//
// This file implements the LiveRange and LiveInterval classes. Given some
// numbering of each the machine instructions an interval [i, j) is said to be a
-// live interval for register v if there is no instruction with number j' > j
+// live range for register v if there is no instruction with number j' >= j
// such that v is live at j' and there is no instruction with number i' < i such
-// that v is live at i'. In this implementation intervals can have holes,
-// i.e. an interval might look like [1,20), [50,65), [1000,1001). Each
-// individual range is represented as an instance of LiveRange, and the whole
-// interval is represented as an instance of LiveInterval.
+// that v is live at i'. In this implementation ranges can have holes,
+// i.e. a range might look like [1,20), [50,65), [1000,1001). Each
+// individual segment is represented as an instance of LiveRange::Segment,
+// and the whole range is represented as an instance of LiveRange.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/LiveInterval.h"
-#include "llvm/CodeGen/LiveIntervalAnalysis.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "RegisterCoalescer.h"
#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include <algorithm>
using namespace llvm;
-// CompEnd - Compare LiveRange ends.
namespace {
-struct CompEnd {
- bool operator()(const LiveRange &A, const LiveRange &B) const {
- return A.end < B.end;
+//===----------------------------------------------------------------------===//
+// Implementation of various methods necessary for calculation of live ranges.
+// The implementation of the methods abstracts from the concrete type of the
+// segment collection.
+//
+// Implementation of the class follows the Template design pattern. The base
+// class contains generic algorithms that call collection-specific methods,
+// which are provided in concrete subclasses. In order to avoid virtual calls
+// these methods are provided by means of C++ template instantiation.
+// The base class calls the methods of the subclass through method impl(),
+// which casts 'this' pointer to the type of the subclass.
+//
+//===----------------------------------------------------------------------===//
+
+template <typename ImplT, typename IteratorT, typename CollectionT>
+class CalcLiveRangeUtilBase {
+protected:
+ LiveRange *LR;
+
+protected:
+ CalcLiveRangeUtilBase(LiveRange *LR) : LR(LR) {}
+
+public:
+ typedef LiveRange::Segment Segment;
+ typedef IteratorT iterator;
+
+ VNInfo *createDeadDef(SlotIndex Def, VNInfo::Allocator &VNInfoAllocator) {
+ assert(!Def.isDead() && "Cannot define a value at the dead slot");
+
+ iterator I = impl().find(Def);
+ if (I == segments().end()) {
+ VNInfo *VNI = LR->getNextValue(Def, VNInfoAllocator);
+ impl().insertAtEnd(Segment(Def, Def.getDeadSlot(), VNI));
+ return VNI;
+ }
+
+ Segment *S = segmentAt(I);
+ if (SlotIndex::isSameInstr(Def, S->start)) {
+ assert(S->valno->def == S->start && "Inconsistent existing value def");
+
+ // It is possible to have both normal and early-clobber defs of the same
+ // register on an instruction. It doesn't make a lot of sense, but it is
+ // possible to specify in inline assembly.
+ //
+ // Just convert everything to early-clobber.
+ Def = std::min(Def, S->start);
+ if (Def != S->start)
+ S->start = S->valno->def = Def;
+ return S->valno;
+ }
+ assert(SlotIndex::isEarlierInstr(Def, S->start) && "Already live at def");
+ VNInfo *VNI = LR->getNextValue(Def, VNInfoAllocator);
+ segments().insert(I, Segment(Def, Def.getDeadSlot(), VNI));
+ return VNI;
+ }
+
+ VNInfo *extendInBlock(SlotIndex StartIdx, SlotIndex Use) {
+ if (segments().empty())
+ return nullptr;
+ iterator I =
+ impl().findInsertPos(Segment(Use.getPrevSlot(), Use, nullptr));
+ if (I == segments().begin())
+ return nullptr;
+ --I;
+ if (I->end <= StartIdx)
+ return nullptr;
+ if (I->end < Use)
+ extendSegmentEndTo(I, Use);
+ return I->valno;
+ }
+
+ /// This method is used when we want to extend the segment specified
+ /// by I to end at the specified endpoint. To do this, we should
+ /// merge and eliminate all segments that this will overlap
+ /// with. The iterator is not invalidated.
+ void extendSegmentEndTo(iterator I, SlotIndex NewEnd) {
+ assert(I != segments().end() && "Not a valid segment!");
+ Segment *S = segmentAt(I);
+ VNInfo *ValNo = I->valno;
+
+ // Search for the first segment that we can't merge with.
+ iterator MergeTo = std::next(I);
+ for (; MergeTo != segments().end() && NewEnd >= MergeTo->end; ++MergeTo)
+ assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
+
+ // If NewEnd was in the middle of a segment, make sure to get its endpoint.
+ S->end = std::max(NewEnd, std::prev(MergeTo)->end);
+
+ // If the newly formed segment now touches the segment after it and if they
+ // have the same value number, merge the two segments into one segment.
+ if (MergeTo != segments().end() && MergeTo->start <= I->end &&
+ MergeTo->valno == ValNo) {
+ S->end = MergeTo->end;
+ ++MergeTo;
+ }
+
+ // Erase any dead segments.
+ segments().erase(std::next(I), MergeTo);
+ }
+
+ /// This method is used when we want to extend the segment specified
+ /// by I to start at the specified endpoint. To do this, we should
+ /// merge and eliminate all segments that this will overlap with.
+ iterator extendSegmentStartTo(iterator I, SlotIndex NewStart) {
+ assert(I != segments().end() && "Not a valid segment!");
+ Segment *S = segmentAt(I);
+ VNInfo *ValNo = I->valno;
+
+ // Search for the first segment that we can't merge with.
+ iterator MergeTo = I;
+ do {
+ if (MergeTo == segments().begin()) {
+ S->start = NewStart;
+ segments().erase(MergeTo, I);
+ return I;
+ }
+ assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
+ --MergeTo;
+ } while (NewStart <= MergeTo->start);
+
+ // If we start in the middle of another segment, just delete a range and
+ // extend that segment.
+ if (MergeTo->end >= NewStart && MergeTo->valno == ValNo) {
+ segmentAt(MergeTo)->end = S->end;
+ } else {
+ // Otherwise, extend the segment right after.
+ ++MergeTo;
+ Segment *MergeToSeg = segmentAt(MergeTo);
+ MergeToSeg->start = NewStart;
+ MergeToSeg->end = S->end;
+ }
+
+ segments().erase(std::next(MergeTo), std::next(I));
+ return MergeTo;
+ }
+
+ iterator addSegment(Segment S) {
+ SlotIndex Start = S.start, End = S.end;
+ iterator I = impl().findInsertPos(S);
+
+ // If the inserted segment starts in the middle or right at the end of
+ // another segment, just extend that segment to contain the segment of S.
+ if (I != segments().begin()) {
+ iterator B = std::prev(I);
+ if (S.valno == B->valno) {
+ if (B->start <= Start && B->end >= Start) {
+ extendSegmentEndTo(B, End);
+ return B;
+ }
+ } else {
+ // Check to make sure that we are not overlapping two live segments with
+ // different valno's.
+ assert(B->end <= Start &&
+ "Cannot overlap two segments with differing ValID's"
+ " (did you def the same reg twice in a MachineInstr?)");
+ }
+ }
+
+ // Otherwise, if this segment ends in the middle of, or right next
+ // to, another segment, merge it into that segment.
+ if (I != segments().end()) {
+ if (S.valno == I->valno) {
+ if (I->start <= End) {
+ I = extendSegmentStartTo(I, Start);
+
+ // If S is a complete superset of a segment, we may need to grow its
+ // endpoint as well.
+ if (End > I->end)
+ extendSegmentEndTo(I, End);
+ return I;
+ }
+ } else {
+ // Check to make sure that we are not overlapping two live segments with
+ // different valno's.
+ assert(I->start >= End &&
+ "Cannot overlap two segments with differing ValID's");
+ }
+ }
+
+ // Otherwise, this is just a new segment that doesn't interact with
+ // anything.
+ // Insert it.
+ return segments().insert(I, S);
}
+
+private:
+ ImplT &impl() { return *static_cast<ImplT *>(this); }
+
+ CollectionT &segments() { return impl().segmentsColl(); }
+
+ Segment *segmentAt(iterator I) { return const_cast<Segment *>(&(*I)); }
};
-}
-LiveInterval::iterator LiveInterval::find(SlotIndex Pos) {
- assert(Pos.isValid() && "Cannot search for an invalid index");
- return std::upper_bound(begin(), end(), LiveRange(SlotIndex(), Pos, 0),
- CompEnd());
-}
+//===----------------------------------------------------------------------===//
+// Instantiation of the methods for calculation of live ranges
+// based on a segment vector.
+//===----------------------------------------------------------------------===//
-/// killedInRange - Return true if the interval has kills in [Start,End).
-bool LiveInterval::killedInRange(SlotIndex Start, SlotIndex End) const {
- Ranges::const_iterator r =
- std::lower_bound(ranges.begin(), ranges.end(), End);
+class CalcLiveRangeUtilVector;
+typedef CalcLiveRangeUtilBase<CalcLiveRangeUtilVector, LiveRange::iterator,
+ LiveRange::Segments> CalcLiveRangeUtilVectorBase;
- // Now r points to the first interval with start >= End, or ranges.end().
- if (r == ranges.begin())
- return false;
+class CalcLiveRangeUtilVector : public CalcLiveRangeUtilVectorBase {
+public:
+ CalcLiveRangeUtilVector(LiveRange *LR) : CalcLiveRangeUtilVectorBase(LR) {}
+
+private:
+ friend CalcLiveRangeUtilVectorBase;
+
+ LiveRange::Segments &segmentsColl() { return LR->segments; }
+
+ void insertAtEnd(const Segment &S) { LR->segments.push_back(S); }
+
+ iterator find(SlotIndex Pos) { return LR->find(Pos); }
+
+ iterator findInsertPos(Segment S) {
+ return std::upper_bound(LR->begin(), LR->end(), S.start);
+ }
+};
+
+//===----------------------------------------------------------------------===//
+// Instantiation of the methods for calculation of live ranges
+// based on a segment set.
+//===----------------------------------------------------------------------===//
+
+class CalcLiveRangeUtilSet;
+typedef CalcLiveRangeUtilBase<CalcLiveRangeUtilSet,
+ LiveRange::SegmentSet::iterator,
+ LiveRange::SegmentSet> CalcLiveRangeUtilSetBase;
+
+class CalcLiveRangeUtilSet : public CalcLiveRangeUtilSetBase {
+public:
+ CalcLiveRangeUtilSet(LiveRange *LR) : CalcLiveRangeUtilSetBase(LR) {}
+
+private:
+ friend CalcLiveRangeUtilSetBase;
+
+ LiveRange::SegmentSet &segmentsColl() { return *LR->segmentSet; }
+
+ void insertAtEnd(const Segment &S) {
+ LR->segmentSet->insert(LR->segmentSet->end(), S);
+ }
+
+ iterator find(SlotIndex Pos) {
+ iterator I =
+ LR->segmentSet->upper_bound(Segment(Pos, Pos.getNextSlot(), nullptr));
+ if (I == LR->segmentSet->begin())
+ return I;
+ iterator PrevI = std::prev(I);
+ if (Pos < (*PrevI).end)
+ return PrevI;
+ return I;
+ }
+
+ iterator findInsertPos(Segment S) {
+ iterator I = LR->segmentSet->upper_bound(S);
+ if (I != LR->segmentSet->end() && !(S.start < *I))
+ ++I;
+ return I;
+ }
+};
+} // namespace
+
+//===----------------------------------------------------------------------===//
+// LiveRange methods
+//===----------------------------------------------------------------------===//
+
+LiveRange::iterator LiveRange::find(SlotIndex Pos) {
+ // This algorithm is basically std::upper_bound.
+ // Unfortunately, std::upper_bound cannot be used with mixed types until we
+ // adopt C++0x. Many libraries can do it, but not all.
+ if (empty() || Pos >= endIndex())
+ return end();
+ iterator I = begin();
+ size_t Len = size();
+ do {
+ size_t Mid = Len >> 1;
+ if (Pos < I[Mid].end)
+ Len = Mid;
+ else
+ I += Mid + 1, Len -= Mid + 1;
+ } while (Len);
+ return I;
+}
- --r;
- // Now r points to the last interval with end <= End.
- // r->end is the kill point.
- return r->end >= Start && r->end < End;
+VNInfo *LiveRange::createDeadDef(SlotIndex Def,
+ VNInfo::Allocator &VNInfoAllocator) {
+ // Use the segment set, if it is available.
+ if (segmentSet != nullptr)
+ return CalcLiveRangeUtilSet(this).createDeadDef(Def, VNInfoAllocator);
+ // Otherwise use the segment vector.
+ return CalcLiveRangeUtilVector(this).createDeadDef(Def, VNInfoAllocator);
}
-// overlaps - Return true if the intersection of the two live intervals is
+// overlaps - Return true if the intersection of the two live ranges is
// not empty.
//
// An example for overlaps():
// 4: B = ...
// 8: C = A + B ;; last use of A
//
-// The live intervals should look like:
+// The live ranges should look like:
//
// A = [3, 11)
// B = [7, x)
// A->overlaps(C) should return false since we want to be able to join
// A and C.
//
-bool LiveInterval::overlapsFrom(const LiveInterval& other,
- const_iterator StartPos) const {
- assert(!empty() && "empty interval");
+bool LiveRange::overlapsFrom(const LiveRange& other,
+ const_iterator StartPos) const {
+ assert(!empty() && "empty range");
const_iterator i = begin();
const_iterator ie = end();
const_iterator j = StartPos;
if (i->start < j->start) {
i = std::upper_bound(i, ie, j->start);
- if (i != ranges.begin()) --i;
+ if (i != begin()) --i;
} else if (j->start < i->start) {
++StartPos;
if (StartPos != other.end() && StartPos->start <= i->start) {
assert(StartPos < other.end() && i < end());
j = std::upper_bound(j, je, i->start);
- if (j != other.ranges.begin()) --j;
+ if (j != other.begin()) --j;
}
} else {
return true;
return false;
}
-/// overlaps - Return true if the live interval overlaps a range specified
+bool LiveRange::overlaps(const LiveRange &Other, const CoalescerPair &CP,
+ const SlotIndexes &Indexes) const {
+ assert(!empty() && "empty range");
+ if (Other.empty())
+ return false;
+
+ // Use binary searches to find initial positions.
+ const_iterator I = find(Other.beginIndex());
+ const_iterator IE = end();
+ if (I == IE)
+ return false;
+ const_iterator J = Other.find(I->start);
+ const_iterator JE = Other.end();
+ if (J == JE)
+ return false;
+
+ for (;;) {
+ // J has just been advanced to satisfy:
+ assert(J->end >= I->start);
+ // Check for an overlap.
+ if (J->start < I->end) {
+ // I and J are overlapping. Find the later start.
+ SlotIndex Def = std::max(I->start, J->start);
+ // Allow the overlap if Def is a coalescable copy.
+ if (Def.isBlock() ||
+ !CP.isCoalescable(Indexes.getInstructionFromIndex(Def)))
+ return true;
+ }
+ // Advance the iterator that ends first to check for more overlaps.
+ if (J->end > I->end) {
+ std::swap(I, J);
+ std::swap(IE, JE);
+ }
+ // Advance J until J->end >= I->start.
+ do
+ if (++J == JE)
+ return false;
+ while (J->end < I->start);
+ }
+}
+
+/// overlaps - Return true if the live range overlaps an interval specified
/// by [Start, End).
-bool LiveInterval::overlaps(SlotIndex Start, SlotIndex End) const {
+bool LiveRange::overlaps(SlotIndex Start, SlotIndex End) const {
assert(Start < End && "Invalid range");
const_iterator I = std::lower_bound(begin(), end(), End);
return I != begin() && (--I)->end > Start;
}
+bool LiveRange::covers(const LiveRange &Other) const {
+ if (empty())
+ return Other.empty();
+
+ const_iterator I = begin();
+ for (const Segment &O : Other.segments) {
+ I = advanceTo(I, O.start);
+ if (I == end() || I->start > O.start)
+ return false;
+
+ // Check adjacent live segments and see if we can get behind O.end.
+ while (I->end < O.end) {
+ const_iterator Last = I;
+ // Get next segment and abort if it was not adjacent.
+ ++I;
+ if (I == end() || Last->end != I->start)
+ return false;
+ }
+ }
+ return true;
+}
/// ValNo 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.
-void LiveInterval::markValNoForDeletion(VNInfo *ValNo) {
+void LiveRange::markValNoForDeletion(VNInfo *ValNo) {
if (ValNo->id == getNumValNums()-1) {
do {
valnos.pop_back();
} while (!valnos.empty() && valnos.back()->isUnused());
} else {
- ValNo->setIsUnused(true);
+ ValNo->markUnused();
}
}
/// RenumberValues - Renumber all values in order of appearance and delete the
/// remaining unused values.
-void LiveInterval::RenumberValues(LiveIntervals &lis) {
+void LiveRange::RenumberValues() {
SmallPtrSet<VNInfo*, 8> Seen;
- bool seenPHIDef = false;
valnos.clear();
- for (const_iterator I = begin(), E = end(); I != E; ++I) {
- VNInfo *VNI = I->valno;
- if (!Seen.insert(VNI))
+ for (const Segment &S : segments) {
+ VNInfo *VNI = S.valno;
+ if (!Seen.insert(VNI).second)
continue;
- assert(!VNI->isUnused() && "Unused valno used by live range");
+ assert(!VNI->isUnused() && "Unused valno used by live segment");
VNI->id = (unsigned)valnos.size();
valnos.push_back(VNI);
- VNI->setHasPHIKill(false);
- if (VNI->isPHIDef())
- seenPHIDef = true;
- }
-
- // Recompute phi kill flags.
- if (!seenPHIDef)
- return;
- for (const_vni_iterator I = vni_begin(), E = vni_end(); I != E; ++I) {
- VNInfo *VNI = *I;
- if (!VNI->isPHIDef())
- continue;
- const MachineBasicBlock *PHIBB = lis.getMBBFromIndex(VNI->def);
- assert(PHIBB && "No basic block for phi-def");
- for (MachineBasicBlock::const_pred_iterator PI = PHIBB->pred_begin(),
- PE = PHIBB->pred_end(); PI != PE; ++PI) {
- VNInfo *KVNI = getVNInfoAt(lis.getMBBEndIdx(*PI).getPrevSlot());
- if (KVNI)
- KVNI->setHasPHIKill(true);
- }
}
}
-/// extendIntervalEndTo - This method is used when we want to extend the range
-/// specified by I to end at the specified endpoint. To do this, we should
-/// merge and eliminate all ranges that this will overlap with. The iterator is
-/// not invalidated.
-void LiveInterval::extendIntervalEndTo(Ranges::iterator I, SlotIndex NewEnd) {
- assert(I != ranges.end() && "Not a valid interval!");
- VNInfo *ValNo = I->valno;
-
- // Search for the first interval that we can't merge with.
- Ranges::iterator MergeTo = llvm::next(I);
- for (; MergeTo != ranges.end() && NewEnd >= MergeTo->end; ++MergeTo) {
- assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
- }
-
- // If NewEnd was in the middle of an interval, make sure to get its endpoint.
- I->end = std::max(NewEnd, prior(MergeTo)->end);
-
- // Erase any dead ranges.
- ranges.erase(llvm::next(I), MergeTo);
-
- // If the newly formed range now touches the range after it and if they have
- // the same value number, merge the two ranges into one range.
- Ranges::iterator Next = llvm::next(I);
- if (Next != ranges.end() && Next->start <= I->end && Next->valno == ValNo) {
- I->end = Next->end;
- ranges.erase(Next);
- }
+void LiveRange::addSegmentToSet(Segment S) {
+ CalcLiveRangeUtilSet(this).addSegment(S);
}
-
-/// extendIntervalStartTo - This method is used when we want to extend the range
-/// specified by I to start at the specified endpoint. To do this, we should
-/// merge and eliminate all ranges that this will overlap with.
-LiveInterval::Ranges::iterator
-LiveInterval::extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStart) {
- assert(I != ranges.end() && "Not a valid interval!");
- VNInfo *ValNo = I->valno;
-
- // Search for the first interval that we can't merge with.
- Ranges::iterator MergeTo = I;
- do {
- if (MergeTo == ranges.begin()) {
- I->start = NewStart;
- ranges.erase(MergeTo, I);
- return I;
- }
- assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
- --MergeTo;
- } while (NewStart <= MergeTo->start);
-
- // If we start in the middle of another interval, just delete a range and
- // extend that interval.
- if (MergeTo->end >= NewStart && MergeTo->valno == ValNo) {
- MergeTo->end = I->end;
- } else {
- // Otherwise, extend the interval right after.
- ++MergeTo;
- MergeTo->start = NewStart;
- MergeTo->end = I->end;
+LiveRange::iterator LiveRange::addSegment(Segment S) {
+ // Use the segment set, if it is available.
+ if (segmentSet != nullptr) {
+ addSegmentToSet(S);
+ return end();
}
-
- ranges.erase(llvm::next(MergeTo), llvm::next(I));
- return MergeTo;
+ // Otherwise use the segment vector.
+ return CalcLiveRangeUtilVector(this).addSegment(S);
}
-LiveInterval::iterator
-LiveInterval::addRangeFrom(LiveRange LR, iterator From) {
- SlotIndex Start = LR.start, End = LR.end;
- iterator it = std::upper_bound(From, ranges.end(), Start);
-
- // If the inserted interval starts in the middle or right at the end of
- // another interval, just extend that interval to contain the range of LR.
- if (it != ranges.begin()) {
- iterator B = prior(it);
- if (LR.valno == B->valno) {
- if (B->start <= Start && B->end >= Start) {
- extendIntervalEndTo(B, End);
- return B;
- }
- } else {
- // Check to make sure that we are not overlapping two live ranges with
- // different valno's.
- assert(B->end <= Start &&
- "Cannot overlap two LiveRanges with differing ValID's"
- " (did you def the same reg twice in a MachineInstr?)");
- }
- }
-
- // Otherwise, if this range ends in the middle of, or right next to, another
- // interval, merge it into that interval.
- if (it != ranges.end()) {
- if (LR.valno == it->valno) {
- if (it->start <= End) {
- it = extendIntervalStartTo(it, Start);
-
- // If LR is a complete superset of an interval, we may need to grow its
- // endpoint as well.
- if (End > it->end)
- extendIntervalEndTo(it, End);
- return it;
- }
- } else {
- // Check to make sure that we are not overlapping two live ranges with
- // different valno's.
- assert(it->start >= End &&
- "Cannot overlap two LiveRanges with differing ValID's");
- }
- }
+void LiveRange::append(const Segment S) {
+ // Check that the segment belongs to the back of the list.
+ assert(segments.empty() || segments.back().end <= S.start);
+ segments.push_back(S);
+}
- // Otherwise, this is just a new range that doesn't interact with anything.
- // Insert it.
- return ranges.insert(it, LR);
+/// extendInBlock - If this range is live before Kill in the basic
+/// block that starts at StartIdx, extend it to be live up to Kill and return
+/// the value. If there is no live range before Kill, return NULL.
+VNInfo *LiveRange::extendInBlock(SlotIndex StartIdx, SlotIndex Kill) {
+ // Use the segment set, if it is available.
+ if (segmentSet != nullptr)
+ return CalcLiveRangeUtilSet(this).extendInBlock(StartIdx, Kill);
+ // Otherwise use the segment vector.
+ return CalcLiveRangeUtilVector(this).extendInBlock(StartIdx, Kill);
}
-/// extendInBlock - If this interval is live before UseIdx in the basic
-/// block that starts at StartIdx, extend it to be live at UseIdx and return
-/// the value. If there is no live range before UseIdx, return NULL.
-VNInfo *LiveInterval::extendInBlock(SlotIndex StartIdx, SlotIndex UseIdx) {
- if (empty())
- return 0;
- iterator I = std::upper_bound(begin(), end(), UseIdx);
- if (I == begin())
- return 0;
- --I;
- if (I->end <= StartIdx)
- return 0;
- if (I->end <= UseIdx)
- extendIntervalEndTo(I, UseIdx.getNextSlot());
- return I->valno;
-}
-
-/// removeRange - Remove the specified range from this interval. Note that
-/// the range must be in a single LiveRange in its entirety.
-void LiveInterval::removeRange(SlotIndex Start, SlotIndex End,
- bool RemoveDeadValNo) {
- // Find the LiveRange containing this span.
- Ranges::iterator I = find(Start);
- assert(I != ranges.end() && "Range is not in interval!");
- assert(I->containsRange(Start, End) && "Range is not entirely in interval!");
-
- // If the span we are removing is at the start of the LiveRange, adjust it.
+/// Remove the specified segment from this range. Note that the segment must
+/// be in a single Segment in its entirety.
+void LiveRange::removeSegment(SlotIndex Start, SlotIndex End,
+ bool RemoveDeadValNo) {
+ // Find the Segment containing this span.
+ iterator I = find(Start);
+ assert(I != end() && "Segment is not in range!");
+ assert(I->containsInterval(Start, End)
+ && "Segment is not entirely in range!");
+
+ // If the span we are removing is at the start of the Segment, adjust it.
VNInfo *ValNo = I->valno;
if (I->start == Start) {
if (I->end == End) {
}
}
- ranges.erase(I); // Removed the whole LiveRange.
+ segments.erase(I); // Removed the whole Segment.
} else
I->start = End;
return;
}
- // Otherwise if the span we are removing is at the end of the LiveRange,
+ // Otherwise if the span we are removing is at the end of the Segment,
// adjust the other way.
if (I->end == End) {
I->end = Start;
return;
}
- // Otherwise, we are splitting the LiveRange into two pieces.
+ // Otherwise, we are splitting the Segment into two pieces.
SlotIndex OldEnd = I->end;
- I->end = Start; // Trim the old interval.
+ I->end = Start; // Trim the old segment.
// Insert the new one.
- ranges.insert(llvm::next(I), LiveRange(End, OldEnd, ValNo));
+ segments.insert(std::next(I), Segment(End, OldEnd, ValNo));
}
-/// removeValNo - Remove all the ranges defined by the specified value#.
+/// removeValNo - Remove all the segments defined by the specified value#.
/// Also remove the value# from value# list.
-void LiveInterval::removeValNo(VNInfo *ValNo) {
+void LiveRange::removeValNo(VNInfo *ValNo) {
if (empty()) return;
- Ranges::iterator I = ranges.end();
- Ranges::iterator E = ranges.begin();
- do {
- --I;
- if (I->valno == ValNo)
- ranges.erase(I);
- } while (I != E);
+ segments.erase(std::remove_if(begin(), end(), [ValNo](const Segment &S) {
+ return S.valno == ValNo;
+ }), end());
// Now that ValNo is dead, remove it.
markValNoForDeletion(ValNo);
}
-/// findDefinedVNInfo - Find the VNInfo defined by the specified
-/// index (register interval).
-VNInfo *LiveInterval::findDefinedVNInfoForRegInt(SlotIndex Idx) const {
- for (LiveInterval::const_vni_iterator i = vni_begin(), e = vni_end();
- i != e; ++i) {
- if ((*i)->def == Idx)
- return *i;
- }
-
- return 0;
-}
+void LiveRange::join(LiveRange &Other,
+ const int *LHSValNoAssignments,
+ const int *RHSValNoAssignments,
+ SmallVectorImpl<VNInfo *> &NewVNInfo) {
+ verify();
-/// join - Join two live intervals (this, and other) together. This applies
-/// mappings to the value numbers in the LHS/RHS intervals as specified. If
-/// the intervals are not joinable, this aborts.
-void LiveInterval::join(LiveInterval &Other,
- const int *LHSValNoAssignments,
- const int *RHSValNoAssignments,
- SmallVector<VNInfo*, 16> &NewVNInfo,
- MachineRegisterInfo *MRI) {
- // Determine if any of our live range values are mapped. This is uncommon, so
- // we want to avoid the interval scan if not.
+ // Determine if any of our values are mapped. This is uncommon, so we want
+ // to avoid the range scan if not.
bool MustMapCurValNos = false;
unsigned NumVals = getNumValNums();
unsigned NumNewVals = NewVNInfo.size();
for (unsigned i = 0; i != NumVals; ++i) {
unsigned LHSValID = LHSValNoAssignments[i];
if (i != LHSValID ||
- (NewVNInfo[LHSValID] && NewVNInfo[LHSValID] != getValNumInfo(i)))
+ (NewVNInfo[LHSValID] && NewVNInfo[LHSValID] != getValNumInfo(i))) {
MustMapCurValNos = true;
+ break;
+ }
}
- // If we have to apply a mapping to our base interval assignment, rewrite it
- // now.
- if (MustMapCurValNos) {
+ // If we have to apply a mapping to our base range assignment, rewrite it now.
+ if (MustMapCurValNos && !empty()) {
// Map the first live range.
+
iterator OutIt = begin();
OutIt->valno = NewVNInfo[LHSValNoAssignments[OutIt->valno->id]];
- ++OutIt;
- for (iterator I = OutIt, E = end(); I != E; ++I) {
- OutIt->valno = NewVNInfo[LHSValNoAssignments[I->valno->id]];
+ for (iterator I = std::next(OutIt), E = end(); I != E; ++I) {
+ VNInfo* nextValNo = NewVNInfo[LHSValNoAssignments[I->valno->id]];
+ assert(nextValNo && "Huh?");
// If this live range has the same value # as its immediate predecessor,
- // and if they are neighbors, remove one LiveRange. This happens when we
- // have [0,3:0)[4,7:1) and map 0/1 onto the same value #.
- if (OutIt->valno == (OutIt-1)->valno && (OutIt-1)->end == OutIt->start) {
- (OutIt-1)->end = OutIt->end;
+ // and if they are neighbors, remove one Segment. This happens when we
+ // have [0,4:0)[4,7:1) and map 0/1 onto the same value #.
+ if (OutIt->valno == nextValNo && OutIt->end == I->start) {
+ OutIt->end = I->end;
} else {
- if (I != OutIt) {
+ // Didn't merge. Move OutIt to the next segment,
+ ++OutIt;
+ OutIt->valno = nextValNo;
+ if (OutIt != I) {
OutIt->start = I->start;
OutIt->end = I->end;
}
-
- // Didn't merge, on to the next one.
- ++OutIt;
}
}
-
- // If we merge some live ranges, chop off the end.
- ranges.erase(OutIt, end());
+ // If we merge some segments, chop off the end.
+ ++OutIt;
+ segments.erase(OutIt, end());
}
- // Remember assignements because val# ids are changing.
- SmallVector<unsigned, 16> OtherAssignments;
- for (iterator I = Other.begin(), E = Other.end(); I != E; ++I)
- OtherAssignments.push_back(RHSValNoAssignments[I->valno->id]);
+ // Rewrite Other values before changing the VNInfo ids.
+ // This can leave Other in an invalid state because we're not coalescing
+ // touching segments that now have identical values. That's OK since Other is
+ // not supposed to be valid after calling join();
+ for (Segment &S : Other.segments)
+ S.valno = NewVNInfo[RHSValNoAssignments[S.valno->id]];
// Update val# info. Renumber them and make sure they all belong to this
- // LiveInterval now. Also remove dead val#'s.
+ // LiveRange now. Also remove dead val#'s.
unsigned NumValNos = 0;
for (unsigned i = 0; i < NumNewVals; ++i) {
VNInfo *VNI = NewVNInfo[i];
if (NumNewVals < NumVals)
valnos.resize(NumNewVals); // shrinkify
- // Okay, now insert the RHS live ranges into the LHS.
- iterator InsertPos = begin();
- unsigned RangeNo = 0;
- for (iterator I = Other.begin(), E = Other.end(); I != E; ++I, ++RangeNo) {
- // Map the valno in the other live range to the current live range.
- I->valno = NewVNInfo[OtherAssignments[RangeNo]];
- assert(I->valno && "Adding a dead range?");
- InsertPos = addRangeFrom(*I, InsertPos);
- }
-
- ComputeJoinedWeight(Other);
-}
-
-/// MergeRangesInAsValue - Merge all of the intervals 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, but only if
-/// the overlapping LiveRanges have the specified value number.
-void LiveInterval::MergeRangesInAsValue(const LiveInterval &RHS,
- VNInfo *LHSValNo) {
- // TODO: Make this more efficient.
- iterator InsertPos = begin();
- for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) {
- // Map the valno in the other live range to the current live range.
- LiveRange Tmp = *I;
- Tmp.valno = LHSValNo;
- InsertPos = addRangeFrom(Tmp, InsertPos);
- }
-}
-
-
-/// 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) {
- assert(I->valno == RHS.getValNumInfo(I->valno->id) && "Bad VNInfo");
- 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.
- markValNoForDeletion(V1);
- }
- }
- }
+ // Okay, now insert the RHS live segments into the LHS.
+ LiveRangeUpdater Updater(this);
+ for (Segment &S : Other.segments)
+ Updater.add(S);
}
+/// Merge all of the segments in RHS into this live range as the specified
+/// value number. The segments in RHS are allowed to overlap with segments in
+/// the current range, but only if the overlapping segments have the
+/// specified value number.
+void LiveRange::MergeSegmentsInAsValue(const LiveRange &RHS,
+ VNInfo *LHSValNo) {
+ LiveRangeUpdater Updater(this);
+ for (const Segment &S : RHS.segments)
+ Updater.add(S.start, S.end, LHSValNo);
+}
+/// MergeValueInAsValue - Merge all of the live segments of a specific val#
+/// in RHS into this live range as the specified value number.
+/// The segments in RHS are allowed to overlap with segments in the
+/// current range, it will replace the value numbers of the overlaped
+/// segments with the specified value number.
+void LiveRange::MergeValueInAsValue(const LiveRange &RHS,
+ const VNInfo *RHSValNo,
+ VNInfo *LHSValNo) {
+ LiveRangeUpdater Updater(this);
+ for (const Segment &S : RHS.segments)
+ if (S.valno == RHSValNo)
+ Updater.add(S.start, S.end, LHSValNo);
+}
/// MergeValueNumberInto - This method is called when two value nubmers
/// are found to be equivalent. This eliminates V1, replacing all
-/// LiveRanges with the V1 value number with the V2 value number. This can
+/// segments with the V1 value number with the V2 value number. This can
/// cause merging of V1/V2 values numbers and compaction of the value space.
-VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) {
+VNInfo *LiveRange::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) {
assert(V1 != V2 && "Identical value#'s are always equivalent!");
// This code actually merges the (numerically) larger value number into the
std::swap(V1, V2);
}
- // Merge V1 live ranges into V2.
+ // Merge V1 segments into V2.
for (iterator I = begin(); I != end(); ) {
- iterator LR = I++;
- if (LR->valno != V1) continue; // Not a V1 LiveRange.
+ iterator S = I++;
+ if (S->valno != V1) continue; // Not a V1 Segment.
// Okay, we found a V1 live range. If it had a previous, touching, V2 live
// range, extend it.
- if (LR != begin()) {
- iterator Prev = LR-1;
- if (Prev->valno == V2 && Prev->end == LR->start) {
- Prev->end = LR->end;
+ if (S != begin()) {
+ iterator Prev = S-1;
+ if (Prev->valno == V2 && Prev->end == S->start) {
+ Prev->end = S->end;
// Erase this live-range.
- ranges.erase(LR);
+ segments.erase(S);
I = Prev+1;
- LR = Prev;
+ S = Prev;
}
}
// Okay, now we have a V1 or V2 live range that is maximally merged forward.
// Ensure that it is a V2 live-range.
- LR->valno = V2;
+ S->valno = V2;
- // If we can merge it into later V2 live ranges, do so now. We ignore any
- // following V1 live ranges, as they will be merged in subsequent iterations
+ // If we can merge it into later V2 segments, do so now. We ignore any
+ // following V1 segments, as they will be merged in subsequent iterations
// of the loop.
if (I != end()) {
- if (I->start == LR->end && I->valno == V2) {
- LR->end = I->end;
- ranges.erase(I);
- I = LR+1;
+ if (I->start == S->end && I->valno == V2) {
+ S->end = I->end;
+ segments.erase(I);
+ I = S+1;
}
}
}
- // Merge the relevant flags.
- V2->mergeFlags(V1);
-
// Now that V1 is dead, remove it.
markValNoForDeletion(V1);
return V2;
}
-void LiveInterval::Copy(const LiveInterval &RHS,
- MachineRegisterInfo *MRI,
- VNInfo::Allocator &VNInfoAllocator) {
- ranges.clear();
- valnos.clear();
- std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(RHS.reg);
- MRI->setRegAllocationHint(reg, Hint.first, Hint.second);
+void LiveRange::flushSegmentSet() {
+ assert(segmentSet != nullptr && "segment set must have been created");
+ assert(
+ segments.empty() &&
+ "segment set can be used only initially before switching to the array");
+ segments.append(segmentSet->begin(), segmentSet->end());
+ segmentSet = nullptr;
+ verify();
+}
+
+bool LiveRange::isLiveAtIndexes(ArrayRef<SlotIndex> Slots) const {
+ ArrayRef<SlotIndex>::iterator SlotI = Slots.begin();
+ ArrayRef<SlotIndex>::iterator SlotE = Slots.end();
+
+ // If there are no regmask slots, we have nothing to search.
+ if (SlotI == SlotE)
+ return false;
+
+ // Start our search at the first segment that ends after the first slot.
+ const_iterator SegmentI = find(*SlotI);
+ const_iterator SegmentE = end();
+
+ // If there are no segments that end after the first slot, we're done.
+ if (SegmentI == SegmentE)
+ return false;
+
+ // Look for each slot in the live range.
+ for ( ; SlotI != SlotE; ++SlotI) {
+ // Go to the next segment that ends after the current slot.
+ // The slot may be within a hole in the range.
+ SegmentI = advanceTo(SegmentI, *SlotI);
+ if (SegmentI == SegmentE)
+ return false;
+
+ // If this segment contains the slot, we're done.
+ if (SegmentI->contains(*SlotI))
+ return true;
+ // Otherwise, look for the next slot.
+ }
- weight = RHS.weight;
- for (unsigned i = 0, e = RHS.getNumValNums(); i != e; ++i) {
- const VNInfo *VNI = RHS.getValNumInfo(i);
- createValueCopy(VNI, VNInfoAllocator);
+ // We didn't find a segment containing any of the slots.
+ return false;
+}
+
+void LiveInterval::freeSubRange(SubRange *S) {
+ S->~SubRange();
+ // Memory was allocated with BumpPtr allocator and is not freed here.
+}
+
+void LiveInterval::removeEmptySubRanges() {
+ SubRange **NextPtr = &SubRanges;
+ SubRange *I = *NextPtr;
+ while (I != nullptr) {
+ if (!I->empty()) {
+ NextPtr = &I->Next;
+ I = *NextPtr;
+ continue;
+ }
+ // Skip empty subranges until we find the first nonempty one.
+ do {
+ SubRange *Next = I->Next;
+ freeSubRange(I);
+ I = Next;
+ } while (I != nullptr && I->empty());
+ *NextPtr = I;
}
- for (unsigned i = 0, e = RHS.ranges.size(); i != e; ++i) {
- const LiveRange &LR = RHS.ranges[i];
- addRange(LiveRange(LR.start, LR.end, getValNumInfo(LR.valno->id)));
+}
+
+void LiveInterval::clearSubRanges() {
+ for (SubRange *I = SubRanges, *Next; I != nullptr; I = Next) {
+ Next = I->Next;
+ freeSubRange(I);
}
+ SubRanges = nullptr;
}
-unsigned LiveInterval::getSize() const {
- unsigned Sum = 0;
- for (const_iterator I = begin(), E = end(); I != E; ++I)
- Sum += I->start.distance(I->end);
- return Sum;
+/// Helper function for constructMainRangeFromSubranges(): Search the CFG
+/// backwards until we find a place covered by a LiveRange segment that actually
+/// has a valno set.
+static VNInfo *searchForVNI(const SlotIndexes &Indexes, LiveRange &LR,
+ const MachineBasicBlock *MBB,
+ SmallPtrSetImpl<const MachineBasicBlock*> &Visited) {
+ // We start the search at the end of MBB.
+ SlotIndex EndIdx = Indexes.getMBBEndIdx(MBB);
+ // In our use case we can't live the area covered by the live segments without
+ // finding an actual VNI def.
+ LiveRange::iterator I = LR.find(EndIdx.getPrevSlot());
+ assert(I != LR.end());
+ LiveRange::Segment &S = *I;
+ if (S.valno != nullptr)
+ return S.valno;
+
+ VNInfo *VNI = nullptr;
+ // Continue at predecessors (we could even go to idom with domtree available).
+ for (const MachineBasicBlock *Pred : MBB->predecessors()) {
+ // Avoid going in circles.
+ if (!Visited.insert(Pred).second)
+ continue;
+
+ VNI = searchForVNI(Indexes, LR, Pred, Visited);
+ if (VNI != nullptr) {
+ S.valno = VNI;
+ break;
+ }
+ }
+
+ return VNI;
}
-/// ComputeJoinedWeight - Set the weight of a live interval Joined
-/// after Other has been merged into it.
-void LiveInterval::ComputeJoinedWeight(const LiveInterval &Other) {
- // If either of these intervals was spilled, the weight is the
- // weight of the non-spilled interval. This can only happen with
- // iterative coalescers.
+static void determineMissingVNIs(const SlotIndexes &Indexes, LiveInterval &LI) {
+ SmallPtrSet<const MachineBasicBlock*, 5> Visited;
+
+ LiveRange::iterator OutIt;
+ VNInfo *PrevValNo = nullptr;
+ for (LiveRange::iterator I = LI.begin(), E = LI.end(); I != E; ++I) {
+ LiveRange::Segment &S = *I;
+ // Determine final VNI if necessary.
+ if (S.valno == nullptr) {
+ // This can only happen at the begin of a basic block.
+ assert(S.start.isBlock() && "valno should only be missing at block begin");
+
+ Visited.clear();
+ const MachineBasicBlock *MBB = Indexes.getMBBFromIndex(S.start);
+ for (const MachineBasicBlock *Pred : MBB->predecessors()) {
+ VNInfo *VNI = searchForVNI(Indexes, LI, Pred, Visited);
+ if (VNI != nullptr) {
+ S.valno = VNI;
+ break;
+ }
+ }
+ assert(S.valno != nullptr && "could not determine valno");
+ }
+ // Merge with previous segment if it has the same VNI.
+ if (PrevValNo == S.valno && OutIt->end == S.start) {
+ OutIt->end = S.end;
+ } else {
+ // Didn't merge. Move OutIt to next segment.
+ if (PrevValNo == nullptr)
+ OutIt = LI.begin();
+ else
+ ++OutIt;
- if (Other.weight != HUGE_VALF) {
- weight += Other.weight;
+ if (OutIt != I)
+ *OutIt = *I;
+ PrevValNo = S.valno;
+ }
}
- else if (weight == HUGE_VALF &&
- !TargetRegisterInfo::isPhysicalRegister(reg)) {
- // Remove this assert if you have an iterative coalescer
- assert(0 && "Joining to spilled interval");
- weight = Other.weight;
+ // If we merged some segments chop off the end.
+ ++OutIt;
+ LI.segments.erase(OutIt, LI.end());
+}
+
+void LiveInterval::constructMainRangeFromSubranges(
+ const SlotIndexes &Indexes, VNInfo::Allocator &VNIAllocator) {
+ // The basic observations on which this algorithm is based:
+ // - Each Def/ValNo in a subrange must have a corresponding def on the main
+ // range, but not further defs/valnos are necessary.
+ // - If any of the subranges is live at a point the main liverange has to be
+ // live too, conversily if no subrange is live the main range mustn't be
+ // live either.
+ // We do this by scanning through all the subranges simultaneously creating new
+ // segments in the main range as segments start/ends come up in the subranges.
+ assert(hasSubRanges() && "expected subranges to be present");
+ assert(segments.empty() && valnos.empty() && "expected empty main range");
+
+ // Collect subrange, iterator pairs for the walk and determine first and last
+ // SlotIndex involved.
+ SmallVector<std::pair<const SubRange*, const_iterator>, 4> SRs;
+ SlotIndex First;
+ SlotIndex Last;
+ for (const SubRange &SR : subranges()) {
+ if (SR.empty())
+ continue;
+ SRs.push_back(std::make_pair(&SR, SR.begin()));
+ if (!First.isValid() || SR.segments.front().start < First)
+ First = SR.segments.front().start;
+ if (!Last.isValid() || SR.segments.back().end > Last)
+ Last = SR.segments.back().end;
}
- else {
- // Otherwise the weight stays the same
- // Remove this assert if you have an iterative coalescer
- assert(0 && "Joining from spilled interval");
+
+ // Walk over all subranges simultaneously.
+ Segment CurrentSegment;
+ bool ConstructingSegment = false;
+ bool NeedVNIFixup = false;
+ LaneBitmask ActiveMask = 0;
+ SlotIndex Pos = First;
+ while (true) {
+ SlotIndex NextPos = Last;
+ enum {
+ NOTHING,
+ BEGIN_SEGMENT,
+ END_SEGMENT,
+ } Event = NOTHING;
+ // Which subregister lanes are affected by the current event.
+ LaneBitmask EventMask = 0;
+ // Whether a BEGIN_SEGMENT is also a valno definition point.
+ bool IsDef = false;
+ // Find the next begin or end of a subrange segment. Combine masks if we
+ // have multiple begins/ends at the same position. Ends take precedence over
+ // Begins.
+ for (auto &SRP : SRs) {
+ const SubRange &SR = *SRP.first;
+ const_iterator &I = SRP.second;
+ // Advance iterator of subrange to a segment involving Pos; the earlier
+ // segments are already merged at this point.
+ while (I != SR.end() &&
+ (I->end < Pos ||
+ (I->end == Pos && (ActiveMask & SR.LaneMask) == 0)))
+ ++I;
+ if (I == SR.end())
+ continue;
+ if ((ActiveMask & SR.LaneMask) == 0 &&
+ Pos <= I->start && I->start <= NextPos) {
+ // Merge multiple begins at the same position.
+ if (I->start == NextPos && Event == BEGIN_SEGMENT) {
+ EventMask |= SR.LaneMask;
+ IsDef |= I->valno->def == I->start;
+ } else if (I->start < NextPos || Event != END_SEGMENT) {
+ Event = BEGIN_SEGMENT;
+ NextPos = I->start;
+ EventMask = SR.LaneMask;
+ IsDef = I->valno->def == I->start;
+ }
+ }
+ if ((ActiveMask & SR.LaneMask) != 0 &&
+ Pos <= I->end && I->end <= NextPos) {
+ // Merge multiple ends at the same position.
+ if (I->end == NextPos && Event == END_SEGMENT)
+ EventMask |= SR.LaneMask;
+ else {
+ Event = END_SEGMENT;
+ NextPos = I->end;
+ EventMask = SR.LaneMask;
+ }
+ }
+ }
+
+ // Advance scan position.
+ Pos = NextPos;
+ if (Event == BEGIN_SEGMENT) {
+ if (ConstructingSegment && IsDef) {
+ // Finish previous segment because we have to start a new one.
+ CurrentSegment.end = Pos;
+ append(CurrentSegment);
+ ConstructingSegment = false;
+ }
+
+ // Start a new segment if necessary.
+ if (!ConstructingSegment) {
+ // Determine value number for the segment.
+ VNInfo *VNI;
+ if (IsDef) {
+ VNI = getNextValue(Pos, VNIAllocator);
+ } else {
+ // We have to reuse an existing value number, if we are lucky
+ // then we already passed one of the predecessor blocks and determined
+ // its value number (with blocks in reverse postorder this would be
+ // always true but we have no such guarantee).
+ assert(Pos.isBlock());
+ const MachineBasicBlock *MBB = Indexes.getMBBFromIndex(Pos);
+ // See if any of the predecessor blocks has a lower number and a VNI
+ for (const MachineBasicBlock *Pred : MBB->predecessors()) {
+ SlotIndex PredEnd = Indexes.getMBBEndIdx(Pred);
+ VNI = getVNInfoBefore(PredEnd);
+ if (VNI != nullptr)
+ break;
+ }
+ // Def will come later: We have to do an extra fixup pass.
+ if (VNI == nullptr)
+ NeedVNIFixup = true;
+ }
+
+ // In rare cases we can produce adjacent segments with the same value
+ // number (if they come from different subranges, but happen to have
+ // the same defining instruction). VNIFixup will fix those cases.
+ if (!empty() && segments.back().end == Pos &&
+ segments.back().valno == VNI)
+ NeedVNIFixup = true;
+ CurrentSegment.start = Pos;
+ CurrentSegment.valno = VNI;
+ ConstructingSegment = true;
+ }
+ ActiveMask |= EventMask;
+ } else if (Event == END_SEGMENT) {
+ assert(ConstructingSegment);
+ // Finish segment if no lane is active anymore.
+ ActiveMask &= ~EventMask;
+ if (ActiveMask == 0) {
+ CurrentSegment.end = Pos;
+ append(CurrentSegment);
+ ConstructingSegment = false;
+ }
+ } else {
+ // We reached the end of the last subranges and can stop.
+ assert(Event == NOTHING);
+ break;
+ }
}
+
+ // We might not be able to assign new valnos for all segments if the basic
+ // block containing the definition comes after a segment using the valno.
+ // Do a fixup pass for this uncommon case.
+ if (NeedVNIFixup)
+ determineMissingVNIs(Indexes, *this);
+
+ assert(ActiveMask == 0 && !ConstructingSegment && "all segments ended");
+ verify();
}
-raw_ostream& llvm::operator<<(raw_ostream& os, const LiveRange &LR) {
- return os << '[' << LR.start << ',' << LR.end << ':' << LR.valno->id << ")";
+unsigned LiveInterval::getSize() const {
+ unsigned Sum = 0;
+ for (const Segment &S : segments)
+ Sum += S.start.distance(S.end);
+ return Sum;
}
-void LiveRange::dump() const {
- dbgs() << *this << "\n";
+raw_ostream& llvm::operator<<(raw_ostream& os, const LiveRange::Segment &S) {
+ return os << '[' << S.start << ',' << S.end << ':' << S.valno->id << ")";
}
-void LiveInterval::print(raw_ostream &OS, const TargetRegisterInfo *TRI) const {
- OS << PrintReg(reg, TRI);
- if (weight != 0)
- OS << ',' << weight;
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void LiveRange::Segment::dump() const {
+ dbgs() << *this << "\n";
+}
+#endif
+void LiveRange::print(raw_ostream &OS) const {
if (empty())
- OS << " EMPTY";
+ OS << "EMPTY";
else {
- OS << " = ";
- for (LiveInterval::Ranges::const_iterator I = ranges.begin(),
- E = ranges.end(); I != E; ++I) {
- OS << *I;
- assert(I->valno == getValNumInfo(I->valno->id) && "Bad VNInfo");
+ for (const Segment &S : segments) {
+ OS << S;
+ assert(S.valno == getValNumInfo(S.valno->id) && "Bad VNInfo");
}
}
} else {
OS << vni->def;
if (vni->isPHIDef())
- OS << "-phidef";
- if (vni->hasPHIKill())
- OS << "-phikill";
- if (vni->hasRedefByEC())
- OS << "-ec";
+ OS << "-phi";
}
}
}
}
+void LiveInterval::print(raw_ostream &OS) const {
+ OS << PrintReg(reg) << ' ';
+ super::print(OS);
+ // Print subranges
+ for (const SubRange &SR : subranges()) {
+ OS << " L" << PrintLaneMask(SR.LaneMask) << ' ' << SR;
+ }
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void LiveRange::dump() const {
+ dbgs() << *this << "\n";
+}
+
void LiveInterval::dump() const {
dbgs() << *this << "\n";
}
+#endif
+
+#ifndef NDEBUG
+void LiveRange::verify() const {
+ for (const_iterator I = begin(), E = end(); I != E; ++I) {
+ assert(I->start.isValid());
+ assert(I->end.isValid());
+ assert(I->start < I->end);
+ assert(I->valno != nullptr);
+ assert(I->valno->id < valnos.size());
+ assert(I->valno == valnos[I->valno->id]);
+ if (std::next(I) != E) {
+ assert(I->end <= std::next(I)->start);
+ if (I->end == std::next(I)->start)
+ assert(I->valno != std::next(I)->valno);
+ }
+ }
+}
+
+void LiveInterval::verify(const MachineRegisterInfo *MRI) const {
+ super::verify();
+
+ // Make sure SubRanges are fine and LaneMasks are disjunct.
+ LaneBitmask Mask = 0;
+ LaneBitmask MaxMask = MRI != nullptr ? MRI->getMaxLaneMaskForVReg(reg) : ~0u;
+ for (const SubRange &SR : subranges()) {
+ // Subrange lanemask should be disjunct to any previous subrange masks.
+ assert((Mask & SR.LaneMask) == 0);
+ Mask |= SR.LaneMask;
+
+ // subrange mask should not contained in maximum lane mask for the vreg.
+ assert((Mask & ~MaxMask) == 0);
+ // empty subranges must be removed.
+ assert(!SR.empty());
+
+ SR.verify();
+ // Main liverange should cover subrange.
+ assert(covers(SR));
+ }
+}
+#endif
+
+
+//===----------------------------------------------------------------------===//
+// LiveRangeUpdater class
+//===----------------------------------------------------------------------===//
+//
+// The LiveRangeUpdater class always maintains these invariants:
+//
+// - When LastStart is invalid, Spills is empty and the iterators are invalid.
+// This is the initial state, and the state created by flush().
+// In this state, isDirty() returns false.
+//
+// Otherwise, segments are kept in three separate areas:
+//
+// 1. [begin; WriteI) at the front of LR.
+// 2. [ReadI; end) at the back of LR.
+// 3. Spills.
+//
+// - LR.begin() <= WriteI <= ReadI <= LR.end().
+// - Segments in all three areas are fully ordered and coalesced.
+// - Segments in area 1 precede and can't coalesce with segments in area 2.
+// - Segments in Spills precede and can't coalesce with segments in area 2.
+// - No coalescing is possible between segments in Spills and segments in area
+// 1, and there are no overlapping segments.
+//
+// The segments in Spills are not ordered with respect to the segments in area
+// 1. They need to be merged.
+//
+// When they exist, Spills.back().start <= LastStart,
+// and WriteI[-1].start <= LastStart.
+
+void LiveRangeUpdater::print(raw_ostream &OS) const {
+ if (!isDirty()) {
+ if (LR)
+ OS << "Clean updater: " << *LR << '\n';
+ else
+ OS << "Null updater.\n";
+ return;
+ }
+ assert(LR && "Can't have null LR in dirty updater.");
+ OS << " updater with gap = " << (ReadI - WriteI)
+ << ", last start = " << LastStart
+ << ":\n Area 1:";
+ for (const auto &S : make_range(LR->begin(), WriteI))
+ OS << ' ' << S;
+ OS << "\n Spills:";
+ for (unsigned I = 0, E = Spills.size(); I != E; ++I)
+ OS << ' ' << Spills[I];
+ OS << "\n Area 2:";
+ for (const auto &S : make_range(ReadI, LR->end()))
+ OS << ' ' << S;
+ OS << '\n';
+}
+void LiveRangeUpdater::dump() const
+{
+ print(errs());
+}
-void LiveRange::print(raw_ostream &os) const {
- os << *this;
+// Determine if A and B should be coalesced.
+static inline bool coalescable(const LiveRange::Segment &A,
+ const LiveRange::Segment &B) {
+ assert(A.start <= B.start && "Unordered live segments.");
+ if (A.end == B.start)
+ return A.valno == B.valno;
+ if (A.end < B.start)
+ return false;
+ assert(A.valno == B.valno && "Cannot overlap different values");
+ return true;
}
-unsigned ConnectedVNInfoEqClasses::Classify(const LiveInterval *LI) {
+void LiveRangeUpdater::add(LiveRange::Segment Seg) {
+ assert(LR && "Cannot add to a null destination");
+
+ // Fall back to the regular add method if the live range
+ // is using the segment set instead of the segment vector.
+ if (LR->segmentSet != nullptr) {
+ LR->addSegmentToSet(Seg);
+ return;
+ }
+
+ // Flush the state if Start moves backwards.
+ if (!LastStart.isValid() || LastStart > Seg.start) {
+ if (isDirty())
+ flush();
+ // This brings us to an uninitialized state. Reinitialize.
+ assert(Spills.empty() && "Leftover spilled segments");
+ WriteI = ReadI = LR->begin();
+ }
+
+ // Remember start for next time.
+ LastStart = Seg.start;
+
+ // Advance ReadI until it ends after Seg.start.
+ LiveRange::iterator E = LR->end();
+ if (ReadI != E && ReadI->end <= Seg.start) {
+ // First try to close the gap between WriteI and ReadI with spills.
+ if (ReadI != WriteI)
+ mergeSpills();
+ // Then advance ReadI.
+ if (ReadI == WriteI)
+ ReadI = WriteI = LR->find(Seg.start);
+ else
+ while (ReadI != E && ReadI->end <= Seg.start)
+ *WriteI++ = *ReadI++;
+ }
+
+ assert(ReadI == E || ReadI->end > Seg.start);
+
+ // Check if the ReadI segment begins early.
+ if (ReadI != E && ReadI->start <= Seg.start) {
+ assert(ReadI->valno == Seg.valno && "Cannot overlap different values");
+ // Bail if Seg is completely contained in ReadI.
+ if (ReadI->end >= Seg.end)
+ return;
+ // Coalesce into Seg.
+ Seg.start = ReadI->start;
+ ++ReadI;
+ }
+
+ // Coalesce as much as possible from ReadI into Seg.
+ while (ReadI != E && coalescable(Seg, *ReadI)) {
+ Seg.end = std::max(Seg.end, ReadI->end);
+ ++ReadI;
+ }
+
+ // Try coalescing Spills.back() into Seg.
+ if (!Spills.empty() && coalescable(Spills.back(), Seg)) {
+ Seg.start = Spills.back().start;
+ Seg.end = std::max(Spills.back().end, Seg.end);
+ Spills.pop_back();
+ }
+
+ // Try coalescing Seg into WriteI[-1].
+ if (WriteI != LR->begin() && coalescable(WriteI[-1], Seg)) {
+ WriteI[-1].end = std::max(WriteI[-1].end, Seg.end);
+ return;
+ }
+
+ // Seg doesn't coalesce with anything, and needs to be inserted somewhere.
+ if (WriteI != ReadI) {
+ *WriteI++ = Seg;
+ return;
+ }
+
+ // Finally, append to LR or Spills.
+ if (WriteI == E) {
+ LR->segments.push_back(Seg);
+ WriteI = ReadI = LR->end();
+ } else
+ Spills.push_back(Seg);
+}
+
+// Merge as many spilled segments as possible into the gap between WriteI
+// and ReadI. Advance WriteI to reflect the inserted instructions.
+void LiveRangeUpdater::mergeSpills() {
+ // Perform a backwards merge of Spills and [SpillI;WriteI).
+ size_t GapSize = ReadI - WriteI;
+ size_t NumMoved = std::min(Spills.size(), GapSize);
+ LiveRange::iterator Src = WriteI;
+ LiveRange::iterator Dst = Src + NumMoved;
+ LiveRange::iterator SpillSrc = Spills.end();
+ LiveRange::iterator B = LR->begin();
+
+ // This is the new WriteI position after merging spills.
+ WriteI = Dst;
+
+ // Now merge Src and Spills backwards.
+ while (Src != Dst) {
+ if (Src != B && Src[-1].start > SpillSrc[-1].start)
+ *--Dst = *--Src;
+ else
+ *--Dst = *--SpillSrc;
+ }
+ assert(NumMoved == size_t(Spills.end() - SpillSrc));
+ Spills.erase(SpillSrc, Spills.end());
+}
+
+void LiveRangeUpdater::flush() {
+ if (!isDirty())
+ return;
+ // Clear the dirty state.
+ LastStart = SlotIndex();
+
+ assert(LR && "Cannot add to a null destination");
+
+ // Nothing to merge?
+ if (Spills.empty()) {
+ LR->segments.erase(WriteI, ReadI);
+ LR->verify();
+ return;
+ }
+
+ // Resize the WriteI - ReadI gap to match Spills.
+ size_t GapSize = ReadI - WriteI;
+ if (GapSize < Spills.size()) {
+ // The gap is too small. Make some room.
+ size_t WritePos = WriteI - LR->begin();
+ LR->segments.insert(ReadI, Spills.size() - GapSize, LiveRange::Segment());
+ // This also invalidated ReadI, but it is recomputed below.
+ WriteI = LR->begin() + WritePos;
+ } else {
+ // Shrink the gap if necessary.
+ LR->segments.erase(WriteI + Spills.size(), ReadI);
+ }
+ ReadI = WriteI + Spills.size();
+ mergeSpills();
+ LR->verify();
+}
+
+unsigned ConnectedVNInfoEqClasses::Classify(const LiveRange &LR) {
// Create initial equivalence classes.
- eqClass_.clear();
- eqClass_.grow(LI->getNumValNums());
+ EqClass.clear();
+ EqClass.grow(LR.getNumValNums());
- const VNInfo *used = 0, *unused = 0;
+ const VNInfo *used = nullptr, *unused = nullptr;
// Determine connections.
- for (LiveInterval::const_vni_iterator I = LI->vni_begin(), E = LI->vni_end();
- I != E; ++I) {
- const VNInfo *VNI = *I;
+ for (const VNInfo *VNI : LR.valnos) {
// Group all unused values into one class.
if (VNI->isUnused()) {
if (unused)
- eqClass_.join(unused->id, VNI->id);
+ EqClass.join(unused->id, VNI->id);
unused = VNI;
continue;
}
used = VNI;
if (VNI->isPHIDef()) {
- const MachineBasicBlock *MBB = lis_.getMBBFromIndex(VNI->def);
+ const MachineBasicBlock *MBB = LIS.getMBBFromIndex(VNI->def);
assert(MBB && "Phi-def has no defining MBB");
// Connect to values live out of predecessors.
for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI)
- if (const VNInfo *PVNI =
- LI->getVNInfoAt(lis_.getMBBEndIdx(*PI).getPrevSlot()))
- eqClass_.join(VNI->id, PVNI->id);
+ if (const VNInfo *PVNI = LR.getVNInfoBefore(LIS.getMBBEndIdx(*PI)))
+ EqClass.join(VNI->id, PVNI->id);
} else {
// Normal value defined by an instruction. Check for two-addr redef.
// FIXME: This could be coincidental. Should we really check for a tied
// operand constraint?
// Note that VNI->def may be a use slot for an early clobber def.
- if (const VNInfo *UVNI = LI->getVNInfoAt(VNI->def.getPrevSlot()))
- eqClass_.join(VNI->id, UVNI->id);
+ if (const VNInfo *UVNI = LR.getVNInfoBefore(VNI->def))
+ EqClass.join(VNI->id, UVNI->id);
}
}
// Lump all the unused values in with the last used value.
if (used && unused)
- eqClass_.join(used->id, unused->id);
+ EqClass.join(used->id, unused->id);
- eqClass_.compress();
- return eqClass_.getNumClasses();
+ EqClass.compress();
+ return EqClass.getNumClasses();
}
-void ConnectedVNInfoEqClasses::Distribute(LiveInterval *LIV[]) {
- assert(LIV[0] && "LIV[0] must be set");
- LiveInterval &LI = *LIV[0];
-
- // First move runs to new intervals.
- LiveInterval::iterator J = LI.begin(), E = LI.end();
- while (J != E && eqClass_[J->valno->id] == 0)
+template<typename LiveRangeT, typename EqClassesT>
+static void DistributeRange(LiveRangeT &LR, LiveRangeT *SplitLRs[],
+ EqClassesT VNIClasses) {
+ // Move segments to new intervals.
+ LiveRange::iterator J = LR.begin(), E = LR.end();
+ while (J != E && VNIClasses[J->valno->id] == 0)
++J;
- for (LiveInterval::iterator I = J; I != E; ++I) {
- if (unsigned eq = eqClass_[I->valno->id]) {
- assert((LIV[eq]->empty() || LIV[eq]->expiredAt(I->start)) &&
+ for (LiveRange::iterator I = J; I != E; ++I) {
+ if (unsigned eq = VNIClasses[I->valno->id]) {
+ assert((SplitLRs[eq-1]->empty() || SplitLRs[eq-1]->expiredAt(I->start)) &&
"New intervals should be empty");
- LIV[eq]->ranges.push_back(*I);
+ SplitLRs[eq-1]->segments.push_back(*I);
} else
*J++ = *I;
}
- LI.ranges.erase(J, E);
+ LR.segments.erase(J, E);
// Transfer VNInfos to their new owners and renumber them.
- unsigned j = 0, e = LI.getNumValNums();
- while (j != e && eqClass_[j] == 0)
+ unsigned j = 0, e = LR.getNumValNums();
+ while (j != e && VNIClasses[j] == 0)
++j;
for (unsigned i = j; i != e; ++i) {
- VNInfo *VNI = LI.getValNumInfo(i);
- if (unsigned eq = eqClass_[i]) {
- VNI->id = LIV[eq]->getNumValNums();
- LIV[eq]->valnos.push_back(VNI);
+ VNInfo *VNI = LR.getValNumInfo(i);
+ if (unsigned eq = VNIClasses[i]) {
+ VNI->id = SplitLRs[eq-1]->getNumValNums();
+ SplitLRs[eq-1]->valnos.push_back(VNI);
} else {
VNI->id = j;
- LI.valnos[j++] = VNI;
+ LR.valnos[j++] = VNI;
+ }
+ }
+ LR.valnos.resize(j);
+}
+
+void ConnectedVNInfoEqClasses::Distribute(LiveInterval &LI, LiveInterval *LIV[],
+ MachineRegisterInfo &MRI) {
+ // Rewrite instructions.
+ for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LI.reg),
+ RE = MRI.reg_end(); RI != RE;) {
+ MachineOperand &MO = *RI;
+ MachineInstr *MI = RI->getParent();
+ ++RI;
+ // DBG_VALUE instructions don't have slot indexes, so get the index of the
+ // instruction before them.
+ // Normally, DBG_VALUE instructions are removed before this function is
+ // called, but it is not a requirement.
+ SlotIndex Idx;
+ if (MI->isDebugValue())
+ Idx = LIS.getSlotIndexes()->getIndexBefore(MI);
+ else
+ Idx = LIS.getInstructionIndex(MI);
+ LiveQueryResult LRQ = LI.Query(Idx);
+ const VNInfo *VNI = MO.readsReg() ? LRQ.valueIn() : LRQ.valueDefined();
+ // In the case of an <undef> use that isn't tied to any def, VNI will be
+ // NULL. If the use is tied to a def, VNI will be the defined value.
+ if (!VNI)
+ continue;
+ if (unsigned EqClass = getEqClass(VNI))
+ MO.setReg(LIV[EqClass-1]->reg);
+ }
+
+ // Distribute subregister liveranges.
+ if (LI.hasSubRanges()) {
+ unsigned NumComponents = EqClass.getNumClasses();
+ SmallVector<unsigned, 8> VNIMapping;
+ SmallVector<LiveInterval::SubRange*, 8> SubRanges;
+ BumpPtrAllocator &Allocator = LIS.getVNInfoAllocator();
+ for (LiveInterval::SubRange &SR : LI.subranges()) {
+ // Create new subranges in the split intervals and construct a mapping
+ // for the VNInfos in the subrange.
+ unsigned NumValNos = SR.valnos.size();
+ VNIMapping.clear();
+ VNIMapping.reserve(NumValNos);
+ SubRanges.clear();
+ SubRanges.resize(NumComponents-1, nullptr);
+ for (unsigned I = 0; I < NumValNos; ++I) {
+ const VNInfo &VNI = *SR.valnos[I];
+ const VNInfo *MainRangeVNI = LI.getVNInfoAt(VNI.def);
+ assert(MainRangeVNI != nullptr
+ && "SubRange def must have corresponding main range def");
+ unsigned ComponentNum = getEqClass(MainRangeVNI);
+ VNIMapping.push_back(ComponentNum);
+ if (ComponentNum > 0 && SubRanges[ComponentNum-1] == nullptr) {
+ SubRanges[ComponentNum-1]
+ = LIV[ComponentNum-1]->createSubRange(Allocator, SR.LaneMask);
+ }
+ }
+ DistributeRange(SR, SubRanges.data(), VNIMapping);
}
+ LI.removeEmptySubRanges();
}
- LI.valnos.resize(j);
+
+ // Distribute main liverange.
+ DistributeRange(LI, LIV, EqClass);
}
projects / oota-llvm.git / blobdiff