1 /*
2 * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved.
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/shenandoahForwarding.hpp"
27 #include "gc/shenandoah/shenandoahHeap.inline.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_lrb = NULL;
45
46 void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
47 Register src, Register dst, Register count, RegSet saved_regs) {
48 if (is_oop) {
49 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
50 if (ShenandoahSATBBarrier && !dest_uninitialized) {
51
52 Label done;
53
54 // Avoid calling runtime if count == 0
55 __ cbz(count, done);
56
57 // Is marking active?
58 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
59 __ ldrb(rscratch1, gc_state);
60 __ tbz(rscratch1, ShenandoahHeap::MARKING_BITPOS, done);
61
62 __ push(saved_regs, sp);
63 if (count == c_rarg0) {
64 if (dst == c_rarg1) {
65 // exactly backwards!!
66 __ mov(rscratch1, c_rarg0);
67 __ mov(c_rarg0, c_rarg1);
68 __ mov(c_rarg1, rscratch1);
69 } else {
70 __ mov(c_rarg1, count);
71 __ mov(c_rarg0, dst);
72 }
73 } else {
74 __ mov(c_rarg0, dst);
75 __ mov(c_rarg1, count);
76 }
77 if (UseCompressedOops) {
78 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry), 2);
79 } else {
80 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry), 2);
81 }
82 __ pop(saved_regs, sp);
83 __ bind(done);
84 }
85 }
86 }
87
88 void ShenandoahBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
89 Register start, Register count, Register scratch, RegSet saved_regs) {
90 if (is_oop) {
91 Label done;
92
93 // Avoid calling runtime if count == 0
94 __ cbz(count, done);
95
96 // Is updating references?
97 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
98 __ ldrb(rscratch1, gc_state);
99 __ tbz(rscratch1, ShenandoahHeap::UPDATEREFS_BITPOS, done);
100
101 __ push(saved_regs, sp);
102 assert_different_registers(start, count, scratch);
103 assert_different_registers(c_rarg0, count);
104 __ mov(c_rarg0, start);
105 __ mov(c_rarg1, count);
106 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_post_entry), 2);
107 __ pop(saved_regs, sp);
108
109 __ bind(done);
110 }
111 }
112
113 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm,
114 Register obj,
115 Register pre_val,
116 Register thread,
117 Register tmp,
118 bool tosca_live,
119 bool expand_call) {
120 if (ShenandoahSATBBarrier) {
121 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call);
122 }
123 }
124
125 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm,
126 Register obj,
127 Register pre_val,
128 Register thread,
129 Register tmp,
130 bool tosca_live,
131 bool expand_call) {
132 // If expand_call is true then we expand the call_VM_leaf macro
133 // directly to skip generating the check by
134 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
135
136 assert(thread == rthread, "must be");
137
138 Label done;
139 Label runtime;
140
141 assert_different_registers(obj, pre_val, tmp, rscratch1);
142 assert(pre_val != noreg && tmp != noreg, "expecting a register");
143
144 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()));
145 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
146 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
147
148 // Is marking active?
149 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
150 __ ldrw(tmp, in_progress);
151 } else {
152 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
153 __ ldrb(tmp, in_progress);
154 }
155 __ cbzw(tmp, done);
156
157 // Do we need to load the previous value?
158 if (obj != noreg) {
159 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW);
160 }
161
162 // Is the previous value null?
163 __ cbz(pre_val, done);
164
165 // Can we store original value in the thread's buffer?
166 // Is index == 0?
167 // (The index field is typed as size_t.)
168
169 __ ldr(tmp, index); // tmp := *index_adr
170 __ cbz(tmp, runtime); // tmp == 0?
171 // If yes, goto runtime
172
173 __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize
174 __ str(tmp, index); // *index_adr := tmp
175 __ ldr(rscratch1, buffer);
176 __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr
177
178 // Record the previous value
179 __ str(pre_val, Address(tmp, 0));
180 __ b(done);
181
182 __ bind(runtime);
183 // save the live input values
184 RegSet saved = RegSet::of(pre_val);
185 if (tosca_live) saved += RegSet::of(r0);
186 if (obj != noreg) saved += RegSet::of(obj);
187
188 __ push(saved, sp);
189
190 // Calling the runtime using the regular call_VM_leaf mechanism generates
191 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
192 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
193 //
194 // If we care generating the pre-barrier without a frame (e.g. in the
195 // intrinsified Reference.get() routine) then ebp might be pointing to
196 // the caller frame and so this check will most likely fail at runtime.
197 //
198 // Expanding the call directly bypasses the generation of the check.
199 // So when we do not have have a full interpreter frame on the stack
200 // expand_call should be passed true.
201
202 if (expand_call) {
203 assert(pre_val != c_rarg1, "smashed arg");
204 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
205 } else {
206 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
207 }
208
209 __ pop(saved, sp);
210
211 __ bind(done);
212 }
213
214 void ShenandoahBarrierSetAssembler::resolve_forward_pointer(MacroAssembler* masm, Register dst, Register tmp) {
215 assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled");
216 Label is_null;
217 __ cbz(dst, is_null);
218 resolve_forward_pointer_not_null(masm, dst, tmp);
219 __ bind(is_null);
220 }
221
222 // IMPORTANT: This must preserve all registers, even rscratch1 and rscratch2, except those explicitely
223 // passed in.
224 void ShenandoahBarrierSetAssembler::resolve_forward_pointer_not_null(MacroAssembler* masm, Register dst, Register tmp) {
225 assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled");
226 // The below loads the mark word, checks if the lowest two bits are
227 // set, and if so, clear the lowest two bits and copy the result
228 // to dst. Otherwise it leaves dst alone.
229 // Implementing this is surprisingly awkward. I do it here by:
230 // - Inverting the mark word
231 // - Test lowest two bits == 0
232 // - If so, set the lowest two bits
233 // - Invert the result back, and copy to dst
234
235 bool borrow_reg = (tmp == noreg);
236 if (borrow_reg) {
237 // No free registers available. Make one useful.
238 tmp = rscratch1;
239 __ push(RegSet::of(tmp), sp);
240 }
241
242 Label done;
243 __ ldr(tmp, Address(dst, oopDesc::mark_offset_in_bytes()));
244 __ eon(tmp, tmp, zr);
245 __ ands(zr, tmp, markOopDesc::lock_mask_in_place);
246 __ br(Assembler::NE, done);
247 __ orr(tmp, tmp, markOopDesc::marked_value);
248 __ eon(dst, tmp, zr);
249 __ bind(done);
250
251 if (borrow_reg) {
252 __ pop(RegSet::of(tmp), sp);
253 }
254 }
255
256 void ShenandoahBarrierSetAssembler::load_reference_barrier_not_null(MacroAssembler* masm, Register dst, Register tmp) {
257 assert(ShenandoahLoadRefBarrier, "Should be enabled");
258 assert(dst != rscratch2, "need rscratch2");
259
260 Label done;
261 __ enter();
262 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
263 __ ldrb(rscratch2, gc_state);
264
265 // Check for heap stability
266 __ tbz(rscratch2, ShenandoahHeap::HAS_FORWARDED_BITPOS, done);
267
268 RegSet to_save = RegSet::of(r0);
269 if (dst != r0) {
270 __ push(to_save, sp);
271 __ mov(r0, dst);
272 }
273
274 __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_lrb())));
275
276 if (dst != r0) {
277 __ mov(dst, r0);
278 __ pop(to_save, sp);
279 }
280
281 __ bind(done);
282 __ leave();
283 }
284
285 void ShenandoahBarrierSetAssembler::load_reference_barrier_native(MacroAssembler* masm, Register dst, Register tmp) {
286 if (!ShenandoahLoadRefBarrier) {
287 return;
288 }
289
290 assert(dst != rscratch2, "need rscratch2");
291
292 Label is_null;
293 Label done;
294
295 __ cbz(dst, is_null);
296
297 __ enter();
298
299 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
300 __ ldrb(rscratch2, gc_state);
301
302 // Check for heap in evacuation phase
303 __ tbz(rscratch2, ShenandoahHeap::EVACUATION_BITPOS, done);
304
305 __ mov(rscratch2, dst);
306 __ push_call_clobbered_registers();
307 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_native));
308 __ mov(r0, rscratch2);
309 __ blrt(lr, 1, 0, MacroAssembler::ret_type_integral);
310 __ mov(rscratch2, r0);
311 __ pop_call_clobbered_registers();
312 __ mov(dst, rscratch2);
313
314 __ bind(done);
315 __ leave();
316 __ bind(is_null);
317 }
318
319 void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) {
320 if (ShenandoahStoreValEnqueueBarrier) {
321 // Save possibly live regs.
322 RegSet live_regs = RegSet::range(r0, r4) - dst;
323 __ push(live_regs, sp);
324 __ strd(v0, __ pre(sp, 2 * -wordSize));
325
326 satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false);
327
328 // Restore possibly live regs.
329 __ ldrd(v0, __ post(sp, 2 * wordSize));
330 __ pop(live_regs, sp);
331 }
332 }
333
334 void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm, Register dst, Register tmp) {
335 if (ShenandoahLoadRefBarrier) {
336 Label is_null;
337 __ cbz(dst, is_null);
338 load_reference_barrier_not_null(masm, dst, tmp);
339 __ bind(is_null);
340 }
341 }
342
343 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
344 Register dst, Address src, Register tmp1, Register tmp_thread) {
345 bool on_oop = type == T_OBJECT || type == T_ARRAY;
346 bool not_in_heap = (decorators & IN_NATIVE) != 0;
347 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
348 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
349 bool on_reference = on_weak || on_phantom;
350 bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0;
351
352 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
353 if (on_oop) {
354 if (not_in_heap) {
355 if (ShenandoahHeap::heap()->is_traversal_mode()) {
356 load_reference_barrier(masm, dst, tmp1);
357 keep_alive = true;
358 } else {
359 load_reference_barrier_native(masm, dst, tmp1);
360 }
361 } else {
362 load_reference_barrier(masm, dst, tmp1);
363 }
364 if (ShenandoahKeepAliveBarrier && on_reference && keep_alive) {
365 __ enter();
366 satb_write_barrier_pre(masm /* masm */,
367 noreg /* obj */,
368 dst /* pre_val */,
369 rthread /* thread */,
370 tmp1 /* tmp */,
371 true /* tosca_live */,
372 true /* expand_call */);
373 __ leave();
374 }
375 }
376 }
377
378 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
379 Address dst, Register val, Register tmp1, Register tmp2) {
380 bool on_oop = type == T_OBJECT || type == T_ARRAY;
381 if (!on_oop) {
382 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2);
383 return;
384 }
385
386 // flatten object address if needed
387 if (dst.index() == noreg && dst.offset() == 0) {
388 if (dst.base() != r3) {
389 __ mov(r3, dst.base());
390 }
391 } else {
392 __ lea(r3, dst);
393 }
394
395 shenandoah_write_barrier_pre(masm,
396 r3 /* obj */,
397 tmp2 /* pre_val */,
398 rthread /* thread */,
399 tmp1 /* tmp */,
400 val != noreg /* tosca_live */,
401 false /* expand_call */);
402
403 if (val == noreg) {
404 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg);
405 } else {
406 storeval_barrier(masm, val, tmp1);
407 // G1 barrier needs uncompressed oop for region cross check.
408 Register new_val = val;
409 if (UseCompressedOops) {
410 new_val = rscratch2;
411 __ mov(new_val, val);
412 }
413 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg);
414 }
415
416 }
417
418 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val,
419 bool acquire, bool release, bool weak, bool is_cae,
420 Register result) {
421 Register tmp1 = rscratch1;
422 Register tmp2 = rscratch2;
423 bool is_narrow = UseCompressedOops;
424 Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword;
425
426 assert_different_registers(addr, expected, new_val, tmp1, tmp2);
427
428 Label retry, done, fail;
429
430 // CAS, using LL/SC pair.
431 __ bind(retry);
432 __ load_exclusive(tmp1, addr, size, acquire);
433 if (is_narrow) {
434 __ cmpw(tmp1, expected);
435 } else {
436 __ cmp(tmp1, expected);
437 }
438 __ br(Assembler::NE, fail);
439 __ store_exclusive(tmp2, new_val, addr, size, release);
440 if (weak) {
441 __ cmpw(tmp2, 0u); // If the store fails, return NE to our caller
442 } else {
443 __ cbnzw(tmp2, retry);
444 }
445 __ b(done);
446
447 __ bind(fail);
448 // Check if rb(expected)==rb(tmp1)
449 // Shuffle registers so that we have memory value ready for next expected.
450 __ mov(tmp2, expected);
451 __ mov(expected, tmp1);
452 if (is_narrow) {
453 __ decode_heap_oop(tmp1, tmp1);
454 __ decode_heap_oop(tmp2, tmp2);
455 }
456 resolve_forward_pointer(masm, tmp1);
457 resolve_forward_pointer(masm, tmp2);
458 __ cmp(tmp1, tmp2);
459 // Retry with expected now being the value we just loaded from addr.
460 __ br(Assembler::EQ, retry);
461 if (is_cae && is_narrow) {
462 // For cmp-and-exchange and narrow oops, we need to restore
463 // the compressed old-value. We moved it to 'expected' a few lines up.
464 __ mov(tmp1, expected);
465 }
466 __ bind(done);
467
468 if (is_cae) {
469 __ mov(result, tmp1);
470 } else {
471 __ cset(result, Assembler::EQ);
472 }
473 }
474
475 // Generate cset check. If obj is in cset, branch to in_cset label, otherwise fall through
476 // obj: Register holding the oop, preserved
477 // tmp1, tmp2: temp registers, trashed
478 void ShenandoahBarrierSetAssembler::gen_cset_check(MacroAssembler* masm, Register obj, Register tmp1, Register tmp2, Label& in_cset) {
479 __ mov(tmp2, ShenandoahHeap::in_cset_fast_test_addr());
480 __ lsr(tmp1, obj, ShenandoahHeapRegion::region_size_bytes_shift_jint());
481 __ ldrb(tmp2, Address(tmp2, tmp1));
482 __ tbnz(tmp2, 0, in_cset);
483 }
484
485 // Generate check if object is resolved. Branch to not_resolved label, if not. Otherwise return resolved
486 // object in obj register.
487 // obj: object, resolved object on normal return
488 // tmp1, tmp2: temp registers, trashed
489 void ShenandoahBarrierSetAssembler::gen_resolved_check(MacroAssembler* masm, Register obj, Register tmp1, Register tmp2, Label& resolved) {
490 __ mov(tmp2, obj);
491 resolve_forward_pointer_not_null(masm, obj, tmp1);
492 __ cmp(tmp2, obj);
493 __ br(Assembler::EQ, resolved);
494 }
495
496 #undef __
497
498 #ifdef COMPILER1
499
500 #define __ ce->masm()->
501
502 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) {
503 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
504 // At this point we know that marking is in progress.
505 // If do_load() is true then we have to emit the
506 // load of the previous value; otherwise it has already
507 // been loaded into _pre_val.
508
509 __ bind(*stub->entry());
510
511 assert(stub->pre_val()->is_register(), "Precondition.");
512
513 Register pre_val_reg = stub->pre_val()->as_register();
514
515 if (stub->do_load()) {
516 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/);
517 }
518 __ cbz(pre_val_reg, *stub->continuation());
519 ce->store_parameter(stub->pre_val()->as_register(), 0);
520 __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
521 __ b(*stub->continuation());
522 }
523
524 void ShenandoahBarrierSetAssembler::gen_load_reference_barrier_stub(LIR_Assembler* ce, ShenandoahLoadReferenceBarrierStub* stub) {
525 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
526 __ bind(*stub->entry());
527
528 Register obj = stub->obj()->as_register();
529 Register res = stub->result()->as_register();
530 assert(res == r0, "result must arrive in r0");
531
532 if (res != obj) {
533 __ mov(res, obj);
534 }
535
536 // Check for null.
537 __ cbz(res, *stub->continuation());
538
539 ce->store_parameter(res, 0);
540 __ far_call(RuntimeAddress(bs->load_reference_barrier_rt_code_blob()->code_begin()));
541
542 __ b(*stub->continuation());
543 }
544
545 #undef __
546
547 #define __ sasm->
548
549 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
550 __ prologue("shenandoah_pre_barrier", false);
551
552 // arg0 : previous value of memory
553
554 BarrierSet* bs = BarrierSet::barrier_set();
555
556 const Register pre_val = r0;
557 const Register thread = rthread;
558 const Register tmp = rscratch1;
559
560 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
561 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
562
563 Label done;
564 Label runtime;
565
566 // Is marking still active?
567 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
568 __ ldrb(tmp, gc_state);
569 __ mov(rscratch2, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL);
570 __ tst(tmp, rscratch2);
571 __ br(Assembler::EQ, done);
572
573 // Can we store original value in the thread's buffer?
574 __ ldr(tmp, queue_index);
575 __ cbz(tmp, runtime);
576
577 __ sub(tmp, tmp, wordSize);
578 __ str(tmp, queue_index);
579 __ ldr(rscratch2, buffer);
580 __ add(tmp, tmp, rscratch2);
581 __ load_parameter(0, rscratch2);
582 __ str(rscratch2, Address(tmp, 0));
583 __ b(done);
584
585 __ bind(runtime);
586 __ push_call_clobbered_registers();
587 __ load_parameter(0, pre_val);
588 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
589 __ pop_call_clobbered_registers();
590 __ bind(done);
591
592 __ epilogue();
593 }
594
595 void ShenandoahBarrierSetAssembler::generate_c1_load_reference_barrier_runtime_stub(StubAssembler* sasm) {
596 __ prologue("shenandoah_load_reference_barrier", false);
597 // arg0 : object to be resolved
598
599 Label work, call_rt;
600 __ load_parameter(0, r0);
601 gen_cset_check(sasm, r0, rscratch1, rscratch2, work);
602 __ epilogue();
603
604 __ bind(work);
605 gen_resolved_check(sasm, r0, rscratch1, rscratch2, call_rt);
606 __ epilogue();
607
608 __ bind(call_rt);
609
610 __ push_call_clobbered_registers();
611
612 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier));
613 __ blrt(lr, 1, 0, MacroAssembler::ret_type_integral);
614 __ mov(rscratch1, r0);
615 __ pop_call_clobbered_registers();
616 __ mov(r0, rscratch1);
617
618 __ epilogue();
619 }
620
621 #undef __
622
623 #endif // COMPILER1
624
625 address ShenandoahBarrierSetAssembler::shenandoah_lrb() {
626 assert(_shenandoah_lrb != NULL, "need load reference barrier stub");
627 return _shenandoah_lrb;
628 }
629
630 #define __ cgen->assembler()->
631
632 // Shenandoah load reference barrier.
633 //
634 // Input:
635 // r0: OOP to evacuate. Not null.
636 //
637 // Output:
638 // r0: Pointer to evacuated OOP.
639 //
640 // Trash rscratch1, rscratch2. Preserve everything else.
641 address ShenandoahBarrierSetAssembler::generate_shenandoah_lrb(StubCodeGenerator* cgen) {
642
643 __ align(6);
644 StubCodeMark mark(cgen, "StubRoutines", "shenandoah_lrb");
645 address start = __ pc();
646
647 Label work, call_rt;
648 gen_cset_check(cgen->assembler(), r0, rscratch1, rscratch2, work);
649 __ ret(lr);
650
651 __ bind(work);
652 gen_resolved_check(cgen->assembler(), r0, rscratch1, rscratch2, call_rt);
653 __ ret(lr);
654
655 __ bind(call_rt);
656 __ enter(); // required for proper stackwalking of RuntimeStub frame
657
658 __ push_call_clobbered_registers();
659
660 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier));
661 __ blrt(lr, 1, 0, MacroAssembler::ret_type_integral);
662 __ mov(rscratch1, r0);
663 __ pop_call_clobbered_registers();
664 __ mov(r0, rscratch1);
665
666 __ leave(); // required for proper stackwalking of RuntimeStub frame
667 __ ret(lr);
668
669 return start;
670 }
671
672 #undef __
673
674 void ShenandoahBarrierSetAssembler::barrier_stubs_init() {
675 if (ShenandoahLoadRefBarrier) {
676 int stub_code_size = 2048;
677 ResourceMark rm;
678 BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size);
679 CodeBuffer buf(bb);
680 StubCodeGenerator cgen(&buf);
681 _shenandoah_lrb = generate_shenandoah_lrb(&cgen);
682 }
683 }