1 /* 2 * Copyright (c) 2018, 2020, Red Hat, Inc. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc/shenandoah/shenandoahBarrierSet.hpp" 27 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp" 28 #include "gc/shenandoah/shenandoahForwarding.hpp" 29 #include "gc/shenandoah/shenandoahHeap.inline.hpp" 30 #include "gc/shenandoah/shenandoahHeapRegion.hpp" 31 #include "gc/shenandoah/shenandoahHeuristics.hpp" 32 #include "gc/shenandoah/shenandoahRuntime.hpp" 33 #include "gc/shenandoah/shenandoahThreadLocalData.hpp" 34 #include "interpreter/interpreter.hpp" 35 #include "interpreter/interp_masm.hpp" 36 #include "runtime/sharedRuntime.hpp" 37 #include "runtime/thread.hpp" 38 #ifdef COMPILER1 39 #include "c1/c1_LIRAssembler.hpp" 40 #include "c1/c1_MacroAssembler.hpp" 41 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp" 42 #endif 43 44 #define __ masm-> 45 46 address ShenandoahBarrierSetAssembler::_shenandoah_lrb = NULL; 47 48 void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop, 49 Register src, Register dst, Register count, RegSet saved_regs) { 50 if (is_oop) { 51 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0; 52 if ((ShenandoahSATBBarrier && !dest_uninitialized) || ShenandoahStoreValEnqueueBarrier || ShenandoahLoadRefBarrier) { 53 54 Label done; 55 56 // Avoid calling runtime if count == 0 57 __ cbz(count, done); 58 59 // Is GC active? 60 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 61 __ ldrb(rscratch1, gc_state); 62 if (ShenandoahSATBBarrier && dest_uninitialized) { 63 __ tbz(rscratch1, ShenandoahHeap::HAS_FORWARDED_BITPOS, done); 64 } else { 65 __ mov(rscratch2, ShenandoahHeap::HAS_FORWARDED | ShenandoahHeap::MARKING); 66 __ tst(rscratch1, rscratch2); 67 __ br(Assembler::EQ, done); 68 } 69 70 __ push(saved_regs, sp); 71 if (UseCompressedOops) { 72 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::arraycopy_barrier_narrow_oop_entry), src, dst, count); 73 } else { 74 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::arraycopy_barrier_oop_entry), src, dst, count); 75 } 76 __ pop(saved_regs, sp); 77 __ bind(done); 78 } 79 } 80 } 81 82 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm, 83 Register obj, 84 Register pre_val, 85 Register thread, 86 Register tmp, 87 bool tosca_live, 88 bool expand_call) { 89 if (ShenandoahSATBBarrier) { 90 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call); 91 } 92 } 93 94 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm, 95 Register obj, 96 Register pre_val, 97 Register thread, 98 Register tmp, 99 bool tosca_live, 100 bool expand_call) { 101 // If expand_call is true then we expand the call_VM_leaf macro 102 // directly to skip generating the check by 103 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp. 104 105 assert(thread == rthread, "must be"); 106 107 Label done; 108 Label runtime; 109 110 assert_different_registers(obj, pre_val, tmp, rscratch1); 111 assert(pre_val != noreg && tmp != noreg, "expecting a register"); 112 113 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset())); 114 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset())); 115 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset())); 116 117 // Is marking active? 118 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) { 119 __ ldrw(tmp, in_progress); 120 } else { 121 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption"); 122 __ ldrb(tmp, in_progress); 123 } 124 __ cbzw(tmp, done); 125 126 // Do we need to load the previous value? 127 if (obj != noreg) { 128 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW); 129 } 130 131 // Is the previous value null? 132 __ cbz(pre_val, done); 133 134 // Can we store original value in the thread's buffer? 135 // Is index == 0? 136 // (The index field is typed as size_t.) 137 138 __ ldr(tmp, index); // tmp := *index_adr 139 __ cbz(tmp, runtime); // tmp == 0? 140 // If yes, goto runtime 141 142 __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize 143 __ str(tmp, index); // *index_adr := tmp 144 __ ldr(rscratch1, buffer); 145 __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr 146 147 // Record the previous value 148 __ str(pre_val, Address(tmp, 0)); 149 __ b(done); 150 151 __ bind(runtime); 152 // save the live input values 153 RegSet saved = RegSet::of(pre_val); 154 if (tosca_live) saved += RegSet::of(r0); 155 if (obj != noreg) saved += RegSet::of(obj); 156 157 __ push(saved, sp); 158 159 // Calling the runtime using the regular call_VM_leaf mechanism generates 160 // code (generated by InterpreterMacroAssember::call_VM_leaf_base) 161 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL. 162 // 163 // If we care generating the pre-barrier without a frame (e.g. in the 164 // intrinsified Reference.get() routine) then ebp might be pointing to 165 // the caller frame and so this check will most likely fail at runtime. 166 // 167 // Expanding the call directly bypasses the generation of the check. 168 // So when we do not have have a full interpreter frame on the stack 169 // expand_call should be passed true. 170 171 if (expand_call) { 172 assert(pre_val != c_rarg1, "smashed arg"); 173 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); 174 } else { 175 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); 176 } 177 178 __ pop(saved, sp); 179 180 __ bind(done); 181 } 182 183 void ShenandoahBarrierSetAssembler::resolve_forward_pointer(MacroAssembler* masm, Register dst, Register tmp) { 184 assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled"); 185 Label is_null; 186 __ cbz(dst, is_null); 187 resolve_forward_pointer_not_null(masm, dst, tmp); 188 __ bind(is_null); 189 } 190 191 // IMPORTANT: This must preserve all registers, even rscratch1 and rscratch2, except those explicitely 192 // passed in. 193 void ShenandoahBarrierSetAssembler::resolve_forward_pointer_not_null(MacroAssembler* masm, Register dst, Register tmp) { 194 assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled"); 195 // The below loads the mark word, checks if the lowest two bits are 196 // set, and if so, clear the lowest two bits and copy the result 197 // to dst. Otherwise it leaves dst alone. 198 // Implementing this is surprisingly awkward. I do it here by: 199 // - Inverting the mark word 200 // - Test lowest two bits == 0 201 // - If so, set the lowest two bits 202 // - Invert the result back, and copy to dst 203 204 bool borrow_reg = (tmp == noreg); 205 if (borrow_reg) { 206 // No free registers available. Make one useful. 207 tmp = rscratch1; 208 if (tmp == dst) { 209 tmp = rscratch2; 210 } 211 __ push(RegSet::of(tmp), sp); 212 } 213 214 assert_different_registers(tmp, dst); 215 216 Label done; 217 __ ldr(tmp, Address(dst, oopDesc::mark_offset_in_bytes())); 218 __ eon(tmp, tmp, zr); 219 __ ands(zr, tmp, markWord::lock_mask_in_place); 220 __ br(Assembler::NE, done); 221 __ orr(tmp, tmp, markWord::marked_value); 222 __ eon(dst, tmp, zr); 223 __ bind(done); 224 225 if (borrow_reg) { 226 __ pop(RegSet::of(tmp), sp); 227 } 228 } 229 230 void ShenandoahBarrierSetAssembler::load_reference_barrier_not_null(MacroAssembler* masm, Register dst, Address load_addr) { 231 assert(ShenandoahLoadRefBarrier, "Should be enabled"); 232 assert(dst != rscratch2, "need rscratch2"); 233 assert_different_registers(load_addr.base(), load_addr.index(), rscratch1, rscratch2); 234 235 Label done; 236 __ enter(); 237 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 238 __ ldrb(rscratch2, gc_state); 239 240 // Check for heap stability 241 __ tbz(rscratch2, ShenandoahHeap::HAS_FORWARDED_BITPOS, done); 242 243 // use r1 for load address 244 Register result_dst = dst; 245 if (dst == r1) { 246 __ mov(rscratch1, dst); 247 dst = rscratch1; 248 } 249 250 // Save r0 and r1, unless it is an output register 251 RegSet to_save = RegSet::of(r0, r1) - result_dst; 252 __ push(to_save, sp); 253 __ lea(r1, load_addr); 254 __ mov(r0, dst); 255 256 __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_lrb()))); 257 258 __ mov(result_dst, r0); 259 __ pop(to_save, sp); 260 261 __ bind(done); 262 __ leave(); 263 } 264 265 void ShenandoahBarrierSetAssembler::load_reference_barrier_native(MacroAssembler* masm, Register dst, Address load_addr) { 266 if (!ShenandoahLoadRefBarrier) { 267 return; 268 } 269 270 assert(dst != rscratch2, "need rscratch2"); 271 272 Label is_null; 273 Label done; 274 275 __ block_comment("load_reference_barrier_native { "); 276 277 __ cbz(dst, is_null); 278 279 __ enter(); 280 281 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 282 __ ldrb(rscratch2, gc_state); 283 284 // Check for heap in evacuation phase 285 __ tbz(rscratch2, ShenandoahHeap::EVACUATION_BITPOS, done); 286 287 __ mov(rscratch2, dst); 288 __ push_call_clobbered_registers(); 289 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_native)); 290 __ lea(r1, load_addr); 291 __ mov(r0, rscratch2); 292 __ blr(lr); 293 __ mov(rscratch2, r0); 294 __ pop_call_clobbered_registers(); 295 __ mov(dst, rscratch2); 296 297 __ bind(done); 298 __ leave(); 299 __ bind(is_null); 300 __ block_comment("} load_reference_barrier_native"); 301 } 302 303 void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) { 304 if (ShenandoahStoreValEnqueueBarrier) { 305 // Save possibly live regs. 306 RegSet live_regs = RegSet::range(r0, r4) - dst; 307 __ push(live_regs, sp); 308 __ strd(v0, __ pre(sp, 2 * -wordSize)); 309 310 satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false); 311 312 // Restore possibly live regs. 313 __ ldrd(v0, __ post(sp, 2 * wordSize)); 314 __ pop(live_regs, sp); 315 } 316 } 317 318 void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm, Register dst, Address load_addr) { 319 if (ShenandoahLoadRefBarrier) { 320 Label is_null; 321 __ cbz(dst, is_null); 322 load_reference_barrier_not_null(masm, dst, load_addr); 323 __ bind(is_null); 324 } 325 } 326 327 // 328 // Arguments: 329 // 330 // Inputs: 331 // src: oop location to load from, might be clobbered 332 // 333 // Output: 334 // dst: oop loaded from src location 335 // 336 // Kill: 337 // rscratch1 (scratch reg) 338 // 339 // Alias: 340 // dst: rscratch1 (might use rscratch1 as temporary output register to avoid clobbering src) 341 // 342 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 343 Register dst, Address src, Register tmp1, Register tmp_thread) { 344 // 1: non-reference load, no additional barrier is needed 345 if (!is_reference_type(type)) { 346 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread); 347 return; 348 } 349 350 // 2: load a reference from src location and apply LRB if needed 351 if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) { 352 Register result_dst = dst; 353 354 // Preserve src location for LRB 355 if (dst == src.base() || dst == src.index()) { 356 dst = rscratch1; 357 } 358 assert_different_registers(dst, src.base(), src.index()); 359 360 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread); 361 362 if (ShenandoahBarrierSet::use_load_reference_barrier_native(decorators, type)) { 363 load_reference_barrier_native(masm, dst, src); 364 } else { 365 load_reference_barrier(masm, dst, src); 366 } 367 368 if (dst != result_dst) { 369 __ mov(result_dst, dst); 370 dst = result_dst; 371 } 372 } else { 373 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread); 374 } 375 376 // 3: apply keep-alive barrier if needed 377 if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) { 378 __ enter(); 379 __ push_call_clobbered_registers(); 380 satb_write_barrier_pre(masm /* masm */, 381 noreg /* obj */, 382 dst /* pre_val */, 383 rthread /* thread */, 384 tmp1 /* tmp */, 385 true /* tosca_live */, 386 true /* expand_call */); 387 __ pop_call_clobbered_registers(); 388 __ leave(); 389 } 390 } 391 392 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 393 Address dst, Register val, Register tmp1, Register tmp2) { 394 bool on_oop = is_reference_type(type); 395 if (!on_oop) { 396 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2); 397 return; 398 } 399 400 // flatten object address if needed 401 if (dst.index() == noreg && dst.offset() == 0) { 402 if (dst.base() != r3) { 403 __ mov(r3, dst.base()); 404 } 405 } else { 406 __ lea(r3, dst); 407 } 408 409 shenandoah_write_barrier_pre(masm, 410 r3 /* obj */, 411 tmp2 /* pre_val */, 412 rthread /* thread */, 413 tmp1 /* tmp */, 414 val != noreg /* tosca_live */, 415 false /* expand_call */); 416 417 if (val == noreg) { 418 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg); 419 } else { 420 storeval_barrier(masm, val, tmp1); 421 // G1 barrier needs uncompressed oop for region cross check. 422 Register new_val = val; 423 if (UseCompressedOops) { 424 new_val = rscratch2; 425 __ mov(new_val, val); 426 } 427 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg); 428 } 429 430 } 431 432 void ShenandoahBarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env, 433 Register obj, Register tmp, Label& slowpath) { 434 Label done; 435 // Resolve jobject 436 BarrierSetAssembler::try_resolve_jobject_in_native(masm, jni_env, obj, tmp, slowpath); 437 438 // Check for null. 439 __ cbz(obj, done); 440 441 assert(obj != rscratch2, "need rscratch2"); 442 Address gc_state(jni_env, ShenandoahThreadLocalData::gc_state_offset() - JavaThread::jni_environment_offset()); 443 __ lea(rscratch2, gc_state); 444 __ ldrb(rscratch2, Address(rscratch2)); 445 446 // Check for heap in evacuation phase 447 __ tbnz(rscratch2, ShenandoahHeap::EVACUATION_BITPOS, slowpath); 448 449 __ bind(done); 450 } 451 452 453 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val, 454 bool acquire, bool release, bool weak, bool is_cae, 455 Register result) { 456 Register tmp1 = rscratch1; 457 Register tmp2 = rscratch2; 458 bool is_narrow = UseCompressedOops; 459 Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword; 460 461 assert_different_registers(addr, expected, new_val, tmp1, tmp2); 462 463 Label retry, done, fail; 464 465 // CAS, using LL/SC pair. 466 __ bind(retry); 467 __ load_exclusive(tmp1, addr, size, acquire); 468 if (is_narrow) { 469 __ cmpw(tmp1, expected); 470 } else { 471 __ cmp(tmp1, expected); 472 } 473 __ br(Assembler::NE, fail); 474 __ store_exclusive(tmp2, new_val, addr, size, release); 475 if (weak) { 476 __ cmpw(tmp2, 0u); // If the store fails, return NE to our caller 477 } else { 478 __ cbnzw(tmp2, retry); 479 } 480 __ b(done); 481 482 __ bind(fail); 483 // Check if rb(expected)==rb(tmp1) 484 // Shuffle registers so that we have memory value ready for next expected. 485 __ mov(tmp2, expected); 486 __ mov(expected, tmp1); 487 if (is_narrow) { 488 __ decode_heap_oop(tmp1, tmp1); 489 __ decode_heap_oop(tmp2, tmp2); 490 } 491 resolve_forward_pointer(masm, tmp1); 492 resolve_forward_pointer(masm, tmp2); 493 __ cmp(tmp1, tmp2); 494 // Retry with expected now being the value we just loaded from addr. 495 __ br(Assembler::EQ, retry); 496 if (is_cae && is_narrow) { 497 // For cmp-and-exchange and narrow oops, we need to restore 498 // the compressed old-value. We moved it to 'expected' a few lines up. 499 __ mov(tmp1, expected); 500 } 501 __ bind(done); 502 503 if (is_cae) { 504 __ mov(result, tmp1); 505 } else { 506 __ cset(result, Assembler::EQ); 507 } 508 } 509 510 #undef __ 511 512 #ifdef COMPILER1 513 514 #define __ ce->masm()-> 515 516 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) { 517 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1(); 518 // At this point we know that marking is in progress. 519 // If do_load() is true then we have to emit the 520 // load of the previous value; otherwise it has already 521 // been loaded into _pre_val. 522 523 __ bind(*stub->entry()); 524 525 assert(stub->pre_val()->is_register(), "Precondition."); 526 527 Register pre_val_reg = stub->pre_val()->as_register(); 528 529 if (stub->do_load()) { 530 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/); 531 } 532 __ cbz(pre_val_reg, *stub->continuation()); 533 ce->store_parameter(stub->pre_val()->as_register(), 0); 534 __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin())); 535 __ b(*stub->continuation()); 536 } 537 538 void ShenandoahBarrierSetAssembler::gen_load_reference_barrier_stub(LIR_Assembler* ce, ShenandoahLoadReferenceBarrierStub* stub) { 539 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1(); 540 __ bind(*stub->entry()); 541 542 Register obj = stub->obj()->as_register(); 543 Register res = stub->result()->as_register(); 544 Register addr = stub->addr()->as_pointer_register(); 545 Register tmp1 = stub->tmp1()->as_register(); 546 Register tmp2 = stub->tmp2()->as_register(); 547 548 assert(res == r0, "result must arrive in r0"); 549 550 if (res != obj) { 551 __ mov(res, obj); 552 } 553 554 // Check for null. 555 __ cbz(res, *stub->continuation()); 556 557 // Check for object in cset. 558 __ mov(tmp2, ShenandoahHeap::in_cset_fast_test_addr()); 559 __ lsr(tmp1, res, ShenandoahHeapRegion::region_size_bytes_shift_jint()); 560 __ ldrb(tmp2, Address(tmp2, tmp1)); 561 __ cbz(tmp2, *stub->continuation()); 562 563 // Check if object is already forwarded. 564 Label slow_path; 565 __ ldr(tmp1, Address(res, oopDesc::mark_offset_in_bytes())); 566 __ eon(tmp1, tmp1, zr); 567 __ ands(zr, tmp1, markWord::lock_mask_in_place); 568 __ br(Assembler::NE, slow_path); 569 570 // Decode forwarded object. 571 __ orr(tmp1, tmp1, markWord::marked_value); 572 __ eon(res, tmp1, zr); 573 __ b(*stub->continuation()); 574 575 __ bind(slow_path); 576 ce->store_parameter(res, 0); 577 ce->store_parameter(addr, 1); 578 if (stub->is_native()) { 579 __ far_call(RuntimeAddress(bs->load_reference_barrier_native_rt_code_blob()->code_begin())); 580 } else { 581 __ far_call(RuntimeAddress(bs->load_reference_barrier_rt_code_blob()->code_begin())); 582 } 583 584 __ b(*stub->continuation()); 585 } 586 587 #undef __ 588 589 #define __ sasm-> 590 591 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) { 592 __ prologue("shenandoah_pre_barrier", false); 593 594 // arg0 : previous value of memory 595 596 BarrierSet* bs = BarrierSet::barrier_set(); 597 598 const Register pre_val = r0; 599 const Register thread = rthread; 600 const Register tmp = rscratch1; 601 602 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset())); 603 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset())); 604 605 Label done; 606 Label runtime; 607 608 // Is marking still active? 609 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 610 __ ldrb(tmp, gc_state); 611 __ mov(rscratch2, ShenandoahHeap::MARKING); 612 __ tst(tmp, rscratch2); 613 __ br(Assembler::EQ, done); 614 615 // Can we store original value in the thread's buffer? 616 __ ldr(tmp, queue_index); 617 __ cbz(tmp, runtime); 618 619 __ sub(tmp, tmp, wordSize); 620 __ str(tmp, queue_index); 621 __ ldr(rscratch2, buffer); 622 __ add(tmp, tmp, rscratch2); 623 __ load_parameter(0, rscratch2); 624 __ str(rscratch2, Address(tmp, 0)); 625 __ b(done); 626 627 __ bind(runtime); 628 __ push_call_clobbered_registers(); 629 __ load_parameter(0, pre_val); 630 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); 631 __ pop_call_clobbered_registers(); 632 __ bind(done); 633 634 __ epilogue(); 635 } 636 637 void ShenandoahBarrierSetAssembler::generate_c1_load_reference_barrier_runtime_stub(StubAssembler* sasm, bool is_native) { 638 __ prologue("shenandoah_load_reference_barrier", false); 639 // arg0 : object to be resolved 640 641 __ push_call_clobbered_registers(); 642 __ load_parameter(0, r0); 643 __ load_parameter(1, r1); 644 if (is_native) { 645 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_native)); 646 } else if (UseCompressedOops) { 647 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_narrow)); 648 } else { 649 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier)); 650 } 651 __ blr(lr); 652 __ mov(rscratch1, r0); 653 __ pop_call_clobbered_registers(); 654 __ mov(r0, rscratch1); 655 656 __ epilogue(); 657 } 658 659 #undef __ 660 661 #endif // COMPILER1 662 663 address ShenandoahBarrierSetAssembler::shenandoah_lrb() { 664 assert(_shenandoah_lrb != NULL, "need load reference barrier stub"); 665 return _shenandoah_lrb; 666 } 667 668 #define __ cgen->assembler()-> 669 670 // Shenandoah load reference barrier. 671 // 672 // Input: 673 // r0: OOP to evacuate. Not null. 674 // r1: load address 675 // 676 // Output: 677 // r0: Pointer to evacuated OOP. 678 // 679 // Trash rscratch1, rscratch2. Preserve everything else. 680 address ShenandoahBarrierSetAssembler::generate_shenandoah_lrb(StubCodeGenerator* cgen) { 681 682 __ align(6); 683 StubCodeMark mark(cgen, "StubRoutines", "shenandoah_lrb"); 684 address start = __ pc(); 685 686 Label work, done; 687 __ mov(rscratch2, ShenandoahHeap::in_cset_fast_test_addr()); 688 __ lsr(rscratch1, r0, ShenandoahHeapRegion::region_size_bytes_shift_jint()); 689 __ ldrb(rscratch2, Address(rscratch2, rscratch1)); 690 __ tbnz(rscratch2, 0, work); 691 __ ret(lr); 692 __ bind(work); 693 694 Label slow_path; 695 __ ldr(rscratch1, Address(r0, oopDesc::mark_offset_in_bytes())); 696 __ eon(rscratch1, rscratch1, zr); 697 __ ands(zr, rscratch1, markWord::lock_mask_in_place); 698 __ br(Assembler::NE, slow_path); 699 700 // Decode forwarded object. 701 __ orr(rscratch1, rscratch1, markWord::marked_value); 702 __ eon(r0, rscratch1, zr); 703 __ ret(lr); 704 705 __ bind(slow_path); 706 __ enter(); // required for proper stackwalking of RuntimeStub frame 707 708 __ push_call_clobbered_registers(); 709 710 if (UseCompressedOops) { 711 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_narrow)); 712 } else { 713 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier)); 714 } 715 __ blr(lr); 716 __ mov(rscratch1, r0); 717 __ pop_call_clobbered_registers(); 718 __ mov(r0, rscratch1); 719 720 __ leave(); // required for proper stackwalking of RuntimeStub frame 721 __ bind(done); 722 __ ret(lr); 723 724 return start; 725 } 726 727 #undef __ 728 729 void ShenandoahBarrierSetAssembler::barrier_stubs_init() { 730 if (ShenandoahLoadRefBarrier) { 731 int stub_code_size = 2048; 732 ResourceMark rm; 733 BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size); 734 CodeBuffer buf(bb); 735 StubCodeGenerator cgen(&buf); 736 _shenandoah_lrb = generate_shenandoah_lrb(&cgen); 737 } 738 }