+
+/// MergeValueInAsValue - Merge all of the live ranges of a specific val#
+/// in RHS into this live interval as the specified value number.
+/// The LiveRanges in RHS are allowed to overlap with LiveRanges in the
+/// current interval, it will replace the value numbers of the overlaped
+/// live ranges with the specified value number.
+void LiveInterval::MergeValueInAsValue(
+ const LiveInterval &RHS,
+ const VNInfo *RHSValNo, VNInfo *LHSValNo) {
+ SmallVector<VNInfo*, 4> ReplacedValNos;
+ iterator IP = begin();
+ for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) {
+ if (I->valno != RHSValNo)
+ continue;
+ SlotIndex Start = I->start, End = I->end;
+ IP = std::upper_bound(IP, end(), Start);
+ // If the start of this range overlaps with an existing liverange, trim it.
+ if (IP != begin() && IP[-1].end > Start) {
+ if (IP[-1].valno != LHSValNo) {
+ ReplacedValNos.push_back(IP[-1].valno);
+ IP[-1].valno = LHSValNo; // Update val#.
+ }
+ Start = IP[-1].end;
+ // Trimmed away the whole range?
+ if (Start >= End) continue;
+ }
+ // If the end of this range overlaps with an existing liverange, trim it.
+ if (IP != end() && End > IP->start) {
+ if (IP->valno != LHSValNo) {
+ ReplacedValNos.push_back(IP->valno);
+ IP->valno = LHSValNo; // Update val#.
+ }
+ End = IP->start;
+ // If this trimmed away the whole range, ignore it.
+ if (Start == End) continue;
+ }
+
+ // Map the valno in the other live range to the current live range.
+ IP = addRangeFrom(LiveRange(Start, End, LHSValNo), IP);
+ }
+
+
+ SmallSet<VNInfo*, 4> Seen;
+ for (unsigned i = 0, e = ReplacedValNos.size(); i != e; ++i) {
+ VNInfo *V1 = ReplacedValNos[i];
+ if (Seen.insert(V1)) {
+ bool isDead = true;
+ for (const_iterator I = begin(), E = end(); I != E; ++I)
+ if (I->valno == V1) {
+ isDead = false;
+ break;
+ }
+ if (isDead) {
+ // Now that V1 is dead, remove it. If it is the largest value number,
+ // just nuke it (and any other deleted values neighboring it), otherwise
+ // mark it as ~1U so it can be nuked later.
+ if (V1->id == getNumValNums()-1) {
+ do {
+ valnos.pop_back();
+ } while (!valnos.empty() && valnos.back()->isUnused());
+ } else {
+ V1->setIsUnused(true);
+ }
+ }
+ }
+ }
+}
+
+
+/// MergeInClobberRanges - For any live ranges that are not defined in the
+/// current interval, but are defined in the Clobbers interval, mark them
+/// used with an unknown definition value.
+void LiveInterval::MergeInClobberRanges(LiveIntervals &li_,
+ const LiveInterval &Clobbers,
+ VNInfo::Allocator &VNInfoAllocator) {
+ if (Clobbers.empty()) return;
+
+ DenseMap<VNInfo*, VNInfo*> ValNoMaps;
+ VNInfo *UnusedValNo = 0;
+ iterator IP = begin();
+ for (const_iterator I = Clobbers.begin(), E = Clobbers.end(); I != E; ++I) {
+ // For every val# in the Clobbers interval, create a new "unknown" val#.
+ VNInfo *ClobberValNo = 0;
+ DenseMap<VNInfo*, VNInfo*>::iterator VI = ValNoMaps.find(I->valno);
+ if (VI != ValNoMaps.end())
+ ClobberValNo = VI->second;
+ else if (UnusedValNo)
+ ClobberValNo = UnusedValNo;
+ else {
+ UnusedValNo = ClobberValNo =
+ getNextValue(li_.getInvalidIndex(), 0, false, VNInfoAllocator);
+ ValNoMaps.insert(std::make_pair(I->valno, ClobberValNo));
+ }
+
+ bool Done = false;
+ SlotIndex Start = I->start, End = I->end;
+ // If a clobber range starts before an existing range and ends after
+ // it, the clobber range will need to be split into multiple ranges.
+ // Loop until the entire clobber range is handled.
+ while (!Done) {
+ Done = true;
+ IP = std::upper_bound(IP, end(), Start);
+ SlotIndex SubRangeStart = Start;
+ SlotIndex SubRangeEnd = End;
+
+ // If the start of this range overlaps with an existing liverange, trim it.
+ if (IP != begin() && IP[-1].end > SubRangeStart) {
+ SubRangeStart = IP[-1].end;
+ // Trimmed away the whole range?
+ if (SubRangeStart >= SubRangeEnd) continue;
+ }
+ // If the end of this range overlaps with an existing liverange, trim it.
+ if (IP != end() && SubRangeEnd > IP->start) {
+ // If the clobber live range extends beyond the existing live range,
+ // it'll need at least another live range, so set the flag to keep
+ // iterating.
+ if (SubRangeEnd > IP->end) {
+ Start = IP->end;
+ Done = false;
+ }
+ SubRangeEnd = IP->start;
+ // If this trimmed away the whole range, ignore it.
+ if (SubRangeStart == SubRangeEnd) continue;
+ }
+
+ // Insert the clobber interval.
+ IP = addRangeFrom(LiveRange(SubRangeStart, SubRangeEnd, ClobberValNo),
+ IP);
+ UnusedValNo = 0;
+ }
+ }
+
+ if (UnusedValNo) {
+ // Delete the last unused val#.
+ valnos.pop_back();
+ }
+}
+
+void LiveInterval::MergeInClobberRange(LiveIntervals &li_,
+ SlotIndex Start,
+ SlotIndex End,
+ VNInfo::Allocator &VNInfoAllocator) {
+ // Find a value # to use for the clobber ranges. If there is already a value#
+ // for unknown values, use it.
+ VNInfo *ClobberValNo =
+ getNextValue(li_.getInvalidIndex(), 0, false, VNInfoAllocator);
+
+ iterator IP = begin();
+ IP = std::upper_bound(IP, end(), Start);
+
+ // If the start of this range overlaps with an existing liverange, trim it.
+ if (IP != begin() && IP[-1].end > Start) {
+ Start = IP[-1].end;
+ // Trimmed away the whole range?
+ if (Start >= End) return;
+ }
+ // If the end of this range overlaps with an existing liverange, trim it.
+ if (IP != end() && End > IP->start) {
+ End = IP->start;
+ // If this trimmed away the whole range, ignore it.
+ if (Start == End) return;
+ }
+
+ // Insert the clobber interval.
+ addRangeFrom(LiveRange(Start, End, ClobberValNo), IP);