1 /* 2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. 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 "asm/macroAssembler.inline.hpp" 26 #include "code/aotCodeCache.hpp" 27 #include "gc/g1/g1BarrierSet.hpp" 28 #include "gc/g1/g1BarrierSetAssembler.hpp" 29 #include "gc/g1/g1BarrierSetRuntime.hpp" 30 #include "gc/g1/g1CardTable.hpp" 31 #include "gc/g1/g1HeapRegion.hpp" 32 #include "gc/g1/g1ThreadLocalData.hpp" 33 #include "interpreter/interp_masm.hpp" 34 #include "runtime/sharedRuntime.hpp" 35 #include "utilities/debug.hpp" 36 #include "utilities/macros.hpp" 37 #ifdef COMPILER1 38 #include "c1/c1_LIRAssembler.hpp" 39 #include "c1/c1_MacroAssembler.hpp" 40 #include "gc/g1/c1/g1BarrierSetC1.hpp" 41 #endif // COMPILER1 42 #ifdef COMPILER2 43 #include "gc/g1/c2/g1BarrierSetC2.hpp" 44 #endif // COMPILER2 45 46 #define __ masm-> 47 48 void G1BarrierSetAssembler::gen_write_ref_array_pre_barrier(MacroAssembler* masm, DecoratorSet decorators, 49 Register addr, Register count) { 50 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0; 51 52 if (!dest_uninitialized) { 53 Register thread = r15_thread; 54 55 Label filtered; 56 Address in_progress(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset())); 57 // Is marking active? 58 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) { 59 __ cmpl(in_progress, 0); 60 } else { 61 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption"); 62 __ cmpb(in_progress, 0); 63 } 64 65 __ jcc(Assembler::equal, filtered); 66 67 __ push_call_clobbered_registers(false /* save_fpu */); 68 if (count == c_rarg0) { 69 if (addr == c_rarg1) { 70 // exactly backwards!! 71 __ xchgptr(c_rarg1, c_rarg0); 72 } else { 73 __ movptr(c_rarg1, count); 74 __ movptr(c_rarg0, addr); 75 } 76 } else { 77 __ movptr(c_rarg0, addr); 78 __ movptr(c_rarg1, count); 79 } 80 if (UseCompressedOops) { 81 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_narrow_oop_entry), 2); 82 } else { 83 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_oop_entry), 2); 84 } 85 __ pop_call_clobbered_registers(false /* save_fpu */); 86 87 __ bind(filtered); 88 } 89 } 90 91 void G1BarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, 92 Register addr, Register count, Register tmp) { 93 Label done; 94 95 __ testptr(count, count); 96 __ jcc(Assembler::zero, done); 97 98 // Calculate end address in "count". 99 Address::ScaleFactor scale = UseCompressedOops ? Address::times_4 : Address::times_8; 100 __ leaq(count, Address(addr, count, scale)); 101 102 // Calculate start card address in "addr". 103 __ shrptr(addr, CardTable::card_shift()); 104 105 Register thread = r15_thread; 106 107 __ movptr(tmp, Address(thread, in_bytes(G1ThreadLocalData::card_table_base_offset()))); 108 __ addptr(addr, tmp); 109 110 // Calculate address of card of last word in the array. 111 __ subptr(count, 1); 112 __ shrptr(count, CardTable::card_shift()); 113 __ addptr(count, tmp); 114 115 Label loop; 116 // Iterate from start card to end card (inclusive). 117 __ bind(loop); 118 119 Label is_clean_card; 120 if (UseCondCardMark) { 121 __ cmpb(Address(addr, 0), G1CardTable::clean_card_val()); 122 __ jcc(Assembler::equal, is_clean_card); 123 } else { 124 __ movb(Address(addr, 0), G1CardTable::dirty_card_val()); 125 } 126 127 Label next_card; 128 __ bind(next_card); 129 __ addptr(addr, sizeof(CardTable::CardValue)); 130 __ cmpptr(addr, count); 131 __ jcc(Assembler::belowEqual, loop); 132 __ jmp(done); 133 134 __ bind(is_clean_card); 135 // Card was clean. Dirty card and go to next.. 136 __ movb(Address(addr, 0), G1CardTable::dirty_card_val()); 137 __ jmp(next_card); 138 139 __ bind(done); 140 } 141 142 void G1BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 143 Register dst, Address src, Register tmp1) { 144 bool on_oop = is_reference_type(type); 145 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0; 146 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0; 147 bool on_reference = on_weak || on_phantom; 148 ModRefBarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1); 149 if (on_oop && on_reference) { 150 // Generate the G1 pre-barrier code to log the value of 151 // the referent field in an SATB buffer. 152 g1_write_barrier_pre(masm /* masm */, 153 noreg /* obj */, 154 dst /* pre_val */, 155 tmp1 /* tmp */, 156 true /* tosca_live */, 157 true /* expand_call */); 158 } 159 } 160 161 static void generate_queue_insertion(MacroAssembler* masm, ByteSize index_offset, ByteSize buffer_offset, Label& runtime, 162 const Register thread, const Register value, const Register temp) { 163 // This code assumes that buffer index is pointer sized. 164 STATIC_ASSERT(in_bytes(SATBMarkQueue::byte_width_of_index()) == sizeof(intptr_t)); 165 // Can we store a value in the given thread's buffer? 166 // (The index field is typed as size_t.) 167 __ movptr(temp, Address(thread, in_bytes(index_offset))); // temp := *(index address) 168 __ testptr(temp, temp); // index == 0? 169 __ jcc(Assembler::zero, runtime); // jump to runtime if index == 0 (full buffer) 170 // The buffer is not full, store value into it. 171 __ subptr(temp, wordSize); // temp := next index 172 __ movptr(Address(thread, in_bytes(index_offset)), temp); // *(index address) := next index 173 __ addptr(temp, Address(thread, in_bytes(buffer_offset))); // temp := buffer address + next index 174 __ movptr(Address(temp, 0), value); // *(buffer address + next index) := value 175 } 176 177 static void generate_pre_barrier_fast_path(MacroAssembler* masm, 178 const Register thread) { 179 Address in_progress(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset())); 180 // Is marking active? 181 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) { 182 __ cmpl(in_progress, 0); 183 } else { 184 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption"); 185 __ cmpb(in_progress, 0); 186 } 187 } 188 189 static void generate_pre_barrier_slow_path(MacroAssembler* masm, 190 const Register obj, 191 const Register pre_val, 192 const Register thread, 193 const Register tmp, 194 Label& done, 195 Label& runtime) { 196 // Do we need to load the previous value? 197 if (obj != noreg) { 198 __ load_heap_oop(pre_val, Address(obj, 0), noreg, AS_RAW); 199 } 200 // Is the previous value null? 201 __ cmpptr(pre_val, NULL_WORD); 202 __ jcc(Assembler::equal, done); 203 generate_queue_insertion(masm, 204 G1ThreadLocalData::satb_mark_queue_index_offset(), 205 G1ThreadLocalData::satb_mark_queue_buffer_offset(), 206 runtime, 207 thread, pre_val, tmp); 208 __ jmp(done); 209 } 210 211 void G1BarrierSetAssembler::g1_write_barrier_pre(MacroAssembler* masm, 212 Register obj, 213 Register pre_val, 214 Register tmp, 215 bool tosca_live, 216 bool expand_call) { 217 // If expand_call is true then we expand the call_VM_leaf macro 218 // directly to skip generating the check by 219 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp. 220 const Register thread = r15_thread; 221 222 Label done; 223 Label runtime; 224 225 assert(pre_val != noreg, "check this code"); 226 227 if (obj != noreg) { 228 assert_different_registers(obj, pre_val, tmp); 229 assert(pre_val != rax, "check this code"); 230 } 231 232 generate_pre_barrier_fast_path(masm, thread); 233 // If marking is not active (*(mark queue active address) == 0), jump to done 234 __ jcc(Assembler::equal, done); 235 generate_pre_barrier_slow_path(masm, obj, pre_val, thread, tmp, done, runtime); 236 237 __ bind(runtime); 238 239 // Determine and save the live input values 240 __ push_call_clobbered_registers(); 241 242 // Calling the runtime using the regular call_VM_leaf mechanism generates 243 // code (generated by InterpreterMacroAssember::call_VM_leaf_base) 244 // that checks that the *(ebp+frame::interpreter_frame_last_sp) == nullptr. 245 // 246 // If we care generating the pre-barrier without a frame (e.g. in the 247 // intrinsified Reference.get() routine) then ebp might be pointing to 248 // the caller frame and so this check will most likely fail at runtime. 249 // 250 // Expanding the call directly bypasses the generation of the check. 251 // So when we do not have have a full interpreter frame on the stack 252 // expand_call should be passed true. 253 254 if (expand_call) { 255 assert(pre_val != c_rarg1, "smashed arg"); 256 if (c_rarg1 != thread) { 257 __ mov(c_rarg1, thread); 258 } 259 if (c_rarg0 != pre_val) { 260 __ mov(c_rarg0, pre_val); 261 } 262 __ MacroAssembler::call_VM_leaf_base(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), 2); 263 } else { 264 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), pre_val, thread); 265 } 266 267 __ pop_call_clobbered_registers(); 268 269 __ bind(done); 270 } 271 272 // return a register that differs from reg1, reg2, reg3 and is not rcx 273 274 static Register pick_different_reg(Register reg1, Register reg2 = noreg, Register reg3= noreg, Register reg4 = noreg) { 275 RegSet available = (RegSet::of(rscratch1, rscratch2, rax, rbx) + rdx - 276 RegSet::of(reg1, reg2, reg3, reg4)); 277 return *(available.begin()); 278 } 279 280 static void generate_post_barrier_fast_path(MacroAssembler* masm, 281 const Register store_addr, 282 const Register new_val, 283 const Register tmp1, 284 Label& done, 285 bool new_val_may_be_null) { 286 287 assert_different_registers(store_addr, new_val, tmp1, noreg); 288 289 Register thread = r15_thread; 290 291 // Does store cross heap regions? 292 #if INCLUDE_CDS 293 // AOT code needs to load the barrier grain shift from the aot 294 // runtime constants area in the code cache otherwise we can compile 295 // it as an immediate operand 296 297 if (AOTCodeCache::is_on_for_dump()) { 298 address grain_shift_addr = AOTRuntimeConstants::grain_shift_address(); 299 Register save = pick_different_reg(rcx, tmp1, new_val, store_addr); 300 __ push(save); 301 __ movptr(save, store_addr); 302 __ xorptr(save, new_val); 303 __ push(rcx); 304 __ lea(rcx, ExternalAddress(grain_shift_addr)); 305 __ movptr(rcx, Address(rcx, 0)); 306 __ shrptr(save); 307 __ pop(rcx); 308 __ mov(tmp1, save); 309 __ pop(save); 310 __ jcc(Assembler::equal, done); 311 } else 312 #endif // INCLUDE_CDS 313 { 314 __ movptr(tmp1, store_addr); // tmp1 := store address 315 __ xorptr(tmp1, new_val); // tmp1 := store address ^ new value 316 __ shrptr(tmp1, G1HeapRegion::LogOfHRGrainBytes); // ((store address ^ new value) >> LogOfHRGrainBytes) == 0? 317 __ jcc(Assembler::equal, done); 318 } 319 320 // Crosses regions, storing null? 321 if (new_val_may_be_null) { 322 __ cmpptr(new_val, NULL_WORD); // new value == null? 323 __ jcc(Assembler::equal, done); 324 } 325 326 __ movptr(tmp1, store_addr); // tmp1 := store address 327 __ shrptr(tmp1, CardTable::card_shift()); // tmp1 := card address relative to card table base 328 329 Address card_table_addr(thread, in_bytes(G1ThreadLocalData::card_table_base_offset())); 330 __ addptr(tmp1, card_table_addr); // tmp1 := card address 331 if (UseCondCardMark) { 332 __ cmpb(Address(tmp1, 0), G1CardTable::clean_card_val()); // *(card address) == clean_card_val? 333 __ jcc(Assembler::notEqual, done); 334 } 335 // Storing a region crossing, non-null oop, card is clean. 336 // Dirty card. 337 __ movb(Address(tmp1, 0), G1CardTable::dirty_card_val()); // *(card address) := dirty_card_val 338 } 339 340 void G1BarrierSetAssembler::g1_write_barrier_post(MacroAssembler* masm, 341 Register store_addr, 342 Register new_val, 343 Register tmp) { 344 Label done; 345 generate_post_barrier_fast_path(masm, store_addr, new_val, tmp, done, true /* new_val_may_be_null */); 346 __ bind(done); 347 } 348 349 #if defined(COMPILER2) 350 351 static void generate_c2_barrier_runtime_call(MacroAssembler* masm, G1BarrierStubC2* stub, const Register arg, const address runtime_path) { 352 SaveLiveRegisters save_registers(masm, stub); 353 if (c_rarg0 != arg) { 354 __ mov(c_rarg0, arg); 355 } 356 __ mov(c_rarg1, r15_thread); 357 // rax is a caller-saved, non-argument-passing register, so it does not 358 // interfere with c_rarg0 or c_rarg1. If it contained any live value before 359 // entering this stub, it is saved at this point, and restored after the 360 // call. If it did not contain any live value, it is free to be used. In 361 // either case, it is safe to use it here as a call scratch register. 362 __ call(RuntimeAddress(runtime_path), rax); 363 } 364 365 void G1BarrierSetAssembler::g1_write_barrier_pre_c2(MacroAssembler* masm, 366 Register obj, 367 Register pre_val, 368 Register tmp, 369 G1PreBarrierStubC2* stub) { 370 const Register thread = r15_thread; 371 372 assert(pre_val != noreg, "check this code"); 373 if (obj != noreg) { 374 assert_different_registers(obj, pre_val, tmp); 375 } 376 377 stub->initialize_registers(obj, pre_val, thread, tmp); 378 379 generate_pre_barrier_fast_path(masm, thread); 380 // If marking is active (*(mark queue active address) != 0), jump to stub (slow path) 381 __ jcc(Assembler::notEqual, *stub->entry()); 382 383 __ bind(*stub->continuation()); 384 } 385 386 void G1BarrierSetAssembler::generate_c2_pre_barrier_stub(MacroAssembler* masm, 387 G1PreBarrierStubC2* stub) const { 388 Assembler::InlineSkippedInstructionsCounter skip_counter(masm); 389 Label runtime; 390 Register obj = stub->obj(); 391 Register pre_val = stub->pre_val(); 392 Register thread = stub->thread(); 393 Register tmp = stub->tmp1(); 394 assert(stub->tmp2() == noreg, "not needed in this platform"); 395 396 __ bind(*stub->entry()); 397 generate_pre_barrier_slow_path(masm, obj, pre_val, thread, tmp, *stub->continuation(), runtime); 398 399 __ bind(runtime); 400 generate_c2_barrier_runtime_call(masm, stub, pre_val, CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry)); 401 __ jmp(*stub->continuation()); 402 } 403 404 void G1BarrierSetAssembler::g1_write_barrier_post_c2(MacroAssembler* masm, 405 Register store_addr, 406 Register new_val, 407 Register tmp, 408 bool new_val_may_be_null) { 409 Label done; 410 generate_post_barrier_fast_path(masm, store_addr, new_val, tmp, done, new_val_may_be_null); 411 __ bind(done); 412 } 413 414 #endif // COMPILER2 415 416 void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 417 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) { 418 bool in_heap = (decorators & IN_HEAP) != 0; 419 bool as_normal = (decorators & AS_NORMAL) != 0; 420 421 bool needs_pre_barrier = as_normal; 422 bool needs_post_barrier = val != noreg && in_heap; 423 424 // flatten object address if needed 425 // We do it regardless of precise because we need the registers 426 if (dst.index() == noreg && dst.disp() == 0) { 427 if (dst.base() != tmp1) { 428 __ movptr(tmp1, dst.base()); 429 } 430 } else { 431 __ lea(tmp1, dst); 432 } 433 434 if (needs_pre_barrier) { 435 g1_write_barrier_pre(masm /*masm*/, 436 tmp1 /* obj */, 437 tmp2 /* pre_val */, 438 tmp3 /* tmp */, 439 val != noreg /* tosca_live */, 440 false /* expand_call */); 441 } 442 if (val == noreg) { 443 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp1, 0), val, noreg, noreg, noreg); 444 } else { 445 Register new_val = val; 446 if (needs_post_barrier) { 447 // G1 barrier needs uncompressed oop for region cross check. 448 if (UseCompressedOops) { 449 new_val = tmp2; 450 __ movptr(new_val, val); 451 } 452 } 453 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp1, 0), val, noreg, noreg, noreg); 454 if (needs_post_barrier) { 455 g1_write_barrier_post(masm /*masm*/, 456 tmp1 /* store_adr */, 457 new_val /* new_val */, 458 tmp3 /* tmp */); 459 } 460 } 461 } 462 463 #ifdef COMPILER1 464 465 #undef __ 466 #define __ ce->masm()-> 467 468 void G1BarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, G1PreBarrierStub* stub) { 469 G1BarrierSetC1* bs = (G1BarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1(); 470 // At this point we know that marking is in progress. 471 // If do_load() is true then we have to emit the 472 // load of the previous value; otherwise it has already 473 // been loaded into _pre_val. 474 475 __ bind(*stub->entry()); 476 assert(stub->pre_val()->is_register(), "Precondition."); 477 478 Register pre_val_reg = stub->pre_val()->as_register(); 479 480 if (stub->do_load()) { 481 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/); 482 } 483 484 __ cmpptr(pre_val_reg, NULL_WORD); 485 __ jcc(Assembler::equal, *stub->continuation()); 486 ce->store_parameter(stub->pre_val()->as_register(), 0); 487 __ call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin())); 488 __ jmp(*stub->continuation()); 489 490 } 491 492 #undef __ 493 494 void G1BarrierSetAssembler::g1_write_barrier_post_c1(MacroAssembler* masm, 495 Register store_addr, 496 Register new_val, 497 Register thread, 498 Register tmp1, 499 Register tmp2 /* unused on x86 */) { 500 Label done; 501 generate_post_barrier_fast_path(masm, store_addr, new_val, tmp1, done, true /* new_val_may_be_null */); 502 masm->bind(done); 503 } 504 505 #define __ sasm-> 506 507 void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) { 508 // Generated code assumes that buffer index is pointer sized. 509 STATIC_ASSERT(in_bytes(SATBMarkQueue::byte_width_of_index()) == sizeof(intptr_t)); 510 511 __ prologue("g1_pre_barrier", false); 512 // arg0 : previous value of memory 513 514 __ push_ppx(rax); 515 __ push_ppx(rdx); 516 517 const Register pre_val = rax; 518 const Register thread = r15_thread; 519 const Register tmp = rdx; 520 521 Address queue_active(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset())); 522 Address queue_index(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_index_offset())); 523 Address buffer(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset())); 524 525 Label done; 526 Label runtime; 527 528 // Is marking still active? 529 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) { 530 __ cmpl(queue_active, 0); 531 } else { 532 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption"); 533 __ cmpb(queue_active, 0); 534 } 535 __ jcc(Assembler::equal, done); 536 537 // Can we store original value in the thread's buffer? 538 539 __ movptr(tmp, queue_index); 540 __ testptr(tmp, tmp); 541 __ jcc(Assembler::zero, runtime); 542 __ subptr(tmp, wordSize); 543 __ movptr(queue_index, tmp); 544 __ addptr(tmp, buffer); 545 546 // prev_val (rax) 547 __ load_parameter(0, pre_val); 548 __ movptr(Address(tmp, 0), pre_val); 549 __ jmp(done); 550 551 __ bind(runtime); 552 553 __ push_call_clobbered_registers(); 554 555 // load the pre-value 556 __ load_parameter(0, rcx); 557 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), rcx, thread); 558 559 __ pop_call_clobbered_registers(); 560 561 __ bind(done); 562 563 __ pop_ppx(rdx); 564 __ pop_ppx(rax); 565 566 __ epilogue(); 567 } 568 569 #undef __ 570 571 #endif // COMPILER1