ShrinkWrapping.cpp

    CSRegSet restored = BI->second;
    CSRegSet spilled;

    if (restored.empty())
      continue;

    DEBUG(dbgs() << "SAVE[" << getBasicBlockName(MBB) << "] = "
                 << stringifyCSRegSet(CSRSave[MBB])
                 << "  RESTORE[" << getBasicBlockName(MBB) << "] = "
                 << stringifyCSRegSet(restored) << "\n");

    if (CSRSave[MBB].intersects(restored)) {
      spilled |= (CSRSave[MBB] & restored);
    }
    // Walk inverse depth first from MBB to find spills of all
    // CSRs restored at MBB:
    for (idf_iterator<MachineBasicBlock*> BI = idf_begin(MBB),
           BE = idf_end(MBB); BI != BE; ++BI) {
      MachineBasicBlock* PBB = *BI;
      if (PBB == MBB)
        continue;
      // Stop when we encounter restores of any CSRs restored at MBB that
      // have not yet been seen to be spilled.
      if (CSRRestore[PBB].intersects(restored) &&
          !spilled.contains(CSRRestore[PBB] & restored))
        break;
      // Collect the CSRs restored at MBB that are spilled
      // at this DF predecessor of MBB.
      if (CSRSave[PBB].intersects(restored))
        spilled |= (CSRSave[PBB] & restored);
    }
    if (spilled != restored) {
      CSRegSet notSpilled = (restored - spilled);
      DEBUG(dbgs() << MF->getFunction()->getName() << ": "
                   << stringifyCSRegSet(notSpilled)
                   << " restored at " << getBasicBlockName(MBB)
                   << " are never spilled\n");
    }
  }
}

// Debugging print methods.
std::string PEI::getBasicBlockName(const MachineBasicBlock* MBB) {
  if (!MBB)
    return "";

  if (MBB->getBasicBlock())
    return MBB->getBasicBlock()->getNameStr();

  std::ostringstream name;
  name << "_MBB_" << MBB->getNumber();
  return name.str();
}

std::string PEI::stringifyCSRegSet(const CSRegSet& s) {
  const TargetRegisterInfo* TRI = MF->getTarget().getRegisterInfo();
  const std::vector<CalleeSavedInfo> CSI =
    MF->getFrameInfo()->getCalleeSavedInfo();

  std::ostringstream srep;
  if (CSI.size() == 0) {
    srep << "[]";
    return srep.str();
  }
  srep << "[";
  CSRegSet::iterator I = s.begin(), E = s.end();
  if (I != E) {
    unsigned reg = CSI[*I].getReg();
    srep << TRI->getName(reg);
    for (++I; I != E; ++I) {
      reg = CSI[*I].getReg();
      srep << ",";
      srep << TRI->getName(reg);
    }
  }
  srep << "]";
  return srep.str();
}

void PEI::dumpSet(const CSRegSet& s) {
  DEBUG(dbgs() << stringifyCSRegSet(s) << "\n");
}

void PEI::dumpUsed(MachineBasicBlock* MBB) {
  DEBUG({
      if (MBB)
        dbgs() << "CSRUsed[" << getBasicBlockName(MBB) << "] = "
               << stringifyCSRegSet(CSRUsed[MBB])  << "\n";
    });
}

void PEI::dumpAllUsed() {
    for (MachineFunction::iterator MBBI = MF->begin(), MBBE = MF->end();
         MBBI != MBBE; ++MBBI) {
      MachineBasicBlock* MBB = MBBI;
      dumpUsed(MBB);
    }
}

void PEI::dumpSets(MachineBasicBlock* MBB) {
  DEBUG({
      if (MBB)
        dbgs() << getBasicBlockName(MBB)           << " | "
               << stringifyCSRegSet(CSRUsed[MBB])  << " | "
               << stringifyCSRegSet(AnticIn[MBB])  << " | "
               << stringifyCSRegSet(AnticOut[MBB]) << " | "
               << stringifyCSRegSet(AvailIn[MBB])  << " | "
               << stringifyCSRegSet(AvailOut[MBB]) << "\n";
    });
}

void PEI::dumpSets1(MachineBasicBlock* MBB) {
  DEBUG({
      if (MBB)
        dbgs() << getBasicBlockName(MBB)             << " | "
               << stringifyCSRegSet(CSRUsed[MBB])    << " | "
               << stringifyCSRegSet(AnticIn[MBB])    << " | "
               << stringifyCSRegSet(AnticOut[MBB])   << " | "
               << stringifyCSRegSet(AvailIn[MBB])    << " | "
               << stringifyCSRegSet(AvailOut[MBB])   << " | "
               << stringifyCSRegSet(CSRSave[MBB])    << " | "
               << stringifyCSRegSet(CSRRestore[MBB]) << "\n";
    });
}

void PEI::dumpAllSets() {
    for (MachineFunction::iterator MBBI = MF->begin(), MBBE = MF->end();
         MBBI != MBBE; ++MBBI) {
      MachineBasicBlock* MBB = MBBI;
      dumpSets1(MBB);
    }
}

void PEI::dumpSRSets() {
  DEBUG({
      for (MachineFunction::iterator MBB = MF->begin(), E = MF->end();
           MBB != E; ++MBB) {
        if (!CSRSave[MBB].empty()) {
          dbgs() << "SAVE[" << getBasicBlockName(MBB) << "] = "
                 << stringifyCSRegSet(CSRSave[MBB]);
          if (CSRRestore[MBB].empty())
            dbgs() << '\n';
        }

        if (!CSRRestore[MBB].empty() && !CSRSave[MBB].empty())
          dbgs() << "    "
                 << "RESTORE[" << getBasicBlockName(MBB) << "] = "
                 << stringifyCSRegSet(CSRRestore[MBB]) << "\n";
      }
    });
}
#endif