Exemple #1
0
void ConnectedVNInfoEqClasses::Distribute(LiveInterval &LI, LiveInterval *LIV[],
                                          MachineRegisterInfo &MRI) {
  // Rewrite instructions.
  for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LI.reg),
       RE = MRI.reg_end(); RI != RE;) {
    MachineOperand &MO = *RI;
    MachineInstr *MI = RI->getParent();
    ++RI;
    // DBG_VALUE instructions don't have slot indexes, so get the index of the
    // instruction before them.
    // Normally, DBG_VALUE instructions are removed before this function is
    // called, but it is not a requirement.
    SlotIndex Idx;
    if (MI->isDebugValue())
      Idx = LIS.getSlotIndexes()->getIndexBefore(MI);
    else
      Idx = LIS.getInstructionIndex(MI);
    LiveQueryResult LRQ = LI.Query(Idx);
    const VNInfo *VNI = MO.readsReg() ? LRQ.valueIn() : LRQ.valueDefined();
    // In the case of an <undef> use that isn't tied to any def, VNI will be
    // NULL. If the use is tied to a def, VNI will be the defined value.
    if (!VNI)
      continue;
    if (unsigned EqClass = getEqClass(VNI))
      MO.setReg(LIV[EqClass-1]->reg);
  }

  // Move runs to new intervals.
  LiveInterval::iterator J = LI.begin(), E = LI.end();
  while (J != E && EqClass[J->valno->id] == 0)
    ++J;
  for (LiveInterval::iterator I = J; I != E; ++I) {
    if (unsigned eq = EqClass[I->valno->id]) {
      assert((LIV[eq-1]->empty() || LIV[eq-1]->expiredAt(I->start)) &&
             "New intervals should be empty");
      LIV[eq-1]->segments.push_back(*I);
    } else
      *J++ = *I;
  }
  // TODO: do not cheat anymore by simply cleaning all subranges
  LI.clearSubRanges();
  LI.segments.erase(J, E);

  // Transfer VNInfos to their new owners and renumber them.
  unsigned j = 0, e = LI.getNumValNums();
  while (j != e && EqClass[j] == 0)
    ++j;
  for (unsigned i = j; i != e; ++i) {
    VNInfo *VNI = LI.getValNumInfo(i);
    if (unsigned eq = EqClass[i]) {
      VNI->id = LIV[eq-1]->getNumValNums();
      LIV[eq-1]->valnos.push_back(VNI);
    } else {
      VNI->id = j;
      LI.valnos[j++] = VNI;
    }
  }
  LI.valnos.resize(j);
}
void ConnectedVNInfoEqClasses::Distribute(LiveInterval &LI, LiveInterval *LIV[],
                                          MachineRegisterInfo &MRI) {
  // Rewrite instructions.
  for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LI.reg),
       RE = MRI.reg_end(); RI != RE;) {
    MachineOperand &MO = *RI;
    MachineInstr *MI = RI->getParent();
    ++RI;
    // DBG_VALUE instructions don't have slot indexes, so get the index of the
    // instruction before them.
    // Normally, DBG_VALUE instructions are removed before this function is
    // called, but it is not a requirement.
    SlotIndex Idx;
    if (MI->isDebugValue())
      Idx = LIS.getSlotIndexes()->getIndexBefore(*MI);
    else
      Idx = LIS.getInstructionIndex(*MI);
    LiveQueryResult LRQ = LI.Query(Idx);
    const VNInfo *VNI = MO.readsReg() ? LRQ.valueIn() : LRQ.valueDefined();
    // In the case of an <undef> use that isn't tied to any def, VNI will be
    // NULL. If the use is tied to a def, VNI will be the defined value.
    if (!VNI)
      continue;
    if (unsigned EqClass = getEqClass(VNI))
      MO.setReg(LIV[EqClass-1]->reg);
  }

  // Distribute subregister liveranges.
  if (LI.hasSubRanges()) {
    unsigned NumComponents = EqClass.getNumClasses();
    SmallVector<unsigned, 8> VNIMapping;
    SmallVector<LiveInterval::SubRange*, 8> SubRanges;
    BumpPtrAllocator &Allocator = LIS.getVNInfoAllocator();
    for (LiveInterval::SubRange &SR : LI.subranges()) {
      // Create new subranges in the split intervals and construct a mapping
      // for the VNInfos in the subrange.
      unsigned NumValNos = SR.valnos.size();
      VNIMapping.clear();
      VNIMapping.reserve(NumValNos);
      SubRanges.clear();
      SubRanges.resize(NumComponents-1, nullptr);
      for (unsigned I = 0; I < NumValNos; ++I) {
        const VNInfo &VNI = *SR.valnos[I];
        unsigned ComponentNum;
        if (VNI.isUnused()) {
          ComponentNum = 0;
        } else {
          const VNInfo *MainRangeVNI = LI.getVNInfoAt(VNI.def);
          assert(MainRangeVNI != nullptr
                 && "SubRange def must have corresponding main range def");
          ComponentNum = getEqClass(MainRangeVNI);
          if (ComponentNum > 0 && SubRanges[ComponentNum-1] == nullptr) {
            SubRanges[ComponentNum-1]
              = LIV[ComponentNum-1]->createSubRange(Allocator, SR.LaneMask);
          }
        }
        VNIMapping.push_back(ComponentNum);
      }
      DistributeRange(SR, SubRanges.data(), VNIMapping);
    }
    LI.removeEmptySubRanges();
  }

  // Distribute main liverange.
  DistributeRange(LI, LIV, EqClass);
}