text: // Copyright 2012 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef V8_X64_ASSEMBLER_X64_INL_H_
  #define V8_X64_ASSEMBLER_X64_INL_H_
  
  #include "src/x64/assembler-x64.h"
  
  #include "src/base/cpu.h"
  #include "src/debug/debug.h"
  #include "src/v8memory.h"
  
  namespace v8 {
  namespace internal {
  
  bool CpuFeatures::SupportsCrankshaft() { return true; }
  
  bool CpuFeatures::SupportsSimd128() { return false; }
  
  // -----------------------------------------------------------------------------
  // Implementation of Assembler
  
  
  static const byte kCallOpcode = 0xE8;
  // The length of pushq(rbp), movp(rbp, rsp), Push(rsi) and Push(rdi).
  static const int kNoCodeAgeSequenceLength = kPointerSize == kInt64Size ? 6 : 17;
  
  
  void Assembler::emitl(uint32_t x) {
    Memory::uint32_at(pc_) = x;
    pc_ += sizeof(uint32_t);
  }
  
  
  void Assembler::emitp(void* x, RelocInfo::Mode rmode) {
    uintptr_t value = reinterpret_cast<uintptr_t>(x);
    Memory::uintptr_at(pc_) = value;
    if (!RelocInfo::IsNone(rmode)) {
      RecordRelocInfo(rmode, value);
    }
    pc_ += sizeof(uintptr_t);
  }
  
  
  void Assembler::emitq(uint64_t x) {
    Memory::uint64_at(pc_) = x;
    pc_ += sizeof(uint64_t);
  }
  
  
  void Assembler::emitw(uint16_t x) {
    Memory::uint16_at(pc_) = x;
    pc_ += sizeof(uint16_t);
  }
  
  
  void Assembler::emit_code_target(Handle<Code> target,
                                   RelocInfo::Mode rmode,
                                   TypeFeedbackId ast_id) {
    DCHECK(RelocInfo::IsCodeTarget(rmode) ||
        rmode == RelocInfo::CODE_AGE_SEQUENCE);
    if (rmode == RelocInfo::CODE_TARGET && !ast_id.IsNone()) {
      RecordRelocInfo(RelocInfo::CODE_TARGET_WITH_ID, ast_id.ToInt());
    } else {
      RecordRelocInfo(rmode);
    }
    int current = code_targets_.length();
    if (current > 0 && code_targets_.last().address() == target.address()) {
      // Optimization if we keep jumping to the same code target.
      emitl(current - 1);
    } else {
      code_targets_.Add(target);
      emitl(current);
    }
  }
  
  
  void Assembler::emit_runtime_entry(Address entry, RelocInfo::Mode rmode) {
    DCHECK(RelocInfo::IsRuntimeEntry(rmode));
    RecordRelocInfo(rmode);
    emitl(static_cast<uint32_t>(
        entry - isolate()->heap()->memory_allocator()->code_range()->start()));
  }
  
  
  void Assembler::emit_rex_64(Register reg, Register rm_reg) {
    emit(0x48 | reg.high_bit() << 2 | rm_reg.high_bit());
  }
  
  
  void Assembler::emit_rex_64(XMMRegister reg, Register rm_reg) {
    emit(0x48 | (reg.code() & 0x8) >> 1 | rm_reg.code() >> 3);
  }
  
  
  void Assembler::emit_rex_64(Register reg, XMMRegister rm_reg) {
    emit(0x48 | (reg.code() & 0x8) >> 1 | rm_reg.code() >> 3);
  }
  
  
  void Assembler::emit_rex_64(Register reg, const Operand& op) {
    emit(0x48 | reg.high_bit() << 2 | op.rex_);
  }
  
  
  void Assembler::emit_rex_64(XMMRegister reg, const Operand& op) {
    emit(0x48 | (reg.code() & 0x8) >> 1 | op.rex_);
  }
  
  
  void Assembler::emit_rex_64(Register rm_reg) {
    DCHECK_EQ(rm_reg.code() & 0xf, rm_reg.code());
    emit(0x48 | rm_reg.high_bit());
  }
  
  
  void Assembler::emit_rex_64(const Operand& op) {
    emit(0x48 | op.rex_);
  }
  
  
  void Assembler::emit_rex_32(Register reg, Register rm_reg) {
    emit(0x40 | reg.high_bit() << 2 | rm_reg.high_bit());
  }
  
  
  void Assembler::emit_rex_32(Register reg, const Operand& op) {
    emit(0x40 | reg.high_bit() << 2  | op.rex_);
  }
  
  
  void Assembler::emit_rex_32(Register rm_reg) {
    emit(0x40 | rm_reg.high_bit());
  }
  
  
  void Assembler::emit_rex_32(const Operand& op) {
    emit(0x40 | op.rex_);
  }
  
  
  void Assembler::emit_optional_rex_32(Register reg, Register rm_reg) {
    byte rex_bits = reg.high_bit() << 2 | rm_reg.high_bit();
    if (rex_bits != 0) emit(0x40 | rex_bits);
  }
  
  
  void Assembler::emit_optional_rex_32(Register reg, const Operand& op) {
    byte rex_bits =  reg.high_bit() << 2 | op.rex_;
    if (rex_bits != 0) emit(0x40 | rex_bits);
  }
  
  
  void Assembler::emit_optional_rex_32(XMMRegister reg, const Operand& op) {
    byte rex_bits =  (reg.code() & 0x8) >> 1 | op.rex_;
    if (rex_bits != 0) emit(0x40 | rex_bits);
  }
  
  
  void Assembler::emit_optional_rex_32(XMMRegister reg, XMMRegister base) {
    byte rex_bits =  (reg.code() & 0x8) >> 1 | (base.code() & 0x8) >> 3;
    if (rex_bits != 0) emit(0x40 | rex_bits);
  }
  
  
  void Assembler::emit_optional_rex_32(XMMRegister reg, Register base) {
    byte rex_bits =  (reg.code() & 0x8) >> 1 | (base.code() & 0x8) >> 3;
    if (rex_bits != 0) emit(0x40 | rex_bits);
  }
  
  
  void Assembler::emit_optional_rex_32(Register reg, XMMRegister base) {
    byte rex_bits =  (reg.code() & 0x8) >> 1 | (base.code() & 0x8) >> 3;
    if (rex_bits != 0) emit(0x40 | rex_bits);
  }
  
  
  void Assembler::emit_optional_rex_32(Register rm_reg) {
    if (rm_reg.high_bit()) emit(0x41);
  }
  
  void Assembler::emit_optional_rex_32(XMMRegister rm_reg) {
    if (rm_reg.high_bit()) emit(0x41);
  }
  
  void Assembler::emit_optional_rex_32(const Operand& op) {
    if (op.rex_ != 0) emit(0x40 | op.rex_);
  }
  
  
  // byte 1 of 3-byte VEX
  void Assembler::emit_vex3_byte1(XMMRegister reg, XMMRegister rm,
                                  LeadingOpcode m) {
    byte rxb = ~((reg.high_bit() << 2) | rm.high_bit()) << 5;
    emit(rxb | m);
  }
  
  
  // byte 1 of 3-byte VEX
  void Assembler::emit_vex3_byte1(XMMRegister reg, const Operand& rm,
                                  LeadingOpcode m) {
    byte rxb = ~((reg.high_bit() << 2) | rm.rex_) << 5;
    emit(rxb | m);
  }
  
  
  // byte 1 of 2-byte VEX
  void Assembler::emit_vex2_byte1(XMMRegister reg, XMMRegister v, VectorLength l,
                                  SIMDPrefix pp) {
    byte rv = ~((reg.high_bit() << 4) | v.code()) << 3;
    emit(rv | l | pp);
  }
  
  
  // byte 2 of 3-byte VEX
  void Assembler::emit_vex3_byte2(VexW w, XMMRegister v, VectorLength l,
                                  SIMDPrefix pp) {
    emit(w | ((~v.code() & 0xf) << 3) | l | pp);
  }
  
  
  void Assembler::emit_vex_prefix(XMMRegister reg, XMMRegister vreg,
                                  XMMRegister rm, VectorLength l, SIMDPrefix pp,
                                  LeadingOpcode mm, VexW w) {
    if (rm.high_bit() || mm != k0F || w != kW0) {
      emit_vex3_byte0();
      emit_vex3_byte1(reg, rm, mm);
      emit_vex3_byte2(w, vreg, l, pp);
    } else {
      emit_vex2_byte0();
      emit_vex2_byte1(reg, vreg, l, pp);
    }
  }
  
  
  void Assembler::emit_vex_prefix(Register reg, Register vreg, Register rm,
                                  VectorLength l, SIMDPrefix pp, LeadingOpcode mm,
                                  VexW w) {
    XMMRegister ireg = {reg.code()};
    XMMRegister ivreg = {vreg.code()};
    XMMRegister irm = {rm.code()};
    emit_vex_prefix(ireg, ivreg, irm, l, pp, mm, w);
  }
  
  
  void Assembler::emit_vex_prefix(XMMRegister reg, XMMRegister vreg,
                                  const Operand& rm, VectorLength l,
                                  SIMDPrefix pp, LeadingOpcode mm, VexW w) {
    if (rm.rex_ || mm != k0F || w != kW0) {
      emit_vex3_byte0();
      emit_vex3_byte1(reg, rm, mm);
      emit_vex3_byte2(w, vreg, l, pp);
    } else {
      emit_vex2_byte0();
      emit_vex2_byte1(reg, vreg, l, pp);
    }
  }
  
  
  void Assembler::emit_vex_prefix(Register reg, Register vreg, const Operand& rm,
                                  VectorLength l, SIMDPrefix pp, LeadingOpcode mm,
                                  VexW w) {
    XMMRegister ireg = {reg.code()};
    XMMRegister ivreg = {vreg.code()};
    emit_vex_prefix(ireg, ivreg, rm, l, pp, mm, w);
  }
  
  
  Address Assembler::target_address_at(Address pc, Address constant_pool) {
    return Memory::int32_at(pc) + pc + 4;
  }
  
  
  void Assembler::set_target_address_at(Isolate* isolate, Address pc,
                                        Address constant_pool, Address target,
                                        ICacheFlushMode icache_flush_mode) {
    Memory::int32_at(pc) = static_cast<int32_t>(target - pc - 4);
    if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
      Assembler::FlushICache(isolate, pc, sizeof(int32_t));
    }
  }
  
  
  void Assembler::deserialization_set_target_internal_reference_at(
      Isolate* isolate, Address pc, Address target, RelocInfo::Mode mode) {
    Memory::Address_at(pc) = target;
  }
  
  
  Address Assembler::target_address_from_return_address(Address pc) {
    return pc - kCallTargetAddressOffset;
  }
  
  
  Handle<Object> Assembler::code_target_object_handle_at(Address pc) {
    return code_targets_[Memory::int32_at(pc)];
  }
  
  
  Address Assembler::runtime_entry_at(Address pc) {
    return Memory::int32_at(pc) +
           isolate()->heap()->memory_allocator()->code_range()->start();
  }
  
  // -----------------------------------------------------------------------------
  // Implementation of RelocInfo
  
  // The modes possibly affected by apply must be in kApplyMask.
  void RelocInfo::apply(intptr_t delta) {
    if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
      Memory::int32_at(pc_) -= static_cast<int32_t>(delta);
    } else if (IsCodeAgeSequence(rmode_)) {
      if (*pc_ == kCallOpcode) {
        int32_t* p = reinterpret_cast<int32_t*>(pc_ + 1);
        *p -= static_cast<int32_t>(delta);  // Relocate entry.
      }
    } else if (IsInternalReference(rmode_)) {
      // absolute code pointer inside code object moves with the code object.
      Memory::Address_at(pc_) += delta;
    }
  }
  
  
  Address RelocInfo::target_address() {
    DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_));
    return Assembler::target_address_at(pc_, host_);
  }
  
  Address RelocInfo::target_address_address() {
    DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
                                || rmode_ == EMBEDDED_OBJECT
                                || rmode_ == EXTERNAL_REFERENCE);
    return reinterpret_cast<Address>(pc_);
  }
  
  
  Address RelocInfo::constant_pool_entry_address() {
    UNREACHABLE();
    return NULL;
  }
  
  
  int RelocInfo::target_address_size() {
    if (IsCodedSpecially()) {
      return Assembler::kSpecialTargetSize;
    } else {
      return kPointerSize;
    }
  }
  
  
  void RelocInfo::set_target_address(Address target,
                                     WriteBarrierMode write_barrier_mode,
                                     ICacheFlushMode icache_flush_mode) {
    DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_));
    Assembler::set_target_address_at(isolate_, pc_, host_, target,
                                     icache_flush_mode);
    if (write_barrier_mode == UPDATE_WRITE_BARRIER && host() != NULL &&
        IsCodeTarget(rmode_)) {
      Object* target_code = Code::GetCodeFromTargetAddress(target);
      host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
          host(), this, HeapObject::cast(target_code));
    }
  }
  
  Object* RelocInfo::target_object() {
    DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
    return Memory::Object_at(pc_);
  }
  
  
  Handle<Object> RelocInfo::target_object_handle(Assembler* origin) {
    DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
    if (rmode_ == EMBEDDED_OBJECT) {
      return Memory::Object_Handle_at(pc_);
    } else {
      return origin->code_target_object_handle_at(pc_);
    }
  }
  
  
  Address RelocInfo::target_external_reference() {
    DCHECK(rmode_ == RelocInfo::EXTERNAL_REFERENCE);
    return Memory::Address_at(pc_);
  }
  
  
  Address RelocInfo::target_internal_reference() {
    DCHECK(rmode_ == INTERNAL_REFERENCE);
    return Memory::Address_at(pc_);
  }
  
  
  Address RelocInfo::target_internal_reference_address() {
    DCHECK(rmode_ == INTERNAL_REFERENCE);
    return reinterpret_cast<Address>(pc_);
  }
  
  
  void RelocInfo::set_target_object(Object* target,
                                    WriteBarrierMode write_barrier_mode,
                                    ICacheFlushMode icache_flush_mode) {
    DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
    Memory::Object_at(pc_) = target;
    if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
      Assembler::FlushICache(isolate_, pc_, sizeof(Address));
    }
    if (write_barrier_mode == UPDATE_WRITE_BARRIER &&
        host() != NULL &&
        target->IsHeapObject()) {
      host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
          host(), this, HeapObject::cast(target));
      host()->GetHeap()->RecordWriteIntoCode(host(), this, target);
    }
  }
  
  
  Address RelocInfo::target_runtime_entry(Assembler* origin) {
    DCHECK(IsRuntimeEntry(rmode_));
    return origin->runtime_entry_at(pc_);
  }
  
  
  void RelocInfo::set_target_runtime_entry(Address target,
                                           WriteBarrierMode write_barrier_mode,
                                           ICacheFlushMode icache_flush_mode) {
    DCHECK(IsRuntimeEntry(rmode_));
    if (target_address() != target) {
      set_target_address(target, write_barrier_mode, icache_flush_mode);
    }
  }
  
  
  Handle<Cell> RelocInfo::target_cell_handle() {
    DCHECK(rmode_ == RelocInfo::CELL);
    Address address = Memory::Address_at(pc_);
    return Handle<Cell>(reinterpret_cast<Cell**>(address));
  }
  
  
  Cell* RelocInfo::target_cell() {
    DCHECK(rmode_ == RelocInfo::CELL);
    return Cell::FromValueAddress(Memory::Address_at(pc_));
  }
  
  
  void RelocInfo::set_target_cell(Cell* cell,
                                  WriteBarrierMode write_barrier_mode,
                                  ICacheFlushMode icache_flush_mode) {
    DCHECK(rmode_ == RelocInfo::CELL);
    Address address = cell->address() + Cell::kValueOffset;
    Memory::Address_at(pc_) = address;
    if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
      Assembler::FlushICache(isolate_, pc_, sizeof(Address));
    }
    if (write_barrier_mode == UPDATE_WRITE_BARRIER &&
        host() != NULL) {
      host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(host(), this,
                                                                    cell);
    }
  }
  
  
  void RelocInfo::WipeOut() {
    if (IsEmbeddedObject(rmode_) || IsExternalReference(rmode_) ||
        IsInternalReference(rmode_)) {
      Memory::Address_at(pc_) = NULL;
    } else if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
      // Effectively write zero into the relocation.
      Assembler::set_target_address_at(isolate_, pc_, host_,
                                       pc_ + sizeof(int32_t));
    } else {
      UNREACHABLE();
    }
  }
  
  
  Handle<Object> RelocInfo::code_age_stub_handle(Assembler* origin) {
    DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
    DCHECK(*pc_ == kCallOpcode);
    return origin->code_target_object_handle_at(pc_ + 1);
  }
  
  
  Code* RelocInfo::code_age_stub() {
    DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
    DCHECK(*pc_ == kCallOpcode);
    return Code::GetCodeFromTargetAddress(
        Assembler::target_address_at(pc_ + 1, host_));
  }
  
  
  void RelocInfo::set_code_age_stub(Code* stub,
                                    ICacheFlushMode icache_flush_mode) {
    DCHECK(*pc_ == kCallOpcode);
    DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
    Assembler::set_target_address_at(
        isolate_, pc_ + 1, host_, stub->instruction_start(), icache_flush_mode);
  }
  
  
  Address RelocInfo::debug_call_address() {
    DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
    return Memory::Address_at(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset);
  }
  
  
  void RelocInfo::set_debug_call_address(Address target) {
    DCHECK(IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence());
    Memory::Address_at(pc_ + Assembler::kPatchDebugBreakSlotAddressOffset) =
        target;
    Assembler::FlushICache(isolate_,
                           pc_ + Assembler::kPatchDebugBreakSlotAddressOffset,
                           sizeof(Address));
    if (host() != NULL) {
      Object* target_code = Code::GetCodeFromTargetAddress(target);
      host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
          host(), this, HeapObject::cast(target_code));
    }
  }
  
  template <typename ObjectVisitor>
  void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
    RelocInfo::Mode mode = rmode();
    if (mode == RelocInfo::EMBEDDED_OBJECT) {
      visitor->VisitEmbeddedPointer(this);
      Assembler::FlushICache(isolate, pc_, sizeof(Address));
    } else if (RelocInfo::IsCodeTarget(mode)) {
      visitor->VisitCodeTarget(this);
    } else if (mode == RelocInfo::CELL) {
      visitor->VisitCell(this);
    } else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
      visitor->VisitExternalReference(this);
    } else if (mode == RelocInfo::INTERNAL_REFERENCE) {
      visitor->VisitInternalReference(this);
    } else if (RelocInfo::IsCodeAgeSequence(mode)) {
      visitor->VisitCodeAgeSequence(this);
    } else if (RelocInfo::IsDebugBreakSlot(mode) &&
               IsPatchedDebugBreakSlotSequence()) {
      visitor->VisitDebugTarget(this);
    } else if (RelocInfo::IsRuntimeEntry(mode)) {
      visitor->VisitRuntimeEntry(this);
    }
  }
  
  
  template<typename StaticVisitor>
  void RelocInfo::Visit(Heap* heap) {
    RelocInfo::Mode mode = rmode();
    if (mode == RelocInfo::EMBEDDED_OBJECT) {
      StaticVisitor::VisitEmbeddedPointer(heap, this);
      Assembler::FlushICache(heap->isolate(), pc_, sizeof(Address));
    } else if (RelocInfo::IsCodeTarget(mode)) {
      StaticVisitor::VisitCodeTarget(heap, this);
    } else if (mode == RelocInfo::CELL) {
      StaticVisitor::VisitCell(heap, this);
    } else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
      StaticVisitor::VisitExternalReference(this);
    } else if (mode == RelocInfo::INTERNAL_REFERENCE) {
      StaticVisitor::VisitInternalReference(this);
    } else if (RelocInfo::IsCodeAgeSequence(mode)) {
      StaticVisitor::VisitCodeAgeSequence(heap, this);
    } else if (RelocInfo::IsDebugBreakSlot(mode) &&
               IsPatchedDebugBreakSlotSequence()) {
      StaticVisitor::VisitDebugTarget(heap, this);
    } else if (RelocInfo::IsRuntimeEntry(mode)) {
      StaticVisitor::VisitRuntimeEntry(this);
    }
  }
  
  
  // -----------------------------------------------------------------------------
  // Implementation of Operand
  
  void Operand::set_modrm(int mod, Register rm_reg) {
    DCHECK(is_uint2(mod));
    buf_[0] = mod << 6 | rm_reg.low_bits();
    // Set REX.B to the high bit of rm.code().
    rex_ |= rm_reg.high_bit();
  }
  
  
  void Operand::set_sib(ScaleFactor scale, Register index, Register base) {
    DCHECK(len_ == 1);
    DCHECK(is_uint2(scale));
    // Use SIB with no index register only for base rsp or r12. Otherwise we
    // would skip the SIB byte entirely.
    DCHECK(!index.is(rsp) || base.is(rsp) || base.is(r12));
    buf_[1] = (scale << 6) | (index.low_bits() << 3) | base.low_bits();
    rex_ |= index.high_bit() << 1 | base.high_bit();
    len_ = 2;
  }
  
  void Operand::set_disp8(int disp) {
    DCHECK(is_int8(disp));
    DCHECK(len_ == 1 || len_ == 2);
    int8_t* p = reinterpret_cast<int8_t*>(&buf_[len_]);
    *p = disp;
    len_ += sizeof(int8_t);
  }
  
  void Operand::set_disp32(int disp) {
    DCHECK(len_ == 1 || len_ == 2);
    int32_t* p = reinterpret_cast<int32_t*>(&buf_[len_]);
    *p = disp;
    len_ += sizeof(int32_t);
  }
  
  void Operand::set_disp64(int64_t disp) {
    DCHECK_EQ(1, len_);
    int64_t* p = reinterpret_cast<int64_t*>(&buf_[len_]);
    *p = disp;
    len_ += sizeof(disp);
  }
  }  // namespace internal
  }  // namespace v8
  
  #endif  // V8_X64_ASSEMBLER_X64_INL_H_
  