text: // Copyright (c) 1994-2006 Sun Microsystems Inc.
  // All Rights Reserved.
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  // - Redistributions of source code must retain the above copyright notice,
  // this list of conditions and the following disclaimer.
  //
  // - Redistribution in binary form must reproduce the above copyright
  // notice, this list of conditions and the following disclaimer in the
  // documentation and/or other materials provided with the distribution.
  //
  // - Neither the name of Sun Microsystems or the names of contributors may
  // be used to endorse or promote products derived from this software without
  // specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  // IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  // THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  // The original source code covered by the above license above has been
  // modified significantly by Google Inc.
  // Copyright 2012 the V8 project authors. All rights reserved.
  
  // A light-weight IA32 Assembler.
  
  #ifndef V8_IA32_ASSEMBLER_IA32_INL_H_
  #define V8_IA32_ASSEMBLER_IA32_INL_H_
  
  #include "src/ia32/assembler-ia32.h"
  
  #include "src/assembler.h"
  #include "src/debug/debug.h"
  #include "src/objects-inl.h"
  
  namespace v8 {
  namespace internal {
  
  bool CpuFeatures::SupportsCrankshaft() { return true; }
  
  bool CpuFeatures::SupportsWasmSimd128() { return IsSupported(SSE4_1); }
  
  static const byte kCallOpcode = 0xE8;
  static const int kNoCodeAgeSequenceLength = 5;
  
  
  // The modes possibly affected by apply must be in kApplyMask.
  void RelocInfo::apply(intptr_t delta) {
    if (IsRuntimeEntry(rmode_) || IsCodeTarget(rmode_)) {
      int32_t* p = reinterpret_cast<int32_t*>(pc_);
      *p -= delta;  // Relocate entry.
    } else if (IsInternalReference(rmode_)) {
      // absolute code pointer inside code object moves with the code object.
      int32_t* p = reinterpret_cast<int32_t*>(pc_);
      *p += delta;  // Relocate entry.
    }
  }
  
  
  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();
  }
  
  
  int RelocInfo::target_address_size() {
    return Assembler::kSpecialTargetSize;
  }
  
  HeapObject* RelocInfo::target_object() {
    DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
    return HeapObject::cast(Memory::Object_at(pc_));
  }
  
  Handle<HeapObject> RelocInfo::target_object_handle(Assembler* origin) {
    DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
    return Handle<HeapObject>::cast(Memory::Object_Handle_at(pc_));
  }
  
  void RelocInfo::set_target_object(HeapObject* 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(target->GetIsolate(), pc_, sizeof(Address));
    }
    if (write_barrier_mode == UPDATE_WRITE_BARRIER && host() != NULL) {
      host()->GetHeap()->RecordWriteIntoCode(host(), this, target);
      host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(host(), this,
                                                                    target);
    }
  }
  
  
  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_);
  }
  
  
  Address RelocInfo::target_runtime_entry(Assembler* origin) {
    DCHECK(IsRuntimeEntry(rmode_));
    return reinterpret_cast<Address>(*reinterpret_cast<int32_t*>(pc_));
  }
  
  void RelocInfo::set_target_runtime_entry(Isolate* isolate, Address target,
                                           WriteBarrierMode write_barrier_mode,
                                           ICacheFlushMode icache_flush_mode) {
    DCHECK(IsRuntimeEntry(rmode_));
    if (target_address() != target) {
      set_target_address(isolate, target, write_barrier_mode, icache_flush_mode);
    }
  }
  
  void RelocInfo::WipeOut(Isolate* isolate) {
    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();
    }
  }
  
  template <typename ObjectVisitor>
  void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
    RelocInfo::Mode mode = rmode();
    if (mode == RelocInfo::EMBEDDED_OBJECT) {
      visitor->VisitEmbeddedPointer(host(), this);
      Assembler::FlushICache(isolate, pc_, sizeof(Address));
    } else if (RelocInfo::IsCodeTarget(mode)) {
      visitor->VisitCodeTarget(host(), this);
    } else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
      visitor->VisitExternalReference(host(), this);
    } else if (mode == RelocInfo::INTERNAL_REFERENCE) {
      visitor->VisitInternalReference(host(), this);
    } else if (IsRuntimeEntry(mode)) {
      visitor->VisitRuntimeEntry(host(), 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::EXTERNAL_REFERENCE) {
      StaticVisitor::VisitExternalReference(this);
    } else if (mode == RelocInfo::INTERNAL_REFERENCE) {
      StaticVisitor::VisitInternalReference(this);
    } else if (IsRuntimeEntry(mode)) {
      StaticVisitor::VisitRuntimeEntry(this);
    }
  }
  
  
  
  Immediate::Immediate(int x)  {
    value_.immediate = x;
    rmode_ = RelocInfo::NONE32;
  }
  
  Immediate::Immediate(Address x, RelocInfo::Mode rmode) {
    value_.immediate = reinterpret_cast<int32_t>(x);
    rmode_ = rmode;
  }
  
  Immediate::Immediate(const ExternalReference& ext) {
    value_.immediate = reinterpret_cast<int32_t>(ext.address());
    rmode_ = RelocInfo::EXTERNAL_REFERENCE;
  }
  
  
  Immediate::Immediate(Label* internal_offset) {
    value_.immediate = reinterpret_cast<int32_t>(internal_offset);
    rmode_ = RelocInfo::INTERNAL_REFERENCE;
  }
  
  Immediate::Immediate(Handle<HeapObject> handle) {
    value_.immediate = reinterpret_cast<intptr_t>(handle.address());
    rmode_ = RelocInfo::EMBEDDED_OBJECT;
  }
  
  
  Immediate::Immediate(Smi* value) {
    value_.immediate = reinterpret_cast<intptr_t>(value);
    rmode_ = RelocInfo::NONE32;
  }
  
  
  Immediate::Immediate(Address addr) {
    value_.immediate = reinterpret_cast<int32_t>(addr);
    rmode_ = RelocInfo::NONE32;
  }
  
  
  void Assembler::emit(uint32_t x) {
    *reinterpret_cast<uint32_t*>(pc_) = x;
    pc_ += sizeof(uint32_t);
  }
  
  
  void Assembler::emit_q(uint64_t x) {
    *reinterpret_cast<uint64_t*>(pc_) = x;
    pc_ += sizeof(uint64_t);
  }
  
  void Assembler::emit(Handle<HeapObject> handle) {
    emit(reinterpret_cast<intptr_t>(handle.address()),
         RelocInfo::EMBEDDED_OBJECT);
  }
  
  void Assembler::emit(uint32_t x, RelocInfo::Mode rmode) {
    if (!RelocInfo::IsNone(rmode)) {
      RecordRelocInfo(rmode);
    }
    emit(x);
  }
  
  void Assembler::emit(Handle<Code> code, RelocInfo::Mode rmode) {
    emit(reinterpret_cast<intptr_t>(code.address()), rmode);
  }
  
  
  void Assembler::emit(const Immediate& x) {
    if (x.rmode_ == RelocInfo::INTERNAL_REFERENCE) {
      Label* label = reinterpret_cast<Label*>(x.immediate());
      emit_code_relative_offset(label);
      return;
    }
    if (!RelocInfo::IsNone(x.rmode_)) RecordRelocInfo(x.rmode_);
    if (x.is_heap_object_request()) {
      RequestHeapObject(x.heap_object_request());
      emit(0);
    } else {
      emit(x.immediate());
    }
  }
  
  
  void Assembler::emit_code_relative_offset(Label* label) {
    if (label->is_bound()) {
      int32_t pos;
      pos = label->pos() + Code::kHeaderSize - kHeapObjectTag;
      emit(pos);
    } else {
      emit_disp(label, Displacement::CODE_RELATIVE);
    }
  }
  
  void Assembler::emit_b(Immediate x) {
    DCHECK(x.is_int8() || x.is_uint8());
    uint8_t value = static_cast<uint8_t>(x.immediate());
    *pc_++ = value;
  }
  
  void Assembler::emit_w(const Immediate& x) {
    DCHECK(RelocInfo::IsNone(x.rmode_));
    uint16_t value = static_cast<uint16_t>(x.immediate());
    reinterpret_cast<uint16_t*>(pc_)[0] = value;
    pc_ += sizeof(uint16_t);
  }
  
  
  Address Assembler::target_address_at(Address pc, Address constant_pool) {
    return pc + sizeof(int32_t) + *reinterpret_cast<int32_t*>(pc);
  }
  
  
  void Assembler::set_target_address_at(Isolate* isolate, Address pc,
                                        Address constant_pool, Address target,
                                        ICacheFlushMode icache_flush_mode) {
    DCHECK_IMPLIES(isolate == nullptr, icache_flush_mode == SKIP_ICACHE_FLUSH);
    int32_t* p = reinterpret_cast<int32_t*>(pc);
    *p = target - (pc + sizeof(int32_t));
    if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
      Assembler::FlushICache(isolate, p, sizeof(int32_t));
    }
  }
  
  Address Assembler::target_address_at(Address pc, Code* code) {
    Address constant_pool = code ? code->constant_pool() : NULL;
    return target_address_at(pc, constant_pool);
  }
  
  void Assembler::set_target_address_at(Isolate* isolate, Address pc, Code* code,
                                        Address target,
                                        ICacheFlushMode icache_flush_mode) {
    Address constant_pool = code ? code->constant_pool() : NULL;
    set_target_address_at(isolate, pc, constant_pool, target);
  }
  
  Address Assembler::target_address_from_return_address(Address pc) {
    return pc - kCallTargetAddressOffset;
  }
  
  
  Displacement Assembler::disp_at(Label* L) {
    return Displacement(long_at(L->pos()));
  }
  
  
  void Assembler::disp_at_put(Label* L, Displacement disp) {
    long_at_put(L->pos(), disp.data());
  }
  
  
  void Assembler::emit_disp(Label* L, Displacement::Type type) {
    Displacement disp(L, type);
    L->link_to(pc_offset());
    emit(static_cast<int>(disp.data()));
  }
  
  
  void Assembler::emit_near_disp(Label* L) {
    byte disp = 0x00;
    if (L->is_near_linked()) {
      int offset = L->near_link_pos() - pc_offset();
      DCHECK(is_int8(offset));
      disp = static_cast<byte>(offset & 0xFF);
    }
    L->link_to(pc_offset(), Label::kNear);
    *pc_++ = disp;
  }
  
  
  void Assembler::deserialization_set_target_internal_reference_at(
      Isolate* isolate, Address pc, Address target, RelocInfo::Mode mode) {
    Memory::Address_at(pc) = target;
  }
  
  
  void Operand::set_modrm(int mod, Register rm) {
    DCHECK((mod & -4) == 0);
    buf_[0] = mod << 6 | rm.code();
    len_ = 1;
  }
  
  
  void Operand::set_sib(ScaleFactor scale, Register index, Register base) {
    DCHECK(len_ == 1);
    DCHECK((scale & -4) == 0);
    // Use SIB with no index register only for base esp.
    DCHECK(!index.is(esp) || base.is(esp));
    buf_[1] = scale << 6 | index.code() << 3 | base.code();
    len_ = 2;
  }
  
  
  void Operand::set_disp8(int8_t disp) {
    DCHECK(len_ == 1 || len_ == 2);
    *reinterpret_cast<int8_t*>(&buf_[len_++]) = disp;
  }
  
  
  void Operand::set_dispr(int32_t disp, RelocInfo::Mode rmode) {
    DCHECK(len_ == 1 || len_ == 2);
    int32_t* p = reinterpret_cast<int32_t*>(&buf_[len_]);
    *p = disp;
    len_ += sizeof(int32_t);
    rmode_ = rmode;
  }
  
  Operand::Operand(Register reg) {
    // reg
    set_modrm(3, reg);
  }
  
  
  Operand::Operand(XMMRegister xmm_reg) {
    Register reg = { xmm_reg.code() };
    set_modrm(3, reg);
  }
  
  
  Operand::Operand(int32_t disp, RelocInfo::Mode rmode) {
    // [disp/r]
    set_modrm(0, ebp);
    set_dispr(disp, rmode);
  }
  
  
  Operand::Operand(Immediate imm) {
    // [disp/r]
    set_modrm(0, ebp);
    set_dispr(imm.immediate(), imm.rmode_);
  }
  }  // namespace internal
  }  // namespace v8
  
  #endif  // V8_IA32_ASSEMBLER_IA32_INL_H_
  