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