1 /*
2 * Copyright (c) 2018, 2021, 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/shenandoahRuntime.hpp"
32 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
33 #include "gc/shenandoah/heuristics/shenandoahHeuristics.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "runtime/javaThread.hpp"
36 #include "runtime/sharedRuntime.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 static void save_machine_state(MacroAssembler* masm, bool handle_gpr, bool handle_fp) {
47 if (handle_gpr) {
48 __ push_IU_state();
49 }
50
51 if (handle_fp) {
52 // Some paths can be reached from the c2i adapter with live fp arguments in registers.
53 LP64_ONLY(assert(Argument::n_float_register_parameters_j == 8, "8 fp registers to save at java call"));
54
55 if (UseSSE >= 2) {
56 const int xmm_size = wordSize * LP64_ONLY(2) NOT_LP64(4);
57 __ subptr(rsp, xmm_size * 8);
58 __ movdbl(Address(rsp, xmm_size * 0), xmm0);
59 __ movdbl(Address(rsp, xmm_size * 1), xmm1);
60 __ movdbl(Address(rsp, xmm_size * 2), xmm2);
61 __ movdbl(Address(rsp, xmm_size * 3), xmm3);
62 __ movdbl(Address(rsp, xmm_size * 4), xmm4);
63 __ movdbl(Address(rsp, xmm_size * 5), xmm5);
64 __ movdbl(Address(rsp, xmm_size * 6), xmm6);
65 __ movdbl(Address(rsp, xmm_size * 7), xmm7);
66 } else if (UseSSE >= 1) {
67 const int xmm_size = wordSize * LP64_ONLY(1) NOT_LP64(2);
68 __ subptr(rsp, xmm_size * 8);
69 __ movflt(Address(rsp, xmm_size * 0), xmm0);
70 __ movflt(Address(rsp, xmm_size * 1), xmm1);
71 __ movflt(Address(rsp, xmm_size * 2), xmm2);
72 __ movflt(Address(rsp, xmm_size * 3), xmm3);
73 __ movflt(Address(rsp, xmm_size * 4), xmm4);
74 __ movflt(Address(rsp, xmm_size * 5), xmm5);
75 __ movflt(Address(rsp, xmm_size * 6), xmm6);
76 __ movflt(Address(rsp, xmm_size * 7), xmm7);
77 } else {
78 __ push_FPU_state();
79 }
80 }
81 }
82
83 static void restore_machine_state(MacroAssembler* masm, bool handle_gpr, bool handle_fp) {
84 if (handle_fp) {
85 if (UseSSE >= 2) {
86 const int xmm_size = wordSize * LP64_ONLY(2) NOT_LP64(4);
87 __ movdbl(xmm0, Address(rsp, xmm_size * 0));
88 __ movdbl(xmm1, Address(rsp, xmm_size * 1));
89 __ movdbl(xmm2, Address(rsp, xmm_size * 2));
90 __ movdbl(xmm3, Address(rsp, xmm_size * 3));
91 __ movdbl(xmm4, Address(rsp, xmm_size * 4));
92 __ movdbl(xmm5, Address(rsp, xmm_size * 5));
93 __ movdbl(xmm6, Address(rsp, xmm_size * 6));
94 __ movdbl(xmm7, Address(rsp, xmm_size * 7));
95 __ addptr(rsp, xmm_size * 8);
96 } else if (UseSSE >= 1) {
97 const int xmm_size = wordSize * LP64_ONLY(1) NOT_LP64(2);
98 __ movflt(xmm0, Address(rsp, xmm_size * 0));
99 __ movflt(xmm1, Address(rsp, xmm_size * 1));
100 __ movflt(xmm2, Address(rsp, xmm_size * 2));
101 __ movflt(xmm3, Address(rsp, xmm_size * 3));
102 __ movflt(xmm4, Address(rsp, xmm_size * 4));
103 __ movflt(xmm5, Address(rsp, xmm_size * 5));
104 __ movflt(xmm6, Address(rsp, xmm_size * 6));
105 __ movflt(xmm7, Address(rsp, xmm_size * 7));
106 __ addptr(rsp, xmm_size * 8);
107 } else {
108 __ pop_FPU_state();
109 }
110 }
111
112 if (handle_gpr) {
113 __ pop_IU_state();
114 }
115 }
116
117 void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
118 Register src, Register dst, Register count) {
119
120 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
121
122 if (is_reference_type(type)) {
123
124 if ((ShenandoahSATBBarrier && !dest_uninitialized) || ShenandoahLoadRefBarrier) {
125 #ifdef _LP64
126 Register thread = r15_thread;
127 #else
128 Register thread = rax;
129 if (thread == src || thread == dst || thread == count) {
130 thread = rbx;
131 }
132 if (thread == src || thread == dst || thread == count) {
133 thread = rcx;
134 }
135 if (thread == src || thread == dst || thread == count) {
136 thread = rdx;
137 }
138 __ push(thread);
139 __ get_thread(thread);
140 #endif
141 assert_different_registers(src, dst, count, thread);
142
143 Label done;
144 // Short-circuit if count == 0.
145 __ testptr(count, count);
146 __ jcc(Assembler::zero, done);
147
148 // Avoid runtime call when not active.
149 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
150 int flags;
151 if (ShenandoahSATBBarrier && dest_uninitialized) {
152 flags = ShenandoahHeap::HAS_FORWARDED;
153 } else {
154 flags = ShenandoahHeap::HAS_FORWARDED | ShenandoahHeap::MARKING;
155 }
156 __ testb(gc_state, flags);
157 __ jcc(Assembler::zero, done);
158
159 save_machine_state(masm, /* handle_gpr = */ true, /* handle_fp = */ false);
160
161 #ifdef _LP64
162 assert(src == rdi, "expected");
163 assert(dst == rsi, "expected");
164 assert(count == rdx, "expected");
165 if (UseCompressedOops) {
166 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::arraycopy_barrier_narrow_oop),
167 src, dst, count);
168 } else
169 #endif
170 {
171 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::arraycopy_barrier_oop),
172 src, dst, count);
173 }
174
175 restore_machine_state(masm, /* handle_gpr = */ true, /* handle_fp = */ false);
176
177 __ bind(done);
178 NOT_LP64(__ pop(thread);)
179 }
180 }
181
182 }
183
184 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm,
185 Register obj,
186 Register pre_val,
187 Register thread,
188 Register tmp,
189 bool tosca_live,
190 bool expand_call) {
191
192 if (ShenandoahSATBBarrier) {
193 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call);
194 }
195 }
196
197 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm,
198 Register obj,
199 Register pre_val,
200 Register thread,
201 Register tmp,
202 bool tosca_live,
203 bool expand_call) {
204 // If expand_call is true then we expand the call_VM_leaf macro
205 // directly to skip generating the check by
206 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
207
208 #ifdef _LP64
209 assert(thread == r15_thread, "must be");
210 #endif // _LP64
211
212 Label done;
213 Label runtime;
214
215 assert(pre_val != noreg, "check this code");
216
217 if (obj != noreg) {
218 assert_different_registers(obj, pre_val, tmp);
219 assert(pre_val != rax, "check this code");
220 }
221
222 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
223 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
224
225 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
226 __ testb(gc_state, ShenandoahHeap::MARKING);
227 __ jcc(Assembler::zero, done);
228
229 // Do we need to load the previous value?
230 if (obj != noreg) {
231 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW);
232 }
233
234 // Is the previous value null?
235 __ cmpptr(pre_val, NULL_WORD);
236 __ jcc(Assembler::equal, done);
237
238 // Can we store original value in the thread's buffer?
239 // Is index == 0?
240 // (The index field is typed as size_t.)
241
242 __ movptr(tmp, index); // tmp := *index_adr
243 __ cmpptr(tmp, 0); // tmp == 0?
244 __ jcc(Assembler::equal, runtime); // If yes, goto runtime
245
246 __ subptr(tmp, wordSize); // tmp := tmp - wordSize
247 __ movptr(index, tmp); // *index_adr := tmp
248 __ addptr(tmp, buffer); // tmp := tmp + *buffer_adr
249
250 // Record the previous value
251 __ movptr(Address(tmp, 0), pre_val);
252 __ jmp(done);
253
254 __ bind(runtime);
255 // save the live input values
256 if(tosca_live) __ push(rax);
257
258 if (obj != noreg && obj != rax)
259 __ push(obj);
260
261 if (pre_val != rax)
262 __ push(pre_val);
263
264 // Calling the runtime using the regular call_VM_leaf mechanism generates
265 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
266 // that checks that the *(ebp+frame::interpreter_frame_last_sp) == nullptr.
267 //
268 // If we care generating the pre-barrier without a frame (e.g. in the
269 // intrinsified Reference.get() routine) then ebp might be pointing to
270 // the caller frame and so this check will most likely fail at runtime.
271 //
272 // Expanding the call directly bypasses the generation of the check.
273 // So when we do not have have a full interpreter frame on the stack
274 // expand_call should be passed true.
275
276 NOT_LP64( __ push(thread); )
277
278 #ifdef _LP64
279 // We move pre_val into c_rarg0 early, in order to avoid smashing it, should
280 // pre_val be c_rarg1 (where the call prologue would copy thread argument).
281 // Note: this should not accidentally smash thread, because thread is always r15.
282 assert(thread != c_rarg0, "smashed arg");
283 if (c_rarg0 != pre_val) {
284 __ mov(c_rarg0, pre_val);
285 }
286 #endif
287
288 if (expand_call) {
289 LP64_ONLY( assert(pre_val != c_rarg1, "smashed arg"); )
290 #ifdef _LP64
291 if (c_rarg1 != thread) {
292 __ mov(c_rarg1, thread);
293 }
294 // Already moved pre_val into c_rarg0 above
295 #else
296 __ push(thread);
297 __ push(pre_val);
298 #endif
299 __ MacroAssembler::call_VM_leaf_base(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre), 2);
300 } else {
301 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre), LP64_ONLY(c_rarg0) NOT_LP64(pre_val), thread);
302 }
303
304 NOT_LP64( __ pop(thread); )
305
306 // save the live input values
307 if (pre_val != rax)
308 __ pop(pre_val);
309
310 if (obj != noreg && obj != rax)
311 __ pop(obj);
312
313 if(tosca_live) __ pop(rax);
314
315 __ bind(done);
316 }
317
318 void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm, Register dst, Address src, DecoratorSet decorators) {
319 assert(ShenandoahLoadRefBarrier, "Should be enabled");
320
321 bool is_strong = ShenandoahBarrierSet::is_strong_access(decorators);
322 bool is_weak = ShenandoahBarrierSet::is_weak_access(decorators);
323 bool is_phantom = ShenandoahBarrierSet::is_phantom_access(decorators);
324 bool is_native = ShenandoahBarrierSet::is_native_access(decorators);
325 bool is_narrow = UseCompressedOops && !is_native;
326
327 Label heap_stable, not_cset;
328
329 __ block_comment("load_reference_barrier { ");
330
331 // Check if GC is active
332 #ifdef _LP64
333 Register thread = r15_thread;
334 #else
335 Register thread = rcx;
336 if (thread == dst) {
337 thread = rbx;
338 }
339 __ push(thread);
340 __ get_thread(thread);
341 #endif
342
343 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
344 int flags = ShenandoahHeap::HAS_FORWARDED;
345 if (!is_strong) {
346 flags |= ShenandoahHeap::WEAK_ROOTS;
347 }
348 __ testb(gc_state, flags);
349 __ jcc(Assembler::zero, heap_stable);
350
351 Register tmp1 = noreg, tmp2 = noreg;
352 if (is_strong) {
353 // Test for object in cset
354 // Allocate temporary registers
355 for (int i = 0; i < 8; i++) {
356 Register r = as_Register(i);
357 if (r != rsp && r != rbp && r != dst && r != src.base() && r != src.index()) {
358 if (tmp1 == noreg) {
359 tmp1 = r;
360 } else {
361 tmp2 = r;
362 break;
363 }
364 }
365 }
366 assert(tmp1 != noreg, "tmp1 allocated");
367 assert(tmp2 != noreg, "tmp2 allocated");
368 assert_different_registers(tmp1, tmp2, src.base(), src.index());
369 assert_different_registers(tmp1, tmp2, dst);
370
371 __ push(tmp1);
372 __ push(tmp2);
373
374 // Optimized cset-test
375 __ movptr(tmp1, dst);
376 __ shrptr(tmp1, ShenandoahHeapRegion::region_size_bytes_shift_jint());
377 __ movptr(tmp2, (intptr_t) ShenandoahHeap::in_cset_fast_test_addr());
378 __ movbool(tmp1, Address(tmp1, tmp2, Address::times_1));
379 __ testbool(tmp1);
380 __ jcc(Assembler::zero, not_cset);
381 }
382
383 save_machine_state(masm, /* handle_gpr = */ false, /* handle_fp = */ true);
384
385 // The rest is saved with the optimized path
386
387 uint num_saved_regs = 4 + (dst != rax ? 1 : 0) LP64_ONLY(+4);
388 __ subptr(rsp, num_saved_regs * wordSize);
389 uint slot = num_saved_regs;
390 if (dst != rax) {
391 __ movptr(Address(rsp, (--slot) * wordSize), rax);
392 }
393 __ movptr(Address(rsp, (--slot) * wordSize), rcx);
394 __ movptr(Address(rsp, (--slot) * wordSize), rdx);
395 __ movptr(Address(rsp, (--slot) * wordSize), rdi);
396 __ movptr(Address(rsp, (--slot) * wordSize), rsi);
397 #ifdef _LP64
398 __ movptr(Address(rsp, (--slot) * wordSize), r8);
399 __ movptr(Address(rsp, (--slot) * wordSize), r9);
400 __ movptr(Address(rsp, (--slot) * wordSize), r10);
401 __ movptr(Address(rsp, (--slot) * wordSize), r11);
402 // r12-r15 are callee saved in all calling conventions
403 #endif
404 assert(slot == 0, "must use all slots");
405
406 // Shuffle registers such that dst is in c_rarg0 and addr in c_rarg1.
407 #ifdef _LP64
408 Register arg0 = c_rarg0, arg1 = c_rarg1;
409 #else
410 Register arg0 = rdi, arg1 = rsi;
411 #endif
412 if (dst == arg1) {
413 __ lea(arg0, src);
414 __ xchgptr(arg1, arg0);
415 } else {
416 __ lea(arg1, src);
417 __ movptr(arg0, dst);
418 }
419
420 if (is_strong) {
421 if (is_narrow) {
422 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_strong_narrow), arg0, arg1);
423 } else {
424 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_strong), arg0, arg1);
425 }
426 } else if (is_weak) {
427 if (is_narrow) {
428 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_weak_narrow), arg0, arg1);
429 } else {
430 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_weak), arg0, arg1);
431 }
432 } else {
433 assert(is_phantom, "only remaining strength");
434 assert(!is_narrow, "phantom access cannot be narrow");
435 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_phantom), arg0, arg1);
436 }
437
438 #ifdef _LP64
439 __ movptr(r11, Address(rsp, (slot++) * wordSize));
440 __ movptr(r10, Address(rsp, (slot++) * wordSize));
441 __ movptr(r9, Address(rsp, (slot++) * wordSize));
442 __ movptr(r8, Address(rsp, (slot++) * wordSize));
443 #endif
444 __ movptr(rsi, Address(rsp, (slot++) * wordSize));
445 __ movptr(rdi, Address(rsp, (slot++) * wordSize));
446 __ movptr(rdx, Address(rsp, (slot++) * wordSize));
447 __ movptr(rcx, Address(rsp, (slot++) * wordSize));
448
449 if (dst != rax) {
450 __ movptr(dst, rax);
451 __ movptr(rax, Address(rsp, (slot++) * wordSize));
452 }
453
454 assert(slot == num_saved_regs, "must use all slots");
455 __ addptr(rsp, num_saved_regs * wordSize);
456
457 restore_machine_state(masm, /* handle_gpr = */ false, /* handle_fp = */ true);
458
459 __ bind(not_cset);
460
461 if (is_strong) {
462 __ pop(tmp2);
463 __ pop(tmp1);
464 }
465
466 __ bind(heap_stable);
467
468 __ block_comment("} load_reference_barrier");
469
470 #ifndef _LP64
471 __ pop(thread);
472 #endif
473 }
474
475 //
476 // Arguments:
477 //
478 // Inputs:
479 // src: oop location, might be clobbered
480 // tmp1: scratch register, might not be valid.
481 //
482 // Output:
483 // dst: oop loaded from src location
484 //
485 // Kill:
486 // tmp1 (if it is valid)
487 //
488 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
489 Register dst, Address src, Register tmp1, Register tmp_thread) {
490 // 1: non-reference load, no additional barrier is needed
491 if (!is_reference_type(type)) {
492 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
493 return;
494 }
495
496 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Not expected");
497
498 // 2: load a reference from src location and apply LRB if needed
499 if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) {
500 Register result_dst = dst;
501 bool use_tmp1_for_dst = false;
502
503 // Preserve src location for LRB
504 if (dst == src.base() || dst == src.index()) {
505 // Use tmp1 for dst if possible, as it is not used in BarrierAssembler::load_at()
506 if (tmp1->is_valid() && tmp1 != src.base() && tmp1 != src.index()) {
507 dst = tmp1;
508 use_tmp1_for_dst = true;
509 } else {
510 dst = rdi;
511 __ push(dst);
512 }
513 assert_different_registers(dst, src.base(), src.index());
514 }
515
516 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
517
518 load_reference_barrier(masm, dst, src, decorators);
519
520 // Move loaded oop to final destination
521 if (dst != result_dst) {
522 __ movptr(result_dst, dst);
523
524 if (!use_tmp1_for_dst) {
525 __ pop(dst);
526 }
527
528 dst = result_dst;
529 }
530 } else {
531 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
532 }
533
534 // 3: apply keep-alive barrier if needed
535 if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) {
536 save_machine_state(masm, /* handle_gpr = */ true, /* handle_fp = */ true);
537
538 Register thread = NOT_LP64(tmp_thread) LP64_ONLY(r15_thread);
539 assert_different_registers(dst, tmp1, tmp_thread);
540 if (!thread->is_valid()) {
541 thread = rdx;
542 }
543 NOT_LP64(__ get_thread(thread));
544 // Generate the SATB pre-barrier code to log the value of
545 // the referent field in an SATB buffer.
546 shenandoah_write_barrier_pre(masm /* masm */,
547 noreg /* obj */,
548 dst /* pre_val */,
549 thread /* thread */,
550 tmp1 /* tmp */,
551 true /* tosca_live */,
552 true /* expand_call */);
553
554 restore_machine_state(masm, /* handle_gpr = */ true, /* handle_fp = */ true);
555 }
556 }
557
558 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
559 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
560
561 bool on_oop = is_reference_type(type);
562 bool in_heap = (decorators & IN_HEAP) != 0;
563 bool as_normal = (decorators & AS_NORMAL) != 0;
564 if (on_oop && in_heap) {
565 bool needs_pre_barrier = as_normal;
566
567 Register rthread = LP64_ONLY(r15_thread) NOT_LP64(rcx);
568 // flatten object address if needed
569 // We do it regardless of precise because we need the registers
570 if (dst.index() == noreg && dst.disp() == 0) {
571 if (dst.base() != tmp1) {
572 __ movptr(tmp1, dst.base());
573 }
574 } else {
575 __ lea(tmp1, dst);
576 }
577
578 assert_different_registers(val, tmp1, tmp2, tmp3, rthread);
579
580 #ifndef _LP64
581 __ get_thread(rthread);
582 InterpreterMacroAssembler *imasm = static_cast<InterpreterMacroAssembler*>(masm);
583 imasm->save_bcp();
584 #endif
585
586 if (needs_pre_barrier) {
587 shenandoah_write_barrier_pre(masm /*masm*/,
588 tmp1 /* obj */,
589 tmp2 /* pre_val */,
590 rthread /* thread */,
591 tmp3 /* tmp */,
592 val != noreg /* tosca_live */,
593 false /* expand_call */);
594 }
595 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp1, 0), val, noreg, noreg, noreg);
596 NOT_LP64(imasm->restore_bcp());
597 } else {
598 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2, tmp3);
599 }
600 }
601
602 void ShenandoahBarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env,
603 Register obj, Register tmp, Label& slowpath) {
604 Label done;
605 // Resolve jobject
606 BarrierSetAssembler::try_resolve_jobject_in_native(masm, jni_env, obj, tmp, slowpath);
607
608 // Check for null.
609 __ testptr(obj, obj);
610 __ jcc(Assembler::zero, done);
611
612 Address gc_state(jni_env, ShenandoahThreadLocalData::gc_state_offset() - JavaThread::jni_environment_offset());
613 __ testb(gc_state, ShenandoahHeap::EVACUATION);
614 __ jccb(Assembler::notZero, slowpath);
615 __ bind(done);
616 }
617
618 // Special Shenandoah CAS implementation that handles false negatives
619 // due to concurrent evacuation.
620 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm,
621 Register res, Address addr, Register oldval, Register newval,
622 bool exchange, Register tmp1, Register tmp2) {
623 assert(ShenandoahCASBarrier, "Should only be used when CAS barrier is enabled");
624 assert(oldval == rax, "must be in rax for implicit use in cmpxchg");
625 assert_different_registers(oldval, tmp1, tmp2);
626 assert_different_registers(newval, tmp1, tmp2);
627
628 Label L_success, L_failure;
629
630 // Remember oldval for retry logic below
631 #ifdef _LP64
632 if (UseCompressedOops) {
633 __ movl(tmp1, oldval);
634 } else
635 #endif
636 {
637 __ movptr(tmp1, oldval);
638 }
639
640 // Step 1. Fast-path.
641 //
642 // Try to CAS with given arguments. If successful, then we are done.
643
644 #ifdef _LP64
645 if (UseCompressedOops) {
646 __ lock();
647 __ cmpxchgl(newval, addr);
648 } else
649 #endif
650 {
651 __ lock();
652 __ cmpxchgptr(newval, addr);
653 }
654 __ jcc(Assembler::equal, L_success);
655
656 // Step 2. CAS had failed. This may be a false negative.
657 //
658 // The trouble comes when we compare the to-space pointer with the from-space
659 // pointer to the same object. To resolve this, it will suffice to resolve
660 // the value from memory -- this will give both to-space pointers.
661 // If they mismatch, then it was a legitimate failure.
662 //
663 // Before reaching to resolve sequence, see if we can avoid the whole shebang
664 // with filters.
665
666 // Filter: when offending in-memory value is null, the failure is definitely legitimate
667 __ testptr(oldval, oldval);
668 __ jcc(Assembler::zero, L_failure);
669
670 // Filter: when heap is stable, the failure is definitely legitimate
671 #ifdef _LP64
672 const Register thread = r15_thread;
673 #else
674 const Register thread = tmp2;
675 __ get_thread(thread);
676 #endif
677 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
678 __ testb(gc_state, ShenandoahHeap::HAS_FORWARDED);
679 __ jcc(Assembler::zero, L_failure);
680
681 #ifdef _LP64
682 if (UseCompressedOops) {
683 __ movl(tmp2, oldval);
684 __ decode_heap_oop(tmp2);
685 } else
686 #endif
687 {
688 __ movptr(tmp2, oldval);
689 }
690
691 // Decode offending in-memory value.
692 // Test if-forwarded
693 __ testb(Address(tmp2, oopDesc::mark_offset_in_bytes()), markWord::marked_value);
694 __ jcc(Assembler::noParity, L_failure); // When odd number of bits, then not forwarded
695 __ jcc(Assembler::zero, L_failure); // When it is 00, then also not forwarded
696
697 // Load and mask forwarding pointer
698 __ movptr(tmp2, Address(tmp2, oopDesc::mark_offset_in_bytes()));
699 __ shrptr(tmp2, 2);
700 __ shlptr(tmp2, 2);
701
702 #ifdef _LP64
703 if (UseCompressedOops) {
704 __ decode_heap_oop(tmp1); // decode for comparison
705 }
706 #endif
707
708 // Now we have the forwarded offender in tmp2.
709 // Compare and if they don't match, we have legitimate failure
710 __ cmpptr(tmp1, tmp2);
711 __ jcc(Assembler::notEqual, L_failure);
712
713 // Step 3. Need to fix the memory ptr before continuing.
714 //
715 // At this point, we have from-space oldval in the register, and its to-space
716 // address is in tmp2. Let's try to update it into memory. We don't care if it
717 // succeeds or not. If it does, then the retrying CAS would see it and succeed.
718 // If this fixup fails, this means somebody else beat us to it, and necessarily
719 // with to-space ptr store. We still have to do the retry, because the GC might
720 // have updated the reference for us.
721
722 #ifdef _LP64
723 if (UseCompressedOops) {
724 __ encode_heap_oop(tmp2); // previously decoded at step 2.
725 }
726 #endif
727
728 #ifdef _LP64
729 if (UseCompressedOops) {
730 __ lock();
731 __ cmpxchgl(tmp2, addr);
732 } else
733 #endif
734 {
735 __ lock();
736 __ cmpxchgptr(tmp2, addr);
737 }
738
739 // Step 4. Try to CAS again.
740 //
741 // This is guaranteed not to have false negatives, because oldval is definitely
742 // to-space, and memory pointer is to-space as well. Nothing is able to store
743 // from-space ptr into memory anymore. Make sure oldval is restored, after being
744 // garbled during retries.
745 //
746 #ifdef _LP64
747 if (UseCompressedOops) {
748 __ movl(oldval, tmp2);
749 } else
750 #endif
751 {
752 __ movptr(oldval, tmp2);
753 }
754
755 #ifdef _LP64
756 if (UseCompressedOops) {
757 __ lock();
758 __ cmpxchgl(newval, addr);
759 } else
760 #endif
761 {
762 __ lock();
763 __ cmpxchgptr(newval, addr);
764 }
765 if (!exchange) {
766 __ jccb(Assembler::equal, L_success); // fastpath, peeking into Step 5, no need to jump
767 }
768
769 // Step 5. If we need a boolean result out of CAS, set the flag appropriately.
770 // and promote the result. Note that we handle the flag from both the 1st and 2nd CAS.
771 // Otherwise, failure witness for CAE is in oldval on all paths, and we can return.
772
773 if (exchange) {
774 __ bind(L_failure);
775 __ bind(L_success);
776 } else {
777 assert(res != noreg, "need result register");
778
779 Label exit;
780 __ bind(L_failure);
781 __ xorptr(res, res);
782 __ jmpb(exit);
783
784 __ bind(L_success);
785 __ movptr(res, 1);
786 __ bind(exit);
787 }
788 }
789
790 #undef __
791
792 #ifdef COMPILER1
793
794 #define __ ce->masm()->
795
796 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) {
797 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
798 // At this point we know that marking is in progress.
799 // If do_load() is true then we have to emit the
800 // load of the previous value; otherwise it has already
801 // been loaded into _pre_val.
802
803 __ bind(*stub->entry());
804 assert(stub->pre_val()->is_register(), "Precondition.");
805
806 Register pre_val_reg = stub->pre_val()->as_register();
807
808 if (stub->do_load()) {
809 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/);
810 }
811
812 __ cmpptr(pre_val_reg, NULL_WORD);
813 __ jcc(Assembler::equal, *stub->continuation());
814 ce->store_parameter(stub->pre_val()->as_register(), 0);
815 __ call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
816 __ jmp(*stub->continuation());
817
818 }
819
820 void ShenandoahBarrierSetAssembler::gen_load_reference_barrier_stub(LIR_Assembler* ce, ShenandoahLoadReferenceBarrierStub* stub) {
821 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
822 __ bind(*stub->entry());
823
824 DecoratorSet decorators = stub->decorators();
825 bool is_strong = ShenandoahBarrierSet::is_strong_access(decorators);
826 bool is_weak = ShenandoahBarrierSet::is_weak_access(decorators);
827 bool is_phantom = ShenandoahBarrierSet::is_phantom_access(decorators);
828 bool is_native = ShenandoahBarrierSet::is_native_access(decorators);
829
830 Register obj = stub->obj()->as_register();
831 Register res = stub->result()->as_register();
832 Register addr = stub->addr()->as_pointer_register();
833 Register tmp1 = stub->tmp1()->as_register();
834 Register tmp2 = stub->tmp2()->as_register();
835 assert_different_registers(obj, res, addr, tmp1, tmp2);
836
837 Label slow_path;
838
839 assert(res == rax, "result must arrive in rax");
840
841 if (res != obj) {
842 __ mov(res, obj);
843 }
844
845 if (is_strong) {
846 // Check for object being in the collection set.
847 __ mov(tmp1, res);
848 __ shrptr(tmp1, ShenandoahHeapRegion::region_size_bytes_shift_jint());
849 __ movptr(tmp2, (intptr_t) ShenandoahHeap::in_cset_fast_test_addr());
850 #ifdef _LP64
851 __ movbool(tmp2, Address(tmp2, tmp1, Address::times_1));
852 __ testbool(tmp2);
853 #else
854 // On x86_32, C1 register allocator can give us the register without 8-bit support.
855 // Do the full-register access and test to avoid compilation failures.
856 __ movptr(tmp2, Address(tmp2, tmp1, Address::times_1));
857 __ testptr(tmp2, 0xFF);
858 #endif
859 __ jcc(Assembler::zero, *stub->continuation());
860 }
861
862 __ bind(slow_path);
863 ce->store_parameter(res, 0);
864 ce->store_parameter(addr, 1);
865 if (is_strong) {
866 if (is_native) {
867 __ call(RuntimeAddress(bs->load_reference_barrier_strong_native_rt_code_blob()->code_begin()));
868 } else {
869 __ call(RuntimeAddress(bs->load_reference_barrier_strong_rt_code_blob()->code_begin()));
870 }
871 } else if (is_weak) {
872 __ call(RuntimeAddress(bs->load_reference_barrier_weak_rt_code_blob()->code_begin()));
873 } else {
874 assert(is_phantom, "only remaining strength");
875 __ call(RuntimeAddress(bs->load_reference_barrier_phantom_rt_code_blob()->code_begin()));
876 }
877 __ jmp(*stub->continuation());
878 }
879
880 #undef __
881
882 #define __ sasm->
883
884 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
885 __ prologue("shenandoah_pre_barrier", false);
886 // arg0 : previous value of memory
887
888 __ push(rax);
889 __ push(rdx);
890
891 const Register pre_val = rax;
892 const Register thread = NOT_LP64(rax) LP64_ONLY(r15_thread);
893 const Register tmp = rdx;
894
895 NOT_LP64(__ get_thread(thread);)
896
897 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
898 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
899
900 Label done;
901 Label runtime;
902
903 // Is SATB still active?
904 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
905 __ testb(gc_state, ShenandoahHeap::MARKING);
906 __ jcc(Assembler::zero, done);
907
908 // Can we store original value in the thread's buffer?
909
910 __ movptr(tmp, queue_index);
911 __ testptr(tmp, tmp);
912 __ jcc(Assembler::zero, runtime);
913 __ subptr(tmp, wordSize);
914 __ movptr(queue_index, tmp);
915 __ addptr(tmp, buffer);
916
917 // prev_val (rax)
918 __ load_parameter(0, pre_val);
919 __ movptr(Address(tmp, 0), pre_val);
920 __ jmp(done);
921
922 __ bind(runtime);
923
924 __ save_live_registers_no_oop_map(true);
925
926 // load the pre-value
927 __ load_parameter(0, rcx);
928 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre), rcx, thread);
929
930 __ restore_live_registers(true);
931
932 __ bind(done);
933
934 __ pop(rdx);
935 __ pop(rax);
936
937 __ epilogue();
938 }
939
940 void ShenandoahBarrierSetAssembler::generate_c1_load_reference_barrier_runtime_stub(StubAssembler* sasm, DecoratorSet decorators) {
941 __ prologue("shenandoah_load_reference_barrier", false);
942 // arg0 : object to be resolved
943
944 __ save_live_registers_no_oop_map(true);
945
946 bool is_strong = ShenandoahBarrierSet::is_strong_access(decorators);
947 bool is_weak = ShenandoahBarrierSet::is_weak_access(decorators);
948 bool is_phantom = ShenandoahBarrierSet::is_phantom_access(decorators);
949 bool is_native = ShenandoahBarrierSet::is_native_access(decorators);
950
951 #ifdef _LP64
952 __ load_parameter(0, c_rarg0);
953 __ load_parameter(1, c_rarg1);
954 if (is_strong) {
955 if (is_native) {
956 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_strong), c_rarg0, c_rarg1);
957 } else {
958 if (UseCompressedOops) {
959 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_strong_narrow), c_rarg0, c_rarg1);
960 } else {
961 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_strong), c_rarg0, c_rarg1);
962 }
963 }
964 } else if (is_weak) {
965 assert(!is_native, "weak must not be called off-heap");
966 if (UseCompressedOops) {
967 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_weak_narrow), c_rarg0, c_rarg1);
968 } else {
969 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_weak), c_rarg0, c_rarg1);
970 }
971 } else {
972 assert(is_phantom, "only remaining strength");
973 assert(is_native, "phantom must only be called off-heap");
974 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_phantom), c_rarg0, c_rarg1);
975 }
976 #else
977 __ load_parameter(0, rax);
978 __ load_parameter(1, rbx);
979 if (is_strong) {
980 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_strong), rax, rbx);
981 } else if (is_weak) {
982 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_weak), rax, rbx);
983 } else {
984 assert(is_phantom, "only remaining strength");
985 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_phantom), rax, rbx);
986 }
987 #endif
988
989 __ restore_live_registers_except_rax(true);
990
991 __ epilogue();
992 }
993
994 #undef __
995
996 #endif // COMPILER1