()) {
364 dst = rscratch1;
365 }
366 assert_different_registers(dst, src.base(), src.index());
367
368 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
369
370 if (ShenandoahBarrierSet::use_load_reference_barrier_native(decorators, type)) {
371 load_reference_barrier_native(masm, dst, src);
372 } else {
373 load_reference_barrier(masm, dst, src);
374 }
375
376 if (dst != result_dst) {
377 __ mov(result_dst, dst);
378 dst = result_dst;
379 }
380 } else {
381 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
382 }
383
384 // 3: apply keep-alive barrier if needed
385 if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) {
386 __ enter();
387 satb_write_barrier_pre(masm /* masm */,
388 noreg /* obj */,
389 dst /* pre_val */,
390 rthread /* thread */,
391 tmp1 /* tmp */,
392 true /* tosca_live */,
393 true /* expand_call */);
394 __ leave();
395 }
396 }
397
398 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
399 Address dst, Register val, Register tmp1, Register tmp2) {
400 bool on_oop = is_reference_type(type);
401 if (!on_oop) {
402 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2);
403 return;
404 }
405
406 // flatten object address if needed
407 if (dst.index() == noreg && dst.offset() == 0) {
408 if (dst.base() != r3) {
409 __ mov(r3, dst.base());
410 }
411 } else {
412 __ lea(r3, dst);
413 }
414
415 shenandoah_write_barrier_pre(masm,
416 r3 /* obj */,
417 tmp2 /* pre_val */,
418 rthread /* thread */,
419 tmp1 /* tmp */,
420 val != noreg /* tosca_live */,
421 false /* expand_call */);
422
423 if (val == noreg) {
424 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg);
425 } else {
426 storeval_barrier(masm, val, tmp1);
427 // G1 barrier needs uncompressed oop for region cross check.
428 Register new_val = val;
429 if (UseCompressedOops) {
430 new_val = rscratch2;
431 __ mov(new_val, val);
432 }
433 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg);
434 }
435
436 }
437
438 void ShenandoahBarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env,
439 Register obj, Register tmp, Label& slowpath) {
440 Label done;
441 // Resolve jobject
442 BarrierSetAssembler::try_resolve_jobject_in_native(masm, jni_env, obj, tmp, slowpath);
443
444 // Check for null.
445 __ cbz(obj, done);
446
447 assert(obj != rscratch2, "need rscratch2");
448 Address gc_state(jni_env, ShenandoahThreadLocalData::gc_state_offset() - JavaThread::jni_environment_offset());
449 __ lea(rscratch2, gc_state);
450 __ ldrb(rscratch2, Address(rscratch2));
451
452 // Check for heap in evacuation phase
453 __ tbnz(rscratch2, ShenandoahHeap::EVACUATION_BITPOS, slowpath);
454
455 __ bind(done);
456 }
457
458
459 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val,
460 bool acquire, bool release, bool weak, bool is_cae,
461 Register result) {
462 Register tmp1 = rscratch1;
463 Register tmp2 = rscratch2;
464 bool is_narrow = UseCompressedOops;
465 Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword;
466
467 assert_different_registers(addr, expected, new_val, tmp1, tmp2);
468
469 Label retry, done, fail;
470
471 // CAS, using LL/SC pair.
472 __ bind(retry);
473 __ load_exclusive(tmp1, addr, size, acquire);
474 if (is_narrow) {
475 __ cmpw(tmp1, expected);
476 } else {
477 __ cmp(tmp1, expected);
478 }
479 __ br(Assembler::NE, fail);
480 __ store_exclusive(tmp2, new_val, addr, size, release);
481 if (weak) {
482 __ cmpw(tmp2, 0u); // If the store fails, return NE to our caller
483 } else {
484 __ cbnzw(tmp2, retry);
485 }
486 __ b(done);
487
488 __ bind(fail);
489 // Check if rb(expected)==rb(tmp1)
490 // Shuffle registers so that we have memory value ready for next expected.
491 __ mov(tmp2, expected);
492 __ mov(expected, tmp1);
493 if (is_narrow) {
494 __ decode_heap_oop(tmp1, tmp1);
495 __ decode_heap_oop(tmp2, tmp2);
496 }
497 resolve_forward_pointer(masm, tmp1);
498 resolve_forward_pointer(masm, tmp2);
499 __ cmp(tmp1, tmp2);
500 // Retry with expected now being the value we just loaded from addr.
501 __ br(Assembler::EQ, retry);
502 if (is_cae && is_narrow) {
503 // For cmp-and-exchange and narrow oops, we need to restore
504 // the compressed old-value. We moved it to 'expected' a few lines up.
505 __ mov(tmp1, expected);
506 }
507 __ bind(done);
508
509 if (is_cae) {
510 __ mov(result, tmp1);
511 } else {
512 __ cset(result, Assembler::EQ);
513 }
514 }
515
516 #undef __
517
518 #ifdef COMPILER1
519
520 #define __ ce->masm()->
521
522 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) {
523 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
524 // At this point we know that marking is in progress.
525 // If do_load() is true then we have to emit the
526 // load of the previous value; otherwise it has already
527 // been loaded into _pre_val.
528
529 __ bind(*stub->entry());
530
531 assert(stub->pre_val()->is_register(), "Precondition.");
532
533 Register pre_val_reg = stub->pre_val()->as_register();
534
535 if (stub->do_load()) {
536 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/);
537 }
538 __ cbz(pre_val_reg, *stub->continuation());
539 ce->store_parameter(stub->pre_val()->as_register(), 0);
540 __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
541 __ b(*stub->continuation());
542 }
543
544 void ShenandoahBarrierSetAssembler::gen_load_reference_barrier_stub(LIR_Assembler* ce, ShenandoahLoadReferenceBarrierStub* stub) {
545 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
546 __ bind(*stub->entry());
547
548 Register obj = stub->obj()->as_register();
549 Register res = stub->result()->as_register();
550 Register addr = stub->addr()->as_pointer_register();
551 Register tmp1 = stub->tmp1()->as_register();
552 Register tmp2 = stub->tmp2()->as_register();
553
554 assert(res == r0, "result must arrive in r0");
555
556 if (res != obj) {
557 __ mov(res, obj);
558 }
559
560 // Check for null.
561 __ cbz(res, *stub->continuation());
562
563 // Check for object in cset.
564 __ mov(tmp2, ShenandoahHeap::in_cset_fast_test_addr());
565 __ lsr(tmp1, res, ShenandoahHeapRegion::region_size_bytes_shift_jint());
566 __ ldrb(tmp2, Address(tmp2, tmp1));
567 __ cbz(tmp2, *stub->continuation());
568
569 // Check if object is already forwarded.
570 Label slow_path;
571 __ ldr(tmp1, Address(res, oopDesc::mark_offset_in_bytes()));
572 __ eon(tmp1, tmp1, zr);
573 __ ands(zr, tmp1, markWord::lock_mask_in_place);
574 __ br(Assembler::NE, slow_path);
575
576 // Decode forwarded object.
577 __ orr(tmp1, tmp1, markWord::marked_value);
578 __ eon(res, tmp1, zr);
579 __ b(*stub->continuation());
580
581 __ bind(slow_path);
582 ce->store_parameter(res, 0);
583 ce->store_parameter(addr, 1);
584 if (stub->is_native()) {
585 __ far_call(RuntimeAddress(bs->load_reference_barrier_native_rt_code_blob()->code_begin()));
586 } else {
587 __ far_call(RuntimeAddress(bs->load_reference_barrier_rt_code_blob()->code_begin()));
588 }
589
590 __ b(*stub->continuation());
591 }
592
593 #undef __
594
595 #define __ sasm->
596
597 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
598 __ prologue("shenandoah_pre_barrier", false);
599
600 // arg0 : previous value of memory
601
602 BarrierSet* bs = BarrierSet::barrier_set();
603
604 const Register pre_val = r0;
605 const Register thread = rthread;
606 const Register tmp = rscratch1;
607
608 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
609 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
610
611 Label done;
612 Label runtime;
613
614 // Is marking still active?
615 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
616 __ ldrb(tmp, gc_state);
617 __ mov(rscratch2, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL);
618 __ tst(tmp, rscratch2);
619 __ br(Assembler::EQ, done);
620
621 // Can we store original value in the thread's buffer?
622 __ ldr(tmp, queue_index);
623 __ cbz(tmp, runtime);
624
625 __ sub(tmp, tmp, wordSize);
626 __ str(tmp, queue_index);
627 __ ldr(rscratch2, buffer);
628 __ add(tmp, tmp, rscratch2);
629 __ load_parameter(0, rscratch2);
630 __ str(rscratch2, Address(tmp, 0));
631 __ b(done);
632
633 __ bind(runtime);
634 __ push_call_clobbered_registers();
635 __ load_parameter(0, pre_val);
636 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
637 __ pop_call_clobbered_registers();
638 __ bind(done);
639
640 __ epilogue();
641 }
642
643 void ShenandoahBarrierSetAssembler::generate_c1_load_reference_barrier_runtime_stub(StubAssembler* sasm, bool native) {
644 __ prologue("shenandoah_load_reference_barrier", false);
645 // arg0 : object to be resolved
646
647 __ push_call_clobbered_registers();
648 __ load_parameter(0, r0);
649 __ load_parameter(1, r1);
650 if (native) {
651 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_native));
652 } else if (UseCompressedOops) {
653 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_narrow));
654 } else {
655 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier));
656 }
657 __ blr(lr);
658 __ mov(rscratch1, r0);
659 __ pop_call_clobbered_registers();
660 __ mov(r0, rscratch1);
661
662 __ epilogue();
663 }
664
665 #undef __
666
667 #endif // COMPILER1
668
669 address ShenandoahBarrierSetAssembler::shenandoah_lrb() {
670 assert(_shenandoah_lrb != NULL, "need load reference barrier stub");
671 return _shenandoah_lrb;
672 }
673
674 #define __ cgen->assembler()->
675
676 // Shenandoah load reference barrier.
677 //
678 // Input:
679 // r0: OOP to evacuate. Not null.
680 // r1: load address
681 //
682 // Output:
683 // r0: Pointer to evacuated OOP.
684 //
685 // Trash rscratch1, rscratch2. Preserve everything else.
686 address ShenandoahBarrierSetAssembler::generate_shenandoah_lrb(StubCodeGenerator* cgen) {
687
688 __ align(6);
689 StubCodeMark mark(cgen, "StubRoutines", "shenandoah_lrb");
690 address start = __ pc();
691
692 Label work, done;
693 __ mov(rscratch2, ShenandoahHeap::in_cset_fast_test_addr());
694 __ lsr(rscratch1, r0, ShenandoahHeapRegion::region_size_bytes_shift_jint());
695 __ ldrb(rscratch2, Address(rscratch2, rscratch1));
696 __ tbnz(rscratch2, 0, work);
697 __ ret(lr);
698 __ bind(work);
699
700 Label slow_path;
701 __ ldr(rscratch1, Address(r0, oopDesc::mark_offset_in_bytes()));
702 __ eon(rscratch1, rscratch1, zr);
703 __ ands(zr, rscratch1, markWord::lock_mask_in_place);
704 __ br(Assembler::NE, slow_path);
705
706 // Decode forwarded object.
707 __ orr(rscratch1, rscratch1, markWord::marked_value);
708 __ eon(r0, rscratch1, zr);
709 __ ret(lr);
710
711 __ bind(slow_path);
712 __ enter(); // required for proper stackwalking of RuntimeStub frame
713
714 __ push_call_clobbered_registers();
715
716 if (UseCompressedOops) {
717 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_narrow));
718 } else {
719 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier));
720 }
721 __ blr(lr);
722 __ mov(rscratch1, r0);
723 __ pop_call_clobbered_registers();
724 __ mov(r0, rscratch1);
725
726 __ leave(); // required for proper stackwalking of RuntimeStub frame
727 __ bind(done);
728 __ ret(lr);
729
730 return start;
731 }
732
733 #undef __
734
735 void ShenandoahBarrierSetAssembler::barrier_stubs_init() {
736 if (ShenandoahLoadRefBarrier) {
737 int stub_code_size = 2048;
738 ResourceMark rm;
739 BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size);
740 CodeBuffer buf(bb);
741 StubCodeGenerator cgen(&buf);
742 _shenandoah_lrb = generate_shenandoah_lrb(&cgen);
743 }
744 }