C++ mop_iterator::isRegMask方法代码示例

std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
                                                const LiveIntervals *lis,
                                                const MachineLoopInfo *loopInfo,
                                                const RegSet &vregs) {

  typedef std::vector<const LiveInterval*> LIVector;
  ArrayRef<SlotIndex> regMaskSlots = lis->getRegMaskSlots();
  MachineRegisterInfo *mri = &mf->getRegInfo();
  const TargetRegisterInfo *tri = mf->getTarget().getRegisterInfo();

  std::auto_ptr<PBQPRAProblem> p(new PBQPRAProblem());
  PBQP::Graph &g = p->getGraph();
  RegSet pregs;

  // Collect the set of preg intervals, record that they're used in the MF.
  for (LiveIntervals::const_iterator itr = lis->begin(), end = lis->end();
       itr != end; ++itr) {
    if (TargetRegisterInfo::isPhysicalRegister(itr->first)) {
      pregs.insert(itr->first);
      mri->setPhysRegUsed(itr->first);
    }
  }

  BitVector reservedRegs = tri->getReservedRegs(*mf);

  // Iterate over vregs.
  for (RegSet::const_iterator vregItr = vregs.begin(), vregEnd = vregs.end();
       vregItr != vregEnd; ++vregItr) {
    unsigned vreg = *vregItr;
    const TargetRegisterClass *trc = mri->getRegClass(vreg);
    const LiveInterval *vregLI = &lis->getInterval(vreg);

    // Compute an initial allowed set for the current vreg.
    typedef std::vector<unsigned> VRAllowed;
    VRAllowed vrAllowed;
    ArrayRef<uint16_t> rawOrder = trc->getRawAllocationOrder(*mf);
    for (unsigned i = 0; i != rawOrder.size(); ++i) {
      unsigned preg = rawOrder[i];
      if (!reservedRegs.test(preg)) {
        vrAllowed.push_back(preg);
      }
    }

    RegSet overlappingPRegs;

    // Record physical registers whose ranges overlap.
    for (RegSet::const_iterator pregItr = pregs.begin(),
                                pregEnd = pregs.end();
         pregItr != pregEnd; ++pregItr) {
      unsigned preg = *pregItr;
      const LiveInterval *pregLI = &lis->getInterval(preg);

      if (pregLI->empty()) {
        continue;
      }

      if (vregLI->overlaps(*pregLI))
        overlappingPRegs.insert(preg);      
    }

    // Record any overlaps with regmask operands.
    BitVector regMaskOverlaps(tri->getNumRegs());
    for (ArrayRef<SlotIndex>::iterator rmItr = regMaskSlots.begin(),
                                       rmEnd = regMaskSlots.end();
         rmItr != rmEnd; ++rmItr) {
      SlotIndex rmIdx = *rmItr;
      if (vregLI->liveAt(rmIdx)) {
        MachineInstr *rmMI = lis->getInstructionFromIndex(rmIdx);
        const uint32_t* regMask = 0;
        for (MachineInstr::mop_iterator mopItr = rmMI->operands_begin(),
                                        mopEnd = rmMI->operands_end();
             mopItr != mopEnd; ++mopItr) {
          if (mopItr->isRegMask()) {
            regMask = mopItr->getRegMask();
            break;
          }
        }
        assert(regMask != 0 && "Couldn't find register mask.");
        regMaskOverlaps.setBitsNotInMask(regMask);
      }
    }

    for (unsigned preg = 0; preg < tri->getNumRegs(); ++preg) {
      if (regMaskOverlaps.test(preg))
        overlappingPRegs.insert(preg);
    }

    for (RegSet::const_iterator pregItr = overlappingPRegs.begin(),
                                pregEnd = overlappingPRegs.end();
         pregItr != pregEnd; ++pregItr) {
      unsigned preg = *pregItr;

      // Remove the register from the allowed set.
      VRAllowed::iterator eraseItr =
        std::find(vrAllowed.begin(), vrAllowed.end(), preg);

      if (eraseItr != vrAllowed.end()) {
        vrAllowed.erase(eraseItr);
      }

//.........这里部分代码省略.........