#include "llvm/CodeGen/LiveInterval.h"
#include "RegisterCoalescer.h"
#include "llvm/ADT/DenseMap.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;
LiveRange::iterator LiveRange::find(SlotIndex Pos) {
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;
}
VNInfo *LiveRange::createDeadDef(SlotIndex Def,
VNInfo::Allocator &VNInfoAllocator) {
assert(!Def.isDead() && "Cannot define a value at the dead slot");
iterator I = find(Def);
if (I == end()) {
VNInfo *VNI = getNextValue(Def, VNInfoAllocator);
segments.push_back(Segment(Def, Def.getDeadSlot(), VNI));
return VNI;
}
if (SlotIndex::isSameInstr(Def, I->start)) {
assert(I->valno->def == I->start && "Inconsistent existing value def");
Def = std::min(Def, I->start);
if (Def != I->start)
I->start = I->valno->def = Def;
return I->valno;
}
assert(SlotIndex::isEarlierInstr(Def, I->start) && "Already live at def");
VNInfo *VNI = getNextValue(Def, VNInfoAllocator);
segments.insert(I, Segment(Def, Def.getDeadSlot(), VNI));
return VNI;
}
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;
const_iterator je = other.end();
assert((StartPos->start <= i->start || StartPos == other.begin()) &&
StartPos != other.end() && "Bogus start position hint!");
if (i->start < j->start) {
i = std::upper_bound(i, ie, j->start);
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.begin()) --j;
}
} else {
return true;
}
if (j == je) return false;
while (i != ie) {
if (i->start > j->start) {
std::swap(i, j);
std::swap(ie, je);
}
if (i->end > j->start)
return true;
++i;
}
return false;
}
bool LiveRange::overlaps(const LiveRange &Other, const CoalescerPair &CP,
const SlotIndexes &Indexes) const {
assert(!empty() && "empty range");
if (Other.empty())
return false;
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 (;;) {
assert(J->end >= I->start);
if (J->start < I->end) {
SlotIndex Def = std::max(I->start, J->start);
if (Def.isBlock() ||
!CP.isCoalescable(Indexes.getInstructionFromIndex(Def)))
return true;
}
if (J->end > I->end) {
std::swap(I, J);
std::swap(IE, JE);
}
do
if (++J == JE)
return false;
while (J->end < I->start);
}
}
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;
}
void LiveRange::markValNoForDeletion(VNInfo *ValNo) {
if (ValNo->id == getNumValNums()-1) {
do {
valnos.pop_back();
} while (!valnos.empty() && valnos.back()->isUnused());
} else {
ValNo->markUnused();
}
}
void LiveRange::RenumberValues() {
SmallPtrSet<VNInfo*, 8> Seen;
valnos.clear();
for (const_iterator I = begin(), E = end(); I != E; ++I) {
VNInfo *VNI = I->valno;
if (!Seen.insert(VNI))
continue;
assert(!VNI->isUnused() && "Unused valno used by live segment");
VNI->id = (unsigned)valnos.size();
valnos.push_back(VNI);
}
}
void LiveRange::extendSegmentEndTo(iterator I, SlotIndex NewEnd) {
assert(I != end() && "Not a valid segment!");
VNInfo *ValNo = I->valno;
iterator MergeTo = llvm::next(I);
for (; MergeTo != end() && NewEnd >= MergeTo->end; ++MergeTo) {
assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
}
I->end = std::max(NewEnd, prior(MergeTo)->end);
if (MergeTo != end() && MergeTo->start <= I->end &&
MergeTo->valno == ValNo) {
I->end = MergeTo->end;
++MergeTo;
}
segments.erase(llvm::next(I), MergeTo);
}
LiveRange::iterator
LiveRange::extendSegmentStartTo(iterator I, SlotIndex NewStart) {
assert(I != end() && "Not a valid segment!");
VNInfo *ValNo = I->valno;
iterator MergeTo = I;
do {
if (MergeTo == begin()) {
I->start = NewStart;
segments.erase(MergeTo, I);
return I;
}
assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
--MergeTo;
} while (NewStart <= MergeTo->start);
if (MergeTo->end >= NewStart && MergeTo->valno == ValNo) {
MergeTo->end = I->end;
} else {
++MergeTo;
MergeTo->start = NewStart;
MergeTo->end = I->end;
}
segments.erase(llvm::next(MergeTo), llvm::next(I));
return MergeTo;
}
LiveRange::iterator LiveRange::addSegmentFrom(Segment S, iterator From) {
SlotIndex Start = S.start, End = S.end;
iterator it = std::upper_bound(From, end(), Start);
if (it != begin()) {
iterator B = prior(it);
if (S.valno == B->valno) {
if (B->start <= Start && B->end >= Start) {
extendSegmentEndTo(B, End);
return B;
}
} else {
assert(B->end <= Start &&
"Cannot overlap two segments with differing ValID's"
" (did you def the same reg twice in a MachineInstr?)");
}
}
if (it != end()) {
if (S.valno == it->valno) {
if (it->start <= End) {
it = extendSegmentStartTo(it, Start);
if (End > it->end)
extendSegmentEndTo(it, End);
return it;
}
} else {
assert(it->start >= End &&
"Cannot overlap two segments with differing ValID's");
}
}
return segments.insert(it, S);
}
VNInfo *LiveRange::extendInBlock(SlotIndex StartIdx, SlotIndex Kill) {
if (empty())
return 0;
iterator I = std::upper_bound(begin(), end(), Kill.getPrevSlot());
if (I == begin())
return 0;
--I;
if (I->end <= StartIdx)
return 0;
if (I->end < Kill)
extendSegmentEndTo(I, Kill);
return I->valno;
}
void LiveRange::removeSegment(SlotIndex Start, SlotIndex End,
bool RemoveDeadValNo) {
iterator I = find(Start);
assert(I != end() && "Segment is not in range!");
assert(I->containsInterval(Start, End)
&& "Segment is not entirely in range!");
VNInfo *ValNo = I->valno;
if (I->start == Start) {
if (I->end == End) {
if (RemoveDeadValNo) {
bool isDead = true;
for (const_iterator II = begin(), EE = end(); II != EE; ++II)
if (II != I && II->valno == ValNo) {
isDead = false;
break;
}
if (isDead) {
markValNoForDeletion(ValNo);
}
}
segments.erase(I); } else
I->start = End;
return;
}
if (I->end == End) {
I->end = Start;
return;
}
SlotIndex OldEnd = I->end;
I->end = Start;
segments.insert(llvm::next(I), Segment(End, OldEnd, ValNo));
}
void LiveRange::removeValNo(VNInfo *ValNo) {
if (empty()) return;
iterator I = end();
iterator E = begin();
do {
--I;
if (I->valno == ValNo)
segments.erase(I);
} while (I != E);
markValNoForDeletion(ValNo);
}
void LiveRange::join(LiveRange &Other,
const int *LHSValNoAssignments,
const int *RHSValNoAssignments,
SmallVectorImpl<VNInfo *> &NewVNInfo) {
verify();
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))) {
MustMapCurValNos = true;
break;
}
}
if (MustMapCurValNos && !empty()) {
iterator OutIt = begin();
OutIt->valno = NewVNInfo[LHSValNoAssignments[OutIt->valno->id]];
for (iterator I = llvm::next(OutIt), E = end(); I != E; ++I) {
VNInfo* nextValNo = NewVNInfo[LHSValNoAssignments[I->valno->id]];
assert(nextValNo != 0 && "Huh?");
if (OutIt->valno == nextValNo && OutIt->end == I->start) {
OutIt->end = I->end;
} else {
++OutIt;
OutIt->valno = nextValNo;
if (OutIt != I) {
OutIt->start = I->start;
OutIt->end = I->end;
}
}
}
++OutIt;
segments.erase(OutIt, end());
}
for (iterator I = Other.begin(), E = Other.end(); I != E; ++I)
I->valno = NewVNInfo[RHSValNoAssignments[I->valno->id]];
unsigned NumValNos = 0;
for (unsigned i = 0; i < NumNewVals; ++i) {
VNInfo *VNI = NewVNInfo[i];
if (VNI) {
if (NumValNos >= NumVals)
valnos.push_back(VNI);
else
valnos[NumValNos] = VNI;
VNI->id = NumValNos++; }
}
if (NumNewVals < NumVals)
valnos.resize(NumNewVals);
LiveRangeUpdater Updater(this);
for (iterator I = Other.begin(), E = Other.end(); I != E; ++I)
Updater.add(*I);
}
void LiveRange::MergeSegmentsInAsValue(const LiveRange &RHS,
VNInfo *LHSValNo) {
LiveRangeUpdater Updater(this);
for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I)
Updater.add(I->start, I->end, LHSValNo);
}
void LiveRange::MergeValueInAsValue(const LiveRange &RHS,
const VNInfo *RHSValNo,
VNInfo *LHSValNo) {
LiveRangeUpdater Updater(this);
for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I)
if (I->valno == RHSValNo)
Updater.add(I->start, I->end, LHSValNo);
}
VNInfo *LiveRange::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) {
assert(V1 != V2 && "Identical value#'s are always equivalent!");
if (V1->id < V2->id) {
V1->copyFrom(*V2);
std::swap(V1, V2);
}
for (iterator I = begin(); I != end(); ) {
iterator S = I++;
if (S->valno != V1) continue;
if (S != begin()) {
iterator Prev = S-1;
if (Prev->valno == V2 && Prev->end == S->start) {
Prev->end = S->end;
segments.erase(S);
I = Prev+1;
S = Prev;
}
}
S->valno = V2;
if (I != end()) {
if (I->start == S->end && I->valno == V2) {
S->end = I->end;
segments.erase(I);
I = S+1;
}
}
}
markValNoForDeletion(V1);
return V2;
}
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;
}
raw_ostream& llvm::operator<<(raw_ostream& os, const LiveRange::Segment &S) {
return os << '[' << S.start << ',' << S.end << ':' << S.valno->id << ")";
}
#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";
else {
for (const_iterator I = begin(), E = end(); I != E; ++I) {
OS << *I;
assert(I->valno == getValNumInfo(I->valno->id) && "Bad VNInfo");
}
}
if (getNumValNums()) {
OS << " ";
unsigned vnum = 0;
for (const_vni_iterator i = vni_begin(), e = vni_end(); i != e;
++i, ++vnum) {
const VNInfo *vni = *i;
if (vnum) OS << " ";
OS << vnum << "@";
if (vni->isUnused()) {
OS << "x";
} else {
OS << vni->def;
if (vni->isPHIDef())
OS << "-phi";
}
}
}
}
void LiveInterval::print(raw_ostream &OS) const {
OS << PrintReg(reg) << ' ';
super::print(OS);
}
#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 != 0);
assert(I->valno->id < valnos.size());
assert(I->valno == valnos[I->valno->id]);
if (llvm::next(I) != E) {
assert(I->end <= llvm::next(I)->start);
if (I->end == llvm::next(I)->start)
assert(I->valno != llvm::next(I)->valno);
}
}
}
#endif
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 (LiveRange::const_iterator I = LR->begin(); I != WriteI; ++I)
OS << ' ' << *I;
OS << "\n Spills:";
for (unsigned I = 0, E = Spills.size(); I != E; ++I)
OS << ' ' << Spills[I];
OS << "\n Area 2:";
for (LiveRange::const_iterator I = ReadI, E = LR->end(); I != E; ++I)
OS << ' ' << *I;
OS << '\n';
}
void LiveRangeUpdater::dump() const
{
print(errs());
}
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;
}
void LiveRangeUpdater::add(LiveRange::Segment Seg) {
assert(LR && "Cannot add to a null destination");
if (!LastStart.isValid() || LastStart > Seg.start) {
if (isDirty())
flush();
assert(Spills.empty() && "Leftover spilled segments");
WriteI = ReadI = LR->begin();
}
LastStart = Seg.start;
LiveRange::iterator E = LR->end();
if (ReadI != E && ReadI->end <= Seg.start) {
if (ReadI != WriteI)
mergeSpills();
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);
if (ReadI != E && ReadI->start <= Seg.start) {
assert(ReadI->valno == Seg.valno && "Cannot overlap different values");
if (ReadI->end >= Seg.end)
return;
Seg.start = ReadI->start;
++ReadI;
}
while (ReadI != E && coalescable(Seg, *ReadI)) {
Seg.end = std::max(Seg.end, ReadI->end);
++ReadI;
}
if (!Spills.empty() && coalescable(Spills.back(), Seg)) {
Seg.start = Spills.back().start;
Seg.end = std::max(Spills.back().end, Seg.end);
Spills.pop_back();
}
if (WriteI != LR->begin() && coalescable(WriteI[-1], Seg)) {
WriteI[-1].end = std::max(WriteI[-1].end, Seg.end);
return;
}
if (WriteI != ReadI) {
*WriteI++ = Seg;
return;
}
if (WriteI == E) {
LR->segments.push_back(Seg);
WriteI = ReadI = LR->end();
} else
Spills.push_back(Seg);
}
void LiveRangeUpdater::mergeSpills() {
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();
WriteI = Dst;
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;
LastStart = SlotIndex();
assert(LR && "Cannot add to a null destination");
if (Spills.empty()) {
LR->segments.erase(WriteI, ReadI);
LR->verify();
return;
}
size_t GapSize = ReadI - WriteI;
if (GapSize < Spills.size()) {
size_t WritePos = WriteI - LR->begin();
LR->segments.insert(ReadI, Spills.size() - GapSize, LiveRange::Segment());
WriteI = LR->begin() + WritePos;
} else {
LR->segments.erase(WriteI + Spills.size(), ReadI);
}
ReadI = WriteI + Spills.size();
mergeSpills();
LR->verify();
}
unsigned ConnectedVNInfoEqClasses::Classify(const LiveInterval *LI) {
EqClass.clear();
EqClass.grow(LI->getNumValNums());
const VNInfo *used = 0, *unused = 0;
for (LiveInterval::const_vni_iterator I = LI->vni_begin(), E = LI->vni_end();
I != E; ++I) {
const VNInfo *VNI = *I;
if (VNI->isUnused()) {
if (unused)
EqClass.join(unused->id, VNI->id);
unused = VNI;
continue;
}
used = VNI;
if (VNI->isPHIDef()) {
const MachineBasicBlock *MBB = LIS.getMBBFromIndex(VNI->def);
assert(MBB && "Phi-def has no defining MBB");
for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI)
if (const VNInfo *PVNI = LI->getVNInfoBefore(LIS.getMBBEndIdx(*PI)))
EqClass.join(VNI->id, PVNI->id);
} else {
if (const VNInfo *UVNI = LI->getVNInfoBefore(VNI->def))
EqClass.join(VNI->id, UVNI->id);
}
}
if (used && unused)
EqClass.join(used->id, unused->id);
EqClass.compress();
return EqClass.getNumClasses();
}
void ConnectedVNInfoEqClasses::Distribute(LiveInterval *LIV[],
MachineRegisterInfo &MRI) {
assert(LIV[0] && "LIV[0] must be set");
LiveInterval &LI = *LIV[0];
for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LI.reg),
RE = MRI.reg_end(); RI != RE;) {
MachineOperand &MO = RI.getOperand();
MachineInstr *MI = MO.getParent();
++RI;
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();
if (!VNI)
continue;
MO.setReg(LIV[getEqClass(VNI)]->reg);
}
LiveInterval::iterator J = LI.begin(), E = LI.end();
while (J != E && EqClass[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)) &&
"New intervals should be empty");
LIV[eq]->segments.push_back(*I);
} else
*J++ = *I;
}
LI.segments.erase(J, E);
unsigned j = 0, e = LI.getNumValNums();
while (j != e && EqClass[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);
} else {
VNI->id = j;
LI.valnos[j++] = VNI;
}
}
LI.valnos.resize(j);
}