1 /* 2 * Copyright (c) 2018, 2019, 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) || ShenandoahLoadRefBarrier) { 53 54 Label done; 55 56 // Avoid calling runtime if count == 0 57 __ cbz(count, done); 58 59 // Is marking active? 60 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 61 __ ldrb(rscratch1, gc_state); 62 if (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 if (dest_uninitialized) { 73 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_duinit_narrow_oop_entry), src, dst, count); 74 } else { 75 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_narrow_oop_entry), src, dst, count); 76 } 77 } else { 78 if (dest_uninitialized) { 79 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_duinit_oop_entry), src, dst, count); 80 } else { 81 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_array_pre_oop_entry), src, dst, count); 82 } 83 } 84 __ pop(saved_regs, sp); 85 __ bind(done); 86 } 87 } 88 } 89 90 void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm, 91 Register obj, 92 Register pre_val, 93 Register thread, 94 Register tmp, 95 bool tosca_live, 96 bool expand_call) { 97 if (ShenandoahSATBBarrier) { 98 satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call); 99 } 100 } 101 102 void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm, 103 Register obj, 104 Register pre_val, 105 Register thread, 106 Register tmp, 107 bool tosca_live, 108 bool expand_call) { 109 // If expand_call is true then we expand the call_VM_leaf macro 110 // directly to skip generating the check by 111 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp. 112 113 assert(thread == rthread, "must be"); 114 115 Label done; 116 Label runtime; 117 118 assert_different_registers(obj, pre_val, tmp, rscratch1); 119 assert(pre_val != noreg && tmp != noreg, "expecting a register"); 120 121 Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset())); 122 Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset())); 123 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset())); 124 125 // Is marking active? 126 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) { 127 __ ldrw(tmp, in_progress); 128 } else { 129 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption"); 130 __ ldrb(tmp, in_progress); 131 } 132 __ cbzw(tmp, done); 133 134 // Do we need to load the previous value? 135 if (obj != noreg) { 136 __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW); 137 } 138 139 // Is the previous value null? 140 __ cbz(pre_val, done); 141 142 // Can we store original value in the thread's buffer? 143 // Is index == 0? 144 // (The index field is typed as size_t.) 145 146 __ ldr(tmp, index); // tmp := *index_adr 147 __ cbz(tmp, runtime); // tmp == 0? 148 // If yes, goto runtime 149 150 __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize 151 __ str(tmp, index); // *index_adr := tmp 152 __ ldr(rscratch1, buffer); 153 __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr 154 155 // Record the previous value 156 __ str(pre_val, Address(tmp, 0)); 157 __ b(done); 158 159 __ bind(runtime); 160 // save the live input values 161 RegSet saved = RegSet::of(pre_val); 162 if (tosca_live) saved += RegSet::of(r0); 163 if (obj != noreg) saved += RegSet::of(obj); 164 165 __ push(saved, sp); 166 167 // Calling the runtime using the regular call_VM_leaf mechanism generates 168 // code (generated by InterpreterMacroAssember::call_VM_leaf_base) 169 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL. 170 // 171 // If we care generating the pre-barrier without a frame (e.g. in the 172 // intrinsified Reference.get() routine) then ebp might be pointing to 173 // the caller frame and so this check will most likely fail at runtime. 174 // 175 // Expanding the call directly bypasses the generation of the check. 176 // So when we do not have have a full interpreter frame on the stack 177 // expand_call should be passed true. 178 179 if (expand_call) { 180 assert(pre_val != c_rarg1, "smashed arg"); 181 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); 182 } else { 183 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); 184 } 185 186 __ pop(saved, sp); 187 188 __ bind(done); 189 } 190 191 void ShenandoahBarrierSetAssembler::resolve_forward_pointer(MacroAssembler* masm, Register dst, Register tmp) { 192 assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled"); 193 Label is_null; 194 __ cbz(dst, is_null); 195 resolve_forward_pointer_not_null(masm, dst, tmp); 196 __ bind(is_null); 197 } 198 199 // IMPORTANT: This must preserve all registers, even rscratch1 and rscratch2, except those explicitely 200 // passed in. 201 void ShenandoahBarrierSetAssembler::resolve_forward_pointer_not_null(MacroAssembler* masm, Register dst, Register tmp) { 202 assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled"); 203 // The below loads the mark word, checks if the lowest two bits are 204 // set, and if so, clear the lowest two bits and copy the result 205 // to dst. Otherwise it leaves dst alone. 206 // Implementing this is surprisingly awkward. I do it here by: 207 // - Inverting the mark word 208 // - Test lowest two bits == 0 209 // - If so, set the lowest two bits 210 // - Invert the result back, and copy to dst 211 212 bool borrow_reg = (tmp == noreg); 213 if (borrow_reg) { 214 // No free registers available. Make one useful. 215 tmp = rscratch1; 216 if (tmp == dst) { 217 tmp = rscratch2; 218 } 219 __ push(RegSet::of(tmp), sp); 220 } 221 222 assert_different_registers(tmp, dst); 223 224 Label done; 225 __ ldr(tmp, Address(dst, oopDesc::mark_offset_in_bytes())); 226 __ eon(tmp, tmp, zr); 227 __ ands(zr, tmp, markWord::lock_mask_in_place); 228 __ br(Assembler::NE, done); 229 __ orr(tmp, tmp, markWord::marked_value); 230 __ eon(dst, tmp, zr); 231 __ bind(done); 232 233 if (borrow_reg) { 234 __ pop(RegSet::of(tmp), sp); 235 } 236 } 237 238 void ShenandoahBarrierSetAssembler::load_reference_barrier_not_null(MacroAssembler* masm, Register dst, Address load_addr) { 239 assert(ShenandoahLoadRefBarrier, "Should be enabled"); 240 assert(dst != rscratch2, "need rscratch2"); 241 assert_different_registers(load_addr.base(), load_addr.index(), rscratch1, rscratch2); 242 243 Label done; 244 __ enter(); 245 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 246 __ ldrb(rscratch2, gc_state); 247 248 // Check for heap stability 249 __ tbz(rscratch2, ShenandoahHeap::HAS_FORWARDED_BITPOS, done); 250 251 // use r1 for load address 252 Register result_dst = dst; 253 if (dst == r1) { 254 __ mov(rscratch1, dst); 255 dst = rscratch1; 256 } 257 258 // Save r0 and r1, unless it is an output register 259 RegSet to_save = RegSet::of(r0, r1) - result_dst; 260 __ push(to_save, sp); 261 __ lea(r1, load_addr); 262 __ mov(r0, dst); 263 264 __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_lrb()))); 265 266 __ mov(result_dst, r0); 267 __ pop(to_save, sp); 268 269 __ bind(done); 270 __ leave(); 271 } 272 273 void ShenandoahBarrierSetAssembler::load_reference_barrier_native(MacroAssembler* masm, Register dst, Address load_addr) { 274 if (!ShenandoahLoadRefBarrier) { 275 return; 276 } 277 278 assert(dst != rscratch2, "need rscratch2"); 279 280 Label is_null; 281 Label done; 282 283 __ block_comment("load_reference_barrier_native { "); 284 285 __ cbz(dst, is_null); 286 287 __ enter(); 288 289 Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 290 __ ldrb(rscratch2, gc_state); 291 292 // Check for heap in evacuation phase 293 __ tbz(rscratch2, ShenandoahHeap::EVACUATION_BITPOS, done); 294 295 __ mov(rscratch2, dst); 296 __ push_call_clobbered_registers(); 297 __ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_native)); 298 __ lea(r1, load_addr); 299 __ mov(r0, rscratch2); 300 __ blr(lr); 301 __ mov(rscratch2, r0); 302 __ pop_call_clobbered_registers(); 303 __ mov(dst, rscratch2); 304 305 __ bind(done); 306 __ leave(); 307 __ bind(is_null); 308 __ block_comment("} load_reference_barrier_native"); 309 } 310 311 void ShenandoahBarrierSetAssembler::storeval_barrier(MacroAssembler* masm, Register dst, Register tmp) { 312 if (ShenandoahStoreValEnqueueBarrier) { 313 // Save possibly live regs. 314 RegSet live_regs = RegSet::range(r0, r4) - dst; 315 __ push(live_regs, sp); 316 __ strd(v0, __ pre(sp, 2 * -wordSize)); 317 318 satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false); 319 320 // Restore possibly live regs. 321 __ ldrd(v0, __ post(sp, 2 * wordSize)); 322 __ pop(live_regs, sp); 323 } 324 } 325 326 void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm, Register dst, Address load_addr) { 327 if (ShenandoahLoadRefBarrier) { 328 Label is_null; 329 __ cbz(dst, is_null); 330 load_reference_barrier_not_null(masm, dst, load_addr); 331 __ bind(is_null); 332 } 333 } 334 335 // 336 // Arguments: 337 // 338 // Inputs: 339 // src: oop location to load from, might be clobbered 340 // 341 // Output: 342 // dst: oop loaded from src location 343 // 344 // Kill: 345 // rscratch1 (scratch reg) 346 // 347 // Alias: 348 // dst: rscratch1 (might use rscratch1 as temporary output register to avoid clobbering src) 349 // 350 void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 351 Register dst, Address src, Register tmp1, Register tmp_thread) { 352 // 1: non-reference load, no additional barrier is needed 353 if (!is_reference_type(type)) { 354 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread); 355 return; 356 } 357 358 // 2: load a reference from src location and apply LRB if needed 359 if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) { 360 Register result_dst = dst; 361 362 // Preserve src location for LRB 363 if (dst == src.base() || dst == src.index()) { 364 dst = rscratch1; 365 } 366 assert_different_registers(dst, src.base(), src.index()); 367 368 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread); 369 370 if (ShenandoahBarrierSet::use_load_reference_barrier_native(decorators, type)) { 371 load_reference_barrier_native(masm, dst, src); 372 } else { 373 load_reference_barrier(masm, dst, src); 374 } 375 376 if (dst != result_dst) { 377 __ mov(result_dst, dst); 378 dst = result_dst; 379 } 380 } else { 381 BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread); 382 } 383 384 // 3: apply keep-alive barrier if needed 385 if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) { 386 __ enter(); 387 satb_write_barrier_pre(masm /* masm */, 388 noreg /* obj */, 389 dst /* pre_val */, 390 rthread /* thread */, 391 tmp1 /* tmp */, 392 true /* tosca_live */, 393 true /* expand_call */); 394 __ leave(); 395 } 396 } 397 398 void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 399 Address dst, Register val, Register tmp1, Register tmp2) { 400 bool on_oop = is_reference_type(type); 401 if (!on_oop) { 402 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2); 403 return; 404 } 405 406 // flatten object address if needed 407 if (dst.index() == noreg && dst.offset() == 0) { 408 if (dst.base() != r3) { 409 __ mov(r3, dst.base()); 410 } 411 } else { 412 __ lea(r3, dst); 413 } 414 415 shenandoah_write_barrier_pre(masm, 416 r3 /* obj */, 417 tmp2 /* pre_val */, 418 rthread /* thread */, 419 tmp1 /* tmp */, 420 val != noreg /* tosca_live */, 421 false /* expand_call */); 422 423 if (val == noreg) { 424 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg); 425 } else { 426 storeval_barrier(masm, val, tmp1); 427 // G1 barrier needs uncompressed oop for region cross check. 428 Register new_val = val; 429 if (UseCompressedOops) { 430 new_val = rscratch2; 431 __ mov(new_val, val); 432 } 433 BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg); 434 } 435 436 } 437 438 void ShenandoahBarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env, 439 Register obj, Register tmp, Label& slowpath) { 440 Label done; 441 // Resolve jobject 442 BarrierSetAssembler::try_resolve_jobject_in_native(masm, jni_env, obj, tmp, slowpath); 443 444 // Check for null. 445 __ cbz(obj, done); 446 447 assert(obj != rscratch2, "need rscratch2"); 448 Address gc_state(jni_env, ShenandoahThreadLocalData::gc_state_offset() - JavaThread::jni_environment_offset()); 449 __ lea(rscratch2, gc_state); 450 __ ldrb(rscratch2, Address(rscratch2)); 451 452 // Check for heap in evacuation phase 453 __ tbnz(rscratch2, ShenandoahHeap::EVACUATION_BITPOS, slowpath); 454 455 __ bind(done); 456 } 457 458 459 void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm, Register addr, Register expected, Register new_val, 460 bool acquire, bool release, bool weak, bool is_cae, 461 Register result) { 462 Register tmp1 = rscratch1; 463 Register tmp2 = rscratch2; 464 bool is_narrow = UseCompressedOops; 465 Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword; 466 467 assert_different_registers(addr, expected, new_val, tmp1, tmp2); 468 469 Label retry, done, fail; 470 471 // CAS, using LL/SC pair. 472 __ bind(retry); 473 __ load_exclusive(tmp1, addr, size, acquire); 474 if (is_narrow) { 475 __ cmpw(tmp1, expected); 476 } else { 477 __ cmp(tmp1, expected); 478 } 479 __ br(Assembler::NE, fail); 480 __ store_exclusive(tmp2, new_val, addr, size, release); 481 if (weak) { 482 __ cmpw(tmp2, 0u); // If the store fails, return NE to our caller 483 } else { 484 __ cbnzw(tmp2, retry); 485 } 486 __ b(done); 487 488 __ bind(fail); 489 // Check if rb(expected)==rb(tmp1) 490 // Shuffle registers so that we have memory value ready for next expected. 491 __ mov(tmp2, expected); 492 __ mov(expected, tmp1); 493 if (is_narrow) { 494 __ decode_heap_oop(tmp1, tmp1); 495 __ decode_heap_oop(tmp2, tmp2); 496 } 497 resolve_forward_pointer(masm, tmp1); 498 resolve_forward_pointer(masm, tmp2); 499 __ cmp(tmp1, tmp2); 500 // Retry with expected now being the value we just loaded from addr. 501 __ br(Assembler::EQ, retry); 502 if (is_cae && is_narrow) { 503 // For cmp-and-exchange and narrow oops, we need to restore 504 // the compressed old-value. We moved it to 'expected' a few lines up. 505 __ mov(tmp1, expected); 506 } 507 __ bind(done); 508 509 if (is_cae) { 510 __ mov(result, tmp1); 511 } else { 512 __ cset(result, Assembler::EQ); 513 } 514 } 515 516 #undef __ 517 518 #ifdef COMPILER1 519 520 #define __ ce->masm()-> 521 522 void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) { 523 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1(); 524 // At this point we know that marking is in progress. 525 // If do_load() is true then we have to emit the 526 // load of the previous value; otherwise it has already 527 // been loaded into _pre_val. 528 529 __ bind(*stub->entry()); 530 531 assert(stub->pre_val()->is_register(), "Precondition."); 532 533 Register pre_val_reg = stub->pre_val()->as_register(); 534 535 if (stub->do_load()) { 536 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/); 537 } 538 __ cbz(pre_val_reg, *stub->continuation()); 539 ce->store_parameter(stub->pre_val()->as_register(), 0); 540 __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin())); 541 __ b(*stub->continuation()); 542 } 543 544 void ShenandoahBarrierSetAssembler::gen_load_reference_barrier_stub(LIR_Assembler* ce, ShenandoahLoadReferenceBarrierStub* stub) { 545 ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1(); 546 __ bind(*stub->entry()); 547 548 Register obj = stub->obj()->as_register(); 549 Register res = stub->result()->as_register(); 550 Register addr = stub->addr()->as_pointer_register(); 551 Register tmp1 = stub->tmp1()->as_register(); 552 Register tmp2 = stub->tmp2()->as_register(); 553 554 assert(res == r0, "result must arrive in r0"); 555 556 if (res != obj) { 557 __ mov(res, obj); 558 } 559 560 // Check for null. 561 __ cbz(res, *stub->continuation()); 562 563 // Check for object in cset. 564 __ mov(tmp2, ShenandoahHeap::in_cset_fast_test_addr()); 565 __ lsr(tmp1, res, ShenandoahHeapRegion::region_size_bytes_shift_jint()); 566 __ ldrb(tmp2, Address(tmp2, tmp1)); 567 __ cbz(tmp2, *stub->continuation()); 568 569 // Check if object is already forwarded. 570 Label slow_path; 571 __ ldr(tmp1, Address(res, oopDesc::mark_offset_in_bytes())); 572 __ eon(tmp1, tmp1, zr); 573 __ ands(zr, tmp1, markWord::lock_mask_in_place); 574 __ br(Assembler::NE, slow_path); 575 576 // Decode forwarded object. 577 __ orr(tmp1, tmp1, markWord::marked_value); 578 __ eon(res, tmp1, zr); 579 __ b(*stub->continuation()); 580 581 __ bind(slow_path); 582 ce->store_parameter(res, 0); 583 ce->store_parameter(addr, 1); 584 __ far_call(RuntimeAddress(bs->load_reference_barrier_rt_code_blob()->code_begin())); 585 586 __ b(*stub->continuation()); 587 } 588 589 #undef __ 590 591 #define __ sasm-> 592 593 void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) { 594 __ prologue("shenandoah_pre_barrier", false); 595 596 // arg0 : previous value of memory 597 598 BarrierSet* bs = BarrierSet::barrier_set(); 599 600 const Register pre_val = r0; 601 const Register thread = rthread; 602 const Register tmp = rscratch1; 603 604 Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset())); 605 Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset())); 606 607 Label done; 608 Label runtime; 609 610 // Is marking still active? 611 Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 612 __ ldrb(tmp, gc_state); 613 __ mov(rscratch2, ShenandoahHeap::MARKING | ShenandoahHeap::TRAVERSAL); 614 __ tst(tmp, rscratch2); 615 __ br(Assembler::EQ, done); 616 617 // Can we store original value in the thread's buffer? 618 __ ldr(tmp, queue_index); 619 __ cbz(tmp, runtime); 620 621 __ sub(tmp, tmp, wordSize); 622 __ str(tmp, queue_index); 623 __ ldr(rscratch2, buffer); 624 __ add(tmp, tmp, rscratch2); 625 __ load_parameter(0, rscratch2); 626 __ str(rscratch2, Address(tmp, 0)); 627 __ b(done); 628 629 __ bind(runtime); 630 __ push_call_clobbered_registers(); 631 __ load_parameter(0, pre_val); 632 __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread); 633 __ pop_call_clobbered_registers(); 634 __ bind(done); 635 636 __ epilogue(); 637 } 638 639 void ShenandoahBarrierSetAssembler::generate_c1_load_reference_barrier_runtime_stub(StubAssembler* sasm) { 640 __ prologue("shenandoah_load_reference_barrier", false); 641 // arg0 : object to be resolved 642 643 __ push_call_clobbered_registers(); 644 __ load_parameter(0, r0); 645 __ load_parameter(1, r1); 646 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 }