+/// addStackInterval - Create a LiveInterval for stack if the specified live
+/// interval has been spilled.
+static void addStackInterval(LiveInterval *cur, LiveStacks *ls_,
+ LiveIntervals *li_,
+ MachineRegisterInfo* mri_, VirtRegMap &vrm_) {
+ int SS = vrm_.getStackSlot(cur->reg);
+ if (SS == VirtRegMap::NO_STACK_SLOT)
+ return;
+
+ const TargetRegisterClass *RC = mri_->getRegClass(cur->reg);
+ LiveInterval &SI = ls_->getOrCreateInterval(SS, RC);
+
+ VNInfo *VNI;
+ if (SI.hasAtLeastOneValue())
+ VNI = SI.getValNumInfo(0);
+ else
+ VNI = SI.getNextValue(LiveIndex(), 0, false,
+ ls_->getVNInfoAllocator());
+
+ LiveInterval &RI = li_->getInterval(cur->reg);
+ // FIXME: This may be overly conservative.
+ SI.MergeRangesInAsValue(RI, VNI);
+}
+
+/// getConflictWeight - Return the number of conflicts between cur
+/// live interval and defs and uses of Reg weighted by loop depthes.
+static
+float getConflictWeight(LiveInterval *cur, unsigned Reg, LiveIntervals *li_,
+ MachineRegisterInfo *mri_,
+ const MachineLoopInfo *loopInfo) {
+ float Conflicts = 0;
+ for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(Reg),
+ E = mri_->reg_end(); I != E; ++I) {
+ MachineInstr *MI = &*I;
+ if (cur->liveAt(li_->getInstructionIndex(MI))) {
+ unsigned loopDepth = loopInfo->getLoopDepth(MI->getParent());
+ Conflicts += powf(10.0f, (float)loopDepth);
+ }
+ }
+ return Conflicts;
+}
+
+/// findIntervalsToSpill - Determine the intervals to spill for the
+/// specified interval. It's passed the physical registers whose spill
+/// weight is the lowest among all the registers whose live intervals
+/// conflict with the interval.
+void RALinScan::findIntervalsToSpill(LiveInterval *cur,
+ std::vector<std::pair<unsigned,float> > &Candidates,
+ unsigned NumCands,
+ SmallVector<LiveInterval*, 8> &SpillIntervals) {
+ // We have figured out the *best* register to spill. But there are other
+ // registers that are pretty good as well (spill weight within 3%). Spill
+ // the one that has fewest defs and uses that conflict with cur.
+ float Conflicts[3] = { 0.0f, 0.0f, 0.0f };
+ SmallVector<LiveInterval*, 8> SLIs[3];
+
+ DEBUG({
+ errs() << "\tConsidering " << NumCands << " candidates: ";
+ for (unsigned i = 0; i != NumCands; ++i)
+ errs() << tri_->getName(Candidates[i].first) << " ";
+ errs() << "\n";
+ });
+
+ // Calculate the number of conflicts of each candidate.
+ for (IntervalPtrs::iterator i = active_.begin(); i != active_.end(); ++i) {
+ unsigned Reg = i->first->reg;
+ unsigned PhysReg = vrm_->getPhys(Reg);
+ if (!cur->overlapsFrom(*i->first, i->second))
+ continue;
+ for (unsigned j = 0; j < NumCands; ++j) {
+ unsigned Candidate = Candidates[j].first;
+ if (tri_->regsOverlap(PhysReg, Candidate)) {
+ if (NumCands > 1)
+ Conflicts[j] += getConflictWeight(cur, Reg, li_, mri_, loopInfo);
+ SLIs[j].push_back(i->first);
+ }
+ }
+ }
+
+ for (IntervalPtrs::iterator i = inactive_.begin(); i != inactive_.end(); ++i){
+ unsigned Reg = i->first->reg;
+ unsigned PhysReg = vrm_->getPhys(Reg);
+ if (!cur->overlapsFrom(*i->first, i->second-1))
+ continue;
+ for (unsigned j = 0; j < NumCands; ++j) {
+ unsigned Candidate = Candidates[j].first;
+ if (tri_->regsOverlap(PhysReg, Candidate)) {
+ if (NumCands > 1)
+ Conflicts[j] += getConflictWeight(cur, Reg, li_, mri_, loopInfo);
+ SLIs[j].push_back(i->first);
+ }
+ }
+ }
+
+ // Which is the best candidate?
+ unsigned BestCandidate = 0;
+ float MinConflicts = Conflicts[0];
+ for (unsigned i = 1; i != NumCands; ++i) {
+ if (Conflicts[i] < MinConflicts) {
+ BestCandidate = i;
+ MinConflicts = Conflicts[i];
+ }
+ }
+
+ std::copy(SLIs[BestCandidate].begin(), SLIs[BestCandidate].end(),
+ std::back_inserter(SpillIntervals));
+}
+
+namespace {
+ struct WeightCompare {
+ typedef std::pair<unsigned, float> RegWeightPair;
+ bool operator()(const RegWeightPair &LHS, const RegWeightPair &RHS) const {
+ return LHS.second < RHS.second;
+ }
+ };
+}
+
+static bool weightsAreClose(float w1, float w2) {
+ if (!NewHeuristic)
+ return false;
+
+ float diff = w1 - w2;
+ if (diff <= 0.02f) // Within 0.02f
+ return true;
+ return (diff / w2) <= 0.05f; // Within 5%.
+}
+
+LiveInterval *RALinScan::hasNextReloadInterval(LiveInterval *cur) {
+ DenseMap<unsigned, unsigned>::iterator I = NextReloadMap.find(cur->reg);
+ if (I == NextReloadMap.end())
+ return 0;
+ return &li_->getInterval(I->second);
+}
+
+void RALinScan::DowngradeRegister(LiveInterval *li, unsigned Reg) {
+ bool isNew = DowngradedRegs.insert(Reg);
+ isNew = isNew; // Silence compiler warning.
+ assert(isNew && "Multiple reloads holding the same register?");
+ DowngradeMap.insert(std::make_pair(li->reg, Reg));
+ for (const unsigned *AS = tri_->getAliasSet(Reg); *AS; ++AS) {
+ isNew = DowngradedRegs.insert(*AS);
+ isNew = isNew; // Silence compiler warning.
+ assert(isNew && "Multiple reloads holding the same register?");
+ DowngradeMap.insert(std::make_pair(li->reg, *AS));
+ }
+ ++NumDowngrade;
+}
+
+void RALinScan::UpgradeRegister(unsigned Reg) {
+ if (Reg) {
+ DowngradedRegs.erase(Reg);
+ for (const unsigned *AS = tri_->getAliasSet(Reg); *AS; ++AS)
+ DowngradedRegs.erase(*AS);
+ }
+}
+
+namespace {
+ struct LISorter {
+ bool operator()(LiveInterval* A, LiveInterval* B) {
+ return A->beginIndex() < B->beginIndex();
+ }
+ };
+}
+