1 /* 2 * Copyright (c) 2018, 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/shenandoahHeap.hpp" 27 #include "gc/shenandoah/shenandoahHeapRegion.hpp" 28 #include "gc/shenandoah/shenandoahHeuristics.hpp" 29 #include "gc/shenandoah/shenandoahRuntime.hpp" 30 #include "gc/shenandoah/shenandoahThreadLocalData.hpp" 31 #include "interpreter/interpreter.hpp" 32 #include "interpreter/interp_masm.hpp" 33 #include "runtime/sharedRuntime.hpp" 34 #include "runtime/thread.hpp" 35 #ifdef COMPILER1 36 #include "c1/c1_LIRAssembler.hpp" 37 #include "c1/c1_MacroAssembler.hpp" 38 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp" 39 #endif 40 41 #define __ masm-> 42 43 address ShenandoahBarrierSetAssembler::_shenandoah_wb = NULL; 44 45 void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop, 46 Register addr, Register count, RegSet saved_regs) { 47 if (is_oop) { 48 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0; 49 if (!dest_uninitialized && !ShenandoahHeap::heap()->heuristics()->can_do_traversal_gc()) { 50 __ push(saved_regs, sp); 51 if (count == c_rarg0) { 52 if (addr == c_rarg1) { 53 // exactly backwards!! 54 __ mov(rscratch1, c_rarg0); 55 __ mov(c_rarg0, c_rarg1); 56 __ mov(c_rarg1, rscratch1); 57 } else { 58 __ mov(c_rarg1, count); 59 __ mov(c_rarg0, addr); 60 } 61 } else { 62 __ mov(c_rarg0, addr); 63 __ mov(c_rarg1, count); 64 } 65 if (UseCompressedOops) { 66 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry), 2); 67 } else { 68 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry), 2); 69 } 70 __ pop(saved_regs, sp); 71 } 72 } 73 } 74 75 void ShenandoahBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop, 76 Register start, Register end, Register scratch, RegSet saved_regs) { 77 if (is_oop) { 78 __ push(saved_regs, sp); 79 // must compute element count unless barrier set interface is changed (other platforms supply count) 80 assert_different_registers(start, end, scratch); 81 __ lea(scratch, Address(end, BytesPerHeapOop)); 82 __ sub(scratch, scratch, start); // subtract start to get #bytes 83 __ lsr(scratch, scratch, LogBytesPerHeapOop); // convert to element count 84 __ mov(c_rarg0, start); 85 __ mov(c_rarg1, scratch); 86 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_post_entry), 2); 87 __ pop(saved_regs, sp); 88 } 89 } 90 91 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm, 92 Register obj, 93 Register pre_val, 94 Register thread, 95 Register tmp, 96 bool tosca_live, 97 bool expand_call) { 98 if (ShenandoahSATBBarrier) { 99 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call); 100 } 101 } 102 103 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm, 104 Register obj, 105 Register pre_val, 106 Register thread, 107 Register tmp, 108 bool tosca_live, 109 bool expand_call) { 110 // If expand_call is true then we expand the call_VM_leaf macro 111 // directly to skip generating the check by 112 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp. 113 114 assert(thread == rthread, "must be"); 115 116 Label done; 117 Label runtime; 118 119 assert_different_registers(obj, pre_val, tmp, rscratch1); 120 assert(pre_val != noreg && tmp != noreg, "expecting a register"); 121 122 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset())); 123 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset())); 124 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset())); 125 126 // Is marking active? 127 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) { 128 __ ldrw(tmp, in_progress); 129 } else { 130 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption"); 131 __ ldrb(tmp, in_progress); 132 } 133 __ cbzw(tmp, done); 134 135 // Do we need to load the previous value? 136 if (obj != noreg) { 137 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW); 138 } 139 140 // Is the previous value null? 141 __ cbz(pre_val, done); 142 143 // Can we store original value in the thread's buffer? 144 // Is index == 0? 145 // (The index field is typed as size_t.) 146 147 __ ldr(tmp, index); // tmp := *index_adr 148 __ cbz(tmp, runtime); // tmp == 0? 149 // If yes, goto runtime 150 151 __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize 152 __ str(tmp, index); // *index_adr := tmp 153 __ ldr(rscratch1, buffer); 154 __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr 155 156 // Record the previous value 157 __ str(pre_val, Address(tmp, 0)); 158 __ b(done); 159 160 __ bind(runtime); 161 // save the live input values 162 RegSet saved = RegSet::of(pre_val); 163 if (tosca_live) saved += RegSet::of(r0); 164 if (obj != noreg) saved += RegSet::of(obj); 165 166 __ push(saved, sp); 167 168 // Calling the runtime using the regular call_VM_leaf mechanism generates 169 // code (generated by InterpreterMacroAssember::call_VM_leaf_base) 170 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL. 171 // 172 // If we care generating the pre-barrier without a frame (e.g. in the 173 // intrinsified Reference.get() routine) then ebp might be pointing to 174 // the caller frame and so this check will most likely fail at runtime. 175 // 176 // Expanding the call directly bypasses the generation of the check. 177 // So when we do not have have a full interpreter frame on the stack 178 // expand_call should be passed true. 179 180 if (expand_call) { 181 assert(pre_val != c_rarg1, "smashed arg"); 182 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); 183 } else { 184 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); 185 } 186 187 __ pop(saved, sp); 188 189 __ bind(done); 190 } 191 192 void ShenandoahBarrierSetAssembler::read_barrier(MacroAssembler* masm, Register dst) { 193 if (ShenandoahReadBarrier) { 194 read_barrier_impl(masm, dst); 195 } 196 } 197 198 void ShenandoahBarrierSetAssembler::read_barrier_impl(MacroAssembler* masm, Register dst) { 199 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier || ShenandoahCASBarrier), "should be enabled"); 200 Label is_null; 201 __ cbz(dst, is_null); 202 read_barrier_not_null_impl(masm, dst); 203 __ bind(is_null); 204 } 205 206 void ShenandoahBarrierSetAssembler::read_barrier_not_null(MacroAssembler* masm, Register dst) { 207 if (ShenandoahReadBarrier) { 208 read_barrier_not_null_impl(masm, dst); 209 } 210 } 211 212 213 void ShenandoahBarrierSetAssembler::read_barrier_not_null_impl(MacroAssembler* masm, Register dst) { 214 assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier || ShenandoahCASBarrier), "should be enabled"); 215 __ ldr(dst, Address(dst, ShenandoahBrooksPointer::byte_offset())); 216 } 217 218 void ShenandoahBarrierSetAssembler::write_barrier(MacroAssembler* masm, Register dst) { 219 if (ShenandoahWriteBarrier) { 220 write_barrier_impl(masm, dst); 221 } 222 } 223 224 void ShenandoahBarrierSetAssembler::write_barrier_impl(MacroAssembler* masm, Register dst) { 225 assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier), "Should be enabled"); 226 assert(dst != rscratch1, "need rscratch1"); 227 assert(dst != rscratch2, "need rscratch2"); 228 229 Label done; 230 231 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 232 __ ldrb(rscratch1, gc_state); 233 234 // Check for heap stability 235 __ mov(rscratch2, ShenandoahHeap::HAS_FORWARDED | ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL); 236 __ tst(rscratch1, rscratch2); 237 __ br(Assembler::EQ, done); 238 239 // Heap is unstable, need to perform the read-barrier even if WB is inactive 240 __ ldr(dst, Address(dst, ShenandoahBrooksPointer::byte_offset())); 241 242 // Check for evacuation-in-progress and jump to WB slow-path if needed 243 __ mov(rscratch2, ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL); 244 __ tst(rscratch1, rscratch2); 245 __ br(Assembler::EQ, done); 246 247 RegSet to_save = RegSet::of(r0); 248 if (dst != r0) { 249 __ push(to_save, sp); 250 __ mov(r0, dst); 251 } 252 253 __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_wb()))); 254 255 if (dst != r0) { 256 __ mov(dst, r0); 257 __ pop(to_save, sp); 258 } 259 260 __ bind(done); 261 } 262 263 void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) { 264 if (ShenandoahStoreValEnqueueBarrier) { 265 Label is_null; 266 __ cbz(dst, is_null); 267 write_barrier_impl(masm, dst); 268 __ bind(is_null); 269 // Save possibly live regs. 270 RegSet live_regs = RegSet::range(r0, r4) - dst; 271 __ push(live_regs, sp); 272 __ strd(v0, __ pre(sp, 2 * -wordSize)); 273 274 satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false); 275 276 // Restore possibly live regs. 277 __ ldrd(v0, __ post(sp, 2 * wordSize)); 278 __ pop(live_regs, sp); 279 } 280 if (ShenandoahStoreValReadBarrier) { 281 read_barrier_impl(masm, dst); 282 } 283 } 284 285 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 286 Register dst, Address src, Register tmp1, Register tmp_thread) { 287 bool on_oop = type == T_OBJECT || type == T_ARRAY; 288 bool in_heap = (decorators & IN_HEAP) != 0; 289 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0; 290 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0; 291 bool on_reference = on_weak || on_phantom; 292 293 if (in_heap) { 294 read_barrier_not_null(masm, src.base()); 295 } 296 297 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread); 298 if (ShenandoahKeepAliveBarrier && on_oop && on_reference) { 299 __ enter(); 300 satb_write_barrier_pre(masm /* masm */, 301 noreg /* obj */, 302 dst /* pre_val */, 303 rthread /* thread */, 304 tmp1 /* tmp */, 305 true /* tosca_live */, 306 true /* expand_call */); 307 __ leave(); 308 } 309 } 310 311 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 312 Address dst, Register val, Register tmp1, Register tmp2) { 313 bool on_oop = type == T_OBJECT || type == T_ARRAY; 314 bool in_heap = (decorators & IN_HEAP) != 0; 315 if (in_heap) { 316 write_barrier(masm, dst.base()); 317 } 318 if (!on_oop) { 319 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2); 320 return; 321 } 322 323 // flatten object address if needed 324 if (dst.index() == noreg && dst.offset() == 0) { 325 if (dst.base() != r3) { 326 __ mov(r3, dst.base()); 327 } 328 } else { 329 __ lea(r3, dst); 330 } 331 332 shenandoah_write_barrier_pre(masm, 333 r3 /* obj */, 334 tmp2 /* pre_val */, 335 rthread /* thread */, 336 tmp1 /* tmp */, 337 val != noreg /* tosca_live */, 338 false /* expand_call */); 339 340 if (val == noreg) { 341 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg); 342 } else { 343 storeval_barrier(masm, val, tmp1); 344 // G1 barrier needs uncompressed oop for region cross check. 345 Register new_val = val; 346 if (UseCompressedOops) { 347 new_val = rscratch2; 348 __ mov(new_val, val); 349 } 350 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg); 351 } 352 353 } 354 355 void ShenandoahBarrierSetAssembler::obj_equals(MacroAssembler* masm, Register op1, Register op2) { 356 __ cmp(op1, op2); 357 if (ShenandoahAcmpBarrier) { 358 Label done; 359 __ br(Assembler::EQ, done); 360 // The object may have been evacuated, but we won't see it without a 361 // membar here. 362 __ membar(Assembler::LoadStore| Assembler::LoadLoad); 363 read_barrier(masm, op1); 364 read_barrier(masm, op2); 365 __ cmp(op1, op2); 366 __ bind(done); 367 } 368 } 369 370 void ShenandoahBarrierSetAssembler::tlab_allocate(MacroAssembler* masm, Register obj, 371 Register var_size_in_bytes, 372 int con_size_in_bytes, 373 Register t1, 374 Register t2, 375 Label& slow_case) { 376 377 assert_different_registers(obj, t2); 378 assert_different_registers(obj, var_size_in_bytes); 379 Register end = t2; 380 381 __ ldr(obj, Address(rthread, JavaThread::tlab_top_offset())); 382 if (var_size_in_bytes == noreg) { 383 __ lea(end, Address(obj, (int) (con_size_in_bytes + ShenandoahBrooksPointer::byte_size()))); 384 } else { 385 __ add(var_size_in_bytes, var_size_in_bytes, ShenandoahBrooksPointer::byte_size()); 386 __ lea(end, Address(obj, var_size_in_bytes)); 387 } 388 __ ldr(rscratch1, Address(rthread, JavaThread::tlab_end_offset())); 389 __ cmp(end, rscratch1); 390 __ br(Assembler::HI, slow_case); 391 392 // update the tlab top pointer 393 __ str(end, Address(rthread, JavaThread::tlab_top_offset())); 394 395 __ add(obj, obj, ShenandoahBrooksPointer::byte_size()); 396 __ str(obj, Address(obj, ShenandoahBrooksPointer::byte_offset())); 397 398 // recover var_size_in_bytes if necessary 399 if (var_size_in_bytes == end) { 400 __ sub(var_size_in_bytes, var_size_in_bytes, obj); 401 } 402 } 403 404 void ShenandoahBarrierSetAssembler::resolve(MacroAssembler* masm, DecoratorSet decorators, Register obj) { 405 bool oop_not_null = (decorators & IS_NOT_NULL) != 0; 406 bool is_write = (decorators & ACCESS_WRITE) != 0; 407 if (is_write) { 408 if (oop_not_null) { 409 write_barrier(masm, obj); 410 } else { 411 Label done; 412 __ cbz(obj, done); 413 write_barrier(masm, obj); 414 __ bind(done); 415 } 416 } else { 417 if (oop_not_null) { 418 read_barrier_not_null(masm, obj); 419 } else { 420 read_barrier(masm, obj); 421 } 422 } 423 } 424 425 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val, 426 bool acquire, bool release, bool weak, bool is_cae, 427 Register result) { 428 429 Register tmp = rscratch2; 430 bool is_narrow = UseCompressedOops; 431 Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword; 432 433 assert_different_registers(addr, expected, new_val, result, tmp); 434 435 Label retry, done, fail; 436 437 // CAS, using LL/SC pair. 438 __ bind(retry); 439 __ load_exclusive(result, addr, size, acquire); 440 if (is_narrow) { 441 __ cmpw(result, expected); 442 } else { 443 __ cmp(result, expected); 444 } 445 __ br(Assembler::NE, fail); 446 __ store_exclusive(tmp, new_val, addr, size, release); 447 if (weak) { 448 __ cmpw(tmp, 0u); // If the store fails, return NE to our caller 449 } else { 450 __ cbnzw(tmp, retry); 451 } 452 __ b(done); 453 454 __ bind(fail); 455 // Check if rb(expected)==rb(result) 456 // Shuffle registers so that we have memory value ready for next expected. 457 __ mov(tmp, expected); 458 __ mov(expected, result); 459 if (is_narrow) { 460 __ decode_heap_oop(result, result); 461 __ decode_heap_oop(tmp, tmp); 462 } 463 read_barrier_impl(masm, result); 464 read_barrier_impl(masm, tmp); 465 __ cmp(result, tmp); 466 // Retry with expected now being the value we just loaded from addr. 467 __ br(Assembler::EQ, retry); 468 if (is_cae && is_narrow) { 469 // For cmp-and-exchange and narrow oops, we need to restore 470 // the compressed old-value. We moved it to 'expected' a few lines up. 471 __ mov(result, expected); 472 } 473 __ bind(done); 474 475 if (!is_cae) { 476 __ cset(result, Assembler::EQ); 477 } 478 } 479 480 #ifdef COMPILER1 481 482 #undef __ 483 #define __ ce->masm()-> 484 485 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) { 486 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1(); 487 // At this point we know that marking is in progress. 488 // If do_load() is true then we have to emit the 489 // load of the previous value; otherwise it has already 490 // been loaded into _pre_val. 491 492 __ bind(*stub->entry()); 493 494 assert(stub->pre_val()->is_register(), "Precondition."); 495 496 Register pre_val_reg = stub->pre_val()->as_register(); 497 498 if (stub->do_load()) { 499 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/); 500 } 501 __ cbz(pre_val_reg, *stub->continuation()); 502 ce->store_parameter(stub->pre_val()->as_register(), 0); 503 __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin())); 504 __ b(*stub->continuation()); 505 } 506 507 void ShenandoahBarrierSetAssembler::gen_write_barrier_stub(LIR_Assembler* ce, ShenandoahWriteBarrierStub* stub) { 508 509 Register obj = stub->obj()->as_register(); 510 Register res = stub->result()->as_register(); 511 512 Label done; 513 514 __ bind(*stub->entry()); 515 516 if (res != obj) { 517 __ mov(res, obj); 518 } 519 // Check for null. 520 if (stub->needs_null_check()) { 521 __ cbz(res, done); 522 } 523 524 write_barrier(ce->masm(), res); 525 526 __ bind(done); 527 __ b(*stub->continuation()); 528 } 529 530 #undef __ 531 532 #define __ sasm-> 533 534 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) { 535 __ prologue("shenandoah_pre_barrier", false); 536 537 // arg0 : previous value of memory 538 539 BarrierSet* bs = BarrierSet::barrier_set(); 540 541 const Register pre_val = r0; 542 const Register thread = rthread; 543 const Register tmp = rscratch1; 544 545 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset())); 546 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset())); 547 548 Label done; 549 Label runtime; 550 551 // Is marking still active? 552 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 553 __ ldrb(tmp, gc_state); 554 __ mov(rscratch2, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL); 555 __ tst(tmp, rscratch2); 556 __ br(Assembler::EQ, done); 557 558 // Can we store original value in the thread's buffer? 559 __ ldr(tmp, queue_index); 560 __ cbz(tmp, runtime); 561 562 __ sub(tmp, tmp, wordSize); 563 __ str(tmp, queue_index); 564 __ ldr(rscratch2, buffer); 565 __ add(tmp, tmp, rscratch2); 566 __ load_parameter(0, rscratch2); 567 __ str(rscratch2, Address(tmp, 0)); 568 __ b(done); 569 570 __ bind(runtime); 571 __ push_call_clobbered_registers(); 572 __ load_parameter(0, pre_val); 573 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); 574 __ pop_call_clobbered_registers(); 575 __ bind(done); 576 577 __ epilogue(); 578 } 579 580 #undef __ 581 582 #endif // COMPILER1 583 584 address ShenandoahBarrierSetAssembler::shenandoah_wb() { 585 assert(_shenandoah_wb != NULL, "need write barrier stub"); 586 return _shenandoah_wb; 587 } 588 589 #define __ cgen->assembler()-> 590 591 // Shenandoah write barrier. 592 // 593 // Input: 594 // r0: OOP to evacuate. Not null. 595 // 596 // Output: 597 // r0: Pointer to evacuated OOP. 598 // 599 // Trash rscratch1, rscratch2. Preserve everything else. 600 address ShenandoahBarrierSetAssembler::generate_shenandoah_wb(StubCodeGenerator* cgen) { 601 602 __ align(6); 603 StubCodeMark mark(cgen, "StubRoutines", "shenandoah_wb"); 604 address start = __ pc(); 605 606 Label work; 607 __ mov(rscratch2, ShenandoahHeap::in_cset_fast_test_addr()); 608 __ lsr(rscratch1, r0, ShenandoahHeapRegion::region_size_bytes_shift_jint()); 609 __ ldrb(rscratch2, Address(rscratch2, rscratch1)); 610 __ tbnz(rscratch2, 0, work); 611 __ ret(lr); 612 __ bind(work); 613 614 Register obj = r0; 615 616 __ enter(); // required for proper stackwalking of RuntimeStub frame 617 618 __ push_call_clobbered_registers(); 619 620 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_JRT)); 621 __ blrt(lr, 1, 0, MacroAssembler::ret_type_integral); 622 __ mov(rscratch1, obj); 623 __ pop_call_clobbered_registers(); 624 __ mov(obj, rscratch1); 625 626 __ leave(); // required for proper stackwalking of RuntimeStub frame 627 __ ret(lr); 628 629 return start; 630 } 631 632 #undef __ 633 634 void ShenandoahBarrierSetAssembler::barrier_stubs_init() { 635 if (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier) { 636 int stub_code_size = 2048; 637 ResourceMark rm; 638 BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size); 639 CodeBuffer buf(bb); 640 StubCodeGenerator cgen(&buf); 641 _shenandoah_wb = generate_shenandoah_wb(&cgen); 642 } 643 }