1 //===-- LiveInterval.cpp - Live Interval Representation -------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the LiveRange and LiveInterval classes. Given some
11 // numbering of each the machine instructions an interval [i, j) is said to be a
12 // live interval for register v if there is no instruction with number j' > j
13 // such that v is live at j' and there is no instruction with number i' < i such
14 // that v is live at i'. In this implementation intervals can have holes,
15 // i.e. an interval might look like [1,20), [50,65), [1000,1001). Each
16 // individual range is represented as an instance of LiveRange, and the whole
17 // interval is represented as an instance of LiveInterval.
19 //===----------------------------------------------------------------------===//
21 #include "llvm/CodeGen/LiveInterval.h"
22 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
23 #include "llvm/CodeGen/MachineRegisterInfo.h"
24 #include "llvm/ADT/DenseMap.h"
25 #include "llvm/ADT/SmallSet.h"
26 #include "llvm/ADT/STLExtras.h"
27 #include "llvm/Support/Debug.h"
28 #include "llvm/Support/raw_ostream.h"
29 #include "llvm/Target/TargetRegisterInfo.h"
33 // CompEnd - Compare LiveRange ends.
36 bool operator()(const LiveRange &A, const LiveRange &B) const {
42 LiveInterval::iterator LiveInterval::find(SlotIndex Pos) {
43 assert(Pos.isValid() && "Cannot search for an invalid index");
44 return std::upper_bound(begin(), end(), LiveRange(SlotIndex(), Pos, 0),
48 /// killedInRange - Return true if the interval has kills in [Start,End).
49 bool LiveInterval::killedInRange(SlotIndex Start, SlotIndex End) const {
50 Ranges::const_iterator r =
51 std::lower_bound(ranges.begin(), ranges.end(), End);
53 // Now r points to the first interval with start >= End, or ranges.end().
54 if (r == ranges.begin())
58 // Now r points to the last interval with end <= End.
59 // r->end is the kill point.
60 return r->end >= Start && r->end < End;
63 // overlaps - Return true if the intersection of the two live intervals is
66 // An example for overlaps():
70 // 8: C = A + B ;; last use of A
72 // The live intervals should look like:
78 // A->overlaps(C) should return false since we want to be able to join
81 bool LiveInterval::overlapsFrom(const LiveInterval& other,
82 const_iterator StartPos) const {
83 assert(!empty() && "empty interval");
84 const_iterator i = begin();
85 const_iterator ie = end();
86 const_iterator j = StartPos;
87 const_iterator je = other.end();
89 assert((StartPos->start <= i->start || StartPos == other.begin()) &&
90 StartPos != other.end() && "Bogus start position hint!");
92 if (i->start < j->start) {
93 i = std::upper_bound(i, ie, j->start);
94 if (i != ranges.begin()) --i;
95 } else if (j->start < i->start) {
97 if (StartPos != other.end() && StartPos->start <= i->start) {
98 assert(StartPos < other.end() && i < end());
99 j = std::upper_bound(j, je, i->start);
100 if (j != other.ranges.begin()) --j;
106 if (j == je) return false;
109 if (i->start > j->start) {
114 if (i->end > j->start)
122 /// overlaps - Return true if the live interval overlaps a range specified
124 bool LiveInterval::overlaps(SlotIndex Start, SlotIndex End) const {
125 assert(Start < End && "Invalid range");
126 const_iterator I = std::lower_bound(begin(), end(), End);
127 return I != begin() && (--I)->end > Start;
131 /// ValNo is dead, remove it. If it is the largest value number, just nuke it
132 /// (and any other deleted values neighboring it), otherwise mark it as ~1U so
133 /// it can be nuked later.
134 void LiveInterval::markValNoForDeletion(VNInfo *ValNo) {
135 if (ValNo->id == getNumValNums()-1) {
138 } while (!valnos.empty() && valnos.back()->isUnused());
140 ValNo->setIsUnused(true);
144 /// RenumberValues - Renumber all values in order of appearance and delete the
145 /// remaining unused values.
146 void LiveInterval::RenumberValues(LiveIntervals &lis) {
147 SmallPtrSet<VNInfo*, 8> Seen;
148 bool seenPHIDef = false;
150 for (const_iterator I = begin(), E = end(); I != E; ++I) {
151 VNInfo *VNI = I->valno;
152 if (!Seen.insert(VNI))
154 assert(!VNI->isUnused() && "Unused valno used by live range");
155 VNI->id = (unsigned)valnos.size();
156 valnos.push_back(VNI);
157 VNI->setHasPHIKill(false);
162 // Recompute phi kill flags.
165 for (const_vni_iterator I = vni_begin(), E = vni_end(); I != E; ++I) {
167 if (!VNI->isPHIDef())
169 const MachineBasicBlock *PHIBB = lis.getMBBFromIndex(VNI->def);
170 assert(PHIBB && "No basic block for phi-def");
171 for (MachineBasicBlock::const_pred_iterator PI = PHIBB->pred_begin(),
172 PE = PHIBB->pred_end(); PI != PE; ++PI) {
173 VNInfo *KVNI = getVNInfoAt(lis.getMBBEndIdx(*PI).getPrevSlot());
175 KVNI->setHasPHIKill(true);
180 /// extendIntervalEndTo - This method is used when we want to extend the range
181 /// specified by I to end at the specified endpoint. To do this, we should
182 /// merge and eliminate all ranges that this will overlap with. The iterator is
184 void LiveInterval::extendIntervalEndTo(Ranges::iterator I, SlotIndex NewEnd) {
185 assert(I != ranges.end() && "Not a valid interval!");
186 VNInfo *ValNo = I->valno;
188 // Search for the first interval that we can't merge with.
189 Ranges::iterator MergeTo = llvm::next(I);
190 for (; MergeTo != ranges.end() && NewEnd >= MergeTo->end; ++MergeTo) {
191 assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
194 // If NewEnd was in the middle of an interval, make sure to get its endpoint.
195 I->end = std::max(NewEnd, prior(MergeTo)->end);
197 // Erase any dead ranges.
198 ranges.erase(llvm::next(I), MergeTo);
200 // If the newly formed range now touches the range after it and if they have
201 // the same value number, merge the two ranges into one range.
202 Ranges::iterator Next = llvm::next(I);
203 if (Next != ranges.end() && Next->start <= I->end && Next->valno == ValNo) {
210 /// extendIntervalStartTo - This method is used when we want to extend the range
211 /// specified by I to start at the specified endpoint. To do this, we should
212 /// merge and eliminate all ranges that this will overlap with.
213 LiveInterval::Ranges::iterator
214 LiveInterval::extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStart) {
215 assert(I != ranges.end() && "Not a valid interval!");
216 VNInfo *ValNo = I->valno;
218 // Search for the first interval that we can't merge with.
219 Ranges::iterator MergeTo = I;
221 if (MergeTo == ranges.begin()) {
223 ranges.erase(MergeTo, I);
226 assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
228 } while (NewStart <= MergeTo->start);
230 // If we start in the middle of another interval, just delete a range and
231 // extend that interval.
232 if (MergeTo->end >= NewStart && MergeTo->valno == ValNo) {
233 MergeTo->end = I->end;
235 // Otherwise, extend the interval right after.
237 MergeTo->start = NewStart;
238 MergeTo->end = I->end;
241 ranges.erase(llvm::next(MergeTo), llvm::next(I));
245 LiveInterval::iterator
246 LiveInterval::addRangeFrom(LiveRange LR, iterator From) {
247 SlotIndex Start = LR.start, End = LR.end;
248 iterator it = std::upper_bound(From, ranges.end(), Start);
250 // If the inserted interval starts in the middle or right at the end of
251 // another interval, just extend that interval to contain the range of LR.
252 if (it != ranges.begin()) {
253 iterator B = prior(it);
254 if (LR.valno == B->valno) {
255 if (B->start <= Start && B->end >= Start) {
256 extendIntervalEndTo(B, End);
260 // Check to make sure that we are not overlapping two live ranges with
261 // different valno's.
262 assert(B->end <= Start &&
263 "Cannot overlap two LiveRanges with differing ValID's"
264 " (did you def the same reg twice in a MachineInstr?)");
268 // Otherwise, if this range ends in the middle of, or right next to, another
269 // interval, merge it into that interval.
270 if (it != ranges.end()) {
271 if (LR.valno == it->valno) {
272 if (it->start <= End) {
273 it = extendIntervalStartTo(it, Start);
275 // If LR is a complete superset of an interval, we may need to grow its
278 extendIntervalEndTo(it, End);
282 // Check to make sure that we are not overlapping two live ranges with
283 // different valno's.
284 assert(it->start >= End &&
285 "Cannot overlap two LiveRanges with differing ValID's");
289 // Otherwise, this is just a new range that doesn't interact with anything.
291 return ranges.insert(it, LR);
295 /// removeRange - Remove the specified range from this interval. Note that
296 /// the range must be in a single LiveRange in its entirety.
297 void LiveInterval::removeRange(SlotIndex Start, SlotIndex End,
298 bool RemoveDeadValNo) {
299 // Find the LiveRange containing this span.
300 Ranges::iterator I = find(Start);
301 assert(I != ranges.end() && "Range is not in interval!");
302 assert(I->containsRange(Start, End) && "Range is not entirely in interval!");
304 // If the span we are removing is at the start of the LiveRange, adjust it.
305 VNInfo *ValNo = I->valno;
306 if (I->start == Start) {
308 if (RemoveDeadValNo) {
309 // Check if val# is dead.
311 for (const_iterator II = begin(), EE = end(); II != EE; ++II)
312 if (II != I && II->valno == ValNo) {
317 // Now that ValNo is dead, remove it.
318 markValNoForDeletion(ValNo);
322 ranges.erase(I); // Removed the whole LiveRange.
328 // Otherwise if the span we are removing is at the end of the LiveRange,
329 // adjust the other way.
335 // Otherwise, we are splitting the LiveRange into two pieces.
336 SlotIndex OldEnd = I->end;
337 I->end = Start; // Trim the old interval.
339 // Insert the new one.
340 ranges.insert(llvm::next(I), LiveRange(End, OldEnd, ValNo));
343 /// removeValNo - Remove all the ranges defined by the specified value#.
344 /// Also remove the value# from value# list.
345 void LiveInterval::removeValNo(VNInfo *ValNo) {
347 Ranges::iterator I = ranges.end();
348 Ranges::iterator E = ranges.begin();
351 if (I->valno == ValNo)
354 // Now that ValNo is dead, remove it.
355 markValNoForDeletion(ValNo);
358 /// findDefinedVNInfo - Find the VNInfo defined by the specified
359 /// index (register interval).
360 VNInfo *LiveInterval::findDefinedVNInfoForRegInt(SlotIndex Idx) const {
361 for (LiveInterval::const_vni_iterator i = vni_begin(), e = vni_end();
363 if ((*i)->def == Idx)
370 /// join - Join two live intervals (this, and other) together. This applies
371 /// mappings to the value numbers in the LHS/RHS intervals as specified. If
372 /// the intervals are not joinable, this aborts.
373 void LiveInterval::join(LiveInterval &Other,
374 const int *LHSValNoAssignments,
375 const int *RHSValNoAssignments,
376 SmallVector<VNInfo*, 16> &NewVNInfo,
377 MachineRegisterInfo *MRI) {
378 // Determine if any of our live range values are mapped. This is uncommon, so
379 // we want to avoid the interval scan if not.
380 bool MustMapCurValNos = false;
381 unsigned NumVals = getNumValNums();
382 unsigned NumNewVals = NewVNInfo.size();
383 for (unsigned i = 0; i != NumVals; ++i) {
384 unsigned LHSValID = LHSValNoAssignments[i];
386 (NewVNInfo[LHSValID] && NewVNInfo[LHSValID] != getValNumInfo(i)))
387 MustMapCurValNos = true;
390 // If we have to apply a mapping to our base interval assignment, rewrite it
392 if (MustMapCurValNos) {
393 // Map the first live range.
394 iterator OutIt = begin();
395 OutIt->valno = NewVNInfo[LHSValNoAssignments[OutIt->valno->id]];
397 for (iterator I = OutIt, E = end(); I != E; ++I) {
398 OutIt->valno = NewVNInfo[LHSValNoAssignments[I->valno->id]];
400 // If this live range has the same value # as its immediate predecessor,
401 // and if they are neighbors, remove one LiveRange. This happens when we
402 // have [0,3:0)[4,7:1) and map 0/1 onto the same value #.
403 if (OutIt->valno == (OutIt-1)->valno && (OutIt-1)->end == OutIt->start) {
404 (OutIt-1)->end = OutIt->end;
407 OutIt->start = I->start;
411 // Didn't merge, on to the next one.
416 // If we merge some live ranges, chop off the end.
417 ranges.erase(OutIt, end());
420 // Remember assignements because val# ids are changing.
421 SmallVector<unsigned, 16> OtherAssignments;
422 for (iterator I = Other.begin(), E = Other.end(); I != E; ++I)
423 OtherAssignments.push_back(RHSValNoAssignments[I->valno->id]);
425 // Update val# info. Renumber them and make sure they all belong to this
426 // LiveInterval now. Also remove dead val#'s.
427 unsigned NumValNos = 0;
428 for (unsigned i = 0; i < NumNewVals; ++i) {
429 VNInfo *VNI = NewVNInfo[i];
431 if (NumValNos >= NumVals)
432 valnos.push_back(VNI);
434 valnos[NumValNos] = VNI;
435 VNI->id = NumValNos++; // Renumber val#.
438 if (NumNewVals < NumVals)
439 valnos.resize(NumNewVals); // shrinkify
441 // Okay, now insert the RHS live ranges into the LHS.
442 iterator InsertPos = begin();
443 unsigned RangeNo = 0;
444 for (iterator I = Other.begin(), E = Other.end(); I != E; ++I, ++RangeNo) {
445 // Map the valno in the other live range to the current live range.
446 I->valno = NewVNInfo[OtherAssignments[RangeNo]];
447 assert(I->valno && "Adding a dead range?");
448 InsertPos = addRangeFrom(*I, InsertPos);
451 ComputeJoinedWeight(Other);
454 /// MergeRangesInAsValue - Merge all of the intervals in RHS into this live
455 /// interval as the specified value number. The LiveRanges in RHS are
456 /// allowed to overlap with LiveRanges in the current interval, but only if
457 /// the overlapping LiveRanges have the specified value number.
458 void LiveInterval::MergeRangesInAsValue(const LiveInterval &RHS,
460 // TODO: Make this more efficient.
461 iterator InsertPos = begin();
462 for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) {
463 // Map the valno in the other live range to the current live range.
465 Tmp.valno = LHSValNo;
466 InsertPos = addRangeFrom(Tmp, InsertPos);
471 /// MergeValueInAsValue - Merge all of the live ranges of a specific val#
472 /// in RHS into this live interval as the specified value number.
473 /// The LiveRanges in RHS are allowed to overlap with LiveRanges in the
474 /// current interval, it will replace the value numbers of the overlaped
475 /// live ranges with the specified value number.
476 void LiveInterval::MergeValueInAsValue(
477 const LiveInterval &RHS,
478 const VNInfo *RHSValNo, VNInfo *LHSValNo) {
479 SmallVector<VNInfo*, 4> ReplacedValNos;
480 iterator IP = begin();
481 for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) {
482 assert(I->valno == RHS.getValNumInfo(I->valno->id) && "Bad VNInfo");
483 if (I->valno != RHSValNo)
485 SlotIndex Start = I->start, End = I->end;
486 IP = std::upper_bound(IP, end(), Start);
487 // If the start of this range overlaps with an existing liverange, trim it.
488 if (IP != begin() && IP[-1].end > Start) {
489 if (IP[-1].valno != LHSValNo) {
490 ReplacedValNos.push_back(IP[-1].valno);
491 IP[-1].valno = LHSValNo; // Update val#.
494 // Trimmed away the whole range?
495 if (Start >= End) continue;
497 // If the end of this range overlaps with an existing liverange, trim it.
498 if (IP != end() && End > IP->start) {
499 if (IP->valno != LHSValNo) {
500 ReplacedValNos.push_back(IP->valno);
501 IP->valno = LHSValNo; // Update val#.
504 // If this trimmed away the whole range, ignore it.
505 if (Start == End) continue;
508 // Map the valno in the other live range to the current live range.
509 IP = addRangeFrom(LiveRange(Start, End, LHSValNo), IP);
513 SmallSet<VNInfo*, 4> Seen;
514 for (unsigned i = 0, e = ReplacedValNos.size(); i != e; ++i) {
515 VNInfo *V1 = ReplacedValNos[i];
516 if (Seen.insert(V1)) {
518 for (const_iterator I = begin(), E = end(); I != E; ++I)
519 if (I->valno == V1) {
524 // Now that V1 is dead, remove it.
525 markValNoForDeletion(V1);
533 /// MergeValueNumberInto - This method is called when two value nubmers
534 /// are found to be equivalent. This eliminates V1, replacing all
535 /// LiveRanges with the V1 value number with the V2 value number. This can
536 /// cause merging of V1/V2 values numbers and compaction of the value space.
537 VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) {
538 assert(V1 != V2 && "Identical value#'s are always equivalent!");
540 // This code actually merges the (numerically) larger value number into the
541 // smaller value number, which is likely to allow us to compactify the value
542 // space. The only thing we have to be careful of is to preserve the
543 // instruction that defines the result value.
545 // Make sure V2 is smaller than V1.
546 if (V1->id < V2->id) {
551 // Merge V1 live ranges into V2.
552 for (iterator I = begin(); I != end(); ) {
554 if (LR->valno != V1) continue; // Not a V1 LiveRange.
556 // Okay, we found a V1 live range. If it had a previous, touching, V2 live
559 iterator Prev = LR-1;
560 if (Prev->valno == V2 && Prev->end == LR->start) {
563 // Erase this live-range.
570 // Okay, now we have a V1 or V2 live range that is maximally merged forward.
571 // Ensure that it is a V2 live-range.
574 // If we can merge it into later V2 live ranges, do so now. We ignore any
575 // following V1 live ranges, as they will be merged in subsequent iterations
578 if (I->start == LR->end && I->valno == V2) {
586 // Merge the relevant flags.
589 // Now that V1 is dead, remove it.
590 markValNoForDeletion(V1);
595 void LiveInterval::Copy(const LiveInterval &RHS,
596 MachineRegisterInfo *MRI,
597 VNInfo::Allocator &VNInfoAllocator) {
600 std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(RHS.reg);
601 MRI->setRegAllocationHint(reg, Hint.first, Hint.second);
604 for (unsigned i = 0, e = RHS.getNumValNums(); i != e; ++i) {
605 const VNInfo *VNI = RHS.getValNumInfo(i);
606 createValueCopy(VNI, VNInfoAllocator);
608 for (unsigned i = 0, e = RHS.ranges.size(); i != e; ++i) {
609 const LiveRange &LR = RHS.ranges[i];
610 addRange(LiveRange(LR.start, LR.end, getValNumInfo(LR.valno->id)));
614 unsigned LiveInterval::getSize() const {
616 for (const_iterator I = begin(), E = end(); I != E; ++I)
617 Sum += I->start.distance(I->end);
621 /// ComputeJoinedWeight - Set the weight of a live interval Joined
622 /// after Other has been merged into it.
623 void LiveInterval::ComputeJoinedWeight(const LiveInterval &Other) {
624 // If either of these intervals was spilled, the weight is the
625 // weight of the non-spilled interval. This can only happen with
626 // iterative coalescers.
628 if (Other.weight != HUGE_VALF) {
629 weight += Other.weight;
631 else if (weight == HUGE_VALF &&
632 !TargetRegisterInfo::isPhysicalRegister(reg)) {
633 // Remove this assert if you have an iterative coalescer
634 assert(0 && "Joining to spilled interval");
635 weight = Other.weight;
638 // Otherwise the weight stays the same
639 // Remove this assert if you have an iterative coalescer
640 assert(0 && "Joining from spilled interval");
644 raw_ostream& llvm::operator<<(raw_ostream& os, const LiveRange &LR) {
645 return os << '[' << LR.start << ',' << LR.end << ':' << LR.valno->id << ")";
648 void LiveRange::dump() const {
649 dbgs() << *this << "\n";
652 void LiveInterval::print(raw_ostream &OS, const TargetRegisterInfo *TRI) const {
654 OS << "SS#" << getStackSlotIndex();
655 else if (TRI && TargetRegisterInfo::isPhysicalRegister(reg))
656 OS << TRI->getName(reg);
666 for (LiveInterval::Ranges::const_iterator I = ranges.begin(),
667 E = ranges.end(); I != E; ++I) {
669 assert(I->valno == getValNumInfo(I->valno->id) && "Bad VNInfo");
673 // Print value number info.
674 if (getNumValNums()) {
677 for (const_vni_iterator i = vni_begin(), e = vni_end(); i != e;
679 const VNInfo *vni = *i;
682 if (vni->isUnused()) {
688 if (vni->hasPHIKill())
690 if (vni->hasRedefByEC())
697 void LiveInterval::dump() const {
698 dbgs() << *this << "\n";
702 void LiveRange::print(raw_ostream &os) const {
706 /// ConnectedVNInfoEqClasses - Helper class that can divide VNInfos in a
707 /// LiveInterval into equivalence clases of connected components. A
708 /// LiveInterval that has multiple connected components can be broken into
709 /// multiple LiveIntervals.
711 void ConnectedVNInfoEqClasses::Connect(unsigned a, unsigned b) {
712 while (eqClass_[a] != eqClass_[b]) {
713 if (eqClass_[a] > eqClass_[b])
715 unsigned t = eqClass_[b];
716 assert(t <= b && "Invariant broken");
717 eqClass_[b] = eqClass_[a];
722 unsigned ConnectedVNInfoEqClasses::Renumber() {
723 // Assign final class numbers.
724 // We use the fact that eqClass_[i] == i for class leaders.
725 // For others, eqClass_[i] points to an earlier value in the same class.
727 for (unsigned i = 0, e = eqClass_.size(); i != e; ++i) {
728 unsigned q = eqClass_[i];
729 assert(q <= i && "Invariant broken");
730 eqClass_[i] = q == i ? count++ : eqClass_[q];
736 unsigned ConnectedVNInfoEqClasses::Classify(const LiveInterval *LI) {
737 // Create initial equivalence classes.
739 eqClass_.reserve(LI->getNumValNums());
740 for (unsigned i = 0, e = LI->getNumValNums(); i != e; ++i)
741 eqClass_.push_back(i);
743 const VNInfo *used = 0, *unused = 0;
745 // Determine connections.
746 for (LiveInterval::const_vni_iterator I = LI->vni_begin(), E = LI->vni_end();
748 const VNInfo *VNI = *I;
749 // Group all unused values into one class.
750 if (VNI->isUnused()) {
752 Connect(unused->id, VNI->id);
757 if (VNI->isPHIDef()) {
758 const MachineBasicBlock *MBB = lis_.getMBBFromIndex(VNI->def);
759 assert(MBB && "Phi-def has no defining MBB");
760 // Connect to values live out of predecessors.
761 for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
762 PE = MBB->pred_end(); PI != PE; ++PI)
763 if (const VNInfo *PVNI =
764 LI->getVNInfoAt(lis_.getMBBEndIdx(*PI).getPrevSlot()))
765 Connect(VNI->id, PVNI->id);
767 // Normal value defined by an instruction. Check for two-addr redef.
768 // FIXME: This could be coincidental. Should we really check for a tied
769 // operand constraint?
770 if (const VNInfo *UVNI = LI->getVNInfoAt(VNI->def.getUseIndex()))
771 Connect(VNI->id, UVNI->id);
775 // Lump all the unused values in with the last used value.
777 Connect(used->id, unused->id);
782 void ConnectedVNInfoEqClasses::Distribute(LiveInterval *LIV[]) {
783 assert(LIV[0] && "LIV[0] must be set");
784 LiveInterval &LI = *LIV[0];
785 // Check that they likely ran Classify() on LIV[0] first.
786 assert(eqClass_.size() == LI.getNumValNums() && "Bad classification data");
788 // First move runs to new intervals.
789 LiveInterval::iterator J = LI.begin(), E = LI.end();
790 while (J != E && eqClass_[J->valno->id] == 0)
792 for (LiveInterval::iterator I = J; I != E; ++I) {
793 if (unsigned eq = eqClass_[I->valno->id]) {
794 assert((LIV[eq]->empty() || LIV[eq]->expiredAt(I->start)) &&
795 "New intervals should be empty");
796 LIV[eq]->ranges.push_back(*I);
800 LI.ranges.erase(J, E);
802 // Transfer VNInfos to their new owners and renumber them.
803 unsigned j = 0, e = LI.getNumValNums();
804 while (j != e && eqClass_[j] == 0)
806 for (unsigned i = j; i != e; ++i) {
807 VNInfo *VNI = LI.getValNumInfo(i);
808 if (unsigned eq = eqClass_[i]) {
809 VNI->id = LIV[eq]->getNumValNums();
810 LIV[eq]->valnos.push_back(VNI);
813 LI.valnos[j++] = VNI;