src/v8/src/x64/assembler-x64-inl.h

   1 // Copyright 2012 the V8 project authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef V8_X64_ASSEMBLER_X64_INL_H_
   6 #define V8_X64_ASSEMBLER_X64_INL_H_
   7
   8 #include "src/x64/assembler-x64.h"
   9
  10 #include "src/base/cpu.h"
  11 #include "src/debug.h"
  12 #include "src/v8memory.h"
  13
  14 namespace v8 {
  15 namespace internal {
  16
  17 bool CpuFeatures::SupportsCrankshaft() { return true; }
  18 bool CpuFeatures::SupportsSIMD128InCrankshaft() { return true; }
  19
  20
  21 // -----------------------------------------------------------------------------
  22 // Implementation of Assembler
  23
  24
  25 static const byte kCallOpcode = 0xE8;
  26 // The length of pushq(rbp), movp(rbp, rsp), Push(rsi) and Push(rdi).
  27 static const int kNoCodeAgeSequenceLength = kPointerSize == kInt64Size ? 6 : 17;
  28
  29
  30 void Assembler::emitl(uint32_t x) {
  31   Memory::uint32_at(pc_) = x;
  32   pc_ += sizeof(uint32_t);
  33 }
  34
  35
  36 void Assembler::emitp(void* x, RelocInfo::Mode rmode) {
  37   uintptr_t value = reinterpret_cast<uintptr_t>(x);
  38   Memory::uintptr_at(pc_) = value;
  39   if (!RelocInfo::IsNone(rmode)) {
  40     RecordRelocInfo(rmode, value);
  41   }
  42   pc_ += sizeof(uintptr_t);
  43 }
  44
  45
  46 void Assembler::emitq(uint64_t x) {
  47   Memory::uint64_at(pc_) = x;
  48   pc_ += sizeof(uint64_t);
  49 }
  50
  51
  52 void Assembler::emitw(uint16_t x) {
  53   Memory::uint16_at(pc_) = x;
  54   pc_ += sizeof(uint16_t);
  55 }
  56
  57
  58 void Assembler::emit_code_target(Handle<Code> target,
  59                                  RelocInfo::Mode rmode,
  60                                  TypeFeedbackId ast_id) {
  61   DCHECK(RelocInfo::IsCodeTarget(rmode) ||
  62       rmode == RelocInfo::CODE_AGE_SEQUENCE);
  63   if (rmode == RelocInfo::CODE_TARGET && !ast_id.IsNone()) {
  64     RecordRelocInfo(RelocInfo::CODE_TARGET_WITH_ID, ast_id.ToInt());
  65   } else {
  66     RecordRelocInfo(rmode);
  67   }
  68   int current = code_targets_.length();
  69   if (current > 0 && code_targets_.last().is_identical_to(target)) {
  70     // Optimization if we keep jumping to the same code target.
  71     emitl(current - 1);
  72   } else {
  73     code_targets_.Add(target);
  74     emitl(current);
  75   }
  76 }
  77
  78
  79 void Assembler::emit_runtime_entry(Address entry, RelocInfo::Mode rmode) {
  80   DCHECK(RelocInfo::IsRuntimeEntry(rmode));
  81   RecordRelocInfo(rmode);
  82   emitl(static_cast<uint32_t>(entry - isolate()->code_range()->start()));
  83 }
  84
  85
  86 void Assembler::emit_rex_64(Register reg, Register rm_reg) {
  87   emit(0x48 | reg.high_bit() << 2 | rm_reg.high_bit());
  88 }
  89
  90
  91 void Assembler::emit_rex_64(XMMRegister reg, Register rm_reg) {
  92   emit(0x48 | (reg.code() & 0x8) >> 1 | rm_reg.code() >> 3);
  93 }
  94
  95
  96 void Assembler::emit_rex_64(Register reg, XMMRegister rm_reg) {
  97   emit(0x48 | (reg.code() & 0x8) >> 1 | rm_reg.code() >> 3);
  98 }
  99
 100
 101 void Assembler::emit_rex_64(Register reg, const Operand& op) {
 102   emit(0x48 | reg.high_bit() << 2 | op.rex_);
 103 }
 104
 105
 106 void Assembler::emit_rex_64(XMMRegister reg, const Operand& op) {
 107   emit(0x48 | (reg.code() & 0x8) >> 1 | op.rex_);
 108 }
 109
 110
 111 void Assembler::emit_rex_64(Register rm_reg) {
 112   DCHECK_EQ(rm_reg.code() & 0xf, rm_reg.code());
 113   emit(0x48 | rm_reg.high_bit());
 114 }
 115
 116
 117 void Assembler::emit_rex_64(const Operand& op) {
 118   emit(0x48 | op.rex_);
 119 }
 120
 121
 122 void Assembler::emit_rex_32(Register reg, Register rm_reg) {
 123   emit(0x40 | reg.high_bit() << 2 | rm_reg.high_bit());
 124 }
 125
 126
 127 void Assembler::emit_rex_32(Register reg, const Operand& op) {
 128   emit(0x40 | reg.high_bit() << 2  | op.rex_);
 129 }
 130
 131
 132 void Assembler::emit_rex_32(Register rm_reg) {
 133   emit(0x40 | rm_reg.high_bit());
 134 }
 135
 136
 137 void Assembler::emit_rex_32(const Operand& op) {
 138   emit(0x40 | op.rex_);
 139 }
 140
 141
 142 void Assembler::emit_optional_rex_32(Register reg, Register rm_reg) {
 143   byte rex_bits = reg.high_bit() << 2 | rm_reg.high_bit();
 144   if (rex_bits != 0) emit(0x40 | rex_bits);
 145 }
 146
 147
 148 void Assembler::emit_optional_rex_32(Register reg, const Operand& op) {
 149   byte rex_bits =  reg.high_bit() << 2 | op.rex_;
 150   if (rex_bits != 0) emit(0x40 | rex_bits);
 151 }
 152
 153
 154 void Assembler::emit_optional_rex_32(XMMRegister reg, const Operand& op) {
 155   byte rex_bits =  (reg.code() & 0x8) >> 1 | op.rex_;
 156   if (rex_bits != 0) emit(0x40 | rex_bits);
 157 }
 158
 159
 160 void Assembler::emit_optional_rex_32(XMMRegister reg, XMMRegister base) {
 161   byte rex_bits =  (reg.code() & 0x8) >> 1 | (base.code() & 0x8) >> 3;
 162   if (rex_bits != 0) emit(0x40 | rex_bits);
 163 }
 164
 165
 166 void Assembler::emit_optional_rex_32(XMMRegister reg, Register base) {
 167   byte rex_bits =  (reg.code() & 0x8) >> 1 | (base.code() & 0x8) >> 3;
 168   if (rex_bits != 0) emit(0x40 | rex_bits);
 169 }
 170
 171
 172 void Assembler::emit_optional_rex_32(Register reg, XMMRegister base) {
 173   byte rex_bits =  (reg.code() & 0x8) >> 1 | (base.code() & 0x8) >> 3;
 174   if (rex_bits != 0) emit(0x40 | rex_bits);
 175 }
 176
 177
 178 void Assembler::emit_optional_rex_32(Register rm_reg) {
 179   if (rm_reg.high_bit()) emit(0x41);
 180 }
 181
 182
 183 void Assembler::emit_optional_rex_32(XMMRegister rm_reg) {
 184   if (rm_reg.high_bit()) emit(0x41);
 185 }
 186
 187
 188 void Assembler::emit_optional_rex_32(const Operand& op) {
 189   if (op.rex_ != 0) emit(0x40 | op.rex_);
 190 }
 191
 192
 193 Address Assembler::target_address_at(Address pc,
 194                                      ConstantPoolArray* constant_pool) {
 195   return Memory::int32_at(pc) + pc + 4;
 196 }
 197
 198
 199 void Assembler::set_target_address_at(Address pc,
 200                                       ConstantPoolArray* constant_pool,
 201                                       Address target,
 202                                       ICacheFlushMode icache_flush_mode) {
 203   Memory::int32_at(pc) = static_cast<int32_t>(target - pc - 4);
 204   if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
 205     CpuFeatures::FlushICache(pc, sizeof(int32_t));
 206   }
 207 }
 208
 209
 210 Address Assembler::target_address_from_return_address(Address pc) {
 211   return pc - kCallTargetAddressOffset;
 212 }
 213
 214
 215 Address Assembler::break_address_from_return_address(Address pc) {
 216   return pc - Assembler::kPatchDebugBreakSlotReturnOffset;
 217 }
 218
 219
 220 Handle<Object> Assembler::code_target_object_handle_at(Address pc) {
 221   return code_targets_[Memory::int32_at(pc)];
 222 }
 223
 224
 225 Address Assembler::runtime_entry_at(Address pc) {
 226   return Memory::int32_at(pc) + isolate()->code_range()->start();
 227 }
 228
 229 // -----------------------------------------------------------------------------
 230 // Implementation of RelocInfo
 231
 232 // The modes possibly affected by apply must be in kApplyMask.
 233 void RelocInfo::apply(intptr_t delta, ICacheFlushMode icache_flush_mode) {
 234   bool flush_icache = icache_flush_mode != SKIP_ICACHE_FLUSH;
 235   if (IsInternalReference(rmode_)) {
 236     // absolute code pointer inside code object moves with the code object.
 237     Memory::Address_at(pc_) += static_cast<int32_t>(delta);
 238     if (flush_icache) CpuFeatures::FlushICache(pc_, sizeof(Address));
 239   } else if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
 240     Memory::int32_at(pc_) -= static_cast<int32_t>(delta);
 241     if (flush_icache) CpuFeatures::FlushICache(pc_, sizeof(int32_t));
 242   } else if (rmode_ == CODE_AGE_SEQUENCE) {
 243     if (*pc_ == kCallOpcode) {
 244       int32_t* p = reinterpret_cast<int32_t*>(pc_ + 1);
 245       *p -= static_cast<int32_t>(delta);  // Relocate entry.
 246       if (flush_icache) CpuFeatures::FlushICache(p, sizeof(uint32_t));
 247     }
 248   }
 249 }
 250
 251
 252 Address RelocInfo::target_address() {
 253   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_));
 254   return Assembler::target_address_at(pc_, host_);
 255 }
 256
 257
 258 Address RelocInfo::target_address_address() {
 259   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
 260                               || rmode_ == EMBEDDED_OBJECT
 261                               || rmode_ == EXTERNAL_REFERENCE);
 262   return reinterpret_cast<Address>(pc_);
 263 }
 264
 265
 266 Address RelocInfo::constant_pool_entry_address() {
 267   UNREACHABLE();
 268   return NULL;
 269 }
 270
 271
 272 int RelocInfo::target_address_size() {
 273   if (IsCodedSpecially()) {
 274     return Assembler::kSpecialTargetSize;
 275   } else {
 276     return kPointerSize;
 277   }
 278 }
 279
 280
 281 void RelocInfo::set_target_address(Address target,
 282                                    WriteBarrierMode write_barrier_mode,
 283                                    ICacheFlushMode icache_flush_mode) {
 284   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_));
 285   Assembler::set_target_address_at(pc_, host_, target, icache_flush_mode);
 286   if (write_barrier_mode == UPDATE_WRITE_BARRIER && host() != NULL &&
 287       IsCodeTarget(rmode_)) {
 288     Object* target_code = Code::GetCodeFromTargetAddress(target);
 289     host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
 290         host(), this, HeapObject::cast(target_code));
 291   }
 292 }
 293
 294
 295 Object* RelocInfo::target_object() {
 296   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
 297   return Memory::Object_at(pc_);
 298 }
 299
 300
 301 Handle<Object> RelocInfo::target_object_handle(Assembler* origin) {
 302   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
 303   if (rmode_ == EMBEDDED_OBJECT) {
 304     return Memory::Object_Handle_at(pc_);
 305   } else {
 306     return origin->code_target_object_handle_at(pc_);
 307   }
 308 }
 309
 310
 311 Address RelocInfo::target_reference() {
 312   DCHECK(rmode_ == RelocInfo::EXTERNAL_REFERENCE);
 313   return Memory::Address_at(pc_);
 314 }
 315
 316
 317 void RelocInfo::set_target_object(Object* target,
 318                                   WriteBarrierMode write_barrier_mode,
 319                                   ICacheFlushMode icache_flush_mode) {
 320   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
 321   Memory::Object_at(pc_) = target;
 322   if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
 323     CpuFeatures::FlushICache(pc_, sizeof(Address));
 324   }
 325   if (write_barrier_mode == UPDATE_WRITE_BARRIER &&
 326       host() != NULL &&
 327       target->IsHeapObject()) {
 328     host()->GetHeap()->incremental_marking()->RecordWrite(
 329         host(), &Memory::Object_at(pc_), HeapObject::cast(target));
 330   }
 331 }
 332
 333
 334 Address RelocInfo::target_runtime_entry(Assembler* origin) {
 335   DCHECK(IsRuntimeEntry(rmode_));
 336   return origin->runtime_entry_at(pc_);
 337 }
 338
 339
 340 void RelocInfo::set_target_runtime_entry(Address target,
 341                                          WriteBarrierMode write_barrier_mode,
 342                                          ICacheFlushMode icache_flush_mode) {
 343   DCHECK(IsRuntimeEntry(rmode_));
 344   if (target_address() != target) {
 345     set_target_address(target, write_barrier_mode, icache_flush_mode);
 346   }
 347 }
 348
 349
 350 Handle<Cell> RelocInfo::target_cell_handle() {
 351   DCHECK(rmode_ == RelocInfo::CELL);
 352   Address address = Memory::Address_at(pc_);
 353   return Handle<Cell>(reinterpret_cast<Cell**>(address));
 354 }
 355
 356
 357 Cell* RelocInfo::target_cell() {
 358   DCHECK(rmode_ == RelocInfo::CELL);
 359   return Cell::FromValueAddress(Memory::Address_at(pc_));
 360 }
 361
 362
 363 void RelocInfo::set_target_cell(Cell* cell,
 364                                 WriteBarrierMode write_barrier_mode,
 365                                 ICacheFlushMode icache_flush_mode) {
 366   DCHECK(rmode_ == RelocInfo::CELL);
 367   Address address = cell->address() + Cell::kValueOffset;
 368   Memory::Address_at(pc_) = address;
 369   if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
 370     CpuFeatures::FlushICache(pc_, sizeof(Address));
 371   }
 372   if (write_barrier_mode == UPDATE_WRITE_BARRIER &&
 373       host() != NULL) {
 374     // TODO(1550) We are passing NULL as a slot because cell can never be on
 375     // evacuation candidate.
 376     host()->GetHeap()->incremental_marking()->RecordWrite(
 377         host(), NULL, cell);
 378   }
 379 }
 380
 381
 382 void RelocInfo::WipeOut() {
 383   if (IsEmbeddedObject(rmode_) || IsExternalReference(rmode_)) {
 384     Memory::Address_at(pc_) = NULL;
 385   } else if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
 386     // Effectively write zero into the relocation.
 387     Assembler::set_target_address_at(pc_, host_, pc_ + sizeof(int32_t));
 388   } else {
 389     UNREACHABLE();
 390   }
 391 }
 392
 393
 394 bool RelocInfo::IsPatchedReturnSequence() {
 395   // The recognized call sequence is:
 396   //  movq(kScratchRegister, address); call(kScratchRegister);
 397   // It only needs to be distinguished from a return sequence
 398   //  movq(rsp, rbp); pop(rbp); ret(n); int3 *6
 399   // The 11th byte is int3 (0xCC) in the return sequence and
 400   // REX.WB (0x48+register bit) for the call sequence.
 401   return pc_[Assembler::kMoveAddressIntoScratchRegisterInstructionLength] !=
 402          0xCC;
 403 }
 404
 405
 406 bool RelocInfo::IsPatchedDebugBreakSlotSequence() {
 407   return !Assembler::IsNop(pc());
 408 }
 409
 410
 411 Handle<Object> RelocInfo::code_age_stub_handle(Assembler* origin) {
 412   DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
 413   DCHECK(*pc_ == kCallOpcode);
 414   return origin->code_target_object_handle_at(pc_ + 1);
 415 }
 416
 417
 418 Code* RelocInfo::code_age_stub() {
 419   DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
 420   DCHECK(*pc_ == kCallOpcode);
 421   return Code::GetCodeFromTargetAddress(
 422       Assembler::target_address_at(pc_ + 1, host_));
 423 }
 424
 425
 426 void RelocInfo::set_code_age_stub(Code* stub,
 427                                   ICacheFlushMode icache_flush_mode) {
 428   DCHECK(*pc_ == kCallOpcode);
 429   DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
 430   Assembler::set_target_address_at(pc_ + 1, host_, stub->instruction_start(),
 431                                    icache_flush_mode);
 432 }
 433
 434
 435 Address RelocInfo::call_address() {
 436   DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
 437          (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
 438   return Memory::Address_at(
 439       pc_ + Assembler::kRealPatchReturnSequenceAddressOffset);
 440 }
 441
 442
 443 void RelocInfo::set_call_address(Address target) {
 444   DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
 445          (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
 446   Memory::Address_at(pc_ + Assembler::kRealPatchReturnSequenceAddressOffset) =
 447       target;
 448   CpuFeatures::FlushICache(
 449       pc_ + Assembler::kRealPatchReturnSequenceAddressOffset, sizeof(Address));
 450   if (host() != NULL) {
 451     Object* target_code = Code::GetCodeFromTargetAddress(target);
 452     host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
 453         host(), this, HeapObject::cast(target_code));
 454   }
 455 }
 456
 457
 458 Object* RelocInfo::call_object() {
 459   return *call_object_address();
 460 }
 461
 462
 463 void RelocInfo::set_call_object(Object* target) {
 464   *call_object_address() = target;
 465 }
 466
 467
 468 Object** RelocInfo::call_object_address() {
 469   DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
 470          (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
 471   return reinterpret_cast<Object**>(
 472       pc_ + Assembler::kPatchReturnSequenceAddressOffset);
 473 }
 474
 475
 476 void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
 477   RelocInfo::Mode mode = rmode();
 478   if (mode == RelocInfo::EMBEDDED_OBJECT) {
 479     visitor->VisitEmbeddedPointer(this);
 480     CpuFeatures::FlushICache(pc_, sizeof(Address));
 481   } else if (RelocInfo::IsCodeTarget(mode)) {
 482     visitor->VisitCodeTarget(this);
 483   } else if (mode == RelocInfo::CELL) {
 484     visitor->VisitCell(this);
 485   } else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
 486     visitor->VisitExternalReference(this);
 487     CpuFeatures::FlushICache(pc_, sizeof(Address));
 488   } else if (RelocInfo::IsCodeAgeSequence(mode)) {
 489     visitor->VisitCodeAgeSequence(this);
 490   } else if (((RelocInfo::IsJSReturn(mode) &&
 491               IsPatchedReturnSequence()) ||
 492              (RelocInfo::IsDebugBreakSlot(mode) &&
 493               IsPatchedDebugBreakSlotSequence())) &&
 494              isolate->debug()->has_break_points()) {
 495     visitor->VisitDebugTarget(this);
 496   } else if (RelocInfo::IsRuntimeEntry(mode)) {
 497     visitor->VisitRuntimeEntry(this);
 498   }
 499 }
 500
 501
 502 template<typename StaticVisitor>
 503 void RelocInfo::Visit(Heap* heap) {
 504   RelocInfo::Mode mode = rmode();
 505   if (mode == RelocInfo::EMBEDDED_OBJECT) {
 506     StaticVisitor::VisitEmbeddedPointer(heap, this);
 507     CpuFeatures::FlushICache(pc_, sizeof(Address));
 508   } else if (RelocInfo::IsCodeTarget(mode)) {
 509     StaticVisitor::VisitCodeTarget(heap, this);
 510   } else if (mode == RelocInfo::CELL) {
 511     StaticVisitor::VisitCell(heap, this);
 512   } else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
 513     StaticVisitor::VisitExternalReference(this);
 514     CpuFeatures::FlushICache(pc_, sizeof(Address));
 515   } else if (RelocInfo::IsCodeAgeSequence(mode)) {
 516     StaticVisitor::VisitCodeAgeSequence(heap, this);
 517   } else if (heap->isolate()->debug()->has_break_points() &&
 518              ((RelocInfo::IsJSReturn(mode) &&
 519               IsPatchedReturnSequence()) ||
 520              (RelocInfo::IsDebugBreakSlot(mode) &&
 521               IsPatchedDebugBreakSlotSequence()))) {
 522     StaticVisitor::VisitDebugTarget(heap, this);
 523   } else if (RelocInfo::IsRuntimeEntry(mode)) {
 524     StaticVisitor::VisitRuntimeEntry(this);
 525   }
 526 }
 527
 528
 529 // -----------------------------------------------------------------------------
 530 // Implementation of Operand
 531
 532 void Operand::set_modrm(int mod, Register rm_reg) {
 533   DCHECK(is_uint2(mod));
 534   buf_[0] = mod << 6 | rm_reg.low_bits();
 535   // Set REX.B to the high bit of rm.code().
 536   rex_ |= rm_reg.high_bit();
 537 }
 538
 539
 540 void Operand::set_sib(ScaleFactor scale, Register index, Register base) {
 541   DCHECK(len_ == 1);
 542   DCHECK(is_uint2(scale));
 543   // Use SIB with no index register only for base rsp or r12. Otherwise we
 544   // would skip the SIB byte entirely.
 545   DCHECK(!index.is(rsp) || base.is(rsp) || base.is(r12));
 546   buf_[1] = (scale << 6) | (index.low_bits() << 3) | base.low_bits();
 547   rex_ |= index.high_bit() << 1 | base.high_bit();
 548   len_ = 2;
 549 }
 550
 551 void Operand::set_disp8(int disp) {
 552   DCHECK(is_int8(disp));
 553   DCHECK(len_ == 1 || len_ == 2);
 554   int8_t* p = reinterpret_cast<int8_t*>(&buf_[len_]);
 555   *p = disp;
 556   len_ += sizeof(int8_t);
 557 }
 558
 559 void Operand::set_disp32(int disp) {
 560   DCHECK(len_ == 1 || len_ == 2);
 561   int32_t* p = reinterpret_cast<int32_t*>(&buf_[len_]);
 562   *p = disp;
 563   len_ += sizeof(int32_t);
 564 }
 565
 566
 567 } }  // namespace v8::internal
 568
 569 #endif  // V8_X64_ASSEMBLER_X64_INL_H_