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 #include "utilities/macros.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_wb = NULL;
47 address ShenandoahBarrierSetAssembler::_shenandoah_wb_C = NULL;
48
49 void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
50 Register src, Register dst, Register count) {
51
52 bool checkcast = (decorators & ARRAYCOPY_CHECKCAST) != 0;
53 bool disjoint = (decorators & ARRAYCOPY_DISJOINT) != 0;
54 bool obj_int = type == T_OBJECT LP64_ONLY(&& UseCompressedOops);
55 bool dest_uninitialized = (decorators & AS_DEST_NOT_INITIALIZED) != 0;
56
57 if (type == T_OBJECT || type == T_ARRAY) {
58 #ifdef _LP64
59 if (!checkcast && !obj_int) {
60 // Save count for barrier
61 __ movptr(r11, count);
62 } else if (disjoint && obj_int) {
63 // Save dst in r11 in the disjoint case
64 __ movq(r11, dst);
65 }
66 #else
67 if (disjoint) {
68 __ mov(rdx, dst); // save 'to'
69 }
70 #endif
71
72 if (!dest_uninitialized && !ShenandoahHeap::heap()->heuristics()->can_do_traversal_gc()) {
73 Register thread = NOT_LP64(rax) LP64_ONLY(r15_thread);
74 #ifndef _LP64
75 __ push(thread);
76 __ get_thread(thread);
77 #endif
78
79 Label filtered;
80 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()));
81 // Is marking active?
82 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
83 __ cmpl(in_progress, 0);
84 } else {
85 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
86 __ cmpb(in_progress, 0);
87 }
88
89 NOT_LP64(__ pop(thread);)
90
91 __ jcc(Assembler::equal, filtered);
92
93 __ pusha(); // push registers
94 #ifdef _LP64
95 if (count == c_rarg0) {
96 if (dst == c_rarg1) {
97 // exactly backwards!!
98 __ xchgptr(c_rarg1, c_rarg0);
99 } else {
100 __ movptr(c_rarg1, count);
101 __ movptr(c_rarg0, dst);
102 }
103 } else {
104 __ movptr(c_rarg0, dst);
105 __ movptr(c_rarg1, count);
106 }
107 if (UseCompressedOops) {
108 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry), 2);
109 } else {
110 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry), 2);
111 }
112 #else
113 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry),
114 dst, count);
115 #endif
116 __ popa();
117 __ bind(filtered);
118 }
119 }
120
121 }
122
123 void ShenandoahBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
124 Register src, Register dst, Register count) {
125 bool checkcast = (decorators & ARRAYCOPY_CHECKCAST) != 0;
126 bool disjoint = (decorators & ARRAYCOPY_DISJOINT) != 0;
127 bool obj_int = type == T_OBJECT LP64_ONLY(&& UseCompressedOops);
128 Register tmp = rax;
129
130 if (type == T_OBJECT || type == T_ARRAY) {
131 #ifdef _LP64
132 if (!checkcast && !obj_int) {
133 // Save count for barrier
134 count = r11;
135 } else if (disjoint && obj_int) {
136 // Use the saved dst in the disjoint case
137 dst = r11;
138 } else if (checkcast) {
139 tmp = rscratch1;
140 }
141 #else
142 if (disjoint) {
143 __ mov(dst, rdx); // restore 'to'
144 }
145 #endif
146
147 __ pusha(); // push registers (overkill)
148 #ifdef _LP64
149 if (c_rarg0 == count) { // On win64 c_rarg0 == rcx
150 assert_different_registers(c_rarg1, dst);
151 __ mov(c_rarg1, count);
152 __ mov(c_rarg0, dst);
153 } else {
154 assert_different_registers(c_rarg0, count);
155 __ mov(c_rarg0, dst);
156 __ mov(c_rarg1, count);
157 }
158 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_post_entry), 2);
159 #else
160 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_post_entry),
161 dst, count);
162 #endif
163 __ popa();
164 }
165 }
166
167 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm,
168 Register obj,
169 Register pre_val,
170 Register thread,
171 Register tmp,
172 bool tosca_live,
173 bool expand_call) {
174
175 if (ShenandoahSATBBarrier) {
176 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call);
177 }
178 }
179
180 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm,
181 Register obj,
182 Register pre_val,
183 Register thread,
184 Register tmp,
185 bool tosca_live,
186 bool expand_call) {
187 // If expand_call is true then we expand the call_VM_leaf macro
188 // directly to skip generating the check by
189 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
190
191 #ifdef _LP64
192 assert(thread == r15_thread, "must be");
193 #endif // _LP64
194
195 Label done;
196 Label runtime;
197
198 assert(pre_val != noreg, "check this code");
199
200 if (obj != noreg) {
201 assert_different_registers(obj, pre_val, tmp);
202 assert(pre_val != rax, "check this code");
203 }
204
205 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()));
206 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
207 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
208
209 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
210 __ testb(gc_state, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL);
211 __ jcc(Assembler::zero, done);
212
213 // Do we need to load the previous value?
214 if (obj != noreg) {
215 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW);
216 }
217
218 // Is the previous value null?
219 __ cmpptr(pre_val, (int32_t) NULL_WORD);
220 __ jcc(Assembler::equal, done);
221
222 // Can we store original value in the thread's buffer?
223 // Is index == 0?
224 // (The index field is typed as size_t.)
225
226 __ movptr(tmp, index); // tmp := *index_adr
227 __ cmpptr(tmp, 0); // tmp == 0?
228 __ jcc(Assembler::equal, runtime); // If yes, goto runtime
229
230 __ subptr(tmp, wordSize); // tmp := tmp - wordSize
231 __ movptr(index, tmp); // *index_adr := tmp
232 __ addptr(tmp, buffer); // tmp := tmp + *buffer_adr
233
234 // Record the previous value
235 __ movptr(Address(tmp, 0), pre_val);
236 __ jmp(done);
237
238 __ bind(runtime);
239 // save the live input values
240 if(tosca_live) __ push(rax);
241
242 if (obj != noreg && obj != rax)
243 __ push(obj);
244
245 if (pre_val != rax)
246 __ push(pre_val);
247
248 // Calling the runtime using the regular call_VM_leaf mechanism generates
249 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
250 // that checks that the *(ebp+frame::interpreter_frame_last_sp) == NULL.
251 //
252 // If we care generating the pre-barrier without a frame (e.g. in the
253 // intrinsified Reference.get() routine) then ebp might be pointing to
254 // the caller frame and so this check will most likely fail at runtime.
255 //
256 // Expanding the call directly bypasses the generation of the check.
257 // So when we do not have have a full interpreter frame on the stack
258 // expand_call should be passed true.
259
260 NOT_LP64( __ push(thread); )
261
262 if (expand_call) {
263 LP64_ONLY( assert(pre_val != c_rarg1, "smashed arg"); )
264 #ifdef _LP64
265 if (c_rarg1 != thread) {
266 __ mov(c_rarg1, thread);
267 }
268 if (c_rarg0 != pre_val) {
269 __ mov(c_rarg0, pre_val);
270 }
271 #else
272 __ push(thread);
273 __ push(pre_val);
274 #endif
275 __ MacroAssembler::call_VM_leaf_base(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), 2);
276 } else {
277 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
278 }
279
280 NOT_LP64( __ pop(thread); )
281
282 // save the live input values
283 if (pre_val != rax)
284 __ pop(pre_val);
285
286 if (obj != noreg && obj != rax)
287 __ pop(obj);
288
289 if(tosca_live) __ pop(rax);
290
291 __ bind(done);
292 }
293
294 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_post(MacroAssembler* masm,
295 Register store_addr,
296 Register new_val,
297 Register thread,
298 Register tmp,
299 Register tmp2) {
300 assert(UseShenandoahGC, "why else should we be here?");
301
302 if (! UseShenandoahMatrix) {
303 // No need for that barrier if not using matrix.
304 return;
305 }
306
307 Label done;
308 __ testptr(new_val, new_val);
309 __ jcc(Assembler::zero, done);
310 ShenandoahConnectionMatrix* matrix = ShenandoahHeap::heap()->connection_matrix();
311 address matrix_addr = matrix->matrix_addr();
312 __ movptr(rscratch1, (intptr_t) ShenandoahHeap::heap()->base());
313 // Compute to-region index
314 __ movptr(tmp, new_val);
315 __ subptr(tmp, rscratch1);
316 __ shrptr(tmp, ShenandoahHeapRegion::region_size_bytes_shift_jint());
317 // Compute from-region index
318 __ movptr(tmp2, store_addr);
319 __ subptr(tmp2, rscratch1);
320 __ shrptr(tmp2, ShenandoahHeapRegion::region_size_bytes_shift_jint());
321 // Compute matrix index
322 __ imulptr(tmp, tmp, matrix->stride_jint());
323 __ addptr(tmp, tmp2);
324 // Address is _matrix[to * stride + from]
325 __ movptr(rscratch1, (intptr_t) matrix_addr);
326 // Test if the element is already set.
327 __ cmpb(Address(rscratch1, tmp, Address::times_1), 0);
328 __ jcc(Assembler::notEqual, done);
329 // Store true, if not yet set.
330 __ movb(Address(rscratch1, tmp, Address::times_1), 1);
331 __ bind(done);
332 }
333
334 void ShenandoahBarrierSetAssembler::read_barrier(MacroAssembler* masm, Register dst) {
335 if (ShenandoahReadBarrier) {
336 read_barrier_impl(masm, dst);
337 }
338 }
339
340 void ShenandoahBarrierSetAssembler::read_barrier_impl(MacroAssembler* masm, Register dst) {
341 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier), "should be enabled");
342 Label is_null;
343 __ testptr(dst, dst);
344 __ jcc(Assembler::zero, is_null);
345 read_barrier_not_null_impl(masm, dst);
346 __ bind(is_null);
347 }
348
349 void ShenandoahBarrierSetAssembler::read_barrier_not_null(MacroAssembler* masm, Register dst) {
350 if (ShenandoahReadBarrier) {
351 read_barrier_not_null_impl(masm, dst);
352 }
353 }
354
355 void ShenandoahBarrierSetAssembler::read_barrier_not_null_impl(MacroAssembler* masm, Register dst) {
356 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier), "should be enabled");
357 __ movptr(dst, Address(dst, BrooksPointer::byte_offset()));
358 }
359
360
361 void ShenandoahBarrierSetAssembler::write_barrier(MacroAssembler* masm, Register dst) {
362 if (ShenandoahWriteBarrier) {
363 write_barrier_impl(masm, dst);
364 }
365 }
366
367 void ShenandoahBarrierSetAssembler::write_barrier_impl(MacroAssembler* masm, Register dst) {
368 assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier), "should be enabled");
369 #ifdef _LP64
370 assert(dst != rscratch1, "different regs");
371
372 Label done;
373
374 Address gc_state(r15_thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
375 __ testb(gc_state, ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
376
377 // Now check if evacuation is in progress.
378 read_barrier_not_null(masm, dst);
379
380 __ jcc(Assembler::zero, done);
381 __ push(rscratch1);
382 __ push(rscratch2);
383
384 __ movptr(rscratch1, dst);
385 __ shrptr(rscratch1, ShenandoahHeapRegion::region_size_bytes_shift_jint());
386 __ movptr(rscratch2, (intptr_t) ShenandoahHeap::in_cset_fast_test_addr());
387 __ movbool(rscratch2, Address(rscratch2, rscratch1, Address::times_1));
388 __ testb(rscratch2, 0x1);
389
390 __ pop(rscratch2);
391 __ pop(rscratch1);
392
393 __ jcc(Assembler::zero, done);
394
395 __ push(rscratch1);
396
397 // Save possibly live regs.
398 if (dst != rax) {
399 __ push(rax);
400 }
401 if (dst != rbx) {
402 __ push(rbx);
403 }
404 if (dst != rcx) {
405 __ push(rcx);
406 }
407 if (dst != rdx) {
408 __ push(rdx);
409 }
410 if (dst != c_rarg1) {
411 __ push(c_rarg1);
412 }
413
414 __ subptr(rsp, 2 * Interpreter::stackElementSize);
415 __ movdbl(Address(rsp, 0), xmm0);
416
417 // Call into runtime
418 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_IRT), dst);
419 __ mov(rscratch1, rax);
420
421 // Restore possibly live regs.
422 __ movdbl(xmm0, Address(rsp, 0));
423 __ addptr(rsp, 2 * Interpreter::stackElementSize);
424
425 if (dst != c_rarg1) {
426 __ pop(c_rarg1);
427 }
428 if (dst != rdx) {
429 __ pop(rdx);
430 }
431 if (dst != rcx) {
432 __ pop(rcx);
433 }
434 if (dst != rbx) {
435 __ pop(rbx);
436 }
437 if (dst != rax) {
438 __ pop(rax);
439 }
440
441 // Move result into dst reg.
442 __ mov(dst, rscratch1);
443
444 __ pop(rscratch1);
445
446 __ bind(done);
447 #else
448 Unimplemented();
449 #endif
450 }
451
452 void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) {
453 if (ShenandoahStoreValReadBarrier || ShenandoahStoreValEnqueueBarrier) {
454 storeval_barrier_impl(masm, dst, tmp);
455 }
456 }
457
458 void ShenandoahBarrierSetAssembler::storeval_barrier_impl(MacroAssembler* masm, Register dst, Register tmp) {
459 assert(UseShenandoahGC && (ShenandoahStoreValReadBarrier || ShenandoahStoreValEnqueueBarrier), "should be enabled");
460
461 if (dst == noreg) return;
462
463 #ifdef _LP64
464 if (ShenandoahStoreValEnqueueBarrier) {
465 Label is_null;
466 __ testptr(dst, dst);
467 __ jcc(Assembler::zero, is_null);
468 write_barrier_impl(masm, dst);
469 __ bind(is_null);
470
471 // The set of registers to be saved+restored is the same as in the write-barrier above.
472 // Those are the commonly used registers in the interpreter.
473 __ pusha();
474 // __ push_callee_saved_registers();
475 __ subptr(rsp, 2 * Interpreter::stackElementSize);
476 __ movdbl(Address(rsp, 0), xmm0);
477
478 satb_write_barrier_pre(masm, noreg, dst, r15_thread, tmp, true, false);
479 __ movdbl(xmm0, Address(rsp, 0));
480 __ addptr(rsp, 2 * Interpreter::stackElementSize);
481 //__ pop_callee_saved_registers();
482 __ popa();
483 }
484 if (ShenandoahStoreValReadBarrier) {
485 read_barrier_impl(masm, dst);
486 }
487 #else
488 Unimplemented();
489 #endif
490 }
491
492 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
493 Register dst, Address src, Register tmp1, Register tmp_thread) {
494 bool on_oop = type == T_OBJECT || type == T_ARRAY;
495 bool in_heap = (decorators & IN_HEAP) != 0;
496 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
497 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
498 bool on_reference = on_weak || on_phantom;
499 if (in_heap) {
500 read_barrier_not_null(masm, src.base());
501 }
502 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
503 if (ShenandoahKeepAliveBarrier && on_oop && on_reference) {
504 const Register thread = NOT_LP64(tmp_thread) LP64_ONLY(r15_thread);
505 NOT_LP64(__ get_thread(thread));
506
507 // Generate the SATB pre-barrier code to log the value of
508 // the referent field in an SATB buffer.
509 shenandoah_write_barrier_pre(masm /* masm */,
510 noreg /* obj */,
511 dst /* pre_val */,
512 thread /* thread */,
513 tmp1 /* tmp */,
514 true /* tosca_live */,
515 true /* expand_call */);
516 }
517 }
518
519 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
520 Address dst, Register val, Register tmp1, Register tmp2) {
521
522 bool in_heap = (decorators & IN_HEAP) != 0;
523 bool in_concurrent_root = (decorators & IN_CONCURRENT_ROOT) != 0;
524 if (in_heap) {
525 write_barrier(masm, dst.base());
526 }
527 if (type == T_OBJECT || type == T_ARRAY) {
528 bool needs_pre_barrier = in_heap || in_concurrent_root;
529 bool needs_post_barrier = val != noreg && in_heap && UseShenandoahMatrix;
530
531 Register tmp3 = LP64_ONLY(r8) NOT_LP64(rsi);
532 Register rthread = LP64_ONLY(r15_thread) NOT_LP64(rcx);
533 // flatten object address if needed
534 // We do it regardless of precise because we need the registers
535 if (dst.index() == noreg && dst.disp() == 0) {
536 if (dst.base() != tmp1) {
537 __ movptr(tmp1, dst.base());
538 }
539 } else {
540 __ lea(tmp1, dst);
541 }
542
543 #ifndef _LP64
544 InterpreterMacroAssembler *imasm = static_cast<InterpreterMacroAssembler*>(masm);
545 #endif
546
547 NOT_LP64(__ get_thread(rcx));
548 NOT_LP64(imasm->save_bcp());
549
550 if (needs_pre_barrier) {
551 shenandoah_write_barrier_pre(masm /*masm*/,
552 tmp1 /* obj */,
553 tmp2 /* pre_val */,
554 rthread /* thread */,
555 tmp3 /* tmp */,
556 val != noreg /* tosca_live */,
557 false /* expand_call */);
558 }
559 if (val == noreg) {
560 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp1, 0), val, noreg, noreg);
561 } else {
562 storeval_barrier(masm, val, tmp3);
563 Register new_val = val;
564 if (needs_post_barrier) {
565 if (UseCompressedOops) {
566 new_val = tmp2;
567 __ movptr(new_val, val);
568 }
569 }
570 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp1, 0), val, noreg, noreg);
571
572 if (needs_post_barrier) {
573 shenandoah_write_barrier_post(masm /*masm*/,
574 tmp1 /* store_adr */,
575 new_val /* new_val */,
576 rthread /* thread */,
577 tmp3 /* tmp */,
578 tmp2 /* tmp2 */);
579 }
580 }
581 NOT_LP64(imasm->restore_bcp());
582
583 } else {
584 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2);
585 }
586 }
587
588 void ShenandoahBarrierSetAssembler::obj_equals(MacroAssembler* masm, DecoratorSet decorators, Register op1, Register op2) {
589 __ cmpptr(op1, op2);
590 if (ShenandoahAcmpBarrier) {
591 Label done;
592 __ jccb(Assembler::equal, done);
593 read_barrier(masm, op1);
594 read_barrier(masm, op2);
595 __ cmpptr(op1, op2);
596 __ bind(done);
597 }
598 }
599
600 void ShenandoahBarrierSetAssembler::obj_equals_addr(MacroAssembler* masm, DecoratorSet decorators, Register src1, Address src2) {
601 __ cmpptr(src1, src2);
602 if (ShenandoahAcmpBarrier) {
603 Label done;
604 __ jccb(Assembler::equal, done);
605 __ movptr(rscratch2, src2);
606 read_barrier(masm, src1);
607 read_barrier(masm, rscratch2);
608 __ cmpptr(src1, rscratch2);
609 __ bind(done);
610 }
611 }
612
613 void ShenandoahBarrierSetAssembler::resolve_for_read(MacroAssembler* masm, DecoratorSet decorators, Register obj) {
614 bool oop_not_null = (decorators & OOP_NOT_NULL) != 0;
615 if (oop_not_null) {
616 read_barrier_not_null(masm, obj);
617 } else {
618 read_barrier(masm, obj);
619 }
620 }
621
622 void ShenandoahBarrierSetAssembler::resolve_for_write(MacroAssembler* masm, DecoratorSet decorators, Register obj) {
623 write_barrier(masm, obj);
624 }
625
626 // Special Shenandoah CAS implementation that handles false negatives
627 // due to concurrent evacuation.
628 #ifndef _LP64
629 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, DecoratorSet decorators,
630 Register res, Address addr, Register oldval, Register newval,
631 bool exchange, bool encode, Register tmp1, Register tmp2) {
632 // Shenandoah has no 32-bit version for this.
633 Unimplemented();
634 }
635 #else
636 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, DecoratorSet decorators,
637 Register res, Address addr, Register oldval, Register newval,
638 bool exchange, bool encode, Register tmp1, Register tmp2) {
639
640 if (!ShenandoahCASBarrier) {
641 BarrierSetAssembler::cmpxchg_oop(masm, decorators, res, addr, oldval, newval, exchange, encode, tmp1, tmp2);
642 return;
643 }
644
645 assert(ShenandoahCASBarrier, "Should only be used when CAS barrier is enabled");
646 assert(oldval == rax, "must be in rax for implicit use in cmpxchg");
647
648 Label retry, done;
649
650 // Apply storeval barrier to newval.
651 if (encode) {
652 if (newval == c_rarg1 && ShenandoahStoreValEnqueueBarrier) {
653 __ mov(tmp2, newval);
654 storeval_barrier(masm, tmp2, tmp1);
655 } else {
656 storeval_barrier(masm, newval, tmp1);
657 }
658 }
659
660 if (UseCompressedOops) {
661 if (encode) {
662 __ encode_heap_oop(oldval);
663 __ mov(rscratch1, newval);
664 __ encode_heap_oop(rscratch1);
665 newval = rscratch1;
666 }
667 }
668
669 // Remember oldval for retry logic below
670 if (UseCompressedOops) {
671 __ movl(tmp1, oldval);
672 } else {
673 __ movptr(tmp1, oldval);
674 }
675
676 // Step 1. Try to CAS with given arguments. If successful, then we are done,
677 // and can safely return.
678 if (os::is_MP()) __ lock();
679 if (UseCompressedOops) {
680 __ cmpxchgl(newval, addr);
681 } else {
682 __ cmpxchgptr(newval, addr);
683 }
684 __ jcc(Assembler::equal, done, true);
685
686 // Step 2. CAS had failed. This may be a false negative.
687 //
688 // The trouble comes when we compare the to-space pointer with the from-space
689 // pointer to the same object. To resolve this, it will suffice to read both
690 // oldval and the value from memory through the read barriers -- this will give
691 // both to-space pointers. If they mismatch, then it was a legitimate failure.
692 //
693 if (UseCompressedOops) {
694 __ decode_heap_oop(tmp1);
695 }
696 __ resolve_for_read(0, tmp1);
697
698 if (UseCompressedOops) {
699 __ movl(tmp2, oldval);
700 __ decode_heap_oop(tmp2);
701 } else {
702 __ movptr(tmp2, oldval);
703 }
704 __ resolve_for_read(0, tmp2);
705
706 __ cmpptr(tmp1, tmp2);
707 __ jcc(Assembler::notEqual, done, true);
708
709 // Step 3. Try to CAS again with resolved to-space pointers.
710 //
711 // Corner case: it may happen that somebody stored the from-space pointer
712 // to memory while we were preparing for retry. Therefore, we can fail again
713 // on retry, and so need to do this in loop, always re-reading the failure
714 // witness through the read barrier.
715 __ bind(retry);
716 if (os::is_MP()) __ lock();
717 if (UseCompressedOops) {
718 __ cmpxchgl(newval, addr);
719 } else {
720 __ cmpxchgptr(newval, addr);
721 }
722 __ jcc(Assembler::equal, done, true);
723
724 if (UseCompressedOops) {
725 __ movl(tmp2, oldval);
726 __ decode_heap_oop(tmp2);
727 } else {
728 __ movptr(tmp2, oldval);
729 }
730 __ resolve_for_read(0, tmp2);
731
732 __ cmpptr(tmp1, tmp2);
733 __ jcc(Assembler::equal, retry, true);
734
735 // Step 4. If we need a boolean result out of CAS, check the flag again,
736 // and promote the result. Note that we handle the flag from both the CAS
737 // itself and from the retry loop.
738 __ bind(done);
739 if (!exchange) {
740 assert(res != NULL, "need result register");
741 __ setb(Assembler::equal, res);
742 __ movzbl(res, res);
743 }
744 }
745 #endif // LP64
746
747 void ShenandoahBarrierSetAssembler::xchg_oop(MacroAssembler* masm, DecoratorSet decorators,
748 Register obj, Address addr, Register tmp) {
749 storeval_barrier(masm, obj, tmp);
750 BarrierSetAssembler::xchg_oop(masm, decorators, obj, addr, tmp);
751 }
752
753 #ifdef COMPILER1
754
755 #undef __
756 #define __ ce->masm()->
757
758 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) {
759 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
760 // At this point we know that marking is in progress.
761 // If do_load() is true then we have to emit the
762 // load of the previous value; otherwise it has already
763 // been loaded into _pre_val.
764
765 __ bind(*stub->entry());
766 assert(stub->pre_val()->is_register(), "Precondition.");
767
768 Register pre_val_reg = stub->pre_val()->as_register();
769
770 if (stub->do_load()) {
771 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/);
772 }
773
774 __ cmpptr(pre_val_reg, (int32_t)NULL_WORD);
775 __ jcc(Assembler::equal, *stub->continuation());
776 ce->store_parameter(stub->pre_val()->as_register(), 0);
777 __ call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
778 __ jmp(*stub->continuation());
779
780 }
781
782 #undef __
783
784 #define __ sasm->
785
786 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
787 __ prologue("shenandoah_pre_barrier", false);
788 // arg0 : previous value of memory
789
790 __ push(rax);
791 __ push(rdx);
792
793 const Register pre_val = rax;
794 const Register thread = NOT_LP64(rax) LP64_ONLY(r15_thread);
795 const Register tmp = rdx;
796
797 NOT_LP64(__ get_thread(thread);)
798
799 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
800 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
801
802 Label done;
803 Label runtime;
804
805 // Is SATB still active?
806 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
807 __ testb(gc_state, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL);
808 __ jcc(Assembler::zero, done);
809
810 // Can we store original value in the thread's buffer?
811
812 __ movptr(tmp, queue_index);
813 __ testptr(tmp, tmp);
814 __ jcc(Assembler::zero, runtime);
815 __ subptr(tmp, wordSize);
816 __ movptr(queue_index, tmp);
817 __ addptr(tmp, buffer);
818
819 // prev_val (rax)
820 __ load_parameter(0, pre_val);
821 __ movptr(Address(tmp, 0), pre_val);
822 __ jmp(done);
823
824 __ bind(runtime);
825
826 __ save_live_registers_no_oop_map(true);
827
828 // load the pre-value
829 __ load_parameter(0, rcx);
830 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), rcx, thread);
831
832 __ restore_live_registers(true);
833
834 __ bind(done);
835
836 __ pop(rdx);
837 __ pop(rax);
838
839 __ epilogue();
840 }
841
842 #undef __
843
844 #endif // COMPILER1
845
846 address ShenandoahBarrierSetAssembler::shenandoah_wb() {
847 assert(_shenandoah_wb != NULL, "need write barrier stub");
848 return _shenandoah_wb;
849 }
850
851 address ShenandoahBarrierSetAssembler::shenandoah_wb_C() {
852 assert(_shenandoah_wb_C != NULL, "need write barrier stub");
853 return _shenandoah_wb_C;
854 }
855
856 #define __ cgen->assembler()->
857
858 address ShenandoahBarrierSetAssembler::generate_shenandoah_wb(StubCodeGenerator* cgen, bool c_abi, bool do_cset_test) {
859 __ align(CodeEntryAlignment);
860 StubCodeMark mark(cgen, "StubRoutines", "shenandoah_wb");
861 address start = __ pc();
862
863 #ifdef _LP64
864 Label not_done;
865
866 // We use RDI, which also serves as argument register for slow call.
867 // RAX always holds the src object ptr, except after the slow call and
868 // the cmpxchg, then it holds the result.
869 // R8 and RCX are used as temporary registers.
870 if (!c_abi) {
871 __ push(rdi);
872 __ push(r8);
873 }
874
875 // Check for object beeing in the collection set.
876 // TODO: Can we use only 1 register here?
877 // The source object arrives here in rax.
878 // live: rax
879 // live: rdi
880 if (!c_abi) {
881 __ mov(rdi, rax);
882 } else {
883 if (rax != c_rarg0) {
884 __ mov(rax, c_rarg0);
885 }
886 }
887 if (do_cset_test) {
888 __ shrptr(rdi, ShenandoahHeapRegion::region_size_bytes_shift_jint());
889 // live: r8
890 __ movptr(r8, (intptr_t) ShenandoahHeap::in_cset_fast_test_addr());
891 __ movbool(r8, Address(r8, rdi, Address::times_1));
892 // unlive: rdi
893 __ testbool(r8);
894 // unlive: r8
895 __ jccb(Assembler::notZero, not_done);
896
897 if (!c_abi) {
898 __ pop(r8);
899 __ pop(rdi);
900 }
901 __ ret(0);
902
903 __ bind(not_done);
904 }
905
906 if (!c_abi) {
907 __ push(rcx);
908 }
909
910 if (!c_abi) {
911 __ push(rdx);
912 __ push(rdi);
913 __ push(rsi);
914 __ push(r8);
915 __ push(r9);
916 __ push(r10);
917 __ push(r11);
918 __ push(r12);
919 __ push(r13);
920 __ push(r14);
921 __ push(r15);
922 }
923 __ save_vector_registers();
924 __ movptr(rdi, rax);
925 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_JRT), rdi);
926 __ restore_vector_registers();
927 if (!c_abi) {
928 __ pop(r15);
929 __ pop(r14);
930 __ pop(r13);
931 __ pop(r12);
932 __ pop(r11);
933 __ pop(r10);
934 __ pop(r9);
935 __ pop(r8);
936 __ pop(rsi);
937 __ pop(rdi);
938 __ pop(rdx);
939
940 __ pop(rcx);
941 __ pop(r8);
942 __ pop(rdi);
943 }
944 __ ret(0);
945 #else
946 ShouldNotReachHere();
947 #endif
948 return start;
949 }
950
951 #undef __
952
953 void ShenandoahBarrierSetAssembler::barrier_stubs_init() {
954 if (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier) {
955 int stub_code_size = 4096;
956 ResourceMark rm;
957 BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size);
958 CodeBuffer buf(bb);
959 StubCodeGenerator cgen(&buf);
960 _shenandoah_wb = generate_shenandoah_wb(&cgen, false, true);
961 _shenandoah_wb_C = generate_shenandoah_wb(&cgen, true, !ShenandoahWriteBarrierCsetTestInIR);
962 }
963 }