src/ppc/assembler-ppc-inl.h

// 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 2014 the V8 project authors. All rights reserved.

#ifndef V8_PPC_ASSEMBLER_PPC_INL_H_
#define V8_PPC_ASSEMBLER_PPC_INL_H_

#include "src/ppc/assembler-ppc.h"

#include "src/assembler.h"
#include "src/debug.h"


namespace v8 {
namespace internal {


bool CpuFeatures::SupportsCrankshaft() { return true; }


void RelocInfo::apply(intptr_t delta, ICacheFlushMode icache_flush_mode) {
#if ABI_USES_FUNCTION_DESCRIPTORS || V8_OOL_CONSTANT_POOL
  if (RelocInfo::IsInternalReference(rmode_)) {
    // absolute code pointer inside code object moves with the code object.
    Assembler::RelocateInternalReference(pc_, delta, 0, icache_flush_mode);
  }
#endif
  // We do not use pc relative addressing on PPC, so there is
  // nothing else to do.
}


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);

#if V8_OOL_CONSTANT_POOL
  if (Assembler::IsConstantPoolLoadStart(pc_)) {
    // We return the PC for ool constant pool since this function is used by the
    // serializerer and expects the address to reside within the code object.
    return reinterpret_cast<Address>(pc_);
  }
#endif

  // Read the address of the word containing the target_address in an
  // instruction stream.
  // The only architecture-independent user of this function is the serializer.
  // The serializer uses it to find out how many raw bytes of instruction to
  // output before the next target.
  // For an instruction like LIS/ORI where the target bits are mixed into the
  // instruction bits, the size of the target will be zero, indicating that the
  // serializer should not step forward in memory after a target is resolved
  // and written.
  return reinterpret_cast<Address>(pc_);
}


Address RelocInfo::constant_pool_entry_address() {
#if V8_OOL_CONSTANT_POOL
  return Assembler::target_constant_pool_address_at(pc_,
                                                    host_->constant_pool());
#else
  UNREACHABLE();
  return NULL;
#endif
}


int RelocInfo::target_address_size() { return Assembler::kSpecialTargetSize; }


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(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));
  }
}


Address Assembler::break_address_from_return_address(Address pc) {
  return target_address_from_return_address(pc);
}


Address Assembler::target_address_from_return_address(Address pc) {
// Returns the address of the call target from the return address that will
// be returned to after a call.
// Call sequence is :
//  mov   ip, @ call address
//  mtlr  ip
//  blrl
//                      @ return address
#if V8_OOL_CONSTANT_POOL
  if (IsConstantPoolLoadEnd(pc - 3 * kInstrSize)) {
    return pc - (kMovInstructionsConstantPool + 2) * kInstrSize;
  }
#endif
  return pc - (kMovInstructionsNoConstantPool + 2) * kInstrSize;
}


Address Assembler::return_address_from_call_start(Address pc) {
#if V8_OOL_CONSTANT_POOL
  Address load_address = pc + (kMovInstructionsConstantPool - 1) * kInstrSize;
  if (IsConstantPoolLoadEnd(load_address))
    return pc + (kMovInstructionsConstantPool + 2) * kInstrSize;
#endif
  return pc + (kMovInstructionsNoConstantPool + 2) * kInstrSize;
}


Object* RelocInfo::target_object() {
  DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
  return reinterpret_cast<Object*>(Assembler::target_address_at(pc_, host_));
}


Handle<Object> RelocInfo::target_object_handle(Assembler* origin) {
  DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
  return Handle<Object>(
      reinterpret_cast<Object**>(Assembler::target_address_at(pc_, host_)));
}


void RelocInfo::set_target_object(Object* target,
                                  WriteBarrierMode write_barrier_mode,
                                  ICacheFlushMode icache_flush_mode) {
  DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
  Assembler::set_target_address_at(
      pc_, host_, reinterpret_cast<Address>(target), icache_flush_mode);
  if (write_barrier_mode == UPDATE_WRITE_BARRIER && host() != NULL &&
      target->IsHeapObject()) {
    host()->GetHeap()->incremental_marking()->RecordWrite(
        host(), &Memory::Object_at(pc_), HeapObject::cast(target));
  }
}


Address RelocInfo::target_reference() {
  DCHECK(rmode_ == EXTERNAL_REFERENCE);
  return Assembler::target_address_at(pc_, host_);
}


Address RelocInfo::target_runtime_entry(Assembler* origin) {
  DCHECK(IsRuntimeEntry(rmode_));
  return target_address();
}


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 (write_barrier_mode == UPDATE_WRITE_BARRIER && host() != NULL) {
    // TODO(1550) We are passing NULL as a slot because cell can never be on
    // evacuation candidate.
    host()->GetHeap()->incremental_marking()->RecordWrite(host(), NULL, cell);
  }
}


#if V8_OOL_CONSTANT_POOL
static const int kNoCodeAgeInstructions = 7;
#else
static const int kNoCodeAgeInstructions = 6;
#endif
static const int kCodeAgingInstructions =
    Assembler::kMovInstructionsNoConstantPool + 3;
static const int kNoCodeAgeSequenceInstructions =
    ((kNoCodeAgeInstructions >= kCodeAgingInstructions)
         ? kNoCodeAgeInstructions
         : kCodeAgingInstructions);
static const int kNoCodeAgeSequenceNops =
    (kNoCodeAgeSequenceInstructions - kNoCodeAgeInstructions);
static const int kCodeAgingSequenceNops =
    (kNoCodeAgeSequenceInstructions - kCodeAgingInstructions);
static const int kCodeAgingTargetDelta = 1 * Assembler::kInstrSize;
static const int kNoCodeAgeSequenceLength =
    (kNoCodeAgeSequenceInstructions * Assembler::kInstrSize);


Handle<Object> RelocInfo::code_age_stub_handle(Assembler* origin) {
  UNREACHABLE();  // This should never be reached on PPC.
  return Handle<Object>();
}


Code* RelocInfo::code_age_stub() {
  DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
  return Code::GetCodeFromTargetAddress(
      Assembler::target_address_at(pc_ + kCodeAgingTargetDelta, host_));
}


void RelocInfo::set_code_age_stub(Code* stub,
                                  ICacheFlushMode icache_flush_mode) {
  DCHECK(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
  Assembler::set_target_address_at(pc_ + kCodeAgingTargetDelta, host_,
                                   stub->instruction_start(),
                                   icache_flush_mode);
}


Address RelocInfo::call_address() {
  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
  // The pc_ offset of 0 assumes patched return sequence per
  // BreakLocationIterator::SetDebugBreakAtReturn(), or debug break
  // slot per BreakLocationIterator::SetDebugBreakAtSlot().
  return Assembler::target_address_at(pc_, host_);
}


void RelocInfo::set_call_address(Address target) {
  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
  Assembler::set_target_address_at(pc_, host_, target);
  if (host() != NULL) {
    Object* target_code = Code::GetCodeFromTargetAddress(target);
    host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
        host(), this, HeapObject::cast(target_code));
  }
}


Object* RelocInfo::call_object() { return *call_object_address(); }


void RelocInfo::set_call_object(Object* target) {
  *call_object_address() = target;
}


Object** RelocInfo::call_object_address() {
  DCHECK((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
         (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
  return reinterpret_cast<Object**>(pc_ + 2 * Assembler::kInstrSize);
}


void RelocInfo::WipeOut() {
  DCHECK(IsEmbeddedObject(rmode_) || IsCodeTarget(rmode_) ||
         IsRuntimeEntry(rmode_) || IsExternalReference(rmode_));
  Assembler::set_target_address_at(pc_, host_, NULL);
}


bool RelocInfo::IsPatchedReturnSequence() {
  //
  // The patched return sequence is defined by
  // BreakLocationIterator::SetDebugBreakAtReturn()
  // FIXED_SEQUENCE

  Instr instr0 = Assembler::instr_at(pc_);
  Instr instr1 = Assembler::instr_at(pc_ + 1 * Assembler::kInstrSize);
#if V8_TARGET_ARCH_PPC64
  Instr instr3 = Assembler::instr_at(pc_ + (3 * Assembler::kInstrSize));
  Instr instr4 = Assembler::instr_at(pc_ + (4 * Assembler::kInstrSize));
  Instr binstr = Assembler::instr_at(pc_ + (7 * Assembler::kInstrSize));
#else
  Instr binstr = Assembler::instr_at(pc_ + 4 * Assembler::kInstrSize);
#endif
  bool patched_return =
      ((instr0 & kOpcodeMask) == ADDIS && (instr1 & kOpcodeMask) == ORI &&
#if V8_TARGET_ARCH_PPC64
       (instr3 & kOpcodeMask) == ORIS && (instr4 & kOpcodeMask) == ORI &&
#endif
       (binstr == 0x7d821008));  // twge r2, r2

  // printf("IsPatchedReturnSequence: %d\n", patched_return);
  return patched_return;
}


bool RelocInfo::IsPatchedDebugBreakSlotSequence() {
  Instr current_instr = Assembler::instr_at(pc_);
  return !Assembler::IsNop(current_instr, Assembler::DEBUG_BREAK_NOP);
}


void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
  RelocInfo::Mode mode = rmode();
  if (mode == RelocInfo::EMBEDDED_OBJECT) {
    visitor->VisitEmbeddedPointer(this);
  } 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 (RelocInfo::IsCodeAgeSequence(mode)) {
    visitor->VisitCodeAgeSequence(this);
  } else if (((RelocInfo::IsJSReturn(mode) && IsPatchedReturnSequence()) ||
              (RelocInfo::IsDebugBreakSlot(mode) &&
               IsPatchedDebugBreakSlotSequence())) &&
             isolate->debug()->has_break_points()) {
    visitor->VisitDebugTarget(this);
  } else if (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);
  } 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 (RelocInfo::IsCodeAgeSequence(mode)) {
    StaticVisitor::VisitCodeAgeSequence(heap, this);
  } else if (heap->isolate()->debug()->has_break_points() &&
             ((RelocInfo::IsJSReturn(mode) && IsPatchedReturnSequence()) ||
              (RelocInfo::IsDebugBreakSlot(mode) &&
               IsPatchedDebugBreakSlotSequence()))) {
    StaticVisitor::VisitDebugTarget(heap, this);
  } else if (IsRuntimeEntry(mode)) {
    StaticVisitor::VisitRuntimeEntry(this);
  }
}

Operand::Operand(intptr_t immediate, RelocInfo::Mode rmode) {
  rm_ = no_reg;
  imm_ = immediate;
  rmode_ = rmode;
}

Operand::Operand(const ExternalReference& f) {
  rm_ = no_reg;
  imm_ = reinterpret_cast<intptr_t>(f.address());
  rmode_ = RelocInfo::EXTERNAL_REFERENCE;
}

Operand::Operand(Smi* value) {
  rm_ = no_reg;
  imm_ = reinterpret_cast<intptr_t>(value);
  rmode_ = kRelocInfo_NONEPTR;
}

Operand::Operand(Register rm) {
  rm_ = rm;
  rmode_ = kRelocInfo_NONEPTR;  // PPC -why doesn't ARM do this?
}

void Assembler::CheckBuffer() {
  if (buffer_space() <= kGap) {
    GrowBuffer();
  }
}

void Assembler::CheckTrampolinePoolQuick() {
  if (pc_offset() >= next_buffer_check_) {
    CheckTrampolinePool();
  }
}

void Assembler::emit(Instr x) {
  CheckBuffer();
  *reinterpret_cast<Instr*>(pc_) = x;
  pc_ += kInstrSize;
  CheckTrampolinePoolQuick();
}

bool Operand::is_reg() const { return rm_.is_valid(); }


// Fetch the 32bit value from the FIXED_SEQUENCE lis/ori
Address Assembler::target_address_at(Address pc,
                                     ConstantPoolArray* constant_pool) {
  Instr instr1 = instr_at(pc);
  Instr instr2 = instr_at(pc + kInstrSize);
  // Interpret 2 instructions generated by lis/ori
  if (IsLis(instr1) && IsOri(instr2)) {
#if V8_TARGET_ARCH_PPC64
    Instr instr4 = instr_at(pc + (3 * kInstrSize));
    Instr instr5 = instr_at(pc + (4 * kInstrSize));
    // Assemble the 64 bit value.
    uint64_t hi = (static_cast<uint32_t>((instr1 & kImm16Mask) << 16) |
                   static_cast<uint32_t>(instr2 & kImm16Mask));
    uint64_t lo = (static_cast<uint32_t>((instr4 & kImm16Mask) << 16) |
                   static_cast<uint32_t>(instr5 & kImm16Mask));
    return reinterpret_cast<Address>((hi << 32) | lo);
#else
    // Assemble the 32 bit value.
    return reinterpret_cast<Address>(((instr1 & kImm16Mask) << 16) |
                                     (instr2 & kImm16Mask));
#endif
  }
#if V8_OOL_CONSTANT_POOL
  return Memory::Address_at(target_constant_pool_address_at(pc, constant_pool));
#else
  DCHECK(false);
  return (Address)0;
#endif
}


#if V8_OOL_CONSTANT_POOL
bool Assembler::IsConstantPoolLoadStart(Address pc) {
#if V8_TARGET_ARCH_PPC64
  if (!IsLi(instr_at(pc))) return false;
  pc += kInstrSize;
#endif
  return GetRA(instr_at(pc)).is(kConstantPoolRegister);
}


bool Assembler::IsConstantPoolLoadEnd(Address pc) {
#if V8_TARGET_ARCH_PPC64
  pc -= kInstrSize;
#endif
  return IsConstantPoolLoadStart(pc);
}


int Assembler::GetConstantPoolOffset(Address pc) {
  DCHECK(IsConstantPoolLoadStart(pc));
  Instr instr = instr_at(pc);
  int offset = SIGN_EXT_IMM16((instr & kImm16Mask));
  return offset;
}


void Assembler::SetConstantPoolOffset(Address pc, int offset) {
  DCHECK(IsConstantPoolLoadStart(pc));
  DCHECK(is_int16(offset));
  Instr instr = instr_at(pc);
  instr &= ~kImm16Mask;
  instr |= (offset & kImm16Mask);
  instr_at_put(pc, instr);
}


Address Assembler::target_constant_pool_address_at(
    Address pc, ConstantPoolArray* constant_pool) {
  Address addr = reinterpret_cast<Address>(constant_pool);
  DCHECK(addr);
  addr += GetConstantPoolOffset(pc);
  return addr;
}
#endif


// This sets the branch destination (which gets loaded at the call address).
// This is for calls and branches within generated code.  The serializer
// has already deserialized the mov instructions etc.
// There is a FIXED_SEQUENCE assumption here
void Assembler::deserialization_set_special_target_at(
    Address instruction_payload, Code* code, Address target) {
  set_target_address_at(instruction_payload, code, target);
}

// This code assumes the FIXED_SEQUENCE of lis/ori
void Assembler::set_target_address_at(Address pc,
                                      ConstantPoolArray* constant_pool,
                                      Address target,
                                      ICacheFlushMode icache_flush_mode) {
  Instr instr1 = instr_at(pc);
  Instr instr2 = instr_at(pc + kInstrSize);
  // Interpret 2 instructions generated by lis/ori
  if (IsLis(instr1) && IsOri(instr2)) {
#if V8_TARGET_ARCH_PPC64
    Instr instr4 = instr_at(pc + (3 * kInstrSize));
    Instr instr5 = instr_at(pc + (4 * kInstrSize));
    // Needs to be fixed up when mov changes to handle 64-bit values.
    uint32_t* p = reinterpret_cast<uint32_t*>(pc);
    uintptr_t itarget = reinterpret_cast<uintptr_t>(target);

    instr5 &= ~kImm16Mask;
    instr5 |= itarget & kImm16Mask;
    itarget = itarget >> 16;

    instr4 &= ~kImm16Mask;
    instr4 |= itarget & kImm16Mask;
    itarget = itarget >> 16;

    instr2 &= ~kImm16Mask;
    instr2 |= itarget & kImm16Mask;
    itarget = itarget >> 16;

    instr1 &= ~kImm16Mask;
    instr1 |= itarget & kImm16Mask;
    itarget = itarget >> 16;

    *p = instr1;
    *(p + 1) = instr2;
    *(p + 3) = instr4;
    *(p + 4) = instr5;
    if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
      CpuFeatures::FlushICache(p, 5 * kInstrSize);
    }
#else
    uint32_t* p = reinterpret_cast<uint32_t*>(pc);
    uint32_t itarget = reinterpret_cast<uint32_t>(target);
    int lo_word = itarget & kImm16Mask;
    int hi_word = itarget >> 16;
    instr1 &= ~kImm16Mask;
    instr1 |= hi_word;
    instr2 &= ~kImm16Mask;
    instr2 |= lo_word;

    *p = instr1;
    *(p + 1) = instr2;
    if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
      CpuFeatures::FlushICache(p, 2 * kInstrSize);
    }
#endif
  } else {
#if V8_OOL_CONSTANT_POOL
    Memory::Address_at(target_constant_pool_address_at(pc, constant_pool)) =
        target;
#else
    UNREACHABLE();
#endif
  }
}
}
}  // namespace v8::internal

#endif  // V8_PPC_ASSEMBLER_PPC_INL_H_